Glossary Glossary 0 dictionary 1 1 1 0 1 1 0 10 A# /A sharp/ A separable component of Version 2 of the AXIOM* computer algebra system. It provides a programming language with an optimising compiler, an intermediate code interpreter, and a library of data structures and mathematical abstractions. The compiler produces stand-alone executable programs, object libraries in native operating system formats, portable bytecode libraries, C and Lisp source code. The A# programming language has support for object-oriented and functional programming styles. Both types and functions are first class values that can be manipulated with a range of flexible and composable primitives and user programs. The A# language design places particular emphasis on compilation for efficient machine code and portability. Ports have been made to various 16, 32, and 64 bit architectures: RS/6000, SPARC, DEC Alpha, i386, i286, Motorola 680x0, S 370; several operating 1 1 1 1 1 A-0 (Or A0) A language for the UNIVAC I or II, using three-address code instructions for solving mathematical problems. A-0 was the first language for which a compiler was developed. It was produced by Grace Hopper's team at Remington Rand in 1952. Later internal versions were A-1, A-2, A-3, AT-3. AT-3 was released as MATH-MATIC. ["The A-2 Compiler System", Rem Rand, 1955]. [Sammet 1969, p. 12]. (1995-12-03) 1 1 1 1 1 a1 Address 1 code. An a1 code interpreter, by Matthew Newhook <matthew@engr.mun.ca> was used to test compiler output. It requires gcc 2.4.2 or higher and is portable to computers with memory segment protection. (ftp://ftp.cs.mun.ca/pub/a1). (1994-07-19) 1 1 1 1 1 A1 security Orange Book 1 1 1 1 1 A20 handler IBM PC memory manager software providing HMA. XMMs usually provide this functionality. Named after the 21st address line (A20), controlling the access to HMA. (1996-01-10) 1 1 1 1 1 A-3 ARITH-MATIC 1 1 1 1 1 A3D (Aureal 3-Dimensional?) A technology developed by Aureal that delivers sound with a three-dimensional effect through two speakers. Many modern sound cards and PC games now support this feature. A3D differs from the various forms of surround sound in that it only requires two speakers, while surround sound typically requires four or five. It is sometimes less convincing than surround sound but is supposedly better in interactive environments. For example, PC games in which sounds often move from one speaker to another favour A3D, while pre-recorded video favours surround sound. (http://a3d.com/). (1999-01-26) 1 1 1 1 1 A4C Authentication, Authorization, Accounting, Auditing and Charging 1 1 1 1 1 a56 An assembler for the Motorola DSP56000 and DSP56001 digital signal processors by Quinn Jensen <jensenq@qcj.icon.com>. Version 1.1 is available from an alt.sources archive or (ftp://wuarchive.wustl.edu/). (1992-08-10) 1 1 1 1 1 AAC Advanced Audio Coding 1 1 1 1 1 AADL Axiomatic Architecture Description Language 1 1 1 1 1 AAL ATM Adaptation Layer 1 1 1 1 1 AAP Association of American Publishers 1 1 1 1 1 AAP DTD A DTD for a standard SGML document type for scientific documents, defined by the Association of American Publishers. (1994-11-08) 1 1 1 1 1 aard (Dutch for "earth") A tool to check memory use for C++ programs, written by Steve Reiss <spr@cs.brown.edu> (who names his programs after living systems). Aard tracks the state of each byte of memory in the heap and the stack. The state can be one of Undefined, Uninitialised, Free or Set. The program can detect invalid transitions (i.e. attempting to set or use undefined or free storage or attempting to access uninitialised storage). In addition, the program keeps track of heap use through malloc and free and at the end of the run reports memory blocks that were not freed and that are not accessible (i.e. memory leaks). The tools works using a spliced-in shared library on SPARCs running C++ 3.0.1 under SunOS 4.X. (ftp://wilma.cs.brown.edu/pub/aard.tar.Z). (1998-03-03) 1 1 1 1 1 AARP Apple Address Resolution Protocol 1 1 1 1 1 AARP probe packets AARP packets sent out on a nonextended AppleTalk network to discover whether a randomly selected node ID is being used by any node. If not, the sending node uses the node ID. If so, it chooses a different ID and sends more AARP probe packets. (1997-05-03) 1 1 1 1 1 AAUI Apple Attachment Unit Interface 1 1 1 1 1 A&B A bit signaling procedure used in most T1 transmission facilities where one bit from every sixth frame of each of 24 T1 subchannels is used for carrying supervisory signaling. [What does it stand for? Is this the same as "bit robbing"?] (1997-05-05) 1 1 1 1 1 abbrev /*-breev'/, /*-brev'/ Common abbreviation for abbreviation. (1995-02-27) 1 1 1 1 1 Abbreviated Test Language for Avionics Systems (ATLAS) A Mil-spec language for automatic testing of avionics equipment. ATLAS replaced Gaelic and several other test languages. ["IEEE Standard ATLAS Test Language", IEEE Std 416-1976]. (2000-04-03) 1 1 1 1 1 ABC 1. <computer> Atanasoff-Berry Computer. 2. <language> An imperative language and programming environment from CWI, Netherlands. It is interactive, structured, high-level, and easy to learn and use. It is a general-purpose language which you might use instead of BASIC, Pascal or AWK. It is not a systems-programming language but is good for teaching or prototyping. ABC has only five data types that can easily be combined; strong typing, yet without declarations; data limited only by memory; refinements to support top-down programming; nesting by indentation. Programs are typically around a quarter the size of the equivalent Pascal or C program, and more readable. ABC includes a programming environment with syntax-directed editing, suggestions, persistent variables and multiple workspaces and infinite precision arithmetic. An example function words to collect the set of all words in a 1 1 1 1 1 ABC ALGOL An extension of ALGOL 60 with arbitrary data structures and user-defined operators, for symbolic mathematics. ["ABC ALGOL, A Portable Language for Formula Manipulation Systems", R.P. van de Riet, Amsterdam Math Centrum 1973]. (1994-10-28) 1 1 1 1 1 ABCL/1 An Object-Based Concurrent Language. The language for the ABCL MIMD system, written by Akinori Yonezawa <matsu@is.s.u-tokyo.ac.jp> of Department of Information Science, Tokyo University in 1986. ABCL/1 uses asynchronous message passing to objects. It requires Common Lisp. Implementations in KCL and Symbolics Lisp are available from the author. (ftp://camille.is.s.u-tokyo.ac.jp/). E-mail: <abcl@is.s.u-tokyo.ac.jp>. ["ABCL: An Object-Oriented Concurrent System", A. Yonezawa ed, MIT Press 1990]. (1990-05-23). (1995-02-09) 1 1 1 1 1 ABCL/c+ A concurrent object-oriented language, an extension of ABCL/1 based on C. ["An Implementation of An Operating System Kernel using Concurrent Object Oriented Language ABCL/c+", N. Doi et al in ECOOP '88, S. Gjessing et al eds, LNCS 322, Springer 1988]. (1994-11-08) 1 1 1 1 1 ABCL/R A reflective subset of ABCL/1, written in ABCL/1 by Yonezawa of Tokyo Institute of Technology in 1988. (ftp://camille.is.s.u-tokyo.ac.jp/pub/abclr). ["Reflection in an Object-Oriented Concurrent Language", T. Watanabe et al, SIGPLAN Notices 23(11):306-315 (Nov 1988)]. (1994-11-08) 1 1 1 1 1 ABCL/R2 An object-oriented, concurrent, reflective language based on Hybrid Group Architecture. ABCL/R2 was produced by <masuhara@is.s.u-tokyo.ac.jp>, <matsu@is.s.u-tokyo.ac.jp>, <takuo@is.s.u-tokyo.ac.jp>, <yonezawa@is.s.u-tokyo.ac.jp>, at the Tokyo Institute of Technology in 1992. As a reflective language, an ABCL/R2 program can dynamically control its own behaviour, such as scheduling policy, from within a user-program. This system has almost all functions of ABCL/1 and is written in Common Lisp. (ftp://camille.is.s.u-tokyo.ac.jp/pub/abclr2/). (1993-01-28) 1 1 1 1 1 abduction The process of inference to the best explanation. Abduction is sometimes used to mean just the generation of hypotheses to explain observations or conclusionsm, but the former definition is more common both in philosophy and computing. The semantics and the implementation of abduction cannot be reduced to those for deduction, as explanation cannot be reduced to implication. Applications include fault diagnosis, plan formation and default reasoning. Negation as failure in logic programming can both be given an abductive interpretation and also can be used to implement abduction. The abductive semantics of negation as failure leads naturally to an argumentation-theoretic interpretation of default reasoning in general. [Better explanation? Example?] ["Abductive Inference", John R. Josephson 1 1 1 1 1 ABEND /o'bend/, /*-bend'/ ABnormal END. Abnormal termination (of software); crash; lossage. Derives from an error message on the IBM 360; used jokingly by hackers but seriously mainly by code grinders. Usually capitalised, but may appear as "abend". Hackers will try to persuade you that ABEND is called "abend" because it is what system operators do to the computer late on Friday when they want to call it a day, and hence is from the German "Abend" = Evening. [Jargon File] (1994-11-08) 1 1 1 1 1 AberMUD The first popular open source MUD. The first version of AberMUD, named after Aberystwyth, UK, was written in B by Alan Cox, Richard Acott, Jim Finnis, and Leon Thrane, at University of Wales, Aberystwyth for an old Honeywell mainframe and opened in 1987. The gameplay was heavily influenced by MUD1, written by Roy Trubshaw and Richard Bartle, which Alan Cox had played at the University of Essex. In late 1988, Alan Cox ported AberMUD to C so it could run under UNIX on Southampton University's Maths machines. This version was named AberMUD2. Various other versions followed. (2008-11-24) 1 1 1 1 1 ABI Application Binary Interface 1 1 1 1 1 ABLE A simple language for accountants. ["ABLE, The Accounting Language, Programming and Reference Manual," Evansville Data Proc Center, Evansville, IN, Mar 1975]. [Listed in SIGPLAN Notices 13(11):56 (Nov 1978)]. (1994-11-08) 1 1 1 1 1 ABM Asynchronous Balanced Mode 1 1 1 1 1 ABNF Augmented Backus-Naur Form 1 1 1 1 1 abort To terminate a program or process abnormally and usually suddenly, with or without diagnostic information. "My program aborted", "I aborted the transmission". The noun form in computing is "abort", not abortion, e.g. "We've had three aborts over the last two days". If a Unix kernel aborts it is known as a panic. (1997-01-07) 1 1 1 1 1 ABP 1. <networking> Alternating bit protocol. 2. Microsoft Address Book Provider. 1 1 1 1 1 ABR automatic baud rate detection 1 1 1 1 1 abscissa The horizontal or x coordinate on an (x, y) graph; the input of a function against which the output is plotted. The vertical or y coordinate is the "ordinate". See Cartesian coordinates. (1997-07-08) 1 1 1 1 1 ABSET An early declarative language from the University of Aberdeen. ["ABSET: A Programming Language Based on Sets", E.W. Elcock et al, Mach Intell 4, Edinburgh U Press, 1969, pp.467-492]. (1994-11-08) 1 1 1 1 1 absolute path A path relative to the root directory. Its first character must be the pathname separator. (1996-11-21) 1 1 1 1 1 absolute pathname A pathname relative to the root directory. (1996-11-21) 1 1 1 1 1 abstract A description of a concept that leaves out some information or details in order to simplify it in some useful way. Abstraction is a powerful technique that is applied in many areas of computing and elsewhere. For example: abstract class, data abstraction, abstract interpretation, abstract syntax, Hardware Abstraction Layer. (2009-12-09) 1 1 1 1 1 abstract class In object-oriented programming, a class designed only as a parent from which sub-classes may be derived, but which is not itself suitable for instantiation. Often used to "abstract out" incomplete sets of features which may then be shared by a group of sibling sub-classes which add different variations of the missing pieces. (1994-11-08) 1 1 1 1 1 abstract data type (ADT) A kind of data abstraction where a type's internal form is hidden behind a set of access functions. Values of the type are created and inspected only by calls to the access functions. This allows the implementation of the type to be changed without requiring any changes outside the module in which it is defined. Objects and ADTs are both forms of data abstraction, but objects are not ADTs. Objects use procedural abstraction (methods), not type abstraction. A classic example of an ADT is a stack data type for which functions might be provided to create an empty stack, to push values onto a stack and to pop values from a stack. Reynolds paper (http://cis.upenn.edu/~gunter/publications/documents/taoop94.html). Cook paper "OOP vs ADTs" (http://wcook.org/papers/OOPvsADT/CookOOPvsADT90.pdf). (2003-07-03) 1 1 1 1 1 abstract interpretation A partial execution of a program which gains information about its semantics (e.g. control structure, flow of information) without performing all the calculations. Abstract interpretation is typically used by compilers to analyse programs in order to decide whether certain optimisations or transformations are applicable. The objects manipulated by the program (typically values and functions) are represented by points in some domain. Each abstract domain point represents some set of real ("concrete") values. For example, we may take the abstract points "+", "0" and "-" to represent positive, zero and negative numbers and then define an abstract version of the multiplication operator, *#, which operates on abstract values: *# | + 0 - 1 1 1 1 1 abstraction 1. Generalisation; ignoring or hiding details to capture some kind of commonality between different instances. Examples are abstract data types (the representation details are hidden), abstract syntax (the details of the concrete syntax are ignored), abstract interpretation (details are ignored to analyse specific properties). 2. <programming> Parameterisation, making something a function of something else. Examples are lambda abstractions (making a term into a function of some variable), higher-order functions (parameters are functions), bracket abstraction (making a term into a function of a variable). Opposite of concretisation. (1998-06-04) 1 1 1 1 1 abstract machine 1. <language> A processor design which is not intended to be implemented as hardware, but which is the notional executor of a particular intermediate language (abstract machine language) used in a compiler or interpreter. An abstract machine has an instruction set, a register set and a model of memory. It may provide instructions which are closer to the language being compiled than any physical computer or it may be used to make the language implementation easier to port to other platforms. A virtual machine is an abstract machine for which an interpreter exists. Examples: ABC, Abstract Machine Notation, ALF, CAML, F-code, FP/M, Hermes, LOWL, Christmas, SDL, S-K reduction machine, SECD, Tbl, Tcode, TL0, WAM. 2. <theory> A procedure for executing a set of instructions in some formal language, possibly also taking in input data and 1 1 1 1 1 Abstract Machine Notation (AMN) A language for specifying abstract machines in the B-Method, based on the mathematical theory of Generalised Substitutions. (1995-03-13) 1 1 1 1 1 abstract syntax A form of representation of data that is independent of machine-oriented structures and encodings and also of the physical representation of the data. Abstract syntax is used to give a high-level description of programs being compiled or messages passing over a communications link. A compiler's internal representation of a program will typically be an abstract syntax tree. The abstract syntax specifies the tree's structure is specified in terms of categories such as "statement", "expression" and identifier. This is independent of the source syntax (concrete syntax) of the language being compiled (though it will often be very similar). A parse tree is similar to an abstract syntax tree but it will typically also contain features such as parentheses which are syntactically significant but which are implicit in the structure of the abstract syntax tree. (1998-05-26) 1 1 1 1 1 Abstract Syntax Notation 1 (ASN.1, X.208, X.680) An ISO/ITU-T standard for transmitting structured data on networks, originally defined in 1984 as part of CCITT X.409 '84. ASN.1 moved to its own standard, X.208, in 1988 due to wide applicability. The substantially revised 1995 version is covered by the X.680 series. ASN.1 defines the abstract syntax of information but does not restrict the way the information is encoded. Various ASN.1 encoding rules provide the transfer syntax (a concrete representation) of the data values whose abstract syntax is described in ASN.1. The standard ASN.1 encoding rules include BER (Basic Encoding Rules - X.209), CER (Canonical Encoding Rules), DER (Distinguished Encoding Rules) and PER (Packed Encoding Rules). ASN.1 together with specific ASN.1 encoding rules facilitates the exchange of structured data especially between application programs over networks by describing data 1 1 1 1 1 abstract syntax tree (AST) A data structure representing something which has been parsed, often used as a compiler or interpreter's internal representation of a program while it is being optimised and from which code generation is performed. The range of all possible such structures is described by the abstract syntax. (1994-11-08) 1 1 1 1 1 Abstract-Type and Scheme-Definition Language (ASDL) A language developed as part of Esprit project GRASPIN, as a basis for generating language-based editors and environments. It combines an object-oriented type system, syntax-directed translation schemes and a target-language interface. ["ASDL - An Object-Oriented Specification Language for Syntax-Directed Environments", M.L. Christ-Neumann et al, European Software Eng Conf, Strasbourg, Sept 1987, pp.77-85]. (1996-02-19) 1 1 1 1 1 Abstract Windowing Toolkit Abstract Window Toolkit 1 1 1 1 1 Abstract Window Toolkit (AWT) Java's platform-independent windowing, graphics, and user-interface toolkit. The AWT is part of the Java Foundation Classes (JFC) - the standard API for providing a graphical user interface (GUI) for a Java program. Compare: SWING. ["Java in a Nutshell", O'Reilly]. (http://java.sun.com/products/jdk/awt/). (2000-07-26) 1 1 1 1 1 ABSYS An early declarative language from the University of Aberdeen which anticipated a number of features of Prolog. ["ABSYS: An Incremental Compiler for Assertions", J.M. Foster et al, Mach Intell 4, Edinburgh U Press, 1969, pp. 423-429]. (1994-11-08) 1 1 1 1 1 AC2 An audio format, succeded by AC3. (2001-12-18) 1 1 1 1 1 AC3 An audio format by Sony[?], the successor of AC2. AC3 is used for multi-channel audio for digital video. (2001-12-18) 1 1 1 1 1 ACA Application Control Architecture 1 1 1 1 1 ACAP Application Configuration Access Protocol 1 1 1 1 1 Accelerated Graphics Port (AGP) A bus specification by Intel which gives low-cost 3D graphics cards faster access to main memory on personal computers than the usual PCI bus. AGP dynamically allocates the PC's normal RAM to store the screen image and to support texture mapping, z-buffering and alpha blending. Intel has built AGP into a chipset for its Pentium II microprocessor. AGP cards are slightly longer than a PCI card. AGP operates at 66 MHz, doubled to 133 MHz, compared with PCI's 33 Mhz. AGP allows for efficient use of frame buffer memory, thereby helping 2D graphics performance as well. AGP provides a coherent memory management design which allows scattered data in system memory to be read in rapid bursts. AGP reduces the overall cost of creating high-end graphics subsystems by using existing system memory. 1 1 1 1 1 accelerator Additional hardware to perform some function faster than is possible in software running on the normal CPU. Examples include graphics accelerators and floating-point accelerators. (1994-11-08) 1 1 1 1 1 Accent A very high level interpreted language from CaseWare, Inc. with strings and tables. It is strongly typed and has remote function calls. (1994-11-08) 1 1 1 1 1 accept Berkeley Unix networking socket library routine to satisfy a connection request from a remote host. A specified socket on the local host (which must be capable of accepting the connection) is connected to the requesting socket on the remote host. The remote socket's socket address is returned. Unix manual pages: accept(2), connect(2). (1994-11-08) 1 1 1 1 1 Acceptable Use Policy (AUP) Rules applied by many transit networks which restrict the use to which the network may be put. A well known example is NSFNet which does not allow commercial use. Enforcement of AUPs varies with the network. (1994-11-08) 1 1 1 1 1 acceptance testing Formal testing conducted to determine whether a system satisfies its acceptance criteria and thus whether the customer should accept the system. (1996-05-10) 1 1 1 1 1 Acceptance, Test Or Launch Language (ATOLL) The language used for automating the checking and launch of Saturn rockets. ["SLCC ATOLL User's Manual", IBM 70-F11-0001, Huntsville AL Dec 1970]. (2000-04-03) 1 1 1 1 1 acceptor Finite State Machine 1 1 1 1 1 Access 1. <language> An English-like query language used in the Pick operating system. 2. <database, product> Microsoft Access. (1994-11-08) 1 1 1 1 1 Access Control List (ACL) A list of the services available on a server, each with a list of the hosts permitted to use the service. (1994-11-08) 1 1 1 1 1 access method 1. The way that network devices access the network medium. 2. Software in an SNA processor that controls the flow of data through a network. [physical layer?] (1998-03-02) 1 1 1 1 1 access permission permission 1 1 1 1 1 access point (AP) Any device that acts as a communication hub to allow users of a wireless network to connect to a wired LAN. APs are important for providing heightened wireless security and for extending the physical range of service a wireless user has access to. (2010-03-21) 1 1 1 1 1 access time The average time interval between a storage peripheral (usually a disk drive or semiconductor memory) receiving a request to read or write a certain location and returning the value read or completing the write. (1997-06-14) 1 1 1 1 1 ACCLAIM A European Union ESPRIT Basic Research Action. [What's it about?] (1994-11-08) 1 1 1 1 1 Accounting File A file which holds records of the resources used by individual jobs. These records are used to regulate, and calculate charges for, resources. An entry is opened in the accounting file as each job begins. (1996-12-08) 1 1 1 1 1 accounting management The process of identifying individual and group access to various network resources to ensure proper access capabilities (bandwidth and security) or to properly charge the various individuals and departments. Accounting management is one of five categories of network management defined by ISO for management of OSI networks. (1997-05-05) 1 1 1 1 1 Account Representative A person in a company who identifies new accounts, analyses customer needs, proposes business solutions, negotiates and oversees the implementation of new projects. (2004-03-08) 1 1 1 1 1 ACCU Association of C and C++ Users 1 1 1 1 1 accumulator In a central processing unit, a register in which intermediate results are stored. Without an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory and read them back. Access to main memory is slower than access to the accumulator which usually has direct paths to and from the arithmetic and logic unit (ALU). The canonical example is summing a list of numbers. The accumulator is set to zero initially, each number in turn is added to the value in the accumulator and only when all numbers have been added is the result written to main memory. Modern CPUs usually have many registers, all or many of which can be used as accumulators. For this reason, the term accumulator is somewhat archaic. Use of it as a synonym for register is a fairly reliable indication that the user has been around for quite a while and/or that the architecture under discussion is quite old. The term in full is almost 1 1 1 1 1 accuracy How close to the real value a measurement is. Compare precision. (1998-04-19) 1 1 1 1 1 ACE 1. Advanced Computing Environment. 2. Adaptive Communication Environment. 1 1 1 1 1 ACF Advanced Communications Function 1 1 1 1 1 ACF/NCP Advanced Communication Function/Network Control Program 1 1 1 1 1 ACIA Asynchronous Communications Interface Adapter 1 1 1 1 1 ACID A mnemonic for the properties a transaction should have to satisfy the Object Management Group Transaction Service specifications. A transaction should be Atomic, its result should be Consistent, Isolated (independent of other transactions) and Durable (its effect should be permanent). The Transaction Service specifications which part of the Object Services, an adjunct to the CORBA specifications. (1997-05-15) 1 1 1 1 1 ACIS Andy, Charles, Ian's System. A geometric engine that most CAD packages now use. ACIS uses a sophisticated object-oriented approach for modelling, the data is stored in boundary representation. Acis is owned by Spatial Technologies. [How does this differ from "solid modelling"?]. (1996-03-21) 1 1 1 1 1 ACK 1. <character> /ak/ The mnemonic for the ACKnowledge character, ASCII code 6. 2. <communications> A message transmitted to indicate that some data has been received correctly. Typically, if the sender does not receive the ACK message after some predetermined time, or receives a NAK, the original data will be sent again. [Jargon File] (1997-01-07) 1 1 1 1 1 ACL 1. Access Control List. 2. Association for Computational Linguistics. 3. A Coroutine Language. 1 1 1 1 1 ACM 1. <body> The Association for Computing. 2. <communications> addressed call mode. 1 1 1 1 1 ACME /ak'mee/ 1. A Company that Makes Everything. The canonical imaginary business. Possibly also derived from the word "acme" meaning "highest point". 2. A program for MS-DOS. [What does it do?] (1994-11-08) 1 1 1 1 1 ACOM An early system on the IBM 705. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-08) 1 1 1 1 1 acorn Acorn Computers Ltd. 1 1 1 1 1 Acorn Archimedes Archimedes 1 1 1 1 1 Acorn Computer Group A holding company for Acorn Computers Limited, Acorn Australia, Acorn New Zealand, Acorn GmbH and Online Media. Acorn Computer Group owns 43% of Advanced RISC Machines Ltd. (1994-11-08) 1 1 1 1 1 Acorn Computers Ltd. A UK computer manufacturer, part of the Acorn Computer Group plc. Acorn was founded on 1978-12-05, on a kitchen table in a back room. Their first creation was an electronic slot machine. After the Acorn System 1, 2 and 3, Acorn launched the first commercial microcomputer - the ATOM in March 1980. In April 1981, Acorn won a contract from the BBC to provide the PROTON. In January 1982 Acorn launched the BBC Microcomputer System. At one time, 70% of microcomputers bought for UK schools were BBC Micros. The Acorn Computer Group went public on the Unlisted Securities Market in September 1983. In April 1984 Acorn won the Queen's Award for Technology for the BBC Micro and in September 1985 Olivetti took a controlling interest in Acorn. The Master 128 Series computers were launched in January 1986 and the BBC Domesday System in November 1986. In 1983 Acorn began to design the Acorn RISC Machine (ARM), the first low-cost, high volume RISC processor chip (later 1 1 1 1 1 Acorn Online Media A company formed in August 1994 by Acorn Computer Group plc to exploit the ARM RISC in television set-top box decoders. They planned to woo British Telecommunications plc to use the box in some of its video on demand trials. The "STB1" box was based on an ARM8 core with additional circuits to enable MPEG to be decoded in software - possibly dedicated instructions for interpolation, inverse DCT or Huffman table extraction. A prototype featured audio MPEG chips, Acorn's RISC OS operating system and supported Oracle Media Objects and Microword. Online planned to reduce component count by transferring functions from boards into the single RISC chip. The company was origianlly wholly owned by Acorn but was expected to bring in external investment. [Article by nobody@tandem.com cross-posted from tandem.news.computergram, 1994-07-07]. 1 1 1 1 1 Acorn RISC Machine The original name of the Advanced RISC Machine. (1995-03-07) 1 1 1 1 1 A Coroutine Language (ACL) A Pascal-based implementation of coroutines. ["Coroutines", C.D. Marlin, LNCS 95, Springer 1980]. (1994-11-08) 1 1 1 1 1 ACOS A BBS language for PRODOS 8 on Apple II. Macos is a hacked version of ACOS. (1994-11-08) 1 1 1 1 1 acoustic coupler A device used to connect a modem to a telephone line via an ordinary handset. The acoustic coupler converts electrical signals from the modem to sound via a loudspeaker, against which the mouthpiece of a telephone handset is placed. The earpiece is placed against a microphone which converts sound to electrical signals which return to the modem. The handset is inserted into a sound-proof box containing the louspeaker and microphone to avoid interference from ambient noise. Acousitic couplers are now rarely used since most modems have a direct electrical connection to the telephone line. This avoids the signal degradation caused by conversion to and from audio. Direct connection is not always possible, and was actually illegal in the United Kingdom before British Telecom was privatised. BT's predecessor, the General Post Office, did not allow subscribers to connect their own equipment to the telephone line. 1 1 1 1 1 ACP Algebra of Communicating Processes 1 1 1 1 1 ACPI Advanced Configuration and Power Interface 1 1 1 1 1 Acrobat A product from Adobe Systems, Inc., for manipulating documents stored in Portable Document Format. Acrobat provides a platform-independent means of creating, viewing, and printing documents. Acropolis: the magazine of Acrobat publishing (http://acropolis.com/acropolis). (1995-04-21) 1 1 1 1 1 acronym An identifier formed from some of the letters (often the initials) of a phrase and used as an abbreviation. A TLA is a meta-acronym, i.e. an acronym about acronyms. This dictionary (FOLDOC) contains a great many acronyms; see the contents page (/contents/all.html) for a list. (2014-08-14) 1 1 1 1 1 ACSE Association Control Service Element 1 1 1 1 1 ACT 1. <software> Annual Change Traffic. 2. <company> Ada Core Technologies. 1 1 1 1 1 ACT++ A concurrent extension of C++ based on actors. ["ACT++: Building a Concurrent C++ With Actors", D.G. Kafura TR89-18, VPI, 1989]. (1994-11-08) 1 1 1 1 1 Act1 An actor language descended from Plasma. ["Concurrent Object Oriented Programming in Act1", H. Lieberman in Object Oriented Concurrent Programming, A. Yonezawa et al eds, MIT Press 1987]. (1994-11-08) 1 1 1 1 1 ACT 1 Algebraic Compiler and Translator 1 1 1 1 1 Act2 An actor language. ["Issues in the Design of Act2", D. Theriault, TR728, MIT AI Lab, June 1983]. (1994-11-08) 1 1 1 1 1 Act3 A high-level actor language by Carl Hewitt. A descendant of Act2 which provides support for automatic generation of customers and for delegation and inheritance. ["Linguistic Support of Receptionists for Shared Resources", C. Hewitt et al in Seminar on Concurrency, S.D. Brookes et al eds, LNCS 197, Springer 1985, pp. 330-359]. (1994-11-08) 1 1 1 1 1 Actalk A Smalltalk-based actor language developed by J-P Briot in 1989. ["Actalk: A Testbed for Classifying and Designing Actor Languages in the Smalltalk-80 Environment", J-P. Briot, Proc ECOOP '89, pp. 109-129]. (1994-11-08) 1 1 1 1 1 Actis An approach to integrated CASE by Apollo. (1994-11-08) 1 1 1 1 1 activation record (Or "data frame", "stack frame") A data structure containing the variables belonging to one particular scope (e.g. a procedure body), as well as links to other activation records. Activation records are usually created (on the stack) on entry to a block and destroyed on exit. If a procedure or function may be returned as a result, stored in a variable and used in an outer scope then its activation record must be stored in a heap so that its variables still exist when it is used. Variables in the current scope are accessed via the frame pointer which points to the current activation record. Variables in an outer scope are accessed by following chains of links between activation records. There are two kinds of link - the static link and the dynamic link. (1995-03-07) 1 1 1 1 1 active DBMS A conventional or passive DBMS combined with a means of event detection and condition monitoring. Event handling is often rule-based, as with an expert system. (1994-11-08) 1 1 1 1 1 Active Directory A directory service from Microsoft Corporation, similar in concept to Novell Netware Directory Services (NDS), that also integrates with the user organisation's DNS structure and is interoperable with LDAP. Active Directory is included in Windows 2000. (2000-03-28) 1 1 1 1 1 Active Language I An early interactive mathematics system for the XDS 930 at the University of California at Berkeley. ["Active Language I", R. de Vogelaere in Interactive Systems for Experimental Applied Mathematics, A-P 1968]. (1994-11-08) 1 1 1 1 1 active matrix display A type of liquid crystal display where each display element (each pixel) includes an active component such as a transistor to maintain its state between scans. Contrast passive matrix display. (1995-12-09) 1 1 1 1 1 Active Measurement Project (AMP) An NLANR project undertaking site-to-site measurement across the HPC networks. This work is intended to compliment the measurements taken by MCI and Abilene within the networks' infrastructure. Currently round trip times, topology, and packet loss are being measured. (2004-01-18) 1 1 1 1 1 Active Monitor A process in an IBM token ring network which ensures a token is present on the ring, removes circulating frames with unknown or invalid destinations, and performs introductions between machines on the ring. (1996-06-18) 1 1 1 1 1 active object An object each instance of which has its own thread running as well as its own copies of the object's instance variables. (1998-03-08) 1 1 1 1 1 Active Reconfiguring Message (ARM) An efficient mechanism which allows reconfiguration of the hardware logic of a system according to the particular data received or transmitted. In ARM each message contains extra information in a Reconfiguring Header in addition to the data to be transferred. Upon arrival of the message the Reconfiguring Header is extracted, decoded and used to perform on-the-fly hardware reconfiguration. As soon as the hardware has been reconfigured the data information of the message can be processed. [In what contect is this term used?] (1997-06-06) 1 1 1 1 1 active record pattern Martin Fowler's name for object relational mapping viewed as a software architecture pattern. (2014-12-03) 1 1 1 1 1 Active Server Pages (ASP) A scripting environment for Microsoft Internet Information Server in which you can combine HTML, scripts and reusable ActiveX server components to create dynamic web pages. IIS 4.0 includes scripting engines for Microsoft Visual Basic Scripting Edition (VBScript) and Microsoft JScript. ActiveX scripting engines for Perl and REXX are available through third-party developers. [URL?] (1999-12-02) 1 1 1 1 1 ActiveX A type of COM component that can self-register, also known as an "ActiveX control". All COM objects implement the "IUnknown" interface but an ActiveX control usually also implements some of the standard interfaces for embedding, user interface, methods, properties, events, and persistence. ActiveX controls were originally called "OLE Controls", and were required to provide all of these interfaces but that requirement was dropped, and the name changed, to make ActiveX controls lean enough to be downloaded as part of a web page. Because ActiveX components can support the OLE embedding interfaces, they can be included in web pages. Because they are COM objects, they can be used from languages such as Visual Basic, Visual C++, Java, VBScript. ["Understanding ActiveX and OLE", David Chappell, MS Press, 1996]. (http://microsoft.com/com/tech/activex.asp). 1 1 1 1 1 ActiveX Data Objects (ADO) Microsoft's library for accessing data sources through OLE DB. Typically it is used to query or modify data stored in a relational database. Home (http://msdn.microsoft.com/library/en-us/ado270/htm/adostartpage1.asp). (2003-07-08) 1 1 1 1 1 ACT ONE A specification language. ["An Algebraic Specification Language with Two Levels of Semantics", H. Ehrig et al, Tech U Berlin 83-1983-02-03]. (1994-11-08) 1 1 1 1 1 Actor An object-oriented language for Microsoft Windows written by Charles Duff of the Whitewater Group ca. 1986. It has Pascal/C-like syntax. Uses a token-threaded interpreter. Early binding is an option. ["Actor Does More than Windows", E.R. Tello, Dr Dobb's J 13(1):114-125 (Jan 1988)]. (1994-11-08) 1 1 1 1 1 actor 1. <programming> In object-oriented programming, an object which exists as a concurrent process. 2. <operating system> In Chorus, the unit of resource allocation. (1994-11-08) 1 1 1 1 1 Actors A model for concurrency by Carl Hewitt. Actors are autonomous and concurrent objects which execute asynchronously. The Actor model provides flexible mechanisms for building parallel and distributed software systems. (http://osl.cs.uiuc.edu/). ["Laws for Communicating Parallel Processes", C. Hewitt et al, IFIP 77, pp. 987-992, N-H 1977]. ["ACTORS: A Model of Concurrent Computation in Distributed Systems", Gul A. Agha <agha@cs.uiuc.edu>, Cambridge Press, MA, 1986]. (1999-11-23) 1 1 1 1 1 actor/singer/waiter/webmaster An elaboration of the ages-old concept of the actor/singer/waiter, someone who waits tables __for now__, but who has aspirations of breaking into the glamorous worlds of acting or New Media or both! He keeps going to auditions and sending a resumes to C|Net (http://cnet.com/) because you have to pay your dues. His credits include being on "Friends" (as an extra), in "ER" (actually, in an ER - he twisted his ankle once; but he counts the x-rays as screen credits), and having been the webmaster of an extensive multimedia interactive website (his hotlist of Simpsons links). (1998-04-04) 1 1 1 1 1 Actra A multi-processor exemplar-based Smalltalk. [LaLonde et al, OOPSLA '86]. (1994-11-08) 1 1 1 1 1 actual argument A value, expression, or reference passed to a function or subroutine when it is called and which replaces or is bound to the corresponding formal argument. See: argument. (2002-07-02) 1 1 1 1 1 Actus Pascal with parallel extensions, similar to the earlier Glypnir. It has parallel constants and index sets. Descendants include Parallel Pascal, Vector C and CMU's language PIE. ["A Language for Array and Vector Processors," R.H. Perrott, ACM TOPLAS 1(2):177-195 (Oct 1979)]. (1994-11-08) 1 1 1 1 1 AD Administrative Domain 1 1 1 1 1 ad The country code for Andorra. (1999-01-26) 1 1 1 1 1 Ada (After Ada Lovelace) A Pascal-descended language, designed by Jean Ichbiah's team at CII Honeywell in 1979, made mandatory for Department of Defense software projects by the Pentagon. The original language was standardised as "Ada 83", the latest is "Ada 95". Ada is a large, complex, block-structured language aimed primarily at embedded applications. It has facilities for real-time response, concurrency, hardware access and reliable run-time error handling. In support of large-scale software engineering, it emphasises strong typing, data abstraction and encapsulation. The type system uses name equivalence and includes both subtypes and derived types. Both fixed and floating-point numerical types are supported. Control flow is fully bracketed: if-then-elsif-end if, case-is-when-end case, loop-exit-end loop, goto. Subprogram parameters are in, out, or inout. Variables imported from other packages may be hidden or directly visible. Operators 1 1 1 1 1 Ada++ An object-oriented extension to Ada, implemented as an Ada preprocessor. Obsoleted by Ada 95 which includes object-oriented features. [Jargon File] (1995-09-19) 1 1 1 1 1 Ada 83 The original Ada, as opposed to Ada 95. (1995-03-13) 1 1 1 1 1 Ada 95 A revision and extension of Ada (Ada 83) begun in 1988 and completed on 1994-12-01 by a team lead by Tucker Taft of Intermetrics. Chris Anderson was the Project Manager. The printed standard was expected to be available around 1995-02-15. Additions include object-orientation (tagged types, abstract types and class-wide types), hierarchical libraries and synchronisation with shared data (protected types) similar to Orca. It lacks multiple inheritance but supports the construction of multiple inheritance type hierarchies through the use of generics and type composition. GNAT aims to be a free implementation of Ada 95. You can get the standard from the Ada Joint Program Office (http://wuarchive.wustl.edu/languages/ada/ajpo/index.shtml). ["Introducing Ada 9X", J.G.P. Barnes, Feb 1993]. (1999-12-02) 1 1 1 1 1 Ada 9X The working title for Ada 95 before its adoption as an ISO standard. (1995-01-19) 1 1 1 1 1 ADABAS A relational database system by Software AG. While it was initially designed for large IBM mainframe systems (e.g. S/370 in the late 1970s), it has been ported to numerous other platforms over the last few years such as several flavors of Unix including AIX. ADABAS stores its data in tables (and is thus "relational") but also uses some non-relational techniques, such as multiple values and periodic groups. (1995-10-30) 1 1 1 1 1 Ada Core Technologies (ACT) The company that maintains GNAT. Ada Core Technologies was founded in 1994 by the original authors of the GNAT compiler. ACT provides software for Ada 95 development. (http://gnat.com/). (2000-10-28) 1 1 1 1 1 Ada/Ed An interpreter, editor, and run-time environment for Ada, intended as a teaching tool. Ada/Ed does not have the capacity, performance, or robustness of commercial Ada compilers. Ada/Ed was developed at New York University as part of a project in language definition and software prototyping. AdaEd runs on Unix, MS-DOS, Atari ST, and Amiga. It handles nearly all of Ada 83 and was last validated with version 1.7 of the ACVC tests. Being an interpreter, it does not implement most representation clauses and thus does not support systems programming close to the machine level. Latest version: 1.11.0a+, as of 1994-08-18. A later version is known as GW-Ada. E-mail: Michael Feldman <mfeldman@seas.gwu.edu>. (ftp://ftp.wustl.edu/amiga/languages/ada), (ftp://cnam.cnam.fr/pub/Ada/Ada-Ed). For Amiga (ftp://cs.nyu.edu/pub/adaed). 1 1 1 1 1 Adaline Name given by Widrow to adaptive linear neurons, that is neurons (see McCulloch-Pitts) which learn using the Widrow-Huff Delta Rule. See also Madaline. (1995-03-14) 1 1 1 1 1 Ada Lovelace (1811-1852) The daughter of Lord Byron, who became the world's first programmer while cooperating with Charles Babbage on the design of his mechanical computing engines in the mid-1800s. The language Ada was named after her. ["Ada, Enchantress of Numbers Prophit of the Computer Age", Betty Alexandra Toole (http://well.com/user/adatoole)]. [More details?] (1999-07-17) 1 1 1 1 1 ADAM A Data Management system 1 1 1 1 1 Adam7 One of the progressive coding methods used in PNG images. Adam7, named after its author, Adam M. Costello, consists of seven distinct passes over the image. Each pass transmits a subset of the pixels in the image. The pass in which each pixel is transmitted is defined by replicating the following 8-by-8 pattern over the entire image, starting at the top left: 1 6 4 6 2 6 4 6 7 7 7 7 7 7 7 7 5 6 5 6 5 6 5 6 7 7 7 7 7 7 7 7 3 6 4 6 3 6 4 6 7 7 7 7 7 7 7 7 5 6 5 6 5 6 5 6 7 7 7 7 7 7 7 7 (2000-09-12) 1 1 1 1 1 Adamakegen A program that generates makefiles for Ada programs. Adamakegen was written by Owen O'Malley <owen@schwartz-omalley.com>. It requires Icon and runs under Verdix and SunAda. Latest version: 2.6.3, as of 1993-03-02. Adamakegen Home (http://schwartz-omalley.com/people/owen/tools/adamakegen.html). (2004-08-21) 1 1 1 1 1 ADAMO A data management system written at CERN, based on the Entity-Relationship model. (1995-03-14) 1 1 1 1 1 Adam Osborne The ex-book publisher who founded Osborne Computer Corporation. (2007-05-21) 1 1 1 1 1 Ada-O An Ada subset developed at the University of Karlsruhe in 1979, used for compiler bootstrapping. It lacks overloading, derived types, real numbers, tasks and generics. ["Revised Ada-O Reference Manual", G. Persch et al, U Karlsruhe, Inst fur Infor II, Bericht Nr 9/81]. (1995-02-14) 1 1 1 1 1 Adaplan A functional database language based upon Backus' FP language. [Erwig&Lipeck, Proc. DBPL-3, 1991]. (1995-05-07) 1 1 1 1 1 Adaplex An extension of Ada for functional databases. ["Adaplex: Rationale and Reference Manual 2nd ed", J.M. Smith et al, Computer Corp America, Cambridge MA, 1983]. (1995-02-14) 1 1 1 1 1 Ada Programming Support Environment (APSE) A program or set of programs to support software development in the Ada language. [Examples?] (1997-06-30) 1 1 1 1 1 ADAPT A subset of APT. [Sammet 1969, p. 606]. (1995-02-14) 1 1 1 1 1 Adaptable User Interface (AUI, Oracle Toolkit) A toolkit from Oracle allowing applications to be written which will be portable between different windowing systems. AUI provides one call level interface along with a resource manager and editor across a range of "standard" GUIs, including Macintosh, Microsoft Windows and the X Window System. (1995-03-16) 1 1 1 1 1 Adaptec A company specialising in the aera of movement of data between computers. Adaptec designs hardware and software products to transfer data from a computer to a peripheral device or network. Founded in 1981, the company achieved profitability in 1984, went public in 1986, and to date has achieved 54 consecutive profitable quarters. Revenues for fiscal 1997 were $934 million, a 42% increase over the prior year. Net income, excluding acquisition charges, for fiscal year 1997 was $198 million or $1.72 per share. (http://adaptec.com). (1999-08-25) 1 1 1 1 1 adaptive answering A feature which allows a faxmodem to answer the telephone and decide whether the incoming call is a fax or data call. Most Class 1 faxmodems do this. The U.S. Robotics Class 1 implementation however seems not to do it, it must be set to answer as either one or the other. (1995-03-16) 1 1 1 1 1 Adaptive Communication Environment A C++ wrapper library for communications from the University of California at Irvine. (1995-03-16) 1 1 1 1 1 Adaptive Digital Pulse Code Modulation (ADPCM) A compression technique which records only the difference between samples and adjusts the coding scale dynamically to accomodate large and small differences. ADPCM is simple to implement, but introduces much noise. [Used where? Does the Sony minidisk use ADPCM or ATRAC?] (1998-12-10) 1 1 1 1 1 adaptive learning (Or "Hebbian learning") Learning where a system programs itself by adjusting weights or strengths until it produces the desired output. (1995-03-16) 1 1 1 1 1 adaptive routing dynamic routing 1 1 1 1 1 Adaptive Server Enterprise (ASE) The relational database management system that started life in the mid-eighties [first release?] as "Sybase SQL Server". For a number of years Microsoft was a Sybase distributor, reselling the Sybase product for OS/2 and (later) Windows NT under the name "Microsoft SQL Server". Around 1994, Microsoft basically bought a copy of the source code of Sybase SQL Server and then went its own way. As competitors, Sybase and Microsoft have been developing their products independently ever since. Microsoft has mostly emphasised ease-of-use and "Window-ising" the product, while Sybase has focused on maximising performance and reliability, and running on high-end hardware. When releasing version 11.5 in 1997, Sybase renamed its product to "ASE" to better distinguish its database from Microsoft's. Both ASE and MS SQL Server call their query language "Transact-SQL" and they are very similar. Sybase SQL Server was the first true client-server RDBMS 1 1 1 1 1 Adaptive Simulated Annealing (ASA) An algorithm for global optimisation of generic functions by Lester Ingber <ingber@alumni.caltech.edu> <ingber@ingber.com>. Latest version: 20.5, as of 2000-02-29. (http://alumni.caltech.edu/~ingber/). (http://ingber.com/). Mailing list: <asa-request@alumni.caltech.edu>. (2000-02-29) 1 1 1 1 1 Adaptive TRansform Acoustic Coding (ATRAC) An audio compression algorithm, introduced by Sony for its Mini Disk, which relies on the masking of low-amplitude frequency components by temporaly adjacent high-amplitude components. ATRAC consists of a three-band subband encoder (0...5.5, 5.5...11, 11...22 kHz) and a MDCT based transformation encoder. [Does Sony Minidisk use ADPCM?] (2001-12-13) 1 1 1 1 1 Adaptor (Automatic DAta Parallelism TranslatOR) A source to source transformation tool that transforms data parallel programs written in Fortran 77 with array extensions, parallel loops, and layout directives to parallel programs with explicit message passing. ADAPTOR generates Fortran 77 host and node programs with message passing. The new generated source codes have to be compiled by the compiler of the parallel computer. Version 1.0 runs on CM-5, iPCS/860, Meiko CS1/CS2, KSR 1, SGI, Alliant or a network of Suns or RS/6000s. (ftp://ftp.gmd.de/gmd/adaptor/adp_1.0.tar.Z). [Connection with Thomas Brandes and GMD?] (1993-06-01) 1 1 1 1 1 Ada Semantic Interface Specification (ASIS) An intermediate representation for Ada. E-mail: <sblake@thomsoft.com>. See also Diana. (1995-02-15) 1 1 1 1 1 Ada Software Repository A collection of Ada programs? (http://wuarchive.wustl.edu/languages/ada/asr/). (1995-01-06) 1 1 1 1 1 A Data Management System (ADAM) A suite of software tools intended to assist in the design and testing of military information processing systems. ADAM was developed by the MITRE Corporation in 1966. It consisted of 53 different programs which ran on an IBM 7030 (STRETCH). It was targetted at systems that had to cope with large volumes of data with complex relationships with rapid response and increasing requirements. ADAM was part of the Information Systems Tools and Software Techniques project. ["Evaluation of ADAM An Advanced Data Management System", R.A.J. Gildea, Aug 1967. (http://www.dtic.mil/dtic/tr/fulltext/u2/661273.pdf)]. (2015-08-14) 1 1 1 1 1 ADC Analog to Digital Converter 1 1 1 1 1 ADCCP Advanced Data Communications Control Protocol 1 1 1 1 1 A/D converter Analog to Digital Converter 1 1 1 1 1 ADCU application developer customer unit 1 1 1 1 1 AD/Cycle Application Development cycle. A set of SAA-compatible IBM-sponsored products for program development, running on workstations accessing a central repository on a mainframe. The stages cover requirements, analysis and design, production of the application, building and testing and maintenance. Technologies used include code generators and knowledge based systems as well as languages and debuggers. (1994-10-24) 1 1 1 1 1 ADD 1 TO COBOL GIVING COBOL (From COBOL's equivalent syntax to C's C++) A tongue-in-cheek suggestion by Bruce Clement for an object-oriented COBOL. [SIGPLAN Notices 27(4):90-91 (Apr 1992)]. (1995-03-17) 1 1 1 1 1 ADDD A Depository of Development Documents. A public domain Software Engineering Environment from GMD developed as part of the STONE project. (1995-02-03) 1 1 1 1 1 additive A function f : X -> Y is additive if for all Z <= X f (lub Z) = lub f z : z in Z (f "preserves lubs"). All additive functions defined over cpos are continuous. ("<=" is written in LaTeX as \subseteq, "lub" as \sqcup ). (1995-02-03) 1 1 1 1 1 address 1. <networking> e-mail address. 2. <networking> IP address. 3. <networking> MAC address. 4. <storage, programming> An unsigned integer used to select one fundamental element of storage, usually known as a word from a computer's main memory or other storage device. The CPU outputs addresses on its address bus which may be connected to an address decoder, cache controller, memory management unit, and other devices. While from a hardware point of view an address is indeed an integer most strongly typed programming languages disallow mixing integers and addresses, and indeed addresses of different data types. This is a fine example for syntactic salt: the compiler could work without it but makes writing bad programs more difficult. (1997-07-01) 1 1 1 1 1 address book A collection of electronic contacts for use in an electronic mail system, mobile phone or any other system for exchanging messages with other people or organisations. (2014-06-20) 1 1 1 1 1 address bus The connections between the CPU and memory which carry the address from/to which the CPU wishes to read or write. The number of bits of address bus determines the maximum size of memory which the processor can access. See also data bus. (1995-03-22) 1 1 1 1 1 addressed call mode (ACM) A mode that permits control signals and commands to establish and terminate calls in V.25bis. (1997-05-07) 1 1 1 1 1 addressee One to whom something is addressed. E.g. "The To, CC, and BCC headers list the addressees of the e-mail message". Normally an addressee will eventually be a recipient, unless there is a failure at some point (an e-mail "bounces") or the message is redirected to a different addressee. (2000-03-22) 1 1 1 1 1 addressing mode 1. <processor, programming> One of a set of methods for specifying the operand(s) for a machine code instruction. Different processors vary greatly in the number of addressing modes they provide. The more complex modes described below can usually be replaced with a short sequence of instructions using only simpler modes. The most common modes are "register" - the operand is stored in a specified register; "absolute" - the operand is stored at a specified memory address; and "immediate" - the operand is contained within the instruction. Most processors also have indirect addressing modes, e.g. register indirect, "memory indirect" where the specified register or memory location does not contain the operand but contains its address, known as the "effective address". For an absolute addressing mode, the effective address is contained within the instruction. Indirect addressing modes often have options for pre- or post- 1 1 1 1 1 address mask (Or "subnet mask") A bit mask used to identify which bits in an IP address correspond to the network address and subnet portions of the address. This mask is often referred to as the subnet mask because the network portion of the address can be determined by the class inherent in an IP address. The address mask has ones in positions corresponding to the network and subnet numbers and zeros in the host number positions. (1996-03-21) 1 1 1 1 1 address resolution Conversion of an Internet address into the corresponding physical address (Ethernet address). This is usually done using Address Resolution Protocol. The resolver is a library routine and a set of processes which converts hostnames into Internet addresses, though this process in not usually referred to as resolution. See DNS. (1996-04-09) 1 1 1 1 1 Address Resolution Protocol (ARP) A method for finding a host's Ethernet address from its Internet address. The sender broadcasts an ARP packet containing the Internet address of another host and waits for it (or some other host) to send back its Ethernet address. Each host maintains a cache of address translations to reduce delay and loading. ARP allows the Internet address to be independent of the Ethernet address but it only works if all hosts support it. ARP is defined in RFC 826. The alternative for hosts that do not do ARP is constant mapping. See also proxy ARP, reverse ARP. (1995-03-20) 1 1 1 1 1 address space The range of addresses which a processor or process can access, or at which a device can be accessed. The term may refer to either physical address or virtual address. The size of a processor's address space depends on the width of the processor's address bus and address registers. Each device, such as a memory integrated circuit, will have its own local address space which starts at zero. This will be mapped to a range of addresses which starts at some base address in the processor's address space. Similarly, each process will have its own address space, which may be all or a part of the processor's address space. In a multitasking system this may depend on where in memory the process happens to have been loaded. For a process to be able to run at any address it must consist of position-independent code. Alternatively, each process may see the same local address space, with the memory management 1 1 1 1 1 Address Strobe (AS) One of the input signals of a memory device, especially semiconductor memory, which is asserted to tell the memory device that the address inputs are valid. Upon receiving this signal the selected memory device starts the memory access (read/write) indicated by its other inputs. It may be driven directly by the processor or by a memory controller. (1996-10-02) 1 1 1 1 1 ADELE A language for specification of attribute grammars, used by the MUG2 compiler compiler. ["An Overview of the Attribute Definition Language ADELE", H. Ganziger in GI3, Fachesprach "Compiler-Compiler", W. Henhapl ed, Munchen Mar 1982, pp.22-53]. (1995-01-23) 1 1 1 1 1 ADES An early system on the IBM 704. Version: ADES II. [Listed in CACM 2(5):16 (May 1959)]. (1995-03-20) 1 1 1 1 1 ad-hockery /ad-hok'*r-ee/ (Purdue) 1. Gratuitous assumptions made inside certain programs, especially expert systems, which lead to the appearance of semi-intelligent behaviour but are in fact entirely arbitrary. For example, fuzzy-matching of input tokens that might be typing errors against a symbol table can make it look as though a program knows how to spell. 2. Special-case code to cope with some awkward input that would otherwise cause a program to fail, presuming normal inputs are dealt with in some cleaner and more regular way. Also called "ad-hackery", "ad-hocity" (/ad-hos'*-tee/), ad-crockery. See also ELIZA effect. [Jargon File] (1995-01-05) 1 1 1 1 1 ad-hoc polymorphism overloading 1 1 1 1 1 Aditi The Aditi Deductive Database System. A multi-user deductive database system from the Machine Intelligence Project at the University of Melbourne. It supports base relations defined by facts (relations in the sense of relational databases) and derived relations defined by rules that specify how to compute new information from old information. Both base relations and the rules defining derived relations are stored on disk and are accessed as required during query evaluation. The rules defining derived relations are expressed in a Prolog-like language, which is also used for expressing queries. Aditi supports the full structured data capability of Prolog. Base relations can store arbitrarily nested terms, for example arbitrary length lists, and rules can directly manipulate such terms. Base relations can be indexed with B-trees or multi-level signature files. 1 1 1 1 1 adjacency A relationship between two network devices, e.g. routers, which are connected by one media segment so that a packet sent by one can reach the other without going through another network device. The concept of adjacency is important in the exchange of routing information. Adjacent SNA nodes are nodes connected to a given node with no intervening nodes. In DECnet and OSI, adjacent nodes share a common segment (Ethernet, FDDI, Token Ring). (1998-03-10) 1 1 1 1 1 adjacent adjacency 1 1 1 1 1 ADL 1. <games> Adventure Definition Language. 2. <language> Ada Development Language. R.A. Lees, 1989. 3. <programming> API Definition Language. A project for Automatic Interface Test Generation. (1995-11-17) 1 1 1 1 1 AdLog A language which adds a Prolog layer to Ada. ["AdLog, An Ada Components Set to Add Logic to Ada", G. Pitette, Proc Ada-Europe Intl Conf Munich, June 1988]. (1995-03-21) 1 1 1 1 1 ADM A picture query language, extension of Sequel2. ["An Image-Oriented Database System", Y. Takao et al, in Database Techniques for Pictorial Applications, A. Blaser ed, pp. 527-538]. (1995-03-21) 1 1 1 1 1 ADMD Administration Management Domain 1 1 1 1 1 admin system administrator 1 1 1 1 1 Administration Management Domain (ADMD) An X.400 Message Handling System public service carrier. The ADMDs in all countries worldwide together provide the X.400 backbone. Examples: MCImail and ATTmail in the U.S., British Telecom Gold400mail in the U.K. See also PRMD. [RFC 1208]. (1997-05-07) 1 1 1 1 1 administrative distance A rating of the trustworthiness of a routing information source set by the router administrator. In Cisco routers, administrative distance is a number between 0 and 255 (the higher the value, the less trustworthy the source). (1998-03-10) 1 1 1 1 1 Administrative Domain (AD) A collection of hosts and routers, and the interconnecting network(s), managed by a single administrative authority. (1994-11-24) 1 1 1 1 1 admissible A description of a search algorithm that is guaranteed to find a minimal solution path before any other solution paths, if a solution exists. An example of an admissible search algorithm is A* search. (1999-07-19) 1 1 1 1 1 ADO ActiveX Data Objects 1 1 1 1 1 Adobe Systems, Inc. A California font foundry and software house. Adobe created the PostScript page description language and wrote the Blue Book, Green Book, Red Book and White Book on it. They also developed PDF. Adobe took over Frame Technology Corporation in late 1995/early 1996. (http://adobe.com/). E-mail: <postmaster@adobe.com>. Address: Silicon Valley, California, USA. (1996-12-13) 1 1 1 1 1 Adobe Type Manager (ATM) Software that produces PostScript outline fonts on screen and paper. There are versions that run under Microsoft Windows and on the Macintosh. ATM can do hinting, multiple master and anti-aliasing. (1998-03-10) 1 1 1 1 1 ADPCM Adaptive Digital Pulse Code Modulation 1 1 1 1 1 ADR Astra Digital Radio 1 1 1 1 1 ADS Aion Development System 1 1 1 1 1 ADSL Asymmetric Digital Subscriber Line 1 1 1 1 1 ADSP AppleTalk Data Stream Protocol 1 1 1 1 1 ADSU ATM Data Service Unit 1 1 1 1 1 ADT abstract data type 1 1 1 1 1 Advanced Audio Coding (AAC) A successor to MP3, allowing lower bit rates and more stable quality. See MPEG-2 AAC Low Profile and MPEG-4 AAC Main Profile. (2001-12-02) 1 1 1 1 1 Advanced Communication Function/Network Control Program (ACF/NCP, usually called just "NCP") The primary SNA network control program, one of the ACF products. ACF/NCP resides in the communications controller and interfaces with ACF/VTAM in the host processor to control network communications. NCP can also communicate with multiple hosts using local channel or remote links (PU type 5 or PU type 4) thus enabling cross domain application communication. In a multiple mainframe SNA environment, any terminal or application can access any other application on any host using cross domain logon. See also Emulator program. [Communication or Communications?] (1999-01-29) 1 1 1 1 1 Advanced Communications Function (ACF) A group of IBM SNA products that provide distributed processing and resource sharing such as VTAM and NCP. [Communication or Communications?] (1997-05-07) 1 1 1 1 1 Advanced Computing Environment (ACE) A consortium to agree on an open architecture based on the MIPS R4000 chip. A computer architecture ARCS will be defined, on which either OS/2 or Open Desktop can be run. (1995-02-03) 1 1 1 1 1 Advanced Configuration and Power Interface (ACPI) An open industry standard developed by Intel, Microsoft, and Toshiba for configuration and power management. The key element of the standard is power management with two important improvements. First, it puts the OS in control of power management. In the currently existing APM model most of the power management tasks are run by the BIOS, with limited intervention from the OS. In ACPI, the BIOS is responsible for the dirty details of communicating with hardware equipment but the control is in the OS. The other important feature is bringing power management features now available only in portable computers to desktop computers and servers. Extremely low consumption states, i.e., in which only memory, or not even memory is powered, but from which ordinary interrupts (real time clock, keyboard, modem, etc.) can quickly wake the system, are today available in portables only. The standard should make these 1 1 1 1 1 Advanced Data Communications Control Protocol An ANSI standard bit-oriented data link control protocol. (1997-05-07) 1 1 1 1 1 Advanced Encryption Standard (AES) The NIST's replacement for the Data Encryption Standard (DES). The Rijndael /rayn-dahl/ symmetric block cipher, designed by Joan Daemen and Vincent Rijmen, was chosen by a NIST contest to be AES. AES is Federal Information Processing Standard FIPS-197. AES currently supports 128, 192 and 256-bit keys and encryption blocks, but may be extended in multiples of 32 bits. (http://csrc.nist.gov/CryptoToolkit/aes/). Rijndael home page (http://esat.kuleuven.ac.be/~rijmen/rijndael/). (2003-07-04) 1 1 1 1 1 Advanced Function Presentation (AFP) A page description language from IBM introduced in 1984 initially as Advanced Function Printing. AFP was first developed for mainframes and then brought to minicomputers and workstations. It is implemented on the various platforms by Print Services Facility (PSF) software, which generates the native IBM printer language, IPDS and, depending on the version, PostScript and LaserJet PCL as well. IBM calls AFP a printer architecture rather than a page description language. 1 1 1 1 1 Advanced Function Printing Advanced Function Presentation 1 1 1 1 1 Advanced Intelligent Tape (AIT) A form of magnetic tape and drive using AME developed by Sony for storing large amounts of data. An AIT can store over 50 gigabytes and transfer data at six megabytes/second (in February 1999). AIT features high speed file access, long head and media life, the ALDC compression algorithm, and a MIC chip. (http://aittape.com/). Seagate (http://seagate.com/support/tape/scsiide/sidewinder/ait_main_page.shtml). (1999-04-16) 1 1 1 1 1 Advanced Interactive eXecutive (AIX) IBM's version of Unix, taken as the basis for the OSF standard. Usenet newsgroup: news:comp.sys.unix.aix. (1994-11-24) 1 1 1 1 1 Advanced Micro Devices, Inc. (AMD) A US manufacturer of integrated circuits, founded in 1969. AMD was the fifth-largest IC manufacturer in 1995. AMD focuses on the personal and networked computation and communications market. They produce microprocessors, embedded processors and related peripherals, memories, programmable logic devices, circuits for telecommunications and networking applications. In 1995, AMD had 12000 employees in the USA and elsewhere and manufacturing facilities in Austin, Texas; Aizu-Wakamatsu, Japan; Bangkok, Thailand; Penang, Malaysia; and Singapore. AMD made the AMD 2900 series of bit-slice TTL components and clones of the Intel 80386 and Intel 486 microprocessors. AMD Home (http://amd.com/). Address: Sunnyvale, CA, USA. (1995-02-27) 1 1 1 1 1 Advanced Network Systems Architecture (ANSA) A "software bus" based on a model for distributed systems developed as an ESPRIT project. (http://ansa.co.uk/). (1996-04-01) 1 1 1 1 1 Advanced Peer-to-Peer Networking (APPN) IBM data communications support that routes data in a network between two or more APPC systems that need not be adjacent. (1995-02-03) 1 1 1 1 1 Advanced Power Management (APM) A feature of some displays, usually but not always, on laptop computers, which turns off power to the display after a preset period of inactivity to conserve electrical power. Monitors with this capability are usually refered to as "green monitors", meaning environmentally friendly. Not to be confused with a screen blanker which is software that causes the display to go black (by setting every pixel to black) to prevent burn-in. (1997-08-25) 1 1 1 1 1 Advanced Programmable Interrupt Controller (APIC) A Programmable Interrupt Controller (PIC) that can handle interrupts from and for multiple CPUs, and, usually, has more available interrupt lines that a typical PIC. (2003-03-18) 1 1 1 1 1 Advanced Program-to-Program Communications (APPC) An implementation of the IBM SNA/SDLC LU6.2 protocol that allows interconnected systems to communicate and share the processing of programs. (1995-02-03) 1 1 1 1 1 Advanced Research Projects Agency Defense Advanced Research Projects Agency 1 1 1 1 1 Advanced Research Projects Agency Network (ARPANET) A pioneering longhaul wide area network funded by DARPA (when it was still called "ARPA"?). It became operational in 1968 and served as the basis for early networking research, as well as a central backbone during the development of the Internet. The ARPANET consisted of individual packet switching computers interconnected by leased lines. Protocols used include FTP and telnet. It has now been replaced by NSFnet. [1968 or 1969?] (1994-11-17) 1 1 1 1 1 Advanced Revelation (AREV) A database development environment for personal computers available from Revelation Software since 1982. Originally based on the PICK operating system, there are over one million users worldwide in 1996. (1996-12-12) 1 1 1 1 1 Advanced RISC Computing Specification (ARC, previously ARCS) The baseline hardware requirements for an ACE-compatible system. (1995-01-16) 1 1 1 1 1 Advanced RISC Machine (ARM, Originally Acorn RISC Machine). A series of low-cost, power-efficient 32-bit RISC microprocessors for embedded control, computing, digital signal processing, games, consumer multimedia and portable applications. It was the first commercial RISC microprocessor (or was the MIPS R2000?) and was licensed for production by Asahi Kasei Microsystems, Cirrus Logic, GEC Plessey Semiconductors, Samsung, Sharp, Texas Instruments and VLSI Technology. The ARM has a small and highly orthogonal instruction set, as do most RISC processors. Every instruction includes a four-bit code which specifies a condition (of the processor status register) which must be satisfied for the instruction to be executed. Unconditional execution is specified with a condition "true". Instructions are split into load and store which access memory and arithmetic and logic instructions which work on registers (two source and one destination). 1 1 1 1 1 Advanced RISC Machines Ltd. (ARM) A company formed in 1990 by Acorn Computers Ltd., Apple Computer, Inc. and VLSI Technology to market and develop the Advanced RISC Machine microprocessor family, originally designed by Acorn. ARM Ltd. also designs and licenses peripheral chips and supplies supporting software and hardware tools. In April 1993, Nippon Investment and Finance, a Daiwa Securities company, became ARM's fourth investor. In May 1994 Samsung became the sixth large company to have a licence to use the ARM processor core. The success of ARM Ltd. and the strategy to widen the availability of RISC technology has resulted in its chips now being used in a range of products including the Apple Newton. As measured by an independent authority, more ARM processors were shipped than SPARC chips in 1993. ARM has also sold three times more chips than the PowerPC consortium. 1 1 1 1 1 Advanced SCSI Peripheral Interface (ASPI) A set of libraries designed to provide programs running under Microsoft Windows with a consistent interface for accessing SCSI devices. ASPI has become a de facto standard. The ASPI layer is a collection of programs (DLLs) that together implement the ASPI interface. Many problems are caused by device manufacturers packaging incomplete sets of these DLLs with their hardware, often with incorrect date stamps, causing newer versions to get replaced with old. ASPICHK from Adaptec will check the ASPI components installed on a computer. The latest ASPI layer as of March 1999 is 1014. The ATAPI standard for IDE devices makes them look to the system like SCSI devices and allows them to work through ASPI. (http://resource.simplenet.com/primer/aspi.htm). (1999-03-30) 1 1 1 1 1 Advanced Software Environment (ASE) An object-oriented application support system from Nixdorf. (1995-09-12) 1 1 1 1 1 Advanced STatistical Analysis Program (ASTAP) A program for analysing electronic circuits and other networks. ["Advanced Statistical Analysis Program (ASTAP) Program Reference Manual", SH-20-1118, IBM, 1973]. (2000-01-27) 1 1 1 1 1 Advanced Technology Attachment (ATA, AT Attachment or Integrated Drive Electronics, IDE) A disk drive interface standard based on the IBM PC ISA 16-bit bus but also used on other personal computers. ATA specifies the power and data signal interfaces between the motherboard and the integrated disk controller and drive. The ATA "bus" only supports two devices - master and slave. ATA drives may in fact use any physical interface the manufacturer desires, so long as an embedded translator is included with the proper ATA interface. ATA "controllers" are actually direct connections to the ISA bus. Originally called IDE, the ATA interface was invented by Compaq around 1986, and was developed with the help of Western Digital, Imprimis, and then-upstart Conner Peripherals. Efforts to standardise the interface started in 1988; the first draft appeared in March 1989, and a finished version was sent to ANSI group X3T10 (who named it "Advanced 1 1 1 1 1 Advanced Technology Attachment Interface with Extensions (ATA-2, Enhanced Integrated Drive Electronics, EIDE) A proposed (May 1996 or earlier?) standard from X3T10 (document 948D rev 3) which extends the Advanced Technology Attachment interface while maintaining compatibility with current IBM PC BIOS designs. ATA-2 provides for faster data rates, 32-bit transactions and (in some drives) DMA. Optional support for power saving modes and removable devices is also in the standard. ATA-2 was developed by Western Digital as "Enhanced Integrated Drive Electronics" (EIDE) around 1994. Marketroids call it "Fast ATA" or "Fast ATA-2". ATA-2 was followed by ATA-3 and ATA-4 ("Ultra DMA"). (2000-10-07) 1 1 1 1 1 Advanced Video Coding H.264 1 1 1 1 1 Advanced WavEffect (AWE) The kind of synthesis used by the EMU 8000 music synthesizer integrated circuit found on the SB AWE32 card. (1996-12-15) 1 1 1 1 1 Advantage Gen A CASE tool for rapid application development which generates code from graphical business process models. Formerly called Information Engineering Facility (IEF) and produced by Texas Instruments, it was then bought by Sterling Software, Inc. who renamed it to COOL:Gen to fit into their COOL line of products. Computer Associates International, Inc. then acquired Sterling Software, Inc., and renamed the tool "Advantage Gen". In 2003, CA are supporting Advantage Gen and adding support for J2EE/EJB, enhanced web enablement, Web services, and .Net. Latest version: 6.5, as of 2003-04-14. (http://www3.ca.com/Solutions/Product.asp?ID=256). (2003-06-23) 1 1 1 1 1 ADVENT /ad'vent/ The prototypical computer adventure game, first implemented by Will Crowther for a CDC computer (probably the CDC 6600?) as an attempt at computer-refereed fantasy gaming. ADVENT was ported to the PDP-10, and expanded to the 350-point Classic puzzle-oriented version, by Don Woods of the Stanford Artificial Intelligence Laboratory (SAIL). The game is now better known as Adventure, but the TOPS-10 operating system permitted only six-letter filenames. All the versions since are based on the SAIL port. David Long of the University of Chicago Graduate School of Business Computing Facility (which had two of the four DEC20s on campus in the late 1970s and early 1980s) was responsible for expanding the cave in a number of ways, and pushing the point count up to 500, then 501 points. Most of his work was in the data files, but he made some changes to the parser as well. 1 1 1 1 1 Adventure Definition Language (ADL) An adventure game language interpreter designed by Ross Cunniff <cunniff@fc.hp.com> and Tim Brengle in 1987. ADL is semi-object-oriented with Lisp-like syntax and is a superset of DDL. It is available for Unix, MS-DOS, Amiga and Acorn Archimedes. (ftp://ftp.uu.net/usenet/comp.sources.games/volume2), (ftp://ftp.wustl.edu/systems/amiga/fish/fish/f0/ff091). (1995-03-20) 1 1 1 1 1 ADVSYS An adventure game language designed by David Betz in 1986. ADVSYS is object-oriented and Lisp-like. (ftp://ftp.uu.net/usenet/comp.sources.games/volume2). (1995-03-20) 1 1 1 1 1 adware Any kind of software which is distributed free of charge along with advertisements that are either placed on the website from which the software is distributed or displayed by the program while it is running. Nagware might be considered a special case of adware where the program tries to persuade the user to buy a license for the program itself. (2007-11-20) 1 1 1 1 1 AE Application Executive 1 1 1 1 1 ae The country code for the United Arab Emirates. (1999-01-27) 1 1 1 1 1 AED Automated Engineering Design 1 1 1 1 1 AEGIS A Unix variant that was used on Apollo workstations before Apollo was bought by Hewlett Packard. AEGIS has some advantages over standard BSD or System V Unix. It includes faster file access and a richer command set; there are commands to find out which process is running on a particular node, which process is locking a particular file, etc. (1997-02-25) 1 1 1 1 1 Aegis A CASE tool for project change management written by Peter Miller, with minor contributions by a few others. Aegis is licensed using the GNU GPL but is not a GNU project. Aegis Home (http://aegis.sourceforge.net/). (2005-03-24) 1 1 1 1 1 Aeolus A concurrent language with atomic transactions. ["Rationale for the Design of Aeolus", C. Wilkes et al, Proc IEEE 1986 Intl Conf Comp Lang, IEEE 1986, pp.107-122]. (1995-03-27) 1 1 1 1 1 AEP Application Environment Profile 1 1 1 1 1 aeroplane rule "Complexity increases the possibility of failure; a twin-engine aeroplane has twice as many engine problems as a single-engine aeroplane." By analogy, in both software and electronics, the implication is that simplicity increases robustness and that the right way to build reliable systems is to put all your eggs in one basket, after making sure that you've built a really *good* basket. While simplicity is a useful design goal, and twin-engine aeroplanes do have twice as many engine problems, the analogy is almost entirely bogus. Commercial passenger aircraft are required to have at least two engines (on different wings or nacelles) so that the aeroplane can land safely if one engine fails. As Albert Einstein said, "Everything should be made as simple as possible, but not simpler". See also KISS Principle. (1999-03-22) 1 1 1 1 1 AES 1. <programming> Application environment specification. 2. <security> Advanced Encryption Standard. 1 1 1 1 1 AESOP An Evolutionary System for On-line Programming 1 1 1 1 1 af The country code for Afghanistan. (1999-01-27) 1 1 1 1 1 AFAC An early system on the IBM 704. [Listed in CACM 2(5):16 (May 1959)]. (1995-04-04) 1 1 1 1 1 AFAIK as far as I know. 1 1 1 1 1 affine transformation A linear transformation followed by a translation. Given a matrix M and a vector v, A(x) = Mx + v is a typical affine transformation. (1995-04-10) 1 1 1 1 1 affordance A visual clue to the function of an object. (1998-10-15) 1 1 1 1 1 AFIPS American Federation of Information Processing Societies 1 1 1 1 1 AFJ April Fool's Joke 1 1 1 1 1 AFK away from keyboard. 1 1 1 1 1 aflex A Lex-like scanner generator that produce Ada output from IRUS (Irvine Research Unit in Software). aflex comes with ayacc. Version 1.2a. Mailing list: <irus-software-request@ics.uci.edu>. (ftp://liege.ics.uci.edu/pub/irus/aflex-ayacc_1.2a.tar.Z). (1993-01-06) 1 1 1 1 1 AFNOR Association Francaise pour la Normalisation. The French national standards institute, a member of ISO. (1994-12-14) 1 1 1 1 1 AFP 1. <protocol> Appletalk Filing Protocol. 2. <printer, language> Advanced Function Presentation. 1 1 1 1 1 AFS Andrew File System 1 1 1 1 1 AFUU Association Française des Utilisateurs d'Unix 1 1 1 1 1 ag The country code for Antigua and Barbuda. (1999-01-27) 1 1 1 1 1 agent In the client-server model, the part of the system that performs information preparation and exchange on behalf of a client or server. Especially in the phrase intelligent agent it implies some kind of automatic process which can communicate with other agents to perform some collective task on behalf of one or more humans. (1995-04-09) 1 1 1 1 1 aggregate type A data type composed of multiple elements. An aggregate can be homogeneous (all elements have the same type) e.g. an array, a list in a functional language, a string of characters, a file; or it can be heterogeneous (elements can have different types) e.g. a structure. In most languages aggregates can contain elements which are themselves aggregates. e.g. a list of lists. See also union. (1996-03-23) 1 1 1 1 1 aggregation A composition technique for building a new object from one or more existing objects that support some or all of the new object's required interfaces. (1996-01-07) 1 1 1 1 1 aggregator A program for watching for new content at user-specified RSS feeds. An example is BottomFeeder. (http://directory.google.com/Top/Reference/Libraries/Library_and_Information_Science/Technical_Services/Cataloguing/Metadata/RDF/Applications/RSS/News_Readers/). (2003-09-29) 1 1 1 1 1 AGL (Atelier de Genie Logiciel) French for IPSE. (1997-01-07) 1 1 1 1 1 AGM Theory for Belief Revision (After the initials of the authors who established the field - Alchourron, Makinson and Gardenfors). A method of belief revision giving minimal properties a revision process should have. [Reference?] (1995-03-20) 1 1 1 1 1 Agner Krarup Erlang (1878-1929) A Danish mathematician. Erlang the language and unit were named after him. Interested in the theory of probability, in 1908 Erlang joined the Copenhagen Telephone Company where he studied the problem of waiting times for telephone calls. He worked out how to calculate the fraction of callers who must wait due to all the lines of an exchange being in use. His formula for loss and waiting time was published in 1917. It is now known as the "Erlang formula" and is still in use today. Biography (http://www-history.mcs.st-andrews.ac.uk/~history/Mathematicians/Erlang.html), Biography (http://pass.maths.org.uk/issue2/erlang/index.html). (2005-02-26) 1 1 1 1 1 AGORA A distributed object-oriented language. 1 1 1 1 1 AGP Accelerated Graphics Port 1 1 1 1 1 AGP graphics Accelerated Graphics Port 1 1 1 1 1 A Hardware Programming Language (AHPL) A register-level language by Hill and Peterson, some of whose operators resemble APL. HPSIM2 is a function-level simulator, available from Engrg Expt Sta, University of Arizona. ["Digital Systems: Hardware Organization and Design", F. Hill et al, Wiley 1987]. (1995-01-26) 1 1 1 1 1 AHDL Analog Hardware Design Language 1 1 1 1 1 AHPL A Hardware Programming Language 1 1 1 1 1 AI artificial intelligence 1 1 1 1 1 ai The country code for Anguilla. (1999-01-27) 1 1 1 1 1 AIA Application Integration Architecture 1 1 1 1 1 AI-complete /A-I k*m-pleet'/ (MIT, Stanford: by analogy with "NP-complete") A term used to describe problems or subproblems in artificial intelligence, to indicate that the solution presupposes a solution to the strong AI problem (that is, the synthesis of a human-level intelligence). A problem that is AI-complete is, in other words, just too hard. See also gedanken. [Jargon File] (1995-04-12) 1 1 1 1 1 AID Algebraic Interpretive Dialogue 1 1 1 1 1 AIDA 1. A functional dialect of Dictionary APL by M. Gfeller. ["APL Arrays and Their Editor", M. Gfeller, SIGPLAN Notices 21(6):18-27 (June 1986) and SIGAPL Conf Proc]. 2. An intermediate representation language for Ada developed at the University of Karlsruhe in 1980. AIDA was merged with TCOL.Ada to form Diana. ["AIDA Introduction and User Manual", M. Dausmann et al, U Karlsruhe, Inst fur Inform II, TR Nr 38/80]. ["AIDA Reference Manual", ibid, TR Nr 39/80, Nov 1980]. (1995-04-12) 1 1 1 1 1 AIDS /aydz/ A* Infected Disk Syndrome ("A*" is a glob pattern that matches, but is not limited to, Apple Computer), this condition is quite often the result of practicing unsafe SEX. See virus, worm, Trojan horse, virgin. [Jargon File] (1995-04-13) 1 1 1 1 1 AIDX /aydkz/ A derogatory term for IBM's perverted version of Unix, AIX, especially for the AIX 3.? used in the IBM RS/6000 series (some hackers think it is funnier just to pronounce "AIX" as "aches"). A victim of the dreaded "hybridism" disease, this attempt to combine the two main currents of the Unix stream (BSD and USG Unix) became a monstrosity to haunt system administrators' dreams. For example, if new accounts are created while many users are logged on, the load average jumps quickly over 20 due to silly implementation of the user databases. For a quite similar disease, compare HP-SUX. Also, compare Macintrash Nominal Semidestructor, Open DeathTrap, ScumOS, sun-stools. [Jargon File] (1995-04-13) 1 1 1 1 1 AIFF Audio IFF 1 1 1 1 1 AI International One of distributors of Prolog++, subsumed by Customer Engagement Company before December 1998. (1998-12-13) 1 1 1 1 1 Aiken code An alternative form of the Binary Coded Decimal (BCD) system for encoding numbers. Where BCD encodes each decimal digit in normal binary, Aiken code uses the encoding shown below. This is supposed to be less prone to corruption. The following table shows the encoding of each decimal digit, D, in BCD and Aiken code: D BCD Aiken 0 0000 0000 1 0001 0001 2 0010 0010 3 0011 0011 4 0100 0100 5 0101 1011 (inverted 4) 6 0110 1100 (inverted 3) 7 0111 1101 (inverted 2) 8 1000 1110 (inverted 1) 9 1001 1111 (inverted 0) 1 1 1 1 1 AI koan /A-I koh'an/ One of a series of pastiches of Zen teaching riddles created by Danny Hillis at the MIT AI Lab around various major figures of the Lab's culture. See also ha ha only serious, mu. In reading these, it is at least useful to know that Marvin Minsky, Gerald Sussman, and Drescher are AI researchers of note, that Tom Knight was one of the Lisp machine's principal designers, and that David Moon wrote much of Lisp Machine Lisp. * * * A novice was trying to fix a broken Lisp machine by turning the power off and on. Knight, seeing what the student was doing, spoke sternly: "You 1 1 1 1 1 AIMACO AIr MAterial COmmand compiler 1 1 1 1 1 Aimnet An Internet access provider for individuals and corporations. They provide dial-up, SLIP, PPP and shell accounts as well as ISDN. (http://aimnet.com/). Address: Cupertino, CA 95014, USA. Telephone: +1 (408) 253 0900 (1995-02-08) 1 1 1 1 1 Aion Development System (ADS) A commericial expert system shell developed by Aion Corporation that supported forward chainging and backward chaining and featured an object-oriented knowledge representation scheme, graphics and integrated with other programming languages like C and Pascal. ["Expert Systems in Chemistry Research", Markus C. Hemmer]. (2014-10-05) 1 1 1 1 1 AIR A future infrared standard from IrDA. AIR will provide in-room multipoint to multipoint connectivity. AIR supports a data rate of 4 Mbps at a distance of 4 metres, and 250 Kbps at up to 8 metres. It is designed for cordless connections to multiple peripherals and meeting room collaboration applications. See also IrDA Data and IrDA Control (1999-10-14) 1 1 1 1 1 AIr MAterial COmmand compiler (AIMACO) A modification of FLOW-MATIC. AIMACO was supplanted by COBOL. [Sammet 1969, p. 378]. (1995-02-20) 1 1 1 1 1 airplane rule aeroplane rule 1 1 1 1 1 AIT Advanced Intelligent Tape 1 1 1 1 1 AIX Advanced Interactive eXecutive 1 1 1 1 1 Ajax (Asynchronous JavaScript And XML) A collection of techniques for creating interactive web applications without having to reload the complete web page in response to each user input, thus making the interaction faster. AJAX typically uses the XMLHttpRequest browser object to exchange data asynchronously with the web server. Alternatively, an IFrame object or dynamically added <script> tags may be used instead of XMLHttpRequest. Despite the name, Ajax can combine any browser scripting language (not just JavaScript) and any data representation (not just XML). Alternative data formats include HTML, plain text or JSON. Several Ajax frameworks are now available to simplify Ajax development. (2007-10-04) 1 1 1 1 1 AKC Ascending Kleene Chain 1 1 1 1 1 AKCL Austin Kyoto Common Lisp 1 1 1 1 1 A. K. Erlang Agner Krarup Erlang 1 1 1 1 1 AKL Andorra Kernel Language 1 1 1 1 1 AL 1. Assembly Language. 2. artificial life. 1 1 1 1 1 al The country code for Albania. (1999-01-27) 1 1 1 1 1 Aladdin Enterprises A small, privately owned, US software consulting and development company, founded in 1986, best known as the original developer of Ghostscript. Address: San Francisco Peninsula, California, USA. Not to be confused with Aladdin Systems, Inc.. Aladdin Enterprises Home (http://aladdin.com/). (2003-09-24) 1 1 1 1 1 Aladdin Systems, Inc. The company that developed and distributes Stuffit and other utility software for the Macintosh, Microsoft Windows, and Palm handheld computers. Not to be confused with Aladdin Enterprises. Aladdin Systems Home (http://aladdinsys.com/). (2003-09-20) 1 1 1 1 1 ALADIN 1. <language> A Language for Attributed Definitions. 2. <tool> An interactive mathematics system for the IBM 360. ["A Conversational System for Engineering Assistance: ALADIN", Y. Siret, Proc Second Symp Symb Algebraic Math, ACM Mar 1971]. (1995-04-13) 1 1 1 1 1 ALAM A language for symbolic mathematics, especially General Relativity. See also CLAM. ["ALAM Programmer's Manual", Ray D'Inverno, 1970]. (1994-10-28) 1 1 1 1 1 Alan F. Shugart The man who founded Shugart Associates and later co-founded Seagate Technology. Alan Shugart left Shugart Associates in 1974 [did he quit or was he fired?] and took a break from the disk-drive business. In 1979, he and Finis Conner founded a new company that at first was called Shugart Technology and later Seagate Technology. (2000-02-09) 1 1 1 1 1 A-language An early ALGOL-like surface syntax for Lisp. ["An Auxiliary Language for More Natural Expression--The A-language", W. Henneman in The Programming Language LISP, E.C. Berkeley et al eds, MIT Press 1964, pp.239- 248]. (1994-10-28) 1 1 1 1 1 A Language Encouraging Program Hierarchy (ALEPH) A language developed in about 1975. ["On the Design of ALEPH", D. Grune, CWI, Netherlands 1986]. (1997-02-27) 1 1 1 1 1 A Language for Attributed Definitions (ALADIN) A language for formal specification of attributed grammars. ALADIN is the input language for the GAG compiler generator. It is applicative and strongly typed. ["GAG: A Practical Compiler Generator", Uwe Kastens <uwe@uni-paderborn.de> et al, LNCS 141, Springer 1982]. (1995-04-14) 1 1 1 1 1 A Language with an Extensible Compiler (ALEC) A language Implemented using RCC on an ICL 1906A. ["ALEC - A User Extensible Scientific Programming Language", R.B.E. Napper et al, Computer J 19(1):25-31]. (1995-04-19) 1 1 1 1 1 Alan Kay The leader of the Software Concepts Group at Xerox Palo Alto Research Centre which developed Smalltalk, the pioneering object-oriented programming system, in 1972. (1994-11-24) 1 1 1 1 1 Alan M. Turing Alan Turing 1 1 1 1 1 Alan Shugart Alan F. Shugart 1 1 1 1 1 Alan Turing Alan M. Turing, 1912-06-22/3? - 1954-06-07. A British mathematician, inventor of the Turing Machine. Turing also proposed the Turing test. Turing's work was fundamental in the theoretical foundations of computer science. Turing was a student and fellow of King's College Cambridge and was a graduate student at Princeton University from 1936 to 1938. While at Princeton Turing published "On Computable Numbers", a paper in which he conceived an abstract machine, now called a Turing Machine. Turing returned to England in 1938 and during World War II, he worked in the British Foreign Office. He masterminded operations at Bletchley Park, UK which were highly successful in cracking the Nazis "Enigma" codes during World War II. Some of his early advances in computer design were inspired by the need to perform many repetitive symbolic manipulations quickly. Before the building of the Colossus 1 1 1 1 1 ALARP As Low As Reasonably Practicable 1 1 1 1 1 A-law The ITU-T standard for nonuniform quantising logarithmic compression. The equation for A-law is | A | ------- (m/mp) |m/mp| =< 1/A | 1+ln A y = | | sgn(m) | ------ (1 + ln A|m/mp|) 1/A =< |m/mp| =< 1 | 1+ln A Values of u=100 and 255, A=87.6, mp is the Peak message value, m is the current quantised message value. (The formulae get simpler if you substitute x for m/mp and sgn(x) for sgn(m); then -1 <= x <= 1.) Converting from u-LAW to A-LAW introduces quantising errors. u-law is used in North America and Japan, and A-law is used in Europe and the rest of the world and international 1 1 1 1 1 ALC 1. Assembly Language Compiler. 2. Airline Line Control. 1 1 1 1 1 Alcool-90 An object-oriented extension of ML with run-time overloading and a type-based notion of modules, functors and inheritance. It is built on CAML Light. (ftp://ftp.inria.fr/lang/alcool). E-mail: <Francois.Rouaix@inria.fr>. (1995-04-18) 1 1 1 1 1 ALCOR A subset of ALGOL. [Sammet 1969, p. 180]. (1995-04-18) 1 1 1 1 1 Aldat A database language, based on extended algebra. [Listed by M.P. Atkinson & J.W. Schmidt in a tutorial in Zurich, 1989]. (1995-04-19) 1 1 1 1 1 ALDES ALgorithm DEScription 1 1 1 1 1 ALDiSP Applicative Language for Digital Signal Processing 1 1 1 1 1 ALEC A Language with an Extensible Compiler 1 1 1 1 1 ALEF A programming language from Bell Labs. ALEF boasts few new ideas but is instead a careful synthesis of ideas from other languages. The result is a practical general purpose programming language which was once displacing C as their main implementation language. Both shared variables and message passing are supported through language constructs. A window system, user interface, operating system network code, news reader, mailer and variety of other tools in Plan 9 are now implemented using ALEF. (1997-02-13) 1 1 1 1 1 ALEPH 1. <language> A Language Encouraging Program Hierarchy. 2. <tool> A system for formal semantics written by Peter Henderson ca. 1970. [CACM 15(11):967-973 (Nov 1972)]. (1994-12-15) 1 1 1 1 1 Aleph ["Aleph: A language for typesetting", Luigi Semenzato <luigi@cs.berkeley.edu> and Edward Wang <edward@cs.berkeley.edu> in Proceedings of Electronic Publishing, 1992 Ed. Vanoirbeek & Coray Cambridge University Press 1992]. (1994-12-15) 1 1 1 1 1 aleph 0 The cardinality of the first infinite ordinal, omega (the number of natural numbers). Aleph 1 is the cardinality of the smallest ordinal whose cardinality is greater than aleph 0, and so on up to aleph omega and beyond. These are all kinds of infinity. The Axiom of Choice (AC) implies that every set can be well-ordered, so every infinite cardinality is an aleph; but in the absence of AC there may be sets that can't be well-ordered (don't posses a bijection with any ordinal) and therefore have cardinality which is not an aleph. These sets don't in some way sit between two alephs; they just float around in an annoying way, and can't be compared to the alephs at all. No ordinal possesses a surjection onto such a set, but it doesn't surject onto any sufficiently large ordinal either. (1995-03-29) 1 1 1 1 1 alert /*'l*rt/ An audible and/or visual message intended to inform a system's users or administrators about a change in the operating conditions of that system or about some kind of error condition. In a graphical user interface, an alert would typically be displayed as a small window containing the message and a button to click to dismiss the window. (1999-03-29) 1 1 1 1 1 Alex 1. A polymorphic language being developed by Stephen Crawley <sxc@itd.dtso.oz.au> of Defence Science & Tech Org, Australia. Alex has abstract data types, type inference and inheritance. 2. <language> An ISWIM-like language with exception handling. ["An Exception Handling Construct for Functional Languages", M. Brez et al, in Proc ESOP88, LNCS 300, Springer 1988]. 3. <tool> A scanner generator. Alexis is its input language. ["Alex: A Simple and Efficient Scanner Generator", H. Mossenbock, SIGPLAN Notices 21(5), May 1986]. (1994-12-15) 1 1 1 1 1 Alexis Alex Input Specification. The input language for the scanner generator Alex. (1995-04-23) 1 1 1 1 1 ALF Algebraic Logic Functional language 1 1 1 1 1 Alfl A lazy function language. A weakly typed, lazy functional language developed by Paul Hudak <hudak-paul@cs.yale.edu> of Yale in 1983. Alfl is implemented as a Scheme preprocessor for the Orbit compiler, by transforming laziness into force-and-delay. ["Alfl Reference Manual and Programmer's Guide", P. Hudak, YALEU/DCS/RR322, Yale U, Oct 1984]. See also ParAlfl. (1995-04-24) 1 1 1 1 1 algebra 1. A loose term for an algebraic structure. 2. A vector space that is also a ring, where the vector space and the ring share the same addition operation and are related in certain other ways. An example algebra is the set of 2x2 matrices with real numbers as entries, with the usual operations of addition and matrix multiplication, and the usual scalar multiplication. Another example is the set of all polynomials with real coefficients, with the usual operations. In more detail, we have: (1) an underlying set, (2) a field of scalars, (3) an operation of scalar multiplication, whose input is a scalar and a member of the underlying set and whose output is a member of the underlying set, just as in a vector space, (4) an operation of addition of members of the underlying set, 1 1 1 1 1 ALGEBRAIC An early system on MIT's Whirlwind. [CACM 2(5):16 (May 1959)]. (1995-01-24) 1 1 1 1 1 algebraic In domain theory, a complete partial order is algebraic if every element is the least upper bound of some chain of compact elements. If the set of compact elements is countable it is called omega-algebraic. [Significance?] (1995-04-25) 1 1 1 1 1 Algebraic Compiler and Translator (ACT 1) A language and compiler for the Royal McBee LGP-30, designed around 1959, apparently by Clay S. Boswell, Jr, and programmed by Mel Kaye. (http://ed-thelen.org/comp-hist/lgp-30-man.html) (2008-08-04) 1 1 1 1 1 algebraic data type (Or "sum of products type") In functional programming, new types can be defined, each of which has one or more constructors. Such a type is known as an algebraic data type. E.g. in Haskell we can define a new type, Tree: data Tree = Empty | Leaf Int | Node Tree Tree with constructors "Empty", "Leaf" and "Node". The constructors can be used much like functions in that they can be (partially) applied to arguments of the appropriate type. For example, the Leaf constructor has the functional type Int -> Tree. A constructor application cannot be reduced (evaluated) like a function application though since it is already in normal form. Functions which operate on algebraic data types can be defined using pattern matching: 1 1 1 1 1 Algebraic Interpretive Dialogue (AID) A version of Joss II for the PDP-10. ["AID (Algebraic Interpretive Dialogue)", DEC manual, 1968]. (1995-04-12) 1 1 1 1 1 Algebraic Logic Functional language (ALF) A language by Rudolf Opalla <opalla@julien.informatik.uni-dortmund.de> which combines functional programming and logic programming techniques. ALF is based on Horn clause logic with equality which consists of predicates and Horn clauses for logic programming, and functions and equations for functional programming. Any functional expression can be used in a goal literal and arbitrary predicates can occur in conditions of equations. ALF uses narrowing and rewriting. ALF includes a compiler to Warren Abstract Machine code and run-time support. (ftp://ftp.germany.eu.net/pub/programming/languages/LogicFunctional). ["The Implementation of the Functional-Logic Language ALF", M. Hanus and A. Schwab]. (1992-10-08) 1 1 1 1 1 Algebraic Manipulation Package (AMP) A symbolic mathematics program written in Modula-2, seen on CompuServe. (1994-10-19) 1 1 1 1 1 Algebraic Specification Language 1. <language> (ASL) ["Structured Algebraic Specifications: A Kernel Language", M. Wirsing, Theor Comput Sci 42, pp.123-249, Elsevier 1986]. 2. <language> (ASF) A language for equational specification of abstract data types. ["Algebraic Specification", J.A. Bergstra et al, A-W 1989]. (1995-12-13) 1 1 1 1 1 algebraic structure Any formal mathematical system consisting of a set of objects and operations on those objects. Examples are Boolean algebra, numerical algebra, set algebra and matrix algebra. [Is this the most common name for this concept?] (1997-02-25) 1 1 1 1 1 Algebra of Communicating Processes (ACP) Compare CCS. ["Algebra of Communicating Processes with Abstraction", J.A. Bergstra & J.W. Klop, Theor Comp Sci 37(1):77-121 1985]. [Summary?] (1994-11-08) 1 1 1 1 1 ALGOL ALGOL 60 1 1 1 1 1 ALGOL 58 An early version of ALGOL 60, originally known as IAL. Michigan Algorithm Decoder (MAD), developed in 1959, was based on IAL. ["Preliminary report - International Algebraic Language", CACM 1(12):8, 1958]. [Details? Relationship to ALGOL 60?] (1999-12-10) 1 1 1 1 1 ALGOL 60 ALGOrithmic Language 1960. A portable language for scientific computations. ALGOL 60 was small and elegant. It was block-structured, nested, recursive and free form. It was also the first language to be described in BNF. There were three lexical representations: hardware, reference, and publication. The only structured data types were arrays, but they were permitted to have lower bounds and could be dynamic. It also had conditional expressions; it introduced :=; if-then-else; very general "for" loops; switch declaration (an array of statement labels generalising Fortran's computed goto). Parameters were call-by-name and call-by-value. It had static local own variables. It lacked user-defined types, character manipulation and standard I/O. See also EULER, ALGOL 58, ALGOL 68, Foogol. ["Report on the Algorithmic Language ALGOL 60", Peter Naur 1 1 1 1 1 ALGOL 60 Modified ["A Supplement to the ALGOL 60 Revised Report", R.M. DeMorgan et al, Computer J 19(4):364]. [SIGPLAN Notices 12(1) 1977]. An erratum in [Computer J 21(3):282 (Aug 1978)] applies to both. (1995-01-25) 1 1 1 1 1 ALGOL 60 Revised (Or "Revised ALGOL 60") A revision of Algol 60 which still lacked standard I/O. ["Revised Report on the Algorithmic Language ALGOL 60", Peter Naur ed, CACM 6(1):1-17 (Jan 1963)]. [Sammet 1969, p.773]. (1995-01-25) 1 1 1 1 1 ALGOL 68 An extensive revision of ALGOL 60 by Adriaan van Wijngaarden et al. ALGOL 68 was discussed from 1963 by Working Group 2.1 of IFIP. Its definition was accepted in December 1968. ALGOL 68 was the first, and still one of very few, programming languages for which a complete formal specification was created before its implementation. However, this specification was hard to understand due to its formality, the fact that it used an unfamiliar metasyntax notation (not BNF) and its unconventional terminology. One of the singular features of ALGOL 68 was its orthogonal design, making for freedom from arbitrary rules (such as restrictions in other languages that arrays could only be used as parameters but not as results). It also allowed user defined data types, then an unheard-of feature. It featured structural equivalence; automatic type conversion ("coercion") including dereferencing; flexible 1 1 1 1 1 ALGOL 68C A variant of ALGOL 68 developed by S. Bourne and Mike Guy of Cambridge University in 1975 and used as the implementation language for the CHAOS OS for the CAP capability computer. ALGOL 68C was ported to the IBM 360, VAX/VMS and several other platforms. (1995-05-02) 1 1 1 1 1 ALGOL 68-R A restriction of ALGOL 68 permitting one-pass compilation, developed at the Royal Signals Radar Establishment, Malvern, Worcester, UK in April 1970. Identifiers, modes and operators must be declared before use. There is no automatic proceduring and no concurrency. It was implemented in ALGOL 60 under GEORGE 3 on an ICL 1907F. ["ALGOL 68-R, Its Implementation and Use", I.F. Currie et al, Proc IFIP Congress 1971, N-H 1971, pp. 360-363]. (1995-05-03) 1 1 1 1 1 ALGOL 68 Revised A significant simplification of ALGOL 68. ["Revised Report on the Algorithmic Language ALGOL 68," A. Van Wijngaarden et al, Acta Informatica 5:1-236, 1975, also Springer 1976, and SIGPLAN Notices 12(5):1-70, May 1977]. (1995-05-03) 1 1 1 1 1 ALGOL 68RS An extension of ALGOL 68 supporting function closures by the Royal Signals Radar Establishment, Malvern UK. It has been ported to Multics and VAX/VMS. (1995-05-04) 1 1 1 1 1 ALGOL 68S A subset of ALGOL 68 allowing simpler compilation, intended mainly for numerical computation. It was rewritten in BLISS for the PDP-11, and later in Pascal. It is available as shareware from Charles Lindsey <chl@cs.man.ac.uk>. Version 2.3 runs on Sun-3 under SunOS 4.x and Atari under GEMDOS (or potentially other computers supported by the Amsterdam Compiler Kit). ["A Sublanguage of ALGOL 68", P.G. Hibbard, SIGPLAN Notices 12(5), May 1977]. (1995-05-04) 1 1 1 1 1 ALGOL C A variant of ALGOL 60 developed by Clive Feather of Cambridge University ca. 1981. ALGOL C added structures and exception handling. It was designed for beginners and students. (1994-11-24) 1 1 1 1 1 ALGOL D ["A Proposal for Definitions in ALGOL", B.A. Galler et al, CACM 10:204-219, 1967]. 1 1 1 1 1 ALGOL N A successor to ALGOL 60 proposed by Yoneda. (1994-11-24) 1 1 1 1 1 ALGOL W A derivative of ALGOL 60. It introduced double precision, complex numbers, bit strings and dynamic data structures. It is parsed entirely by operator precedence and used the call-by-value-result calling convention. ["A Contribution to the Development of Algol", N. Wirth, CACM 9(6):413-431, June 1966]. ["ALGOL W Implementation", H. Bauer et al, TR CS98, Stanford U, 1968]. (1994-11-24) 1 1 1 1 1 ALGOL X A proposed successor to ALGOL 60, a "short-term solution to existing difficulties". Three designs were proposed, by Wirth, Seegmuller and van Wijngaarden. [Sammet 1969, p. 194]. (1995-05-07) 1 1 1 1 1 ALGOL Y A proposed successor to ALGOL 60, a "radical reconstruction". Originally a language that could manipulate its own programs at run time, it became a collection of features that were not accepted for ALGOL X. (1995-05-09) 1 1 1 1 1 algorithim It's spelled "algorithm". (1997-02-25) 1 1 1 1 1 algorithm A detailed sequence of actions to perform to accomplish some task. Named after the Iranian, Islamic mathematician, astronomer, astrologer and geographer, Muhammad ibn Musa al-Khwarizmi. Technically, an algorithm must reach a result after a finite number of steps, thus ruling out brute force search methods for certain problems, though some might claim that brute force search was also a valid (generic) algorithm. The term is also used loosely for any sequence of actions (which may or may not terminate). Paul E. Black's Dictionary of Algorithms, Data Structures, and Problems (http://nist.gov/dads/). (2002-02-05) 1 1 1 1 1 ALgorithm DEScription (ALDES) ["The Algorithm Description Language ALDES", R.G.K. Loos, SIGSAM Bull 14(1):15-39 (Jan 1976)]. (1995-04-19) 1 1 1 1 1 ALgorIthmic ASsembly language (ALIAS) A machine oriented variant of BLISS. ALIAS was implemented in BCPL for the PDP-9. ["ALIAS", H.E. Barreveld, Int Rep, Math Dept, Delft U Tech, Netherlands, 1973]. (1997-03-13) 1 1 1 1 1 Algorithmic Language Algol 60 1 1 1 1 1 Algorithmic Model A method of estimating software cost using mathematical algorithms based on the parameters which are considered to be the major cost drivers. These estimate of effort or cost are based primarily on the size of the software or Delivered Source Instructions (DSI)s, and other productivity factors known as Cost Driver Attributes. See also Parametric Model. (1996-05-28) 1 1 1 1 1 Algorithmic Processor Description Language (APDL) An ALGOL 60-like language for describing computer design, for the CDC G-21. ["The Description, Simulation, and Automatic Implementation of Digital Computer Processors", J.A. Darringer, Ph.D Thesis EE Dept, CMU May 1969]. (1995-11-26) 1 1 1 1 1 Algorithmic Test Case Generation A computational method for identifying test cases from data, logical relationships or other software requirements information. (1996-05-10) 1 1 1 1 1 ALGY An early language for symbolic mathematics. [Sammet 1969, p. 520]. (1995-04-12) 1 1 1 1 1 ALIAS ALgorIthmic ASsembly language 1 1 1 1 1 alias 1. <operating system> A name, usually short and easy to remember and type, that is translated into another name or string, usually long and difficult to remember or type. Most command interpreters (e.g. Unix's csh) allow the user to define aliases for commands, e.g. "alias l ls -al". These are loaded into memory when the interpreter starts and are expanded without needing to refer to any file. 2. <networking> One of several alternative hostnames with the same Internet address. E.g. in the Unix hosts database (/etc/hosts or NIS map) the first field on a line is the Internet address, the next is the official hostname (the "canonical name" or "CNAME"), and any others are aliases. Hostname aliases often indicate that the host with that alias provides a particular network service such as archie, finger, FTP, or web. The assignment of services to computers can then be changed simply by moving an 1 1 1 1 1 aliasing 1. <jargon> When several different identifiers refer to the same object. The term is very general and is used in many contexts. See alias, aliasing bug, anti-aliasing. 2. <hardware> (Or "shadowing") Where a hardware device responds at multiple addresses because it only decodes a subset of the address lines, so different values on the other lines are ignored. (1998-03-13) 1 1 1 1 1 aliasing bug stale pointer bug 1 1 1 1 1 Alice A parallel graph rewriting computer developed by Imperial College, University of Edinburgh and ICL. (1995-01-19) 1 1 1 1 1 alife artificial life 1 1 1 1 1 A-Life artificial life 1 1 1 1 1 ALJABR An implementation of MACSYMA for the Macintosh by Fort Pond Research. (1995-02-21) 1 1 1 1 1 al-Khwarizmi Muhammad ibn Musa al-Khwarizmi 1 1 1 1 1 Allegro The code name for the major Mac OS release due in mid-1998. (http://devworld.apple.com/mkt/informed/appledirections/mar97/roadmap.html). (1997-10-15) 1 1 1 1 1 all-elbows Said of a TSR (terminate-and-stay-resident) mess-dos program, such as the N pop-up calendar and calculator utilities that circulate on BBS systems: unsociable. Used to describe a program that rudely steals the resources that it needs without considering that other TSRs may also be resident. One particularly common form of rudeness is lock-up due to programs fighting over the keyboard interrupt. [Jargon File] (1995-02-21) 1 1 1 1 1 ALLIANCE A complete set of CAD tools for teaching Digital CMOS VLSI Design in Universities. It includes a VHDL compiler and simulator, logic synthesis tools, and automatic place and route tools. ALLIANCE is the result of a ten years effort at University Pierre et Marie Curie (PARIS VI, France). It runs on Sun-4, not well supported: MIPS/Ultrix, 386/SystemV. Latest version: 1.1, as of 1993-02-16. (1993-02-16) 1 1 1 1 1 Allman style indent style 1 1 1 1 1 allow-none An annotation in GTk documentation indicating that the annotated entity may be null. (http://live.gnome.org/GObjectIntrospection/Annotations). (2009-09-29) 1 1 1 1 1 ALLOY A language by Thanasis Mitsolides <mitsolid@cs.nyu.edu> which combines functional programming, object-oriented programming and logic programming ideas, and is suitable for massively parallel systems. Evaluating modes support serial or parallel execution, eager evaluation or lazy evaluation, nondeterminism or multiple solutions etc. ALLOY is simple as it only requires 29 primitives in all (half of which are for object oriented programming support). It runs on SPARC. (ftp://cs.nyu.edu/pub/local/alloy/). ["The Design and Implementation of ALLOY, a Parallel Higher Level Programming Language", Thanasis Mitsolides <mitsolid@cs2.nyu.edu>, PhD Thesis NYU 1990]. (1991-06-11) 1 1 1 1 1 ALM 1. <programming> application lifecycle management. 2. <language> Assembly Language for Multics. 1 1 1 1 1 Aloha (From the Hawaiian greeting) A system of contention resolution devised at The University of Hawaii. Packets are broadcast when ready, the sender listens to see if they collide and if so re-transmits after a random time. Slotted Aloha constrains packets to start at the beginning of a time slot. Basic Aloha is appropriate to long propagation time nets (e.g. satellite). For shorter propagation times, carrier sense protocols are possible. (1995-12-10) 1 1 1 1 1 Aloha Net (From the Hawaiian greeting) One of the first functioning networks in the USA, conceived and implimented at the University of Hawaii campus at Manoa. Its purpose was to link the University mainframe computer to client computers located on outer islands at University campuses. Put in place in the early 1970s, it was dubed the Aloha Net. Key punch cards were fed through a reader, and sent over the commercial phone lines. (1995-12-10) 1 1 1 1 1 Alonzo Church A twentieth century mathematician and logician, and one of the founders of computer science. Church invented the lambda-calculus and posited a version of the Church-Turing thesis. (1995-03-25) 1 1 1 1 1 ALP A list processing extension of Mercury Autocode. ["ALP, An Autocode List-Processing Language", D.C. Cooper et al, Computer J 5:28-31, 1962]. (1995-01-24) 1 1 1 1 1 ALPAK A subroutine package used by ALTRAN. ["The ALPAK System for Nonnumerical Algebra on a Digital Computer", W.S. Brown, Bell Sys Tech J 42:2081, 1963]. [Sammet 1969, p. 502]. (1995-05-10) 1 1 1 1 1 ALPHA (Or "Input") An extension of ALGOL 60 for the M-20 computer developed by A.P. Ershov at Novosibirsk in 1961. ALPHA includes matrix operations, slices, and complex arithmetic. ["The Alpha Automatic Programming System", A.P. Ershov ed., A-P 1971]. (1995-05-10) 1 1 1 1 1 Alpha 1. <tool> A compiler generator written by Andreas Koschinsky <koschins@cs.tu-berlin.de> and described in his thesis at the Technische Universitaet Berlin. Alpha takes an attribute grammar and uses Bison and Flex to generate a parser, a scanner and an ASE evaluator (Jazayeri and Walter). The documentation is in german. (1993-02-16) 2. <processor> DEC Alpha. (1995-05-10) 1 1 1 1 1 Alpha AXP 21164 A 1 GIPS version of the DEC Alpha processor. The first commercially available sequential 1 GIPS processor. Announced 1994-09-7. (http://digital.com/info/semiconductor/dsc-21164.html). (1995-05-10) 1 1 1 1 1 alpha/beta pruning An optimisation of the minimax algorithm for choosing the next move in a two-player game. The position after each move is assigned a value. The larger this value, the better the position is for me. Thus, I will choose moves with maximum value and you will choose moves with minimum value (for me). If it is my move and I have already found one move M with value alpha then I am only interested in other moves with value greater than alpha. I now consider another of my possible moves, M', to which you could reply with a move with value beta. I know that you would only make a different reply if it had a value less than beta. If beta is already less than alpha then M' is definitely worth less than M so I can reject it without considering any other replies you might make. The same reasoning applies when considering my replies to your reply. An alpha cutoff is when your reply gives a lower value 1 1 1 1 1 alphabetic language A written human language in which symbols reflect the pronunciation of the words. Examples are English, Greek, Russian, Thai, Arabic and Hebrew. Alphabetic languages contrast with ideographic languages. I18N Encyclopedia (http://i18ngurus.com/encyclopedia/alphabetic_language.html). (2004-08-29) 1 1 1 1 1 alpha conversion In lambda-calculus and reduction, the renaming of a formal parameter in a lambda abstraction. This does not change the meaning of the abstraction. For example: \ x . x+1 <--> \ y . y+1 If the actual argument to a lambda abstraction contains instances of the abstraction's formal parameter then it is necessary to rename the parameter before applying the abstraction to avoid name capture. (1995-05-10) 1 1 1 1 1 Alpha EV6 EV6 1 1 1 1 1 Alpha Geek The head geek or geek's geek. When no one else knows the answer, or several techno-types give conflicting advise, or the error message says "consult your administrator" and you *are* the administrator, you ask the Alpha Geek. (1997-06-25) 1 1 1 1 1 alphanumeric A decimal digit or a letter (upper or lower case). Typically, "letters" means only English letters (ASCII A-Z plus a-z) but it may also include non-English letters in the Roman alphabet, e.g., e-acute, c-cedilla, the thorn letter, and so on. Perversely, it may also include the underscore character in some contexts. (1997-09-11) 1 1 1 1 1 alpha particle bit rot 1 1 1 1 1 Alphard (Named after the brightest star in Hydra) A Pascal-like language developed by Wulf, Shaw and London of CMU in 1974. Alphard supports data abstraction using the 'form', which combines a specification and an implementation. ["Abstraction and Verification in Alphard: Defining and Specifying Iteration and Generators", Mary Shaw, CACM 20(8):553-563, Aug 1977]. (1995-05-10) 1 1 1 1 1 alpha testing Testing of software at the developer's site by the customer. The stage before beta testing. (1996-05-10) 1 1 1 1 1 ALPS 1. An interpreted algebraic language for the Bendix G15 developed by Dr. Richard V. Andree (? - 1987), Joel C. Ewing and others of the University of Oklahoma from Spring 1966 (possibly 1965). Dale Peters <dpeters@theshop.net> reports that in the summer of 1966 he attended the second year of an NSF-sponsored summer institute in mathematics and computing at the University of Oklahoma. Dr. Andree's computing class mostly used the language GO-GO, later renamed ALPS. The language changed frequently during the class, which was occasionally disorienting. Dale believes it was also used in Summer 1965 and that it was about this time that John G. Kemeny (one of the designers of Dartmouth BASIC, 1963) saw it during a visit. Dr. Andree's January 1967 class mimeo notes on ALPS begin: "ALPS is a new programming language designed and perfected by Mr. Harold Bradbury, Mr. Joel Ewing and Mr. Harold Wiebe, members of the O.U. Mathematics Computer Consultants Group under the direction of Dr. Richard V. Andree. ALPS is designed to be used with a minimum of training to solve numerical problems on a computer with typewriter stations and using man-computer cooperation by persons who have little familiarity with advanced mathematics." The initial version of what evolved into ALPS was designed and 1 1 1 1 1 alt /awlt/ 1. The alt modifier key on many keyboards, including the IBM PC. On some keyboards and operating systems, (but not the IBM PC) the alt key sets bit 7 of the character generated. See bucky bits. 2. The "clover" or "Command" key on a Macintosh; use of this term usually reveals that the speaker hacked PCs before coming to the Mac (see also feature key). Some Mac hackers, confusingly, reserve "alt" for the Option key (and it is so labelled on some Mac II keyboards). 3. (Obsolete PDP-10; often "ALT") An alternate name for the ASCII ESC character (Escape, ASCII 27), after the keycap labelling on some older terminals; also "altmode" (/awlt'mohd/). This character was almost never pronounced escape on an ITS system, in TECO or under TOPS-10, always alt, as in "Type alt alt to end a TECO command" or alt-U onto the system (for "log onto the [ITS] system"). 1 1 1 1 1 ALTAC An extended Fortran II for the Philco 2000, built on TAC. [Sammet 1969, p.146]. (1995-03-16) 1 1 1 1 1 Altair 8800 An Intel 8080-based machine made by MITS. The Altair was the first popular microcomputer kit. It appeared on the cover of the January 1975 "Popular Electronics" magazine with an article (probably) by Leslie Solomon. Leslie Solomon was an editor at Popular Electronics who had a knack for spotting kits that would interest people and make them buy the magazine. The Altair 8800 was one such. The MITS guys took the prototype Altair to New York to show Solomon, but couldn't get it to work after the flight. Nonetheless, he liked it, and it appeared on the cover as "The first minicomputer in a kit." Solomon's blessing was important enough that some MITS competitors named their product the "SOL" to gain his favour. Some wags suggested SOL was actually an abbreviation for the condition in which kit purchasers would find themselves. Bill Gates and Paul Allen saw the article on the Altair 8800 in Popular Electronics. They realised that the Altair, which 1 1 1 1 1 Alta Vista A website provided by Digital which features a very fast Web and Usenet search engine. As of April 1996 its word index is 33GB in size. AltaVista is currently (June 1996) the largest Web index, with 30 million pages from 225,000 servers, and three million articles from 14,000 Usenet news groups. It is accessed over 12 million times per weekday. (http://altavista.digital.com/). (1996-06-10) 1 1 1 1 1 alt bit meta bit 1 1 1 1 1 ALTER An SQL Data Definition Language command that adds or removes columns or indexes to/from a table or modifies the table definition in some other way. This differs from the INSERT, UPDATE and DELETE (Data Modification Language) commands in that those change the data stored in the table but not its definition. MySQL ALTER TABLE command (http://dev.mysql.com/doc/refman/5.1/en/alter-table.html). (2009-11-10) 1 1 1 1 1 Alternating bit protocol (ABP) A simple data link layer protocol that retransmits lost or corrupted messages. Messages are sent from transmitter A to receiver B. Assume that the channel from A to B is initialised and that there are no messages in transit. Each message contains a data part, a checksum, and a one-bit sequence number, i.e. a value that is 0 or 1. When A sends a message, it sends it continuously, with the same sequence number, until it receives an acknowledgment (ACK) from B that contains the same sequence number. When that happens, A complements (flips) the sequence number and starts transmitting the next message. When B receives a message from A, it checks the checksum. If the message is not corrupted B sends back an ACK with the same sequence number. If it is the first message with that sequence number then it is sent for processing. Subsequent messages with the same sequence bit are simply acknowledged. 1 1 1 1 1 altmode alt 1 1 1 1 1 ALTRAN A Fortran extension for rational algebra developed by W.S. Brown of Bell Labs ca. 1968. ["The ALTRAN System for Rational Function Manipulation - A Survey", A.D. Hall, CACM 14(8):517-521 (Aug 1971)]. (1995-06-01) 1 1 1 1 1 alt.sources A Usenet newsgroup for posting program source code. Archive (ftp://wuarchive.wustl.edu/usenet/alt.sources/). (1995-10-18) 1 1 1 1 1 ALU 1. <processor> Arithmetic and Logic Unit. 2. <body> Association of Lisp Users. 1 1 1 1 1 Aluminum Book ["Common LISP: The Language, 2nd Edition", Guy L. Steele Jr., Digital Press 1990, ISBN 1-55558-041-6]. Due to a technical screwup some printings of the second edition are actually what the author calls "yucky green". On-line version (http://cs.cmu.edu/Groups/AI/html/cltl/cltl2.html). See also book titles. [Jargon File] (1997-06-25) 1 1 1 1 1 Alvey A funding programme for collaborative research in the UK. (1995-06-01) 1 1 1 1 1 AM 1. <communications> Amplitude Modulation. 2. <artificial intelligence> A program by Doug Lenat to discover concepts in elementary mathematics. AM was written in 1976 in Interlisp. From 100 fundamental concepts and about 250 heuristics it discovered several important mathematical concepts including subsets, disjoint sets, sets with the same number of elements, and numbers. It worked by filling slots in frames maintaining an agenda of resource-limited prioritised tasks. AM's successor was Eurisko. (http://homepages.enterprise.net/hibou/aicourse/lenat.txt). (1999-04-19) 1 1 1 1 1 am The country code for Armenia. Used for the vanity domain "i.am". (1999-01-27) 1 1 1 1 1 Amanda A functional programming language derived mostly from Miranda with some small changes. Amanda was written by Dick Bruin and implemented on MS-DOS and NeXT. It is available as an interperator only. (1998-04-27) 1 1 1 1 1 A Manufacturing Language (AML) A high-level language developed by IBM in the 1980s for industrial robots. ["AML: A Manufacturing Language", R.H. Taylor et al, Inst J Robot Res 1(3):19-43]. (1995-09-25) 1 1 1 1 1 amateur packet radio (PR) The use of packet radio by amateurs to communicate between computers. PR is a complete amateur radio computer network with "digipeaters" (relays), mailboxes (BBS) and other special nodes. In Germany, it is on HF, say, 2m (300 and 1200 BPS), 70cm (1200 to 9600 BPS), 23cm (normally 9600 BPS and up, currently most links between digipeaters) and higher frequencies. There is a KW (short wave) Packet Radio at 300 BPS, too. Satellites with OSCAR (Orbiting Sattelite Carring Amateur Radio) transponders (mostly attached to commercial satellites by the AMateur SATellite (AMSAT) group) carry Packet Radio mailboxes or digipeaters. There are both on-line and off-line services on the packet radio network: You can send electronic mail, read bulletins, chat, transfer files, connect to on-line DX-Clusters (DX=far distance) to catch notes typed in by other HAMs about the hottest international KW connections currently coming up (so 1 1 1 1 1 Amber 1. A functional programming language which adds CSP-like concurrency, multiple inheritance and persistence to ML and generalises its type system. It is similar to Galileo. Programs must be written in two type faces, roman and italics! It has both static types and dynamic types. There is an implementation for Macintosh. ["Amber", L. Cardelli, TR Bell Labs, 1984]. 2. An object-oriented distributed language based on a subset of C++, developed at Washington University in the late 1980s. (1994-12-08) 1 1 1 1 1 AMBIT Algebraic Manipulation by Identity Translation (also claimed: "Acronym May Be Ignored Totally"). An early pattern-matching language, developed by C. Christensen of Massachusetts Computer Assocs in 1964, aimed at algebraic manipulation. [Sammet 1969, pp. 454-457]. (1994-12-08) 1 1 1 1 1 AMBIT/G AMBIT for graphs. ["An Example of the Manipulation of Directed Graphs in the AMBIT/G Programming Language", C. Christensen, in Interactive Systems for Experimental Applied Mathematics, M. Klerer et al, eds, Academic Press 1968, pp. 423-435]. (1994-12-08) 1 1 1 1 1 AMBIT/L AMBIT for lists. A variant of AMBIT supporting list handling and pattern matching rules based on two-dimensional diagrams. ["An Introduction to AMBIT/L, A Diagrammatic Language for List Processing", Carlos Christensen, Proc 2nd ACM Symp Symb and Alg Manip (Mar 1971)]. (1994-12-08) 1 1 1 1 1 AMBIT/S AMBIT for strings. 1 1 1 1 1 AMBUSH A language for linear programming problems in a materials processing and transportation network. ["AMBUSH - An Advanced Model Builder for Linear Programming", T.R. White et al, National Petroleum Refiners Assoc Comp Conf (Nov 1971)]. (1995-06-19) 1 1 1 1 1 AMD 1. <company> Advanced Micro Devices. 2. <jargon> According to Don Olivier <don@hsph.harvard.edu>, his system manager came in to work one morning to find his IBM system down with a message on the console that said "AMD failure". After he and the service rep had puzzled over documentation for an hour or so they called headquarters and eventually learned that it the failure was in the cooling system: an AMD is an "air movement device", IBM for "fan". (1995-01-16) 1 1 1 1 1 AMD 29000 A RISC microprocessor descended from the Berkley RISC design. Like the SPARC design that was introduced shortly afterward, the 29000 has a large register set split into local and global sets. But though it was introduced before the SPARC, it has a more elegant method of register management. The 29000 has 64 global registers, in comparison to the SPARC's eight. In addition, the 29000 allows variable sized windows allocated from the 128 register stack cache. The current window or stack frame is indicated by a stack pointer, a pointer to the caller's frame is stored in the current frame, like in an ordinary stack (directly supporting stack languages like C, a CISC-like philosophy). Spills and fills occur only at the ends of the cache, and registers are saved/loaded from the memory stack. This allows variable window sizes, from 1 to 128 registers. This flexibility, plus the large set of global registers, makes register allocation 1 1 1 1 1 AMD 29027 The FPU for the AMD 29000. (1995-01-16) 1 1 1 1 1 Amdahl 1. <company> Amdahl Corporation. 2. <person> Gene Amdahl. 1 1 1 1 1 Amdahl Corporation A US computer manufacturer. Amdahl is a major supplier of large mainframes, UNIX and Open Systems software and servers, data storage subsystems, data communications products, applications development software, and a variety of educational and consulting services. Amdahl products are sold in more than 30 countries for use in both open systems and IBM plug-compatible mainframe computing environments. Quarterly sales $397M, profits $13M (Aug 1994). In 1997 Amdahl became a division of Fujitsu. (http://amdahl.com/). (1995-05-23) 1 1 1 1 1 Amdahl's Law (Named after Gene Amdahl) If F is the fraction of a calculation that is sequential, and (1-F) is the fraction that can be parallelised, then the maximum speedup that can be achieved by using P processors is 1/(F+(1-F)/P). [Gene Amdahl, "Validity of the Single Processor Approach to Achieving Large-Scale Computing Capabilities", AFIPS Conference Proceedings, (30), pp. 483-485, 1967]. (2002-10-16) 1 1 1 1 1 AMD Am2901 A 4-bit bit-slice processor from Advanced Micro Devices. It featured sixteen 4-bit registers and a 4-bit ALU and operation signals to allow carry/borrow or shift operations and such to operate across any number of other 2901s. An address sequencer (such as the 2910) could provide control signals with the use of custom microcode in ROM. (1994-11-16) 1 1 1 1 1 AMD Am2903 A bit-slice prcessor from Advanced Micro Devices which featured hardware multiply. (1994-11-16) 1 1 1 1 1 AMD Am2910 An address sequencer from Advanced Micro Devices. (1994-11-16) 1 1 1 1 1 AMD K7 Athlon 1 1 1 1 1 American National Standard (ANS) A common prefix for ANSI documents or standards, e.g.: "ANS Forth", or "American National Standard X3.215-1994". (1998-07-01) 1 1 1 1 1 American National Standards Institute (ANSI) The private, non-profit organisation (501(c)3) responsible for approving US standards in many areas, including computers and communications. ANSI is a member of ISO. ANSI sells ANSI and ISO (international) standards. ANSI Home (http://ansi.org/). Address: New York, NY 10036, USA. Sales: 1430 Broadway, NY NY 10018. Telephone: +1 (212) 642 4900. (2004-01-14) 1 1 1 1 1 American Society of Mechanical Engineers (ASME) A group involved in CAD standardisation. (1995-04-21) 1 1 1 1 1 American Standard Code for Information Interchange The basis of character sets used in almost all present-day computers. US-ASCII uses only the lower seven bits (character points 0 to 127) to convey some control codes, space, numbers, most basic punctuation, and unaccented letters a-z and A-Z. More modern coded character sets (e.g., Latin-1, Unicode) define extensions to ASCII for values above 127 for conveying special Latin characters (like accented characters, or German ess-tsett), characters from non-Latin writing systems (e.g., Cyrillic, or Han characters), and such desirable glyphs as distinct open- and close-quotation marks. ASCII replaced earlier systems such as EBCDIC and Baudot, which used fewer bytes, but were each broken in their own way. Computers are much pickier about spelling than humans; thus, hackers need to be very precise when talking about characters, and have developed a considerable amount of verbal shorthand for them. Every character has one or more names - some formal, some concise, some silly. 1 1 1 1 1 American Telephone and Telegraph, Inc. (AT&T) One of the largest US telecommunications providers, also noted for being the birthplace of the Unix operating system and the C and C++ programming languages. AT&T was incorporated in 1885, but traces its lineage to Alexander Graham Bell and his invention of the telephone in 1876. As parent company of the former Bell System, AT&T's primary mission was to provide telephone service to virtually everyone in the United States. In its first 50 years, AT&T established subsidiaries and allied companies in more than a dozen other countries. It sold these interests in 1925 and focused on achieving its mission in the United States. It did, however, continue to provide international long distance service. The Bell System was dissolved at the end of 1983 with AT&T's divestiture of the Bell telephone companies. AT&T split into three parts in 1996, one of which is Lucent 1 1 1 1 1 American Wire Gauge (AWG, sometimes "Brown and Sharpe Wire Gauge") A U.S. standard set of non-ferrous wire conductor sizes. Typical household wiring is AWG number 12 or 14. Telephone wire is usually 22, 24, or 26. The higher the gauge number, the smaller the diameter and the thinner the wire. Thicker wire is better for long distances due to its lower resistance per unit length. (2001-03-26) 1 1 1 1 1 America On-Line, Inc. (AOL) A US on-line service provider based in Vienna, Virginia, USA. AOL claims to be the largest and fastest growing provider of on-line services in the world, with the most active subscriber base. AOL offers its three million subscribers electronic mail, interactive newspapers and magazines, conferencing, software libraries, computing support, and on-line classes. In October 1994 AOL made Internet FTP available to its members and in May 1995, full Internet access including web. AOL's main competitors are Prodigy and Compuserve. (http://aol.com/). (1997-08-26) 1 1 1 1 1 America's Multimedia Online (AMO) An Internet technologies company which invented Never Offline in 1995 and was officially started in 1996. (http://amo.net/). E-mail: AMO <amo@amo.net>. Address: Albuquerque, NM, USA. (1999-11-03) 1 1 1 1 1 AMI Alternate Mark Inversion 1 1 1 1 1 Amiga A range of home computers first released by Commodore Business Machines in early 1985 (though they did not design the original - see below). Amigas were popular for games, video processing, and multimedia. One notable feature is a hardware blitter for speeding up graphics operations on whole areas of the screen. The Amiga was originally called the Lorraine, and was developed by a company named "Amiga" or "Amiga, Inc.", funded by some doctors to produce a killer game machine. After the US game machine market collapsed, the Amiga company sold some joysticks but no Lorraines or any other computer. They eventually floundered and looked for a buyer. Commodore at that time bought the (mostly complete) Amiga machine, infused some money, and pushed it through the final stages of development in a hurry. Commodore released it sometime[?] in 1985. Most components within the machine were known by nicknames. 1 1 1 1 1 Amiga E An Amiga E compiler by Wouter van Oortmerssen. Amiga E compiles 20000 lines/minute on a 7 Mhz Amiga. It allows in-line assembly code and has an integrated linker. It has a large set of integrated functions and modules. V2.04 includes as modules a flexible type system, quoted expressions, immediate and typed lists, low level polymorphism and exception handling. It is written in assembly language and E. Version 2.1b (ftp://ftp.wustl.edu/pub/aminet/dev/e/AmigaE21b.lha). (ftp://amiga.physik.unizh.ch/amiga/dev/lang/AmigaE21b.lha). Usenet newsgroup: news:comp.sys.amiga.programmer. (1997-08-26) 1 1 1 1 1 Aminet (Amiga network) A collection of FTP mirrors that contain several gigabytes of freely distributable software for the Amiga range of computers. Home, ftp.wustl.edu (ftp://ftp.wustl.edu). (1997-08-31) 1 1 1 1 1 AML A Manufacturing Language 1 1 1 1 1 AML/E (AML Entry) A simple version of AML, implemented on the IBM PC, with a graphic display of the robot position. (1995-10-03) 1 1 1 1 1 AMO America's Multimedia Online 1 1 1 1 1 Amoeba 1. <operating system> A distributed operating system developed by Andrew S. Tanenbaum and others of Vrije Universiteit, Amsterdam. Amoeba is only available under licence from the VUA, but is free of charge and includes all source, binaries and documentation. (http://am.cs.vu.nl/). [Features?] 2. <computer, abuse> A derogatory term for Commodore's Amiga personal computer. [Jargon File] (1997-05-07) 1 1 1 1 1 AMP 1. <mathematics, tool> Algebraic Manipulation Package. 2. <networking, tool> Active Measurement Project. 1 1 1 1 1 amper ampersand 1 1 1 1 1 Ampere (Amp, A) The unit of electrical current flow. One Amp is the current that will flow through a one-ohm resistance when one Volt DC is applied across it. (2004-01-18) 1 1 1 1 1 ampersand "&" ASCII character 38. Common names: ITU-T, INTERCAL: ampersand; amper; and. Rare: address (from C); reference (from C++); bitand; background (from sh); pretzel; amp. A common symbol for "and", used as the "address of" operator in C, the "reference" operator in C++ and a bitwise and or logical and operator in several programming languages. Visual BASIC uses it as the string concatenation operator and to prefix octal and hexadecimal numbers. UNIX shells use the character to indicate that a task should be run in the background (single "&" suffix) or (following C's lazy and), in a compound command of the form "a && b" to indicate that the command b should only be run if command a terminates successfully. The ampersand is a ligature (combination) of the cursive letters "e" and "t", invented in 63 BC by Marcus Tirus [Tiro?] as shorthand for the Latin word for "and", "et". 1 1 1 1 1 AMPL Along with mpl, the intrinsic parallel languages for MasPar's computers. AMPL and mpl are parallel variants of C. Ampl is actually now a gcc port. ["AMPL: Design, Implementation and Evaluation of a Multiprocessing Language", R. Dannenberg, CMU 1981]. ["Loglan Implementation of the AMPL Message Passing System", J. Milewski SIGPLAN Notices 19(9):21-29 (Sept 1984)]. [Are these the same language?] (1995-11-01) 1 1 1 1 1 AMPLE A FORTH-like language for programming the 500/5000 series of add-on music synthesisers for the BBC Microcomputer. AMPLE was produced by Hybrid Technologies, Cambridge, England in the mid 1980s. Many AMPLE programs were published in Acorn User magazine. (1995-11-01) 1 1 1 1 1 Amplitude Modulation (AM) A method of encoding data by varying the amplitude of a constant frequency carrier. Contrast Frequency Modulation. (2001-04-30) 1 1 1 1 1 amp off (Purdue) To run in background. From the Unix shell "&" (ampersand) operator. [Jargon File] (1995-11-14) 1 1 1 1 1 AMPPL-II Associative Memory Parallel Processing Language 1 1 1 1 1 AMPS Advanced Mobile Phone Service 1 1 1 1 1 AMS Andrew Message System 1 1 1 1 1 AMTRAN Automatic Mathematical TRANslation 1 1 1 1 1 Amulet An implementation or the Advanced RISC Machine microprocessor architecture using the micropipeline design style. In April 1994 the Amulet group in the Computer Science department of Manchester University took delivery of the AMULET1 microprocessor. This was their first large scale asynchronous circuit and the world's first implementation of a commercial microprocessor architecture (ARM) in asynchronous logic. Work was begun at the end of 1990 and the design despatched for fabrication in February 1993. The primary intent was to demonstrate that an asynchronous microprocessor can consume less power than a synchronous design. The design incorporates a number of concurrent units which cooperate to give instruction level compatibility with the existing synchronous part. These include an Address unit, which autonomously generates instruction fetch requests and interleaves (nondeterministically) data requests from the 1 1 1 1 1 an The country code for the Netherlands Antilles (Dutch Antilles). (1999-01-27) 1 1 1 1 1 analog American spelling of analogue. (1995-11-14) 1 1 1 1 1 analog computer analogue computer 1 1 1 1 1 Analog Hardware Design Language (AHDL) A language under development by the US Air Force. (1995-04-09) 1 1 1 1 1 analogue (US: "analog") A description of a continuously variable signal or a circuit or device designed to handle such signals. The opposite is "discrete" or "digital". Analogue circuits are much harder to design and analyse than digital ones because the designer must take into account effects such as the gain, linearity and power handling of components, the resistance, capacitance and inductance of PCB tracks, wires and connectors, interference between signals, power supply stability and more. A digital circuit design, especially for high switching speeds, must also take these factors into account if it is to work reliably, but they are usually less critical because most digital components will function correctly within a range of parameters whereas such variations will corrupt the outputs of an analogue circuit. See also analogue computer. (1995-11-14) 1 1 1 1 1 analogue computer A machine or electronic circuit designed to work on numerical data represented by some physical quantity (e.g. rotation or displacement) or electrical quantity (e.g. voltage or charge) which varies continuously, in contrast to digital signals which are either 0 or 1. For example, the turning of a wheel or changes in voltage can be used as input. Analogue computers are said to operate in real time and are used for research in design where many different shapes and speeds can be tried out quickly. A computer model of a car suspension allows the designer to see the effects of changing size, stiffness and damping. (1995-05-01) 1 1 1 1 1 Analogy Model A method of estimating the cost of a proposed software project by extrapolating from the costs and schedules of similar completed projects. (1996-05-28) 1 1 1 1 1 analytical CRM Software which helps a business build customer relationships and analyse ways to improve them. [Typical functions? Example?] (2007-06-11) 1 1 1 1 1 Analytical Engine A design for a general-purpose digital computer proposed by Charles Babbage in 1837 as a successor to his earlier special-purpose Difference Engine. The Analytical Engine was to be built from brass gears powered by steam with input given on punched cards. Babbage could never secure enough funding to build it, and so it was, and never has been, constructed. (http://fourmilab.ch/babbage/). (1998-10-19) 1 1 1 1 1 Analytical Machine Analytical Engine 1 1 1 1 1 Analytical Solutions Forum (ASF) The business intelligence trade body that, in October 1999, replaced the ineffective OLAP Council intending to produce standards for OLAP. The ASF managed the remarkably achievement of being even less effective and eventually disappeared, its only achievement having been the issuing of a press release announcing its formation. (2005-05-28) 1 1 1 1 1 anchor hypertext link 1 1 1 1 1 ANCP An early system on the Datatron 200 series. [Listed in CACM 2(5):16, May 1959]. (1995-11-15) 1 1 1 1 1 AND (Or "conjunction") The Boolean function which is true only if all its arguments are true. The truth table for the two argument AND function is: A | B | A AND B --+---+--------- F | F | F F | T | F T | F | F T | T | T AND is often written as an inverted "V" in texts on logic. In the C programming language it is represented by the && (logical and) operator. (1997-11-15) 1 1 1 1 1 ANDF Architecture Neutral Distribution Format 1 1 1 1 1 Andorra-I A parallel logic programming language with the OR-parallelism of Aurora and the AND-parallelism of Parlog. ["Andorra-I: A Parallel Prolog System that Transparently Exploits both And- and Or-Parallelism", V.S Costa et al, SIGPLAN Notices 26(7):83-93 (July 1991)]. [Imperial College? Who?] (1995-11-24) 1 1 1 1 1 Andorra Kernel Language (AKL) The successor to KAP by S. Janson <sverker@sics.se>. A prototype implementation is available from the author. ["Programming Paradigms of the Andorra Kernel Language", S. Janson et al in Logic Programming: Proc 1991 Intl Symp, MIT Press 1991]. (1994-11-24) 1 1 1 1 1 Andorra-Prolog ["Andorra-Prolog: An Integration of Prolog and Committed Choice Languages", S. Haridi et al, Intl Conf Fifth Gen Comp Sys 1988, ICOT 1988]. (1995-11-24) 1 1 1 1 1 Andrei Markov 1856-1922. The Russian mathematician, after who Markov chains were named. Biography (http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Markov.html). [Other contributions?] (1995-10-06) 1 1 1 1 1 Andrew File System (AFS) The distributed file system of the Andrew Project, adopted by the OSF as part of their Distributed Computing Environment. Frequently Asked Questions (http://transarc.com/Product/AFS/FAQ/faq.html). (1994-11-24) 1 1 1 1 1 Andrew Fluegelman A successful attorney, editor of PC World Magazine, and author of the MS-DOS communications program PC-TALK III, written in 1982. He once owned the trademark freeware but it wasn't enforced after his disappearance. In 1985, Fluegelman was diagnosed with cancer. He was last seen a week later, on 1985-07-06, when he left his Marin County home to go to his office in Tiburon. He called his wife later that day and has not been heard from since. His car was found at Vista Point on the north end of the Golden Gate Bridge. [San Francisco Examiner Sunday Magazine, October 1985]. Shareware history (http://paulspicks.com/history.asp). NEWSBYTES article (http://textfiles.fisher.hu/news/freeware.txt). (http://doenetwork.bravepages.com/579dmca.html). (2003-07-25) 1 1 1 1 1 Andrew Message System A multimedia interface to electronic mail and bulletin boards, developed as part of the Andrew Project. (1994-11-24) 1 1 1 1 1 Andrew Project A distributed system project for support of educational and research computing at Carnegie Mellon University, named after Andrew Carnegie, an American philanthropist who provided money to establish CMU. See also Andrew File System, Andrew Message System, Andrew Toolkit, class. Home FTP (ftp://emsworth.andrew.cmu.edu). Usenet newsgroup: news:comp.soft-sys.andrew. [More detail?] (1997-11-17) 1 1 1 1 1 Andrew S. Tanenbaum Andrew Tanenbaum 1 1 1 1 1 Andrew Tanenbaum Professor Andrew S. Tanenbaum (1941-) of the Vrije Universiteit, Amsterdam in The Netherlands. Tanenbaum is famous for his work and books on computer architecture, operating systems and networks. He wrote the textbook "Computer Networks", Second Edition, Prentice-Hall, 1981, which describes the International Standards Organisation, Open Systems Interconnection (ISO-OSI) network model. See Amoeba, Mac-1, Mic-1, Mic-2, Micro Assembly Language, MINIX, MicroProgramming Language, standard. [Home page?] (1996-04-23) 1 1 1 1 1 Andrew Toolkit (ATK) A portable user interface toolkit developed as part of the Andrew project, running on the X Window System and distributed with X11R5. (1995-11-24) 1 1 1 1 1 Andy Tanenbaum Andrew Tanenbaum 1 1 1 1 1 An Evolutionary System for On-line Programming (AESOP) An early interactive query system on the IBM 1800 using a light pen. ["AESOP: A Final Report: A Prototype Interactive Information Control System", J.K. Summers et al, in Information System Science and Technology, D. Walker ed, 1967]. [Sammet 1969, p. 703]. (1995-04-04) 1 1 1 1 1 Angel A single address space, micro-kernel operating system for multiprocessor computers, developed at Imperial College and City University, London, UK. [Ariel Burton] (1995-11-24) 1 1 1 1 1 angle bracket Either of the characters "<" (less-than, ASCII 60) and ">" (greater-than, ASCII 62). Typographers in the Real World use angle brackets which are either taller and slimmer (the ISO "Bra" and "Ket" characters), or significantly smaller (single or double guillemets) than the less-than and greater-than signs. See broket. (1995-11-24) 1 1 1 1 1 Anglo-Saxon point ATA point 1 1 1 1 1 angry fruit salad A bad visual-interface design that uses too many colours. (This term derives, of course, from the bizarre day-glo colours found in canned fruit salad). Too often one sees similar effects from interface designers using colour window systems such as X; there is a tendency to create displays that are flashy and attention-getting but uncomfortable for long-term use. [Jargon File] (1995-11-24) 1 1 1 1 1 ANI Automatic Number Identification 1 1 1 1 1 Animated GIF (GIF89a) A variant of the GIF image format, often used on web pages to provide moving icons and banners. The GIF89a format supports multiple "frames" that give the impression of motion when displayed in sequence, much like a flip book. The animation may repeat continuously or play once. Animated GIFs aren't supported by earlier web browsers, however the first frame of the image is still shown. There are many utilities to create animated GIFs from a sequence of individual GIF files. There are also utilities that will produce animated GIFs automatically from a piece of text or a single image. One problem with this format is the size of the files produced, as they are by definition a sequence of individual images. Apart from minimising the number of frames, the best way to decrease file size is to assist the LZW compression 1 1 1 1 1 animation The creation of artificial moving images. Usenet newsgroup: news:comp.graphics.animation. FAQ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.graphics.animation). (1995-11-24) 1 1 1 1 1 Animus A system described by Robert Adamy Duisberg of the University of Washington for creating animations by specifying constraints that describe the appearance and structure of pictures as well as how those pictures evolve in time. ["Constraint-Based Animation: The Implementation of Temporal Constraints in the Animus System", Robert Adamy Duisberg, PhD Thesis U Washington 1986]. (1995-11-24) 1 1 1 1 1 ANL Argonne National Laboratory 1 1 1 1 1 Anna ANNotated Ada 1 1 1 1 1 annealing simulated annealing 1 1 1 1 1 annotate annotation 1 1 1 1 1 ANNotated Ada (Anna) A specification language developed at Stanford University ca. 1980 for formally specifying Ada programs. It has a Specification Analyzer and a Consistency Checking System. It adds semantic assertions in the form of Ada comments. (ftp://anna.stanford.edu/pub/anna/). ["ANNA - A Language for Annotating Ada Programs", David Luckham et al, Springer 1987]. (1994-11-01) 1 1 1 1 1 annotation 1. <programming, compiler> Extra information associated with a particular point in a document or program. Annotations may be added either by a compiler or by the programmer. They are not usually essential to the correct function of the program but give hints to improve performance. 2. <hypertext> A new commentary node linked to an existing node. If readers, as well as authors, can annotate nodes, then they can immediately provide feedback if the information is misleading, out of date or plain wrong. (1995-11-26) 1 1 1 1 1 annoybot /*-noy-bot/ An irksome IRC robot. [Jargon File] (1997-12-23) 1 1 1 1 1 annoyware Shareware that reminds you frequently that you are using an unregistered copy. (1998-04-29) 1 1 1 1 1 Annual Change Traffic (ACT) The fraction of the software product's source code which changes during a year, either through addition or modification. The ACT can be used to determine the product size in order to estimate software maintenance effort. (1996-05-29) 1 1 1 1 1 annulled branch delayed control-transfer 1 1 1 1 1 anonymous FTP An interactive service provided by many Internet hosts allowing any user to transfer documents, files, programs, and other archived data using File Transfer Protocol. The user logs in using the special user name ftp or "anonymous" and his e-mail address as password. He then has access to a special directory hierarchy containing the publically accessible files, typically in a subdirectory called "pub". This is usually a separate area from files used by local users. A reference like ftp: euagate.eua.ericsson.se /pub/eua/erlang/info means that files are available by anonymous FTP from the host called euagate.eua.ericsson.se in the directory (or file) /pub/eua/erlang/info. Sometimes the hostname will be followed by an Internet address in parentheses. The directory will usually be given as a path relative to the 1 1 1 1 1 ANother Tool for Language Recognition (ANTLR) The parser generator in the Purdue Compiler-Construction Tool Set. (1995-10-26) 1 1 1 1 1 ANR Automatic Network Routing 1 1 1 1 1 ANS American National Standard 1 1 1 1 1 ANSA Advanced Network Systems Architecture 1 1 1 1 1 ANSI American National Standards Institute 1 1 1 1 1 ANSI C (American National Standards Institute C) A revision of C, adding function prototypes, structure passing, structure assignment and standardised library functions. ANSI X3.159-1989. cgram is a grammar for ANSI C, written in Scheme. unproto is a program for removing function prototypes to translate ANSI C to standard C. lcc is a retargetable compiler for ANSI C. (1995-11-26) 1 1 1 1 1 ANSI Minimal BASIC ANS X3.60-1978. [Details?] (1995-11-29) 1 1 1 1 1 ANSI/SPARC ANSI Standards Planning And Requirments Committee 1 1 1 1 1 ANSI/SPARC Architecture (Or "ANSI/SPARC model") ANSI/SPARC's layered model of database architecture comprising a physical schema, a conceptual schema and user views. [Reference?] (1998-12-17) 1 1 1 1 1 ANSI/SPARC model ANSI/SPARC Architecture 1 1 1 1 1 ANSI X12 Standards defining the structure, format, and content of business transactions conducted through Electronic Data Interchange (EDI). ANSI X12 is produced by the committee ASC X12, supported by the Data Interchange Standards Association, Inc. (DISA). [(http://onlinewbc.org/Docs/procure/standard.html)]. (1999-09-18) 1 1 1 1 1 ANSI Z39.50 Information Retrieval Service Definition and Protocol Specification for Library Applications, officially known as ANSI/NISO Z39.50-1992, and ANSI/NISO Z39.50-1995. This standard, used by WAIS, specifies an OSI application layer service to allow an application on one computer to query a database on another. Z39.50 is used in libraries and for searching some databases on the Internet. The US Library of Congress (http://lcweb.loc.gov/z3950/agency/) is the official maintanence agency for Z39.50. Index Data, a Danish company, have released a lot of Z39.50 code. Their website explains the relevant ISO standards and how they are amicably converging in Z39.50 version 4.0. Overview (http://nlc-bnc.ca/ifla/VI/5/op/udtop3.htm). Z39.50 resources (http://lamp.cs.utas.edu.au/net.html#Z3950). (1996-07-22) 1 1 1 1 1 antenna gain The factor by which a radio antenna of a given shape focusses the emitted power into a smaller beamwidth compared with an omnidirectional antenna. (2008-02-26) 1 1 1 1 1 Anthony Hoare (C. Anthony R. Hoare, Tony) A computer scientist working on programming languages, especially parallel ones. Hoare was responsible for Communicating Sequential Processes (CSP). See also: pointer, Simone. [Did he invent the Hoare powerdomain? Other details?] (1999-07-22) 1 1 1 1 1 anti-aliasing A technique used on a grey-scale or colour bitmap display to make diagonal edges appear smoother by setting pixels near the edge to intermediate colours according to where the edge crosses them. The most common example is black characters on a white background. Without anti-aliasing, diagonal edges appear jagged, like staircases, which may be noticeable on a low resolution display. If the display can show intermediate greys then anti-aliasing can be applied. A pixel will be black if it is completely within the black area, or white if it is completely outside the black area, or an intermediate shade of grey according to the proportions of it which overlap the black and white areas. The technique works similarly with other foreground and background colours. Aliasing refers to the fact that many points (which would differ in the real image) are mapped or "aliased" to the same pixel (with a single value) in the digital representation. 1 1 1 1 1 antichain A subset S of a partially ordered set P is an antichain if, for all x, y in S, x <= y => x = y I.e. no two different elements are related. ("<=" is written in LaTeX as \subseteq). (1995-02-03) 1 1 1 1 1 antisymmetric A relation R is antisymmetric if, for all x and y, x R y and y R x => x == y. I.e. no two different elements are mutually related. Partial orders and total orders are antisymmetric. If R is also symmetric, i.e. x R y => y R x then x R y => x == y I.e. different elements are not related. (1995-04-18) 1 1 1 1 1 antivirus antivirus software 1 1 1 1 1 antivirus program antivirus software 1 1 1 1 1 antivirus software Programs to detect and remove computer viruses. The simplest kind scans executable files and boot blocks for a list of known viruses. Others are constantly active, attempting to detect the actions of general classes of viruses. antivirus software should always include a regular update service allowing it to keep up with the latest viruses as they are released. (1998-02-25) 1 1 1 1 1 ANTLR ANother Tool for Language Recognition 1 1 1 1 1 ANU Australian National University 1 1 1 1 1 ANU ML An implementation of SML by the Australian National University for Motorola 68020, Vax and Pyramid. (1995-11-26) 1 1 1 1 1 any key The key that particularly confused users look for on their computer keyboards when instructed to "Press any key to continue". "But my keyboard doesn't have a key labelled 'any'!". Compaq FAQ (http://web14.compaq.com/falco/detail.asp?FAQnum=FAQ2859). (2003-09-30) 1 1 1 1 1 anytime algorithm An algorithm that returns a sequence of approximations to the correct answer such that each approximation is no worse than the previous one, i.e. the algorithm can be stopped at _any time_. Newton-Raphson iteration applied to finding the square root of a number b is another example: x = (x + b / x) / 2 Each new x is closer to the square root than the previous one. Applications might include a real-time control system or a chess program that is allowed a fixed thinking time. (2007-06-19) 1 1 1 1 1 ao The country code for Angola. (1999-01-27) 1 1 1 1 1 AOCE Apple Open Collaboration Environment 1 1 1 1 1 AOL America On-Line 1 1 1 1 1 AOP aspect-oriented programming 1 1 1 1 1 AOS 1. <programming> /aws/ (East Coast), /ay-os/ (West Coast) A PDP-10 instruction that took any memory location and added 1 to it. AOS meant "Add One and do not Skip". Why, you may ask, does the "S" stand for "do not Skip" rather than for "Skip"? Ah, here was a beloved piece of PDP-10 folklore. There were eight such instructions: AOSE added 1 and then skipped the next instruction if the result was Equal to zero; AOSG added 1 and then skipped if the result was Greater than 0; AOSN added 1 and then skipped if the result was Not 0; AOSA added 1 and then skipped Always; and so on. Just plain AOS didn't say when to skip, so it never skipped. For similar reasons, AOJ meant "Add One and do not Jump". Even more bizarre, SKIP meant "do not SKIP"! If you wanted to skip the next instruction, you had to say "SKIPA". Likewise, JUMP meant "do not JUMP"; the unconditional form was JUMPA. However, hackers never did this. By some quirk of the 10's design, the JRST (Jump and ReSTore flag with no flag specified) was actually faster and so was invariably used. 1 1 1 1 1 APA Application Portability Architecture 1 1 1 1 1 Apache A open source HTTP server for Unix, Windows NT, and other platforms. Apache was developed in early 1995, based on code and ideas found in the most popular HTTP server of the time, NCSA httpd 1.3. It has since evolved to rival (and probably surpass) almost any other Unix based HTTP server in terms of functionality, and speed. Since April 1996 Apache has been the most popular HTTP server on the Internet, in May 1999 it was running on 57% of all web servers. It features highly configurable error messages, DBM-based authentication databases, and content negotiation. Latest version: 1.3.9, as of 1999-10-27. (http://apache.org/httpd.html). FAQ (http://apache.org/docs/misc/FAQ.html). (1999-10-27) 1 1 1 1 1 Apache Software Foundation (ASF) A consortium that manages the development of the Apache web server, dozens of XML- and Java-based projects (under the name Jakarta), the Ant build tool, the Geronimo J2EE server, the SpamAssassin anti-SPAM tool, and much more. Apache Home (http://apache.org/). (2005-01-26) 1 1 1 1 1 APAL Array Processor Assembly Language 1 1 1 1 1 APAREL A PArse REquest Language 1 1 1 1 1 A PArse REquest Language (APAREL) A PL/I extension to provide BNF parsing routines, for IBM 360. ["APAREL: A Parse Request Language", R.W. Balzer et al, CACM 12(11) (Nov 1969)]. (1995-11-26) 1 1 1 1 1 APC Association for Progressive Communications 1 1 1 1 1 APDL Algorithmic Processor Description Language 1 1 1 1 1 APE A lossless audio compression algorithm from MonkeysAudio. (2001-12-20) 1 1 1 1 1 apE A graphics package from the Ohio Supercomputer Centre. (1995-11-29) 1 1 1 1 1 API Application Program Interface 1 1 1 1 1 APIC Advanced Programmable Interrupt Controller 1 1 1 1 1 APL A Programming Language 1 1 1 1 1 APL2 An APL extension from IBM with nested arrays. ["APL2 Programming: Language Reference", IBM, Aug 1984. Order No. SH20-9227-0]. (1995-11-29) 1 1 1 1 1 APLGOL An APL variant with ALGOL-like control structure, from Hewlett-Packard(?). (1995-11-29) 1 1 1 1 1 APLWEB A Web to APL and Web to TeX translator by Dr. Christoph von Basum of The University of Bielefeld, Germany. (ftp://watserv1.uwaterloo.ca/languages/apl/aplweb/). (1992-12-27) 1 1 1 1 1 APM Advanced Power Management 1 1 1 1 1 Apollo Computer A company making workstations often used for CAD. From 1980 to 1987, Apollo were the largest manufacturer of network workstations. Apollo workstations ran Aegis, a proprietary operating system with a Posix-compliant Unix alternative frontend. Apollo's networking was particularly elegant, among the first to allow demand paging over the network, and allowing a degree of network transparency and low sysadmin-to-machine ratio that is still unmatched. Apollo's largest customers were Mentor Graphics (electronic design), GM, Ford, Chrysler, and Boeing (mechanical design). Apollo was acquired by Hewlett-Packard in 1989, and gradually closed down over the period 1990-1997. (2003-07-18) 1 1 1 1 1 apostrophe single quote 1 1 1 1 1 app application program 1 1 1 1 1 APPC Advanced Program-to-Program Communications 1 1 1 1 1 AppKit A set of objects used by the application builder for the NEXTSTEP environment. (1995-03-13) 1 1 1 1 1 APPLE A revision of APL for the Illiac IV. (1995-04-28) 1 1 1 1 1 Apple Apple Computer, Inc. 1 1 1 1 1 Apple Address Resolution Protocol (AARP) Apple's system to allow AppleTalk protocol to work over networks other than LocalTalk, such as Ethernet or Token Ring. AppleTalk nodes announce their presence to the network so that other nodes can address messages to them. AARP maps between AppleTalk addresses and other schemes. It is actually a general address mapping protocol that can be used to map between addresses at any protocol level. [G. Sidhu, R. Andrews, and A. Oppenheimer, "Inside AppleTalk", Addison Wesley, 1990]. (2006-04-18) 1 1 1 1 1 Apple Attachment Unit Interface (AAUI) A 14-position, 0.050-inch-spaced ribbon contact connector. Early Power Macs and Quadras had an AAUI (Apple Attachment Unit Interface) port (rectangular shaped) for Ethernet, which requires a transceiver. To use twisted pair cabling, you would need to get a twisted pair transceiver for the computer with an AAUI port. Some Power Mac computers had both an AAUI and RJ-45 port; you can use one or the other, but not both. The pin-out is: Pin Signal Name Signal Description ---- -------------- --------------------------------- 1 FN Pwr Power (+12V @ 2.1W or +5V @ 1.9W) 2 DI-A Data In circuit A 3 DI-B Data In circuit B 4 VCC Voltage Common 5 CI-A Control In circuit A 6 CI-B Control In circuit B 1 1 1 1 1 Apple Computer, Inc. Manufacturers of the Macintosh range of personal computers as well as the earlier Apple I, Apple II and Lisa. Founded on 1 April 1976 by Steve Jobs and Steve Wozniak. Apples were among the first microcomputers. They originally used the 6502 processor and are still being made (August 1994), now using the 65816. The Apple II line, which includes the Apple I, is the longest existing line of microcomputers. Steve Jobs left Apple (involuntarily) and started NeXT and later returned when Apple bought NeXT in late 1997(?). Quarterly sales $2150M, profits $138M (Aug 1994). (http://apple.com/). [Dates? More?] (1998-03-13) 1 1 1 1 1 Apple II An 8-bit personal computer with a 6502 processor, from Apple Computer. It was invented by Steve Wozniak and was very popular from about 1980 until the first several years of MS-DOS IBM PCs. (1995-01-12) 1 1 1 1 1 Apple Macintosh Macintosh 1 1 1 1 1 Apple Newton A Personal Digital Assistant produced by Apple Computer. The Newton provides a clever, user-friendly interface and relies solely on pen-based input. Eagerly anticipated, the Newton uses handwriting recognition software to "learn" the users handwriting and provide reliable character recognition. Various third-party software applications are available and add-on peripherals like wireless modems for Internet access are being sold by Apple Computer, Inc. and its licensees. Newton Inc.'s NewtonOS competes with Microsoft Corporation's Windows CE, and was to be compatible with DEC's StrongARM SA-1100, an embedded 200MHz microprocessor, which was due in 1998. (http://newton.apple.com/). Handwriting recognition example (http://www-personal.engin.umich.edu/~jxm/tablespoons.html). 1 1 1 1 1 Apple Open Collaboration Environment (AOCE) Software for electronic mail and directory services. (1995-03-08) 1 1 1 1 1 AppleScript An object-oriented shell language for the Macintosh, approximately a superset of HyperTalk. (1995-12-10) 1 1 1 1 1 Applesoft BASIC A version of BASIC for Apple computers. (1995-12-10) 1 1 1 1 1 applet A Java program which can be distributed as an attachment in a web document and executed by a Java-enabled web browser such as Sun's HotJava, Netscape Navigator version 2.0, or Internet Explorer. Navigator severely restricts the applet's file system and network access in order to prevent accidental or deliberate security violations. Full Java applications, which run outside of the browser, do not have these restrictions. Web browsers can also be extended with plug-ins though these differ from applets in that they usually require manual installation and are platform-specific. Various other languages can now be embedded within HTML documents, the most common being JavaScript. Despite Java's aim to be a "write once, run anywhere" language, the difficulty of accomodating the variety of browsers in use on the Internet has led many to abandon client-side processing in favour of server-side Java 1 1 1 1 1 Appletalk A proprietary local area network protocol developed by Apple Computer, Inc. for communication between Apple products (e.g. Macintosh) and other computers. This protocol is independent of the network layer on which it runs. Current implementations exist for Localtalk, a 235 kilobyte per second local area network and Ethertalk, a 10 megabyte per second local area network. (1995-03-08) 1 1 1 1 1 AppleTalk Data Stream Protocol (ADSP) A protocol which provides a simple transport method for data accross a network. (1996-06-18) 1 1 1 1 1 AppleTalk Filing Protocol (AFP) A client/server protocol used in AppleTalk communications networks. In order for non-Apple networks to access data in an AppleShare server, their protocols must translate into the AFP language. See also: Columbia AppleTalk Package. (1998-06-28) 1 1 1 1 1 apple-touch-icon (apple-touch-icon.png) Apple's default icon (image) used to represent a website, e.g. when saved as a bookmark or on the home screen of an iOS device such as an iPhone or iPad. Apple's scheme allows a site to offer images of different sizes so the client can choose the most appropriate one according to its screen size and resolution. Apple devices and applications completely ignore the favicon.ico de facto standard which, while somewhat quirky in its use of the ico format, has been pretty much universally adopted elsewhere. Conversely, apple-touch-icon.png will be ignored by non-Apple devices, possibly because its 16x16 resolution would look pretty shabby on most smart phones. (https://developer.apple.com/library/ios/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html) Apple documentation. (2014-08-03) 1 1 1 1 1 apple-touch-icon-precomposed An alternative form of apple-touch-icon that is not subject to automatic modification (rounding, drop-shadow, reflective shine) as applied by iOS versions prior to iOS 7. A web page specifies a pre-composed icon by including an element in the <head> like: <link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png"> Everything you always wanted to know about touch icons (https://mathiasbynens.be/notes/touch-icons). (2014-10-03) 1 1 1 1 1 appletviewer A simplified web browser used for testing applets. You can't browse HTML with it but you can run applets to test them before embedding them in a web page. (2004-08-22) 1 1 1 1 1 application 1. application program. 2. function application. 1 1 1 1 1 Application Binary Interface (ABI) The interface by which an application program gains access to operating system and other services. It should be possible to run the same compiled binary applications on any system with the right ABI. Examples are 88open's Binary Compatibility Standard, the PowerOpen Environment and Windows sockets. (1994-11-08) 1 1 1 1 1 Application Configuration Access Protocol (ACAP) A protocol which enhances IMAP by allowing the user to set up address books, user options, and other data for universal access. Currently (Feb 1997) no Internet proprietary products have implemented ACAP because the Internet Engineering Task Force has not yet approved the final specification. This was expected early in 1997. ["Your E-Mail Is Obsolete", Byte, Feb 1997]. (1997-05-03) 1 1 1 1 1 Application Control Architecture (ACA) DEC's implementation of ORB. (1994-11-08) 1 1 1 1 1 Application Developer Someone who does application development. (2013-08-15) 1 1 1 1 1 application development Writing computer programs to meet specific requirements; the job of an Application Developer. Application development often includes responsibility for requirements capture and/or testing as well as actual programming (the more limited activity implied by the term programmer). (2013-08-15) 1 1 1 1 1 application enablement services IBM-speak for APIs to services such as telecoms, database, etc. within and between address spaces. (1999-01-20) 1 1 1 1 1 Application environment specification (AES) A set of specifications from OSF for programming and user interfaces, aimed at providing a consistent application environment on different hardware. It includes "O/S" for the operating system (user commands and program interfaces), "U/E" for the User Environment (Motif), and "N/S" for Network services. [Reference?] (1994-12-07) 1 1 1 1 1 Application Executive (AE) An embeddable language, written as a C interpreter by Brian Bliss at UIUC. AE is compiled with an application and thus exists in the same process and address space. It includes a dbx symbol table scanner to access compiled variables and routines, or you can enter them manually by providing a type/name declaration and the address. When the interpreter is invoked, source code fragments are read from the input stream (or a string), parsed, and evaluated immediately. The user can call compiled functions in addition to a few built-in intrinsics, declare new data types and data objects, etc. Different input streams can be evaluated in parallel on Alliant computers. AE has been ported to SunOS (cc or gcc), Alliant FX and Cray YMP (soon). (ftp://sp2.csrd.uiuc.edu/pub/at.tar.Z). (ftp://sp2.csrd.uiuc.edu/pub/bliss/ae.tex.Z). (1992-04-21) 1 1 1 1 1 Application Integration Architecture (AIA) DEC's "open standards" specifications. 1 1 1 1 1 application layer The top layer of the OSI seven layer model. This layer handles issues like network transparency, resource allocation and problem partitioning. The application layer is concerned with the user's view of the network (e.g. formatting electronic mail messages). The presentation layer provides the application layer with a familiar local representation of data independent of the format used on the network. (1994-11-28) 1 1 1 1 1 application lifecycle management (ALM) A combination of software engineering, requirements management, architecture, coding, testing, tracking and release management. (2009-06-10) 1 1 1 1 1 Application Portability Architecture (APA) DEC's plan for portable applications software. (1994-11-28) 1 1 1 1 1 application program (Or "application", "app") A complete, self-contained program that performs a specific function directly for the user. This is in contrast to system software such as the operating system kernel, server processes, libraries which exists to support application programs and utility programs. Editors for various kinds of documents, spreadsheets, and text formatters are common examples of applications. Network applications include clients such as those for FTP, electronic mail, telnet and WWW. The term is used fairly loosely, for instance, some might say that a client and server together form a distributed application, others might argue that editors and compilers were not applications but utility programs for building applications. One distinction between an application program and the operating system is that applications always run in user 1 1 1 1 1 Application Program Interface (API, or "application programming interface") The interface (calling conventions) by which an application program accesses operating system and other services. An API is defined at source code level and provides a level of abstraction between the application and the kernel (or other privileged utilities) to ensure the portability of the code. An API can also provide an interface between a high level language and lower level utilities and services which were written without consideration for the calling conventions supported by compiled languages. In this case, the API's main task may be the translation of parameter lists from one format to another and the interpretation of call-by-value and call-by-reference arguments in one or both directions. (1995-02-15) 1 1 1 1 1 Application Programming Interface Application Program Interface 1 1 1 1 1 Application Protocol Data Unit (APDU) A packet of data exchanged between two application programs across a network. This is the highest level view of communication in the OSI seven layer model and a single packet exchanged at this level may actually be transmitted as several packets at a lower layer as well as having extra information (headers) added for routing etc. (1995-12-19) 1 1 1 1 1 Applications Development Manager (Or "Director") The person in a company who plans and oversees multiple projects and project managers. The Applications Development Managers works with the CIO and senior management to determine systems development strategy and standards. He or she administers department budget and reviews project managers. (2004-03-06) 1 1 1 1 1 application server 1. <software> A designer's or developer's suite of software that helps programmers isolate the business logic in their programs from the platform-related code. Application servers can handle all of the application logic and connectivity found in client-server applications. Many application servers also offer features such as transaction management, clustering and failover, and load balancing; nearly all offer ODBC support. Application servers range from small footprint, web-based processors for intelligent appliances or remote embedded devices, to complete environments for assembling, deploying, and maintaining scalable multi-tier applications across an enterprise. 2. <software> Production programs run on a mid-sized computer that handle all application operations between browser-based computers and an organisation's back-end 1 1 1 1 1 Application Service Element (ASE) Software in the presentation layer of the OSI seven layer model which provides an abstracted interface layer to service application protocol data units (APDU). Because applications and networks vary, ASEs are split into common services and specific services. Examples of services provided by the common application service element (CASE) include remote operations (ROSE) and database concurrency control and recovery (CCR). The specific application service element (SASE) provides more specialised services such as file transfer, database access, and order entry. Csico docs (http://cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/osi_prot.htm). (2003-09-27) 1 1 1 1 1 application service provider (ASP) A service (usually a business) that provides remote access to an application program across a network protocol, typically HTTP. A common example is a website that other websites use for accepting payment by credit card as part of their online ordering systems. As this term is complex-sounding but vague, it is widely used by marketroids who want to avoid being specific and clear at all costs. (2001-03-26) 1 1 1 1 1 applications language Ousterhout's dichotomy 1 1 1 1 1 application software application program 1 1 1 1 1 Application Software Installation Server (ASIS) A service once offered by CERN's IT division that included a repository containing CERN and HEP software and tools in the form of compressed source and documentation. As of 2014-11-13, the service appears to be dead. (http://consult.cern.ch/writeup/Abstracts/asis.html) (2014-11-13) 1 1 1 1 1 Application-Specific Integrated Circuit (ASIC) An integrated circuit designed to perform a particular function by defining the interconnection of a set of basic circuit building blocks drawn from a library provided by the circuit manufacturer. (1995-02-15) 1 1 1 1 1 Applications Programming Interface Application Programming Interface 1 1 1 1 1 applications software application program 1 1 1 1 1 application testing system testing 1 1 1 1 1 Application Visualisation System (AVS) A portable, modular, Unix-based graphics package supported by a consortium of vendors including Convex, DEC, IBM, HP, SET Technologies, Stardent and WaveTracer. (1994-11-28) 1 1 1 1 1 applicative language A functional language. Sometimes used loosely for any declarative language though logic programming languages are declarative but not applicative. (1995-12-24) 1 1 1 1 1 Applicative Language for Digital Signal Processing (ALDiSP) A functional language with special features for real-time I/O and numerical processing, developed at the Technical University of Berlin in 1989. ["An Applicative Real-Time Language for DSP - Programming Supporting Asynchronous Data-Flow Concepts", M. Freericks <mfx@cs.tu-berlin.de> in Microprocessing and Microprogramming 32, N-H 1991]. (1995-04-19) 1 1 1 1 1 applicative order reduction An evaluation strategy under which an expression is evaluated by repeatedly evaluating its leftmost innermost redex. This means that a function's arguments are evaluated before the function is applied. This method will not terminate if a function is given a non-terminating expression as an argument even if the function is not strict in that argument. Also known as call-by-value since the values of arguments are passed rather than their names. This is the evaluation strategy used by ML, Scheme, Hope and most procedural languages such as C and Pascal. See also normal order reduction, parallel reduction. (1995-01-25) 1 1 1 1 1 APPLOG A language which unifies logic programming and functional programming. ["The APPLOG Language", S. Cohen in Logic Programming, deGroot et al eds, P-H 1986, pp.39-276]. (1995-01-25) 1 1 1 1 1 APPN Advanced Peer-to-Peer Networking 1 1 1 1 1 approximation algorithm An algorithm for an optimisation problem that generates feasible but not necessarily optimal solutions. Unlike "heuristic", the term "approximation algorithm" often implies some proven worst or average case bound on performance. The terms are often used interchangeably however. (1997-10-28) 1 1 1 1 1 April Fool's Joke (AFJ) Elaborate April Fool's hoaxes are a long-established tradition on Usenet and Internet; see kremvax for an example. In fact, April Fool's Day is the *only* seasonal holiday marked by customary observances on the hacker networks. (1995-01-25) 1 1 1 1 1 A Programming Language (APL) A programming language designed originally by Ken Iverson at Harvard University in 1957-1960 as a notation for the concise expression of mathematical algorithms. It went unnamed (or just called Iverson's Language) and unimplemented for many years. Finally a subset, APL\360, was implemented in 1964. APL is an interactive array-oriented language and programming environment with many innovative features. It was originally written using a non-standard character set. It is dynamically typed with dynamic scope. APL introduced several functional forms but is not purely functional. Dyalog APL/W and Visual APL are recognized .NET languages. Dyalog APL/W, APLX and APL2000 all offer object-oriented extensions to the language. ISO 8485 is the 1989 standard defining the language. Commercial versions: APL SV, VS APL, Sharp APL, Sharp APL/PC, APL*PLUS, APL*PLUS/PC, APL*PLUS/PC II, MCM APL, Honeyapple, 1 1 1 1 1 APSE Ada Programming Support Environment 1 1 1 1 1 APT 1. <language> Automatically Programmed Tools. 2. <company> Audio Processing Technology. 1 1 1 1 1 APX III An early system on the Datatron 200 series. [Listed in CACM 2(5):16 (May 1959)]. (1995-05-04) 1 1 1 1 1 aq The country code for Antarctica. (1999-01-27) 1 1 1 1 1 AQL A picture query language, extension of APL. ["AQL: A Relational Database Management System and Its Geographical Applications", F. Antonacci et al, in Database Techniques for Pictorial Applications, A. Blaser ed, pp. 569-599]. (1995-05-04) 1 1 1 1 1 ar The country code for Argentina. (1999-01-27) 1 1 1 1 1 arbitrary precision calculator An arbitrary precision C-like calculator. Interpreter version 1.26.4 by David I. Bell <dbell@canb.auug.org.au>. Ported to Linux. (ftp://ftp.uu.net/pub/calc). (1993-06-15) 1 1 1 1 1 ARC Advanced RISC Computing Specification 1 1 1 1 1 arc 1. <file format, tool> An old archive format for IBM PC. The format is now so obscure that it is only likely to be supported by jack-of-all-trades decompression programs such as WINZIP. 2. <mathematics, data> An edge in a tree. "branch" is a generally more common synonym. (1998-12-29) 1 1 1 1 1 Arcade A UK BBS for the Acorn Archimedes. Also has links with Demon Internet. Telephone: +44 (181) 654 2212 (24hrs, most speeds). (1994-11-08) 1 1 1 1 1 ArchBSD 4.4 BSD-Lite for the Acorn Archimedes. (1994-11-08) 1 1 1 1 1 archie A system to automatically gather, index and serve information on the Internet. The initial implementation of archie by McGill University School of Computer Science provided an indexed directory of filenames from all anonymous FTP archives on the Internet. Later versions provide other collections of information. See also archive site, Gopher, Prospero, Wide Area Information Servers. (1995-12-28) 1 1 1 1 1 Archimedes A family of microcomputers produced by Acorn Computers, Cambridge, UK. The Archimedes, launched in June 1987, was the first RISC based personal computer (predating Apple Computer's Power Mac by some seven years). It uses the Advanced RISC Machine (ARM) processor and includes Acorn's multitasking operating system and graphical user interface, RISC OS on ROM, along with an interpreter for Acorn's enhanced BASIC, BASIC V. The Archimedes was designed as the successor to Acorn's sucessful BBC Microcomputer series and includes some backward compatibility and a 6502 emulator. Several utilities are included free on disk (later in ROM) such as a text editor, paint and draw programs. Software emulators are also available for the IBM PC as well as add-on Intel processor cards. There have been several series of Archimedes: A300, A400, A3000, A5000, A4000 and RISC PC. 1 1 1 1 1 architecture Design, the way components fit together. The term is used particularly of processors, both individual and in general. "The ARM has a really clean architecture". It may also be used of any complex system, e.g. "software architecture", "network architecture". (1995-05-02) 1 1 1 1 1 Architecture Neutral Distribution Format (ANDF) An emerging OSF standard for software distribution. Programs are compiled into ANDF before distribution and executables are produced from it for the local target system. This allows software to be developed and distributed in a single version then installed on a variety of hardware. See also UNCOL. ["Architecture Neutral Distribution Format: A White Paper", Open Software Foundation, Nov 1990]. (1995-10-20) 1 1 1 1 1 archive 1. <file format> A single file containing one or (usually) more separate files plus information to allow them to be extracted (separated) by a suitable program. Archives are usually created for software distribution or backup. tar is a common format for Unix archives, and arc or PKZIP for MS-DOS and Microsoft Windows. 2. <operating system> To transfer files to slower, cheaper media (usually magnetic tape) to free the hard disk space they occupied. This is now normally done for long-term storage but in the 1960s, when disk was much more expensive, files were often shuffled regularly between disk and tape. 3. <networking> archive site. (1996-12-08) 1 1 1 1 1 archive site (Or "FTP site", "FTP archive") An Internet host where program source, documents, e-mail or news messages are stored for public access via anonymous FTP, Gopher, web or other document distribution system. There may be several archive sites (mirrors) for, e.g., a Usenet newsgroup though one may be recognised as the main one. FTP servers were common on the Internet for about ten years but have been largely replaced by web servers since the invention of the World-Wide Web and its HTTP protocol. Some well-known archive sites included Imperial College, UK (ftp://src.doc.ic.ac.uk/), UUNET, USA (ftp://ftp.uu.net/), GNU archive site. The archie service attempted to index the contents of FTP archives, foreshadowing the indexing of the web by Google and others. (2014-07-06) 1 1 1 1 1 ARCnet A network developed by DataPoint. ARCnet was proprietary until the late 1980s and had about as large a marketshare as Ethernet among small businesses. It was almost as fast and was considerably cheaper at the time. (1995-01-16) 1 1 1 1 1 ARCS ARC 1 1 1 1 1 Arctic A real-time functional language, used for music synthesis. ["Arctic: A Functional Language for Real-Time Control", R.B. Dannenberg, Conf Record 1984 ACM Symp on LISP and Functional Prog, ACM]. (1995-01-16) 1 1 1 1 1 arena The area of memory attached to a Unix process by the brk and sbrk system calls and used by malloc as dynamic storage. So named from a "malloc: corrupt arena" message emitted when some early versions detected an impossible value in the free block list. See overrun screw, aliasing bug, memory leak, memory smash, smash the stack. [Jargon File] (1995-12-28) 1 1 1 1 1 ARES A pictorial query language. ["A Query Manipulation System for Image Data Retrieval", T. Ichikawa et al, Proc IEEE Workshop Picture Data Description and Management, Aug 1980, pp. 61-67]. (1995-10-10) 1 1 1 1 1 AREV Advanced Revelation 1 1 1 1 1 AREXX REXX for the Amiga. ARexxGuide (http://halcyon.com/robin/www/arexxguide/main.html). (1996-02-06) 1 1 1 1 1 arg argument 1 1 1 1 1 argument (Or "arg") A value or reference passed to a function, procedure, subroutine, command or program, by the caller. For example, in the function definition square(x) = x * x x is the formal argument or "parameter", and in the call y = square(3+4) 3+4 is the actual argument. This will execute the function square with x having the value 7 and return the result 49. There are many different conventions for passing arguments to functions and procedures including call-by-value, call-by-name, call-by-reference, call-by-need. These affect whether the value of the argument is computed by the caller or the callee (the function) and whether the callee can modify the value of the argument as seen by the caller (if it is a variable). 1 1 1 1 1 Argus A successor to CLU, from LCS at MIT. Argus supports distributed programming through guardians (like monitors, but can be created dynamically) and atomic actions (indivisible activity). It also has cobegin and coend. ["Argus Reference Manual", B. Liskov et al., TR-400, MIT/LCS, 1987]. ["Guardians and Actions: Linguistic Support for Robust, Distributed Programs", B. Liskov <liskov@lcs.mit.edu> et al, TOPLAS 5(3):381-404 (1983)]. (1995-12-28) 1 1 1 1 1 Ariel An array-oriented language for the CDC 6400. ["Ariel Reference Manual", P. Devel, TR 22, CC UC Berkeley, Apr 1968]. ["A New Survey of the Ariel Programming Language", P. Deuel, TR 4, Ariel Consortium, UC Berkeley, June 1972]. [Deuel or Devel?] (1995-12-29) 1 1 1 1 1 ARI Service The trading name of the remnants of AST Research, Inc.. ARI Services is a wholly owned subsidiary of Samsung Electronics Co. Ltd., of Seoul, Korea. They no longer manufacture or distribute computer hardware, but they continue to provide worldwide technical and service support to owners of systems that they manufactured. AST Computers, LLC is a separate company. Headquarters: 16225 Alton Parkway, POB 57005, Irvine, California 92619-7005, USA. (http://ari-service.com/). (2000-03-28) 1 1 1 1 1 ARITH-MATIC An extension of Grace Hopper's A-2 programming language, developed in about 1955. ARITH-MATIC was originally known as A-3, but was renamed by the marketing department of Remington Rand UNIVAC. (http://cispom.boisestate.edu/cis221emaxson/hophtm.htm). [How was A-2 extended?] (2001-01-27) 1 1 1 1 1 Arithmetic and Logic Unit (ALU or "mill") The part of the central processing unit which performs operations such as addition, subtraction and multiplication of integers and bit-wise AND, OR, NOT, XOR and other Boolean operations. The CPU's instruction decode logic determines which particular operation the ALU should perform, the source of the operands and the destination of the result. The width in bits of the words which the ALU handles is usually the same as that quoted for the processor as a whole whereas its external busses may be narrower. Floating-point operations are usually done by a separate "floating-point unit". Some processors use the ALU for address calculations (e.g. incrementing the program counter), others have separate logic for this. (1995-03-24) 1 1 1 1 1 arithmetic mean The mean of a list of N numbers calculated by dividing their sum by N. The arithmetic mean is appropriate for sets of numbers that are added together or that form an arithmetic series. If all the numbers in the list were changed to their arithmetic mean then their total would stay the same. For sets of numbers that are multiplied together, the geometric mean is more appropriate. (2007-03-20) 1 1 1 1 1 arity The number of arguments a function or operator takes. In some languages functions may have variable arity which sometimes means their last or only argument is actually a list of arguments. (1997-07-21) 1 1 1 1 1 arj An archive format for the IBM PC. ARJ files are handled by the ARJ program, created by the American programmer Robert Jung. [Available from? Compare with PKZIP?] (1996-11-03) 1 1 1 1 1 Arjuna An object-oriented programming system developed by a team led by Professor Santosh Shrivastava at the University of Newcastle, implemented entirely in C++. Arjuna provides a set of tools for the construction of fault-tolerant distributed applications. It exploits features found in most object-oriented languages (such as inheritance) and only requires a limited set of system capabilities commonly found in conventional operating systems. Arjuna provides the programmer with classes that implement atomic transactions, object level recovery, concurrency control and persistence. The system is portable, modular and flexible; the system software has been available via FTP since 1992. (http://arjuna.ncl.ac.uk/). (1995-03-06) 1 1 1 1 1 ARL ASSET Reuse Library 1 1 1 1 1 ARM 1. <processor> Advanced RISC Machine. Originally Acorn RISC Machine. 2. <company> Advanced RISC Machines Ltd. 3. <publication> ["The Annotated C++ Reference Manual", Margaret A. Ellis and Bjarne Stroustrup, Addison-Wesley, 1990]. 4. <hardware> Active Reconfiguring Message. (1997-10-03) 1 1 1 1 1 ARM610 A 32-bit RISC microprocessor based on the ARM6 processor core designed by Advanced RISC Machines Ltd. The ARM610 is the successor to the ARM3 processor and is produced by VLSI Technology Inc. It consumes 500mW at 33MHz with a 5V supply. (1995-12-29) 1 1 1 1 1 ARM7 A RISC microprocessor architecture from Advanced RISC Machines Ltd. (ARM). Building upon the ARM6 family, the goal of the ARM7 design was to offer higher levels of raw compute performance at even lower levels of power consumption. The ARM7 architecture is now (Dec 1994) the most powerful low voltage RISC processor available on the market. The ARM7 offers several architectural extensions which address specific market needs, encompassing fast multiply and innovative embedded ICE support. Software development tools are available. The ARM7 architecture is made up of a core CPU plus a range of system peripherals which can be added to a CPU core to give a complete system on a chip, e.g. 4K or 8K cache, Memory Management Unit, Write Buffer, coprocessor interface, ICEbreaker embedded ICE support and JTAG boundary scan. The ARM710 microprocessor is built around the ARM7 core. 1 1 1 1 1 ARM710 A 32-bit RISC microprocessor based on the ARM7 processor core designed by Advanced RISC Machines Ltd. The A710 is the successor to the ARM610 processor. It was released in July 1994 by VLSI Technology Inc. The ARM710 can run at 40MHz (fastest sample 55MHz) dissipating 500mW with a 5V supply or 25MHz with 3.3V supply. It has an 8 kilobyte on-chip cache, memory management unit and write buffer. The ARM700 and ARM710 processors represent a significant improvement over the ARM610 processors. They have a higher maximum clock speed and a number of architectural improvements such as double the size of internal cache, this means that more of any process can be executed internally without accessing the (relatively) slow external memory. Other improvements are an improved write buffer and an enlarged Translation Lookaside Buffer in the MMU. All of these improvements increase the performance of the system and 1 1 1 1 1 ARM7500 An ARM7 core with I/O and VIDC20 all on one integrated circuit. (1994-09-23) 1 1 1 1 1 ARM8 A RISC microprocessor core designed by Advanced RISC Machines Ltd. with 50000 transistors. The design of the ARM8 is not yet public but it is not superscalar. The ARM8 will form the core of the ARM800 microprocessor integrated circuit. (1995-03-03) 1 1 1 1 1 ARM800 A microprocessor based on the ARM8 processor core designed by Advanced RISC Machines Ltd. Planned features include a 60-100Mhz clock rate; 0.35-0.4 micron silicon fabrication; an improvement on the ARM7's 1.4 cycle/instruction; a 16 Kbyte cache. Some estimates were 100 MIPS and 120 Kdhrystones at 70Mhz (twice the ARM700). Samples of the ARM800 are expected to be available in late 1995. It may run on a voltage below 3.3V. Digital Semiconductor's Hudson fab is 0.35 micron and they have announced a licensing deal for the ARM architecture (see StrongARM). (1995-02-07) 1 1 1 1 1 ARM Ltd Advanced RISC Machines Ltd. 1 1 1 1 1 ARMM Automated Retroactive Minimal Moderation 1 1 1 1 1 armour-plated bulletproof 1 1 1 1 1 ARP Address Resolution Protocol 1 1 1 1 1 ARPA Defense Advanced Research Projects Agency 1 1 1 1 1 ARPANET Advanced Research Projects Agency Network 1 1 1 1 1 ARQ Automatic Repeat Request 1 1 1 1 1 array 1. <programming> A collection of identically typed data items distinguished by their indices (or "subscripts"). The number of dimensions an array can have depends on the language but is usually unlimited. An array is a kind of aggregate data type. A single ordinary variable (a "scalar") could be considered as a zero-dimensional array. A one-dimensional array is also known as a "vector". A reference to an array element is written something like A[i,j,k] where A is the array name and i, j and k are the indices. The C language is peculiar in that each index is written in separate brackets, e.g. A[i][j][k]. This expresses the fact that, in C, an N-dimensional array is actually a vector, each of whose elements is an N-1 dimensional array. Elements of an array are usually stored contiguously. Languages differ as to whether the leftmost or rightmost index varies most rapidly, i.e. whether each row is stored 1 1 1 1 1 array processor (Or "vector processor") A computer, or extension to its arithmetic unit, that is capable of performing simultaneous computations on elements of an array or table of data in some number of dimensions. The IBM AltiVec (the "Velocity Engine" used in the Apple G4 computers) is a vector processor. Common uses for array processors include analysis of fluid dynamics and rotation of 3d objects, as well as data retrieval, in which elements of a database are scanned simultaneously. Array processors are very rare now (1998). Array presentation (http://cs.njit.edu/leon/105/c5/index.htm). (2003-09-11) 1 1 1 1 1 Array Processor Assembly Language (APAL) The assembly language for the DAP parallel computer. (1994-11-28) 1 1 1 1 1 Array Theory A theory developed by Trenchard More Jr. and used as the basis for the NIAL language. Papers are available from the IBM Cambridge Scientific Center, Cambridge MA. (1995-01-25) 1 1 1 1 1 arrow key One of four keys on a keyboard marked with arrows pointing up, down, left and right. The arrow keys are used for such things as moving the cursor in a text document, for moving the input focus between the fields of a form or sometimes for scrolling a picture. (1998-06-26) 1 1 1 1 1 ART A real-time functional language. It timestamps each data value when it was created. ["Applicative Real-Time Programming", M. Broy, PROC IFIP 1983, N-H]. (1996-01-15) 1 1 1 1 1 Artemis microkernel A microkernel currently under development by Dave Hudson <dave@humbug.demon.co.uk>, scheduled for release under GPL in May 1995. It is targeted at embedded applications on Intel 80386, Intel 486 and Pentium based systems. (1995-03-29) 1 1 1 1 1 Artifex A CASE environment from ARTIS of Turin for the development of large event-driven distributed systems. It has code-generation and rapid prototyping features. (1996-01-24) 1 1 1 1 1 artificial intelligence (AI) The subfield of computer science concerned with the concepts and methods of symbolic inference by computer and symbolic knowledge representation for use in making inferences. AI can be seen as an attempt to model aspects of human thought on computers. It is also sometimes defined as trying to solve by computer any problem that a human can solve faster. The term was coined by Stanford Professor John McCarthy, a leading AI researcher. Examples of AI problems are computer vision (building a system that can understand images as well as a human) and natural language processing (building a system that can understand and speak a human language as well as a human). These may appear to be modular, but all attempts so far (1993) to solve them have foundered on the amount of context information and "intelligence" they seem to require. The term is often used as a selling point, e.g. to describe programming that drives the behaviour of computer characters 1 1 1 1 1 Artificial Intelligence Lab MIT AI Lab 1 1 1 1 1 Artificial Life (a-life) The study of synthetic systems which behave like natural living systems in some way. Artificial Life complements the traditional biological sciences concerned with the analysis of living organisms by attempting to create lifelike behaviours within computers and other artificial media. Artificial Life can contribute to theoretical biology by modelling forms of life other than those which exist in nature. It has applications in environmental and financial modelling and network communications. There are some interesting implementations of artificial life using strangely shaped blocks. A video, probably by the company Artificial Creatures who build insect-like robots in Cambridge, MA (USA), has several mechanical implementations of artificial life forms. See also evolutionary computing, Life. [Christopher G. Langton (Ed.), "Artificial Life", Proceedings 1 1 1 1 1 artificial neural network (ANN, commonly just "neural network" or "neural net") A network of many very simple processors ("units" or "neurons"), each possibly having a (small amount of) local memory. The units are connected by unidirectional communication channels ("connections"), which carry numeric (as opposed to symbolic) data. The units operate only on their local data and on the inputs they receive via the connections. A neural network is a processing device, either an algorithm, or actual hardware, whose design was inspired by the design and functioning of animal brains and components thereof. Most neural networks have some sort of "training" rule whereby the weights of connections are adjusted on the basis of presented patterns. In other words, neural networks "learn" from examples, just like children learn to recognise dogs from examples of dogs, and exhibit some structural capability for 1 1 1 1 1 Artisoft, Inc. A company, known for the LANtastic range of networking products. Originally providers of proprietary, peer-to-peer network hardware and software for small installations, Artisoft now also sells Ethernet and Novell-compatible hardware and software. (http://artisoft.com/). Telephone: +1 (800) 809 1257. Address: Tucson, Arizona, USA; Phoenix, Arizona, USA. (1995-04-24) 1 1 1 1 1 Artistic license The open source license applicable to Perl. (1999-12-29) 1 1 1 1 1 ARTSPEAK An early simple language for plotter graphics. ["The Art of Programming, ARTSPEAK", Henry Mullish, Courant Inst (Nov 1974)]. (1995-02-21) 1 1 1 1 1 AS 1. <networking> Autonomous System. 2. <storage> Address Strobe. 1 1 1 1 1 as The country code for American Samoa. (1999-01-27) 1 1 1 1 1 as31 An 8031/8051 assembler by Ken Stauffer <stauffer@cpsc.ucalgary.ca> and Theo Deraadt which produces a variety of object code output formats. The distribution includes an assembler, yacc parser, and documentation. as31 runs on Sun-3, Sun-4, SunOS 4.0, Tandy 6000, and Xenix. Latest version: 1, as of 1990-01-26. as31 Home (http://pjrc.com/tech/8051/#as31_assembler). (2002-05-07) 1 1 1 1 1 AS/400 An IBM minicomputer for small business and departmental users, released in 1988 and still in production in October 1998. Features include a menu-driven interface, multi-user support, terminals that are (in the grand IBM tradition) incompatible with anything else including the IBM 3270 series, and an extensive library-based operating system. The machine survives because its API layer allows the operating system and application programs to take advantage of advances in hardware without recompilation and which means that a complete system that costs $9000 runs the exact same operating system and software as a $2 million system. There is a 64-bit RISC processor operating system implementation. Programming languages include RPG, assembly language, C, COBOL, SQL, BASIC, and REXX. Several CASE tools are available: Synon, AS/SET, Lansa. 1 1 1 1 1 ASA Adaptive Simulated Annealing 1 1 1 1 1 asap As soon as possible. (1999-10-13) 1 1 1 1 1 asbestos Used as a modifier to anything intended to protect one from flames; also in other highly flame-suggestive usages. E.g., asbestos longjohns, asbestos cork award. [Jargon File] (1996-02-06) 1 1 1 1 1 asbestos cork award Once, long ago at MIT, there was a flamer so consistently obnoxious that another hacker designed, had made, and distributed posters announcing that said flamer had been nominated for the "asbestos cork award". (Any reader in doubt as to the intended application of the cork should consult the etymology under flame.) Since then, it is agreed that only a select few have risen to the heights of bombast required to earn this dubious dignity - but there is no agreement on *which* few. [Jargon File] (1996-02-06) 1 1 1 1 1 asbestos longjohns Notional garments donned by Usenet posters just before emitting a remark they expect will elicit flamage. This is the most common of the asbestos coinages. Also asbestos underwear, "asbestos overcoat", etc. [Jargon File] (1997-07-04) 1 1 1 1 1 ascender A lowercase letter that extends above the "x-height" (the height of the letter "x"), such as "d", "t", or "h". Also used to denote the part of the letter extending above the x-height. Compare descender. (1998-03-27) 1 1 1 1 1 ASCI Did you mean ASCII? 1 1 1 1 1 ASCII American Standard Code for Information Interchange 1 1 1 1 1 ASCII art (Or "character graphics", "ASCII graphics") The fine art of drawing diagrams using the ASCII character set (mainly "|-/\+"). See also boxology. Here is a serious example: o----)||(--+--|<----+ +---------o + D O L )||( | | | C U A I )||( +-->|-+ | +-\/\/-+--o - T C N )||( | | | | P E )||( +-->|-+--)---+--)|--+-o U )||( | | | GND T o----)||(--+--|<----+----------+ A power supply consisting of a full wave rectifier circuit feeding a capacitor input filter circuit Figure 1. And here are some very silly examples: |\/\/\/| ____/| ___ |\_/| ___ | | \ o.O| ACK! / \_ |` '| _/ \ 1 1 1 1 1 ASCIIbetical order /as'kee-be'-t*-kl or'dr/ Used to indicate that data is sorted in ASCII collated order rather than alphabetical order. The main difference is that, in ASCII, all the upper case letters come before any of the lower case letters so, e.g., "Z" comes before "a". [Jargon File] (1999-04-08) 1 1 1 1 1 ASCIIbonics (From ASCII and Ebonics) A style of text communication in English which is most common on talk systems such as irc. Its notable characteristics are: Typing all in lowercase (and occasionally all in uppercase). Copious use of abbreviations of the sort "u" for "you" "1" for one (and therefore "some1" for "someone", "ne1" for anyone), "2" for "to", "r" for "are", etc. A general lack of punctuation, except for strings of question marks and exclamation marks. Common use of the idiom "m or f?", meant to elicit a statement of the listener's gender. Typical extended discourse in ASCIIbonics: "hey wasup ne1 want 2 cyber?" "m or f?" ASCIIbonics is similar to the way B1FF talked, although B1FF used more punctuation (lots more), and used all uppercase, rather than all lowercase. What's more, B1FF was only interested in warez, and so never asked "m or f?". 1 1 1 1 1 ASCII character table The following list gives the octal, decimal and hexadecimal ASCII codes for each character along with its printed representation and common name(s). Oct Dec Hex Name 000 0 0x00 NUL 001 1 0x01 SOH, Control-A 002 2 0x02 STX, Control-B 003 3 0x03 ETX, Control-C 004 4 0x04 EOT, Control-D 005 5 0x05 ENQ, Control-E 006 6 0x06 ACK, Control-F 007 7 0x07 BEL, Control-G 010 8 0x08 BS, backspace, Control-H 011 9 0x09 HT, tab, Control-I 012 10 0x0a LF, line feed, newline, Control-J 013 11 0x0b VT, Control-K 014 12 0x0c FF, form feed, NP, Control-L 1 1 1 1 1 ASCII graphics ASCII art 1 1 1 1 1 ASDIMPL ASDO IMPlementation Language 1 1 1 1 1 ASDL Abstract-Type and Scheme-Definition Language 1 1 1 1 1 ASDO IMPlementation Language (ASDIMPL) A C-like language, run on Burroughs' mainframes in the early 1980s, and cross-compiled to x86-based embedded processors. (1996-02-06) 1 1 1 1 1 ASE 1. <programming> Advanced Software Environment. 2. <networking> Application Service Element. 3. <database> Adaptive Server Enterprise. 1 1 1 1 1 A* search A graph search algorithm. A* is guaranteed to find a minimal solution path before any other solution paths, if a solution exists, in other words, it is an "admissible" search algorithm. Each path is assigned a value based on the cost of the path (e.g. its length) and an (under)estimate of the cost of completing the path, i.e. the cost of a path from the end of the current path to a solution. (1995-03-31) 1 1 1 1 1 ASF 1. <language> Algebraic Specification Language. 2. <body> Analytical Solutions Forum. 1 1 1 1 1 ash A Bourne Shell clone by Kenneth Almquist. It works pretty well. For running scripts, it is sometimes better and sometimes worse than Bash. Ash runs under 386BSD, NetBSD, FreeBSD, and Linux. FTP Linux version (ftp://ftp.win.tue.nl/pub/linux/ports/ash-linux-0.1.tar.gz). (1995-07-20) 1 1 1 1 1 Ashmedai A symbolic mathematics package by Michael Levine <levine@cpwsca.psc.edu> that influenced SMP and FORM. There are versions for the Univac 1108 and VAX/VMS. (1995-03-21) 1 1 1 1 1 Ashton-Tate Corporation The original vendor of dBASE and joint developers of EEMS. Ashton-Tate was founded by Charles Tate and Ashton was his pet parrot's name. The parrot lived in the lobby of the company's LA headquarters. In the early 1990s Ashton-Tate was taken over by Borland International, Inc., who later became Borland Software Corporation. [Dates? Address?] (2004-12-05) 1 1 1 1 1 ASIC Application-Specific Integrated Circuit 1 1 1 1 1 Asiliant Technologies A company founded by a group of former Chips and Technologies employees with experience with the CHIPS products, suppliers, distributors and customers. Asiliant offer C&T's industry standard Flat Panel and CRT controller family. (2006-09-19) 1 1 1 1 1 A Simulation Process-Oriented Language (ASPOL) An ALGOL-like language for computer simulation. ["Process and Event Control in ASPOL", M.H. MacDougall, Proc Symp on Simulation of Computer Systems, NBS (Aug 1975)]. (1996-03-25) 1 1 1 1 1 ASIS 1. Application Software Installation Server. 2. <language> Ada Semantic Interface Specification. 1 1 1 1 1 ASK Amplitude Shift Keying 1 1 1 1 1 ASL 1. <language> Algebraic Specification Language. 2. <chat> A rather gruff way of asking someone their age, sex, and location. (2008-01-21) 1 1 1 1 1 ASL+ An algebraic specification language by David Aspinall of the University of Edinburgh. ASL+ has rules for proving the satisfaction of specifications. It can also be viewed as a type theory with subtyping, featuring contravariant refinement for Pi-abstracted specifications and a notion of stratified equality for higher-order objects. (1994-09-14) 1 1 1 1 1 As Low As Reasonably Practicable (ALARP) A term from UK health and safety (http://hse.gov.uk/risk/theory/alarpglance.htm) law that mandates reducting the risk to workers to the point where the cost of further reduction is grossly disproportionate to the benefit. (2010-10-05) 1 1 1 1 1 ASM assembly language 1 1 1 1 1 ASME American Society of Mechanical Engineers 1 1 1 1 1 ASN Autonomous System Number 1 1 1 1 1 ASN.1 Abstract Syntax Notation 1 1 1 1 1 1 ASP 1. <web> Active Server Pages. 2. <networking> application service provider. 3. <language> A query language(?). [Sammet 1969, p.702]. 4. <processor> Attached Support Processor. (2000-07-08) 1 1 1 1 1 ASPECT An IPSE developed by an Alvey project, using Z to specify the object-management system and tool interface. (1996-03-25) 1 1 1 1 1 ASpecT Algebraic specification of abstract data types. A strict functional language that compiles to C. Versions of ASpecT are available for Sun, Ultrix, NeXT, Macintosh, OS/2 2.0, Linux, RS/6000, Atari, Amiga. (ftp://wowbagger.uni-bremen.de/pub/programming/languages). (1996-03-25) 1 1 1 1 1 aspect In aspect-oriented programming, a modular unit of control over emergent entities. (1999-08-31) 1 1 1 1 1 aspect-oriented programming (AOP) A style of programming that attempts to abstract out features common to many parts of the code beyond simple functional modules and thereby improve the quality of software. Mechanisms for defining and composing abstractions are essential elements of programming languages. The design style supported by the abstraction mechanisms of most current languages is one of breaking a system down into parameterised components that can be called upon to perform a function. But many systems have properties that don't necessarily align with the system's functional components, such as failure handling, persistence, communication, replication, coordination, memory management, or real-time constraints, and tend to cut across groups of functional components. While they can be thought about and analysed relatively separately from the basic functionality, programming them using current component-oriented languages tends to result 1 1 1 1 1 aspect ratio The ratio of width to height of a pixel, image, or display screen. Square pixels (1:1) are considered preferable but displays are usually about 5:4. (1994-11-30) 1 1 1 1 1 ASPEN A toy language for teaching compiler construction. ["ASPEN Language Specifications", T.R. Wilcox, SIGPLAN Notices 12(11):70-87, Nov 1977]. (1994-11-30) 1 1 1 1 1 ASPI Advanced SCSI Peripheral Interface 1 1 1 1 1 ASPIK A multiple-style specification language. ["Algebraic Specifications in an Integrated Software Development and Verification System", A. Voss, Diss, U Kaiserslautern, 1985]. (1994-11-30) 1 1 1 1 1 Aspirin A freeware language from MITRE Corporation for the description of neural networks. A compiler, bpmake, is included. Aspirin is designed for use with the MIGRAINES interface. Version: 6.0, as of 1995-03-08. (ftp://ftp.cognet.ucla.edu/alexis/). (1995-03-08) 1 1 1 1 1 ASPLE A toy language. ["A Sampler of Formal Definitions", M. Marcotty et al, Computing Surveys 8(2):191-276 (Feb 1976)]. (1995-02-08) 1 1 1 1 1 ASPOL A Simulation Process-Oriented Language 1 1 1 1 1 ASQC American Society for Quality Control 1 1 1 1 1 ASR Automatic Send Receive 1 1 1 1 1 assembler A program which converts assembly language into machine code. (1996-03-25) 1 1 1 1 1 ASSEMBLY An early system on the IBM 702. [Listed in CACM 2(5):1959-05-16]. (1996-06-27) 1 1 1 1 1 assembly code assembly language 1 1 1 1 1 Assembly Language (AL) A language for industrial robots developed at Stanford University in the 1970s. ["The AL Language for an Intelligent Robot", T. Binford in Langages et Methods de Programation des Robots Industriels, pp. 73-88, IRIA Press 1979]. ["AL User's Manual", M.S. Mujtaba et al, Stanford AI Lab, Memo AIM-323 (Jan 1979)]. (1994-11-24) 1 1 1 1 1 assembly language (Or "assembly code") A symbolic representation of the machine language of a specific processor. Assembly language is converted to machine code by an assembler. Usually, each line of assembly code produces one machine instruction, though the use of macros is common. Programming in assembly language is slow and error-prone but is the only way to squeeze every last bit of performance out of the hardware. Filename extension: .s (Unix), .asm (CP/M and others). See also second generation language. (1996-09-17) 1 1 1 1 1 Assembly Language Compiler (ALC) An alternative name for IBM 360 assembly language. Compare BAL. (1995-01-04) 1 1 1 1 1 Assembly Language for Multics (ALM) The assembly language of the GE-645 in which critical portions of the Multics kernel were written. (1994-11-24) 1 1 1 1 1 as sensible as a dictionary In Lewis Carroll's Through the Looking Glass and what Alice found there (http://www.Germany.EU.net/books/carroll/alice.html), in the chapter The Garden of Live Flowers (http://www.Germany.EU.net/books/carroll/alice_21.html#SEC24), the Red Queen is talking to Alice about what she's been up to: I only wanted to see what the garden was like, your Majesty - That's right, said the Queen, patting her on the head, which Alice didn't like at all, "though, when you say "garden" - I've seen gardens, compared with which this would be a wilderness." Alice didn't dare argue the point, but went on: "- and I thought I'd try and find my way to the top of that hill -" When you say hill"", the Queen interrupted, "I could show you hills, in comparison with which you'd call that a valley." No, I shouldn't, said Alice, surprised into contradicting her at last: "a hill can't be a valley, you know. That would be nonsense -" The Red Queen shook her head. "You may call it "nonsense" if you 1 1 1 1 1 assertion 1. An expression which, if false, indicates an error. Assertions are used for debugging by catching can't happen errors. 2. In logic programming, a new fact or rule added to the database by the program at run time. This is an extralogical or impure feature of logic programming languages. (1997-06-30) 1 1 1 1 1 ASSET Asset Source for Software Engineering Technology 1 1 1 1 1 asset management The process whereby a large organisation collects and maintains a comprehensive list of the items it owns such as hardware and software. This data is used in connection with the financial aspects of ownership such as calculating the total cost of ownership, depreciation, licensing, maintenance, and insurance. (1997-03-30) 1 1 1 1 1 Asset Source for Software Engineering Technology (ASSET) A programme to promote software reuse by the US DoD. See also ASSET Reuse Library. (1996-08-19) 1 1 1 1 1 assigned numbers The RFC STD 2 documenting the currently assigned values from several series of numbers used in network protocol implementations. This RFC is updated periodically and, in any case, current information can be obtained from the Internet Assigned Numbers Authority (IANA). If you are developing a protocol or application that will require the use of a link, socket, port, protocol, etc., you should contact the IANA to receive a number assignment. (1996-08-19) 1 1 1 1 1 assignment Storing the value of an expression in a variable. This is commonly written in the form "v = e". In Algol the assignment operator was ":=" (pronounced becomes) to avoid mathematicians qualms about writing statements like x = x+1. Assignment is not allowed in functional languages, where an identifier always has the same value. See also referential transparency, single assignment, zero assignment. (1996-08-19) 1 1 1 1 1 assignment problem (Or "linear assignment") Any problem involving minimising the sum of C(a, b) over a set P of pairs (a, b) where a is an element of some set A and b is an element of set B, and C is some function, under constraints such as each element of A must appear exactly once in P or similarly for B, or both. For example, the a's could be workers and the b's projects. The problem is "linear" because the "cost function" C() depends only on the particular pairing (a, b) and is independent of all other pairings. (http://forum.swarthmore.edu/epigone/comp.soft-sys.matlab/bringhyclu). (http://soci.swt.edu/capps/prob.htm). (http://mat.gsia.cmu.edu/GROUP95/0577.html). (http://informs.org/Conf/WA96/TALKS/SB24.3.html). [Algorithms?] (1999-07-12) 1 1 1 1 1 Association Control Service Element (ACSE) The OSI method for establishing a call between two application programs. ACSE checks the identities and contexts of the application entities, and could apply an authentication security check. Documents: ITU Rec. X.227 (ISO 8650), X.217 (ISO 8649) (1997-12-07) 1 1 1 1 1 Association for Computational Linguistics (ACL) The international scientific and professional society for people working on problems involving natural language and computation. Membership includes the ACL quarterly journal, "Computational Linguistics", reduced registration at most ACL-sponsored conferences, discounts on ACL-sponsored publications, and participation in ACL Special Interest Groups. The ACL started in 1968; there are more than 2000 members worldwide. E-mail: <acl@aclweb.org>. (http://cs.columbia.edu/~acl/). (1999-08-31) 1 1 1 1 1 Association for Computing (ACM, before 1997 - "Association for Computing Machinery") The largest and oldest international scientific and educational computer society in the industry. Founded in 1947, only a year after the unveiling of ENIAC, ACM was established by mathematicians and electrical engineers to advance the science and application of Information Technology. John Mauchly, co-inventor of the ENIAC, was one of ACM's founders. Since its inception ACM has provided its members and the world of computer science a forum for the sharing of knowledge on developments and achievements necessary to the fruitful interchange of ideas. ACM has 90,000 members - educators, researchers, practitioners, managers, and engineers - who drive the Association's major programs and services - publications, special interest groups, chapters, conferences, awards, and special activities. 1 1 1 1 1 Association for Computing Machinery Association for Computing 1 1 1 1 1 Association for Progressive Communications (APC) A world-wide organisation of like-minded computer networks providing a global communications network dedicated to the free and balanced flow of information. The APC defends and promotes non-commercial, productive online space for NGOs (Non-Governmental Organisations) and collaborates with like-minded organisations to ensure that the information and communication needs of civil society are considered in telecommunications, donor and investment policy. A few of APC's partner organisations include The Institute for Global Communications (USA), GreenNet (UK), Nicarao (Nicaragua) Enda-Tiers Monde (Senegal) and GlasNet (Ukraine). These organisations serve people working toward goals that include the prevention of warfare, elimination of militarism and poverty, protection of the environment, human rights, social and economic justice, participatory democracy, non-violent conflict resolution, and the promotion of 1 1 1 1 1 Association for SIMULA Users See SIMULA. Address: Royal Institute of Technology, S-100 44 Stockholm, Sweden. [Details?] (1995-03-29) 1 1 1 1 1 Association Française des Utilisateurs d'Unix (et des systèmes ouverts, AFUU) French Association of Unix Users. (http://afuu.fr/). (1996-06-07) 1 1 1 1 1 Association of American Publishers <body> (AAP) A group engaged in standardisation efforts in document preparation. (2000-01-27) 1 1 1 1 1 Association of C and C++ Users (ACCU) A community of people with an interest in the C family of programming languages: K&R C, ANSI C, and C++. The community includes professional programmers, the suppliers of compilers, and those who are just interested in the languages. ACCU members are using C and C++ on a wide range of platforms - Unix, MS-DOS, OS/2, CP/M - home computers, IBM PCs, workstations, and super-computers. Although the organisation is based in the UK, the membership is worldwide. There are members in the US, mainland Europe, Russia, the Middle East, and Australia. E-mail: <info@accu.org>, <membership@accu.org>, <academic@accu.org> (Academic Liaison Officer). Address: The Membership Secretary, 64 Southfield Road, Oxford OX4 1PA, United Kingdom. (1996-12-02) 1 1 1 1 1 Association of Lisp Users (ALU) A user group which aims to promote Lisp, help inform and educate Lisp users in general, and help represent Lisp users as a group to the vendors. The ALU holds an annual conference and supports the formation of inter-vendor standards. ALU has international membership and is incorporated in the US. (http://cs.rochester.edu/u/miller/ALU/home.html). Usenet newsgroups: news:comp.org.lisp-users news:comp.std.lisp. Mailing list: <alu@ai.sri.com>. (1996-12-07) 1 1 1 1 1 associative array (Or "hash", "map", "dictionary") An array where the indices are not just integers but may be arbitrary strings. awk and its descendants (e.g. Perl) have associative arrays which are implemented using hash coding for faster look-up. (2007-10-02) 1 1 1 1 1 associative memory content addressable memory 1 1 1 1 1 Associative Memory Parallel Processing Language (AMPPL-II) A language from the early 1970s. (1995-11-14) 1 1 1 1 1 associativity The property of an operator that says whether a sequence of three or more expressions combined by the operator will be evaluated from left to right (left associative) or right to left (right associative). For example, in Perl, the lazy and operator && is left associative so in the expression: $i >= 0 && $x[$i] >= 0 && $y[$x[$i]] == 0 the left-most && is evaluated first, whereas = is right associative, so in $a = $b = 42 the right-most assignment is performed first. (2007-06-16) 1 1 1 1 1 AST 1. ARI Service. 2. AST Computers, LLC. (2000-03-21) 1 1 1 1 1 ASTAP Advanced STatistical Analysis Program 1 1 1 1 1 AST Computers, LLC The private company formed in January 1999 when Mr. Beny Alagem, the former chairman of Packard Bell NEC, Inc., bought the name and intellectual property of AST Research, Inc.. AST Computers, LLC provide hardware, software, and services for small US businesses. Samsung Electronics Co. Ltd., of Seoul, Korea, owns a minority stake. (http://ast.com/). Address: Los Angeles, CA, USA. (2000-03-28) 1 1 1 1 1 asterisk "*" ASCII code 42. Common names include: star; INTERCAL: splat; ITU-T: asterisk. Rare: wild card; gear; dingle; mult; spider; aster; times; twinkle; glob; Nathan Hale. Commonly used as the multiplication operator and as the Kleene star. Often doubled, as in "x**2", to mean "to the power". In C and related languages, asterisk is used as the dereference operator, "*p" meaning "the thing pointed to by p". (2006-09-10) 1 1 1 1 1 asterix Do you mean "asterisk" (the star-shaped character), or Asterix the Gaul (http://webring.org/cgi-bin/webring?ring=asterixwebring&index), the popular French cartoon by Goscinny and Uderzo? (2000-07-26) 1 1 1 1 1 Astra Digital Radio Digital Radio over satellite, compatible with analog television transmissions. Alternatively the normal TV subcarriers can be modulated by a MPEG-1 Layer-2 48 kHz 192 kbps signal. Quality is better than analog carriers and only needs half the bandwidth (analog stereo = 2 carrier, digital stereo = 1 carrier). Quality is limited and the data rate can't be increased. (2001-12-13) 1 1 1 1 1 Astral A programming language based on Pascal, never implemented. ["ASTRAL: A Structured and Unified Approach to Database Design and Manipulation", T. Amble et al, in Proc of the Database Architecture Conf, Venice, June 1979]. (2000-01-27) 1 1 1 1 1 AST Research, Inc. A company, formed some time before 1980, that was a leading personal computer manufacturer. AST developed desktop computers, mobile computers, and servers that were sold in more than 100 countries worldwide. In January 1999 the name and intellectual property were acquired by a new company named AST Computers, LLC. As of 2000-03-02 it was trading as ARI Service. (2000-03-21) 1 1 1 1 1 asymmetrical modulation A scheme to maximise use of a communications line by giving a larger share of the bandwidth to the modem at the end which is transmitting the most information. Only one end of the connection has full bandwidth, the other has only a fraction of the bandwidth. Normally, which end gets the full bandwidth is chosen dynamically. Asymmetrical modulation was made famous by the HST mode of the early high-speed modems from US Robotics. (1998-03-13) 1 1 1 1 1 Asymmetric Digital Subscriber Line (ADSL, or Asymmetric Digital Subscriber Loop) A form of Digital Subscriber Line in which the bandwidth available for downstream connection is significantly larger then for upstream. Although designed to minimise the effect of crosstalk between the upstream and downstream channels this setup is well suited for web browsing and client-server applications as well as for some emerging applications such as video on demand. The data-rate of ADSL strongly depends on the length and quality of the line connecting the end-user to the telephone company. Typically the upstream data flow is between 16 and 640 kilobits per second while the downstream data flow is between 1.5 and 9 megabits per second. ADSL also provides a voice channel. ADSL can carry digital data, analog voice, and broadcast MPEG2 video in a variety of implementations to meet customer needs. 1 1 1 1 1 Asymmetric Digital Subscriber Loop Asymmetric Digital Subscriber Line 1 1 1 1 1 asynchronous Not synchronised by a shared signal such as clock or semaphore, proceeding independently. Opposite: synchronous. 1. <operating system> A process in a multitasking system whose execution can proceed independently, "in the background". Other processes may be started before the asynchronous process has finished. 2. <communications> A communications system in which data transmission may start at any time and is indicated by a start bit, e.g. EIA-232. A data byte (or other element defined by the protocol) ends with a stop bit. A continuous marking condition (identical to stop bits but not quantized in time), is then maintained until data resumes. (1995-12-08) 1 1 1 1 1 Asynchronous Balanced Mode A communication mode of HDLC and derivative protocols, supporting peer-oriented point-to-point communications between two nodes, where either node can initiate transmission. (1997-05-07) 1 1 1 1 1 Asynchronous Communications Interface Adapter (ACIA) A kind of integrated circuit that provides data formatting and control to EIA-232 serial interfaces. [Is this the same as a UART?] (1997-05-07) 1 1 1 1 1 asynchronous logic A data-driven circuit design technique where, instead of the components sharing a common clock and exchanging data on clock edges, data is passed on as soon as it is available. This removes the need to distribute a common clock signal throughout the circuit with acceptable clock skew. It also helps to reduce power dissipation in CMOS circuits because gates only switch when they are doing useful work rather than on every clock edge. There are many kinds of asynchronous logic. Data signals may use either "dual rail encoding" or "data bundling". Each dual rail encoded Boolean is implemented as two wires. This allows the value and the timing information to be communicated for each data bit. Bundled data has one wire for each data bit and another for timing. Level sensitive circuits typically represent a logic one by a high voltage and a logic zero by a low voltage whereas transition signalling uses a change in the signal level to convey information. A speed 1 1 1 1 1 Asynchronous Transfer Mode (ATM, or "fast packet", "Asynchronous Transfer Mode Protocol", ATMP) A network protocol that dynamically allocates bandwidth between incoming channels and multiplexes them onto a stream of fixed 53-byte packets (called "cells"). A fixed-size packet simplifies switching and multiplexing. ATM is a connection-oriented protocol. It can use different physical layer transports including SONET, DS3, fiber or twisted pair. The ATM Forum is one of the main bodies promoting ATM. Wideband ATM is an enhancement. ATM acronyms (http://atmforum.com/atmforum/acronym_index.html). Indiana acronyms (http://cell-relay.indiana.edu/cell-relay/FAQ/ATM-Acronyms.html). [More detail? Data rate(s)?] (1996-04-01) 1 1 1 1 1 asyncronous It's spelled "asynchronous". (1996-12-13) 1 1 1 1 1 AT IBM PC AT 1 1 1 1 1 at 1. <character> commercial at. 2. <networking> The country code for Austria. 1 1 1 1 1 AT-3 The original name of MATH-MATIC. [Sammet 1969, p. 135]. (2000-02-24) 1 1 1 1 1 ATA Advanced Technology Attachment 1 1 1 1 1 ATA-2 Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 ATA-4 (Or "Ultra DMA", "UDMA", "Ultra-ATA", "Ultra-DMA/33") A development of the Advanced Technology Attachment specifications which gives nearly twice the maximum transfer rate of the ATA-3 standard (PIO Mode 4). ATA-4 Extensions Ultra DMA/33 Synchronous DMA Mode maximum burst transfer rates: Mode Cycle Time Transfer Rate 1 1 1 1 1 Atanasoff-Berry Computer (ABC) An early design for a binary calculator, one of the predecessors of the digital computer. The ABC was partially constructed between 1937 and 1942 by Dr. John Vincent Atanasoff and Clifford Berry at Iowa State College. As well as binary arithmetic, it incorporated regenerative memory, parallel processing, and separation of memory and computing functions. The electronic parts were mounted on a rotating drum, making it hybrid electronic/electromechanical. It was designed to handle only a single type of mathematical problem and was not automated. The results of a single calculation cycle had to be retrieved by a human operator, and fed back into the machine with all new instructions, to perform complex operations. It lacked any serious form of logical control or conditional statements. Atanasoff's patent application was denied because he never have a completed, working product. Ideas from the ABC were 1 1 1 1 1 Atanasoff, John Vincent John Vincent Atanasoff 1 1 1 1 1 ATAPI AT Attachment Packet Interface 1 1 1 1 1 ATA point (Or "Anglo-Saxon point") One of the two most common variants of the point, equal to 0.3514598 mm, or 0.0138366 inch, or 1/72.272 inch. The ATA point is used on the island of the United Kingdom and on the American continent. [What point do they use in Ireland?] (2002-03-11) 1 1 1 1 1 Atari A maker of arcade games, home video game systems, and home computers, especially during the 1970s and 1980s. Atari are best known for their range of 16- and 32-bit microcomputers, notable for having a built-in MIDI interface. As of February 1994 the range included the Atari 520ST, 1040ST, Mega ST, STe, STacy, Mega STe, TT, and Falcon. There are also emulators that run on the Apple Macintosh and IBM PC/XT/AT. Atari ceased to be a separate company in 1996 when merged with JTS. In 1998, JTS sold the Atari assets to Hasbro. In 2001, Infogrames North America operations officially changed their name to Atari. (http://atarigames.com/). Usenet newsgroups: news:comp.binaries.atari.st, news:comp.sys.atari.st.tech, news:comp.sources.atari.st, news:comp.sys.atari.st, news:comp.sys.atari.advocacy, news:comp.sys.atari.programmer. 1 1 1 1 1 Atari ST A personal computer released by Atari in 1985. The "ST" stands for "Sixteen/Thirty-two", from the Motorola 68000's 16-bit external bus and 32-bit processor. The original 520ST model had an external floppy drive and power supply whereas the 1040ST had them built-in. The 520 and later 520STFM came with 512 KB of RAM, the 1040 had 1 MB. Several upgraded models followed, up to the 1993 Motorola 68030 based Falcon. The ST was the first home computer with built-in MIDI ports and plenty of MIDI software. A wide range of other software from office to games was also available. (2006-10-30) 1 1 1 1 1 AT Attachment Advanced Technology Attachment 1 1 1 1 1 AT Attachment Packet Interface (ATAPI) Part of the EIDE interface that provides additional commands to control a CD-ROM drive or magnetic tape. [Winn L. Rosch "The Winn L. Rosch Hardware Bible" (Third Edition), Sams Publishing, 1994]. (1998-11-01) 1 1 1 1 1 AT bus architecture Industry Standard Architecture 1 1 1 1 1 AtFS Attributed File System 1 1 1 1 1 Athena Project Athena 1 1 1 1 1 Atherton Technology The comapny that developed the Software BackPlane CASE framework. Their Atherton Tool Integration Services were the basis for the ATIS standard. (2000-02-24) 1 1 1 1 1 Athlon (K7) AMD's 7th generation x86 processor, released in June 1999. Athlon uses a Slot A motherboard and is not compatible with Slot 1 motherboards. [Details? Reference?] (1999-08-05) 1 1 1 1 1 ATIS A Tools Integration Standard 1 1 1 1 1 ATK Andrew Toolkit 1 1 1 1 1 ATLAS Abbreviated Test Language for Avionics Systems 1 1 1 1 1 Atlas Autocode The Autocode for the Ferranti Atlas, which may have been the first commercial computer with hardware-paged virtual memory. Whereas other autocodes were basically assembly languages, Atlas Autocode was high-level and block-structured, resembling a cross between Fortran and ALGOL 60. It had call-by value, loops (loop), declarations, complex numbers, pointers, heap and stack storage generators, dynamic arrays, and extensible syntax. (2000-04-03) 1 1 1 1 1 ATM 1. <communications> Asynchronous Transfer Mode. 2. Automatic Teller Machine - a cash dispenser. 3. <chat> At the moment. 4. <text> Adobe Type Manager. 1 1 1 1 1 ATM Forum An international non-profit arganisation aiming to encourage the user of Asynchronous Transfer Mode through interoperability specifications and to promote cooperation and awareness. The ATM Forum consists of a worldwide Technical Committee, three Marketing Committees for North America, Europe and Asia-Pacific as well as the User Committee, through which ATM end-users participate. Worldwide Headquarters: 2570 West El Camino Real, Suite 304 Mountain View, CA 94040-1313 USA. Telephone: +1 (650) 949 6700. E-mail: ATM Forum <info@atmforum.com>. (http://atmforum.com/). (1999-06-14) 1 1 1 1 1 ATMP Asynchronous Transfer Mode 1 1 1 1 1 atob /A too B/ Utility software that converts ASCII to binary. The reverse process is btoa. [Algorithm?] (1997-08-08) 1 1 1 1 1 ATOLL Acceptance, Test Or Launch Language 1 1 1 1 1 atomic (From Greek "atomos", indivisible) Indivisible; cannot be split up. For example, an instruction may be said to do several things atomically, i.e. all the things are done immediately, and there is no chance of the instruction being half-completed or of another being interspersed. Used especially to convey that an operation cannot be interrupted. An atomic data type has no internal structure visible to the program. It can be represented by a flat domain (all elements are equally defined). Machine integers and Booleans are two examples. An atomic database transaction is one which is guaranteed to complete successfully or not at all. If an error prevents a partially-performed transaction from proceeding to completion, it must be "backed out" to prevent the database being left in an inconsistent state. [Jargon File] 1 1 1 1 1 A Tools Integration Standard (ATIS) An object-oriented interface to a set of services that allows the saving, accessing and managing of information in a common repository. Developed by Atherton Technology and DEC, based on an extended version of the Software BackPlane, proposed as an industry standard. (1994-10-25) 1 1 1 1 1 ATRAC Adaptive TRansform Acoustic Coding 1 1 1 1 1 ATS Attribute Translation System 1 1 1 1 1 at sign commercial at 1 1 1 1 1 AT&T American Telephone and Telegraph, Inc. 1 1 1 1 1 Attachment Unit Interface (AUI) The part of the IEEE Ethernet standard located between the MAC, and the MAU. The AUI is a transceiver cable that provides a path between a node's Ethernet interface and the MAU. (1996-12-08) 1 1 1 1 1 attacks as a service A kind of cybercrime as a service in which the service provider performs denial of service attacks on behalf of others for money. (2015-02-23) 1 1 1 1 1 AT&T Bell Labs Bell Laboratories 1 1 1 1 1 attenuation The progressive reduction in amplitude of a signal as it travels farther from the point of origin. For example, an electric signal's amplitude reduces with distance due to electrical impedance. Attenuation is usually measured in decibels [per metre?]. Attenuation does not imply appreciable modification of the shape of the waveform (distortion), though as the signal amplitude falls the signal-to-noise ratio will also fall unless the channel itself is noise free or the signal is amplified at some intermediate point(s) along the channel. ["Networking Essentials, second edition", Microsoft Corporation, pub. Microsoft Press 1997]. (2003-07-29) 1 1 1 1 1 atto- prefix 1 1 1 1 1 attoparsec About 31 mm (one inch). "atto-" is the standard SI prefix for multiplication by 10^-18. A parsec (parallax-second) is 3.26 light-years; an attoparsec is thus 3.26 * 10^-18 light years. Thus, one attoparsec per microfortnight is about one inch per second. This unit is reported to be in use (though probably not very seriously) among hackers in the UK. [Jargon File] (1996-12-08) 1 1 1 1 1 attribute A named value or relationship that exists for some or all instances of some entity and is directly associated with that instance. Examples include the href attribute of an HTML anchor element, the columns of a database table considered as attributes of each row, and the members (properties and methods of an object in OOP. This contrasts with the contents of some kind of container (e.g. an array), which are typically not named. The contents of an associative array, though they might be considered to be named by their key values, are not normally thought of as attributes. (2001-02-04) 1 1 1 1 1 Attributed File System (AtFS) The basis of the Shape_VC toolkit. Cooperative work within projects is supported by a status model controlling visibility of version objects, locking, and long transactions for synchronising concurrent updates. The concept of object attributes provides a basis for storing management information with versions and passing this information between individual tools. This mechanism is useful for building integrated environments from a set of unrelated tools. (2000-02-24) 1 1 1 1 1 Attribute Translation System (ATS) A BNF-based parser generator from the University of Saskatchewan(?). ATS generates table-driven LL1 parsers with full insert-only error recovery. It also has full left-attribute semantic handling, which is a dream compared to using YACC's parser actions. (2000-04-08) 1 1 1 1 1 ATX An open PC motherboard specification by Intel. ATX is a development of the Baby AT specification with the motherboard rotated 90 degrees in the chassis. The CPU and SIMM sockets have been relocated away from the expansion card slots meaning that all the slots support full-length cards. More I/O functions are integrated on the motherboard. As the longer edge of the board is now at the back of the chassis, there is more space for connectors; also, the I/O opening on the back panel of the chassis has been defined as double the previous height, allowing vendors to add extra on-board I/O functions over and above the standard. Most Pentium Pro boards use this form factor. As well as the motherboard size, layout, and placement, the ATX specification also includes requirements for power supply and fan specification and location. The full size ATX board measures 305mm wide by 244mm deep. 1 1 1 1 1 au 1. <networking> The two character country code for Australia used in Internet domain names. 2. <filename extension> audio. (1995-02-15) 1 1 1 1 1 aubergine A secret term used to refer to computers in the presence of computerphobic third parties. (1995-01-24) 1 1 1 1 1 audio Sound, one component of multimedia. Computers (and audio compact discs and digital audio tape) work with digital audio, in contrast to vinyl disks or analogue tape. (1999-07-30) 1 1 1 1 1 audiographics Audiographic Teleconferencing 1 1 1 1 1 audiographic teleconferencing (Or "electronic whiteboarding", "screen sharing") A form of teleconferencing in real time using both an audio and a data connection. The computer screen is shared by more than one site, and used as an electronic blackboard, overhead projector or still video projector. Some systems allow for sharing software also. (1995-10-06) 1 1 1 1 1 Audio IFF (AIFF) A format developed by Apple Computer Inc. for storing high-quality digital audio and musical instrument information. It is also used by SGI and several professional audio packages. (1994-10-10) 1 1 1 1 1 AudioOne Digital recording and editing software developed by BizTrack Software Development for the dance, music, and audio industries. AudioOne includes a waveform recorder that allows signal manipulation, editing, and recording. (1996-09-28) 1 1 1 1 1 Audio Processing Technology (APT) A company that produces codecs based on predictive analysis rather than frequency coding. (1996-01-15) 1 1 1 1 1 Audio Video Interleave (AVI) An audio-video standard designed by Microsoft. Apparently proprietary and Microsoft Windows-specific. (http://www2.echo.lu/oii/en/video.html#AVI). [Details?] (1996-09-08) 1 1 1 1 1 Augmented Backus-Naur Form An extension of Backus-Naur Form documented in RFC 2234. [Summary?] (1997-11-23) 1 1 1 1 1 AUI 1. <tool, product> Adaptable User Interface. 2. <networking> Attachment Unit Interface. 1 1 1 1 1 A'UM A stream-based, concurrent, logic, object-oriented language by K. Yoshida and Takashi Chikayama <chikayama@klic.org>, built on top of KL1. ["A'UM - A Stream-based Concurrent Logic Object-Oriented Language", K. Yoshida et al, Proc 3rd Intl Conf Fifth Gen Comp Sys, Springer 1988, pp. 638-649]. (2000-07-16) 1 1 1 1 1 AUP acceptable use policy 1 1 1 1 1 Aurora ["The Aurora Or-Parallel Prolog System", E. Lusk et al, Proc 3rd Intl Conf on Fifth Generation Comp Systems, pp. 819-830, ICOT, A-W 1988]. 1 1 1 1 1 Austin Kyoto Common Lisp (AKCL) A collection of ports, bug fixes, and performance improvements to KCL by William Schelter <wfs@cli.com>, <wfs@math.utexas.edu>, University of Texas. Version 1-615 includes ports to Decstation 3100, HP9000/300, i386/Sys V, IBM-PS2/AIX, IBM-RT/AIX, SGI, Sun-3/Sunos 3 or 4, Sun-4, Sequent Symmetry, IBM370/AIX, VAX/BSD VAX/Ultrix, NeXT. (ftp://rascal.ics.utexas.edu/pub/akcl-1-609.tar.Z). (1992-04-29) 1 1 1 1 1 authentication The verification of the identity of a person or process. In a communication system, authentication verifies that messages really come from their stated source, like the signature on a (paper) letter. The most common form of authentication is typing a user name (which may be widely known or easily guessable) and a corresponding password that is presumed to be known only to the individual being authenticated. Another form of authentication is biometrics. (2007-02-22) 1 1 1 1 1 authoring Creating a hypertext or hypermedia document. (1994-11-07) 1 1 1 1 1 autobaud automatic baud rate detection 1 1 1 1 1 autobogotiphobia bogotify 1 1 1 1 1 AutoCAD A CAD software package for mechanical engineering, marketed by Autodesk, Inc. (1994-11-09) 1 1 1 1 1 Autocode 1. The assembly language accepted by AUTOCODER. 2. A generic term for symbolic assembly language. Versions of Autocode were developed for Ferranti Atlas, Titan, Mercury and Pegasus and IBM 702 and IBM 705. (2001-05-14) 1 1 1 1 1 AUTOCODER Possibly the first primitive compiler. AUTOCODER was written by Alick E. Glennie in 1952. It translated symbolic statements into machine language for the Manchester Mark I computer. Autocoding later came to be a generic term for assembly language programming. (1994-11-07) 1 1 1 1 1 autoconf The GNU project's tool that configures a source code distribution to compile and run on a different platform. Among open source hackers, a mere running binary of a program is not considered a full release; what's interesting is a source tree that can be built into binaries using standard tools. Since the mid-1990s, autoconf, automake, and libtools have been the standard way to make a distribution portable so that it can be built on multiple operating systems without change. (2002-09-20) 1 1 1 1 1 autoconfiscate A term coined by Noah Friedman meaning to set up or modify a source-code distribution so that it configures and builds using the GNU project's autoconf/automake/libtools suite. (2002-09-20) 1 1 1 1 1 Autodesk, Inc. The distributors of the AutoCAD CAD package. Address: Sausalito, CA, USA. (1994-11-09) 1 1 1 1 1 AUTOEXEC.BAT The batch file containing commands, loaded by MS-DOS after running CONFIG.SYS. AUTOEXEC.BAT contains normal DOS commands and can be used for additional system configuration such as setting paths and variables, configuring network connections and running application programs. (1995-03-18) 1 1 1 1 1 AUTOGRAF A system for describing bar charts. ["User's Manual for AUTOGRAF", Cambridge Computer Assoc, Dec 1972]. (2001-05-14) 1 1 1 1 1 AUTOGRP AUTOmated GRouPing system 1 1 1 1 1 Auto Idle A facility provided by some Intel clock doubled microprocessors where the internal clock can be slowed to the external clock rate while the processor is waiting for data from memory, returning to full speed as soon as the data arrives. See also System Management Mode. (1994-11-09) 1 1 1 1 1 Autolisp A dialect of Lisp used by the Autocad CAD package from Autodesk. (1994-11-09) 1 1 1 1 1 autoloader stack loader 1 1 1 1 1 automagically /aw-toh-maj'i-klee/ or /aw-toh-maj'i-k*l-ee/ Automatically, but in a way that, for some reason (typically because it is too complicated, or too ugly, or perhaps even too trivial), the speaker doesn't feel like explaining to you. E.g. "The C-INTERCAL compiler generates C, then automagically invokes cc to produce an executable." See magic. [Jargon File] (2001-05-18) 1 1 1 1 1 automata automaton 1 1 1 1 1 automata theory automaton 1 1 1 1 1 Automated Engineering Design (AED) (Or "ALGOL Extended for Design") A systems language for the IBM 7090 and IBM 360 developed at MIT System Laboratory ca. 1965 by a team led by Douglas T. Ross (now at Softech). AED is an extension of ALGOL 60 with records ("plexes"), pointers, and dynamic allocation. DYNAMO II was written in AED, as was the first BCPL compiler. Versions: AED-0, AED-1, AED-JR. ["The Automated Engineering Design (AED) Approach to Generalized Computer-Aided Design", D.T. Ross, Proc ACM 22nd Natl Conf, 1967]. [Sammet 1969 and 1978]. (1995-03-26) 1 1 1 1 1 AUTOmated GRouPing system (AUTOGRP) An interactive statistical analysis system, an extension of CML. ["AUTOGRP: An Interactive Computer System for the Analysis of Health Care Data", R.E. Mills et al, Medical Care 14(7), Jul 1976]. (1994-11-07) 1 1 1 1 1 Automated Retroactive Minimal Moderation (ARMM) A Usenet robot created by Dick Depew of Munroe Falls, Ohio. ARMM was intended to automatically cancel posts from anonymous-posting sites. Unfortunately, the robot's recogniser for anonymous postings triggered on its own automatically-generated control messages! Transformed by this stroke of programming ineptitude into a monster of Frankensteinian proportions, it broke loose on the night of 1993-03-31 and proceeded to spam news:news.admin.policy with a recursive explosion of over 200 messages. Reactions varied from amusement to outrage. The pathological messages crashed at least one mail system, and upset people paying line charges for their Usenet feeds. One poster described the ARMM debacle as "instant Usenet history" (also establishing the term despew), and it has since been widely cited as a cautionary example of the havoc the combination of good intentions and incompetence can wreak on a network. Compare Great Worm; sorcerer's apprentice mode. See also 1 1 1 1 1 automated testing Software testing assisted with software tools that require no operator input, analysis, or evaluation. (2001-05-20) 1 1 1 1 1 AUTOMATH A very high level language for writing proofs, from Eindhoven, Netherlands. ["The Mathematical Language AUTOMATH, Its Usage and Some of its Extensions", N.G. deBruijn, in Symp on Automatic Demonstration, LNM 125, Springer 1970]. (2001-07-09) 1 1 1 1 1 Automatically Programmed Tools (APT) A language for numerically controlled machine tools. Versions: APT II (IBM 704, 1958), APT III (IBM 7090, 1961). ["APT Part Programming", McGraw-Hill]. [Sammet 1969, p. 605]. (1995-05-04) 1 1 1 1 1 automatic baud rate detection (ABR, autobaud) A process by which a receiving device determines the speed, code level, and stop bits of incoming data by examining the first character, usually a preselected sign-on character. ABR allows the receiving device to accept data from a variety of transmitting devices operating at different speeds without needing to establish data rates in advance. (1996-06-18) 1 1 1 1 1 automatic hyphenation A feature of some word processors which can insert hyphens into words which would otherwise extend beyond the right hand margin of the page. More advanced word processors may have options to control the position of the hyphen, to restrict certain words from being hyphenated, and to allow custom dictionaries of hyphenation points to be built up. (1996-08-02) 1 1 1 1 1 Automatic Mathematical TRANslation (AMTRAN) A system developed by NASA in Huntsville in 1966 for the IBM 1620, based on the Culler-Fried System. It required a special terminal. ["AMTRAN: An Interactive Computing System", J. Reinfelds, Proc FJCC 37:537- 542, AFIPS (Fall 1970)]. (1995-11-14) 1 1 1 1 1 Automatic Network Routing (ANR) A source routing protocol used to route LU6.2 session and control traffic from node to node through a High Performance Routing network or subnet. ANR operates at the lower end of the SNA Path Control layer. [Relationship to OS/390?] (1997-05-08) 1 1 1 1 1 Automatic Number Identification (ANI) A service that tells the recipient of a telephone call the telephone number of the person making the call. This number can be passed to computer equipment to automatically retrieve associated information about the caller, i.e. account status, billing records, etc. See CTI. (1996-12-08) 1 1 1 1 1 Automatic Repeat Request (ARQ) A modem error control protocol in which the receiver asks the transmitter to resend corrupted data. (1995-11-14) 1 1 1 1 1 Automatic Send Receive (ASR) Part of a designation for a hard-copy terminal, manufactured by Teletype Corporation, which could be commanded remotely to send the contents of its paper tape reader. The ASR-33 was the most common minicomputer terminal in the early 1970s. (1995-11-23) 1 1 1 1 1 Automatic Sequence Controlled Calculator Mark 1 1 1 1 1 1 automation Automatic, as opposed to human, operation or control of a process, equipment or a system; or the techniques and equipment used to achieve this. Most often applied to computer (or at least electronic) control of a manufacturing process. See also design automation, office automation, manularity, Manufacturing Automation Protocol, PEARL, QBE. (1994-10-21) 1 1 1 1 1 Automatische Rechenplanfertigung A programming language published in 1952 by Heinz Rutishauser (1918-70). [Features?] (2001-07-09) 1 1 1 1 1 automaton (Plural automata) A machine, robot, or formal system designed to follow a precise sequence of instructions. Automata theory, the invention and study of automata, includes the study of the capabilities and limitations of computing processes, the manner in which systems receive input, process it, and produce output, and the relationships between behavioural theories and the operation and use of automated devices. See also cellular automaton, finite state machine. (1996-04-23) 1 1 1 1 1 Automatrix, Inc. The company which produced CAM-PC. Address: Ballston Spa, NY, USA. (http://automatrix.com/). (1995-04-21) 1 1 1 1 1 Autonomous System (AS) A collection of routers under a single administrative authority, using a common Interior Gateway Protocol for routing packets. (2001-09-16) 1 1 1 1 1 Autonomous System Number (ASN) Used for routing on the Internet. [Does each ASN uniquely identify an Autonomous System?] (2001-09-16) 1 1 1 1 1 Autopass ["Autopass: An Automatic Programming System for Computer-Controlled Mechanical Assembly", L.I. Lieberman et al, IBM J Res Dev 21(4):321-333, 1979]. (2001-09-16) 1 1 1 1 1 autopilot code Code that was written by a programmer on auto-pilot who wasn't really thinking about what they were doing. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-08-21) 1 1 1 1 1 autoprojector A self-applicable partial evaluator. (2001-09-16) 1 1 1 1 1 AUTO-PROMPT A numerical control language from IBM for 3D milling. [Sammet 1969, p.606]. (2001-09-25) 1 1 1 1 1 Autostat A language for statistical programming. ["Autostat: A Language for Statistical Programming", A.S. Douglas et al, Computer J 3:61, 1960]. (2001-09-25) 1 1 1 1 1 autostereogram SIRDS 1 1 1 1 1 A/UX (Apple's UniX) Apple's first version of Unix for Macintosh computers. A/UX merges the Macintosh Finder (GUI) with a Unix core, offering functions from both systems. It will run on some late-model Motorola 68000 Macs, but not on the Power Mac. A/UX is based on AT&T Unix System V.2.2 with numerous extensions from V.3, V.4 and BSD 4.2/4.3. It also provides full POSIX compliance. A/UX 3.x.x incorporates System 7 for the Macintosh, thus supporting the vast majority of Macintosh applications. System 7 and Unix are fully integrated under A/UX 3.x.x with the Unix file system being seen as a disk drive by the Finder. jagubox's A/UX Home Page (http://jagubox.gsfc.nasa.gov/aux/Info/FAQ.auxl). (1997-12-13) 1 1 1 1 1 auxiliary storage An obsolete term for a hard disk drive. (1997-04-14) 1 1 1 1 1 av avatar 1 1 1 1 1 availability The degree to which a system suffers degradation or interruption in its service to the customer as a consequence of failures of one or more of its parts. One of the components of RAS. (2000-08-13) 1 1 1 1 1 Avalon/C++ A concurrent extension of C++ with servers and transactions developed in 1986 for fault-tolerant distributed systems. Avalon/C++ was influenced by Argus. ["Camelot and Avalon: A Distributed Transaction Facility", J.L. Eppinger et al, Morgan Kaufmann 1990]. (2002-01-13) 1 1 1 1 1 Avalon/Common LISP A LISP dialect available as a prototype only. ["Reliable Distributed Computing with Avalon/Common LISP", S.M. Clamen et al, CMU-CS-89-186 and Proc Intl Conf on Computer Languages, Mar 1990]. (2002-02-03) 1 1 1 1 1 avatar 1. <chat, virtual reality> An image representing a user in a multi-user virtual reality (or VR-like, in the case of Palace) space. 2. (CMU, Tektronix) root, superuser. There are quite a few Unix computers on which the name of the superuser account is "avatar" rather than "root". This quirk was originated by a CMU hacker who disliked the term superuser, and was propagated through an ex-CMU hacker at Tektronix. [Jargon File] (1997-09-14) 1 1 1 1 1 AVC H.264 1 1 1 1 1 average seek time The mean time it takes to move the head of a disk drive from one track to another, averaged over the source and destination cylinders. Usually measured in milliseconds (ms). The average seek time gives a good measure of the speed of the drive in a multi-user environment where successive read/write request are largely uncorrelated. Ten ms is common for a hard disk and 200 ms for an eight-speed CD-ROM. (2007-03-16) 1 1 1 1 1 AverStar The US software engineering company that developed Hal, under their former name, "Intermetrics". Other products include CS-4, Red, Mwave Developers Toolkit (multimedia for IBM PC), cross-compilers for C and C++; Ada '83, Ada 95, and SAMeDL. AverStar also supply client/server systems; custom software applications and turnkey systems; independent verification and validation; CAE integration technology; languages and compilers: Ada, C, C++, HDLs (MHDL), Modula, SPL/1. Address: Intermetrics, Inc., 733 Concord Avenue, Cambridge, MA 02138, USA. Telephone: +1 (617) 661 1840. Fax: +1 (617) 868 2843 Address: 7918 Jones Branch Drive, McLean, Va 22102, USA. Telephone: +1 (703) 827-2606. Fax: +1 (703) 827-5560. Also Houston, TX, Huntington Beach, CA, Warminster, PA, and others. 1 1 1 1 1 AVI Audio Video Interleave 1 1 1 1 1 Avon A dataflow language. ["AVON: A Dataflow Language", A. Deb, ICS 87, Second Intl Conf on Supercomputing, v.3, pp.9-19, ISI 1987]. (1994-11-28) 1 1 1 1 1 AVS Application Visualisation System 1 1 1 1 1 aw The country code for Aruba. (1999-01-27) 1 1 1 1 1 AWE Advanced WavEffect 1 1 1 1 1 AWG American Wire Gauge 1 1 1 1 1 awk 1. <tool, language> (Named from the authors' initials) An interpreted language included with many versions of Unix for massaging text data, developed by Alfred Aho, Peter Weinberger, and Brian Kernighan in 1978. It is characterised by C-like syntax, declaration-free variables, associative arrays, and field-oriented text processing. There is a GNU version called gawk and other varients including bawk, mawk, nawk, tawk. Perl was inspired in part by awk but is much more powerful. Unix manual page: awk(1). netlib WWW (http://plan9.att.com/netlib/research/index.html). netlib FTP (ftp://netlib.att.com/netlib/research/). ["The AWK Programming Language" A. Aho, B. Kernighan, P. Weinberger, A-W 1988]. 2. <jargon> An expression which is awkward to manipulate through normal regexp facilities, for example, one 1 1 1 1 1 AWT Abstract Window Toolkit 1 1 1 1 1 aXe A text editor for the X Window System. No longer maintained. (1998-03-13) 1 1 1 1 1 AXIOM A commercially available subset of the Scratchpad, symbolic mathematics system from IBM. ["Axiom - The Scientific Computing System", R. Jenks et al, Springer 1992]. [Relationship with AXIOM*?] (1995-02-21) 1 1 1 1 1 axiom A well-formed formula which is taken to be true without proof in the construction of a theory. Compare: lemma. (1995-03-31) 1 1 1 1 1 AXIOM* A symbolic mathematics system. A# is one component of AXIOM*. Version: 2. [Relationship with AXIOM?] (1995-02-21) 1 1 1 1 1 Axiomatic Architecture Description Language (AADL) A language allowing concise modular specification of multiprocessor architectures from the compiler/operating-system interface level down to chip level. AADL is rich enough to specify target architectures while providing a concise model for clocked microarchitectures. ["AADL: A Net-Based Specification Method for Computer Architecture Design", W. Damm et al in Languages for Parallel Architectures, J.W. deBakker ed, Wiley, 1989]. (2003-06-30) 1 1 1 1 1 axiomatic semantics A set of assertions about properties of a system and how they are effected by program execution. The axiomatic semantics of a program could include pre- and post-conditions for operations. In particular if you view the program as a state transformer (or collection of state transformers), the axiomatic semantics is a set of invariants on the state which the state transformer satisfies. E.g. for a function with the type: sort_list :: [T] -> [T] we might give the precondition that the argument of the function is a list, and a postcondition that the return value is a list that is sorted. One interesting use of axiomatic semantics is to have a language that has a finitely computable sublanguage that is used for specifying pre and post conditions, and then have the compiler prove that the program will satisfy those conditions. 1 1 1 1 1 axiomatic set theory One of several approaches to set theory, consisting of a formal language for talking about sets and a collection of axioms describing how they behave. There are many different axiomatisations for set theory. Each takes a slightly different approach to the problem of finding a theory that captures as much as possible of the intuitive idea of what a set is, while avoiding the paradoxes that result from accepting all of it, the most famous being Russell's paradox. The main source of trouble in naive set theory is the idea that you can specify a set by saying whether each object in the universe is in the "set" or not. Accordingly, the most important differences between different axiomatisations of set theory concern the restrictions they place on this idea (known as "comprehension"). Zermelo Fränkel set theory, the most commonly used axiomatisation, gets round it by (in effect) saying that you can 1 1 1 1 1 Axiom of Choice (AC, or "Choice") An axiom of set theory: If X is a set of sets, and S is the union of all the elements of X, then there exists a function f:X -> S such that for all non-empty x in X, f(x) is an element of x. In other words, we can always choose an element from each set in a set of sets, simultaneously. Function f is a "choice function" for X - for each x in X, it chooses an element of x. Most people's reaction to AC is: "But of course that's true! From each set, just take the element that's biggest, stupidest, closest to the North Pole, or whatever". Indeed, for any finite set of sets, we can simply consider each set in turn and pick an arbitrary element in some such way. We can also construct a choice function for most simple infinite sets of sets if they are generated in some regular way. However, there are some infinite sets for which the construction or specification of such a choice function would 1 1 1 1 1 Axiom of Comprehension An axiom schema of set theory which states: if P(x) is a property then x : P is a set. I.e. all the things with some property form a set. Acceptance of this axiom leads to Russell's Paradox which is why Zermelo set theory replaces it with a restricted form. (1995-03-31) 1 1 1 1 1 axiom schema A formula in the language of an axiomatic system, containing one or more. These metasyntactic variables (or schematic variables) that stand for terms or subformulae. An example is the Axiom of Comprehension. (2009-02-10) 1 1 1 1 1 AXLE An early string processing language in which a program consists of an "assertion table" specifying patterns and an "imperative table" specifying replacements. ["AXLE: An Axiomatic Language for String Transformations", K. Cohen et al, CACM 8(11):657-661, Nov 1965]. (2009-02-10) 1 1 1 1 1 ayacc A Yacc-like parser generator from the Irvine Research Unit in Software written in Ada that produce Ada output. Comes with aflex. Version 1.2a. (ftp://liege.ics.uci.edu/pub/irus/aflex-ayacc_1.2a.tar.Z). Mailing list: <irus-software-request@ics.uci.edu>. (1993-01-06) 1 1 1 1 1 AYT Are you there? (1996-03-09) 1 1 1 1 1 az The country code for Azerbaijan. (1999-01-27) 1 1 1 1 1 AZERTY QWERTY 1 1 1 1 1 B 1. byte. 2. <language> A systems language written by Ken Thompson in 1970 mostly for his own use under Unix on the PDP-11. B was later improved by Kerninghan(?) and Ritchie to produce C. B was used as the systems language on Honeywell's GCOS-3. B was, according to Ken, greatly influenced by BCPL, but the name B had nothing to do with BCPL. B was in fact a revision of an earlier language, bon, named after Ken Thompson's wife, Bonnie. ["The Programming Language B", S.C. Johnson & B.W. Kernighan, CS TR 8, Bell Labs (Jan 1973)]. [Features? Differences from C?] (1997-02-02) 3. <language> A simple interactive programming language designed by Lambert Meertens and Steven Pemberton. B was the predecessor of ABC. B was the first published (and 1 1 1 1 1 b bit or maybe byte (B). (1996-11-03) 1 1 1 1 1 B-0 The original name of FLOW-MATIC from Remington Rand. B-0 was used on the UNIVAC I or II about 1958. (1997-01-09) 1 1 1 1 1 B1FF BIFF 1 1 1 1 1 B1 security Orange Book 1 1 1 1 1 B2B business to business 1 1 1 1 1 B2 security Orange Book 1 1 1 1 1 B3 security Orange Book 1 1 1 1 1 b4 before. 1 1 1 1 1 ba The country code for Bosnia and Herzegowina. (1999-01-27) 1 1 1 1 1 Baan A provider of enterprise resource planning and manufacturer resource planning software. (http://baan.com/). (1998-07-07) 1 1 1 1 1 Babbage The structured assembly language for the General Electric Company 4xxx range of computers and their OS4000 operating system. It is strictly an assembler in that the generated code is relatively predictable but it can be written in a sufficiently structured manner, with indentation, control statements, function and procedure calls, to make the resultant source easy to read and manage. Even with this visible structure however, it is important to remember that the assembly of the statement is done left to right. The British videotext system, Prestel is programmed in Babbage. [Datamation, 1980s]. (2007-10-24) 1 1 1 1 1 Babbage, Charles Charles Babbage 1 1 1 1 1 babbling error An Ethernet node attempting to transmit more than 1518 data bytes - the largest allowed Ethernet packet. This is why the Maximum Transmission Unit for IP traffic on Ethernet is 1500. [Why 1518?] (1998-03-13) 1 1 1 1 1 BABEL 1. A subset of ALGOL 60, with many ALGOL W extensions. ["BABEL, A New Programming Language", R.S. Scowen, Natl Phys Lab UK, Report CCU7, 1969]. 2. Mentioned in The Psychology of Computer Programming, G.M. Weinberg, Van Nostrand 1971, p.241. 3. A language based on higher-order functions and first-order logic. ["Graph-Based Implementation of a Functional Logic Language", H. Kuchen et al, Proc ESOP 90, LNCS 432, Springer 1990, pp.271-290]. ["Logic Programming with Functions and Predicates: The Language BABEL", Moreno-Navarro et al, J Logic Prog 12(3) (Feb 1992)]. (1994-11-28) 1 1 1 1 1 BABT British Approval Boards for Telecommunications 1 1 1 1 1 Baby AT The redesigned AT motherboard that had the same size as the XT motherboard had (8.5" x 11") and could thus fit into an XT case. The original 12" x 13" AT motherboards are now largely forgotten. Compare ATX. (1997-02-20) 1 1 1 1 1 BABYLON A development environment for expert systems. It includes frames, constraints, a prolog-like logic formalism, and a description language for diagnostic applications. It requires Common Lisp. (ftp://ftp.gmd.de/gmd/ai-research/Software/). (1995-02-08) 1 1 1 1 1 BACAIC Boeing Airplane Company Algebraic Interpreter Coding system. A pre-Fortran system on the IBM 701 and IBM 650. (1995-02-08) 1 1 1 1 1 Bachman A proposed a style of Entity-Relationship model which differs from Chen's. (1995-02-08) 1 1 1 1 1 Bachman Information Systems The company which merged with CADRE to form Cayenne Software in July 1996. (1998-02-06) 1 1 1 1 1 backbone The top level in a hierarchical network. Stub networks and transit networks which connect to the same backbone are guaranteed to be interconnected. See also: Internet backbone. (1998-07-02) 1 1 1 1 1 backbone cabal A group of large-site administrators who pushed through the Great Renaming and reined in the chaos of Usenet during most of the 1980s. The cabal mailing list disbanded in late 1988 after a bitter internal cat-fight. [Jargon File] (1994-11-28) 1 1 1 1 1 backbone site A key Usenet, electronic mail and/or Internet site; one that processes a large amount of third-party traffic, especially if it is the home site of any of the regional coordinators for the Usenet maps. Notable backbone sites as of early 1993 include uunet and the mail machines at Rutgers University, UC Berkeley, DEC's Western Research Laboratories, Ohio State University and the University of Texas. Compare rib site, leaf site. [Jargon File] (1994-11-28) 1 1 1 1 1 back door (Or "trap door", "wormhole"). A hole in the security of a system deliberately left in place by designers or maintainers. The motivation for such holes is not always sinister; some operating systems, for example, come out of the box with privileged accounts intended for use by field service technicians or the vendor's maintenance programmers. See also iron box, cracker, worm, logic bomb. Historically, back doors have often lurked in systems longer than anyone expected or planned, and a few have become widely known. The infamous RTM worm of late 1988, for example, used a back door in the BSD Unix "sendmail(8)" utility. Ken Thompson's 1983 Turing Award lecture to the ACM revealed the existence of a back door in early Unix versions that may have qualified as the most fiendishly clever security hack of all time. The C compiler contained code that would recognise when the "login" command was being recompiled and insert some code recognizing a password chosen by Thompson, 1 1 1 1 1 back-end Any software performing either the final stage in a process, or a task not apparent to the user. A common usage is in a compiler. A compiler's back-end generates machine language and performs optimisations specific to the machine's architecture. The term can also be used in the context of network applications. E.g. "The back-end of the system handles socket protocols". Contrast front end. (1996-04-09) 1 1 1 1 1 Back End Generator (BEG) A code generator developed by H. Emmelmann et al at GMD, University Karlsruhe, Germany. Its input language is Back End Generator Language (BEGL). (ftp://gatekeeper.dec.com/pub/gmd/cocktail/beg). ["BEG - A Generator for Efficient Back Ends", H. Emmelmann et al, SIGPLAN Notices 24(7):227-237 (Jul 1989)]. ["BEG - A Back End Generator - User Manual", H. Emmelmann, GMD, U Karlsruhe, 1990]. [Summary?] (2000-12-16) 1 1 1 1 1 Back End Generator Language Back End Generator 1 1 1 1 1 backgammon See bignum, moby, pseudoprime. [Jargon File] 1 1 1 1 1 background 1. <operating system> A task running in the background (a background task) is detached from the terminal where it was started (and often running at a lower priority); opposite of foreground. This means that the task's input and output must be from/to files (or other processes). Nowadays this term is primarily associated with Unix, but it appears to have been first used in this sense on OS/360. Compare amp off, batch, slopsucker. 2. <jargon> For a human to do a task "in the background" is to do it whenever foreground matters are not claiming your undivided attention, and "to background" something means to relegate it to a lower priority. "For now, we'll just print a list of nodes and links; I'm working on the graph-printing problem in the background." Note that this implies ongoing activity but at a reduced level or in spare time, in contrast to mainstream "back burner" (which connotes benign neglect until some future resumption of activity). Some people prefer 1 1 1 1 1 backing store 1. <storage> Computer memory, usually magnetic disks, storing data and programs. Sections of this information can then be copied into the main memory (RAM) for processing. Backing store is cheaper but RAM is faster. Such a hierarchy of memory devices allows a trade-off between performance and cost. 2. <text> Character storage in memory or on disk, as opposed to displayed or printed characters. This distinction is important where the visual ordering of characters differs from the order in which they are stored, e.g. bidirectional or non-spacing layout. In a Unicode encoding, text is stored in sequential order in the backing store. Logical or backing store order corresponds to the order in which text is typed on the keyboard (after corrections such as insertions, deletions, and overtyping). A text rendering process converts Unicode text in the backing store to readable text. 1 1 1 1 1 back link A link in one direction implied by the existence of an explicit link in the other direction. (1996-05-28) 1 1 1 1 1 backoff A host which has experienced a collision on a network waits for a amount of time before attempting to retransmit. A random backoff minimises the probability that the same nodes will collide again, even if they are using the same backoff algorithm. Increasing the backoff period after each collision also helps to prevent repeated collisions, especially when the network is heavily loaded. An example algorithm is binary exponential backoff. (1996-05-28) 1 1 1 1 1 BackOffice A suite of network server software from Microsoft that includes Windows NT Server, BackOffice Server (for the integrated development, deployment, and management of BackOffice applications in departments, branch offices, and medium sized businesses); Exchange Server; Proxy Server; Site Server for intranet publishing, management, and search; Site Server Commerce Edition For comprehensive Internet commerce transactions; Small Business Server for business operations, resource management, and customer relations; SNA Server for the integration of existing and new systems and data; SQL Server for scalable, reliable database and data-warehousing; Systems Management Server (SMS) for centralised change- and configuration-management. Latest version: 4.5, as of 2000-12-16. (http://microsoft.com/backofficeserver/). (2000-12-16) 1 1 1 1 1 backplane A printed circuit board with slots into which other cards are plugged. A backplane,is typically just a connector and does not usually have many active components on it. This contrasts with a motherboard. Designing a backplane (http://iec.org/online/tutorials/design_backplane/index.html). (2002-09-08) 1 1 1 1 1 backport To make a feature from a later version of a piece of software available in an earlier version. Backporting of features enables users of the older version to benefit from a feature without upgrading fully. (2003-12-18) 1 1 1 1 1 back-propagation (Or "backpropagation") A learning algorithm for modifying a feed-forward neural network which minimises a continuous error function or "objective function." Back-propagation is a "gradient descent" method of training in that it uses gradient information to modify the network weights to decrease the value of the error function on subsequent tests of the inputs. Other gradient-based methods from numerical analysis can be used to train networks more efficiently. Back-propagation makes use of a mathematical trick when the network is simulated on a digital computer, yielding in just two traversals of the network (once forward, and once back) both the difference between the desired and actual output, and the derivatives of this difference with respect to the connection weights. 1 1 1 1 1 back quote "`" ASCII code 96. Common names: left quote; left single quote; open quote; ITU-T: grave accent; grave. Rare: backprime; INTERCAL: backspark; unapostrophe; birk; blugle; back tick; back glitch; push; ITU-T: opening single quotation mark; quasiquote. Back quote is used in Unix shells to invoke command substitution. (1996-11-26) 1 1 1 1 1 backronym (Backward acronym) A word which has been turned into an acronym by inventing an expansion, rather than the other way around. E.g. "ping". (2005-06-22) 1 1 1 1 1 backside cache An implementation of secondary cache memory that allows it to be directly accessed by the CPU. Backside cache is used by Apple Computers, Inc. in their PowerPC G3 processor. Previous PowerPC processors used the system bus to access both secondary cache and main memory. In the PowerPC G3 a dedicated bus handles only CPU/cache transactions. This bus can operate faster than the system bus thus improving the overall performance of the processor. The term apparently derives from the relocation of the secondary cache from the motherboard to the processor card itself, i.e. on the backside of the processor card. (1998-09-10) 1 1 1 1 1 backslash "\" ASCII code 92. Common names: escape (from C/Unix); reverse slash; slosh; backslant; backwhack. Rare: bash; ITU-T: reverse slant; reversed virgule; INTERCAL: backslat. Backslash is used to separate components in MS-DOS pathnames, and to introduce special character sequence in C and Unix strings, e.g. "\n" for newline. (2000-02-21) 1 1 1 1 1 backspace (BS) ASCII code 8, Control-H. The control character that should cause most output devices to move their current output position back to the previous character so that the next character output will replace (or overprint) it. Inputting a backspace (typically by pressing the backspace key) causes many systems to delete the character before the input cursor, though others use delete for this. See twirling baton for an imaginitive use of backspace. (2003-10-25) 1 1 1 1 1 backtick back quote 1 1 1 1 1 backtracking A scheme for solving a series of sub-problems each of which may have multiple possible solutions and where the solution chosen for one sub-problem may affect the possible solutions of later sub-problems. To solve the overall problem, we find a solution to the first sub-problem and then attempt to recursively solve the other sub-problems based on this first solution. If we cannot, or we want all possible solutions, we backtrack and try the next possible solution to the first sub-problem and so on. Backtracking terminates when there are no more solutions to the first sub-problem. This is the algorithm used by logic programming languages such as Prolog to find all possible ways of proving a goal. An optimisation known as "intelligent backtracking" keeps track of the dependencies between sub-problems and only re-solves those which depend on an earlier solution which has changed. 1 1 1 1 1 backup ("back up" when used as a verb) A spare copy of a file, file system, or other resource for use in the event of failure or loss of the original. The term commonly refers to a copy of the files on a computer's disks, made periodically and kept on magnetic tape or other removable medium (also called a "dump"). This essential precaution is neglected by most new computer users until the first time they experience a disk crash or accidentally delete the only copy of the file they have been working on for the last six months. Ideally the backup copies should be kept at a different site or in a fire safe since, though your hardware may be insured against fire, the data on it is almost certainly neither insured nor easily replaced. See also backup software, differential backup, incremental backup, full backup. Compare archive, source code management. (2004-03-16) 1 1 1 1 1 Backup Domain Controller (BDC) A server in a network of Microsoft Windows computers that maintains a copy of the SAM database and handles access requests that the Primary Domain Controller (PDC) doesn't respond to. There may be zero or more BDCs in a network. They increase reliability and reduce load on the PDC. (2006-09-18) 1 1 1 1 1 backup pumpkin pumpkin 1 1 1 1 1 backup rotation Any system for re-using backup media, e.g. magnetic tape. One extreme would be to use the same media for every backup (e.g. copy disk A to disk B), the other extreme would be to use new media every time. The trade-off is between the cost of buying and storing media and the ability to restore any version of any file. One example is the Grandfather, Father, Son (GFS) scheme. (2004-10-08) 1 1 1 1 1 backup software Software for doing a backup, often included as part of the operating system. Backup software should provide ways to specify what files get backed up and to where. It may include its own scheduling function to automate the procedure or, preferably, work with generic scheduling facilities. It may include facilities for managing the backup media (e.g. maintaining an index of tapes) and for restoring files from backups. Examples are Unix's dump command and Windows's ntbackup. (2004-03-16) 1 1 1 1 1 Backus-Naur Form (BNF, originally "Backus Normal Form") A formal metasyntax used to express context-free grammars. Backus Normal Form was renamed Backus-Naur Form at the suggestion of Donald Knuth. BNF is one of the most commonly used metasyntactic notations for specifying the syntax of programming languages, command sets, and the like. It is widely used for language descriptions but seldom documented anywhere (how do you document a metasyntax?), so that it must usually be learned by osmosis (but see RFC 2234). Consider this BNF for a US postal address: <postal-address> ::= <name-part> <street-address> <zip-part> <personal-part> ::= <name> | <initial> "." <name-part> ::= <personal-part> <last-name> [<jr-part>] <EOL> | <personal-part> <name-part> <street-address> ::= [<apt>] <house-num> <street-name> <EOL> 1 1 1 1 1 Backus Normal Form Backus-Naur Form 1 1 1 1 1 backward analysis An analysis to determine properties of the inputs of a program from properties or context of the outputs. E.g. if the output of this function is needed then this argument is needed. Compare forward analysis. (1997-11-23) 1 1 1 1 1 backward chaining An algorithm for proving a goal by recursively breaking it down into sub-goals and trying to prove these until facts are reached. Facts are goals with no sub-goals which are therefore always true. Backward training is the program execution mechanism used by most logic programming language like Prolog. Opposite: forward chaining. (2004-01-26) 1 1 1 1 1 backward combatability /bak'w*d k*m-bat'*-bil'*-tee/ (Play on "backward compatibility") A property of hardware or software revisions in which previous protocols, formats, layouts, etc. are irrevocably discarded in favour of "new and improved" protocols, formats and layouts, leaving the previous ones not merely deprecated but actively defeated. (Too often, the old and new versions cannot definitively be distinguished, such that lingering instances of the previous ones yield crashes or other infelicitous effects, as opposed to a simple "version mismatch" message.) A backward compatible change, on the other hand, allows old versions to coexist without crashes or error messages, but too many major changes incorporating elaborate backward compatibility processing can lead to extreme software bloat. See also flag day. [Jargon File] (2003-06-23) 1 1 1 1 1 backward compatibility Able to share data or commands with older versions of itself, or sometimes other older systems, particularly systems it intends to supplant. Sometimes backward compatibility is limited to being able to read old data but does not extend to being able to write data in a format that can be read by old versions. For example, WordPerfect 6.0 can read WordPerfect 5.1 files, so it is backward compatible. It can be said that Perl is backward compatible with awk, because Perl was (among other things) intended to replace awk, and can, with a converter, run awk programs. See also: backward combatability. Compare: forward compatible. (2003-06-23) 1 1 1 1 1 backward compatible backward compatibility 1 1 1 1 1 backwards compatibility backward compatibility 1 1 1 1 1 backwards compatible backward compatibility 1 1 1 1 1 BAD /B-A-D/ Broken As Designed, a play on "working as designed", from IBM. Failing because of bad design and misfeatures rather than because of bugs. [Jargon File] (2002-04-14) 1 1 1 1 1 Bad command or file name The error message printed by MS DOS when it can't find a program or command to execute due to a typing error, incorrect PATH variable, or misplaced or missing executable. (1996-04-07) 1 1 1 1 1 Bad Thing (From the 1930 Sellar & Yeatman parody "1066 And All That") Something that can't possibly result in improvement of the subject. This term is always capitalised, as in "Replacing all of the 9600-baud modems with bicycle couriers would be a Bad Thing." Opposite: Good Thing. British correspondents confirm that Bad Thing and Good Thing (and probably therefore Right Thing and Wrong Thing) come from the book referenced in the etymology, which discusses rulers who were Good Kings but Bad Things. This has apparently created a mainstream idiom on the British side of the pond. [Jargon File] 1 1 1 1 1 bag on the side An extension to an established hack that is supposed to add some functionality to the original. Usually derogatory, implying that the original was being overextended and should have been thrown away, and the new product is ugly, inelegant, or bloated. Also "to hang a bag on the side [of]". "C++? That's just a bag on the side of C." "They want me to hang a bag on the side of the accounting system." 1 1 1 1 1 baklava code Code with too many layers. Also known as Lasagne Code. [john-d-cook, Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-09-14) 1 1 1 1 1 BAL Basic Assembly Language 1 1 1 1 1 balanced computing Matching computer tools to job activities so that the computer system structure parallels the organisation structure and work functions. Both personal computers and employees operate in a decentralised environment with monitoring of achievement of management objectives from centralised corporate systems. (http://moultonco.com/balanced.htm). (1996-04-15) 1 1 1 1 1 balanced tree An optimisation of a tree which aims to keep equal numbers of items on each subtree of each node so as to minimise the maximum path from the root to any leaf node. As items are inserted and deleted, the tree is restructured to keep the nodes balanced and the search paths uniform. Such an algorithm is appropriate where the overheads of the reorganisation on update are outweighed by the benefits of faster search. A B-tree is a kind of balanced tree that can have more than two subtrees at each node (i.e. one that is not restricted to being a binary tree). (2000-01-10) 1 1 1 1 1 BALGOL ALGOL on Burroughs 220. [Sammet 1969, p. 174]. (1996-04-15) 1 1 1 1 1 BALITAC Early system on IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 BALM (Block And List Manipulation) An extensible language, developed by Malcolm Harrison in 1970, with LISP-like features and ALGOL-like syntax, for CDC 6600. ["The Balm Programming Language", Malcolm Harrison, Courant Inst, May 1973]. (2007-03-01) 1 1 1 1 1 balun A transformer connected between a balanced source or load and an unbalanced source or load. A balanced line has two conductors, with equal currents in opposite directions. The unbalanced line has just one conductor; the current in it returns via a common ground or earth path. (1996-10-17) 1 1 1 1 1 bamf /bamf/ 1. [Old X-Men comics] Notional sound made by a person or object teleporting in or out of the hearer's vicinity. Often used in virtual reality (especially MUD) electronic fora when a character wishes to make a dramatic entrance or exit. 2. The sound of magical transformation, used in virtual reality fora. [Jargon File] 1 1 1 1 1 Banach algebra An algebra in which the vector space is a Banach space. (1997-02-25) 1 1 1 1 1 Banach inverse mapping theorem In a Banach space the inverse to a continuous linear mapping is continuous. (1998-06-25) 1 1 1 1 1 Banach space A complete normed vector space. Metric is induced by the norm: d(x,y) = ||x-y||. Completeness means that every Cauchy sequence converges to an element of the space. All finite-dimensional real and complex normed vector spaces are complete and thus are Banach spaces. Using absolute value for the norm, the real numbers are a Banach space whereas the rationals are not. This is because there are sequences of rationals that converges to irrationals. Several theorems hold only in Banach spaces, e.g. the Banach inverse mapping theorem. All finite-dimensional real and complex vector spaces are Banach spaces. Hilbert spaces, spaces of integrable functions, and spaces of absolutely convergent series are examples of infinite-dimensional Banach spaces. Applications include wavelets, signal processing, and radar. [Robert E. Megginson, "An Introduction to Banach Space 1 1 1 1 1 Banach-Tarski paradox It is possible to cut a solid ball into finitely many pieces (actually about half a dozen), and then put the pieces together again to get two solid balls, each the same size as the original. This paradox is a consequence of the Axiom of Choice. (1995-03-29) 1 1 1 1 1 banana label The labels used on the sides of macrotape reels, so called because they were shaped roughly like blunt-ended bananas. This term, like macrotapes themselves, is obsolete. [Jargon File] (2007-10-17) 1 1 1 1 1 banana phenomenon banana problem 1 1 1 1 1 banana problem From the story of the little girl who said "I know how to spell "banana", but I don't know when to stop". Not knowing where or when to bring a production to a close (compare fencepost error). One may say "there is a banana problem" of an algorithm with poorly defined or incorrect termination conditions, or in discussing the evolution of a design that may be succumbing to featuritis (see also creeping elegance, creeping featuritis). HAKMEM item 176 describes a banana problem in a Dissociated Press implementation. Also, see one-banana problem for a superficially similar but unrelated usage. (2010-03-20) 1 1 1 1 1 bandwidth The difference between the highest and lowest frequencies of a transmission channel (the width of its allocated band of frequencies). The term is often used erroneously to mean data rate or capacity - the amount of data that is, or can be, sent through a given communications circuit per second. [How is data capacity related to bandwidth?] [Jargon File] (2001-04-24) 1 1 1 1 1 bang 1. A common spoken name for "!" (ASCII 33), especially when used in pronouncing a bang path in spoken hackish. In elder days this was considered a CMUish usage, with MIT and Stanford hackers preferring excl or shriek; but the spread of Unix has carried "bang" with it (especially via the term bang path) and it is now certainly the most common spoken name for "!". Note that it is used exclusively for non-emphatic written "!"; one would not say "Congratulations bang" (except possibly for humorous purposes), but if one wanted to specify the exact characters "foo!" one would speak Eff oh oh bang. See pling, shriek, ASCII. 2. An exclamation signifying roughly "I have achieved enlightenment!", or "The dynamite has cleared out my brain!" Often used to acknowledge that one has perpetrated a thinko immediately after one has been called on it. [Jargon File] 1 1 1 1 1 bang on (Or "pound on"). To stress-test a piece of hardware or software: "I banged on the new version of the simulator all day yesterday and it didn't crash once. I guess it is ready for release." [Jargon File] 1 1 1 1 1 bang path 1. <communications> An old-style UUCP electronic-mail address naming a sequence of hosts through which a message must pass to get from some assumed-reachable location to the addressee (a "source route"). So called because each hop is signified by a bang sign (exclamation mark). Thus, for example, the path ...!bigsite!foovax!barbox!me directs people to route their mail to computer bigsite (presumably a well-known location accessible to everybody) and from there through the computer foovax to the account of user me on barbox. Before autorouting mailers became commonplace, people often published compound bang addresses using the convention (see glob) to give paths from *several* big computers, in the hope that one's correspondent might be able to get mail to one of them reliably. e.g. 1 1 1 1 1 banner 1. The title page added to printouts by most print spoolers. Typically includes user or account ID information in very large character-graphics capitals. Also called a "burst page", because it indicates where to burst (tear apart) fanfold paper to separate one user's printout from the next. 2. A similar printout generated (typically on multiple pages of fan-fold paper) from user-specified text, e.g. by a program such as Unix's "banner". 3. splash screen. [Jargon File] (1994-11-28) 1 1 1 1 1 Banyan A personal computer networking company, best known for its "Vines" products for local area networks. Address: Westborough MA, USA. [More info?] (1995-03-01) 1 1 1 1 1 BAP 1. <language> An early system used on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-28) 2. <language> Brain Aid Prolog. (1995-03-07) 1 1 1 1 1 BAPI Business Application Programming Interface 1 1 1 1 1 bar 1. <programming, convention> /bar/ The second metasyntactic variable, after foo and before baz. E.g. "Suppose function FOO calls functions BAR..." 2. Often appended to foo to produce foobar. [Jargon File] (1995-03-07) 1 1 1 1 1 Barbara Liskov Professor Barbara Liskov was the first US woman to be awarded a PhD in computing, and her innovations can be found in every modern programming language. She currently (2009) heads the Programming Methodology Group at the Massachusetts Institute of Technology. Professor Liskov's design innovations have, over the decades, made software more reliable and easier to maintain. She has invented two computer progamming languages: CLU, an object-orientated language, and Argus, a distributed programming language. Liskov's research forms the basis of modern programming languages such as Java, C# and C++. One of the biggest impacts of her work came from her contributions to the use of data abstraction, a method for organising complex programs. See Liskov substitution principle. In June 2009 she will receive the A. M. Turing Award. Barbara Liskov home (http://www.pmg.csail.mit.edu/~liskov/). 1 1 1 1 1 bar code A printed horizontal strip of vertical bars of varying widths, groups of which represent decimal digits and are used for identifying commercial products or parts. Bar codes are read by a bar code reader and the code interpreted either through software or a hardware decoder. All products sold in open trade are numbered and bar-coded to a worldwide standard, which was introduced in the US in 1973 and to the rest of the world in 1977. The Uniform Code Council in the US, along with the international article numbering authority, EAN International, allocate blocks of unique 12 or 13-digit numbers to member companies through a national numbering authority. In Britain this is the Article Number Association. Most companies are allocated 100,000 numbers that they can use to identify any of their products, services or locations. Each code typically contains a leading "quiet" zone, start character, data character, optional check digit, stop 1 1 1 1 1 bare metal 1. New computer hardware, unadorned with such snares and delusions as an operating system, an HLL, or even assembler. Commonly used in the phrase "programming on the bare metal", which refers to the arduous work of bit bashing needed to create these basic tools for a new computer. Real bare-metal programming involves things like building boot PROMs and BIOS chips, implementing basic monitors used to test device drivers, and writing the assemblers that will be used to write the compiler back ends that will give the new computer a real development environment. 2. "Programming on the bare metal" is also used to describe a style of hand-hacking that relies on bit-level peculiarities of a particular hardware design, especially tricks for speed and space optimisation that rely on crocks such as overlapping instructions (or, as in the famous case described in The Story of Mel, interleaving of opcodes on a magnetic drum to minimise fetch delays due to the device's rotational latency). 1 1 1 1 1 barf /barf/ [mainstream slang for "vomit"] 1. Term of disgust. This is the closest hackish equivalent of the Val\-speak "gag me with a spoon". (Like, euwww!) See bletch. 2. To say "Barf!" or emit some similar expression of disgust. I showed him my latest hack and he barfed means only that he complained about it, not that he literally vomited. 3. To fail to work because of unacceptable input, perhaps with a suitable error message, perhaps not. Examples: "The division operation barfs if you try to divide by 0." (That is, the division operation checks for an attempt to divide by zero, and if one is encountered it causes the operation to fail in some unspecified, but generally obvious, manner.) "The text editor barfs if you try to read in a new file before writing out the old one". See choke, gag. In Commonwealth Hackish, "barf" is generally replaced by puke or "vom". barf is sometimes also used as a 1 1 1 1 1 barfmail Multiple bounce messages accumulating to the level of serious annoyance, or worse. The sort of thing that happens when an inter-network mail gateway goes down or misbehaves. [Jargon File] (1996-01-05) 1 1 1 1 1 barfulation /bar`fyoo-lay'sh*n/ Variation of barf used around the Stanford area. An exclamation, expressing disgust. On seeing some particularly bad code one might exclaim, "Barfulation! Who wrote this, Quux?" [Jargon File] 1 1 1 1 1 barfulous /bar'fyoo-l*s/ (Or "barfucious", /bar-fyoo-sh*s/) Said of something that would make anyone barf, if only for aesthetic reasons. (1995-02-22) 1 1 1 1 1 barnacle code Any piece of code (usually a static method) that has been appended to a class where it doesn't logically belong, due to a lack of anywhere else to put it. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-08-10) 1 1 1 1 1 barney In Commonwealth hackish, "barney" is to fred as bar is to foo. That is, people who commonly use "fred" as their first metasyntactic variable will often use "barney" second. The reference is, of course, to Fred Flintstone and Barney Rubble in the Flintstones cartoons. [Jargon File] (1994-11-28) 1 1 1 1 1 Baroque An early logic programming language written by Boyer and Moore in 1972. ["Computational Logic: Structure Sharing and Proof of program Properties", J. Moore, DCL Memo 67, U Edinburgh 1974]. [Jargon File] (1995-02-22) 1 1 1 1 1 baroque Feature-encrusted; complex; gaudy; verging on excessive. Said of hardware or (especially) software designs, this has many of the connotations of elephantine or monstrosity but is less extreme and not pejorative in itself. "Metafont even has features to introduce random variations to its letterform output. Now *that* is baroque!" See also rococo. [Jargon File] (1995-02-22) 1 1 1 1 1 barrel shifter A hardware device that can shift or rotate a data word by any number of bits in a single operation. It is implemented like a multiplexor, each output can be connected to any input depending on the shift distance. (1995-03-28) 1 1 1 1 1 barycentric Centre of gravity, mean. (2007-07-10) 1 1 1 1 1 base radix. 1 1 1 1 1 base 64 A file format using 64 ASCII characters to encode the six bit binary data values 0-63. To convert data to base 64, the first byte is placed in the most significant eight bits of a 24-bit buffer, the next in the middle eight, and the third in the least significant eight bits. If there a fewer than three bytes to encode, the corresponding buffer bits will be zero. The buffer is then used, six bits at a time, most significant first, as indices into the string ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ and the indicated character output. If there were only one or two input bytes, the output is padded with two or one "=" characters respectively. This prevents extra bits being added to the reconstructed data. The process then repeats on the remaining input data. Base 64 is used when transmitting binary data through text-only media such as electronic mail, and has largely 1 1 1 1 1 baseband A transmission medium through which digital signals are sent without frequency shifting. In general, only one communication channel is available at any given time. Ethernet is an example of a baseband network. See also broadband. (1995-02-22) 1 1 1 1 1 base class superclass 1 1 1 1 1 baseline released version 1 1 1 1 1 base memory The lowest 640 kilobytes of memory in an IBM PC-compatible computer running MS-DOS. Other PC operating systems can usually compensate and "ignore" the fact that there is a 640K limit to base memory. This was put in place because the original CPU - the Intel 8088 - could only access one megabyte of memory, and IBM wanted to reserve the upper 384KB for device drivers. The high memory area (HMA) lies above 640KB and can be accessed on MS-DOS computers that have an A20 handler. (1997-05-30) 1 1 1 1 1 basename The name of a file which, in contrast to a pathname, does not mention any of the directories containing the file. Examples: pathname basename -------- -------- /etc/hosts hosts ./alma alma 1 1 1 1 1 Base Technology The company which developed and distributes Liana. (http://BaseTechnology.com/). E-mail: Jack Krupansky <Jack@BaseTechnology.com> (owner). Address: Base Technology, Attn: Jack Krupansky, 1500 Mass. Ave. NW #114 Washington, DC 2005, USA. 800-786-9505 Telephone: +1 800 876 9505. (1999-06-29) 1 1 1 1 1 bash Bourne Again SHell. GNU's command interpreter for Unix. Bash is a Posix-compatible shell with full Bourne shell syntax, and some C shell commands built in. The Bourne Again Shell supports Emacs-style command-line editing, job control, functions, and on-line help. Written by Brian Fox of UCSB. The latest version is 1.14.1. It includes a yacc parser, the interpreter and documentation. (ftp://ftp.gnu.org/bash-1.14.1.tar.gz) or from a GNU archive site. E-mail: <bug-bash@gnu.org>. Usenet newsgroup: news:gnu.bash.bug. (1994-07-15) 1 1 1 1 1 BASIC Beginner's All-purpose Symbolic Instruction Code. A simple language originally designed for ease of programming by students and beginners. Many dialects exist, and BASIC is popular on microcomputers with sound and graphics support. Most micro versions are interactive and interpreted. BASIC has become the leading cause of brain-damage in proto-hackers. This is another case (like Pascal) of the cascading lossage that happens when a language deliberately designed as an educational toy gets taken too seriously. A novice can write short BASIC programs (on the order of 10-20 lines) very easily; writing anything longer is painful and encourages bad habits that will make it harder to use more powerful languages. This wouldn't be so bad if historical accidents hadn't made BASIC so common on low-end micros. As it is, it ruins thousands of potential wizards a year. Originally, all references to code, both GOTO and GOSUB (subroutine call) referred to the destination by its line 1 1 1 1 1 Basic Assembly Language (BAL) What most people called IBM 360 assembly language. See ALC. (1995-04-13) 1 1 1 1 1 BASIC AUTOCODER Early system on IBM 7070. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 Basic COBOL A subset of COBOL from COBOL-60 standards. [Sammet 1969, p. 339]. (1997-12-07) 1 1 1 1 1 Basic Encoding Rules (BER) ASN.1 encoding rules for producing self-identifying and self-delimiting transfer syntax for data structures described in ASN.1 notations. BER is an self-identifying and self-delimiting encoding scheme, which means that each data value can be identified, extracted and decoded individually. Huw Rogers once described BER as "a triumph of bloated theory over clean implementation". He also criticises it as designed around bitstreams with arbitrary boundaries between data which can only be determined at a high level. Documents: ITU-T X.690, ISO 8825-1. See also CER, DER, PER. (1998-05-28) 1 1 1 1 1 Basic Fortran A subset of Fortran. [Sammet 1969, p. 150]. (1999-06-09) 1 1 1 1 1 Basic Input/Output System (BIOS, ROM BIOS) The part of the system software of the IBM PC and compatibles that provides the lowest level interface to peripheral devices and controls the first stage of the bootstrap process, including installing the operating system. The BIOS is stored in ROM, or equivalent, in every PC. Its main task is to load and execute the operating system which is usually stored on the computer's hard disk, but may be loaded from CD-ROM or floppy disk at install time. In order to provide acceptable performance (e.g. for screen display), some software vendors access the routines in the BIOS directly, rather than using the higher level operating system calls. Thus, the BIOS in the compatible computer must be 100% compatible with the IBM BIOS. As if that wasn't bad enough, many application programs bypass even the BIOS and address the screen hardware directly just as the BIOS does. Consequently, register level 1 1 1 1 1 Basic JOVIAL A subset of JOVIAL written ca. 1965. [Sammet 1969, p.529]. (1995-04-19) 1 1 1 1 1 Basic Language for Implementation of System Software (BLISS, or allegedly, "System Software Implementation Language, Backwards") A language designed by W.A. Wulf at CMU around 1969. BLISS is an expression language. It is block-structured, and typeless, with exception handling facilities, coroutines, a macro system, and a highly optimising compiler. It was one of the first non-assembly languages for operating system implementation. It gained fame for its lack of a goto and also lacks implicit dereferencing: all symbols stand for addresses, not values. Another characteristic (and possible explanation for the backward acronym) was that BLISS fairly uniformly used backward keywords for closing blocks, a famous example being ELUDOM to close a MODULE. An exception was BEGIN...END though you could use (...) instead. DEC introduced the NOVALUE keyword in their dialects to allow statements to not return a value. 1 1 1 1 1 Basic Multilingual Plane (BMP) The first plane defined in Unicode/ISO 10646, designed to include all scripts in active modern use. The BMP currently includes the Latin, Greek, Cyrillic, Devangari, hiragana, katakana, and Cherokee scripts, among others, and a large body of mathematical, APL-related, and other miscellaneous characters. Most of the Han ideographs in current use are present in the BMP, but due to the large number of ideographs, many were placed in the Supplementary Ideographic Plane. Unicode home (http://unicode.org). (2002-03-19) 1 1 1 1 1 Basic Object Adapter (BOA) Part of the CORBA architecture. [Details?] (2004-06-23) 1 1 1 1 1 Basic Object System (BOS) A C-callable library that implements the notion of object and which uses Tcl as its interpreter for interpreted methods (you can have "compiled" methods in C, and mix compiled and interpreted methods in the same object, plus lots more). You can subclass and mix in existing objects using BOS to extend, among other things, the set of tk widgets. BOS is a class-free object system, also called a prototype-based object system; it is modelled loosely on the Self system from Stanford University. Version 1.31 by Sean Levy <Sean.Levy@cs.cmu.edu>. (ftp://barkley.berkeley.edu/tcl). (1992-08-21) 1 1 1 1 1 Basic Operating System (BOS) An early [when?] IBM operating system. According to folklore, BOS was the predecessor to TOS on the IBM 360 and it was IPL'd from a card reader. It may have been intended for very small 360's with no disks and limited tape drives. BOS died out really early [when?] as disks such as the 2311 and 2314 became common with the IBM 360, whereas disks had been a real luxury on the IBM 7090. (1999-01-29) 1 1 1 1 1 Basic Programming Support (BPS, colloquially: Barely Programming Support) A suite of utility routines from IBM to perform very simple procedures like formatting a disk or labelling a tape. BPS was only available on punched cards. [Dates?] (1998-07-08) 1 1 1 1 1 Basic Rate Interface (BRI, 2B+D, 2B1D) An Integrated Services Digital Network channel consisting of two 64 kbps "bearer" (B) channels and one 16 kbps "delta" (D) channel, giving a total data rate of 144 kbps. The B channels are used for voice or user data, and the D channel is used for control and signalling and/or X.25 packet networking. BRI is the kind of ISDN interface most likely to be found in residential service. (2002-01-13) 1 1 1 1 1 Basic Service Set (BSS) A wireless local area network and all the wireless devices (e.g. PCs and laptops) that are associated with it. A BSS may or may not include an access point and is identified by a BSSID. (2009-05-12) 1 1 1 1 1 BASIC V The version of the Basic programming language which comes on ROM in Acorn's RISC computers: the Archimedes range and the RiscPC. It features REPEAT and WHILE loops, multi-line IF statements, procedures and functions, local variables, error handling, system calls and a built-in assembler. (1995-01-05) 1 1 1 1 1 Bastard Operator From Hell (BOFH) A rogue network operator character invented by Simon Travaglia <simontrav@hotmail.com>, regularly featured in "Computing" and "DATAMATION" magazine. See also: Dilbert. (http://angelfire.com/bc/simont/index.html). (1999-09-17) 1 1 1 1 1 bastion host proxy gateway 1 1 1 1 1 batch batch processing 1 1 1 1 1 batch file (Or script) A text file containing operating system commands which are executed automatically by the command-line interpreter. In Unix, this is called a "shell script" since it is the Unix shell which includes the command-line interpreter. Batch files can be used as a simple way to combine existing commands into new commands. In Microsoft Windows, batch files have filename extension, .bat or ".cmd". A special example is autoexec.bat which MS-DOS runs when Windows starts. (2009-09-14) 1 1 1 1 1 batch processing A system that takes a sequence (a "batch") of commands or jobs, executes them and returns the results, all without human intervention. This contrasts with an interactive system where the user's commands and the computer's responses are interleaved during a single run. A batch system typically takes its commands from a disk file (or a set of punched cards or magnetic tape in the mainframe days) and returns the results to a file (or prints them). Often there is a queue of jobs which the system processes as resources become available. Since the advent of the personal computer, the term "batch" has come to mean automating frequently performed tasks that would otherwise be done interactively by storing those commands in a "batch file" or "script". Usually this file is read by some kind of command interpreter but batch processing is sometimes used with GUI-based applications that define script equivalents for menu selections and other mouse 1 1 1 1 1 bathtub curve Common term for the curve (resembling an end-to-end section of one of those claw-footed antique bathtubs) that describes the expected failure rate of electronics with time: initially high, dropping to near 0 for most of the system's lifetime, then rising again as it "tires out". See also burn-in period, infant mortality. [Jargon File] 1 1 1 1 1 baud /bawd/ (plural "baud") The unit in which the information carrying capacity or "signalling rate" of a communication channel is measured. One baud is one symbol (state-transition or level-transition) per second. This coincides with bits per second only for two-level modulation with no framing or stop bits. A symbol is a unique state of the communication channel, distinguishable by the receiver from all other possible states. For example, it may be one of two voltage levels on a wire for a direct digital connection or it might be the phase or frequency of a carrier. The term "baud" was originally a unit of telegraph signalling speed, set at one Morse code dot per second. Or, more generally, the reciprocal of the duration of the shortest signalling element. It was proposed at the International Telegraph Conference of 1927, and named after J.M.E. Baudot (1845-1903), the French engineer who constructed the first 1 1 1 1 1 baud barf /bawd barf/ The garbage one gets on the display screen when using a modem connection with some protocol setting (especially line speed) incorrect, or when someone picks up a voice extension on the same line, or when really bad line noise disrupts the connection. Baud barf is not completely random, by the way; hackers with a lot of serial-line experience can usually tell whether the device at the other end is expecting a higher or lower speed than the terminal is set to. *Really* experienced ones can identify particular speeds. [Jargon File] (1996-02-22) 1 1 1 1 1 Baudot Jean-Maurice-Émile Baudot 1 1 1 1 1 Baudotbetical order /baw do bet' i k*l/ Sorted into an order where numerics and special characters are intermixed by sorting a 5-bit Baudot code file ignoring the numeric shift and unshift codes. (1997-02-11) 1 1 1 1 1 Baudot code (For etymology, see baud) A character set predating EBCDIC and used originally and primarily on paper tape. Use of Baudot reportedly survives in TDDs and some HAM radio applications. In Baudot, characters are expressed using five bits. Baudot uses two code sub-sets, the "letter set" (LTRS), and the figure set (FIGS). The FIGS character (11011) signals that the following code is to be interpreted as being in the FIGS set, until this is reset by the LTRS (11111) character. binary hex LTRS FIGS -------------------------- 00011 03 A - 11001 19 B ? 01110 0E C : 01001 09 D $ 00001 01 E 3 01101 0D F ! 1 1 1 1 1 baud rate baud 1 1 1 1 1 bawk An Awk-like string pattern matching language by Bob Brodt, distributed with MINIX. (1994-11-28) 1 1 1 1 1 bay (As in an aeroplane "cargo bay") A space in a cabinet into which a device of a certain size can be physically mounted and connected to power and data. Common examples are a "drive bay" into which a disk drive (usually either 3.5 inch or 5.25 inch) can be inserted or the space in a docking station where you insert a notebook computer or laptop computer to work as a desktop computer or to charge their batteries, print or connect to the office network, etc. (1999-01-11) 1 1 1 1 1 baz /baz/ The third metasyntactic variable "Suppose we have three functions: FOO, BAR, and BAZ. FOO calls BAR, which calls BAZ..." (See also fum). Occasionally appended to foo to produce "foobaz". Early versions of the Hacker Jargon dictionary derived "baz" as a Stanford corruption of bar. However, Pete Samson (compiler of the TMRC lexicon) reports it was already current when he joined TMRC in 1958. He says "It came from Pogo. Albert the Alligator, when vexed or outraged, would shout "Bazz Fazz!" or "Rowrbazzle!" The club layout was said to model the (mythical) New England counties of Rowrfolk and Bassex (Rowrbazzle mingled with Norfolk/Suffolk/Middlesex/ Essex)." [Jargon File] (2008-06-30) 1 1 1 1 1 bb The country code for Barbados. (1999-01-27) 1 1 1 1 1 BBC British Broadcasting Corporation 1 1 1 1 1 BBC Micro BBC Microcomputer 1 1 1 1 1 BBC Microcomputer A series of 6502-based personal computers launched by Acorn Computers Ltd. in January 1982, for use in the British Broadcasting Corporation's educational programmes on computing. The computers are noted for their reliability (many are still in active service in 1994) and both hardware and software were designed for easy expansion. The 6502-based computers were succeeded in 1987 by the Acorn Archimedes family. xbeeb is a BBC Micro emulator for Unix and X11. 1 1 1 1 1 BBC Networking Club A bulletin board run by the British Broadcasting Corporation Education department from April 1994 to 30 Nov 1995 (1997-01-20) 1 1 1 1 1 BBL (I will) be back later. 1 1 1 1 1 BBN Butterfly A supercomputer developed at BBN Technologies, named after the "butterfly" multi-stage switching network around which it was built. It could have up to 512 CPUs connected to allow every CPU access to every other CPU's memory, albeit with about 15 times the latency than for its own. The earlier GP-1000 models used up to 256 Motorola 68020s. The later TC-2000 models used up to 512 Motorola 88100s. Language developed for, or ported to, the BBN Butterfly were Butterfly Common LISP, Butterfly Scheme, Delirium, and MultiScheme. (http://paralogos.com/DeadSuper/Misc/BBN.html). (2003-11-10) 1 1 1 1 1 BBN Technologies A company, originally known as Bolt, Beranek and Newman, Inc. (BBN), based in Cambridge, Massachusetts, USA. BBN were awarded the original contract to build the ARPANET and have been extensively involved in Internet development. They are responsible for managing NNSC, CSNET, and NEARnet. The language LOGO was developed at BBN, as was the BBN Butterfly supercomputer. BBN Home (http://bbn.com/). (2003-11-10) 1 1 1 1 1 bboard bulletin board system 1 1 1 1 1 BBS bulletin board system 1 1 1 1 1 BC An arbitrary precision numeric processing language with C-like syntax. Traditionally implemented as a front-end to DC. There is a GNU version called GNU BC. Unix manual page: bc(1). 1 1 1 1 1 BCBF Branch on Chip Box Full 1 1 1 1 1 BCC 1. Blind Carbon Copy. 2. Block Check Character. 3. Blocked Call Cleared. 1 1 1 1 1 BCD binary coded decimal 1 1 1 1 1 BCL The successor to Atlas Commercial Language. ["The Provisional BCL Manual", D. Hendry, U London 1966]. 1 1 1 1 1 BC NELIAC Version of NELIAC, post 1962. Sammet 1969, p.197. 1 1 1 1 1 BCNU Be seein' you. 1 1 1 1 1 BCPL (Basic CPL) A British systems language developed by Richards in 1969 and descended from CPL (Combined Programming Language). BCPL is low-level, typeless and block-structured, and provides only one-dimensional arrays. Case is not significant, but conventionally reserved words begin with a capital. Flow control constructs include: If-Then, Test-Then-Else, Unless-Do, While-Do, Until-Do, Repeat, Repeatwhile, Repeatuntil, For-to-By-Do, Loop, Break and Switchon-Into-Case-Default-Endcase. BCPL has conditional expressions, pointers, and manifest constants. It has both procedures: 'Let foo(bar) Be command' and functions: 'Let foo(bar) = expression'. 'Valof $(..Resultis..$)' causes a compound command to produce a value. Parameters are call-by-value. Program segments communicate via the global vector where system and user variables are stored in fixed numerical locations in a single array. 1 1 1 1 1 BCS 1. British Computer Society. 2. Binary Compatibility Standard. 1 1 1 1 1 bd The country code for Bangladesh. (1999-01-27) 1 1 1 1 1 BDC Backup Domain Controller 1 1 1 1 1 BDL Block Diagram Compiler 1 1 1 1 1 BDPA Black Data Processing Associates 1 1 1 1 1 be The country code for Belgium. (1999-01-27) 1 1 1 1 1 BEA Basic programming Environment for interactive-graphical Applications, from Siemens-Nixdorf. 1 1 1 1 1 beam (From Star Trek Classic's "Beam me up, Scotty!") To transfer softcopy of a file electronically; most often in combining forms such as "beam me a copy" or "beam that over to his site". Compare blast, snarf, BLT. [Jargon File] (2009-06-09) 1 1 1 1 1 beamer A personal video station (PVS) that adds video to standard telephone lines at no additional cost. (1999-10-24) 1 1 1 1 1 beam search An optimisation of the best first search graph search algorithm where only a predetermined number of paths are kept as candidates. The number of paths is the "width of the beam". If more paths than this are generated, the worst paths are discarded. This reduces the space requirements of best first search. (2007-11-03) 1 1 1 1 1 bean JavaBeans 1 1 1 1 1 beanie key feature key 1 1 1 1 1 bearer channel Originally, a channel suited for carrying one voice-grade connection. Typically a DS0 channel. Compare data channel. (1997-03-7) 1 1 1 1 1 bear paw The Vulcan nerve pinch for SGI computers. The five key keyboard combination <left Ctrl><left Alt><left Shift><numeric keypad /><F12> resets the graphics subsystem, including the window manager. (1996-10-28) 1 1 1 1 1 Beats the shit outa me (BSOM) "I don't understand it". The last thing you say as you walk out on someone whose system you can't fix. (1998-06-15) 1 1 1 1 1 Bebo A social networking website based in California, USA. Bebo Home (http://bebo.com/). (2006-11-20) 1 1 1 1 1 BeBOP A language combining sequential and parallel logic programming, object-oriented and meta-level programming. Both don't know nondeterminism and stream AND-parallelism. Prolog theories are first order entities and may be updated or passed in messages. BeBOP is implemented by translation to NU-Prolog and PNU-Prolog. (ftp://munnari.oz.au/pub/bebop.tar.Z). E-mail: Andrew Davidson <ad@cs.mu.oz.au>. (1996-10-27) 1 1 1 1 1 BeBox A microcomputer produced by Be Inc, containing between two and eight PowerPCs (the initial model has two PPC 603s). The BeBox can take standard IBM PC peripherals, such as ISA and PCI cards, IDE and SCSI disks, and a standard PS/2 keyboard. Newsgroup: news:comp.sys.be. (http://be.com/). [Dates?] (1996-10-05) 1 1 1 1 1 BEDO Burst Extended Data Out DRAM 1 1 1 1 1 Bedrock A C++ class library for Macintosh user interface portability. 1 1 1 1 1 beep bell 1 1 1 1 1 beeper pager 1 1 1 1 1 BEG Back End Generator 1 1 1 1 1 BEGL Back End Generator 1 1 1 1 1 beige toaster Macintosh 1 1 1 1 1 Be Inc The company that produced the BeBox, founded by Jean-Louis Gassee, former product chief at Apple. (1996-10-05) 1 1 1 1 1 BEL bell 1 1 1 1 1 belief revision The area of theory change in which preservation of the information in the theory to be changed plays a key role. A fundamental issue in belief revision is how to decide what information to retract in order to maintain consistency, when the addition of a new belief to a theory would make it inconsistent. Usually, an ordering on the sentences of the theory is used to determine priorities among sentences, so that those with lower priority can be retracted. This ordering can be difficult to generate and maintain. The postulates of the AGM Theory for Belief Revision describe minimal properties a revision process should have. [Better definition?] (1995-03-20) 1 1 1 1 1 BELL An early system on the IBM 650 and Datatron 200 series. Versions: BELL L2, BELL L3. [Listed in CACM 2(5):16 (May 1959)]. [Is Datatron version the same?] (1994-12-06) 1 1 1 1 1 Bell Bell Telephone or Bell Laboratories. (1997-04-07) 1 1 1 1 1 bell ASCII 7, ASCII mnemonic "BEL", the character code which prodces a standard audibile warning from the computer or terminal. In the teletype days it really was a bell, since the advent of the VDU it is more likely to be a sound sample (e.g. the sound of a bell) played through a loudspeaker. Also called "G-bell", because it is typed as Control-G. The term "beep" is preferred among some microcomputer hobbyists. Compare feep, visible bell. (1997-04-08) 1 1 1 1 1 Bell 103 The original variant of V.21 created by AT&T when they had a telephone system monopoly in the USA. (1995-02-02) 1 1 1 1 1 Bell Communications Research, Inc (Bellcore) The research laboratory for the seven regional Bell Telephone companies in the USA that were created by the divestiture of AT&T in 1984. It can be compared to Bell Laboratories, for which many Bellcore employees used to work. Currently jointly owned by the seven baby bells (as they are called), there are rumours that it is to be sold by its current owners to become an independent research laboratory Its headquarters are in Livingstone, New Jersey. It has offices in Morristown, Lincroft, and Piscataway, all in New Jersey, USA. Telephone: +1 (201) 74 3000, +1 (800) 521 CORE. (1994-12-06) 1 1 1 1 1 Bellcore Bell Communications Research, Inc. 1 1 1 1 1 bell curve normal distribution 1 1 1 1 1 Bell Laboratories One of AT&T's research sites, in Murray Hill, New Jersey, USA. It was the birthplace of the transistor, Unix, C and C++ and the current home of research on Plan 9 and ODE. AT&T Research (http://research.att.com/). (ftp://ftp.research.att.com/). netlib sources (ftp://netlib.att.com). (1994-11-17) 1 1 1 1 1 Bell Labs Bell Laboratories 1 1 1 1 1 bells and whistles (By analogy with the "toyboxes" on theatre organs). Features added to a program or system to make it more flavourful from a hacker's point of view, without necessarily adding to its utility for its primary function. Distinguished from chrome, which is intended to attract users. "Now that we've got the basic program working, let's go back and add some bells and whistles." No one seems to know what distinguishes a bell from a whistle. [Jargon File] (2007-04-03) 1 1 1 1 1 bells, whistles, and gongs A standard elaborated form of bells and whistles; typically said with a pronounced and ironic accent on the "gongs". 1 1 1 1 1 benchmark A standard program or set of programs which can be run on different computers to give an inaccurate measure of their performance. "In the computer industry, there are three kinds of lies: lies, damn lies, and benchmarks." A benchmark may attempt to indicate the overall power of a system by including a "typical" mixture of programs or it may attempt to measure more specific aspects of performance, like graphics, I/O or computation (integer or floating-point). Others measure specific tasks like rendering polygons, reading and writing files or performing operations on matrices. The most useful kind of benchmark is one which is tailored to a user's own typical tasks. While no one benchmark can fully characterise overall system performance, the results of a variety of realistic benchmarks can give valuable insight into expected real performance. Benchmarks should be carefully interpreted, you should know exactly which benchmark was run (name, version); exactly what 1 1 1 1 1 Bend Over, Here It Comes Again (BOHICA) An utterance of frustration by computer support personnel who anticipate being told (usually via phone) to do something that can't be done, by a boss who doesn't know his ass from deep center field about what he's asking his minions to do. (1995-09-20) 1 1 1 1 1 Benoit B. Mandelbrot Benoit Mandelbrot 1 1 1 1 1 Benoit Mandelbrot /ben'wa man'dl-bro/ Benoit B. Mandelbrot. The IBM scientist who wrote several original books on fractals and gave his name to the set he was discovered, the Mandelbrot set and coined the term "fractal" in 1975 from the Latin fractus or "to break". (1997-07-02) 1 1 1 1 1 Bentley Systems, Inc. The company that sells MicroStation. Address: Exton, PA, USA. (http://bentley.com/). (2001-05-18) 1 1 1 1 1 BeOS The operating system originally designed to run on the BeBox microcomputer. BeOS is good at both multitasking and real-time operation. It has a bash command shell, with ports of many GNU programs by Be, Inc. It has a GUI front end (not X). A C++ compiler is supplied with the machine, and there are rumours of other languages being ported in the future. BeOs eventually became used on the x86 and standard PPC. Be, Inc. went bankrupt in 1999, after releasing the last upgrade of BeOS (R5.0.3), and was sold to Palm. Several groups are currently (2003) attempting to create an R6 version of the OS. The most likely to succeed are Yellowtab and OpenBeOS, which is likely to be renamed. (2003-05-30) 1 1 1 1 1 BER 1. <protocol, standard> Basic Encoding Rules. 2. <communications> Bit Error Rate. 1 1 1 1 1 Berard Object and Class Specifier (BOCS) An object-oriented CASE tool released by US company, Berard Software Engineering on 1993-07-05. BOCS helps users document and model a system and its underlying objects. It includes libraries to manage requirements, object and class specifications and graphical models. [Computerworld, 1993-07-05, p63]. (2015-06-17) 1 1 1 1 1 Berkeley University of California at Berkeley 1 1 1 1 1 Berkeley 4.2 Berkeley Software Distribution 1 1 1 1 1 Berkeley EDIF200 translator-building toolkit Wendell C. Baker and Prof A. Richard Newton of the Electronics Research Laboratory, Department of Electrical Engineering and Computer Sciences at the University of California, Berkeley. Version 7.6. Restriction: no-profit without permission. (ftp://ic.berkeley.edu/pub/edif). (1990-07-01) 1 1 1 1 1 Berkeley FP A version of Backus's FP distributed with 4.2BSD Unix. (ftp://apple.com/ArchiveVol1/Unix_lang). (1997-12-15) 1 1 1 1 1 Berkeley Internet Name Domain (BIND) An implementation of a DNS server developed and distributed by the University of California at Berkeley. Many Internet hosts run BIND, and it is the ancestor of many commercial implementations. (1997-12-15) 1 1 1 1 1 Berkeley Logo A Logo interpreter by Brian Harvey <bh@cs.berkeley.edu>. Berkeley Logo programs will run on Unix, IBM PC, or Macintosh. It doesn't do anything fancy about graphics and only allows one turtle. Version: 4.6, as of 2000-03-21. MswLogo is a Microsoft Windows front end. (ftp://anarres.cs.berkeley.edu/pub/ucblogo). (2000-03-28) 1 1 1 1 1 Berkeley Network (B-NET) Top level Unix Ethernet software developed at the University of California at Berkeley. There are no formal specifications but UCB's 4.2BSD Unix implementation on the VAX is the de facto standard. Distributed by Unisoft. Includes net.o driver routines for specific hardware, pseudo ttys, daemons, hostname command to set/get name, /etc/hosts database of names and Internet addresses of other hosts, /etc/hosts.equiv host-wide database to control remote access, .rhosts per user version of hosts.equiv. UCB's implementation of the Internet Protocol includes trailers to improve performance on paged memory management systems such as VAXen. These trailers are an exception to the Internet Protocol specification. 1 1 1 1 1 Berkeley Quality Software (Often abbreviated "BQS") Term used in a pejorative sense to refer to software that was apparently created by rather spaced-out hackers late at night to solve some unique problem. It usually has nonexistent, incomplete, or incorrect documentation, has been tested on at least two examples, and core dumps when anyone else attempts to use it. This term was frequently applied to early versions of the "dbx(1)" debugger. See also Berzerkeley. [Jargon File] (1996-01-15) 1 1 1 1 1 Berkeley Software Design, Inc (BSDI) A company that sells BSD/OS, a commercial version of Berkeley Standard Distribution Unix, networking, and Internet technologies originally developed by the Computer Systems Research Group (CSRG) at the University of California at Berkeley. Leading CSRG computer scientists founded BSDI in 1991. BSDI's BSD/OS represents over 20 years of development by the worldwide BSD technical community. BSD technology is known worldwide for its powerful, flexible and portable architecture and advanced development environments. BSDI designs, develops, markets, and supports the BSD/OS operating system, Internet server software for IBM PCs, and other products. BSDI planned to release an Internet gateway product for Novell IPX networks in 1995. (http://bsdi.com/). E-mail: <bsdi-info@bsdi.com>. Address: 5575 Tech Center Drive, #110, Colorado Springs, CO 1 1 1 1 1 Berkeley Software Distribution (BSD) A family of Unix versions developed by Bill Joy and others at the University of California at Berkeley, originally for the DEC VAX and PDP-11 computers, and subsequently ported to almost all modern general-purpose computers. BSD Unix incorporates paged virtual memory, TCP/IP networking enhancements and many other features. BSD UNIX 4.0 was released on 1980-10-19. The BSD versions (4.1, 4.2, and 4.3) and the commercial versions derived from them (SunOS, ULTRIX, Mt. Xinu, Dynix) held the technical lead in the Unix world until AT&T's successful standardisation efforts after about 1986, and are still widely popular. See also Berzerkeley, USG Unix. (2005-01-20) 1 1 1 1 1 Berkeley Softworks The company that wrote Graffiti and a similar scheme for the Commodore 64 (made it very Macintosh-like) and the Commodore 128 (which could multitask). (1995-01-24) 1 1 1 1 1 Berkeley Unix Berkeley Software Distribution 1 1 1 1 1 Berkeley Yacc (byacc, previously Zeus, then Zoo) Probably the best variant of the Yacc parser generator. Written by Robert Corbett <Robert.Corbett@eng.sun.com>. Latest version: 1.9, as of 2000-06-09. (ftp://ftp.cs.berkeley.edu/pub/4bsd/byacc.1.9.tar.Z). (2000-07-16) 1 1 1 1 1 berklix /berk'liks/ (From Berkeley Unix) Berkeley Software Distribution. Not used at Berkeley itself. May be more common among suits attempting to sound like cognoscenti than among hackers, who usually just say "BSD". [Jargon File] (1995-02-23) 1 1 1 1 1 Berners-Lee, Tim Tim Berners-Lee 1 1 1 1 1 Bernoulli Box A high capacity storage device, Iomega Corporation's first popular product, that spins a mylar disk over a read-write head using the Bernoulli principle. (1997-04-15) 1 1 1 1 1 Bernoulli principle (Or "air foil principle", after Swiss mathematician Daniel Bernoulli, 1700-1782) The law that pressure in a fluid decreases with the rate of flow. It has been applied to a class of hard disk drives. See Bernoulli Box. (1997-04-15) 1 1 1 1 1 Bernstein condition Processes cannot execute in parallel if one effects values used by the other. Nor can they execute in parallel if any subsequent process uses data effected by both, i.e. whose value might depend on the order of execution. (1995-02-23) 1 1 1 1 1 BERR bus error 1 1 1 1 1 Bertrand (Named after the British mathematician Bertrand Russell (1872-1970)). Wm. Leler. Rule-based specification language based on augmented term rewriting. Used to implement constraint languages. The user must explicitly specify the tree-search and the constraint propagation. (ftp://nexus.yorku.ca/pub/scheme/scm/bevan.shar). ["Constraint Programming Languages - Their Specification and Generation", W. Leler, A-W 1988, ISBN 0-201-06243-7]. 1 1 1 1 1 Bertrand Meyer The author of the Eiffel Language and many articles on object-oriented software techniques. (1995-03-01) 1 1 1 1 1 Bertrand Russell (1872-1970) A British mathematician, the discoverer of Russell's paradox. (1995-03-27) 1 1 1 1 1 Berzerkeley /b*r-zer'klee/ (From "berserk", via the name of a now-deceased record label) A humorous distortion of "Berkeley" used especially to refer to the practices or products of the BSD Unix hackers. See software bloat, Missed'em-five, Berkeley Quality Software. Mainstream use of this term in reference to the cultural and political peculiarities of UC Berkeley as a whole has been reported from as far back as the 1960s. [Jargon File] (1996-06-01) 1 1 1 1 1 Berzerkley Berzerkeley 1 1 1 1 1 bespoke custom 1 1 1 1 1 best effort A classification of low priority network traffic, used especially the Internet. Different kinds of traffic have different priorities. Videoconferencing and other types of real-time communication, for example, require a certain minimum guaranteed bandwidth and latency and so must be given a high priority. Electronic mail, on the other hand, can tolerate an arbitrarily long delay and is classified as a best-effort service. [Scientific American, Nov. 1994, pp. 83-84]. (1995-04-04) 1 1 1 1 1 best first search A graph search algorithm which optimises breadth first search by ordering all current paths according to some heuristic. The heuristic attempts to predict how close the end of a path is to a solution. Paths which are judged to be closer to a solution are extended first. See also beam search, hill climbing. (1995-12-09) 1 1 1 1 1 best fit A resource allocation scheme (usually for memory). Best Fit allocates resources in a way that optimises some parameter. Alternative schemes such as first fit or random allocation are likely to be quicker but sub-optimal in use of resources. For example, when allocating a new block of memory from a pool of free blocks (a heap), one might choose the smallest space which is big enough. This would leave larger spaces free to satisfy larger requests and reduce fragmentation of the remaining free space. (2015-01-31) 1 1 1 1 1 BETA Kristensen, Madsen <olmadsen@daimi.aau.dk>, Moller-Pedersen & Nygaard, 1983. Object-oriented language with block structure, coroutines, concurrency, strong typing, part objects, separate objects and classless objects. Central feature is a single abstraction mechanism called "patterns", a generalisation of classes, providing instantiation and hierarchical inheritance for all objects including procedures and processes. Mjolner Informatics ApS, Aarhus, implementations for Mac, Sun, HP, Apollo. E-mail: <info@mjolner.dk>. Mailing list: <usergroup@mjolner.dk>. ["Object-Oriented Programming in the BETA Programming Language", Ole Lehrmann et al, A-W June 1993, ISBN 0-201-62430-3]. [Jargon File] (1995-10-31) 1 1 1 1 1 beta /bay't*/, /be't*/ or (Commonwealth) /bee't*/ See beta conversion, beta test. [Jargon File] 1 1 1 1 1 beta abstraction [lambda-calculus] The conversion of an expression to an application of a lambda abstraction to an argument expression. Some subterm of the original expression becomes the argument of the abstraction and the rest becomes its body. E.g. 4+1 --> (\ x . x+1) 4 The opposite of beta abstraction is beta reduction. These are the two kinds of beta conversion. 1 1 1 1 1 beta conversion A term from lambda-calculus for beta reduction or beta abstraction. (1999-01-15) 1 1 1 1 1 Betamaxed When a technology is overtaken in the market by inferior but better marketed competition. E.g. "Microsoft betamaxed Apple right out of the market". The Betamex videotape standard lost to VHS. (1999-01-15) 1 1 1 1 1 beta reduction [lambda-calculus] The application of a lambda abstraction to an argument expression. A copy of the body of the lambda abstraction is made and occurrences of the bound variable being replaced by the argument. E.g. (\ x . x+1) 4 --> 4+1 Beta reduction is the only kind of reduction in the pure lambda-calculus. The opposite of beta reduction is beta abstraction. These are the two kinds of beta conversion. See also name capture. 1 1 1 1 1 beta test beta testing 1 1 1 1 1 beta testing Evaluation of a pre-release (potentially unreliable) version of a piece of software (or possibly hardware) by making it available to selected users ("beta testers") before it goes on general distribution. Beta testign aims to discover bugs that only occur in certain environments or under certain patterns of use, while reducing the volume of feedback to a manageable level. The testers benefit by having earlier access to new products, features and fixes. Beta testing may be preceded by "alpha testing", performed in-house by a handful of users (e.g. other developers or friends), who can be expected to give rapid, high quality feedback on design and usability. Once the product is considered to be usable for its intended purpose it then moves on to "beta testing" by a larger, but typically still limited, number of ordinary users, who may include external customers. Some companies such as Google or Degree Jungle (http://www.degreejungle.com/rankings/best-online-colleges) 1 1 1 1 1 beta version beta testing 1 1 1 1 1 Bezier (After Frenchman Pierre Bézier from Regie Renault) A collection of formulae for describing curved lines (Bezier curve) and surfaces (Bezier surface), first used in 1972 to model automobile surfaces. Curves and surfaces are defined by a set of "control points" which can be moved interactively making Bezier curves and surfaces convenient for interactive graphic design. ["Principles of interactive computer graphics", William M. Newman, Graw-Hill]. (1995-04-04) 1 1 1 1 1 Bezier curve A type of curve defined by mathematical formulae, used in computer graphics. A curve with coordinates P(u), where u varies from 0 at one end of the curve to 1 at the other, is defined by a set of n+1 "control points" (X(i), Y(i), Z(i)) for i = 0 to n. P(u) = Sum i=0..n [(X(i), Y(i), Z(i)) * B(i, n, u)] B(i, n, u) = C(n, i) * u^i * (1-u)^(n-i) C(n, i) = n!/i!/(n-i)! A Bezier curve (or surface) is defined by its control points, which makes it invariant under any affine mapping (translation, rotation, parallel projection), and thus even under a change in the axis system. You need only to transform the control points and then compute the new curve. The control polygon defined by the points is itself affine 1 1 1 1 1 Bezier surface A surface defined by mathematical formulae, used in computer graphics. A surface P(u, v), where u and v vary orthogonally from 0 to 1 from one edge of the surface to the other, is defined by a set of (n+1)*(m+1) "control points" (X(i, j), Y(i, j), Z(i, j)) for i = 0 to n, j = 0 to m. P(u, v) = Sum i=0..n Sum j=0..m [ (X(i, j), Y(i, j), Z(i, j)) * B(i, n, u) * B(j, m, v)] B(i, n, u) = C(n, i) * u^i * (1-u)^(n-i) C(n, i) = n!/i!/(n-i)! 1 1 1 1 1 bf The country code for Burkina Faso. (1999-01-27) 1 1 1 1 1 BFI brute force and ignorance 1 1 1 1 1 bg The country code for Bulgaria. (1999-01-27) 1 1 1 1 1 BGA Ball Grid Array 1 1 1 1 1 bgh Be Good Humans. (2001-03-28) 1 1 1 1 1 BGP Border Gateway Protocol 1 1 1 1 1 bh The country code for Bahrain. (1999-01-27) 1 1 1 1 1 BHC Code Bose-Chaudhuri-Hocquenghem Code 1 1 1 1 1 bi The country code for Burundi. (1999-01-27) 1 1 1 1 1 bib BibTeX 1 1 1 1 1 bible The most detailed and authoritative reference for a particular language, operating system or other complex software system. It is also used to denote one of a small number of such books such as Knuth and K&R. [Jargon File] (1996-12-03) 1 1 1 1 1 BIBOP Big bag of pages 1 1 1 1 1 BibTeX A Tex extension package for bibliographic citations, distributed with LaTeX. BibTeX uses a style-independent bibliography database (.bib file) to produce a list of sources, in a customisable style, from citations in a Latex document. It also supports some other formats. BibTeX is a separate program from LaTeX. LaTeX writes information about citations and which .bib files to use in a .aux file. BibTeX reads this file and outputs a ".bbl" file containing LaTeX commands to produce the source list. You must then run LaTeX again to incorporate the source list in your document. In typeset documents, "BibTeX" is written in upper case, with the "IB" slightly smaller and with the "E" as a subscript. BibTeX is described in the LaTeX book by Lamport. 1 1 1 1 1 BiCapitalisation The act said to have been performed on trademarks (such as PostScript, NeXT, NeWS, VisiCalc, FrameMaker, TK!solver, EasyWriter) that have been raised above the ruck of common coinage by nonstandard capitalisation. Too many marketroid types think this sort of thing is really cute, even the 2,317th time they do it. Compare studlycaps. (1995-02-23) 1 1 1 1 1 BiCMOS A manufacturing process for semiconductor devices that combines bipolar and CMOS to give the best balance between available output current and power consumption. (1995-03-28) 1 1 1 1 1 bidirectional printing A feature of a printer whose printer head can print both when moving left to right and when moving right to left. Also known as "boustrophedonic". (1995-04-13) 1 1 1 1 1 Bidouilleurs Sans Argent (BSA, French for "Moneyless Hackers") An association which aim is to help computer users who can't afford to buy commercial software. The main purpose of the association is the promotion of free software, and distribution of ex-commercial software. This is clearly an answer to the repressive attitude of the "other" BSA. Among BSA members are Richard Stallman, creator of the GNU project. (http://bsa.lu/). (1998-10-27) 1 1 1 1 1 bi-endian Silicon schizophrenia. Processors and other chips that have can be switched to work in big-endian or little-endian mode. The PowerPC chip has this ability, which allows it to run the little-endian Windows NT, or the big-endian Mac OS/PPC. (1995-02-23) 1 1 1 1 1 BIFF /bif/ (Or "B1FF", from Usenet) The most famous pseudo, and the prototypical newbie. Articles from BIFF are characterised by all uppercase letters sprinkled liberally with bangs, typos, "cute" misspellings (EVRY BUDY LUVS GOOD OLD BIFF CUZ HE'S A K00L DOOD AN HE RITES REEL AWESUM THINGZ IN CAPITULL LETTRS LIKE THIS!!!), use (and often misuse) of fragments of chat abbreviations, a long sig block (sometimes even a doubled sig), and unbounded naivete. BIFF posts articles using his elder brother's VIC-20. BIFF's location is a mystery, as his articles appear to come from a variety of sites. However, BITNET seems to be the most frequent origin. The theory that BIFF is a denizen of BITNET is supported by BIFF's (unfortunately invalid) electronic mail address: <BIFF@BIT.NET>. [1993: Now It Can Be Told! My spies inform me that BIFF was originally created by Joe Talmadge <jat@cup.hp.com>, also the author of the infamous and much-plagiarised "Flamer's Bible". 1 1 1 1 1 biff /bif/ To notify someone of incoming mail. From the BSD utility "biff(1)", which was in turn named after a friendly golden Labrador who used to chase frisbees in the halls at UCB while 4.2BSD was in development (it had a well-known habit of barking whenever the mailman came). No relation to BIFF. [Jargon File] 1 1 1 1 1 Big bag of pages (BIBOP) Where data objects are tagged with some kind of descriptor (giving their size or type for example) memory can be saved by storing objects with the same descriptor in one page of memory. The most significant bits of an object's address are used as the BIBOP page number. This is looked up in a BIBOP table to find the descriptor for all objects in that page. This idea is similar to the "zones" used in some Lisp systems (e.g. LeLisp). [David R. Hanson. "A portable storage management system for the Icon programming language". Software - Practise and Experience, 10:489-500 1980]. (1994-11-29) 1 1 1 1 1 big blue International Business Machines 1 1 1 1 1 big-endian 1. <data, architecture> A computer architecture in which, within a given multi-byte numeric representation, the most significant byte has the lowest address (the word is stored big-end-first). Most processors, including the IBM 370 family, the PDP-10, the Motorola microprocessor families, and most of the various RISC designs current in mid-1993, are big-endian. See -endian. 2. <networking, standard> A backward electronic mail address. The world now follows the Internet hostname standard (see FQDN) and writes e-mail addresses starting with the name of the computer and ending up with the country code (e.g. fred@doc.acme.ac.uk). In the United Kingdom the Joint Networking Team decided to do it the other way round (e.g. me@uk.ac.wigan.cs) before the Internet domain standard was established. Most gateway sites required ad-hockery in their mailers to handle this. 1 1 1 1 1 Big Gray Wall What faces a VMS user searching for documentation. A full VMS kit comes on a pallet, the documentation taking up around 15 feet of shelf space before the addition of layered products such as compilers, databases, multi-vendor networking, and programming tools. Recent (since VMS version 5) DEC documentation comes with grey binders; under VMS version 4 the binders were orange and under version 3 they were blue. Often contracted to "Gray Wall". [Jargon File] (1995-03-07) 1 1 1 1 1 big iron (Or "heavy metal [Cambridge]) Large, expensive, ultra-fast computers. Used generally of number crunching supercomputers such as Crays, but can include more conventional big commercial IBMish mainframes. The term implies approval, in contrast to "dinosaur". [Jargon File] (2000-11-09) 1 1 1 1 1 BIG-LAN ["BIG-LAN Frequently Asked Questions Memo", BIG-LAN DIGEST V4:I8, February 14, 1992.] 1 1 1 1 1 Bigloo A Scheme interpreter, compiler and run-time system by Manuel Serrano <Manuel.Serrano@inria.fr> which aims to deliver small, fast stand-alone applications. It supports modules and optimisation. Bigloo's features enable Scheme programs to be used where C or C++ might usually be required. The Bigloo compiler produces ANSI C which is compiled into stand-alone executables, JVM bytecode, or .NET bytecode. Hence Bigloo enables Scheme programs to interwork with C, Java and C# programs. Bigloo conforms to the IEEE Scheme standard with some extensions for regular expression handling. It runs on Sun, Sony News, SGI, Linux, HP-UX and is easy to port to any Unix system. Latest version: 2.6f, as of 2005-03-29. Bigloo Home (http://www-sop.inria.fr/mimosa/fp/Bigloo/). (2005-04-05) 1 1 1 1 1 bignum /big'nuhm/ (Originally from MIT MacLISP) A multiple-precision computer representation for very large integers. Most computer languages provide a type of data called integer, but such computer integers are usually limited in size; usually they must be smaller than 2^31 (2,147,483,648) or (on a bitty box) 2^15 (32,768). If you want to work with numbers larger than that, you have to use floating-point numbers, which are usually accurate to only six or seven decimal places. Computer languages that provide bignums can perform exact calculations on very large numbers, such as 1000! (the factorial of 1000, which is 1000 times 999 times 998 times ... times 2 times 1). For example, this value for 1000! was computed by the MacLISP system using bignums: 4.02387E+49 4.63254E+49 4.79989E+47 1 1 1 1 1 bigot A person who is religiously attached to a particular computer, language, operating system, editor, or other tool (see religious issues). Usually found with a specifier; thus, Cray bigot, "ITS bigot", "APL bigot", "VMS bigot", "Berkeley bigot". Real bigots can be distinguished from mere partisans or zealots by the fact that they refuse to learn alternatives even when the march of time and/or technology is threatening to obsolete the favoured tool. It is truly said "You can tell a bigot, but you can't tell him much." Compare weenie. [Jargon File] 1 1 1 1 1 Big Red Switch (BRS) IBM jargon for the power switch on a computer, especially the "Emergency Pull" switch on an IBM mainframe or the power switch on an IBM PC where it really is large and red. "This !@%$% bitty box is hung again; time to hit the Big Red Switch." It is alleged that the emergency pull switch on an IBM 360/91 actually fired a non-conducting bolt into the main power feed; the BRSes on more recent mainframes physically drop a block into place so that they can't be pushed back in. People get fired for pulling them, especially inappropriately (see also molly-guard). Compare power cycle, three-finger salute, 120 reset; see also scram switch. [Jargon File] (2014-08-10) 1 1 1 1 1 Big Room The extremely large room with the blue ceiling and intensely bright light (during the day) or black ceiling with lots of tiny night-lights (during the night) found outside all computer installations. "He can't come to the phone right now, he's somewhere out in the Big Room." (1996-03-04) 1 1 1 1 1 big win An MIT term for a Good Thing or a lucky accident. [Jargon File] (1996-03-06) 1 1 1 1 1 bijection A function is bijective or a bijection or a one-to-one correspondence if it is both injective (no two values map to the same value) and surjective (for every element of the codomain there is some element of the domain which maps to it). I.e. there is exactly one element of the domain which maps to each element of the codomain. For a general bijection f from the set A to the set B: f'(f(a)) = a where a is in A and f(f'(b)) = b where b is in B. A and B could be disjoint sets. See also injection, surjection, isomorphism, permutation. (2001-05-10) 1 1 1 1 1 Bill Gates William Henry Gates III, Chief Executive Officer of Microsoft, which he co-founded in 1975 with Paul Allen. In 1994 Gates is a billionaire, worth $9.35b and Microsoft is worth about $27b. He was a computer nerd who dropped out of Harvard and one of the first programmers to oppose software piracy ("Open Letter to Hobbyists," Computer Notes, February 3, 1976). (1995-03-02) 1 1 1 1 1 Bill Joy William Joy 1 1 1 1 1 binaries binary file 1 1 1 1 1 binary 1. <mathematics> Base two. A number representation consisting of zeros and ones used by practically all computers because of its ease of implementation using digital electronics and Boolean algebra. 2. <file format> binary file. 3. <programming> A description of an operator which takes two arguments. See also unary, ternary. (2005-02-21) 1 1 1 1 1 binary coded decimal (BCD, packed decimal) A number representation where a number is expressed as a sequence of decimal digits and then each decimal digit is encoded as a four-bit binary number (a nibble). E.g. decimal 92 would be encoded as the eight-bit sequence 1001 0010. In some cases, the right-most nibble contains the sign (positive or negative). It is easier to convert decimal numbers to and from BCD than binary and, though BCD is often converted to binary for arithmetic processing, it is possible to build hardware that operates directly on BCD. [Do calculators use BCD?] (2001-01-27) 1 1 1 1 1 Binary Compatibility Standard (BCS) The ABI of 88open. (1997-07-03) 1 1 1 1 1 binary counter A digital circuit which has a clock input and a number of count outputs which give the number of clock cycles. The output may change either on rising or falling clock edges. The circuit may also have a reset input which sets all outputs to zero when asserted. The counter may be either a synchronous counter or a ripple counter. (1997-07-03) 1 1 1 1 1 binary data binary file 1 1 1 1 1 binary exponential backoff An algorithm for dealing with contention in the use of a network. To transmit a packet the host sets a local parameter, L to 1 and transmits in one of the next L slots. If a collision occurs, it doubles L and repeats. 1 1 1 1 1 binary file Any file format for digital data that does not consist of a sequence of printable characters (text). The term is often used for executable machine code. All digital data, including characters, is actually binary data (unless it uses some (rare) system with more than two discrete levels) but the distinction between binary and text is well established. On modern operating systems a text file is simply a binary file that happens to contain only printable characters, but some older systems distinguish the two file types, requiring programs to handle them differently. A common class of binary files is programs in machine language ("executable files") ready to load into memory and execute. Binary files may also be used to store data output by a program, and intended to be read by that or another program but not by humans. Binary files are more efficient for this purpose because the data (e.g. numerical data) does not need to be converted between the binary form used by the 1 1 1 1 1 binary large object (BLOB) A large block of data stored in a database, such as an image or sound file. A BLOB has no structure which can be interpreted by the database management system but is known only by its size and location. (1997-11-04) 1 1 1 1 1 binary package An archive file that contains all files and directories that must be installed in order to make a working installation of the program(s) included in the package, and the maintainer scripts necessary for the installation. A binary package is usually specific to a certain platform, in contrast to a source package. (2001-01-27) 1 1 1 1 1 binary prefix (Or "IEC prefix") A prefix used with a unit of data to mean multiplication by a power of 1024. Binary prefixes are most often used with "byte" (e.g. "kilobyte") but also with bit (e.g. "megabit"). For example, the term kilobyte has historically been used to mean 1024 bytes, and megabyte to mean 1,048,576 bytes. The multipliers 1024 and 1,048,576 are powers of 1024, which is itself a power of two (1024 = 2^10). It is this factor of two that gives the name "binary prefix". This is in contrast to a decimal prefix denoting a power of 1000, which is itself a power of ten (1000 = 10^3). Decimal prefixes are used in science and engineering and are specified in widely adopted SI standards. Note that the actual prefix - kilo or mega - is the same, it is the interpretation that differs. The difference between the two interpretations increases with each multiplication, so while 1000 and 1024 differ by only 2.4%, 1000^6 and 1024^6 differ by 15%. 1 1 1 1 1 binary search A search algorithm which repeatedly divides an ordered search space in half according to how the required (key) value compares with the middle element. The following pseudo-C routine performs a binary search return the index of the element of vector "thing[first..last]" equal to "target": if (target < thing[first] || target > thing[last]) return NOT_FOUND; while (first < last) mid = (first+last)/2; /* truncate to integer */ if (target == thing[mid]) return mid; if (target < thing[mid]) last = mid-1; else 1 1 1 1 1 Binary Synchronous Transmission (Bisynch) An IBM link protocol, developed in the 1960 and popular in the 1970s and 1980s. Binary Synchronous Transmission has been largely replaced in IBM environments with SDLC. Bisync was developed for batch communications between a System 360 computer and the IBM 2780 and 3780 Remote Job Entry (RJE) terminals. It supports RJE and on-line terminals in the CICS/VSE environment. It operates with EBCDIC or ASCII character sets. It requires that every message be acknowledged (ACK) or negatively acknowledged (NACK) so it has high transmission overhead. It is typically character oriented and half-duplex, although some of the bisync protocol flavours or dialects support binary transmission and full-duplex operation. (1997-01-07) 1 1 1 1 1 binary tree (btree) A tree in which each node has at most two successors or child nodes. In Haskell this could be represented as data BTree a = NilTree | Node a (BTree a) (BTree a) See also balanced tree. (1994-11-29) 1 1 1 1 1 BIND Berkeley Internet Name Domain 1 1 1 1 1 bindery A Novell Netware database that contains definitions for entities such as users, groups, and workgroups. The bindery allows the network supervisor to design an organised and secure operating environment based on the individual requirements of each of these entities. The bindery has three components: objects, properties, and property data sets. Objects represent any physical or logical entity, including users, user groups, file servers. Properties are characteristics of each object (e.g. passwords, account restrictions, internetwork addresses). Property data sets are the values assigned to an entity's bindery properties. [Netware Version 3.11 "Concepts" documentation (a glossary of Netware-related terms)]. (1996-03-07) 1 1 1 1 1 binding handle An identifier representing the connection between a client and server. An association between client/server end-points and protocols. (1997-03-18) 1 1 1 1 1 binding-time analysis An analysis to identify sub-expressions which can be evaluated at compile-time or where versions of a function can be generated and called which are specialised to certain values of one or more arguments. See partial evaluation. (1995-03-28) 1 1 1 1 1 BinHex A Macintosh format for representing a binary file using only printable characters. The file is converted to lines of letters, numbers and punctuation. Because BinHex files are simply text they can be sent through most electronic mail systems and stored on most computers. However the conversion to text makes the file larger, so it takes longer to transmit a file in BinHex format than if the file was represented some other way. Filename extension: .hqx. See also BinHex 4.0, uuencode. [Encoding algorithm?] (1994-11-30) 1 1 1 1 1 Binhex 4.0 A seven bit wide representation of a Macintosh file with CRC error checking. Binhex 4.0 files are designed for communication of Mac files over long distance, possibly noisy, seven bit wide paths. [Difference from other binhex formats?] (1996-09-17) 1 1 1 1 1 BinProlog Probably the fastest freely available C-emulated Prolog. BinProlog features: logical and permanent global variables; backtrackable destructive assignment; circular term unification; extended DCGs (now built into the engine as "invisible grammars"); intuitionistic and linear implication based hypothetical reasoning; a Tcl/Tk interface. Version 3.30 runs on SPARC/Solaris 2.x, SunOS 4.x; DEC Alpha 64-bit version; DEC MIPS; SGI MIPS; 68k - NeXT, Sun-3; IBM RS6000; HP PA-RISC (two variants); Intel 80386, Intel 486/Linux, MS-DOS, Microsoft Windows 3.1 (with DOS-extender go32 v1.10). Multi-BinProlog is a multi-threaded Linda-style parallel extension to BinProlog for Solaris 2.3. (ftp://clement.info.umoncton.ca/BinProlog/). E-mail: Paul Tarau <tarau@info.umoncton.ca>. (1995-04-04) 1 1 1 1 1 bioinformatics The field of science concerning the application of computer science and information technology to biology; using computers to handle biological information, especially computational molecular biology. (2005-01-07) 1 1 1 1 1 BioMeDical Package (BMDP) A statistical language and library of over forty statistical routines developed in 1961 at UCLA, Health Sciences Computing Facility under Dr. Wilford Dixon. BMDP was first implemented in Fortran for the IBM 7090. Tapes of the original source were distributed for free all over the world. BMDP is the second iteration of the original BIMED programs. It was developed at UCLA Health Sciences Computing facility, with NIH funding. The "P" in BMDP originally stood for parameter but was later changed to "package". BMDP used keyword parameters to defined what was to be done rather than the fixed card format used by original BIMED programs. BMDP supports many statistical funtions: simple data description, survival analysis, ANOVA, multivariate analyses, regression analysis, and time series analysis. BMDP Professional combines the full suite of BMDP Classic (Dynamic) release 7.0 with the BMDP New System 2.0 Windows 1 1 1 1 1 biometric device biometrics 1 1 1 1 1 biometrics The use of special input devices to analyse some physical parameter assumed to be unique to an individual, in order to confirm their identity as part of an authentication procedure. Examples include fingerprint scanning, iris recognition, facial recognition, voice recognition (speaker recognition), signature, vascular pattern recognition. (http://www.findbiometrics.com/Pages/guide2.html). (2007-02-22) 1 1 1 1 1 BIOR An early system on UNIVAC I or II. [Listed in CACM 2(5):16 (May 1959)]. (1995-04-01) 1 1 1 1 1 BIOS Basic Input/Output System 1 1 1 1 1 BIP An incorrect singular of BIPS. One billion instructions per second is 1 BIPS, not 1 BIP. 1 1 1 1 1 bipartite graph complete graph 1 1 1 1 1 BIPM Bureau International des Poids et Mesures 1 1 1 1 1 bipolar 1. <electronics> See bipolar transistor. 2. <communications> In digital transmission, an electrical line signalling method where the mark value alternates between positive and negative polarities. See also AMI. (1995-03-02) 1 1 1 1 1 bipolar transistor A transistor made from a sandwich of n- and p-type semiconductor material: either npn or pnp. The middle section is known as the "base" and the other two as the collector and "emitter". When used as an amplifying element, the base to emitter junction is in a "forward-biased" (conducting) condition, and the base to collector junction is reverse-biased or non-conducting. Small changes in the base to emitter current (the input signal) cause either holes (for pnp devices) or free electrons (for npn) to enter the base from the emitter. The attracting voltage of the collector causes the majority of these charges to cross into and be collected by the collector, resulting in amplification. Contrast field effect transistor. (1995-10-04) 1 1 1 1 1 BIPS Billion (10^9) instructions per second. Same as GIPS. 1 1 1 1 1 Bird-Meertens Formalism (BMF) (Or "Squiggol") A calculus for derivation of functional programs from a specification. It consists of a set of higher-order functions that operate on lists including map, fold, scan, filter, inits, tails, cross product and function composition. ["A Calculus of Functions for Program Derivation", R.S. Bird, in Res Topics in Fnl Prog, D. Turner ed, A-W 1990]. ["The Squiggolist", ed Johan Jeuring, published irregularly by CWI Amsterdam]. (1995-05-01) 1 1 1 1 1 Birds Of a Feather (BOF) (From the saying "Birds of a feather flock together") An informal discussion group, scheduled on a conference program or formed ad hoc, to consider a specific issue or subject. It is not clear where or when this term originated, but it is now associated with the USENIX conferences for Unix techies and was already established there by 1984. It was used earlier than that at DECUS conferences and is reported to have been common at SHARE meetings as far back as the early 1960s. (1994-10-11) 1 1 1 1 1 BISDN Broadband Integrated Services Digital Network. 1 1 1 1 1 Bison GNU's replacement for the yacc parser generator. Bison runs under Unix and on Atari computers. It was written by Robert Corbett. Latest version: 1.28, as of 2000-05-22. As of version 1.24, Bison will no longer apply the GNU General Public License to your code. You can use the output files without restriction. FTP GNU.org (ftp://ftp.gnu.org/gnu/bison/) or your nearest GNU archive site. E-mail: <bug-bison@gnu.org>. Bison++ is a version which produces C++ output. (2000-07-05) 1 1 1 1 1 Bison++ GNU's Yacc parser generator retargeted to C++ by Alain Coetmeur <coetmeur@icdc.fr>. Version 1.04. (ftp://iecc.com/pub/file/bison++.tar.gz). (ftp://iecc.com/pub/file/misc++.tar.gz). (ftp://psuvax1.cs.psu.edu/pub/src/gnu/bison++-1.04.tar.Z). (1993-07-08) 1 1 1 1 1 BIST Built-in Self Test 1 1 1 1 1 bisync Binary Synchronous Transmission 1 1 1 1 1 bit (b) binary digit. The unit of information; the amount of information obtained by asking a yes-or-no question; a computational quantity that can take on one of two values, such as false and true or 0 and 1; the smallest unit of storage - sufficient to hold one bit. A bit is said to be "set" if its value is true or 1, and reset or "clear" if its value is false or 0. One speaks of setting and clearing bits. To toggle or "invert" a bit is to change it, either from 0 to 1 or from 1 to 0. The term "bit" first appeared in print in the computer-science sense in 1949, and seems to have been coined by the eminent statistician, John Tukey. Tukey records that it evolved over a lunch table as a handier alternative to "bigit" or binit. See also flag, trit, mode bit, byte, word. [Jargon File] (2002-01-22) 1 1 1 1 1 bit bang Transmission of data on a serial line accomplished by rapidly changing a single output bit, in software, at the appropriate times. The technique is a simple loop with eight OUT and SHIFT instruction pairs for each byte. Input is more interesting. And full-duplex (doing input and output at the same time) is one way to separate the real hackers from the wannabees. Bit bang was used on certain early models of Prime computers, presumably when UARTs were too expensive, and on archaic Zilog Z80 micros with a Zilog PIO but no SIO. In an interesting instance of the cycle of reincarnation, this technique is now (1991) coming back into use on some RISC architectures because it consumes such an infinitesimal part of the processor that it actually makes sense not to have a UART. [Jargon File] 1 1 1 1 1 bit bashing (Also "bit diddling" or bit twiddling). Any of several kinds of low-level programming characterised by manipulation of bit, flag, nibble, and other smaller-than-character-sized pieces of data. These include low-level device control, encryption algorithms, checksum and error-correcting codes, hash functions, some flavours of graphics programming (see bitblt), and assembler/compiler code generation. May connote either tedium or a real technical challenge (more usually the former). "The command decoding for the new tape driver looks pretty solid but the bit-bashing for the control registers still has bugs." See also bit bang, mode bit. 1 1 1 1 1 bitblt /bit'blit/ [BLT] 1. Any of a family of closely related algorithms for moving and copying rectangles of bits between main and display memory on a bit-mapped device, or between two areas of either main or display memory (the requirement to do the Right Thing in the case of overlapping source and destination rectangles is what makes BitBlt tricky). 2. blit, BLT. [Jargon File] 1 1 1 1 1 bit bucket 1. (Or "write-only memory", "WOM") The universal data sink (originally, the mythical receptacle used to catch bits when they fall off the end of a register during a shift instruction). Discarded, lost, or destroyed data is said to have "gone to the bit bucket". On Unix, often used for /dev/null. Sometimes amplified as "the Great Bit Bucket in the Sky". 2. The place where all lost mail and news messages eventually go. The selection is performed according to Finagle's Law; important mail is much more likely to end up in the bit bucket than junk mail, which has an almost 100% probability of getting delivered. Routing to the bit bucket is automatically performed by mail-transfer agents, news systems, and the lower layers of the network. 3. The ideal location for all unwanted mail responses: "Flames about this article to the bit bucket." Such a request is guaranteed to overflow one's mailbox with flames. 1 1 1 1 1 bit decay bit rot 1 1 1 1 1 bit diddling bit bashing 1 1 1 1 1 bite byte 1 1 1 1 1 Bit Error Rate (BER) The fraction of a message or block of data that is wrong. (2003-03-25) 1 1 1 1 1 bit field Part of an item of data, storage location or message, identified as a certain number of contiguous bits starting at a certain bit position within the data. Bit position zero is usually the least significant bit. For example, in an ARM machine code instruction the four-bit field at bits 28 to 31 (the four most significant bits in the 32-bit word) is the "condition code". (2007-03-26) 1 1 1 1 1 bitmap A data file or structure which corresponds bit for bit with an image displayed on a screen, probably in the same format as it would be stored in the display's video memory or maybe as a device independent bitmap. A bitmap is characterised by the width and height of the image in pixels and the number of bits per pixel which determines the number of shades of grey or colours it can represent. A bitmap representing a coloured image (a pixmap) will usually have pixels with between one and eight bits for each of the red, green, and blue components, though other colour encodings are also used. The green component sometimes has more bits that the other two to cater for the human eye's greater discrimination in this component. See also vector graphics, image formats. (1996-09-21) 1 1 1 1 1 bitmap display A computer output device where each pixel displayed on the monitor screen corresponds directly to one or more bits in the computer's video memory. Such a display can be updated extremely rapidly since changing a pixel involves only a single processor write to memory compared with a terminal or VDU connected via a serial line where the speed of the serial line limits the speed at which the display can be changed. Most modern personal computers and workstations have bitmap displays, allowing the efficient use of graphical user interfaces, interactive graphics and a choice of on-screen fonts. Some more expensive systems still delegate graphics operations to dedicated hardware such as graphics accelerators. The bitmap display might be traced back to the earliest days of computing when the Manchester University Mark I(?) computer, developed by F.C. Williams and T. Kilburn shortly 1 1 1 1 1 bitmap font A font where each character is stored as an array of pixels (a bitmap). Such fonts are not easily scalable, in contrast to vectored fonts (like those used in PostScript). [Examples?] (1995-02-16) 1 1 1 1 1 bitmapped display bitmap display 1 1 1 1 1 bit mask A pattern of binary values which is combined with some value using bitwise AND with the result that bits in the value in positions where the mask is zero are also set to zero. For example, if, in C, we want to test if bits 0 or 2 of x are set, we can write int mask = 5; /* binary 101 */ if (x & mask) ... A bit mask might also be used to set certain bits using bitwise OR, or to invert them using bitwise exclusive OR. (1995-05-12) 1 1 1 1 1 BITNET /bit'net/ (Because It's Time NETwork) An academic and research computer network connecting approximately 2500 computers. BITNET provides interactive, electronic mail and file transfer services, using a store and forward protocol, based on IBM Network Job Entry protocols. Bitnet-II encapsulates the Bitnet protocol within IP packets and depends on the Internet to route them. BITNET traffic and Internet traffic are exchanged via several gateway hosts. BITNET is now operated by CREN. BITNET is everybody's least favourite piece of the network. The BITNET hosts are a collection of IBM dinosaurs, VAXen (with lobotomised communications hardware), and Prime Computer supermini computers. They communicate using 80-character EBCDIC card images (see eighty-column mind); thus, they tend to mangle the headers and text of third-party traffic from the rest of the ASCII/RFC 822 1 1 1 1 1 bitonal image An image consisting only of a foreground colour and a background colour. Compare monochrome. (1998-03-14) 1 1 1 1 1 bit-paired keyboard (Obsolete, or "bit-shift keyboard") A non-standard keyboard layout that seems to have originated with the Teletype ASR-33 and remained common for several years on early computer equipment. The ASR-33 was a mechanical device (see EOU), so the only way to generate the character codes from keystrokes was by some physical linkage. The design of the ASR-33 assigned each character key a basic pattern that could be modified by flipping bits if the SHIFT or the CTRL key was pressed. In order to avoid making the thing more of a Rube Goldberg kluge than it already was, the design had to group characters that shared the same basic bit pattern on one key. Looking at the ASCII chart, we find: high low bits bits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 010 ! " # $ % & ' ( ) 011 0 1 2 3 4 5 6 7 8 9 This is why the characters !"#$%&'() appear where they do on a 1 1 1 1 1 bit pattern A sequence of bits, in a memory, a communications channel or some other device. The term is used to contrast this with some higher level interpretation of the bits such as an integer or an image. A bit string is similar but suggests an arbitrary, as opposed to predetermined, length. (1998-09-27) 1 1 1 1 1 bit plane (Or "bitplane") The memory in a graphic display device which holds a complete one-bit-per-pixel image. Several bit planes may be used in conjunction to give more bits per pixel or to overlay several images or mask one with another. Bit plane may be used as a synonym for "bitmap", though the latter suggests the data itself rather than the memory and also suggests a graphics file format. (1997-03-16) 1 1 1 1 1 bit rate (Or "bitrate") A data rate expressed in bits per second. This is a similar to baud but the latter is more applicable to channels with more than two states. The common units of bit rate are kilobits per second (Kbps) and megabits per second (Mbps). In data rates, the multipliers "k", "M", etc. stand for powers of 1000 not powers of 1024. The term is also commonly used when discussing digital sampling and sample rates. For example, the MP3 audio compaction algorithm is often set to ouput files with a bitrate of 120 kbps. This means that the file contains an average of 120 kilobits for each second of audio (900 KB per minute). This compares with CD audio which is encoded at 44100 16-bit stereo samples per second or 1408 kbps. (2003-05-19) 1 1 1 1 1 bit-robbing in-band signalling 1 1 1 1 1 bit rot A hypothetical disease the existence of which has been deduced from the observation that unused programs or features will often stop working after sufficient time has passed, even if "nothing has changed". The theory explains that bits decay as if they were radioactive. As time passes, the contents of a file or the code in a program will become increasingly garbled. People with a physics background tend to prefer the variant bit decay for the analogy with particle decay. There actually are physical processes that produce such effects (alpha particles generated by trace radionuclides in ceramic chip packages, for example, can change the contents of a computer memory unpredictably, and various kinds of subtle media failures can corrupt files in mass storage), but they are quite rare (and computers are built with error detection circuitry to compensate for them). The notion long favoured among hackers that cosmic rays are among the causes of such 1 1 1 1 1 bit slice A technique for constructing a processor from modules, each of which processes one bit-field or "slice" of an operand. Bit slice processors usually consist of an ALU of 1, 2, 4 or 8 bits and control lines (including carry or overflow signals usually internal to the CPU). For example, two 4-bit ALUs could be arranged side by side, with control lines between them, to form an 8-bit ALU. A sequencer executes a program to provide data and control signals. The AMD Am2901 is an example. (1994-11-15) 1 1 1 1 1 bits per inch (BPI) A measure of the recording density of a magnetic tape or disk. (1995-04-13) 1 1 1 1 1 bits per pixel (bpp) The number of bits of information stored per pixel of an image or displayed by a graphics adapter. The more bits there are, the more colours can be represented, but the more memory is required to store or display the image. A colour can be described by the intensities of red, green and blue (RGB) components. Allowing 8 bits (1 byte) per component (24 bits per pixel) gives 256 levels for each component and over 16 million different colours - more than the human eye can distinguish. Microsoft Windows [and others?] calls this truecolour. An image of 1024x768 with 24 bpp requires over 2 MB of memory. High colour uses 16 bpp (or 15 bpp), 5 bits for blue, 5 bits for red and 6 bits for green. This reduced colour precision gives a slight loss of image quality at a 1/3 saving on memory. Standard VGA uses a palette of 16 colours (4 bpp), each 1 1 1 1 1 bits per second (bps, b/s) The unit in which data rate is measured. For example, a modem's data rate is usually measured in kilobits per second. In 1996, the maximum modem speed for use on the PSTN was 33.6 kbps, rising to 56 kbps in 1997. Note that kilo- (k), mega- (M), etc. in data rates denote powers of 1000, not 1024. (2002-03-23) 1 1 1 1 1 bit string An ordered sequence of bits. This is very similar to a bit pattern except that the term "string" suggests an arbitrary length sequence as opposed to a pre-determined length "pattern". 1 1 1 1 1 bit stuffing A protocol which guarantees the receiver of synchronous data can recover the sender's clock. When the data stream sent contains a large number of adjacent bits which cause no transition of the signal, the receiver cannot adjust its clock to maintain proper synchronised reception. To eliminate the possibility of such a pathological case, when a preset number of transitionless bits have been transmitted, a bit which does cause a transition is "stuffed" (transmitted) by the sender. The receiver follows the same protocol and removes the stuffed bit after the specified number of transitionless bits, but can use the stuffed bit to recover the sender's clock. The advantage of bit stuffing is that only a bit (not a byte) is inserted in the data stream, and that only when the content of the data stream fails to provide a timing signal to the receiver. Thus very nearly 100% of the bits transported are useful data. In contrast, asynchronous transmission of 1 1 1 1 1 BitTorrent A popular, distributed form of peer-to-peer file sharing that enables a client program to fetch different parts of a file (a "torrent") from different sources in parallel. The system is designed to encourage users to make downloaded data available for others to upload. This is aided by a scheme for exchanging unique identifiers, commonly stored in ".torrent" files. A downloader who does not serve data to others is called a "leech". A "seed" is a computer that has a complete copy of a file, possibly the original. The bittorrent.com site claims there are over 100 million users as of 2007-03-24. Most of the data is copyright material like films or commercial software. (http://www.bittorrent.com/what-is-bittorrent). (2007-03-27) 1 1 1 1 1 bit twiddling 1. (pejorative) An exercise in tuning (see tune) in which incredible amounts of time and effort go to produce little noticeable improvement, often with the result that the code becomes incomprehensible. 2. Aimless small modification to a program, especially for some pointless goal. 3. bit bashing, especially used for the act of frobbing the device control register of a peripheral in an attempt to get it back to a known state. [Jargon File] 1 1 1 1 1 bitty box (Or "calculator") /bit'ee boks/ A computer sufficiently small, primitive, or incapable as to cause a hacker acute claustrophobia at the thought of developing software on or for it. The term is especially used of small, obsolescent, single-tasking-only personal computers such as the Atari 800, Osborne, Sinclair, VIC-20, TRS-80 or IBM PC, but the term is a general pejorative opposite of real computer (see Get a real computer!). See also mess-dos, toaster, toy. (1994-11-29) 1 1 1 1 1 bitwise A bitwise operator treats its operands as a vector of bits rather than a single number. Boolean bitwise operators combine bit N of each operand using a Boolean function (NOT, AND, OR, XOR) to produce bit N of the result. For example, a bitwise AND operator ("&" in C) would evaluate 13 & 9 as (binary) 1101 & 1001 = 1001 = 9, whereas, the logical AND, (C "&&") would evaluate 13 && 9 as TRUE && TRUE = TRUE = 1. In some languages, e.g. Acorn's BASIC V, the same operators are used for both bitwise and logical operations. This usually works except when applying NOT to a value x which is neither 0 (false) nor -1 (true), in which case both x and (NOT x) will be non-zero and thus treated as TRUE. Other operations at the bit level, which are not normally described as "bitwise" include shift and rotate. (1995-05-12) 1 1 1 1 1 bitwise complement The bitwise complement of a bit field is a bit field of the same length but with each zero changed to a one and vice versa. This is the same as the ones complement of a binary integer. (1994-11-14) 1 1 1 1 1 bixie /bik'see/ Variant emoticons used on Byte Information eXchange. The smiley bixie is <@_@>, apparently intending to represent two cartoon eyes and a mouth. A few others have been reported. [Jargon File] (1994-11-29) 1 1 1 1 1 biz-core stability Internet security products which secure the business core. [Examples?] (2003-03-09) 1 1 1 1 1 bj The country code for Benin. (1999-01-27) 1 1 1 1 1 Bjarne Stroustrup The father of C++ and author of the C++ bible. ["The C++ Programming Language", Bjarne Stroustrup, Addison-Wesley, 1986]. [Details?] (2000-05-12) 1 1 1 1 1 BJC4000 A colour bubble jet printer from Canon. Released in September 1994. It features 720 x 360 dots per inch in black and white mode and 360 x 360 in colour. It has two cartridges: one for black and one for the three primary colours so it prints true black when printing in colour. (1994-11-29) 1 1 1 1 1 black art A collection of arcane, unpublished, and (by implication) mostly ad-hoc techniques developed for a particular application or systems area (compare black magic). VLSI design and compiler code optimisation were (in their beginnings) considered classic examples of black art; as theory developed they became deep magic, and once standard textbooks had been written, became merely heavy wizardry. The huge proliferation of formal and informal channels for spreading around new computer-related technologies during the last twenty years has made both the term "black art" and what it describes less common than formerly. See also voodoo programming. [Jargon File] 1 1 1 1 1 black box An abstraction of a device or system in which only its externally visible behaviour is considered and not its implementation or "inner workings". See also functional testing. (1997-07-03) 1 1 1 1 1 black-box testing functional testing 1 1 1 1 1 Black Data Processing Associates (BDPA) A non-profit professional association, founded in 1975 to promote positive influence in the information technology (IT) industry and how it affects African Americans. The BDPA facilitates African American professional participation in local and national activities keeping up with developing IT trends. BDPA offers a forum for exchanging information and ideas about the computer industry. It provides numerous networking opportunities through monthly program meetings, seminars, and workshops and the annual national conference. Membership is open to anyone interested in IT. The Foundation provides scholarships to students who compete in an annual Visual Basic competition. (http://bdpa.org/conf96). E-mail: <nbdpa@ix.netcom.com>. Telephone: Ms. Pat Drumming, +1 (800) 727-BDPA. (1996-04-07) 1 1 1 1 1 black hole 1. An expression which depends on its own value or a technique to detect such expressions. In graph reduction, when the reduction of an expression is begun, the root of the expression can be overwritten with a black hole. If the expression depends on its own value, e.g. x = x + 1 then it will try to evaluate the black hole which will usually print an error message and abort the program. A secondary effect is that, once the root of the expression has been black-holed, parts of the expression which are no longer required may be freed for garbage collection. Without black holes the usual result of attempting to evaluate an expression which depends on itself would be a stack overflow. If the expression is evaluated successfully then the black hole will be updated with the value. Expressions such as 1 1 1 1 1 BlackIce A commercial firewall and intrusion detection system. BlackIce Home (http://blackice.iss.net/). (2003-09-13) 1 1 1 1 1 black magic (Or "FM") A technique that works, though nobody really understands why. More obscure than voodoo programming, which may be done by cookbook. Compare black art, deep magic, and magic number. (2001-04-30) 1 1 1 1 1 blargh /blarg/ [MIT] The opposite of ping. An exclamation indicating that one has absorbed or is emitting a quantum of unhappiness. Less common than ping. [Jargon File] 1 1 1 1 1 blast 1. BLT, used especially for large data sends over a network or comm line. Opposite of snarf. Usage: uncommon. The variant "blat" has been reported. 2. [HP/Apollo] Synonymous with nuke. Sometimes the message Unable to kill all processes. Blast them (y/n)? would appear in the command window upon logout. 1 1 1 1 1 blat 1. blast. 2. See thud. [Jargon File] 1 1 1 1 1 BLAZE A single assignment language for parallel processing. ["The BLAZE Language: A Parallel Language for Scientific Programming", P. Mehrotra <mehrotra@csrd.uiuc.edu> et al, J Parallel Comp 5(3):339-361 (Nov 1987)]. 1 1 1 1 1 BLAZE 2 An object-oriented successor to BLAZE. ["Concurrent Object Access in BLAZE 2", P. Mehrotra et al, SIGPLAN Notices 24(4):40-42 (Apr 1989)]. 1 1 1 1 1 bleam To transmit or send data. Bleam that binary to me in an e-mail. [Origin? Used where?] (1997-05-14) 1 1 1 1 1 bleeper pager 1 1 1 1 1 bletcherous /blech'*-r*s/ Disgusting in design or function; aesthetically unappealing. This word is seldom used of people. "This keyboard is bletcherous!" (Perhaps the keys don't work very well, or are misplaced.) The term bletcherous applies to the esthetics of the thing so described; similarly for cretinous. By contrast, something that is "losing" or bagbiting may be failing to meet objective criteria. [Jargon File] 1 1 1 1 1 Bletchley Park A country house and grounds some 50 miles North of London, England, where highly secret work deciphering intercepted German military radio messages was carried out during World War Two. Thousands of people were working there at the end of the war, including a number of early computer pioneers such as Alan Turing. The nature and scale of the work has only emerged recently, with total secrecy having been observed by all the people involved. Throughout the war, Bletchley Park produced highly important strategic and tactical intelligence used by the Allies, (Churchill's "golden eggs"), and it has been claimed that the war in Europe was probably shortened by two years as a result. An exhibition of wartime code-breaking memorabilia, including an entire working Colossus, restored by Tony Sale, can be seen at Bletchley Park on alternate weekends. The Computer Conservation Society (CCS), a specialist group 1 1 1 1 1 Blind Carbon Copy (BCC) An electronic mail header which lists addresses to which a message should be sent, but which will not be seen by the recipients. Bcc is defined in RFC 822 and supported by most e-mail systems. A normal, non-blind "CC" header would be visible to all recipients, thus allowing them to reply to each other as well as to the sender. According to RFC 822, the addresses listed in a BCC header are not included in the copies of the message sent to the recipients. RFC 822 says BCC addresses may appear in the copy sent to "BCC" recipients themselves (though this would be unusual). (1998-03-14) 1 1 1 1 1 B-LINE An early CAD language. ["B-LINE, Bell Line Drawing Language", A.J. Frank, Proc Fall JCC 33 1968]. (1994-11-17) 1 1 1 1 1 blinkenlights /blink'*n-li:tz/ Front-panel diagnostic lights on a computer, especially a dinosaur. Derives from the last word of the famous blackletter-Gothic sign in mangled pseudo-German that once graced about half the computer rooms in the English-speaking world. One version ran in its entirety as follows: ACHTUNG! ALLES LOOKENSPEEPERS! Das computermachine ist nicht fuer gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitzensparken. Ist nicht fuer gewerken bei das dumpkopfen. Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das pockets muss; relaxen und watchen das blinkenlichten. This silliness dates back at least as far as 1959 at Stanford University and had already gone international by the early 1 1 1 1 1 BLISS Basic Language for Implementation of System Software 1 1 1 1 1 BLISS-10 A version of BLISS from CMU for the PDP-10. (2002-02-01) 1 1 1 1 1 BLISS-11 A cross-compiler for the PDP-11 running on a PDP-10. Written at CMU to support the C.mmp/Hydra project. (2002-02-01) 1 1 1 1 1 BLISS-16C DEC's cross-compiler equivalent of BLISS-11. (2002-02-01) 1 1 1 1 1 BLISS-32 A version of BLISS from DEC for VAX/VMS. (2002-02-01) 1 1 1 1 1 BLISS-36 DEC's equivalent of BLISS-10. (2002-02-01) 1 1 1 1 1 blit /blit/ 1. To copy a large array of bits from one part of a computer's memory to another part, particularly when the memory is being used to determine what is shown on a display screen. "The storage allocator picks through the table and copies the good parts up into high memory, and then blits it all back down again." See bitblt, BLT, dd, cat, blast, snarf. More generally, to perform some operation (such as toggling) on a large array of bits while moving them. 2. Sometimes all-capitalised as "BLIT": an early experimental bit-mapped terminal designed by Rob Pike at Bell Labs, later commercialised as the AT&T 5620. (The folk etymology from "Bell Labs Intelligent Terminal" is incorrect. Its creators liked to claim that "Blit" stood for the Bacon, Lettuce, and Interactive Tomato). [Jargon File] (1994-11-16) 1 1 1 1 1 blitter /blit'r/ (Or "raster blaster"). A special-purpose integrated circuit or hardware system built to perform blit (or "bit bang") operations, especially used for fast implementation of bit-mapped graphics. The Commodore Amiga and a few other microcomputers have these, but in 1991 the trend is away from them (however, see cycle of reincarnation). [Jargon File] (1996-04-30) 1 1 1 1 1 blivet /bliv'*t/ [allegedly from a World War II military term meaning ten pounds of manure in a five-pound bag] 1. An intractable problem. 2. A crucial piece of hardware that can't be fixed or replaced if it breaks. 3. A tool that has been hacked over by so many incompetent programmers that it has become an unmaintainable tissue of hacks. 4. An out-of-control but unkillable development effort. 5. An embarrassing bug that pops up during a customer demo. 6. In the subjargon of computer security specialists, a denial-of-service attack performed by hogging limited resources that have no access controls (for example, shared spool space on a multi-user system). This term has other meanings in other technical cultures; among experimental physicists and hardware engineers of various kinds it seems to mean any random object of unknown 1 1 1 1 1 bloat software bloat 1 1 1 1 1 bloatware Software suffering from software bloat. (1995-10-14) 1 1 1 1 1 BLOB 1. binary large object. 2. <architecture> blitter object. [Jargon File] 1 1 1 1 1 block 1. <unit> A unit of data or memory, often, but not exclusively, on a magnetic disk or magnetic tape. Compare record, sector. (2000-07-17) 2. <operating system> To delay or sit idle while waiting for something. Compare busy-wait. (2000-07-17) 3. <programming> A delimited section of source code in a block-structured language. (2004-09-29) 1 1 1 1 1 Block And List Manipulation BALM 1 1 1 1 1 Block Diagram Compiler (BDL) A block diagram simulation tool, with associated language. ["A Software Environment for Digital Signal-Processing Simulations," D.H. Johnson & R.E. Vaughan, Circuits Systems and Signal Processing 6(1):31-43, 1987]. (2000-07-17) 1 1 1 1 1 blocked records Several records written as a contiguous block on magnetic tape so that they may be accessed in a single I/O operation. Blocking increases the amount of data that may be stored on a tape because there are fewer inter-block gaps. It requires that the tape drive or processor have a sufficiently large buffer to store the whole block. (1995-04-13) 1 1 1 1 1 Block Redundancy Check Longitudinal Redundancy Check 1 1 1 1 1 Block Started by Symbol (BSS) The uninitialised data segment produced by Unix linkers. Objects in the bss segment have only a name and a size but no value. Executable code is located in the code segment and initialised data in the data segment. (2004-02-24) 1 1 1 1 1 block-structured Any programming language in which sections of source code contained within pairs of matching delimiters such as "" and "" (e.g. in C) or "begin" and "end" (e.g. Algol) are executed as a single unit. A block of code may be the body of a subroutine or function, or it may be controlled by conditional execution (if statement) or repeated execution (while statement, for statement, etc.). In all but the most primitive block structured languages a variable's scope can be limited to the block in which it is declared. Block-structured languages support structured programming where each block can be written without detailed knowledge of the inner workings of other blocks, thus allowing a top-down design approach. See also abstract data type, module. (2004-09-29) 1 1 1 1 1 block transfer computations (From the UK television series "Dr. Who") Computations so fiendishly subtle and complex that they could not be performed by machines. Used to refer to any task that should be expressible as an algorithm in theory, but isn't. [Jargon File] (2004-09-28) 1 1 1 1 1 blog (From "web log") Any kind of diary published on the web, usually written by an individual (a blogger) but also by corporate bodies. Blogging is regarded by some as an important social phenomenon as it contributes to the easy exchange of ideas among a large and growing international community ("the blogosphere"). A blog is just a special kind of website. The home page usually shows the most recent article and links to earlier articles, the owner's profile and web logs written by the owner's friends. There is usually a facility for readers to add comments to the bottom of articles. Blogs usually provide an RSS feed of current articles, allowing readers to subscribe by adding the feed to their favourite RSS reader. Many sites, e.g. (http://blogger.com/), let you create a blog for free. Many blogs consist almost entirely of links to other web logs, some publish original content, a few are worth reading. (2013-08-15) 1 1 1 1 1 blog-driven development cut-and-waste code 1 1 1 1 1 Bloggs Family, the An imaginary family consisting of Fred and Mary Bloggs and their children. Used as a standard example in knowledge representation to show the difference between extensional and intensional objects. For example, every occurrence of "Fred Bloggs" is the same unique person, whereas occurrences of person may refer to different people. Members of the Bloggs family have been known to pop up in bizarre places such as the DEC Telephone Directory. Compare Mbogo, Dr. Fred. 1 1 1 1 1 Bloombug A bug that accidentally generates money. [After "Bloomberg"?] (2012-11-10) 1 1 1 1 1 Blosim Block-Diagram Simulator. A block-diagram simulator. "A Tool for Structured Functional Simulation", D.G. Messerschmitt, IEEE J on Selected Areas in Comm, SAC-2(1):137-147, 1984. 1 1 1 1 1 blow an EPROM /bloh *n ee'prom/ (Or "blast", "burn") To program a read-only memory, e.g. for use with an embedded system. This term arose because the programming process for the Programmable Read-Only Memory (PROM) that preceded present-day Erasable Programmable Read-Only Memory (EPROM) involved intentionally blowing tiny electrical fuses on the chip. The usage lives on (it's too vivid and expressive to discard) even though the write process on EPROMs is nondestructive. [Jargon File] (1994-11-29) 1 1 1 1 1 blow away To remove (files and directories) from permanent storage, generally by accident. "He reformatted the wrong partition and blew away last night's netnews". Compare: nuke. [Jargon File] (1996-01-05) 1 1 1 1 1 blowing your buffer Losing your train of thought. A reference to buffer overflow. (1999-01-15) 1 1 1 1 1 blow out (Probably from mining and tunnelling jargon) Of software, to fail spectacularly; almost as serious as crash and burn. See blow past, blow up, die horribly. [Jargon File] (1994-11-29) 1 1 1 1 1 blow past To blow out despite a safeguard. "The server blew past the 5K reserve buffer." [Jargon File] (1994-11-29) 1 1 1 1 1 blow up 1. Of a scientific computation: to become unstable. It suggests that the computation is diverging so rapidly that it will soon overflow or at least go nonlinear. 2. blow out. [Jargon File] 1 1 1 1 1 BLOX A visual language. 1 1 1 1 1 BLT 1. /B-L-T/, /bl*t/ or (rarely) /belt/ Synonym for blit. This is the original form of blit and the ancestor of bitblt. It refers to any large bit-field copy or move operation (one resource-intensive memory-shuffling operation done on pre-paged versions of ITS, WAITS and TOPS-10 was sardonically referred to as "The Big BLT"). The jargon usage has outlasted the PDP-10 BLock Transfer instruction from which BLT derives; nowadays, the assembly language mnemonic BLT almost always means "Branch if Less Than zero". 2. bacon, lettuce and tomato (sandwich). [Jargon File] 1 1 1 1 1 Blue A language proposed by Softech to meet the DoD Ironman requirements which led to Ada. ["On the BLUE Language Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices 13(10):10-15 (Oct 1978)]. 1 1 1 1 1 Blue Book 1. <publication> Informal name for one of the four standard references on the page-layout and graphics-control language PostScript. The other three official guides are known as the Green Book, the Red Book, and the White Book. ["PostScript Language Tutorial and Cookbook", Adobe Systems, Addison-Wesley 1985, (ISBN 0-201-10179-3)]. 2. <publication> Informal name for one of the three standard references on Smalltalk. This book also has green and red siblings. ["Smalltalk-80: The Language and its Implementation", David Robson, Addison-Wesley 1983, (ISBN 0-201-11371-63)]. 3. <publication> Any of the 1988 standards issued by the ITU-T's ninth plenary assembly. These include, among other things, the X.400 electronic mail specification and the Group 1 through 4 fax standards. See also book titles. [Jargon File] 1 1 1 1 1 Blue Box The complete implementation of the Mac OS run-time environment on the more modern Rhapsody operating system. Blue Box is not an emulation layer; at any given time it will be based on the same source code and ROM image as the current version of Mac OS and will thus incorporate future Mac OS improvements. (1997-10-15) 1 1 1 1 1 blue dot syndrome The inability to display an image file or text embedded in an image file on your monitor. [Why?] (2002-05-28) 1 1 1 1 1 Blue Glue Systems Network Architecture 1 1 1 1 1 Blue Screen of Death (BSOD) The infamous white-on-blue text screen which appears when Microsoft Windows crashes. BSOD is mostly seen on the 16-bit systems such as Windows 3.1, but also on Windows 95 and apparently even under Windows NT 4. It is most likely to be caused by a GPF, although Windows 95 can do it if you've removed a required CD-ROM from the drive. It is often impossible to recover cleanly from a BSOD. The acronym BSOD is sometimes used as a verb, e.g. "Windoze just keeps BSODing on me today". (1998-09-08) 1 1 1 1 1 Blue Screen of Life (BSOL, by analogy with "Blue Screen of Death") The opening screen of Microsoft Windows NT. This screen shows the file system loading, and any problems such as conversions from FAT to NTFS or a scan of a hard drive. The Blue Screen of Life occurs in one way, as opposed to the Blue Screen of Death, which can occur in many different ways and times. [Is this term ever used in connection with Windows 3.x or Windows 9x?] (1999-04-18) 1 1 1 1 1 Blue Sky Software eHelp Corporation 1 1 1 1 1 Bluetooth A specification for short-range radio links between mobile computers, mobile phones, digital cameras, and other portable devices. (http://bluetooth.com). (2001-03-16) 1 1 1 1 1 blue wire (IBM) Patch wires added to circuit boards at the factory to correct design or fabrication problems. These may be necessary if there hasn't been time to design and qualify another board version. Compare purple wire, red wire, yellow wire. [Jargon File] (1994-11-29) 1 1 1 1 1 blurgle /bler'gl/ [Great Britain] Spoken metasyntactic variable, to indicate some text that is obvious from context, or which is already known. If several words are to be replaced, blurgle may well be doubled or trebled. "To look for something in several files use "grep string blurgle blurgle"." In each case, "blurgle blurgle" would be understood to be replaced by the file you wished to search. Compare mumble. [Jargon File] 1 1 1 1 1 bm The country code for Bermuda. (1999-01-27) 1 1 1 1 1 BMAN Broadband Metropolitan Area Network 1 1 1 1 1 BMASF Basic Module Algebra Specification Language? "Design of a Specification Language by Abstract Syntax Engineering", J.C.M. Baeten et al, in LNCS 490, pp.363-394. 1 1 1 1 1 BMDP BioMeDical Package 1 1 1 1 1 B-Method A system for rigorous or formal development of software using the notion of Abstract Machines to specify and design software systems. The B-Method is supported by the B-Toolkit. Abstract Machines are specified using the Abstract Machine Notation (AMN) which is in turn based on the mathematical theory of Generalised Substitutions. (1995-03-13) 1 1 1 1 1 BMF Bird-Meertens Formalism 1 1 1 1 1 BMP Basic Multilingual Plane 1 1 1 1 1 bmp Microsoft Windows bitmap format. Bmp files may use run-length encoding. This is the only graphics format where compression actually enlarges the file. The format is widely used nonetheless. [Format?] (1998-03-14) 1 1 1 1 1 BMWF The Austrian, German and Swiss(?) Ministries of Science. [Expansion?] (1998-12-09) 1 1 1 1 1 bn The country code for Brunei Darussalam. (1999-01-27) 1 1 1 1 1 BNC A connector for coaxial cable such as that used for some video connections and RG58 "cheapernet" connections. A BNC connector has a bayonet-type shell with two small knobs on the female connector which lock into spiral slots in the male connector when it is twisted on. Different sources expand BNC as Bayonet Navy Connector, British Naval Connector, Bayonet Neill Concelman, or Bayonet Nut Connection. (1995-09-18) 1 1 1 1 1 BNF Backus-Naur Form. Originally Backus Normal Form. [Jargon File] 1 1 1 1 1 BNR Pascal ["Remote Rendezvous", N. Gammage et al, Soft Prac & Exp 17(10):741-755 (Oct 1987)]. (1994-12-21) 1 1 1 1 1 BNR Prolog A constraint logic language. [Details?] (1994-12-21) 1 1 1 1 1 bo The country code for Bolivia. (1999-01-27) 1 1 1 1 1 BOA Basic Object Adapter 1 1 1 1 1 boa [IBM] Any one of the fat cables that lurk under the floor in a dinosaur pen. Possibly so called because they display a ferocious life of their own when you try to lay them straight and flat after they have been coiled for some time. It is rumored within IBM that channel cables for the 370 are limited to 200 feet because beyond that length the boas get dangerous #NAME? uses the trademark "Anaconda". [Jargon File] 1 1 1 1 1 board 1. In-context synonym for bboard; sometimes used even for Usenet newsgroups. 2. An electronic circuit board. 1 1 1 1 1 boat anchor 1. Like doorstop but more severe; implies that the offending hardware is irreversibly dead or useless. "That was a working motherboard once. One lightning strike later, instant boat anchor!" 2. A person who just takes up space. 3. Obsolete but still working hardware, especially when used of an old S100-bus hobbyist system; originally a term of annoyance, but became more and more affectionate as the hardware became more and more obsolete. [Jargon File] 1 1 1 1 1 Bob David Betz. A tiny object-oriented language. (ftp://ftp.mv.com/pub/ddj/packages/bob15.arc). [Dr Dobbs J, Sep 1991, p.26]. 1 1 1 1 1 Bobo the Webmonkey What B1FF was to BITNET users, Bobo the Webmonkey is to webmonkeys - the mythical prototype of incompetent web designers everywhere. In fact, Bobo may be what B1FF became when he grew up. Bobo knows about HTML only what he has learned from viewing the source of other people's Web pages. Bobo doesn't know what a MIME type is, even though someone gave him a hardcopy of the FOLDOC entry for it. Bobo may have used an HTML code validator (http://validator.w3.org/) before, but isn't sure. Bobo doesn't know what the difference between GIF and JPEG is. He thinks PNG is a foreign country. All the pages Bobo has designed say "Welcome to [organisation] online!" at the top, and say "click here!" at least three times per page. Bobo has used Photoshop before; he doesn't understand why people keep asking if he's ever been tested for 1 1 1 1 1 BOCS Berard Object and Class Specifier 1 1 1 1 1 Boehm B. Proposed the COCOMO technique for evaluating the cost of a software project. 1 1 1 1 1 BOEING An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 1 1 1 1 1 BOF /B-O-F/ or /bof/ 1. Birds Of a Feather. 2. Boring Old Fart. [Jargon File] 1 1 1 1 1 BOFH Bastard Operator From Hell 1 1 1 1 1 bogometer /boh-gom'-*t-er/ A notional instrument for measuring bogosity. Compare the "wankometer" described in the wank entry. [Jargon File] (1999-06-10) 1 1 1 1 1 BogoMips (From "bogus", "MIPS") The timing unit of the Linux kernel. A BogoMips is an unscientific measurement of processor speed made by the Linux kernel when it boots, to calibrate an internal busy-loop. BogoMips MiniHowto (http://metalab.unc.edu/LDP/HOWTO/mini/BogoMips.html). (1999-05-06) 1 1 1 1 1 bogon /boh'gon/ (By analogy with proton/electron/neutron, but doubtless reinforced after 1980 by the similarity to Douglas Adams's "Vogons") 1. The elementary particle of bogosity (see quantum bogodynamics). For instance, "the Ethernet is emitting bogons again" means that it is broken or acting in an erratic or bogus fashion. 2. A query packet sent from a TCP/IP domain resolver to a root server, having the reply bit set instead of the query bit. 3. Any bogus or incorrectly formed packet sent on a network. 4. A person who is bogus or who says bogus things. This was historically the original usage, but has been overtaken by its derivative senses. See also bogosity; compare psyton, fat electrons, magic smoke. The bogon has become the type case for a whole bestiary of nonce particle names, including the "clutron" or "cluon" 1 1 1 1 1 bogon filter /boh'gon fil'tr/ Any device, software or hardware, that limits or suppresses the flow and/or emission of bogons. "Engineering hacked a bogon filter between the Cray and the VAXen, and now we're getting fewer dropped packets. See" also bogosity. 1 1 1 1 1 bogon flux /boh'gon fluhks/ A measure of a supposed field of bogosity emitted by a speaker, measured by a bogometer; as a speaker starts to wander into increasing bogosity a listener might say Warning, warning, bogon flux is rising. See quantum bogodynamics. [Jargon File] 1 1 1 1 1 bogosity /boh-go's*-tee/ The degree to which something is "bogus" in the hackish sense of "bad". At CMU, bogosity is measured with a bogometer; in a seminar, when a speaker says something bogus, a listener might raise his hand and say "My bogometer just triggered". More extremely, "You just pinned my bogometer" means you just said or did something so outrageously bogus that it is off the scale, pinning the bogometer needle at the highest possible reading (one might also say "You just redlined my bogometer"). The agreed-upon unit of bogosity is the microLenat. Also, the potential field generated by a bogon flux; see quantum bogodynamics. See also bogon flux, bogon filter. (2002-04-14) 1 1 1 1 1 bogo-sort /boh"goh-sort"/ (Or "stupid-sort") The archetypical perversely awful algorithm (as opposed to bubble sort, which is merely the generic *bad* algorithm). Bogo-sort is equivalent to repeatedly throwing a deck of cards in the air, picking them up at random, and then testing whether they are in order. It serves as a sort of canonical example of awfulness. Looking at a program and seeing a dumb algorithm, one might say "Oh, I see, this program uses bogo-sort." Also known as "monkey sort" after the Infinite Monkey Theorem. Compare brute force, Lasherism. An implementation (http://stdout.org/~adam/psort). [Jargon File] (2002-04-07) 1 1 1 1 1 bogotify /boh-go't*-fi:/ To make or become bad. A program that has been changed so many times as to become completely disorganised has become bogotified. If you tighten a nut too hard and strip the threads on the bolt, the bolt has become bogotified. See also bogosity. (2003-01-25) 1 1 1 1 1 bogue out /bohg owt/ To become bogus, suddenly and unexpectedly. "His talk was relatively sane until somebody asked him a trick question; then he bogued out and did nothing but flame afterward." See also bogosity. [Jargon File] 1 1 1 1 1 BOHICA /bo-hee-ka/ Bend Over, Here It Comes Again. 1 1 1 1 1 Bohr bug /bohr buhg/ (From Quantum physics) A repeatable bug; one that manifests reliably under a possibly unknown but well-defined set of conditions. Compare heisenbug. See also mandelbug, schroedinbug. [Jargon File] (1995-02-28) 1 1 1 1 1 boink /boynk/ [Usenet: variously ascribed to the TV series Cheers "Moonlighting", and "Soap"] 1. To have sex with; compare bounce. (This is mainstream slang.) In Commonwealth hackish the variant "bonk" is more common. 2. After the original Peter Korn "Boinkon" Usenet parties, used for almost any net social gathering, e.g. Miniboink, a small boink held by Nancy Gillett in 1988; Minniboink, a Boinkcon in Minnesota in 1989; Humpdayboinks, Wednesday get-togethers held in the San Francisco Bay Area. Compare @-party. 3. Variant of "bonk"; see bonk/oif. [Jargon File] 1 1 1 1 1 BOLERO Software AG's object-oriented development environment and application server for Electronic Business applications. (1999-03-06) 1 1 1 1 1 Bolt, Beranek and Newman, Inc. BBN Technologies 1 1 1 1 1 bomb 1. <software> General synonym for crash except that it is not used as a noun. Especially used of software or OS failures. "Don't run Empire with less than 32K stack, it'll bomb". 2. <operating system> Atari ST and Macintosh equivalents of a Unix "panic" or Amiga guru, in which icons of little black-powder bombs or mushroom clouds are displayed, indicating that the system has died. On the Macintosh, this may be accompanied by a decimal (or occasionally hexadecimal) number indicating what went wrong, similar to the Amiga guru meditation number. MS-DOS computers tend to lock up in this situation. 3. <software> A piece of code embedded in a program that remains dormant until it is triggered. Logic bombs are triggered by an event whereas time bombs are triggered either after a set amount of time has elapsed, or when a specific date is reached. 1 1 1 1 1 bon (From "Bonnie", Ken Thompson's wife) A language designed by Ken Thompson and later revised by him to produce B. [When? Features?] (1997-02-04) 1 1 1 1 1 bondage-and-discipline language A language (such as Pascal, Ada, APL, or Prolog) that, though ostensibly general-purpose, is designed so as to enforce an author's theory of "right programming" even though said theory is demonstrably inadequate for systems hacking or even vanilla general-purpose programming. Often abbreviated B&D; thus, one may speak of things "having the B&D nature". See Pascal. Compare languages of choice. [Jargon File] (1996-01-05) 1 1 1 1 1 bonk/oif /bonk/, /oyf/ In the MUD community, it has become traditional to express pique or censure by "bonking" the offending person. Convention holds that one should acknowledge a bonk by saying "oif!" and there is a myth to the effect that failing to do so upsets the cosmic bonk/oif balance, causing much trouble in the universe. Some MUDs have implemented special commands for bonking and oifing. [Jargon File] (1998-01-18) 1 1 1 1 1 Booch method A widely used object-oriented analysis and object-oriented design method. (http://hsr.ch/div/Booch/BoochReference/). [Grady Booch, "Object-oriented Analysis and Design with Applications", 2nd edition. Benjamin Cummings, Redwood City, ISBN 0-8053-5340-2, 1993] (2000-05-23) 1 1 1 1 1 book 1. <text> e-book. 2. book titles. 3. <computer> MacBook. 4. O'Reilly and Associates. 1 1 1 1 1 bookmark A user's reference to a document on the web or other hypermedia system, usually in the form of a URL and a title or comment string. Most web and Gopher browsers can save and load a file of bookmarks to allow you to quickly locate documents to which you want to refer again. (1997-06-09) 1 1 1 1 1 Bookreader DEC's CD-ROM-based on-line documentation browser. 1 1 1 1 1 book titles There is a tradition in hackerdom of informally tagging important textbooks and standards documents with the dominant colour of their covers or with some other conspicuous feature of the cover. Many of these are described in this dictionary under their own entries. See Aluminum Book, Blue Book, Cinderella Book, Devil Book, Dragon Book, Green Book, Orange Book, Pink-Shirt Book, Purple Book, Red Book, Silver Book, White Book, Wizard Book, Yellow Book, bible, rainbow series. [Jargon File] (1996-12-03) 1 1 1 1 1 Bookviewer A hypertext documentation system from Oracle based on Oracle Toolkit. It allows the user to create private links and bookmarks, and to make multimedia annotations. 1 1 1 1 1 bool Boolean 1 1 1 1 1 Boolean 1. Boolean algebra. <programming> 2. (bool) The type of an expression with two possible values, "true" and "false". Also, a variable of Boolean type or a function with Boolean arguments or result. The most common Boolean functions are AND, OR and NOT. (1997-12-01) 1 1 1 1 1 Boolean algebra (After the logician George Boole) 1. Commonly, and especially in computer science and digital electronics, this term is used to mean two-valued logic. 2. This is in stark contrast with the definition used by pure mathematicians who in the 1960s introduced "Boolean-valued models" into logic precisely because a "Boolean-valued model" is an interpretation of a theory that allows more than two possible truth values! Strangely, a Boolean algebra (in the mathematical sense) is not strictly an algebra, but is in fact a lattice. A Boolean algebra is sometimes defined as a "complemented distributive lattice". Boole's work which inspired the mathematical definition concerned algebras of sets, involving the operations of intersection, union and complement on sets. Such algebras obey the following identities where the operators ^, V, - and constants 1 and 0 can be thought of either as set 1 1 1 1 1 Boolean logic A logic based on Boolean algebra. (1995-03-25) 1 1 1 1 1 Boolean search (Or "Boolean query") A query using the Boolean operators, AND, OR, and NOT, and parentheses to construct a complex condition from simpler criteria. A typical example is searching for combinatons of keywords on a web search engine. Examples: car or automobile New York and not "New York state" The term is sometimes stretched to include searches using other operators, e.g. "near". Not to be confused with binary search. See also: weighted search. (1999-10-23) 1 1 1 1 1 Boole, George George Boole 1 1 1 1 1 Booster A data-parallel language. The Booster Language, E. Paalvast, TR PL 89-ITI-B-18, Inst voor Toegepaste Informatica TNO, Delft, 1989. 1 1 1 1 1 boot bootstrap 1 1 1 1 1 boot block A program on a hard disk, floppy disk or other media, which is loaded when the computer is turned on or rebooted and which controls the next phase of loading the actual operating system. The loading and execution of the boot block is usually controlled by firmware in ROM or PROM. It may be at some fixed location possibly or may be pointed to by the master boot record. (2009-05-19) 1 1 1 1 1 boot disk The magnetic disk (usually a hard disk) from which an operating system kernel is loaded (or bootstrapped). This second phase in system start-up is performed by a simple bootstrap loader program held in ROM, possibly configured by data stored in some form of writable non-volatile storage. MS-DOS and Microsoft Windows can be configured (in the BIOS) to try to boot off either floppy disk or hard disk, in either order. By default they first check for the presence of a floppy disk in the drive at start-up and try to use that as a boot disk if present. If no disk is in the drive they then try to boot off the hard disk. Some operating systems, notably SunOS and Solaris, can be configured to boot from a network rather than from disk. Such a system can thus run as a diskless workstation. (1997-06-09) 1 1 1 1 1 booting bootstrap 1 1 1 1 1 BOOTP The Bootstrap Protocol. A protocol described in RFCs 951 and 1084 and used for booting diskless workstations. See also Reverse Address Resolution Protocol. (1995-02-16) 1 1 1 1 1 bootstrap To load and initialise the operating system on a computer. Normally abbreviated to boot. From the curious expression "to pull oneself up by one's bootstraps", one of the legendary feats of Baron von Munchhausen. The bootstrap loader is the program that runs on the computer before any (normal) program can run. Derived terms include reboot, cold boot, warm boot, soft boot and hard boot. The term also applies to the use of a compiler to compile itself. The usual process is to write an interpreter for a language, L, in some other existing language. The compiler is then written in L and the interpreter is used to run it. This produces an executable for compiling programs in L from the source of the compiler in L. This technique is often used to verify the correctness of a compiler. It was first used in the LISP community. See also My Favourite Toy Language. 1 1 1 1 1 bootstrap loader A short program loaded from non-volatile storage and used to bootstrap a computer. On early computers great efforts were expended on making the bootstrap loader short, in order to make it easy to toggle in via the front panel switches. It was just clever enough to read in a slightly more complex program (usually from punched cards or paper tape), to which it handed control. This program in turn read the application or operating system from a magnetic tape drive or disk drive. Thus, in successive steps, the computer "pulled itself up by its bootstraps" to a useful operating state. Nowadays the bootstrap loader is usually found in ROM or EPROM, and reads the first stage in from a fixed location on the disk, called the "boot block". When this program gains control, it is powerful enough to load the actual OS and hand control over to it. A diskless workstation can use bootp to load its OS from the network. 1 1 1 1 1 boot virus An MS-DOS virus that infects the boot record program on hard disks and floppy disks or the master boot record on hard disks. The virus gets loaded into memory before MS-DOS and takes control of the computer, infecting any floppy disks subsequently accessed. An infected boot disk may stop the computer starting up at all. (1995-02-16) 1 1 1 1 1 Border Gateway Protocol (BGP) An Exterior Gateway Protocol defined in RFC 1267 and RFC 1268. Its design is based on experience gained with Exterior Gateway Protocol (EGP), as defined in STD 18, RFC 904 and EGP usage in the NSFNet backbone, as described in RFCs 1092 and 1093. (1994-11-29) 1 1 1 1 1 borf To uncerimoniously disconnect someone from a system without prior warning. BBS Sysops routinely "borf" pest users by turning off the modem or by hitting the "auto-borf" key sequence. You can also be "borfed" by software dropping carrier due to a bug. The origin of the term is unknown but it has been in use since at least 1982. (1997-03-21) 1 1 1 1 1 Borland International, Inc. Borland Software Corporation 1 1 1 1 1 Borland Software Corporation A company that sells a variety of PC software development and database systems. Borland was founded in 1983 and initially became famous for their low-cost software, particularly Turbo Pascal, Turbo C, and Turbo Prolog. Current and past products include the Borland C++ C++ and C developement environment, the Paradox and dBASE databases, Delphi, JBuilder, and InterBase. Borland has approximately 1000 employees worldwide and has operations in Australia, Canada, France, Germany, Japan, Netherlands, and the United Kingdom. Borland sold Quattro Pro to Novell in 1994 for $100M. Novell later sold the product to Corel Corporation, who also bought Paradox. dBASE was sold in March(?) 1999 to dBase Inc. In Febuary 1998 Borland bought Visigenic Software, Inc.. The company changed its name to Inprise Corporation on 1998-04-29 and then on 2000-11-14 they announced they were 1 1 1 1 1 BOS 1. <operating system> Basic Operating System. 2. <tool> A data management system written at DESY and used in some high energy physics programs. 3. <programming> The Basic Object System. (1999-01-20) 1 1 1 1 1 Bose-Chaudhuri-Hocquenghem Code (BHC Code) An error detection and correction technique based on Cyclic Redundancy Code, used in telecommunications applications. (1995-01-16) 1 1 1 1 1 BOSS Bridgport Operating System Software. A derivative of the ISO 1054 numerical machine control language for milling, etc. 1 1 1 1 1 bot (From "robot") Any type of autonomous software that operates as an agent for a user or a program or simulates a human activity. On the Internet, the most popular bots are programs (called spiders or crawlers) used for searching. They access web sites, retrieve documents and follow all the hypertext links in them; then they generate catalogs that are accessed by search engines. A chatbot converses with humans (or other bots). A shopbot searches the Web to find the best price for a product. Other bots (such as OpenSesame) observe a user's patterns in navigating a website and customises the site for that user. Knowbots collect specific information from websites. (1999-05-20) 1 1 1 1 1 botmaster The owner of a bot. (1997-04-07) 1 1 1 1 1 bottom The least defined element in a given domain. Often used to represent a non-terminating computation. (In LaTeX, bottom is written as \perp, sometimes with the domain as a subscript). (1997-01-07) 1 1 1 1 1 BottomFeeder An RSS aggregator. BottomFeeder Home (http://cincomsmalltalk.com/BottomFeeder). (2003-09-29) 1 1 1 1 1 bottom feeder slopsucker 1 1 1 1 1 bottom-unique In domain theory, a function f is bottom-unique if f x = bottom <=> x = bottom A bottom-unique function is also strict. 1 1 1 1 1 bottom-up implementation The opposite of top-down design. It is now received wisdom in most programming cultures that it is best to design from higher levels of abstraction down to lower, specifying sequences of action in increasing detail until you get to actual code. Hackers often find (especially in exploratory designs that cannot be closely specified in advance) that it works best to *build* things in the opposite order, by writing and testing a clean set of primitive operations and then knitting them together. [Jargon File] (1996-05-10) 1 1 1 1 1 bottom-up model A method for estimating the cost of a complete software project by combining estimates for each component. (1996-05-28) 1 1 1 1 1 bottom-up testing An integration testing technique that tests the low-level components first using test drivers for those components that have not yet been developed to call the low-level components for test. Compare bottom-up implementation. (1996-05-10) 1 1 1 1 1 botwar The epic struggle of bots vying for dominance. Botwars are generally (and quite inappropriately) carried out on talk systems, typically IRC, where botwar crossfire (such as pingflooding) absorbs scarce server resources and obstructs human conversation. The wisdom of experience indicates that Core Wars, not talk systems, are the appropriate venue for aggressive bots and their botmasters. Compare penis war. (1997-04-08) 1 1 1 1 1 bounce 1. (Perhaps by analogy to a bouncing check) An electronic mail message that is undeliverable and returns an error notification (a "bounce message") to the sender is said to bounce. 2. To play volleyball. The now-demolished D. C. Power Lab building used by the Stanford AI Lab in the 1970s had a volleyball court on the front lawn. From 5 PM to 7 PM was the scheduled maintenance time for the computer, so every afternoon at 5 would come over the intercom the cry: "Now hear this: bounce, bounce!", followed by Brian McCune loudly bouncing a volleyball on the floor outside the offices of known volleyballers. 3. To engage in sexual intercourse; probably from the expression "bouncing the mattress", but influenced by Roo's psychosexually loaded "Try bouncing me, Tigger!" from the Winnie-the-Pooh books. Compare boink. 1 1 1 1 1 bounce message A notification message returned to the sender by a site unable to relay e-mail to the intended recipient or the next link in a bang path. Reasons might include a nonexistent or misspelled user name or a down relay site. Bounce messages can themselves fail, with occasionally ugly results; see sorcerer's apprentice mode and software laser. The terms bounce mail and "barfmail" are also common. [Jargon File] (1994-11-29) 1 1 1 1 1 boundary scan The use of scan registers to capture state from device input and output pins. IEEE Standard 1149.1-1990 describes the international standard implementation (sometimes called JTAG after the Joint Test Action Group which began the standardisation work). (1995-02-14) 1 1 1 1 1 boundary value boundary value analysis 1 1 1 1 1 boundary value analysis A test data selection technique in which values are chosen to lie along data extremes. Boundary values include maximum, minimum, just inside/outside boundaries, typical values, and error values. The hope is that, if a systems works correctly for these special values then it will work correctly for all values in between. (1996-05-10) 1 1 1 1 1 bounded In domain theory, a subset S of a cpo X is bounded if there exists x in X such that for all s in S, s <= x. In other words, there is some element above all of S. If every bounded subset of X has a least upper bound then X is boundedly complete. ("<=" is written in LaTeX as \subseteq). (1995-02-03) 1 1 1 1 1 boundedly complete (Or "consistently complete") In domain theory, a complete partial order is boundedly complete if every bounded subset has a least upper bound. (2014-07-01) 1 1 1 1 1 bound variable 1. A bound variable or formal argument in a function definition is replaced by the actual argument when the function is applied. In the lambda abstraction \ x . M x is the bound variable. However, x is a free variable of the term M when M is considered on its own. M is the scope of the binding of x. 2. In logic a bound variable is a quantified variable. See quantifier. 1 1 1 1 1 bournebasic A BASIC interpreter. comp.sources.misc archives volume 1. 1 1 1 1 1 Bourne shell (sh, Shellish). The original command-line interpreter shell and script language for Unix written by S.R. Bourne of Bell Laboratories in 1978. sh has been superseded for interactive use by the Berkeley C shell, csh but still widely used for writing shell scripts. There were even earlier shells, see glob. [Details?] ash is a Bourne Shell clone. ["Unix Time-Sharing System: The Unix Shell", S.R. Bourne, Bell Sys Tech J 57(6):1971-1990 (Jul 1978)]. 1 1 1 1 1 boustrophedonic (From the Greek "boustrophe-don": turning like oxen in plowing; from "bous": ox, cow; "strephein": to turn) An ancient method of writing using alternate left-to-right and right-to-left lines. It used for an optimisation performed by some computer typesetting software and moving-head printers to reduce physical movement of the print head. The adverbial form "boustrophedonically" is also found. (1994-11-29) 1 1 1 1 1 box 1. A computer; especially in the construction "foo box" where foo is some functional qualifier, like "graphics", or the name of an operating system (thus, "Unix box", MS-DOS box, etc.) "We preprocess the data on Unix boxes before handing it up to the mainframe." The plural boxen is sometimes seen. 2. Without qualification in an IBM SNA site, "box" refers specifically to an IBM front-end processor. [Jargon File] (1994-11-29) 1 1 1 1 1 boxed comments Comments that occupy several lines by themselves; so called because in assembler and C code they are often surrounded by a box in a style similar to this: /************************************************* * * This is a boxed comment in C style * *************************************************/ Common variants of this style omit the asterisks in column 2 or add a matching row of asterisks closing the right side of the box. The sparest variant omits all but the comment delimiters themselves; the "box" is implied. Opposite of winged comments. [Jargon File] (1997-07-21) 1 1 1 1 1 boxen /bok'sn/ (By analogy with VAXen) A fanciful plural of box often encountered in the phrase "Unix boxen", used to describe commodity Unix hardware. The connotation is that any two Unix boxen are interchangeable. [Jargon File] (1994-11-29) 1 1 1 1 1 Boxer 1. <language> A visual language by Hal Abelson and Andy diSessa of Berkeley which claims to be the successor to Logo. Boxes are used to represent scope. 2. <tool> A text editor for MS-DOS and Microsoft Windows. (http://boxersoftware.com/users/dhamel). (2001-04-30) 1 1 1 1 1 boxology /bok-sol'*-jee/ ASCII art. This term implies a more restricted domain, that of box-and-arrow drawings. "His report has a lot of boxology in it." Compare macrology. [Jargon File] (1994-12-02) 1 1 1 1 1 Boycott Apple Some time before 1989, Apple Computer, Inc. started a lawsuit against Hewlett-Packard and Microsoft, claiming they had breeched Apple's copyright on the look and feel of the Macintosh user interface. In December 1989, Xerox failed to sue Apple Computer, claiming that the software for Apple's Lisa computer and Macintosh Finder, both copyrighted in 1987, were derived from two Xerox programs: Smalltalk, developed in the mid-1970s and Star, copyrighted in 1981. Apple wanted to stop people from writing any program that worked even vaguely like a Macintosh. If such look and feel lawsuits succeed they could put an end to free software that could substitute for commercial software. In the weeks after the suit was filed, Usenet reverberated with condemnation for Apple. GNU supporters Richard Stallman, John Gilmore and Paul Rubin decided to take action against Apple. Apple's reputation as a force for progress came from having made better computers; but The League for Programming 1 1 1 1 1 bozotic (From Bozo the Clown, a famous circus personality, via bozo - a clod, idiot or generally silly person) any form of clown-like or ludicrous behaviour. The word also has echoes of "robotic", so bozotic behaviour is mindless, automaton-like stupidity. [Jargon File] (1996-01-05) 1 1 1 1 1 BPEL Web Services Business Process Execution Language 1 1 1 1 1 BPI bits per inch 1 1 1 1 1 bpmake Aspirin 1 1 1 1 1 bpp bits per pixel 1 1 1 1 1 BPR Business Process Re-engineering 1 1 1 1 1 BPS Basic Programming Support 1 1 1 1 1 bps bits per second 1 1 1 1 1 BQS Berkeley Quality Software 1 1 1 1 1 br The country code for Brazil. (1999-01-27) 1 1 1 1 1 brace left brace or right brace. 1 1 1 1 1 bracket (Or square bracket) A left bracket or right bracket. Often used loosely for parentheses, square brackets, braces, angle brackets, or any other kind of unequal paired delimiters. (1996-09-08) 1 1 1 1 1 bracket abstraction An algorithm which turns a term into a function of some variable. The result of using bracket abstraction on T with respect to variable v, written as [v]T, is a term containing no occurrences of v and denoting a function f such that f v = T. This defines the function f = (\ v . T). Using bracket abstraction and currying we can define a language without bound variables in which the only operation is monadic function application. See combinator. (1995-03-07) 1 1 1 1 1 braille /breyl/ (Often capitalised) A class of writing systems, intended for use by blind and low-vision users, which express glyphs as raised dots. Currently employed braille standards use eight dots per cell, where a cell is a glyph-space two dots across by four dots high; most glyphs use only the top six dots. Braille was developed by Louis Braille (pronounced /looy bray/) in France in the 1820s. Braille systems for most languages can be fairly trivially converted to and from the usual script. Braille has several totally coincidental parallels with digital computing: it is binary, it is based on groups of eight bits/dots and its development began in the 1820s, at the same time Charles Babbage proposed the Difference Engine. Computers output Braille on braille displays and braille printers for hard copy. British Royal National Institute for the Blind 1 1 1 1 1 braille display (Or "refreshable braille display", "refreshable display") An electromechanical device that renders braille with tiny, independently controlled pins used to represent the state of dots in braille cells. Each pin, in its "on" state, raises above the top of its hole in the screen; in its "off" state, it drops below the top of its hole. Older systems used tiny solenoids to control the state of the pins; modern systems are piezoelectric. Typical dimensions of a braille display are 1 line of 40 cells, each cell of two-by-eight dots. (1998-10-19) 1 1 1 1 1 Braille embosser Braille printer 1 1 1 1 1 Braille printer (Or "(Braille) embosser") A printer, necessarily an impact printer, that renders text as Braille. Blind users call other printers ink printers. (1999-02-26) 1 1 1 1 1 Brain Aid Prolog (BAP) A parallel Prolog environment for transputer systems by Frank Bergmann <fraber@fraber.de>, Martin Ostermann <ost@xan.dfv.rwth-aachen.de>, and Guido von Walter <guido@parsytec.de> of Brain Aid Systems GbR. BAP is based on a model of communicating sequential Prolog processes. The run-time system consists of a multi-process operating system with support for several applications running concurrently. (http://fraber.de/bap/). (2002-11-12) 1 1 1 1 1 brain-damaged 1. [generalisation of "Honeywell Brain Damage" (HBD), a theoretical disease invented to explain certain utter cretinisms in Honeywell Multics] Obviously wrong; cretinous; demented. There is an implication that the person responsible must have suffered brain damage, because he should have known better. Calling something brain-damaged is really bad; it also implies it is unusable, and that its failure to work is due to poor design rather than some accident. "Only six monocase characters per file name? Now *that's* brain-damaged!" 2. [especially in the Mac world] May refer to free demonstration software that has been deliberately crippled in some way so as not to compete with the commercial product it is intended to sell. Synonym crippleware. [Jargon File] (2011-01-04) 1 1 1 1 1 brain-dead Brain-damaged in the extreme. It tends to imply terminal design failure rather than malfunction or simple stupidity. 1 1 1 1 1 brain dump (The act of telling someone) everything one knows about a particular topic. Typically used when someone is going to let a new party maintain a piece of code. Conceptually analogous to an operating system core dump in that it saves a lot of useful state before an exit. "You'll have to give me a brain dump on FOOBAR before you start your new job at HackerCorp." At Sun, this is also known as "TOI" (transfer of information). [Jargon File] 1 1 1 1 1 brain fart 1. The actual result of a braino, as opposed to the mental glitch that is the braino itself. E.g. typing "dir" on a Unix box after a session with MS-DOS. 2. A biproduct of a bloated mind producing information effortlessly. A burst of useful information. "I know you're busy on the Microsoft story, but can you give us a brain fart on the Mitnik bust?" (1997-04-29) 1 1 1 1 1 Brainfuck An eight-instruction esoteric programming language created by Urban Müller. His goal was apparently to create a Turing-complete language with the smallest compiler ever, for the Amiga OS 2.0. He eventually reduced his compiler to under 200 bytes. A Brainfuck program has a pointer that moves within an array of 30000 bytes, initially all set to zero. The pointer initially points to the beginning of this array. The language has eight commands, each of which is represented as a single character, and which can be expressed in terms of C as follows: > ==> ++p; < ==> --p; + ==> ++*p; - ==> --*p; . ==> putchar(*p); , ==> *p = getchar(); 1 1 1 1 1 braino thinko 1 1 1 1 1 branch 1. <mathematics> An edge in a tree. 2. <programming> A jump. 1 1 1 1 1 Branch and Hang (BRH) Originally a mythical instruction for the IBM 1130 at Indiana University. Later some real examples were discovered. The Texas Instruments TI-980 allowed all addressing modes with all instructions, including Store Immediate Extended (stores the value into the extension word of the instruction) and Branch and Link Immediate (makes a subroutine call to the same instruction -- Branch and Hang). Compare HCF. (1997-02-12) 1 1 1 1 1 branch coverage testing A test method which aims to ensure that each possible branch from each decision point (e.g. "if" statement) is executed at least once, thus ensuring that all reachable code is executed. (1996-05-10) 1 1 1 1 1 branch delay slot delayed control-transfer 1 1 1 1 1 Branch on Chip Box Full (BCBF) A mythical IBM 1130 instruction whose action depended on the contents of the chip box. This was one of a long list of fake assembly language instructions that went around Indiana University in the 1970s. (1997-02-12) 1 1 1 1 1 branch prediction A technique used in some processors with instruction prefetch to guess whether a conditional branch will be taken or not and prefetch code from the appropriate location. When a branch instruction is executed, its address and that of the next instruction executed (the chosen destination of the branch) are stored in the Branch Target Buffer. This information is used to predict which way the instruction will branch the next time it is executed so that instruction prefetch can continue. When the prediction is correct (and it is over 90% of the time), executing a branch does not cause a pipeline break. Some later CPUs simply prefetch both paths instead of trying to predict which way the branch will go. An extension of the idea of branch prediction is speculative execution. (1998-03-14) 1 1 1 1 1 Branch Target Buffer (BTB) A register used to store the predicted destination of a branch in a processor using branch prediction? [Is this correct? Examples?] (1995-05-05) 1 1 1 1 1 branch to Fishkill (IBM: from the location of one of the corporation's facilities) Any unexpected jump in a program that produces catastrophic or just plain weird results. See jump off into never-never land, hyperspace. [Jargon File] 1 1 1 1 1 Brazil An operating system from Acorn Computers used on an ARM card which could be fitted to an IBM PC. There was also an ARM second processor for the BBC Microcomputer which used Brazil. Never used on the Archimedes(?). (1994-12-05) 1 1 1 1 1 BRB (I will) be right back. (1998-01-18) 1 1 1 1 1 breadcrumbs (After the story "Hansel and Gretel" by the Brothers Grimm). 1. <web> Links displayed across the top of a web page listing the most recently visited pages so the reader can quickly jump back to one. Since this function is provided by the web browser, breadcrumbs are a waste of space. A better use of the space is to display links to the page's logical parent pages in the information hierarchy. 2. <programming> Information output by statements inserted into a program for debugging by printf. [Jargon File] (2007-03-07) 1 1 1 1 1 breadth-first search A graph search algorithm which tries all one-step extensions of current paths before trying larger extensions. This requires all current paths to be kept in memory simultaneously, or at least their end points. Opposite of depth-first search. See also best first search. (1996-01-05) 1 1 1 1 1 break 1. To cause to be broken. "Your latest patch to the editor broke the paragraph commands." 2. (Of a program) To stop temporarily, so that it may debugged. The place where it stops is a "breakpoint". 3. To send an EIA-232 break (two character widths of line high) over a serial line. 4. [Unix] To strike whatever key currently causes the tty driver to send SIGINT to the current process. Normally, break, delete or control-C does this. 5. "break break" may be said to interrupt a conversation (this is an example of verb doubling). This usage comes from radio communications, which in turn probably came from landline telegraph/teleprinter usage, as badly abused in the Citizen's Band craze. 6. pipeline break. 7. break statement. [Jargon File] 1 1 1 1 1 break-even point In the process of implementing a new computer language, the point at which the language is sufficiently effective that one can implement the language in itself. That is, for a new language called, hypothetically, FOOGOL, one has reached break-even when one can write a demonstration compiler for FOOGOL in FOOGOL, discard the original implementation language, and thereafter use working versions of FOOGOL to develop newer ones. This is an important milestone. See My Favourite Toy Language. [There actually is a language called Foogol]. 1 1 1 1 1 breakpoint A point in a program that, when reached, triggers some special behavior useful to the process of debugging; generally, breakpoints are used to either pause program execution, and/or dump the values of some or all of the program variables. Breakpoints may be part of the program itself; or they may be set by the programmer as part of an interactive session with a debugging tool for scrutinizing the program's execution. (1999-06-07) 1 1 1 1 1 break statement A statement in the C programming language that transfers control out of the innermost enclosing switch, while, do, or for statement. The statement also exists in languages derived from C, such as C++ and Java. (2004-03-24) 1 1 1 1 1 breath-of-life packet (XEROX PARC) An Ethernet packet that contains bootstrap code, periodically sent out from a working computer to infuse the "breath of life" into any computer on the network that has crashed. Computers depending on such packets have sufficient hardware or firmware code to wait for (or request) such a packet during the reboot process. See also dickless workstation. The notional "kiss-of-death packet", with a function complementary to that of a breath-of-life packet, is recommended for dealing with hosts that consume too many network resources. Though "kiss-of-death packet" is usually used in jest, there is at least one documented instance of an Internet subnet with limited address-table slots in a gateway computer in which such packets were routinely used to compete for slots, rather like Christmas shoppers competing for scarce parking spaces. [Jargon File] 1 1 1 1 1 breedle feep 1 1 1 1 1 BRH Branch and Hang 1 1 1 1 1 BRI Basic Rate Interface 1 1 1 1 1 Brian Reid The person who cofounded Usenet's anarchic alt.* newsgroup hierarchy with John Gilmore. (1997-04-12) 1 1 1 1 1 BRIDGE A component of ICES for civil engineers. [Sammet 1969, p. 616]. 1 1 1 1 1 bridge A device which forwards traffic between network segments based on data link layer information. These segments would have a common network layer address. Every network should only have one root bridge. See also gateway, router. (2001-03-04) 1 1 1 1 1 Bridgetalk A visual language. (2001-03-04) 1 1 1 1 1 briefcase A Win95/WinNT utility for keeping files on two computers without permanent connection in sync. The scenario briefcase was designed for is the combination of an office computer and a portable one. You connect the two before leaving your office, create a briefcase on the portable (if you don't already have one on it), then copy the files you want to work on while away into the briefcase. You can at this point disconnect the two computers, take the portable with you and work on the files in the briefcase at home or on the road. When you get back to your office the briefcase utility can automatically update the files you changed on the office computer. (1998-05-18) 1 1 1 1 1 brightness (Or "tone", "luminance", "value", "luminosity", lightness) The coordinate in the HSB colour model that determines the total amount of light in the colour. Zero brightness is black and 100% is white, intermediate values are light or "dark" colours. The other coordinates are hue and saturation. (1999-07-05) 1 1 1 1 1 Brilliant One of five pedagogical languages based on Markov algorithms, used in ["Nonpareil, a Machine Level Machine Independent Language for the Study of Semantics", B. Higman, ULICS Intl Report No ICSI 170, U London (1968)]. See also Diamond, Nonpareil, Pearl, Ruby. 1 1 1 1 1 bring X to its knees To present a computer, operating system, piece of software, or algorithm with a load so extreme or pathological that it grinds to a halt. "To bring a MicroVAX to its knees, try twenty users running vi - or four running Emacs." Compare hog. [Jargon File] 1 1 1 1 1 British Broadcasting Corporation (BBC) The non-commercial UK organisation that commissions, produces and broadcasts television and radio programmes. The BBC commissioned the "BBC Micro" from Acorn Computers for use in a television series about using computers. They also have one of the world's most respected news websites (on which I work!). BBC Home (http://bbc.co.uk/). BBC News (http://news.bbc.co.uk/). (2003-07-02) 1 1 1 1 1 British Library Method Brute force searching. According to legends circulating in the 1970s, in the British Library books are searched for by examining each book sequentially in the first shelf, then the next shelf, continuing until the book is found or the entire library has been searched. The term was referred to in a Dutch coursebook, "Inleiding In De Informatica" (Introduction to Informatics) from a course given by C.H.A. Koster and Th.A. Zoethout. This was based on a course given at the TU Berlin. [Reference?] (1999-04-14) 1 1 1 1 1 British Standards Institute (BSI) The British member of ISO. (1996-06-12) 1 1 1 1 1 British Telecom (BT) The largest telecommunications provider in the UK. Due to regulatory issues, BT had to sell off its interest in McCaw Cellular. BT sold it to AT&T for something like 4B$. BT then invested that in MCI. As a part of the deal, MCI was given BT North America, which was the old Tymnet. MCI laid off about 40% of the Tymnet staff. (http://intervid.co.uk/). (1995-05-09) 1 1 1 1 1 British Telecom Research Laboratories (BTRL) The laboratories where British Telecom develops many of its new Network services. (http://labs.bt.com/). Address: Martlesham Heath, near Ipswich, Suffolk, UK. (1995-04-25) 1 1 1 1 1 brittle Said of software that is functional but easily broken by changes in operating environment or configuration, or by any minor tweak to the software itself. Also, any system that responds inappropriately and disastrously to abnormal but expected external stimuli; e.g. a file system that is usually totally scrambled by a power failure is said to be brittle. This term is often used to describe the results of a research effort that were never intended to be robust, but it can be applied to commercially developed software, which displays the quality far more often than it ought to. Opposite of robust. [Jargon File] (1995-05-09) 1 1 1 1 1 broadband A class of communication channel capable of supporting a wide range of frequencies, typically from audio up to video frequencies. A broadband channel can carry multiple signals by dividing the total capacity into multiple, independent bandwidth channels, where each channel operates only on a specific range of frequencies. The term has come to be used for any kind of Internet connection with a download speed of more than 56 kbps, usually some kind of Digital Subscriber Line, e.g. ADSL. A broadband connection is typically always connected, in contrast to a dial-up connection, and a fixed monthly rate is charged, often with a cap on the total amount of data that can be transferred. Domestic broadband connections typically share a telephone line with normal voice calls and the two uses can occur simultaneously without interference. See also baseband, narrowband. (2006-03-30) 1 1 1 1 1 broadcast A transmission to multiple, unspecified recipients. On Ethernet, a broadcast packet is a special type of multicast packet which all nodes on the network are always willing to receive. 1 1 1 1 1 broadcast quality video Roughly, video with more than 30 frames per second at a resolution of 800 x 640 pixels. The quality of moving pictures and sound is determined by the complete chain from camera to receiver. Relevant factors are the colour temperature of the lighting, the balance of the red, green and blue vision pick-up tubes to produce the correct display colour temperature (which will be different) and the gamma pre-correction to cancel the non-linear characteristic of cathode-ray tubes in television receivers. The resolution of the camera tube and video coding system will determine the maximum number of pixels in the picture. Different colour coding systems have different defects. The NTSC system (National Television Systems Committee) can produce hue errors. The PAL system (Phase Alternation by Line) can produce saturation errors. Television modulation systems are specified by ITU CCIR Report 624. Low-resolution systems have bandwidths of 4.2 MHz with 1 1 1 1 1 broadcast storm A broadcast on a network that causes multiple hosts to respond by broadcasting themselves, causing the storm to grow exponentially in severity. See network meltdown. [Jargon File] (1995-02-07) 1 1 1 1 1 Broadway A standard which the X Consortium is currently (January 1997) developing and plans to release soon as an open standard. A prime goal is to be more bandwidth-efficient and easier to develop for (and to port) than the X Window System, which has been widely described as over-sized, over-featured, over-engineered and incredibly over-complicated. (http://x.org/consortium/broadway.html). (1997-05-15) 1 1 1 1 1 brochureware A planned, but non-existent, product, like vaporware but with the added implication that marketing is actively selling and promoting it (they've printed brochures). Brochureware is often deployed to con customers into not committing to a competing existing product. The term is now especially applicable to new websites, website revisions, and ancillary services such as customer support and product return. Owing to the explosion of database-driven, cookie-using dot-coms (of the sort that can now deduce that you are, in fact, a dog), the term is now also used to describe sites made up of static HTML pages that contain not much more than contact info and mission statements. The term suggests that the company is small, irrelevant to the web, local in scope, clueless, broke, just starting out, or some combination thereof. Many new companies without product, funding, or even staff, 1 1 1 1 1 broken Not working properly (of programs). 1 1 1 1 1 broken arrow The error code displayed on line 25 of a IBM 3270 terminal (or a terminal emulator emulating a 3270) for various kinds of protocol violations and "unexpected" error conditions (including connection to a down computer). On a PC, simulated with "->/_", with the two centre characters overstruck. Broken arrow is also military jargon for an accident involving nuclear weapons. [Jargon File] (1995-02-07) 1 1 1 1 1 broker object request broker 1 1 1 1 1 broket /broh'k*t/ or /broh'ket/ (From broken bracket) Either of the characters "<" or ">" when used as paired enclosing delimiters (angle brackets). [Jargon File] (1997-07-21) 1 1 1 1 1 brontobyte A proposed unit of data equal to 10^27 bytes. A brontobyte is 1000^9 bytes or 1000 yottabytes. Bronto- is not an official prefix and the term brontobyte is generally attributed to the IBM Dictionary of Computing. One brontobyte would be enough data to store a three-dimensional map of the Earth with one byte for each voxel of a one-centimetre grid. See prefix. [Where did IBM get it from?] (2013-11-04) 1 1 1 1 1 Brooks's Law "Adding manpower to a late software project makes it later" - a result of the fact that the expected advantage from splitting work among N programmers is O(N) (that is, proportional to N), but the complexity and communications cost associated with coordinating and then merging their work is O(N^2) (that is, proportional to the square of N). The quote is from Fred Brooks, a manager of IBM's OS/360 project and author of "The Mythical Man-Month". The myth in question has been most tersely expressed as Programmer time is fungible and Brooks established conclusively that it is not. Hackers have never forgotten his advice; too often, management still does. See also creationism, second-system effect, optimism. [Jargon File] (1996-09-17) 1 1 1 1 1 brouter A device which bridges some packets (i.e. forwards based on data link layer information) and routes other packets (i.e. forwards based on network layer information). The bridge/route decision is based on configuration information. 1 1 1 1 1 Brouwer Fixed-Point Theorem A well-known result in topology stating that any continuous transformation of an n-dimensional disk must have at least one fixed point. [Is this correct?] (2001-03-29) 1 1 1 1 1 Brown and Sharpe Wire Gauge American Wire Gauge 1 1 1 1 1 brown paper bag bug A programming bug that is so stupid that it makes the programmer want to put a brown paper bag over his head. (2001-01-16) 1 1 1 1 1 browser A program which allows a person to read hypertext. The browser gives some means of viewing the contents of nodes (or "pages") and of navigating from one node to another. Netscape Navigator, NCSA Mosaic, Lynx, and W3 are examples for browsers for the web. They act as clients to remote web servers. (1996-05-31) 1 1 1 1 1 browserconfig.xml A Microsoft configuration file used to customise the appearance and behaviour of website links pinned to the Windows start screen or desktop taskbar. browserconfig.xml allows the site owner to specify things like badges and tile images. browserconfig.xml reference (http://msdn.microsoft.com/en-us/library/ie/dn320426%28v=vs.85%29.aspx). (2014-07-24) 1 1 1 1 1 BRS Big Red Switch 1 1 1 1 1 BRUIN Brown University Interactive Language. A simple interactive language with PL/I-like syntax, for IBM 360. ["Meeting the Computational Requirements of the University, Brown University Interactive Language", R.G. Munck, Proc 24th ACM Conf, 1969]. (1995-02-14) 1 1 1 1 1 brute force A primitive programming style in which the programmer relies on the computer's processing power instead of using his own intelligence to simplify the problem, often ignoring problems of scale and applying naive methods suited to small problems directly to large ones. The term can also be used in reference to programming style: brute-force programs are written in a heavy-handed, tedious way, full of repetition and devoid of any elegance or useful abstraction (see also brute force and ignorance). The canonical example of a brute-force algorithm is associated with the "travelling salesman problem" (TSP), a classical NP-hard problem: Suppose a person is in, say, Boston, and wishes to drive to N other cities. In what order should the cities be visited in order to minimise the distance travelled? The brute-force method is to simply generate all possible routes and compare the distances; while guaranteed to work and 1 1 1 1 1 brute force and ignorance (BFI) A popular design technique at many software houses - brute force coding unrelieved by any knowledge of how problems have been previously solved in elegant ways. Dogmatic adherence to design methods tends to encourage this sort of thing. Characteristic of early larval stage programming; unfortunately, many never outgrow it. Also encountered in the variants BFMI - brute force and massive ignorance, and BFBI - brute force and bloody ignorance. Gak, they used a bubble sort! That's strictly BFI. Compare bogosity. [Jargon File] (1996-06-12) 1 1 1 1 1 brute force attack A method of breaking a cipher (that is, to decrypt a specific encrypted text) by trying every possible key. The quicker the brute force attack, the weaker the cipher. Feasibility of brute force attack depends on the key length of the cipher, and on the amount of computational power available to the attacker. Brute force attack is impossible against the ciphers with variable-size key, such as a one-time pad cipher. Breaking ciphers with many workstations (http://distributed.net/projects.html.en). (2000-01-16) 1 1 1 1 1 BS backspace 1 1 1 1 1 bs The country code for the Bahamas. (1999-01-27) 1 1 1 1 1 BS2000 An operating system from SNI for mainframes. (http://mch.sni.de.public/bs2000/server.htm). (1997-06-13) 1 1 1 1 1 BSA 1. Business Software Alliance. 2. Bidouilleurs Sans Argent. 1 1 1 1 1 BSD Berkeley Software Distribution 1 1 1 1 1 BSD386 386BSD 1 1 1 1 1 BSDI Berkeley Software Design, Inc. 1 1 1 1 1 BSD/OS BSDI's commercial version of Berkeley Standard Distribution Unix. BSD/OS is a POSIX-compatible, Unix-like system for the 80386, 486, and Pentium. It is based on the BSD software from UCB, a number of other sources, and components engineered by BSDI. The initial production release of BSD/OS shipped in March, 1993 (1996-01-13) 1 1 1 1 1 BSD Unix Berkeley Software Distribution 1 1 1 1 1 BSI British Standards Institute 1 1 1 1 1 BSL A variant of IBM's PL/S systems language. Versions: BSL1, BSL2. (1998-06-15) 1 1 1 1 1 BSOD Blue Screen of Death 1 1 1 1 1 BSOL Blue Screen of Life 1 1 1 1 1 BSOM Beats the shit outa me 1 1 1 1 1 BSP method A CASE method from IBM. (1998-02-24) 1 1 1 1 1 BSRAM Burst Static Random Access Memory 1 1 1 1 1 BSS 1. <programming> Block Started by Symbol. 2. <networking> Basic Service Set 1 1 1 1 1 BSS segment Block Started by Symbol 1 1 1 1 1 BST British Summer Time. The name for daylight-saving time in the UK GMT time zone. (2000-03-28) 1 1 1 1 1 bt The country code for Bhutan. (1999-01-27) 1 1 1 1 1 BTB Branch Target Buffer 1 1 1 1 1 btoa /B too A/ A binary to ASCII conversion utility. btoa is a uuencode or base 64 equivalent which addresses some of the problems with the uuencode standard but not as many as the base 64 standard. It avoids problems that some hosts have with spaces (e.g. conversion of groups of spaces to tabs) by not including them in its character set, but may still have problems on non-ASCII systems (e.g. EBCDIC). btoa is primarily used to transfer binary files between systems across connections which are not eight-bit clean, e.g. electronic mail. btoa takes adjacent sets of four binary octets and encodes them as five ASCII octets using ASCII characters '!' through to 'u'. Special characters are also used: 'x' marks the beginning or end of the archive; 'z' marks four consecutive zeros and 'y' (version 5.2) four consecutive spaces. Each group of four octets is processed as a 32-bit integer. 1 1 1 1 1 B-Toolkit A set of software tools designed to support a rigorous or formal development of software systems using the B-Method. The Toolkit also provides a development environment automating the management of all associated files, ensuring that the entire development, including code and documentation, is always in a consistent state. The Toolkit includes: a specification, design and code configuration management system, including integrity and dependency management and source file editing facilities; a set of software specification and design analysis tools, which includes syntax checkers, type checkers and a specification animator; a set of verification tools, which includes a proof-obligation generator and automatic and interactive provers; a set of coding tools, which includes a translator, linker, rapid prototyping facilities and a reusable specification/code module library; a documentation tool for 1 1 1 1 1 BTOS Convergent Technologies Operating System 1 1 1 1 1 B-tree A multi-way balanced tree. The "B" in B-tree has never been officially defined. It could stand for "balanced" or "Bayer", after one of the original designers of the algorithms and structure. A B-tree is _not_ (necessarily?) a "binary tree". A B+-tree (as used by IBM's VSAM) is a B-tree where the leaves are also linked sequentially, thus allowing both fast random access and sequential access to data. [Knuth's Art of Computer Programming]. [Example algorithm?] (2000-01-10) 1 1 1 1 1 BTRIEVE 1. <company> BTRIEVE Technologies, Inc.. 2. <tool> A trademark of BTRIEVE Technologies, Inc. for their ISAM index file manager for IBM PCs. (1995-03-28) 1 1 1 1 1 BTRIEVE Technologies, Inc. /bee-treev/ (BTI) A provider of client-server database engines. BTI was founded by former Novell, Inc. employees, including the original developers of the Btrieve database engine. BTI acquired the database product line from Novell in April, 1994. (http://btrieve.com/). Address: Austin, Texas, USA. (1995-12-14) 1 1 1 1 1 BTRL British Telecom Research Laboratories. 1 1 1 1 1 BTS Bug Tracking System 1 1 1 1 1 BTW By the way. (2002-06-12) 1 1 1 1 1 BUAF [alt.fan.warlord] Big Ugly ASCII Font. A special form of ASCII art. Various programs exist for rendering text strings into block, bloob, and pseudo-script fonts in cells between four and six character cells on a side; this is smaller than the letters generated by older banner programs. These are sometimes used to render one's name in a sig block, and are critically referred to as "BUAF"s. See warlording. [Jargon File] 1 1 1 1 1 BUAG [alt.fan.warlord] Big Ugly ASCII Graphic. Pejorative term for ugly ASCII ART, especially as found in sig blocks. For some reason, mutations of the head of Bart Simpson are particularly common in the least imaginative sig blocks. See warlording. 1 1 1 1 1 bubble memory A storage device built using materials such as gadolinium gallium garnet which are can be magnetised easily in only one direction. A film of these materials can be created so that it is magnetisable in an up-down direction. The magnetic fields tend to join together, some with the north pole facing up, some with the south. When a veritcal magnetic field is imposed on this, the areas in opposite alignment to the field shrink to circles, or 'bubbles'. A bubble can be formed by reversing the field in a small spot, and can be destroyed by increasing the field. Bubble memory is a kind of non-volatile storage but EEPROM, Flash Erasable Programmable Read-Only Memory and ferroelectric technologies, which are also non-volatile, are faster. ["Great Microprocessors of the Past and Present", V 4.0.0, John Bayko <bayko@hercules.cs.uregina.ca>, Appendix C] (1995-02-03) 1 1 1 1 1 bubble sort A sorting technique in which pairs of adjacent values in the list to be sorted are compared and interchanged if they are out of order; thus, list entries "bubble upward" in the list until they bump into one with a lower sort value. Because it is not very good relative to other methods and is the one typically stumbled on by naive and untutored programmers, hackers consider it the canonical example of a naive algorithm. The canonical example of a really *bad* algorithm is bogo-sort. A bubble sort might be used out of ignorance, but any use of bogo-sort could issue only from brain damage or willful perversity. [Jargon File] 1 1 1 1 1 bucky bits /buh'kee bits/ 1. Obsolete. The bits produced by the CONTROL and META shift keys on a SAIL keyboard (octal 200 and 400 respectively), resulting in a 9-bit keyboard character set. The MIT AI TV (Knight) keyboards extended this with TOP and separate left and right CONTROL and META keys, resulting in a 12-bit character set; later, LISP Machines added such keys as SUPER, HYPER, and GREEK (see space-cadet keyboard). 2. By extension, bits associated with "extra" shift keys on any keyboard, e.g. the ALT on an IBM PC or command and option keys on a Macintosh. It has long been rumored that "bucky bits" were named after Buckminster Fuller during a period when he was consulting at Stanford. Actually, bucky bits were invented by Niklaus Wirth when *he* was at Stanford in 1964--65; he first suggested the idea of an EDIT key to set the 8th bit of an otherwise 7 bit ASCII character. It seems that, unknown to Wirth, certain Stanford hackers had privately nicknamed him "Bucky" after a 1 1 1 1 1 buffer 1. An area of memory used for storing messages. Typically, a buffer will have other attributes such as an input pointer (where new data will be written into the buffer), and output pointer (where the next item will be read from) and/or a count of the space used or free. Buffers are used to decouple processes so that the reader and writer may operate at different speeds or on different sized blocks of data. There are many different algorithms for using buffers, e.g. first-in first-out (FIFO or shelf), last-in first-out (LIFO or stack), double buffering (allowing one buffer to be read while the other is being written), cyclic buffer (reading or writing past the end wraps around to the beginning). 2. An electronic device to provide compatibility between two signals, e.g. changing voltage levels or current capability. 1 1 1 1 1 buffered write-through A variation of write-through where the cache uses a "write buffer" to hold data being written back to main memory. This frees the cache to service read requests while the write is taking place. There is usually only one stage of buffering so subsequent writes must wait until the first is complete. Most accesses are reads so buffered write-through is only useful for very slow main memory. (1998-04-24) 1 1 1 1 1 buffer overflow What happens when you try to store more data in a buffer than it can handle. This may be due to a mismatch in the processing rates of the producing and consuming processes (see overrun and firehose syndrome), or because the buffer is simply too small to hold all the data that must accumulate before a piece of it can be processed. For example, in a text-processing tool that crunches a line at a time, a short line buffer can result in lossage as input from a long line overflows the buffer and overwrites data beyond it. Good defensive programming would check for overflow on each character and stop accepting data when the buffer is full. See also spam, overrun screw. [Jargon File] (1996-05-13) 1 1 1 1 1 buffer overrun buffer overflow 1 1 1 1 1 bug An unwanted and unintended property of a program or piece of hardware, especially one that causes it to malfunction. Antonym of feature. E.g. "There's a bug in the editor: it writes things out backward." The identification and removal of bugs in a program is called debugging. Admiral Grace Hopper (an early computing pioneer better known for inventing COBOL) liked to tell a story in which a technician solved a glitch in the Harvard Mark II machine by pulling an actual insect out from between the contacts of one of its relays, and she subsequently promulgated bug in its hackish sense as a joke about the incident (though, as she was careful to admit, she was not there when it happened). For many years the logbook associated with the incident and the actual bug in question (a moth) sat in a display case at the Naval Surface Warfare Center (NSWC). The entire story, with a picture of the logbook and the moth taped into it, is 1 1 1 1 1 bug-compatible Said of a design or revision that has been badly compromised by a requirement to be compatible with fossils or misfeatures in other programs or (especially) previous releases of itself. "MS-DOS 2.0 used \ as a path separator to be bug-compatible with some cretin's choice of / as an option character in 1.0." [Jargon File] 1 1 1 1 1 bug fix A change to a program or system intended to permanently cure a bug. Often a fix for one bug inadvertantly introduces new bugs, hence the need for careful forethought and testing. Compare: workaround. (1998-06-25) 1 1 1 1 1 bug fix release A release which introduces no new features, but which merely aims to fix bugs in previous releases. All too commonly new bugs are introduced at the same time. (1996-08-04) 1 1 1 1 1 Bugfoot Loch Ness Monster Bug 1 1 1 1 1 bug-for-bug compatible Same as bug-compatible, with the additional implication that much tedious effort went into ensuring that each (known) bug was replicated. [Jargon File] 1 1 1 1 1 buglix /buhg'liks/ Pejorative term referring to DEC's ULTRIX operating system in its earlier *severely* buggy versions. Still used to describe ULTRIX, but without nearly so much venom. Compare AIDX, HP-SUX, Nominal Semidestructor, Telerat, sun-stools. 1 1 1 1 1 bugs bug 1 1 1 1 1 BUGSYS A programming system for pattern recognition and preparing animated films, for IBM 7094 and IBM 360. ["BUGSYS: A Programming System for Picture Processing - Not for Debugging", R.A. Ledley et al, CACM 9(2) (Feb 1966)]. (1995-02-14) 1 1 1 1 1 bug tracking system (BTS) A system for receiving and filing bugs reported against a software project, and tracking those bugs until they are fixed. Most major software projects have their own BTS, the source code of which is often available for use by other projects. Well known BTSs include GNATS, Bugzilla, and Debbugs. (2002-06-12) 1 1 1 1 1 Bugzilla The web-based bug tracking system used by the Mozilla project. Bugzilla home (http://bugzilla.mozilla.org/). (2002-06-12) 1 1 1 1 1 build To process all of a project's source code and other digital assets or resources in order to produce a deployable product. In the simplest case this might mean compiling one file of C source to produce an executable file. More complex builds would typically involve compiling multiple source files, building library modules, packaging intermediate build products (e.g. Java class files in a jar file), adding or updating version information and other data about the product (e.g. intended deployment platform), running tests and interacting with a source code control system. The build process is normally automated using tools such as Unix make, Apache ant or as part of an integrated development environment. This is taken one step further by continuous integration set-ups which periodically build the system while you are working on it. (2011-12-16) 1 1 1 1 1 built-in (Or "primitive") A built-in function or operator is one provided by the lowest level of a language implementation. This usually means it is not possible (or efficient) to express it in the language itself. Typical examples are the basic arithmetic and Boolean operators (in C syntax: +, -, *, /, %, !, &&, ||), bit manipulation operators (~, &, |, ^) and I/O primitives. Other common functions may be provided in libraries but are not built-in if they are written in the language being implemented. (1995-02-14) 1 1 1 1 1 Built-in Self Test (BIST) The technique of designing circuits with additional logic which can be used to test proper operation of the primary (functional) logic. (1995-02-14) 1 1 1 1 1 Bull Bull Information Systems 1 1 1 1 1 bulletin board bulletin board system 1 1 1 1 1 bulletin board system (BBS, bboard /bee'bord/, message board, forum; plural: BBSes) A computer and associated software which typically provides an electronic message database where people can log in and leave messages. Messages are typically split into topic groups similar to the newsgroups on Usenet (which is like a distributed BBS). Any user may submit or read any message in these public areas. The term comes from physical pieces of board on which people can pin messages written on paper for general consumption - a physical bulletin board. Ward Christensen, the programmer and operator of the first BBS (on-line 1978-02-16) called it a CBBS for "computer bulletin board system". Since the rise of the World-Wide Web, the term has become antiquated, though the concept is more popular than ever, with many websites featuring discussion areas where users can post messages for public consumption. Apart from public message areas, some BBSes provided archives 1 1 1 1 1 bulletproof Used of an algorithm or implementation considered extremely robust; lossage-resistant; capable of correctly recovering from any imaginable exception condition - a rare and valued quality. Synonym armor-plated. [Jargon File] 1 1 1 1 1 Bull Information Systems A multinational I.T. group based in Europe with 21,000 people and operations in more than 85 countries. In 1997, Bull earned revenues of over $4 billion, including over 65% outside of France, its country of origin. The company is ranked as the third largest systems integrator in Europe. (http://bull.com/). (1998-07-02) 1 1 1 1 1 bum 1. To make highly efficient, either in time or space, often at the expense of clarity. "I managed to bum three more instructions out of that code." "I spent half the night bumming the interrupt code." In elder days, John McCarthy (inventor of Lisp) used to compare some efficiency-obsessed hackers among his students to "ski bums"; thus, optimisation became "program bumming", and eventually just "bumming". 2. To squeeze out excess; to remove something in order to improve whatever it was removed from (without changing function; this distinguishes the process from a featurectomy). 3. A small change to an algorithm, program, or hardware device to make it more efficient. "This hardware bum makes the jump instruction faster." Usage: now uncommon, largely superseded by v. tune (and tweak, hack), though none of these exactly capture sense 2. All these uses are rare in Commonwealth hackish, because 1 1 1 1 1 bump Increment. E.g. C's ++ operator. It is used especially of counter variables, pointers and index dummies in "for", while, and "do-while" loops. (1994-11-29) 1 1 1 1 1 burble [Lewis Carroll's "Jabberwocky"] Like flame, but connotes that the source is truly clueless and ineffectual (mere flamers can be competent). A term of deep contempt. "There's some guy on the phone burbling about how he got a DISK FULL error and it's all our comm software's fault." This is mainstream slang in some parts of England. [Jargon File] 1 1 1 1 1 Bureau International des Poids et Mesures (BIPM) The standards body that ensures world-wide uniformity of measurements and their traceability to the International System of Units (SI). The BIPM is based in France and operates with the authority of the Convention of the Metre, a diplomatic treaty between fifty-one nations. It operates through a series of committees, whose members are the national metrology laboratories of the member states of the convention, and through its own laboratory work. The BIPM carries out measurement-related research. It takes part in, and organises, international comparisons of national measurement standards, and it carries out calibrations for member states. BIPM Home (http://www.bipm.org/). (2014-07-08) 1 1 1 1 1 Burge's Language Unnamed functional language based on lambda-calculus. Recursive Programming techniques", W.H. Burge, A-W 1975. 1 1 1 1 1 buried treasure A surprising piece of code found in some program. While usually not wrong, it tends to vary from crufty to bletcherous, and has lain undiscovered only because it was functionally correct, however horrible it is. Used sarcastically, because what is found is anything *but* treasure. Buried treasure almost always needs to be dug up and removed. "I just found that the scheduler sorts its queue using bubble sort! Buried treasure!" [Jargon File] 1 1 1 1 1 burn-in 1. <hardware> screen saver. 2. <hardware, testing> burn-in period. 1 1 1 1 1 burn-in period 1. <testing> A factory soak test intended to increase the chance that components that fail early due to infant mortality will fail before the system leaves the factory. 2. <jargon> When one is so intensely involved in a new project that one forgets basic needs such as food, drink and sleep. Excessive burn-in can lead to burn-out. See hack mode, larval stage. [Jargon File] (2007-01-17) 1 1 1 1 1 Burroughs Corporation A company which merged with Sperry Univac to form Unisys Corporation. They produced the Datatron 200 series among other computers. (2007-01-16) 1 1 1 1 1 Burst EDO Burst Extended Data Out DRAM 1 1 1 1 1 Burst Extended Data Out DRAM (Burst EDO, BEDO) A variant on EDO DRAM in which read or write cycles are batched in bursts of four. The bursts wrap around on a four byte boundary which means that only the two least significant bits of the CAS address are modified internally to produce each address of the burst sequence. Consequently, burst EDO bus speeds will range from 40MHz to 66MHz, well above the 33MHz bus speeds that can be accomplished using Fast Page Mode or EDO DRAM. Burst EDO was introduced sometime before May 1995. (1996-06-25) 1 1 1 1 1 burst page banner 1 1 1 1 1 Burst Static Random Access Memory (BSRAM) A kind of SRAM used primarily for external Level 2 cache memory. [How does it work?] (1998-02-24) 1 1 1 1 1 bus A set of electrical conductors (wires, PCB tracks or connections in an integrated circuit) connecting various "stations", which can be functional units in a computer or nodes in a network. A bus is a broadcast channel, meaning that each station receives every other station's transmissions and all stations have equal access to the bus. Various schemes have been invented to solve the problem of collisions: multiple stations trying to transmit at once, e.g. CSMA/CD, bus master. The term is almost certainly derived from the electrical engineering term "bus bar" - a substantial, rigid power supply conductor to which several connections are made. This was once written "'bus bar" as it was a contraction of "omnibus bar" - a connection bar "for all", by analogy with the passenger omnibus - a conveyance "for all". More on derivation (/pub/misc/omnibus.html). 1 1 1 1 1 bus error A fatal failure in the execution of a machine language instruction resulting from the processor detecting an anomalous condition on its bus. Such conditions include invalid address alignment (accessing a multi-byte number at an odd address), accessing a physical address that does not correspond to any device, or some other device-specific hardware error. A bus error triggers a processor-level exception which Unix translates into a "SIGBUS" signal which, if not caught, will terminate the current process. (2000-04-04) 1 1 1 1 1 Bush, Vannevar Vannevar Bush 1 1 1 1 1 Business Analyst A person who analyses the operations of a department or functional unit to develop a general systems solution to the problem. The solution will typically involve a combination of manual and automated processes. The business analyst can provide insights into an operation for an information systems analyst. (2004-03-09) 1 1 1 1 1 Business Application Programming Interface (BAPI) /bap'ee/ A set of methods provided by an SAP business object. Release 4.0 of SAP AG's R/3 system supports object-oriented programming via an interface defined in terms of objects and methods called BAPIs. For example if a material object provides a function to check availability, the corresponding SAP business object type "Material" might provide a BAPI called "Material.CheckAvailability". The definitions of SAP business objects and their BAPIs are kept in an SAP business object repository. SAP provide classes and libraries to enable a programming team to build SAP applications that use business objects and BAPIs. Supported environments include COM and Java. The Open BAPI Network (http://sap.com/solutions/technology/bapis/index.htm). gives background information and lists objects and BAPIs. (2002-08-30) 1 1 1 1 1 Business Process Re-engineering (BPR) Any radical change in the way in which an organisation performs its business activities. BPR involves a fundamental re-think of the business processes followed by a redesign of business activities to enhance all or most of its critical measures - costs, quality of service, staff dynamics, etc. (1999-09-27) 1 1 1 1 1 Business Software Alliance The BSA was created by Microsoft in 1988 in an attempt to combat software theft. The alliance includes the majority of leading software publishers including Novell, Symantec, and Autodesk and is actively campaigning in over 65 countries. The BSA operates a three-pronged approach: 1. Lobbying to strengthen copyright laws and co-operation with law enforcement agencies. 2. Educating the public through marketing, roadshows, etc. 3. Bringing legal actions against counterfeiters. BSA's aims are the same as the Federation Against Software Theft but it is not limited to the UK. In December 1990 the BSA obtained the first legal order in the UK which allowed a surprise search on a company's offices for suspected copyright infringement. (http://bsa.org/bsa). UK Office: Business Software Alliance, 1st Floor, Leaconfield House, Curzon Street, London W1Y 8AS, United Kingdom. 1 1 1 1 1 Business Systems Analyst A person who works directly with management and users to analyse, specify, and design business applications. The Business Systems Analyst develops detailed functional, system, and program specifications using structured design methodologies and CASE tools. He must have strong business sense and communications skills. He works with both the information systems team and the strategic planning business group. (2004-03-09) 1 1 1 1 1 business to business (B2B) Electronic commerce between businesses, as opposed to between a consumer and a business (B2C). While derived from "business to business", "B2B" is narrower in meaning. (2001-03-26) 1 1 1 1 1 bus master The device in a computer which is driving the address bus and bus control signals at some point in time. In a simple architecture only the (single) CPU can be bus master but this means that all communications between ("slave") I/O devices must involve the CPU. More sophisticated architectures allow other capable devices (or multiple CPUs) to take turns at controling the bus. This allows, for example, a network controller card to access a disk controller directly while the CPU performs other tasks which do not require the bus, e.g. fetching code from its cache. Note that any device can drive data onto the data bus when the CPU reads from that device, but only the bus master drives the address bus and control signals. Direct Memory Access is a simple form of bus mastering where the I/O device is set up by the CPU to read from or write to one or more contiguous blocks of memory and then signal to the 1 1 1 1 1 bus mastering bus master 1 1 1 1 1 bus network A network topology in which all nodes are connected to a single wire or set of wires (the bus). Bus networks typically use CSMA/CD techniques to determine which node should transmit data at any given time. Some networks are implemented as a bus, e.g. Ethernet - a one-bit bus operating at 10, 100, 1000 or 10,000 megabits per second. Originally Ethernet was a physical layer bus consisting of a wire (with terminators at each end) to which each node was attached. Switched Ethernet, while no longer physically a bus still acts as one at the logical layers. 1 1 1 1 1 bus topology bus 1 1 1 1 1 Busy Beaver (BB) One of a series of sets of Turing Machine programs. The BBs in the Nth set are programs of N states that produce a larger finite number of ones on an initially blank tape than any other program of N states. There is no program that, given input N, can deduce the productivity (number of ones output) of the BB of size N. The productivity of the BB of size 1 is 1. Some work has been done to figure out productivities of bigger Busy Beavers - the 7th is in the thousands. (1994-10-24) 1 1 1 1 1 busy-loop tight loop 1 1 1 1 1 busy-wait To wait for an event by spinning through a tight loop or timed-delay loop that polls for the event on each pass, as opposed to setting up an interrupt handler and continuing execution on another part of the task. This is a wasteful technique, best avoided on time-sharing systems where a busy-waiting program may hog the processor. [Jargon File] (1999-06-10) 1 1 1 1 1 Butterfly Common LISP A parallel version of Common LISP for the BBN Butterfly computer. 1 1 1 1 1 Butterfly Scheme A parallel version of Scheme for the BBN Butterfly computer. 1 1 1 1 1 button 1. <electronics> push-button. 2. <operating system> A graphical representation of an electrical push-button appearing as part of a graphical user interface. Moving the mouse pointer over the graphical button and pressing one of the physical mouse buttons starts some software action such as closing a window or deleting a file. See also radio button. (1997-07-07) 1 1 1 1 1 buzz 1. Of a program, to run with no indication of progress and perhaps without guarantee of ever finishing; especially said of programs thought to be executing a tight loop of code. A program that is buzzing appears to be catatonic, but never gets out of catatonia, while a buzzing loop may eventually end of its own accord. "The program buzzes for about 10 seconds trying to sort all the names into order." See spin; see also grovel. 2. [ETA Systems] To test a wire or printed circuit trace for continuity by applying an AC rather than DC signal. Some wire faults will pass DC tests but fail a buzz test. 3. To process an array or list in sequence, doing the same thing to each element. "This loop buzzes through the tz array looking for a terminator type." [Jargon File] 1 1 1 1 1 bv The country code for Bouvet Island. (1999-01-27) 1 1 1 1 1 bw The country code for Botswana. (1999-01-27) 1 1 1 1 1 bwBASIC Bywater BASIC interpreter. A BASIC interpreter by Ted A. Campbell <tcamp@delphi.com> which implements a large superset of the ANSI Standard for Minimal BASIC (X3.60-1978) in ANSI C, and offers a simple interactive environment including some shell program facilities as an extension of BASIC. The interpreter source has been compiled successfully on a range of ANSI C compilers on varying platforms including MS-DOS, Unix, and Acorn RISC OS. Version 2.10 was posted to news:comp.sources.misc, volume 40 (1993-10-29) 1 1 1 1 1 BWQ [IBM] Buzz Word Quotient. The percentage of buzzwords in a speech or documents. Usually roughly proportional to bogosity. See TLA. [Jargon File] 1 1 1 1 1 by The country code for Belarus. (1999-01-27) 1 1 1 1 1 byacc Berkeley Yacc 1 1 1 1 1 by hand 1. Said of an operation (especially a repetitive, trivial, and/or tedious one) that ought to be performed automatically by the computer, but which a hacker instead has to step tediously through. "My mailer doesn't have a command to include the text of the message I'm replying to, so I have to do it by hand." This does not necessarily mean the speaker has to retype a copy of the message; it might refer to, say, dropping into a subshell from the mailer, making a copy of one's mailbox file, reading that into an editor, locating the top and bottom of the message in question, deleting the rest of the file, inserting ">" characters on each line, writing the file, leaving the editor, returning to the mailer, reading the file in, and later remembering to delete the file. Compare eyeball search. 2. By extension, writing code which does something in an explicit or low-level way for which a presupplied library routine ought to have been available. "This cretinous 1 1 1 1 1 Byte A popular computing magazine. (http://byte.com). (1997-03-27) 1 1 1 1 1 byte /bi:t/ (B) A component in the machine data hierarchy larger than a bit and usually smaller than a word; now nearly always eight bits and the smallest addressable unit of storage. A byte typically holds one character. A byte may be 9 bits on 36-bit computers. Some older architectures used "byte" for quantities of 6 or 7 bits, and the PDP-10 and IBM 7030 supported "bytes" that were actually bit-fields of 1 to 36 (or 64) bits! These usages are now obsolete, and even 9-bit bytes have become rare in the general trend toward power-of-2 word sizes. The term was coined by Werner Buchholz in 1956 during the early design phase for the IBM Stretch computer. It was a mutation of the word "bite" intended to avoid confusion with bit. In 1962 he described it as "a group of bits used to encode a character, or the number of bits transmitted in parallel to and from input-output units". The move to an 8-bit byte happened in late 1956, and this size was later 1 1 1 1 1 byte-code A binary file containing an executable program, consisting of a sequence of (op code, data) pairs. Byte-code op codes are most often fixed size bit patterns, but can be variable size. The data portion consists of zero or more bits whose format typically depends on the op code. A byte-code program is interpreted by a byte-code interpreter. The advantage of this technique compared with outputing machine code for some particular processor is that the same byte-code can be executed on any processor on which the byte-code interpreter runs. The byte-code may be compiled to machine code ("native code") for speed of execution but this usually requires significantly greater effort for each new taraget architecture than simply porting the interpreter. For example, Java is compiled to byte-code which runs on the Java Virtual Machine. (2006-05-29) 1 1 1 1 1 byte-code compiler A compiler which outputs a program in some kind of byte-code. Compare: byte-code interpreter. (1995-11-04) 1 1 1 1 1 byte-code interpreter A program that executes a byte code program. An example is the Java Virtual Machine. (1999-11-28) 1 1 1 1 1 byte compiler byte-code compiler 1 1 1 1 1 bytesexual /bi:t" sek"shu-*l/ An adjective used to describe hardware, denotes willingness to compute or pass data in either big-endian or little-endian format (depending, presumably, on a mode bit somewhere). See also NUXI problem. [Jargon File] (2009-05-28) 1 1 1 1 1 Byzantine A term describing any system that has so many labyrinthine internal interconnections that it would be impossible to simplify by separation into loosely coupled or linked components. The city of Byzantium, later renamed Constantinople and then Istanbul, and the Byzantine Empire were vitiated by a bureaucratic overelaboration bordering on lunacy: quadruple banked agencies, dozens or even scores of superfluous levels and officials with high flown titles unrelated to their actual function, if any. Access to the Emperor and his council was controlled by powerful and inscrutable eunuchs and by rival sports factions. [Edward Gibbon, "Decline and Fall of the Roman Empire"]. (1999-01-15) 1 1 1 1 1 bz The country code for Belize. (1999-01-27) 1 1 1 1 1 bzzzt, wrong /bzt rong/ (Usenet, Internet) From the flim "Dead Poets Society", spoofing quiz shows such as "Truth or Consequences" where an incorrect answer earns a blast from the buzzer. An expression of mock-rude disagreement, often following a quote from another poster in a forum. The less abbreviated *Bzzzzt*, wrong, but thank you for playing is also common. [Jargon File] (2009-10-28) 1 1 1 1 1 C A programming language designed by Dennis Ritchie at AT&T Bell Labs ca. 1972 for systems programming on the PDP-11 and immediately used to reimplement Unix. It was called "C" because many features derived from an earlier compiler named "B". In fact, C was briefly named NB. B was itself strongly influenced by BCPL. Before Bjarne Stroustrup settled the question by designing C++, there was a humorous debate over whether C's successor should be named "D" or "P" (following B and C in "BCPL"). C is terse, low-level and permissive. It has a macro preprocessor, cpp. Partly due to its distribution with Unix, C became immensely popular outside Bell Labs after about 1980 and is now the dominant language in systems and microcomputer applications programming. It has grown popular due to its simplicity, efficiency, and flexibility. C programs are often easily adapted to new environments. 1 1 1 1 1 C# An object-oriented language devised and promoted by Microsoft, intended to replace Java, which it strongly resembles. The name is pronounced "C sharp", as in the musical note. The language is sometimes humorously referred to as "D-flat" (which is the same note). (http://wiht.link/csharp-resources). (2016-03-02) 1 1 1 1 1 C* An object-oriented, data-parallel superset of ANSI C with synchronous semantics, for the Connection Machine, designed by Thinking Machines, 1987. C* adds a "domain" data type and a selection statement for parallel execution in domains. An unimplemented language called "Parallel C" [which one?] influenced the design of C*. Dataparallel-C was based on C*. Latest version: 6.x, as of 1993-07-27. ["C*: An Extended C Language for Data Parallel Programming", J.R. Rose et al, Proc Second Intl Conf on Supercomputing, L.P. Kartashev et al eds, May 1987, pp 2-16]. ["C* Programming Manual", Thinking Machines Corp, 1986]. [Jargon File] (2000-11-14) 1 1 1 1 1 C++ One of the most used object-oriented languages, a superset of C developed primarily by Bjarne Stroustrup <bs@alice.att.com> at AT&T Bell Laboratories in 1986. In C++ a class is a user-defined type, syntactically a struct with member functions. Constructors and destructors are member functions called to create or destroy instances. A friend is a nonmember function that is allowed to access the private portion of a class. C++ allows implicit type conversion, function inlining, overloading of operators and function names, and default function arguments. It has streams for I/O and references. C++ 2.0 (May 1989) introduced multiple inheritance, type-safe linkage, pointers to members, and abstract classes. C++ 2.1 was introduced in ["Annotated C++ Reference Manual", B. Stroustrup et al, A-W 1990]. MS-DOS 1 1 1 1 1 C+- (C More or Less) A subject-oriented language (SOL). Each C+- class instance, known as a subject, holds hidden members, known as prejudices, agendas or undeclared preferences, which are impervious to outside messages; as well as public members, known as boasts or claims. The following C operators are overridden as shown: > better than < worse than >> way better than << forget it ! not on your life == comparable, other things being equal !== get a life, guy! C+- is strongly typed, based on stereotyping and self-righteous logic. The Boolean variables TRUE and FALSE (known as constants in other, less realistic languages) are supplemented with CREDIBLE and DUBIOUS, which are fuzzier than Zadeh's 1 1 1 1 1 C+@ (Formerly "Calico"). An object-oriented language from Bell Laboratories which uniformly represents all data as pointers to self-described objects. C+@ provides multiple inheritance with delegation and with control over which methods come from which delegated object; and default methodologies. It has a simple syntax with emphasis on graphics. It was originally used for prototyping of telecommunication services. The language is patented by AT&T and Unir Tech has the exclusive license from Bell Labs to distribute C+@. Unfortunately Unir is owned and operated by well-known anti-IETF ranter, Jim Fleming, which may have had something to do with the language's rapid disappearence from the radar screen. It runs under SunOS and compiles to Vcode. E-mail: Jim Vandendorpe <jimvan@iexist.att.com>. ["A Dynamic C-Based Object-Oriented System for Unix", S. 1 1 1 1 1 C-10 An improved version of COLINGO. [Sammet 1969, p.702]. (1994-10-28) 1 1 1 1 1 C1 security Orange Book 1 1 1 1 1 c2man An automatic documentation extraction tool by Graham Stoney. c2man extracts comments from C source code to generate functional interface documentation in the same format as sections 2 and 3 of the Unix Programmer's Manual. It looks for comments near the objects they document, rather than imposing a rigid syntax or requiring the programmer to use a typesetting language. Acceptable documentation can often be generated from existing code with no modifications. c2man supports both K&R and ISO/ANSI C coding styles. Output can be in nroff -man, Texinfo or LaTeX format. It automagically documents enum parameter and return values, it handles both C (/* */) and C++ (//) style comments, but not C++ grammar (yet). It requires yacc, byacc or bison for syntax analysis; lex or flex for lexical analysis and nroff, groff, texinfo or LaTeX to format the output. It runs under Unix, OS/2 and MS-DOS. 1 1 1 1 1 C2 security Orange Book 1 1 1 1 1 c386 A compiler for K&R C plus prototypes and other ANSI C features by Matthew Brandt, Christoph van Wuellen, Keith and Dave Walker. c386 is targetted to several 68000 and Intel 80386 assemblers, including gas. floating-point support is by inline code or emulation. It can produce lots of warnings and generates better code than ACK. Version 4.2a (ftp://bugs.nosc.mil/pub/Minix/common-pkgs/c386-4.2.tar.Z). (2009-11-11) 1 1 1 1 1 C5 An OPS5 implementation in C. (2009-11-13) 1 1 1 1 1 C64 Commodore 64 1 1 1 1 1 c68 c386 1 1 1 1 1 CA 1. <theory, architecture> cellular automaton. 2. <company> Computer Associates. 3. <cryptography> Certificate Authority. 1 1 1 1 1 ca The country code for Canada. (1995-04-19) 1 1 1 1 1 cable modem A type of modem that allows people to access the Internet via their cable television service. A cable modem can transfer data at 500 kbps or higher, compared with 28.8 kbps for common telephone line modems, but the actual transfer rates may be lower depending on the number of other simultaneous users on the same cable. Industry pundits often point out that the cable system still does not have the bandwidth or service level in many areas to make this feasible. For example, it has to be capable of two-way communication. See also: DOCSIS. (2000-12-19) 1 1 1 1 1 cache /kash/ A small fast memory holding recently accessed data, designed to speed up subsequent access to the same data. Most often applied to processor-memory access but also used for a local copy of data accessible over a network etc. When data is read from, or written to, main memory a copy is also saved in the cache, along with the associated main memory address. The cache monitors addresses of subsequent reads to see if the required data is already in the cache. If it is (a cache hit) then it is returned immediately and the main memory read is aborted (or not started). If the data is not cached (a cache miss) then it is fetched from main memory and also saved in the cache. The cache is built from faster memory chips than main memory so a cache hit takes much less time to complete than a normal memory access. The cache may be located on the same integrated circuit as the CPU, in order to further reduce 1 1 1 1 1 cache block cache line 1 1 1 1 1 cache coherency (Or "cache consistency") /kash koh-heer'n-see/ The synchronisation of data in multiple caches such that reading a memory location via any cache will return the most recent data written to that location via any (other) cache. Some parallel processors do not cache accesses to shared memory to avoid the issue of cache coherency. If caches are used with shared memory then some system is required to detect when data in one processor's cache should be discarded or replaced because another processor has updated that memory location. Several such schemes have been devised. (1998-11-10) 1 1 1 1 1 cache conflict A sequence of accesses to memory repeatedly overwriting the same cache entry. This can happen if two blocks of data, which are mapped to the same set of cache locations, are needed simultaneously. For example, in the case of a direct mapped cache, if arrays A, B, and C map to the same range of cache locations, thrashing will occur when the following loop is executed: for (i=1; i<n; i++) C[i] = A[i] + B[i]; Cache conflict can also occur between a program loop and the data it is accessing. See also ping-pong. (1997-01-21) 1 1 1 1 1 cache consistency cache coherency 1 1 1 1 1 cache hit A request to read from memory which can satisfied from the cache without using the main memory. Opposite: cache miss. (1997-01-21) 1 1 1 1 1 cache line (Or cache block) The smallest unit of memory than can be transferred between the main memory and the cache. Rather than reading a single word or byte from main memory at a time, each cache entry is usually holds a certain number of words, known as a "cache line" or "cache block" and a whole line is read and cached at once. This takes advantage of the principle of locality of reference: if one location is read then nearby locations (particularly following locations) are likely to be read soon afterward. It can also take advantage of page-mode DRAM which allows faster access to consecutive locations. (1997-01-21) 1 1 1 1 1 cache memory cache 1 1 1 1 1 cache miss A request to read from memory which cannot be satisfied from the cache, for which the main memory has to be consulted. Opposite: cache hit. (1997-01-21) 1 1 1 1 1 Cache On A STick (COAST) Intel Corporation attempt to's standardise the modular L2 cache subsystem in Pentium-based computers. A COAST module should be about 4.35" wide by 1.14" high. According to earlier specifications from Motorola, a module between 4.33" and 4.36" wide, and between 1.12" and 1.16" high is within the COAST standard. Some module vendors, including some major motherboard suppliers, greatly violate the height specification. Another COAST specification violated by many suppliers concerns clock distribution in synchronous modules. The specification requires that the clock tree to each synchronous chip be balanced, i.e. equal length from edge of the connector to individual chips. An unbalanced clock tree increases reflections and noise. For a 256 kilobyte cache module the standard requires the same clock be used for both chips but some vendors use 1 1 1 1 1 caching cache 1 1 1 1 1 CACI A company developing and marketing SIMSCRIPT, MODSIM and other simulation software products. Telephone: +1 (619) 457-9681. (1994-09-22) 1 1 1 1 1 CACM Communications of the ACM 1 1 1 1 1 CAD Computer Aided Design 1 1 1 1 1 CAD/CAM Computer Aided Design/Computer Aided Manufacturing. 1 1 1 1 1 CADD Computer Aided Detector Design 1 1 1 1 1 Cadence Design Systems A company that sells electronic design automation software and services. (http://cadence.com/). See also Verilog. (1999-04-16) 1 1 1 1 1 CADET Computer Aided Design Experimental Translator. [Sammet 1969, p. 683]. (1994-11-29) 1 1 1 1 1 CADRE The US software engineering vendor which merged with Bachman Information Systems to form Cayenne Software in July 1996. (1998-02-08) 1 1 1 1 1 CAE 1. <operating system> Common Applications Environment. 2. <application> Computer Aided Engineering. 1 1 1 1 1 CAF constant applicative form 1 1 1 1 1 CAFE ["Job Control Languages: MAXIMOP and CAFE", J. Brandon, Proc BCS Symp on Job Control Languages--Past Present and Future, NCC, Manchester, England 1974]. (1994-10-28) 1 1 1 1 1 CAGE Early system on IBM 704. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 CAI Computer-Aided Instruction 1 1 1 1 1 Cairo Windows NT 4 1 1 1 1 1 CAIS Common APSE Interface Specification 1 1 1 1 1 CAIS-A Common APSE Interface Set A DoD-STD-1838A. 1 1 1 1 1 CAiSE Conference on Advanced Information Systems Engineering. 1 1 1 1 1 CAJOLE (Chris And John's Own LanguagE) A dataflow language developed by Chris Hankin <clh@doc.ic.ac.uk> and John Sharp at Westfield College. ["The Data Flow Programming Language CAJOLE: An Informal Introduction", C.L. Hankin et al, SIGPLAN Notices 16(7):35-44 (Jul 1981)]. (1994-11-08) 1 1 1 1 1 CAL 1. Computer Assisted Learning. 2. Course Author Language. 1 1 1 1 1 Calc An extensible, advanced desk calculator and mathematical tool written in Emacs Lisp by Dave Gillespie <daveg@synaptics.com>. Calc runs as part of GNU Emacs. You can use Calc as only a simple four-function calculator, but it also provides additional features including choice of algebraic or RPN (stack-based) entry, logarithms, trigonometric and financial functions, arbitrary precision, complex numbers, vectors, matrices, dates, times, infinities, sets, algebraic simplification, differentiation, and integration. Latest version: 2.02, as of 1994-11-08. FTP calc-2.02.tar.z from your nearest GNU archive site. (2000-10-20) 1 1 1 1 1 calculator bitty box 1 1 1 1 1 Calculus of Communicating Systems (CCS) A mathematical model (a formal language) for describing processes, mostly used in the study of parallelism. A CCS program, written in behaviour expressions syntax denotes a process behaviour. Programs can be compared using the notion of observational equivalence. ["A Calculus of Communicating Systems", LNCS 92, Springer 1980]. ["Communication and Concurrency", R. Milner, P-H 1989]. (1994-11-29) 1 1 1 1 1 Calendar API Calendar Application Programming Interface 1 1 1 1 1 Calendar Application Programming Interface (CAPI, Calendar API) An API for calendar software. Microsoft has defined a CAPI for their Schedule+ application. (1995-01-11) 1 1 1 1 1 Caliban A declarative annotation language for controlling the partitioning and placement of the evaluation of expressions in a distributed functional language. Designed by Paul Kelly <phjk@doc.ic.ac.uk>, Imperial College. ["Functional Programming for Loosely-coupled Multiprocessors", P. Kelly, Pitman/MIT Press, 1989]. (1995-01-11) 1 1 1 1 1 Calico C+@ 1 1 1 1 1 California State University San Marcos (CSUSM) (http://coyote.csusm.edu/). (1994-12-21) 1 1 1 1 1 callback 1. <programming> A scheme used in event-driven programs where the program registers a subroutine (a "callback handler") to handle a certain event. The program does not call the handler directly but when the event occurs, the run-time system calls the handler, usually passing it arguments to describe the event. 2. <communications, security> A user authentication scheme used by some computers running dial-up services. The user dials in to the computer and gives his user name and password. The computer then hangs up the connection and uses an auto-dial modem to call back to the user's registered telephone number. Thus, if an unauthorised person discovers a user's password, the callback will go, not to him, but to the owner of that login who will then know that his account is under attack. However, some PABXs can be fooled into thinking that the caller has hung up by sending them a dial tone. When the 1 1 1 1 1 call-by-name (CBN) (Normal order reduction, leftmost, outermost reduction). An argument passing convention (first provided by ALGOL 60?) where argument expressions are passed unevaluated. This is usually implemented by passing a pointer to a thunk - some code which will return the value of the argument and an environment giving the values of its free variables. This evaluation strategy is guaranteed to reach a normal form if one exists. When used to implement functional programming languages, call-by-name is usually combined with graph reduction to avoid repeated evaluation of the same expression. This is then known as call-by-need. The opposite of call-by-name is call-by-value where arguments are evaluated before they are passed to a function. This is more efficient but is less likely to terminate in the presence of infinite data structures and recursive 1 1 1 1 1 call-by-need A reduction strategy which delays evaluation of function arguments until their values are needed. A value is needed if it is an argument to a primitive function or it is the condition in a conditional. Call-by-need is one aspect of lazy evaluation. The term first appears in Chris Wadsworth's thesis "Semantics and Pragmatics of the Lambda calculus" (Oxford, 1971, p. 183). It was used later, by J. Vuillemin in his thesis (Stanford, 1973). (1995-05-27) 1 1 1 1 1 call-by-reference An argument passing convention where the address of an argument variable is passed to a function or procedure, as opposed to passing the value of the argument expression. Execution of the function or procedure may have side-effects on the actual argument as seen by the caller. The C language's "&" (address of) and "*" (dereference) operators allow the programmer to code explicit call-by-reference. Other languages provide special syntax to declare reference arguments (e.g. ALGOL 60). See also call-by-name, call-by-value, call-by-value-result. (2006-05-27) 1 1 1 1 1 call-by-value (CBV) An evaluation strategy where arguments are evaluated before the function or procedure is entered. Only the values of the arguments are passed and changes to the arguments within the called procedure have no effect on the actual arguments as seen by the caller. See applicative order reduction, call-by-value-result, strict evaluation, call-by-name, lazy evaluation. 1 1 1 1 1 call-by-value-result An argument passing convention where the actual argument is a variable V whose value is copied to a local variable L inside the called function or procedure. If the procedure modifies L, these changes will not affect V, which may also be in scope inside the procedure, until the procedure returns when the final value of L is copied to V. Under call-by-reference changes to L would affect V immediately. Used, for example, by BBC BASIC V on the Acorn Archimedes. 1 1 1 1 1 call/cc call-with-current-continuation 1 1 1 1 1 Call Data Record (CDR) A data record that contains information related to a telephone call, including the origination and destination addresses of the call, the time the call started and ended, the duration of the call, the time of day the call was made, toll charges that were added through the network, or charges for operator services. [Context?] (2010-03-21) 1 1 1 1 1 callee The function or subroutine being called by the caller. (2001-05-09) 1 1 1 1 1 Caller ID (CID) A short piece of text transmitted by some telephone systems describing the origin of a call, e.g. the name of the caller. Some telephone handsets can display this. A computer telephony integration system might use it to trigger actions on the callee's computer such as looking up the caller in a database and displaying their details on screen. There may also be a separate "caller id number" giving the telephone number of the originator of the call. (2008-04-30) 1 1 1 1 1 calling convention The arrangement of arguments for a procedure or function call. Different programming languages may require arguments to be pushed onto a stack or entered in registers in left-to-right or right-to left order, and either the caller or the callee can be responsible for removing the arguments. The calling convention also determines if a variable number of arguments is allowed. (1995-11-11) 1 1 1 1 1 Call-Level Interface (SQL/CLI) A programming interface designed to support SQL access to databases from shrink-wrapped application programs. CLI was originally created by a subcommittee of the SQL Access Group (SAG). The SAG/CLI specification was published as the Microsoft Open DataBase Connectivity (ODBC) specification in 1992. In 1993, SAG submitted the CLI to the ANSI and ISO SQL committees. SQL/CLI provides an international standard implementation-independent CLI to access SQL databases. Client-server tools can easily access databases through dynamic link libraries. It supports and encourages a rich set of client-server tools. SQL/CLI is an addendum to 1992 SQL standard (SQL-92). It was completed as ISO standard ISO/IEC 9075-3:1995 Information technology -- Database languages -- SQL -- Part 3: Call-Level Interface (SQL/CLI). The current SQL/CLI effort is adding 1 1 1 1 1 Call Unix (cu) The original Unix virtual terminal utility. cu allows a user on one computer to log in to another connected via Ethernet, direct serial line or modem. It shares some configuration files with UUCP in order to be able to use the same connections without conflict. Unix manual page: cu(1). (1997-12-01) 1 1 1 1 1 Callware The developers of Phonetastic. (1996-12-08) 1 1 1 1 1 call-with-current-continuation (call/cc) A Lisp control function that implements the continuation passing style of programming. In continuation passing style (CPS), every function f takes an extra final argument k called the "continuation". The continuation is itself a function and represents the rest of the program. Instead of just returning a value in the normal way, f passes it as an argument to k and returns the result of that. call/cc takes a function f as its argument and calls f, passing it the current continuation k. It thus allows a CPS function to be called in a non-CPS (direct) context. For example, if the final result is to print the value returned by call/cc then anything passed to k will also be printed. E.g, in Scheme: (define (f k) (k 1) 1 1 1 1 1 CALS Computer-Aided Acquisition and Logistics Support: a DoD standard for electronic exchange of data with commercial suppliers. 1 1 1 1 1 Caltech Intermediate Form (CIF) A geometry language for VLSI design, in which the primitives are coloured rectangles. ["Introduction to VLSI Systems", Mead & Conway, A-W 1980, Section 4.5]. (1995-01-25) 1 1 1 1 1 CAM 1. <storage, architecture> content addressable memory. 2. <application> computer aided manufacturing. 1 1 1 1 1 CAM-6 Software for running cellular automata. CAM-6 has been implemented in hardware as CAM-PC. (1995-04-21) 1 1 1 1 1 CAMAL CAMbridge ALgebra system. A symbolic mathematics system used in Celestial Mechanics and General Relativity. CAMAL was implemented in BCPL on Titan. ["CAMAL User's Manual", John P. Fitch, Cambridge U, England (1975)]. ["The Design of the Cambridge Algebra System", S.R. Bourne et al, Proc 2nd Symp of Symb & Alg Manip, SIGSAM 1971]. (1995-02-16) 1 1 1 1 1 Cambridge Lisp A flavour of Lisp using BCPL. Sources owned by Fitznorman partners. 1 1 1 1 1 CamelCase The practice of concatenating words with either all words capitalised (e.g. "ICantReadThis" - sometimes called UpperCamelCase or "PascalCase") or all except the first ("iCantReadThis" - called "lowerCamelCase"). It is used in contexts where space characters are not allowed, such as identifiers in source code. Modern best practice separates words in identifiers with underscore for readability (like_this_example). CamelCase is probably a historical throw-back to systems that had no underscore or when the length of identifiers was constrained either by the programming language or by the width of computer displays. Unfortunately it has infected many projects, origanisations and programming languages such as Java where the uniniated create identifiers like "MemberSubmissionAddressingWSDLParserExtension". (2014-12-02) 1 1 1 1 1 Camelot Library ["The Camelot Library", J. Bloch, in "Guide to the Camelot Distributed Transaction Facility: Release I", A.Z. Spector et al eds, CMU 1988, pp. 29-62]. [What is it?] (1995-04-19) 1 1 1 1 1 camera ready A final edition of a document or graphic (e.g. a newspaper advertisement or a technical paper for a journal) that is of suitable quality for mass reproduction by making printing plates from the negatives by photoengraving. (1996-11-15) 1 1 1 1 1 CAMIL Computer Assisted/Managed Instructional Language. A language used for CAI at Lowry AFB, CO. ["The CAMIL Programming Language", David Pflasterer, SIGPLAN Notices 13(11):43 (Nov 1978)]. (1994-11-09) 1 1 1 1 1 CAML 1. A language for preparation of animated movies. 1976. (1994-11-09) 2. Categorical Abstract Machine Language. (2000-07-06) 1 1 1 1 1 Caml Light A small portable implementation of a version of CAML by Xavier Leroy <Xavier.Leroy@inria.fr> and Damien Doligez of INRIA. Caml Light uses a bytecode interpreter written in C. It adds a Modula-2-like module system, separate compilation, lazy streams for parsing and printing, graphics primitives and an interface with C. Version 0.6 runs on Unix, MS-DOS, Macintosh, Atari ST and Amiga. It includes an interpreter, compiler, Emacs mode, libraries, scanner generator, parser generator, run-time support and an interactive development environment. The latest version, as of April 2003, is 0.75 and runs on Unix, Macintosh and Windows. The development of Caml Light has been stopped; current development is on Objective Caml. (http://caml.inria.fr/distrib-caml-light-eng.html). (ftp://ftp.inria.fr/lang/caml-light/). 1 1 1 1 1 CAM-PC A cellular automata circuit board which is a hardware implementation from Automatrix of the MIT CAM-6 machine. It comes with dozens of experiments and applications. (http://automatrix.com/campc/index.html). (1995-04-21) 1 1 1 1 1 Campus Wide Information System (CWIS) Information and services made publicly available at university sites via kiosks running interactive computing systems, possibly via campus networks. Services routinely include directory information, calendars, bulletin boards and databases. (1994-11-09) 1 1 1 1 1 CAN Cancel 1 1 1 1 1 Canada Country with domain "ca". (1995-04-06) 1 1 1 1 1 Cancel (CAN, Control-X) ASCII character 24. (1996-06-28) 1 1 1 1 1 Cancelbunny Cancelpoodle 1 1 1 1 1 Cancelm00se Cancelmoose 1 1 1 1 1 Cancelmoose A semi-mythical being that cancels Usenet articles posted by others. (In general, an article can only be cancelled by its original author.) The Cancelmoose's usual target is spam or extremely excessive cross-posting. Some believe that the Cancelmoose exists only in the same mythic sense that B1FF, the NSA line eater and Shub Internet exist; others consider Cancelmoose's historicity to be closer to that of Kibo. The latter group assume that the real Cancelmoose is not one person (or moose), but instead is a cabal of NNTP wonks. However, the Cancelmoose is probably real, seeing as how it has its own website. (http://nocem.org/). (1999-01-14) 1 1 1 1 1 Cancelpoodle (Or Cancelbunny) A manifestation of the Cancelmoose in the form of a more selective (and probably not automated) way to cancel Usenet articles. The term became common during the alt.religion.scientology wars of the mid-90s, during which Cancelpoodles were used. The "poodle" part is an allusion to one of the parties obliquely involved in the fray, who an earlier well-known witticism had compared to "a psychotic poodle". (1999-01-14) 1 1 1 1 1 candidate key One of several possible attributes or combinations of attributes which can be used to uniquely identify a body of information (a "record"). The chosen candidate key is called the primary key. (2006-05-29) 1 1 1 1 1 Candle Part of the Scorpion environment development system. (1994-11-09) 1 1 1 1 1 candygrammar A programming-language grammar that is mostly syntactic sugar; a play on "candygram". COBOL, Apple Computer's Hypertalk language, and many 4GLs share this property. The intent is to be as English-like as possible and thus easier for unskilled people to program. However, syntax isn't what makes programming hard; it's the mental effort and organisation required to specify an algorithm precisely. Thus "candygrammar" languages are just as difficult to program in, and far more painful for the experienced hacker. GLS notes: The overtones from the 1977 Chevy Chase "Jaws" parody on Saturday Night Live should not be overlooked. Someone lurking outside an apartment door tries to get the occupant to open up, while ominous music plays in the background. The last attempt is a half-hearted "Candygram!" When the door is opened, a shark bursts in and chomps the poor occupant. There is a moral here for those attracted to 1 1 1 1 1 canonical (Historically, "according to religious law") 1. <mathematics> A standard way of writing a formula. Two formulas such as 9 + x and x + 9 are said to be equivalent because they mean the same thing, but the second one is in canonical form because it is written in the usual way, with the highest power of x first. Usually there are fixed rules you can use to decide whether something is in canonical form. Things in canonical form are easier to compare. 2. <jargon> The usual or standard state or manner of something. The term acquired this meaning in computer-science culture largely through its prominence in Alonzo Church's work in computation theory and mathematical logic (see Knights of the Lambda-Calculus). Compare vanilla. This word has an interesting history. Non-technical academics do not use the adjective "canonical" in any of the senses defined above with any regularity; they do however use the 1 1 1 1 1 Canonical Encoding Rules (CER) A restricted variant of BER for producing unequivocal transfer syntax for data structures described by ASN.1. Whereas BER gives choices as to how data values may be encoded, CER and DER select just one encoding from those allowed by the basic encoding rules, eliminating all of the options. They are useful when the encodings must be preserved, e.g. in security exchanges. CER and DER differ in the set of restrictions that they place on the encoder. The basic difference between CER and DER is that DER uses definitive length form and CER uses indefinite length form. Documents: ITU-T X.690, ISO 8825-1. See also PER. (1998-05-19) 1 1 1 1 1 canonical name (CNAME) A host's official name as opposed to an alias. The official name is the first hostname listed for its Internet address in the hostname database, /etc/hosts or the Network Information Service (NIS) map hosts.byaddr ("hosts" for short). A host with multiple network interfaces may have more than one Internet address, each with its own canonical name (and zero or more aliases). You can find a host's canonical name using nslookup if you say set querytype=CNAME and then type a hostname. (1994-11-29) 1 1 1 1 1 canonicity The extent to which something is canonical. (1995-03-03) 1 1 1 1 1 C (ANSI) ANSI C 1 1 1 1 1 can't happen The traditional program comment for code executed under a condition that should never be true, for example a file size computed as negative. Often, such a condition being true indicates data corruption or a faulty algorithm; it is almost always handled by emitting a fatal error message and terminating or crashing, since there is little else that can be done. Some case variant of "can't happen" is also often the text emitted if the "impossible" error actually happens. Although can't happen events are genuinely infrequent in production code, programmers wise enough to check for them habitually are often surprised at how frequently they are triggered during development and how many headaches checking for them turns out to head off. See also firewall code, professional programming. [Jargon File] (1996-05-10) 1 1 1 1 1 Cantor 1. <person, mathematics> A mathematician. Cantor devised the diagonal proof of the uncountability of the real numbers: Given a function, f, from the natural numbers to the real numbers, consider the real number r whose binary expansion is given as follows: for each natural number i, r's i-th digit is the complement of the i-th digit of f(i). Thus, since r and f(i) differ in their i-th digits, r differs from any value taken by f. Therefore, f is not surjective (there are values of its result type which it cannot return). Consequently, no function from the natural numbers to the reals is surjective. A further theorem dependent on the axiom of choice turns this result into the statement that the reals are uncountable. This is just a special case of a diagonal proof that a function from a set to its power set cannot be surjective: Let f be a function from a set S to its power set, P(S) and 1 1 1 1 1 CAP 1. <networking> Columbia AppleTalk Package. 2. <communications> Carrierless Amplitude/Phase Modulation. 3. <networking> Competitive Access Provider 1 1 1 1 1 Capabilities Maturity Model Capability Maturity Model 1 1 1 1 1 capability An operating system security or access control model where specific types of access to a specific object are granted by giving a process this data structure or token. The token may be unforgeable (typically by using encryption or hardware "tagged" memory). Capabilities are used in OSes such as Hydra, KeyKOS, EROS, Chorus/Mix, and the Stanford V system. Similar to Kerberos, but in an OS context. Compare access control list. (1998-03-08) 1 1 1 1 1 Capability Maturity Model (CMM) The Software Engineering Institute's model of software engineering that specifies five levels of maturity of the processes of a software organisation. CMM offers a framework for evolutionary process improvement. Originally applied to software development (SE-CMM), it has been expanded to cover other areas including Human Resources and Software Acquitition. The levels - focii - and key process areas are: Level 1 Initial - Heroes - None. Level 2 Repeatable - Project Management - Software Project Planning, Software Project Tracking and Oversight, Software Subcontract Management, Software Quality Assurance, Software Configuration Management, Requirements Management. Level 3 Defined - Engineering Process - Organisation Process Focus, Organisation Process Definition, Peer Reviews, Training Program, Inter-group Coordination, Software Product Engineering, Integrated Software Management. 1 1 1 1 1 capacitor An electronic device that can store electrical charge. The charge stored Q in Coulombs is related to the capacitance C in Farads and the voltage V across the capacitor in Volts by Q = CV. The basis of a dynamic RAM cell is a capacitor. They are also used for power-supply smoothing (or "decoupling"). This is especially important in digital circuits where a digital device switching between states causes a sudden demand for current. Without sufficient local power supply decoupling, this current "spike" cannot be supplied directly from the power supply due to the inductance of the connectors and so will cause a sharp drop in the power supply voltage near the switching device. This can cause other devices to malfunction resulting in hard to trace glitches. (1995-04-12) 1 1 1 1 1 capacity The maximum possible data transfer rate of a communications channel under ideal conditions. The total capacity of a channel may be shared between several independent data streams using some kind of multiplexing, in which case, each stream's data rate may be limited to a fixed fraction of the total capacity. (2001-05-22) 1 1 1 1 1 CAPI 1. Calendar Application Programming Interface. 2. <cryptography> Cryptographic Application Programming Interface. 3. <networking> Common ISDN Application Programming Interface. 1 1 1 1 1 Cap'n Crunch Captain Crunch 1 1 1 1 1 Captain Abstraction The champion of the principles of abstraction and modularity, who protects unwary students on MIT's course 6.001 from the nefarious designs of Sergeant Spaghetticode and his vile concrete programming practices. See also spaghetti code. (1994-11-22) 1 1 1 1 1 Captain Crunch 1. <person> ("Cap'n Crunch") An early 1970s hacker/phreaker/phacker who used a free whistle included with "Cap'n Crunch" breakfast cereal to fake pay phone system tones and make large quantities of free phone calls. Also alludes to "crunch". (http://well.com/user/crunch/). 2. (After the above) wardialer. 3. Reportedly, a program which crashes a computer by overloading the interrupt stack. (1998-08-25) 1 1 1 1 1 CAPTCHA A type of test used to determine whether a request to a website comes from a human or a computer program, typically by asking the user to perform some kind of image recognition task such as reading distorted text. The term was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper (all of Carnegie Mellon University) and John Langford (of IBM) as a contrived acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart". CAPTCHA aims to prevent software tools from performing actions which might degrade the service, such as registering user accounts or automating the playing of a game. (2009-01-02) 1 1 1 1 1 car Contents of Address part of Register 1 1 1 1 1 card 1. <hardware> A circuit board. 2. <storage> SD card. 3. <history> A punched card. 4. <hypertext> An alternative term for a node in a system (e.g. HyperCard, Notecards) in which the node size is limited. 1 1 1 1 1 Cardbox for Windows A database handling program, especially useful for scholars and librarians. [Details? Features? Developer? URL?] (1997-05-14) 1 1 1 1 1 Cardbus The 32-bit version of the PCMCIA (PC Card) bus. [Spec?] (1996-08-20) 1 1 1 1 1 card creep chip creep 1 1 1 1 1 cardinality The number of elements in a set. If two sets have the same number of elements (i.e. there is a bijection between them) then they have the same cardinality. A cardinality is thus an isomorphism class in the category of sets. aleph 0 is defined as the cardinality of the first infinite ordinal, omega (the number of natural numbers). (1995-03-29) 1 1 1 1 1 cardinal number The cardinality of some set. 1 1 1 1 1 CARDS Central Archive for Reusable Defense Software of the DoD. 1 1 1 1 1 card walloper An EDP programmer who grinds out batch programs that do things like print people's paychecks. Compare code grinder. See also punched card, eighty-column mind. [Jargon File] (2003-09-20) 1 1 1 1 1 Career Limiting Move (CLM, Sun) Any action endangering one's future prospects of getting plum projects and raises, and possibly one's job. E.g. "His Halloween costume was a parody of his manager. He won the prize for "best CLM"." A severe bug discovered by a customer might be a "CLM bug". (2000-08-09) 1 1 1 1 1 caret ^ Common: hat; control; uparrow; caret; ITU-T: circumflex. Rare: chevron; INTERCAL: shark (or shark-fin); to the ("to the power of"); fang; pointer (in Pascal). 1 1 1 1 1 careware /keir'weir/ (Or "charityware") Shareware for which either the author suggests that some payment be made to a nominated charity or a levy directed to charity is included on top of the distribution charge. Compare crippleware. [Jargon File] (1994-12-16) 1 1 1 1 1 cargo cult programming A style of (incompetent) programming dominated by ritual inclusion of code or program structures that serve no real purpose. A cargo cult programmer will usually explain the extra code as a way of working around some bug encountered in the past, but usually neither the bug nor the reason the code apparently avoided the bug was ever fully understood (compare shotgun debugging, voodoo programming). The term "cargo cult" is a reference to aboriginal religions that grew up in the South Pacific after World War II. The practices of these cults centre on building elaborate mockups of aeroplanes and military style landing strips in the hope of bringing the return of the god-like aeroplanes that brought such marvelous cargo during the war. Hackish usage probably derives from Richard Feynman's characterisation of certain practices as "cargo cult science" in his book "Surely You're Joking, Mr. Feynman" (W. W. Norton & Co, New York 1985, ISBN 1 1 1 1 1 Caribou CodeWorks The company which sells QTRADER. Director of Marketing: Norm Larsen <wwcoinc@winternet.com>. (1995-11-05) 1 1 1 1 1 Carl Friedrich Gauss A German mathematician (1777 - 1855), one of all time greatest. Gauss discovered the method of least squares and Gaussian elimination. Gauss was something of a child prodigy; the most commonly told story relates that when he was 10 his teacher, wanting a rest, told his class to add up all the numbers from 1 to 100. Gauss did it in seconds, having noticed that 1+...+100 = 100+...+1 = (101+...+101)/2. He did important work in almost every area of mathematics. Such eclecticism is probably impossible today, since further progress in most areas of mathematics requires much hard background study. Some idea of the range of his work can be obtained by noting the many mathematical terms with "Gauss" in their names. E.g. Gaussian elimination (linear algebra); Gaussian primes (number theory); Gaussian distribution (statistics); Gauss [unit] (electromagnetism); Gaussian curvature (differential 1 1 1 1 1 Carnegie Mellon University (CMU) A university in Pittsburgh, Pennsylvania. School of Computer Science (http://cs.cmu.edu/Web/FrontDoor.html). (1997-06-23) 1 1 1 1 1 carpal tunnel syndrome overuse strain injury 1 1 1 1 1 carriage return (CR, Control-M, ASCII 13) The character which causes the cursor to move to the left margin, often used with line feed to start a new line of output. Encoded in C and Unix as "\r". (1996-06-24) 1 1 1 1 1 Carrierless Amplitude/Phase Modulation (CAP) A design of Asymmetric Digital Subscriber Line transceiver developed by Bell Labs. CAP was the first ADSL design to be commercially deployed and, as of August 1996, was installed on more lines than any other. CAP is a variation of Quadrature Amplitude Modulation, the modulation used by most existing modems in 1997. With CAP, the three channels (POTS, downstream data and upstream data) are supported by splitting the frequency spectrum. Voice occupies the standard 0-4 Khz frequency band, followed by the upstream channel and the high-speed downstream channel. (1997-10-08) 1 1 1 1 1 carrier scanner (Or "wardialer") A program which uses a modem to dial a series of phone numbers (say, from 770-0000 to 770-9999), and keeps a log of what phone numbers answer with a modem carrier. The results of such a search were generally used by people looking to engage in random mischief in random machines. Since the 1980s, wardialers have generally fallen into disuse, partly because of easily available "caller ID" technology, partly because fax machines are now in wide use and would often be logged as a carrier by a wardialer, and partly because there are so many new and more interesting venues for computerised mischief these days. (1997-03-16) 1 1 1 1 1 carrier signal A continuous signal of a single frequency capable of being modulated by a second, data-carrying signal. In radio communication, the two common kinds of modulation are amplitude modulation and frequency modulation. (1995-03-01) 1 1 1 1 1 Cartesian coordinates (After Renee Descartes, French philosopher and mathematician) A pair of numbers, (x, y), defining the position of a point in a two-dimensional space by its perpendicular projection onto two axes which are at right angles to each other. x and y are also known as the abscissa and ordinate. The idea can be generalised to any number of independent axes. Compare polar coordinates. (1997-07-08) 1 1 1 1 1 Cartesian product (After Renee Descartes, French philosper and mathematician) The Cartesian product of two sets A and B is the set A x B = (a, b) | a in A, b in B. I.e. the product set contains all possible combinations of one element from each set. The idea can be extended to products of any number of sets. If we consider the elements in sets A and B as points along perpendicular axes in a two-dimensional space then the elements of the product are the "Cartesian coordinates" of points in that space. See also tuple. (1995-03-01) 1 1 1 1 1 CAS 1. <hardware> Column Address Strobe. 2. <communications> (channel associated signaling) in-band signalling. 1 1 1 1 1 CAS 8051 Assembler An experimental one-pass assembler for the 8051 with C-like syntax by Mark Hopkins. Most features of a modern assembler included except macros (soon to be added). Requires an ANSI-C compiler. Ported to MS-DOS, Ultrix, Sun-4. (July 1993). Version 1.2. Assembler/linker, disassembler, documentation, examples. (ftp://lyman.pppl.gov/pub/8051/assem), (ftp://nic.funet.fi/pub/microprocs/MCS-51/csd4-archive/assem). Other software tools and applications (ftp://nic.funet.fi/pub/compilers/8051/). (1995-01-26) 1 1 1 1 1 cascade 1. <compiler> A huge volume of spurious error-messages output by a compiler with poor error recovery. Too frequently, one trivial syntax error (such as a missing ")" or "") throws the parser out of synch so that much of the remaining program text, whether correct or not, is interpreted as garbaged or ill-formed. 2. <messaging> A chain of Usenet followups, each adding some trivial variation or riposte to the text of the previous one, all of which is reproduced in the new message; an include war in which the object is to create a sort of communal graffito. 3. <networking> A collection of interconneced networking devices, typically hubs, that allows those devices to act together as a logical repeater. [Jargon File] (1997-07-17) 1 1 1 1 1 Cascading Style Sheets (CSS) An extension to HTML to allow styles, e.g. colour, font, size to be specified for certain elements of a hypertext document. Style information can be included in-line in the HTML file or in a separate CSS file (which can then be easily shared by multiple HTML files). Multiple levels of CSS can be used to allow selective overriding of styles. (http://w3.org/Style/CSS/). (2000-07-26) 1 1 1 1 1 CASE 1. Computer Aided Software Engineering. 2. Common Application Service Element. 1 1 1 1 1 case 1. <programming> switch statement. 2. <character> Whether a character is a capital letter ("upper case" - ABC..Z) or a small letter ("lower case" - abc..z). The term case comes from the printing trade when the use of moving type was invented in the early Middle Ages (Caxton or Gutenberg?) and the letters for each font were stored in a box with two sections (or "cases"), the upper case was for the capital letters and the lower case was for the small letters. The Oxford Universal Dictionary of Historical Principles (Feb 1993, reprinted 1952) indicates that this usage of "case" (as the box or frame used by a compositor in the printing trade) was first used in 1588. (1996-03-01) 1 1 1 1 1 case and paste (From "cut and paste") The addition of a new feature to an existing system by selecting the code from an existing feature and pasting it in with minor changes. This usually results in gross violation of the fundamental programming tenet, Don't Repeat Yourself. Common in telephony circles because most operations in a telephone switch are selected using "case" statements. Leads to software bloat. In some circles of Emacs users this is called "programming by Meta-W", because Meta-W is the Emacs command for copying a block of text to a kill buffer in preparation to pasting it in elsewhere. The term is condescending, implying that the programmer is acting mindlessly rather than thinking carefully about what is required to integrate the code for two similar cases. At DEC, this is sometimes called "clone-and-hack" coding. [Jargon File] 1 1 1 1 1 case based reasoning (CBR) A technique for problem solving which looks for previous examples which are similar to the current problem. This is useful where heuristic knowledge is not available. There are many situations where experts are not happy to be questioned about their knowledge by people who want to write the knowledge in rules, for use in expert systems. In most of these situations, the natural way for an expert to describe his or her knowledge is through examples, stories or cases (which are all basically the same thing). Such an expert will teach trainees about the expertise by apprenticeship, i.e. by giving examples and by asking the trainees to remember them, copy them and adapt them in solving new problems if they describe situations that are similar to the new problems. CBR aims to exploit such knowledge. Some key research areas are efficient indexing, how to define similarity between cases and how to use temporal 1 1 1 1 1 CASE Data Interchange Format (CDIF) An emerging standard for interchange of data between CASE tools. (1994-11-03) 1 1 1 1 1 CASE framework A set of products and conventions that allow CASE tools to be integrated into a coherent environment. 1 1 1 1 1 case insensitive case sensitivity 1 1 1 1 1 Case Integration Services (CIS) A committee formed to discuss CASE tool integration standards related to ATIS. (1994-10-25) 1 1 1 1 1 CASE*Method An analysis and design method from Oracle targeted at information management applications. (1994-10-28) 1 1 1 1 1 case sensitive case sensitivity 1 1 1 1 1 case sensitivity Whether a text matching operation distinguishes upper-case (capital) letters from lower case (is "case sensitive") or not ("case insensitive"). Case in file names should be preserved (for readability) but ignored when matching (so the user doesn't have to get it right). MS-DOS does not preserve case in file names, Unix preserves case and matches are case sensitive. Any decent text editor will allow the user to specify whether or not text searches should be case sensitive. Case sensitivity is also relevant in programming (most programming languages distiguish between case in the names of identifiers), and addressing (Internet domain names are case insensitive but RFC 822 local mailbox names are case sensitive). Case insensitive operations are sometimes said to "fold case", from the idea of folding the character code table so that upper and lower case letters coincide. The alternative "smash 1 1 1 1 1 CASE SOAP III Version of SOAP assembly language for IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 case statement switch statement 1 1 1 1 1 CASE tools Software tools to help in the application of CASE methods to a software project. 1 1 1 1 1 cashe It's spelled "cache". (1996-12-13) 1 1 1 1 1 CAST Computer Aided Software Testing 1 1 1 1 1 cast explicit type conversion 1 1 1 1 1 casters-up mode [IBM, probably from slang belly up] Yet another synonym for broken or "down". Usually connotes a major failure. A system (hardware or software) which is "down" may be already being restarted before the failure is noticed, whereas one which is "casters up" is usually a good excuse to take the rest of the day off (as long as you're not responsible for fixing it). [Jargon File] 1 1 1 1 1 casting the runes What a guru does when you ask him or her to run a particular program because it never works for anyone else; especially used when nobody can ever see what the guru is doing different from what J. Random Luser does. Compare incantation, runes, examining the entrails; also see the AI koan about Tom Knight. (1997-12-26) 1 1 1 1 1 CAT Common Abstract Tree Language. R. Voeller & Uwe Schmidt, U Kiel, Germany 1983. Universal intermediate language, used by Norsk Data in their family of compilers. "A Multi-Language Compiler System with Automatically Generated Codegenerators, U. Schmidt et al, SIGPLAN Notices 19(6):202-2121 (June 1984). [Jargon File] 1 1 1 1 1 cat (From "catenate") Unix's command which copies one or more entire files to the screen or some other output sink without pause. See also dd, BLT. Among Unix fans, cat is considered an excellent example of user-interface design, because it delivers the file contents without such verbosity as spacing or headers between the files (the pr command can be used to do this), and because it does not require the files to consist of lines of text, but works with any sort of data. Among Unix haters, cat is considered the canonical example of *bad* user-interface design, because of its woefully unobvious name. It is far more often used to blast a file to standard output than to concatenate files. The name "cat" for the former operation is just as unintuitive as, say, LISP's cdr. Of such oppositions are holy wars made. 1 1 1 1 1 Cat 3 Category 3 1 1 1 1 1 Cat 5 Category 5 1 1 1 1 1 catatonic A description of a system that gives no indication that it is still working. This might be because it has crashed without being able to give any error message or because it is busy but not designed to give any feedback. Compare buzz. [Jargon File] (2004-08-19) 1 1 1 1 1 CATE Computer Aided Test Engineering 1 1 1 1 1 Categorical Abstract Machine Language (Originally "CAML" - Categorical Abstract Machine Language) A version of ML by G. Huet, G. Cousineau, Ascander Suarez, Pierre Weis, Michel Mauny and others of INRIA and ENS. CAML is intermediate between LCF ML and SML [in what sense?]. It has first-class functions, static type inference with polymorphic types, user-defined variant types and product types, and pattern matching. It is built on a proprietary run-time system. The CAML V3.1 implementation added lazy and mutable data structures, a "grammar" mechanism for interfacing with the Yacc parser generator, pretty-printing tools, high-performance arbitrary-precision arithmetic, and a complete library. CAML V3 is often nicknamed "heavy CAML", because of its heavy memory and CPU requirements compared to Caml Light. in 1990 Xavier Leroy and Damien Doligez designed a new implementation called Caml Light, freeing the previous 1 1 1 1 1 category A category K is a collection of objects, obj(K), and a collection of morphisms (or "arrows"), mor(K) such that 1. Each morphism f has a "typing" on a pair of objects A, B written f:A->B. This is read 'f is a morphism from A to B'. A is the "source" or "domain" of f and B is its "target" or co-domain. 2. There is a partial function on morphisms called composition and denoted by an infix ring symbol, o. We may form the "composite" g o f : A -> C if we have g:B->C and f:A->B. 3. This composition is associative: h o (g o f) = (h o g) o f. 4. Each object A has an identity morphism id_A:A->A associated with it. This is the identity under composition, shown by the equations id__B o f = f = f o id__A. In general, the morphisms between two objects need not form a set (to avoid problems with Russell's paradox). An 1 1 1 1 1 Category 3 (Cat 3, or "voice grade") An American Standards Institute standard for UTP cables. Used, e.g., for 100BaseVG network cabling. (1998-06-30) 1 1 1 1 1 Category 5 (Cat 5) An American Standards Institute standard for UTP cables. Used, e.g., for 100BaseTX cabling. (1998-06-30) 1 1 1 1 1 CA-Telon A Computer Aided Software Engineering (CASE) tool for designing, generating and maintaining COBOL and PL/I application programs. Telon was developed by Pansophic Systems who were bought by Computer Associates in 1991, whereupon it was renamed CA-Telon. It supports high-level, non-prodedural design and prototyping, combined with automatic code generation. There are mainframe and PC versions. The generated COBOL applications can execute in AIX, HP-UX, VSE, OS/400 for the AS/400, PC-DOS, or OS/2. (2000-01-19) 1 1 1 1 1 cathode ray tube (CRT) An electrical device for displaying images by exciting phosphor dots with a scanned electron beam. CRTs are found in computer VDUs and monitors, televisions and oscilloscopes. The first commercially practical CRT was perfected on 29 January 1901 by Allen B DuMont. A large glass envelope containing a negative electrode (the cathode) emits electrons (formerly called "cathode rays") when heated, as in a vacuum tube. The electrons are accelerated across a large voltage gradient toward the flat surface of the tube (the screen) which is covered with phosphor. When an electron strikes the phosphor, light is emitted. The electron beam is deflected by electromagnetic coils around the outside of the tube so that it scans across the screen, usually in horizontal stripes. This scan pattern is known as a raster. By controlling the current in the beam, the brightness at any particular point (roughly a "pixel") can be varied. Different phosphors have different "persistence" - the 1 1 1 1 1 CATIA A CAD/CAM system produced by Dassault Systemes and sold by IBM. CATIA is used heavily in the car and aerospace industries. It runs on various Unix platforms and Windows NT. (http://catia.ibm.com/catmain.html). (2002-06-12) 1 1 1 1 1 cationic cocktail (Or "Downy cocktail") Diluted fabric softener sprayed on computer room carpets to prevent static electricity from being built up by feet shuffling on carpet. The canonical cationic cocktail is one part unscented liquid fabric softener (in the US, usually "Downy" brand) to five parts water. Cationic is the chemical term for the most common active ingredient in fabric softeners. The use of the term cocktail may be influenced by its use in other jargons, especially pharmacological and chemical, to denote a mixture which, like cationic cocktail, typically contains no alcohol and would be unwise to drink. (1998-04-04) 1 1 1 1 1 C/ATLAS A DoD test language. It is a variant of ATLAS. (1995-05-01) 1 1 1 1 1 CATNIP Common Architecture for Next Generation Internet Protocol 1 1 1 1 1 CATO Fortran-like CAI language for PLATO system on CDC 1604. "CSL PLATO System Manual", L.A. Fillman, U Illinois, June 1966. 1 1 1 1 1 Cauchy sequence A sequence of elements from some vector space that converge and stay arbitrarily close to each other (using the norm definied for the space). (2000-03-10) 1 1 1 1 1 cause-effect graphing A testing technique that aids in selecting, in a systematic way, a high-yield set of test cases that logically relates causes to effects to produce test cases. It has a beneficial side effect in pointing out incompleteness and ambiguities in specifications. (1996-05-10) 1 1 1 1 1 CAV Constant Angular Velocity 1 1 1 1 1 Cayenne Software The company formed when CADRE merged with Bachman Information Systems in July 1996. (http://cayennesoft.com/). [Details?] (2001-04-30) 1 1 1 1 1 CAYLEY A symbolic mathematics system for group theory written by John Cannon of the University of Sydney, Australia in 1976. Cayley was used at about 100 sites but has been superseded by a much more general system, Magma. ["An Introduction to the Group Theory Language CAYLEY", J. Cannon, Computational Group Theory, M.D. Atkinson ed, Academic Press 1984, pp. 148-183]. Latest version: V3.7, for Sun, Apollo, VAX/VMS. (2000-09-03) 1 1 1 1 1 cb C Beautifier 1 1 1 1 1 CBASIC A BASIC compiler by Gordon Eubanks, now at Symantec. It evolved from/into EBASIC. (1994-11-29) 1 1 1 1 1 CBBS bulletin board system 1 1 1 1 1 C-BC A strongly typed version of BC by Mark Hopkins, with expanded C-like syntax, more base types and the ability to form array and pointer types of any dimension and to allocate/free arrays at run time. Most POSIX-BC features are supported, except that functions must be declared consistently and declared before first use. String handling is slightly different. It requires an ANSI-C compiler and runs under MS-DOS or Unix. Version: 1.1. Posted to alt.sources 1993-04-10. (1993-08-23) 1 1 1 1 1 CBD component based development 1 1 1 1 1 C Beautifier (cb) A Unix tool for reformatting C source code. Unix manual page: cb(1). 1 1 1 1 1 CBIR content-based information retrieval. (1995-11-23) 1 1 1 1 1 CBN call-by-name 1 1 1 1 1 CBR case based reasoning 1 1 1 1 1 CBT Computer-Based Training 1 1 1 1 1 CBV call-by-value 1 1 1 1 1 cbw Crypt Breakers Workbench 1 1 1 1 1 cc The country code for the Cocos (Keeling) Islands. (1999-01-27) 1 1 1 1 1 CC++ Compositional C++ 1 1 1 1 1 C/C++ 1. Borland C/C++. 2. Watcom C/C++. 3. Either C or C++. 1 1 1 1 1 CCalc A symbolic mathematics system for MS-DOS, available from Simtel. (1995-04-12) 1 1 1 1 1 CCD Charge-Coupled Device 1 1 1 1 1 CCIRN Coordinating Committee for Intercontinental Research Networks. 1 1 1 1 1 CCITT Commite' Consultatif International de Telegraphique et Telephonique. (International consultative committee on telecommunications and Telegraphy). CCITT changed its name to ITU-T on 1 March 1993. (1994-11-03) 1 1 1 1 1 CCITT HIgh-Level Language (CHILL) A real-time language widely used in telecommunications. CHILL was developed in the 1970s and improved in 1984, 1988, 1992, and 1996. It is used in several countries including Germany, Norway, Brasil, and South Korea. Cygnus are developing a compiler based on gcc. (http://www1.informatik.uni-jena.de/languages/chill/chill.htm). ["An Analytical Description of CHILL, the CCITT High Level Language", P. Branquart, LNCS 128, Springer 1982]. ["CHILL User's Manual", ITU, 1986, ISBN 92-61-02601-X. ISO-9496 (1988?)]. (1997-01-20) 1 1 1 1 1 CCL 1. Coral Common LISP. 2. Computer Control Language. English-like query language based on COLINGO, for IBM 1401 and IBM 1410. 1 1 1 1 1 CCLU Cambridge CLU. CLU extended to support concurrency, distributed programming and remote procedure call, by G. Hamilton et al at CUCL. E-mail: Jean Bacon <jmb@cl.cam.ac.uk>. (1994-10-13) 1 1 1 1 1 ccmail It's written cc:mail. 1 1 1 1 1 cc:mail Commercial electronic mail software by Lotus Corporation for Microsoft Windows. (1995-03-14) 1 1 1 1 1 CCP 1. <language> Concurrent Constraint Programming. 2. Command Control Processor. 1 1 1 1 1 CCR 1. condition code register. 2. (Database) concurrency control and recovery. 1 1 1 1 1 CCS 1. <networking> Common Communication Services. 2. <language, parallel> Calculus of Communicating Systems. 3. <history> Computer Conservation Society. 4. <storage, standard> Common Command Set. 5. <communications> centum call second. 1 1 1 1 1 CCSP Contextually Communicating Sequential Processes 1 1 1 1 1 CCTA The Government Centre for Information Systems. (Originally "Central Computer and Telecommunications Agency"). CCTA is part of the Office of Public Service and Science, which works to improve government's services to the public. They are responsible for stimulating and promoting the effective use of Information Systems in support of the efficient delivery of business objectives and improved quality of services by the public sector. CCTA had to change its name as it was not an agency in the Next Steps sense. The letters were retained as customers were familiar with them. (http://open.gov.uk/). E-mail: <info@open.gov.uk>. Address: Norwich, UK. (1995-01-18) 1 1 1 1 1 CD Compact Disc 1 1 1 1 1 cd 1. <operating system> change directory. 2. <networking> The country code for the Democratic Republic of the Congo (formerly Zaire, zr). (1999-01-27) 1 1 1 1 1 CDA 1. <file format> Compound Document Architecture. 2. <legal> Communications Decency Act. 1 1 1 1 1 CD burner Compact Disc writer 1 1 1 1 1 CDC Control Data Corporation 1 1 1 1 1 CDC 6600 A mainframe computer from Control Data Corporation, first delivered in 1964. It is generally considered to be the first successful supercomputer, about three times faster than STRETCH. Its successor was the CDC 7600. (2007-03-01) 1 1 1 1 1 CDDI Copper Distributed Data Interface 1 1 1 1 1 CDD/Plus DEC's CASE repository. 1 1 1 1 1 CDE 1. C Development environment from IDE. 2. Common Desktop Environment. 3. Co-operative Development Environment. (1996-07-11) 1 1 1 1 1 CDF Common Data Format 1 1 1 1 1 CD-i Compact Disc interactive 1 1 1 1 1 CDIF CASE Data Interchange Format 1 1 1 1 1 CDL 1. Computer Definition [Design?] Language. A hardware description language. "Computer Organisation and Microprogramming", Yaohan Chu, P-H 1970. 2. Command Definition Language. Portion of ICES used to implement commands. Sammet 1969, p.618-620. 3. Compiler Description Language. C.H.A. Koster, 1969. Intended for implementation of the rules of an affix grammar by recursive procedures. A procedure may be a set of tree-structured alternatives, each alternative is executed until one successfully exits. Used in a portable COBOL-74 compiler from MPB, mprolog system from SzKI, and the Mephisto chess computer. "CDL: A Compiler Implementation Language", in Methods of Algorithmic Language Implementation, C.H.A. Koster, LNCS 47, Springer 1977, pp.341-351. "Using the CDL Compiler Compiler", C.H.A. Koster, 1974. Versions: CDL2, CDLM used at Manchester. 4. Common Design Language. "Common Design Language", IBM, 1 1 1 1 1 CDM 1. Content Data Model 2. Code Division Multiplexing 1 1 1 1 1 CDMA Code Division Multiple Access 1 1 1 1 1 CDP1802 RCA 1802 1 1 1 1 1 CDPD Cellular Digital Packet Data 1 1 1 1 1 CDR 1. <networking> Committed Data Rate. 2. <storage> Compact Disc Recordable (CD-R). 3. <telecommunications> Call Data Record. 1 1 1 1 1 cdr Contents of Decrement part of Register 1 1 1 1 1 CD-Read-Write Compact Disc Rewritable 1 1 1 1 1 CD-Rewritable Compact Disc Rewritable 1 1 1 1 1 CD-ROM Compact Disc Read-Only Memory 1 1 1 1 1 CD-ROM drive Compact Disc Read-Only Memory 1 1 1 1 1 CD-RW Compact Disc Rewritable 1 1 1 1 1 CDS Concrete Data Structure 1 1 1 1 1 cd tilde /C-D til-d*/ To go home. From the Unix C shell and Korn-shell command "cd ~", which takes one to one's "$HOME" directory. "cd" with no arguments does the same thing. [Jargon File] (1994-10-28) 1 1 1 1 1 CDW data warehouse 1 1 1 1 1 CE IBM Customer Engineer 1 1 1 1 1 Cecil AN object-oriented language combining multi-methods with a classless object model, object-based encapsulation and optional static type checking. It distinguishes between subtyping and code inheritance. Includes both explicit and implicit parameterisation of objects, types, and methods. (ftp://cs.washington.edu/pub/chambers/cecil-spec.ps.Z). ["The Cecil Language: Specification and Rationale", C. Chambers, TR 93-03-05, U Wash (Mar 1993)]. (1994-10-28) 1 1 1 1 1 Cedar A superset of Mesa, from Xerox PARC, adding garbage collection, dynamic types and a universal pointer type (REF ANY). Cedar is a large complex language designed for custom Xerox hardware and the Cedar operating system/environment. Data types are atoms, lists, ropes ("industrial strength" strings), conditions. Multi-processing features include threads, monitors, signals and catch phrases. It was used to develop the Cedar integrated programming environment. ["A Description of the Cedar Language", Butler Lampson, Xerox PARC, CSL-83-15 (Dec 1983)]. ["The Structure of Cedar", D. Swinehart et al, SIGPLAN Notices 20(7):230-244 (July 1985)]. (1995-01-26) 1 1 1 1 1 CEEMAC+ Graphics language for DOS 3.3 on Apple II. 1 1 1 1 1 CEI-PACT Central European Initiative on Parallel Computation. 1 1 1 1 1 Celeron Intel Corporation's trade name for its family of Pentium II microprocessors meant for use in low-end computers. The Celeron is constructed on the 0.25 micron Deschutes base. Clock rates of 266, 300 and 333 MHz are supported. It is built on the same daughterboard as the Pentium II without the black plastic case and heat sink. Four Celeron models are in production as of October 1998. The 266 and 300 MHz models are essentially Pentium II CPUs without the Level 2 cache RAM. The 300A and 333 MHz Celerons include 128k of Level 2 cache. A special mounting bracket on the motherboard is used to secure the Celeron in place in its standard 242-pin Slot 1 socket. Intel calls the caseless design SEPP (Single Edge Processor Package) to differentiate it from the Pentium II SEC (Single Edge Cartridge). Some believe that the real purpose for the different mounting configurations is to prevent users 1 1 1 1 1 CELIP A cellular language for image processing. ["CELIP: A cellular Language for Image Processing", W. Hasselbring <willi@informatik.uni-essen.de>, Parallel Computing 14:99-109 (1990)]. (1994-12-05) 1 1 1 1 1 cell 1. <spreadsheet> In a spreadsheet, the intersection of a row a column and a sheet, the smallest addressable unit of data. A cell contains either a constant value or a formula that is used to calculate a value. The cell has a format that determines how to display the value. A cell can be part of a range. A cell is usually referred to by its column (labelled by one or more letters from the sequence A, B, ..., Z, AA, AB, ..., AZ, BA, BB, ..., BZ, ... ) and its row number counting up from one, e.g. cell B3 is in the second column across and the third row down. A cell also belongs to a particular sheet, e.g. "Sheet 1". 2. <networking> ATM's term for a packet. (2007-10-22) 1 1 1 1 1 Cellang See Cellular. 1 1 1 1 1 CELLAS CELLular ASsemblies. A concurrent block-structured language. [Mentioned in "Attribute Grammars", LNCS 323, p.97]. (1994-12-05) 1 1 1 1 1 Cello A web browser client for IBM PCs. Runs under Microsoft Windows. (2014-08-23) 1 1 1 1 1 cell reference A string identifying a particular cell in a spreadsheet, possibly relative to the cell containing the reference. A cell reference may be absolute (denoted by a "$" prefix in Excel) or relative (no prefix) in each dimension, thus, e.g. B$6 refers to the second cell across in the sixth row. The distinction between absolute and relative is only significant when the referring cell is copied, e.g. if cell A1, which refers to B$6, is copied to cell B1, then B1 will refer to C6. If the reference is to a cell in a different sheet then it is prefixed with the target sheet's name and an exclamation mark. E.g. "Sheet 1!B3". (2007-10-22) 1 1 1 1 1 CELLSIM A program for modelling populations of biological cells. ["CELLSIM II User's Manual", C.E. Donaghey, U Houston. Sep 1975]. (1994-12-05) 1 1 1 1 1 CEll Space Simulation Language (CESSL) A language for simulating cellular space models. ["The CESSL Programming Language", D.R. Frantz, 012520-6-T, CS Dept, U Michigan, Sept 1971]. (1994-12-14) 1 1 1 1 1 Cellular A system for cellular automaton programming by J Dana Eckart <dana@faculty.cs.runet.edu>. Cellular includes a byte-code compiler, run-time system, and a viewer. Latest version: 2.0, as of 1993-04-03. Posted to comp.sources.unix, volume 26. See also Cellang. (2000-10-07) 1 1 1 1 1 cellular automata cellular automaton 1 1 1 1 1 cellular automaton (CA, plural "- automata") A regular spatial lattice of "cells", each of which can have any one of a finite number of states. The state of all cells in the lattice are updated simultaneously and the state of the entire lattice advances in discrete time steps. The state of each cell in the lattice is updated according to a local rule which may depend on the state of the cell and its neighbors at the previous time step. Each cell in a cellular automaton could be considered to be a finite state machine which takes its neighbours' states as input and outputs its own state. The best known example is J.H. Conway's game of Life. FAQ (http://alife.santafe.edu/alife/topics/cas/ca-faq/ca-faq.html). Usenet newsgroups: news:comp.theory.cell-automata, news:comp.theory.self-org-sys. (1995-03-03) 1 1 1 1 1 Cellular Digital Packet Data (CDPD) A wireless standard providing two-way, 19.2 kbps packet data transmission over exisiting cellular telephone channels. [Reference?] (1994-12-05) 1 1 1 1 1 cellular multiprocessing (CMP) The partitioning of processors into separate computing environments running different operating systems. The term cellular multiprocessing appears to have been coined by Unisys, who are developing a system where computers communicate as clustered machines through a high speed bus, rather than through communication protocols such as TCP/IP. The Unisys system is based on Intel processors, initially the Pentium II Xeon and moving on to the 64-bit Merced processors later in 1999. It will be scalable from four up to 32 processors, which can be clustered or partitioned in various ways. For example a sixteen processor system could be configured as four Windows NT systems (each functioning as a four-processor symmetric multiprocessing system), or an 8-way NT and 8-way Unix system. Supported operating systems will be Windows NT, SCO's 1 1 1 1 1 Cellular Neural Network (CNN) The CNN Universal Machine is a low cost, low power, extremely high speed supercomputer on a chip. It is at least 1000 times faster than equivalent DSP solutions of many complex image processing tasks. It is a stored program supercomputer where a complex sequence of image processing algorithms is programmed and downloaded into the chip, just like any digital computer. Because the entire computer is integrated into a chip, no signal leaves the chip until the image processing task is completed. Although the CNN universal chip is based on analogue and logic operating principles, it has an on-chip analog-to-digital input-output interface so that at the system design and application perspective, it can be used as a digital component, just like a DSP. In particular, a development system is available for rapid design and prototyping. Moreover, a compiler, an operating system, and a user-friendly CNN high-level language, like the C 1 1 1 1 1 CELP Computationally Extended Logic Programming. ["Computationally Extended Logic Programming", M.C. Rubenstein et al, Comp Langs 12(1):1-7 (1987)]. (1995-04-27) 1 1 1 1 1 CEN Conseil Européen pour la Normalisation. A body coordinating standardisation activities in the EEC and EFTA countries. (1994-12-14) 1 1 1 1 1 CENELEC The European Committee for Electrotechnical Standardization. A body developing electrotechnical standards for the Single European Market / European Economic Area in order to reduce internal frontiers and trade barriers for electrotechnical products, systems and services. CENELEC's 19 member countries and 11 affiliate countries aim to adopt and implement the required standards, which are mostly identical to the International Electrotechnical Commission (IEC) standards. CENELEC works in co-operation with Comité Européen de Normalisation (CEN) and European Telecommunications Standards Institute (ETSI). (1999-09-28) 1 1 1 1 1 centi-call second No, it's centum call second. (2002-03-25) 1 1 1 1 1 central office The place where telephone companies terminate customer lines and locate switching equipment to interconnect those lines with other networks. (1995-03-20) 1 1 1 1 1 Central office exchange service (Centrex) A PBX service providing switching at the central office instead of at the company premises. Typically, the telephone company owns and manages all the communications equipment necessary to implement the PBX and then sells various services to the company. (1999-10-27) 1 1 1 1 1 central processing unit (CPU, processor) The part of a computer which controls all the other parts. Designs vary widely but the CPU generally consists of the control unit, the arithmetic and logic unit (ALU), registers, temporary buffers and various other logic. The control unit fetches instructions from memory and decodes them to produce signals which control the other parts of the computer. These signals cause it to transfer data between memory and ALU or to activate peripherals to perform input or output. Various types of memory, including cache, RAM and ROM, are often considered to be part of the CPU, particularly in modern microprocessors where a single integrated circuit may contain one or more processors as well as any or all of the above types of memory. The CPU, and any of these components that are in separate chips, are usually all located on the same printed circuit board, known as the 1 1 1 1 1 Centrex Central office exchange service 1 1 1 1 1 Centronics A company in Hudson N.H., USA, best known for designing the parallel interface for printers with the same name, found on many microcomputers. [Pin-out?] (1998-03-15) 1 1 1 1 1 Centrum voor Wiskunde en Informatica (CWI, Centre for Mathematics and Computer Science) An independent research institute active in the fields of mathematics and computer science. CWI also aims to transfer new knowledge in these fields to society, trade and industry CWI is funded for 70 percent by NWO, the National Organisation for Scientific Research. The remaining 30 percent is obtained through national and international programmes and contract research commissioned by industry. Address: Kruislaan 413, 1098 SJ Amsterdam, The Netherlands; P.O.Box 94079, 1090 GB Amsterdam, The Netherlands. Telephone: +31 (20) 5929 333. (http://cwi.nl/). (ftp://ftp.cwi.nl/pub/). 1 1 1 1 1 centum call second (CCS) A unit used (in North America) to quantify the total traffic running in a network. 1 CCS is 100 call-seconds. That means 1 CCS could be 2 calls of 50 seconds duration or 20 calls of 5 seconds duration. (2002-03-25) 1 1 1 1 1 century meltdown Year 2000 1 1 1 1 1 CEN/XFS Extensions for Financial Services 1 1 1 1 1 cepstra cepstrum 1 1 1 1 1 cepstrum (Coined in a 1963 paper by Bogert, Healey, and Tukey) The Fourier transform of the log-magnitude spectrum: fFt(ln( | fFt(window . signal) | )) This function is used in speech recognition and possibly elsewhere. Note that the outer transform is NOT an inverse Fourier transform (as reported in many respectable DSP texts). [What's it for?] (1997-01-07) 1 1 1 1 1 CEPT Comite Europeen des Postes et Telecommunications 1 1 1 1 1 CER Canonical Encoding Rules 1 1 1 1 1 Ceramic Pin Grid Array (CPGA) A form of Pin Grid Array package used by Cyrix III processors. Compare PPGA and FC-PGA. [Other uses?] (2000-08-26) 1 1 1 1 1 Ceres workstation Oberon System A complete Oberon compiler written in Oberon. Source to most of the complete Ceres workstation Oberon System, including the National Semiconductor 32032 code generator is available. Less of the low level system specific code is available. (ftp://neptune.ethz.ch/Oberon/). (1994-12-14) 1 1 1 1 1 Cerf, Vint Vint Cerf 1 1 1 1 1 CERN The European Laboratory for Particle Physics in Swizerland. Tim Berners-Lee invented the World-Wide Web while working at CERN. Other notable computing developments at CERN include ADAMO, Application Software Installation Server, CERNLIB, cfortran.h, CHEOPS, CICERO, Cortex, EMDIR, HBOOK, LIGHT, NFT, PATCHY, PL-11, Schoonschip, SHIFT, and ZEBRA. CERN Home (http://cern.ch/). (2004-10-24) 1 1 1 1 1 CERNLIB The CERN Program Library. (2004-09-01) 1 1 1 1 1 CERT Computer Emergency Response Team 1 1 1 1 1 Certificate Authority (CA or "Trusted Third Party") An entity (typically a company) that issues digital certificates to other entities (organisations or individuals) to allow them to prove their identity to others. A Certificate Authority might be an external company such as VeriSign that offers digital certificate services or they might be an internal organisation such as a corporate MIS department. The Certificate Authority's chief function is to verify the identity of entities and issue digital certificates attesting to that identity. The process uses public key cryptography to create a network of trust. If I want to prove my identity to you, I ask a CA (who you trust to have verified my identity) to encrypt a hash of my signed key with their private key. Then you can use the CA's public key to decrypt the hash and compare it with a hash you calculate yourself. Hashes are used to decrease the amount of data that needs to be 1 1 1 1 1 CESP Common ESP 1 1 1 1 1 CESSL CEll Space Simulation Language 1 1 1 1 1 cextract A C prototype extractor by Adam Bryant <adb@cs.bu.edu>. cextract can generate header files for large multi-file C programs, and will automatically generate prototypes for all of the functions in such a program. It can also generate a sorted list of all functions and their locations. cextract version 1.7 works with both ANSI C and K&R C and runs under Unix and VMS. Posted to comp.sources.reviewed. (1992-11-03) 1 1 1 1 1 cf The country code for the Central African Republic. (1999-01-27) 1 1 1 1 1 CFD Computational Fluid Dynamics 1 1 1 1 1 CFG context-free grammar 1 1 1 1 1 CFML ColdFusion Markup Language 1 1 1 1 1 cforth A Forth interpreter. Posted to comp.sources.unix volume 1. (1994-11-29) 1 1 1 1 1 cfortran.h A transparent, machine independent interface between C and Fortran routines and global data, developed by Burkhard Burow at CERN. It provides macros which allow the C preprocessor to translate a simple description of a C (Fortran) routine or global data into a Fortran (C) interface. Version 2.6 runs on VAX/VMS/Ultrix, DECstation, Silicon Graphics, IBM RS/6000, Sun, Cray, Apollo, HP9000, LynxOS, f2c, NAG f90. (ftp://zebra.desy.de/cfortran/). cfortran.h was reviewed in RS/Magazine November 1992 and a user's experiences with cfortran.h are described in the Jan 93 issue of Computers in Physics. (1992-04-12) 1 1 1 1 1 CFP 1. Constraint Functional Programming. 2. Communicating Functional Processes. 3. Call For Papers (for a conference). 1 1 1 1 1 CFP92 SPEC CFP92 1 1 1 1 1 cg The country code for Congo. (1999-01-27) 1 1 1 1 1 CGA Color Graphics Adapter 1 1 1 1 1 CGGL Code-Generator Generator Language 1 1 1 1 1 CGI 1. <web> Common Gateway Interface. 2. <graphics> computer-generated imagery. 3. <company> A French software engineering vendor in the US. 4. <company> Computer Generation Incorporated. 1 1 1 1 1 cgi-bin Common Gateway Interface 1 1 1 1 1 CGI Joe (From "GI Joe") A hard-core CGI script programmer with all the social skills and charisma of a plastic action figure. (1997-03-30) 1 1 1 1 1 CGI program Common Gateway Interface 1 1 1 1 1 CGI script Common Gateway Interface 1 1 1 1 1 CGM Computer Graphics Metafile 1 1 1 1 1 CGOL A package providing ALGOL-like surface syntax for MACLISP, written by V.R. Pratt in 1977. (ftp://mc.lcs.mit.edu/its/ai/lisp/cgol.fasl). ["CGOL - An Alternative Exetrnal Representation for LISP Users", V. Pratt, MIT AI Lab, Working Paper 89, 1976]. (2005-01-07) 1 1 1 1 1 cgram An ANSI C LL1 or LL2 grammar written in Scheme by Mohd Hanafiah Abdullah <napi@cs.indiana.edu>. A program (f-f-d.s) extracts the FIRST/FOLLOW/DIRECTOR sets. (ftp://primost.cs.wisc.edu/pub/comp.compilers/cgram-ll1.Z). (2005-01-07) 1 1 1 1 1 Ch An interpreted programming language sold by Soft Integration and marketed for scripting, shell programming and graph plotting, it is a superset of C++. Ch is also the name of Soft Integration's interpreter for the language. Currently the Ch interpreter is available for Windows, Solaris, HP-UX, Linux and Mac platforms. Soft Integration (http://softintegration.com/). (2003-08-15) 1 1 1 1 1 ch The country code for Switzerland. (1999-01-27) 1 1 1 1 1 chad /chad/ (Or "selvage" /sel'v*j/ (sewing and weaving), "perf", "perfory", "snaf"). 1. The perforated edge strips on paper for sprocket feed printers, after they have been separated from the printed portion. The term perf may also refer to the perforations themselves, rather than the chad they produce when torn. [Why "snaf"?] 2. (Or "chaff", "computer confetti", "keypunch droppings") The confetti-like bits punched out of punched cards or paper tape which collected in the chad box. One of the Jargon File's correspondents believed that "chad" derived from the chadless keypunch. [Jargon File] (1997-07-18) 1 1 1 1 1 chad box (IBM called this a "chip box") A metal box about the size of a lunchbox (or in some models a large wastebasket), for collecting the chad that accumulated in Iron Age card punches. You had to open the covers of the card punch periodically and empty the chad box. The bit bucket was notionally the equivalent device in the CPU enclosure, which was typically across the room in another great grey-and-blue box. [Jargon File] (1996-11-20) 1 1 1 1 1 Chadless keypunch A card punch which cut little U-shapes in punched cards, rather than punching out a circle or rectangle. The U's made a hole when folded back. One of the Jargon File's correspondents believed that the term "chad" derived from the Chadless keypunch. Obviously, if the Chadless keypunch didn't make them, then the stuff that other keypunches made had to be "chad". The assertion that the keypunch was named after its inventor is not supported by any record in US or UK patents or surname references. (2000-11-22) 1 1 1 1 1 chain 1. <operating system> (From BASIC's "CHAIN" statement) To pass control to a child or successor without going through the operating system command interpreter that invoked you. The state of the parent program is lost and there is no returning to it. Though this facility used to be common on memory-limited microcomputers and is still widely supported for backward compatibility, the jargon usage is semi-obsolescent; in particular, Unix calls this exec. Compare with the more modern "subshell". 2. <programming> A series of linked data areas within an operating system or application program. "Chain rattling" is the process of repeatedly running through the linked data areas searching for one which is of interest. The implication is that there are many links in the chain. 3. <theory> A possibly infinite, non-decreasing sequence of elements of some total ordering, S 1 1 1 1 1 Challenge-Handshake Authentication Protocol (CHAP) An authentication scheme used by PPP servers to validate the identity of the originator of the connection upon connection or any time later. CHAP applies a three-way handshaking procedure. After the link is established, the server sends a "challenge" message to the originator. The originator responds with a value calculated using a one-way hash function. The server checks the response against its own calculation of the expected hash value. If the values match, the authentication is acknowledged; otherwise the connection is usually terminated. CHAP provides protection against playback attack through the use of an incrementally changing identifier and a variable challenge value. The authentication can be repeated any time while the connection is open limiting the time of exposure to any single attack, and the server is in control of the frequency and timing of the challenges. As a result, CHAP 1 1 1 1 1 Chalmers University of Technology A Swedish university founded in 1829 offering master of science and doctoral degrees. Research is carried out in the main engineering sciences as well as in technology related mathematical and natural sciences. Five hundred faculty members work in more than 100 departments organised in nine schools. Chalmers collaborates with the University of Göteborg. Around 8500 people work and study on the Chalmers campus, including around 500 faculty members and some 600 teachers and doctoral students. About 4800 students follow the master degree programs. Every year 700 Masters of Science in Engineering and in Architecture graduate from Chalmers, and about 190 PhDs and licentiates are awarded. Some 40% of Sweden's engineers and architects are Chalmers graduates. About a thousand research projects are in progress and more than 1500 scientific articles and research reports are published every year. Chalmers is a partner in 80 EC research 1 1 1 1 1 change management Techniques that aid in evolution, composition and policy management of the design and implementation of an object or system. (1995-02-16) 1 1 1 1 1 changeover The time when a new system has been tested successfully and replaces the old system. (2003-11-12) 1 1 1 1 1 channel (Or "chat room", "room", depending on the system in question) The basic unit of group discussion in chat systems like IRC. Once one joins a channel, everything one types is read by others on that channel. Channels can either be named with numbers or with strings that begin with a "#" sign and can have topic descriptions (which are generally irrelevant to the actual subject of discussion). Some notable channels are "#initgame", "#hottub" and #report. At times of international crisis, "#report" has hundreds of members, some of whom take turns listening to various news services and typing in summaries of the news, or in some cases, giving first-hand accounts of the action (e.g. Scud missile attacks in Tel Aviv during the Gulf War in 1991). [Jargon File] (1998-01-25) 1 1 1 1 1 channel associated signaling in-band signalling 1 1 1 1 1 channel hopping To rapidly switch channels on IRC, or a GEnie chat board. This term may derive from the TV idiom, "channel surfing". [Jargon File] (1994-11-29) 1 1 1 1 1 channel op /chan'l op/ (Or "op", "chan op", "chop") Someone who is endowed with privileges on a particular IRC channel. These privileges include the right to kick users, to change various status bits and to make others into CHOPs. The full form, "channel operator", is almost never used. [Jargon File] (1998-01-08) 1 1 1 1 1 channel service unit (CSU) A type of interface used to connect a terminal or computer to a digital medium in the same way that a modem is used for connection to an analogue medium. A CSU is provided by the communication carrier to customers who wish to use their own equipment to retime and regenerate the incoming signals. The customer must supply all of the transmit logic, receive logic and timing recovery in order to use the CSU, whereas a digital service unit DSU performs these functions. (1995-01-30) 1 1 1 1 1 channel service unit/data service unit (CSU/DSU, or "..digital..") A device that performs both the channel service unit (CSU) and data service unit (DSU) functions. The Channel Service Unit (CSU) is used to terminate a DS1 or DS0 (56/64 kb/s) digital circuit. It peforms line conditioning, protection, loop-back and timing functions. The Data Service Unit (DSU) terminates the data circuit to the Data Terminal Equipment (DTE) and converts the customer's data stream into a bi-polar format for transmission. (2001-10-19) 1 1 1 1 1 chan op channel op 1 1 1 1 1 chaos A property of some non-linear dynamic systems which exhibit sensitive dependence on initial conditions. This means that there are initial states which evolve within some finite time to states whose separation in one or more dimensions of state space depends, in an average sense, exponentially on their initial separation. Such systems may still be completely deterministic in that any future state of the system depends only on the initial conditions and the equations describing the change of the system with time. It may, however, require arbitrarily high precision to actually calculate a future state to within some finite precision. ["On defining chaos", R. Glynn Holt <rgholt@voyager.jpl.nasa.gov> and D. Lynn Holt <lholt@seraph1.sewanee.edu>. (ftp://mrcnext.cso.uiuc.edu/pub/etext/ippe/preprints/Phil_of_Science/Holt_and_Holt.On_Defining_Chaos)] Fixed precision floating-point arithmetic, as used by most 1 1 1 1 1 CHAP Challenge-Handshake Authentication Protocol 1 1 1 1 1 char /keir/ or /char/; rarely, /kar/ character. Especially used by C programmers, as "char" is C's typename for character data. [Jargon File] (1994-11-29) 1 1 1 1 1 character A letter of some alphabet (either upper case or lower case), a digit, a punctuation or other symbol or a control character. In a computer, a character is represented as an integer. What character is represented by what integer is determined by the current character set. For example, in the ASCII character set, "A" is 65. These integers are then stored as a sequence of bytes according to a character encoding. The character set and encoding is usually implicit in the environment in which the character is being interpreted but it may be specified explicitly, e.g. to convert input to some standard internal representation. A sequence of characters is a (character) string. Compare with glyph. (1998-10-18) 1 1 1 1 1 character encoding (Or "character encoding scheme") A mapping between binary data values and character code positions (or "code points"). Early systems stored characters in a variety of ways, e.g. four six-bit characters in a 24-bit word, but around 1960, eight-bit bytes started to become the most common data storage layout, with each character stored in one byte, typically in the ASCII character set. In the case of ASCII, the character encoding is an identity mapping: code position 65 maps to the byte value 65. This is possible because ASCII uses only code positions representable as single bytes, i.e., values between 0 and 255. (US-ASCII only uses values 0 to 127, in fact.) From the late 1990s, there was increased use of larger character sets such as Unicode and many CJK coded character sets. These can represent characters from many languages and more symbols. 1 1 1 1 1 character encoding scheme character encoding 1 1 1 1 1 character graphics ASCII art 1 1 1 1 1 characteristic function The characteristic function of set returns True if its argument is an element of the set and False otherwise. (1995-04-13) 1 1 1 1 1 character key key 1 1 1 1 1 character repertoire The set of all characters onto which a coded character set maps integers (code positions). For example, consider these two simple coded character sets: Coded Character Set One: integer 0 -> the character "A" integer 1 -> the character "B" Coded Character Set Two: integer 0 -> the character "B" integer 1 -> the character "A" Both of these coded character sets map to the characters "A" and "B", so they have the same character repertoire. But since the mapping is different (and obviously incompatible), these are different coded character sets. (1998-12-17) 1 1 1 1 1 character set A particular mapping between characters and byte strings, i.e. the combination of a particular character encoding (which maps between byte strings and integers) and a particular coded character set (which maps between integers and characters). For example: ASCII (the ASCII coded character set, encoded directly as single-byte values), or UTF-8 (the Unicode coded character set, encoded with an 8-bit transformation method). The character repertoire is the complete set of all characters in the character set. (2015-11-29) 1 1 1 1 1 character set identifier (CSID) (IBM) A number that identifies a character set. (1995-03-21) 1 1 1 1 1 charge-coupled device (CCD) A semiconductor technology used to build light-sensitive electronic devices such as cameras and image scanners. CCDs can be made to detect either colour or black-and-white. Each CCD chip consists of an array of light-sensitive photocells. The photocell is sensitised by giving it an electrical charge prior to exposure. (2006-04-29) 1 1 1 1 1 CHARITY A functional language based purely on category theory by Cockett, Spencer, and Fukushima, 1990-1991. A version for Sun-4 is available from Tom Fukushima <fukushim@ucalgary.ca>. ["About Charity", J.R.B. Cockett, U. Calgary, Canada, et al]. (2000-10-30) 1 1 1 1 1 charityware careware 1 1 1 1 1 Charles Babbage The british inventor known to some as the "Father of Computing" for his contributions to the basic design of the computer through his Analytical Engine. His previous Difference Engine was a special purpose device intended for the production of mathematical tables. Babbage was born on December 26, 1791 in Teignmouth, Devonshire UK. He entered Trinity College, Cambridge in 1814 and graduated from Peterhouse. In 1817 he received an MA from Cambridge and in 1823 started work on the Difference Engine through funding from the British Government. In 1827 he published a table of logarithms from 1 to 108000. In 1828 he was appointed to the Lucasian Chair of Mathematics at Cambridge (though he never presented a lecture). In 1831 he founded the British Association for the Advancement of Science and in 1832 he published "Economy of Manufactures and Machinery". In 1833 he began work on the Analytical Engine. In 1834 he founded the Statistical Society of London. 1 1 1 1 1 Charles Simonyi Microsoft programmer, most famously responsible for Hungarian Notation. Simonyi was born in Budapest in 1948, and for more than a decade was senior programmer at Microsoft in Redmond. (1999-05-25) 1 1 1 1 1 CHARM An explicitly parallel programming language based on C, for both shared and nonshared MIMD computers. (ftp://a.cs.uiuc.edu/pub/CHARM). Mailing list: <charm@cs.uiuc.edu>. ["The CHARM(3.2) Programming Language Manual", UIUC, Dec 1992]. (2006-04-29) 1 1 1 1 1 CHARM++ An object-oriented parallel programming system, similar to CHARM but based on C++. (ftp://a.cs.uiuc.edu/pub/CHARM/Charm++). E-mail: Sanjeev Krishnan <sanjeev@cs.uiuc.edu>. [TR 1796, UIUC]. (1994-11-29) 1 1 1 1 1 Charme A language with discrete combinatorial constraint logic, aimed at industrial problems such as planning and scheduling. Implemented in C at Bull in 1989. Charme is an outgrowth of ideas from CHIP. It is semantically nondeterministic, with choice and backtracking, similar to Prolog. ["Charme Reference Manual", AI Development Centre, Bull, France 1990]. (1994-11-15) 1 1 1 1 1 CHARYBDIS A Lisp program to display mathematical expressions. It is related to MATHLAB. [Sammet 1969, p. 522]. (1994-11-15) 1 1 1 1 1 chase pointers To determine a chain of memory locations where each location holds a pointer to the next, starting from some initial pointer, e.g. traversing a linked list or other graph structure. This may be performed by a computer executing a program or by a programmer going through a core dump or using a debugger. [Jargon File] (2006-05-06) 1 1 1 1 1 CHASM CHeap ASseMbler 1 1 1 1 1 chat Any system that allows any number of logged-in users to have a typed, real-time, on-line conversation via a network. The medium of chat is descended from talk, but the terms (and the media) have been distinct since at least the early 1990s. talk is prototypically for a small number of people, generally with no provision for channels. In chat systems, however, there are many channels in which any number of people can talk; and users may send private (one-to-one) messages. Some early chat systems (in use 1998) include IRC, ICQ and Palace. More recent alternatives include MSN Messenger and Google Talk. Chat systems have given rise to a distinctive style combining the immediacy of talking with all the precision (and verbosity) that written language entails. It is difficult to communicate inflection, though conventions have arisen to help 1 1 1 1 1 chatbot (Or "chatterbot") A bot meant to be able to interact conversationally with humans. A chatbot is either an exercise in AI or merely an interface as in an infobot. One of the first and most famous chatterbots (prior to the Web) was Eliza. (1999-06-19) 1 1 1 1 1 chat room channel 1 1 1 1 1 chatterbot chatbot 1 1 1 1 1 CHeap ASseMbler (CHASM) A shareware assembler for MS-DOS. (1994-11-15) 1 1 1 1 1 cheapernet (Or "thinnet") A colloquial term for thin-wire Ethernet (10base2) that uses RG58 coaxial cable instead of the full-spec "Yellow Cable". (1995-03-28) 1 1 1 1 1 checkdigit A one-digit checksum. 1 1 1 1 1 Checkout Test language (CTL) ["Checkout Test Language: An Interpretive Language Designed for Aerospace Checkout Tasks", G.S. Metsker, Proc FJCC 33(2) 1968]. (1994-11-14) 1 1 1 1 1 checkpoint Saving the current state of a program and its data, including intermediate results, to disk or other non-volatile storage, so that if interrupted the program could be restarted at the point at which the last checkpoint occurred. This facility came into popular use in mainframe operating systemss such as OS/360 in which programs frequently ran for longer than the mean time between system failures. If a program run fails because of some event beyond the program's control (e.g. hardware or operating system failure) then the processor time invested before the checkpoint will not have been wasted. (1995-02-07) 1 1 1 1 1 checksum A computed value which depends on the contents of a block of data and which is transmitted or stored along with the data in order to detect corruption of the data. The receiving system recomputes the checksum based upon the received data and compares this value with the one sent with the data. If the two values are the same, the receiver has some confidence that the data was received correctly. The checksum may be 8 bits (modulo 256 sum), 16, 32, or some other size. It is computed by summing the bytes or words of the data block ignoring overflow. The checksum may be negated so that the total of the data words plus the checksum is zero. Internet packets use a 32-bit checksum. See also digital signature, cyclic redundancy check. (1996-03-01) 1 1 1 1 1 chemist (Cambridge) Someone who wastes computer time on number crunching when you'd far rather the computer were working out anagrams of your name or printing Snoopy calendars or running life patterns. May or may not refer to someone who actually studies chemistry. [Jargon File] (1995-02-07) 1 1 1 1 1 Chen Peter Chen 1 1 1 1 1 CHEOPS A satellite-based batch data dissemination project between CERN and member state institutes. (2006-06-21) 1 1 1 1 1 Chernobyl packet /cher-noh'b*l pak'*t/ A network packet that induces a broadcast storm and/or network meltdown, named in memory of the April 1986 nuclear accident at Chernobyl in Ukraine. The typical scenario involves an IP Ethernet datagram that passes through a gateway with both source and destination Ethernet address and IP address set as the respective broadcast addresses for the subnetworks being gated between. Compare Christmas tree packet. [Jargon File] (2004-02-17) 1 1 1 1 1 chess A two-player game with perfect information. Usenet newsgroup: news:rec.games.chess. See also Internet Chess Server. (1995-03-25) 1 1 1 1 1 CHI A wide spectrum language, the forerunner of Refine. ["Research on Knowledge-Based Software Environments at Kestrel Institute", D.R. Smith et al, IEEE Trans Soft Eng, SE-11(11) 1985] (2006-07-11) 1 1 1 1 1 Chicago Windows 95 1 1 1 1 1 chicken head The Commodore Business Machines logo, which strongly resembles a poultry part. Rendered in ASCII as "C=". With the arguable exception of the Amiga, Commodore's computers are notoriously crocky little bitty boxes (see also PETSCII). Thus, this usage may owe something to Philip K. Dick's novel "Do Androids Dream of Electric Sheep?" (the basis for the movie "Blade Runner"; the novel is now sold under that title), in which a "chickenhead" is a mutant with below-average intelligence. [Jargon File] (2006-07-12) 1 1 1 1 1 chicklet keyboard It's spelled "chiclet keyboard". (1997-05-16) 1 1 1 1 1 chiclet keyboard A keyboard with a small, flat rectangular or lozenge-shaped rubber or plastic keys that look like pieces of Chiclets chewing gum. Used especially to describe the original IBM PCjr keyboard. Vendors unanimously liked these because they were cheap, and a lot of early portable and laptop computers were launched with them. Customers rejected the idea with almost equal unanimity, and chiclets are not often seen on anything larger than a digital watch any more. [Jargon File] (1997-05-16) 1 1 1 1 1 Chief Information Officer (CIO) The person who determines the overall strategic direction and business contribution of the information systems function in a business. (2004-03-18) 1 1 1 1 1 child daughter 1 1 1 1 1 child process A process created by another process (the parent process). Each process may create many child processes but will have only one parent process, except for the very first process which has no parent. The first process, called init in Unix, is started by the kernel at boot time and never terminates. A child process inherits most of its attributes, such as open files, from its parent. In fact in Unix, a child process is created (using fork) as a copy of the parent. The chid process can then overlay itself with a different program (using exec) as required. (1997-11-22) 1 1 1 1 1 child record A record lower in the hierarchical tree than a parent record; it is also directly liked to the parent and hierarchical databases. (1995-04-13) 1 1 1 1 1 child version In change management, a configuration item derived by altering another item (its parent version). (2006-07-12) 1 1 1 1 1 CHILI D.L. Abt. A language for systems programming, based on ALGOL 60 with extensions for structures and type declarations. ["CHILI, An Algorithmic Language for Systems Programming", CHI-1014, Chi Corp, Sep 1975] (2006-07-12) 1 1 1 1 1 CHILL CCITT HIgh-Level Language 1 1 1 1 1 Chimera A modular, X Window System-based web browser for Unix. Chimera uses the Athena widget set so Motif is not needed. It supports forms, inline images, TERM, SOCKS, proxy servers, Gopher, FTP, HTTP and local file accesses. Chimera can be extended using external programs. New protocols can easily be added and alternate image formats can be used for inline images (e.g. PostScript). Version 1.60 is available for (ftp://ftp.cs.unlv.edu/pub/chimera). (http://unlv.edu/chimera/). Chimera runs on Sun SPARC SunOS 4.1.x, IBM RS/6000 AIX 3.2.5, Linux 1.1.x. It should run on anything with X11R[3-6], imake and a C compiler. (1994-11-08) 1 1 1 1 1 chine nual /sheen'yu-*l/ (MIT) The LISP Machine Manual, so called because the title was wrapped around the cover so only those letters showed on the front. [Jargon File] (1994-12-02) 1 1 1 1 1 Chinese Army technique Mongolian Hordes technique 1 1 1 1 1 CHIP 1. An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 2. Constraint Handling In Prolog. 1 1 1 1 1 chip integrated circuit 1 1 1 1 1 CHIP-48 A reimplementation of CHIP-8 for the HP-48 calculator by Andreas Gustafson <gson@niksula.hut.fi>. Posted to news:comp.sys.handhelds in Sep 1990. (ftp://vega.hut.fi/pub/misc/hp48sx/asap). (1994-12-02) 1 1 1 1 1 CHIP-8 A low-level interpretive language (really a high-level machine code) developed at RCA in the late 1970s for video games on computers using RCA's CDP1802 processor. It could also be used on the DREAM 6800. Amiga interpreter (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f5/ff537/CHIP8.lzh). (2002-04-09) 1 1 1 1 1 chip art microchip art 1 1 1 1 1 chip box chad box 1 1 1 1 1 chip creep Gradual loosening of an integrated circuit ("chip") in its socket as a result of expansion and contraction during the normal heating and cooling cycles of an electronic system, combined with vibration, e.g. due to cooling fans. The chip can loosen to the point that poor electrical contact between chip and socket reduces the signal quality, causing failure. Pushing chips back into their sockets can cure such symptoms temporarily. Permanent solutions include soldering chips directly to the PCB and clipping the component into the socket (as on some in-line memory modules). The same phenomenon can affect anything plugged into a socket but not held securely in place, e.g. a circuit board plugged into an edge connector on a motherboard or backplane can suffer "card creep". (2007-06-19) 1 1 1 1 1 chip graffiti microchip art 1 1 1 1 1 Chip Jewelry A euphamism for old computers destined to be scrapped or turned into decorative ornaments. "I paid three grand for that Mac SE, and now it's nothing but chip jewelry." (1997-03-30) 1 1 1 1 1 Chip Scale Packaging (CSP) A type of surface mount integrated circuit packaging that provides pre-speed-sorted, pre-tested and pre-packaged die without requiring special testing. An example is Motorola's Micro SMT packaging. See also: chip-on-board, flip chip, multichip module, known good die, ball grid array. ["Chip scale packaging gains at SMI. (Surface Mount International)", Bernard Levine, Electronic News (1991), Sept 4, 1995 v41 n2081 p1(2)]. (2006-08-14) 1 1 1 1 1 chip set A collection of integrated circuits that are designed to be used together for some specific purpose. E.g. control circuitry in an IBM PC. (1995-03-27) 1 1 1 1 1 Chips & Technologies A former leading distributor and supplier of integrated circuits and software to personal computer manufacturers. As well as semiconductors they also made flat panel displays, video controllers and other computer related products. In 1998, Intel Corporation bought Chips and Technologies for their flat panel controllers. In January 2000, Asiliant Technologies licensed the rights from Intel to continue to manufacturer and sell Chips and Technologies components. Address: 2950 Zanker Road, San Jose, California 95134, USA. (2006-09-19) 1 1 1 1 1 CHISEL An extension of C for VLSI design, implemented as a C preprocessor. It produces CIF as output. ["CHISEL - An Extension to the Programming language C for VLSI Layout", K. Karplus, PHD Thesis, Stanford U, 1982]. (2006-09-19) 1 1 1 1 1 chm Compiled HTML 1 1 1 1 1 chmod ("Change mode") The Unix command and system call to change the access permissions of a named file. Each file (directory, device, etc.) has nine kinds of access which can be allowed or denied. Different permissions apply to the owner of the file, the members of the group the file belongs to, and all users. Each of these classes of user (owner, group and other) can have permission to read, write or execute the file. Chmod can also set various other mode bits for a file or directory such as the sticky bit and the set user id bit. Unix man page: chmod (1995-01-31) 1 1 1 1 1 CHOCS A generalisation of CCS. ["A Calculus of Higher-Order Communicating Systems", B. Thomsen, 16th POPL pp. 143-154, 1989]. (2006-09-20) 1 1 1 1 1 choke To fail to process input or, more generally, to fail at any endeavor. E.g. "NULs make System V's "lpr(1)" choke." See barf, gag. [Jargon File] (2006-09-20) 1 1 1 1 1 chomp To fail. (1996-06-01) 1 1 1 1 1 CHOP channel op 1 1 1 1 1 Chop A code generator by Alan L. Wendt <wendt@CS.ColoState.EDU> for the lcc C compiler front end. Version 0.6 is interfaced with Fraser and Hanson's lcc front end. The result is a C compiler with good code selection but no global optimisation. In 1993, Chop could compile and run small test programs on the VAX. The National Semiconductor 32000 and Motorola 68000 code generators are being upgraded for lcc compatibility. (ftp://beethoven.cs.colostate.edu/pub/chop/0.6.tar.Z). ["Fast Code Generation Using Automatically-Generated Decision Trees", ACM SIGPLAN '90 PLDI]. (1993-04-28) 1 1 1 1 1 Chorus A distributed operating system developed at INRIA. (2006-09-20) 1 1 1 1 1 Christmas tree A kind of EIA-232 line tester or breakout box featuring rows of blinking red and green LEDs suggestive of Christmas lights. [Jargon File] (2006-09-20) 1 1 1 1 1 Christmas tree packet (Or kamikaze packet) A packet with every single option set for whatever protocol is in use. The term doubtless derives from a fanciful image of each little option bit being represented by a different-coloured light bulb, all turned on. RFC 1025, "TCP and IP Bake Off" says: 10 points for correctly being able to process a "Kamikaze" packet (AKA nastygram, Christmas tree packet, lamp test segment, et al.). That is, correctly handle a segment with the maximum combination of features at once (e.g. a SYN URG PUSH FIN segment with options and data). Compare: Chernobyl packet. [Jargon File] (1994-11-09) 1 1 1 1 1 Christopher Strachey Professor of Computation at Oxford, England, born 1916, died May 1975. He invented the term "currying". See also: General Purpose Macro-generator. (1998-06-29) 1 1 1 1 1 chromatic number The smallest number of colours necessary to colour the nodes of a graph so that no two adjacent nodes have the same colour. See also: four colour map theorem. Graph Theory Lessons (http://utc.edu/~cpmawata/petersen/lesson8.htm). Eric Weisstein's World Of Mathematics (http://mathworld.wolfram.com/ChromaticNumber.html). The Geometry Center (http://geom.umn.edu/~zarembe/grapht1.html). (2000-03-18) 1 1 1 1 1 chrome (From automotive slang via wargaming) Showy features added to attract users but contributing little or nothing to the power of a system. "The 3D icons in Motif are just chrome, but they certainly are *pretty* chrome!" Chrome is distinguished from bells and whistles by the fact that the latter are usually added to gratify developers' own desires for featurefulness. Often used as a term of contempt and sometimes used in conjunction with 'fluff', "all the fluff and chrome that comes with Motif". [Jargon File] (1997-09-19) 1 1 1 1 1 chroot The UNIX command to make the root directory (/) become something other than its default for the lifetime of the current process. It can only be run by privileged users and is used to give a process (commonly a network server such as FTP or HTTP) access to a restricted portion of the file system. The new root contains copies of all the essential files and directories, e.g. /lib, /dev/tty, /tmp. (1996-12-08) 1 1 1 1 1 CHRP PowerPC Platform 1 1 1 1 1 chug To run slowly; to grind or grovel. "The disk is chugging like crazy." [Jargon File] (1995-03-25) 1 1 1 1 1 chug report From "chug" - to drink heavily. A bug report whose the submitter is thought to have had one too many. Not as bad as a drug report. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2011-12-03) 1 1 1 1 1 chunker A program like Unix's "split" which breaks an input file into parts, usually of a pre-set size, e.g. the maximum size that can fit on a floppy. The parts can then be assembled with a dechunker, which is usually just the chunker in a different mode. (1998-12-15) 1 1 1 1 1 Church, Alonzo Alonzo Church 1 1 1 1 1 Church integer A representation of integers as functions invented by Alonzo Church, inventor of lambda-calculus. The integer N is represented as a higher-order function which applies a given function N times to a given expression. In the pure lambda-calculus there are no constants but numbers can be represented by Church integers. A Haskell function to return a given Church integer could be written: church n = c where c f x = if n == 0 then x else c' f (f x) 1 1 1 1 1 Church of the SubGenius A mutant offshoot of Discordianism launched in 1981 as a spoof of fundamentalist Christianity by the Reverend Ivan Stang, a brilliant satirist with a gift for promotion. Popular among hackers as a rich source of bizarre imagery and references such as "Bob" the divine drilling-equipment salesman, the Benevolent Space Xists, and the Stark Fist of Removal. Much SubGenius theory is concerned with the acquisition of the mystical substance or quality of slack. (http://sunsite.unc.edu/subgenius/slack.html). (1996-01-02) 1 1 1 1 1 Church-Rosser Theorem A property of a reduction system that states that if an expression can be reduced by zero or more reduction steps to either expression M or expression N then there exists some other expression to which both M and N can be reduced. This implies that there is a unique normal form for any expression since M and N cannot be different normal forms because the theorem says they can be reduced to some other expression and normal forms are irreducible by definition. It does not imply that a normal form is reachable, only that if reduction terminates it will reach a unique normal form. (1995-01-25) 1 1 1 1 1 ci The country code for Cote d'Ivoire (the Ivory Coast). [Jargon File] (1999-01-27) 1 1 1 1 1 CI$ CompuServe Information Service 1 1 1 1 1 CICERO Control Information system Concepts based on Encapsulated Real-time Objects. A CERN DRDC proposal. (1995-01-25) 1 1 1 1 1 Cichlid A tool for rapidly visualising arbitrary data in high-quality 3D, while allowing the viewer to explore and interact with the data in real time. Cichlid was designed with remote data generation and machine independence in mind; data is transmitted via TCP from any number of sources (data servers) to the visualisation code (the client), which displays them concurrently. [Who? URL?] (2004-01-22) 1 1 1 1 1 CICS Customer Information Control System 1 1 1 1 1 CID Caller ID 1 1 1 1 1 CIDR Classless Inter-Domain Routing 1 1 1 1 1 CIEL An object-oriented Prolog-like language. ["CIEL: Classes et Instances En Logique", M. Gandriau, Thesis ENSEEIHT, 1988]. (1995-01-25) 1 1 1 1 1 CIF Caltech Intermediate Form 1 1 1 1 1 CIFS Common Internet File System 1 1 1 1 1 Cigale A parser generator language with extensible syntax. ["CIGALE: A Tool for Interactive Grammar Construction and Expression Parsing", F. Voisin, Sci Comp Prog 7:61-86, 1986]. (1999-01-14) 1 1 1 1 1 CIL 1. <project> Component Integration Laboratories. 2. <language> Common Intermediate Language. 1 1 1 1 1 CIM 1. <application> Computer Integrated Manufacturing. 2. <standard> Common Information Model. 1 1 1 1 1 CIMS PL/I A PL/I subset from the Courant Institute of Mathematical Sciences. ["CIMS PL/I", P.W. Abrahams, Courant Inst]. (1997-12-15) 1 1 1 1 1 Cinderella Book "Introduction to Automata Theory, Languages, and Computation", by John Hopcroft and Jeffrey Ullman, (Addison-Wesley, 1979). So called because the cover depicts a girl (putatively Cinderella) sitting in front of a Rube Goldberg device and holding a rope coming out of it. On the back cover, the device is in shambles after she has (inevitably) pulled on the rope. See also book titles. [Jargon File] (1996-12-03) 1 1 1 1 1 CINT92 SPEC CINT92 1 1 1 1 1 C-Interp An interpreter for a small subset of C, originally part of a communications package. (ftp://oac2.hsc.uth.tmc.edu/Mac/Misc/C_Interp.sit). E-mail: Chuck Shotton <cshotton@oac.hsc.uth.tmc.edu>. (1993-05-14) 1 1 1 1 1 CIO Chief Information Officer 1 1 1 1 1 ciphertext Text which has been encrypted by some encryption system. Opposite: plaintext. (1994-10-27) 1 1 1 1 1 CIP-L CIP Language 1 1 1 1 1 CIP Language language> (CIP-L, Computer-aided Intuition-guided Programming Language) A wide-spectrum language for incremental program transformation. There are ALGOL- and Pascal-like variants. ["The Munich Project CIP, v.I: The Wide Spectrum Language CIP-L", LNCS 183, Springer 1984. Version: CIP85]. (2006-09-20) 1 1 1 1 1 CIR Committed Information Rate 1 1 1 1 1 CIRCAL CIRcuit CALculus 1 1 1 1 1 circuit 1. <communications> A communications path in a circuit switching network. 2. <electronics> A complete path through which an electric current can flow. The term is used loosely for any device or subsystem using electrical or electronic components. E.g. "That lightning bolt fried the circuits in my GPS receiver". An integrated circuit (IC) contains components built on a Silicon die. (2002-07-15) 1 1 1 1 1 CIRcuit CALculus (CIRCAL) A process algebra used to model and verify the design correctness of concurrent systems such as digital logic. ["CIRCAL and the Representation of Communication, Concurrency and Time", G.J. Milne <milne@cis.unisa.edu.au>, ACM TOPLAS 7(2):270-298, 1985]. (2001-03-25) 1 1 1 1 1 circuit switch circuit switching 1 1 1 1 1 circuit switched circuit switching 1 1 1 1 1 circuit switching Communication via a single dedicated path between the sender and receiver. The telephone system is an example of a circuit switched network. The term connection-oriented is used in packet-based networks in contrast to connectionless communication or packet switching. (2006-09-20) 1 1 1 1 1 circular buffer An area of memory used to store a continuous stream of data by starting again at the beginning of the buffer after reaching the end. A circular buffer is usually written by one process and read by another. Separate read and write pointers are maintained. These are not allowed to pass each other otherwise either unread data would be overwritten or invalid data would be read. A circuit may implement a hardware circular buffer. (2000-06-17) 1 1 1 1 1 Cirrus Logic A manufacturer of integrated circuits including the Advanced RISC Machine and display interface processors and cards for use as Windows accelerators (requiring dedicated driver software). (http://cirrus.com/). [Other products?] (1996-10-13) 1 1 1 1 1 CIS 1. <standard, programming> Case Integration Services. 2. <networking> Cooperative Information System. 3. <business> Customer Interaction Software, Customer Information Systems. 1 1 1 1 1 CISC Complex Instruction Set Computer 1 1 1 1 1 Cisco Systems, Inc. Ethernet hardware manufacturers. (http://cisco.com/). Address: 170 West Tasman Drive, San Jose, CA 95134-1706, USA. Telephone: +1 408 526 4000, +1 800 553 6387. Fax: +1 408 526 4100 (1995-04-19) 1 1 1 1 1 CISI A French software producer. (2006-09-20) 1 1 1 1 1 CITRAN Caltech's answer to MIT's JOSS. [Sammet 1969, p. 217]. (2006-09-20) 1 1 1 1 1 CityScape A re-seller of Internet connections to the PIPEX backbone. E-Mail: <sales@cityscape.co.uk>. Address: CityScape Internet Services, 59 Wycliffe Rd., Cambridge, CB1 3JE, England. Telephone: +44 (1223) 566 950. (1994-11-08) 1 1 1 1 1 CIX 1. <networking> Commercial Internet Exchange. 2. <messaging> Compulink Information eXchange. 1 1 1 1 1 CJK In internationalisation, a collective term for Chinese, Japanese, and Korean. The characters of these languages are all partly based on Han characters (i.e., "hanzi" or "kanji"), which require 16-bit character encodings. CJK character encodings should consist minimally of Han characters plus language-specific phonetic scripts such as pinyin, bopomofo, hiragana, hangul, etc. CJKV is CJK plus Vietnamese. (ftp://ftp.ora.com/pub/examples/nutshell/ujip/doc/cjk.inf). (2001-01-01) 1 1 1 1 1 CJKV CJK plus Vietnamese. Vietnamese, like the other three CJK languages, requires 16-bit character encodings but it does not use Han characters. ["CJKV Information Processing: Chinese, Japanese, Korean & Vietnamese Computing", Ken Lunde, pub. O'Reilly 1998, (http://oreilly.com/catalog/cjkvinfo/)]. (2001-03-18) 1 1 1 1 1 ck The country code for the Cook Islands. (1999-01-27) 1 1 1 1 1 CL 1. Control Language. 2. Clausal Language. 1 1 1 1 1 cl The country code for Chile. (1999-01-27) 1 1 1 1 1 CLAM A system for symbolic mathematics, especially General Relativity. It was first implemented in ATLAS assembly language and later Lisp. See also ALAM. ["CLAM Programmer's Manual", Ray d'Inverno & Russell-Clark, King's College London, 1971]. (1994-11-08) 1 1 1 1 1 C Language Integrated Production System (CLIPS) A language produced by Gary Riley of NASA JSC in Houston, Texas, for developing expert systems, with the inferencing and representation capabilities of OPS5 and support for forward chaining rule-based, object-oriented and procedural programming. CLIPS has a Lisp-like syntax. It is available for MS-DOS and comes with source code in C. COSMIC, U Georgia, (404) 542-3265. Austin Code Works <info@acw.com> (512) 258-0785. Versions include CLIPS 5.1, CLIPS/Ada 4.3 and CLIPS6.0 (see PCLIPS). (http://jsc.nasa.gov/~clips/CLIPS.html). E-mail: <service@cossack.cosmic.uga.edu>. Telnet: cosmic.uga.edu, user: cosline. U. Michigan (ftp://earth.rs.itd.umich.edu/mac.bin/etc/compsci/Clips/), ENSMP, France (ftp://ftp.ensmp.fr/pub/clips/). 1 1 1 1 1 Clarify A software vendor, specialising in Customer Relationship Management software. Nortel Networks sold Clarify to Amdocs in 2002. (http://amdocsclarify.com/). (2003-06-20) 1 1 1 1 1 Clarion A family of systems from SoftVelocity, Inc. for building database applications on Microsoft Windows. Clarion products include Clarion 4GL language with a C++ and Modula-2 compiler. Clarion products support fast, efficient database application development. Clarion was originally developed by Clarion Software Corporation, later to become TopSpeed Corporation. In 2000, the Clarion product line was acquired by SoftVelocity Inc. (2003-10-15) 1 1 1 1 1 Claris A subsidiary company of Apple Computer, Inc.. In January 1998, Apple restructured Claris to concentrate on their FileMaker line of database software and changed the company's name to FileMaker, Inc.. (1998-02-18) 1 1 1 1 1 CLASP Computer Language for AeronauticS and Programming 1 1 1 1 1 class 1. <programming> The prototype for an object in an object-oriented language; analogous to a derived type in a procedural language. A class may also be considered to be a set of objects which share a common structure and behaviour. The structure of a class is determined by the class variables which represent the state of an object of that class and the behaviour is given by a set of methods associated with the class. Classes are related in a class hierarchy. One class may be a specialisation (a "subclass") of another (one of its superclasses) or it may be composed of other classes or it may use other classes in a client-server relationship. A class may be an abstract class or a concrete class. See also signature. 2. <programming> See type class. 3. <networking> One of three types of Internet addresses distinguished by their most significant bits. 1 1 1 1 1 Class 5 switch The lowest designation used in AT&T's hierarchical General Toll Switching Plan, developed in 1929. (2013-09-14) 1 1 1 1 1 class hierarchy In object-oriented programming, a set of classes related by inheritance. Each class is a "subclass" of another class - its "superclass". The subclass contains all the features of its superclass, but may add new features or redefine existing features. The features of a class are the set of attributes (or properties) that an object of that class has and the methods that can be invoked on it. If each class has a just one superclass, this is called single inheritance. The opposite is multiple inheritance, under which a class may have multiple superclasses. Single inheritance gives the class hierarchy a tree structure whereas multiple inheritance gives a directed graph. Typically there is one class at the top of the hierarchy which is the "object" class, the most general class that is an ancestor of all others and which has no superclass. In computing, as in genealogy, trees grow downwards, which is why subclasses are considered to be "below" their superclasses. 1 1 1 1 1 classic An adjective used before or after a noun to describe the original version of something, especially if the original is considered to be better. Examples include "Star Trek Classic" - the original TV series as opposed to the films, ST The Next Generation or any of the other spin-offs and follow-ups; or "PC Classic" - IBM's ISA-bus computers as opposed to the PS/2 series. (1996-10-27) 1 1 1 1 1 Classic-Ada An object-oriented extension to Ada, said to be like Smalltalk. It is implemented as an Ada preprocessor. (1994-12-05) 1 1 1 1 1 classical logic Non-intuitionistic logic. (1995-04-13) 1 1 1 1 1 Classic C K&R C 1 1 1 1 1 Classless Inter-Domain Routing (CIDR) /sid*r/ A technique that summarises a block of Internet addresses in a routing table as an address in dotted decimal notation followed by a forward slash and a two-digit decimal number giving the number of leading one bits in the subnet mask. For example, 123.123.123.0/24 specifies a subnet mask of 11111111.11111111.11111111.00000000 (binary), implying the block of addresses 123.123.123.0 through 123.123.123.255. CIDR is "classless" because it is not limited to the subnet masks specified by Internet address classes A, B and C. According to RFC 1519, CIDR was implemented to distribute Internet address space more efficiently and to provide a mechanism for IP route aggregation. This in turn reduces the number of entries in IP routing tables, enabling faster, more efficient routing, e.g. using routing protocols such as OSPF. CIDR is supported by BGP4. See also RFC 1467, RFC 1518, RFC 1520. 1 1 1 1 1 class library A library of reusable classes for use with an object-oriented programming system. (1994-12-05) 1 1 1 1 1 class method 1. A method that operates on a class object (an object of class "class"). A class method is really just an ordinary object method that happens to operate on class objects. A class method might, for example, return a list of objects representing the methods and attributes of the given class. 2. A static method. (2014-09-06) 1 1 1 1 1 class object In object-oriented programming, an object of class "class" that represents a class at run time. The existence of class objects allows introspection - the ability for a program to discover and modify attributes of its own code. (See self-modifying code). A class object may also be used for "housekeeping" tasks like keeping count of how many objects of the class have been created, though this may also be done by some kind of collection object. A class method is a method that operates on class objects. (2014-09-06) 1 1 1 1 1 Class Oriented Ring Associated Language (CORAL) A language developed by L.G. Roberts at MIT in 1964 for graphical display and systems programming on the TX-2. It used "rings" (circular lists) from Sketchpad. ["Graphical Communication and Control Languages", L.B. Roberts, Information System Sciences: Proc Second Congress, 1965]. [Sammet 1969, p.462]. (1994-11-30) 1 1 1 1 1 Class-Relation Method A design technique based on the concepts of object-oriented programming and the Entity-Relationship model from the French company Softeam. (1994-12-05) 1 1 1 1 1 Clausal Language (CL) A programming language and proof system developed by Paul Voda and a colleague since 1997, written in Trilogy II. Paul Voda Home (http://fmph.uniba.sk/~voda). (2002-05-28) 1 1 1 1 1 clause 1. <logic> A logical formula in conjunctive normal form, which has the schema p1 ^ ...^ pm => q1 V ... V qn. or, equivalently, ~p1 V ... V ~pn V q1 V ... V qn, where pi and qi are atoms. The operators ~, ^, V, => are connectives, where ~ stands for negation, ^ for conjunction, V for disjunction and => for implication. 2. <grammar> A part of a sentence (or programming language statement) that does not constitute a full sentence, e.g. an adjectival clause in human language or a WHERE clause in a SQL statement. (2004-05-28) 1 1 1 1 1 Clean A lazy higher-order purely functional language from the University of Nijmegen. Clean was originally a subset of Lean, designed to be an experimental intermediate language and used to study the graph rewriting model. To help focus on the essential implementation issues it deliberately lacked all syntactic sugar, even infix expressions or complex lists, As it was used more and more to construct all kinds of applications it was eventually turned into a general purpose functional programming language, first released in May 1995. The new language is strongly typed (Milner/Mycroft type system), provides modules and functional I/O (including a WIMP interface), and supports parallel processing and distributed processing on loosely coupled parallel architectures. Parallel execution was originally based on the PABC abstract machine. It is one of the fastest implementations of functional 1 1 1 1 1 clean 1. Used of hardware or software designs, implies "elegance in the small", that is, a design or implementation that may not hold any surprises but does things in a way that is reasonably intuitive and relatively easy to comprehend from the outside. The antonym is "grungy" or crufty. 2. To remove unneeded or undesired files in a effort to reduce clutter: "I'm cleaning up my account." "I cleaned up the garbage and now have 100 Meg free on that partition." [Jargon File] (1994-12-12) 1 1 1 1 1 cleanroom A software development approach aimed at producing software with the minimum number of errors. (1994-12-12) 1 1 1 1 1 CLEAR A specification language based on initial algebras. ["An Informal Introduction to Specification Using CLEAR", R.M. Burstall in The Correctness Problem in Computer Science, R.S. Boyer et al eds, Academic Press 1981, pp. 185-213]. (1994-11-03) 1 1 1 1 1 clear box testing white box testing 1 1 1 1 1 Clear Language for Expressing Orders (CLEO) A language developed by ICL in the 1960s and used until early 1972 on Leo III mainframes. (1994-11-03) 1 1 1 1 1 CLEO Clear Language for Expressing Orders 1 1 1 1 1 CLHEP A C++ class library for high energy physics applications. (1994-12-12) 1 1 1 1 1 CLI 1. <operating system> Command Line Interface. 2. <database, standard> Call-Level Interface. 1 1 1 1 1 CLiCC A Common Lisp to C compiler by Heinz Knutzen <hk@informatik.uni-kiel.de>, Ulrich Hoffman <uho@informatik.uni-kiel.de> and Wolfgang Goerigk <wg@informatik.uni-kiel.de>. CLiCC is meant to be used as a supplement to existing CLISP systems for generating portable applications. Target C code must be linked with the CLiCC run-time library to produce an executable. Version 0.6.2 conforms to a subset of Common Lisp and CLOS called CL_0 or CommonLisp_0 and based on CLtL1. It runs with Lucid Lisp, AKCL or CLISP. Work on CLtL2 and ANSI-CL conformance is in progress. (ftp://ftp.informatik.uni-kiel.de/pub/kiel/apply/). (1994-01-04) 1 1 1 1 1 click To press and release a button on a mouse or other pointing device. This generates an event, also specifying the screen position, which is processed by the window manager or application program. On a mouse with more than one button, the unqualified term usually implies pressing the left-most button (with the right index finger), other buttons would be qualified, e.g. "right-click". Multiple clicks in quick succession, e.g. a double-click, often have a different meaning from slow single clicks. Keyboard modifiers may also be used, e.g. "shift-click", meaning to hold down the shift key on the keyboard while clicking the mouse button. If the mouse moves while the button is pressed then this is a drag. (1995-03-14) 1 1 1 1 1 client A computer system or process that requests a service of another computer system or process (a "server") using some kind of protocol and accepts the server's responses. A client is part of a client-server software architecture. For example, a workstation requesting the contents of a file from a file server is a client of the file server. (1997-10-27) 1 1 1 1 1 client-server A common form of distributed system in which software is split between server tasks and client tasks. A client sends requests to a server, according to some protocol, asking for information or action, and the server responds. This is analogous to a customer (client) who sends an order (request) on an order form to a supplier (server) who despatches the goods and an invoice (response). The order form and invoice are part of the "protocol" used to communicate in this case. There may be either one centralised server or several distributed ones. This model allows clients and servers to be placed independently on nodes in a network, possibly on different hardware and operating systems appropriate to their function, e.g. fast server/cheap client. Examples are the name-server/name-resolver relationship in DNS, the file-server/file-client relationship in NFS and 1 1 1 1 1 client/server client-server 1 1 1 1 1 Client-Server Analyst Programmer A person who analyses and designs application programs for a client-server architecture. Typical skills include ODBC, Windows 95, Windows NT, Macintosh, Novell, OS/2, Unix, and RPC. (2004-03-09) 1 1 1 1 1 client-server model client-server 1 1 1 1 1 Client To Client Protocol (CTCP) A type of protocol created to allow structured data such as font information to be exchanged between users on IRC. It is also used to send a query to a user. The available CTCP commands include VERSION, FINGER, DCC CHAT, DCC SEND, TIME, PING, ECHO, CLIENTINFO. Some commands are not available on some IRC client software. (1995-04-12) 1 1 1 1 1 C++Linda ["The AUC C++Linda System", C. Callsen et al, U Aalborg, in Linda-Like Systems and Their Implementation, G. Wilson ed, U Edinburgh TR 91-13, 1991]. (1994-12-12) 1 1 1 1 1 C-Linda The most widely used variant of Linda, with C as the base language. It is available from Sci Comp Assocs <linda@sca.com>. (1994-12-12) 1 1 1 1 1 CLIP 1. Compiler Language for Information Processing. 2. Common LISP in Parallel. 1 1 1 1 1 CLiP A documentation extractor by Eric W. van Ammers that recognises a particular style of comments. This style can be adjusted to suit virtually any programming language and target documentation language. CLiP was designed to be compatible with hypertext systems. Version 2.1 runs on MS-DOS, VAX/VMS and Unix (ftp://sun01.info.wau.nl/clip/). (1993-11-18) 1 1 1 1 1 clipboard A temporary memory area, used to transfer information within a document being edited or between documents or between programs. The fundamental operations are cut which moves data from a document to the clipboard, copy which copies it to the clipboard, and "paste" which inserts the clipboard contents into the current document in place of the current selection. Different Graphical User Interfaces vary in how they handle the different types of data which a user might want to transfer via the clipboard, some (e.g. the X Window System) support only plain text, others (e.g. NEXTSTEP) support arbitrarily typed data such as images. (1996-08-23) 1 1 1 1 1 Clipper 1. <hardware, cryptography> An integrated circuit which implements the SkipJack algorithm. The Clipper is manufactured by the US government to encrypt telephone data. It has the added feature that it can be decrypted by the US government, which has tried to make the chip compulsory in the United States. Phil Zimmerman (inventor of PGP) remarked, This doesn't even pass the sniff test (i.e. it stinks). (http://wired.com/clipper/). news:alt.privacy.clipper 2. A compiled dBASE dialect from Nantucket Corp, LA. Versions: Winter 85, Spring 86, Autumn 86, Summer 87, 4.5 (Japanese Kanji), 5.0. It uses the Xbase programming language. (2004-09-01) 1 1 1 1 1 CLIPS C Language Integrated Production System 1 1 1 1 1 clique A maximal totally connected subgraph. Given a graph with nodes N, a clique C is a subset of N where every node in C is directly connected to every other node in C (i.e. C is totally connected), and C contains all such nodes (C is maximal). In other words, a clique contains all, and only, those nodes which are directly connected to all other nodes in the clique. [Is this correct?] (1996-09-22) 1 1 1 1 1 CLISP 1. Conversational LISP. 2. A Common Lisp implementation by Bruno Haible (http://haible.de/bruno/) of Karlsruhe University and Michael Stoll (http://math.uni-duesseldorf.de/~stoll/). of Munich University, both in Germany. CLISP includes an interpreter, bytecode compiler, almost all of the CLOS object system, a foreign language interface and a socket interface. An X11 interface is available through CLX and Garnet. Command line editing is provided by the GNU readline library. CLISP requires only 2 MB of RAM. The user interface comes in German, English, French, Spanish, Dutch, and Russian and can be changed at run time. CLISP is Free Software and distributed under the GPL. It runs on microcomputers (OS/2, Microsoft Windows, Amiga, Acorn) as well as on Unix workstations (Linux, BSD, SVR4, Sun4, Alpha, HP-UX, NeXTstep, SGI, 1 1 1 1 1 Clive Sinclair Sir Clive Sinclair (1939- ) The British inventor who pioneered the home microcomputer market in the early 1980s, with the introduction of low-cost, easy to use, 8-bit computers produced by his company, Sinclair Research. Sir Clive also invented and produced a variety of electronic devices from the 1960s to 1990s, including pocket calculators (he marketed the first pocket calculator in the world), radios and televisions. Perhaps he is most famous (or some might say notorious) for his range electric vehicles, especially the Sinclair C5, introduced in 1985. He has been a member of MENSA, the high IQ society, since 1962. Planet Sinclair (http://nvg.ntnu.no/sinclair/). ["The Sinclair Story", Rodney Dale, pub. Duckworth 1985] (1998-11-09) 1 1 1 1 1 CLIX ["Overview of a Parallel Object-Oriented Language CLIX", J. Hur et al, in ECOOP '87, LNCS 276, Springer 1987, pp. 265-273]. (1994-12-16) 1 1 1 1 1 CLM Career Limiting Move 1 1 1 1 1 CLNP ConnectionLess Network Protocol 1 1 1 1 1 clobber To overwrite, usually unintentionally: "I walked off the end of the array and clobbered the stack." Compare mung, scribble, trash, smash the stack. [Jargon File] (1994-12-16) 1 1 1 1 1 clock A circuit in a processor that generates a regular sequence of electronic pulses used to synchronise operations of the processor's components. The time between pulses is the cycle time and the number of pulses per second is the clock rate (or frequency). The execution times of instructions on a computer are usually measured by a number of clock cycles rather than seconds. Clock rates for various models of the computer may increase as technology improves, and it is usually the relative times one is interested in when discussing the instruction set. (1994-12-16) 1 1 1 1 1 clock frequency clock rate 1 1 1 1 1 clock rate The fundamental rate in cycles per second at which a computer performs its most basic operations such as adding two numbers or transfering a value from one register to another. The clock rate of a computer is normally determined by the frequency of a crystal. The original IBM PC, circa 1981, had a clock rate of 4.77 MHz (almost five million cycles/second). As of 1995, Intel's Pentium chip runs at 100 MHz (100 million cycles/second). The clock rate of a computer is only useful for providing comparisons between computer chips in the same processor family. An IBM PC with an Intel 486 CPU running at 50 MHz will be about twice as fast as one with the same CPU, memory and display running at 25 MHz. However, there are many other factors to consider when comparing different computers. Clock rate should not be used when comparing different computers or different processor families. Rather, some benchmark should 1 1 1 1 1 clock speed clock rate 1 1 1 1 1 clone 1. An exact copy of a product, made legally or illegally, from documentation or by reverse engineering, and usually cheaper. E.g. "PC clone": a PC-BUS/ISA, EISA, VESA, or PCI compatible x86-based microcomputer (this use is sometimes misspelled "klone" or "PClone"). These invariably have much more bang per buck than the IB PCM they resemble. E.g. "Unix clone": An operating system designed to deliver a Unix-like environment without Unix licence fees or with additional "mission-critical" features such as support for real-time programming. 2. <chat> A clonebot. [Jargon File] (2000-06-15) 1 1 1 1 1 clone-and-hack coding case and paste 1 1 1 1 1 clonebot (Or "clone") A bot meant to replicate itself en masse on a talk network (generally IRC). A bot appears on the network as several agents, and then carries out some task, typically that of flooding another user. Compare ghost. (1997-04-07) 1 1 1 1 1 CLOS Common LISP Object System 1 1 1 1 1 close brace right brace 1 1 1 1 1 closed-box testing functional testing 1 1 1 1 1 closed set A set S is closed under an operator * if x*y is in S for all x, y in S. (1994-12-16) 1 1 1 1 1 closed term A term with no free variables. (1994-12-16) 1 1 1 1 1 close parenthesis right parenthesis 1 1 1 1 1 Clos network A type of network topology that can connect N inputs to N outputs with less that N^2 crosspoint switches. (2006-10-07) 1 1 1 1 1 closure 1. <programming> In a reduction system, a closure is a data structure that holds an expression and an environment of variable bindings in which that expression is to be evaluated. The variables may be local or global. Closures are used to represent unevaluated expressions when implementing functional programming languages with lazy evaluation. In a real implementation, both expression and environment are represented by pointers. A suspension is a closure which includes a flag to say whether or not it has been evaluated. The term "thunk" has come to be synonymous with "closure" but originated outside functional programming. 2. <theory> In domain theory, given a partially ordered set, D and a subset, X of D, the upward closure of X in D is the union over all x in X of the sets of all d in D such that x <= d. Thus the upward closure of X in D contains the elements of X and any greater element of D. A set is "upward 1 1 1 1 1 closure conversion The transformation of continuation passing style code so that the only free variables of functions are names of other functions. See also Lambda lifting. (1994-12-16) 1 1 1 1 1 cloud cloud computing 1 1 1 1 1 cloud computing A loosely defined term for any system providing access via the Internet to processing power, storage, software or other computing services, often via a web browser. Typically these services will be rented from an external company that hosts and manages them. (2009-04-21) 1 1 1 1 1 Clover A protocoll similar to packet radio or AMTOR. (1995-03-03) 1 1 1 1 1 clover key feature key 1 1 1 1 1 CLP 1. Cornell List Processor. 2. Constraint Logic Programming. 1 1 1 1 1 CLP* A derivative of Constraint Logic Programming (CLP). ["CLP* and Constraint Abstraction", T. Hickey, 16th POPL, pp. 125-133, 1989]. [Difference?] (1994-11-01) 1 1 1 1 1 CLP(R) Constraint Logic Programming (Real) A constraint logic programming language with real arithmetic constraints developed by Joxan Jaffar <joxan@watson.ibm.com> of IBM TJWRC and S. Michaylov of Monash University in 1986 The implementation contains a byte-code compiler and a built-in constraint solver which deals with linear arithmetic and contains a mechanism for delaying nonlinear constraints until they become linear. Since CLP(R) is a superset of PROLOG, the system is also usable as a general-purpose logic programming language. There are also powerful facilities for meta programming with constraints. Significant CLP(R) applications have been published in diverse areas such as molecular biology, finance and physical modelling. Version 1.2 for Unix, MS-DOS and OS/2 is available from the authors. It is free for academic and research purposes. 1 1 1 1 1 CLP(sigma*) A constraint logic programming language with regular sets. ["CLP(sigma*): Constraint Logic Programming with Regular Sets", C. Walinsky, Proc ICLP, 1989, pp.181-190]. (1994-12-16) 1 1 1 1 1 CLR Consortium for Lexical Research 1 1 1 1 1 CLtL1 A report on Common LISP: ["Common LISP: The Language", Guy L. Steele, Digital Press 1984, ISBN 0-932376-41-X]. (1994-12-16) 1 1 1 1 1 CLtL2 Aluminum Book 1 1 1 1 1 CLU (CLUster) An object-oriented programming language developed at MIT by Liskov et al in 1974-1975. CLU is an object-oriented language of the Pascal family designed to support data abstraction, similar to Alphard. It introduced the iterator: a coroutine yielding the elements of a data object, to be used as the sequence of values in a for loop. A CLU program consists of separately compilable procedures, clusters and iterators, no nesting. A cluster is a module naming an abstract type and its operations, its internal representation and implementation. Clusters and iterators may be generic. Supplying actual constant values for the parameters instantiates the module. There are no implicit type conversions. In a cluster, the explicit type conversions 'up' and 'down' change between the abstract type and the representation. There is a universal type 'any', and a procedure force[] to check that an object is 1 1 1 1 1 clu2c A CLU to C compiler. (ftp://ftp.is.titech.ac.jp/pub/clu2c/). (2000-08-06) 1 1 1 1 1 cluster 1. <architecture> Multiple servers providing the same service. The term may imply resilience to failure and/or some kind of load balancing between the servers. Compare RAIS. 2. <file system> An elementary unit of allocation of a disk made up of one or more physical blocks. A file is made up of a whole number of possibly non-contiguous clusters. The cluster size is a tradeoff between space efficiency (the bigger is the cluster, the bigger is on the average the wasted space at the end of each file) and the length of the FAT. (1996-11-04) 1 1 1 1 1 Cluster 86 A distributed object-oriented language by L. Shang <lshang@inf.ethz.ch> of Nanjing University, ca. 1986. A cluster is a metatype. There are versions for MS-DOS and Unix. ["Cluster: An Informal Report", L. Shang, SIGPLAN Notices 26(1):57-76, Jan 1991]. (1994-12-21) 1 1 1 1 1 clustergeeking /kluh'st*r-gee"king/ (CMU) Spending more time at a computer cluster doing CS homework than most people spend breathing. [Jargon File] (1994-12-21) 1 1 1 1 1 clustering cluster 1 1 1 1 1 CLUT colour palette 1 1 1 1 1 CLV Constant Linear Velocity 1 1 1 1 1 CLX The Common Lisp library providing a low-level interface to the X Window System, equivalent to Xlib. Graphics toolkits can be built on top of CLX, e.g. McCLIM, Garnet, CLUE and CLIO. Various LISP implementors have independently ported CLX to their own platforms, fixing bugs and, in some cases, adding features in the process. CLX Wiki (http://cliki.net/CLX). (2004-08-27) 1 1 1 1 1 CM Configuration Management 1 1 1 1 1 cm The country code for Cameroon. (1999-01-27) 1 1 1 1 1 CMA Concert Multithread Architecture from DEC. 1 1 1 1 1 CMAY A microkernel. ["A Microkernel for Distributed Applications", R. Bagrodia et al, Proc 5th Intl Conf Distrib Comp Sys IEEE 1985, pp. 140-149]. (1994-12-21) 1 1 1 1 1 CMC 1. <messaging> Computer Mediated Communication. 2. <hardware> Common Mezzanine Card. 1 1 1 1 1 cmd The command interpreter of Microsoft Disk Operating System. cmd.exe appears as the interactive Command Prompt window in later versions of Microsoft Windows and is also responsible for executing .bat batch files. (2009-11-30) 1 1 1 1 1 CMGA 1. <body> Computer Management Group of Australia 2. <body> Community of Massive Gaming Agency. 1 1 1 1 1 CMIP Common Management Information Protocol 1 1 1 1 1 CMIS Common Management Information Services 1 1 1 1 1 CML 1. A query language. ["Towards a Knowledge Description Language", A. Borgida et al, in On Knowledge Base Management Systems, J. Mylopoulos et al eds, Springer 1986]. 2. Concurrent ML. (1994-12-21) 1 1 1 1 1 CMM Capability Maturity Model 1 1 1 1 1 CMOS Complementary Metal Oxide Semiconductor 1 1 1 1 1 CMP 1. cellular multiprocessing. 2. Container Managed Persistance. 3. Configuration Management Plan. 1 1 1 1 1 CMS A code management system from DEC. (1994-12-21) 1 1 1 1 1 CMS-2 A general purpose language used for command and control applications in the US Navy. Variants: CMS-2M and CMS-2Y. ["CMS-2Y Programmers Reference Manual", M-5049, PDCSSA, San Diego CA, Oct 1976]. (1994-12-21) 1 1 1 1 1 CMU Carnegie Mellon University 1 1 1 1 1 CMU CL CMU Common Lisp 1 1 1 1 1 CMU Common Lisp (CMU CL) A public domain "industrial strength" Common Lisp programming environment. Many of the X3J13 changes have been incorporated into CMU CL. Wherever possible, this has been done so as to transparently allow use of either CLtL1 or proposed ANSI CL. Probably the new features most interesting to users are SETF functions, LOOP and the WITH-COMPILATION-UNIT macro. The new CMU CL compiler is called Python. Version 17c includes an incremental compiler, profiler, run-time support, documentation, an editor and a debugger. It runs under Mach on SPARC, MIPS and IBM PC RT and under SunOS on SPARC. (ftp://lisp-sun1.slisp.cs.cmu.edu/pub/). E-mail: <slisp@cs.cmu.edu>. (1993-11-18) 1 1 1 1 1 CMVC Configuration Management Version Control from IBM. 1 1 1 1 1 CMYK cyan, magenta, yellow, key. A colour model that describes each colour in terms of the quantity of each secondary colour (cyan, magenta, yellow), and key (black) it contains. The CMYK system is used for printing. For mixing of pigments, it is better to use the secondary colours, since they mix subtractively instead of additively. The secondary colours of light are cyan, magenta and yellow, which correspond to the primary colours of pigment (blue, red and yellow). In addition, although black could be obtained by mixing these three in equal proportions, in four-colour printing it always has its own ink. This gives the CMYK model. The K stands for "Key' or 'blacK,' so as not to cause confusion with the B in RGB. Alternative colour models are RGB and HSB. (1994-12-22) 1 1 1 1 1 CMZ A portable interactive code management system from CodeME S.A.R.L in use in the high-energy physics community. (1994-12-22) 1 1 1 1 1 cn The country code for China. (1999-01-27) 1 1 1 1 1 CNAME The canonical name query type for Domain Name System. This query asks a DNS server for a host's official hostname. (1994-12-22) 1 1 1 1 1 CNC Collaborative Networked Communication 1 1 1 1 1 CNET Centre national d'Etudes des Telecommunications. The French national telecommunications research centre at Lannion. (1994-12-22) 1 1 1 1 1 CNI Coalition for Networked Information 1 1 1 1 1 CNN Cellular Neural Network. 1 1 1 1 1 CNR Communication and Network Riser 1 1 1 1 1 CNRI Corporation for National Research Initiatives 1 1 1 1 1 co The country code for Colombia. (1999-01-27) 1 1 1 1 1 CO2 An object-oriented database language combining C and O2, from GIP Altair, Versailles, France. [Francois Bancilon et al, in Advances in Object-Oriented Database Systems, K.R. Dittrich ed, LNCS 334, Springer 1988]. (1994-12-22) 1 1 1 1 1 Coad/Yourdon An object-oriented analysis and design methodology, developed by edward Yourdon and Peter Coad. (1995-04-07) 1 1 1 1 1 COALA ["COALA: The Object Code of the Compiler Producing System", S. Kruszewski et al, MERA, Warsaw 1974]. (1994-12-22) 1 1 1 1 1 coalesced sum (Or "smash sum") In domain theory, the coalesced sum of domains A and B, A (+) B, contains all the non-bottom elements of both domains, tagged to show which part of the sum they come from, and a new bottom element. D (+) E = bottom(D(+)E) U (0,d) | d in D, d /= bottom(D) U (1,e) | e in E, e /= bottom(E) The bottoms of the constituent domains are coalesced into a single bottom in the sum. This may be generalised to any number of domains. The ordering is bottom(D(+)E) <= v For all v in D(+)E (i,v1) <= (j,v2) iff i = j & v1 <= v2 1 1 1 1 1 Coalition for Networked Information (CNI) A consortium formed by American Research Libraries, CAUSE and EDUCOM to promote the creation of, and access to, information resources in networked environments in order to enrich scholarship and enhance intellectual productivity. (1994-12-22) 1 1 1 1 1 coarse grain granularity 1 1 1 1 1 COAST Cache On A STick 1 1 1 1 1 coax coaxial cable 1 1 1 1 1 coaxial cable A kind of cable with a solid central conductor surrounded by insulator, in turn surrounded by a cylindrical shield woven from fine wires. It is used to carry high frequency signals such as video or radio. The shield is usually connected to electrical ground to reduce electrical interference. (1995-03-28) 1 1 1 1 1 COBOL COmmon Business Oriented Language 1 1 1 1 1 COBOL-1961 Extended A short-lived separation of COBOL specifications. [Sammet 1969, p. 339]. (1994-10-28) 1 1 1 1 1 COBOL fingers /koh'bol fing'grz/ Reported from Sweden, a hypothetical disease one might get from coding in COBOL. The language requires code verbose beyond all reason (see candygrammar); thus it is alleged that programming too much in COBOL causes one's fingers to wear down to stubs by the endless typing. [Jargon File] (1994-12-22) 1 1 1 1 1 COBRA Do you mean CORBA? Or is there a COBRA? (1996-05-10) 1 1 1 1 1 cobwebsite A website that hasn't been updated for a long time. A dead web page. (1997-04-29) 1 1 1 1 1 Cocktail GMD Toolbox for Compiler Construction 1 1 1 1 1 cocktail shaker sort A bi-directional bubble sort. Passes alternate between ascending through array indexes, pushing the largest item to the bottom; and descending through array indexes, pushing the smallest item to the top. [Performace vs plain bubble?] (2001-03-26) 1 1 1 1 1 CoCo The Tandy Color Computer with a Motorola MC6809E CPU. The Dragon is a CoCo clone. The CoCo was as powerful as the IBM XT at the time it was made, and could run OS-9. (1997-02-12) 1 1 1 1 1 Cocol Coco Language 1 1 1 1 1 Coco Language (Cocol) A language for writing left-attributed LL1 grammars, used as the input language for the Coco LL1 parser generator, which produces Modula-2 table-driven parsers as output. Cocol-2 is a version for the Coco-2 generator. Cocol/R is an improvement over the original Cocol and Cocol-2. (ftp://neptune.inf.ethz.ch/). ["A Compiler Generator for Microcomputers", P. Rechenberg et al, P-H 1989]. (1997-12-09) 1 1 1 1 1 Cocol/R (Coco Language) A language for writing left-attributed LL1 grammars, used as the input language for the Coco/R LL1 parser generators, which produce C++, Pascal, Modula-2, Java or Oberon recursive-descent parsers and associated scanners as output. Cocol/R is an improvement over the original Cocol and Cocol-2. [Moessenboeck, H., "A Generator for Fast Compiler Front-Ends", Report 127, Dept. Informatik, ETH Zurich, 1990]. (1997-12-09) 1 1 1 1 1 COCOMO Constructive Cost Model 1 1 1 1 1 Coco/R A program by Hanspeter Moessenboeck <moessenboeck@ssw.uni-linz.ac.at> which generates recursive descent parsers and their associated scanners from attributed grammars (LL1). Coco/R can bootstrap itself to generate its own driver, parser, scanner and semantic evaluator from an attributed grammar included in the distribution. Versions exist for generating Oberon, Modula-2, Pascal, C, and C++ source for MS-DOS and Unix. A Java implementation was planned. Latest version: 1.34, as gf 1994-10-13. Coco/R was ported to Modula-2 by Marc Brandis, Christof Brass, and Pat Terry. (ftp://ftp.ssw.uni-linz.ac.at/pub/Coco). Mail server: <server@ftp.psg.com> (Subject: send pub/modula-2/coco/). E-mail: Pat Terry <p.terry@ru.ac.za> (Modula/Pascal versions), 1 1 1 1 1 CODASYL Conference On DAta SYstems Languages 1 1 1 1 1 Codd's First Normal Form database normalisation 1 1 1 1 1 Codd's reduction algorithm An algorithm to convert an arbitrary expression of the relational calculus to an equivalent expression of the relational algebra. This can be used as the basis of an implementation of the relational calculus. (1998-10-05) 1 1 1 1 1 code 1. <software> Instructions for a computer in some programming language, often machine language (machine code). The word "code" is often used to distinguish instructions from data (e.g. "The code is marked 'read-only'") whereas the word "software" is used in contrast with "hardware" and may consist of more than just code. (2000-04-08) 2. <cryptography> Some method of encryption or the resulting encrypted message. (2006-11-10) 1 1 1 1 1 Code 2.0 A coarse-grain dataflow language with a graphical interface for users to draw communication structure. (http://cs.utexas.edu/users/code). E-mail: Emery Berger <emery@cs.utexas.edu>. ["The CODE 2.0 Parallel Programming Language", P. Newton et al, Proc ACM Intl Conf on Supercomput, Jul 1992]. (1996-01-13) 1 1 1 1 1 codebook data dictionary 1 1 1 1 1 CODEC coder/decoder 1 1 1 1 1 CodeCenter (Formerly Saber-C) A proprietary software development environment for C programs, offering an integrated toolkit for developing, testing, debugging and maintainance. (1994-12-23) 1 1 1 1 1 coded character set A mapping, generally 1:1, from a set of integers, known as character codes or code positions, to a set of characters that may include letters, digits, punctuation, control codes, mathematical and typographic symbols. There are several standard coded character sets, the most widely used is ASCII, generally in its Latin-1 dialect, with Unicode becoming slowly more common; while EBCDIC and Baudot are extinct except in legacy systems. (2009-01-06) 1 1 1 1 1 Code Division Multiple Access (CDMA) (Or "spread spectrum") A form of multiplexing where the transmitter encodes the signal using a pseudorandom sequence which the receiver also knows and can use to decode the received signal. Each different random sequence corresponds to a different communication channel. Motorola uses CDMA for digital cellular phones. Qualcomm pioneered the introduction of CDMA into wireless telephone services. (2001-03-28) 1 1 1 1 1 code division multiplexing Code Division Multiple Access 1 1 1 1 1 Code-Generator Generator Language ("seagull") (CGGL) A machine description language based on modelling the computer as a finite-state machine. ["A Code Generator Generator Language", M.K. Donegan et al, SIGPLAN Notices 14(8):58-64, Aug 1979]. (1994-10-24) 1 1 1 1 1 code grinder A suit-wearing minion of the sort hired in legion strength by banks and insurance companies in the Real World to implement payroll packages in RPG and other such unspeakable horrors. In its native habitat, the code grinder often removes the suit jacket to reveal an underplumage consisting of button-down shirt (starch optional) and a tie. In times of dire stress, the sleeves (if long) may be rolled up and the tie loosened about half an inch. It seldom helps. The code grinder's milieu is about as far from hackerdom as one can get and still touch a computer; the term connotes pity. Used of or to a hacker, this term is a really serious slur on the person's creative ability; it connotes a design style characterised by primitive technique, rule-boundedness, brute force and utter lack of imagination. Compare card walloper. Contrast real programmer. [Jargon File] 1 1 1 1 1 code management source code management 1 1 1 1 1 code police (By analogy with George Orwell's "Thought Police" in 1984) A mythical team of Gestapo-like storm troopers that enforce programming style rules. Used ironically, to suggest that the practice under discussion is condemned mainly by anal-retentive weenies. "Dike out that goto or the code police will get you!" The ironic usage is perhaps more common. [Jargon File] (1994-12-08) 1 1 1 1 1 code position An integer that a coded character set maps to a character. A code position is normally stored or transmitted by applying a character encoding to turn it into a byte string. (2002-03-03) 1 1 1 1 1 coder/decoder (CODEC) An electronic device or component combining the circuits needed to convert digital signals to and from analog (Pulse Code Modulation) form. (1997-07-22) 1 1 1 1 1 codes 1. <jargon> Programs. This usage is common among scientific computing people who use supercumputers for heavy-duty number crunching. 2. <cryptography> Something to do with cryptography. [Jargon File] (1994-10-28) 1 1 1 1 1 C-odeScript A Liana interpreter, embeddable in C and C++ programs. (1995-03-09) 1 1 1 1 1 code segment (Intel 8086 CS) The area of memory containing the machine code instructions of a program. The code segment of a program may be shared between multiple processes running that code so long as none of them tries to modify it. Unix, confusingly, calls this the "text segment" and the area for uninitialied data, the bss segment. Initialised data is located in the data segment. (1996-12-21) 1 1 1 1 1 code walk Stepping through source code as part of a code review. Where a code walk probably only follows the potential control flow of a program, a dry run is a more detailed manual execution of a program that also keeps track of the value of every variable involved. (2006-11-27) 1 1 1 1 1 codewalker A program component that analyses other programs. Compilers have codewalkers in their front ends; so do cross-reference generators and some database front ends. Other utility programs that try to do too much with source code may turn into codewalkers. As in "This new 'vgrind' feature would require a codewalker to implement." [Jargon File] (1994-12-23) 1 1 1 1 1 CODIL COntext Dependent Information Language 1 1 1 1 1 codomain The set of values or type containing all possible results of a function. The codomain of a function f of type D -> C is C. A function's image is a subset of its codomain. (1994-12-23) 1 1 1 1 1 coercion implicit type conversion 1 1 1 1 1 COFF Common Object File Format 1 1 1 1 1 COGENT COmpiler and GENeralized Translator 1 1 1 1 1 Cogent Prolog A full Edinburgh standard Prolog with debugger, listener, DCG, many built-ins, text windows, support for modules, and support for both 16-bit and 32-bit protected mode. Contact: Dennis C. Merritt. (1999-11-24) 1 1 1 1 1 Cognitech A French software company specialising in artificial intelligence. (1995-01-04) 1 1 1 1 1 cognitive architecture A computer architecure involving non-deterministic, multiple inference processes, as found in neural networks. Cognitive architectures model the human brain and contrast with single processor computers. The term might also refer to software architectures, e.g. fuzzy logic. [Origin? Better definition? Reference?] (1995-11-29) 1 1 1 1 1 COGO A subsystem of ICES aimed at coordinate geometry problems in civil engineering. ["Engineer's Guide to ICES COGO I", R67-46, CE Dept MIT, Aug 1967]. (1995-01-04) 1 1 1 1 1 Coherent Parallel C A data parallel version of C. ["Coherent Parallel C", E. Felten et al in Third Conf on Hypercube Concurrent Computers and Appls, ACM, 1988, pp. 440-450]. (1995-01-04) 1 1 1 1 1 COHESION DEC's CASE environment. [Details?]. (1995-01-04) 1 1 1 1 1 COIF Fortran with interactive graphic extensions for circuit design, on UNIVAC 1108. ["An Interactive Software System for Computer-Aided Design: An Application to Circuit Projects", CACM 9(13), Sep 1970]. (1995-01-04) 1 1 1 1 1 CoIP Conferencing over IP 1 1 1 1 1 cokebottle /kohk'bot-l/ Any unusual character, particularly one you can't type because it isn't on your keyboard. MIT people used to complain about the control-meta-cokebottle commands at SAIL, and SAIL people complained about the "altmode-altmode-cokebottle" commands at MIT. After the demise of the space-cadet keyboard, "cokebottle" was used less, but was often used to describe weird or non-intuitive keystrokes. The OSF/Motif window manager, "mwm" keystroke for switching to the default keybindings and behaviour is control-meta-bang. Since exclamation mark might be thought to look like a Coke bottle, Motif hackers referred to this keystroke as "cokebottle". See also quadruple bucky. [Jargon File] (1995-01-04) 1 1 1 1 1 COLASL An early system for numerical problems on the IBM 7030. It used a special character set for input of natural mathematical expressions. [Sammet 1969, pp. 265-271]. (1995-01-04) 1 1 1 1 1 COLD 1. <language> A sugared version of COLD-K. 2. <storage> Computer Output to Laser Disk - see Enterprise Report Management. (2007-07-24) 1 1 1 1 1 cold boot A boot from power off. Contrast warm boot. [Jargon File] (1995-11-27) 1 1 1 1 1 ColdFusion Allaire Corporation's commercial database application development tool that allows databases to have a web interface, so a database can be queried and updated using a web browser. The ColdFusion Server application runs on the web server and has access to a database. ColdFusion files on the web server are HTML pages with additional ColdFusion commands to query or update the database, written in CFML. When the page is requested by the user, the web server passes the page to the Cold Fusion application, which executes the CFML commands, places the results of the CFML commands in the HTML file, and returns the page to the web server. The page returned to the web server is now an ordinary HTML file, and it is sent to the user. Examples of ColdFusion applications include order entry, event registration, catalogue search, directories, calendars, and interactive training. ColdFusion applications are robust 1 1 1 1 1 ColdFusion Markup Language (CFML) A tag based markup language used to create ColdFusion web applications by embedding ColdFusion commands in HTML files. (1999-08-01) 1 1 1 1 1 COLD-K A formal design kernel language for describing (sequential) software systems in intermediate stages of their design. ["An Introduction to COLD-K", H.B.M. Jonkers in Algebraic Methods: Theory, Tools and Applications, M. Wirsing et al eds, LNCS 394, Springer 1989, pp. 139-205]. (1995-01-04) 1 1 1 1 1 COLINGO Compile On-LINe and GO. An english-like query system from MITRE Corporation for the IBM 1401. ["The COLINGO System Design Philosophy", Information System Sciences, Proc Second Congress, 1965]. [Sammet 1969, p. 664]. (1995-01-04) 1 1 1 1 1 collision 1. <networking> When two hosts transmit on a network at once causing their packets to corrupt each other. See collision detection. 2. <programming> hash collision. (1995-01-06) 1 1 1 1 1 collision detection A class of methods for sharing a data transmission medium in which hosts transmit as soon as they have data to send and then check to see whether their transmission has suffered a collision with another host's. If a collision is detected then the data must be resent. The resending algorithm should try to minimise the chance that two hosts's data will repeatedly collide. For example, the CSMA/CD protocol used on Ethernet specifies that they should then wait for a random time before re-transmitting. See also backoff. This contrasts with slotted protocols and token passing. (1997-03-18) 1 1 1 1 1 collocation co-location 1 1 1 1 1 co-location /koh'loh-kay`sh*n/ or /koh`loh-kay'sh*n/ (Or colocation) Providing network connections such as Internet leased lines to several servers housed together in a server room. This is typically provided as a commercial service. The hyphenated form is correct and the most common on the web, followed by "colocation". "collocation" (/ko`loh-kay'sh*n/, not /koh'-/), is an old word with a similar meaning. It is common in dictionaries and follows the pattern of other Latin-derived words like collect, college, and collate, but is least common on the web. The verbal form is "to colocate" or "co-locate" (commonly /koh'loh`kayt/, also (US) /koh`loh'kayt/). (2000-10-03) 1 1 1 1 1 colon ":" ASCII character 58. Common names: ITU-T: colon. Rare: dots; INTERCAL: two-spot. (1995-09-25) 1 1 1 1 1 color colour 1 1 1 1 1 Color Graphics Adapter (CGA) One of IBM's earliest hardware video display standards for use in IBM PCs. CGA can display 80*25 or 40*25 text in 16 colors, 640*200 pixels of graphics in two colors or 320*200 in four colors (IBM PC video modes 0-6). It is now obsolete. (1995-11-11) 1 1 1 1 1 color model colour model 1 1 1 1 1 Colossus (A huge and ancient statue on the Greek island of Rhodes). 1. <computer> The Colossus and Colossus Mark II computers used by Alan Turing at Bletchley Park, UK during the Second World War to crack the "Tunny" cipher produced by the Lorenz SZ 40 and SZ 42 machines. Colossus was a semi-fixed-program vacuum tube calculator (unlike its near-contemporary, the freely programmable Z3). ["Breaking the enemy's code", Glenn Zorpette, IEEE Spectrum, September 1987, pp. 47-51.] 2. The computer in the 1970 film, "Colossus: The Forbin Project". Forbin is the designer of a computer that will run all of America's nuclear defences. Shortly after being turned on, it detects the existence of Goliath, the Soviet counterpart, previously unknown to US Planners. Both computers insist that they be linked, whereupon the two become a new super computer and threaten the world with the immediate launch of nuclear weapons if they are detached. Colossus 1 1 1 1 1 colour (US "color") Colours are usually represented as RGB triples in a digital image because this corresponds most closely to the electronic signals needed to drive a CRT. Several equivalent systems ("colour models") exist, e.g. HSB. A colour image may be stored as three separate images, one for each of red, green, and blue, or each pixel may encode the colour using separate bit-fields for each colour component, or each pixel may store a logical colour number which is looked up in a hardware colour palette to find the colour to display. Printers may use the CMYK or Pantone representations of colours as well as RGB. (1999-08-02) 1 1 1 1 1 colour depth bits per pixel 1 1 1 1 1 colour look-up table colour palette 1 1 1 1 1 colour model Any system for representing colours as ordered sets of numbers. The most common colour models are RGB, CMYK, and HSB. There are several others, e.g. CMY, and the "Lab" system(?). See also: Pantone. (1999-10-21) 1 1 1 1 1 colour palette (colour look-up table, CLUT) A device which converts the logical colour numbers stored in each pixel of video memory into physical colours, normally represented as RGB triplets, that can be displayed on the monitor. The palette is simply a block of fast RAM which is addressed by the logical colour and whose output is split into the red, green and blue levels which drive the actual display (e.g. CRT). The number of entries (logical colours) in the palette is the total number of colours which can appear on screen simultaneously. The width of each entry determines the number of colours which the palette can be set to produce. A common example would be a palette of 256 colours (i.e. addressed by eight-bit pixel values) where each colour can be chosen from a total of 16.7 million colours (i.e. eight bits output for each of red, green and blue). Changes to the palette affect the whole screen at once and can 1 1 1 1 1 Columbia AppleTalk Package (CAP) An implementation of Apple Computer's AppleTalk protocols for Unix 4.2BSD and its derivatives, from Columbia University. There are two different LAP delivery mechanisms for: IPTalk and Ethertalk (possibly using UAB). CAP supports the following AppleTalk protocols: AppleTalk Transaction Protocol (ATP), Name Binding Protocol (NBP), Printer Access Protocol (PAP), AppleTalk Session Protocol (ASP), AppleTalk Filing Protocol (AFP) client side. In addition, the Datagram Delivery Protocol (DDP) and Zone Information Protocol (ZIP) are partially available. The structure of the Internet Appletalk Bridge software makes it impossible to provide full DDP service. Only the Get Zone List ATP ZIP command is implemented for ZIP. (1995-01-10) 1 1 1 1 1 column 1. <database> A named slice through a database table that includes the same field of each row. For example, a telephone directory table might have a row for each person with a name column and a telephone number column. 2. <storage> A line of memory cells in a dynamic random-access memory, that is selected by a particular column address. (2007-10-12) 1 1 1 1 1 Column Address Strobe (CAS) A signal sent from a processor (or memory controller) to a dynamic random-access memory (DRAM) (qv) circuit to indicate that the column address lines are valid. (1996-10-17) 1 1 1 1 1 COM 1. <programming> Component Object Model. 2. <storage> Computer Output on Microfilm - see Enterprise Report Management. 1 1 1 1 1 com (.com, "commercial") The top-level domain originally for American companies but, since the explosion of the web, used by most companies and for vanity domains of all types, whether in the US or not, often in addition to country code domains like amazon.co.uk. The term "dot com" is now widely used to refer to any Internet business as in "My dot com turned into a dot bomb". (2007-02-18) 1 1 1 1 1 COMAL COMmon Algorithmic Language 1 1 1 1 1 combination 1. <mathematics> A set containing a certain number of objects selected from another set. The number of combinations of r objects chosen from a set of n is n C r = n! / ((n-r)! r!) where "n C r" is normally with n and r as subscripts or as n above r in parentheses. See also permutation. 2. <reduction> In the theory of combinators, a combination denotes an expression in which function application is the only operation. (1995-04-10) 1 1 1 1 1 combinator A function with no free variables. A term is either a constant, a variable or of the form A B denoting the application of term A (a function of one argument) to term B. Juxtaposition associates to the left in the absence of parentheses. All combinators can be defined from two basic combinators - S and K. These two and a third, I, are defined thus: S f g x #NAME? K x y #NAME? I x #NAME? 1 1 1 1 1 combinatory logic A system for reducing the operational notation of logic, mathematics or a functional language to a sequence of modifications to the input data structure. First introduced in the 1920's by Schoenfinkel. Re-introduced independently by Haskell Curry in the late 1920's (who quickly learned of Schoenfinkel's work after he had the idea). Curry is really responsible for most of the development, at least up until work with Feys in 1958. See combinator. (1995-01-05) 1 1 1 1 1 Comdex A computer show that is held twice yearly, once in the spring (in Atlanta) and once in autumn (in Las Vegas). Comdex is a major show during which new releases of software and hardware are made. Microsoft, for example, often annouces its products at Comdex. (1995-01-11) 1 1 1 1 1 COME FROM A semi-mythical language construct dual to the "go to"; "COME FROM" <label> would cause the referenced label to act as a sort of trapdoor, so that if the program ever reached it, control would quietly and automagically be transferred to the statement following the "COME FROM". COME FROM was first proposed in R.L. Clark's "A Linguistic Contribution to GOTO-less programming", which appeared in a 1973 Datamation issue (and was reprinted in the April 1984 issue of "Communications of the ACM"). This parodied the then-raging "structured programming" holy wars (see considered harmful). Mythically, some variants are the "assigned COME FROM" and the computed COME FROM (parodying some nasty control constructs in Fortran and some extended BASICs). Of course, multitasking (or nondeterminism) could be implemented by having more than one "COME FROM" statement coming from the same label. 1 1 1 1 1 COMIS A COMpilation and Interpretation System. A Fortran interpreter use by the PAW system. (1994-11-30) 1 1 1 1 1 COMIT The first string-handling and pattern-matching language, designed in 1957-8 for applications in natural language translation. The user has a workspace organised into shelves. Strings are made of constituents (words), accessed by subscript. A program is a set of rules, each of which has a pattern, a replacement and goto another rule. ["COMIT Programmer's Reference Manual", V.H. Yngve, MIT Press 1961]. [Sammet 1969, pp. 416-436]. (1994-11-30) 1 1 1 1 1 Comite Europeen des Postes et Telecommunications (CEPT, European Conference of Post and Telecommunications) The committee that defined the CEPT speech compression scheme. [Details of compression scheme?] (1998-03-16) 1 1 1 1 1 COMIT II ["Computer Programming with COMIT II", Victor H. Yngve, MIT Press, 1963]. (1995-01-11) 1 1 1 1 1 Comma COMputable MAthematics. An ESPRIT project at KU Nijmegen. (1994-11-30) 1 1 1 1 1 comma "," ASCII character 44. Common names: ITU-T: comma. Rare: ITU-T: cedilla; INTERCAL: tail. In the C programming language, "," is an operator which evaluates its first argument (which presumably has side-effects) and then returns the value of its second argument. This is useful in "for" statements and macros. (1995-03-10) 1 1 1 1 1 command A character string which tells a program to perform a specific action. Most commands take arguments which either modify the action performed or supply it with input. Commands may be typed by the user or read from a file by a command interpreter. It is also common to refer to menu items as commands. (1997-06-21) 1 1 1 1 1 Command Control Processor (CCP) CP/M's command-line interpreter. (2001-11-01) 1 1 1 1 1 command interpreter A program which reads textual commands from the user or from a file and executes them. Some commands may be executed directly within the interpreter itself (e.g. setting variables or control constructs), others may cause it to load and execute other files. Unix's command interpreters are known as shells. When an IBM PC is booted BIOS loads and runs the MS-DOS command interpreter into memory from file COMMAND.COM found on a floppy disk or hard disk drive. The commands that COMMAND.COM recognizes (e.g. COPY, DIR, PRN) are called internal commands, in contrast to external commands which are executable files. (1995-03-16) 1 1 1 1 1 command key feature key 1 1 1 1 1 command line interface A means of communication between a program and its user, based solely on textual input and output. Commands are input with the help of a keyboard or similar device and are interpreted and executed by the program. Results are output as text or graphics to the terminal. Command line interfaces usually provide greater flexibility than graphical user interfaces, at the cost of being harder for the novice to use. Consequently, some hackers look down on GUIs as designed For The Rest Of Them. (1996-01-12) 1 1 1 1 1 command-line interpreter command interpreter 1 1 1 1 1 command line option (Or "option", "flag", "switch", "option switch") An argument to a command that modifies its function rather than providing data. Options generally start with "-" in Unix or / in MS-DOS. This is usually followed by a single letter or occasionally a digit. More recently, GNU software adopted the --longoptionname style, usually in addition to traditional, single-character, -x style equivalents. Some commands require each option to be a separate argument, introduced by a new "-" or "/", others allow multiple option letters to be concatenated into a single argument with a single "-" or "/", e.g. "ls -al". A few Unix commands (e.g. ar, tar) allow the "-" to be omitted. Some options may or must be followed by a value, e.g. "cc prog.c -o prog", sometimes with and sometimes without an intervening space. getopt and getopts are commands for parsing command line options. There is also a C library routine called getopt for the same purpose. 1 1 1 1 1 comma separated values (CSV) A file format used as a portable representation of a database. Each line is one entry or record and the fields in a record are separated by commas. Commas may be followed by arbitrary space and/or tab characters which are ignored. If field includes a comma, the whole field must be surrounded with double quotes. (1995-05-06) 1 1 1 1 1 COMMEN [L.J. Cohen. Proc SJCC 30:671-676, AFIPS (Spring 1967)]. (1994-11-30) 1 1 1 1 1 comment (Or "remark") Explanatory text embedded in program source (or less often data) intended to help human readers understand it. Code completely without comments is often hard to read, but code with too many comments is also bad, especially if the comments are not kept up-to-date with changes to the code. Too much commenting may mean that the code is over-complicated. A good rule is to comment everything that needs it but write code that doesn't need much of it. Comments that explain __why__ something is done and how the code relates to its environment are useful. A particularly irksome form of over-commenting explains exactly what each statement does, even when it is obvious to any reasonably competant programmer, e.g. /* Open the input file */ 1 1 1 1 1 commented out comment out 1 1 1 1 1 comment out To surround a section of code with comment delimiters or to prefix every line in the section with a comment marker. This prevents it from being compiled or interpreted. It is often done to temporarily disable the code, e.g. during debugging or when the code is redundant or obsolete, but is being left in the source to make the intent of the active code clearer. The word "comment" is sometimes replaced with whatever syntax is used to mark comments in the language in question, e.g. "hash out" (shell script, Perl), "REM out" (BASIC), etc. Compare condition out. [Jargon File] (1998-04-28) 1 1 1 1 1 commercial at "@". ASCII code 64. Common names: at sign, at, strudel. Rare: each, vortex, whorl, INTERCAL: whirlpool, cyclone, snail, ape, cat, rose, cabbage, amphora. ITU-T: commercial at. The @ sign is used in an electronic mail address to separate the local part from the hostname. This dates back to July 1972 when Ray Tomlinson was designing the first[?] e-mail program. It is ironic that @ has become a trendy mark of Internet awareness since it is a very old symbol, derived from the latin preposition "ad" (at). Giorgio Stabile, a professor of history in Rome, has traced the symbol back to the Italian Renaissance in a Roman mercantile document signed by Francesco Lapi on 1536-05-04. In Dutch it is called "apestaartje" (little ape-tail), in German "affenschwanz" (ape tail). The French name is arobase. In Spain and Portugal it denotes a weight of about 1 1 1 1 1 Commercial Internet eXchange (CIX) The CIX is a non-profit, 501(c)6, trade association coordinating Internet services. Its member organisations provide TCP/IP or OSI data internetwork services to the general public. The CIX gives them unrestricted access to other worldwide networks. It also takes an interest in the development and future direction of the Internet. The CIX provides a neutral forum to exchange ideas, information, and experimental projects among suppliers of internetworking services. The CIX broadens the base of national and international cooperation and coordination among member networks. Together, the membership may develop consensus positions on legislative and policy issues of mutual interest. The CIX encourages technical research and development for the mutual benefit of suppliers and customers of data communications internetworking services. It assists its 1 1 1 1 1 commercial off-the-shelf software commercial software 1 1 1 1 1 commercial software (Or "commercial off-the-shelf software", COTS) Software that is produced for sale. This contrasts with free software, which is produced for free distribution, meaning without charge and/or without restriction on further distribution. Some companies that sell software distribute some (versions) of products free of charge (but usually with restricted distribution rights), this would probably still be called commercial software. Conversely, software that an individual distributes for free, but for which he accepts donations, would still be called free software. (2007-02-07) 1 1 1 1 1 Commercial Translator An English-like pre-COBOL language for business data processing. [Sammet 1969, p. 378]. (1994-11-08) 1 1 1 1 1 Committed Data Rate (CDR) The data transfer rate that an ISP guarantees a virtual circuit will carry. The CDR is the data portion of Committed Information Rate (CIR). (2007-02-28) 1 1 1 1 1 Committed Information Rate (CIR) The guaranteed average data rate of a virtual circuit in a frame relay network. The CIR plus the Excess Information Rate (EIR, burst rate) is equal to or less than the speed of the access port into the network. The term CIR includes voice and non-data packets that are not included in the Committed Data Rate (CDR). CIR is generally used in reference to leased lines and similar classes of network services, not dial-up. (2010-05-07) 1 1 1 1 1 comm mode (Or "com mode") An ITS feature supporting interactive on-line chat. [Jargon File] (1998-01-18) 1 1 1 1 1 Commodore Commodore Business Machines or one of their computers such as the Commodore 64. (2010-09-14) 1 1 1 1 1 Commodore 1010 A 3.5-inch floppy disk drive for the Amiga. (1998-12-23) 1 1 1 1 1 Commodore 128 (C128) An expanded Commodore 64, Commodore Business Machines' last commercially released 8-bit computer. However, they did prototype the Commodore 65 and Commodore SX64. (1996-06-05) 1 1 1 1 1 Commodore 1541 The best known floppy disk drive for the Commodore 64. The 1541 was a single-sided 160 Kb drive but converting to flippy disks would give another 160 Kb. The disk drive used Group Code Recording and contained a 6502 processor as a disk controller. Some people wrote code for it to vibrate the head at different frequencies to play tunes. The transfer rate was about 300 bytes per second. The 1541 used a bit-serial version of the IEEE 488 parallel protocol. Some third-party speed-ups could transfer about 4 kilobytes per second over the interface, and some "fast loaders" managed up to 10 kbps. The Commodore 1570 was an upgraded 1541 for use with the Commodore 128. (2000-03-07) 1 1 1 1 1 Commodore 1570 Commodore Business Machines's allegedly "advanced" disk drive for use with the C128. It is basically a 1541 with the capability to use "burst loading" (like the Commodore 1571), and lots of new bugs. The Commodore 1571 was a double-sided version of the 1570. (1996-04-07) 1 1 1 1 1 Commodore 1571 Commodore Business Machines's "advanced" disk drive for the C128. It was the double-sided version of the Commodore 1570 disk drive but, unlike the 1570, worked quite well. The 1571 supported "burst mode" loading when used on a C128 in native mode, which increased the transfer speed from 1541 speed to about three kilobytes per second (about a 10-fold increase). The 1571 could be told to emulate a 1541 for use with a C64 or 1541 disks. Bugs in early releases of the 1571 ROM affected access to the second side of the disk. (1996-04-07) 1 1 1 1 1 Commodore 1581 Commodore Business Machines's 3.5 inch disk drive for the Commodore 64 and Commodore 128. The drive stores 800 kilobytes using an MFM format which is different from both messy-dos 720 kb, and the Amiga 880 kb formats. The 1581 supports a poor imitation of directories which are really just partitions and largely unused. It also supports burst loading like the Commodore 1571, but is actually faster as it is better designed. It has 3160 blocks free when formatted. The 1581 is the highest density C64 serial bus drive made by Commodore. However Creative Micro Designs (CMD) make the FD2000 (1.6MB) and (until recently) the FD4000 (3.2MB) 3.5" disk drives. GEOS users like 1581s as they are very fast when used with GEOS. See also Commodore 1541, Commodore 1571. (1998-12-23) 1 1 1 1 1 Commodore 64 (C64) An 8-bit Commodore Business Machines personal computer released around September 1981. Prototypes were (apparently) made before Christmas 1980 (and shown at some computer fair). The CPU was a 6510 from MOS Technology (who were a wholly owned subsiduary of Commodore at this time(?)). The C64 had 64 kilobytes of RAM as standard and a 40-column text, 320x200 pixel display generating composite video, usually connected to a television. DMA-based memory expanders for the C64 (and C128) allowed 128, 256, and 512 kb of RAM. Several third party manufacturers produce accelerators and RAM expanders for the C64 and C128. (Some, risking a holy war, compare this to putting a brick on roller-skates). Such accelerators come in speeds up to 20MHz (20 times the original) and RAM expanders to 16MB. The C64's 1541 5.25 floppy disk drive had a 6502 1 1 1 1 1 Commodore 64DX Commodore 65 1 1 1 1 1 Commodore 65 (Or Commodore 64DX, C65, C64DX) The last 8-bit computer designed by Commodore Business Machines, about 1989-1991. The C65 boasts an ugly collection of custom integrated circuits which makes even the Amiga hardware look standard. The core of the C65 chipset is the CSG 4510 and CSG 4569. The 4510 is a 65CE02 with two 6526 CIAs. The 4569 is equivalent to a combination of the 6569 VIC-II and the MMU of the Commodore 64. The C65 also has a DMA controller (Commodore's purpose built DMAgic) which also functions as a simple blitter, and a floppy controller for the internal Commodore 1581-like disk drive. The floppy controller, known as the F011, supports seven drives (though the DOS only supports 2). The 4510 supports all the C64 video modes, plus an 80 column text mode, and bitplane modes. The bitplane modes can use up to eight bitplanes, and resolutions of up to 1280 x 400. The palette is 12-bit 1 1 1 1 1 Commodore Business Machines (CBM) Makers of the PET, Commodore 64, Commodore 16, Commodore 128, and Amiga personal computers. Their logo is a chicken head. The Commodore name is controlled by Commodore Licensing BV, now a subsidiary of Asiarim. Commodore USA signed an agreement with Commodore Licensing BV. On 1994-04-29, Commodore International announced that it had been unable to renegotiate terms of outstanding loans and was closing down the business. Commodore US was expected to go into liquidation. Commodore US, France, Spain, and Belgium were liquidated for various reasons. The names Commodore and Amiga were maintained after the liquidation. After 1994, the rights to the Commodore name bounced across several European companies. On 1995-04-21, German retailer Escom AG bought Commodore International for $14m and production of the Amiga resumed. Netherlands-based Tulip Computers took over the brand. 1 1 1 1 1 Commodore SX64 A "portable" Commodore 64. Shaped vaguely like a seat cushion, this cumbersome experiment in transportable computers had a detachable keyboard on one end which, when removed, revealed a 6" monitor and a 5 1/4" floppy disk drive. The curious combination of a bulky design and microscopic display are the most likely cause for the SX64's discontinuation. [Processor? RAM? Dates?] (1997-10-25) 1 1 1 1 1 COMmon Algorithmic Language (COMAL) A language for beginners developed by Benedict Loefstedt and Borge Christensen in 1973 and popular in Europe and Scandinavia. It has a Pascal-like structure added to BASIC. COMAL-80 has been adopted as an introductory language in Denmark. There is a version for the Amiga and a well-supported version for the PC, running under MS-DOS and Microsoft Windows, called UniCOMAL. Recently, it has been developed as a web-scripting language called WebCOMAL. macharsoft (http://macharsoft.demon.co.uk/). There is a COMAL User's Group at 5501 Groveland Terr, Madison WI 53716, USA. ["Beginning COMAL", B. Christensen, Ellis Harwood 1982]. (2000-11-14) 1 1 1 1 1 Common Applications Environment (CAE) Part of X/Open, based on POSIX and C. [Details?] (2007-03-01) 1 1 1 1 1 Common Applications Service Element Common Application Service Element 1 1 1 1 1 Common Architecture for Next Generation Internet Protocol (CATNIP, originally Common Architecture Technology for Next-generation Internet Protocol) A network architecture designed to provide a compressed form of the existing network layer protocols and to integrate CLNP, IP, and IPX. It provides for any of the transport layer protocols in use, including TP4, CLTP, TCP, UDP, IPX, and SPX, to run over any of the network layer protocol formats: CLNP, IP (version 4), IPX and CATNIP. CATNIP was originally proposed by Robert L. Ullmann of Lotus Development Corporation on 1993-12-22. It was published as RFC 1707 in October 1994 but it is not an Internet standard of any kind. (1996-03-23) 1 1 1 1 1 COmmon Business Oriented Language /koh'bol/ (COBOL) A programming language for simple computations on large amounts of data, designed by the CODASYL Committee in April 1960. COBOL's natural language style is intended to be largely self-documenting. It introduced the record structure. COBOL was probably the most widely used programming language during the 1960s and 1970s. Many of the major programs that required repair or replacement due to Year 2000 software rot issues were originally written in COBOL, and this was responsible for a short-lived increased demand for COBOL programmers. Even in 2002 though, new COBOL programs are still being written in some organisations and many old COBOL programs are still running in dinosaur shops. Major revisions in 1968 (ANS X3.23-1968), 1974 (ANS X3.23-1974) and 1985. Usenet newsgroup: news:comp.lang.cobol. ["Initial Specifications for a Common Business Oriented 1 1 1 1 1 common carrier (Or "phone company") A private company that offers telecommunications services to the public. (1995-03-20) 1 1 1 1 1 Common Command Set (CCS) Additional requirements and features for direct-access SCSI devices. In 1985 when the first SCSI standard was being finalised as an American National Standard, the X3T9.2 Task Group was approached by some manufacturers who wanted changes. Rather than delay the SCSI standard, X3T9.2 formed an ad hoc group to define CCS. [Spec? Status? "direct-access"?] (1997-03-23) 1 1 1 1 1 Common Communication Services (CCS) The standard program interface to networks in IBM's SAA. (2007-05-14) 1 1 1 1 1 Common Data Format (CDF) A library and toolkit based on a self-describing data format for scalar and multidimensional data. CDF aims to be platform- and discipline-independent. A scientific data management package (CDF Library) allows developers to manage data and metadata through APIs. CDF has built-in support for data compression (gZip, RLE, Huffman) and files larger than two gigabytes. There are interfaces for C, FORTRAN, Java, Perl, C#, Visual Basic, IDL and MATLAB. CDF Home (http://cdf.gsfc.nasa.gov/) (2015-04-26) 1 1 1 1 1 Common Desktop Environment (CDE) A desktop manager from COSE. (1994-10-31) 1 1 1 1 1 Common ESP (CESP) A Unix-based version of ESP (Extended Self-containing Prolog) from Mitsubishi's AI Language Institute. (2000-07-11) 1 1 1 1 1 Common Gateway Interface (CGI) A standard for running external programs from a web HTTP server. CGI specifies how to pass arguments to the program as part of the HTTP request. It also defines a set of environment variables that are made available to the program. The program generates output, typically HTML, which the web server processes and passes back to the browser. Alternatively, the program can request URL redirection. CGI allows the returned output to depend in any arbitrary way on the request. The CGI program can, for example, access information in a database and format the results as HTML. The program can access any data that a normal application program can, however the facilities available to CGI programs are usually limited for security reasons. Although CGI programs can be compiled programs, they are more often written in a (semi) interpreted language such as 1 1 1 1 1 Common Hardware Reference Platform PowerPC Platform 1 1 1 1 1 Common Information Model (CIM) An open systems management standard driven by the Distributed Management Task Force (DMTF). (2003-06-07) 1 1 1 1 1 Common Intermediate Format (CIF) A video format used in videoconferencing systems, which supports both NTSC and PAL signals, with a data rate of 30 frames per second (fps), with each frame containing 288 lines and 352 luminance pixels per line. CIF is part of the ITU H.261 videoconferencing standard. CIF is also known as Full CIF (FCIF) to distinguish it from Quarter CIF (QCIF), a related video format standard that transfers one fourth as much data as CIF. (2007-05-14) 1 1 1 1 1 Common Intermediate Language (CIL) [Details?] ["Construction of a Transportable, Milti-Pass Compiler for Extended Pascal", G.J. Hansen et al, SIGPLAN Notices 14(8):117-126, Aug 1979]. (1994-10-24) 1 1 1 1 1 Common Internet File System (CIFS) An Internet file system protocol, based on Microsoft's SMB. Microsoft has given CIFS to the Internet Engineering Task Force (IETF) as an Internet Draft. CIFS is intended to complement existing protocols such as HTTP, FTP, and NFS. CIFS runs on top of TCP/IP and uses the Internet's Domain Name Service (DNS). It is optimised to support the slower speed dial-up connections common on the Internet. CIFS is more flexible than FTP. FTP operations are carried out on entire files whereas CIFS is aimed at routine data access and incorporates high-performance multi-user read and write operations, locking, and file-sharing semantics. CIFS is probably closest in functionality to NFS. NFS gives random access to files and directories, but is stateless. With CIFS, once a file is open, state about the current access to that file is stored on both the client and the server. This allows changes on the server side to be notified to the 1 1 1 1 1 Common-ISDN-API Common ISDN Application Programming Interface 1 1 1 1 1 Common ISDN Application Programming Interface (CAPI, Common-ISDN-API) A programming interface standard for an application program to communicate with an ISDN card. Work on CAPI began in 1989, focussing on the German ISDN protocol, and was finished in 1990 by a CAPI working group consisting of application providers, ISDN equipment manufacturers, large customers, user groups and DBP Telekom, resulting in COMMON-ISDN-API Version 1.1. Following completion of the international protocol specification, almost every telecommunication provider offers BRI and PRI with protocols based on Q.931 / ETS 3009 102. Common-ISDN-API Version 2.0 was developed to support all Q.931 protocols. Latest version: 2.0, as of 1998-09-07. (http://capi.org/). [Why not CIAPI?] (1998-09-07) 1 1 1 1 1 Common Lisp A dialect of Lisp defined by a consortium of companies brought together in 1981 by the Defence Advanced Research Projects Agency (DARPA). Companies included Symbolics, Lisp Machines, Inc., Digital Equipment Corporation, Bell Labs., Xerox, Hewlett-Packard, Lawrence Livermore Labs., Carnegie-Mellon University, Stanford University, Yale, MIT and USC Berkeley. Common Lisp is lexically scoped by default but can be dynamically scoped. Common Lisp is a large and complex language, fairly close to a superset of MacLisp. It features lexical binding, data structures using defstruct and setf, closures, multiple values, types using declare and a variety of numerical types. Function calls allow "&optional", keyword and "&rest" arguments. Generic sequence can either be a list or an array. It provides formatted printing using escape characters. Common LISP now includes CLOS, an extended LOOP 1 1 1 1 1 Common LISP in Parallel (CLIP) A version of Common LISP from Allegro for the Sequent Symmetry. (1994-12-12) 1 1 1 1 1 Common LISP Object System (CLOS) An object-oriented extension to Common LISP, based on generic functions, multiple inheritance, declarative method combination and a meta-object protocol. A descendant of CommonLoops and based on Symbolics FLAVORS and Xerox LOOPS, among others. See also PCL. ["Common LISP Object System Specification X3J13 Document 88-002R", D.G. Bobrow et al, SIGPLAN Notices 23, Sep 1988]. (1994-11-30) 1 1 1 1 1 CommonLoops Xerox's object-oriented Lisp which led to CLOS. See also Portable CommonLoops. (ftp://arisia.xerox.com/pub/pcl/September-16-92-PCL-c.tar.Z). ["CommonLoops: Merging Lisp and Object-Oriented Programming", D.G. Bobrow et al, SIGPLAN Notices 21(11):17-29, Nov 1986]. (1999-07-02) 1 1 1 1 1 Common Management Information Protocol (CMIP) Part of the OSI body of standards specifying protocol elements that may be used to provide the operation and notification services described in the related standard, CMIS (Common Management Information Services). Document: ISO/IEC 9596, or equivalent ITU X.711. (1997-12-07) 1 1 1 1 1 Common Management Information Services (CMIS) Part of the OSI body of network standards. Network management information services are used by peer processes to exchange information and commands for the purpose of network management. CMIS defines a message set (GET, CANCEL-GET, SET, CREATE, DELETE, EVENT-REPORT and ACTION), and the structure and content of the messages such that they might be used by "open" systems. In concept, it is similar to SNMP, but more powerful (and hence more complex). ISO/IEC 9595. (2007-08-07) 1 1 1 1 1 Common Object File Format (COFF) The executable file and object file format used by Unix System V Release 3 and later. Unix manual page: coff(5). (2007-08-15) 1 1 1 1 1 Common Object Model Component Object Model 1 1 1 1 1 Common Object Request Broker Architecture (CORBA) An Object Management Group specification which provides a standard messaging interface between distributed objects. The original CORBA specification (1.1) has been revised through version 2 (CORBA 2) with the latest specification being version 3 (CORBA 3). In its most basic form CORBA consists of the Interface Definition Language (IDL) and the Dynamic Invocation Interface (DII). The IDL definition is complied into a Stub (client) and Skeleton (server) component that communicate through an Object Request Broker (ORB). When an ORB determines that a request is to a remote object, it may execute the request by communicating with the remote ORB. The Corba IDL can be mapped to a number of languages including C, C++, Java, COBOL, Smalltalk, Ada, Lisp, Python, and IDLscript. CORBA ORBs are widely available for a number of platforms. The OMG standard for inter-ORB 1 1 1 1 1 Common Objects An object-oriented Lisp from Hewlett-Packard. ["Inheritance and the Development of Encapsulated Software Components", A. Snyder, Proc 20th Hawaii Conf on Sys Sci, pp. 227-238, 1987]. (1995-01-18) 1 1 1 1 1 Common Program Interface (CPI) The API of SAA. (1997-12-01) 1 1 1 1 1 Common User Access (CUA) The user interface standard of SAA. (1997-12-01) 1 1 1 1 1 Commonwealth Hackish Hacker jargon as spoken outside the US, especially in the British Commonwealth. It is reported that Commonwealth speakers are more likely to pronounce truncations like "char" and "soc", etc., as spelled (/char/, /sok/), as opposed to American /keir/ and /sohsh/. Dots in newsgroup names (especially two-component names) tend to be pronounced more often (so soc.wibble is /sok dot wib'l/ rather than /sohsh wib'l/). The prefix meta may be pronounced /mee't*/; similarly, Greek letter beta is usually /bee't*/, zeta is usually /zee't*/, and so forth. Preferred metasyntactic variables include blurgle, "eek", "ook", "frodo", and bilbo; "wibble", "wobble", and in emergencies "wubble"; banana, "tom", "dick", "harry", "wombat", "frog", fish, and so on and on (see foo). Alternatives to verb doubling include suffixes "-o-rama", frenzy (as in feeding frenzy), and "city" (examples: "barf city!" "hack-o-rama!" "core dump frenzy!"). Finally, note 1 1 1 1 1 Communicating Functional Processes (CFP) A parallel functional programming language. ["Communicating Functional Processes", M.C. van Eekelen et al, TR 89-3, U Nijmegen, Netherlands, 1989]. (1994-11-30) 1 1 1 1 1 Communicating Sequential Processes (CSP) A notation for concurrency based on synchronous message passing and selective communications designed by Anthony Hoare in 1978. It features cobegin and coend and was a precursor to occam. See also Contextually Communicating Sequential Processes. ["Communicating Sequential Processes", A.R. Hoare, P-H 1985]. (1994-11-01) 1 1 1 1 1 Communication and Network Riser (CNR) A specification for audio, modem, USB and Local Area Networking interfaces of core computer logic chip sets. Intel introduced CNR on 2000-02-07. It was mainly developed by hardware and software developers who helped release AMR (Audio/Modem Riser) and is used by several computer manufacturers. (http://www.computerhope.com/jargon/c/cnr.htm). (2007-03-15) 1 1 1 1 1 Communications Decency Act (CDA) An amendment to the U.S. 1996 Telecommunications Bill that went into effect on 1996-02-08. The law, originally proposed by Senator James Exon to protect children from obscenity on the Internet, ended up making it punishable by fines of up to $250,000 to post indecent language on the Internet anywhere that a minor could read it. Thousands of outraged Internet users turned their web pages black in protest or displayed the Electronic Frontier Foundation's special icons. On 1996-06-12, a three-judge panel in Philadelphia ruled the CDA unconstitutional and issued an injunction against the United States Justice Department forbidding them to enforce the "indecency" provisions of the law. Internet users celebrated by displaying an animated "Free Speech" fireworks icon to their web pages, courtesy of the Voters Telecommunications Watch. The Justice Department appealed the decision to the U.S. Supreme Court. 1 1 1 1 1 Communications of the ACM (CACM) A monthly publication by the Association for Computing Machinery sent to all members. CACM is an influential publication that keeps computer science professionals up to date on developments. Each issue includes articles, case studies, practitioner oriented pieces, regular columns, commentary, departments, the ACM Forum, technical correspondence and advertisements. (http://acm.org/cacm/). (1995-01-18) 1 1 1 1 1 communications port A connector for a communications interface, usually, a serial port. (1996-08-04) 1 1 1 1 1 Communications Server IBM's rebranding of ACF. (1999-01-20) 1 1 1 1 1 communications software Application programs, operating system components, and probably firmware, forming part of a communication system. These different software components might be classified according to the functions within the Open Systems Interconnect model which they provide. Typical applications include a web browser, Mail User Agent, chat and telnet. (2001-03-18) 1 1 1 1 1 communication system A system or facility for transfering data between persons and equipment. The system usually consists of a collection of individual communication networks, transmission systems, relay stations, tributary stations and terminal equipment capable of interconnection and interoperation so as to form an integrated whole. These individual components must serve a common purpose, be technically compatible, employ common procedures, respond to some form of control and generally operate in unison. ["Communications Standard Dictionary", 2nd Edition, Martin H. Weik]. (1995-02-06) 1 1 1 1 1 Community of Massive Gaming Agency (CMGA) An online gaming portal introduced by German Telekom. (2003-06-15) 1 1 1 1 1 COMNET A simulation tool from CACI for analysing wide-area voice or data networks, based on SIMSCRIPT. (2008-10-13) 1 1 1 1 1 compact 1. <theory> (Or "finite", "isolated") In domain theory, an element d of a cpo D is compact if and only if, for any chain S, a subset of D, d <= lub S => there exists s in S such that d <= s. I.e. you always reach d (or better) after a finite number of steps up the chain. ("<=" is written in LaTeX as \sqsubseteq). [Jargon File] (1995-01-13) 2. <jargon> Of a design, describes the valuable property that it can all be apprehended at once in one's head. This generally means the thing created from the design can be used with greater facility and fewer errors than an equivalent tool that is not compact. Compactness does not imply triviality or lack of power; for example, C is compact and Fortran is not, but C is more powerful than Fortran. Designs become 1 1 1 1 1 Compact COBOL A subset of COBOL defined, but not published, ca. 1961. [Sammet 1969, p. 339]. (2008-10-13) 1 1 1 1 1 Compact Disc (CD) (Not "disk", this spelling is part of the standard). A 4.72 inch disc developed by Sony and Philips that can store, on the same disc, still and/or moving images in monochrome and/or color; stereo or two separate sound tracks integrated with and/or separate from the images; and digital program and information files. The same fabrication process is used to make both audio CDs and CD-ROMs for storing computer data, the only difference is in the device used to read the CD (the player or drive). CD Information Center (http://cd-info.com/cd-info/CDInfoCenter.html). (1999-06-23) 1 1 1 1 1 Compact Disc interactive (CD-i) An embedded application of CD-ROM allowing the user limited interaction with films, games and educational applications via a special controller. (1994-11-02) 1 1 1 1 1 Compact Disc Read-Only Memory (CD-ROM) A non-volatile optical data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. CD-ROM is popular for distribution of large databases, software and especially multimedia applications. The maximum capacity is about 600 megabytes. A CD can store around 640 megabytes of data - about 12 billion bytes per pound weight. CD-ROM drives are rated with a speed factor relative to music CDs (1x or 1-speed which gives a data transfer rate of 150 kilobytes per second). 12x drives were common in April 1997. Above 12x speed, there are problems with vibration and heat. Constant angular velocity (CAV) drives give speeds up to 20x but due to the nature of CAV the actual throughput increase over 12x is less than 20/12. 20x was thought to be the maximum speed due to mechanical constraints but on 1998-02-24, Samsung Electronics 1 1 1 1 1 Compact Disc Read-Write Compact Disc Rewritable 1 1 1 1 1 Compact Disc Recordable (CD-R) A write-once version of CD-ROM. CD-Rs can hold about 650 megabytes of data. They are very durable and can be read by normal CD-ROM drives, but once data has been written it cannot be altered. Standard prerecorded CDs have their information permanently stamped into an aluminium reflecting layer. CD-R discs have a dye-based recording layer and an additional golden reflecting layer. Digital information is written to the disc by burning (forming) pits in the recording layer in a pattern corresponding to that of a conventional CD. The laser beam heats the substrate and recording layer to approximately 250 C. The recording layer melts and the substrate expands into the space that becomes available. Phillips: New Technologies (http://www-us.sv.philips.com/newtech/cdrewritable.html). See also CD-RW and DVD-RAM. 1 1 1 1 1 Compact Disc Rewritable (CD-RW) A rewritable version of CD-ROM. A CD-RW drive can write about 650 megabytes of data to CD-RW media an unlimited number of times. Most CD-RW drives can also write once to CD-R media. CD-RW media cannot be read by CD-ROM drives built prior to 1997 due to the reduced reflectivity (15% compared to 70%) of CD-RW media. CD-RW drives and media are currently (1999) more expensive than CD-R drives and media. CD-R is sometimes considered a better technology for archival purposes as the data cannot be accidentally modified or tampered with, and encourages better archival practices. Standard prerecorded CDs have their information permanently stamped into an aluminium reflecting layer. CD-WR discs have a phase-change recording layer and an additional silver (aluminium) reflecting layer. A laser beam can melt crystals in the recording layer into a 1 1 1 1 1 Compact Disc writer (CD burner) A device that can write data to Compact Disc Recordable (CD-R) or Compact Disc Rewritable (CD-RW) discs. Now both these CD formats are often combined with a DVD writer. (2008-09-16) 1 1 1 1 1 compaction compression 1 1 1 1 1 compactness preserving In domain theory, a function f is compactness preserving if f c is compact whenever c is. (1995-01-13) 1 1 1 1 1 Compaq Computer Corporation A US manufacturer and vendor of IBM PC compatible personal computers and servers. Compaq was started in 1982 by three ex-Texas Instruments employees and by 1995 had become the largest PC manufacturer. Quarterly sales $2499M, profits $210M (Aug 1994). Compaq was acquired by Hewlett-Packard in 2004. (http://compaq.com/). (1995-10-24) 1 1 1 1 1 Compas Pascal The predecessor of Turbo Pascal, sol by POLY Data of Denmark. It was later renamed POLY Pascal, and afterward sold to Borland. (1995-01-19) 1 1 1 1 1 COMPASS COMPrehensive ASSembler. The assembly language on CDC computers. (1995-01-19) 1 1 1 1 1 compatibility compatible 1 1 1 1 1 compatible Different systems (e.g., programs, file formats, protocols, even programming languages) that can work together or exchange data are said to be compatible. See also backward compatible, forward compatible. (1998-01-15) 1 1 1 1 1 Compatible Timesharing System (CTSS) One of the earliest (1963) experiments in the design of interactive time-sharing operating systems. CTSS was ancestral to Multics, Unix, and ITS. It was developed at the MIT Computation Center by a team led by Fernando J. Corbato. CTSS ran on a modified IBM 7094 with a second 32K-word bank of memory, using two 2301 drums for swapping. Remote access was provided to up to 30 users via an IBM 7750 communications controller connected to dial-up modems. The name ITS (Incompatible time-sharing System) was a hack on CTSS, meant both as a joke and to express some basic differences in philosophy about the way I/O services should be presented to user programs. (1997-01-29) 1 1 1 1 1 Compel COMpute ParallEL 1 1 1 1 1 Competitive Access Provider (CAP, or "Bypass Carrier") A company which provides network links between the customer and the IntereXchange Carrier or even directly to the Internet Service Provider. CAPs operate private networks independent of Local Exchange Carriers. ["Getting Connected The Internet at 56k and Up", Kevin Dowd, First Edition, p. 49, O'Reilly & Associates, Inc., June 1996, ISBN 1-56592-154-2 (US), ISBN 1-56592-203-4 (international)]. (1997-07-23) 1 1 1 1 1 Compiled HTML A Microsoft file format for distributing a collection of HTML files, along with their associated images, sounds, etc., as a single compressed archive file. Microsoft use this format for Windows HTML Help files. Most chms include a project (.hhp) file listing the included files and basic settings, a contents (.hhc) file, an index (.hhk) file, html files, and, optionally, image files. Users view chms with hh.exe, the HTML Help viewer installed with Internet Explorer. Filename extension: .chm. (http://msdn.microsoft.com/library/en-us/htmlhelp/html/vsconHH1Start.asp). (2003-05-17) 1 1 1 1 1 compiler A program that converts another program from some source language (or programming language) to machine language (object code). Some compilers output assembly language which is then converted to machine language by a separate assembler. A compiler is distinguished from an assembler by the fact that each input statement does not, in general, correspond to a single machine instruction or fixed sequence of instructions. A compiler may support such features as automatic allocation of variables, arbitrary arithmetic expressions, control structures such as FOR and WHILE loops, variable scope, input/ouput operations, higher-order functions and portability of source code. AUTOCODER, written in 1952, was possibly the first primitive compiler. Laning and Zierler's compiler, written in 1953-1954, was possibly the first true working algebraic compiler. 1 1 1 1 1 COmpiler and GENeralized Translator (COGENT) A compiler writing language with pattern-directed string and list processing features, for CDC 3600 and CDC 3800. A COGENT program consists of productions defining a context-free language, plus analysis and synthesis function generators. ["COGENT Programming Manual", J.C. Reynolds, ANL-7022, Argonne, Mar 1965]. [Sammet 1969, p.638]. ["An Introduction to the COGENT System", J.C. Reynolds, Proc ACM 20th Natl Conf, 1965]. (1994-12-23) 1 1 1 1 1 compiler compiler compiler-compiler 1 1 1 1 1 Compiler-Compiler An early compiler generator for the Atlas, with its own distinctive input language. ["The Compiler-Compiler", R.A. Brooker et al, Ann Rev Automatic Programming 3:229-275, Pergamon 1963]. (1994-10-24) 1 1 1 1 1 compiler-compiler A utility to generate the source code of a parser, interpreter or compiler from an annotated language description (usually in BNF). Most so called compiler-compilers are really just parser generators. Examples are Bison, Eli, FSL, META 5, MUG2, Parsley, Pre-cc, Yacc. (1995-01-23) 1 1 1 1 1 compiler jock A programmer who specialises in writing compilers. [Jargon File] (1995-01-19) 1 1 1 1 1 Compiler Language for Information Processing (CLIP) A language written in 1958-1959, based on IAL, which led to JOVIAL. CLIP was one of the first languages used to write its own compiler. [Sammet 1969, p. 635]. (1994-12-12) 1 1 1 1 1 Compiler Target Language (CTL) The intermediate language used by the ALICE parallel machine. ["The Design and Implementation of ALICE: A Parallel Graph Reduction Machine", M.D. Cripps et al, Proc Workshop on Graph Reduction, Springer 1987]. (1994-11-14) 1 1 1 1 1 compile time The period of time during which a program's source code is being translated into machine code, as opposed to run time when the program is being executed. As well as the work done by the compiler, this may include macro preprocessing as done by cpp for example. The final stage of program construction, performed by the linker, would generally also be classed as compile time but might be distinguished as link time. For example, static data in a C program is allocated at compile time whereas non-static data is allocated at run time, typically on the stack. (2004-09-28) 1 1 1 1 1 COMPL ["The COMPL Language and Operating System", A.G. Fraser et al, Computer J 9(2):144-156, 1966]. (1995-01-24) 1 1 1 1 1 complement The other value or values in the set of possible values. See logical complement, bitwise complement, set complement. (1995-01-24) 1 1 1 1 1 Complementary Metal Oxide Semiconductor (CMOS) A semiconductor fabrication technology using a combination of n- and p-doped semiconductor material to achieve low power dissipation. Any path through a gate through which current can flow includes both n and p type transistors. Only one type is turned on in any stable state so there is no static power dissipation and current only flows when a gate switches in order to charge the parasitic capacitance. (1999-06-04) 1 1 1 1 1 complementary nondeterministic polynomial (Co-NP) The set (or property) of problems with a yes/no answer where the complementary no/yes problem takes nondeterministic polynomial time (NP). For example, "Is n prime" is Co-NP and "Is n not prime" is NP, since it is only necessary to find one factor to prove that n is not prime whereas to prove that it is prime all possible factors must be eliminated. (2009-05-21) 1 1 1 1 1 complete See also complete graph, complete inference system, complete lattice, complete metric space, complete partial ordering, complete theory. [1. or 2. or both?] (1996-04-24) 1 1 1 1 1 complete graph A graph which has a link between every pair of nodes. A complete bipartite graph can be partitioned into two subsets of nodes such that each node is joined to every node in the other subset. (1995-01-24) 1 1 1 1 1 complete inference system An inference system A is complete with respect to another system B if A can reach every conclusion which is true in B. The dual to completeness is soundness. (1998-07-05) 1 1 1 1 1 complete lattice A lattice is a partial ordering of a set under a relation where all finite subsets have a least upper bound and a greatest lower bound. A complete lattice also has these for infinite subsets. Every finite lattice is complete. Some authors drop the requirement for greatest lower bounds. (1994-12-02) 1 1 1 1 1 complete metric space A metric space in which every sequence that converges in itself has a limit. For example, the space of real numbers is complete by Dedekind's axiom, whereas the space of rational numbers is not - e.g. the sequence a[0]=1; a[n_+1]:=a[n]/2+1/a[n]. (1998-07-05) 1 1 1 1 1 completeness complete 1 1 1 1 1 complete partial ordering (cpo) A partial ordering of a set under a relation, where all directed subsets have a least upper bound. A cpo is usually defined to include a least element, bottom (David Schmidt calls this a pointed cpo). A cpo which is algebraic and boundedly complete is a (Scott) domain. (1994-11-30) 1 1 1 1 1 complete theory An abstract logical theory in which all true statements have formal proofs within the theory. (1998-07-05) 1 1 1 1 1 complete unification W.P. Weijland's name for unification without occur check. (1996-01-11) 1 1 1 1 1 Complex Instruction Set Computer (CISC) A processor where each instruction can perform several low-level operations such as memory access, arithmetic operations or address calculations. The term was coined in contrast to Reduced Instruction Set Computer. Before the first RISC processors were designed, many computer architects were trying to bridge the "semantic gap" - to design instruction sets to support high-level languages by providing "high-level" instructions such as procedure call and return, loop instructions such as "decrement and branch if non-zero" and complex addressing modes to allow data structure and array accesses to be compiled into single instructions. While these architectures achieved their aim of allowing high-level language constructs to be expressed in fewer instructions, it was observed that they did not always result in improved performance. For example, on one processor it was discovered that it was possible to improve the performance by 1 1 1 1 1 complexity The level in difficulty in solving mathematically posed problems as measured by the time, number of steps or arithmetic operations, or memory space required (called time complexity, computational complexity, and space complexity, respectively). The interesting aspect is usually how complexity scales with the size of the input (the "scalability"), where the size of the input is described by some number N. Thus an algorithm may have computational complexity O(N^2) (of the order of the square of the size of the input), in which case if the input doubles in size, the computation will take four times as many steps. The ideal is a constant time algorithm (O(1)) or failing that, O(N). See also NP-complete. (1994-10-20) 1 1 1 1 1 complexity analysis In sructured program design, a quality-control operation that counts the number of "compares" in the logic implementing a function; a value of less than 10 is considered acceptable. 1 1 1 1 1 complexity class A collection of algorithms or computable functions with the same complexity. (1996-04-24) 1 1 1 1 1 complexity measure A quantity describing the complexity of a computation. (1996-04-24) 1 1 1 1 1 complex number A number of the form x+iy where i is the square root of -1, and x and y are real numbers, known as the real and "imaginary" part. Complex numbers can be plotted as points on a two-dimensional plane, known as an Argand diagram, where x and y are the Cartesian coordinates. An alternative, polar notation, expresses a complex number as (r e^it) where e is the base of natural logarithms, and r and t are real numbers, known as the magnitude and phase. The two forms are related: r e^it = r cos(t) + i r sin(t) = x + i y where x = r cos(t) 1 1 1 1 1 complex programmable logic device (CPLD) A programmable circuit similar to an FPGA, but generally on a smaller scale, invented by Xilinx, Inc. (1998-09-26) 1 1 1 1 1 component An object adhering to a component architecture. (1997-11-20) 1 1 1 1 1 component architecture A notion in object-oriented programming where components of a program are completely generic. Instead of having a specialised set of methods and fields they have generic methods through which the component can advertise the functionality it supports to the system into which it is loaded. This enables completely dynamic loading of objects. JavaBeans is an example of a component architecture. See also design pattern. (1997-11-20) 1 1 1 1 1 component based development (CBD) The creation, integration, and re-use of components of program code, each of which has a common interface for use by multiple systems. (1999-08-23) 1 1 1 1 1 Component Integration Laboratories (CIL) An effort to create a common framework for interoperability between application programs on desktop platforms, formed by Apple Computer, Inc., IBM, Novell, Oracle, Taligent, WordPerfect and Xerox. [When? What happened?] (1994-10-24) 1 1 1 1 1 Component Object Model (COM) An open software architecture from DEC and Microsoft, allowing interoperation between ObjectBroker and OLE. Microsoft evolved COM into DCOM. On page XV of Box's book in the foreword by Charlie Kindel he says, "It is Mark Ryland's fault that some people call COM the 'Common Object Model.' He deeply regrets it and apologizes profusely." ["Essential COM", Don Box]. [Details? URL?] (1999-06-12) 1 1 1 1 1 com port communications port 1 1 1 1 1 composite aggregate 1 1 1 1 1 composition 1. function composition. 2. typesetting. 1 1 1 1 1 Compositional C++ (CC++) Extensions to C++ for compositional parallel programming. FTP Caltech (ftp://csvax.cs.caltech.edu/pub/comp). [Did Carl Kesselman at Cal Tech develop it?] (2000-08-16) 1 1 1 1 1 Compound Document Architecture (CDA) DEC's set of standards for compound document creation, storage, retrieval, interchange and manipulation. (1996-11-03) 1 1 1 1 1 compound key (Or "multi-part key", "concatenated key") A key which consists of more than one attribute of the body of information (e.g. database "record") it identifies. (1997-04-26) 1 1 1 1 1 COMPREHENSIVE An early system on MIT's Whirlwind. [Listed in CACM 2(5):16, May 1959]. (2002-06-03) 1 1 1 1 1 Comprehensive Perl Archive Network (CPAN) A collection of Internet archives containing material related to the Perl programming language. (http://perl.com/CPAN). (1999-12-04) 1 1 1 1 1 Comprehensive TeX Archive Network (CTAN) An archive site for the TeX text formatting package. (http://tex.ac.uk). Gopher (gopher://gopher.tex.ac.uk/). (ftp://ftp.tex.ac.uk/). NFS: nfs.tex.ac.uk. (1995-01-18) 1 1 1 1 1 compress 1. To feed data through any compression algorithm. 2. <tool> The Unix program "compress", now largely supplanted by gzip. Unix compress was written in C by Joseph M. Orost, James A. Woods et al., and was widely circulated via Usenet. It uses the Lempel-Ziv Welch algorithm and normally produces files with the suffix ".Z". Compress uses variable length codes. Initially, nine-bit codes are output until they are all used. When this occurs, ten-bit codes are used and so on, until an implementation-dependent maximum is reached. After every 10 kilobytes of input the compression ratio is checked. If it is decreasing then the entire string table is discarded and information is collected from scratch. 1 1 1 1 1 Compressed SLIP (CSLIP) VanJacobsen TCP header compression. A version of SLIP using compression. CSLIP has no effect on the data portion of the packet and has nothing to do with compression by modem. It does reduce the TCP header from 40 bytes to 7 bytes, a noticeable difference when doing telnet with lots of little packets. CSLIP has no effect on UDP, only TCP. (1995-05-28) 1 1 1 1 1 compressed video video compression 1 1 1 1 1 compression 1. <application> (Or "compaction") The coding of data to save storage space or transmission time. Although data is already coded in digital form for computer processing, it can often be coded more efficiently (using fewer bits). For example, run-length encoding replaces strings of repeated characters (or other units of data) with a single character and a count. There are many compression algorithms and utilities. Compressed data must be decompressed before it can be used. The standard Unix compression utilty is called compress though GNU's superior gzip has largely replaced it. Other compression utilties include pack, zip and PKZIP. When compressing several similar files, it is usually better to join the files together into an archive of some kind (using tar for example) and then compress them, rather than to join together individually compressed files. This is because some common compression algorithms build up tables based on the data from their current input which they have 1 1 1 1 1 COMPROSL COMpound PROcedural Scientific Language. A language for scientists and engineers. [Sammet 1969, pp. 299-300]. 1 1 1 1 1 Compu$erve (Or "CompuSpend", "Compu$pend") A pejorative name for CompuServe Information Service (CI$) drawing attention to perceived high charges. [Jargon File] (1994-11-08) 1 1 1 1 1 Compulink Information eXchange (CIX) A London-based conferencing system, also providing electronic mail, FTP, telnet, IRC, Gopher and web. Includes conferences "archimedes" or "bbc" for users of Acorn computers. E-mail: <cixadmin@cix.compulink.co.uk>. Telephone: +44 (181) 390 8446. (1994-11-08) 1 1 1 1 1 CompuServe CompuServe Information Service 1 1 1 1 1 CompuServe Corporation The parent organisation of CompuServe Information Service, CompuServe Network Services and CompuServe Remote Computing Services. CompuServe was owned by H.R. Block but is now (1999) owned by America On-Line. (http://compuserve.com/). (1995-09-12) 1 1 1 1 1 CompuServe Information Service (CIS, CompuServe Interactive Services). An ISP and on-line service portal based in Columbus, Ohio, USA; part of AOL since February 1998. CIS was founded in 1969 as a computer time-sharing service. Along with AOL and Prodigy, CIS was one of the first pre-Internet, on-line services for consumers, providing bulletin boards, on-line conferencing, business news, sports and weather, financial transactions, electronic mail, Usenet news, travel and entertainment data and on-line editions of computer publications. CIS was originally run by CompuServe Corporation. In 1979, CompuServe was the first service to offer electronic mail and technical support to personal computer users. In 1980 they were the first to offer real-time chat with its CB Simulator. By 1982, the company had formed its Network Services Division to provide wide-area networking to corporate clients. 1 1 1 1 1 CompuServe Interactive Services CompuServe Information Service 1 1 1 1 1 Compusult Ltd. A computer consulting firm (in Newfoundland, Canada?) that provides a public access Unix. (1994-10-20) 1 1 1 1 1 computability theory The area of theoretical computer science concerning what problems can be solved by any computer. A function is computable if an algorithm can be implemented which will give the correct output for any valid input. Since computer programs are countable but real numbers are not, it follows that there must exist real numbers that cannot be calculated by any program. Unfortunately, by definition, there isn't an easy way of describing any of them! In fact, there are many tasks (not just calculating real numbers) that computers cannot perform. The most well-known is the halting problem, the busy beaver problem is less famous but just as fascinating. ["Computability", N.J. Cutland. (A well written undergraduate-level introduction to the subject)]. ["The Turing Omnibus", A.K. Dewdeney]. (1995-01-13) 1 1 1 1 1 computable computability theory 1 1 1 1 1 Computational Adequacy Theorem This states that for any program (a non-function typed term in the typed lambda-calculus with constants) normal order reduction (outermost first) fails to terminate if and only if the standard semantics of the term is bottom. Moreover, if the reduction of program e1 terminates with some head normal form e2 then the standard semantics of e1 and e2 will be equal. This theorem is significant because it relates the operational notion of a reduction sequence and the denotational semantics of the input and output of a reduction sequence. 1 1 1 1 1 computational complexity The number of steps or arithmetic operations required to solve a computational problem. One of the three kinds of complexity. (1996-04-24) 1 1 1 1 1 Computational Fluid Dynamics (CFD) A Fortran-based parallel language for the Illiac IV. (1994-11-29) 1 1 1 1 1 computational geometry The study of algorithms for combinatorial, topological, and metric problems concerning sets of points, typically in Euclidean space. Representative areas of research include geometric search, convexity, proximity, intersection, and linear programming. (1997-08-03) 1 1 1 1 1 computational learning grammatical inference 1 1 1 1 1 computational molecular biology The area of bioinformatics concerning the use of computers to characterise the molecular components of living things. (2005-01-07) 1 1 1 1 1 COMpute ParallEL (Compel) The first single-assignment language. ["A Language Design for Concurrent Processes", L.G. Tesler et al, Proc SJCC 32:403-408, AFIPS (Spring 1968)]. (1995-01-19) 1 1 1 1 1 Computer A journal of the IEEE Computer Society. (1995-03-10) 1 1 1 1 1 computer A machine that can be programmed to manipulate symbols. Computers can perform complex and repetitive procedures quickly, precisely and reliably and can quickly store and retrieve large amounts of data. The physical components from which a computer is constructed (electronic circuits and input/output devices) are known as hardware. Most computers have four types of hardware component: CPU, input, output and memory. The CPU (central processing unit) executes programs ("software") which tell the computer what to do. Input and output (I/O) devices allow the computer to communicate with the user and the outside world. There are several kinds of memory - fast, expensive, short term memory (e.g. RAM) to hold intermediate results, and slower, cheaper, long-term memory (e.g. magnetic disk and magnetic tape) to hold programs and data between jobs. See also analogue computer. (1995-03-10) 1 1 1 1 1 Computer Aided Design (CAD) The part of CAE concerning the drawing or physical layout steps of engineering design. Often found in the phrase "CAD/CAM" for ".. manufacturing". (1994-11-30) 1 1 1 1 1 Computer Aided Detector Design (CADD) A project to standardise HEP detector designer. (2011-02-18) 1 1 1 1 1 Computer Aided Engineering (CAE) The use of software to help with all phases of engineering design work. Like computer aided design, but also involving the conceptual and analytical design steps and extending into Computer-Integrated Manufacturing (CIM). (1994-10-28) 1 1 1 1 1 Computer-Aided Instruction (CAI, or "- assisted", "- learning", CAL, Computer-Based Training CBT, "e-learning") The use of computers for education and training. The programs and data used in CAI, known as "courseware", may be supplied on media such as CD-ROM or delivered via a network which also enables centralised logging of student progress. CAI may constitute the whole or part of a course, may be done individually or in groups ("Computer Supported Collaborative Learning", CSCL), with or without human guidance. (2011-11-25) 1 1 1 1 1 Computer-Aided Learning Computer-Aided Instruction 1 1 1 1 1 Computer Aided Software Engineering (CASE, or "- assisted -") A technique for using computers to help with one or more phases of the software life-cycle, including the systematic analysis, design, implementation and maintenance of software. Adopting the CASE approach to building and maintaining systems involves software tools and training for the developers who will use them. (1996-05-10) 1 1 1 1 1 Computer-Aided Software Testing (CAST) Automated software testing in one or more phases of the software life-cycle. (1996-05-10) 1 1 1 1 1 Computer Aided Test Engineering (CATE) CASE methods applied to electronics testing and linked to CAE. (2007-05-03) 1 1 1 1 1 Computer Animation Movie Language A programming language for generating animation. ["A Computer Animation Movie Language for Educational Motion Pictures", D.D. Weiner et al, Proc FJCC 33(2), AFIPS, Fall 1968]. (2012-01-30) 1 1 1 1 1 Computer-Assisted Learning Computer-Aided Instruction 1 1 1 1 1 Computer-Assisted Software Engineering Computer-Aided Software Engineering 1 1 1 1 1 Computer Associates International, Inc. (CA) A US software development company, founded in 1976. CA have purchased many other software companies, including Spectrum Software, Inc., Cheyenne Software, Platinum Technology, Inc., ASK Corporation. They produce a number of popular software packages, including Unicenter TNG and Ingres. They had an Initial Public Offering in 1981 valued at more than US$3.2M, had more than US$6B in revenue in 2000, and employ more than 17,000 people. (http://ca.com/). (20002-04-20) 1 1 1 1 1 Computer-Based Training Computer-Aided Instruction 1 1 1 1 1 computer bus bus 1 1 1 1 1 Computer Compiler 1. <language> A proposed language for compiler design. [Sammet 1969, p. 695]. 2. A discussion of various applications of computers to the design and production of computers. ACM (http://dl.acm.org/citation.cfm?id=1464213&CFID=83216609&CFTOKEN=42516197). ["A proposal for a computer compiler", Gernot Metze (University of Illinois), Sundaram Seshu (University of Illinois), AFIPS '66 (Spring) Proceedings of the 1966-04-26 - 28, Spring joint computer conference]. (2007-02-13) 1 1 1 1 1 computer confetti (Or "chad") A common term for punched-card chad, which, however, does not make good confetti, as the pieces are stiff and have sharp corners that could injure the eyes. GLS reports that he once attended a wedding at MIT during which he and a few other guests enthusiastically threw chad instead of rice. The groom later grumbled that he and his bride had spent most of the evening trying to get the stuff out of their hair. [Jargon File] (2001-06-22) 1 1 1 1 1 Computer Conservation Society (CCS) A british group that aims to promote the conservation and study of historic computers, past and future. The CCS is a co-operative venture between the British Computer Society, the Science Museum of London and the Museum of Science and Industry in Manchester. The CCS was constituted in September 1989 as a Specialist Group of the BCS. A number of active projects and working groups focus on specific computer restorations, early computer technologies and software. Membership is open to anyone interested. Home (http://computerconservationsociety.org). See also Bletchley Park. (2012-03-22) 1 1 1 1 1 computer cookie HTTP cookie 1 1 1 1 1 computer crime Breaking the criminal law by use of a computer. See also computer ethics, software law. (1997-07-09) 1 1 1 1 1 Computer Design Language An ALGOL-like language for computer design. ["An ALGOL-like Computer Design Language", Y. Chu, CACM 8(10) (Oct 1965)]. (1994-11-17) 1 1 1 1 1 computer dictionary Free On-line Dictionary of Computing 1 1 1 1 1 Computer Emergency Response Team (CERT) An organisation formed by DARPA in November 1988 in response to the Internet worm incident. The CERT charter is to work with the Internet community to help it responf to computer security events involving Internet hosts, to raise awareness of computer security issues and to conduct research targeted at improving the security of existing systems. CERT products and services include 24-hour technical assistance for responding to computer security incidents, product vulnerability assistance, technical documents and tutorials. CERT Home (http://cert.org/). E-mail: <cert@cert.org> (incident reports). Telephone +1 (412) 268 7090 (24-hour hotline). (2012-05-18) 1 1 1 1 1 computer ethics Ethics is the field of study that is concerned with questions of value, that is, judgments about what human behaviour is "good" or "bad". Ethical judgments are no different in the area of computing from those in any other area. Computers raise problems of privacy, ownership, theft, and power, to name but a few. Computer ethics can be grounded in one of four basic world-views: Idealism, Realism, Pragmatism, or Existentialism. Idealists believe that reality is basically ideas and that ethics therefore involves conforming to ideals. Realists believe that reality is basically nature and that ethics therefore involves acting according to what is natural. Pragmatists believe that reality is not fixed but is in process and that ethics therefore is practical (that is, concerned with what will produce socially-desired results). Existentialists believe reality is self-defined and that ethics therefore is individual (that is, concerned only with 1 1 1 1 1 computer file file 1 1 1 1 1 computer geek (Or "turbo nerd", "turbo geek") One who eats (computer) bugs for a living. One who fulfils all the dreariest negative stereotypes about hackers: an asocial, malodourous, pasty-faced monomaniac with all the personality of a cheese grater. The term cannot be used by outsiders without implied insult to all hackers; compare black-on-black usage of "nigger". A computer geek may be either a fundamentally clueless individual or a proto-hacker in larval stage. See also Alpha Geek, propeller head, clustergeeking, geek out, wannabee, terminal junkie, spod, weenie. [Jargon File] (1997-06-26) 1 1 1 1 1 computer-generated imagery (CGI) Animatied graphics produced by computer and used in film or television. (1998-10-13) 1 1 1 1 1 Computer Generation Incorporated (CGI) A US software development company and systems integrator. (http://compgen.com/). E-mail: Paul G. Smith <pauls@compgen.com> Telephone: +1 (404) 705 2800 Address: Bldg. G, 4th Floor, 5775 Peachtree-Dunwoody Rd., Atlanta, GA 30342, USA. (1997-02-11) 1 1 1 1 1 Computer Graphics Metafile (CGM) A standard file format for storage and communication of graphical information, widely used on personal computers and accepted by desktop publishing and technical illustration systems. MIME type: image/cgm. ANSI/ISO 8632-1987. Worked on by the ISO/IEC group JTC1/SC24. CGM Open Consortium (http://cgmopen.org/). See also: WebCGM. (1999-02-16) 1 1 1 1 1 Computer Integrated Manufacturing (CIM) Use of computers to control multiple aspects of a production process in a factory. A CIM system may control and/or monitor areas such as design, analysis, planning, purchasing, cost accounting, inventory control, distribution, materials handling and management. (2003-06-07) 1 1 1 1 1 computer language programming language 1 1 1 1 1 Computer Language for AeronauticS and Programming (CLASP) A real-time language from NASA, focussing on fixed-point mathematics. CLASP is a near subset of SPL, with some ideas from PL/I. ["Flight Computer and Language Processor Study", Raymond J. Rubey, Management Information Services, Detroit, 1971]. (1994-10-13) 1 1 1 1 1 computer law Legal aspects of the production, sale and use of computers; including areas such as software law, copyright, patents, sale of goods, communication law and general media issues such as free speech. (2012-08-30) 1 1 1 1 1 computer literacy Basic skill in use of computers, from the perspective of such skill being a necessary societal skill. The term was coined by Andrew Molnar, while director of the Office of Computing Activities at the National Science Foundation. "We started computer literacy in '72 [...] We coined that phrase. It's sort of ironic. Nobody knows what computer literacy is. Nobody can define it. And the reason we selected [it] was because nobody could define it, and [...] it was a broad enough term that you could get all of these programs together under one roof (cited in Aspray, W.," (September 25, 1991) "Interview with Andrew Molnar," OH 234. Center for the History of Information Processing, Charles Babbage Institute, University of Minnesota). The term, as a coinage, is similar to earlier coinages, such as "visual literacy", which Merriam-Webster (http://m-w.com/) dates to 1971, and the more recent media literacy. A more useful definition from (http://www.computerliteracyusa.com/) is: Computer literacy is an understanding of the concepts, terminology and operations that relate to general computer 1 1 1 1 1 Computer Management Group of Australia (CMGA) An Australian group that organises conferences, exhibitions, meetings and seminars about IT management for its corporate and individual members. CMGA Home (http://cmga.org.au/). (2012-10-25) 1 1 1 1 1 Computer Mediated Communication (CMC) Communication that takes place through, or is facilitated by, computers. Examples include e-mail, the web, real-time chat tools like IRC, Windows Live Messenger and video conferencing. (2012-10-25) 1 1 1 1 1 computer nerd computer geek 1 1 1 1 1 computer network network 1 1 1 1 1 Computer Output on Microfilm Enterprise Report Management 1 1 1 1 1 Computer Output to Laser Disc Enterprise Report Management 1 1 1 1 1 Computer Output to Laser Disk Enterprise Report Management 1 1 1 1 1 Computer Professionals for Social Responsibility (CPSR) A non-profit organisation whose mission is to provide the public and policymakers with realistic assessments of the power, promise and problems of Information Technology and the effects of computers on society. CPSR was founded in the USA in 1981 but has spread to many other countries. CPSR is supported by its membership. CPSR sponsors conferences such as their Annual Meeting, Directions and Implications in Advanced Computing (DIAC), the Participatory Design Conference (PDC) and the Computers, Freedom and Privacy (CFP) conference. CPSR Home (http://cpsr.org/). (2012-11-04) 1 1 1 1 1 computer program software 1 1 1 1 1 computer programming language A somewhat redundant term for programming language. (2014-10-18) 1 1 1 1 1 Computer + Science NETwork (CSNET) The networking organisation which combined with BITNET to form CREN. (1994-11-30) 1 1 1 1 1 computer security security 1 1 1 1 1 computer sex Two computers interfaced with each other. (1996-02-22) 1 1 1 1 1 Computer Software Configuration Item (CSCI) A configuration item consisting of software. (2012-11-07) 1 1 1 1 1 Computer-Supported Collaborative Learning (CSCL) Any form of Computer-Aided Instruction that emphasises group learning as opposed to working alone. (2011-11-25) 1 1 1 1 1 Computer Supported Cooperative Work (CSCW) (Or "groupware") Software tools and technology to support groups of people working together on a project, often at different sites. See also Lotus Notes. (1994-11-30) 1 1 1 1 1 Computer Telephone Integration (CTI or "- Telephony -") Enabling computers to know about and control telephony functions such as making and receiving voice, fax and data calls, telephone directory services and caller identification. CTI is used in call centres to link incoming calls to computer software functions such as database look-up of the caller's number, supported by services such as Automatic Number Identification and Dialled Number Identification Service. Application software (middleware) can link personal computers and servers with telephones and/or a PBX. Telephony and software vendors such as AT&T, British Telecom, IBM, Novell, Microsoft and Intel have developed CTI services. The main CTI functions are integrating messaging with databases, word processors etc.; controlling voice, fax, and e-mail messaging systems from a single application program; graphical call control - using a graphical user interface to perform functions such as making and receiving 1 1 1 1 1 Computer Telephony Computer Telephone Integration 1 1 1 1 1 Computer Telephony Integration Computer Telephone Integration 1 1 1 1 1 computer virus virus 1 1 1 1 1 computer vision A branch of artificial intelligence and image processing concerned with computer processing of images from the real world. Computer vision typically requires a combination of low level image processing to enhance the image quality (e.g. remove noise, increase contrast), pattern recognition to recognise features such as lines, areas and colours and image understanding to translate these features into knowledge about the objects in the scene. Usenet newsgroup: news:comp.ai.vision. (2012-12-25) 1 1 1 1 1 compute server A kind of parallel processor where the parallel processors have no I/O except via a bus or other connection to a front-end processor which handles all I/O to disks, terminals and network. In some antiquated IBM mainframes, a second CPU was provided that could not access I/O devices, known as the slave or attached processor, while the CPU having access to all devices was known as the master processor. (1995-03-19) 1 1 1 1 1 computing computer 1 1 1 1 1 Computing Devices Canada Ltd. General Dynamics Canada Ltd. 1 1 1 1 1 computing dictionary Free On-line Dictionary of Computing 1 1 1 1 1 computron /kom'pyoo-tron"/ 1. A notional unit of computing power combining execution speed and storage capacity. E.g. "That machine can't run GNU Emacs, it doesn't have enough computrons!" 2. A mythical subatomic particle that carries computation or information, in much the same way that an electron carries electric charge (see also bogon). [Jargon File] (2013-03-02) 1 1 1 1 1 Compuware Corporation A US software and service company established in 1973. Since 1973, Compuware focused on optimising business software development, testing and operation. In 1999 the company had grown to over 15,000 employees worldwide and revenues of more than $1.6B. By 2013 it had shrunk to less than 5000. Current (2013) products and services include performance optimisation, availability and quality of web, non-web, mobile, streaming and cloud applications; project portfolio management, professional services automation; mainframe applications and developer tools; rapid application development and professional services. (http://compuware.com/). (2013-03-08) 1 1 1 1 1 COMSL ["COMSL - A Communication System Simulation Language", R.L. Granger, Proc FJCC 37 (1970)]. (2013-03-08) 1 1 1 1 1 COMTRAN ["Communications Computer Language COMTRAN", D.W. Clark et al, RADC-TR-69-190, Rose Air Development Center, Griffiss AFB, NY, July 1969]. [Sammet 1969, p.324, 331]. 1 1 1 1 1 ConC A concurrent extension of C based on decomposed Petri nets. It uses the 'handshake' and 'unit' constructs. ["ConC: A Language for Distributed Real-Time Programming", V.K. Garg et al, Computer Langs 16(1):5-18 (1991)]. (1995-03-02) 1 1 1 1 1 concatenate To join together two or more files or lists to form one big one. The Unix cat command can be used to concatenate files. (1995-12-22) 1 1 1 1 1 concatenated key compound key 1 1 1 1 1 concentrator A device that combines the data streams from many simultaneously active inputs into one shared channel in such a way that the streams can be separated after transmission. The concentrator's output bandwidth must be at least as great as the total bandwidth of all simultaneously active inputs. A concentrator is one kind of multiplexing device. For example, a concentrator may be used to connect 24 2400 bps TTYs to a host via a 57600 bps channel. (2000-03-01) 1 1 1 1 1 conceptualisation The process or result of listing the types of objects, concepts and other entities that are assumed to exist in some area of interest and the relationships that hold among them. A conceptualisation is an abstract, simplified view of the world that we wish to represent. For example, we may conceptualise a family as the set of names, sexes and the relationships of the family members. Choosing a conceptualisation is the first stage of knowledge representation. A conceptualisation is a high-level data model. Every knowledge base, knowledge-based system, or knowledge-level agent is committed to some conceptualisation, explicitly or implicitly. (2013-04-17) 1 1 1 1 1 Concert/C A parallel extension of ANSI C with asynchronous message passing, developed at the IBM TJWRC in July 1993. Concert/C provides primitives to create and terminate processes and communicate between them. The programmer explicitly expresses parallelization and distribution. 1994 Announcement (http://www.cs.bu.edu/~best/courses/cs551/projects/concert.txt). (2013-05-05) 1 1 1 1 1 ConCoord An environment for programming networks of sequential and parallel computers. ConCoord supports explicit parallelism with different granularity. (2013-05-22) 1 1 1 1 1 concrete class In object-oriented programming, a class suitable to be instantiated, as opposed to an abstract class. (1995-05-01) 1 1 1 1 1 Concrete Data Structure (CDS) A model of programming language terms developed in the context of constructing fully abstract semantics for sequential languages. A CDS is a 4-tuple (C,V,E,|-) where C is a cell, V is a value, E is an event and |- is an "enabling relation". An event is a cell and a value. A cell C is "enabled" by a set of events S if S |- C. A state is a set of events which are consistent in that the values they give for any cell are all equal. Every cell in a state is enabled. [G. Berry, P.-L. Curien, "Theory and practice of sequential algorithms: the kernel of applicative language CDS", Algebraic methods in semantics, CUP 1985]. (1994-11-30) 1 1 1 1 1 concrete syntax The syntax of a language including all the features visible in the source code such as parentheses and delimiters. The concrete syntax is used when parsing the program or other input, during which it is usually converted into some kind of abstract syntax tree (conforming to an abstract syntax). In communications, concrete syntax is called transfer syntax. (1997-07-21) 1 1 1 1 1 CONCUR A proposal for a language for programming with concurrent processes. CONCUR was inspired by Modula but removes Modula's restrictions on the placement of process declarations and invocations in order to study the implications of process support more fully. Anderson presents a compiler which translates CONCUR into the object language for a hypothetical machine. ["CONCUR, A Language for Continuous Concurrent Processes", R.M. Salter et al, Comp Langs 5(3):163-189, 1981]. ["Concur: a High-Level Language for Concurrent Programming", Karen Anderson Thesis, B. Thomas Golisano College of Computing and Information Sciences, 1979] (https://ritdml.rit.edu/handle/1850/15968?show=full) (2013-06-05) 1 1 1 1 1 concurrency multitasking 1 1 1 1 1 Concurrent C 1. <language> An extension of C with rendezvous-based concurrency. Versions for most Unix systems were available commercially from AT&T. ["Concurrent C", N.H. Gehani et al, Soft Prac & Exp 16(9):821-844 (1986)]. ["The Concurrent C Programming Language", N. Gehani et al, Silicon Press 1989]. (1994-11-11) 2. <language> An extension of C with asynchronous message passing. ["Concurrent C: A Language for Distributed Systems", Y. Tsujino et al, Soft Prac & Exp 14(11):1061-1078 (Nov 1984)]. (1994-11-11) 1 1 1 1 1 Concurrent C++ A programming language developed by Gehani and Roome at Bell Labs by merging their earlier Concurrent C language with C++. ["Concurrent C++: Concurrent Programming with Class(es)", N. Gehani, W.D. Roome, Bell Labs, 1986]. (2013-06-26) 1 1 1 1 1 Concurrent Clean An alternative name for Clean 1.0. (1995-11-08) 1 1 1 1 1 Concurrent CLU A programming language extending CLU for concurrent processes, developed by by Hamilton in 1984. ["Preserving Abstraction in Concurrent Programming", R.C.B. Cooper, K.G. Hamilton, IEEE Trans Soft Eng SE-14(2):258-263, Feb 1988].1 (2013-09-28) 1 1 1 1 1 Concurrent Constraint Programming (CCP) Not a language, but a general approach. [Details?] (2001-11-01) 1 1 1 1 1 Concurrent Euclid A concurrent extension of a subset of Euclid ("Simple Euclid") developed by J.R. Cordy and R.C. Holt of the University of Toronto in 1980. Concurrent Euclid features separate compilation, modules, processes and monitors, signal and wait on condition variables, 'converters' to defeat strong type checking, absolute addresses. All procedures and functions are re-entrant. TUNIS (a Unix-like operating system) is written in Concurrent Euclid. ["Specification of Concurrent Euclid", J.R. Cordy & R.C. Holt, Reports CSRI-115 & CSRI-133, CSRI, U Toronto, Jul 1980, rev. Aug 1981]. ["Concurrent Euclid, The Unix System, and Tunis," R.C. Holt, A-W, 1983]. (2005-02-19) 1 1 1 1 1 Concurrent LISP A concurrent version of Lisp. Sugimoto et al implemented an interpreter on a "large scale computer" and were planning to implement it on multiple microprocessors. ["A Multi-Processor System for Concurrent Lisp", S. Sugimoto et al, Proc 1983 Intl Conf parallel Proc, 1983 pp.135-143]. (2013-10-18) 1 1 1 1 1 Concurrent Massey Hope An extension of Massey Hope, by Peter Burgess, Robert Pointon, and Nigel Perry <N.Perry@massey.ac.nz> of Massey University, NZ, that provides multithreading and typed inter-thread communication. It uses C for intermediate code rather than assembly language. (1999-08-04) 1 1 1 1 1 Concurrent ML (CML) A concurrent extension of SML/NJ written by J. Reppy at Cornell University in 1990. CML supports dynamic thread creation and synchronous message passing on typed channels. Threads are implemented using first-class continuations. First-class synchronous operations allow users to tailor their synchronisation abstractions for their application. CML also supports both stream I/O and low-level I/O in an integrated fashion. Latest version 0.9.8, as of 1994-12-21, requires SML/NJ 0.75 or later. (ftp://ftp.cs.cornell.edu/pub/). E-mail: <sml-bugs@research.att.com> (bugs). ["CML: A Higher-Order Concurrent Language", John H. Reppy, SIGPLAN Notices 26(6):293-305, June 1991]. (2000-08-09) 1 1 1 1 1 Concurrent Oberon A concurrent version of Oberon. There is an implementation the Ceres workstation. ["Adding Concurrency to the Oberon System", S. Lalis et al, ETH Zurich, 1993]. (1994-11-11) 1 1 1 1 1 Concurrent Object-Oriented C (cooC) A language with concurrent object execution from Toshiba. It has synchronous and asynchronous message passing. It has been implemented for SunOS. (ftp://tsbgw.isl.rdc.toshiba.co.jp/pub/toshiba/cooc-beta.1.1.tar.Z). [SIGPLAN Notices 28(2)]. (2000-08-13) 1 1 1 1 1 Concurrent Object-Oriented Language (COOL) An extension of C++ with task-level parallelism for shared-memory multi-processors. ["COOL: A Language for Parallel Programming", R. Chandra <rohit@seagull.stanford.edu> et al in Languages and Compilers for Parallel Computing, D. Gelernter et al eds, MIT Press 1990, pp. 126-148]. E-mail: Rohit Chandra <rohit@cool.stanford.edu>. (1994-11-30) 1 1 1 1 1 Concurrent Pascal An extension of a Pascal subset, Sequential Pascal, developed by Brinch Hansen in 1972-75. Concurrent Pascal was the first language to support monitors. It provided access to hardware devices through monitor calls and also supported processes and classes. ["The Programming Language Concurrent Pascal", Per Brinch Hansen, IEEE Trans Soft Eng 1(2):199-207 (Jun 1975)]. (1994-11-30) 1 1 1 1 1 concurrent processing multitasking 1 1 1 1 1 Concurrent Prolog A Prolog variant with guarded clauses and committed-choice nondeterminism (don't-care nondeterminism) by Ehud "Udi" Shapiro, Yale <shapiro-ehud@yale.edu>. A subset has been implemented, but not the full language. See also Mandala. ["Concurrent Prolog: Collected Papers", E. Shapiro, V.1-2, MIT Press 1987]. (1994-11-30) 1 1 1 1 1 Concurrent Scheme A parallel Lisp, for the Mayfly by M. Swanson <swanson%teewinot@cs.utah.edu>. ["Concurrent Scheme", R.R. Kessler et al, in Parallel Lisp: Languages and Systems, T. Ito et al eds, LNCS 441, Springer 1989]. (1994-11-30) 1 1 1 1 1 ConcurrentSmalltalk A concurrent variant of Smalltalk. ["Concurrent Programming in ConcurrentSmalltalk", Y. Yokote et al in Object-Oriented Concurrent Programming, A. Yonezawa et al eds, MIT Press 1987, pp. 129-158]. (1994-11-30) 1 1 1 1 1 Concurrent SP/k (CSP/k) A PL/I-like concurrent language. ["Structured Concurrent Programming with Operating System Applications", R.C. Holt et al, A-W 1978]. (1997-12-15) 1 1 1 1 1 Concurrent Versions System (CVS) A cross-platform code management system originally based on RCS. CVS tracks all revisions to a file in an associated file with the same name as the original file but with the string ",v" (for version) appended to the filename. These files are stored in a (possibly centralised) repository. Changes are checked in or "committed" along with a comment (which appears in the the "commit log"). CVS has the notions of projects, branches, file locking and many others needed to provide a full-functioned repository. It is commonly accessed over over its own "anonCVS" protocol for read-only access (many open source projects are available by anonymous CVS) and over the SSH protocol by those with commit privileges ("committers"). CVS has been rewritten several times and does not depend on RCS. However, files are still largely compatible; one can easily migrate a project from RCS to CVS by copying the 1 1 1 1 1 condela Connection Definition Language 1 1 1 1 1 condition out A programming technique that prevents a section of code from being executed by putting it in an if statement whose condition is always false. It is often easier to do this than to comment out the code because you don't need to modify the code itself (as you would if commenting out each line individually) or worry about nested comments within the code (as you would if putting nesting comment delimiters around it). For example, in Perl you could write: if (0) ...code to be ignored... In a compiled language, the compiler could simply generate no code for the whole if statement. Some compiled languages such as C provide compile-time directives that achieve the same effect, e.g.: #if 0 1 1 1 1 1 condom 1. The protective plastic bag that accompanies 3.5-inch microfloppy diskettes. Rarely, also used of (paper) disk envelopes. Unlike the write protect tab, the condom (when left on) not only impedes the practice of SEX but has also been shown to have a high failure rate as drive mechanisms attempt to access the disk - and can even fatally frustrate insertion. 2. The protective cladding on a light pipe. 3. "keyboard condom": A flexible, transparent plastic cover for a keyboard, designed to provide some protection against dust and programming fluid without impeding typing. 4. "elephant condom": the plastic shipping bags used inside cardboard boxes to protect hardware in transit. [Jargon File] (1995-03-14) 1 1 1 1 1 Conference On DAta SYstems Languages (CODASYL) A consortium that developed database models and standard database extensions for COBOL. CODASYL was formed in 1959 to guide the development of a standard programming language that could be used on many computers. Members came from industry and government data processing departments. Its goal was to promote more effective data systems analysis, design and implementation. It published specifications for various languages over the years, handing these over to official standards bodies (ISO, ANSI or their predecessors) for formal standardisation. The 1965 List Processing Task Force worked on the IDS/I database extension. It later renamed itself to the Data Base Task Group (DBTG) and publishing the Codasyl Data Model, the first to allow one-to-many relations. This work also introduced data definition languages (DDLs) to define the database schema and a data manipulation language (DML) to be embedded in COBOL programs to request and update data in the database. 1 1 1 1 1 Conferencing over IP (CoIP) Standards for the transmission of multimedia over the Internet. CoIP extends VoIP (voice over Internet Protocol) with text, images, video. The main CoIP standard is based on H.323. The VoIP forum of the IMTC merged with the H.323 Activity Group in January 1999 to form the Conferencing over IP (CoIP) Activity Group. VoIP uses "VoIP Devices" as gateways to route voice data packets over the Internet or PSTN. Protocols such as SGCP and its successor MGCP extend VoIP to handle media other than voice data. (2013-12-29) 1 1 1 1 1 confidence test Tests to confirm that the results of a program lie within certain ranges according to the expected probability distribution. (1997-10-27) 1 1 1 1 1 CONFIG.SYS A text file containing special system configuration commands, found in the root directory on an MS-DOS computer, typically on drive C (the hard disk). It is read by MS-DOS at boot time, after the setup has been read from CMOS RAM and before running AUTOEXEC.BAT. It can be modified by the user. Some example commands which CONFIG.SYS might contain are: DEVICE=C:\DOS\HIMEM.SYS /testmem:off Load the extended memory manager. DEVICE=C:\DOS\EMM386.EXE RAM Load the expanded memory manager. BUFFERS=10,0 Specify memory for disk buffers. 1 1 1 1 1 configuraholic A luser who twiddles with computer settings until it no longer works and must be fixed by the system administror. (2007-03-20) 1 1 1 1 1 configuration item Hardware or software, or an aggregate of both, which is designated by the project configuration manager (or contracting agency) for configuration management. (1996-05-29) 1 1 1 1 1 configuration management A discipline applying technical and administrative controls to identifying, documentating and reporting on configuration items, their physical and functional characteristics and changes to characteristics of those configuration items. Change management is one aspect of configuration management but may also refer to the softer, human side of getting people to adapt to changing processes and organisation. Source code management or "code management" is configuration management applied to code through the various stages of the software life-cycle. (2014-01-21) 1 1 1 1 1 configuration programming An approach that advocates the use of a separate configuration language to specify the coarse-grain structure of programs. Configuration programming is particularly attractive for concurrent, parallel and distributed systems that have inherently complex program structures. Darwin is an example of a configuration language. (1995-03-14) 1 1 1 1 1 configure A program by Richard Stallman to discover properties of the current platform and to set up make to compile and install gcc. Cygnus configure was a similar system developed by K. Richard Pixley in collaboration with Richard Stallman. In 1994, David MacKenzie and others modified autoconf to incorporate all the features of Cygnus configure and many GNU programs, including gcc now use autoconf. Metaconfig is a similar program used in building Perl. (http://airs.com/ian/configure). (2005-04-15) 1 1 1 1 1 conflation Combining or blending of two or more versions of a text; confusion or mixing up. Conflation algorithms are used in databases. [Any specific technical meaning?] (1996-04-14) 1 1 1 1 1 congestion The condition that arises when the amount of data senders want to send down a communication path exceeds its capacity. Typically this will result in some packets being delayed, thus increasing the average latency. (2014-05-04) 1 1 1 1 1 CONIC A distributed system language and operating system developed at Imperial College to support dynamic configuration. Paper (http://spiral.imperial.ac.uk/bitstream/10044/1/452/1/Dynamic%20Configuration%20for%20Distributed.pdf). ["Dynamic Configuration for Distributed Systems", J. Kramer et al, IEEE Trans Soft Eng SE-11(4):424-436, Apr 1985]. (2014-05-04) 1 1 1 1 1 conjunction AND 1 1 1 1 1 Conjunctive Normal Form (CNF) A logical formula consisting of a conjunction of disjunctions of terms where no disjunction contains a conjunction. Such a formula might also be described as a product of sums. E.g. the CNF of (A and B) or C is (A or C) and (B or C). Contrast Disjunctive Normal Form. (1995-12-10) 1 1 1 1 1 connect Unix socket library routine to connect a socket that has been created on the local hosts to one at a specified socket address on the remote host. Unix manual pages: connect(2), accept(2). (1995-03-21) 1 1 1 1 1 connected graph A graph such that there is a path between any pair of nodes (via zero or more other nodes). Thus if we start from any node and visit all nodes connected to it by a single edge, then all nodes connected to any of them, and so on, then we will eventually have visited every node in the connected graph. (1996-09-22) 1 1 1 1 1 connected subgraph A connected graph consisting of a subset of the nodes and edges of some other graph. (1996-09-22) 1 1 1 1 1 Connection Definition Language (condela) A procedural, parallel language for defining neural networks. (ftp://tut.cis.ohio-state.edu/pub/condela). (1994-11-30) 1 1 1 1 1 connectionless protocol The data communication method in which communication occurs between hosts with no previous setup. Packets sent between two hosts may take different routes. UDP is a connectionless protocol. Also called packet switching. Contrast circuit switching, connection-oriented. (2014-05-04) 1 1 1 1 1 Connection Machine LISP Lisp with a parallel data structure, the 'xapping', an array of values assigned to an array of sites. [G.L. Steele et al, "Connection Machine LISP: Fine-Grained Parallel Symbolic Processing", in Proc 1986 ACM Conf on LISP and Functional Prog, Aug 1986, pp.279-297]. ["Connection Machine LISP Reference Manual", Thinking Machines Corp, Feb 1987]. (1995-02-28) 1 1 1 1 1 connection-oriented (Or connection-based, stream-oriented). A type of transport layer data communication service that allows a host to send data in a continuous stream to another host. The transport service will guarantee that all data will be delivered to the other end in the same order as sent and without duplication. Communication proceeds through three well-defined phases: connection establishment, data transfer, connection release. The most common example is Transmission Control Protocol (TCP), another is ATM. The network nodes at either end needs to inform all intermediate nodes about their service requirements and traffic parameters in order to establish communication. Opposite of connectionless, datagram. See also circuit switching, packet switching, virtual circuit. (2014-11-27) 1 1 1 1 1 connection-oriented network service (CONS) Because of the relatively long transit delays and inferior bit error rate of WANs, a more sophisticated connection-oriented protocol is normally used. (1997-11-08) 1 1 1 1 1 connective An operator used in first order logic to combine two logical formulas. (2014-05-04) 1 1 1 1 1 connector conspiracy The tendency of manufacturers (or, by extension, other designers) to come up with products that don't fit with the old stuff, thereby making you buy either all new stuff or expensive interface devices. The term probably came into prominence with the appearance of the DEC KL-10, none of whose connectors matched anything else. The KL-10 Massbus connector was actually *patented* by DEC, who reputedly refused to licence the design, thus effectively locking out competition for the lucrative Massbus peripherals market. This policy was a source of frustration for the owners of dying, obsolescent disk and tape drives. A related phenomenon is the invention of new screw heads so that only Designated Persons, possessing the magic screwdrivers, can remove covers and make repairs or install options. Older Apple Macintoshes took this one step further, requiring not only a hex wrench but a specialised case-cracking tool to open the box. 1 1 1 1 1 CONNIVER An artificial intelligence programming language for automatic theorem proving from MIT. CONNIVER grew out of PLANNER and was based on coroutines rather than backtracking. It allowed multiple database contexts with hypothetical assertions. ["The CONNIVER Reference Manual", D. McDermott & G.J. Sussman <gjs@zurich.ai.mit.edu>, AI Memo 259, MIT AI Lab, 1973]. (1995-01-10) 1 1 1 1 1 Co-NP complementary nondeterministic polynomial 1 1 1 1 1 CONS connection-oriented network service 1 1 1 1 1 cons The Lisp function that creates a cons cell. (2014-11-09) 1 1 1 1 1 cons cell /konz sel/ or /kons sel/ A Lisp pair object containing any two objects. In Lisp, "cons" (short for construct) is the fundamental operation for building structures such as lists and other binary trees. The application of cons to objects H and T is written (cons H T) and returns a pair object known as a "cons", "cons cell" or dotted pair. Typically, a cons would be stored in memory as a two consecutive pointers. The two objects in a cons, and the functions to extract them, are called "car" and "cdr" after two 15-bit fields of the machine code instruction format of the IBM 7090 that hosted the original LISP implementation. These fields were called the address and "decrement" parts so "car" stood for "Contents of Address part of Register" and "cdr" for "Contents of Decrement 1 1 1 1 1 conservative evaluation Under this parallel evaluation strategy, no evaluation is started unless it is known to be needed. The opposite of conservative evaluation is speculative evaluation. (2014-06-21) 1 1 1 1 1 considered harmful A type of phrase based on the title of Edsger W. Dijkstra's famous note in the March 1968 Communications of the ACM, "Goto Statement Considered Harmful", which fired the first salvo in the structured programming wars. Amusingly, the ACM considered the resulting acrimony sufficiently harmful that it will (by policy) no longer print articles taking so assertive a position against a coding practice. In the ensuing decades, a large number of both serious papers and parodies bore titles of the form "X considered Y". The structured-programming wars eventually blew over with the realisation that both sides were wrong, but use of such titles has remained as a persistent minor in-joke. [Jargon File] (2014-06-21) 1 1 1 1 1 consistently complete boundedly complete 1 1 1 1 1 console 1. <hardware, operating system, history> The operator's station of a mainframe as opposed to an ordinary user's terminal. In times past, the console was a privileged location that conveyed godlike powers to anyone with fingers on its keys. Under Unix and other modern time-sharing operating systems, such privileges are guarded by passwords instead, and the console is just the tty the system was booted from. On Unix the device is called /dev/console. On a microcomputer Unix box, the console is the main screen and keyboard. Other, character-only, terminals may be connected to serial ports. Typically only the console can do real graphics or run X. See also CTY. 2. <games> A self-contained microcomputer optimised for gaming, with powerful graphical output designed to be displayed on a television; equipped with one or more joystick controllers for input and an optical drive to load software. Later generations also feature Internet connection via wireless or wired 1 1 1 1 1 console jockey terminal junkie 1 1 1 1 1 consortium A group of two or more companies, educational institutions, governments or other bodies with some shared purpose. Examples from computing include the World Wide Web Consortium (W3C), Apache Software Foundation, The Open Group, X Consortium. (2009-06-05) 1 1 1 1 1 Consortium for Lexical Research (CLR) A repository for natural language processing software, lexical data, tools and resources; set up in July 1991 in the Computing Research Laboratory of New Mexico State University, Las Cruces, New Mexico, USA. CLR maintained a public FTP archive site and a separate members-only library. As of 1994-02-01, CLR had about 60 members, mostly academic institutions, including most US natural language processing centres. Materials could be contributed in exchange for membership. In 2006, the CRL closed down due to lack of funding. The CLR FTP server and e-mail address seems to have disappeared with it. [The Consortium for Lexical Research, Y. Wilks, Principal Investigator, Computing Research Laboratory, New Mexico State University (http://clair.eecs.umich.edu/aan/paper.php?paper_id=H92-1114)]. (2014-07-06) 1 1 1 1 1 constant angular velocity (CAV) One of the two schemes for controlling the rate of rotation of the disk in a disk drive. Constant angular velocity keeps the rate of rotation constant. This means that the linear velocity of the disk under the head is larger when reading or writing the outer tracks. This in turn implies either a variation in the data rate to and from the heads or the bits per unit length along the track. The alternative, constant linear velocity, requires the rate of rotation of the disk to accelerate and decelerate according to the radial postion of the heads, increasing the energy use and vibration. (2014-07-16) 1 1 1 1 1 constant applicative form (CAF) A supercombinator which is not a lambda abstraction. This includes truly constant expressions such as 12, (+ 1 2), [1, 2, 3] as well as partially applied functions such as (+ 4). Note that this last example is equivalent under eta abstraction to \ x . + 4 x which is not a CAF. Since a CAF is a supercombinator, it contains no free variables. Moreover, since it is not a lambda abstraction it contains no variables at all. It may however contain identifiers which refer to other CAFs, e.g. c 3 where c = (* 2). A CAF can always be lifted to the top level of the program. It can either be compiled to a piece of graph which will be shared by all uses or to some shared code which will overwrite itself with some graph the first time it is evaluated. A CAF such as 1 1 1 1 1 constant folding A compiler optimisation technique where constant subexpressions are evaluated at compile time. This is usually only applied to built-in numerical and boolean operators whereas partial evaluation is more general in that expressions involving user-defined functions may also be evaluated at compile time. (1997-02-20) 1 1 1 1 1 Constantine/Yourdon Yourdon/Constantine 1 1 1 1 1 constant linear velocity (CLV) A way of controlling the rotation of the disks in a disk drive in which the linear velocity of the disk surface relative to the read/write heads is kept constant. In order to achieve constant linear velocity, the disk must rotate faster (at a higher angular velocity) when reading or writing tracks closer to the centre. Having a constant linear read/write speed along the track means that the electrical signal to and from the heads has a constant data rate (bits per second), thus simplifying the timing of the drive electronics somewhat. However, rotating at less than the maximum possible rate sacrifices some potential performance compared to the alternative, constant angular velocity. Also, varying the rate causes more vibration and consumes more energy. (2014-07-27) 1 1 1 1 1 constant mapping A precursor to ARP used by some TCP software in which the destination Ethernet address is constructed from the top 24 bits of the source Ethernet address followed by the low 24 bits of the (class A) destination Internet address. For this scheme the top 24 bits of the Ethernet address must be the same on all hosts on the network. (2014-08-06) 1 1 1 1 1 constraint A Boolean relation, often an equality or ineqality relation, between the values of one or more mathematical variables. E.g. x>3 is a constraint on x. The process of constraint satisfaction attempts to assign values to variables so that all constraints are true. Usenet newsgroup: news:comp.constraints. FAQ (http://cs.unh.edu/ccc/archive/). (2002-06-08) 1 1 1 1 1 constraint functional programming (CFP) functional programming plus constraints. (2002-06-08) 1 1 1 1 1 Constraint Handling In Prolog (CHIP) A constraint logic programming language developed by M. Dincbas at ECRC, Munich, Germany in 1985 which includes Boolean unification and a symbolic simplex-like algorithm. CHIP introduced the domain-variable model. ["The Constraint Logic Programming Language CHIP", M. Dincbas et al, Proc 2nd Intl Conf on Fifth Generation Computer Sys, Tokyo (Nov 1988), pp.249-264]. ["Constraint Satisfaction in Logic Programming", Van Hentenryck. Available from COSYTEC, 4 rue Jean Rostand, F91893 Orsay, France]. (1994-11-15) 1 1 1 1 1 ConstraintLisp An object-oriented constraint language based on CSP. An extension of Common Lisp and CLOS. ["ConstraintLisp: An Object-Oriented Constraint Programming Language", Bing Liu (ex bing@iti.gov.sg) et al, SIGPLAN Notices 27(11):17-26, Nov 1992]. (2000-04-02) 1 1 1 1 1 Constraint Logic Programming (CLP) A programming framework based (like Prolog) on LUSH (or SLD) resolution, but in which unification has been replaced by a constraint solver. A CLP interpreter contains a Prolog-like inference engine and an incremental constraint solver. The engine sends constraints to the solver one at a time. If the new constraint is consistent with the collected constraints it will be added to the set. If it is inconsistent, it will cause the engine to backtrack. CLP* is a variant. ["Constraint Logic Programming", J. Jaffar et al, 14th POPL, ACM 1987]. (1994-11-01) 1 1 1 1 1 CONSTRAINTS A programming language for solving constraints using value inference. ["CONSTRAINTS: A Language for Expressing Almost-Hierarchical Descriptions", G.J. Sussman et al, Artif Intell 14(1):1-39, Aug 1980]. (1994-11-01) 1 1 1 1 1 constraint satisfaction The process of assigning values to variables while meeting certain requirements or "constraints". For example, in graph colouring, a node is a variable, the colour assigned to it is its value and a link between two nodes represents the constraint that those two nodes must not be assigned the same colour. In scheduling, constraints apply to such variables as the starting and ending times for tasks. The Simplex method is one well known technique for solving numerical constraints. The search difficulty of constraint satisfaction problems can be determined on average from knowledge of easily computed structural properties of the problems. In fact, hard instances of NP-complete problems are concentrated near an abrupt transition between under- and over-constrained problems. This transition is analogous to phase transitions in physical systems and offers a way to estimate the likely difficulty of a constraint problem before attempting to solve it with search. 1 1 1 1 1 constructed type A type formed by applying some type constructor function to one or more other types. The usual constructions are functions: t1 -> t2, products: (t1, t2), sums: t1 + t2 and lifting: lift(t1). (In LaTeX, the lifted type is written with a subscript \perp). See also algebraic data type, primitive type. (1995-02-03) 1 1 1 1 1 Constructive Cost Model (COCOMO) A method for estimating the cost of a software package, proposed by Dr Barry Boehm. The Basic COCOMO Model estimates the effort required to develop software in three modes of development (Organic Mode, Semidetached Mode, or Embedded Mode) using only DSIs as an input. The Basic model is good for quick estimates. The Intermediate Model extends the Basic Model with an Effort Adjustment Factor (EAF) and different coefficients for the effort equation. The user supplies settings for cost drivers that determine the effort and duration of the software projects. It also allows DSI values and cost drivers to be chosen for individual components instead of for the system as a whole. The Detailed COCOMO Model uses effort multipliers for each phase of the project and provides a three-level product hierarchy and has some other capabilities such as a procedure for adjusting the phase distribution of the development schedule. ["Software Engineering Economics", B. Boehm, Prentice-Hall, 1 1 1 1 1 constructive proof A proof that something exists that provides an example or a method for actually constructing it. For example, for any pair of finite real numbers n < 0 and p > 0, there exists a real number 0 < k < 1 such that f(k) = (1-k)*n + k*p = 0. A constructive proof would proceed by rearranging the above to derive an equation for k: k = 1/(1-n/p) From this and the constraints on n and p, we can show that 0 < k < 1 A few mathematicians actually reject *all* non-constructive arguments as invalid; this means, for instance, that the law of the excluded middle (either P or not-P must hold, whatever P is) has to go; this makes proof by contradiction invalid. See intuitionistic logic. 1 1 1 1 1 constructive solid geometry (CSG) A method used in solid modeling to describe the geometry of complex three-dimensional scenes by applying set operations (union, difference, intersection) to primitive shapes (cuboids, cylinders, prisms, pyramids, spheres and cones). See also CSG-tree. CSG in JavaScript (http://evanw.github.io/csg.js/). (2014-09-22) 1 1 1 1 1 constructor 1. In object-oriented languages, a function provided by a class to initialise a newly created object. The constructor function typically has the same name as the class. It may take arguments, e.g. to set various attributes of the object or it may just leave everything undefined to be set elsewhere. A class may also have a destructor function that is called when objects of the class are destroyed. 2. In functional programming and type theory, one of the symbols used to create an object with an algebraic data type. (2014-10-04) 1 1 1 1 1 Consul A constraint-based declarative language based on axiomatic set theory and designed for parallel execution on MIMD architectures. Consul's fundamental data type is the set and its fundamental operators are the logical connectives ("and", "or", "not") and quantifiers ("forall", exists). It is written in Lisp-like syntax, e.g., (plus x y z) which means the relation x = y+z (not an assignment statement). ["Design of the CONSUL Programming Language", D. Baldwin, C. A. Quiroz Gonzalez, University of Rochester. Computer Science Department, TR208, 1987 Feb (http://hdl.handle.net/1802/6372)] ["Consul: A Parallel Constraint Language", D. Baldwin, IEEE Software 6(4):62-71, 1989 July (http://dx.doi.org/10.1109/52.31653)] (2014-10-04) 1 1 1 1 1 consultant A person who facilitates organisational change and/or provides subject matter expertise on technical, functional and business topics during development or implementation. Consultants perform business requirements analysis, recommend selection of packaged software, develop proposals for consulting services and manage implementation projects at client sites. They provides expert knowledge of products such as SAP R/3, PeopleSoft, HRMS/Financials and SmartStream. (2004-03-09) 1 1 1 1 1 container class A class whose instances are collections of other objects. Examples include arrays, lists, queues and stacks. A container class typically provides methods such as count, insert, delete and search. (2014-10-15) 1 1 1 1 1 content addressable memory (CAM, or "associative memory") A kind of storage device which includes comparison logic with each bit of storage. A data value is broadcast to all words of storage and compared with the values there. Words which match are flagged in some way. Subsequent operations can then work on flagged words, e.g. read them out one at a time or write to certain bit positions in all of them. A CAM can thus operate as a data parallel (SIMD) processor. CAMs are often used in caches and memory management units. (1995-02-16) 1 1 1 1 1 content-based information retrieval (CBIR) A general term for methods for using information stored in image archives. [Details?] [IEEE Computer, September 1995]. (1995-11-23) 1 1 1 1 1 Content Data Model (CDM) An SGML-based specification for interactive maintenance manuals, developed by the Air Force Human Resourceas Laboratory (AFHRL) with assistance from RJO Enterprises, Incorporated. CDM models data hierachically and data are identified by their content structure with SGML mark-up used to identify information classes such as "system information", "functions", "tasks" and "steps". (http://www.dtic.mil/dtic/tr/fulltext/u2/a205916.pdf). ["Final Report - Content Data Model of Organizational Maintenance Information for Automated Interchange of Technical Source Data.", Chicago, Illinois, Datalogics, Inc., 1998-07-07]. (2014-10-20) 1 1 1 1 1 content-free 1. (By analogy with "context-free") Used of a message that adds nothing to the recipient's knowledge. Though this adjective is sometimes applied to flamage, it more usually connotes derision for communication styles that exalt form over substance or are centred on concerns irrelevant to the subject ostensibly at hand. Perhaps most used with reference to speeches by company presidents and other professional manipulators. See also four-colour glossies. <education> 2. Within British schools the term refers to general-purpose software such as a word processor, a spreadsheet or a program that tests spelling of words supplied by the teacher. This is in contrast to software designed to teach a particular topic, e.g. a plant growth simulation, an interactive periodic table or a program that tests spelling of a predetermined list of words. Content-free software can be more cost-effective as it can be reused for many lessons throughout the syllabus. [Jargon File] 1 1 1 1 1 contention slot In a communication system where only one node at a time may transmit successfully on a shared channel, the contention slot or contention period is the time a node must wait before it can be sure that no other node's transmission has collided (collision) with its transmission. If node A starts to transmit at time t0 and then another node starts to transmit just before it recieves A's transmission at time t0 + T, then the transmissions will collide but node A will not detect the collision until time t0 + 2T. The contention slot, 2T, for nodes seperated by the maximum propagation delay thus determines how much data the node must be prepared to re-transmit in the event of a collision. (2014-11-06) 1 1 1 1 1 Contents of Address part of Register (car) /kar/ The left-hand element of a Lisp cons cell. (2014-11-09) 1 1 1 1 1 Contents of Decrement part of Register (cdr) /ku'dr/ or /kuh'dr/ The right-hand element of a Lisp cons cell. (2014-11-09) 1 1 1 1 1 context In a grammar, context refers to the symbols before and after the symbol under consideration. If the syntax of a symbol is independent of its context, the grammar is a context-free grammar. (2014-11-24) 1 1 1 1 1 context clash When a parser cannot tell which alternative production of a syntax applies by looking at the next input token ("lexeme"). For example, given syntax C -> A | b c A -> d | b e If you're parsing non-terminal C and the next token is 'b', you don't know whether it's the first or second alternative of C since they both can start with b. If a grammar can generate the same sentence in multiple different ways (with different parse tress) then it is ambiguous. An ambiguity must start with a context clash (but not all context clashes imply ambiguity). To see if a context clash is also a case of ambiguity you would need to follow the alternatives involved in each context clash to see if they can generate the same complete sequence of tokens. 1 1 1 1 1 COntext Dependent Information Language (CODIL) An early language for non-numerical business problems. ["CODIL, Part1. The Importance of Flexibility", C.F. Reynolds et al, Computer J 14(3):217-220, May 1971]. (1994-12-23) 1 1 1 1 1 context-free grammar (CFG) A grammar where the syntax of each constituent (syntactic category or terminal symbol) is independent of the symbols occuring before and after it in a sentence. A context-free grammar describes a context-free language. Context-free grammars can be expressed by a set of "production rules" or syntactic rules. For example, a language with symbols a and "b" that must occur in unequal numbers can be represented by the CFG: S → U | V U → TaU | TaT | UaT V → TbV | TbT | VbT T → aTbT | bTaT | ε meaning the top-level category "S" consists of either a "U" or a V and so on. The special category "ε" represents the empty string. This grammar is context-free because each rule has a single symbol on its left-hand side. Parsers for context-free grammars are simpler than those for 1 1 1 1 1 context-sensitive menu A menu which appears in response to a user action (typically a mouse click) and whose contents are determined by which application window was clicked or has the input focus. Most GUIs use a secondary mouse button (right or middle) to call up a context-sensitive menu as the primary mouse button is normally used to interact with objects which are already visible. The context-sensitive menu often contains functions that are also available in a menu bar but the context-sensitive menu provides quick access to a subset of functions that are particularly relevant to the window area clicked on. The RISC OS WIMP uses only context-sensitive menus (always invoked using the middle mouse button). This saves screen space and reduces mouse movement compared to a menu bar. (1999-09-22) 1 1 1 1 1 context switch When a multitasking operating system stops running one process and starts running another. Many operating systems implement concurrency by maintaining separate environments or "contexts" for each process. The amount of separation between processes, and the amount of information in a context, depends on the operating system but generally the OS should prevent processes interfering with each other, e.g. by modifying each other's memory. A context switch can be as simple as changing the value of the program counter and stack pointer or it might involve resetting the MMU to make a different set of memory pages available. In order to present the user with an impression of parallism, and to allow processes to respond quickly to external events, many systems will context switch tens or hundreds of times per second. (1996-12-18) 1 1 1 1 1 Contextually Communicating Sequential Processes (CCSP) A notation based on CSP. ["Contextually Communicating Sequential Processes - A Software Engineering Approach", M. Hull et al, Software Prac & Exp 16(9):845-864, Sept 1986]. (1994-11-01) 1 1 1 1 1 continental drift Very, very slow. In 1980 David Turner remarked that KRC ran "at the speed of the continental drift". (1994-12-06) 1 1 1 1 1 continuation continuation passing style 1 1 1 1 1 Continuation Passing Style (CPS) An intermediate language for Scheme that implements continuation passing style. The CPS language is semantically clean and is used for the SML/NJ compiler. ["Rabbit: A Compiler for Scheme", G.L. Steele, AI-TR-474, MIT (May 1978)]. ["Compiling With Continuations", A. Appel, Cambridge U Press 1992]. (2014-09-24) 1 1 1 1 1 continuation passing style (CPS) A style of programming in which every user function f takes an extra argument c known as a "continuation". Whenever f would normally return a result r to its caller, it instead returns the result of applying the continuation to r. The continuation thus represents the whole of the rest of the computation. Some examples: normal (direct style) continuation passing style square x = x * x square x k = k (x * x) g (square 23) 1 1 1 1 1 continuations continuation passing style 1 1 1 1 1 continuous function A function f : D -> E, where D and E are cpos, is continuous if it is monotonic and f (lub Z) = lub f z | z in Z for all directed sets Z in D. In other words, the image of the lub is the lub of any directed image. All additive functions (functions which preserve all lubs) are continuous. A continuous function has a least fixed point if its domain has a least element, bottom (i.e. it is a cpo or a "pointed cpo" depending on your definition of a cpo). The least fixed point is fix f = lub f^n bottom | n = 0..infinity (1994-11-30) 1 1 1 1 1 Continuous System Modeling Program (CSMP) A program for simulation of dynamics of continuous systems. CSMP is similar to CSSL. ["A Guide to Using CSMP - The Continuous System Modeling Program", Frank H. Speckhart et al, P-H 1976]. (1995-02-23) 1 1 1 1 1 Continuous System Simulation Language (CSSL) Versions include ACSL, HYTRAN, SL-I, S/360 and CSMP. CSSL(Continuous System Simulation Language) versions I, II, III, IV and V have been commercially available since 1968. CSSL-I was developed for Jet Propulsion Labs in 1968. CSSL-III was widely distributed from 1969-1975. CSSL-IV (interactive version) was developed by R. Nilsen and ran on over 30 different computers. Currently CSSL-V is marketed by Simulation Services International and available on PCs and workstations. ["The SCi Continuous System Simulation Language (CSSL)", Simulation, 9(6), Dec 1967]. (2003-04-15) 1 1 1 1 1 continuous wave (CW) A term from early radio history for a transmitter using an electron tube (valve) oscillator to constantly add energy to a tuned circuit connected to an antenna. The term is used in contrast with the use of a spark gap to initiate a damped sinusoidal wave in a tuned circuit consisting of an inductor and capacitor. The energy in this circuit constantly changes between the capacitor's electrostatic field and the inductor's magnetic field. The energy is then coupled to the radiating antenna, loosely (so as not to dampen the wave too quickly). Some radio amateurs understand "CW" to mean transmission by means a single frequency signal which is either on or off (e.g. Morse code), as opposed to a carrier which varies continuously in amplitude, frequency or phase. Some would even call the former "unmodulated" even though turning on and off is actually the most extreme form of amplitude modulation. 1 1 1 1 1 contraction reduction 1 1 1 1 1 contract programmer A programmer who works on a fixed-length or temporary contract, and is often employed to write certain types of code or to work on a specific project. Despite the fact that contractors usually cost more than hiring a permanent employee with the same skills, it is common for organisations to employ them for extended periods, sometimes renewing their contracts for many years, due to lack of certainty about the future or simple lack of planning. A contract programmer may be independent or they may work in a supplier's professional services department, providing consultancy and programming services for the supplier's products. (2015-03-07) 1 1 1 1 1 control 1. <character, hardware> A control key on a keyboard used to input control characters. 2. <programming, operating system, graphics> A component in a graphical user interface, e.g. an Active-X control. 1 1 1 1 1 Control and Status Register (CSR) A register in most CPUs which stores additional information about the results of machine instructions, e.g. comparisons. It usually consists of several independent flags such as carry, overflow and zero. The CSR is chiefly used to determine the outcome of conditional branch instructions or other forms of conditional execution. (1998-06-26) 1 1 1 1 1 control bus In a digital computer, the signal paths that carry commands from the instruction decode logic to various different functional units such as the ALU, memory address register, memory data register and other buffers. Named by analogy with the address bus and data bus, each of which carries a set of related signals, the signals carried by the control bus are more independent. Some might include other signals such as timing (clock) and status under the term, further reducing its similarity to other busses. (2007-07-25) 1 1 1 1 1 control-C (Or ETX, End of Text) The ASCII character with code 3. Control-C is the interrupt character used on many operating systems, including Unix and MS-DOS to abort a running program. Among BSD Unix hackers, the canonical humorous response to "Give me a break!" is "Control C". [Jargon File] (1995-03-16) 1 1 1 1 1 control character Any of a number of special characters that exist in most coded character sets and that are input or output to cause some special action rather than as part of the normal textual data. Control characters are input by holding down a control key on the keyboard and simultaneously pressing a letter key or (depending on the keyboard and operating system) certain punctuation characters. Some control codes have their own special keys: escape, tab, delete, backspace, return, allowing them to be entered with a single key press. Control characters may be output for their effect on the output device, e.g. moving the cursor or print head to the start of a new line (carriage return, Control-M), advancing down to the next line (line feed, Control-J) or ringing the bell (Control-G). Different operating systems and application programs have different conventions for what effect typing certain control 1 1 1 1 1 control code A character code for a control character, normally including the values 0..31 or 127, inherited from ASCII, possibly extended to include other characters by the operating system or application program. 1 1 1 1 1 control flow (Or "flow of control") The sequence of execution of instructions in a program. This is determined at run time by the input data and by the control structures (e.g. "if" statements) used in the program. Not to be confused with "flow control". (1997-09-14) 1 1 1 1 1 control-G bell 1 1 1 1 1 control key A modifier key found on modern keyboards. Holding down a control key while pressing and releasing letter keys or certain other keys generates a "control character". E.g. holding control and hitting "A" generates control-A (ASCII code 1). The ASCII code for the control character is generally 64 less than that for the unmodified character. Standard PC keyboards have two control keys, both labeled Ctrl, at the bottom left and bottom right of the main block of keys. The control key does not generate any character on its own but most modern keyboards and operating systems allow a program to tell whether each of the individual keys on the keyboard (including modifier keys) is pressed at any time. (2015-03-07) 1 1 1 1 1 Control Language (CL) The batch language for IBM RPG/38, used in conjunction with RPG III. See also OCL. (2000-04-08) 1 1 1 1 1 controller Part of a computer, typically a separate circuit board, which allows the computer to use certain kinds of peripheral devices. A disk controller is used to connect hard disks and floppy disks, a network controller is used for Ethernet. Other controllers are: keyboard controller, interrupt controller and graphics controller. (1998-03-16) 1 1 1 1 1 control-O ASCII character 15 (SI). The character used on some operating systems to abort output but allow the program to keep on running. The name "SI" comes from its use on some terminals to "shift in" an alternative character set. "SO" is Control-N. Compare control-S. [Jargon File] (1995-03-16) 1 1 1 1 1 Control Program (CP) The component of IBM's Virtual Machine (VM) that provides "guest support" for operating systems that run on IBM mainframe compatible processors. Cp does this by providing a seamless emulation of privileged functions in the problem program environment. (1999-01-19) 1 1 1 1 1 Control Program for Microcomputers (CP/M) An early microcomputer operating system written by Gary Kildall of Digital Research for 8080 and Zilog Z80-based 8-bit computers. CP/M was very popular in the late 1970s but was virtually wiped out by MS-DOS after the release of the IBM PC in 1981. Many of CP/M's features and conventions strongly resemble those of early DEC operating systems such as TOPS-10, OS/8, RSTS and RSX-11. CP/M might have been the OS for the IBM PC instead of MS-DOS but Kildall wanted to keep control of his creation and only license it to IBM. Big Blue however wanted to own and control it completely. Kildall spent the day IBM's reps wanted to meet him enjoying the perfect flying weather in his private plane. [Did CP/M use the same FAT file system as MS-DOS?] (1996-01-07) 1 1 1 1 1 control-Q (Or XON, DC1, Device Control 1) The character with ASCII code 17, used in software handshaking to resume output after a previous control-S. [Jargon File] (1996-06-28) 1 1 1 1 1 control-S (Or XOFF, DC3, Device Control 3) The character with ASCII code 19, used in software handshaking to temporarily suspend output until a control-Q is received. [Jargon File] (1996-06-28) 1 1 1 1 1 control structure One of the instructions, statements or groups of statements in a programming language which determines the sequence of execution of other instructions or statements (the control flow). In assembly language this typically consists of jumps and conditional jumps along with procedure call and return though some architectures include other constructs such as an instruction which skips the following instruction depending on some condition (PDP?), various kinds of loop instructions (later Motorola 680x0) or conditional execution of all instructions (Advanced RISC Machine). Basic control structures (whatever their names in particular languages) include "if CONDITION then EXPRESSION else EXPRESSION", the switch statement, "while CONDITION do EXPRESSION", "gosub", the suspect "goto" and the much-feared come from. Other constructs handle errors and exceptions such as traps and interrupts. 1 1 1 1 1 control tty (/dev/ptyp*) The network side of a pseudo-tty. 1 1 1 1 1 control unit 1. <processor> The part of a CPU that sends control signals to other components to cause them to execute the machine cycle - fetch, decode, execute, store. 2. <architecture> Any device that controls the I/O operations of one or more peripheral devices, e.g. a disk controller. (2008-05-21) 1 1 1 1 1 conventional memory The first 640 kilobytes of an IBM PC's memory. Prior to EMS, XMS, and HMA, real mode application could use only this part of the memory. (1996-01-10) 1 1 1 1 1 converged network A single network that can carry voice, video and data. (2007-06-07) 1 1 1 1 1 Convergent Technologies A company formed by a small group of people who left Intel Corporation in 1979. Convergent Technologies' first product was the IWS (Integrated Workstation) based on the Intel 8086, which ran Convergent Technologies Operating System - their first operating system. Unisys bought Convergent Technologies in 1988. [Who bought/merged with who and when?] (1998-04-03) 1 1 1 1 1 Convergent Technologies Operating System (CTOS, BTOS, STARSYS) /see-toss/ A modular, message-passing, multi-process based operating system. Convergent Technologies' first product was the IWS (Integrated Workstation) based on the Intel 8086, which had CTOS as its operating system. It is a modular operating system with built in local area networking. CTOS supports multiple processes or threads, and message-based inter-process communication. Companies which have licensed CTOS include Burroughs (BTOS) and Bull (STARSYS). The largest customer was Unisys, with whom Convergent Technologies merged to become one company in 1988. CTOS now has over 800,000 users worldwide. CTOS runs on Intel Pentium computers, and can run concurrently with Microsoft Windows NT. For some reason, CTOS is no longer marketted to new customers, although there is a support comittment for existing customers until 2001. Major customers include Police Forces, Banks, and 1 1 1 1 1 Conversational LISP (CLISP) A mixed English-like, ALGOL-like surface syntax for Interlisp. ["CLISP: Conversational LISP", W. Teitelman, in Proc Third Intl Joint Conf on AI, Stanford, Aug 1973, pp.686-690]. (1994-11-01) 1 1 1 1 1 Conversational Monitor System Virtual Machine/Conversational Monitor System 1 1 1 1 1 converse The truth of a proposition of the form A => B and its converse B => A are shown in the following truth table: A B | A => B B => A ------+---------------- f f | t t f t | t f t f | f 1 1 1 1 1 conversion to iteration A transformation applied to functional programs to replace recursion with iteration. A tail-recursive function can be compiled to an iterative loop where the recursive call becomes a jump back to the start and the parameters are held in registers which are updated with new values each time around the loop. See Iteration, Tail recursion optimisation. 1 1 1 1 1 CONVERT 1. (Or "REC", "Regular Expression Converter") A string processing language that combined the pattern matching and transformation operations of COMIT with the recursive data structures of Lisp. ["Convert", A. Guzman et al, CACM 9(8):604-615, Aug 1966]. 2. An early language to convert programs and data from one language to another. ["CONVERT Manual", OLI Systems Inc, Oct 1976]. (2007-02-05) 1 1 1 1 1 convert.f90 A Fortran77 to Fortran90 translator by Michael Metcalf <metcalf@cernvm.cern.ch>. The significant differences between the two Fortrans make this package useful. (ftp://jkr.cc.rl.ac.uk/pub/MandR/convert.f90). (1993-07-17) 1 1 1 1 1 Convex Computer Corporation A mini-super-computer manufacturer. Address: Richardson, Texas, USA. (1995-03-01) 1 1 1 1 1 convex hull For a set S in space, the smallest convex set containing S. In the plane, the convex hull can be visualized as the shape assumed by a rubber band that has been stretched around the set S and released to conform as closely as possible to S. (1997-08-03) 1 1 1 1 1 Conway, John Horton John Horton Conway 1 1 1 1 1 Conway's Law The rule (presumably formulated by Melvin Conway) that the organisation of software and the organisation of the software team will be congruent; originally stated as "If you have four groups working on a compiler, you'll get a 4-pass compiler". [Jargon File] (2015-12-30) 1 1 1 1 1 Conway's Game of Life The first popular cellular automata based artificial life simulation. Life was invented by British mathematician John Horton Conway in 1970 and was first introduced publicly in "Scientific American" later that year. Conway first devised what he called "The Game of Life" and ran it using plates placed on floor tiles in his house. Because of he ran out of floor space and kept stepping on the plates, he later moved to doing it on paper or on a checkerboard and then moved to running Life as a computer program on a PDP-7. That first implementation of Life as a computer program was written by M. J. T. Guy and S. R. Bourne (the author of Unix's Bourne shell). Life uses a rectangular grid of binary (live or dead) cells each of which is updated at each step according to the previous state of its eight neighbours as follows: a live cell with less than two, or more than three, live neighbours dies. A dead cell with exactly three neighbours becomes alive. 1 1 1 1 1 Conway's Life Conway's Game of Life 1 1 1 1 1 cooC Concurrent Object-Oriented C. 1 1 1 1 1 cooccurrence matrix Given a position operator P(i,j), let A be a nxn matrix whose element A[i][j] is the number of times that points with grey level (intensity) g[i] occur, in the position specified by P, relative to points with grey level g[j]. Let C be the nxn matrix that is produced by dividing A with the total number of point pairs that satisfy P. C[i][j] is a measure of the joint probability that a pair of points satisfying P will have values g[i], g[j]. C is called a cooccurrence matrix defined by P. Examples for the operator P are: "i above j", "i one position to the right and two below j", etc. (1995-05-11) 1 1 1 1 1 cookbook (From amateur electronics and radio) A book of small code segments that the reader can use to do various magic things in programs. One current example is the "PostScript Language Tutorial and Cookbook" by Adobe Systems, Inc (Addison-Wesley, ISBN 0-201-10179-3), also known as the Blue Book which has recipes for things like wrapping text around arbitrary curves and making 3D fonts. Cookbooks, slavishly followed, can lead one into voodoo programming, but are useful for hackers trying to monkey up small programs in unknown languages. This function is analogous to the role of phrasebooks in human languages. [Jargon File] (1994-11-04) 1 1 1 1 1 cooked mode The normalUnix character-input mode, with interrupts enabled and with erase, kill and other special-character interpretations performed directly by the tty driver. Opposite of raw mode. See also rare mode. Other operating systems often have similar mode distinctions, and the raw/rare/cooked way of describing them has spread widely along with the C language and other Unix exports. Most generally, "cooked mode" may refer to any mode of a system that does extensive preprocessing before presenting data to a program. [Jargon File] 1 1 1 1 1 cookie 1. <web> HTTP cookie. 2. <protocol> A handle, transaction ID, or other token of agreement between cooperating programs. "I give him a packet, he gives me back a cookie". The ticket you get from a dry-cleaning shop is an example of a cookie; the only thing it's useful for is to relate a later transaction to this one (so you get the same clothes back). Compare magic cookie; see also fortune cookie. 3. <security, jargon> A cracker term for the password list on a multi-user computer. 4. <jargon> An adjective describing a computer that just became toast. (1997-04-14) 1 1 1 1 1 cookie bear cookie monster 1 1 1 1 1 cookie file A collection of fortune cookies in a format that facilitates retrieval by a fortune program. There are many cookie files in public distribution, and site admins often assemble their own from various sources. [Jargon File] (1997-01-07) 1 1 1 1 1 cookie jar 1. <programming> An area of memory set aside for storing cookies. Most commonly heard in the Atari ST community; many useful ST programs record their presence by storing a distinctive magic number in the jar. Programs can inquire after the presence or otherwise of other programs by searching the contents of the jar. 2. <security> A cracker term for the password file of a multi-user computer. [Jargon File] (1997-02-12) 1 1 1 1 1 cookie monster (From the children's TV program "Sesame Street") Any of a family of early (1970s) hacks reported on TOPS-10, ITS, Multics and elsewhere that would lock up either the victim's terminal (on a time-sharing machine) or the console (on a batch mainframe), repeatedly demanding "I WANT A COOKIE". The required responses ranged in complexity from "COOKIE" through "HAVE A COOKIE" and upward. See also wabbit. [Jargon File] (1997-02-12) 1 1 1 1 1 cooky cookie 1 1 1 1 1 COOL 1. Concurrent Object-Oriented Language. 2. CLIPS Object-Oriented Language? 3. A C++ class library developed at Texas Instruments that defines containers like Vectors, List, Hash_Table, etc. It uses a shallow hierarchy with no common base class. The functionality is close to Common Lisp data structures (like libg++). The template syntax is very close to Cfront 3.x and g++ 2.x. JCOOL's main difference from COOL and GECOOL is that it uses real C++ templates instead of a similar syntax that is preprocessed by a special 'cpp' distributed with COOL and GECOOL. (ftp://csc.ti.com/pub/COOL.tar.Z). GECOOL, JCOOL: (ftp://cs.utexas.edu/pub/COOL/). E-mail: Van-Duc Nguyen <nguyen@crd.ge.com> (1992-08-05) 1 1 1 1 1 CooL Combined object-oriented Language. An object-oriented language from the ITHACA Esprit project, which combines C-based languages with database technology. (1995-03-15) 1 1 1 1 1 COOL:Gen Advantage Gen 1 1 1 1 1 Co-operative Development Environment (CDE) A set of tools from Oracle for enterprise-wide, client/server application development. (1995-03-15) 1 1 1 1 1 Cooperative Information System (CIS) Networked computers which support individual or collaborative human work, and manage access to information and computing services. Computation is done concurrently over the network by cooperative database systems, expert systems, multi-agent planning systems, and other software application systems ranging from the conventional to the advanced. (1995-05-11) 1 1 1 1 1 cooperative multitasking A form of multitasking where it is the responsibility of the currently running task to give up the processor to allow other tasks to run. This contrasts with pre-emptive multitasking where the task scheduler periodically suspends the running task and restarts another. Cooperative multitasking requires the programmer to place calls at suitable points in his code to allow his task to be descheduled which is not always easy if there is no obvious top-level main loop or some routines run for a long time. If a task does not allow itself to be descheduled all other tasks on the system will appear to "freeze" and will not respond to user action. The advantage of cooperative multitasking is that the programmer knows where the program will be descheduled and can make sure that this will not cause unwanted interaction with other processes. Under pre-emptive multitasking, the scheduler must ensure that sufficient state for each process 1 1 1 1 1 coordinate One member of a tuple of numbers which defines the position of a point in some space. Commonly used coordinate systems have as many coordinates as their are dimensions in the space, e.g. a pair for two dimensions. The most common coordinate system is Cartesian coordinates, probably followed by polar coordinates. (1997-07-09) 1 1 1 1 1 Coordinated Universal Time (UTC, World Time) The standard time common to every place in the world. UTC is derived from International Atomic Time (TAI) by the addition of a whole number of "leap seconds" to synchronise it with Universal Time 1 (UT1), thus allowing for the eccentricity of the Earth's orbit, the rotational axis tilt (23.5 degrees), but still showing the Earth's irregular rotation, on which UT1 is based. Coordinated Universal Time is expressed using a 24-hour clock and uses the Gregorian calendar. It is used in aeroplane and ship navigation, where it also sometimes known by the military name, "Zulu time". "Zulu" in the phonetic alphabet stands for "Z" which stands for longitude zero. UTC was defined by the International Radio Consultative Committee (CCIR), a predecessor of the ITU-T. CCIR Recommendation 460-4, or ITU-T Recommendation X.680 (7/94), contains the full definition. The language-independent international abbreviation, UTC, is 1 1 1 1 1 Coordinating Committee for Intercontinental Research Networks (CCIRN) A committee that includes the United States FNC and its counterparts in North America and Europe. Co-chaired by the executive directors of the Federal Networking Council and the European Association of Research Networks (RARE), the CCIRN provides a forum for cooperative planning among the principal North American and European research networking bodies. (1994-11-30) 1 1 1 1 1 coordination language A language defined specifically to allow two or more parties (components) to communicate in order to accomplish some shared goal. Examples of coordination languages are Linda and Xerox's CLF (STITCH). (2004-04-18) 1 1 1 1 1 copious free time (Apple; originally from the introduction to Tom Lehrer's song "It Makes A Fellow Proud To Be A Soldier") Used ironically to indicate the speaker's lack of the quantity in question; a mythical schedule slot for accomplishing tasks held to be unlikely or impossible. Sometimes used to indicate that the speaker is interested in accomplishing the task, but believes that the opportunity will not arise. "I'll implement the automatic layout stuff in my copious free time." The phrase is also used for time reserved for bogus or otherwise idiotic tasks, such as implementation of bad chrome, or the stroking of suits. "I'll get back to him on that feature in my copious free time." [Jargon File] (1994-11-30) 1 1 1 1 1 copper Conventional electrical network cable with a core conductor of copper (or aluminium!) Opposed to light pipe or, say, a short-range microwave link. [Jargon File] (1994-11-30) 1 1 1 1 1 Copper Distributed Data Interface (CDDI) FDDI running over conventional copper cables. A Cisco/Crescendo copyright term(?). All FDDI connections, single-attached or dual-attached, can be either optical fibre or copper. (1994-12-14) 1 1 1 1 1 coprocessor Any computer processor which assists the main processor (the CPU) by performing certain special functions, usually much faster than the main processor could perform them in software. The coprocessor often decodes instructions in parallel with the main processor and executes only those instructions intended for it. The most common example is a floating point coprocessor (or FPU), others are graphics and networking. (1995-01-05) 1 1 1 1 1 copy and paste (Or "cut and paste", after the paper, scissors and glue method of document production) The system supported by most document editing applications (e.g. text editors) and most operating systems that allows you to select a part of the document and then save it in a temporary buffer (known variously as the "clipboard", "cut buffer", "kill ring"). A copy leaves the document unchanged whereas a "cut" deletes the selected part. A "paste" inserts the data from the clipboard at the current position in the document (usually replacing any currently selected data). This may be done more than once, in more than one position and in different documents. More sophisticated operating systems support copy and paste of different data types between different applications, possibly with automatic format conversion, e.g from rich text to plain ASCII. GNU Emacs uses the terms "kill" instead of "cut" and "yank" 1 1 1 1 1 copybook (Or "copy member", "copy module") A common piece of source code designed to be copied into many source programs, used mainly in IBM DOS mainframe programming. In mainframe DOS (DOS/VS, DOS/VSE, etc.), the copybook was stored as a "book" in a source library. A library was comprised of "books", prefixed with a letter designating the language, e.g., A.name for Assembler, C.name for Cobol, etc., because DOS didn't support multiple libraries, private libraries, or anything. This term is commonly used by COBOL programmers but is supported by most mainframe languages. The IBM OS series did not use the term "copybook", instead it referred to such files as "libraries" implemented as partitioned data sets or PDS. Copybooks are functionally equivalent to C and C++ include files. (1997-07-31) 1 1 1 1 1 copybroke /kop'ee-brohk/ (Or "copywronged" - a play on copyright) 1. Used to describe an instance of a copy-protected program that has been "broken"; that is, a copy with the copy-protection scheme disabled or removed. 2. Copy-protected software which is unusable because of some bit-rot or bug that has confused the copy protection. 3. Used to describe data damaged because of a side effect of a copy protection system. [Jargon File] (1997-03-16) 1 1 1 1 1 copying garbage collection A garbage collection method where memory is divided into two equal halves, known as the "from space" and "to space". Garbage collection copies active cells from the from space to the to space and leaves behind an invisible pointer (an indirection) from the old position to the new copy. Once all active cells have been copied in one direction, the spaces are swapped and the process repeated in the opposite direction. 1 1 1 1 1 copyleft /kop'ee-left/ (A play on "copyright") The copyright notice and General Public License applying to the works of the Free Software Foundation, granting reuse and reproduction rights to everyone. Typically copyrights take away freedoms; copyleft preserves them. It is a legal instrument that requires those who pass on a program to include the rights to use, modify, and redistribute the code; the code and the freedoms become legally inseparable. The copyleft used by the GNU Project combines a regular copyright notice and the "GNU General Public License" (GPL). The GPL is a copying license which basically says that you have the aforementioned freedoms. The license is included in each GNU source code distribution and manual. See also General Public Virus. [Jargon File] (1995-04-18) 1 1 1 1 1 copy member copybook 1 1 1 1 1 copy module copybook 1 1 1 1 1 copy protection Any technique designed to prevent unauthorised copying of software. Such techniques will only hinder the most incompetant attempts at software theft but often prevent legitimate customers from using products they have paid for in the way they want. Considered silly. [Jargon File] (2010-02-03) 1 1 1 1 1 copyright The exclusive rights of the owner of the copyright on a work to make and distribute copies, prepare derivative works, and perform and display the work in public (these last two mainly apply to plays, films, dances and the like, but could also apply to software). A work, including a piece of software, is under copyright by default in most coutries, whether of not it displays a copyright notice. However, a copyright notice may make it easier to assert ownership. The copyright owner is the person or company whose name appears in the copyright notice on the box, or the disk or the screen or wherever. Most countries have agreed to uphold each others' copyrights. A copyright notice has three parts. The first can be either the copyright symbol (a letter C in a circle), the word "Copyright" or the abbreviation "Copr". Only the first of these is recognised internationally and the common ASCII rendering "(C)" is not valid anywhere. This is followed by the name of the copyright 1 1 1 1 1 copyright symbol "&copy;" The internationally recognised symbol required to introduce a copyright notice, a letter C with a circle around it. This can be encoded in ISO 8859-1 as character code decimal 169, hexadecimal A9, in HTML as &amp;copy;, &amp;#169; or &amp;#xA9;. A "c" in parentheses: "(c)" is sometimes used in documents stored in a coded character set such as ASCII that does not include the C in a circle, but this has no legal meaning. (2009-01-06) 1 1 1 1 1 copywronged copybroke 1 1 1 1 1 CORAL 1. Class Oriented Ring Associated Language. 2. A deductive database and logic programming system based on Horn-clause rules with extensions like SQL's group-by and aggregation operators. CORAL was developed at the University of Wisconsin-Madison. It is implemented in C++ and has a Prolog-like syntax. Many evaluation techniques are supported, including bottom-up fixpoint evaluation and top-down backtracking. Modules are separately compiled; different evaluation methods can be used in different modules within a single program. Disk-resident data is supported via an interface to the Exodus storage manager. There is an on-line help facility. It requires AT&T C++ 2.0 (or G++ soon) and runs on Decstation and Sun-4. (ftp://ftp.cs.wisc.edu/). (1993-01-29) 1 1 1 1 1 CORAL 66 A real-time system programming language derived from JOVIAL and ALGOL 60. It was adopted as the British military standard from 1970 until the arrival of Ada. ["Official Definition of CORAL 66", P.M. Woodward et al, HMSO, London, 1970]. 1 1 1 1 1 CORBA Common Object Request Broker Architecture 1 1 1 1 1 CORBIE An early system on the IBM 704. [Listed in CACM 2(5):16, May 1959]. (1996-05-10) 1 1 1 1 1 CORC CORnell Compiler. Simple language for student math problems. ["The Cornell Computing Language", R.W. Conway et al, CACM 6(6):317-320 (Jun 1963) Sammet 1969, p.294-296]. 1 1 1 1 1 core 1. <storage> Main memory or RAM. This term dates from the days of ferrite core memory and, like the technology, is now archaic. Some derived idioms outlived the hardware: for example, "in core" (meaning paged in), core dump, "core image", "core file". Some varieties of Commonwealth hackish prefer store. [Jargon File] (2009-11-06) 2. <processor> An integrated circuit design, usually for a microprocessor, which includes only the CPU and which is intended to be incorporated on a chiip with other circuits such as cache, memory management unit, I/O ports and timers. The trend in 2009 is to have multiple cores per chip. The ARM6, ARM7 and ARM8 are early examples, the Intel Core i9 more recent. 3. <language> A varient on kernel as used to describe features built into a language as opposed to those provided by 1 1 1 1 1 core cancer A process that exhibits a slow but inexorable resource leak - like a cancer, it kills by crowding out productive "tissue". [Jargon File] (1997-11-10) 1 1 1 1 1 core dump Common Iron Age jargon, preserved by Unix for a memory dump. The term is also used for a complete account of a human's knowledge on some subject (also brain dump), especially in a lecture or answer to an exam question. [Jargon File] (2007-05-09) 1 1 1 1 1 core gateway Historically, one of a set of gateways (routers) operated by the Internet Network Operations Center at Bolt, Beranek and Newman (BBN). The core gateway system formed a central part of Internet routing in that all groups must advertise paths to their networks from a core gateway. 1 1 1 1 1 Corel Corporation A software publisher best known for the CorelDraw application. Founded in June 1985 by Dr. Michael Cowpland, Corel Corporation was originally a systems integration company. In January 1989, however they entered the software publishing market with the introduction of CorelDraw. Corel became the second largest maker of personal productivity software in January 1996 when they purchased the WordPerfect family of software from Novell, Inc.. (http://corel.com/). (1997-03-12) 1 1 1 1 1 core leak memory leak 1 1 1 1 1 Corel VENTURA (Previously "Ventura Publisher") The first full-featured desktop publishing program available for the IBM personal computer and compatibles. Ventura Publisher was originally distributed by Ventura, a wholy owned subsiduary of Xerox Corporation but was acquired by Corel Corporation in September 1993. Latest version: Corel VENTURA 8, as of 1999-04-05. Home (http://corelnet.com/products/graphicsandpublishing/ventura8/index.htm). (1999-04-05) 1 1 1 1 1 Core Protocol Stack 1. A portion of the Web Services architecture for defining and describing various Web Services. 2. The architectural protocol layers of a Bluetooth wireless communication system, comprising the Host Control Interface (HCI), Logical Link Control and Adaptation Protocol (L2CAP), RS232 Serial Cable Emulation Profile (RFCOMM), Service Discovery Protocol (SDP), and Object Exchange (OBEX). (2002-06-28) 1 1 1 1 1 Core War (Or more recently, "Core Wars") A game played between assembly code programs running in the core of a simulated machine (and vicariously by their authors). The objective is to kill your opponents' programs by overwriting them. The programs are written using an instruction set called Redcode and run on a virtual machine called "MARS" (Memory Array Redcode Simulator). Core War was devised by Victor Vyssotsky, Robert Morris Sr., and Dennis Ritchie in the early 1960s (their original game was called "Darwin" and ran on a PDP-1 at Bell Labs). It was first described in the "Core War Guidelines" of March, 1984 by D. G. Jones and A. K. Dewdney of the Department of Computer Science at The University of Western Ontario (Canada). Dewdney wrote several "Computer Recreations" articles in Scientific American which discussed Core War, starting with the May 1984 article. Those articles are contained in the two 1 1 1 1 1 corge /korj/ Yet another metasyntactic variable, named after a cat invented by Mike Gallaher and propagated by the GOSMACS documentation. See grault. [Jargon File] (1994-12-08) 1 1 1 1 1 Cornell List Processor (CLP) A list processing language, an extension of CORC, used for simulation. [Sammet 1969, p. 461]. (1994-11-01) 1 1 1 1 1 Cornell Theory Center (CTC) One of four supercomputing centers funded by the US National Science Foundation. The CTC also receives funding from the Advanced Research Projects Agency, the National Institutes of Health, New York State, IBM Corporation, and other members of the center's Corporate Research Institute. (http://tc.cornell.edu/). (1994-12-08) 1 1 1 1 1 Cornell University A US Ivy League University founded in 1868 by businessman Ezra Cornell and respected scholar Andrew Dickson White. Cornell includes thirteen colleges and schools. On the Ithaca campus are the seven undergraduate units and four graduate and professional units. The Medical College and the Graduate School of Medical Sciences are in New York City. Cornell has 13,300 undergraduates and 6,200 graduate and professional students. See also Concurrent ML, Cornell Theory Center, Cornell University Programming Language, CU-SeeMe, ISIS. (http://cornell.edu/). (1996-12-01) 1 1 1 1 1 Coroutine Pascal ["Control Separation in Programming languages", Lemon et al, ACM Ann Conf 1977]. (1994-12-08) 1 1 1 1 1 Corporation for National Research Initiatives (CNRI) A US research and development organisation that leads and funds research and development of network-based information technology including the National Information Infrastructure. Address: Reston, VA, USA. CNRI Home (http://cnri.reston.va.us/). (2004-08-27) 1 1 1 1 1 Corporation for Open Systems (COS) An international consortium of computer users and vendors set up to provide ways of testing OSI implementations. (1994-11-30) 1 1 1 1 1 Corporation for Research and Educational Networking (CREN) The organisation responsible for providing networking service to BITNET and CSNET users. CREN was formed in October 1989, when BITNET and CSNET were combined under one authority. CSNET is no longer operational, but CREN still runs BITNET. [Still true?] (1996-05-17) 1 1 1 1 1 CORREGATE Based on Internal Translator (IT). [Sammet 1969, p. 139]. (1994-11-30) 1 1 1 1 1 Correlatives and Conversions The data description language used in the Pick operating system. ["Exploring the Pick Operating System", J.E. Sisk et al, Hayden 1986]. (1994-11-30) 1 1 1 1 1 Cortex An experimental slow controls project at CERN. (1994-11-30) 1 1 1 1 1 CORTL An intermediate language, a form of RTL, by Carl McConnell <mcconnell@cs.uiuc.edu>. (1994-11-30) 1 1 1 1 1 COS 1. Cray Operating System. 2. Corporation for Open Systems. 1 1 1 1 1 COSE Common Open Software Environment. An initiative by Hewlett-Packard, Sun, IBM, Novell, Univel and SCO to move toward consistency and interoperability between Unix suppliers. 1 1 1 1 1 COSINE Cooperation for Open Systems Interconnection Networking in Europe. A EUREKA project. 1 1 1 1 1 cosmic rays Notionally, the cause of bit rot. However, this is a semi-independent usage that may be invoked as a humorous way to handwave away any minor randomness that doesn't seem worth the bother of investigating. "Hey, Eric - I just got a burst of garbage on my tube, where did that come from?" Cosmic rays, I guess. Compare sunspots, phase of the moon. The British seem to prefer the usage "cosmic showers"; alpha particles is also heard, because stray alpha particles passing through a memory chip can cause single bit errors (this becomes increasingly more likely as memory sizes and densities increase). Factual note: Alpha particles cause bit rot, cosmic rays do not (except occasionally in spaceborne computers). Intel could not explain random bit drops in their early chips, and one hypothesis was cosmic rays. So they created the World's Largest Lead Safe, using 25 tons of the stuff, and used two identical boards for testing. One was placed in the safe, one 1 1 1 1 1 COSS Common Object Services Specification in CORBA. 1 1 1 1 1 cost control callback A system where a computer automatically rejects incoming dial-up calls from certain telephone numbers and calls them back, with the result that the caller pays nothing for the connection. This differs from security callback in that it applies to certain phone numbers instead of to certain user names. (2003-07-13) 1 1 1 1 1 Cost Driver Attribute Factors affecting the productivity of software development. These include attributes of the software, computers, personnel, and project. (1996-05-28) 1 1 1 1 1 Cost/Schedule Control System Criteria (C/SCSC) A set of criteria specified by the Federal Government for reporting project schedule and financial information. (1996-05-29) 1 1 1 1 1 COTS commercial off-the-shelf. See commercial software. (2007-02-08) 1 1 1 1 1 Cougar A former (development) name for the W3C's HTML 4 standard. (2001-02-06) 1 1 1 1 1 cough and die barf. Connotes that the program is throwing its hands up by design rather than because of a bug or oversight. "The parser saw a control-A in its input where it was looking for a printable, so it coughed and died." Compare die, die horribly, scream and die. [Jargon File] (1995-03-07) 1 1 1 1 1 count One of the built-in aggregate functions in relational database systems, that returns the number of rows in a result. The argument to the function is nearly always *, e.g. SELECT COUNT(*) FROM books which returns the number of rows in the "books" table. If, instead, we say SELECT COUNT(publisher) FROM books then only rows with a non-null value in the "publisher" column will be counted. (2010-09-26) 1 1 1 1 1 countable A term describing a set which is isomorphic to a subet of the natural numbers. A countable set has countably many elements. If the isomorphism is stated explicitly then the set is called "a counted set" or "an enumeration". Examples of countable sets are any finite set, the natural numbers, integers, and rational numbers. The real numbers and complex numbers are not [proof?]. (1999-08-29) 1 1 1 1 1 countably many countable 1 1 1 1 1 counted A term describing a set with an explicit isomorphism to the natural numbers. Compare: countable. (1995-04-13) 1 1 1 1 1 counterbug A bug used as a relpy to refute another person's bug report, as in "counterargument". [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-10-24) 1 1 1 1 1 country code Originally, a two-letter abbreviation for a particular country (or geographical region), generally used as a top-level domain. Originally country codes were just for countries; but country codes have been allocated for many areas (mostly islands) that aren't countries, such as Antarctica (aq), Christmas Island (cx) and Saint Pierre et Miquelon (pm). Country codes are defined in ISO 3166 and are used as the top level domain for Internet hostnames in most countries but hardly ever in the USA (code "us"). ISO 3166 defines short and full english and french names, two- and three-letter codes and a three-digit code for each country. There are also language codes. Latest list (http://www.iso.org/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html). (2006-12-11) 1 1 1 1 1 coupling The degree to which components depend on one another. There are two types of coupling, "tight" and loose. Loose coupling is desirable for good software engineering but tight coupling may be necessary for maximum performance. Coupling is increased when the data exchanged between components becomes larger or more complex. (1996-08-01) 1 1 1 1 1 Course Author Language (CAL) The CAI language for the IBM 360. ["Design of a Programming Language for Computer Assisted Learning", F.M. Tonge, Proc IFIP Congress 1968, v2]. (1994-11-08) 1 1 1 1 1 courseware Programs and data used in Computer-Based Training. (1995-03-13) 1 1 1 1 1 Coursewriter III A simple CAI language, developed around 1976. ["Coursewriter III, Version 3 Author's Guide", SH20-1009, IBM]. (1995-03-13) 1 1 1 1 1 cowboy [Sun, from William Gibson's cyberpunk SF] Synonym for hacker. It is reported that at Sun this word is often said with reverence. [Jargon File] 1 1 1 1 1 COWSEL COntrolled Working SpacE Language. Burstall and Popplestone, U Edinburgh, 1964-66. LISP-like semantics with FORTH-like stack, and reverse Polish syntax. Forerunner of POP. EPU-R-12, U Edinburgh (Apr 1966). 1 1 1 1 1 CP A concurrent Prolog. The Concurrent Logic Programming Language CP: Definition and Operational Semantics", V. Saraswat, 14th POPL, ACM 1987, pp.49-62. 1 1 1 1 1 CPAN Comprehensive Perl Archive Network 1 1 1 1 1 CParaOps5 A parallel version of OPS5 written at CMU, in C and compiling to C. CParaOps5 is available for Unix, Mach, Encore Multimaxen, and Sequent. Latest version: 5.4, as of 1999-08-30. (http://cs.ucsb.edu/~acha/software.html). (1999-08-30) 1 1 1 1 1 CPE Customer Premises Equipment 1 1 1 1 1 CPGA Ceramic Pin Grid Array 1 1 1 1 1 CPI Common Program Interface 1 1 1 1 1 CPL Combined Programming Language. U Cambridge and U London. A very complex language, syntactically based on ALGOL 60, with a pure functional subset. Provides the ..where.. form of local definitions. Strongly typed but has a "general" type enabling a weak form of polymorphism. Functions may be defined as either normal or applicative order. Typed array and polymorphic list structures. List selection is through structure matching. Partially implemented on the Titan (Atlas 2) computer at Cambridge. Led to the much simpler BCPL. "The Main Features of CPL", D.W. Barron et al, Computer J 6(2):134-143 (Jul 1963). 1 1 1 1 1 CPLD complex programmable logic device 1 1 1 1 1 CPM Control Program for Microcomputers 1 1 1 1 1 CP/M Control Program for Microcomputers 1 1 1 1 1 cpo complete partial ordering 1 1 1 1 1 cpp C preprocessor. 1 1 1 1 1 cppp A compiler front-end for C++ by Tony Davis <ted@cs.brown.edu> with complete semantic processing. cppp is based on Yacc and outputs an abstract syntax graph. Version: 1.14. (ftp://wilma.cs.brown.edu/pub/cppp.tar.Z). (1993-05-26) 1 1 1 1 1 C preprocessor (cpp) The standard Unix macro-expansion utility run as the first phase of the C compiler, cc. Cpp interprets lines beginning with "#" such as #define BUFFER_SIZE 256 as a textual assignment giving the symbol BUFFER_SIZE a value "256". Symbols defined with cpp are traditionally given upper case names to distinguish them from C identifiers. This symbol can be used later in the input, as in char input_buffer[BUFFER_SIZE]; This use of cpp to name constants, rather than writing these magic numbers inline, makes a program easier to read and maintain, especially if there is more than one occurrence of BUFFER_SIZE all of which must all have the same value. Cpp macros can have parameters: 1 1 1 1 1 C Programmer's Disease The tendency of the undisciplined C programmer to set arbitrary but supposedly generous static limits on table sizes (defined, if you're lucky, by constants in header files) rather than taking the trouble to do proper dynamic storage allocation. If an application user later needs to put 68 elements into a table of size 50, the afflicted programmer reasons that he or she can easily reset the table size to 68 (or even as much as 70, to allow for future expansion) and recompile. This gives the programmer the comfortable feeling of having made the effort to satisfy the user's (unreasonable) demands, and often affords the user multiple opportunities to explore the marvellous consequences of fandango on core. In severe cases of the disease, the programmer cannot comprehend why each fix of this kind seems only to further disgruntle the user. [Jargon File] (2001-12-31) 1 1 1 1 1 C-Prolog An implementation of Prolog in C, developed by F. Pereira <pereira@research.att.com> et al in July 1982. It had no garbage collection. It is not in the public domain. (1994-10-13) 1 1 1 1 1 cproto A translator , written by Chin Huang at canrem.com, that generates ANSI C function prototypes from K&R C function definitions. It can also translate function definition heads between K&R style and ANSI C style. Posted to comp.sources.misc, volume 29. Runs under Unix, MS-DOS. (1992-07-18) 1 1 1 1 1 CPS 1. Conversational Programming System. An interactive extended subset of PL/I from Allen-Babcock Corp in 1965. ["Conversational Programming System under TSO (PBPO), Terminal User's Manual", SH20-1197, IBM]. [Sammet 1969, p. 232-240]. 2. Continuation Passing Style. 1 1 1 1 1 CPSR Computer Professionals for Social Responsibility 1 1 1 1 1 CPU central processing unit 1 1 1 1 1 CPU Info Center An old website at the University of California at Berkeley describing many different computers and their performance. (http://bwrc.eecs.berkeley.edu/CIC/). (2000-01-12) 1 1 1 1 1 CPU time processor time 1 1 1 1 1 CPU Wars /C-P-U worz/ A 1979 large-format comic by Chas Andres chronicling the attempts of the brainwashed androids of IPM (Impossible to Program Machines) to conquer and destroy the peaceful denizens of HEC (Human Engineered Computers). This rather transparent allegory featured many references to ADVENT and the immortal line "Eat flaming death, minicomputer mongrels!" (uttered, of course, by an IPM stormtrooper). It is alleged that the author subsequently received a letter of appreciation on IBM company stationery from the head of IBM's Thomas J. Watson Research Laboratories (then, as now, one of the few islands of true hackerdom in the IBM archipelago). The lower loop of the B in the IBM logo, it is said, had been carefully whited out. See eat flaming death. [Jargon File] 1 1 1 1 1 CR Carriage Return 1 1 1 1 1 cr The country code for Costa Rica. (1999-01-27) 1 1 1 1 1 cracker An individual who attempts to gain unauthorised access to a computer system. These individuals are often malicious and have many means at their disposal for breaking into a system. The term was coined ca. 1985 by hackers in defence against journalistic misuse of "hacker". An earlier attempt to establish "worm" in this sense around 1981--82 on Usenet was largely a failure. Use of both these neologisms reflects a strong revulsion against the theft and vandalism perpetrated by cracking rings. The neologism "cracker" in this sense may have been influenced not so much by the term "safe-cracker" as by the non-jargon term "cracker", which in Middle English meant an obnoxious person (e.g., "What cracker is this same that deafs our ears / With this abundance of superfluous breath?" -- Shakespeare's King John, Act II, Scene I) and in modern colloquial American English survives as a barely gentler synonym for "white trash". 1 1 1 1 1 cracking cracker 1 1 1 1 1 crack root To defeat the security system of a Unix machine and gain root privileges thereby. The sort of thing a cracker wants to do. [Jargon File] (2010-02-04) 1 1 1 1 1 crank (Automotive slang) Verb used to describe the performance of a machine, especially sustained performance. "This box cranks (or, cranks at) about 6 megaflops, with a burst mode of twice that on vectorised operations." [Jargon File] (1994-12-01) 1 1 1 1 1 crapplet A badly written or profoundly useless Java applet. "I just wasted 30 minutes downloading this stinkin' crapplet!" (1997-03-30) 1 1 1 1 1 CrApTeX /krap'tekh/ (University of York, England) Term of abuse used to describe TeX and LaTeX when they don't work (when used by TeXhackers), or all the time (by everyone else). The non-TeX enthusiasts generally dislike it because it is more verbose than other formatters (e.g. troff) and because (particularly if the standard Computer Modern fonts are used) it generates vast output files. See religious issues. [Jargon File] (1994-12-01) 1 1 1 1 1 crash 1. A sudden, usually drastic failure. Most often said of the system, especially of magnetic disk drives (the term originally described what happened when the air gap of a hard disk collapses). "Three lusers lost their files in last night's disk crash." A disk crash that involves the read/write heads dropping onto the surface of the disks and scraping off the oxide may also be referred to as a "head crash", whereas the term "system crash" usually, though not always, implies that the operating system or other software was at fault. 2. To fail suddenly. "Has the system just crashed?" Something crashed the OS! See down. Also used transitively to indicate the cause of the crash (usually a person or a program, or both). "Those idiots playing SPACEWAR crashed the system." [Jargon File] (1994-12-01) 1 1 1 1 1 crash and burn A spectacular crash, in the mode of the conclusion of the car-chase scene in the movie "Bullitt" and many subsequent imitators (compare die horribly). A Sun-3 display screen losing the flyback transformer and lightning strikes on VAX-11/780 backplanes are notable crash and burn generators. The construction "crash-and-burn machine" is reported for a computer used exclusively for alpha or beta testing, or reproducing bugs (i.e. not for development). The implication is that it wouldn't be such a disaster if that machine crashed, since only the testers would be inconvenienced. [Jargon File] (1996-02-22) 1 1 1 1 1 crawler robot 1 1 1 1 1 crawling horror Ancient crufty hardware or software that is kept obstinately alive by forces beyond the control of the hackers at a site. Like dusty deck or gonkulator, but connotes that the thing described is not just an irritation but an active menace to health and sanity. "Mostly we code new stuff in C, but they pay us to maintain one big Fortran II application from nineteen-sixty-X that's a real crawling horror." Compare WOMBAT. [Jargon File] (1994-12-01) 1 1 1 1 1 Cray instability A shortcoming of a program or algorithm that manifests itself only when a large problem is being run on a powerful machine such as a Cray. Generally more subtle than bugs that can be detected in smaller problems running on a workstation or minicomputer. [Jargon File] (1994-10-13) 1 1 1 1 1 crayola /kray-oh'l*/ A super-minicomputer or super-microcomputer that provides some reasonable percentage of supercomputer performance for an unreasonably low price. A crayola might also be a killer micro. [Jargon File] (1994-10-13) 1 1 1 1 1 crayola books A humorous and/or disparaging term for the rainbow series of National Computer Security Center (NCSC) computer security standards. See also Orange Book. [Jargon File] (1996-12-03) 1 1 1 1 1 crayon 1. Someone who works on Cray supercomputers. More specifically, it implies a programmer, probably of the CDC ilk, probably male, and almost certainly wearing a tie (irrespective of gender). Systems types who have a Unix background tend not to be described as crayons. 2. A computron that participates only in number crunching. 3. A unit of computational power equal to that of a single Cray-1. There is a standard joke about this usage that derives from an old Crayola crayon promotional gimmick: When you buy 64 crayons you get a free sharpener. [Jargon File] (1994-10-13) 1 1 1 1 1 Cray Research, Inc. US manufacturer of large powerful mainframe supercomputers, co-founded by noted computer architect, Seymour Cray. Quarterly sales $216M, profits $8M (Aug 1994). Cray were bought by Silicon Graphics, Inc.. [More details?] (1999-10-19) 1 1 1 1 1 CRC cyclic redundancy check 1 1 1 1 1 creationism The (false) belief that large, innovative software designs can be completely specified in advance and then painlessly magicked out of the void by the normal efforts of a team of normally talented programmers. In fact, experience has shown repeatedly that good designs arise only from evolutionary, exploratory interaction between one (or at most a small handful of) exceptionally able designer(s) and an active user population - and that the first try at a big new idea is always wrong. Unfortunately, because these truths don't fit the planning models beloved of management, they are generally ignored. [Jargon File] 1 1 1 1 1 creeping elegance Describes a tendency for parts of a design to become elegant past the point of diminishing return, something which often happens at the expense of the less interesting parts of the design, the schedule, and other things deemed important in the Real World. See also creeping featurism, second-system effect, tense. 1 1 1 1 1 creeping featurism /kree'ping fee'chr-izm/ (Or "feature creep") A systematic tendency to load more chrome and features onto systems at the expense of whatever elegance they may have possessed when originally designed. "The main problem with BSD Unix has always been creeping featurism." More generally, creeping featurism is the tendency for anything to become more complicated because people keep saying Gee, it would be even better if it had this feature too. The result is usually a patchwork because it grew one ad-hoc step at a time, rather than being planned. Planning is a lot of work, but it's easy to add just one extra little feature to help someone, and then another, and another, .... When creeping featurism gets out of hand, it's like a cancer. Usually this term is used to describe computer programs, but it could also be said of the federal government, the IRS 1040 form, and new cars. A similar phenomenon sometimes afflicts conscious redesigns; see second-system effect. See also 1 1 1 1 1 creeping featuritis /kree'ping fee'-chr-i:`t*s/ A variant of creeping featurism, with its own spoonerism: "feeping creaturitis". Some people like to reserve this form for the disease as it actually manifests in software or hardware, as opposed to the lurking general tendency in designers' minds. -ism means condition or "pursuit of", whereas -itis usually means inflammation of. [Jargon File] (1997-08-03) 1 1 1 1 1 C-Refine A preprocessor for C and languages with similar syntax by Lutz Prechelt <prechelt@ira.uka.de>. C-Refine allows symbolic naming of code fragments so as to redistribute complexity and provide running commentary. Version 3.0 is available from comp.sources.reviewed archives. It is highly portable and has been ported to Unix, MS-DOS, Atari, Amiga. (ftp://ftp.uu.net/usenet/comp.sources.reviewed/volume02/crefine). (1992-07-16) 1 1 1 1 1 CREN Corporation for Research and Educational Networking 1 1 1 1 1 CREW PRAM concurrent read, exclusive write PRAM. 1 1 1 1 1 crippleware 1. Software that has some important functionality deliberately removed, so as to entice potential users to pay for a working version. 2. (Cambridge) Guiltware that exhorts you to donate to some charity. Compare careware, nagware. 3. Hardware deliberately crippled, which can be upgraded to a more expensive model by a trivial change (e.g. removing a jumper). A correspondant gave the following example: In 1982-5, a friend had a Sharp scientific calculator which was on the list of those permitted in exams. No programmable calculators were allowed. A very similar, more expensive, programmable model had two extra keys for programming where the cheaper version just had blank metal. My friend took his calculator apart (as you would) and lo and behold, the rubber switches of the program keys were there on 1 1 1 1 1 criptography It's spelled "cryptography". (1996-12-13) 1 1 1 1 1 Crisis Software A small UK company producing software for the Acorn Archimedes range of computers. (http://dcs.warwick.ac.uk/~phid/Crisis/). (1994-11-10) 1 1 1 1 1 CRISP A Lisp-like language and compiler for the IBM 370 written by Jeff Barnett of SDC, Santa Monica, CA, USA in the early 1970s. It generalised Lisp's two-part cons nodes to n-part nodes. (1994-11-10) 1 1 1 1 1 crisp (Or "discrete") The opposite of "fuzzy". (1994-12-23) 1 1 1 1 1 Crispy Critters (Or "Crispy Crittered". From the "Post" breakfast cereal of the same name) hardware which is fried or toast. (1995-01-31) 1 1 1 1 1 critical mass In physics, the minimum amount of fissionable material required to sustain a chain reaction. Of a software product, describes a condition of the software such that fixing one bug introduces one plus epsilon bugs. (This malady has many causes: creeping featurism, ports to too many disparate environments, poor initial design, etc.) When software achieves critical mass, it can never be fixed; it can only be discarded and rewritten. [Jargon File] (1994-12-23) 1 1 1 1 1 critical section A non-re-entrant piece of code that can only be executed by one process at a time. It will usually terminate in bounded time and a process will only have to wait a bounded time to enter it. Some synchronisation mechanism is required at the entry and exit of the critical section to ensure exclusive use. 1 1 1 1 1 CRL Carnegie Representation Language. Carnegie Group, Inc. Frame language derived from SRL. Written in Common LISP. Used in the product Knowledge Craft. 1 1 1 1 1 CRLF /ker'l*f/, sometimes /kru'l*f/ or /C-R-L-F/ A carriage return (CR, ASCII 13) followed by a line feed (LF, ASCII 10). Under Unix influence this usage has become less common because Unix uses just line feed as its line terminator. See newline, terpri. [Jargon File] (1995-03-27) 1 1 1 1 1 CRM 1. <business> Customer Relationship Management. 2. <networking> Cisco Resource Manager. 1 1 1 1 1 crock [American scatologism "crock of shit"] 1. An awkward feature or programming technique that ought to be made cleaner. For example, using small integers to represent error codes without the program interpreting them to the user (as in, for example, Unix "make(1)", which returns code 139 for a process that dies due to segfault). 2. A technique that works acceptably, but which is quite prone to failure if disturbed in the least. For example, a too-clever programmer might write an assembler which mapped instruction mnemonics to numeric opcodes algorithmically, a trick which depends far too intimately on the particular bit patterns of the opcodes. (For another example of programming with a dependence on actual opcode values, see The Story of Mel.) Many crocks have a tightly woven, almost completely unmodifiable structure. See kluge, brittle. The adjectives "crockish" and "crocky", and the nouns "crockishness" and "crockitude", are also used. 1 1 1 1 1 cron The Unix clock daemon that executes commands at specified dates and times according to instructions in a "crontab" file. Unix manual page: cron(8). (1997-04-10) 1 1 1 1 1 cross-assembler An assembler which runs on one type of processor and produces machine code for another. There is a set of 6502, 68xx and Zilog Z80 and 8085 cross-assemblers in C by <msmakela@cc.helsinki.fi> and Alan R. Baldwin. They run under MS-DOS and could be compiled to run under Unix and on the Amiga and Atari ST. See also fas. (ftp://ccosun.caltech.edu/). (1993-03-10) 1 1 1 1 1 cross-compiler A compiler which runs on one platform and produces code for another, as opposed to a native code compiler which produces code for the platform on which it runs. (1998-02-24) 1 1 1 1 1 cross-platform A term that describes a language, software application or hardware device that works on more than one system platform (e.g. Unix, Microsoft Windows, Macintosh). E.g. Netscape Navigator, Java. (1998-02-24) 1 1 1 1 1 cross-post [Usenet] To post a single article simultaneously to several newsgroups. Distinguished from posting the article repeatedly, once to each newsgroup, which causes people to see it multiple times (which is very bad form). Gratuitous cross-posting without a Followup-To line directing responses to a single followup group is frowned upon, as it tends to cause followup articles to go to inappropriate newsgroups when people respond to only one part of the original posting. [Jargon File] 1 1 1 1 1 cross software Software developed on one kind of computer for use on another (usually because the other computer does not have itself adequate facilities for software development). 1 1 1 1 1 CROSSTABS Simple language for statistical analysis of tabular data. User's Manual for the CROSSTABS System, Cambridge Computer Assoc (Feb 1977). 1 1 1 1 1 crosstalk Interference caused by two signals becoming partially superimposed on each other due to electromagnetic (inductive) or electrostatic (capacitive) coupling between the conductors carrying the signals. A common example of crosstalk is where the magnetic field from changing current flow in one wire induces current in another wire running parallel to the other, as in a transformer. Crosstalk can be reduced by using shielded cables and increasing the distance between conductors. (1995-12-20) 1 1 1 1 1 CROW PRAM concurrent read, owner write PRAM. 1 1 1 1 1 CRT cathode ray tube 1 1 1 1 1 CRUD A mnemonic for the four most important kinds of activity that almost any system of any type needs to support: create, read, update, delete. The absence or failure of any one of these is often a sign of a bad design or poor testing. (2014-08-06) 1 1 1 1 1 crudware /kruhd'weir/ Pejorative term for the hundreds of megabytes of low-quality freeware circulated by user's groups and BBSs in the micro-hobbyist world. [Jargon File] 1 1 1 1 1 cruft (back-formation from "crufty") Anything unpleasant that accumulates over time. Also used as a verb, as in cruft together, hand cruft. [Jargon File] (2006-01-19) 1 1 1 1 1 crufted cruft 1 1 1 1 1 cruft together To hack together though with the suggestion that the result may be cruft. [Jargon File] (2006-01-19) 1 1 1 1 1 crumb (Or tayste /tayst/) Silly suggested term for two binary digits. The term "quarter" has also been suggested, referring to the US 25-cent coin. This was once equal in value to two of the eight "bits" - pie-slice-shaped "pieces of eight" - into which Spanish silver crowns were cut to make change. [Jargon File] (2007-05-31) 1 1 1 1 1 crunch 1. <jargon> To process, usually in a time-consuming or complicated way. Connotes an essentially trivial operation that is nonetheless painful to perform. The pain may be due to the triviality's being embedded in a loop from 1 to 1,000,000,000. "Fortran programs do mostly number crunching." 2. <compression> To reduce the size of a file without losing information by a scheme such as Huffman coding. Since such lossless compression usually takes more computations than simpler methods such as run-length encoding, the term is doubly appropriate. 3. The hash character. Used at XEROX and CMU, among other places. 4. To squeeze program source to the minimum size that will still compile or execute. The term came from a BBC Microcomputer program that crunched BBC BASIC source in order to make it run more quickly (apart from storing 1 1 1 1 1 cruncha cruncha cruncha /kruhn'ch* kruhn'ch* kruhn'ch*/ An encouragement sometimes muttered to a machine bogged down in a serious grovel. Also describes a notional sound made by grovelling hardware. See grind (sense 3). (2003-06-02) 1 1 1 1 1 crunchy floppy disk 1 1 1 1 1 cryppie /krip'ee/ A cryptographer. One who hacks or implements software or hardware for cryptography. [Jargon File] (1996-08-23) 1 1 1 1 1 crypt Unix command to perform encryption and decryption. 1 1 1 1 1 cryptanalysis The branch of cryptography concerned with decoding encrypted messages when you're not supposed to be able to. (1994-12-06) 1 1 1 1 1 Crypt Breakers Workbench (cbw) A freely distributable multi-window integrated workbench of tools for cryptanalysis of files encrypted with the 4.2BSD Unix crypt command. It was originally written by Robert W. Baldwin at MIT. (ftp://black.ox.ac.uk/src/security), (ftp://scitsc.wlv.ac.uk/pub/infomagic/usenet.cdrom/sources/unix/volume10), (ftp://ftp.sunet.se/pub/usenet/comp.sources.unix/volume10). (1994-12-06) 1 1 1 1 1 cryptography The practise and study of encryption and decryption - encoding data so that it can only be decoded by specific individuals. A system for encrypting and decrypting data is a cryptosystem. These usually involve an algorithm for combining the original data ("plaintext") with one or more "keys" - numbers or strings of characters known only to the sender and/or recipient. The resulting output is known as ciphertext. The security of a cryptosystem usually depends on the secrecy of (some of) the keys rather than with the supposed secrecy of the algorithm. A strong cryptosystem has a large range of possible keys so that it is not possible to just try all possible keys (a "brute force" approach). A strong cryptosystem will produce ciphertext which appears random to all standard statistical tests. A strong cryptosystem will resist all known previous methods for breaking codes ("cryptanalysis"). 1 1 1 1 1 CryptoLocker The best known example of the kind of malware known as ransomware. CryptoLocker encrypts files on your computer and then demands that you send the malware operator money in order to have the files decrypted. According to FBI estimates, CryptoLocker had more than 500,000 victims between September 2013 and May 2014. Around 1.3 percent paid to free their files, earning the malware makers around $3 million. The criminal network was smashed by authorities and security researchers in May 2014 and a tool put online to decryt victim's files for free. (http://thehackernews.com/2014/08/CryptoLocker-Decryption-Keys-Tool.html). (2015-01-22) 1 1 1 1 1 cryptology The study of cryptography and cryptanalysis. (1994-12-06) 1 1 1 1 1 Crystal Concurrent Representation of Your Space-Time ALgorithms. A recursion equation parallel language. ["A Parallel Language and its Compilation to Multiprocessor Machines or VLSI", M.C. Chen, 13th POPL, ACM 1986 pp.131-139]. (1994-12-06) 1 1 1 1 1 CS-4 ["CS-4 Language Reference Manual and Operating System Interface", Ben M. Brosgol et al, Report IR-130-2, Intermetrics, Cambridge MA, Oct 1975]. (1995-01-19) 1 1 1 1 1 C-Scheme MIT Scheme 1 1 1 1 1 CSCI Computer Software Configuration Item 1 1 1 1 1 C/SCSC Cost/Schedule Control System Criteria 1 1 1 1 1 CSCW Computer Supported Cooperative Work 1 1 1 1 1 CSG constructive solid geometry 1 1 1 1 1 CSG-tree (Or "status tree"?) An approach used in ray tracing to evaluate constructive solid geometry structures. [Better explanation? "Evaluate"?] (1998-06-09) 1 1 1 1 1 csh C shell 1 1 1 1 1 C-sharp C# 1 1 1 1 1 C shell (csh) The Unix command-line interpreter shell and script language by William Joy, originating from Berkeley Unix. Unix systems up to around Unix Version 7 only had one shell - the Bourne shell, sh. Csh had better interactive features, notably command input history, allowing earlier commands to be recalled and edited (though it was still not as good as the VMS equivalent of the time). Presumably, csh's C-like syntax was intended to endear it to programmers but sadly it lacks some sh features which are useful for writing shell scripts so you need to know two different syntaxes for every shell construct. A plethora of different shells followed csh, e.g. tcsh, ksh, bash, rc, but sh and csh are the only ones which are provided with most versions of Unix. (1998-04-04) 1 1 1 1 1 CSID character set identifier 1 1 1 1 1 C++SIM A class library like the simulation class libraries of SIMULA, by Mark Little <M.C.Little@newcastle.ac.uk>. Version: 1.0. (ftp://arjuna.ncl.ac.uk/). (1993-06-04) 1 1 1 1 1 CSK Corporation The japanese company that owns CSK Software and Sega. CSK Corp. is the largest independent japanese software company. (2003-05-13) 1 1 1 1 1 CSK Software An international software company formed by the merger of Quay Financial Software and Micrognosis, and fully owned by CSK Corporation, Japan. CSK Software is based in Frankfurt/Main (Germany) with offices in London (UK), Zurich (Switzerland), Madrid (Spain), and Singapore. Products segments are RDD: Real-time data delivery, main product is Slingshot for delivering real-time data over the Internet (real push technology). ETS: Electronic Trading Systems, price calculation and automatic trading (with connections to XONTRO and XETRA). EAI: Enterprise Application Integration, main product is XGen, a universal message converter with GUI and connections also to SWIFT. (http://csksoftware.com/). E-mail: <info@csksoftware.com>. Address: CSK Software AG, Opernplatz 2, D-60313 Frankfurt, Germany. 1 1 1 1 1 CSL 1. Computer Structure Language. A computer hardware description language, written in BCPL. ["Computer Structure Language (CSL)", Proc 1975 Symp on Comp Hardware Description Languages and their Appl, ACM (Sep 1975)]. 2. Control and Simulation Language. A language for industrial simulation from Esso and IBM. ["Control and Simulation Language", J.N. Buxton et al, Computer J 5(3):194-199 (Oct 1962). Version: CSL 2 (1966 for IBM 7094)]. 1 1 1 1 1 CSLIP Compressed SLIP 1 1 1 1 1 CSM ["CSM - A Distributed Programming Language", S. Zhongxiu et al, IEEE Trans Soft Eng SE-13(4):497-500 (Apr 1987)]. 1 1 1 1 1 CSMA/CD Carrier Sense Multiple Access / Collision Detect. The low level network arbitration protocol used on Ethernet. Nodes wait for quiet on the net before starting to transmit and listen while they are transmitting. If two nodes transmit at once the data gets corrupted. The nodes detect this and continue to transmit for a certain length of time to ensure that all nodes detect the collision. The transmitting nodes then wait for a random time before attempting to transmit again thus minimising the chance of another collision. The ability to detect collision during transmission reduces the amount of bandwidth wasted on collisions compared with simple ALOHA broadcasting. (1995-02-23) 1 1 1 1 1 CSMP Continuous System Modeling Program 1 1 1 1 1 CSNET Computers and Science Network, operated by CREN for US computer science institutes. It provides electronic mail service via dial-up lines, X.25 and Internet services. 1 1 1 1 1 CSO Campus Phone Book software developed for, and originally used at, the Computer Services Office of the University of Illinois at Urbana-Champaign. The server software is known as "qi" and the client is "ph". Recent versions of the software refer to CCSO (Computing & Communications Service Office). (ftp://uxc.cso.uiuc.edu/). 1 1 1 1 1 CSP 1. <language> Communicating Sequential Processes. 2. <hardware> Chip Scale Packaging. 1 1 1 1 1 CSP/80 Based on CSP. CSP/80: A Language for Communicating Processes, M. Jazayeri et al, Proc Fall COMPCON80, IEEE pp.736-740 (Sept 1980). 1 1 1 1 1 CS/PCode Used at Microsoft. 1 1 1 1 1 CSP/k Concurrent SP/k 1 1 1 1 1 CS-Prolog Distributed logic language. CS-Prolog on Multi-Transputer Systems, I. Futo et al, Microprocessors & Microsystems, March 1989. 1 1 1 1 1 CSPS ["Toward Comprehensive Specification of Distributed Systems", G. Roman et al, Proc 7th Intl Conf on Distrib Comp Sys, IEEE 1987, pp. 282-289]. 1 1 1 1 1 CSP-S ["Implementation of CSP-S for Description of Distributed Algorithms", L. Patniak et al, Comput Lang 9(3):193-202 (1984)]. 1 1 1 1 1 CS/QCode Used at Microsoft. [More detail?] 1 1 1 1 1 CSR Control and Status Register 1 1 1 1 1 CSS Cascading Style Sheets 1 1 1 1 1 CSSA An object-oriented language. ["Key Concepts in the INCAS Multicomputer Project", J. Nehmer et al, IEEE Trans Soft Eng SE-13(8):913-923 (Aug 1987)]. 1 1 1 1 1 CSS/II Computer System Simulator II. Like GPSS, for IBM 360. ["Computer System Simulator II (CSS II) Program Description and Operations Manual", SH20-0875, IBM]. 1 1 1 1 1 CSSL Continuous System Simulation Language 1 1 1 1 1 CSTools Concurrency through message-passing to named message queues. 1 1 1 1 1 CSU 1. California State University. 2. Cleveland State University. 3. Channel Service Unit. 1 1 1 1 1 CSU/DSU channel service unit/digital service unit 1 1 1 1 1 CSV comma separated values 1 1 1 1 1 CT Computer Telephone Integration 1 1 1 1 1 CTC Cornell Theory Center 1 1 1 1 1 CTC++ A test coverage analysis tool from Testwell for C and C++ that checks for function, decision, condition and multicondtion coverage in host, target and kernel. CTC++ Home (http://testwell.fi/). (2004-10-20) 1 1 1 1 1 CTCP Client To Client Protocol 1 1 1 1 1 CTI 1. <communications> Computer Telephone Integration. 2. <education> Computers in Teaching Initiative. A UK government scheme. (1996-12-08) 1 1 1 1 1 CTL 1. Checkout Test language. 2. Compiler Target Language. 3. Computational Tree Logic 1 1 1 1 1 CTOS 1. <operating system> Computerised Tomography Operating System. 2. <operating system> Convergent Technologies Operating System. 1 1 1 1 1 ctrl control 1 1 1 1 1 CTS 1. <communications> clear to send. 2. <medical> overuse strain injury. 1 1 1 1 1 CTSS Compatible Timesharing System 1 1 1 1 1 CTY /sit'ee/ or /C-T-Y/ [MIT] The terminal physically associated with a computer's system console. The term is a contraction of "Console tty", that is, "Console TeleTYpe". This ITS- and TOPS-10-associated term has become less common, as most Unix hackers simply refer to the CTY as "the console". [Jargon File] 1 1 1 1 1 CU "see you". (1997-12-01) 1 1 1 1 1 cu 1. <communications> Call Unix. 2. <networking> The country code for Cuba. 1 1 1 1 1 CUA Common User Access 1 1 1 1 1 Cube Three-dimensional visual language for higher-order logic. The Cube Language, M. Najork et al, 1991 IEEE Workshop on Visual Langs, Oct 1991, pp.218-224. [Jargon File] 1 1 1 1 1 cube 1. [short for "cubicle"] A module in the open-plan offices used at many programming shops. "I've got the manuals in my cube." 2. A NeXT machine (which resembles a matte-black cube). 1 1 1 1 1 cubing By analogy with "tubing", hacking on an IPSC (Intel Personal SuperComputer) hypercube. "Louella's gone cubing *again*!!" [Jargon File] (2003-10-09) 1 1 1 1 1 CUCH CUrry-CHurch. Lambda-calculus ["A Type-Theoretical Alternative to CUCH, ISWIM, OWHY", Dana Scott, Oxford U 1969]. ["Introduction to the CUCH", C. Bohm et al, in Automata Theory, E.R. Caianiello ed, A-P 1966, pp.35-65]. (1994-12-02) 1 1 1 1 1 Cuckoo's Egg The Cuckoo's Egg 1 1 1 1 1 CUL "See you later". (1997-12-01) 1 1 1 1 1 Culler-Fried System A system for interactive mathematics. [Sammet 1969, p. 253-255]. (1994-11-15) 1 1 1 1 1 CUPID A graphic query language. ["CUPID: A Graphic Oriented Facility for Support of Nonprogrammer Interactions with a Database", N. McDonald, PhD Thesis, CS Dept, UC Berkeley 1975]. 1 1 1 1 1 CUPL Cornell University Programming Language. A language for simple mathematics problems, based on CORC, with PL/I-like syntax. ["An Instruction Language for CUPL", R.J. Walker, Cornell U, Jul 1967]. (1994-11-15) 1 1 1 1 1 curly bracket brace 1 1 1 1 1 current The quantity of charge per unit time, measured in Amperes (Amps, A). By historical convention, the sign of current is positive for currents flowing from positive to negative potential, but experience indicates that electrons are negatively charged and flow in the opposite direction. (1995-10-05) 1 1 1 1 1 curried function A function of N arguments that is considered as a function of one argument which returns another function of N-1 arguments. E.g. in Haskell we can define: average :: Int -> (Int -> Int) (The parentheses are optional). A partial application of average, to one Int, e.g. (average 4), returns a function of type (Int -> Int) which averages its argument with 4. In uncurried languages a function must always be applied to all its arguments but a partial application can be represented using a lambda abstraction: \ x -> average(4,x) Currying is necessary if full laziness is to be applied to functional sub-expressions. It was named after the logician Haskell Curry but the 1 1 1 1 1 currying Turning an uncurried function into a curried function. 1 1 1 1 1 curseperl A curses library for Perl by the author of Perl, Larry Wall <lwall@netlabs.com>. It comes with Perl. (1994-12-06) 1 1 1 1 1 curses A set of subroutines in Unix for handling navigation on a terminal screen using the cursor. 1 1 1 1 1 cursor 1. <hardware> A visually distinct mark on a display indicating where newly typed text will be inserted. The cursor moves as text is typed and, in most modern editors, can be moved around within a document by the user to change the insertion point. 2. <database> In SQL, a named control structure used by an application program to point to a row of data. The position of the row is within a table or view, and the cursor is used interactively so select rows from columns. (1996-12-27) 1 1 1 1 1 cursor dipped in X The metaphorical source of the electronic equivalent of a poisoned-pen letter. Derived from English metaphors of the form "pen dipped in X" (where X = e.g. "acid", "bile", vitriol). These map over neatly to this hackish usage (the cursor being what moves, leaving letters behind, when one is composing on-line). "Talk about a nastygram! He must've had his cursor dipped in acid when he wrote that one!" [Jargon File] (1996-12-27) 1 1 1 1 1 CU-SeeMe /see`-yoo-see'-mee/ ("CU" from Cornell University) A shareware personal computer-based videoconferencing program for use over the Internet, developed at Cornell University, starting in 1992. CU-SeeMe allows for direct audiovisual connections between clients, or, like irc, it can support multi-user converencing via servers (here called "reflectors") to distribute the video and audio signals between multiple clients. CU-SeeMe was the first videoconferencing tool available at a reasonable price (in this case, free) to users of personal computers. (http://cu-seeme.cornell.edu/). (http://home.stlnet.com/~hubble/cuseeme/index.html). Compare with multicast backbone. (1996-12-01) 1 1 1 1 1 CUSI A collection of indices to various web and other Internet documents. It is located at Nexor in the UK. (http://web.nexor.co.uk/public/cusi/cusi.html). (1994-11-29) 1 1 1 1 1 cuspy /kuhs'pee/ [WPI: from the DEC abbreviation CUSP, for Commonly Used System Program, i.e. a utility program used by many people] 1. (of a program) Well-written. 2. Functionally excellent. A program that performs well and interfaces well to users is cuspy. See rude. [Jargon File] 1 1 1 1 1 custom (Or "bespoke") An adjective describing any product that is special in some way, individually created for a specific user or system, as opposed to generic or off-the-shelf. (2008-06-25) 1 1 1 1 1 Customer Information Control System (CICS) An IBM communications system that was converted for database handling. [Huh?] (1994-11-29) 1 1 1 1 1 Customer Information Systems Customer Relationship Management 1 1 1 1 1 Customer Interaction Software Customer Relationship Management 1 1 1 1 1 Customer Relationship Management (CRM, CIS, Customer Information Systems, Customer Interaction Software, TERM, Technology Enabled Relationship Manager) Enterprise-wide software applications that allow companies to manage every aspect of their relationship with a customer. The aim of these systems is to assist in building lasting customer relationships - to turn customer satisfaction into customer loyalty. Customer information acquired from sales, marketing, customer service, and support is captured and stored in a centralised database. The system may provide data-mining facilities that support an opportunity management system. It may also be integrated with other systems such as accounting and manufacturing for a truly enterprise-wide system with thousands of users. (1999-08-20) 1 1 1 1 1 CUT Coordinated Universal Time 1 1 1 1 1 cut and paste copy and paste 1 1 1 1 1 cut-and-waste code Code that someone found online (e.g. in a blog) and copied and pasted into a product. The result is usually a lot of wasted time trying to track down obscure bugs from code that may have made sense in the original context but not in the new one. Also known as blog-driven development. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-07-03) 1 1 1 1 1 cut a tape To write a software or document distribution on magnetic tape for shipment. Has nothing to do with physically cutting the medium! "Cutting a disk" has also been reported as live usage. Related slang usages are mainstream business's "cut a check", the recording industry's "cut a record", and the military's "cut an order". All of these usages reflect physical processes in obsolete recording and duplication technologies. The first stage in manufacturing an old-style vinyl record involved cutting grooves in a stamping die with a precision lathe. More mundanely, the dominant technology for mass duplication of paper documents in pre-photocopying days involved "cutting a stencil", punching away portions of the wax overlay on a silk screen. More directly, paper tape with holes punched in it was an important early storage medium. [Jargon File] 1 1 1 1 1 cutover /cut-ov*/ Switching from an old (hardware and/or software) system to a replacement system, covering the overlap from when the new system is live until the old system has been shut down. (1997-07-09) 1 1 1 1 1 cut-through switching The application of wormhole routing to packets in a packet switching system so that forwarding of a packet starts as soon as its destination is known, before the whole packet has arrived. Compare store and forward. (2006-12-06) 1 1 1 1 1 cv The country code for Cape Verde. (1999-01-27) 1 1 1 1 1 CVS Concurrent Versions System 1 1 1 1 1 CW continuous wave 1 1 1 1 1 CWeb An ANSI C implementation of the Web literate programming language. Version 3.1 by Levy, Knuth, and Marc van Leeuwen is writen in, and outputs, ANSI C and C++. (ftp://ftp.cwi.nl/pub/cweb/). (1993-12-16) 1 1 1 1 1 CWI Centrum voor Wiskunde en Informatica 1 1 1 1 1 CWIC Compiler for Writing and Implementing Compilers. Val Schorre. One of the early metacompilers. Compare Meta-II. 1 1 1 1 1 CWIS Campus-Wide Information System 1 1 1 1 1 C with Classes Short-lived predecessor to C++. ["Classes: An Abstract Data Type Facility for the C Language", B. Stroustrup, CSTR-84 Bell Labs, Apr 1980]. Also in [SIGPLAN Notices (Jan 1982)]. 1 1 1 1 1 cx The country code for Christmas Island. (1999-01-27) 1 1 1 1 1 cxref A cross-reference generator by Arnold Robbins from Georgia Institute of Technology. (2000-02-29) 1 1 1 1 1 cy The country code for Cyprus. (1999-01-27) 1 1 1 1 1 Cy486SLC A version of the Intel 486 made by Cyrix. It has a 486SX instruction set, a 1 kilobyte cache, and an Intel 80386SX-compatible pinout and thus, 16-bit data bus. (1994-11-30) 1 1 1 1 1 cyber To have cybersex. (1997-06-21) 1 1 1 1 1 cyberbunny Someone who knows absolutely nothing about computers and advises people who know absolutely nothing about computers. The term is used mostly on AOL, Prodigy, Compuserve, etc. (1996-02-18) 1 1 1 1 1 cyberchondriac (After "hypochondriac") 1. A user who always thinks there is something wrong with his computer. 2. Someone who uses the web to indulge their hyperchondria. (2001-03-10) 1 1 1 1 1 cybercrime Any of a broad range of activities that use computers or networks to commit illegal acts, including theft of personal data, phishing, distribution of malware, copyright infringement, denial of service attacks, cyberstalking, bullying, online harassment, child pornography, child predation, stock market manipulation and corporate espionage. For example, a vulnerability in a victim's web browser might result in him unknowingly downloading a Trojan horse virus, which installs a keystroke logger on his computer, which allows the cracker to steal private data such as Internet banking or e-mail passwords. The degree to which an activity counts as "cybercrime" rather than just "crime" depends on whether they could exist without computers or networks. (2015-02-14) 1 1 1 1 1 cybercrime as a service (CaaS) A kind of software as a service that involves performing illegal online activities (cybercrime) on behalf of others for money. Cybercrime as a service represents an evolution of online crime from the sale of illegal products such as malware and exploit kits to offering everything necessary to arrange a cyber fraud or to conduct a cyber attack. As well as providing malicious code, the service provider also rents out the infrastructure to control the distribution and operation of the malware, e.g., bullet-proof hosting or huge botnets. (2015-02-22) 1 1 1 1 1 cybercrud /si:'ber-kruhd/ 1. (Coined by Ted Nelson) Obfuscatory tech-talk. Verbiage with a high MEGO factor. The computer equivalent of bureaucratese. 2. Incomprehensible stuff embedded in e-mail. First there were the "Received" headers that show how mail flows through systems, then MIME (Multi-purpose Internet Mail Extensions) headers and part boundaries, and now huge blocks of hex for PEM (Privacy Enhanced Mail) or PGP (Pretty Good Privacy) digital signatures and certificates of authenticity. This stuff all has a purpose and good user interfaces should hide it, but all too often users are forced to wade through it. [Jargon File] (1995-04-04) 1 1 1 1 1 CyberGlove A data glove sold by Virtual Technologies. The spandex-like glove houses 18 sensors to track accurately just about every move your hand is capable of making. The accompanying software includes a three-dimensional hand model that can he added to any virtual reality application. The glove includes a mount for Polhemus and Ascension sensors. (2003-06-17) 1 1 1 1 1 cybernetics /si:`b*-net'iks/ The study of control and communication in living and man-made systems. The term was first proposed by Norbert Wiener in the book referenced below. Originally, cybernetics drew upon electrical engineering, mathematics, biology, neurophysiology, anthropology, and psychology to study and describe actions, feedback, and response in systems of all kinds. It aims to understand the similarities and differences in internal workings of organic and machine processes and, by formulating abstract concepts common to all systems, to understand their behaviour. Modern "second-order cybernetics" places emphasis on how the process of constructing models of the systems is influenced by those very systems, hence an elegant definition - "applied epistemology". Related recent developments (often referred to as sciences of complexity) that are distinguished as separate disciplines 1 1 1 1 1 cyberpunk /si:'ber-puhnk/ (Originally coined by SF writer Bruce Bethke and/or editor Gardner Dozois) A subgenre of SF launched in 1982 by William Gibson's epoch-making novel "Neuromancer" (though its roots go back through Vernor Vinge's "True Names" to John Brunner's 1975 novel "The Shockwave Rider"). Gibson's near-total ignorance of computers and the present-day hacker culture enabled him to speculate about the role of computers and hackers in the future in ways hackers have since found both irritatingly na"ive and tremendously stimulating. Gibson's work was widely imitated, in particular by the short-lived but innovative "Max Headroom" TV series. See cyberspace, ice, jack in, go flatline. Since 1990 or so, popular culture has included a movement or fashion trend that calls itself "cyberpunk", associated especially with the rave/techno subculture. Hackers have mixed feelings about this. On the one hand, self-described cyberpunks too often seem to be shallow trendoids in black 1 1 1 1 1 cyberrhea /si:'ber-eer/ An affliction of some word processor users; excessive frequency and looseness of productivity. Particularly virulent among those who have not discovered the fortifying virtues of revision. ["Right Words, Right Places" Scott Rice, Wadsworth, 1993, A5.] (1997-02-25) 1 1 1 1 1 cybersex Sex performed in real time via a digital medium. Compare teledildonics. [Details?] (1998-02-10) 1 1 1 1 1 cyberspace /si:'ber-spays/ 1. (Coined by William Gibson) Notional "information-space" loaded with visual cues and navigable with brain-computer interfaces called "cyberspace decks"; a characteristic prop of cyberpunk SF. In 1991 serious efforts to construct virtual reality interfaces modelled explicitly on Gibsonian cyberspace were already under way, using more conventional devices such as glove sensors and binocular TV headsets. Few hackers are prepared to deny outright the possibility of a cyberspace someday evolving out of the network (see network, the). 2. Occasionally, the metaphoric location of the mind of a person in hack mode. Some hackers report experiencing strong eidetic imagery when in hack mode; interestingly, independent reports from multiple sources suggest that there are common features to the experience. In particular, the dominant colours of this subjective "cyberspace" are often grey and silver, and the imagery often involves constellations 1 1 1 1 1 cyberspastic A person suffering from information overload while browsing the Internet or web. Compare webhead. (1995-11-09) 1 1 1 1 1 cyber-squatting The practice of registering famous brand names as Internet domain names, e.g. harrods.com, ibm.firm or sears.shop, in the hope of later selling them to the appropriate owner at a profit. (1998-01-22) 1 1 1 1 1 CyberWand A virtual reality controller. The CyberWand costs $99, or $765 with optional Polhemus sensor. It is basically the handle of a flight control system without the base. The controller's four buttons and 2-D hat sensor track six degrees of movement. (1995-04-04) 1 1 1 1 1 CyberZine A combination paper and web on-line Cyberspace guide. Upon payment you will be given a user name and password to access CyberZine on-line and the paper version will be posted first class. Subscribers can also use the CyberZine help desk. (http://cyberzine.org/). (1994-09-22) 1 1 1 1 1 CYBIL Control Data's system programming language in the 80's. Major parts of CDC systems written in this. 1 1 1 1 1 Cyc A large knowledge-based system. Cyc is a very large, multi-contextual knowledge base and inference engine, the development of which started at the Microelectronics and Computer Technology Corporation (MCC) in Austin, Texas during the early 1980s. Over the past eleven years the members of the Cyc team, lead by Doug Lenat, have added to the knowledge base a huge amount of fundamental human knowledge: facts, rules of thumb, and heuristics for reasoning about the objects and events of modern everyday life. Cyc is an attempt to do symbolic AI on a massive scale. It is not based on numerical methods such as statistical probabilities, nor is it based on neural networks or fuzzy logic. All of the knowledge in Cyc is represented declaratively in the form of logical assertions. Cyc presently contains approximately 400,000 significant assertions, which include simple statements of fact, rules 1 1 1 1 1 CYCL A frame language. ["Building Large Knowledge-Based Systems", Doug B. Lenat et al, A-W 1990]. 1 1 1 1 1 cycle A basic unit of computation, one period of a computer clock. Each instruction takes a number of clock cycles. Often the computer can access its memory once on every clock cycle, and so one speaks also of "memory cycles". Every hacker wants more cycles (noted hacker Bill Gosper describes himself as a "cycle junkie"). There are only so many cycles per second, and when you are sharing a computer the cycles get divided up among the users. The more cycles the computer spends working on your program rather than someone else's, the faster your program will run. That's why every hacker wants more cycles: so he can spend less time waiting for the computer to respond. The use of the term "cycle" for a computer clock period can probably be traced back to the rotation of a generator generating alternating current though computers generally use a clock signal which is more like a square wave. 1 1 1 1 1 cyclebabble Advertising raw clock speed, instead of bus speed. IBM uses raw clock speed as the speed of the computer. In the IBM PC and IBM PC XT, the clock is divided by 4 to produce the 4-phase bus clocks. Thus a 4 MHz IBM XT really runs at 0.895 MHz, because that 4 MHz was really 3.58 MHz which gets divided by four. A Tandy Color Computer ran at exactly the same speed, but clock speed was specified as bus speed, 0.895 MHz, leaving the impression that it was 4 times slower. Actually it ran a little faster with a more efficient instruction set. If the actual clock rate had been specified on a CoCo 3, it would have been 14.32 MHz, although the bus speed was still 0.895 MHz. That high speed also generated video, color, and hidden refresh timing. 100 MHz computers are running at bus speeds of around 25 MHz. (1997-02-13) 1 1 1 1 1 cycle crunch A situation wherein the number of people trying to use a computer simultaneously has reached the point where no one can get enough cycles because they are spread too thin and the system has probably begun to thrash. This scenario is an inevitable result of Parkinson's Law applied to time-sharing. Usually the only solution is to buy more computer. Happily, this has rapidly become easier since the mid-1980s, so much so that the very term "cycle crunch" now has a faintly archaic flavour; most hackers now use workstations or personal computers as opposed to traditional time-sharing systems. [Jargon File] (1994-11-29) 1 1 1 1 1 cycle drought A scarcity of cycles. It may be due to a cycle crunch, but it could also occur because part of the computer is temporarily not working, leaving fewer cycles to go around. "The high moby is down, so we're running with only half the usual amount of memory. There will be a cycle drought until it's fixed." [Jargon File] (1994-11-29) 1 1 1 1 1 cycle of reincarnation A term coined by Ivan Sutherland ca. 1970 to refer to a well-known effect whereby function in a computing system family is migrated out to special-purpose peripheral hardware for speed, then the peripheral evolves toward more computing power as it does its job, then somebody notices that it is inefficient to support two asymmetrical processors in the architecture and folds the function back into the main CPU, at which point the cycle begins again. Several iterations of this cycle have been observed in graphics-processor (blitter) design, and at least one or two in communications and floating-point processors. Also known as "the Wheel of Life", "the Wheel of Samsara" and other variations of the basic Hindu/Buddhist theological idea. [Jargon File] (1994-11-16) 1 1 1 1 1 cycle server A powerful computer that exists primarily for running large batch jobs. The term implies that interactive tasks such as editing are done on other machines on the network, such as workstations. [Jargon File] (1998-03-13) 1 1 1 1 1 cyclic redundancy check (CRC or "cyclic redundancy code") A number derived from, and stored or transmitted with, a block of data in order to detect corruption. By recalculating the CRC and comparing it to the value originally transmitted, the receiver can detect some types of transmission errors. A CRC is more complicated than a checksum. It is calculated using division either using shifts and exclusive ORs or table lookup (modulo 256 or 65536). The CRC is "redundant" in that it adds no information. A single corrupted bit in the data will result in a one bit change in the calculated CRC but multiple corrupted bits may cancel each other out. CRCs treat blocks of input bits as coefficient-sets for polynomials. E.g., binary 10100000 implies the polynomial: 1*x^7 + 0*x^6 + 1*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 + 0*x^0. This is the "message polynomial". A second polynomial, with constant coefficients, is called the "generator polynomial". 1 1 1 1 1 cyclic redundancy code cyclic redundancy check 1 1 1 1 1 Cyclo (Cyclomatic complexity tool) A C and C++ code analysis tool by Roger D. Binns. It measures cyclomatic complexity, shows function calls, and can draw flowgraphs of ANSI C and C++ code. It requires Lex and C++. Posted to alt.sources, 1993-06-28. (1993-06-28) 1 1 1 1 1 cyclomatic complexity A measure of the number of linearly independent paths through a program module. Cyclomatic complexity is a measure for the complexity of code related to the number of ways there are to traverse a piece of code. This determines the minimum number of inputs you need to test all ways to execute the program. (1998-03-17) 1 1 1 1 1 Cygnus Tcl Tools A rebundling of Tcl and Tk into the Cygnus GNU build framework with "configure" by david d 'zoo' zuhn <zoo@cygnus.com>. Latest version: Release-930124, as of 1993-01-24. (ftp://cygnus.com/pub/). (2000-09-25) 1 1 1 1 1 cylinder The set of tracks on a multi-headed disk that may be accessed without head movement. That is, the collection of disk tracks which are the same distance from the spindle about which the disks rotate. Each such group forms the shape of a cylinder. Placing data that are likely to be accessed together in cylinders reduces the access significantly as head movement (seeking) is slow compared to disk rotation and switching between heads. (1997-07-15) 1 1 1 1 1 CypherText An interactive language for text formatting and typesetting. ["CypherText: An Extensible Composing and Typesetting Language", C.G. Moore et al, Proc FJCC 37, AFIPS (Fall 1970)]. (1995-05-10) 1 1 1 1 1 Cyrix A microprocessor manufacturer. They produce an Intel 486 equivalent - the Cy486SLC and a Pentium equivalent - the Cyrix 6x86. (http://cyrix.com/). (1996-03-23) 1 1 1 1 1 Cyrix 6x86 (6x86) IBM and Cyrix's sixth-generation, 64-bit 80x86-compatible microprocessor. The 6x86 combines aspects of both RISC and CISC. It has a superscalar, superpipelined core, and performs register renaming, speculative execution, out-of-order completion, and data dependency removal. It has a 16-kilobyte primary cache and is socket-compatible with the Pentium P54C. It has four performance levels: PR 120+, PR 150+, PR 166+ and PR 200+. The chip was designed by Cyrix and is manufactured by IBM. The architecture of the 6x86 is more advanced than that of the Pentium, incorporating some of the features of Intel's Pentium Pro. At a given clock rate it executes most code more quickly than a Pentium would. However, its FPU is considerably less efficient than Intel's. IBM FAQ (http://chips.ibm.com/products/x86/6x86/faqs/6x86_faqs.html), Cyrix FAQ 1 1 1 1 1 cz The country code for the Czech Republic. (1999-01-27) 1 1 1 1 1 D 1. "The Data Language." MS-DOS 4GL. 2. A Haskell-like language, with type classes. E-mail: <polar@cs.syr.edu>. 1 1 1 1 1 D-1000 Datamatic Corporation's first computer, which weighed 25 tons, took up 6,000 square feet and cost $1.5 million, produced some time after 1955. (2009-01-14) 1 1 1 1 1 DAA Distributed Application Architecture: under design by Hewlett-Packard and Sun. A distributed object management environment that will allow applications to be developed independent of operating system, network or windowing system. 1 1 1 1 1 DAC Digital to Analog Converter 1 1 1 1 1 DACAPO Broad-range hardware specification language. "Mixed Level Modelling and Simulation of VLSI Systems", F.J. Rammig in Logic Design and Simulation, E. Horbst ed, N-H 1986. 1 1 1 1 1 DACNOS A prototype network operating system for multi-vendor environments, from IBM European Networking Centre Heidelberg and University of Karlsruhe. (1995-01-16) 1 1 1 1 1 D/A converter Digital to Analog Converter 1 1 1 1 1 DACTL Declarative Alvey Compiler Target Language. An intermediate language from the University of East Anglia, used in the Flagship project. DACTL is based on a form of graph rewriting which can be used to implement functional languages, logic languages and imperative languages. The current version is Dactl0. ["DACTL - A Computational Model and Compiler Target Language Based on Graph Reduction", J.R.W. Glauert et al, ICL Tech J 5(3) (1987)]. (1994-09-22) 1 1 1 1 1 DADS Dictionary of Algorithms and Data Structures 1 1 1 1 1 daemon /day'mn/ or /dee'mn/ (From the mythological meaning, later rationalised as the acronym "Disk And Execution MONitor") A program that is not invoked explicitly, but lies dormant waiting for some condition(s) to occur. The idea is that the perpetrator of the condition need not be aware that a daemon is lurking (though often a program will commit an action only because it knows that it will implicitly invoke a daemon). For example, under ITS writing a file on the LPT spooler's directory would invoke the spooling daemon, which would then print the file. The advantage is that programs wanting files printed need neither compete for access to, nor understand any idiosyncrasies of, the LPT. They simply enter their implicit requests and let the daemon decide what to do with them. Daemons are usually spawned automatically by the system, and may either live forever or be regenerated at intervals. 1 1 1 1 1 DAG 1. <architecture> Data Address Generator. 2. <mathematics> directed acyclic graph. (1997-08-30) 1 1 1 1 1 Daisy A functional language. ["Daisy Programming Manual", S.D. Johnson, CS Dept TR, Indiana U, 1988]. 1 1 1 1 1 DAISY 201 An early system on G-15. [Listed in CACM 2(5):16 (May 1959)]. 1 1 1 1 1 daisy chain A bus wiring scheme in which, for example, device A is wired to device B, device B is wired to device C, etc. The last device is normally wired to a resistor or terminator. All devices may receive identical signals or, in contrast to a simple bus, each device in the chain may modify one or more signals before passing them on. Characteristic of RS-485, of Apple's LocalTalk, and of various industrial control networks; also often used to describe Thinwire Ethernet (10base2). (1997-01-07) 1 1 1 1 1 daisywheel printer A kind of impact printer where the characters are arranged on the ends of the spokes of a wheel (resembling the petals on a daisy). The wheel (usually made of plastic) is rotated to select the character to print and then an electrically operated hammer mechanism bends the selected spoke forward slightly, sandwiching an ink ribbon between the character and the paper, as in a typewriter. One advantage of this arrangement over that of a typewriter is that different wheels may be inserted to produce different typefaces. (1998-04-28) 1 1 1 1 1 dancing frog A bug or glitch that only occurs for a particular user; never when the user tries to show it to anyone else. The term is derived from a Warner Brothers cartoon in which a man discovers a frog which can sing and dance; he believes this will make his fortune but the frog never performs in front of anyone else. (2004-10-16) 1 1 1 1 1 dangling pointer A reference that doesn't actually lead anywhere. In C and some other languages, a pointer that doesn't actually point at anything valid. Usually this happens because it formerly pointed to something that has moved or disappeared, e.g. a heap-allocated block which has been freed and reused. Used as jargon in a generalisation of its technical meaning; for example, a local phone number for a person who has since moved is a dangling pointer. This dictionary contains many dangling pointers - cross-references to non-existent entries, as explained in the Help page (help.html). [Jargon File] (2014-09-20) 1 1 1 1 1 DANTE A company established by the national research networks in Europe to provide international network services. 1 1 1 1 1 DAP Fortran ["Efficient High Speed Computing with the Distributed Array Processor", P.M. Flanders et al, pp.113-127 (1977)]. [Same as Fortran- Plus?] 1 1 1 1 1 DAPLEX ["The Functional Data Model and the Data Language DAPLEX", D.W. Shipman, ACM Trans Database Sys, 6(1):140-173 (Mar 1981)]. 1 1 1 1 1 DARE Differential Analyzer REplacement. A family of simulation languages for continuous systems. ["Digital Continuous System Simulation", G.A. Korn et al, P-H 1978]. 1 1 1 1 1 dark-side hacker A criminal or malicious hacker; a cracker. From George Lucas's Darth Vader, "seduced by the dark side of the Force". The implication that hackers form a sort of elite of technological Jedi Knights is intended. Opposite: samurai. [Jargon File] (1997-04-28) 1 1 1 1 1 Darms A music language. ["The Darms Project: A Status Report", R.F. Erickson, Computers and the Humanities 9(6):291-298 (June 1975)]. (1995-05-12) 1 1 1 1 1 DARPA Defense Advanced Research Projects Agency 1 1 1 1 1 Dartmouth BASIC The original BASIC language, designed by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963. Dartmouth BASIC first ran on a GE 235 [date?] and on an IBM 704 on 1964-05-01. It was designed for quick and easy programming by students and beginners using Dartmouth's experimental time-sharing system. Unlike most later BASIC dialects, Dartmouth BASIC was compiled. (2003-07-02) 1 1 1 1 1 Darwin 1. <operating system> An operating system based on the FreeBSD version of Unix, running on top of a microkernel (Mach 3.0 with darwin 1.02) that offers advanced networking, services such as the Apache web server, and support for both Macintosh and Unix file systems. Darwin was originally released in March 1999. It currently runs on PowerPC based Macintosh computers, and, in October 2000, was being ported to Intel processor-based computers and compatible systems by the Darwin community. 2. <programming, tool> A general purpose structuring tool of use in building complex distributed systems from diverse components and diverse component interaction mechanisms. Darwin is being developed by the Distributed Software Engineering Section of the Department of Computing at Imperial College. It is in essence a declarative binding language which can be used to define hierarchic compositions of interconnected components. Distribution is dealt with 1 1 1 1 1 DAS Digital Analog Simulator. Represents analog computer design. (1994-11-08) 1 1 1 1 1 DASD Direct-Access Storage Device 1 1 1 1 1 DASE Distributed Application Support Environment 1 1 1 1 1 DASL Datapoint's Advanced System Language. A cross between C and Pascal by Gene Hughes with custom features for Datapoint hardware (no stack). It is used internally by Datapoint. (1994-11-08) 1 1 1 1 1 DAT 1. Digital Audio Tape. 2. Dynamic Address Translation. 1 1 1 1 1 data /day't*/ (Or "raw data") Numbers, characters, images, or other method of recording, in a form which can be assessed by a human or (especially) input into a computer, stored and processed there, or transmitted on some digital channel. Computers nearly always represent data in binary. Data on its own has no meaning, only when interpreted by some kind of data processing system does it take on meaning and become information. For example, the binary data 01110101 might represent the integer 117 or the ASCII lower case U character or the blue component of a pixel in some video. Which of these it represents is determined by the way it is processed (added, printed, displayed, etc.). Even these numbers, characters or pixels however are still not really information until their context is known, e.g. my bank balance is £117, there are two Us in "vacuum", you have blue eyes. (2007-09-10) 1 1 1 1 1 data abstraction Any representation of data in which the implementation details are hidden (abstracted). Abstract data types and objects are the two primary forms of data abstraction. [Other forms?]. (2003-07-03) 1 1 1 1 1 data acquisition data logging 1 1 1 1 1 Data Address Generator (DAG) The mechanism which generates temporary memory addresses for data that is transferred between memory and registers in a Digital Signal Processor. Certain DSP architectures incorporate more than one DAG to simplify the programming needed to move blocks of data between buffers. For instance, certain Fast Fourier Transform algorithms requiring bit reversing, can use the DAG for that purpose, or they can use two DAGS, one for Program Memory Data (PMD), and the other for Data Memory Data (DMD). (1997-08-12) 1 1 1 1 1 database 1. <database> One or more large structured sets of persistent data, usually associated with software to update and query the data. A simple database might be a single file containing many records, each of which contains the same set of fields where each field is a certain fixed width. A database is one component of a database management system. See also ANSI/SPARC Architecture, atomic, blob, data definition language, deductive database, distributed database, fourth generation language, functional database, object-oriented database, relational database. Carol E. Brown's tutorial (http://accounting.rutgers.edu/raw/aies/www.bus.orst.edu/faculty/brownc/lectures/db_tutor/db_tutor.htm). 2. <hypertext> A collection of nodes managed and stored in one place and all accessible via the same server. Links outside this are "external", and those inside are "internal". On the World-Wide Web this is called a website. 3. All the facts and rules comprising a logic programming 1 1 1 1 1 database administrator A person responsible for the design and management of one or more databases and for the evaluation, selection and implementation of database management systems. In smaller organisations, the data administrator and database administrator are often one in the same; however, when they are different, the database administrator's function is more technical. The database administrator would implement the database software that meets the requirements outlined by the organisation's data administrator and systems analysts. Tasks might include controling an organisation's data resources, using data dictionary software to ensure data integrity and security, recovering corrupted data and eliminating data redundancy and uses tuning tools to improve database performance. (2004-03-11) 1 1 1 1 1 database analyst A person who uses data modeling to analyse and specify data use within an application area. A database analyst defines both logical views and physical data structures. In a client/server environment, he defines the database part of the back end system. (2004-03-11) 1 1 1 1 1 database machine A computer or special hardware that stores and retrieves data from a database. It is specially designed for database access and is coupled to the main (front-end) computer(s) by a high-speed channel. This contrasts with a database server, which is a computer in a local area network that holds a database. The database machine is tightly coupled to the main CPU, whereas the database server is loosely coupled via the network. [Example?] (2004-03-11) 1 1 1 1 1 database management system (DBMS) A suite of programs which typically manage large structured sets of persistent data, offering ad hoc query facilities to many users. They are widely used in business applications. A database management system (DBMS) can be an extremely complex set of software programs that controls the organisation, storage and retrieval of data (fields, records and files) in a database. It also controls the security and integrity of the database. The DBMS accepts requests for data from the application program and instructs the operating system to transfer the appropriate data. When a DBMS is used, information systems can be changed much more easily as the organisation's information requirements change. New categories of data can be added to the database without disruption to the existing system. Data security prevents unauthorised users from viewing or updating the database. Using passwords, users are allowed 1 1 1 1 1 database manager The part of the database management system (DBMS) that handles the organisation, storage and retrieval of the data. A database manager may work with traditional programming languages, such as COBOL and BASIC, or may work only with its proprietary programming language. The terms database manager and database management system are used interchangeably. A database manager links two or more files together and is the foundation for developing routine business systems. Contrast with file manager, which works with only one file at a time and is typically used interactively on a personal computer for managing personal, independent files, such as name and address lists. 1 1 1 1 1 database normalisation A series of steps followed to obtain a database design that allows for efficient access and storage of data in a relational database. These steps reduce data redundancy and the chances of data becoming inconsistent. A table in a relational database is said to be in normal form if it satisfies certain constraints. Codd's original work defined three such forms but there are now five generally accepted steps of normalisation. The output of the first step is called First Normal Form (1NF), the output of the second step is Second Normal Form (2NF), etc. First Normal Form eliminates repeating groups by putting each value of a multi-valued attribute into a new row. Second Normal Form eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key. Third Normal Form eliminates functional dependencies on non-key fields by putting them in a separate table. At this 1 1 1 1 1 database query language A language in which users of a database can (interactively) formulate requests and generate reports. The best known is SQL. (1998-04-15) 1 1 1 1 1 database server A stand-alone computer in a local area network that holds and manages the database. It implies that database management functions, such as locating the actual record being requested, is performed in the server computer. Contrast with file server, which acts as a remote disk drive and requires that large parts of the database, for example, entire indexes, be transmitted to the user's computer where the real database management tasks are performed. First-generation personal computer database software was not designed for a network; thus, modified versions of the software released by the vendors employed the file server concept. Second-generation products, designed for local area networks, perform the management tasks in the server where they should be done, and consequently are turning the file server into a database server. 1 1 1 1 1 database transaction A set of related changes applied to a database. The term typically implies that either all of the changes should be applied or, in the event of an error, none of them, i.e. the transaction should be atomic. Atomicity is one of the ACID properties a transaction can have, another is isolation - preventing interference between processes trying to access the database cocurrently. This is usually achieved by some form of locking - where one process takes exclusive control of a database table or row for the duration of the transaction, preventing other processes from accessing the locked data. The canonical example of a transaction is transferring money between two bank accounts by subtracting it from one and adding it to the other. Some relational database management systems require the user to explicitly start a transaction and then either commit it (if all the individual steps are successful) or roll it back (if there are any errors). 1 1 1 1 1 Data/BASIC (Or "Pick BASIC") A BASIC-like language with database capabilities, the main programming language on the Pick OS. ["The Data/BASIC Language - A Data Processing Language for Non-Professional Programmers", P.C. Dressen, Proc SJCC 36, AFIPS, Spring 1970]. (2001-04-30) 1 1 1 1 1 DATABUS DATApoint BUSiness Language. A language like an interpreted assembly language, used for custom applications on Datapoint computers. (1995-01-16) 1 1 1 1 1 data bus The bus (connections between and within the CPU, memory, and peripherals) used to carry data. Other connections are the address bus and control signals. The width and clock rate of the data bus determine its data rate (the number of bytes per second it can carry), which is one of the main factors determining the processing power of a computer. Most current processor designs use a 32-bit bus, meaning that 32 bits of data can be transferred at once. Some processors have an internal data bus which is wider than their external bus in order to make external connections cheaper while retaining some of the benefits in processing power of a wider bus. See also data path. (1995-01-16) 1 1 1 1 1 datacenter manager A person who plans and directs all computer and peripheral operations, data entry, data control scheduling and quality control. (2004-03-11) 1 1 1 1 1 data channel A channel (on a BRI or PRI line) used to carry control information, to set up connections on the associated bearer channels. The name wasn't too bad back when users were sending voice (not data) over the bearer channels, but in 1997 it's quite a misnomer. (1997-03-10) 1 1 1 1 1 DATACODE I An early system used on the Datatron 200 series. [Listed in CACM 2(5):16, May 1959]. (1994-12-06) 1 1 1 1 1 Datacom A DBMS from Computer Associates International. (1994-12-06) 1 1 1 1 1 Data Communication Equipment (DCE) The devices and connections of a communications network that connect the communication circuit between the data source and destination (the Data Terminal Equipment or DTE). A modem is the most common kind of DCE. Before data can be transmited over a modem, the DTR (Data Terminal Ready) signal must be active. DTR tells the DCE that the DTE is ready to transmit and receive data. DCE and DTE are usually connected by an EIA-232 serial line. It is necessary to distinguish these two types of device because their connectors must be wired differently if a straight-through cable (pin 1 to pin 1, pin 2 to pin 2 etc.) is to be used. DCE should have a female connector and should transmit on pin two and receive on pin three. It is a curious fact that many modems are "DTE" according to the original standard. (1995-02-28) 1 1 1 1 1 data communications analyst A person who installs, maintains, and troubleshoots data networks. A data communications analyst may have knowledge of T1 lines, TCP/IP, fiber optics, SNA, frame relay. He assists users with problems related to connectivity, analyses data flow, configures modems, DSUs, multiplexors, and routers, and uses network tools such as NetView or Netspy. (2004-03-11) 1 1 1 1 1 Data Communications Equipment Data Communication Equipment 1 1 1 1 1 data compression compression. Probably to distinguish it from (electronic) signal compression. (1995-04-02) 1 1 1 1 1 Data definition language (DDL) 1. A language enabling the structure and instances of a database to be defined in a human-, and machine-readable form. SQL contains DDL commands that can be used either interactively, or within programming language source code, to define databases and their components, e.g. CREATE and DROP. See also Data manipulation language (DML). 2. A specification language for databases, based on the entity-relationship model. It is used in the Eli compiler-compiler to manage type definitions. ["DDL Reference Manual", ECE Dept U Colorado, 1991]. (1999-04-26) 1 1 1 1 1 data dictionary A data structure that stores metadata, i.e. data about data. The term "data dictionary" has several uses. Most generally it is a set of data descriptions that can be shared by several applications. Usually it means a table in a database that stores the names, field types, length, and other characteristics of the fields in the database tables. An active data dictionary is automatically updated as changes occur in the database. A passive data dictionary must be manually updated. In a DBMS, this functionality is performed by the system catalog. The data dictionary is a more general software utility used by designers, users, and administrators for information resource management. The data dictionary may maintain information on system hardware, software, documentation, users, and other aspects. Data dictionaries are also used to document the database 1 1 1 1 1 data dictionary file (DDF) A set of files describing the structure of a database file. DDFs define database tables and include information about file locations, field layouts and indexes. DDFs are the standard method for defining field and index characteristics for Btrieve files. (1997-06-03) 1 1 1 1 1 data driven A data driven architecture/language performs computations in an order dictated by data dependencies. Two kinds of data driven computation are dataflow and demand driven. From about 1970 research in parallel data driven computation increased. Centres of excellence emerged at MIT, CERT-ONERA in France, NTT and ETL in Japan and Manchester University. 1 1 1 1 1 Data Driven Machine (DDM) A dataflow language. ["The Architecture and System Method of DDM-1: A Recursively Structured Data Driven Machine", A. Davis, Proc 5th Ann Symp Comp Arch, IEEE 1978]. (1999-04-26) 1 1 1 1 1 Data Encryption Algorithm (DEA) An ANSI standard defined in ANSI X3.92-1981. It is identical to the Data Encryption Standard (DES). (1994-12-06) 1 1 1 1 1 Data Encryption Key (DEK) Used for the encryption of message text and for the computation of message integrity checks (signatures). See cryptography. (1994-12-06) 1 1 1 1 1 Data Encryption Standard (DES) The NBS's popular, standard encryption algorithm. It is a product cipher that operates on 64-bit blocks of data, using a 56-bit key. It is defined in FIPS 46-1 (1988) (which supersedes FIPS 46 (1977)). DES is identical to the ANSI standard Data Encryption Algorithm (DEA) defined in ANSI X3.92-1981. DES has been implemented in VLSI. SunOS provides a des command which can make use of DES hardware if fitted. Neither the software nor the hardware are supposed to be distributed outside the USA. Unix manual pages: des(1), des(3), des(4). (1994-12-06) 1 1 1 1 1 data feed Some process for transferring data from one system to another in a predetermined form. (2009-05-17) 1 1 1 1 1 data flow A data flow architecture or language performs a computation when all the operands are available. Data flow is one kind of data driven architecture, the other is demand driven. It is a technique for specifying fine-grain concurrency, usually in the form of two-dimensional graphs in which instructions that are available for concurrent execution are written alongside each other while those that must be executed in sequence are written one under the other. Data dependencies between instructions are indicated by directed arcs. Instructions do not reference memory since the data dependence arcs allow data to be transmitted directly from the producing instruction to the consuming one. Data flow schemes differ chiefly in the way that they handle re-entrant code. Static schemes disallow it, dynamic schemes use either "code copying" or "tagging" at every point of reentry. An example of a data flow architecture is MIT's VAL 1 1 1 1 1 data flow analysis A process to discover the dependencies between different data items manipulated by a program. The order of execution in a data driven language is determined solely by the data dependencies. For example, given the equations 1. X = A + B 2. B = 2 + 2 3. A = 3 + 4 a data-flow analysis would find that 2 and 3 must be evaluated before 1. Since there are no data dependencies between 2 and 3, they may be evaluated in any order, including in parallel. This technique is implemented in hardware in some pipelined processors with multiple functional units. It allows instructions to be executed as soon as their inputs are available, independent of the original program order. 1 1 1 1 1 Data Flow Diagram A graphical notation used to describe how data flows between processes in a system. Data flow diagrams are an important tool of most structured analysis techniques. (http://smartdraw.com/resources/centers/software/dfd.htm). (2003-05-17) 1 1 1 1 1 data fork Macintosh file system 1 1 1 1 1 data frame activation record 1 1 1 1 1 Data General A US computer manufacturer. Responsible for the Nova minicomputer. Quarterly sales $284M, profits -$12M (Aug 1994). (1994-09-26) 1 1 1 1 1 Data General mN601 Data General MicroNova 601 1 1 1 1 1 data glove An input device for virtual reality in the form of a glove which measures the movements of the wearer's fingers and transmits them to the computer. Sophisticated data gloves also measure movement of the wrist and elbow. A data glove may also contain control buttons or act as an output device, e.g. vibrating under control of the computer. The user usually sees a virtual image of the data glove and can point or grip and push objects. Examples are Fifth Dimension Technologies (5DT)'s 5th Glove, and Virtual Technologies' CyberGlove. A cheaper alternative is InWorld VR's CyberWand. ["Full freedom plus input", PC Magazine, Mar 14 1995, pp. 168-190]. [Inventor?] (1995-04-04) 1 1 1 1 1 datagram A self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination computer without reliance on earlier exchanges between this source and destination computer and the transporting network. See also connectionless, frame, packet. 1 1 1 1 1 data hierarchy The system of data objects which provide the methods for information storage and retrieval. Broadly, a data hierarchy may be considered to be either natural, which arises from the alphabet or syntax of the language in which the information is expressed, or machine, which reflects the facilities of the computer, both hardware and software. A natural data hierarchy might consist of bits, characters, words, phrases, sentences, paragraphs, and chapters. One might use components bound to an application, such as field, record, and file, and these would ordinarily be further specified by having data descriptors such as name field, address field, etc. On the other hand, a machine or software system might use bit, byte, word, block, partition, channel, and port. Programming languages often provide types or objects which can create data hierarchies of arbitrary complexity, thus allowing software system designers to model language 1 1 1 1 1 data integrity The absence of unintended changes or errors in some data. Integrity implies that the data is an exact copy of some original version, e.g. that it has not been corrupted in the process of being written to, and read back from, a hard disk or during transmission via some communications channel. Integrity may further imply that the information represented by the data has been validated, i.e. verified to conform to certain constraints, e.g. a date's year, month and day parts are within the appropriate ranges and the date actually exists. (2009-06-03) 1 1 1 1 1 Data Interchange Standards Association (DISA) A not-for-profit corporation that acts as the secretariat for ANSI's EDI standards committee, ASC X12 that works on ANSI X12. DISA manages ASC X12's membership, balloting, standards development and maintenance, publications, and communications with ANSI. (1999-09-18) 1 1 1 1 1 Data Jack A wall-mounted or desk-mounted connector (frequently a wide telephone-style 8-pin RJ-45) for connecting to data cabling in a building. (1997-01-07) 1 1 1 1 1 Datakit A circuit-switched digital network, similar to X.25. Datakit supports host-to-host connections and EIA-232 connections for terminals, printers, and hosts. Most of Bell Laboratories is trunked together on Datakit. On top of DK transport service, people run UUCP for electronic mail and dkcu for remote login. ISN is the version of Datakit supported by AT&T Information Systems. Bell Laboratories in Holmdel, New Jersey, uses ISN for internal data communication. (http://fc.net:80/phrack/files/p18/p18-9.html). ["Towards a universal data transport system", A. G. Fraser, IEEE Journal on Selected Areas in Communications, SAC-1(5) pp. 803-16, 1983]. (1996-10-20) 1 1 1 1 1 Dataless Management Services (DMS) (http://cs.arizona.edu/computer.help/policy/DIGITAL_unix/AA-PS3LE-TE_html/sharing10.html). (2005-09-15) 1 1 1 1 1 dataless management utility (DMU) A Dataless Management Services (DMS) utility for managing the sharing of installed operating software between DMS servers and clients. It allows users to install, configure, show and delete DMS environments and add, list, modify and remove DMS clients. (2005-09-15) 1 1 1 1 1 Data Link Connection Identifier (DLCI) A channel number which is attached to data frames to tell a Frame Relay network how to route the data. In Frame Relay, multiple logical channels are multiplexed over a single physical channel. The DLCI says which of these logical channels a particular data frame belongs to. (http://etinc.com/frmain.htm#whatsadlci). (2000-02-13) 1 1 1 1 1 data link layer Layer two, the second lowest layer in the OSI seven layer model. The data link layer splits data into frames (see fragmentation) for sending on the physical layer and receives acknowledgement frames. It performs error checking and re-transmits frames not received correctly. It provides an error-free virtual channel to the network layer. The data link layer is split into an upper sublayer, Logical Link Control (LLC), and a lower sublayer, Media Access Control (MAC). Example protocols at this layer are ABP, Go Back N, SRP. (1995-02-14) 1 1 1 1 1 data link level data link layer 1 1 1 1 1 Data Link Provider Interface (DLPI) The interface that a network driver presents to the (higher level) logical link layer for driving the network at the datagram level in a Unix STREAMS environment and possibly elsewhere. DLPI corresponds to ISO 8802/2 (LLC) which covers both connection-oriented and connectionless protocols. [Is this correct? Better explanation?] (1996-01-29) 1 1 1 1 1 Data Link Switching (DLSw) A standard for transporting IBM Systems Network Architecture (SNA) and network basic input/output system (NetBIOS) traffic over an Internet protocol network. Initially, in 1992, DLSw was proprietary to IBM. It was submitted to the IETF as RFC 1434 in 1993, later updated by RFC 1795. (http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/dlsw.htm). (2008-01-11) 1 1 1 1 1 data logger data logging 1 1 1 1 1 data logging (data acquisition) Storing a series of measurements over time, usually from a sensor that converts a physical quantity such as temperature, pressure, relative humidity, light, resistance, current, power, speed, vibration into a voltage that is then converted by a digital to analog converter (DAC) into a binary number. Data logging hardware may have several DACs for multiple simultaneous measurements. The hardware usually connects to a parallel port, serial port or USB port on a PC. (2004-11-15) 1 1 1 1 1 Data Management Language (DML) 1. Any language for manipulating data or files, e.g. IBM's Distributed Data Management (DDM). 2. An early ALGOL-like language with lists and graphics, that ran on the Honeywell 635. ["DML: A Data Management Language", D.W. Bray et al, GE, Syracuse NY]. (1999-06-07) 1 1 1 1 1 Data Manipulation Language (DML, or Data Management Language) A language for the manipulation of data in a database by applications and/or directly by end-users. SQL contains DML commands such as INSERT, UPDATE, and DELETE. See also Data Definition Language (DDL). (1999-04-26) 1 1 1 1 1 data mart A type of data warehouse designed primarily to address a specific function or department's needs, as opposed to a data warehouse which is traditionally meant to address the needs of the organisation from an enterprise perspective. In addition, a data mart often uses aggregation or summarisation of the data to enhance query performance. However, it is important to maintain the ability to access the underlying base data to enable drill-down analysis as necessary. (1998-04-24) 1 1 1 1 1 Datamatic Corporation Honeywell 1 1 1 1 1 Datamation /day"t*-may"sh*n/ A magazine that many hackers assume all suits read. Used to question an unbelieved quote, as in Did you read that in Datamation?"" It used to publish something hackishly funny every once in a while, like the original paper on COME FROM in 1973, and Ed Post's "Real Programmers Don't Use Pascal" ten years later, but it has since become much more exclusively suit-oriented and boring. [Jargon File] 1 1 1 1 1 data mining Analysis of data in a database using tools which look for trends or anomalies without knowledge of the meaning of the data. Data mining was invented by IBM who hold some related patents. Data mining may well be done on a data warehouse. ShowCase STRATEGY (http://showcasecorp.com/) is an example of a data mining tool. (2001-02-08) 1 1 1 1 1 data model The product of the database design process which aims to identify and organize the required data logically and physically. A data model says what information is to be contained in a database, how the information will be used, and how the items in the database will be related to each other. For example, a data model might specify that a customer is represented by a customer name and credit card number and a product as a product code and price, and that there is a one-to-many relation between a customer and a product. It can be difficult to change a database layout once code has been written and data inserted. A well thought-out data model reduces the need for such changes. Data modelling enhances application maintainability and future systems may re-use parts of existing models, which should lower development costs. A data modelling language is a mathematical formalism with a 1 1 1 1 1 data modeling US spelling of "data modelling". (2000-06-24) 1 1 1 1 1 data modelling data model 1 1 1 1 1 Data Over Cable Service Interface Specification (DOCSIS) ITU-approved interface requirements for cable modems involved in high-speed data distribution over a cable television network. DOCSIS compatible equipment uses a 6 MHz carrier band for downstream, using 64 and 256 QAM (ITU Annex B), and QPSK and 16 QAM for upstream, allowing up to 36 and 10 Mb/s, respectively for downstream and upstream channels. CableLabs FAQ (http://cablemodem.com/FAQs.html). (2001-07-10) 1 1 1 1 1 Data Over Cable Systems Interface Specifications Data Over Cable Service Interface Specification 1 1 1 1 1 data packet packet 1 1 1 1 1 Dataparallel-C C with parallel extensions by Hatcher and Quinn of the University of New Hampshire. Dataparallel-C was based on an early version of C* and runs on the Intel iPSC-2 and nCube. 1 1 1 1 1 Data Parallel Haskell Adds Parallel Objects with arbitrary Dimension (PODs) and POD comprehensions to Haskell. (ftp://redstar.dcs.qmw.ac.uk/cpc/jon_hill/dpGlue.ps.Z). ["Data Parallel Haskell: Mixing Old and New Glue", J. Hill]. (1995-03-30) 1 1 1 1 1 data path A CPU's internal data bus and functional units. The width of the data path in bits is a major determiner of the processor's performance. (1997-07-09) 1 1 1 1 1 Dataphone Digital Service (DDS) The first private-line digital service offered by AT&T, with data rates typically at 2.4, 4.8, 9.6 and 56 kilobits per second. DDS is now part of AT&T's Accunet family of services. Most LEC (local exchange carriers) and IXC (IntereXchange Carriers) offer similar services. (1995-02-28) 1 1 1 1 1 DataPoint An early minicomputer manufacturer which also developed ARCnet. (2004-08-25) 1 1 1 1 1 data processing The input, verification, organisation, storage, retrieval, transformation, and extraction of information from data. The term is normally associated with commercial applications such as stock control or payroll. (1995-03-30) 1 1 1 1 1 Data Protection Act (DPA) A UK law guaranteeing rights to individuals in relation to personal data that others hold on them. For example, under the DPA, you have the right to see what data a company holds on you. (2007-06-17) 1 1 1 1 1 data rate data transfer rate 1 1 1 1 1 data redundancy Any technique that stores or transmits extra, derived data that can be used to detect or repair errors, either in hardware or software. Examples are parity bits and the cyclic redundancy check. If the cost of errors is high enough, e.g. in a safety-critical system, redundancy may be used in both hardware AND software with three separate computers programmed by three separate teams ("triple redundancy") and some system to check that they all produce the same answer, or some kind of majority voting system. The term is not typically used for other, less beneficial, duplication of data. 2. <communications> The proportion of a message's gross information content that can be eliminated without losing essential information. Technically, redundancy is one minus the ratio of the actual uncertainty to the maximum uncertainty. This is the fraction 1 1 1 1 1 data segment The range of memory locations where the initialised data of a program produced by a Unix linker is located. Executable code is located in the code segment and uninitialised data in the bss segment. (2004-02-24) 1 1 1 1 1 data service unit (DSU or "data service unit") A device used in digital transmission for connecting a CSU (Channel Service Unit) to Data Terminal Equipment (a terminal or computer), in the same way that a modem is used for connection to an analogue medium. A DSU provides a standard interface to a user's terminal which is compatible with modems and handles such functions as signal translation, regeneration, reformatting, and timing. The transmitting portion of the DSU processeses the customers' signal into bipolar pulses suitable for transmission over the digital facility. The receiving portion of the DSU is used both to extract timing information and to regenerate mark and space information from the received bipolar signal. (1995-01-30) 1 1 1 1 1 data set An IBM term for a file. (1997-04-15) 1 1 1 1 1 data set organization (DSORG) An IBM term for file structure. These include PS physical sequential, DA direct access, IS indexed sequential, PO partitioned (a library). This system dates from OS/360, and breaks down beginning with VSAM and VTAM, where it is no longer applied. Sequential and indexed data sets can be accessed using either a "basic" or a "queued" "access method." For example a DSORG=PS file can use either BSAM (basic sequential access method) or QSAM (queued sequential access method). It can also be processed as a direct file using BDAM. Likewise a library can be processed using BPAM (basic partitioned access method), BSAM, QSAM, or BDAM. DSORG and access method are somewhat, but not completely, orthogonal. The "basic" access method deals with physical blocks rather than records, and usually provides more control over the specific device. Each I/O operation using the "basic" 1 1 1 1 1 DataStage A tool set for designing, developing, and running applications that populate one or more tables in a data warehouse or data mart. [Reference]? (2004-06-23) 1 1 1 1 1 Datastorm Technologies, Inc. The original suppliers of Procomm. Address: Columbia MO, USA. (2004-06-29) 1 1 1 1 1 data striping Segmentation of logically sequential data, such as a single file, so that segments can be written to multiple physical devices (usually disk drives) in a round-robin fashion. This technique is useful if the processor is capable of reading or writing data faster than a single disk can supply or accept it. While data is being transferred from the first disk, the second disk can locate the next segment. Data striping is used in some modern databases, such as Sybase, and in certain RAID devices under hardware control, such as IBM's RAMAC array subsystem (9304/9395). Data striping is different from, and may be used in conjunction with, mirroring. (1996-10-17) 1 1 1 1 1 data structure Any method of organising a collection of data to allow it to be manipulated effectively. It may include meta data to describe the properties of the structure. Examples data structures are: array, dictionary, graph, hash, heap, linked list, matrix, object, queue, ring, stack, tree, vector. (2003-09-11) 1 1 1 1 1 Data Structures Language A dialect of MAD with extensions for lists and graphics, on Philco 212. ["A Compiler Language for Data Structures", N. Laurance, Proc ACM 23rd Natl Conf 36 (1968)]. (1995-02-28) 1 1 1 1 1 Data Terminal Equipment (DTE) A device which acts as the source and/or destination of data and which controls the communication channel. DTE includes terminals, computers, protocol converters, and multiplexors. DTE is usually connected via an EIA-232 serial line to Data Communication Equipment (DCE), typically a modem. It is necessary to distinguish these two types of device because their connectors must be wired differently if a straight-through cable (pin 1 to pin 1, pin 2 to pin 2 etc.) is to be used. DTE should have a male connector and should transmit on pin three and receive on pin two. It is a curious fact that many modems are actually "DTE" according to the original standard. (1995-02-28) 1 1 1 1 1 Data Terminal Ready (DTR) The wire in a full RS-232 connection that tells the Data Communication Equipment (DCE, typically a modem) that the Data Terminal Equipment (DTE, typically a computer or terminal) is ready to transmit and receive data. (2000-04-05) 1 1 1 1 1 DATA-TEXT A system from Harvard for numerical computations in the Social Sciences. ["DATA-TEXT Primer", D.J. Armor, Free Press 1972]. (1994-12-06) 1 1 1 1 1 data transfer Copying or moving data from one place to another, typically via some kind of network (e.g. Asynchronous Transfer Mode, File Transfer Protocol) or local data connection (bus, SCSI, IDE, SATA). (2009-06-09) 1 1 1 1 1 data transfer rate (Or "throughput, data rate", "transmission rate") The amount of data transferred in one direction over a link divided by the time taken to transfer it, usually expressed in bits per second (bps), bytes per second (Bps) or baud. The link may be anything from an interface to a hard disk to a radio transmission from a satellite. Where data transfer is not continuous throughout the given time interval, the data transfer rate is thus an average rate that will be lower than the peak rate. The peak or maximum possible rate may itself be lower than the capacity of the communication channel if the channel is shared, or part of the signal is not considered as data, e.g. checksum or routing information. When applied to data rate, the multiplier prefixes "kilo-", mega-, "giga-", etc. (and their abbreviations, "k", "M", G, etc.) always denote powers of 1000. For example, 64 kbps is 64,000 bits per second. This contrasts with units of 1 1 1 1 1 DATATRIEVE A query and report system for use with DEC's VMS (RMS, VAX Rdb/VMS or VAX DBMS). (2007-01-16) 1 1 1 1 1 Datatron 200 series A family of computers produced by Burroughs that included the Datatron 204 and Datatron 220. (2007-01-16) 1 1 1 1 1 data type type 1 1 1 1 1 DataViews Graphical user interface development software from V.I.Corporation, aimed at constructing platform-independent interactive views of dynamic data. (1994-12-07) 1 1 1 1 1 DataVis A dataflow language for scientific visualisation. ["Data Flow Visual Programming Languages", D. Hils, J Vis Langs and Comput, Dec 1991]. (1994-12-06) 1 1 1 1 1 data warehouse (Or corporate data warehouse, CDW) Any system for storing, retrieving and managing large amounts of data. Data warehouse software often includes sophisticated compression and hashing techniques for fast searches, as well as advanced filtering. A data warehouse is often a relational database containing a recent snapshot of corporate data and optimised for searching. Planners and researchers can use this database without worrying about slowing down day-to-day operations of the production database. The latter can be optimised for transaction processing (inserts and updates). Compare data mart. (2007-05-16) 1 1 1 1 1 data warehousing data warehouse 1 1 1 1 1 date A string unique to a time duration of 24 hours between 2 successive midnights defined by the local time zone. The specific representation of a date will depend on which calendar convention is in force; e.g., Gregorian, Islamic, Japanese, Chinese, Hebrew etc. as well as local ordering conventions such as UK: day/month/year, US: month/day/year. Inputting and outputting dates on computers is greatly complicated by these localisation issues which is why they tend to operate on dates internally in some unified form such as seconds past midnight at the start of the first of January 1970 Many software and hardware representations of dates allow only two digits for the year, leading to the year 2000 problem. Unix manual page: date(1), ctime(3). (1997-07-11) 1 1 1 1 1 DAU /dow/ [German Fidonet] D"ummster Anzunehmender User. A German acronym for stupidest imaginable user. From the engineering-slang GAU for Gr"osster Anzunehmender Unfall (worst foreseeable accident), especially of a LNG tank farm plant or something with similarly disastrous consequences. In popular German, GAU is used only to refer to worst-case nuclear accidents such as a core meltdown. See cretin, loser and weasel. [Jargon File] (1994-12-06) 1 1 1 1 1 daughter (Or "child", "successor") In a tree, a node pointed to by a parent, i.e. another node closer to the root node. (1998-11-14) 1 1 1 1 1 daughterboard (Or "daughter board", "daughtercard", "daughter card") A printed circuit board that connects to the motherboard. The daughterboard is typically smaller than the motherboard. A daughterdboard often adds to or supports the main functions of the motherboard, unlike an expansion card which provides some new function. For example, a post-release hardware modification might be released as a daughterboard for soldering onto the motherboard. (2004-09-28) 1 1 1 1 1 daughtercard daughterboard 1 1 1 1 1 David Turner Professor David A Turner. One of the pioneers of functional languages. He designed several languages, including, SASL (1976), KRC (1981), and Miranda, many of which were implemented using combinators and the S-K reduction machine which he defined. He coined the name "ZF expression" for the list comprehension. He worked at UKC and set up a company, Research Software Limited to market Miranda. (1994-12-06) 1 1 1 1 1 day mode phase 1 1 1 1 1 DAZIX Daisy/Cadnetix Corporation. A supplier of digital electronic CAE systems. (1994-12-06) 1 1 1 1 1 DB database 1 1 1 1 1 DB2 A relational database from IBM. When running under IBM's MVS (Multiple Virtual Storage) operating system, DB2 is implemented on top of VSAM and uses its underlying data structures. DB2, later called "DB2 Universal DataBase", also runs under windows NT, AIX, Solaris and, most recently, Linux. [Details? Was there a "DB1"?] (1999-02-01) 1 1 1 1 1 DB-25 The standard 25-pin D-shell connector used for EIA-232 serial communication. DE-9 is a common alternative. (1996-12-08) 1 1 1 1 1 DB2 catalog An IBM DB2 system table listing all objects in a database installation including hosts, servers, databases, tables and many more. Commands are provided to manage the catalog, e.g. db2 catalog database mydatabase on /databases/mydatabase to add a database reference. Catalog documentation (http://www-01.ibm.com/support/knowledgecenter/SSEPGG_9.7.0/com.ibm.db2.luw.sql.ref.doc/doc/r0011297.html). (2014-08-16) 1 1 1 1 1 DBA database administrator 1 1 1 1 1 dBASE An interactive DBMS, originally from Ashton-Tate Corporation, and the language used by it. dBASE evolved from Vulcan by Wayne Ratliffe, which came out in around 1980 and ran on CP/M. It was called dBaseII when sold to Ashton-Tate Corporation. The first release was dBASE II, ca 1980. There never was a dBASE I. Later versions included: dBASE III, dBASE III+, and dBASE IV. Ashton-Tate was taken over in the early 1990s by what became Borland Software Corporation who sold dBase in March(?) 1999 to the newly formed dBase Inc. dBase Inc's first release was Visual dBASE 5.7, a Y2K upgrade to Visual dBASE 5.x. Current version, as of 2003-11-24: dBASE PLUS 2.0x build 1703. dBase Home (http://dbase.com/). (2003-11-24) 1 1 1 1 1 DBC A data-parallel bit-serial C based on MPL. SRC, Bowie MD. E-mail: <maya@super.org>. (1995-05-01) 1 1 1 1 1 DBCS (IBM) double-byte character set. A character set that uses 16 bits to represent a character. (1995-03-21) 1 1 1 1 1 dBFAST dBASE dialect for MS-DOS and MS-Windows. 1 1 1 1 1 DBH Denis Howe 1 1 1 1 1 DBMS database management system 1 1 1 1 1 DBPL A procedural language with relational database constructs. A successor to Pascal/R and Modula/R. ["DBPL Report", J.W. Schmidt et al, DBPL-Memo 111-88, Fachbereich Informatik, Johann Wolfgang Goethe-Universitaet, Frankfurt, Germany, 1988]. (1994-12-07) 1 1 1 1 1 DBRI Dual Basic Rate Interface 1 1 1 1 1 dbx A source-level debugger originating from BSD Unix but now available for many other Unix distributions. Sun documentation (http://developers.sun.com/sunstudio/documentation/ss12/mr/man1/dbx.1.html). (2009-04-27) 1 1 1 1 1 dBXL A dBASE-like interpreter/language for MS-DOS from WordTech, Orinda, CA. (1994-12-07) 1 1 1 1 1 DC The Unix arbitrary precision postfix calculator and its language. Here is an example program which prints out factorials: echo "[la1+dsa*pla2220>y]sy0sa1lyx" | dc Unix manual page: dc(1). bc provides a somewhat more readable syntax which is compiled into dc. There is also a GNU DC. (1995-03-17) 1 1 1 1 1 DC1 control-Q 1 1 1 1 1 DC2 Device Control 2 1 1 1 1 1 DC3 Control-S 1 1 1 1 1 DC4 Device Control 4 1 1 1 1 1 DCA 1. Defense Communications Agency. See DISA. 2. Document Content Architecture from IBM. 1 1 1 1 1 DCAC Domestic Communications Assistance Center 1 1 1 1 1 DCALGOL Data Communications ALGOL. A superset of Burroughs Extended ALGOL used for writing Message Control Systems. 1 1 1 1 1 DCC 1. <audio> Digital Compact Cassette. 2. <networking> Direct Client to Client Protocol. (2001-12-02) 1 1 1 1 1 DCDL Digital Control Design Language. A language for simulating computer systems. ["DCDS Digital Simulating System", H. Potash et al, Proc FJCC 35, AFIPS (Fall 1969)]. 1 1 1 1 1 DCE 1. Data Communication Equipment. 2. Data Circuit-terminating Equipment. 3. Distributed Computing Environment from OSF. 1 1 1 1 1 DCG Definite Clause Grammar 1 1 1 1 1 DCI Display Control Interface 1 1 1 1 1 DCL 1. DIGITAL Command Language. The interactive command and scripting language for VAX/VMS. 2. Delphi Common LISP. An implementation of Common LISP that has been used as a basis for CLOS. 1 1 1 1 1 DCOM Distributed Component Object Model 1 1 1 1 1 DCP definitional constraint programming 1 1 1 1 1 D. C. Power Lab The former site of SAIL. This name was very funny because the obvious connection to electrical engineering was nonexistent - the lab was named after a Donald C. Power. Compare Marginal Hacks. [But did DCP's parents realise the joke?] [Jargon File] 1 1 1 1 1 DCS 1. Digital Cellular System. 2. Digital Control System. 1 1 1 1 1 DCT Discrete Cosine Transform 1 1 1 1 1 DD 1. <storage> double density. 2. <database> data dictionary. 3. <programming> Deployment Descriptor. (2005-01-26) 1 1 1 1 1 dd A Unix copy command with special options suitable for block-oriented devices; it was often used in heavy-handed system maintenance, as in "Let's "dd" the root partition onto a tape, then use the boot PROM to load it back on to a new disk". dd had a distinctly non-Unixy keyword option syntax reminiscent of IBM System/360 JCL (which had an elaborate DD "Dataset Definition" specification for I/O devices). Though the command filled a need, the interface design was clearly a prank. [Jargon File] (2005-08-08) 1 1 1 1 1 DDB device independent bitmap 1 1 1 1 1 DDCMP Digital Data Communications Message Protocol (DEC). 1 1 1 1 1 DDE Dynamic Data Exchange 1 1 1 1 1 DDE Manager An Oracle product that lets Microsoft Windows applications that support the Dynamic Data Exchange (DDE) protocol act as front end tools for Oracle. It allows applications like Excel, Word, Ami Professional, WingZ and ToolBook to query, update, graph and report information stored in Oracle. 1 1 1 1 1 DDIF Digital Document Interchange Format. A CDA specification for representing compound documents in revisable format; a DEC standard for document encoding. 1 1 1 1 1 DDL 1. ["A Digital System Design Language (DDL)", J.R. Duley, IEEE Trans on Computers c-17(9), pp. 850-861, Sep 1968]. 2. <language, games> An adventure language developed by M. Urban, C. Kostanick et al of the UCLA Computer Club. DDL was the forerunner of ADL. 3. Data Definition Language. 4. Document Description Language. 5. Dynamic Data Exchange. (Originally "Linking"). (1997-06-05) 1 1 1 1 1 DDM 1. <protocol, database> Distributed Data Management. 2. <language> Data Driven Machine. (1999-06-07) 1 1 1 1 1 DDN Defense Data Network 1 1 1 1 1 DDO Dynamic Drive Overlay 1 1 1 1 1 DDP Distributed Data Processing 1 1 1 1 1 DDR Double Data Rate Random Access Memory 1 1 1 1 1 DDR-RAM Double Data Rate Random Access Memory 1 1 1 1 1 DDR-SDRAM Double Data Rate Random Access Memory 1 1 1 1 1 DDS 1. Digital Data Service. 2. Digital Data System. 3. Dataphone Digital Service. 1 1 1 1 1 DDT 1. Generic term for a program that assists in debugging other programs by showing individual machine instructions in a readable symbolic form and letting the user change them. In this sense the term DDT is now archaic, having been widely displaced by "debugger" or names of individual programs like adb, "sdb", "dbx", or "gdb". 2. Under MIT's fabled ITS operating system, DDT (running under the alias HACTRN) was also used as the shell or top level command language used to execute other programs. 3. Any one of several specific debuggers supported on early DEC hardware. The DEC PDP-10 Reference Handbook (1969) contained a footnote on the first page of the documentation for DDT that illuminates the origin of the term: Historical footnote: DDT was developed at MIT for the PDP-1 computer in 1961. At that time DDT stood for "DEC Debugging Tape". Since then, the idea of an on-line debugging program has propagated throughout the computer industry. DDT 1 1 1 1 1 DDW distributed data warehouse 1 1 1 1 1 de The country code for Germany. (1999-01-27) 1 1 1 1 1 DE-9 The standard 9-pin D-shell connector used for EIA-232 serial communication. DE-9 is a common alternative to DB-25, especially on personal computers. (1999-12-08) 1 1 1 1 1 DEA Data Encryption Algorithm 1 1 1 1 1 DEACON Direct English Access and CONtrol. English-like query system. Sammet 1969, p.668. 1 1 1 1 1 dead 1. Non-functional; down; crashed. Especially used of hardware. 2. At XEROX PARC, software that is working but not undergoing continued development and support. [Jargon File] 1 1 1 1 1 DEADBEEF /ded-beef/ The hexadecimal pattern used to fill words of freshly allocated memory under a number of IBM environments including the RS/6000; equal to decimal 3,735,928,559 (unsigned) or -559,038,737 (32-bit signed). As in "Your program is DEADBEEF" (meaning gone, aborted, flushed from memory). (1998-06-29) 1 1 1 1 1 dead code (Or "infeasible path", "grunge") Any part of a program that can never be accessed because all calls to it have been removed, or because it is guarded by a control structure that provably must always transfer control somewhere else. The presence of dead code may reveal either logical errors due to alterations in the program or significant changes in the assumptions and environment of the program (see also software rot); a good compiler should report dead code so a maintainer can think about what it means. Sometimes it simply means that an *extremely* defensive programmer has inserted can't happen tests which really can't happen - yet. Synonym grunge. [Jargon File] (1996-05-22) 1 1 1 1 1 deadlock A situation where two or more processes are unable to proceed because each is waiting for one of the others to do something. A common example is a program waiting for output from a server while the server is waiting for more input from the controlling program before outputting anything. It is reported that this particular flavour of deadlock is sometimes called a "starvation deadlock", though the term "starvation" is more properly used for situations where a program can never run simply because it never gets high enough priority. Another common flavour is "constipation", in which each process is trying to send stuff to the other but all buffers are full because nobody is reading anything). See deadly embrace. Another example, common in database programming, is two processes that are sharing some resource (e.g. read access to a table) but then both decide to wait for exclusive 1 1 1 1 1 deadly embrace deadlock 1 1 1 1 1 dead tree Paper. Use of this term emphasises the waste of natural resources and limited features available from the printed form of a document compared with an electronic rendition. E.g. "I read the dead tree edition of the Guardian (http://guardian.co.uk/) on the train". See also tree-killer. (1999-11-03) 1 1 1 1 1 dead tree edition dead tree 1 1 1 1 1 deamon It's spelled "daemon". (1996-12-13) 1 1 1 1 1 death code A routine whose job is to set everything in the computer - registers, memory, flags - to zero, including that portion of memory where it is running; its last act is to stomp on its own "store zero" instruction. Death code isn't very useful, but writing it is an interesting hacking challenge on architectures where the instruction set makes it possible, such as the PDP-8 or the Data General Nova. Perhaps the ultimate death code is on the TI 990 series, where all registers are actually in RAM, and the instruction "store immediate 0" has the opcode 0. The program counter will immediately wrap around core as many times as it can until a user hits HALT. Any empty memory location is death code. Worse, the manufacturer recommended use of this instruction in startup code (which would be in ROM and therefore survive). [Jargon File] 1 1 1 1 1 Death Star ["Star Wars" film] 1. The AT&T corporate logo, which appears on computers sold by AT&T and bears an uncanny resemblance to the Death Star in the movie. This usage is particularly common among partisans of BSD Unix, who tend to regard the AT&T versions as inferior and AT&T as a bad guy. Copies still circulate of a poster printed by Mt. Xinu showing a starscape with a space fighter labelled 4.2BSD streaking away from a broken AT&T logo wreathed in flames. 2. AT&T's internal magazine, "Focus", uses "death star" to describe an incorrectly done AT&T logo in which the inner circle in the top left is dark instead of light - a frequent result of dark-on-light logo images. 1 1 1 1 1 deb The filename extension for a Debian binary package. (2001-01-27) 1 1 1 1 1 Debbugs The bug tracking system used by the Debian Project. Each bug is given a number, and is kept on file until it is marked as having been dealt with. The system is mainly controlled by electronic mail, but the bug reports can be viewed via the web. Debbugs home (http://debian.org/Bugs/). (2002-06-12) 1 1 1 1 1 Debian /deb'ee`n/, *not* /deeb'ee`n/ The non-profit volunteer organisation responsible for Debian GNU/Linux and Debian GNU/Hurd. Debian's Linux distribution is dedicated to free and open source software; the main goal of the distribution is to ensure that one can download and install a fully-functional operating system that is completely adherent to the Debian Free Software Guidelines (DFSG). Debian was begun in August 1993 by Ian Murdock, and was sponsored by the Free Software Foundation from November 1994 to November 1995. The name Debian is a contraction of DEB(ra) and IAN Murdock. Debian's packaging system (dpkg) is similar to other popular packaging systems like RPM. There are over 2200 packages of precompiled software available in the main (free) section of the Debian 2.1 distribution alone -- this is what sets Debian apart from many other Linux distributions. The high quality 1 1 1 1 1 Debian GNU/Hurd A GNU distribution based on the Hurd kernel instead of the more well known Linux kernel. [Reference?] (2001-12-02) 1 1 1 1 1 Debian GNU/Linux Debian 1 1 1 1 1 debianize To take a source package and make the necessary modifications to allow it to be built as a policy compliant Debian package. (2000-05-31) 1 1 1 1 1 deboursification Removal of irrelevant newsgroups from the Newsgroups header of a followup. The term applies particularly to the removal of frivolous groups added by one of the Kooks. See also: sneck. [Sam Spade anti-spam software]. (1999-09-15) 1 1 1 1 1 De Bruijn graph A class of graphs with elegant properties. De Bruijn graphs are especially easy to use for routing, with shifting of source and destination addresses. [What properties? How are they used in routing?] (1998-04-28) 1 1 1 1 1 De Bruijn notation A variation of lambda notation for specifying functions using numbers instead of names to refer to formal parameters. A reference to a formal parameter is a number which gives the number of lambdas (written as \ here) between the reference and the lambda which binds the parameter. E.g. the function \ f . \ x . f x would be written \ . \ . 1 0. The 0 refers to the innermost lambda, the 1 to the next etc. The chief advantage of this notation is that it avoids the possibility of name capture and removes the need for alpha conversion. [N.G. De Bruijn, "Lambda Calculus Notation with Nameless Dummies: A Tool for Automatic Formula Manipulation, with Application to the Church-Rosser Theorem", Indag Math. 34, pp 381-392]. (2003-06-15) 1 1 1 1 1 DEBUG The bundled compiler/assembler for DOS/Windows after CP/M. [Did CP/M have "DEBUG"?] ["DOS Power Tools, Techniques, Tricks, and Utilities, PC Magazine, Paul Somerson Executive Editor, Bantam Books, 1988]. (2003-06-17) 1 1 1 1 1 debugger A tool used by a programmer to monitor and control a program he is trying to fix. The most important functions of a debugger are tracing, stepping, breakpoints and watches. Tracing displays a step-by-step report on what statement the program is currently executing, allowing the programmer to follow the flow of control through if statements, loops (loop), subroutine calls, etc. Breakpoints and watches both pause execution of the program and return control to the debugger under certain conditions. A breakpoint triggers when execution reaches a particular statement in the program and a watch triggers whenever a specific variable is modified. Stepping is like a breakpoint on every statement, often with the option to step "into" or "over" a subroutine, i.e. continue stepping through the statements of the subroutine or just execute it without pausing and resume stepping when it returns. 1 1 1 1 1 debugging The process of attempting to determine the cause of the symptoms of malfunctions in a program or other system. These symptoms may be detected during testing or use by real users. Symptoms are often caused by factors outside the program, such as misconfiguration of the user's operating system, misunderstanding by the user (see PEBCAK) or failures in other external systems on which the program relies. Some of these are more in the realm of technical support but need to be eliminated. Debugging really starts when it has been established that the program is not behaving according to its specification (which may be formal or informal). It can be done by visual inspection of the source code, debugging by printf or using a debugger. The result may be that the program is actually behaving as specified but that the spec is wrong or the requirements on which it was based were deficient in some way (see BAD). Once a bug has been identified and a fix applied, the program must 1 1 1 1 1 debugging an empty file A humourous definition of programming that considers a complete absence of any code as a bug to be fixed. test-driven development proceeds by the programmer writing tests for code that doesn't exist yet, which could be described as testing an empty file. (2012-05-01) 1 1 1 1 1 debugging by printf The debugging technique where the programmer inserts print statements into a program so that when run the program leaves a "trail of breadcrumbs" allowing him to see which parts were executed. The information output may just be a short string to indicate that a particular point in the code has been reached or it might be a complete stack trace. The output typically just goes to the window or terminal in which the program is running or may be written to a log file. printf is the standard C print function, other languages would use different names. (2007-03-08) 1 1 1 1 1 debugging tool debugger 1 1 1 1 1 DEC Digital Equipment Corporation 1 1 1 1 1 dec /dek/ decrement, decrease by one. Especially used by assembly language programmers, as many assembly languages have a "dec" mnemonic. Opposite: inc. [Jargon File] 1 1 1 1 1 DEC Alpha A RISC microprocessor from DEC. In November 1995, the Alpha was purportedly the fastest non-research chip used in commonly available workstations. It is superpipelined and superscalar. In February 1996 it was clocked at 200 MHz and in March 1998 at 666 MHz. (1998-03-17) 1 1 1 1 1 decay [Nuclear physics] An automatic conversion which is applied to most array-valued expressions in C; they "decay into" pointer-valued expressions pointing to the array's first element. This term is not used in the official standard for the language. [Jargon File] 1 1 1 1 1 DECdesign A software analysis and design tool from DEC supporting several methodologies. Now replaced by Teamwork. (1994-09-05) 1 1 1 1 1 DECdns Distributed Naming Service. Adopted by OSF as the naming service for DCE. 1 1 1 1 1 DEChead /dek'hed/ 1. A DEC field servoid. Not flattering. 2. ["deadhead"] A Grateful Dead fan working at DEC. [Jargon File] 1 1 1 1 1 dechunker chunker 1 1 1 1 1 decidability A property of sets for which one can determine whether something is a member or not in a finite number of computational steps. Decidability is an important concept in computability theory. A set (e.g. "all numbers with a 5 in them") is said to be "decidable" if I can write a program (usually for a Turing Machine) to determine whether a number is in the set and the program will always terminate with an answer YES or NO after a finite number of steps. Most sets you can describe easily are decidable, but there are infinitely many sets so most sets are undecidable, assuming any finite limit on the size (number of instructions or number of states) of our programs. I.e. how ever big you allow your program to be there will always be sets which need a bigger program to decide membership. One example of an undecidable set comes from the halting problem. It turns out that you can encode every program as a 1 1 1 1 1 decidable decidability 1 1 1 1 1 decimal point "." ASCII character 46. Common names are: point; dot; ITU-T, USA: period; ITU-T: decimal point. Rare: radix point; UK: full stop; INTERCAL: spot. (1995-03-14) 1 1 1 1 1 decision problem A problem with a yes/no answer. Determining whether some potential solution to a question is actually a solution or not. E.g. "Is 43669" a prime number?". This is in contrast to a "search problem" which must find a solution from scratch, e.g. "What is the millionth prime number?". See decidability. (1996-05-03) 1 1 1 1 1 decision support Software used to aid management decision making, typically relying on a decision support database. [Examples?] (1995-02-14) 1 1 1 1 1 decision support database A database from which data is extracted and analysed statistically (but not modified) in order to inform business or other decisions. This is in contrast to an operational database which is being continuously updated. For example, a decision support database might provide data to determine the average salary of different types of workers, whereas an operational database containing the same data would be used to calculate pay check amounts. Often, decision support data is extracted from operation databases. (1995-02-14) 1 1 1 1 1 Decision Support Systems (DSS) Software tools to help with decision support. (1995-02-14) 1 1 1 1 1 decision theory A branch of statistics concerning strategies for decision making in non-deterministic systems. Decision theory seeks to find strategies that maximise the expected value of a utility function measuring the desirability of possible outcomes. (1995-09-22) 1 1 1 1 1 deckle /dek'l/ (From "dec-" and "nibble"; the original spelling seems to have been "decle") Two nickles; 10 bits. Reported among developers for Mattel's GI 1600 (the Intellivision games processor), a chip with 16-bit wide RAM but 10-bit wide ROM. [Jargon File] (1994-11-23) 1 1 1 1 1 declarative language Any relational language or functional language. These kinds of programming language describe relationships between variables in terms of functions or inference rules, and the language executor (interpreter or compiler) applies some fixed algorithm to these relations to produce a result. Declarative languages contrast with imperative languages which specify explicit manipulation of the computer's internal state; or procedural languages which specify an explicit sequence of steps to follow. The most common examples of declarative languages are logic programming languages such as Prolog and functional languages like Haskell. See also production system. (2004-05-17) 1 1 1 1 1 DECmate I The first in DEC's series of miniaturised PDP-8 computers based on the Intersil 6120 [Harris 6120?] microprocessor and dedicated to wordprocessing. The DECmate was DEC's original competition for the IBM PC. The DECmate I was introduced in 1980 as the successor to the WT78. The processor ran at 10 MHz, and was housed in a VT100 CRT terminal. It was a very limted model, no EAE option was available, memory was 32 Kwords. It used the RX02 8" dual floppy drive. Options were the DP278-A and -B communication ports and RL278: 1 to 4 RL02 cartridge disk drives. (http://telnet.hu/hamster/dr/decmate.html). [Processor manufacturer?] (2003-05-29) 1 1 1 1 1 DECnet A proprietary network protocol designed by Digital Equipment Corporation. The functionality of each Phase of the implementation, such as Phase IV and Phase V, is different. 1 1 1 1 1 decode To apply decryption. (2004-05-22) 1 1 1 1 1 Decomposed Petri Net (DPN) A Petri net that has been split into multiple, interconnected nets. This makes it easier to analyse or run the net. DPNs are the basis of concurrency in ConC. (2006-11-27) 1 1 1 1 1 decompress To reverse the effects of data compression. (2001-01-30) 1 1 1 1 1 decryption Any procedure used in cryptography to convert ciphertext (encrypted data) into plaintext. (1995-05-10) 1 1 1 1 1 DECstation A range of RISC based workstations manufactured by DEC. [Details?] (1997-04-29) 1 1 1 1 1 DECT Digital Enhanced Cordless Telecommunications 1 1 1 1 1 DECtape A reel of magnetic tape about 4 inches in diameter and one inch wide. Unlike today's macrotapes, microtape drivers allowed random access to the data, and therefore could be used to support file systems and even for swapping (this was generally done purely for hack value, as they were far too slow for practical use). DECtape was a variant on LINCtape. In their heyday DECtapes were used in pretty much the same ways one would now use a floppy disk: as a small, portable way to save and transport files and programs. (1995-03-16) 1 1 1 1 1 DECUS Digital Equipment Computer Users Society 1 1 1 1 1 Decus cpp An almost-ANSI C preprocessor by Martin Minow. It is shipped with X11R5 (contrib/util/cpp) because some systems don't have a working cpp. It runs on VMS (Vax C, Decus C), RSX-11M, RSTS/E, P/OS, RT11, A/UX and Apollo Domain/IX 9.6 and is highly portable. (1994-11-03) 1 1 1 1 1 DEC Wars A 1983 Usenet posting by Alan Hastings and Steve Tarr spoofing the "Star Wars" movies in hackish terms. Some years later, ESR (disappointed by Hastings and Tarr's failure to exploit a great premise more thoroughly) posted a 3-times-longer complete rewrite called "Unix WARS"; the two are often confused. [Jargon File] 1 1 1 1 1 DECwindows DEC's windowing environment based on the X Window System. 1 1 1 1 1 DECwrite DEC's CDA-based, WYSIWYG document processing application. It can generate and import SGML marked-up documents. 1 1 1 1 1 DED Dark-Emitting Diode (that is, a burned-out LED). Compare SED, LER, write-only memory. In the early 1970s both Signetics and Texas instruments released DED spec sheets as AFJs (suggested uses included "as a power-off indicator"). [Jargon File] 1 1 1 1 1 dedicated line A telephone line leased expressly for the purpose of connecting two users more-or-less permenantly.. Such lines may be "voice grade" which provides the bandwidth and signal to noise ratio of ordinary public switched telephone network circuits, or specified in ways which allow transport of suitably encoded digital signals at faster rates. In some cases, lines may be physical wires between the communicating parties. Over longer distances, it is common for the connection to be virtual, which means that although the two users can communicate only with each other, their signals and others are multiplexed, amplified, switched, scrambled, demultiplexed and so on in complex ways between the end points. This contrasts with a dial-up connection which is only opened when one end requires it. (1996-08-10) 1 1 1 1 1 deductive database A combination of a conventional database containing facts, a knowledge base containing rules, and an inference engine which allows the derivation of information implied by the facts and rules. Commonly, the knowledge base is expressed in a subset of first-order logic and either a SLDNF or Datalog inference engine is used. (1995-04-27) 1 1 1 1 1 deductive tableau A theorem proof system consisting of a table whose rows contain assertions or goals. Variables in assertions are implicitly universally quantified and variables in goals are implicitly existentially quantified. The declarative meaning of a tableau is that if every instance of every assertion is true then some instance of at least one of the goals is true. (1994-12-07) 1 1 1 1 1 Deep Blue A super computer developed by researchers at IBM to explore the use of parallel processing to solve complex computing problems. It is known as the first computer to beat the current chess World Grand Master. Deep Blue started it's life as a PhD project at Carnegie Mellon University by PhD students Feng-hsiung Hsu and Murray Campbell. Chiptest, as it was known then, consisted of a custom designed chip hosted in a Sun 3/160 computer. The project moved over to IBM in 1989 when Hsu and Campbell joined IBM. Deep Thought, as it was known by then, played for the first time against Garry Kasparov in the same year. The game of two matches was easily won by Kasparov. The next match against Kasparov took place in February 1996. By then the machine was again renamed, at that time it was known as Deep Blue. It was also heavily re-engineered: it was by then running on a 32-node RS/6000 cluster, each containing 8 custom designed chips. Alas, Kasparov won again. 1 1 1 1 1 deep hack mode hack mode 1 1 1 1 1 deep magic [possibly from C. S. Lewis's "Narnia" books] An awesomely arcane technique central to a program or system, especially one neither generally published nor available to hackers at large (compare black art); one that could only have been composed by a true wizard. Compiler optimisation techniques and many aspects of OS design used to be deep magic; many techniques in cryptography, signal processing, graphics, and AI still are. Compare heavy wizardry. Especially found in comments of the form "Deep magic begins here.". Compare voodoo programming. 1 1 1 1 1 deep space 1. The notional location of any program that has gone off the trolley. Especially used of programs that just sit there silently grinding long after either failure or some output is expected. "Uh oh. I should have had a prompt ten seconds ago. The program's in deep space somewhere." Compare buzz, catatonic, hyperspace. 2. The metaphorical location of a human so dazed and/or confused or caught up in some esoteric form of bogosity that he or she no longer responds coherently to normal communication. [Jargon File] 1 1 1 1 1 de facto standard A widespread consensus on a particular product or protocol which has not been ratified by any official standards body, such as ISO, but which nevertheless has a large market share. The archetypal example of a de facto standard is the IBM PC which, despite is many glaring technical deficiencies, has gained such a large share of the personal computer market that it is now popular simply because it is popular and therefore enjoys fierce competition in pricing and software development. (1994-10-27) 1 1 1 1 1 default A value or thing to use when none is specified by the user. Defaults are important for making systems behave in a predictable way without the user having to give lots of obvious details. For example: the default TCP/IP port for the HTTP protocol is 80, the Unix ls command does not list files whose names begin with ".", the default number base in most contexts is 10 (decimal), the default filename extension for Microsoft Word documents is ".doc". (2009-02-20) 1 1 1 1 1 default.htm index.html 1 1 1 1 1 default route A routing table entry which is used to direct packets addressed to hosts or networks not explicitly listed in the routing table. (1996-05-13) 1 1 1 1 1 defect bug 1 1 1 1 1 defect analysis Using defects as data for continuous quality improvement. Defect analysis generally seeks to classify defects into categories and identify possible causes in order to direct process improvement efforts. (1996-05-13) 1 1 1 1 1 defect density The ratio of the number of defects to program length. (1996-05-13) 1 1 1 1 1 Defense Advanced Research Project Agency Defense Advanced Research Projects Agency 1 1 1 1 1 Defense Advanced Research Projects Agency (DARPA, ARPA) An agency of the US Department of Defense responsible for the development of new technology for use by the military. DARPA was established in 1958 in response to the Soviet launching of Sputnik, with the mission of keeping the US's military technology ahead of its enemies. DARPA is independent from other more conventional military R&D and reports directly to senior DoD management. DARPA has around 240 personnel (about 140 technical) directly managing a $2 billion budget. These figures are "on average" since DARPA focusses on short (two to four-year) projects run by small, purpose-built teams. ARPA was its original name, then it was renamed DARPA (for Defense) in 1972, then back to ARPA [When?], and then, incredibly, back to DARPA again on 1996-03-11! ARPA was responsible for funding development of ARPANET (which grew into the Internet), as well as the Berkeley version of Unix and TCP/IP. 1 1 1 1 1 Defense Calculator IBM 701 1 1 1 1 1 Defense Communications Agency (DCA) Now called Defense Information Systems Agency (DISA). 1 1 1 1 1 Defense Data Network (DDN) A global communications network serving the US Department of Defense. Composed of MILNET, other portions of the Internet, and classified networks which are not part of the Internet. The DDN is used to connect military installations and is managed by the Defense Information Systems Agency. (1994-12-01) 1 1 1 1 1 Defense Data Network Network Information Center (DDN NIC or just "The NIC") The DDN NIC's primary responsibility is the assignment of Internet addresses and Autonomous System numbers, the administration of the root domain, and providing information and support services to the DDN. It is also a primary repository for RFCs. See also Internet Registry. (1994-12-07) 1 1 1 1 1 Defense Information Systems Agency (DISA) Formerly called the Defense Communications Agency (DCA), this is the government agency responsible for managing the Defense Data Network (DDN) portion of the Internet, including the MILNET. Currently, DISA administers the DDN, and supports the user assistance services of the DDN NIC. (http://disa.mil/). (1994-12-01) 1 1 1 1 1 Defense Trade Regulations The U.S. law governening munitions export and defense technology (F-16s, TOW missiles and cryptology). According to the U.S. (and Canada) cryptography is a munition and people who export it can be charged as though they were exporting bombs or state secrets. People have been. See also EFF. (1995-06-19) 1 1 1 1 1 deferral Waiting for quiet on the Ethernet. 1 1 1 1 1 definite clause A Horn clause that has exactly one positive literal. (2000-01-24) 1 1 1 1 1 definite sentence A collection of definite clauses. (2003-12-04) 1 1 1 1 1 definitional constraint programming (DCP) A declarative, programming paradigm which integrates concurrent constraint programming, constraint logic programming and functional programming. In this setting a concurrent constraint language becomes a coordination system that organises the concurrent interaction of parallel functional computations. The language is also a generalisation of parallel functional programming languages, such as Id, where constraints and constraint abstractions are reused to define new constraints, as the means of programming logical variables for parallel coordination. Goffin is a DCP language. (1995-03-28) 1 1 1 1 1 deflate A compression standard derived from LZ77; it is reportedly used in zip, gzip, PKZIP, and png, among others. Unlike LZW, deflate compression does not use patented compression algorithms. Used as a verb to mean to compress (not decompress!) a file which has been compressed using deflate compression. The opposite, inflate, means to decompress data which has been deflated. Deflate is described in RFC 1951. (1997-06-21) 1 1 1 1 1 deflate compression deflate 1 1 1 1 1 deflate/inflate compression deflate 1 1 1 1 1 deforestation A technique invented by Phil Wadler for eliminating intermediate data structures built and passed between composed functions in function languages. (1997-06-21) 1 1 1 1 1 defrag defragment 1 1 1 1 1 defragment /dee-frag(-ment)'/ (Or "defrag") To coalesce files and free space on a file system; to reduce fragmentation. (2004-08-19) 1 1 1 1 1 defunct process zombie process 1 1 1 1 1 degree The degree (or valency) of a node in a graph is the number of edges joined to it. 1 1 1 1 1 degrees of freedom The number of independent parameters required to specify the position and orientation of an object. Often used to classify robot arms. For example, an arm with six degrees of freedom could reach any position close enough and could orient it's end effector (grip or tool etc.) at any angle about the three perpendicular axes. 1 1 1 1 1 dehose /dee-hohz/ To clear a hosed condition. [Jargon File] 1 1 1 1 1 DEK Data Encryption Key 1 1 1 1 1 Delaunay triangulation (After B. Delaunay) For a set S of points in the Euclidean plane, the unique triangulation DT(S) of S such that no point in S is inside the circumcircle of any triangle in DT(S). DT(S) is the dual of the voronoi diagram of S. 1 1 1 1 1 delayed control-transfer A technique used on the SPARC processor to reduce the effect of pipeline breaks by executing the instruction after a branch instruction (the "delay instruction" in the "delay slot"). If there is no useful instruction which can be placed in the delay slot then the "annul bit" on the control transfer instruction can be set, preventing execution of the delay instruction (unless the control transfer is conditional and is taken). Annulled branches are indicated in SPARC assembler language by appending ",A" to the operation code. For example, LOOP: ... CMP %L0,10 BLE,A LOOP ADD %L2, %L3, #L4 If the delay instruction is also a control transfer instruction then it gets more complicated. Both control transfer instructions are executed (but not the following instruction) and, assuming 1 1 1 1 1 delay instruction delayed control-transfer 1 1 1 1 1 delay slot delayed control-transfer 1 1 1 1 1 delete 1. <operating system> (Or "erase") To make a file inaccessible. Usually this operation only deletes information from the tables the file system uses to locate named files; the file's contents still exist on disk and can sometimes be recovered by scanning the whole disk for strings which are known to have been in the file. Files created subsequently on the same disk are quite likely to reuse the same blocks and thus overwrite the deleted file's data permanently. 2. <character> The control character with ASCII code 127. Usually entering this character from the keyboard deletes the last character typed from the input buffer. Sadly there is great confusion between operating systems and keyboard manufacturers as to whether this function should be assigned to the delete or backspace key/character. The choice of code 127 (binary 1111111) is not arbitrary but dates back to the use of paper tape for input. The delete 1 1 1 1 1 delimiter A character or string used to separate, or mark the start and end of, items of data in, e.g., a database, source code, or text file. See also: record. (2001-03-16) 1 1 1 1 1 delint /dee-lint/ To modify code to remove problems detected when linting. Confusingly, this process is also referred to as linting code. [Jargon File] 1 1 1 1 1 Delirium An embedding coordinate language for parallel programming, implemented on Sequent Symmetry, Cray, BBN Butterfly. ["Parallel Programming with Coordination Structures", S. Lucco et al, 18th POPL, pp.197-208 (1991)]. 1 1 1 1 1 Delivered Source Instruction (DSI) One line of source code (LOC) developed by a project. DSI is the primary input to many tools for estimating software cost. The term "delivered" is generally meant to exclude non-delivered support software such as test drivers. However, if these are developed with the same care as delivered software, with their own reviews, test plans, documentation, etc., then they should be counted. The "source instructions" include all program instructions created by project personnel and processed into machine code by some combination of preprocessors, compilers, and assemblers. It excludes comments and unmodified utility software. It includes job control language, format statements, and data declarations. (1996-05-29) 1 1 1 1 1 Dell Computer Corporation One of the biggest US manufacturers of IBM PC compatibles. From notebooks to networks, their slogan says. (http://us.dell.com). (1996-05-29) 1 1 1 1 1 Delphi 1. <company, communications> A US Internet service provider. [Addresses?] (1995-04-06) 2. <language> Borland's Object Oriented Pascal (OOPascal) Rapid Application Development package for Microsoft Windows. Delphi combines visual, component-based design with an optimising native code compiler and scalable database access. (1996-05-27) 1 1 1 1 1 Delphi Technique A group forecasting technique, generally used for future events such as technological developments, that uses estimates from experts and feedback summaries of these estimates for additional estimates by these experts until reasonable consensus occurs. It has been used in various software cost-estimating activities, including estimation of factors influencing software costs. (1996-05-29) 1 1 1 1 1 Delta 1. An expression-based language developed by J.C. Cleaveland in 1978. 2. A string-processing language with single-character commands from Tandem Computers. 3. A language for system specification of simulation execution. ["System Description and the DELTA Language", E. Holback-Hansen et al, DELTA Proj Rep 4, Norweg Comput Ctr, Feb 1977]. 4. A COBOL generating language produced by Delta Software Entwicklung GmbH (http://delta-software.de/). (2000-08-02) 1 1 1 1 1 delta 1. A quantitative change, especially a small or incremental one (this use is general in physics and engineering). "I just doubled the speed of my program!" "What was the delta on program size?" "About 30 percent." (He doubled the speed of his program, but increased its size by only 30 percent.) 2. [Unix] A diff, especially a diff stored under the set of version-control tools called SCCS (Source Code Control System) or RCS (Revision Control System). See change management. 3. A small quantity, but not as small as epsilon. The jargon usage of delta and epsilon stems from the traditional use of these letters in mathematics for very small numerical quantities, particularly in "epsilon-delta" proofs in limit theory (as in the differential calculus). The term delta is often used, once epsilon has been mentioned, to mean a quantity that is slightly bigger than epsilon but still very small. "The cost isn't epsilon, but it's delta" 1 1 1 1 1 Delta-4 Definition and Design of an open Dependable Distributed system architecture. An Esprit project investigating the achievement of dependability in open distributed systems, including real-time systems. 1 1 1 1 1 delta conversion delta reduction 1 1 1 1 1 Delta-Prolog A Prolog extension with AND-parallelism, don't-know nondeterminism and interprocess communication using synchronous event goals and distributed backtracking. ["Delta-Prolog: A Distributed Logic Programming Language", L.M. Pereira et al, Intl Conf 5th Gen Comp Sys, Nov 1984]. 1 1 1 1 1 delta reduction In lambda-calculus extended with constants, delta reduction replaces a function applied to the required number of arguments (a redex) by a result. E.g. plus 2 3 --> 5. In contrast with beta reduction (the only kind of reduction in the pure lambda-calculus) the result is not formed simply by textual substitution of arguments into the body of a function. Instead, a delta redex is matched against the left hand side of all delta rules and is replaced by the right hand side of the (first) matching rule. There is notionally one delta rule for each possible combination of function and arguments. Where this implies an infinite number of rules, the result is usually defined by reference to some external system such as mathematical addition or the hardware operations of some computer. For other types, all rules can be given explicitly, for example Boolean negation: not True = False 1 1 1 1 1 DELTASE A distributed processing environment concerned with fault-tolerant and process-control applications from the Esprit Delta-4 project. 1 1 1 1 1 demand driven A demand driven architecture/language performs computations when the result is required by some other computation. E.g. Imperial College's ALICE running HOPE. See also data flow, lazy evaluation, reduction. (1995-02-16) 1 1 1 1 1 demand paged demand paging 1 1 1 1 1 demand paging A kind of virtual memory where a page of memory will be paged in if an attempt is made to access it and it is not already present in main memory. This normally involves a memory management unit which looks up the virtual address in a page map to see if it is paged in. If it is not then the operating system will page it in, update the page map and restart the failed access. This implies that the processor must be able to recover from and restart a failed memory access or must be suspended while some other mechanism is used to perform the paging. Paging in a page may first require some other page to be moved from main memory to disk ("paged out") to make room. If this page has not been modified since it was paged in, it can simply be reused without writing it back to disk. This is determined from the "modified" or "dirty" flag bit in the page map. A replacement algorithm or policy is used to select the page to be paged out, often this is the least 1 1 1 1 1 DeMarco Tom DeMarco proposed a form of structured analysis. (1995-02-16) 1 1 1 1 1 DeMarco/Yourdon Yourdon/Demarco 1 1 1 1 1 demented Yet another term of disgust used to describe a program. The connotation in this case is that the program works as designed, but the design is bad. Said, for example, of a program that generates large numbers of meaningless error messages, implying that it is on the brink of imminent collapse. [Jargon File] (1994-12-07) 1 1 1 1 1 Demeter A CASE tool developed mainly by Karl Lieberherr. ["Contributions to Teaching Object-Oriented Design and Programming" Aug/Sep 1988 issue of JOOP, OOPSLA '89 Proceedings]. (1994-12-07) 1 1 1 1 1 demigod A hacker with years of experience, a national reputation, and a major role in the development of at least one design, tool, or game used by or known to more than half of the hacker community. To qualify as a genuine demigod, the person must recognisably identify with the hacker community and have helped shape it. Major demigods include Ken Thompson and Dennis Ritchie (co-inventors of Unix and C) and Richard Stallman (inventor of Emacs). In their hearts of hearts, most hackers dream of someday becoming demigods themselves, and more than one major software project has been driven to completion by the author's veiled hopes of apotheosis. See also net.god, true-hacker. [Jargon File] (1994-10-27) 1 1 1 1 1 De-Militarised Zone (DMZ) (From the military term for an area between two opponents where fighting is prevented) DMZ Ethernets connect networks and computers controlled by different bodies. They may be external or internal. External DMZ Ethernets link regional networks with routers to internal networks. Internal DMZ Ethernets link local nodes with routers to the regional networks. Compare red zone. (1995-02-23) 1 1 1 1 1 demo /de'moh/ 1. A demonstration of a product, often of an early version or prototype. A demo is a far more effective way of inducing bugs to manifest themselves than any number of test runs, especially when important people are watching. 2. demo version. 3. A program written to demonstrate the programmer's coding ability and/or the power of the computer it runs on. Such demos are nearly always written in machine code and traditionally feature scrolling text about the author, his friends, his code and anything else he fancies and animated graphics. [Jargon File] (1994-11-04) 1 1 1 1 1 demodulate demodulation 1 1 1 1 1 demodulation To recover the signal from the carrier. For example, in a radio broadcast using amplitude modulation the audio signal is transmitted as the mean amplitude of a radio-frequency carrier so demodulation requires a circuit which measures the amplitude and filters out the carrier. There are many other kinds of modulation and corresponding demodulation. (1998-07-29) 1 1 1 1 1 demo mode (Sun) 1. The state of being heads down in order to finish code in time for a demo, usually due yesterday. 2. <games> (Or "attract mode") A mode in which video games sit by themselves running through a portion of the game. Some serious apps have a demo mode they use as a screen saver, or may go through a demo mode on startup (for example, the Microsoft Windows opening screen - which lets you impress your neighbors without actually having to put up with Microsloth Windows). [Jargon File] (1995-02-22) 1 1 1 1 1 demon 1. <operating system> (Often used equivalently to daemon, especially in the Unix world, where the latter spelling and pronunciation is considered mildly archaic). A program or part of a program which is not invoked explicitly, but that lies dormant waiting for some condition(s) to occur. At MIT they use "demon" for part of a program and "daemon" for an operating system process. Demons (parts of programs) are particularly common in AI programs. For example, a knowledge-manipulation program might implement inference rules as demons. Whenever a new piece of knowledge was added, various demons would activate (which demons depends on the particular piece of data) and would create additional pieces of knowledge by applying their respective inference rules to the original piece. These new pieces could in turn activate more demons as the inferences filtered down through chains of logic. Meanwhile, the main program could continue with whatever its primary task was. 1 1 1 1 1 Demon Internet Ltd. One of the first company to provide public Internet access in the UK. The staff of Demon Systems Ltd., an established software house, started Demon Internet on 1992-06-01 and it was the first system in the United Kingdom to offer low cost full Internet access. It was started with the support of about 100 founder members who discussed the idea on Compulink Information Exchange, and were brave enough to pay a year's subscription in advance. They aimed to have 200 members in the first year to cover costs, ignoring any time spent. After about two weeks they realised they needed nearer 400. By November 1993 they had over 2000 subscribers and by August 1994 they had about 11000 with 20% per month growth. All revenues have been reinvested in resources and expansion of service. Demon link to Sprintlink in the United States making them totally independent. They peer with EUNet and PIPEX to 1 1 1 1 1 DeMorgan's theorem A logical theorem which states that the complement of a conjunction is the disjunction of the complements or vice versa. In symbols: not (x and y) = (not x) or (not y) not (x or y) = (not x) and (not y) E.g. if it is not the case that I am tall and thin then I am either short or fat (or both). The theorem can be extended to combinations of more than two terms in the obvious way. The same laws also apply to sets, replacing logical complement with set complement, conjunction ("and") with set intersection, and disjunction ("or") with set union. A (C) programmer might use this to re-write if (!foo && !bar) ... as 1 1 1 1 1 demo version 1. An early, barely-functional version of a program which can be used for demonstration purposes as long as the operator uses *exactly* the right commands and skirts its numerous bugs, deficiencies, and unimplemented portions. 2. A special version of a finished program (frequently with some features crippled) which is distributed at little or no cost to the user for enticement purposes. See crippleware. (1994-11-04) 1 1 1 1 1 Denis Howe Denis B. Howe (1960 -) Editor of the Free On-line Dictionary of Computing. (2008-03-26) 1 1 1 1 1 Dennis Ritchie Dennis M. Ritchie, co-author of the Unix operating system, inventor of the C programming language and demigod. See also K&R, Core War, If you want X, you know where to find it. (2008-03-26) 1 1 1 1 1 denotational semantics A technique for describing the meaning of programs in terms of mathematical functions on programs and program components. Programs are translated into functions about which properties can be proved using the standard mathematical theory of functions, and especially domain theory. Compare axiomatic semantics, operational semantics, standard semantics. (1996-08-21) 1 1 1 1 1 Denotational Semantics Language (DSL) The specification language used by the SIS compiler generator. ["SIS - Semantics Implementation System", P.D. Mosses, TR DAIMI MD-30, Aarhus U, Denmark]. (1996-10-13) 1 1 1 1 1 Department of Defense (DoD) The US military body responsible for sponsoring many software engineering standards. (1996-05-29) 1 1 1 1 1 Department of Defense Network (DDN) A military subset of the Internet, which includes ARPAnet. (1994-12-07) 1 1 1 1 1 depeditate /dee-ped'*-tayt/ [by (faulty) analogy with "decapitate"] Humorously, to cut off the feet of. When one is using some computer-aided typesetting tools, careless placement of text blocks within a page or above a rule can result in chopped-off letter descenders. Such letters are said to have been depeditated. [Jargon File] 1 1 1 1 1 dependability software reliability 1 1 1 1 1 dependable software software reliability 1 1 1 1 1 Deployment Descriptor (DD) A J2EE configuration file. (2005-01-26) 1 1 1 1 1 deprecated Said of a program or feature that is considered obsolescent and in the process of being phased out, usually in favour of a specified replacement. Deprecated features can, unfortunately, linger on for many years. This term appears with distressing frequency in standards documents when the committees writing the documents realise that large amounts of extant (and presumably happily working) code depend on the feature(s) that have passed out of favour. See also dusty deck. [Jargon File] (1995-04-19) 1 1 1 1 1 depth-first search A graph search algorithm which extends the current path as far as possible before backtracking to the last choice point and trying the next alternative path. Depth-first search may fail to find a solution if it enters a cycle in the graph. This can be avoided if we never extend a path to a node which it already contains. Opposite of breadth first search. See also iterative deepening. (1995-04-19) 1 1 1 1 1 deque double-ended queue 1 1 1 1 1 dequeue queue 1 1 1 1 1 DER Distinguished Encoding Rules 1 1 1 1 1 dereference To access the thing to which a pointer points, i.e. to follow the pointer. E.g. in C, the declarations int i; int *p = &i; declare i as an integer and p as a pointer to integer. p is initialised to point at i ("&i" is the address of i - the inverse of "*"). The expression *p dereferences p to yield i as an lvalue, i.e. something which can appear either on the left of an assignment or anywhere an integer expression is valid. Thus *p = 17; would set i to 17. *p++ is not the same as i++ however since it is parsed as *(p++), i.e. increment p (which would be an invalid thing to do if it was pointing to a single int, as in 1 1 1 1 1 de-rezz /dee-rez'/ (Or "derez") "de-resolve" via the film Tron. 1. To disappear or dissolve; the image that goes with it is of an object breaking up into raster lines and static and then dissolving. Occasionally used of a person who seems to have suddenly "fuzzed out" mentally rather than physically. Usage: extremely silly, also rare. This verb was actually invented as *fictional* hacker jargon, and adopted in a spirit of irony by real hackers years after the fact. 2. The Macintosh resource decompiler. On a Macintosh, many program structures (including the code itself) are managed in small segments of the program file known as "resources"; "Rez" and "DeRez" are a pair of utilities for compiling and decompiling resource files. Thus, decompiling a resource is derezzing. Usage: very common. [Jargon File] 1 1 1 1 1 derived class subclass 1 1 1 1 1 derived type A type constructed from primitive types or other derived types using a type constructor function. This term is usually applied to procedural languages such as C or Ada. C's derived types are the array, function, pointer, structure, and union. Compare derived class. (2001-09-14) 1 1 1 1 1 DES Data Encryption Standard 1 1 1 1 1 descender A lowercase letter that extends below the base line, such as "g", "j", or "p". Also used to denote the part of the letter extending below the base line. Compare ascender. (1998-03-27) 1 1 1 1 1 descent function If a recursive function is of the form f x = ... f (d x) ... then d is known as the descent function. 1 1 1 1 1 Descriptive Intermediate Attributed Notation for Ada (DIANA) A formerly de facto standard intermediate language for Ada programs, developed by Goos and Wulf at CMU in January 1981. DIANA is an attributed tree representation, with an abstract interface defined in Interface Description Language (Nestor, Lamb and Wulf, CMU, 1981; Snodgrass(?), 1989(?)). DIANA resulted from a merger of AIDA and TCOL.Ada. At the present (2001) it is no longer used by the major ADA compilers ["DIANA - An Intermediate Language for Ada", G.T. Goos et al, LNCS 161, Springer 1983]. (2001-09-15) 1 1 1 1 1 Descriptive Top-Level Specification (DTLS) A language used in POSIX and TRUSIX. (1994-11-11) 1 1 1 1 1 descriptor An integer, string or other small data value which refers to one of several objects allocated to a program by the operating system, usually the kernel. A common example is a Unix file descriptor which is a small integer that identifies an I/O channel. Another example is a reference to an area of memory (e.g. shared memory). Compare capability. (1998-02-06) 1 1 1 1 1 design The approach that engineering (and some other) disciplines use to specify how to create or do something. A successful design must satisfies a (perhaps informal) functional specification (do what it was designed to do); conforms to the limitations of the target medium (it is possible to implement); meets implicit or explicit requirements on performance and resource usage (it is efficient enough). A design may also have to satisfy restrictions on the design process itself, such as its length or cost, or the tools available for doing the design. In the software life-cycle, design follows requirements analysis and is followed by implementation. ["Object-Oriented Analysis and Design with Applications", 2nd ed., Grady Booch]. (1996-12-08) 1 1 1 1 1 Design In Real Time (Dirt) A user interface builder for the X Window System by R. Hesketh. (1994-12-07) 1 1 1 1 1 design pattern A description of an object-oriented design technique which names, abstracts and identifies aspects of a design structure that are useful for creating an object-oriented design. The design pattern identifies classes and instances, their roles, collaborations and responsibilities. Each design pattern focuses on a particular object-oriented design problem or issue. It describes when it applies, whether it can be applied in the presence of other design constraints, and the consequences and trade-offs of its use. Home (http://st-www.cs.uiuc.edu/users/patterns/patterns.html). ["Design Patterns: Elements of Reusable Object-Oriented Software", Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides]. (1997-07-21) 1 1 1 1 1 design recovery A subtask of reverse engineering in which domain knowledge, external information, and deduction of fuzzy reasoning are added to the observations of the subject system to identify meaningful higher level abstractions beyond those obtained directly by examining the system itself. In other words, design recovery aims to work out what a system or component was designed to do rather than just examining its subcomponents and their interrelationships. (1996-12-08) 1 1 1 1 1 Design System language J. Gaffney, Evans & Sutherland 1976. Interpretive FORTH-like language for 3d graphics databases. Earliest forerunner of both Interpress and PostScript. Mentioned in PostScript Language Reference Manual, Adobe Systems, A-W 1985. 1 1 1 1 1 desk check To grovel over hardcopy of source code, mentally simulating the control flow; a method of catching bugs. No longer common practice in this age of on-screen editing, fast compiles, and sophisticated debuggers - though some maintain stoutly that it ought to be. Compare dry run, eyeball search, vdiff, vgrep. [Jargon File] (1996-05-13) 1 1 1 1 1 desktop 1. <operating system> In a WIMP graphical user interface, the visual representation of a real desktop (the top surface of a piece of furniture) with documents, folders and a rubbish bin arranged on it. The user manipulates files on the computer by using a mouse to click and drag their representations (icons) on the desktop. The WIMP interface and desktop metaphor was invented at Xerox PARC and popularised by the Apple Macintosh. 2. <computer> desktop computer. (2007-09-12) 1 1 1 1 1 desktop database Macintosh file system 1 1 1 1 1 Desktop Management Interface (DMI) A specification from the Desktop Management Task Force (DMTF) that establishes a standard framework for managing networked computers. DMI covers hardware and software, desktop systems and servers, and defines a model for filtering events and describing interfaces. DMI provides a common path for technical support, IT managers, and individual users to access information about all aspects of a computer - including processor type, installation date, attached printers and other peripherals, power sources, and maintenance history. It provides a common format for describing products to aid vendors, systems integrators, and end users in enterprise desktop management. DMI is not tied to any specific hardware, operating system, or management protocols. It is easy for vendors to adopt, mappable to existing management protocols such as Simple Network Management Protocol (SNMP), and can be used on 1 1 1 1 1 Desktop Management Task Force (DMTF) The industry consortium that develops, supports, and maintains standards for systems management of PC systems and products, to reduce total cost of ownership. These include the Desktop Management Interface (DMI), the most-widely used management standard today. The DMTF is participating in an industry effort to create a standard for management over the Internet. They are defining an object-oriented Common Information Model (CIM). (http://dmtf.org/). (2000-01-19) 1 1 1 1 1 desktop manager A user interface to system services, usually icon and menu based like the Macintosh Finder, enabling the user to run application programs and use a file system without directly using the command language of the operating system. (1994-12-07) 1 1 1 1 1 desktop publisher desktop publishing 1 1 1 1 1 desktop publishing (DTP) Using computers to lay out text and graphics for printing in magazines, newsletters, brochures, etc. A good DTP system provides precise control over templates, styles, fonts, sizes, colour, paragraph formatting, images and fitting text into irregular shapes. Example programs include FrameMaker, PageMaker, InDesign and GeoPublish. (http://cs.purdue.edu/homes/gwp/dtp/dtp.html). Usenet newsgroup: news:comp.text.desktop. (2005-03-14) 1 1 1 1 1 DESQview A system from Quarterdeck Office Systems implementing multitasking under MS-DOS. 1 1 1 1 1 destructor A function provided by a class in C++ and some other object-oriented languages to delete an object, the inverse of a constructor. (1998-04-28) 1 1 1 1 1 DESY Deutsches Electronen Synchrotron Laboratory, Hamburg, Germany. 1 1 1 1 1 DETAB DEcision TABle. A decision table COBOL preprocessor written by A. Chapman in 1964. Versions: DETAB 65, DETAB X. [Sammet 1969, p. 315]. (1994-12-07) 1 1 1 1 1 deterministic 1. <probability> Describes a system whose time evolution can be predicted exactly. Contrast probabilistic. 2. <algorithm> Describes an algorithm in which the correct next step depends only on the current state. This contrasts with an algorithm involving backtracking where at each point there may be several possible actions and no way to chose between them except by trying each one and backtracking if it fails. (1995-09-22) 1 1 1 1 1 deterministic automaton A finite-state automaton in which the overall course of the computation is completely determined by the program, the starting state, and the initial inputs. The class of problems solvable by such automata is the class P (see polynomial-time algorithm). (1996-05-03) 1 1 1 1 1 DETOL Directly Executable Test Oriented Language. (1995-09-29) 1 1 1 1 1 developer programmer 1 1 1 1 1 development The process of analysis, design, coding and testing software. 1 1 1 1 1 Developmental Test and Evaluation (DT&E) Activity which focuses on the technological and engineering aspects of a system or piece of equipment. (1996-05-13) 1 1 1 1 1 development environment An integrated suite of tools to aid the development of software in a particular language or for a particular application. Usually, this consists of a compiler and editor and may also include one or more of a debugger, profiler, and source code manager. See also: IDE. (1999-08-01) 1 1 1 1 1 device peripheral 1 1 1 1 1 Device Control One of the four ASCII characters, DC1, DC2, DC3, and DC4, once used to remotely control equipment (e.g. a paper tape reader) via electromagnetic switches. The characters were usually paired, DC1/DC3 turning one device on/off, and DC2/DC4 another. [Other examples of equipment?] (1996-08-20) 1 1 1 1 1 Device Control 1 Control-Q 1 1 1 1 1 Device Control 2 (DC2) The mnemonic for ASCII character 18, one of the four Device Control characters. (1996-06-28) 1 1 1 1 1 Device Control 3 Control-S 1 1 1 1 1 Device Control 4 (DC4) The mnemonic for ASCII character 20, one of the four Device Control characters. (1996-06-28) 1 1 1 1 1 device driver Software to control a hardware component or peripheral device of a computer such as a magnetic disk, magnetic tape or printer. A device driver is responsible for accessing the hardware registers of the device and often includes an interrupt handler to service interrupts generated by the device. Device drivers often form part of the lowest level of the operating system kernel, with which they are linked when the kernel is built. Some more recent systems have loadable device drivers which can be installed from files after the operating system is running. (1994-10-27) 1 1 1 1 1 device independent bitmap (DIB) An image format in which the sequence and depth of pixels in the file is not specifically related to their layout in any particular device. This allows any device dependent bitmap (DDB) image to be converted to or DIB format without loss of information, and this can then later be converted to other DDB formats for, e.g., printing or display. Rather than requiring converters from each DDB format to all other formats, only converters to and from DIB are needed. DIB images are normally transferred in metafiles, bmp files, and the clipboard. Transferring colour bitmaps from one device to another was not possible in versions of Microsoft Windows earlier than 3.0. Application programs can build DIB images without any interaction with Windows. If Windows lacks a drawing primitive, the application can simulate it directly into the DIB instead of using the existing graphics device interface 1 1 1 1 1 Device Manager The Microsoft Windows control panel applet used to enable, disable and configure the hardware on which Windows is running. You can launch Device Manager via the Control Panel/System or directly with: rundll32.exe devmgr.dll DeviceManager_Execute (2008-04-16) 1 1 1 1 1 Devil Book "The Design and Implementation of the 4.3BSD Unix Operating System", by Samuel J. Leffler, Marshall Kirk McKusick, Michael J. Karels, and John S. Quarterman (Addison-Wesley Publishers, 1989, ISBN 0-201-06196-1). The standard reference book on the internals of BSD Unix. So called because the cover has a picture depicting a little devil (a visual play on daemon) in sneakers, holding a pitchfork (referring to one of the characteristic features of Unix, the "fork(2)" system call). [Jargon File] (1996-12-03) 1 1 1 1 1 devo /dee'voh/ (In-house jargon at Symbolics) A person in a development group. See also doco and mango. (1994-11-04) 1 1 1 1 1 DEX A cross between Modula-2 and C by W. van Oortmerssen. Amiga version 1.2 (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f7/ff743/TurboDEX.lzh). 1 1 1 1 1 DFA Deterministic Finite-state Automaton. See Finite State Machine. 1 1 1 1 1 DFC A dataflow language. ["Data Flow Language DFC: Design and Implementation", S. Toshio et al, Systems and Computers in Japan, 20(6):1- 10 (Jun 1989)]. 1 1 1 1 1 DFD Data Flow Diagram 1 1 1 1 1 D-Flat C# 1 1 1 1 1 DFS 1. <algorithm> Depth-First Search. 2. <file system> Distributed File System. 1 1 1 1 1 DFT discrete Fourier transform 1 1 1 1 1 DGL 1. Data Generation Language. A tool for generating test data for hardware or software systems. 2. Distributed GL. 1 1 1 1 1 DG/L 1. Descriptive Geometry Language. Early CAD/CAE language, used light pen. "Interactive Graphic Consoles - Environment and Software", R.L. Beckermeyer, Proc FJCC 37 (1970). 2. Data General ca 1973-1974. Derivative of ALGOL 60, developed from DG's ALGOL-5, used as the systems language under AOS and RDOS for the DG Eclipse family of computers. Replaced by PL/I in the early 80's. Data General manual 093-000229-01. 1 1 1 1 1 DHCP Dynamic Host Configuration Protocol 1 1 1 1 1 Dhrystone A short synthetic benchmark program by Reinhold Weicker <weicker.muc@sni.de>, <weicker.muc@sni-usa.com>, intended to be representative of system (integer) programming. It is available in ADA, Pascal and C. The current version is Dhrystone 2.1. The author says, "Relying on MIPS V1.1 (the result of V1.1) numbers can be hazardous to your professional health." Due to its small size, the memory system outside the cache is not tested. Compilers can too easily optimise for Dhrystone. String operations are somewhat over-represented. Sources (ftp://ftp.nosc.mil/pub/aburto/). Results (http://performance.netlib.org/performance/html/dhrystone.data.col0.html). (2002-03-26) 1 1 1 1 1 DHSD Duplex High Speed Data 1 1 1 1 1 DHTML Dynamic HTML 1 1 1 1 1 Dialled Number Identification Service (DNIS) A service that tells the recipient of a telephone call the telephone number dialled by the person making the call. It is used by call centres hosting multiple numbers, voicemail systems and ISPs offering shared dial-in services. Compare ANI, Caller ID. (2005-02-09) 1 1 1 1 1 DIALOG 1. A commercial bibliographic database and retrieval service from DIALOG Information Services. 2. Interactive mathematics using a graphics tablet by Illinois Inst Tech, 1966. ["DIALOG: A Conversational Programming System with a Graphical Orientation", S.H. Cameron et al, CACM 10:349-357 (1967). Sammet 1969, p.255-258]. 1 1 1 1 1 dialup A temporary, as opposed to dedicated, connection between machines established over a telephone line using modems. 1 1 1 1 1 DIAMAG An interactive extension of ALGOL. [Sammet 1969, p.195]. 1 1 1 1 1 diameter The diameter of a graph is the maximum value of the minimum distance between any two nodes. 1 1 1 1 1 Diamond One of five pedagogical languages based on Markov algorithms, used in "Nonpareil, a Machine Level Machine Independent Language for the Study of Semantics", B. Higman, ULICS Intl Report No ICSI 170, U London (1968). (cf. Brilliant, Nonpareil, Pearl[3], Ruby[2]). 1 1 1 1 1 DIANA Descriptive Intermediate Attributed Notation for Ada 1 1 1 1 1 DIB device independent bitmap 1 1 1 1 1 DIBOL Digital Interactive Business Oriented Language. DEC, 1970. Fortran syntax with BCD arithmetic. Versions for PDP-8 and RT-11. ANSI X3.165-1988. 1 1 1 1 1 dickless workstation Extremely pejorative hackerism for "diskless workstation". [Jargon File] (1995-03-28) 1 1 1 1 1 Dick Size War penis war 1 1 1 1 1 DICOM (From Digital Imaging and COmmunications in Medicine) A standard developed by ACR-NEMA (American College of Radiology - National Electrical Manufacturer's Association) for communications between medical imaging devices. It conforms to the ISO reference model for network communications and incorporates object-oriented design concepts. (1995-03-29) 1 1 1 1 1 dictionary 1. data dictionary. 2. associative array. 3. Free On-line Dictionary of Computing. 1 1 1 1 1 Dictionary APL Sharp APL 1 1 1 1 1 dictionary flame [Usenet] An attempt to sidetrack a debate away from issues by insisting on meanings for key terms that presuppose a desired conclusion or smuggle in an implicit premise. A common tactic of people who prefer argument over definitions to disputes about reality. Compare spelling flame. [Jargon File] 1 1 1 1 1 Dictionary of Algorithms and Data Structures (DADS) A dictionary by Paul Black. (http://www.aprendelo.com/rec/dictionary-algorithms-and-data-structures.html). (2001-03-26) 1 1 1 1 1 Dictionary of Computing Free On-line Dictionary of Computing 1 1 1 1 1 DID Direct Inward Dialing 1 1 1 1 1 diddle (US) To work in a casual manner, or the result of such work. (In the UK "to diddle someone" means to cheat them). "I diddled a copy of ADVENT so it didn't double-space all the time. ""Let's diddle this piece of code and see if the problem" goes away." Similar to twiddle, less purposeful than tweak. [Jargon File] (2013-08-18) 1 1 1 1 1 Didot point A variant of the point, equal to 0.3759 mm, or 1/72 of a French Royal inch (27.07 mm), or about 1/68 inch. Didot points are used in Europe. This unit is named after the French printer François Ambroise Didot (1730 - 1804) who defined the "point-based" typographical measurement system. (2002-03-11) 1 1 1 1 1 die 1. <jargon> crash. Unlike crash, which is used primarily of hardware, this verb is used of both hardware and software. See also go flatline, casters-up mode. 2. <electronics> Plural: dies. An unpackaged integrated circuit. [Jargon File] (2002-12-09) 1 1 1 1 1 die horribly The software equivalent of crash and burn, and the preferred emphatic form of die. "The converter choked on an FF in its input and died horribly". [Jargon File] (1996-05-28) 1 1 1 1 1 diff /dif/ 1. A change listing, especially giving differences between (and additions to) different versions of a piece of source code or documentation (the term is often used in the plural "diffs"). "Send me your diffs for the Jargon File!" Compare vdiff. 2. Specifically, such a listing produced by the diff Unix command, especially when used as input to the patch utility (which actually performs the modifications). This is a common method of distributing patches and source updates. 3. To compare (whether or not by use of automated tools on machine-readable files). See also vdiff, mod. [Jargon File] (1995-02-10) 1 1 1 1 1 Difference Engine Charles Babbage's design for the first automatic mechanical calculator. The Difference Engine was a special purpose device intended for the production of mathematical tables. Babbage started work on the Difference Engine in 1823 with funding from the British Government. Only one-seventh of the complete engine, about 2000 parts, was built in 1832 by Babbage's engineer, Joseph Clement. This was demonstrated successfully by Babbage and still works perfectly. The engine was never completed and most of the 12,000 parts manufactured were later melted for scrap. It was left to Georg and Edvard Schuetz to construct the first working devices to the same design which were successful in limited applications. The Difference Engine No. 2 was finally completed in 1991 at the Science Museum, London, UK and is on display there. The engine used gears to compute cumulative sums in a series of registers: r[i] := r[i] + r[i+1]. However, the addition 1 1 1 1 1 difference equation A relation between consecutive elements of a sequence. The first difference is D u(n) = u(n+1) - u(n) where u(n) is the nth element of sequence u. The second difference is D2 u(n) = D (D u(n)) #NAME? = u(n+2) - 2u(n+1) + u(n) And so on. A recurrence relation such as u(n+2) + a u(n+1) + b u(n) = 0 1 1 1 1 1 differential backup A kind of backup that copies all files that have changed since the last full backup. Each differential backup will include all files in previous differential backups since the full backup so to restore a version of a file, you only need to search the full backup and the relevant differential backup. Some systems support differential backup by associating an Archive flag with each file and setting this flag whenever the file is modified to indicate that it should be included in the next backup. A differential backup does not change this flag, whereas an incremental backup resets it. (2004-03-05) 1 1 1 1 1 differential driver An electronic device (commonly an integrated circuit), containing two amplifiers, used to drive a differential line. (1995-03-14) 1 1 1 1 1 differential line A kind of electrical connection using two wires, one of which carries the normal signal (V) and the other carries an inverted version the signal (-V). A differential amplifier at the receiver subtracts the inverted signal from the normal signal to yield a signal proportional to V. This subtraction is intended to cancel out any noise induced in the wires, on the assmption that the same level of noise will have been induced in both wires. Twisted pair wiring is often used to try to ensure that this is the case. The two wires might be connected at the receiver to separate analogue to digital converters and the subtraction performed digitally. The RS-422 serial line standard specifies differential drivers and receivers, whereas the earlier RS-232 standard does not. Opposite: single ended. (1995-03-08) 1 1 1 1 1 Diffie-Hellman A public-key encryption key exchange algorithm. FAQ (http://rsa.com/rsalabs/faq/html/3-6-1.html). (1999-03-15) 1 1 1 1 1 digerati (Or "digirati". By analogy with "literati" - people knowledgeable about literature) People knowledgeable about computers, "computer literate". [Newsweek, March 1995?]. (1995-05-07) 1 1 1 1 1 digest A periodical collection of messages which have been posted to a newsgroup or mailing list. A digest is prepared by a moderator who selects articles from the group or list, formats them and adds a contents list. The digest is then either mailed to an alternative mailing list or posted to an alternative newsgroup. Some news readers and electronic mail programs provide commands to "undigestify" a digest, i.e. to split it up into individual articles which may then be read and saved or discarded separately. 1 1 1 1 1 Digex Digital Express Group, Inc. 1 1 1 1 1 DigiCash A company, started in April 1990, which aims to develop and license products to support electronic payment methods including chip card, software only, and hybrid. Ecash is their trial form of software-only electronic money. (http://digicash.com/home.html). (1995-04-10) 1 1 1 1 1 Digicom (ftp://ftp.whnet.com/pub/wolfgang), (ftp://softmodem.whnet.com/pub/wolfgang), (ftp://ftp.netcom.com/pub/wolfgang). (http://ftp.whnet.com/wolfgang/). [Description?] 1 1 1 1 1 digirati digerati 1 1 1 1 1 digit An employee of Digital Equipment Corporation. See also VAX, VMS, PDP-10, TOPS-10, DEChead, double DECkers, field circus. [Jargon File] 1 1 1 1 1 Digital Common abbreviation for Digital Equipment Corporation. (1995-12-18) 1 1 1 1 1 digital A description of data which is stored or transmitted as a sequence of discrete symbols from a finite set, most commonly this means binary data represented using electronic or electromagnetic signals. The opposite is analogue. (1998-10-28) 1 1 1 1 1 digital audio A sequence of discrete samples taken from a continuous sound (audio) waveform. Tens of thousands of samples are taken each second. Each sample represents the intensity of the sound pressure wave at that instant. Apart from the sampling frequency, the other parameter is the digital encoding of each sample including the number of bits used. The encoding may be linear, logarithmic or mu-law. Digital audio is typically created by taking 16-bit samples over a spectrum of 44.1 thousand cycles per second (kHz), this means that CD quality sound requires 1.4 million bits of data per second. Digital telephone systems use lower sample rates. Filename extension: .au (Unix), .snd (MS-DOS, MS Windows). See also Audio IFF, MP3, wav. Usenet newsgroups: alt.binaries.sounds.*. A FAQ on audio file formats is available. Part 1 (ftp://ftp.cwi.nl/pub/audio/AudioFormats.part1), Part 2 1 1 1 1 1 Digital Audio Tape (DAT) A format for storing music on magnetic tape, developed in the mid-1980s by Sony and Philips. As digital music was popularized by compact discs, the need for a digital recording format for the consumer existed. The problem is that digital music contains over 5 megabytes of data per minute before error correction and supplementary information. Before DAT, the only way to record digitally was to use a video or a reel-to-reel recorder. DAT uses a rotary-head (or "helical scan") format, where the read/write head spins diagonally across the tape like a video cassette recorder. Thus the proper name is "R-DAT", where "R" for rotary distinguishes it from "S-DAT", a stationary design that did not make it out of the laboratories. Studio reel-to-reel decks are able to use stationary heads because they can have wider tape and faster tape speeds, but for the desired small medium of DAT the rotary-head compromise was made despite the potential problems with more moving parts. 1 1 1 1 1 digital camera A camera that captures and stores still images as digital data instead of on photographic film. The first digital cameras became available in the early 1990s[?]. [Which and when was the first?] (2000-08-10) 1 1 1 1 1 digital carrier A medium which can carry digital signals; broadly equivalent to the physical layer of the OSI seven layer model of networks. Carriers can be described as baseband or broadband. A baseband carrier can include direct current (DC), whereas broadband carriers are modulated by various methods into frequency bands which do not include DC. Sometimes a modem (modulator/demodulator) or codec (coder/decoder) combines several channels on one transmission path. The combining of channels is called multiplexing, and their separation is called demultiplexing, independent of whether a modem or codec bank is used. Modems can be associated with frequency division multiplexing (FDM) and codecs with time division multiplexing (TDM) though this grouping of concepts is somewhat arbitrary. If the medium of a carrier is copper telephone wire, the circuit may be called T1, T3, etc. as these designations 1 1 1 1 1 digital certificate An attachment to an electronic mail message used for security purposes, e.g. to verify that a user sending a message is who he or she claims to be, and to provide the receiver with the means to encode a reply. An individual wishing to send an encrypted message applies for a digital certificate from a certificate authority (CA). The CA issues an encrypted digital certificate containing the applicant's public key and a variety of other identification information. The CA makes its own public key readily available on the Internet. The recipient of an encrypted message uses the CA's public key to decode the digital certificate attached to the message, verifies it as issued by the CA and then obtains the sender's public key and identification information held within the certificate. (2006-05-27) 1 1 1 1 1 digital computer A computer that represents numbers and other data using discrete internal states, in contrast to the continuously varying quantities used in an analog computer. Some of the fundamental ideas behind the digital computer were proposed by Alan Turing between 1936 and 1938. The design of the Atanasoff-Berry Computer (1937-1942) included some of the important implementation details but the first digital computer to successfully run real programs was the Z3 (1941). ENIAC (1943-1946) was the first electronic digital computer but was only programmable by manual rewiring or switches. (2003-10-01) 1 1 1 1 1 Digital Control System (DCS) A digital computer used for real-time control of a dynamic system, usually in an industrial environment, possibly as part of a Supervisory Control and Data Acquisition (SCADA) system. A DCS samples feedback from the system under control and modifies the control signals in an attempt to achieve some desired behaviour. Analysis of such digital-analogue feedback systems can involve mathematical methods such as difference equations, Laplace transforms, z transfer functions, state space models and state transition matrices. (2004-08-22) 1 1 1 1 1 digital dashboard A personalised desktop portal that focuses on business intelligence and knowledge management. Microsoft's version has a launch screen including stock quotes, voice mail and e-mail messages, a calendar, a weather forecast, traffic information, access to news feeds, customer and sales data, and Internet conferences. A digital dashboard might previously have been thought of as an executive information system. In the future, digital dashboards could be available on personal digital assistants and cellular phones. ["Gates pitches 'digital dashboards' to bevy of top CEOs", Bob Trott, pub. InfoWorld Electric, 1999-05-19]. (1999-09-14) 1 1 1 1 1 Digital Data Service (DDS) The class of service offered by telecommunications companies for transmitting digital data as opposed to voice. (1995-02-28) 1 1 1 1 1 digital electronics The implementation of two-valued logic using electronic logic gates such as and gates, or gates and flip-flops. In such circuits the logical values true and false are represented by two different voltages, e.g. 0V for false and +5V for true. Similarly, numbers are normally represented in binary using two different voltages to represented zero and one. Digital electronics contrasts with analogue electronics which represents continuously varying quantities like sound pressure using continuously varying voltages. Digital electronics is the foundation of modern computers and digital communications. Massively complex digital logic circuits with millions of gates can now be built onto a single integrated circuit such as a microprocessor and these circuits can perform millions of operations per second. (2006-01-14) 1 1 1 1 1 Digital Enhanced Cordless Telecommunications (DECT, formerly ".. European ..") A standard developed by the European Telecommunication Standard Institute from 1988, governing pan-European digital mobile telephony. DECT covers wireless PBXs, telepoint, residential cordless telephones, wireless access to the public switched telephone network, Closed User Groups (CUGs), Local Area Networks, and wireless local loop. DECT defines only the radio connection between two points and can be used for remote access to public and private networks. Other mobility standards, such as GSM, TACS, and DCS 1800 add the necessary switching, signaling, and management functions that are not specified by DECT. The DECT Common Interface radio standard is a multicarrier time division multiple access, time division duplex (MC-TDMA-TDD) radio transmission technique using ten radio frequency channels from 1880 to 1930 MHz, each divided into 24 time slots of 10ms, and twelve full-duplex accesses per 1 1 1 1 1 digital envelope (http://rsa.com/rsalabs/faq/html/2-2-4.html). [Summary?] (1999-03-16) 1 1 1 1 1 Digital Equipment Computer Users Society (DECUS) A world-wide organisation of Information Technology professionals interested in the products, services, and technologies of Digital Equipment Corporation and related vendors. Membership in the US chapter is free and provides participants with the means to enhance their professional development, forums for technical training, mechanisms for obtaining up-to-date information, advocacy programs and opportunities for informal disclosure and interaction with professional colleagues of like interest. DECUS Home (http://www.decus.org/). (2014-08-26) 1 1 1 1 1 Digital Equipment Corporation (DEC) A computer manufacturer and software vendor. Before the killer micro revolution of the late 1980s, hackerdom was closely symbiotic with DEC's pioneering time-sharing machines. The first of the group of hacker cultures nucleated around the PDP-1 (see TMRC). Subsequently, the PDP-6, PDP-10, PDP-20, PDP-11 and VAX were all foci of large and important hackerdoms and DEC machines long dominated the ARPANET and Internet machine population. The first PC from DEC was a CP/M computer called Rainbow, announced in 1981-82. DEC was the technological leader of the minicomputer era (roughly 1967 to 1987), but its failure to embrace microcomputers and Unix early cost it heavily in profits and prestige after silicon got cheap. However, the microprocessor design tradition owes a heavy debt to the 1 1 1 1 1 Digital Equipment Corporation Network (DECNET) Ethernet software used on DEC computers such as the Vax. [More details?] (1999-06-03) 1 1 1 1 1 Digital European Cordless Telecommunications Digital Enhanced Cordless Telecommunications 1 1 1 1 1 Digital Express Group, Inc. (Digex) The largest Internet provider in the Washington metropolitan area with POPs in Maryland, Virginia, New Jersey, New York and California. (http://digex.net). (1994-10-25) 1 1 1 1 1 Digital Lempel Ziv 1 (DLZ1) A Lempel-Ziv compression algorithm which maps variable length input strings to variable length output symbols. During compression, the algorithm builds a dictionary of strings which is accessed by means of a hash table. Compression occurs when input data matches a string in the table and is replaced with the output symbol. DLZ1 is used on Digital Linear Tape. (1997-04-05) 1 1 1 1 1 Digital Library Initiative A project to research digital libraries which aims to provide real collections to real users (high school students, University researchers and students, users in public libraries). The project is sponsored jointly by three US federal funding agencies, led by the National Science Foundation. The University of Michigan, one of the six sites selected in 1994 to collaborate, will provide collections on earth and space sciences. The project, known there as the University of Michigan Digital Library Project (UMDL), is a large, multi-year project headed by Daniel Atkins, Dean of the School of Information and Library Studies. UMDL (http://http2.sils.umich.edu/UMDL/HomePage.html). (1995-02-23) 1 1 1 1 1 Digital Linear Tape (DLT) A kind of magnetic tape drive originally developed by DEC and now marketed by Quantum. DLT drives implement the Digital Lempel Ziv 1 (DLZ1) compression algorithm in a combination of hardware and firmware. They use a popular chip by Stac (now hi/fn) to do the string searching. Counting, sorting and Huffman coding are done in firmware (with hardware support for the Huffman algorithm?). In April 1997 DLT drives can transfer 5 megabytes per second and can store 35 gigabytes on a single cartridge. Compression might roughly double these figures. (1997-04-05) 1 1 1 1 1 digital logic two-valued logic 1 1 1 1 1 Digital Multimeter (DMM) A peice of test equipment used for measuring voltage, current, resistance, and possibly other electircal quantities and displaying the value in number form. (1997-02-12) 1 1 1 1 1 Digital Radio Mondiale (DRM) A form of monaural digital broadcast using carrier frequencies below 30 MHz. DRM uses MPEG-4 AAC Main Profile and SBR at data rates of 16-25 kbps. (http://drm.org/). (2001-12-20) 1 1 1 1 1 Digital Research The company which developed CP/M, the operating system used on many of the first generation 8-bit microprocessor-based personal computers. Digital Research also produced DR-DOS. Address: Santa Cruz, CA, USA. (1998-03-17) 1 1 1 1 1 Digital Rights Management (DRM) Any technology used to limit the use of software, music, movies or other digital data. This generally relies on some interaction between the media and the system that plays it. For example, video DVDs usually include a region code. If this does not match the player's region code, the player will refuse to play the disc. (2006-02-02) 1 1 1 1 1 digital service unit data service unit 1 1 1 1 1 Digital Signal Processing (DSP) Computer manipulation of analog signals (commonly sound or image) which have been converted to digital form (sampled). (1994-12-07) 1 1 1 1 1 Digital Signal Processing Language (DSPL) A C-derived DSP language. ["The Programming Language DSPL", A. Schwarte & H. Hanselmann, Proc PCIM 90, 1990]. (1994-12-01) 1 1 1 1 1 digital signature Extra data appended to a message which identifies and authenticates the sender and message data using public-key encryption. The sender uses a one-way hash function to generate a hash-code of about 32 bits from the message data. He then encrypts the hash-code with his private key. The receiver recomputes the hash-code from the data and decrypts the received hash with the sender's public key. If the two hash-codes are equal, the receiver can be sure that data has not been corrupted and that it came from the given sender. (1995-02-07) 1 1 1 1 1 digital signatures digital signature 1 1 1 1 1 Digital Signature Standard The NIST's standard for digital signatures (authenticating both a message and the signer) that was first announced in 1991. It is based on an algorithm using discrete logarithms, which is a variant of the Elgamal algorithm with Schnorr's improvements. DSS's security is currently considered very strong - comparable to RSA. It is estimated that DSS's 1024-bit keys would take 1.4E16 MIPS-years to crack. (1995-11-16) 1 1 1 1 1 Digital Simulation Language (DSL) Extensions to Fortran to simulate analog computer functions. Version DSL/90 ran on the IBM 7090. ["DSL/90 - A Digital Simulation Program for Continuous System Modelling", Proc SJCC 28, AFIPS, Spring 1966]. [Sammet 1969, p 632]. (1996-10-13) 1 1 1 1 1 Digital Simultaneous Voice and Data (DSVD) A technique supported by some modems for multiplexing compressed speech with digital data for transmission over a normal telephone line. DSVD isn't standardised yet, so generally you have to have the same make of modem at both ends for it to work. [How does it work? Which modems? References?] (1997-06-05) 1 1 1 1 1 DIGITAL Standard MUMPS (DSM) DEC's version of MUMPS. (1995-01-10) 1 1 1 1 1 Digital Subscriber Line (DSL, or Digital Subscriber Loop, xDSL - see below) A family of digital telecommunications protocols designed to allow high speed data communication over the existing copper telephone lines between end-users and telephone companies. When two conventional modems are connected through the telephone system (PSTN), it treats the communication the same as voice conversations. This has the advantage that there is no investment required from the telephone company (telco) but the disadvantage is that the bandwidth available for the communication is the same as that available for voice conversations, usually 64 kb/s (DS0) at most. The twisted-pair copper cables into individual homes or offices can usually carry significantly more than 64 kb/s but the telco needs to handle the signal as digital rather than analog. There are many implementation of the basic scheme, differing 1 1 1 1 1 Digital Subscriber Line Access Module (DSLAM, or Digital Subscriber Line Access Multiplexer) The generic term for the Central Office (CO) equipment where xDSL lines are terminated. The multiple DSL signals may be multiplexed onto a wideband channel such as ATM. (2000-04-05) 1 1 1 1 1 Digital Subscriber Loop Digital Subscriber Line 1 1 1 1 1 Digital Switched Network (DSN) The completely digital version of the PSTN. (1997-07-18) 1 1 1 1 1 Digital to Analog Converter (DAC) A device which takes a digital value and outputs a voltage which is proportional to the input value. Typical uses include digital generation of audio signals or conversion of a bitmap image to a signal to drive a CRT. (1998-02-15) 1 1 1 1 1 Digital Versatile Disc (DVD, formerly "Digital Video Disc") An optical storage medium with improved capacity and bandwidth compared with the Compact Disc. DVD, like CD, was initally marketed for entertainment and later for computer users. [When was it first available?] A DVD can hold a full-length film with up to 133 minutes of high quality video, in MPEG-2 format, and audio. The first DVD drives for computers were read-only drives ("DVD-ROM"). These can store 4.7 GBytes - over seven times the storage capacity of CD-ROM. DVD-ROM drives read existing CD-ROMs and music CDs and are compatible with installed sound and video boards. Additionally, the DVD-ROM drive can read DVD films and modern computers can decode them in software in real-time. The DVD video standard was announced in November 1995. Matshusita did much of the early development but Philips made the first DVD player, which appeared in Japan in November 1 1 1 1 1 Digital Versatile Disk Random Access Memory (DVD-RAM) Rewritable DVD media that is recordable on both sides, giving up to 9.6GB of storage. A drive can record to disk and read from it at the same time, so the term full duplex is often used. There are two general types of media: traditional discrete disk in DVD or Jewel case, and one in a permanent case like a large floppy; the disk remains in the case, and the case goes into the drive. The former can sometimes be read by regular DVD drives; the latter obviously cannot. Technical details, somewhat dated, at burnworld.com (http://burnworld.com/dvd/primer/dvdram.htm). (2005-01-26) 1 1 1 1 1 Digital Video Disc Digital Versatile Disc 1 1 1 1 1 Dijkstra's guarded command language A language invented by Edsger Dijkstra ca. 1974. It introduced the concept of guards and committed choice nondeterminism (don't care nondeterminism). Described and used in ["A Discipline of Programming", E. Dijkstra, P-H 1976]. (1994-12-07) 1 1 1 1 1 dike To remove or disable a portion of something, as a wire from a computer or a subroutine from a program. A standard slogan is When in doubt, dike it out. (The implication is that it is usually more effective to attack software problems by reducing complexity than by increasing it.) The word "dikes" is widely used among mechanics and engineers to mean "diagonal cutters", especially the heavy-duty metal-cutting version, but may also refer to a kind of wire-cutters used by electronics technicians. To "dike something out" means to use such cutters to remove something. Indeed, the TMRC Dictionary defined dike as "to attack with dikes". Among hackers this term has been metaphorically extended to informational objects such as sections of code. [Jargon File] 1 1 1 1 1 DIL Dual In-Line Package 1 1 1 1 1 Dilbert A cartoon computer worker drawn by Scott Adams <scottadams@aol.com>, who works in Silicon Valley. The cartoon became so popular he left his day job. The cartoon satirises typical corporate life, especially that which revolves around computers. See also: BOFH. (http://unitedmedia.com/comics/dilbert/). (1996-10-11) 1 1 1 1 1 Dilberted To be exploited and oppressed by your boss. Derived from the experiences of Dilbert, the geek-in-hell comic strip character. "I've been dilberted again. The old man revised the specs for the fourth time this week." (1997-03-29) 1 1 1 1 1 DIM DIM statement 1 1 1 1 1 DIMATE Depot Installed Maintenance Automatic Test Equipment. A language for programming automatic test equipment. It Runs on the RCA 301. ["A Simple User-Oriented Source Language for Programming Automatic Test Equipment", B.H. Scheff, CACM 9(4) (Apr 1966)]. [Sammet 1969, p. 647]. (1996-01-07) 1 1 1 1 1 DIMM Dual In-Line Memory Module 1 1 1 1 1 DIM statement (From "dimension") A keyword in most versions of the BASIC programming language that declares the size of an array. E.g. DIM A(100) declares a one-dimensional array with 101 numeric elements (including A(0)). Visual Basic uses the DIM (or "Dim") statement for any variable declaration, even scalars, e.g. Dim DepartmentNumber As Integer which declares a single (scalar) variable of type Integer. (1999-03-26) 1 1 1 1 1 DIN Deutsche Institut fuer Normung. The German standardisation body, a member of ISO. 1 1 1 1 1 DIN-8 An 8-pin round connector, sometimes used for EIA-232 serial communication when space is restricted, such as on laptop computers. (1996-12-08) 1 1 1 1 1 ding 1. Synonym for feep. Usage: rare among hackers, but commoner in the Real World. 2. "dinged": What happens when someone in authority gives you a minor bitching about something, especially something trivial. "I was dinged for having a messy desk." [Jargon File] 1 1 1 1 1 Dining Philosophers Problem (DPP) A problem introduced by Dijkstra concerning resource allocation between processes. The DPP is a model and universal method for testing and comparing theories on resource allocation. Dijkstra hoped to use it to help create a layered operating system, by creating a machine which could be consider to be an entirely deterministic automaton. The problem consists of a finite set of processes which share a finite set of resources, each of which can be used by only one process at a time, thus leading to potential deadlock. The DPP visualises this as a number of philosophers sitting round a dining table with a fork between each adjacent pair. Each philosopher may arbitrarily decide to use either the fork to his left or the one to his right but each fork may only be used by one philosopher at a time. Several potential solutions have been considered. Semaphores - a simple, but unfair solution where each 1 1 1 1 1 dink /dink/ Said of a machine that has the bitty box nature; a machine too small to be worth bothering with - sometimes the system you're currently forced to work on. First heard from an MIT hacker working on a CP/M system with 64K, in reference to any 6502 system, then from fans of 32 bit architectures about 16-bit machines. "GNUMACS will never work on that dink machine." Probably derived from mainstream dinky, which isn't sufficiently pejorative. See macdink. [Jargon File] (1994-10-31) 1 1 1 1 1 DinnerBell An object-oriented dataflow language with single assignment. ["Object-Oriented Load Distribution in DinnerBell", S. Kono <kono@csl.sony.co.jp> et al, in TOOLS Pacific 90]. (1994-10-31) 1 1 1 1 1 DINO Data parallel superset of C. (ftp://ftp.cs.colorado.edu/pub/cs/distribs/dino/). ["The DINO Parallel Programming Language", M. Rosing et al, J Parallel Dist Comp 13(9):30-42 (Sep 1991)]. ["DINO Parallel Programming Language", M. Rosing et al, CU-CS-457-90, U Colorado, April 1990]. 1 1 1 1 1 dinosaur 1. Any hardware requiring raised flooring and special power. Used especially of old minicomputers and mainframes, in contrast with newer microprocessor-based machines. In a famous quote from the 1988 Unix EXPO, Bill Joy compared the liquid-cooled mainframe in the massive IBM display with a grazing dinosaur "with a truck outside pumping its bodily fluids through it". IBM was not amused. Compare big iron; see also dinosaurs mating. 2. [IBM] A very conservative user; a zipperhead. [Jargon File] 1 1 1 1 1 dinosaur pen A traditional mainframe computer room complete with raised flooring, special power, its own ultra-heavy-duty air conditioning, and a side order of Halon fire extinguishers. See boa. (1995-11-17) 1 1 1 1 1 dinosaurs mating The activity said to occur when yet another big iron merger or buy-out occurs; reflects a perception by hackers that these signal another stage in the long, slow dying of the mainframe industry. Also described as elephants mating: lots of noise and action at a high level, with an eventual outcome in the somewhat distant future. In its glory days of the 1960s, it was "IBM and the Seven Dwarves": Burroughs, Control Data, General Electric, Honeywell, NCR, RCA, and Univac. Early on, RCA sold out to Univac and GE also sold out, and it was "IBM and the BUNCH" (an acronym for Burroughs, Univac, NCR, Control Data, and Honeywell) for a while. Honeywell was bought out by Bull. Univac in turn merged with Sperry to form Sperry/Univac, which was later merged (although the employees of Sperry called it a hostile takeover) with Burroughs to form Unisys in 1986 (this was when the phrase "dinosaurs mating" was coined). In 1991 AT&T absorbed NCR, only to spit it out 1 1 1 1 1 diode A semiconductor device which conducts electric current run in one direction only. This is the simplest kind of semiconductor device, it has two terminals and a single PN junction. One diode can be used as a half-wave rectifier or four as a full-wave rectifier. (1995-03-14) 1 1 1 1 1 Diophantine equation Equations with integer coefficients to which integer solutions are sought. Because the results are restricted to integers, different algorithms must be used from those which find real solutions. [More details?] (1998-08-27) 1 1 1 1 1 DIP 1. Dual In-line Package. 2. Document Image Processing. 1 1 1 1 1 diplex (From telegraphy) Two simultaneous transmissions in one direction. Compare: duplex. (2000-03-30) 1 1 1 1 1 DIPP Dual Inline Pin Package 1 1 1 1 1 Direct-Access Storage Device (DASD) IBM mainframe terminology for a disk drive, in contrast with a tape drive which is a sequential access device. (1995-03-01) 1 1 1 1 1 Direct Client to Client Protocol (DCC) An IRC protocol created to allow users to chat privately and to send and receive files directly instead of having to go thorugh the IRC servers. DCC protects users from being monitored by IRC Server operators that have enabled conversation logging. It also allows much more efficient use of available bandwidth as the data does not need to be broadcast all over the world just to reach a specific user. The available DCC commands include DCC CHAT (direct user to user chat), DCC SEND (direct user to user file send) and DCC GET (file acknowledgement from a receiver). (1995-04-12) 1 1 1 1 1 Direct Connection A re-seller of Internet connections to the PIPEX backbone. 1 1 1 1 1 directed acyclic graph (DAG) A directed graph containing no cycles. This means that if there is a route from node A to node B then there is no way back. (1994-12-07) 1 1 1 1 1 directed graph (digraph) A graph with one-way edges. See also directed acyclic graph. (1994-11-11) 1 1 1 1 1 Directed Oc (Doc) A language related to Oc. ["Programming Language Doc and Its Self-Description, or 'X=X Is Considered Harmful'", M. Hirata, Proc 3rd Conf Japan Soc Soft Sci Tech, pp. 69-72, 1986]. (1999-10-08) 1 1 1 1 1 directed set A set X is directed under some relation, <= (less than or equal), if it is non-empty and if for any two elements x and y there exists an element z such that x <= z and y <= z. I.e. all pairs have an upper bound. (1994-11-11) 1 1 1 1 1 Direct Inward Dialing (DID) A service offered by telephone companies which allows the last 3 or 4 digits of a phone number to be transmitted to the destination exchange. For example, a company could have 10 incoming lines, all with the number 234 000. If a caller dials 234 697, the call is sent to 234 000 (the company's exchange), and the digits 697 are transmitted. The company's exchange then routes the call to extension 697. This gives the impression of 1000 direct dial lines, whereas in fact there are only 10. Obviously, only 10 at a time can be used. This system is also used by fax servers. Instead of an exchange at the end of the 234 000 line, a computer running fax server software and fax modem cards uses the last three digits to identify the recipient of the fax. This allows 1000 people to have their own individual fax numbers, even though there is only one 'fax machine'. Dictionary of PC Hardware and Data Communications Terms 1 1 1 1 1 directional coupler (tap) A passive device used in cable systems to divide and combine radio frequency signals. A directional coupler has at least three ports: line in, line out, and the tap. The signal passes between line in and line out ports with loss referred to as the insertion loss. A small portion of the signal power applied to the line in port passes to the tap port. A signal applied to the tap port is passed to the line in port less the tap attenuation value. The tap signals are isolated from the line out port to prevent reflections. A signal applied to the line out port passes to the line in port and is isolated from the tap port. Some devices provide more than one tap output line (multi-taps). (1995-12-23) 1 1 1 1 1 Directly Executable Test Oriented Language (DETOL) A simple language to control a specific type of test equipment. ["Improved DETOL Programming Manual for the Series 5500 Automatic Test System", Pub. 5500-31-0-1, AAI Corporation Sep 1973]. (1995-09-29) 1 1 1 1 1 direct mapped cache A cache where the cache location for a given address is determined from the middle address bits. If the cache line size is 2^n then the bottom n address bits correspond to an offset within a cache entry. If the cache can hold 2^m entries then the next m address bits give the cache location. The remaining top address bits are stored as a "tag" along with the entry. In this scheme, there is no choice of which block to flush on a cache miss since there is only one place for any block to go. This simple scheme has the disadvantage that if the program alternately accesses different addresses which map to the same cache location then it will suffer a cache miss on every access to these locations. This kind of cache conflict is quite likely on a multi-processor. See also fully associative cache, set associative cache. 1 1 1 1 1 Direct Memory Access (DMA) A facility of some architectures which allows a peripheral to read and write memory without intervention by the CPU. DMA is a limited form of bus mastering. (1996-08-23) 1 1 1 1 1 directories directory 1 1 1 1 1 directory A node in a hierarchical file system which contains zero or more other nodes - generally, files or other directories. The term "folder" is sometimes used in systems such as the Macintosh or Microsoft Windows in which directories are traditionally depicted as folders (like small briefcases). (2007-02-21) 1 1 1 1 1 Directory Access Protocol X.500 protocol used for communication between a Directory User Agent and a Directory System Agent. 1 1 1 1 1 directory service A structured repository of information on people and resources within an organisation, facilitating management and communication. On a LAN or WAN the directory service identifies all aspects of the network including users, software, hardware, and the various rights and policies assigned to each. As a result applications can access information without knowing where a particular resource is physically located, and users interact oblivious to the network topology and protocols. To allow heterogeneous networks to share directory information the ITU proposed a common structure called X.500. However, its complexity and lack of seamless Internet support led to the development of Lightweight Directory Access Protocol (LDAP) which has continued to evolve under the aegis of the IETF. Despite its name LDAP is too closely linked to X.500 to be "lightweight". LDAP was adopted by several companies such as Netscape 1 1 1 1 1 Directory System Agent (DSA) The software that provides the X.500 Directory Service for a portion of the directory information base. Generally, each DSA is responsible for the directory information for a single organisation or organisational unit. (1994-12-07) 1 1 1 1 1 Directory User Agent (DUA) The software that accesses the X.500 Directory Service on behalf of the directory user. The directory user may be a person or another software element. (1994-12-07) 1 1 1 1 1 DirectX A Microsoft programming interface standard, first included with Windows 95. DirectX gives (games) programmers a standard way to gain direct access to enhanced hardware features under Windows 95 instead of going via the Windows 95 GDI. Some DirectX code runs faster than the equivalent under MS DOS. DirectX promises performance improvements for graphics, sound, video, 3D, and network capabilites of games, but only where both hardware and software support DirectX. DirectX 2 introduced the Direct3D interface. Version 5 was current at 1998-02-01. Version 8.1 is included in Windows XP. Latest version: 8.1 (as of 2001-12-31). (http://microsoft.com/directx/). (2001-12-31) 1 1 1 1 1 DIRFT Do It Right the First Time 1 1 1 1 1 Dirt Design In Real Time 1 1 1 1 1 dirtball (XEROX PARC) A small, perhaps struggling outsider; not in the major or even the minor leagues. For example, "Xerox is not a dirtball company". Outsiders often observe in the PARC culture an institutional arrogance which usage of this term exemplifies. The brilliance and scope of PARC's contributions to computer science have been such that this superior attitude is not much resented. - ESR [Jargon File] (1994-12-07) 1 1 1 1 1 dirty power Electrical mains voltage that is unfriendly to the delicate innards of computers. Spikes, drop-outs, average voltage significantly higher or lower than nominal, or just plain noise can all cause problems of varying subtlety and severity (these are collectively known as power hits). [Jargon File] 1 1 1 1 1 dis A CPython bytecode disassembler. dis home (https://docs.python.org/2/library/dis.html). (2014-06-08) 1 1 1 1 1 DISA 1. <body> Defense Information Systems Agency. 2. <standard> Data Interchange Standards Association. (1999-09-18) 1 1 1 1 1 disaster planning disaster recovery 1 1 1 1 1 disaster recovery (DR) Planning and implementation of procedures and facilities for use when essential systems are not available for a period long enough to have a significant impact on the business, e.g. when the head office is blown up. Disasters include natural: fire, flood, lightning, hurricane; hardware: power failure, component failure, head crash; software failure: bugs, resources; vandalism: arson, bombing, cracking, theft; data corruption or loss: human error, media failure; communications: computer network equipment, network storm, telephones; security: passwords compromised, computer virus; legal: change in legislation; personnel: unavailability of essential staff, industrial action. Companies need to plan for disaster: before: risk analysis, preventive measures, training; during: how should staff and systems respond; after: recovery measures, post mortem analysis. 1 1 1 1 1 disc British spelling of "disk", normally only used for "compact disc". (1995-07-30) 1 1 1 1 1 disc drive disc 1 1 1 1 1 disclaimer Statement ritually appended to many Usenet postings (sometimes automatically, by the posting software) reiterating the fact (which should be obvious, but is easily forgotten) that the article reflects its author's opinions and not necessarily those of the organisation running the computer through which the article entered the network. [Jargon File] (1995-07-30) 1 1 1 1 1 disconnect SCSI reconnect 1 1 1 1 1 Discordianism /dis-kor'di-*n-ism/ The veneration of Eris, also known as Discordia; widely popular among hackers. Discordianism was popularised by Robert Shea and Robert Anton Wilson's novel "Illuminatus!" as a sort of self-subverting Dada-Zen for Westerners - it should on no account be taken seriously but is far more serious than most jokes. Consider, for example, the Fifth Commandment of the Pentabarf, from Principia Discordia: "A Discordian is Prohibited of Believing What he Reads." Discordianism is usually connected with an elaborate conspiracy theory/joke involving millennia-long warfare between the anarcho-surrealist partisans of Eris and a malevolent, authoritarian secret society called the Illuminati. See Religion, Church of the SubGenius, and ha ha only serious. [Jargon File] (1997-04-12) 1 1 1 1 1 discrete A description of a quantity whose value is one of a fixed set of values, as opposed to a continuous - a value capable of infinitessimal variation. For example, integers are discrete values whereas real numbers are continuous; digital sound has discrete amplitude leves whereas analog sound is continuous. (2009-10-08) 1 1 1 1 1 discrete cosine transform (DCT) A technique for expressing a waveform as a weighted sum of cosines. The DCT is central to many kinds of signal processing, especially video compression. Given data A(i), where i is an integer in the range 0 to N-1, the forward DCT (which would be used e.g. by an encoder) is: B(k) = sum A(i) cos((pi k/N) (2 i + 1)/2) i=0 to N-1 B(k) is defined for all values of the frequency-space variable k, but we only care about integer k in the range 0 to N-1. The inverse DCT (which would be used e.g. by a decoder) is: AA(i)= sum B(k) (2-delta(k-0)) cos((pi k/N)(2 i + 1)/2) k=0 to N-1 where delta(k) is the Kronecker delta. The main difference between this and a discrete Fourier transform (DFT) is that the DFT traditionally assumes that the data A(i) is periodically continued with a period of N, 1 1 1 1 1 discrete Fourier transform (DFT) A Fourier transform, specialized to the case where the abscissas are integers. The DFT is central to many kinds of signal processing, including the analysis and compression of video and sound information. A common implementation of the DFT is the Fast Fourier Transform (FFT). See also discrete cosine transform. (1997-03-10) 1 1 1 1 1 discrete preorder A preorder is said to be discrete if any two of its elements are incomparable. (1995-09-21) 1 1 1 1 1 discriminated union The discriminated union of two sets A and B is A + B = (inA, a) | a in A U (inB, b)| b in B where inA and inB are arbitrary tags which specify which summand an element originates from. A type (especially an algebraic data type) might be described as a discriminated union if it is a sum type whose objects consist of a tag to say which part of the union they belong to and a value of the corresponding type. (1995-04-25) 1 1 1 1 1 discussion group Any system that supports group messaging, e.g. a shared mailbox, Usenet, bulletin board system, or possibly a mailing list, used to publish messages on some particular topic. (2000-11-16) 1 1 1 1 1 Disiple A DSP language. ["A Compiler that Easily Retargets High Level Language Programs for Different Signal Processing Architectures", J.E. Peters & S.M. Dunn, Proc ICASSP 89, pp. 1103-1106, May 1989]. (2000-11-16) 1 1 1 1 1 disjoint union In domain theory, a union (or sum) which results in a domain without a least element. 1 1 1 1 1 Disjunctive Normal Form (DNF) A logical formula consisting of a disjunction of conjunctions where no conjunction contains a disjunction. E.g. the DNF of (A or B) and C is (A and C) or (B and C). (1994-12-07) 1 1 1 1 1 disk 1. magnetic disk. 2. compact disc. 3. optical disk. Note: the american spelling, "disk", is normal for most computer disks whereas "compact disc", having come to computers via the audio world, is correctly spelled with a c, indeed, this spelling is part of the CD standard. (1995-07-30) 1 1 1 1 1 disk controller (Or "hard disk controller", HDC) The circuit which allows the CPU to communicate with a hard disk, floppy disk or other kind of disk drive. The most common disk controllers in use are IDE and SCSI controllers. Most home personal computers use IDE controllers. High end PCs, workstations and network file servers mostly have SCSI adaptors. (1998-03-16) 1 1 1 1 1 disk drive (Or "hard disk drive", "hard drive", floppy disk drive, "floppy drive") A peripheral device that reads and writes hard disks or floppy disks. The drive contains a motor to rotate the disk at a constant rate and one or more read/write heads which are positioned over the desired track by a servo mechanism. It also contains the electronics to amplify the signals from the heads to normal digital logic levels and vice versa. In order for a disk drive to start to read or write a given location a read/write head must be positioned radially over the right track and rotationally over the start of the right sector. Radial motion is known as "seeking" and it is this which causes most of the intermittent noise heard during disk activity. There is usually one head for each disk surface and all heads move together. The set of locations which are accessible with the heads in a given radial position are known 1 1 1 1 1 disk duplexing A variation on disk mirroring where, as well as redundant disk drives, a second disk controller or host adapter is also present. (1996-02-22) 1 1 1 1 1 diskette floppy disk 1 1 1 1 1 disk farm (Or "laundromat") A large room or rooms filled with disk drives (especially washing machines). [Jargon File] (1995-03-27) 1 1 1 1 1 diskless workstation A personal computer or workstation which has neither a hard disk nor floppy disk drive and which performs all file access via a local area network connection to a file server. The lowest level bootstrap code is stored in non-volatile storage. This uses a simple protocol such as BOOTP to request and download more sophisticated boot code and eventually, the operating system. The archtypal product was the 3Station developed by Bob Metcalfe at 3Com. Another example was the Sun 3/50. Diskless workstations are ideal when many users are running the same application. They are small, quiet, more reliable than products with disks, and help prevent both the theft of data and the introduction of viruses since the software and data available on them is controlled by the network administrator or system administrator. They do however rely on a server which becomes a disadvantage if it is heavily 1 1 1 1 1 disk mirroring Use of one or more mirrors of a hard disk. (1996-02-17) 1 1 1 1 1 Disk Operating System (DOS) The original disk operating system from IBM. DOS was the low-end OS of choice on the IBM 360, the high-end system was called just "OS". DOS had a smaller kernel and less functionality than OS and could run on the typical 32K 360/30 and 64K 360/40 class machines. DOS was a successor to TOS. (1999-01-20) 1 1 1 1 1 disk operating system (DOS) The name of a number of operating systems which include facilities for storing files on disk, often used to refer to Microsoft DOS. Such a system must handle physical disk I/O, the mapping of file names to disk addresses and protection of files from unauthorised access (in a multi-user system). A DOS should present a uniform interface to different storage device such as floppy disks, hard disks and magnetic tape drives. It may also provide some kind of locking to prevent unintentional simultaneous access by two processes to the same file (or record). (1998-07-08) 1 1 1 1 1 disks disk 1 1 1 1 1 disk striping data striping 1 1 1 1 1 Dislang ["Dislang: A Distributed Programming Language/System", C. Li et al, Proc 2nd Intl Conf Distrib Comp Sys, IEEE 1981, pp. 162-172]. (1995-05-10) 1 1 1 1 1 disman Distributed Management 1 1 1 1 1 display 1. <hardware> monitor. 2. <language> A vector of pointers to activation records. The Nth element points to the activation record containing variables declared at lexical depth N. This allows faster access to variables from outer scopes than the alternative of linked activation records (but most variable accesses are either local or global or occasionally to the immediately enclosing scope). Displays were used in some ALGOL implementations. (1996-02-22) 1 1 1 1 1 display hack A program with the same approximate purpose as a kaleidoscope: to make pretty pictures. Famous display hacks include munching squares, smoking clover, the BSD Unix rain(6) program, "worms(6)" on miscellaneous Unixes, and the X "kaleid(1)" program. Display hacks can also be implemented without programming by creating text files containing numerous escape sequences for interpretation by a video terminal; one notable example displayed, on any VT100, a Christmas tree with twinkling lights and a toy train circling its base. The hack value of a display hack is proportional to the aesthetic value of the images times the cleverness of the algorithm divided by the size of the code. Synonym psychedelicware. [Jargon File] (1995-05-10) 1 1 1 1 1 Display PostScript An extended form of PostScript permitting its interactive use with bitmap displays. 1 1 1 1 1 Display Screen Equipment Visual Display Unit 1 1 1 1 1 display standard IBM and others have introduced a bewildering plethora of graphics and text display standards for IBM PCs. The standards are mostly implemented by plugging in a video display board (or "graphics adaptor") and connecting the appropriate monitor to it. Each new standard subsumes its predecessors. For example, an EGA board can also do CGA and MDA. With the PS/2, IBM introduced the VGA standard and built it into the main system board motherboard. VGA is also available as a plug-in board for PCs from third-party vendors. Also with the PS/2, IBM introduced the 8514 high-resolution graphics standard. An 8514 adaptor board plugs into the PS/2, providing a dual-monitor capability. Graphics software had to support the major IBM graphics standards and many non-IBM, proprietary standards for displays. Either software vendors provided display drivers or display vendors provided drivers for the software package. 1 1 1 1 1 display standards display standard 1 1 1 1 1 display terminal visual display unit 1 1 1 1 1 Dissociated Press [Play on "Associated Press"; perhaps inspired by a reference in the 1949 Bugs Bunny cartoon "What's Up, Doc?"] An algorithm for transforming any text into potentially humorous garbage even more efficiently than by passing it through a marketroid. The algorithm starts by printing any N consecutive words (or letters) in the text. Then at every step it searches for any random occurrence in the original text of the last N words (or letters) already printed and then prints the next word or letter. Emacs has a handy command for this. Here is a short example of word-based Dissociated Press applied to an earlier version of the Jargon File: wart: A small, crocky feature that sticks out of an array (C has no checks for this). This is relatively benign and easy to spot if the phrase is bent so as to be not worth paying attention to the medium in question. Here is a short example of letter-based Dissociated Press applied to the same source: 1 1 1 1 1 distfix ("distributed fixity"?) A description of an operator represented by multiple symbols before, between, and/or after the arguments. The classical example is the C conditional operator, "?:" which is written E1 ? E2 : E3 If E1 is true it returns E2 otherwise it returns E3. Several functional programming languages, e.g. Hope, Haskell, have similar operators ("if E1 then E2 else E3"). Objective C messages are effectively distfix operator applications: getRow:row andColumn:col ofCell:cell is a message with three arguments, row, col, and cell. (1997-01-21) 1 1 1 1 1 Distinguished Encoding Rules (DER) An X.690 encoding format (or transfer syntax) for data structures described by ASN.1 that specifies exactly one way to encode a value thus ensuring a unique, canonical, serialised representation. DER is a restricted variant of BER. For example, DER has exactly one way to encode a Boolean value. DER is used in cryptography, e.g. for digital certificates such as X.509. (2016-05-05) 1 1 1 1 1 Distributed Component Object Model (DCOM) Microsoft's extension of their Component Object Model (COM) to support objects distributed across a network. DCOM has been submitted to the IETF as a draft standard. Since 1996, it has been part of Windows NT and is also available for Windows 95. Unlike CORBA, which runs on many operating systems, DCOM is currently (Dec 1997) only implemented by Microsoft for Microsoft Windows and by Software AG, under the name EntireX, for Unix and IBM mainframes. DCOM serves the same purpose as IBM's DSOM protocol. DCOM is broken because it's an object model that has no provisions for inheritance, one of the major reasons for object oriented programming in the first place. (http://microsoft.com/com/tech/DCOM.asp). [Details?] (2000-08-02) 1 1 1 1 1 Distributed Computing Environment (DCE) An architecture consisting of standard programming interfaces, conventions and server functionalities (e.g. naming, distributed file system, remote procedure call) for distributing applications transparently across networks of heterogeneous computers. DCE is promoted and controlled by the Open Software Foundation (OSF). Usenet newsgroup: news:comp.soft-sys.dce. (http://dstc.edu.au/AU/research_news/dce/dce.html). (1994-12-07) 1 1 1 1 1 distributed database A collection of several different databases that looks like a single database to the user. An example is the Internet Domain Name System (DNS). (1994-12-07) 1 1 1 1 1 Distributed Data Management (DDM) An IBM data protocol architecture for data management services across distributed systems in an SNA environment. DDM provides a common data management language for data interchange among different IBM system platforms. Products supporting DDM include AS/400, System/36, System/38 and CICS/DDM. On the AS/400, DDM controls remote file processing. DDM enables application programs running on one AS/400 system to access data files stored on another system supporting DDM. Similarly, other systems that have DDM can access files in the database of the local AS/400 system. DDM makes it easier to distribute file processing between two or more systems. OS/400 Distributed Data Management V3R6 Reference (http://as400bks.rochester.ibm.com/cgi-bin/bookmgr/bookmgr.cmd/BOOKS/QBJALH00/CCONTENTS). 1 1 1 1 1 distributed data warehouse (DDW) Data shared across multiple data repositories, for the purpose of OLAP. Each data warehouse may belong to one or many organisations. The sharing im;plies a common format or definition of data elements (e.g. using XML). (2008-03-15) 1 1 1 1 1 Distributed Eiffel ["Distributed Eiffel: A Language for Programming Multi-Granular Distributed Objects on the Clouds Operating System", L. Gunaseelan et al, IEEE Conf Comp Langs, 1992]. (1994-12-07) 1 1 1 1 1 Distributed Logic Programming (DLP) A logic programming language similar to Prolog, combined with parallel object orientation similar to POOL. DLP supports distributed backtracking over the results of a rendezvous between objects. Multi-threaded objects have autonomous activity and may simultaneously evaluate method calls. ["DLP: A Language for Distributed Logic Programming", A. Eliens, Wiley 1992]. (1996-01-07) 1 1 1 1 1 Distributed Management Environment (DME) An OSF standard. It had reached the RFT stage. (1995-02-22) 1 1 1 1 1 distributed memory The kind of memory in a parallel processor where each processor has fast access to its own local memory and where to access another processor's memory it must send a message via the inter-processor network. Opposite: shared memory. (1995-03-22) 1 1 1 1 1 Distributed Network Operating System (DNOS) A proprietary operating system for Texas Instruments 990-series minicomputers. (1996-04-01) 1 1 1 1 1 Distributed Operating Multi Access Interactive Network (DOMAIN) The proprietary network protocol used by Apollo workstations. (1995-02-16) 1 1 1 1 1 Distributed Processes (DP) The first concurrent language based on remote procedure calls. ["Distributed Processes: A Concurrent Programming Concept", Per Brinch Hansen CACM 21(11):934-940 (Nov 1978)]. (1994-12-02) 1 1 1 1 1 Distributed Queue Dual Bus (DQDB) An IEEE standard for metropolitan area networks. (http://ece.wpi.edu/~vlad/ee535/hw5/page1.html). [Details?] (2000-08-02) 1 1 1 1 1 Distributed Smalltalk ["The Design and Implementation of Distributed Smalltalk", J. Bennett, SIGPLAN Notices 22(12):318-330 (Dec 1980)]. (1994-12-02) 1 1 1 1 1 distributed system A collection of (probably heterogeneous) automata whose distribution is transparent to the user so that the system appears as one local machine. This is in contrast to a network, where the user is aware that there are several machines, and their location, storage replication, load balancing and functionality is not transparent. Distributed systems usually use some kind of client-server organisation. Distributed systems are considered by some to be the "next wave" of computing. Distributed Computing Environment is the Open Software Foundation's software architecture for distributed systems. (http://dstc.edu.au/AU/research_news/dist-env.html). (1994-12-06) 1 1 1 1 1 distributed systems distributed system 1 1 1 1 1 distribution 1. <software> A software source tree packaged for distribution; but see kit. 2. <messaging> A vague term encompassing mailing lists and Usenet newsgroups (but not BBS fora); any topic-oriented message channel with multiple recipients. 3. <messaging> An information-space domain (usually loosely correlated with geography) to which propagation of a Usenet message is restricted; a much-underused feature. [Jargon File] 1 1 1 1 1 distributive lattice A lattice for which the least upper bound (lub) and greatest lower bound (glb) operators distribute over one another so that a lub (b glb c) == (a lub c) glb (a lub b) and vice versa. ("lub" and "glb" are written in LateX as \sqcup and \sqcap). (1998-11-09) 1 1 1 1 1 disusered (Usenet) Said of a person whose account on a computer has been removed to prevent access. Setting the DISUSER account status flag on VMS disables the account. "He got disusered when they found out he'd been cracking through the school's Internet access." [Jargon File] (1994-12-08) 1 1 1 1 1 dithering A technique used in quantisation processes such as graphics and audio to reduce or remove the correlation between noise and signal. Dithering is used in computer graphics to create additional colors and shades from an existing palette by interspersing pixels of different colours. On a monochrome display, areas of grey are created by varying the proportion of black and white pixels. In colour displays and printers, colours and textures are created by varying the proportions of existing colours. The different colours can either be distributed randomly or regularly. The higher the resolution of the display, the smoother the dithered colour will appear to the eye. Dithering doesn't reduce resolution. There are three types: regular dithering which uses a very regular predefined pattern; random dither where the pattern is a random noise; and pseudo random dither which uses a very large, very 1 1 1 1 1 Ditto Drive The Ditto tape drives range in capacity from 120 megabytes to 1.6 gigabytes (data compression can roughly double these figures). The newer devices are designed for special tapes, though they will read standard tape types. The largest of tape stores up 3.2 GB. Using an enhanced floppy drive card the transfer rate approaches the claimed 19 MB/minute. External parallel port versions are also available. Compatibility details (http://iomega.com/support/techs/ditto/3040.html). (1997-03-26) 1 1 1 1 1 diverge If a series of approximations to some value get progressively further from it then the series is said to diverge. The reduction of some term under some evaluation strategy diverges if it does not reach a normal form after a finite number of reductions. (1994-12-08) 1 1 1 1 1 divisor A quantity that evenly divides another quantity. Unless otherwise stated, use of this term implies that the quantities involved are integers. (For non-integers, the more general term factor may be more appropriate.) Example: 3 is a divisor of 15. Example: 3 is not a divisor of 14. (1997-03-07) 1 1 1 1 1 dj The country code for Djibouti. (1999-01-27) 1 1 1 1 1 DJGPP A 32-bit GNU C/C++/etc development system for MS-DOS. (http://delorie.com/djgpp/). Address: DJ Delorie, Rochester, NH, USA. (1995-04-10) 1 1 1 1 1 DjVu (pronounced like "deja vu") An image compression algorithm and program developed by Yann LeCun's research group at AT&T Labs. DjVu provides high resolution digital images for distribution over the Internet. DjVu is five to 20 times more efficient than JPEG or GIF. A free web browser plug-in allows users to display DjVu images. (http://djvu.research.att.com/). (1999-10-07) 1 1 1 1 1 DK Datakit 1 1 1 1 1 dk The country code for Denmark. (1999-01-27) 1 1 1 1 1 DL/1 Query language, linear keyword. 1 1 1 1 1 DLC Data Link Control 1 1 1 1 1 DLCI Data Link Connection Identifier [Is this correct?] (1997-03-01) 1 1 1 1 1 DLE Data Link Escape, the mnemonic for ASCII 16. (1996-06-24) 1 1 1 1 1 DLG (DFA-based Lexical analyser Generator) The lexical analyser generator in the Purdue Compiler-Construction Tool Set. 1 1 1 1 1 DL/I The data manipulation language of IMS. 1 1 1 1 1 DLL 1. <networking> Data Link Layer. 2. <library> Dynamically Linked Library. 3. Dial Long Line equipment. (2000-04-05) 1 1 1 1 1 DLM Distributed Lock Manager on distributed VMS systems. 1 1 1 1 1 DLP Distributed Logic Programming. (1996-01-07) 1 1 1 1 1 DLPI Data Link Provider Interface 1 1 1 1 1 DLSw Data Link Switching 1 1 1 1 1 DLT Digital Linear Tape 1 1 1 1 1 DLUR/DLUS Dependent Logical Unit Requester/Server. The DLUR function is an APPN enhancement for an end node or network node that supports dependent LUs. The DLUS function is a product feature of an interchange node or a T5 network node supporting session services extensions. (http://booksrv2.raleigh.ibm.com/cgi-bin/bookmgr/bookmgr.cmd/BOOKS/DLUR7/). (1997-05-08) 1 1 1 1 1 DLZ1 Digital Lempel Ziv 1 1 1 1 1 1 dm The country code for Dominica. (1999-01-27) 1 1 1 1 1 DMA Direct Memory Access 1 1 1 1 1 DMAD Diagnostic Machine Aid-Digital. A system for functional testing of digital devices. ["DMAD M/MM Manual", BR-8392, Raytheon Co. (Oct 1973)] (1994-11-02) 1 1 1 1 1 dmake Required by uC++. (ftp://plg.uwaterloo.ca/pub/dmake/dmake38.tar.Z). [What is it?] (1994-11-02) 1 1 1 1 1 DMALGOL ALGOL with extensions to interface to DMS II, the Burroughs database. (1995-02-22) 1 1 1 1 1 DME Distributed Management Environment 1 1 1 1 1 DMI Desktop Management Interface 1 1 1 1 1 DML 1. Data Manipulation Language. 2. Data Management Language. 3. ["DML: A Meta-language and System for the Generation of Practical and Efficient Compilers from Denotational Specifications", M. Pettersson et al, IEEE Conf Comp Langs, 1992]. (1999-04-27) 1 1 1 1 1 DMM Digital Multimeter 1 1 1 1 1 DMS Dataless Management Services 1 1 1 1 1 DMTF Desktop Management Task Force 1 1 1 1 1 DMU Data Management Unit Data Manipulation Unit Data Multiplexer Unit dataless management utility 1 1 1 1 1 DMZ De-Militarised Zone 1 1 1 1 1 DNA computing The use of DNA molecules to encode computational problems. Standard operations of molecular biology can then be used to solve some NP-hard search problems in parallel using a very large number of molecules. The exponential scaling of NP-hard problems still remains, so this method will require a huge amount of DNA to solve large problems. [L. M. Adleman, "Molecular Computation of Solutions to Combinatorial Problems", Science 266:1021-1024, 1994]. (1997-02-11) 1 1 1 1 1 DNF disjunctive normal form 1 1 1 1 1 DNIS Dialled Number Identification Service 1 1 1 1 1 DNIX A flavor of Unix that is proprietary to Olivetti and Wang Global. [Details? Reference?] (2000-12-16) 1 1 1 1 1 DNOS Distributed Network Operating System 1 1 1 1 1 DNS 1. Domain Name System. 2. Distributed Name Service. See DECdns. 1 1 1 1 1 do 1. <programming> repeat loop. 2. <networking> The country code for Dominican Republic. (1999-06-10) 1 1 1 1 1 DOA Dead on arrival. A piece of hardware that has never worked. (2000-12-19) 1 1 1 1 1 Doc Directed Oc 1 1 1 1 1 doc /dok/ Common spoken and written shorthand for "documentation". Often used in the plural "docs" and in the construction "doc file" (i.e. documentation available on-line). [Jargon File] 1 1 1 1 1 docking station A desktop mains powered unit into which a laptop or other portable computer can be connected via fixed connectors at the rear of the computer to provide quick and convenient connection of peripherals not normally used with a laptop. These can include power supply, expansion cards, additional storage, an external monitor, network card, CD-ROM, full-size keyboard, printer, and mouse. The alternative would require each of the above to be connected to the laptop individually. (2000-04-10) 1 1 1 1 1 DOCMaker An application for the Apple Macintosh which creates stand-alone, self-running document files. It features scrollable and re-sizable windows, graphics, varied text styles and fonts, full printing capability, and links to other software and information. Companies such as Federal Express, GTE, Hewlett-Packard, Iomega, Adobe Systems, Inc., Apple Computer and Aladdin use DOCMaker to distribute disk-based documentation with their products. (http://hsv.tis.net/~greenmtn/docm1.html). (1998-01-27) 1 1 1 1 1 doco /do'koh/ 1. (In-house jargon at Symbolics) A documentation writer. See also devo and mango. 2. (UK) A short technical document. A "doco" is often not the documentation passed to management. Compare doc. [Jargon File] (1999-10-08) 1 1 1 1 1 DOCSIS Data Over Cable Service Interface Specification 1 1 1 1 1 doctype decoration When a web author adds a doctype declaration but doesn't bother to write valid HTML. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-05-30) 1 1 1 1 1 document 1. <application> Any specific type of file produced or edited by a specific application; usually capable of being printed. E.g. "Word document", "Photoshop document", etc. 2. <hypertext> A term used on some systems (e.g. Intermedia) for a hypertext node. It is sometimes used for a collection of nodes on related topics, possibly stored or distributed as one. 3. <programming> To write documentation on a certain piece of code. (2003-10-25) 1 1 1 1 1 documentation The multiple kilograms of macerated, pounded, steamed, bleached, and pressed trees that accompany most modern software or hardware products (see also tree-killer). Hackers seldom read paper documentation and (too) often resist writing it; they prefer theirs to be terse and on-line. A common comment on this predilection is "You can't grep dead trees". See drool-proof paper, verbiage, treeware. [Jargon File] (2003-10-25) 1 1 1 1 1 Document Examiner A high-performance hypertext system by Symbolics that provides on-line access to their user documentation. (1995-04-16) 1 1 1 1 1 Document Image Processing (DIP) Storage, management and retrieval of images. (1994-11-11) 1 1 1 1 1 Document Object Model A W3C specification for application program interfaces for accessing the content of HTML and XML documents. (http://w3.org/DOM/). (1999-12-14) 1 1 1 1 1 Document Style Semantics and Specification Language (DSSSL) An ISO standard under preparation, addressing the semantics of high-quality composition in a manner independent of particular formatting systems or processes. DSSSL is intended as a complementary standard to SGML for the specification of semantics. 1 1 1 1 1 Document Type Definition (DTD) The definition of a document type in SGML or XML, consisting of a set of mark-up tags and their interpretation. Docbook DTD home (http://oasis-open.org/docbook/). XML DTD Tutorial (http://xml101.com/dtd). (2001-04-30) 1 1 1 1 1 DOCUS Display Oriented Computer Usage System. Interactive system using push buttons. Sammet 1969, p.678 1 1 1 1 1 DoD 1. <body> Department of Defense. 2. Dial on Demand. (2000-03-25) 1 1 1 1 1 DoD-1 Unofficial name of the language that became Ada. 1 1 1 1 1 dodgy Synonym with flaky. Preferred outside the US [Jargon File] 1 1 1 1 1 DOD-STD-2167A A DoD standard specifying the overall process for the development and documentation of mission-critical software systems. (1996-05-28) 1 1 1 1 1 DoD-STD-2168 A DoD standard for software quality assurance procedures. (1996-05-29) 1 1 1 1 1 DOE Distributed Object Environment: a distributed object-oriented application framework from SunSoft. 1 1 1 1 1 DOF degrees of freedom 1 1 1 1 1 dog An enhanced version of the Unix cat command that, in addition to outputting the contents of files, can output the data obtained by fetching URLs. It also offers various output options such as line numbering. Unix manual page: (http://www.penguin-soft.com/penguin/man/1/dog.html). (2009-06-12) 1 1 1 1 1 dogcow /dog'kow/ See Moof. [Jargon File] 1 1 1 1 1 dogfood eating one's own dogfood 1 1 1 1 1 dogfooding eating one's own dogfood 1 1 1 1 1 dogpile (Usenet, probably from mainstream "puppy pile") When many people post unfriendly responses in short order to a single posting, they are sometimes said to "dogpile" or "dogpile on" the person to whom they're responding. For example, when a religious missionary posts a simplistic appeal to alt.atheism, he can expect to be dogpiled. (1994-12-08) 1 1 1 1 1 dogwash /dog'wosh/ (A quip in the "urgency" field of a very optional software change request, ca. 1982. It was something like Urgency: Wash your dog first) A project of minimal priority, undertaken as an escape from more serious work. Many games and much freeware get written this way, including this dictionary. [Jargon File] (1994-12-08) 1 1 1 1 1 Do It Right the First Time (DIRFT) A programming approach that aims to avoid the overheads of debugging and testing incomplete or incorrect code by careful specification, design and implementation. DIRFT contrasts with rapid prototyping which emphasises the benefits of having running code as soon as possible, even if it is not perfect. DIRFT is appropriate in the rare cases where the requirements are well understood and unlikely to change, e.g. reimplementing exactly the same function in a different language. (2012-11-17) 1 1 1 1 1 Dojo The Dojo Toolkit 1 1 1 1 1 DOL Display Oriented Language. Subsystem of DOCUS. Sammet 1969, p.678. 1 1 1 1 1 dollar "$", numeric character reference: "&#36;", Common names: ITU-T: dollar sign. Rare: currency symbol; buck; cash; string; escape (when used as the echo of ASCII ESC); ding; cache; INTERCAL: big money. Well-known uses of the dollar symbol in computing include as a prefix on the names of string variables in BASIC, shell and related languages like Perl. In shell languages it is also used in positional parameters so "$1" is the first parameter to a shell script, "$2" the second, etc. In a regular expression, $ matches the end of the string. (2015-01-24) 1 1 1 1 1 do loop repeat loop 1 1 1 1 1 DOM Document Object Model 1 1 1 1 1 domain 1. <networking> A group of computers whose fully qualified domain names (FQDN) share a common suffix, the "domain name". The Domain Name System maps hostnames to Internet address using a hierarchical namespace where each level in the hierarchy contributes one component to the FQDN. For example, the computer foldoc.doc.ic.ac.uk is in the doc.ic.ac.uk domain, which is in the ic.ac.uk domain, which is in the ac.uk domain, which is in the uk top-level domain. A domain name can contain up to 67 characters including the dots that separate components. These can be letters, numbers and hyphens. 2. An administrative domain is something to do with routing. 3. Distributed Operating Multi Access Interactive Network. 4. <mathematics> In the theory of functions, the set of argument values for which a function is defined. See domain theory. 5. <programming> A specific phase of the software life cycle 1 1 1 1 1 domain address The name of a host on the Internet belonging to the hierarchy of Internet domains. (1994-10-27) 1 1 1 1 1 Domain Analysis 1. Determining the operations, data objects, properties and abstractions appropriate for designing solutions to problems in a given domain. 2. The domain engineering activity in which domain knowledge is studied and formalised as a domain definition and a domain specification. A software reuse approach that involves combining software components, subsystems, etc., into a single application system. 3. The process of identifying, collecting organising, analysing and representing a domain model and software architecture from the study of existing systems, underlying theory, emerging technology and development histories within the domain of interest. 4. The analysis of systems within a domain to discover commonalities and differences among them. (1997-12-26) 1 1 1 1 1 domain architecture A generic, organisational structure or design for software systems in a domain. The domain architecture contains the designs that are intended to satisfy requirements specified in the domain model. A domain architecture can be adapted to create designs for software systems within a domain and also provides a framework for configuring assets within individual software systems. (1997-12-26) 1 1 1 1 1 Domain Architecture Model A set of software architectures generic to a domain that define organising frameworks for constructing new application designs and implementations within the domain, consistent with the domain requirements model. (1997-12-26) 1 1 1 1 1 domain calculus A form of relational calculus in which scalar variables take values drawn from a given domain. Examples of the domain calculus are ILL, FQL, DEDUCE and the well known Query By Example (QBE). INGRES is a relational DBMS whose DML is based on the relational calculus. 1 1 1 1 1 domain engineering 1. The development and evolution of domain specific knowledge and artifacts to support the development and evolution of systems in the domain. Domain engineering includes engineering of domain models, components, methods and tools and may also include asset management. 2. The engineering process of analysing and modelling a domain, designing and modelling a generic solution architecture for a product line within that domain, implementing and using reusable components of that architecture and maintaining and evolving the domain, architecture and implementation models. 3. A reuse-based approach to defining the scope (domain definition), specifying the structure (domain architecture) and building the Assets (requirements, designs, software code, documentation) for a class of systems, subsystems or applications. Domain engineering can include domain 1 1 1 1 1 domain handle Information held by a domain name registrar about a registrant (the person or organisation that owns the name). Typically the registrar stores one copy of this information and refers to that copy for each additional domain registered by the same person. The information would include basic contact details: name, e-mail address, etc. and billing information. Some of this information would be used to populate the whois database entry for a domain. (http://www.easyname.eu/support/domains/20-what-is-a-domain-handle). (2009-09-17) 1 1 1 1 1 domainist /doh-mayn'ist/ 1. Said of a domain address (as opposed to a bang path) because the part to the right of the @ specifies a nested series of "domains"; for example, esr@snark.thyrsus.com specifies the machine called snark in the subdomain called thyrsus within the top-level domain called com. See also big-endian. 2. Said of a site, mailer or routing program which knows how to handle domainist addresses. 3. Said of a person (especially a site admin) who prefers domain addressing, supports a domainist mailer, or proselytises for domainist addressing and disdains bang paths. This term is now (1993) semi-obsolete, as most sites have converted. [Jargon File] (1995-04-21) 1 1 1 1 1 domain maturity The level of stability and depth of understanding that has been achieved in an area for which applications are developed. (1997-12-26) 1 1 1 1 1 domain model 1. A definition of the functions, objects, data, requirements, relationships and variations in a particular domain. 2. A product of domain analysis which provides a representation of the requirements of the domain. The domain model identifies and describes the structure of data, flow of information, functions, constraints and controls within the Domain that are included in software systems in the domain. The Domain Model describes commonalities and variabilities among requirements for software systems in the domain. (1997-12-26) 1 1 1 1 1 domain name fully qualified domain name 1 1 1 1 1 Domain Name Server Domain Name System. (1997-12-15) 1 1 1 1 1 Domain Name System (DNS) A general-purpose distributed, replicated, data query service chiefly used on Internet for translating hostnames into Internet addresses. Also, the style of hostname used on the Internet, though such a name is properly called a fully qualified domain name. DNS can be configured to use a sequence of name servers, based on the domains in the name being looked for, until a match is found. The name resolution client (e.g. Unix's gethostbyname() library function) can be configured to search for host information in the following order: first in the local hosts file, second in NIS and third in DNS. This sequencing of Naming Services is sometimes called "name service switching". Under Solaris is configured in the file /etc/nsswitch.conf. DNS can be queried interactively using the command nslookup. It is defined in STD 13, RFC 1034, RFC 1035, RFC 1591. BIND is a common DNS server. Info from Virtual Office, Inc. 1 1 1 1 1 domain selection The prioritisation and selection of one or more domains for which specific software reuse engineering projects are to be initiated. (1997-12-26) 1 1 1 1 1 Domain Software Engineering Environment (DSEE) A proprietary CASE framework and configuration management system from Apollo. (1996-05-29) 1 1 1 1 1 domain-specific language A machine-processable language whose terms are derived from a domain model and that is used for the definition of components or software architectures supporting that domain. A domain-specific language is often used as input to an application generator. (1997-12-26) 1 1 1 1 1 domain squatter An unscrupulous person who registers a domain name in the hope of selling it to the rightful, expected owner at a profit. E.g. (http://foldoc.com/). (2007-07-15) 1 1 1 1 1 domain theory A branch of mathematics introduced by Dana Scott in 1970 as a mathematical theory of programming languages, and for nearly a quarter of a century developed almost exclusively in connection with denotational semantics in computer science. In denotational semantics of programming languages, the meaning of a program is taken to be an element of a domain. A domain is a mathematical structure consisting of a set of values (or "points") and an ordering relation, <= on those values. Domain theory is the study of such structures. ("<=" is written in LaTeX as \subseteq) Different domains correspond to the different types of object with which a program deals. In a language containing functions, we might have a domain X -> Y which is the set of functions from domain X to domain Y with the ordering f <= g iff for all x in X, f x <= g x. In the pure lambda-calculus all objects are functions or applications of functions to 1 1 1 1 1 Domestic Communications Assistance Center (DCAC) A joint effort between the U.S. Marshals Service, FBI and Drug Enforcement Agency. The DCAC is charged with developing customised hardware for intercepting Internet and wireless communications. The DCAC is under the control and budget of the FBI. CNET article (http://news.cnet.com/8301-1009_3-57439734-83/fbi-quietly-forms-secretive-net-surveillance-unit/). (2012-06-24) 1 1 1 1 1 DOMF Distributed Object Management Facility. An OMG-compliant object management system; part of DOE. Produced by SunSoft. (1994-11-04) 1 1 1 1 1 Donald Knuth Donald E. Knuth, the author of the TeX document formatting system, Metafont its font-design program and the 3 volume computer science "Bible" of algorithms, "The Art of Computer Programming". Knuth suggested the name "Backus-Naur Form" and was also involved in the SOL simulation language, and developed the WEB literate programming system. See also MIX, Turingol. (1994-11-04) 1 1 1 1 1 dongle /dong'gl/ (From "dangle" - because it dangles off the computer?) 1. <security> A security or copy protection device for commercial microcomputer programs that must be connected to an I/O port of the computer while the program is run. Programs that use a dongle query the port at start-up and at programmed intervals thereafter, and terminate if it does not respond with the expected validation code. One common form consisted of a serialised EPROM and some drivers in a D-25 connector shell. Dongles attempt to combat software theft by ensuring that, while users can still make copies of the program (e.g. for backup), they must buy one dongle for each simultaneous use of the program. The idea was clever, but initially unpopular with users who disliked tying up a port this way. By 1993 almost all dongles passed data through transparently while monitoring for their 1 1 1 1 1 dongle cracker Someone who enables software that has been written to require a dongle to run without it. (2007-06-11) 1 1 1 1 1 dongle-disk /don'gl disk/ (Or "key disk") A kind of dongle consisting of a special floppy disk that is required in order to perform some task. Some contain special coding that allows an application to identify it uniquely, others *are* special code that does something that normally-resident programs don't or can't. For example, AT&T's "Unix PC" would only come up in root mode with a special boot disk. [Jargon File] (1998-12-13) 1 1 1 1 1 Don't do that then! (From an old doctor's office joke about a patient with a trivial complaint) A stock response to a user complaint. "When I type control-S, the whole system comes to a halt for thirty seconds." "Well don't do that then!" [Jargon File] (1998-12-13) 1 1 1 1 1 donuts (Obsolete) A collective noun for any set of memory bits. This usage is extremely archaic and may no longer be live jargon; it dates from the days of ferrite core memories in which each bit was implemented by a doughnut-shaped magnetic flip-flop. [Jargon File] 1 1 1 1 1 Dooced Losing your job because of something posted on a personal website. After (http://dooce.com/) where Heather Armstrong posted details about her job. (2012-04-13) 1 1 1 1 1 DOOM A simulated 3D moster-hunting action game for IBM PCs, created and published by id Software. The original press release was dated January 1993. A cut-down shareware version v1.0 was released on 10 December 1993 and again with some bug-fixes, as v1.4 in June 1994. DOOM is similar to Wolfenstein 3d (id Software, Apogee) but has better texture mapping; walls can be at any angle, of any thickness and have windows; lighting can fade into the distance or come from point sources; floors and ceilings can be of any height; many surfaces are animated; up to four players can play over a network or two by serial link; it has a high frame rate (comparable to TV on a 486/33); DOOM isn't just a collection of connected closed rooms like Wolfenstein but sounds can travel anywhere and alert monsters of your approach. The shareware version is available from these sites: Cactus (ftp://cactus.org/pub/IHHD/multi-player/), 1 1 1 1 1 DOORS Dynamic Object Oriented Requirements System 1 1 1 1 1 doorstop Used to describe equipment that is non-functional and halfway expected to remain so, especially obsolete equipment kept around for political reasons or ostensibly as a backup. "When we get another Wyse-50 in here, that ADM 3 will turn into a doorstop." Compare boat anchor. [Jargon File] 1 1 1 1 1 Dorito Syndrome Feelings of emptiness and dissatisfaction triggered by addictive substances that lack nutritional content. "I just spent six hours surfing the Web, and now I've got a bad case of Dorito Syndrome." (1997-03-30) 1 1 1 1 1 DORUM Draft Once ReUse Many 1 1 1 1 1 DOS 1. The common abbreviation for MS-DOS. 2. IBM's Disk Operating System. 3. Any disk operating system. (2001-03-16) 1 1 1 1 1 DOS/360 The operating system announced by IBM at the low end for the System/360 in 1964 and delivered in 1965 or 1966. Following the failure of OS, IBM designed DOS for the low end machines, able to run in 16KB(?) and 64KB memory. DOS/360 used three memory partitions, but it had no serious memory protection. The three partitions were not specialised, but frequently one was used for spooling punched cards to disk, another one for batch job execution and another for spooling disk to printers. With DOS/VS, introduced in 1970, the number of partitions was increased, virtual memory was introduced and the minimum memory requirements increased. Later they released DOS/VSE and ESA/VSE. DOS/360 successors are still alive today (1997) though not as popular as in the late 1960s. Contrary to the Hacker's Jargon File, GECOS was not copied 1 1 1 1 1 DOS Protected Mode Interface (DPMI) The method which Microsoft prescribes for a DOS program to access extended memory under a multitasking environment, e.g. Microsoft Windows. This service is provided by the HIMEM.SYS driver on IBM PCs. The DPMI specification was finalized in 1990. The specification itself is available from Intel Literature Sales. VCPI (Virtual Control Program Interface), which was an alternative, and incompatible method for doing the same thing. ["Windows 3.1 Secrets", Brian Livingston, 1992, ISBN 1-878058-43-6, pages 280-281 and 302]. (1995-01-12) 1 1 1 1 1 DOS requester An MS-DOS client that provides transparent redirection of printing and file accesses to a network server. It handles levels 3, 4 and 5 of the Open Systems Interconnect seven layer model. A DOS requester under Novell NetWare will interface to a network card driver with an ODI interface, and will be either a single executable (netx.exe) or a set of VLMs that are loaded on demand. In the IBM/Microsoft LAN Manager/SMB world, where the name DOS redirector is more common, there will be an NDIS interface driver and a net.exe executable. NetWare Client 32 for DOS/Windows (http://developer.novell.com/research/appnotes/1996/may/01/). (http://cad.strath.ac.uk/~davidm/projects/guide/requester.html). (1998-01-05) 1 1 1 1 1 dot decimal point. See also dot file, dot notation. (1995-03-14) 1 1 1 1 1 dot address An Internet address in dot notation. 1 1 1 1 1 dot com com 1 1 1 1 1 dot file A Unix application program configuration file. On Unix, files named with a leading dot are not normally shown in directory listings. Many programs define one or more dot files in which startup or configuration information may be optionally recorded; a user can customise the program's behaviour by creating the appropriate file in the current or home directory. Dot files tend to proliferate - with every nontrivial application program defining at least one, a user's home directory can be filled with scores of dot files, without the user really being aware of it. Common examples are .profile, .cshrc, .login, .emacs, .mailrc, .forward, .newsrc, .plan, .rhosts, .sig, .xsession. See also profile, rc file. [Jargon File] (1994-12-07) 1 1 1 1 1 dot leaders A row of full stops intended to guide the reader's eye across the page from a column of variable length items on the left to the corresponding items in a column on the right. Used, for example, in the contents page of a book to tie a heading on the left to its page number on the right. (2010-07-25) 1 1 1 1 1 dot matrix printer A kind of printer with a vertical column of up to 48 small closely packed needles or "pins" each of which can be individually forced forward to press an ink ribbon against the paper. The print head is repeatedly scanned across the page and different combinations of needles activated at each point. Dot matrix printers are noisy compared to non-impact printers. [Other pin arrangements?] (1995-03-14) 1 1 1 1 1 dot notation Berkeley Unix notation for an Internet address, consisting of one to four numbers (a "dotted quad") in hexadecimal (leading 0x), octal (leading 0), or (usually) decimal. It represents a 32-bit address. Each leading number represents eight bits of the address (high byte first) and the last number represents the rest. E.g. address 0x25.32.0xab represents 0x252000ab. By far the most common form is four decimal numbers, e.g. 146.169.22.42. Many programs accept an address in dot notation in place of a hostname. (2000-08-10) 1 1 1 1 1 dot pitch The distance between a dot and the closest dot of the same colour (red, green or blue) on a color CRT. Dot pitch is typically from 0.28 to 0.51 mm but large presentation monitors may go up to 1.0 mm. The smaller the dot pitch, the crisper the image, 0.31 or less provides a sharp image, especially when displaying text. Dot pitch measurements between conventional tubes and Sony's Trinitron tubes are roughly, but not exactly comparable. Sony's CRTs use vertical stripes, not dots, and its measurement is the distance between stripes, not the diagonal distance between dots. ["The Computer Glossary", Alan Freedman]. (1995-12-14) 1 1 1 1 1 dotted pair The usual LISP syntax for representing a cons cell that is not a list. For example, the expression (cons 'foo 42) returns a cons cell that is output as (foo . 42) which represents a cons cell whose car is the symbol "foo" and whose cdr is the integer 42. (2014-11-09) 1 1 1 1 1 dotted quad dot notation 1 1 1 1 1 double bucky Using both the CTRL and META keys. "The command to burn all LEDs is double bucky F." This term originated on the Stanford extended-ASCII keyboard, and was later taken up by users of the space-cadet keyboard at MIT. A typical MIT comment was that the Stanford bucky bits (control and meta shifting keys) were nice, but there weren't enough of them; you could type only 512 different characters on a Stanford keyboard. An obvious way to address this was simply to add more shifting keys, and this was eventually done; but a keyboard with that many shifting keys is hard on touch-typists, who don't like to move their hands away from the home position on the keyboard. It was half-seriously suggested that the extra shifting keys be implemented as pedals; typing on such a keyboard would be very much like playing a full pipe organ. This idea is mentioned in a parody of a very fine song by Jeffrey Moss called "Rubber Duckie", which was published in "The Sesame Street Songbook" 1 1 1 1 1 double-click Two clicks of a mouse button made in rapid succession without moving the mouse. A double-click often combines the actions of selecting, and then activating an object in a GUI, e.g. selecting and opening a document. Some text editors use double-click to select the word under the mouse pointer. When used as a verb it is often written as two words with a space instead of a hyphen. (2006-07-09) 1 1 1 1 1 Double Data Rate Random Access Memory (DDR-RAM, DDR-SDRAM ...Synchronous...) RAM that transfers data on both 0-1 and 1-0 clock transitions, theoretically yielding twice the data transfer rate of normal RAM or SDRAM. DDR-RAM Article (http://pcreview.co.uk/Article.php?aid=9). DDR-SDRAM Article (http://www4.tomshardware.com/mainboard/00q4/001030/). (2001-05-24) 1 1 1 1 1 Double Data Rate Synchronous Random Access Memory Double Data Rate Random Access Memory 1 1 1 1 1 double DECkers Married couples in which both partners work for Digital Equipment Corporation. [Jargon File] (1994-12-07) 1 1 1 1 1 double density floppy disk 1 1 1 1 1 doubled sig A sig block that has been included twice in a Usenet article or, less commonly, in an electronic mail message. An article or message with a doubled sig can be caused by improperly configured software. More often, however, it reveals the author's lack of experience in electronic communication. See BIFF, pseudo. [Jargon File] (1994-12-07) 1 1 1 1 1 double-duplex (From telegraphy) A full-duplex link with two telegraphers (a sender and a receiver) at each end, to simultaneously transmit in both directions. Compare: single-duplex. (2000-03-30) 1 1 1 1 1 double-ended queue /dek/ (deque) A queue which can have items added or removed from either end[?]. The Knuth reference below reports that the name was coined by E. J. Schweppe. [D. E. Knuth, "The Art of Computer Programming. Volume 1: Fundamental Algorithms", second edition, Sections 2.2.1, 2.6, Addison-Wesley, 1973]. Silicon Graphics (http://sgi.com/tech/stl/Deque.html). [Correct definition? Example use?] (2003-12-17) 1 1 1 1 1 double quote "' ASCII character 34. Often used in programming languages to delimit strings. In Unix shells and Perl it delimits a string inside which variable substitution may occur. Common names: quote. Rare: literal mark; double-glitch; ITU-T: quotation marks; ITU-T: dieresis; dirk; INTERCAL: rabbit-ears; double prime. (1995-03-28) 1 1 1 1 1 doubly linked list A data structure in which each element contains pointers to the next and previous elements in the list, thus forming a bidirectional linear list. (1995-03-28) 1 1 1 1 1 DOUGLAS An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-07) 1 1 1 1 1 Douglas Engelbart Douglas C. Engelbart, the inventor of the mouse. On 1968-12-09, Douglas C. Engelbart and the group of 17 researchers working with him in the Augmentation Research Center at Stanford Research Institute in Menlo Park, California, USA, presented a 90-minute live public demonstration of the on live system, NLS, they had been working on since 1962. The presentation was a session in the of the Fall Joint Computer Conference held at the Convention Center in San Francisco, and it was attended by about 1000 computer professionals. This was the public debut of the computer mouse, hypertext, object addressing, dynamic file linking and shared-screen collaboration involving two persons at different sites communicating over a network with audio and video interface. The original 90-minute video: Hyperlinks (http://vodreal.stanford.edu/engel/08engel200.ram), Mouse (http://vodreal.stanford.edu/engel/12engel200.ram), 1 1 1 1 1 Doug Lenat One of the world's leading computer scientists specialising in Artificial Intelligence. He is currently (1999) head of the Cyc Project at MCC, and President of Cycorp. He has been a Professor of Computer Science at Carnegie-Mellon University and Stanford University. See also microLenat. (1999-08-24) 1 1 1 1 1 DOW COMPILER An early system on the Datatron 200 series. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-07) 1 1 1 1 1 Do What the Fuck You Want to Public License (WTFPL) An obscenely permissive license for software and other scientific or artistic works. As the name suggests, the WTFPL does not restrict what you can do with the licenced work at all. The only restriction on the use of the license itself is that if you change it you also change the name. The WTFPL aims to expose and remove the problems of the popular but competing GPL and BSD licences. Since, according to its own terms, the license can be completely ignored, it can be little more than an amusing paradox. Unlicense is a more serious template for dedicating software to the public domain. WTFPL Home (http://www.wtfpl.net/). (2013-11-05) 1 1 1 1 1 down 1. Not operating. "The up escalator is down" is considered a humorous thing to say, and "The elevator is down" always means "The elevator isn't working" and never refers to what floor the elevator is on. With respect to computers, this term has passed into the mainstream; the extension to other kinds of machine is still hackish. 2. "go down" To stop functioning; usually said of the system. The message from the console that every hacker hates to hear from the operator is "System going down in 5 minutes". 3. "take down", "bring down" To deactivate purposely, usually for repair work or PM. "I'm taking the system down to work on that bug in the tape drive." Occasionally one hears the word "down" by itself used as a verb in this sense. See crash; opposite: up. [Jargon File] (1994-12-07) 1 1 1 1 1 download To transfer data from one computer to another. Downloading usually refers to transfer from a larger "host" system (especially a server or mainframe) to a smaller client system, especially a microcomputer or specialised peripheral, and "upload" usually means from small to large. Others hold that, technically, download means "receive" and upload means "send", irrespective of the size of the systems involved. Note that in communications between ground and space, space-to-earth transmission is always "down" and the reverse up, regardless of size. So far the in-space machines have invariably been smaller; thus the upload/download distinction has been reversed from its usual sense. [Jargon File] (2003-11-04) 1 1 1 1 1 downloading download 1 1 1 1 1 downsizing The process of moving an application program from a mainframe to a cheaper system, typically a client-server system. (1995-03-27) 1 1 1 1 1 downstream upstream 1 1 1 1 1 down-time A period of time during which a (computer) system is not operational, due to a malfunction or maintenance. (1997-06-08) 1 1 1 1 1 downward closed closure 1 1 1 1 1 Downy cocktail cationic cocktail 1 1 1 1 1 DP 1. data processing. According to hackers, use of the term marks one immediately as a suit. See DPer. 2. dot pitch. 3. Dissociated Press. [Jargon File] (1996-07-22) 1 1 1 1 1 DPA Data Protection Act 1 1 1 1 1 DPB /d*-pib'/ The PDP-10 instruction "DePosit Byte" that inserts some bits into the middle of some other bits. Hackish usage has been kept alive by the Common LISP function of the same name. [Jargon File] (1994-12-07) 1 1 1 1 1 DPer /dee-pee-er/ Data Processor. Hackers are absolutely amazed that suits use this term self-referentially. *Computers* process data, not people! See DP. [Jargon File] (1994-12-07) 1 1 1 1 1 dpi Dots per inch. A measure of resolution for printers, scanners and displays. Laser printers typically reach 300 DPI, though 600 DPI is becoming more common. Commercial typesetters are usually around 1200 DPI. (1995-01-05) 1 1 1 1 1 DPL DECmmp Parallel Language. A C-like parallel language for the DECmpp machine. (1994-12-07) 1 1 1 1 1 DPL-82 ["DPL-82: A Language for Distributed Processing", L. Ericson, Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982, pp.526-531]. (1994-12-07) 1 1 1 1 1 DPLL Digital Phase-Locked Loop 1 1 1 1 1 DPMI DOS Protected Mode Interface 1 1 1 1 1 DPMS Display Power Management Signaling. (1995-12-11) 1 1 1 1 1 DPN Decomposed Petri Net 1 1 1 1 1 DPP Dining Philosophers Problem 1 1 1 1 1 d-Prolog A version of Prolog extended with defeasible reasoning. (ftp://aisun1.ai.uga.edu/ai.prolog/) for MS-DOS and Unix. (1994-12-07) 1 1 1 1 1 DPS 1. <language, text> Display PostScript. 2. <language> A real-time language with direct expression of timing requests. ["Language Constructs for Distributed Real-Time PRogramming", I. Lee et al Proc IEEE Real-Time Sys Symp pp.57-66 (Dec 1985)]. [What does it stand for?] (1995-03-28) 1 1 1 1 1 DPS-6 A Honeywell minicomputer from the 1980s-1990s. It originally ran the GCOS-6 operating system. (2004-08-24) 1 1 1 1 1 dpSather Data-parallel Sather. deterministic fine-grained parallelism. E-mail: <hws@csis.dit.csiro.au>. (ftp://lynx.csis.dit.csiro.au/p/pub/ather/dpsather.papers). 1 1 1 1 1 DPSK Differential Phase-Shift Keying. 1 1 1 1 1 DQDB Distributed Queue Dual Bus 1 1 1 1 1 draco A blend of Pascal, C and ALGOL 68 developed by Chris Gray in 1987. It has been implemented for CP/M-80 and Amiga. (1994-11-04) 1 1 1 1 1 Draft Once ReUse Many (DORUM) Reusing parts of a document to produce parts of an entirely new document. The term normally refers to text documents but the practise is equally common in programming. (1998-05-09) 1 1 1 1 1 drag drag and drop 1 1 1 1 1 drag and drop A common method for manipulating files (and sometimes text) under a graphical user interface or WIMP environment. The user moves the pointer over an icon representing a file and presses a mouse button. He holds the button down while moving the pointer (dragging the file) to another place, usually a directory viewer or an icon for some application program, and then releases the button (dropping the file). The meaning of this action can often be modified by holding certain keys on the keyboard at the same time. Some systems also use this technique for objects other than files, e.g. portions of text in a word processor. The biggest problem with drag and drop is does it mean "copy" or "move"? The answer to this question is not intuitively evident, and there is no consensus for which is the right answer. The same vendor even makes it move in some cases and copy in others. Not being sure whether an operation is copy or move will cause you to check very often, perhaps every time 1 1 1 1 1 dragging drag 1 1 1 1 1 drag-n-drop Stupid spelling of drag and drop. (1996-12-13) 1 1 1 1 1 DRAGON 1. An Esprit project aimed at providing effective support to reuse in real-time distributed Ada application programs. 2. An implementation language used by BTI Computer Systems. E-mail: Pat Helland <helland@hal.com>. [Jargon File] (1994-12-08) 1 1 1 1 1 dragon [MIT] A program similar to a daemon, except that it is not invoked at all, but is instead used by the system to perform various secondary tasks. A typical example would be an accounting program, which keeps track of who is logged in, accumulates load-average statistics, etc. Under ITS, many terminals displayed a list of people logged in, where they were, what they were running, etc., along with some random picture (such as a unicorn, Snoopy or the Enterprise), which was generated by the "name dragon". Use is rare outside MIT, under Unix and most other operating systems this would be called a "background demon" or daemon. The best-known Unix example of a dragon is cron. At SAIL, they called this sort of thing a "phantom". [Jargon File] 1 1 1 1 1 Dragon Book The classic text "Compilers: Principles, Techniques and Tools", by Alfred V. Aho, Ravi Sethi, and Jeffrey D. Ullman (Addison-Wesley 1986; ISBN 0-201-10088-6). So called because of the cover design featuring a dragon labelled "complexity of compiler design" and a knight bearing the lance "LALR parser generator" among his other trappings. This one is more specifically known as the "Red Dragon Book" (1986); an earlier edition, sans Sethi and titled "Principles Of Compiler Design" (Alfred V. Aho and Jeffrey D. Ullman; Addison-Wesley, 1977; ISBN 0-201-00022-9), was the "Green Dragon Book" (1977). (Also "New Dragon Book", "Old Dragon Book".) The horsed knight and the Green Dragon were warily eying each other at a distance; now the knight is typing (wearing gauntlets!) at a terminal showing a video-game representation of the Red Dragon's head while the rest of the beast extends back in normal space. See also book titles. 1 1 1 1 1 DRAGOON A distributed, concurrent, object-oriented Ada-based language developed in the Esprit DRAGON project by Colin Atkinson at Imperial College in 1989 (Now at University of Houston, Clear Lake). DRAGOON supports object-oriented programming for embeddable systems and is presently implemented as an Ada preprocessor. ["Object-Oriented Reuse, Concurrency and Distribution: An Ada-Based Approach", C. Atkinson, A-W 1991, ISBN 0-2015-6-5277]. (1999-11-22) 1 1 1 1 1 drain (IBM) To allow a system to complete the processing of its current work before the system becomes unavailable. E.g. draining a device before taking it off-line or telling a web server in a server farm not to accept any new requests but to finish processing any requests it has already accepted. [Jargon File] (2005-07-18) 1 1 1 1 1 DRAM dynamic random-access memory 1 1 1 1 1 DRAM refresh The operation which cycles through a DRAM reading each row and writing it back again to compensate for the gradual leakage of charge from the capacitors which store the data. This may be done by the CPU but is often done by a dedicated memory controller. (1997-02-23) 1 1 1 1 1 Drawing eXchange Format (DXF) A file format for graphical information, similar to IGES. Commonly used by CAD systems like AutoCAD. (1994-12-08) 1 1 1 1 1 dread high bit disease A condition endemic to PRIME (also known as PR1ME) minicomputers that results in all the characters having their high bit (0x80, see meta bit) ON rather than OFF. This complicates transporting files to other systems and talking to true 8-bit devices. Folklore had it that PRIME adopted the convention in order to save 25 cents per serial line per machine; PRIME old-timers, on the other hand, claim they inherited the disease from Honeywell via customer NASA's compatibility requirements and struggled heroically to cure it. Whoever was responsible, this probably qualifies as one of the most cretinous design tradeoffs ever made. A few other machines have exhibited similar brain damage. [Jargon File] (2002-04-09) 1 1 1 1 1 DREAM 6800 A computer based on the Motorola 6800 microprocessor. The DREAM 6800 could be programmed in CHIP-8. (2002-04-09) 1 1 1 1 1 DRECNET /drek'net/ [Yiddish/German "dreck", meaning filth] Deliberate distortion of DECNET, a networking protocol used in the VMS community. So called because DEC helped write the Ethernet specification and then (either stupidly or as a malignant customer-control tactic) violated that spec in the design of DRECNET in a way that made it incompatible. See also connector conspiracy. 1 1 1 1 1 drill down (Or "drill-down analysis") To examine data in greater detail, especially, in reporting, to interactively select some item from a summary and display the data that contributed to that item, broken down by some extra parameter. For example, when viewing your company's total worldwide sales for each month of this year, you might drill down to see October's sales by country, then again to see October's sales in Afghanistan by product and so on. This kind of analysis is often supported by some kind of data warehouse. (2007-06-04) 1 1 1 1 1 drill-down analysis drill down 1 1 1 1 1 drive A peripheral device that allows a computer to read or/or write some storage medium such as a hard disk, floppy disk, magnetic tape, compact disc or DVD. These would be called a disk drive, magnetic tape drive, etc. CD and DVD drives are known collectively as optical drives. When unqualified the term probably refers to a hard disk drive. The term "drive" refers particularly to the electrical components such as electric motors and head positioning system, read-write heads and associated electronics. Of the above storage media, typically only hard disks are fixed, the rest being removable. Most PCs in 2009 include one disk drive and one optical drive housed in the main PC enclosure. Extra drives can be connected externally via USB, SCSI or Firewire. Magnetic tape is always removable and tape drives are typically external. Not to be confused with a "driver" meaning device driver - software used to access a peripheral device. 1 1 1 1 1 driver 1. <operating system> device driver. 2. <programming> The main loop of an event-processing program; the code that gets commands and dispatches them for execution. 3. <tool> In the TeX world and the computerised typesetting world in general, a program that translates some device-independent or other common format to something a real device can actually understand. [Jargon File] 1 1 1 1 1 drivers driver 1 1 1 1 1 Dr. James H. Clark The founder of Silicon Graphics, Inc. and co-founder of Netscape Communications Corporation. (1998-05-21) 1 1 1 1 1 DRM 1. Digital Rights Management 2. Digital Radio Mondiale (2006-02-02) 1 1 1 1 1 droid (From "android") The robots of the Star Wars universe. While androids look somewhat human-like, Star Wars' droids are typically fashioned in the likeness of their creators or in a utilitarian design that stresses function over appearance. Droids are equipped with artificial intelligence, though some are naturally created smarter than others depending on the function they are designed to serve. Droid is a Lucasfilm Ltd. trademark. starwars.com (http://starwars.com/databank/droid/). ["A Guide to the Star Wars Universe", Bill Slavicsek, 1994, Lucasfilm Ltd.] [Was George Lucas really the first to use the abbreviation (in 1977)?] (2006-07-21) 1 1 1 1 1 DROOL Dave's Recycled Object-Oriented Language. Language for writing adventure games. An updated implementation of AdvSys. multiple inheritance, garbage collection. ["Dave's Recycled OO Language", David Betz, Dr. Dobbs J, Oct 1993, pp.74-78]. 1 1 1 1 1 drool-proof paper Documentation that has been obsessively dumbed down, to the point where only a cretin could bear to read it, is said to have succumbed to the "drool-proof paper syndrome" or to have been "written on drool-proof paper". For example, this is an actual quote from Apple Computer's LaserWriter manual: "Do not expose your LaserWriter to open fire or flame." [Jargon File] (1997-06-23) 1 1 1 1 1 drop cable Wiring between a computer and its Ethernet transceiver. Maximum length if full-spec is 47m. 1 1 1 1 1 drop-down list pull-down list 1 1 1 1 1 drop-down menu pull-down menu 1 1 1 1 1 drop-ins [analogy with drop-outs] Spurious characters appearing on a terminal or console as a result of line noise or a system malfunction of some sort. Especially used when these are interspersed with one's own typed input. [Jargon File] 1 1 1 1 1 drop on the floor To react to an error condition by silently discarding messages or other valuable data. "The gateway ran out of memory, so it just started dropping packets on the floor." Also frequently used of faulty mail and netnews relay sites that lose messages. See also black hole, bit bucket. 1 1 1 1 1 drop-outs 1. A variety of "power glitch" (see glitch); momentary zero voltage on the electrical mains. 2. Missing characters in typed input due to software malfunction or system overload (one cause of such behaviour under Unix when a bad connection to a modem swamps the processor with spurious character interrupts; see screaming tty). 3. Mental glitches; used as a way of describing those occasions when the mind just seems to shut down for a couple of beats. See glitch, fried. [Jargon File] (2001-02-22) 1 1 1 1 1 DrScheme A popular Scheme implementation from the PLT team at Rice University. (http://cs.rice.edu/CS/PLT/packages/drscheme/). (2001-02-22) 1 1 1 1 1 DRUCO I Early system on IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 drugged (Or "on drugs") 1. Conspicuously stupid, heading toward brain-damaged. Often accompanied by a pantomime of toking a joint. 2. Of hardware, very slow relative to normal performance. [Jargon File] (2011-12-03) 1 1 1 1 1 drug report A bug report so utterly incomprehensible that whoever submitted it must have been smoking crack. Even worse than a chug report. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2011-12-03) 1 1 1 1 1 drum Ancient slow, cylindrical magnetic media that were once state-of-the-art storage devices. Under BSD Unix the disk partition used for swapping is still called "/dev/drum"; this has led to considerable humour and not a few straight-faced but utterly bogus "explanations" getting foisted on newbies. See also "The Story of Mel". (1994-12-22) 1 1 1 1 1 drunk mouse syndrome (Also "mouse on drugs") A malady exhibited by the mouse pointing device of some computers. The typical symptom is for the mouse cursor on the screen to move in random directions and not in sync with the motion of the actual mouse. Can usually be corrected by unplugging the mouse and plugging it back again. Another recommended fix for optical mice is to rotate your mouse mat 90 degrees. At Xerox PARC in the 1970s, most people kept a can of copier cleaner (isopropyl alcohol) at their desks. When the steel ball on the mouse had picked up enough cruft to be unreliable, the mouse was doused in cleaner, which restored it for a while. However, this operation left a fine residue that accelerated the accumulation of cruft, so the dousings became more and more frequent. Finally, the mouse was declared alcoholic and sent to the clinic to be dried out in a CFC ultrasonic bath. [Jargon File] 1 1 1 1 1 dry run To execute a program by hand, writing values of variables and other run-time data on paper, in order to check its operation and control flow or to track down a bug (as part of debugging). A dry run is an extreme form of desk check or code review and is practical only for fairly simple programs, small amounts of data and simple external interfaces. It was often performed off-line using a hardcopy of the source code. Dry runs were common practice in the days when access to computers was limited but the availability of screen editors and fast compilers makes debugging by printf a more productive method in most cases. Sophisticated debuggers that allow you to get the computer to step through your source code line by line and show values of variables make even this unnecessary. (2006-11-27) 1 1 1 1 1 DS0 The zeroth DS level, having a transmission rate of 64,000 bits per second (64 kb/s), intended to carry one voice channel (a phone call). (2001-03-18) 1 1 1 1 1 DS1 A DS level and framing specification for synchronous digital streams, over circuits in the North American digital transmission hierarchy, at the T1 transmission rate of 1,544,000 bits per second (baud). DS1 is commonly used to multiplex 24 DS0 channels. Each DS0 channel, originally a digitised voice-grade telephone signal, carries 8000 bytes per second (64,000 bits per second). A DS1 frame includes one byte from each of the 24 DS0 channels and adds one framing bit, making a total of 193 bits per frame at 8000 frames per second. The result is 193*8000 = 1,544,000 bits per second. In the original standard, the successive framing bits continuously repeated the 12-bit sequence 110111001000, and such a 12-frame unit is called a super-frame. In voice telephony, errors are acceptable (early standards allowed as much as one frame in six to be missing entirely), so the least significant bit in two of the 24 streams was used for 1 1 1 1 1 DS1C A DS level and framing specification for digital signals in the North American digital transmission hierarchy. A DS1C signal uses 48 PCM channels and has a transmission rate of 3.15 Megabits per second, twice that of DS1. DS1C uses two DS1 signals combined and sent on a 3.152 megabit per second carrier which allows 64 kilobits per second for synchronisation and framing using "pulse stuffing". The channel 2 signal is logically inverted, and a framing bit is stuffed in two out of three code words, resulting in 26-bit information units. The channels are interleaved and then scrambled by the addition modulo 2 of the signal with the previous bit. Finally the bit stream is combined with a control bit sequence that permits the demultiplexor to function by preceding each 52 bits with one DS1C framing bit. A series of 24 such 53-bit frames forms a 1272-bit "M-frame". 1 1 1 1 1 DS2 A DS level and framing specification for digital signals in the North American digital transmission hierarchy. A DS2 signal uses 96 PCM channels and has a transmission rate of 6.31 Megabits per second, twice that of DS1C. (1995-02-07) 1 1 1 1 1 DS3 The third DS level, a framing specification for digital signals in the North American digital transmission hierarchy. A DS3 signal has a transmission rate of 44.736 Megabits per second. DS3 is used, for example, on T3 synchronous Integrated Services Digital Network lines. (1995-01-12) 1 1 1 1 1 DSA Directory System Agent 1 1 1 1 1 DSDM Dynamic Systems Development Method 1 1 1 1 1 DSE 1. Display Screen Equipment. See Visual Display Unit. 2. Data Structure Editor. (2002-11-09) 1 1 1 1 1 DSEE Domain Software Engineering Environment 1 1 1 1 1 D-shell connector One of the family of connectors: DA-15, DB-25, DC-37, DD-50, DE-9, and DEH-15 [VGA]. The "D" is the shape of the shell, the next letter determines connector size, and the number is the maximum pin count. (1999-12-08) 1 1 1 1 1 DSI Delivered Source Instruction 1 1 1 1 1 DSL 1. <communications> Digital Subscriber Line. 2. <language> Digital Simulation Language. 3. <language> Denotational Semantics Language. (1996-10-13) 1 1 1 1 1 DSLAM Digital Subscriber Line Access Module 1 1 1 1 1 DS level (Digital Signal or Data Service level) Originally an AT&T classification of transmitting one or more voice conversations in one digital data stream. The best known DS levels are DS0 (a single conversation), DS1 (24 conversations multiplexed), DS1C, DS2, and DS3. By extension, the DS level can refer to the raw data rate necessary for transmission: DS0 64 Kb/s DS1 1.544 Mb/s DS1C 3.15 Mb/s DS2 6.31 Mb/s DS3 44.736 Mb/s DS4 274.1 Mb/s (where K and M signify multiplication by 1000 and 1000000, rather than powers of two). In this sense it can be used to measure of data service rates classifying the user access rates for various point-to-point WAN technologies or 1 1 1 1 1 DSM 1. Data Structure Manager. An object-oriented language by J.E. Rumbaugh and M.E. Loomis of GE, similar to C++. It is used in implementation of CAD/CAE software. DSM is written in DSM and C and produces C as output. ["DSM: An Object-Relationship Modeling Language", A. Shah et al, SIGPLAN Notices 24(10):191-202 (OOPSLA '89) (Oct 1989)]. 2. DIGITAL Standard MUMPS. (1995-01-10) 1 1 1 1 1 DSN Digital Switched Network 1 1 1 1 1 DSO dynamic shared object 1 1 1 1 1 DSORG data set organization 1 1 1 1 1 DSP digital signal processing 1 1 1 1 1 DSP32 Assembly Language A high-level assembly language for the DSP32 Programmable DSP Chip. 1 1 1 1 1 DSP56000 A digital signal processing chip from Motorola. An assembler called a56 and a port of gcc called dsp56k-gcc are available. 1 1 1 1 1 DSP56001 A digital signal processing chip from Motorola. An assembler called a56 is available. 1 1 1 1 1 dsp56165-gcc A port of gcc version 1.40 to the Motorola DSP56156 and DSP56000 by Andrew Sterian <asterian@eecs.umich.edu>. alt.sources 1 1 1 1 1 dsp56k-gcc Motorola's port of gcc version 1.37.1 to the Motorola DSP56000. Finland (ftp://nic.funet.fi/pub/ham/dsp/dsp56k-tools/dsp56k-gcc.tar.Z). Australia (ftp://evans.ee.adfa.oz.au/pub/micros/56k/g56k.tar.Z). 1 1 1 1 1 DSP/C Numerical extension to C, for DSP applications. ["DSP/C: A Standard High Level Language for DSP and Numeric Processing", K. Leary & W. Waddington, Proc ICASSP 90, Apr 1990, pp.1065-1068]. 1 1 1 1 1 DSPL Digital Signal Processing Language 1 1 1 1 1 DSR Dynamic Service Register 1 1 1 1 1 DSS 1. Decision Support Systems. 2. Digital Signature Standard. (1995-11-16) 1 1 1 1 1 DSSSL Document Style Semantics and Specification Language 1 1 1 1 1 DST Daylight-Saving Time. 1 1 1 1 1 DSU 1. <communications> Data Service Unit. 2. Disk Subsystem Unit (Artecon). 3. <humour> Dwarf Storage Unit. (1996-12-01) 1 1 1 1 1 DSVD Digital Simultaneous Voice and Data 1 1 1 1 1 DSW penis war 1 1 1 1 1 DTALGOL Decision Table ALGOL. An ALGOL superset from Victoria University, Wellington that added decision tables and runs on Burroughs Large System. (1995-02-02) 1 1 1 1 1 DTD Document Type Definition 1 1 1 1 1 DTE Data Terminal Equipment 1 1 1 1 1 DT&E Developmental Test and Evaluation 1 1 1 1 1 DTLS Descriptive Top-Level Specification 1 1 1 1 1 DTMF Dual Tone Multi Frequency 1 1 1 1 1 DTP desktop publishing 1 1 1 1 1 DTR Data Terminal Ready 1 1 1 1 1 DTS 1. Distributed Time Service. 2. <audio> Digital Theatre Sound. (2001-12-24) 1 1 1 1 1 DTSS The first commercial time-sharing system, created by Dartmouth College and sold by General Electric around 1967. GE's Information Service Divsion (ISD) marketed DTSS which was running on a system called GE-265 (a combination of the front-end processor the Datanet-30 and the GE-235). DTSS was ported (and significantly improved by GE ISD around 1965-1966 on a combination of DN-30 and GE-635). This proprietary system, called Mk-II, later improved by GE and renamed Mk-III, is still working today (1997) as part of the GE service bureau that also includes IBM and Unix computers. (1997-09-16) 1 1 1 1 1 D-type 1. <hardware> A type of computer peripheral connector so named because one side is shorter (with one less pin) than the other giving a (squarish) "D" shape. The connectors have two rows of pins (or holes). Common types are 25-way (13+12 pins) and 9-way (5+4 pins). They are often used for serial lines, especially EIA-232. (1995-01-05) 2. D-type flip-flop. 1 1 1 1 1 D-type flip-flop A digital logic device that stores the status of its "D" input whenever its clock input makes a certain transition (low to high or high to low). The output, "Q", shows the currently stored value. Compare J-K flip-flop. (1995-03-28) 1 1 1 1 1 du ("disk usage") The Unix command to list the amount of disk space consumed by a directory and its subdirectories. Unix manual page: du(1). (2004-04-01) 1 1 1 1 1 DUA Directory User Agent 1 1 1 1 1 dual Every field of mathematics has a different meaning of dual. Loosely, where there is some binary symmetry of a theory, the image of what you look at normally under this symmetry is referred to as the dual of your normal things. In linear algebra for example, for any vector space V, over a field, F, the vector space of linear maps from V to F is known as the dual of V. It can be shown that if V is finite-dimensional, V and its dual are isomorphic (though no isomorphism between them is any more natural than any other). There is a natural embedding of any vector space in the dual of its dual: V -> V'': v -> (V': w -> wv : F) (x' is normally written as x with a horizontal bar above it). I.e. v'' is the linear map, from V' to F, which maps any w to the scalar obtained by applying w to v. In short, this double-dual mapping simply exchanges the roles of function and argument. 1 1 1 1 1 DUAL-607 An early system on the IBM 701. [CACM 2(5):16 (May 1959)]. (1994-12-13) 1 1 1 1 1 dual-attached The form of FDDI interface where a device is connected to both FDDI token-passing rings, so that uninterrupted operation continues in the event of a failure of either of the rings. All connections to the main FDDI rings are dual-attached. Typically, a small number of critical infrastructure devices such as routers and concentrators are dual-attached, whereas host computers are normally single-attached or dual-homed to a router or concentrator. For example, a ring could be formed between a single router and two concentrators (all dual-attached) then all other components that need to be fault-tolerant (typically file servers) can be dual-homed to both concentrators. (1994-12-13) 1 1 1 1 1 dual boot Any system offering the user the choice of two operation systems (OSes) under which to start a computer. A dual boot system allows the user to run programs for both operating systems on a single computer (though not simultaneously). The term "multiple boot" or "multiboot" extends the idea to more than two OSes. The OSes are generally unaware of each other's existence. They are installed on separate hard disk partitions or on separate disks. They may be able to access each other's files, possibly via some extra driver software if they use different file systems. The OSes need not be completely different - they might be different versions of Microsoft Windows (e.g. Windows XP and Windows NT) or Linux (e.g. Debian and Fedora). A dual boot system differs from an emulator such as vmware, which runs one or more OSes "on top" of the primary OS, using its resources. 1 1 1 1 1 dual-homed A kind of connection to a FDDI network where a host is simultaneously connected to two separate devices in the same FDDI ring. One of the connections becomes active while the other one is automatically blocked. If the first connection fails, the backup link takes over with no perceptible delay. A dual-homed device can tolerate a fault in one of its "homes" whereas a dual-attached device can tolerate a fault in one of the rings. (1994-12-13) 1 1 1 1 1 Dual In-Line Dual In-Line Package. 1 1 1 1 1 Dual In-line Memory Module Small circuit boards carrying memory integrated circuits, with signal and power pins on both sides of the board, in contrast to single-in-line memory modules (SIMM). The individual gold or lead connectors (pins) on SIMMs, although they are on both sides of the chip, are connected to the same memory chip, while on a DIMM, the connections on each side of the module connect to different chips. This allows for a wider data path, as more modules can be accessed at once. DIMM pins are arranged in a zigzag design to allow PCB tracks to pass between them. The 8-byte DIMM format with dual-sided contacts can accommodate 4- and 16-megabit dynamic RAM chips, and is predicted to handle 64- and 256-Mbit devices. The 8-byte DIMM will hold up to 32 megabytes of memory using 16-Mbit DRAMs, but with the 256-Mbit future-generation DRAM, it will be able to hold a 64-Mx64 configuration. Another variation, the 72-pin SO-DIMM, is designed to connect directly to 32 bit 1 1 1 1 1 Dual In-Line Package (DIL, DIP) The most common type of package for small and medium scale integrated circuits, with up to about 48 pins. The pins hang vertically from the two long edges of the rectangular package, spaced at intervals of 0.1 inch. The pins fit through holes in the circuit board to which they are soldered or into a socket. [More than 48 pins?] (1995-02-06) 1 1 1 1 1 dual ported A term used to describe memory integrated circuits which can be accessed simultaneously via two independent address and data busses. Dual ported memory is often used in video display hardware, especially in conjunction with Video Random Access Memory (VRAM). The two ports allow the video display hardware to read memory to display the contents on screen at the same time as the CPU writes data to other areas of the same memory. In single-ported memory these two processes cannot occur simultanteously, the CPU must wait, thus resulting in slower access times. Cycle stealing is one technique used to avoid this in single-ported video memory. (1995-01-12) 1 1 1 1 1 dual-stack A term used to describe a network node running both IPv4 and IPv6 protocol stacks (or possibly others) at the same time. Such a machine can act as a protocol converter between the two networks. A node without dual-stack support can relay traffic in a protocol it does not support natively by use of tunnelling. RFC 4213 (http://tools.ietf.org/html/rfc4213) (2013-10-08) 1 1 1 1 1 Dual Tone Multi Frequency (DTMF, or "touch-tone") A method used by the telephone system to communicate the keys pressed when dialling. Pressing a key on the phone's keypad generates two simultaneous tones, one for the row and one for the column. These are decoded by the exchange to determine which key was pressed. (1995-03-28) 1 1 1 1 1 duck typing A term coined by Dave Thomas for a kind of dynamic typing typical of some programming languages, such as Smalltalk, Ruby or Visual FoxPro, where a variable's run-time value determines the operations that can be performed on it. The term comes from the "duck test": if it walks like a duck and quacks like a duck, it must be a duck. Duck typing considers the methods to which a value responds and the attributes it posesses rather than its relationship to a type hierarchy. This encourages greater polymorphism because types are enforced as late as possible. (http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/100511). (2006-09-13) 1 1 1 1 1 DUEL A front end to gdb by Michael Golan <mg@cs.princeton.edu>. DUEL implements a language designed for debugging C programs. It features efficient ways to select and display data items. It is normally linked into the gdb executable, but could stand alone. It interprets a subset of C in addition to its own language. Version 1.10. (ftp://ftp.cs.princeton.edu/duel/). (1993-03-20) 1 1 1 1 1 duff 1. <programming> Duff's device. 2. <person> Tom Duff. 1 1 1 1 1 Duff's device The most dramatic use yet seen of fall through in C, invented by Tom Duff when he was at Lucasfilm. Trying to bum all the instructions he could out of an inner loop that copied data serially onto an output port, he decided to unroll it. He then realised that the unrolled version could be implemented by *interlacing* the structures of a switch and a loop: register n = (count + 7) / 8; /* count > 0 assumed */ switch (count % 8) case 0: do *to = *from++; case 7: *to = *from++; case 6: *to = *from++; case 5: *to = *from++; case 4: *to = *from++; case 3: *to = *from++; case 2: *to = *from++; 1 1 1 1 1 dumbed down Simplified, with a strong connotation of *over*simplified. Often, a marketroid will insist that the interfaces and documentation of software be dumbed down after the designer has burned untold gallons of midnight oil making it smart. This creates friction. See user-friendly. (1995-04-14) 1 1 1 1 1 dumb terminal A type of terminal that consists of a keyboard and a display screen that can be used to enter and transmit data to, or display data from, a computer to which it is connected. A dumb terminal, in contrast to an intelligent terminal, has no independent processing capability or auxiliary storage and thus cannot function as a stand-alone device. The dumbest kind of terminal is a glass tty. The next step up has a minimally addressable cursor but no on-screen editing or other features normally supported by an intelligent terminal. Once upon a time, when glass ttys were common and addressable cursors were something special, what is now called a dumb terminal could pass for a smart terminal. [Examples?] [Jargon File] (1995-04-14) 1 1 1 1 1 dump 1. An undigested and voluminous mass of information about a problem or the state of a system, especially one routed to the slowest available output device (compare core dump), and most especially one consisting of hexadecimal or octal runes describing the byte-by-byte state of memory, mass storage, or some file. In elder days, debugging was generally done by "groveling over" a dump (see grovel); increasing use of high-level languages and interactive debuggers has made such tedium uncommon, and the term "dump" now has a faintly archaic flavour. 2. A backup. This usage is typical only at large time-sharing installations. Unix manual page: dump(1). [Jargon File] (1994-12-01) 1 1 1 1 1 dumpster diving /dump'-ster di:'-ving/ 1. The practice of sifting refuse from an office or technical installation to extract confidential data, especially security-compromising information ("dumpster" is an Americanism for what is elsewhere called a "skip"). Back in AT&T's monopoly days, before paper shredders became common office equipment, phone phreaks (see phreaking) used to organise regular dumpster runs against phone company plants and offices. Discarded and damaged copies of AT&T internal manuals taught them much. The technique is still rumored to be a favourite of crackers operating against careless targets. 2. The practice of raiding the dumpsters behind buildings where producers and/or consumers of high-tech equipment are located, with the expectation (usually justified) of finding discarded but still-valuable equipment to be nursed back to health in some hacker's den. Experienced dumpster-divers not infrequently accumulate basements full of moldering (but still potentially useful) cruft. 1 1 1 1 1 Dungeon Zork 1 1 1 1 1 dup killer /d[y]oop kill'r/ Software that is supposed to detect and delete duplicates of a message that may have reached the FidoNet system via different routes. See also dup loop. [Jargon File] (1995-02-02) 1 1 1 1 1 duplex Used to describe a communications channel that can carry signals in both directions, in contrast to a simplex channel which only ever carries a signal in one direction. If signals can only flow in one direction at a time the communications is "half-duplex", like a single-lane road with traffic lights at each end. Walkie-talkies with a press-to-talk button provide half-duplex communications. If signals can flow in both directions simultaneously the communications is "full-duplex", like a normal two-lane road. Telephones provide full-duplex communications. The term "duplex" was first used in wireless, telegraph, and telephone communications. Nearly all communications circuits used by computers are two-way, so the term is seldom used. (http://cit.ac.nz/smac/dc100www/dc_014.htm). (2001-07-21) 1 1 1 1 1 Duplex High Speed Data (DHSD) A term which describes a full-duplex channel that can carry 64 kilobits per second. This is the kind of service provided by an Inmarsat-B type portable earth station or a leased line (not ISDN). (1995-02-02) 1 1 1 1 1 dup loop /d[y]oop loop/ (also "dupe loop") [FidoNet] An infinite stream of duplicated, near-identical messages on a FidoNet echo, the only difference being unique or mangled identification information applied by a faulty or incorrectly configured system or network gateway, thus rendering dup killers ineffective. If such a duplicate message eventually reaches a system through which it has already passed (with the original identification information), all systems passed on the way back to that system are said to be involved in a dup loop. [Jargon File] (2003-12-15) 1 1 1 1 1 Durra Description language for coarse-grained concurrency on heterogeneous processors. "Durra: A Task-level Description Language", M.R. Barbacci et al, CMU/SEI-86-TR-3, CMU 1986. 1 1 1 1 1 dusty deck Old software (especially applications) which one is obliged to remain compatible with, or to maintain. DP types call this legacy code, a term hackers consider smarmy and excessively reverent. The term implies that the software in question is a holdover from card-punch days. Used especially when referring to old scientific and number crunching software, much of which was written in Fortran and very poorly documented but is believed to be too expensive to replace. See fossil; compare crawling horror. [Jargon File] 1 1 1 1 1 DV cartridge (Digital Video?) A plug-in circuit cartridge required by some games consoles in order to play MPEG video material. (1994-11-02) 1 1 1 1 1 DVD Digital Versatile Disc 1 1 1 1 1 DVD-R Digital Versatile Disc 1 1 1 1 1 DVD-RAM Digital Versatile Disk Random Access Memory 1 1 1 1 1 DVD-ROM Digital Versatile Disc 1 1 1 1 1 DVI 1. <file format> (device independent) The usual output format of TeX, giving a description of a formatted document that is not related to any specific hardware or other standard document format. Utilities exist to view and print DVI files on various systems and devices. 2. Digital Video Input. (2003-09-11) 1 1 1 1 1 Dvorak A configuration of (computer) keyboard keys arranged to increase the speed and ease of typing over the normal qwerty layout; the most common characters (for English) have been put on the home row. The standard Dvorak International layout is: `~ 1! 2@ 3# 4% 5^ 6^ 7& 8* 9( 0) [\ ]\ \\| '" ,< .> p y f g c r l /? += a o e u i d h t n s -_ ;: q j k x b m w v z [Do other Dvorak-like layout standards exist for other languages?] (2002-03-14) 1 1 1 1 1 Dwarf Storage Unit (DSU) An IBM term for a cupboard. (1996-06-24) 1 1 1 1 1 DWDM wavelength division multiplexing 1 1 1 1 1 dweeb An even lower form of life than the spod, found in much the same habitat as the former. though more prevailent on talker systems. Unlike spods, upon receiving the desired response to the question "Are you male or female?", dweebs will then engage upon a detailed description of themselves and how wonderful they are, often in the hopes of truly impressing the other with their "charm" and "wit". Nearly all dweebs are male, but very few actually live up to the image that they present. Dweebs, unfortunately, are often the cause of ill-will, and may well bring a bad reputation to the system in question. They are often, however, easy to wind up and can be the source of great mirth to the seasoned user. 1 1 1 1 1 dwg The filename extension for Autodesk drawing files. (http://faqs.org/faqs/graphics/fileformats-faq/part3/). (2000-08-02) 1 1 1 1 1 DWIM /dwim/ [acronym, "Do What I Mean" (not what I say)] 1. Able to guess, sometimes even correctly, the result intended when bogus input was provided. 2. The BBNLISP/INTERLISP function that attempted to accomplish this feat by correcting many of the more common errors. See hairy. 3. Occasionally, an interjection hurled at a balky computer, especially when one senses one might be tripping over legalisms (see legalese). Warren Teitelman originally wrote DWIM to fix his typos and spelling errors, so it was somewhat idiosyncratic to his style, and would often make hash of anyone else's typos if they were stylistically different. Some victims of DWIM thus claimed that the acronym stood for "Damn Warren's Infernal Machine!'. In one notorious incident, Warren added a DWIM feature to the command interpreter used at Xerox PARC. One day another 1 1 1 1 1 DX4 Intel DX4 1 1 1 1 1 DXF Drawing Exchange Format 1 1 1 1 1 dyadic binary (describing an operator). Compare monadic. (1998-07-24) 1 1 1 1 1 Dyadic Systems Limited Dyalog Limited 1 1 1 1 1 Dyalog APL Arguably the current (2001) market-leading implementation of APL, from Dyalog Limited. Dyalog APL runs under Windows 95, Windows 98, Windows NT, and Windows 2000; and several popular UNIX systems including Linux. Dyalog APL complies with ISO 8485 and has many features that make it good for complex GUI applications. Dyalog APL was introduced in 1983 and is currently (2002) in active development. (2003-11-17) 1 1 1 1 1 Dyalog Limited The company that distributes Dyalog APL. Previously known as Dyadic Systems Limited. Dyalog Home (http://dyalog.com). (2003-11-17) 1 1 1 1 1 DYANA DYnamics ANAlyzer 1 1 1 1 1 Dylan DYnamic LANguage 1 1 1 1 1 Dylperl A dynamic linking package for Perl by Roberto Salama <rs@fi.gs.com>. Dynamically loaded functions are accessed as if they were user-defined functions. This code is based on Oliver Sharp's May 1993 article in Dr. Dobbs Journal ("Dynamic Linking under Berkeley Unix"). Posted to news:comp.lang.perl on 1993-08-11. (1993-08-11) 1 1 1 1 1 dynamic adaptive routing Automatic rerouting of traffic based on analysis of current network conditions. This does not include routing decisions based on predefined information. (1995-01-30) 1 1 1 1 1 Dynamic Address Translation (DAT) Conversion of a virtual address into a physical address, as performed by a memory management unit and an operating system which supports virtual memory. (1995-01-30) 1 1 1 1 1 Dynamically Linked Library (DLL) A library which is linked to application programs when they are loaded or run rather than as the final phase of compilation. This means that the same block of library code can be shared between several tasks rather than each task containing copies of the routines it uses. The executable is compiled with a library of "stubs" which allow link errors to be detected at compile-time. Then, at run time, either the system loader or the task's entry code must arrange for library calls to be patched with the addresses of the real shared library routines, possibly via a jump table. The alternative is to make library calls part of the operating system kernel and enter them via some kind of trap instruction. This is generally less efficient than an ordinary subroutine call. It is important to ensure that the version of a dynamically linked library is compatible with what the executable expects. 1 1 1 1 1 dynamically scoped dynamic scope 1 1 1 1 1 dynamically typed dynamic typing 1 1 1 1 1 dynamic analysis Evaluation of a program based on its execution. Dynamic analysis relies on executing a piece of software with selected test data. (1996-05-13) 1 1 1 1 1 dynamic binding The property of object-oriented programming languages where the code executed to perform a given operation is determined at run time from the class of the operand(s) (the receiver of the message). There may be several different classes of objects which can receive a given message. An expression may denote an object which may have more than one possible class and that class can only be determined at run time. New classes may be created that can receive a particular message, without changing (or recompiling) the code which sends the message. An class may be created that can receive any set of existing messages. C++ implements dynamic binding using "virtual member functions". One important reason for having dynamic binding is that it provides a mechanism for selecting between alternatives which is arguably more robust than explicit selection by conditionals or pattern matching. When a new subclass is 1 1 1 1 1 dynamic database management system (dynamic DBMS) A database with "value-based" relationships where typically the relationship is specified at retrieval time and the locations of related records are discovered during retrieval. Both Independent Logical File (ILF) databases and relational databases are value-based. The opposite is a static database management system. (1998-10-07) 1 1 1 1 1 Dynamic Data Exchange (DDE, originally Dynamic Data Linking, DDL) A Microsoft Windows 3 hotlink protocol that allows application programs to communicate using a client-server model. Whenever the server (or "publisher") modifies part of a document which is being shared via DDE, one or more clients ("subscribers") are informed and include the modification in the copy of the data on which they are working. (1997-06-05) 1 1 1 1 1 Dynamic Data Linking Dynamic Data Exchange 1 1 1 1 1 dynamic DBMS dynamic database management system 1 1 1 1 1 Dynamic Drive Overlay (DDO) Software to allow a system BIOS that does not support Logical Block Addressing to access drives larger than 528 MB. The alternatives are to update the system BIOS or install an EIDE controller card with a suitable on-board BIOS. Seagate (http://seagate.com/support/disc/drivers/discfile.shtml). (2001-03-18) 1 1 1 1 1 Dynamic Execution A combination of techniques - multiple branch prediction, data flow analysis and speculative execution. Intel implemented Dynamic Execution in the P6 after analysing the execution of billions of lines of code. (1995-05-05) 1 1 1 1 1 Dynamic Host Configuration Protocol (DHCP) A protocol that provides a means to dynamically allocate IP addresses to computers on a local area network. The system administrator assigns a range of IP addresses to DHCP and each client computer on the LAN has its TCP/IP software configured to request an IP address from the DHCP server. The request and grant process uses a lease concept with a controllable time period. DHCP is defined in RFC 2131. Microsoft introduced DHCP on their NT server with version 3.5 in late 1994. (http://dhcp.org/). (1998-11-22) 1 1 1 1 1 Dynamic HTML (DHTML) The addition of JavaScript to HTML to allow web pages to change and interact with the user without having to communicate with the server. JavaScript allows the behaviour of the page to be controlled by code that is downloaded with the HTML. It does this by manipulating the Document Object Model (DOM). The term DHTML is often also taken to include the use of style information to give finer control of HTML layout. The style information can be supplied as Cascading Style Sheets (CSS) or as "style" attributes (which can be manipulated by JavaScript). Layers are often also used with DHTML. Both the JavaScript and style data can be included in the HTML file or in a separate file referred to from the HTML. Some web browsers allow other languages (e.g. VBScript or Perl) to be used instead of JavaScript but this is less common. DHTML can be viewed in Internet Explorer 4+, Firefox and Netscape Communicator 4+ but, as usual, Microsoft disagree 1 1 1 1 1 DYnamic LANguage (Dylan) A simple object-oriented Lisp dialect, most closely resembling CLOS and Scheme, developed by Advanced Technology Group East at Apple Computer. Thomas is a Dylan compiler implemented in Scheme. See also Marlais. ["Dylan(TM) an Object-Oriented Dynamic Language", Apple Computer, Eastern Research and Technology, April 1992]. (1995-04-19) 1 1 1 1 1 dynamic link A pointer from an activation record to the activation record for the scope from which the current scope was called at run time. This is used in a statically scoped language to restore the environment pointer on exit from a scope. To access a non-local variable in a dynamically scoped language, dynamic links are followed until a binding for the given variable name is found. (1995-03-07) 1 1 1 1 1 dynamic link library Dynamically Linked Library 1 1 1 1 1 Dynamic Object-Oriented Requirements System (DOORS) A tool from Quality Systems & Software Ltd. for handling all kinds of requirements (in fact, any information at all) as modules containing trees of text objects, qualified by an arbitrary number of user-defined attributes, and cross-linked by directional links. 1 1 1 1 1 dynamic RAM dynamic random-access memory 1 1 1 1 1 dynamic random-access memory (DRAM) A type of semiconductor memory in which the information is stored in capacitors on a MOS integrated circuit. Typically each bit is stored as an amount of electrical charge in a storage cell consisting of a capacitor and a transistor. Due to leakage the capacitor discharges gradually and the memory cell loses the information. Therefore, to preserve the information, the memory has to be refreshed periodically. Despite this inconvenience, the DRAM is a very popular memory technology because of its high density and consequent low price. The first commercially available DRAM chip was the Intel 1103, introduced in 1970. Early DRAM chips, containing up to a 16k x 1 (16384 locations of one bit each), needed 3 supply voltages (+5V, -5V and +12V). Beginning with the 64 kilobit chips, charge pumps were included on-chip to create the necessary supply voltages out of a single +5V supply. This was necessary to fit the 1 1 1 1 1 dynamic routing (Or "adaptive routing") Routing that adjusts automatically to network topology or traffic changes. (1997-05-08) 1 1 1 1 1 DYnamics ANAlyzer (DYANA) An early language specialised for vibrational and other dynamic physical systems. [Sammet 1969, p. 628]. (1997-07-20) 1 1 1 1 1 dynamic scope In a dynamically scoped language, e.g. most versions of Lisp, an identifier can be referred to, not only in the block where it is declared, but also in any function or procedure called from within that block, even if the called procedure is declared outside the block. This can be implemented as a simple stack of (identifier, value) pairs, accessed by searching down from the top of stack for the most recent instance of a given identifier. The opposite is lexical scope. A common implementation of dynamic scope is shallow binding. (1996-07-11) 1 1 1 1 1 dynamic scoping dynamic scope 1 1 1 1 1 Dynamic Systems Development Method (DSDM) An independent software development framework. DSDM.org Home (http://dsdm.org/). [What is it?] (2002-02-14) 1 1 1 1 1 dynamic translation A virtual machine implementation approach, used to speed up execution of byte-code programs. To execute a program unit such as a method or a function, the virtual machine compiles its bytecodes into (hardware) machine code. The translated code is also placed in a cache, so that next time that unit's machine code can be executed immediately, without repeating the translation. This technique was pioneered by the commercial Smalltalk implementation currently known as VisualWorks, in the early 1980s. Currently it is also used by some implementations of the Java Virtual Machine under the name JIT (Just In Time compilation). [Peter L. Deutsch and Alan Schiffman. "Efficient Implementation of the Smalltalk-80 System", 11th Annual Symposium on Principles of Programming Languages, Jan 1984, pp. 297-302]. (2002-04-15) 1 1 1 1 1 dynamic typing Enforcement of type rules at run time as opposed to compile time. Dynamic typing catches more errors as run-time exceptions than static typing. Tcl, Perl, PHP, Python and Visual Basic are examples of dynamically typed languages. A dynamically typed language may have strong typing or weak typing. (2004-07-20) 1 1 1 1 1 DYNAMO DYNamic MOdels. A language for continuous simulation including economic, industrial and social systems, developed by Phyllis Fox and A.L. Pugh in 1959. Versions include DYNAMO II, DYNAMO II/370, DYNAMO II/F, DYNAMO III and Gaming DYNAMO. ["DYNAMO User's Manual", A.L. Pugh, MIT Press 1976]. 1 1 1 1 1 Dynix A host-based library automation system from Dynix Automated Library Systems. First installed in 1993, it is now used in over 2000 libraries worldwide. Dynix runs on Unix using the UniVerse post relational database. The software is configurable using tables of parameters. It includes modules for cataloguing, circulation, OPAC, acquisitions, serials, reserve book room, advance bookings, homebound, BiblioBus, Pac Plus for Windows, Kids Catalog, Dynix Online Catalog, media bookings, and community information. (http://uk.dynix.com/classic.html). (1995-04-28) 1 1 1 1 1 Dynix Automated Library Systems The world's largest supplier of library automation systems with European offices in France, Germany, Ireland, the Netherlands and the UK. Dynix sell two library management systems - Horizon (client/server) and, Dynix (host-based). Both have GUI or terminal interfaces. Dynix also sell other products and services for database enrichment, interconnectivity, and on-line and CD-ROM databases. (http://uk.dynix.com/dynix.html). (1995-04-28) 1 1 1 1 1 dynner /din'r/ 32 bits, by analogy with byte. Usage: rare and extremely silly. See also playte, tayste, crumb. [Jargon File] (1997-12-03) 1 1 1 1 1 DYSAC Digital Simulated Analog Computer. [Sammet 1969, p. 629]. 1 1 1 1 1 DYSTAL DYnamic STorage ALlocation. Adds lists, strings, sorting, statistics and matrix operations to Fortran. Sammet 1969, p.388. "DYSTAL: Dynamic Storage Allocation Language in FORTRAN", J.M. Sakoda, in Symbol Manipulation Languages and Techniques, D.G. Bobrow ed, N-H 1971, pp.302- 311. (1995-03-17) 1 1 1 1 1 dz The country code for Algeria. (1999-01-27) 1 1 1 1 1 E 1. An extension of C++ with database types and persistent objects. E is a powerful and flexible procedural programming language. It is used in the Exodus database system. See also GNU E. (ftp://ftp.cs.wisc.edu/exodus/E/). ["Persistence in the E Language: Issues and Implementation", J.E. Richardson et al, Soft Prac & Exp 19(12):1115-1150 (Dec 1989)]. 2. <language> A procedural language by Wouter van Oortmerssen with semantics similar to C. E features lists, low-level polymorphism, exception handling, quoted expressions, pattern matching and object inheritance. Amiga E is a version for the Amiga. (1999-10-05) 1 1 1 1 1 E1 A European framing specification for the transmission of 32 DS0 (64 kb/s) data streams. By extension, it can also denote the transmission rate required (2.048 Mb/s = 2048 kb/s). Unlike DS1 it is free of bit-robbing. (2002-03-22) 1 1 1 1 1 E2 A European framing specification for the transmission of four multiplexed E1 data streams, resulting in a transmission rate of 8.448 Mb/s (= 8448 kb/s). (2002-03-22) 1 1 1 1 1 E2ES end-to-end solution 1 1 1 1 1 E3 A European framing specification for the transmission of 16 multiplexed E1 data streams, resulting in a transmission rate of 34.368 Mb/s (= 34,368 kb/s). (2002-03-22) 1 1 1 1 1 E4 A European framing specification for the transmission of 64 multiplexed E1 data streams, resulting in a transmission rate of 139.264 Mb/s (= 139,264 kb/s). (2002-03-22) 1 1 1 1 1 E5 A European framing specification for the transmission of 256 multiplexed E1 data streams, resulting in a transmission rate of 565.148 Mbps (= 565,148 kb/s). (2002-03-22) 1 1 1 1 1 E-acute "É" - a capital "E" with an acute accent. Character code 201, 0xC9. Entity reference: &amp;Eacute;. (2013-01-13) 1 1 1 1 1 EAF Effort Adjustment Factor 1 1 1 1 1 EAG Extended Affix Grammar 1 1 1 1 1 eager evaluation Any evaluation strategy where evaluation of some or all function arguments is started before their value is required. A typical example is call-by-value, where all arguments are passed evaluated. The opposite of eager evaluation is call-by-need where evaluation of an argument is only started when it is required. The term "speculative evaluation" is very close in meaning to eager evaluation but is applied mostly to parallel architectures whereas eager evaluation is used of both sequential and parallel evaluators. Eager evaluation does not specify exactly when argument evaluation takes place - it might be done fully speculatively (all redexes in the program reduced in parallel) or may be done by the caller just before the function is entered. The term "eager evaluation" was invented by Carl Hewitt and Henry Baker <hbaker@netcom.com> and used in their paper ["The Incremental Garbage Collection of Processes", Sigplan Notices, 1 1 1 1 1 Eagle A dBASE-like dialect bundled with Emerald Bay, sold by Migent from 1986-1988, later renamed Vulcan when Wayne Ratliff reacquired the product. 1 1 1 1 1 EAI Enterprise Application Integration 1 1 1 1 1 EAPROM Electrically Alterable Programmable Read-Only Memory 1 1 1 1 1 earliest deadline first (EDF) A strategy for CPU or disk access scheduling. With EDF, the task with the earliest deadline is always executed first. Scan-EDF is an example. (1995-11-15) 1 1 1 1 1 Early PL/I (EPL) A PL/I subset dialect by McIlroy, Morris et al, the first running PL/I compiler. It was used by Bell Labs and MIT to write Multics. EPL had extensions to handle the segment/offset nature of Multics pointers. See also REPL, TMG. ["EPL Reference Manual", Project MAC, April 1966]. [Sammet 1969, p. 542]. (1995-11-15) 1 1 1 1 1 EARN European Academic and Research Network. (1995-11-15) 1 1 1 1 1 EAROM Electrically Alterable Read-Only Memory. EEPROM 1 1 1 1 1 earthquake (IBM) The ultimate real-world shock test for computer hardware. Hackish sources at IBM deny the rumor that the San Francisco Bay Area quake of 1989 was initiated by the company to test quality-assurance procedures at its California plants. [Jargon File] (1995-04-22) 1 1 1 1 1 Ease General purpose parallel programming language, combining the process constructs of CSP and the distributed data structures of Linda. "Programming with Ease: Semiotic Definition of the Language", S.E. Zenith, <zenith-steven@yale.edu> Yale U TR-809, Jul 1990. 1 1 1 1 1 EASE II Early system on IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 EASIAC Early system on Midac computer. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 EAST A Eureka project developing a software engineering platform. (1994-12-07) 1 1 1 1 1 easter egg (From the custom of the Easter Egg hunt observed in the US and many parts of Europe) 1. A message hidden in the object code of a program as a joke, intended to be found by persons disassembling or browsing the code. 2. A message, graphic, sound effect, or other behaviour emitted by a program (or, on an IBM PC, the BIOS ROM) in response to some undocumented set of commands or keystrokes, intended as a joke or to display program credits. One well-known early Easter egg found in a couple of operating systems caused them to respond to the command make love with "not war?". Many personal computers, and even satellite control computers, have much more elaborate eggs hidden in ROM, including lists of the developers' names (e.g. Microsoft Windows 3.1x), political exhortations and snatches of music. The Tandy Color Computer 3 (CoCo) had images of the entire development team. Microsoft Excel 97 1 1 1 1 1 Easter egging (IBM, From the custom of the Easter Egg hunt observed in the US and many parts of Europe) The act of replacing unrelated components more or less at random in the hope that a malfunction will go away. Hackers consider this the normal operating mode of field circus techs and do not love them for it. Compare Easter egg, shotgun debugging. [Jargon File] (1998-03-18) 1 1 1 1 1 Eastern Washington University A university 20 miles southwest of Spokane, WA on the edge of the rolling Palouse Prairie. (http://ewu.edu/). Address: Cheney, Washington, USA. (1995-02-28) 1 1 1 1 1 EASY FOX An early system on the JOHNNIAC computer. [Listed in CACM 2(5):16 (May 1959)]. 1 1 1 1 1 eat flaming death A construction popularised among hackers by the infamous CPU Wars comic; supposedly derive from a famously turgid line in a WWII-era anti-Nazi propaganda comic that ran "Eat flaming death, non-Aryan mongrels!" or something of the sort (however, it is also reported that the Firesign Theater's 1975 album "In The Next World, You're On Your Own" included the phrase "Eat flaming death, fascist media pigs"; this may have been an influence). Used in humorously overblown expressions of hostility. "Eat flaming death, EBCDIC users!" [Jargon File] (2006-12-12) 1 1 1 1 1 eating one's own dogfood When a developer uses their own code for their own daily needs. Being a user as well as a developer creates the user empathy that is the hallmark of good software. The term seems to have originated at Microsoft. (http://www.joelonsoftware.com/items/2004/04/16.html) (2006-12-12) 1 1 1 1 1 eating your own dogfood eating one's own dogfood 1 1 1 1 1 EAX Environmental Audio eXtensions 1 1 1 1 1 EBASIC A BASIC by Gordon Eubanks, now at Symantec, that led to CBASIC. (2006-12-12) 1 1 1 1 1 EBCDIC Extended Binary Coded Decimal Interchange Code 1 1 1 1 1 EBCIDIC It's spelled "EBCDIC". (1996-12-13) 1 1 1 1 1 EBNF Extended Backus-Naur Form. 1 1 1 1 1 Ebone A pan-European backbone network service. 1 1 1 1 1 ec The country code for Ecuador. (1999-01-27) 1 1 1 1 1 EC++ A preprocessor by Glauco Masotti <masotti@lipari.usc.edu> that translates Extended C++ into C++. (ftp://ftp.uu.net/languages/c++/EC++.tar.Z). (1989-10-10) 1 1 1 1 1 ECAP II Electronic Circuit Analysis Program. Simple language for analysing electrical networks. "Introduction to Computer Analysis: ECAP for Electronics Technicians and Engineers", H. Levin, P-H 1970. 1 1 1 1 1 E-carrier system A series of digital transmission formats promulgated by the ITU and used outside of North America and Japan. The basic unit of the E-carrier system is the DS0, which has a transmission rate of 64 Kbps, and is commonly used for one voice circuit. The E1 format consists of 32 DS0 channels, for a total capacity of 2.048 Mbps. E2, E3, E4, and E5 circuits carry multiple E1 channels multiplexed, resulting in transmission rates of up to 565.148 Mbps. The E-carrier system is similar to, and compatible with, the T-carrier system used in North America, but has higher capacity since it uses out-of-band signaling in contrast to the in-band signaling or bit-robbing used in the T-system. (2000-03-10) 1 1 1 1 1 Ecash A trial form of electronic funds transfer over the Internet (and soon by electronic mail). The ecash software stores digital money, signed by a bank, on the user's local computer. The user can spend the digital money at any shop accepting ecash, without the trouble of having to open an account there first, or having to transmit credit card numbers. The shop just has to accept the money, and deposit it at the bank. The security is provided by a public-key digital signature. There process involves the issuing banks who exchange real money for ecash, users who have and spend ecash, shops who accept ecash payments, and clearing banks who clear payments received by shops. At the moment, all users and shops must have an account at DigiCash's own bank, the "First Digital Bank" at bank.digicash.com. They can withdraw money from the bank, and convert it to ecash. Shops can be started by any ecash user. 1 1 1 1 1 ECC error detection and correction 1 1 1 1 1 Eccles-Jordan circuit flip-flop 1 1 1 1 1 Echidna Constraint logic programming embedded in an object-oriented language. The syntax is an extension of Edinburgh Prolog. ["Hierarchical Arc Consistency Applied to Numeric Processing in Constraint Logic Programming", G. Sidebottom et al, TR-91-06, CSS-IS, Simon Fraser U, and Comp Intell 8(4) (1992)]. (ftp://cs.sfu.edu/pub/ecl/papers). E-mail: <expert@cs.sfu.edu>. (1994-12-08) 1 1 1 1 1 echo 1. A topic group on FidoNet's echomail system. Compare newsgroup. 2. A Unix command that just prints its arguments. [Jargon File] 1 1 1 1 1 echo cancellation A process which removes unwanted echoes from the signal on a telephone line. Echoes are usually caused by impedance mismatches along an analogue line. 1 1 1 1 1 ECHT European Conference on Hypertext. 1 1 1 1 1 ECIP2 An Esprit project on the definition of a specification language at the requirement level. 1 1 1 1 1 ECIS European Committee for Interoperable Systems 1 1 1 1 1 Eckert-Mauchly Computer Corporation The company which designed and built Univac computers. (1995-03-01) 1 1 1 1 1 ECL 1. <hardware> Emitter Coupled Logic. 2. <language> Extensible CL. Wegbreit, ca 1970. ["The ECL Programming System", B. Wegbreit, Proc FJCC 39:253-261, AFIPS (Fall 1971)]. ["ECL Programmer's Manual", B. Wegbreit, TR 23-74, Harvard U (Dec 1974)]. (1994-11-09) 1 1 1 1 1 ECLIPSE A Prolog + CLP compiler from ECRC. 1 1 1 1 1 ECM error correcting memory. (1995-10-10) 1 1 1 1 1 ECMA 1. European Computer Manufacturers Association, now ECMA International. 2. A subset of ALGOL. [Sammet 1969, p.180]. (1998-09-07) 1 1 1 1 1 ECMA International (Formerly European Computer Manufacturers Association) An industry association founded in 1961 and dedicated to the standardisation of information and communication systems. ECMA edits standards and technical reports. All ECMA publications are available free of charge. The best known ECMA standard is ECMA 262, defining the scripting language ECMAScript. (2003-06-23) 1 1 1 1 1 ECMAScript (ECMA standard 262, ISO standard 16262) The standardised version of the core JavaScript language. (2005-07-28) 1 1 1 1 1 Ecole Normale Superieure (ENS) A higher education and research institution in Paris, France. 1 1 1 1 1 e-commerce electronic commerce 1 1 1 1 1 Econet 1. One of the IGC networks. EcoNet serves individuals and organisations working for environmental preservation and sustainability. Important issues covered include: global warming, energy policy, rainforest preservation, legislative activities, water quality, toxics and environmental education. EcoNet users can send and receive private messages, including fax and telex, to and from more than 18,000 international users on the APC networks or to millions on other networks. EcoNet seeks to build coalitions and partnerships with activist and non-profit organisations to develop the use of the electronic communications medium. EcoNet provides subsidies and financial incentives to environmental organisations and committed individuals who foster the effectiveness of organisations through the use of electronic networking. FTP/Telnet: igc.apc.org. 2. A network produced by Acorn Computers Ltd. for the BBC Microcomputer and its successors. 1 1 1 1 1 ECOOP European Conference on Object-oriented Programming. 1 1 1 1 1 ECP 1. Engineering Change Proposal. 2. Enhanced Capabilities Port. 3. Extended Capabilities Port. 4. Extended Concurrent Prolog. (1997-12-01) 1 1 1 1 1 ECRC European Computer-Industry Research Centre GmbH 1 1 1 1 1 ECRC-Prolog Evidently Prolog with coroutine extensions. See also SEPIA. ["ECRC-Prolog User's Manual Version 1.0", K. Estenfeld, TR-LP-08 ECRC, Feb 1986]. (1994-12-01) 1 1 1 1 1 ECSL Extended CSL. A discrete simulation language, the successor to CSL. ["Extended Control and Simulation Language", A.T. Clementson, Comp J 9(3):215-220 (1966)]. (1994-12-08) 1 1 1 1 1 ECSP An extension to CSP, supporting dynamic communication channels and nested processes. ["Static Type Checking of Interprocess Communication in ECSP", F. Baiardi et al, SIGPLAN Notices 19(6):290-299 (June 1984)]. (1994-12-08) 1 1 1 1 1 ECSS II Extendable Computer System Simulator. An extension of SIMSCRIPT II. ["The ECSS II Language for Simulating Computer Systems", D.W. Kosy, R-1895-GSA, Rand Corp]. (1994-12-08) 1 1 1 1 1 ECSSL Formerly APSE. An equation-oriented specification language for continuous simulations. The compiler outputs HYTRAN, which must be run on an analog processor. (1994-12-08) 1 1 1 1 1 ed (editor) Unix's line editor. Ed is rarely used by humans since even vi is better. Unix manual page: ed(1). (1999-03-01) 1 1 1 1 1 EDA 1. Electronic Design Automation. 2. Exploratory Data Analysis. 3. A product line from Dazix. (1995-10-02) 1 1 1 1 1 EDAC error detection and correction 1 1 1 1 1 e-ddress electronic mail address 1 1 1 1 1 Eden A concurrent, object-oriented, distributed operating system and language, Eden Programming Language (EPL), based on remote procedure call. It has both synchronous and asynchronous message passing. ["The Eden System: A Technical Review", G. Almes et al, IEEE Trans Soft Eng SE-11(1):43-59, Jan 1985]. (2009-05-26) 1 1 1 1 1 Eden Programming Language (EPL) A language developed at the University of Washington, based on Concurrent Euclid and used with the Eden distributed operating system. EPL influenced Emerald and Distributed Smalltalk. ["EPL Programmer's Guide", A. Black et al, U Washington June 1984]. Eden 1 1 1 1 1 EDF earliest deadline first 1 1 1 1 1 EDI Electronic Data Interchange 1 1 1 1 1 EDI analyst A person who introduces EDI standards and technology. An EDI analyst makes decisions for information construction and selects resources for EDI processing and application expansion. He coordinates processing and transmission schedules and mapping of standard data formats. He generally serves as a key contact for trading partners and value-added network consultants. (2004-03-11) 1 1 1 1 1 EDIF Electronic Design Interchange Format. Not a programming language, but a format to simplify data transfer between CAD/CAE systems. LISP-like syntax. See also Berkeley EDIF200. E-mail: <edif-support@cs.man.ac.uk> (ftp://edif.cs.man.ac.uk/pub/edif). ["Designer's Guide to EDIF", E. Marx et al, EDN 1987."EDIF Electronic Design Interchange Format Version 200", ANSI/EIA Standard 548]. (1995-03-10) 1 1 1 1 1 EDIFACT ISO 9735:1988 1 1 1 1 1 Edinburgh Multi Access System (EMAS) One of the first operating systems written in a high-level language (IMProved Mercury autocode), apparently predating Unix. [Papers in J. British Computer Society]. [More info? Dates?] (1996-04-07) 1 1 1 1 1 Edinburgh Prolog Prolog dialect which eventually developed into the standard, as opposed to Marseille Prolog. (The difference is largely syntax.) Clocksin & Mellish describe Edinburgh Prolog. Version: C-Prolog. (1995-03-10) 1 1 1 1 1 Edinburgh SML (EdML) Implementation of the Core language of SML. Byte-code interpreter in C. Ported to Amiga, Atari, Archimedes and IBM PC. Version: 0.44. (ftp://ftp.dcs.ed.ac.uk/pub/edml/EDML4). E-mail: <lfcs@ed.ac.uk>. (1994-12-08) 1 1 1 1 1 Edison 1. (Named after the American inventor Thomas Edison (1847-1931)) A simplified Pascal by Per Brinch Hansen with modules and concurrency (cobegin/coend). ["Edison - A Multiprocessor Language", P. Brinch Hansen, CS Dept, USC, Sep 1980]. ["Programming a Personal Computer", Brinch Hansen, P-H 1977]. 2. A language which adds an OPS5-like rete-based production system system to C. It is implemented as a C preprocessor. ["Edison, A Unix and C Friendly Rete Based Production System", B. Thirion, SIGPLAN Notices 27(1):75-84 (Jan 1992)]. (1994-12-08) 1 1 1 1 1 edit Use of some kind of editor program to modify a document. Also used to refer to the modification itself, e.g. "my last edit only made things worse". To edit something usually implies that the changes will persist for some time, usually by saving the edited document to a file, though one might open an editor, create a new document in memory, print it and exit without saving it to disk. Editing is normally done by a human but see, e.g., sed. (2007-07-11) 1 1 1 1 1 editor A program used to edit a document. Different types of document have different editors, e.g. a text editor for text files, an image editor for images, an HTML editor for web pages, etc. The term can be used for pretty much any kind of data modification, e.g. a disk sector editor which operates directly on the hard disk, bypassing the filesystem. (2007-07-11) 1 1 1 1 1 EDL 1. Experiment Description Language. 2. Event Description Language. 1 1 1 1 1 EDM Electronic Data Management 1 1 1 1 1 EdML Edinburgh SML 1 1 1 1 1 EDMS Electronic Document Management System 1 1 1 1 1 EDO DRAM Extended Data Out Dynamic Random Access Memory 1 1 1 1 1 EDO memory Extended Data Out Dynamic Random Access Memory 1 1 1 1 1 EDO RAM Extended Data Out Dynamic Random Access Memory 1 1 1 1 1 EDP Electronic Data Processing 1 1 1 1 1 EDP auditor A person who analyses system functions and operations to determine adequate security and controls. An EDP analyst evaluates systems and operational procedures and reports findings to senior management. He writes ad hoc report programs using 4GLs and specialised audit software. (2004-03-11) 1 1 1 1 1 EDRAM Enhanced Dynamic Random Access Memory 1 1 1 1 1 EDS Enhanced Directory Service 1 1 1 1 1 EDS+ A database accelerator built by ICL as part of the EDS project. The machine has up to 64 nodes, each node having 64Mb of memory, 2 SPARC processors and a 1Gb of disk. See also PARADE. (1994-11-02) 1 1 1 1 1 EDSAC Electronic Discrete Sequential Automatic Computer 1 1 1 1 1 edu ("education") The top-level domain for educational establishments in the USA (and some other countries). E.g. "mit.edu". The UK equivalent is "ac.uk". (1999-01-26) 1 1 1 1 1 education contact The person at a company who should receive educational material. (2004-03-11) 1 1 1 1 1 edutainment Interactive education and entertainment services or software, usually supplied commercially via a cable network or on CD-ROM. (1995-03-30) 1 1 1 1 1 Edward Lorenz A mathematical meteorologist who discovered the Lorenz attractor in the 1960s. (1996-01-13) 1 1 1 1 1 Edward Yourdon A software engineering consultant, widely known as the developer of the "Yourdon method" of structured systems analysis and design, as well as the co-developer of the Coad/Yourdon method of object-oriented analysis and design. He is also the editor of three software journals - American Programmer, Guerrilla Programmer, and Application Development Strategies - that analyse software technology trends and products in the United States and several other countries around the world. Ed Yourdon received a B.S. in Applied Mathematics from MIT, and has done graduate work at MIT and at the Polytechnic Institute of New York. He has been appointed an Honorary Professor of Information Technology at Universidad CAECE in Buenos Aires, Argentina and has received numerous honors and awards from other universities and professional societies around the world. He has worked in the computer industry for 30 years, including 1 1 1 1 1 Edwin MIT Scheme 1 1 1 1 1 ee The country code for Estonia. (1999-01-27) 1 1 1 1 1 EEMA European Electronic Messaging Association 1 1 1 1 1 EEPROM Electrically Erasable Programmable Read-Only Memory See also EAPROM. 1 1 1 1 1 EER An extended entity-relationship model. 1 1 1 1 1 E. F. Codd The inventor of the relational data model of databases. [Name? More?] (1995-11-29) 1 1 1 1 1 EFF Electronic Frontier Foundation 1 1 1 1 1 effective computable A term describing a function for which there is an effective algorithm that correctly calculates the function. The algorithm must consist of a finite sequence of instructions. (1996-05-03) 1 1 1 1 1 effective number of bits (ENOB) An indication of the quality of an analog to digital converter. The measurement is related to the test frequency and the signal-to-noise ratio. [Better definition?] (1998-06-15) 1 1 1 1 1 Effort Adjustment Factor (EAF) A term used in COCOMO to calculate a cost driver attribute's effect on a project. It is the product of the effort multipliers corresponding to each of the cost drivers for the project. (1996-05-29) 1 1 1 1 1 EFI Extensible Firmware Interface 1 1 1 1 1 EFL Extended Fortran Language 1 1 1 1 1 EFNet (From "Eris-free Net", eris being eris.berkeley.edu). The dominant Internet Relay Chat network. See also Undernet. (1995-11-09) 1 1 1 1 1 Eforth A system produced by Ting to help implementers produce Forths for different targets, using assemblers. (1996-07-28) 1 1 1 1 1 E-Forth A Forth interpreter written in Motorla 6809 assembly code by Lennart Benschop <lennart@blade.stack.urc.tue.nl>. Posted to Usenet newsgroup alt.sources on 1993-11-03 with a Motorola 6809 assembler. (1993-11-03) 1 1 1 1 1 EFT electronic funds transfer 1 1 1 1 1 EFTPOS Electronic Funds Transfer Point of Sale 1 1 1 1 1 EFTS electronic funds transfer 1 1 1 1 1 eg The country code for Egypt. (1999-01-27) 1 1 1 1 1 EGA Enhanced Graphics Adapter 1 1 1 1 1 Eggdrop The world's most popular open source IRC bot, designed for flexibility and ease of use. Eggdrop is freely distributable under the GPL. It was originally developed by Robey Pointer but he no longer works on it. Eggdrop is designed to run on Linux, *BSD, SunOs, Windows, Mac OS X and other platforms. It is extendable with Tcl scripts and/or C modules. It supports Undernet, DALnet, EFnet, IRCnet, and QuakeNet. It can form botnets and share partylines and userfiles between bots. (2005-07-07) 1 1 1 1 1 egosurfing Scanning the web, databases, print media or research papers looking for the mention of your name. (1997-04-17) 1 1 1 1 1 EGP Exterior Gateway Protocol 1 1 1 1 1 egrep An extended version of the Unix grep command. Egrep accepts extended regular expressions (REs) including * following multi-character REs; "+" (one or more matches); ? (zero or one matches); "|" separating two REs matches either. REs may be bracketed with (). Despite its additional complexity, egrep is usually faster than fgrep or grep. (2004-07-20) 1 1 1 1 1 Egyptian brackets A humourous term for K&R indent style, referring to the "one hand up in front, one down behind" pose which popular culture inexplicably associates with Egypt. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2011-11-30) 1 1 1 1 1 Eh /A/. Software Portability Group, U Waterloo. A typeless language derived from (and similar to) B. Provides guaranteed order of evaluation for side effects in expressions. Also character indexing operators. See also Zed. ["Eh Reference Manual", R.S.C. Braga, RR CS-76-45, U Waterloo, Nov 1976]. 1 1 1 1 1 eh The country code for Western Sahara. (1999-01-27) 1 1 1 1 1 eHelp Corporation A vendor of Microsoft Windows application development tools such as RoboHELP and RoboDemo. EHelp were formerly (around 1997) Blue Sky Software. eHelp Home (http://ehelp.com/). Address: 7777 Fay Avenue, Suite 201, La Jolla, CA 92037, USA. Telephone: +1-800-793-0364, +1 (619) 459 6365. Fax: +1 (619) 459 6366. (2003-07-24) 1 1 1 1 1 EHTS Emacs HyperText System. An experimental multi-user hypertext system from the University of Aalborg. It consists of a text editor (based on Epoch and GNU Emacs and written in elisp) and a graphical browser (based on XView and written in C) running under the X Window System and OpenWindows. Both tools use HyperBase as their database. (1995-01-05) 1 1 1 1 1 EIA Electronics Industry Association 1 1 1 1 1 EIA-232 (Formerly "RS-232") The most common asynchronous serial line standard. EIA-232 is the EIA equivalent of ITU-T V.24, and V.28. EIA-232 specifies the gender and pin use of connectors, but not their physical type. RS-423 specifies the electrical signals. 25-way D-type connectors are common but often only three wires are connected - one ground (pin 7) and one for data in each direction. The other pins are primarily related to hardware handshaking between sender and receiver and to carrier detection on modems, inoperative circuits, busy conditions etc. The standard classifies equipment as either Data Communications Equipment (DCE) or Data Terminal Equipment (DTE). DTE receives data on pin 3 and transmits on pin 2 (TD). A DCE EIA-232 interface has a female connector. DCE receives data from DTE on pin 2 (TD) and sends that data out the analog line. Data received from the analog line is sent 1 1 1 1 1 EIA-232C The EIA equivalent of ITU-T standard V.24. The EIA EIA-232C electrical signal is unbalanced +/- 5 to +/- 12V, polar non return to zero and handles data speeds up to 19.2 kilobits per second. [Correct name? Relationship to RS-232C? Difference from EIA-232?] (2004-08-02) 1 1 1 1 1 EIA-422 (Formerly "RS-422") An EIA serial line standard which specifies 4-wire, full-duplex, differential line, multi-drop communications. The mechanical connections for this interface are specified by EIA-449. The maximum cable length is 1200m. Maximum data rates are 10Mbps at 1.2m or 100Kbps at 1200m. EIA-422 cannot implement a truly multi-point communications network (such as with EIA-485), although only one driver can be connected to up to ten receivers. The best use of EIA-422 is probably in EIA-232 extension cords. Comparing EIA-422, 423, 449 to RS-232-C (http://rad.com/networks/1995/rs232/rs449.htm). Details on RS-232, 422, 423 and 485 (http://rs485.com/rs485spec.html). (2002-10-05) 1 1 1 1 1 EIA-423 (Formerly "RS-423") An EIA serial line standard which specifies single ended communication. The mechanical connections for this interface are specified by EIA-449. Although it was originally intented as a successor of EIA-232 it is not widely used. The EIA-232 standard has its limits at 20kbps and 1.5m. EIA-423 can have a cable lenght of 1200m, and achieve a data rate of 100Kbps. When no data is being transmitted, the serial line is at a logical zero (+3 to +15 Volts). A logical one is represented as a signal level of -15 to -3 Volts. In practise, one often finds signals which switch between nominally +4.5 and +0.5 Volts. Such signals are large by modern standards, and because the impedance of the circuits is relatively high, the allowable bit rate is modest. The data is preceded by a start bit which is always a logical one. There may be seven or eight bits of data, possibly followed by an even or odd parity bit and one or two stop 1 1 1 1 1 EIA-449 (Formerly "RS-449") An EIA standard for a 37-pin or 9-pin D-type connector (functional- and mechanical characteristics), usually used with EIA-422 or EIA-423 electrical specifications. (2002-10-05) 1 1 1 1 1 EIA-485 (Formerly "RS-485") An EIA serial line standard which specifies 2-wire, half-duplex, differential line, multi-point communications. Maximum cable length is 1200m. Maximum data rates are 10Mbps at 1.2m or 100Kbps at 1200m. EIA-485 can implement a truly multi-point communications network, and specifies up to 32 drivers and 32 receivers on a single (2-wire) bus. Differential SCSI uses EIA-485. Details on RS-232, 422, 423, and 485 (http://rs485.com/rs485spec.html). (2003-04-18) 1 1 1 1 1 EIA-530 (Formerly "RS-530") An EIA serial line standard which specifies differential line and singe ended communications. Combining EIA-422 and EIA-423, and defining a 25-pin connector for mechanical connections, this standard serves as a complement to EIA-232 for high(er) speed data transmissions. (2002-10-05) 1 1 1 1 1 EIDE Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 Eiffel An object-oriented language produced by Bertrand Meyer in 1985. Eiffel has classes with multiple inheritance and repeated inheritance, deferred classes (like Smalltalk's abstract class), and clusters of classes. Objects can have both static types and dynamic types. The dynamic type must be a descendant of the static (declared) type. Dynamic binding resolves multiple inheritance clashes. It has flattened forms of classes, in which all of the inherited features are added at the same level and generic classes parametrised by type. Other features are persistent objects, garbage collection, exception handling, foreign language interface. Classes may be equipped with assertions (routine preconditions and postconditions, class invariants) implementing the theory of Design by Contract and helping produce more reliable software. Eiffel is compiled to C. It comes with libraries containing 1 1 1 1 1 Eiffel source checker A compiler front-end for Eiffel 3 by Olaf Langmack <langmack@inf.fu-berlin.de> and Burghardt Groeber. It was generated automatically with the Karlsruhe toolbox for compiler construction according to the most recent public language definition. The parser derives an easy-to-use abstract syntax tree, supports elementary error recovery and provides a precise source code indication of errors. It performs a strict syntax check and analyses 4000 lines of source code per second on a Sun SPARC workstation. (ftp://ftp.fu-berlin.de/pub/heron/ep.tar.Z). (1992-12-14) 1 1 1 1 1 eigenvalue The factor by which a linear transformation multiplies one of its eigenvectors. (1995-04-10) 1 1 1 1 1 eigenvector A vector which, when acted on by a particular linear transformation, produces a scalar multiple of the original vector. The scalar in question is called the eigenvalue corresponding to this eigenvector. It should be noted that "vector" here means "element of a vector space" which can include many mathematical entities. Ordinary vectors are elements of a vector space, and multiplication by a matrix is a linear transformation on them; smooth functions "are vectors", and many partial differential operators are linear transformations on the space of such functions; quantum-mechanical states "are vectors", and observables are linear transformations on the state space. An important theorem says, roughly, that certain linear transformations have enough eigenvectors that they form a basis of the whole vector states. This is why Fourier analysis works, and why in quantum mechanics every state is a 1 1 1 1 1 eight-bit clean A term which describes a system that deals correctly with extended character sets which (unlike ASCII) use all eight bits of a byte. Many programs and communications systems assume that all characters have codes in the range 0 to 127. This leaves the top bit of each byte free for use as a parity bit or some kind of flag bit. These assumptions break down when the program is used in some non-english-speaking countries with larger alphabets. If a binary file is transmitted via a communications link which is not eight-bit clean, it will be corrupted. To combat this you can encode it with uuencode which uses only ASCII characters. There are some links however which are not even seven-bit clean and cause problems even for uuencoded data. (1995-01-05) 1 1 1 1 1 eight queens problem eight queens puzzle 1 1 1 1 1 eight queens puzzle A puzzle in which one has to place eight queens on a chessboard such that no queen is attacking any other, i.e. no two queens occupy the same row, column or diagonal. One may have to produce all possible such configurations or just one. It is a common students assignment to devise a program to solve the eight queens puzzle. The brute force algorithm tries all 64*63*62*61*60*59*58*57 = 178,462,987,637,760 possible layouts of eight pieces on a chessboard to see which ones meet the criterion. More intelligent algorithms use the fact that there are only ten positions for the first queen that are not reflections of each other, and that the first queen leaves at most 42 safe squares, giving only 10*42*41*40*39*38*37*36 = 1,359,707,731,200 layouts to try, and so on. The puzzle may be varied with different number of pieces and different size boards. 1 1 1 1 1 eighty-column mind The sort said to be possessed by persons for whom the transition from punched card to paper tape was traumatic (nobody has dared tell them about disks yet). It is said that these people, including (according to an old joke) the founder of IBM, will be buried "face down, 9-edge first" (the 9-edge being the bottom of the card). This directive is inscribed on IBM's 1402 and 1622 card readers and is referenced in a famous bit of doggerel called "The Last Bug", the climactic lines of which are as follows: He died at the console Of hunger and thirst. Next day he was buried, Face down, 9-edge first. The eighty-column mind is thought by most hackers to dominate IBM's customer base and its thinking. See fear and loathing, card walloper. [Jargon File] 1 1 1 1 1 eighty-twenty rule The program-design version of the law of diminishing returns. The 80/20 rule says that roughly 80% of the problem can be solved with 20% of the effort that it would take to solve the whole problem. For example, parsing e-mail addresses in "From:" lines in e-mail messages is notoriously difficult if you follow the RFC 2822 specification. However, about 60% of actual "From:" lines are in the format "From: Their Name <user@host>", with a far more constrained idea of what can be in "user" or "host" than in RFC 2822. Another 25% just add double-quotes around Their Name. Matching just those two patterns would thus cover 85% of "From:" lines, with a tiny portion of the code required to fully implement RFC2822. (Adding support for "From: user@host" and "From: user@host (Their Name) " brings coverage to almost 100%, leaving only really baroque things that RFC-2822 permits, like "From: Pete(A wonderful \) chap) <pete(his account)@silly.test(his 1 1 1 1 1 EIRP equivalent isotropically radiated power 1 1 1 1 1 EISA Extended Industry-Standard Architecture 1 1 1 1 1 EJB Enterprise JavaBeans 1 1 1 1 1 Eksi Sozluk ("Sour Dictionary") An online, Turkish, colaborative, hypertext dictionary. Eksi Sozluk Home (http://sourtimes.org/). (2006-11-02) 1 1 1 1 1 EL1 Extensible Language One. An extensible language by B. Wegbreit of Harvard ca 1974. EL1 is internally somewhat Lisp-like, but fully typed with records and pointers. The external syntax is ALGOL-like and extensible, supporting user-defined data structures, control structures and operations. The parser is table-driven, with a modifiable set of productions. Used as the basis for the ECL operating system. ["Studies in Extensible Programming Languages", B. Wegbreit, Garland. Pub 1980]. 1 1 1 1 1 el(alpha) Aims to be a high-level language that knows about real hardware, for systems programming. "Essential Language el(alpha) - A Reduced Expression Set Language for Systems Programming", T. Watanabe et al, SIGPLAN Notices 26(1):85-98. 1 1 1 1 1 Elan ["Top-down Programming with Elan", C.H.A. Koster, Ellis Horwood 1987]. 1 1 1 1 1 El Camino Bignum /el' k*-mee'noh big'nuhm/ The road mundanely called El Camino Real, a road through the San Francisco peninsula that originally extended all the way down to Mexico City and many portions of which are still intact. Navigation on the San Francisco peninsula is usually done relative to El Camino Real, which defines logical north and south even though it isn't really north-south many places. El Camino Real runs right past Stanford University. The Spanish word "real" (which has two syllables: /ray-al'/) means "royal"; El Camino Real is "the royal road". In the Fortran language, a "real" quantity is a number typically precise to seven significant digits, and a "double precision" quantity is a larger floating-point number, precise to perhaps fourteen significant digits (other languages have similar "real" types). When a hacker from MIT visited Stanford in 1976, he remarked what a long road El Camino Real was. Making a pun on 1 1 1 1 1 elder days The heroic age of hackerdom (roughly, pre-1980); the era of the PDP-10, TECO, ITS and the ARPANET. This term has been rather consciously adopted from J. R. R. Tolkien's fantasy epic "The Lord of the Rings". Compare Iron Age. See also elvish and Great Worm. [Jargon File] 1 1 1 1 1 e-learning Computer-Aided Instruction 1 1 1 1 1 Electing a Pope (From the smoke signals given out when the guys in funny hats choose a new Pope) Causing an integrated circuit or other electronic component to emit smoke by passing too much current through it. See magic smoke. (1995-08-18) 1 1 1 1 1 Electrically Alterable Programmable Read-Only Memory (EAPROM) A PROM whose contents can be changed. [What's the difference between EAPROM and EEPROM?] (1995-11-12) 1 1 1 1 1 Electrically Erasable Programmable Read-Only Memory (EEPROM) A non-volatile storage device using a technique similar to the floating gates in EPROMs but with the capability to discharge the floating gate electrically. Usually bytes or words can be erased and reprogrammed individually during system operation. In contrast to RAM, writing takes much longer than reading and EEPROM is more expensive and less dense than RAM. It is appropriate for storing small amounts of data which is changed infrequently, e.g. the hardware configuration of an Acorn Archimedes. [Difference from EAPROM?] (1995-04-22) 1 1 1 1 1 Electromagnetic Compatibility (EMC) The extent to which a piece of hardware will tolerate electrical interference from other equipment, and will interfere with other equipment. There are strict legal EMC requirements for the sale of any electrical or electronic hardware in most countries, although the actual standards differ. See, for example, EMCNet (http://emcnet.com/). See also Electrostatic Discharge, Radio Frequency Interference. (1997-12-19) 1 1 1 1 1 electromigration Mass transport due to momentum exchange between conducting electrons and diffusing metal atoms. Electromigration causes progressive damage to the metal conductors in an integrated circuit. It is characteristic of metals at very high current density and temperatures of 100C or more. The term was coined by Professor Hilbert Huntington in the late 1950s because he didn't like the German use of the word electrotransport. Mass transoport occurs via the Einstein relation J=DFC/kT where F is the driving force for the transoport. For electromigraiton F is z*epj and z* is an electromigration parameter relating the momentum exchange and z is the charge of the "diffusing" species. (1999-02-25) 1 1 1 1 1 electron A sub-atomic particle with a negative quantised charge. A flow of electrical current consists of the unidirectional (on average) movement of many electrons. The more mobile electrons are in a given material, the greater it electrical conductance (or equivalently, the lower its resistance). (1995-10-06) 1 1 1 1 1 electronic commerce (EC) The conducting of business communication and transactions over networks and through computers. As most restrictively defined, electronic commerce is the buying and selling of goods and services, and the transfer of funds, through digital communications. However EC also includes all inter-company and intra-company functions (such as marketing, finance, manufacturing, selling, and negotiation) that enable commerce and use electronic mail, EDI, file transfer, fax, video conferencing, workflow, or interaction with a remote computer. Electronic commerce also includes buying and selling over the web and the Internet, electronic funds transfer, smart cards, digital cash (e.g. Mondex), and all other ways of doing business over digital networks. [Electronic Commerce Dictionary]. (1995-10-08) 1 1 1 1 1 Electronic Commerce Dictionary A lexicon of electronic commerce terms. It includes over 900 terms and acronyms, and over 200 website addresses. It has entries on commerce over the World-Wide Web, Internet payment systems, The National Information Infrastructure, Electronic Data Interchange, Electronic Funds Transfer, Public Key Cryptography, smart cards and digital cash, computer and network security for commerce, marketing through electronic media. (http://tedhaynes.com/haynes1/intro.html). (1999-03-24) 1 1 1 1 1 electronic data interchange (EDI) The exchange of standardised document forms between computer systems for business use. EDI is part of electronic commerce. EDI is most often used between different companies ("trading partners") and uses some variation of the ANSI X12 standard (USA) or EDIFACT (UN sponsored global standard). [Electronic Commerce Dictionary]. (1995-10-06) 1 1 1 1 1 Electronic Data Processing 1. <application> (EDP) data processing by computers. 2. <company> The name of Honeywell's computer business between 1960, when it gained complete ownership of Datamatic Corporation, and 1963, when it was officially renamed Honeywell Inc. (1995-03-30) 1 1 1 1 1 Electronic Design Automation (EDA) Software tools for the development of integrated circuits and systems. Companies selling EDA tools include Cadence, Intergraph, Mentor, Synopsys, Viewlogic. Zuken-Redac Dazix has been acquired by Intergraph. (1995-10-09) 1 1 1 1 1 Electronic Discrete Sequential Automatic Computer (EDSAC, often "Electronic Delay Storage Automatic Computer") Based upon the EDVAC (Electronic Discrete Variable Automatic Computer) designed in 1945, the EDSAC was completed in 1949 at the University of Cambridge Mathematical Laboratory in England. The EDSAC performed its first calculation on 1949-05-06. EDSAC was considered to be the first computer to store programs. It ceased to exist in about 1951. [What happened to it?] (2010-01-07) 1 1 1 1 1 Electronic Frontier Foundation (EFF) A group established to address social and legal issues arising from the impact on society of the increasingly pervasive use of computers as a means of communication and information distribution. EFF is a non-profit civil liberties public interest organisation working to protect freedom of expression, privacy, and access to on-line resources and information. (http://eff.org/). (1994-12-08) 1 1 1 1 1 electronic funds transfer (EFT, EFTS, - system) Transfer of money initiated through electronic terminal, automated teller machine, computer, telephone, or magnetic tape. In the late 1990s, this increasingly includes transfer initiated via the web. The term also applies to credit card and automated bill payments. Glossary (http://fms.treas.gov/eft/glossary.html). (1999-12-08) 1 1 1 1 1 Electronic Funds Transfer Point of Sale A method of electronic payment which allows money to be transferred from the account of the shopper to the merchant in close-to real-time. Generally the shopper will give the merchant a credit or debit card, which will be swiped to obtain the account information. The shopper will then be required to either sign a receipt or enter a PIN via a keypad to authorise the transaction. (2003-06-22) 1 1 1 1 1 electronic funds transfer system electronic funds transfer 1 1 1 1 1 electronic magazine (e-zine) A regular publication on some particular topic distributed in digital form, chiefly now via the web but also by electronic mail or floppy disk. E-zines are often distributed for free by enthusiasts. (1996-08-04) 1 1 1 1 1 electronic mail (e-mail) Messages automatically passed from one computer user to another, often through computer networks and/or via modems over telephone lines. A message, especially one following the common RFC 822 standard, begins with several lines of headers, followed by a blank line, and the body of the message. Most e-mail systems now support the MIME standard which allows the message body to contain "attachments" of different kinds rather than just one block of plain ASCII text. It is conventional for the body to end with a signature. Headers give the name and electronic mail address of the sender and recipient(s), the time and date when it was sent and a subject. There are many other headers which may get added by different message handling systems during delivery. The message is "composed" by the sender, usually using a special program - a "Mail User Agent" (MUA). It is then passed to some kind of "Message Transfer Agent" (MTA) - a 1 1 1 1 1 electronic mail address (Usually "e-mail address") The string used to specify the source or destination of an electronic mail message. E.g. "john@doc.acme.ac.uk". The RFC 822 standard is probably the most widely used on the Internet. X.400 was once used in Europe and Canada. UUCP-style (bang path) addresses or other kinds of source route became virtually extinct in the 1990s. In the example above, "john" is the local part which is the name of a mailbox on the destination computer. If the sender and recipient use the same computer, or the same LAN, for electronic mail then the local part is usually all that is required. If they use different computers, e.g. they work at different companies or use different Internet service providers, then the "host part", e.g. "sales.acme.com" must be appended after an "@". This usually takes the form of a fully qualified domain name or, within a large organisation, it may be just 1 1 1 1 1 electronic mail client Mail User Agent 1 1 1 1 1 electronic meeting The use of a network of personal computers to improve communication that takes place in a meeting. Electronic meetings are effective with as few as two participants and with over 100 participants. Participants can be face-to-face in a meeting room or distributed around the world. They may all be participating at the same time or different times. Getting Results from Electronic Meetings (http://emsl.co.uk/). (2014-09-20) 1 1 1 1 1 Electronic Numerical Integrator and Computer (ENIAC) The first electronic digital computer and an ancestor of most computers in use today. ENIAC was developed by Dr. John Mauchly and J. Presper Eckert during World War II at the Moore School of the University of Pennsylvania. In 1940 Dr. John Vincent Atanasoff attended a lecture by Mauchly and subsequently agreed to show him his binary calculator, the Atanasoff-Berry Computer (ABC), which was partially built between 1937-1942. Mauchly used ideas from the ABC in the design of ENIAC, which was started in June 1943 and released publicly in 1946. ENIAC was not the first digital computer, Konrad Zuse's Z3 was released in 1941. Though, like the ABC, the Z3 was electromechanical rather than electronic, it was freely programmable via paper tape whereas ENIAC was only programmable by manual rewiring or switches. Z3 used binary representation like modern computers whereas ENIAC used 1 1 1 1 1 Electronic Performance Support System (EPSS) A system that provides electronic task guidance and support to the user at the moment of need. EPSS can provide application help, reference information, guided instructions and/or tutorials, subject matter expert advice and hints on how to perform a task more efficiently. An EPSS can combine various technologies to present the desired information. The information can be in the form of text, graphical displays, sound, and video presentations. ["Electronic Performance Support Systems: How and Why to Remake the Workplace Through the Strategic Application of Technology", Gloria Gerry, Weingarten Press]. (1997-10-24) 1 1 1 1 1 Electronic Piece Of Cheese EPOC 1 1 1 1 1 Electronic Report Management (ERM, Enterprise Report Management) The capture, archiving and publishing, in digital form, of (typically mainframe generated) documents such as accounting and financial reports. ERM often replaces systems based on paper or microfilm. ERM usually captures data from print streams and stores it on hard drives, storage area networks or optical disk drives. The data is indexed and can be retreived at the desktop with a web browser or a fat client. ERM systems are part of enterprise content management or electronic document management. An example application is PearlDoc QuickFile Information Management System (http://pearldoc.com/) (IMS). An early replacement for greenbar printed reports was Computer Output on Microfilm (COM, not to be confused with Microsoft's Component Object Model). This was superseded by Computer Output to Laser Disk (or Disc - COLD) which used 1 1 1 1 1 Electronics Industry Association (EIA) A body which publishes "Recommended Standards" (RS) for physical devices and their means of interfacing. EIA-232 is their standard that defines a computer's serial port, connector pin-outs, and electrical signaling. (1995-03-02) 1 1 1 1 1 electronic whiteboarding Audiographic Teleconferencing 1 1 1 1 1 electron model A model of semiconductor behaviour in which donors contribute the charge of an electron, and acceptors contribute a space for same, in effect contributing a fictional positive charge of similiar magnitude. Physicists use the electron model. Some language theorists consider language and the electron to be models in themselves. Contrast hole model. (1995-10-06) 1 1 1 1 1 electron tube (Or tube, vacuum tube, UK: valve, electron valve, thermionic valve, firebottle, glassfet) An electronic component consisting of a space exhausted of gas to such an extent that electrons may move about freely, and two or more electrodes with external connections. Nearly all tubes are of the thermionic type where one electrode, called the cathode, is heated, and electrons are emitted from its surface with a small energy (typically a Volt or less). A second electrode, called the anode (plate) will attract the electrons when it is positive with respect to the cathode, allowing current in one direction but not the other. In types which are used for amplification of signals, additional electrodes, called grids, beam-forming electrodes, focussing electrodes and so on according to their purpose, are introduced between cathode and plate and modify the flow of electrons by electrostatic attraction or (usually) repulsion. A voltage change on a grid can control a substantially greater 1 1 1 1 1 Electrostatic Discharge (ESD) One kind of test that hardware usually has to pass to prove it is suitable for sale and use. The hardware must still work after is has been subjected to some level of electrostatic discharge. Some organisations have their own ESD requirements which hardware must meet before it will be considered for purchase. Different countries have different legal regulations about levels of ESD. See also Radio Frequency Interference, Electromagnetic Compatibility. (1997-12-19) 1 1 1 1 1 elegant (From Mathematics) Combining simplicity, power, and a certain ineffable grace of design. Higher praise than "clever", winning or even cuspy. The French aviator, adventurer, and author Antoine de Saint-Exup'ery, probably best known for his classic children's book "The Little Prince", was also an aircraft designer. He gave us perhaps the best definition of engineering elegance when he said "A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away." [Jargon File] (1994-11-29) 1 1 1 1 1 element 1. <data, programming> One of the items of data in an array. 2. <language, text> One kind of node in an SGML, HTML, or XML document tree. An SGML element is typically represented by a start tag ("<p>") and an end tag ("</p>"). In some SGML implementations, some tags are omissible, as with </p> in HTML. The start tag can contain attributes ("<p lang="en-UK" class='stuff'>"), which are an unordered set of key-value bindings for that element. Both the start tag and end tag for an element typically contain the "tag name" (also called the GI or generic identifier) for that element. In XML, an element is always represented either by an explicit start tag and end tag, or by an empty element tag ("<img src='thing.png' alt='a dodad' />"). Other kinds of SGML node are: a section of character data ("foo"), a comment ("<!-- bar -->"), a markup declaration ("<!ENTITY reg CDATA '&#174'>"), or a processing instruction 1 1 1 1 1 elephant Large, grey, four-legged mammal. 1 1 1 1 1 elephantine Used of programs or systems that are both conspicuous hogs (owing perhaps to poor design founded on brute force and ignorance) and exceedingly hairy in source form. An elephantine program may be functional and even friendly, but (as in the old joke about being in bed with an elephant) it's tough to have around all the same (and, like a pachyderm, difficult to maintain). In extreme cases, hackers have been known to make trumpeting sounds or perform expressive proboscatory mime at the mention of the offending program. Usage: semi-humorous. Compare "has the elephant nature" and the somewhat more pejorative monstrosity. See also second-system effect and baroque. [Jargon File] 1 1 1 1 1 elevator controller An archetypal dumb embedded-systems application, like toaster (which superseded it). During one period (1983--84) in the deliberations of ANSI X3J11 (the C standardisation committee) this was the canonical example of a really stupid, memory-limited computation environment. "You can't require printf(3) to be part of the default run-time library - what if you're targeting an elevator controller?" Elevator controllers became important rhetorical weapons on both sides of several holy wars. 1 1 1 1 1 ELF Binary format used by System V Release 4 Unix. 1 1 1 1 1 ELI 1. <language> An early system on the IBM 705 and IBM 650. [Listed in CACM 2(5):16 (May 1959)]. 2. Embedded Lisp Interpreter. 1 1 1 1 1 Eli Compiler Construction System A compiler generation package which integrates off-the-shelf tools and libraries with specialised language processors to generate complete compilers quickly and reliably. It simplifies the development of new special-purpose languages, implementation of existing languages on new hardware and extension of the constructs and features of existing languages. It runs on Sun-4 SunOS 4, 5, Ultrix/MIPS, RS/6000, HP-UX, SGI, Linux. Latest version 4.3.1, as of 2000-08-07 Colorado U (ftp://ftp.cs.colorado.edu/pub/cs/distribs/eli/). Europe (ftp://ftp.upb.de/unix/eli). Mailing list: <eli-request@cs.colorado.edu>. E-mail: <compiler@uni-paderborn.de>, Developers <elibugs@cs.colorado.edu>, Users <eli@cs.colorado.edu>. (2000-08-12) 1 1 1 1 1 ELISP 1. <language> A Lisp variant originally implemented for DEC-20s by Chuck Hedrick of Rutgers. 2. <language> A common abbreviation for Emacs Lisp. Use of this abbreviation is discouraged because "Elisp" is or was a trademark. [Still a trademark? Whose?] (1995-04-04) 1 1 1 1 1 elite 1. <security> A term used to describe skilled crackers or hackers, or their deeds. In the last sense, compare to elegant. The term is also used to describe exclusive forums (ftp sites, BBSs) used for trading pirated software, cracking tools, or phreaking codes. (1997-01-31) 1 1 1 1 1 ELIZA A famous program by Joseph Weizenbaum, which simulated a Rogerian psychoanalyst by rephrasing many of the patient's statements as questions and posing them to the patient. It worked by simple pattern recognition and substitution of key words into canned phrases. It was so convincing, however, that there are many anecdotes about people becoming very emotionally caught up in dealing with ELIZA. All this was due to people's tendency to attach to words meanings which the computer never put there. See also ELIZA effect. (1997-09-13) 1 1 1 1 1 ELIZA effect /e-li:'z* *-fekt'/ (From ELIZA) The tendency of humans to attach associations to terms from prior experience. For example, there is nothing magic about the symbol "+" that makes it well-suited to indicate addition; it's just that people associate it with addition. Using "+" or "plus" to mean addition in a computer language is taking advantage of the ELIZA effect. The ELIZA effect is a Good Thing when writing a programming language, but it can blind you to serious shortcomings when analysing an Artificial Intelligence system. Compare ad-hockery; see also AI-complete. [Jargon File] (1997-09-13) 1 1 1 1 1 Elk Extension Language Kit 1 1 1 1 1 ELLA A hardware design language from DRA Malvern. Implemented in ALGOL68-RS. E-mail: <ella@dra.hmg.gb>. SPARC version (ftp://src.doc.ic.ac.uk/packages/ELLA). ["ELLA 2000: A Language for Electronic System Design", J.D. Morison and A.S. Clarke, McGraw-Hill 1993]. 1 1 1 1 1 Ellemtel A C++ style-guide originated by Ellemtel Telecom Systems, Stockholm. 1 1 1 1 1 Ellie An object-oriented language with fine-grained parallelism for distributed computing. Ellie is based on BETA, Smalltalk, and others. Parallelism is supported by unbounded RPC and "future" objects. Synchronisation is by dynamic interfaces. Classes, methods, blocks, and objects are all modelled by first-class "Ellie objects". It supports genericity, polymorphism, and delegation/inheritance. (http://diku.dk/ellie/papers/)? ["Ellie Language Definition Report", Birger Andersen <birger.andersen@acm.org>, SIGPLAN Notices 25(11):45-65, Nov 1990]. (2000-04-02) 1 1 1 1 1 ELLIS EuLisp LInda System. An object-oriented Linda system written for EuLisp. "Using Object-Oriented Mechanisms to Describe Linda", P. Broadbery <pab@maths.bath.ac.uk> et al, in Linda-Like Systems and Their Implementation, G. Wilson ed, U Edinburgh TR 91-13, 1991. 1 1 1 1 1 elm A full-screen MUA for Unix, MS-DOS, MS Windows, and OS/2. Usenet newsgroup: news:comp.mail.elm. FAQ (http://cis.ohio-state.edu/hypertext/faq/usenet/elm/FAQ/faq.html). (1996-03-20) 1 1 1 1 1 ELMAGUIDE The metalanguage used for interpretation of user actions in the ELMA compiler writer developed at Tallinn Poly Institute in 1978. (1996-03-20) 1 1 1 1 1 ELMAMETA A Fortran extension, written at the Tallinn Poly Inst in 1978, used for lexical, syntactic and semantic sepecification in the ELMA compiler writer. This system was widely used in the Soviet Union, and produced an Ada to Diana compiler. (1994-12-08) 1 1 1 1 1 ELP 1. English Language Programs. Language for testing avionics equipment, on Varian 620/i. "Multiband Automatic test Equipment - A Computer Controlled Checkout System, T. Kuroda et al, Proc SJCC, 38 (1971)." 2. Equational Logic Programming. A semantically pure, fully lazy language by M.J. O'Donnell <odonnell@cs.uchicago.edu>. Latest version: 4.2. Sun and DEC versions (ftp://gargoyle.uchicago.edu/pub/equations/eq4.2.tar.Z). ["Equational Logic as a Programming Language", M.J. O'Donnell, MIT Press 1985]. 1 1 1 1 1 ELSIE A distributed version of ELLIS. ["Using Object-Oriented Mechanisms to Describe Linda", P. Broadbery <pab@maths.bath.ac.uk> et al, in "Linda-Like Systems and Their Implementati"on, G. Wilson ed, U Edinburgh TR 91-13, 1991]. (1995-11-16) 1 1 1 1 1 Elvis A vi lookalike which supports nearly all of the vi/ex commands, in both visual mode and colon mode. Like vi/ex, elvis stores most of the text in a temporary file instead of RAM. This allows it to edit files that are too large to fit in a single process' data space. Elvis runs under BSD UNIX, AT&T SysV UNIX, MINIX, MS-DOS, Atari TOS, Coherent, OS9/68000, VMS, Windows 95 and Windows NT. Elvis is just as awful to use as vi, so someone will like it. Version 1.8pl14 (1995-09-04). FTP Delft (ftp://dutepp0.et.tudelft.nl/pub/Unix/Editors/), FTP PDX (ftp://ftp.cs.pdx.edu/pub/elvis/). E-mail: Steve Kirkendall <kirkenda@cs.pdx.edu>. (1995-11-16) 1 1 1 1 1 elvish 1. The Tengwar of Feanor, a table of letterforms resembling the beautiful Celtic half-uncial hand of the "Book of Kells". Invented and described by J.R.R. Tolkien in "The Lord of The Rings" as an orthography for his fictional elvish languages, this system (which is both visually and phonetically elegant) has long fascinated hackers (who tend to be intrigued by artificial languages in general). It is traditional for graphics printers, plotters, window systems, and the like to support a Feanorian typeface as one of their demo items. By extension, the term might be used for any odd or unreadable typeface produced by a graphics device. 2. The typeface mundanely called "B"ocklin", an art-decoish display font. [Why?] [Jargon File] (1998-04-28) 1 1 1 1 1 EM End of Medium 1 1 1 1 1 EM-1 A stack-oriented intermediate language from Vrije University Amsterdam, used by the Amsterdam Compiler Kit. E-mail: Andrew Tanenbaum <ast@cs.vu.nl>. (1996-04-07) 1 1 1 1 1 EMA Extended Mercury Autocode. See Autocode. (1995-01-24) 1 1 1 1 1 Emacs /ee'maks/ (Editing MACroS, or Extensible MACro System, GNU Emacs) A popular screen editor for Unix and most other operating systems. Emacs is distributed by the Free Software Foundation and was Richard Stallman's first step in the GNU project. Emacs is extensible - it is easy to add new functions; customisable #NAME? functions; self-documenting - there is extensive on-line, context-sensitive help; and has a real-time "what you see is what you get" display. Emacs is writen in C and the higher levels are programmed in Emacs Lisp. Emacs has an entire Lisp system inside it. It was originally written in TECO under ITS at the MIT AI lab. AI Memo 554 described it as "an advanced, self-documenting, customisable, extensible real-time display editor". It includes facilities to view directories, run compilation 1 1 1 1 1 Emacs Lisp A dialect of Lisp used to implement the higher layers of the Free Software Foundation's editor, GNU Emacs. Sometimes abbreviated to "elisp". An enormous number of Emacs Lisp packages have been written including modes for editing many programming languages and interfaces to many Unix programs. 1 1 1 1 1 e-mail electronic mail 1 1 1 1 1 e-mail address electronic mail address 1 1 1 1 1 e-mail client Mail User Agent 1 1 1 1 1 EMAS Edinburgh Multi Access System 1 1 1 1 1 Embedded Lisp Interpreter (ELI) A small Common Lisp-like interpreter embedded in the Andrew mail system, written by Bob Glickstein at CMU. (2000-04-05) 1 1 1 1 1 Embedded Mode A term used by COCOMO to describe a project development that is characterised by tight, inflexible constraints and interface requirements. The product must operate within (is embedded in) a strongly coupled complex of hardware, software, regulations and operational procedures. An embedded mode project will require a great deal of innovation. An example would be a real-time system with timing constraints and customised hardware. (1996-05-29) 1 1 1 1 1 embedded system Hardware and software which forms a component of some larger system and which is expected to function without human intervention. A typical embedded system consists of a single-board microcomputer with software in ROM, which starts running some special purpose application program as soon as it is turned on and will not stop until it is turned off (if ever). An embedded system may include some kind of operating system but often it will be simple enough to be written as a single program. It will not usually have any of the normal peripherals such as a keyboard, monitor, serial connections, mass storage, etc. or any kind of user interface software unless these are required by the overall system of which it is a part. Often it must provide real-time response. Usenet newsgroup: news:comp.arch.embedded. (1995-04-12) 1 1 1 1 1 embedding 1. <mathematics> One instance of some mathematical object contained with in another instance, e.g. a group which is a subgroup. 2. <theory> (domain theory) A complete partial order F in [X -> Y] is an embedding if (1) For all x1, x2 in X, x1 <= x2 <=> F x1 <= F x2 and (2) For all y in Y, x | F x <= y is directed. ("<=" is written in LaTeX as \sqsubseteq). (1995-03-27) 1 1 1 1 1 EMBLA Pro An IMAP-compliant electronic mail client from WinSoft Products Ltd. EMBLA Pro allows you to use an IMAP mail server in a true client/server network manner, once you've connected to the IMAP server, you can organise messages into folders on the server and you can view messages and any attached files at the server before deciding whether or not to download them to your local system. IMAP allows the user to select individual message attachments to be viewed and/or downloaded. You can delete files and messages from the server, move or copy them to the local computer or leave them for future retrieval. EMBLA Pro also supports the standard POP3 protocol. Both POP3 and IMAP2 run over E-SMTP. The IMAP Unix daemons can support specific environments, for example, Sun MailTool attachments. All flavours of Unix are catered for with a suite of binary mail daemons, eg: SunSoft Solaris, HP, IBM and SCO. 1 1 1 1 1 embosser Braille printer 1 1 1 1 1 EMC Electromagnetic Compatibility 1 1 1 1 1 EMD Enterprises, Inc. A software development and consulting firm specialising in database and client-server applications. (http://emdent.com/). (1994-12-12) 1 1 1 1 1 EMDIR The CERN Electronic Mail DIRectory utility. [Details?] (1995-02-23) 1 1 1 1 1 Emerald An object-oriented distributed programming language and environment developed at the University of Washington in the early 1980s. Emeral was the successor to EPL. It is strongly typed and uses signatures and prototypes rather than inheritance. ["Distribution and Abstract Types in Emerald", A. Black et al, IEEE Trans Soft Eng SE-13(1):65-76 (Jan 1987)]. (1994-11-09) 1 1 1 1 1 EMI External Machine Interface 1 1 1 1 1 Emitter Coupled Logic (ECL) (Or "Current Mode Logic") A technology for building logic gates where the emitter of a transistor is used as the output rather than its collector. ECL has a propagation time of 0.5 - 2 ns (faster than TTL) and a power dissipation 3 - 10 times higher than TTL. (1994-11-09) 1 1 1 1 1 EML Extended ML. A language for formally specifying SML programs. ["Formal Program Development in Extended ML for the Working Programmer", D. Sannella, Proc 3rd BCS/FACS Workshop on Refinement", Springer 1990]. 1 1 1 1 1 EMM Expanded Memory Manager. (1996-01-12) 1 1 1 1 1 EMM386 An expanded memory manager for IBM PCs with an Intel 80386 or higher processor, part of MS-DOS version 5.00 or higher. EMM386 uses extended memory to simulate expanded memory and also provides upper memory blocks. It must be loaded by a DEVICE= command in your CONFIG.SYS file. (1996-01-13) 1 1 1 1 1 emote (emotion) A command used on talk systems and MUDs to indicate the performance of an action, usually a facial expression of emotional state. (1996-11-28) 1 1 1 1 1 emoticon /ee-moh'ti-kon/ (Or "smiley") An ASCII glyph used to indicate an emotional state in text-only electronic messaging systems such as chat, electronic mail, SMS or news. Although originally intended mostly as jokes, emoticons are widely recognised if not expected; the lack of verbal and visual cues can otherwise cause non-serious comments to be misinterpreted, resulting in offence, arguments and flame wars. Hundreds of emoticons have been proposed, but only a few are in common use. These include: :-) smiley face (for humour, laughter, friendliness, occasionally sarcasm) :-( frowney face (for sadness, anger, or upset) ;-) 1 1 1 1 1 empeg An in-car audio product that plays MP3 files from a hard disk. It is based around a DEC/Intel StrongARM S-1100 processor and runs a version of Linux. The user interface is written in Python. (http://empeg.com/). See also MPEG. (1999-09-14) 1 1 1 1 1 empire Any of a family of military simulations derived from a game written by Peter Langston many years ago. Five or six multi-player variants of varying degrees of sophistication exist, and one single-player version implemented for both Unix and VMS; the latter is even available as MS-DOS freeware. All are notoriously addictive. [Jargon File] (1995-08-06) 1 1 1 1 1 empty element tag tag 1 1 1 1 1 Empty Nest (()) 1 1 1 1 1 EMS Expanded Memory Specification 1 1 1 1 1 emTeX (Eberhard Mattes TeX) Eberhard Mattes <mattes@azu.informatik.uni-stuttgart.de>'s version of the LaTeX document preparation system designed for DOS and OS/2. (2001-05-24) 1 1 1 1 1 EMU8000 The "Advanced WavEffect" music synthesizer integrated circuit used on the SB AWE32 card. The EMU8000 is a sub-system offering high quality music synthesis and an "effect engine" which provides musical effects like reverb and chorus to MIDI playback. The EMU8000 supports up to 32 voices, and the effect amount for each voice can be controlled via MIDI. (1996-12-15) 1 1 1 1 1 emulation When one system performs in exactly the same way as another, though perhaps not at the same speed. A typical example would be emulation of one computer by (a program running on) another. You might use an emulation as a replacement for a system whereas you would use a simulation if you just wanted to analyse it and make predictions about it. (2003-05-22) 1 1 1 1 1 emulator Hardware or software that performs emulation. (1995-05-12) 1 1 1 1 1 Emulator program (EP) IBM software that emulates a 2701/2/3 hard-wired IBM 360 communications controller and resides in a 370x/372x/374x comms controller. See also Partitioned Emulation Program (PEP). (1999-01-29) 1 1 1 1 1 EMX A programming environment for OS/2 by Eberhard Mattes <mattes@azu.informatik.uni-stuttgart.de>. EMX supports programming in C, C++ and Objective C. It works with gcc, g++, gdb, libg++, .obj linkage, DLL and headers. Version 0.8g. Europe (ftp://ftp.uni-stuttgart.de/soft/os2/emx-0.8g). US (ftp://ftp-os2.cdrom.com/os2/2_x/Unix/gnu/emx0.8g). Mailing list: <listserv@ludd.luth.se> ("subscribe to emx-list"). (1992-09-21) 1 1 1 1 1 enabling software enabling 1 1 1 1 1 Encapsulated PostScript (EPS) An extension of the PostScript graphics file format developed by Adobe Systems. EPS is used for PostScript graphics files that are to be incorporated into other documents. An EPS file includes pragmas (special PostScript comments) giving information such as the bounding box, page number and fonts used. On some computers, EPS files include a low resolution version of the PostScript image. On the Macintosh this is in PICT format, while on the IBM PC it is in TIFF or Microsoft Windows metafile format. [Spec?] (1995-01-04) 1 1 1 1 1 encapsulation 1. The technique used by layered protocols in which a layer adds header information to the protocol data unit (PDU) from the layer above. As an example, in Internet terminology, a packet would contain a header from the physical layer, followed by a header from the network layer (IP), followed by a header from the transport layer (TCP), followed by the application protocol data. 2. The ability to provide users with a well-defined interface to a set of functions in a way which hides their internal workings. In object-oriented programming, the technique of keeping together data structures and the methods (procedures) which act on them. (1998-09-07) 1 1 1 1 1 encode 1. <algorithm, hardware> To convert data or some physical quantity into a given format. E.g. uuencode. See also encoder. 2. <cryptography> To encrypt, to perform encryption. (1999-07-06) 1 1 1 1 1 encoder 1. <algorithm, hardware> Any program, circuit or algorithm which encodes. Example usages: "MPEG encoder", "NTSC encoder", RealAudio encoder. 2. <hardware> A sensor or transducer for converting rotary motion or position to a series of electronic pulses. (1997-03-04) 1 1 1 1 1 encryption Any procedure used in cryptography to convert plaintext into ciphertext (encrypted message) in order to prevent any but the intended recipient from reading that data. Schematically, there are two classes of encryption primitives: public-key cryptography and private-key cryptography; they are generally used complementarily. Public-key encryption algorithms include RSA; private-key algorithms include the obsolescent Data Encryption Standard, the Advanced Encryption Standard, as well as RC4. The Unix command crypt performs a weak form of encryption. Stronger encryption programs include Pretty Good Privacy and the GNU Privacy Guard. Other closely related aspects of cryptograph include message digests. (2003-04-12) 1 1 1 1 1 endian Suffix used in the terms big-endian and little-endian that describe the ordering of bytes in a multi-byte number. The term comes from Swift's "Gulliver's Travels" via the famous paper "On Holy Wars and a Plea for Peace" by Danny Cohen, USC/ISI IEN 137, 1980-04-01. The Lilliputians, being very small, had correspondingly small political problems. The Big-Endian and Little-Endian parties debated over whether soft-boiled eggs should be opened at the big end or the little end. See also middle-endian, holy wars, NUXI problem, swab. (2007-08-14) 1 1 1 1 1 endless loop infinite loop 1 1 1 1 1 End Of Line (EOL) Synonym for newline, derived perhaps from the original CDC 6600 Pascal. The abbreviation "EOL" is now rare, but widely recognised and occasionally used for brevity. Used in the example entry under BNF. Out of context this would probably be (deliberately) ambiguous because different systems used different (combinations of) characters to mark the end of a line. Unix uses a line feed; DOS uses carriage return, line feed (CRLF) and the Macintosh uses carriage return. See also EOF. (2002-03-22) 1 1 1 1 1 End of Medium (EM) ASCII character 25. (1996-06-28) 1 1 1 1 1 End Of Text control-C 1 1 1 1 1 End Of Transmission (EOT) The mnemonic for ASCII character 4. 1 1 1 1 1 end tag tag 1 1 1 1 1 end-to-end solution (E2ES) A term that suggests that the supplier of an application program or system will provide all the hardware and/or software components and resouces to meet the customer's requirement and no other supplier need be involved. Compare: turn-key solution. (2006-03-30) 1 1 1 1 1 End Transmission Block (ETB) The mnemonic for ASCII character 23. (1996-06-28) 1 1 1 1 1 end-user The person who uses a computer application, as opposed to those who developed or support it. The end-user may or may not know anything about computers, how they work, or what to do if something goes wrong. End-users do not usually have administrative responsibilities or privileges. End users are certain to have a different set of assumptions than the developers who created the application. (1997-03-29) 1 1 1 1 1 engage Do you mean Nokia N-Gage? (2005-01-18) 1 1 1 1 1 Engelbart, Douglas Douglas Engelbart 1 1 1 1 1 engine 1. A piece of hardware that encapsulates some function but can't be used without some kind of front end. Today we have, especially, "print engine": the guts of a laser printer. 2. An analogous piece of software; notionally, one that does a lot of noisy crunching, such as a "database engine", or search engine. The hackish senses of "engine" are actually close to its original, pre-Industrial-Revolution sense of a skill, clever device, or instrument (the word is cognate to "ingenuity"). This sense had not been completely eclipsed by the modern connotation of power-transducing machinery in Charles Babbage's time, which explains why he named the stored-program computer that he designed in 1844 the Analytical Engine. [Jargon File] (1996-05-31) 1 1 1 1 1 English The official name of the database language used by the Pick operating system, actually a sort of crufty, brain-damaged SQL with delusions of grandeur. The name permits marketroids to say "Yes, and you can program our computers in English!" to ignorant suits without quite running afoul of the truth-in-advertising laws. ["Exploring the Pick Operating System", J.E. Sisk et al, Hayden 1986]. [Jargon File] (2014-06-27) 1 1 1 1 1 English shellcode A kind of malware that is embedded in ordinary English sentences. English shellcode attempts to avoid detection by antivirus software by making the code resemble, e.g. e-mail text or Wikipedia entries. It was first revealed by researchers at Johns Hopkins. (2010-03-02) 1 1 1 1 1 Enhanced Capabilities Port (ECP) The most common parallel printer interface on current (1997) IBM PC compatibles. Enhanced Capabilities Port is defined in standard IEEE 1284. It is bi-directional and faster than earlier parallel ports. Not to be confused with Extended Capabilities Port. (1997-12-01) 1 1 1 1 1 Enhanced Directory Service (EDS) A common, distributed, integrated, directory service with centralized and/or replicated administration. [Reference?] (2003-06-18) 1 1 1 1 1 Enhanced Dynamic Random Access Memory (EDRAM) (http://ruralnet.net/~prairie). [Summary?] (1995-11-23) 1 1 1 1 1 Enhanced Graphics Adapter (EGA) An IBM PC display standard with a resolution of 640 x 350 pixels of 16 colours. (1995-06-28) 1 1 1 1 1 Enhanced IDE Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 Enhanced Integrated Drive Electronics Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 enhanced parallel port (EPP) A parallel port that confirms to the IEEE's EPP standard. An EPP is actually an expansion bus that can handle 64 disk drives and other peripherals. ["PC Magazine", 1996-01-09, p. 262]. [Details? Manufacturers?] (1996-04-07) 1 1 1 1 1 Enhanced Small Disk Interface (ESDI) An obsolete hard disk controller standard, first introduced by Maxtor in 1983, and intended to be the successor to the original ST-506/ST-412. ESDI was faster and more reliable, but still could not compete with IDE and SCSI. EDSI used two cables: a 20-pin data cable to each drive and a single 34-pin control cable daisy chain with the controller at one end and a terminator at the other. In PCs, it supported up to two drives at 1-2MB/s with drives up to 2GB. PC Guide (http://pcguide.com/ref/hdd/if/obsoESDI-c.html). (2003-08-01) 1 1 1 1 1 enhancement 1. A change to a product which is intended to make it better in some way, e.g. new functions, faster, or occasionally more compatible with other systems. Enhancements to hardware components, especially integrated circuits often mean they are smaller and less demanding of resources. Sadly, this is almost never true of software enhancements. 2. Marketroid-speak for a bug fix. This abuse of language is a popular and time-tested way to turn incompetence into increased revenue. A hacker being ironic would instead call the fix a feature, or perhaps save some effort by declaring That's not a bug, that's a feature!. [Jargon File] (1998-04-04) 1 1 1 1 1 ENIAC Electronic Numerical Integrator and Computer 1 1 1 1 1 Enigma The electro-mechanical cipher engine used by the Germans in World War II to encrypt and decrypt field orders. Many of their messages were deciphered at Bletchley Park, by Alan Turing and others. See also: Tunny Emulator. (2012-03-25) 1 1 1 1 1 ENOB effective number of bits 1 1 1 1 1 ENQ 1. <character> /enkw/ or /enk/ ENQuire. The mnemonic for ASCII character 5. 2. <chat> An on-line convention for querying someone's availability. After opening a chat connection to someone apparently in heavy hack mode, one might type "SYN SYN ENQ?" (the SYNs representing notional synchronisation bytes), and expect a return of ACK or NAK depending on whether or not the person felt interruptible. Compare ping, finger. [Jargon File] (1998-01-18) 1 1 1 1 1 enqueue queue 1 1 1 1 1 ENS See Ecole Normale Superieure 1 1 1 1 1 Ente Nazionale Italiano di Unificazione (UNI) The Italian national standards body, a member of ISO. 1 1 1 1 1 enterprise A business, generally a large one. (1994-11-22) 1 1 1 1 1 Enterprise Application Integration (EAI) The use of middleware to integrate the application programs, databases, and legacy systems involved in an organisation's critical business processes. [Example?] (1999-09-28) 1 1 1 1 1 Enterprise JavaBeans (EJB) A server-side component architecture for writing reusable business logic and portable enterprise applications. EJB is the basis of Sun's Java 2 Platform, Enterprise Edition (J2EE). Enterprise JavaBean components are written entirely in Java and run on any EJB compliant server. They are operating system, platform, and middleware independent, preventing vendor lock-in. EJB servers provide system-level services (the "plumbing") such as transactions, security, threading, and persistence. The EJB architecture is inherently transactional, distributed, multi-tier, scalable, secure, and wire protocol neutral - any protocol can be used: IIOP, JRMP, HTTP, DCOM etc. EJB 1.1 requires RMI for communication with components. EJB 2.0 is expected to require support for RMI/IIOP. 1 1 1 1 1 Enterprise Report Management Electronic Report Management 1 1 1 1 1 Enterprise Resource Planning (ERP) Any software system designed to support and automate the business processes of medium and large businesses. This may include manufacturing, distribution, personnel, project management, payroll, and financials. ERP systems are accounting-oriented information systems for identifying and planning the enterprise-wide resources needed to take, make, distribute, and account for customer orders. ERP systems were originally extensions of MRP II systems, but have since widened their scope. An ERP system also differs from the typical MRP II system in technical requirements such as relational database, use of object oriented programming language, computer aided software engineering tools in development, client/server architecture, and open system portability. JBOPS are the major producers of ERP software. "ERP Systems - Using IT to gain a competitive advantage", 1 1 1 1 1 Enterprise Systems CONnectivity (ESCON) Optical fibre connections between a mainframe and its peripherals. Also an IBM registered trademark. (1997-03-31) 1 1 1 1 1 EntireX The German company Software AG's implementation of DCOM under Unix and on IBM mainframes, released at the end of 1997. EntireX enables users to exchange their DCOM components between Windows 95, Windows NT, Unix and OS/390 and to build application programs with components running on any of those platforms. Home (http://softwareag.com/corporat/solutions/entirex/entirex.htm). (1999-02-05) 1 1 1 1 1 entity In an entity-relationship model, an entity is a type of thing being modeled such as "person" or "product". Different entities have different sets of attributes such as name or "price" and are connected via relationships like bought. Entities are closely related to classes (class). (2009-11-22) 1 1 1 1 1 entity-relationship diagram entity-relationship model 1 1 1 1 1 entity-relationship model An approach to data modelling proposed by P. Chen in 1976. The model says that you divide your database in two logical parts, entities (e.g. "customer", product) and relations ("buys", "pays for"). One of the first activities in specifying an application is defining the entities involved and their relationships, e.g. using an entity-relationship diagram to represent a model. ["The entity-relationship model: toward a unified view of data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp 9-36, 1976]. (2009-11-21) 1 1 1 1 1 entropy A measure of the disorder of a system. Systems tend to go from a state of order (low entropy) to a state of maximum disorder (high entropy). The entropy of a system is related to the amount of information it contains. A highly ordered system can be described using fewer bits of information than a disordered one. For example, a string containing one million "0"s can be described using run-length encoding as [("0", 1000000)] whereas a string of random symbols (e.g. bits, or characters) will be much harder, if not impossible, to compress in this way. Shannon's formula gives the entropy H(M) of a message M in bits: H(M) = -log2 p(M) Where p(M) is the probability of message M. (1998-11-23) 1 1 1 1 1 Entry Sequenced Data Set (ESDS) An IBM straight sequential flat file (like QSAM) but externally managed via IDCAMS. ESDS is used in VSAM. (1999-01-11) 1 1 1 1 1 enumerated type (Or "enumeration") A type which includes in its definition an exhaustive list of possible values for variables of that type. Common examples include Boolean, which takes values from the list [true, false], and day-of-week which takes values [Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday]. Enumerated types are a feature of strongly typed languages, including C and Ada. Characters, (fixed-size) integers and even floating-point types could be (but are not usually) considered to be (large) enumerated types. (1996-11-28) 1 1 1 1 1 enumeration 1. <mathematics> A bijection with the natural numbers; a counted set. Compare well-ordered. 2. <programming> enumerated type. (1996-11-28) 1 1 1 1 1 environment environment variable 1 1 1 1 1 Environmental Audio eXtensions (EAX) Something from Creative Labs for generating sound effects. EAX is a competitor to Aureal's A3D. [Hardware or software?] (2008-02-17) 1 1 1 1 1 environment variable A variable that is bound in the current environment. When evaluating an expression in some environment, the evaluation of a variable consists of looking up its name in the environment and substituting its value. Most programming languages have some concept of an environment but in Unix shell scripts it has a specific meaning slightly different from other contexts. In shell scripts, environment variables are one kind of shell variable. They differ from local variables and command line arguments in that they are inheritted by a child process. Examples are the PATH variable that tells the shell the file system paths to search to find command executables and the TZ variable which contains the local time zone. The variable called "SHELL" specifies the type of shell being used. These variables are used by commands or shell scripts to discover things about the environment they are operating in. 1 1 1 1 1 Envoy Motorola's integrated personal wireless communicator. Envoy is a personal digital assistant which incorporates two-way wireless and wireline communication. It was announced on 7 March 1994 and released in the third quarter of 1994. It runs Genral Magic's Magic Cap operating system and Telescript(TM) communications language on Motorola's Dragon chip set. This includes the highly integrated Motorola 68349 processor and a special purpose application specific integrated circuit (ASIC) referred to as Astro. This chip set was designed specifically for Magic Cap and Telescript. A user can write on the Envoy communicator with the accompanying stylus or a finger, to type and select or move objects on its screen. An on-screen keyboard can be used to input information, draw or write personal notations, or send handwritten messages and faxes. Envoy can send a wireless message to another Envoy, PC or 1 1 1 1 1 EOF End Of File 1. The out-of-band value returned by C's sequential character-input functions (and their equivalents in other environments) when end of file has been reached. This value is -1 under C libraries postdating V6 Unix, but was originally 0. 2. The keyboard character (usually control-D, the ASCII EOT (End Of Transmission) character) that is mapped by the Unix terminal driver into an end-of-file condition. [Jargon File] (1995-01-18) 1 1 1 1 1 EOL 1. End Of Line. 2. Expression Oriented Language. A low-level language for strings. Versions: EOL-1, EOL-2, EOL-3. ["EOL - A Symbol Manipulation Language", L. Lukaszewicz, Computer J 10(1):53 (May 1967)]. [Jargon File] 1 1 1 1 1 EOR exclusive or 1 1 1 1 1 EOT 1. <character> End Of Transmission 2. <storage> End Of Tape. A marker used on magnetic tapes. (1996-06-24) 1 1 1 1 1 EOU The mnemonic of a mythical ASCII control character (End Of User) that would make an ASR-33 Teletype explode on receipt. This construction parodies the numerous obscure delimiter and control characters left in ASCII from the days when it was associated more with wire-service teletypes than computers (e.g. FS, GS, RS, US, EM, SUB, ETX, and especially EOT). It is worth remembering that ASR-33s were big, noisy mechanical beasts with a lot of clattering parts; the notion that one might explode was nowhere near as ridiculous as it might seem to someone sitting in front of a tube or flatscreen today. [Jargon File] (1996-06-29) 1 1 1 1 1 EOUG European ORACLE Users Group. 1 1 1 1 1 EP Emulator program 1 1 1 1 1 EPCS Experimental Physics Control Systems 1 1 1 1 1 ephemeral port A TCP or UDP port number that is automatically allocated from a predefined range by the TCP/IP stack software, typically to provide the port for the client end of a client-server communication. BSD used ports 1024 through 4999 as ephemeral ports, though it is often desirable to increase this allocation. (http://ncftpd.com/ncftpd/doc/misc/ephemeral_ports.html). (2002-10-06) 1 1 1 1 1 EPILOG 1. Extended Programming In LOGic. PROLOG with several AND's having different time constraints. ["Epilog: A Language for Extended Programming in Logic", A. Porto in Implementations of Prolog, J.A. Campbell ed, Ellis Horwood 1984]. 2. A data-driven PROLOG, with both AND parallelism and OR parallelism. ["EPILOG = PROLOG + Data Flow", M.J. Wise, SIGPLAN Noices 17:80-86 (1982)]. 1 1 1 1 1 EPIM Enterprise Product Information Management 1 1 1 1 1 EPL 1. Early PL/I. 2. Experimental Programming Language. 3. Eden Programming Language. 4. Equational Programming Language 5. Ethernet Private Line 1 1 1 1 1 EPOC A family of graphical operating systems developed by Psion for portable devices, primarily PDAs. The name EPOC came from epoch, the beginning of an era, but was backfitted by the engineers to "Electronic Piece Of Cheese". The first version, later known as EPOC16, was developed in the late 1980s and early 1990s for Psion's "SIBO" (SIxteen Bit Organisers) devices. All EPOC16 devices feature an 8086-family processor and a 16-bit architecture. EPOC16 is a single-user pre-emptive multitasking operating system, written in Intel 8086 assembler language and C and designed to be delivered in ROM. It supported a simple programming language called OPL and an IDE called OVAL. EPOC16 was followed by EPOC32 in 1997. (2009-05-26) 1 1 1 1 1 epoch 1. <operating system> (Probably from astronomical timekeeping) A term used originally in Unix documentation for the time and date corresponding to zero in an operating system's clock and timestamp values. Under most Unix versions the epoch is 1970-01-01 00:00:00 GMT; under VMS, it's 1858-11-17 00:00:00 (the base date of the US Naval Observatory's ephemerides); on a Macintosh, it's 1/1/04 0:00 System time is measured in seconds or ticks past the epoch. Weird problems may ensue when the clock wraps around (see wrap around), which is not necessarily a rare event; on systems counting 10 ticks per second, a signed 32-bit count of ticks is good only for 0.1 * 2**31-1 seconds, or 6.8 years. The one-tick-per-second clock of Unix is good only until 2038-01-18, assuming at least some software continues to consider it signed and that word lengths don't increase by then. See also wall time. 1 1 1 1 1 EPP Enhanced Parallel Port 1 1 1 1 1 EPROM Erasable Programmable Read-Only Memory 1 1 1 1 1 EPROM OTP Erasable Programmable Read-Only Memory One Time Programmable 1 1 1 1 1 EPROS A specification/prototyping language. Implemented in Franz Lisp. (ftp://utsun.s.u-tokyo.jp/lang/epros). ["Software Prototyping, Formal Methods and VDM", Sharam Hekmatpour et al, A-W 1988]. 1 1 1 1 1 EPS Encapsulated PostScript 1 1 1 1 1 EPSILON A macro language with high level features including strings and lists, developed by A.P. Ershov at Novosibirsk in 1967. EPSILON was used to implement ALGOL 68 on the M-220. ["Application of the Machine-Oriented Language Epsilon to Software Development", I.V. Pottosin et al, in Machine Oriented Higher Level Languages, W. van der Poel, N-H 1974, pp. 417-434]. [Jargon File] (1995-05-10) 1 1 1 1 1 epsilon 1. <character> The fifth letter of the Greek alphabet. 2. <mathematics> (From the Hungarian mathematician Paul Erdos) A very small, insignificant, or negligible quantity of something. The use of epsilon is from the epsilon-delta method of proof in differential calculus. (2001-07-06) 1 1 1 1 1 epsilon squared A quantity even smaller than epsilon, as small in comparison to epsilon as epsilon is to something normal; completely negligible. If you buy a supercomputer for a million dollars, the cost of the thousand-dollar terminal to go with it is epsilon, and the cost of the ten-dollar cable to connect them is epsilon squared. Compare lost in the underflow, lost in the noise. (1997-09-05) 1 1 1 1 1 EPSIMONE Concurrent simulation language derived from Simone. "EPSIMONE Manual", J. Beziin et al, Pub Int No 90, IRISA, Sept 1978. 1 1 1 1 1 EPSS Electronic Performance Support System 1 1 1 1 1 EqL An equational language. Bharat Jayaraman <bharat@cs.buffalo.edu>. "EqL: The Language and its Implementation", B. Jayaraman et al, IEEE Trans Soft Eng SE-15(6):771-780 (June 1989). 1 1 1 1 1 EQLOG Equality, types and generic modules for logic programming. A language using Horn clauses. J.A. Goguen, J. Meseguer. 1 1 1 1 1 EQLog OBJ2 plus logic programming based on Horn logic with equality. "EQLog: Equality, Types and Generic Modules for Logic Programming, J. Goguen et al in Functional and Logic" Programming, D. DeGroot et al eds, pp.295-363, P-H 1986. 1 1 1 1 1 Eqn Language for typesetting mathematics. A System for Typesetting Mathematics, B.W. Kernighan and L.L. Cherry, CACM 18(3):151-157 (Mar 1975). 1 1 1 1 1 equals "=", ASCII character 61. Common names: ITU-T: equals; gets; takes. Rare: quadrathorpe; INTERCAL: half-mesh. Equals is used in many languages as the assignment operator though earlier languages used ":=" ("becomes equal to") to avoid upsetting mathematicians with statements such as "x = x+1". It is also used in compounds such as "<=", ">=", "==", /=, "!=" for various comparison operators and in C's "+=", *= etc. which mimic the primitive operations of two-address code. (1995-03-29) 1 1 1 1 1 equational logic First-order equational logic consists of quantifier-free terms of ordinary first-order logic, with equality as the only predicate symbol. The model theory of this logic was developed into Universal algebra by Birkhoff et al. [Birkhoff, Gratzer, Cohn]. It was later made into a branch of category theory by Lawvere ("algebraic theories"). (1995-02-21) 1 1 1 1 1 Equational Programming Language (EPL) An equational language for parallel scientific applications, developed by RPI. Szymanski. ["EPL - Parallel Programming with Recurrent Equations", B. Szymanski in Parallel Functional Languages and Compilers, B. Szymanski et al, A-W 1991]. (2010-09-21) 1 1 1 1 1 Equel Embedded Quel. INGRES, Inc. Combines QUEL theories with C code. 1 1 1 1 1 equivalence class An equivalence class is a subset whose elements are related to each other by an equivalence relation. The equivalence classes of a set under some relation form a partition of that set (i.e. any two are either equal or disjoint and every element of the set is in some class). (1996-05-13) 1 1 1 1 1 equivalence class partitioning A software testing technique that involves identifying a small set of representative input values that invoke as many different input conditions as possible. For example, for binary search the following partitions exist: inputs that do or do not conform to pre-conditions, Inputs where the key element is or is not a member of the array. One can combine these into finer partitions. One can also pick specific conditions of the array, e.g. a single value, even or odd number of elements. One should look at boundary conditions, e.g. inputs where the key element is the first or last element in the array. (2004-01-18) 1 1 1 1 1 equivalence partitioning equivalence class partitioning 1 1 1 1 1 equivalence relation A relation R on a set including elements a, b, c, which is reflexive (a R a), symmetric (a R b => b R a) and transitive (a R b R c => a R c). An equivalence relation defines an equivalence class. See also partial equivalence relation. (1996-05-13) 1 1 1 1 1 equivalent isotropically radiated power (EIRP) The power radiated by a radio antenna calculated as the power output of the intentional radiator multiplied by the gain of the antenna (due to its shape). Limits are defined by the FCC and other national regulators. (2008-02-11) 1 1 1 1 1 ER Entity-Relationship 1 1 1 1 1 er The country code for Eritrea. (1999-01-27) 1 1 1 1 1 ERA Entity-Relationship-Attribute 1 1 1 1 1 era Synonym epoch. Webster's Unabridged makes these words almost synonymous, but "era" usually connotes a span of time rather than a point in time. 1 1 1 1 1 Erasable Programmable Read-Only Memory (EPROM) A type of storage device in which the data is determined by electrical charge stored in an isolated ("floating") MOS transistor gate. The isolation is good enough to retain the charge almost indefinitely (more than ten years) without an external power supply. The EPROM is programmed by "injecting" charge into the floating gate, using a technique based on the tunnel effect. This requires higher voltage than in normal operation (usually 12V - 25V). The floating gate can be discharged by applying ultraviolet light to the chip's surface through a quartz window in the package, erasing the memory contents and allowing the chip to be reprogrammed. (1995-04-22) 1 1 1 1 1 erase delete 1 1 1 1 1 eraser stains code Code that has been refactored many times, leaving swaths of legacy code and design; like paper that has been written on and erased so many times that the pencil marks are no longer the problem - the large greasy stain is. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-07-22) 1 1 1 1 1 ERC An extended entity-relationship model. [Details? What does it stand for?] (1997-12-23) 1 1 1 1 1 ERCIM European Research Consortium on Informatics and Mathematics. An association of European research organisations promoting cooperative research on key issues in Information Technology. (2000-12-30) 1 1 1 1 1 ERD entity-relationship diagram 1 1 1 1 1 EREW PRAM exclusive read, exclusive write PRAM. 1 1 1 1 1 ERFPI An early system on the LGP-30 computer. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-08) 1 1 1 1 1 ergonomic Concerning ergonomics or exhibitting good ergonimics. (1995-04-14) 1 1 1 1 1 ergonomics The study of the design and arrangement of equipment so that people will interact with the equipment in healthy, comfortable, and efficient manner. As related to computer equipment, ergonomics is concerned with such factors as the physical design of the keyboard, screens, and related hardware, and the manner in which people interact with these hardware devices. (1995-04-14) 1 1 1 1 1 ERGO-Shell An ergonomic X Window System Unix shell for software engineers by Regine Freitag <freitag@gmd.de>. ERGO-Shell is now obsolete. Version: 2.1. (ftp://ftp.gmd.de/gmd/ergo/). E-mail: Dr. Wolfgang Dzida, GMD <dzida@gmd.de> or the author. (2000-12-19) 1 1 1 1 1 Eric Conspiracy A shadowy group of moustachioed hackers named Eric first pinpointed as a sinister conspiracy by an infamous talk.bizarre posting ca. 1986. This was doubtless influenced by the numerous "Eric" jokes in the Monty Python oeuvre. There do indeed seem to be considerably more moustachioed Erics in hackerdom than the frequency of these three traits can account for unless they are correlated in some arcane way. Well-known examples include Eric Allman (of the "Allman style" described under indent style), Erik Fair (co-author of NNTP), Eric S. Raymond and about fifteen others. The organisation line "Eric Conspiracy Secret Laboratories" now emanates regularly from more than one site. [Jargon File] (1998-10-20) 1 1 1 1 1 Eric S. Raymond One of the authors of the Hacker's Jargon File. Eric was involved in the JOLT project and GNU Emacs as well as maintaining several FAQ lists. He is a keen advocate of open source. (http://ccil.org/~esr). E-mail: <esr@snark.thyrsus.com> (1998-10-20) 1 1 1 1 1 Eris /e'ris/ The Greek goddess of Chaos, Discord, Confusion, and Things You Know Not Of; her name was latinised to Discordia and she was worshiped by that name in Rome. Not a very friendly deity in the Classical original, she was reinvented as a more benign personification of creative anarchy starting in 1959 by the adherents of Discordianism and has since been a semi-serious subject of veneration in several "fringe" cultures, including hackerdom. See Church of the SubGenius. [Jargon File] (1994-12-08) 1 1 1 1 1 Erlang 1. <person> Agner Krarup Erlang. (The other senses were named after him). 2. <language> A concurrent functional language for large industrial real-time systems by Armstrong, Williams and Virding of Ellemtel, Sweden. Erlang is untyped. It has pattern matching syntax, recursion equations, explicit concurrency, asynchronous message passing and is relatively free from side-effects. It supports transparent cross-platform distribution. It has primitives for detecting run-time errors, real-time garbage collection, modules, dynamic code replacement (change code in a continuously running real-time system) and a foreign language interface. An unsupported free version is available (subject to a non-commercial licence). Commercial versions with support are available from Erlang Systems AB. An interpreter in SICStus Prolog and compilers in C and Erlang are available 1 1 1 1 1 ERM Electronic Report Management 1 1 1 1 1 erotica pornography 1 1 1 1 1 ERP Enterprise Resource Planning 1 1 1 1 1 error 1. A discrepancy between a computed, observed, or measured value or condition and the true, specified, or theoretically correct value or condition. 2. <programming> A mental mistake made by a programmer that may result in a program fault. 3. (verb) What a program does when it stops as result of a programming error. (2000-03-28) 1 1 1 1 1 error-based testing Testing where information about programming style, error-prone language constructs, and other programming knowledge is applied to select test data capable of detecting faults, either a specified class of faults or all possible faults. (1996-05-13) 1 1 1 1 1 error correcting memory (ECM) RAM using some kind of error detection and correction (EDAC) scheme. The two types of memory errors in RAM (especially DRAM) are "soft" errors due to radiation-induced bit switching, and "hard" errors due to the unexpected deterioration of a memory chip. Soft errors do not indicate lasting damage to the memory board, but they do corrupt programs or data. Hard errors demand physical repairs. Single bit memory failures are the most common. A hard single bit failure, such as that caused by a completely dead chip can be corrected by EDAC if each chip supplies only one bit of each word. EDAC memory is the most common level of protection for minicomputers and mainframes whereas the cheaper parity protection is more common in microcomputers. [Clearpoint, "The Designer's Guide to Add-In Memory", Third Addition]. (1995-10-10) 1 1 1 1 1 error detection and correction (EDAC, or "error checking and correction", ECC) A collection of methods to detect errors in transmitted or stored data and to correct them. This is done in many ways, all of them involving some form of coding. The simplest form of error detection is a single added parity bit or a cyclic redundancy check. Multiple parity bits can not only detect that an error has occurred, but also which bits have been inverted, and should therefore be re-inverted to restore the original data. The more extra bits are added, the greater the chance that multiple errors will be detectable and correctable. Several codes can perform Single Error Correction, Double Error Detection (SECDEC). One of the most commonly used is the Hamming code. At the other technological extreme, cuniform texts from about 1500 B.C. which recorded the dates when Venus was visible, were examined on the basis of contained redundancies (the 1 1 1 1 1 es 1. <networking> The country code for Spain. 2. <operating system> Extensible Shell. 3. (Expert System) An expert system for the IBM PC featuring forward chaining, backward chaining and fuzzy set relations. (ftp://ftp.uu.net/pub/ai/expert-sys/summers.tar.Z). [BYTE Oct 1990]. (1999-02-01) 1 1 1 1 1 ES-1 An early text editing interpreter. [Sammet 1969, p. 684]. (1999-02-01) 1 1 1 1 1 ESA 1. <architecture> Enterprise Systems Architecture. 2. <body> European Space Agency. (1999-10-31) 1 1 1 1 1 ESC escape 1 1 1 1 1 ESCAPE An early system on the IBM 650. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-05) 1 1 1 1 1 escape (ESC) ASCII character 27. When sent by the user, escape is often used to abort execution or data entry. When sent by the computer it often starts an escape sequence. (1997-11-27) 1 1 1 1 1 escape sequence (Or "escape code") A series of characters starting with the escape character (ASCII 27). Escape sequences are often used to control display devices such as VDUs. An escape sequence might change the colour of subsequent text, reassign keys on the keyboard, change printer settings or reposition the cursor. The escape sequences of the DEC vt100 video terminal have become a de facto standard for this purpose. The term is also used for any sequence of characters that temporarily suspends normal processing of a stream of characters to perform some special function. For example, the Hayes modem uses the sequence "+++" to escape to command mode in which characters are interpreted as commands to the modem itself rather than as data to pass through. [Was the character named after this use or vice versa?] (1997-11-27) 1 1 1 1 1 ESCD Extended System Configuration Data 1 1 1 1 1 ESCON Enterprise Systems CONnectivity 1 1 1 1 1 escrow An arrangement where something (generally money or documents) is held in trust ("in escrow") by a trusted third party until certain agreed conditions are met. In computing the term is used for key escrow and also for source code escrow. (1999-12-14) 1 1 1 1 1 ESD Electrostatic Discharge 1 1 1 1 1 ESDI Enhanced Small Disk Interface 1 1 1 1 1 ESF Eureka Software Factory. 1 1 1 1 1 ESI 1. European Software Institute. 2. A dialect of JOSS. [Sammet 1969, p. 217]. 1 1 1 1 1 esim A language for simulation of VLSI at the switch level. The primitives are nodes and transistors. [C.M. Baker et al, "Tools for Verifying Integrated CIrcuit Design", Lambda 1(3):22-30 (1980)]. (1994-10-20) 1 1 1 1 1 ESL Expert Systems Ltd. 1 1 1 1 1 ESLPDPRO ESL public domain version of Edinburgh Prolog for MS-DOS. The code is totally compatible with C-Prolog. (ftp://aisun1.ai.uga.edu/ai.prolog/eslpdpro.zip). 1 1 1 1 1 ESML Extended Systems Modelling Language 1 1 1 1 1 ESMTP Extended SMTP. Initially defined in RFC 1869 and extended thereafter. See also ETRN. (1997-11-21) 1 1 1 1 1 esolang esoteric programming language 1 1 1 1 1 esoteric programming language (esolang) An intentionally unconventional computer programming language designed not for practical use but, rather, to experiment with weird ideas, to be hard to program in or as a joke. Brainfuck is one of the best known esolangs. esolangs.org wiki (http://esolangs.org/). (2014-10-18) 1 1 1 1 1 ESP 1. Extra Simple Pascal. Subset of Pascal. 2. Econometric Software Package. Statistical analysis of time series. "Econometric Software Package, User's Manual", J.P. Cooper, Graduate School of Business, U Chicago. Sammet 1978 3. Extended Self-containing Prolog. 4. An early symbolic mathematics system. [A. Rom, Celest Mech 3:331-345 (1971)]. (1994-12-08) 1 1 1 1 1 ESPOL Executive Systems Programming Oriented Language 1 1 1 1 1 ESPRIT European Strategic Programme for Research in Information Technology 1 1 1 1 1 ESR Eric S. Raymond 1 1 1 1 1 essential complexity A measure of the "structuredness" of a program. (1996-05-13) 1 1 1 1 1 Estelle A Pascal extension for formal specification of computer network protocols. Protocols are described by modules which are communicating NFAs. Modules are arranged in a dynamic hierarchy and communicate at named interaction points. EstPC (ftp:osi.ncsl.nist.gov/pub/osikit/estpc) Compiles Estelle into C. petdingo Translates Estelle into C++ Adopted by ITU-T. ISO 9074 (1989). ["The Formal Description Technique Estelle", M. Diaz et al eds, N-H 1989]. 1 1 1 1 1 Esterel A distributed language for synchronous interaction of real-time systems with their environment. Uses explicit timing requests. Esterel programs are compiled into finite automata. ["The ESTEREL Programming Language and its Mathematical Semantics", G. Berry & L. Cosserat, TR 327, INRIA, 1984]. 1 1 1 1 1 EstPC A compiler from Estelle to C. (ftp:osi.ncsl.nist.gov/pub/osikit/estpc). (1994-09-19) 1 1 1 1 1 ET Bernd Gersdorf, U Bremen. An integration of functional and logic programming. 1 1 1 1 1 et The country code for Ethiopia. (1999-01-27) 1 1 1 1 1 ET++ A Smalltalk-like system for Suns, built on C++ by Weinand of UBILAB Zurich. Version 3.0-alpha includes class libraries and documentation. (ftp://iamsun.unibe.ch/C++/ET++/et2.2.tar.Z). E-mail: Erich Gamma <gamma@ifi.unizh.ch>. (1992-10-26) 1 1 1 1 1 eta abstraction eta conversion 1 1 1 1 1 eta conversion In lambda-calculus, the eta conversion rule states \ x . f x <--> f provided x does not occur as a free variable in f and f is a function. Left to right is eta reduction, right to left is eta abstraction (or eta expansion). This conversion is only valid if bottom and \ x . bottom are equivalent in all contexts. They are certainly equivalent when applied to some argument - they both fail to terminate. If we are allowed to force the evaluation of an expression in any other way, e.g. using seq in Miranda or returning a function as the overall result of a program, then bottom and \ x . bottom will not be equivalent. See also observational equivalence, reduction. 1 1 1 1 1 eta expansion eta conversion 1 1 1 1 1 eta reduction eta conversion 1 1 1 1 1 ETB End Transmission Block 1 1 1 1 1 ETC ExTendible Compiler 1 1 1 1 1 e-text electronic text 1 1 1 1 1 ETHER A concurrent object-oriented language? (1997-03-18) 1 1 1 1 1 EtherGate Multi-protocol Ethernet gateway made by LRT. See Computer Systems, October 1985. 1 1 1 1 1 Ethernet A local area network first described by Metcalfe & Boggs of Xerox PARC in 1976. Specified by DEC, Intel and XEROX (DIX) as IEEE 802.3 and now recognised as the industry standard. Data is broken into packets and each one is transmitted using the CSMA/CD algorithm until it arrives at the destination without colliding with any other packet. The first contention slot after a transmission is reserved for an acknowledge packet. A node is either transmitting or receiving at any instant. The bandwidth is about 10 Mbit/s. Disk-Ethernet-Disk transfer rate with TCP/IP is typically 30 kilobyte per second. Version 2 specifies that collision detect of the transceiver must be activated during the inter-packet gap and that when transmission finishes, the differential transmit lines are driven to 0V (half step). It also specifies some network management functions such as reporting collisions, retries 1 1 1 1 1 Ethernet address (Or "MAC address") The physical address identifying an individual Ethernet controller board. An Ethernet addess is a 48-bit number aabbccddeeff where a-f are hexadecimal digits. The first 24 bits, aabbcc, identify the manufacturer of the controller. The Ethernet address is hard-wired on some controllers, stored in a ROM on some, and others allow it to be changed from software. It is usually written as six hexadecimal numbers, e.g. 08:00:20:03:72:DC. See also ARP, Internet address. (1996-02-21) 1 1 1 1 1 Ethernet meltdown A network meltdown on Ethernet. (1994-11-29) 1 1 1 1 1 Ethernet Private Line (EPL) A data service defined by the Metro Ethernet Forum, providing a point-to-point Ethernet connection between a pair of dedicated User-Network Interfaces (UNIs), with a high degree of transparency. (2010-09-21) 1 1 1 1 1 EtherTalk An Apple Computer network standard used to extend an AppleTalk network across an Ethernet network. Compare LocalTalk. (1994-11-29) 1 1 1 1 1 ethics computer ethics 1 1 1 1 1 ETL The processes of Extracting, Transforming (or Transporting), and Loading data from source systems into a data warehouse. (2003-12-31) 1 1 1 1 1 ETM An active DBMS from the University of Karlsruhe. [Expansion? Features?] (1997-06-23) 1 1 1 1 1 ETRN ("Extended TURN") An ESMTP command (first defined in RFC 1985) with which a client asks the server to deliver queued mail to the client via a new ESMTP connection. ETRN supersedes the SMTP "TURN" command in the same way that ESMTP's "EHLO" supersedes SMTP's "HELO". (1997-11-21) 1 1 1 1 1 ETSI European Telecommunications Standards Institute 1 1 1 1 1 ETX End Of Text 1 1 1 1 1 Euclid (Named after the Greek geometer, fl ca 300 BC.) A Pascal descendant for development of verifiable system software. No goto, no side effects, no global assignments, no functional arguments, no nested procedures, no floats, no enumeration types. Pointers are treated as indices of special arrays called collections. To prevent aliasing, Euclid forbids any overlap in the list of actual parameters of a procedure. Each procedure gives an imports list, and the compiler determines the identifiers that are implicitly imported. Iterators. Ottawa Euclid is a variant. ["Report on the Programming Language Euclid", B.W. Lampson et al, SIGPLAN Notices 12(2):1-79, Feb 1977]. (1998-11-23) 1 1 1 1 1 Euclidean Algorithm Euclid's Algorithm 1 1 1 1 1 Euclidean norm The most common norm, calculated by summing the squares of all coordinates and taking the square root. This is the essence of Pythagoras's theorem. In the infinite-dimensional case, the sum is infinite or is replaced with an integral when the number of dimensions is uncountable. (2004-02-15) 1 1 1 1 1 Euclid's Algorithm (Or "Euclidean Algorithm") An algorithm for finding the greatest common divisor (GCD) of two numbers. It relies on the identity gcd(a, b) = gcd(a-b, b) To find the GCD of two numbers by this algorithm, repeatedly replace the larger by subtracting the smaller from it until the two numbers are equal. E.g. 132, 168 -> 132, 36 -> 96, 36 -> 60, 36 -> 24, 36 -> 24, 12 -> 12, 12 so the GCD of 132 and 168 is 12. This algorithm requires only subtraction and comparison operations but can take a number of steps proportional to the difference between the initial numbers (e.g. gcd(1, 1001) will take 1000 steps). (1997-06-30) 1 1 1 1 1 Eudora Electronic mail software for communicating over TCP/IP from Macintosh, Microsoft Windows, Windows NT, and IBM OS/2 computers. Both commercial and free versions are produced by QUALCOMM, Inc. 1 1 1 1 1 EULA end-user license agreement 1 1 1 1 1 EULER [Named after the Swiss mathematician Leonhard Euler (1707-1783)] A revision of ALGOL by Niklaus Wirth. A small predecessor of Pascal. ["EULER: A Generalisation of ALGOL and Its Formal Definition", N. Wirth, CACM 9(1) (Jan 1966) and 9(2) (Feb 1966)]. 1 1 1 1 1 EuLisp 1985-present. A Lisp dialect intended to be a common European standard, with influences from Common LISP, Le LISP, Scheme and T. First-class functions, classes and continuations, both static scope and dynamic scope, modules, support for parallelism. The class system (TELOS) incorporates ideas from CLOS, ObjVLisp and Oaklisp. See also Feel. E-mail: <eudist@maths.bath.ac.uk>. 1 1 1 1 1 EUnet Ltd. EUnet Ltd. is jointly owned by the EUnet national service providers and EurOpen, the European Forum for Open Systems. EUnet services include electronic mail (Internet-style RFC 822 as well as X.400), InterEUnet (Internet Protocol) connectivity and services such as remote login and file transfer over leased lines, dial-up lines, X.25 and Integrated Services Digital Network. EUnet is the primary European region provider of network news and the top-level European distributor of Internet Talk Radio. EUnet operates its own infrastructure across Europe and is the largest European component of the Internet. EUnet is a member of Commercial Internet Exchange and Ebone93, a research network consortium. E-mail: <info@EU.net>. (http://eu.net/). 1 1 1 1 1 Euphoria End User Programming with Hierarchical Objects for Robust Interpreted Applications. Interpreted language with dynamic storage and dynamic typing. Rapid Deployment Software. E-mail: <robert.craig@canrem.com>. 1 1 1 1 1 Eureka A European technological development programme. 1 1 1 1 1 Eureka step In program transformation, a transformation which is not obvious or easy to define as an algorithm. (1994-12-08) 1 1 1 1 1 Eurisko A language for "opportunistic programming" written by Doug Lenat in 1978. Eurisko constructs its own methods and modifies its strategies as it tries to solve a problem. (http://homepages.enterprise.net/hibou/aicourse/lenat.txt). [Mentioned by Alan Kay, SIGPLAN Notices 28(3), March 1993, p. 88]. (1994-12-08) 1 1 1 1 1 Eurocard A range of standard circuit board sizes. Normal double Eurocard = 233.4 x 160 mm Extended double Eurocard = 233.4 x 220 mm Super extended double Eurocard = 233.4 x 250 mm Hyper extended double Eurocard = 233.4 x 280 mm 1 1 1 1 1 Euro-ISDN European Integrated Services Digital Network. An ETSI standard for Integrated Services Digital Network being phased in in March 1994. Euro-ISDN will allow full transparent interworking between all European countries (members of the CEPT). It is available on a commercial basis in most European countries. (1994-12-08) 1 1 1 1 1 EuroNet An IAP from Amsterdam, The Netherlands operating since 1994-08-01 and owned by France Telecom since 1998-11-06. (http://euronet.nl/). E-mail: <info@euro.net>. Telephone: +31 (020) 535 5555. Fax: +31 (020) 535 5400. Address: Herengracht 208-214, 1016 BS Amsterdam, The Netherlands. (1999-01-17) 1 1 1 1 1 EuropaNET A combination of pan-European backbone services run by DANTE. 1 1 1 1 1 European Academic and Research Network (EARN) A self-managing network in the research community originally sponsored by IBM. It uses BITNET protocols and connects to BITNET in the USA. (1995-11-15) 1 1 1 1 1 European Computer-Industry Research Centre GmbH (ECRC) A joint research organisation founded in 1984 on the initiative of three major European manufacturers: Bull (France), ICL (UK) and Siemens (Germany). Its activities were intended to enhance the future competitive ability of the European Information Technology industry and thus complement the work of national and international bodies. The Centre is intended to be the breeding ground for those ideas, techniques and products which are essential for the future use of electronic information processing. The work of the Centre will focus on advanced information processing technology for the next generation of computers. ECRC is an independent company, owned equally by its shareholders. The formal interface between ECRC and its shareholders consists of two bodies: The Shareholders' Council, which approves the Centre's programmes and budgets and supervises their execution and the Scientific Advisory Board, which advises the Shareholders' Council in determining 1 1 1 1 1 European Computer Manufacturers Association (ECMA) The former name of ECMA International 1 1 1 1 1 European Strategic Programme for Research in Information Technology (ESPRIT) A funding programme to develop Information Technology in the European Economic Communities. Superseded by Framework 4. (1996-05-13) 1 1 1 1 1 European Telecommunications Standards Institute (ETSI) A European version of the ITU-T(?). (1996-05-13) 1 1 1 1 1 EUUG European Unix User Group 1 1 1 1 1 EV6 (Alpha EV6) Compaq's bus protocol for Slot A motherboards. The Alpha EV6 bus protocol is capable of bus speeds from 40 to 400 MHz and uses a point-to-point topology with clock forwarding. (1999-08-05) 1 1 1 1 1 Eva 1. A toy ALGOL-like language used in "Formal Specification of Programming Languages: A Panoramic Primer", F.G. Pagan, P-H 1981 2. Explicit Vector Language. 1 1 1 1 1 EVALUATE The COBOL85 keyword for a switch statement. (1997-06-10) 1 1 1 1 1 evaluation 1. Converting an expression into a value using some reduction strategy. 2. The process of examining a system or system component to determine the extent to which specified properties are present. (1996-05-13) 1 1 1 1 1 evaluation strategy reduction strategy 1 1 1 1 1 evaluator Geoff Burn defines evaluators E0, E1, E2 and E3 which when applied to an expression, reduce it to varying degrees. E0 does no evaluation, E1 it evaluates to weak head normal form (WHNF), E2 evaluates the structure of a list, i.e. it evaluates it either to NIL or evaluates it to a CONS and then applies E2 to the second argument of the CONS. E3 evaluates the structure of a list and evaluates each element of the list to WHNF. This concept can be extended to data structures other than lists and forms the basis of the evaluation transformer style of strictness analysis. (1994-12-12) 1 1 1 1 1 EVE Extensible VAX Editor 1 1 1 1 1 event 1. <software> An occurrence or happening of significance to a task or program, such as the completion of an asynchronous input/output operation. A task may wait for an event or any of a set of events or it may (request to) receive asynchronous notification (a signal or interrupt) that the event has occurred. See also event-driven. 2. <data> A transaction or other activity that affects the records in a file. (2000-02-09) 1 1 1 1 1 Event Description Language (EDL) ["EDL: A Basis for Distributed System Debugging Tools", P.C. Bates et al, in Proc Hawaii Intl Conf on Sys Sci, Jan 1982, pp.86-93]. (2007-07-11) 1 1 1 1 1 event-driven A kind of program, such as a graphical user interface, with a main loop which just waits for events to occur. Each event has an associated handler which is passed the details of the event, e.g. mouse button 3 pressed at position (355, 990). For example, X window system and most Visual Basic application programs are event-driven. See also callback. (2000-02-09) 1 1 1 1 1 EVGA Extended Video Graphics Array 1 1 1 1 1 evolutionary algorithm (EA) An algorithm which incorporates aspects of natural selection or survival of the fittest. An evolutionary algorithm maintains a population of structures (usually randomly generated initially), that evolves according to rules of selection, recombination, mutation and survival, referred to as genetic operators. A shared "environment" determines the fitness or performance of each individual in the population. The fittest individuals are more likely to be selected for reproduction (retention or duplication), while recombination and mutation modify those individuals, yielding potentially superior ones. EAs are one kind of evolutionary computation and differ from genetic algorithms. A GA generates each individual from some encoded form known as a "chromosome" and it is these which are combined or mutated to breed new individuals. EAs are useful for optimisation when other techniques such as gradient descent or direct, analytical discovery are not 1 1 1 1 1 evolutionary computation Computer-based problem solving systems that use computational models of evolutionary processes as the key elements in design and implementation. A number of evolutionary computational models have been proposed, including evolutionary algorithms, genetic algorithms, the evolution strategy, evolutionary programming, and artificial life. The Hitchhiker's Guide to Evolutionary Computation (http://cis.ohio-state.edu/hypertext/faq/bngusenet/comp/ai/genetic/top.html). Bibliography (http://liinwww.ira.uka.de/bibliography/Ai/EC-ref.html). Usenet newsgroup: news:comp.ai.genetic. (1995-03-02) 1 1 1 1 1 evolutionary programming (EP) A stochastic optimisation strategy originally conceived by Lawrence J. Fogel in 1960. An initially random population of individuals (trial solutions) is created. Mutations are then applied to each individual to create new individuals. Mutations vary in the severity of their effect on the behaviour of the individual. The new individuals are then compared in a "tournament" to select which should survive to form the new population. EP is similar to a genetic algorithm, but models only the behavioural linkage between parents and their offspring, rather than seeking to emulate specific genetic operators from nature such as the encoding of behaviour in a genome and recombination by genetic crossover. EP is also similar to an evolution strategy (ES) although the two approaches developed independently. In EP, selection is by comparison with a randomly chosen set of other individuals whereas ES typically uses deterministic 1 1 1 1 1 evolution strategy (ES) A kind of evolutionary algorithm where individuals (potential solutions) are encoded by a set of real-valued object variables (the individual's "genome"). For each object variable an individual also has a "strategy variable" which determines the degree of mutation to be applied to the corresponding object variable. The strategy variables also mutate, allowing the rate of mutation of the object variables to vary. An ES is characterised by the population size, the number of offspring produced in each generation and whether the new population is selected from parents and offspring or only from the offspring. ES were invented in 1963 by Ingo Rechenberg, Hans-Paul Schwefel at the Technical University of Berlin (TUB) while searching for the optimal shapes of bodies in a flow. (1995-02-03) 1 1 1 1 1 EWOS European Workshop for Open Systems 1 1 1 1 1 exa- prefix 1 1 1 1 1 Exabyte A company and, by extension, a tape format for computer data backup and transfer. The tape is a data quality 8mm video cassette recorder tape. Exabyte units can store between five and fourteen gigabytes of data per tape. Exabytes are usually attached to Unix workstations. [What different tape capacities exist? Compare with DAT?] (1995-07-06) 1 1 1 1 1 exabyte (EB) A unit of data equal to 10^18 bytes but see binary prefix for other definitions. An exabyte is exactly 1000^6 bytes or 1000 petabytes. 1000 exabytes are one zettabyte. See prefix. (2013-11-04) 1 1 1 1 1 examining the entrails The process of grovelling through a core dump or hex image in an attempt to discover the bug that brought a program or system down. The reference is to divination from the entrails of a sacrified animal. Compare runes, incantation, black art, desk check. [Jargon File] (1994-12-12) 1 1 1 1 1 EXAPT EXtended APT. 1 1 1 1 1 Excalibur bug The legendary bug that, despite repeated valliant attempts, none but the true king of all programmers can fix. Named after the sword in the stone in the legend of King Arthur. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-03-20) 1 1 1 1 1 Exceed A tool to display remote X Window System applications on Microsoft Windows. Exceed is not an X server. (2001-04-29) 1 1 1 1 1 Excel Microsoft Excel 1 1 1 1 1 Excelan Manufacturers of intelligent Ethernet cards. Software and addresses are down-loadable. The cards have their own RAM for buffers. 1 1 1 1 1 Excelerator A set of CASE tools from Index Technology Corporation. 1 1 1 1 1 exception An error condition that changes the normal flow of control in a program. An exception may be generated ("raised") by hardware or software. Hardware exceptions include reset, interrupt or a signal from a memory management unit. Exceptions may be generated by the arithmetic logic unit or floating-point unit for numerical errors such as divide by zero, overflow or underflow or instruction decoding errors such as privileged, reserved, trap or undefined instructions. Software exceptions are even more varied and the term could be applied to any kind of error checking which alters the normal behaviour of the program. (1994-10-31) 1 1 1 1 1 exception handler Special code which is called when an exception occurs during the execution of a program. If the programmer does not provide a handler for a given exception, a built-in system exception handler will usually be called resulting in abortion of the program run and some kind of error indication being returned to the user. Examples of exception handler mechanisms are Unix's signal calls and Lisp's catch and throw. (1994-10-31) 1 1 1 1 1 EXCH /eks'ch*/ or /eksch/ To exchange two things, each for the other; to swap places. If you point to two people sitting down and say "Exch!", you are asking them to trade places. EXCH, meaning EXCHange, was originally the name of a PDP-10 instruction that exchanged the contents of a register and a memory location. Many newer hackers are probably thinking instead of the PostScript exchange operator (which is usually written in lowercase). [Jargon File] (1999-09-17) 1 1 1 1 1 Exchange Server Microsoft Exchange 1 1 1 1 1 excl exclamation mark 1 1 1 1 1 exclamation mark The character "!" with ASCII code 33. Common names: bang; pling; excl (/eks'kl/); shriek; ITU-T: exclamation mark, exclamation point (US). Rare: factorial; exclam; smash; cuss; boing; yell; wow; hey; wham; eureka; soldier; INTERCAL: spark-spot. The Commonwealth Hackish, "pling", is common among Acorn Archimedes owners. Bang is more common in the USA. The occasional CMU usage, "shriek", is also used by APL fans and mathematicians, especially category theorists. Exclamation mark is used in C and elsewhere as the logical negation operation (NOT). (1998-09-17) 1 1 1 1 1 exclamation point exclamation mark 1 1 1 1 1 exclusive or (XOR, EOR) /X or, E or/ A two-input Boolean logic function whose result is true if one input is true and the other is false. The truth table is A | B | A xor B --+---+-------- F | F | F F | T | T T | F | T T | T | F The output is thus true if the inputs are not equal. If one input is false, the other is passed unchanged whereas if one 1 1 1 1 1 EXCP Execute Channel Program 1 1 1 1 1 EXE /eks'ee/ or /eek'see/ or /E-X-E/ An executable binary file. Some operating systems (notably MS-DOS, VMS, and TWENEX) use the extension .EXE to mark such files. This usage is also occasionally found among Unix programmers even though Unix executables don't have any required suffix. [Jargon File] 1 1 1 1 1 EXEC An early batch language for the IBM VM/CMS systems. [SC19-6209 Virtual Machine/ System Product CMS Command and Macro Reference, Appendix F. CMS EXEC Control Statements]. [Was EXEC 2 was a later version?] (2000-08-06) 1 1 1 1 1 exec /eg-zek'/ <operating system> 1. execute. A synonym for chain derived from the Unix "exec" system call. Unix manual page: execve(2). 2. (Obsolete) executive. The mainstream "exec" as an abbreviation for (human) executive is *not* used. To a hacker, an "exec" is a always a program, never a person. 3. At IBM and VM/CMS shops, the equivalent of a shell command file. 4. <operating system> The innermost kernel of the Amiga operating system which provides shared-library support, device interface, memory management, CPU management, basic IPC, and the basic structures for OS extension. The rest of the Amiga OS (windowing, file system, third-party extensions, etc.) is built using these structures. [Jargon File] 1 1 1 1 1 EXEC 2 1. <language> A scripting language produced by IBM in the late 1970s. Superseded by REXX. [SC24-5219, "Virtual Machine/System Product EXEC 2 Reference"]. [Successor to EXEC 1? With or without a space?] 2. <operating system> An archaic operating system from UNIVAC. By about 1980 it had been replaced by EXEC 8. [Dates? Did EXEC 3 to EXEC 7 exist?] (2000-08-06) 1 1 1 1 1 EXEC 8 Unisys's operating system from about 1980 to 2000, by which time it was a dying breed with Unisys moving to Windows NT and Unix. [Was 8 the successor to EXEC 2?] (2000-08-06) 1 1 1 1 1 executable A binary file containing a program in machine language which is ready to be executed (run). The term might also be, but generally isn't, applied to scripts which are interpreted by a command line interpreter. Executables are distinguished in Unix by having the execute permission bits set, at least for the owner. MS-DOS uses the filename extension ".exe". (1997-06-21) 1 1 1 1 1 executable content Executable programs sent by one computer to another via a network. For example a Java applet is executable content. Usage: rare. (1998-03-23) 1 1 1 1 1 execute execution 1 1 1 1 1 Execute Channel Program (EXCP) An IBM system for low-level file access, where the programmer is completely responsible for providing a list of device-specific "channel comands" to be executed by I/O channels, control units and/or devices. The operating system will simply check the "CCW" chains for security purposes (access invalid memory or outside of file extents) and then schedule them for execution. (2005-08-08) 1 1 1 1 1 execution The process of carrying out the instructions in a computer program by a computer. See also dry run. (1996-05-13) 1 1 1 1 1 executive The command interpreter or shell for an operating system. The term is used especially around mainframes and probably derived from UNIVAC's archaic EXEC 2 and current (in 2000) EXEC 8 operating systems. (2000-08-06) 1 1 1 1 1 Executive Systems Programming Oriented Language An ALGOL superset with high level instructions for low level actions, e.g. interrupting another processor on a multiprocessor system. Its single pass compiler was very fast: over 250 lines/s on a 10MHz processor. ESPOL was used to write the MCP (Master Control Program) on the Burroughs 6700. It was superseded by NEWP. ["The B6700 ESPOL Reference Manual", Burroughs, 1970]. (2001-06-14) 1 1 1 1 1 exercise, left as an Used to complete a proof in technical books when one doesn't mind a handwave, or to avoid one entirely. The complete phrase is: "The proof [or "the rest"] is left as an exercise for the reader." This comment *has* occasionally been attached to unsolved research problems by authors possessed of either an evil sense of humour or a vast faith in the capabilities of their audiences. [Jargon File] (1995-02-20) 1 1 1 1 1 exhaustive testing Executing a program with all possible combinations of inputs or values for program variables. (1996-05-13) 1 1 1 1 1 existence proof non-constructive proof 1 1 1 1 1 existential quantifier quantifier 1 1 1 1 1 exit 1. <programming> A library function in the C and Unix run-time library that causes the program to terminate and return control to the shell. The alternative to calling exit is simply to "fall off the end" of the program or its top-level, main, routine. Equivalent functions, possibly with different names, exist in pretty much every programming language, e.g. "exit" in Microsoft DOS or "END" in BASIC. On exit, the run-time system closes open files and releases other resources. An exit status code (a small integer, with zero meaning OK and other values typically indicating some kind of error) can be passed as the only argument to "exit"; this will be made available to the shell. Some languages allow the programmer to set up exit handler code which will be called before the standard system clean-up actions. 2. Any point in a piece of code where control is returned to the caller, possibly activating one or more user-provided exit 1 1 1 1 1 EXODUS An extensible database project developed at the University of Wisconsin. (1996-05-13) 1 1 1 1 1 eXodus A package from White Pines allowing the Macintosh to be used as an X server. 1 1 1 1 1 EXOS A brand of Ethernet controller card and Ethernet software for Unix. (1995-01-12) 1 1 1 1 1 expanded memory Memory used through EMS. In systems based on Intel 80386 or later processor expanded memory is part of the extended memory that is mapped into the expanded memory page frame by the processor. The mapping is controlled by the EMM. In earlier systems, a dedicated EMS hardware adaptor is needed to map memory into the page frame. In both cases, an appropriate device driver is needed for the proper communication between hardware and EMM. (1996-01-10) 1 1 1 1 1 expanded memory manager (EMM) IBM PC memory manager software implementing Expanded Memory Specification, such as EMM386 or QEMM386. EMMs can usually provide UMB as well. (1996-01-10) 1 1 1 1 1 expanded memory page frame The part of the IBM PC reserved memory address space used by EMS. (1996-01-10) 1 1 1 1 1 Expanded Memory Specification (EMS) An IBM PC memory paging scheme enabling access to memory other than conventional memory in real mode. Expanded memory is provided through a page frame of at least 64 kilobytes in the reserved memory address region. Access to this memory is provided by an expanded memory manager (EMM) software. The EMM functions are accessible through interrupt 67H. In 8086 or 8088 based systems this is the only way to use memory beyond conventional memory. In systems based on 80286 or later, XMS and HMA provide alternative methods. EMS was developed jointly by Lotus, Intel, and Microsoft prior to 1988. Accordingly, this specification is sometimes referred to as LIM EMS. A complete discussion of EMS and programming examples can be found in ["PC System Programming for developers", 1989, ISBN 1-55755-035-2 (Book only) and ISBN 1-55755-036-0 (Book and 1 1 1 1 1 expansion card A circuit board which can be plugged into one of a computer's expansion slots to provide some optional extra facility such as additional RAM, disk controller, coprocessor, graphics accelerator, communication device or some special-purpose interface. Different computers have different standards for the cards they accept, e.g. PCI. (1998-06-26) 1 1 1 1 1 expansion slot A connector in a computer into which an expansion card can be plugged. The connector supplies power to the card and connects it to the data bus, address bus and control signals of the motherboard. (1998-06-26) 1 1 1 1 1 expect A Unix tool written in Tcl and a script language for automating the operation of interactive applications such as telnet, FTP, passwd, fsck, rlogin, tip, etc.. Expect can feed input to other programs and perform pattern matching on their output. It is also useful for testing these applications. By adding Tk, you can also wrap interactive applications in X11 GUIs. (http://expect.nist.gov/). ["expect: Scripts for Controlling Interactive Tasks", Don Libes, Comp Sys 4(2), U Cal Press Journals, Nov 1991]. (1997-06-09) 1 1 1 1 1 eXperimental LISP (xlisp) An experimental programming language combining a subset of Common Lisp with an object-oriented extension capability (Class and Object types). It was implemented by David Micheal Betz at Apple to allow experimentation with object-oriented programming on small computers. The C source code has been ported to Unix, Microsoft Windows, Macintosh, Amiga, Atari, and MS-DOS. Version 2.1 of the interpreter, by Tom Almy is closer to Common Lisp. Latest version: 2.1, as of 1992-05-26. (ftp://wasp.eng.ufl.edu/), (ftp://cs.orst.edu/), (ftp://glia.biostr.washington.edu/). E-mail: Tom Almy <toma@sail.labs.tek.com>. Microsoft Windows version (ftp://ftp.cica.indiana.edu/util/wxlslib.zip). Macintosh version (ftp://netcom.com/pub/bskendig/). 1 1 1 1 1 Experimental Physics Control Systems (EPCS) A group of the European Physical Society, focussing on all aspects of controls, especially informatics, in experimental physics, including accelerators and experiments. (1994-12-12) 1 1 1 1 1 Experimental Programming Language (EPL) A language by David May which influenced occam. ["EPL: An Experimental Language for Distributed Computing", D.C. May, in Trends and Applications 1978: Distributed Processing, NBS, pp.69-71]. (1994-11-18) 1 1 1 1 1 Experiment Description Language (EDL) J.S. Jenkins. ["A Programmable System for Acquisition and Reduction of Respiratory Physiological Data", J.S. Jenkins et al, Ann Biomed Eng, 17:93-108 1989]. (2007-07-11) 1 1 1 1 1 Expert Judgement Models A method of software estimation that is based on consultation with one or more experts that have experience with similar projects. An expert-consensus mechanism such as the Delphi Technique may be used to produce the estimate. (1996-05-29) 1 1 1 1 1 expert system A computer program that contains a knowledge base and a set of algorithms or rules that infer new facts from knowledge and from incoming data. An expert system is an artificial intelligence application that uses a knowledge base of human expertise to aid in solving problems. The degree of problem solving is based on the quality of the data and rules obtained from the human expert. Expert systems are designed to perform at a human expert level. In practice, they will perform both well below and well above that of an individual expert. The expert system derives its answers by running the knowledge base through an inference engine, a software program that interacts with the user and processes the results from the rules and data in the knowledge base. Expert systems are used in applications such as medical diagnosis, equipment repair, investment analysis, financial, estate and insurance planning, route scheduling for delivery 1 1 1 1 1 Expert Systems Ltd. (ESL) Distributors of ESLPDPRO. Adderss: Magdalen Centre, Oxford Science Park, Oxford, OX4 4GA. Telephone +44 (865) 784474. (1996-05-29) 1 1 1 1 1 explicit parallelism A feature of a programming language for a parallel processing system which allows or forces the programmer to annotate his program to indicate which parts should be executed as independent parallel tasks. This is obviously more work for the programmer than a system with implicit parallelism (where the system decides automatically which parts to run in parallel) but may allow higher performance. 1 1 1 1 1 explicit type conversion (Or "cast" in C and elsewhere). A programming construct (syntax) to specify that an expression's value should be converted to a different type. For example, in C, to convert an integer (usually 32 bits) to a char (usually 8 bits) we might write: int i = 42; char *p = &buf; *p = (char) i; The expression "(char)" (called a "cast") converts i's value to char type. Casts (including this one) are often not strictly necessary, due to automatic coercions performed by the compiler, but can be used to make the conversion obvious and to avoid warning messages. (1999-09-19) 1 1 1 1 1 exploit A security vulnerability or an instance of taking advantage of a security vulnerability. [...] hackers say exploit. sysadmins say hole -- Mike Emke (http://emke.com/). (2014-10-25) 1 1 1 1 1 Exploratory Data Analysis (EDA) [J.W.Tukey, "Exploratory Data Analysis", 1977, Addisson Wesley]. 1 1 1 1 1 exponent (Or "characteristic") The part of a floating-point number specifying the power of ten by which the mantissa should be multiplied. In the common notation, e.g. 3.1E8, the exponent is 8. (1995-02-27) 1 1 1 1 1 exponential 1. <mathematics> A function which raises some given constant (the "base") to the power of its argument. I.e. f x = b^x If no base is specified, e, the base of natural logarthims, is assumed. 2. <complexity> exponential-time algorithm. (1995-04-27) 1 1 1 1 1 exponential-time The set or property of problems which can be solved by an exponential-time algorithm but for which no polynomial-time algorithm is known. (1995-04-27) 1 1 1 1 1 exponential-time algorithm An algorithm (or Turing Machine) that is guaranteed to terminate within a number of steps which is a exponential function of the size of the problem. For example, if you have to check every number of n digits to find a solution, the complexity is O(10^n), and if you add an extra digit, you must check ten times as many numbers. Even if such an algorithm is practical for some given value of n, it is likely to become impractical for larger values. This is in contrast to a polynomial-time algorithm which grows more slowly. See also computational complexity, polynomial-time, NP-complete. (1995-04-27) 1 1 1 1 1 Express 1. A language supporting concurrency through message passing to named message queues from ParaSoft Corporation (ftp://ftp.parasoft.com/express/docs). 2. Data definition language, meant to become an ISO standard for product data representation and exchange. TC 184/SC4 N83, ISO, 1991-05-31. E-mail: <smith@cme.nist.gov>. 3. A data modelling language adopted by the ISO working group on STEP. 1 1 1 1 1 expression Any piece of program code in a high-level language which, when (if) its execution terminates, returns a value. In most programming languages, expressions consist of constants, variables, operators, functions, and parentheses. The operators and functions may be built-in or user defined. Languages differ on how expressions of different types may be combined - with some combination of explicit casts and implicit coercions. The syntax of expressions generally follows conventional mathematical notation, though some languages such as Lisp or Forth have their own idiosyncratic syntax. (2001-05-14) 1 1 1 1 1 expression tree The syntax tree of an expression. (1998-11-14) 1 1 1 1 1 extend To add features to a program, especially through the use of hooks. Extend is very often used in the phrase "extend the functionality of a program." Plug-ins are one form of extension. (1997-06-21) 1 1 1 1 1 Extended Affix Grammar (EAG) A formalism for describing both the context free syntax and the context sensitive syntax of languages. EAGs belong to the family of two-level grammars. They are very closely related to two-level van Wijngaarden grammars. EAG can be used as a specification formalism, specifying in relations rather than functions, or as a relational programming language like PROLOG. (http://www.cs.ru.nl/~kees/eag/) (2009-02-06) 1 1 1 1 1 Extended ALGOL An extension of ALGOL 60, used to write the ESPOL compiler on the Burroughs B5500, Burroughs B6500, and Burroughs B6700. ["Burroughs B6700 Extended ALGOL Language Information Manual", No. 5000128 (Jul 1971)]. [Sammet 1969, p. 196]. (1995-05-09) 1 1 1 1 1 Extended Architecture (XA) A CD-ROM drive specification required by Green Book CD-ROM and White Book CD-ROM formats. Drives labelled "XA ready" may require a firmware upgrade. (1994-11-02) 1 1 1 1 1 Extended Backus-Naur Form Any variation on the basic Backus-Naur Form (BNF) meta-syntax notation with (some of) the following additional constructs: square brackets "[..]" surrounding optional items, suffix "*" for Kleene closure (a sequence of zero or more of an item), suffix "+" for one or more of an item, curly brackets enclosing a list of alternatives, and super/subscripts indicating between n and m occurrences. All these constructs can be expressed in plain BNF using extra productions and have been added for readability and succinctness. (1995-04-28) 1 1 1 1 1 Extended Binary Coded Decimal Interchange Code /eb's*-dik/, /eb'see`dik/, /eb'k*-dik/, /ee`bik'dik`/, /*-bik'dik`/ (EBCDIC) A proprietary 8-bit character set used on IBM dinosaurs, the AS/400, and e-Server. EBCDIC is an extension to 8 bits of BCDIC (Binary Coded Decimal Interchange Code), an earlier 6-bit character set used on IBM computers. EBCDIC was [first?] used on the successful System/360, anounced on 1964-04-07, and survived for many years despite the almost universal adoption of ASCII elsewhere. Was this concern for backward compatibility or, as many believe, a marketing strategy to lock in IBM customers? IBM created 57 national EBCDIC character sets and an International Reference Version (IRV) based on ISO 646 (and hence ASCII compatible). Documentation on these was not easily accessible making international exchange of data even between IBM mainframes a tricky task. 1 1 1 1 1 Extended BNF Extended Backus-Naur Form 1 1 1 1 1 Extended C++ EC++ extended by G. Masotti <masotti@lipari.usc.edu> with preconditions, postconditions and class invariants, parameterised classes, exception handling and garbage collection. EC++ translates Extended C++ into C++. (1989-10-10) 1 1 1 1 1 Extended Capabilities Port (ECP) A parallel printer interface for IBM PC compatibles, supported by several, mainly US, manufacturers. Not to be confused with the more common Enhanced Capabilities Port. (1997-12-01) 1 1 1 1 1 Extended Concurrent Prolog (ECP) Concurrent Prolog with OR parallelism, set abstraction and meta-inference features. ["AND-OR Queuing in Extended Concurrent Prolog", J. Tanaka et al, Proc Logic Prog Conf '85, LNCS 193, Springer 1985]. (1994-12-01) 1 1 1 1 1 Extended Data Out Dynamic Random Access Memory (EDO DRAM, EDO RAM) A type of DRAM designed to access nearby memory locations faster than FPM DRAM. Extended Data Out DRAM (EDO-DRAM) allows the data outputs to be kept active after the CAS\ signal goes inactive, using an additional signal OE\ to control the data outputs. This can be used in pipelined systems for overlapping accesses where the next cycle is started before the data from the last cycle is removed from the bus. EDO DRAM is primarily used with Intel's Pentium processors since with slower processors there is no significant performance gain. To make use of the advanced features of EDO an appropriate chipset, such as Triton, must be used. In early 1995, EDO DRAM was available for computers from Micron, Gateway 2000, and Intel Corporation; since then other manufactures followed suit. Note that in comparison to Burst EDO EDO is sometimes referred to as "Standard EDO". 1 1 1 1 1 Extended Data Out Random Access Memory Extended Data Out Dynamic Random Access Memory 1 1 1 1 1 Extended Fortran Language (EFL) A Fortran preprocessor to provide structured programming constructs much like C. EFL is a descendant of RATFOR. It is written in C. ["An Informal Description of EFL", S.I. Feldman]. 1 1 1 1 1 eXtended Graphics Array (XGA) An IBM display standard introduced in 1990 XGA supports a resolution of 1024 x 768 pixels with a palette of 256 colours, or 640 x 480 with high colour (16 bits per pixel). XGA-2 added 1024 x 768 support for high colour and higher refresh rates, improved performance, and supports 1360 x 1024 in 16 colours. XGA is probably not the same as 8514-A. See also VESA's EVGA released at a similar time. (1999-08-01) 1 1 1 1 1 Extended Industry-Standard Architecture (EISA) /eesa/ A bus standard for IBM compatibles that extends the ISA bus architecture to 32 bits and allows more than one CPU to share the bus. The bus mastering support is also enhanced to provide access to 4 GB of memory. Unlike MCA, EISA can accept older XT bus architecture and ISA boards. EISA was announced in late 1988 by compatible vendors as a counter to IBM's MCA in its PS/2 series. Although somewhat inferior to the MCA it became much more popular due to the proprietary nature of MCA. [Main sponsors? Open standard?] (1996-06-25) 1 1 1 1 1 extended memory Memory above the first megabyte of address space in an IBM PC with an 80286 or later processor. Extended memory is not directly available in real mode, only through EMS, UMB, XMS, or HMA; only applications executing in protected mode can use extended memory directly. In this case, the extended memory is provided by a supervising protected-mode operating system such as Microsoft Windows. The processor makes this memory available through a system of global descriptor tables and local descriptor tables. The memory is "protected" in the sense that memory assigned a local descriptor cannot be accessed by another program without causing a hardware trap. This prevents programs running in protected mode from interfering with each other's memory. A protected-mode operating system such as Windows can also run real-mode programs and provide expanded memory to them. DOS Protected Mode Interface is Microsoft's 1 1 1 1 1 extended memory manager (XMM) The memory manager software implementing Extended Memory Specification, such as HIMEM or QEMM386. XMM's can usually also act as A20 handlers. (1996-01-10) 1 1 1 1 1 Extended Memory Specification (XMS) The specification describing the use of IBM PC extended memory in real mode for storing data (but not executable code). Memory is made available by extended memory manager (XMM) software. The XMM functions are accessible through interrupt 2FH. (1996-01-10) 1 1 1 1 1 Extended ML A language by Don Sannella of the University of Edinburgh combining algebraic specification and functional programming. ["Program Specification and Development in Standard ML", D. Sannella et al, 12th POPL, ACM 1985]. (1994-12-12) 1 1 1 1 1 Extended Pascal A superset of ANSI and ISO Pascal with many enhancements, including modules, separate compilation, type schemata, variable-length strings, direct-access files, complex numbers, initial values, constant expressions. ANSI/IEEE770X3.160-1989 and ISO 10206. (1994-12-12) 1 1 1 1 1 Extended Self-containing Prolog (ESP) An object-oriented extension of KL0 by Chikayama. ESP has backtracking-based control, unification-based parameter passing and object-oriented calling. An object in ESP is an axiom set. A class definition consists of nature definitions (inheritance), slot definitions (class variables) and clause definitions. ESP has multiple inheritance similar to Flavors. It has been implemented for ICOT's PSI Sequential Inference machine. See also CESP. E-mail: <k-hata@air.co.jp>. ["Unique Features of ESP", T. Chikayama, Proc Intl Conf 5th Gen Comp Sys, ICOT 1984]. (1994-12-08) 1 1 1 1 1 Extended System Configuration Data (ESCD) An area of memory, not exceeding 32 kilobytes in size, used by MS-DOS(?) as NVRAM for PNP BIOS and PNP OS. It must be writeable at run time. Intel's ICU also uses ESCD to store information for PNP ISA cards and legacy ISA cards. (1999-11-22) 1 1 1 1 1 Extended Systems Modelling Language (ESML) A real-time software engineering methodology based on RTSA. (2009-05-11) 1 1 1 1 1 Extended Tcl (TclX) Tcl extended by Mark Diekhans <markd@NeoSoft.com> and Karl Lehenbauer from 1989 on with statements to provide high-level access Unix system primitives. Latest version: 7.6p2, as of 2003-02-12. TclX Home (http://neosoft.com/tclx/). E-mail: <tcl-project@NeoSoft.com>. (2003-02-12) 1 1 1 1 1 Extended Tiny A research/educational tool for experimenting with array data dependence tests and reordering transformations. It works with a language tiny, which does not have procedures, goto's, pointers, or other features that complicate dependence testing. Michael Wolfe's original tiny has been extended substantially by William Pugh <pugh@cs.umd.edu> et al. at the University of Maryland. Version 3.0 (Dec 12th, 1992) includes a programming environment, dependence tester, tests translator (Fortran->tiny), documentation, and technical reports. It should run on any Unix system. (ftp://cs.umd.edu/pub/omega). E-mail: Omega test research group <omega@cs.umd.edu>. (1992-12-12) 1 1 1 1 1 Extended Video Graphics Array (EVGA) A display standard introduced by VESA in 1991. It offers a maximum resolution of 1024 x 768 pixels (non-interlaced) and a 70 Hz refresh rate. EVGA should not be confused with the older EGA (Enhanced Graphics Array) or XGA (eXtended Graphics Array). [Same as "eXtended Video Graphics Array" (XVGA)?] (1999-08-01) 1 1 1 1 1 eXtended Video Graphics Array (XVGA) A display standard with a resolution of 1024 by 768 pixels of 256 colours. IBM call this mode 8514. [Same as "Extended Video Graphics Array" (EVGA)?] (1997-12-11) 1 1 1 1 1 ExTendible Compiler (ETC) A Fortran-like compiler that can be extended with macros. ["ETC - An Extendible Macro-Based Compiler", B.N. Dickman, Proc SJCC 38 1971]. (2010-01-28) 1 1 1 1 1 extensible Said of a system (e.g., program, file format, programming language, protocol, etc.) designed to easily allow the addition of new features at a later date, e.g. through the use of hooks, an API or plug-ins. See also extend, forward compatible. (1998-01-15) 1 1 1 1 1 extensible database A DBMS that allows access to data from remote sources as if the remote data were part of the database. [Example?] (1997-11-20) 1 1 1 1 1 Extensible Firmware Interface (EFI) A specification originating from Intel Corporation, defining the interface between an operating system and platform firmware, and aiming to reduce OS dependence on details of the firmware implementation. EFI Home (http://intel.com/technology/efi/). (2004-10-23) 1 1 1 1 1 Extensible HyperText Markup Language (XHTML) A reformulation of HTML 4.01 in XML. Being XML means that XHTML can be viewed, edited, and validated with standard XML tools. At the same time, it operates as well as or better than HTML 4 in existing HTML 4 conforming user agents. The most important change is that all elements must be terminated, either with a closing tag or using the <tag.../> shorthand. So, instead of <input type=submit> you would write <input type="submit" /> The space before the "/" is required by some older browsers. Other differences are that tag and attribute names should be lower case and all attributes should be quoted. XHTML Home (http://w3.org/TR/xhtml1/). 1 1 1 1 1 Extensible Markup Language (XML) An initiative from the W3C defining an "extremely simple" dialect of SGML suitable for use on the web. (http://w3.org/XML/). [Relationship to the XSL forthcoming subset of DSSSL?] (1997-11-20) 1 1 1 1 1 Extensible Shell (es) A Unix shell written by Byron Rakitzis <byron@netapp.com> and Paul Haahr <haahr@adobe.com>, derived from rc. Es has real functions, closures, exceptions and lets you redefine most internal shell operations. Version: 0.84. (ftp://ftp.sys.utoronto.ca/pub/es/). ["Es - A Shell with Higher Order Functions", P. Haahr et al, Proc Winter 1993 Usenix Technical Conference]. (1993-04-30) 1 1 1 1 1 Extensible Stylesheet Language (XSL) A standard developed by the World Wide Web Consortium defining a language for transforming and formatting XML (eXtensible Markup Language) documents. An XSL stylesheet is written in XML and consists of instructions for tree transformation and formatting. The tree transformations describe how each XML tag relates to other data and the formatting instructions describe how to output the various types of data. (http://w3.org/Style/XSL/). See also Extensible Stylesheet Language Transformations. (2005-09-30) 1 1 1 1 1 Extensible Stylesheet Language Transformations (XSLT) A W3C standard for transforming XML documents into other XML documents or other formats. This was conceived as part of XSL but has been found to have wider applications. (http://w3.org/TR/xslt). (2001-10-04) 1 1 1 1 1 Extensible VAX Editor (EVE) A DEC product implemented using DEC's Text Processing Utility (TPU). [Details?] (2000-05-08) 1 1 1 1 1 extension 1. <filename extension> filename extension. 2. <programming> A feature or piece of code which extends a program's functionality, e.g. a plug-in. (1997-06-21) 1 1 1 1 1 extensional Extensional properties, e.g. extensional equality, relate to the "black-box" behaviour of an object, i.e. how its output depends on its input. The opposite is intensional which concerns how the object is implemented. 1 1 1 1 1 extensional equality (Or extensionality). Functions, f and g are extensionally equal if and only if f x = g x for all x. where "=" means both expressions fail to terminate (under some given reduction strategy) or they both terminate with the same basic value. Two functions may be extensionally equal but not inter-convertible (neither is reducible to the other). E.g. \ x . x+x and \ x . 2*x. See also observational equivalence, referential transparency. 1 1 1 1 1 extensionality extensional equality 1 1 1 1 1 Extension Language Kit (Elk) A Scheme interpreter by Oliver Laumann <net@cs.tu-berlin.de> and Carsten Bormann <cabo@cs.tu-berlin.de> of the Technical University of Berlin. Elk was designed to be used as a general extension language. New types and primitive procedures can easily be added. It has first-class environments, dynamic-wind, fluid-let, macros, autoloading and a dump. It provides interfaces to Xlib, Xt and various widget sets; dynamic loading of extensions and object files; almost all artificial limitations removed; generational/incremental garbage collector; Unix system call extensions; Records (structures) and bit strings. Version: 2.2 is mostly R3RS compatible and runs on Unix, Ultrix, VAX, Sun-3, Sun-4, 68000, i386, MIPS, IBM PC RT, RS/6000, HP700, SGI, Sony, MS-DOS (gcc+DJGPP or go32). Germany 1 1 1 1 1 Exterior Gateway Protocol (EGP) A protocol which distributes routing information to the routers which connect autonomous systems. The term gateway is historical, and "router" is currently the preferred term. There is also a routing protocol called EGP defined in STD 18, RFC 904. See also Border Gateway Protocol, Interior Gateway Protocol. 1 1 1 1 1 eXternal Data Representation (XDR) A standard for machine independent data structures developed by Sun Microsystems for use in remote procedure call systems. It is defined in RFC 1014 and is similar to ASN.1. (1994-12-13) 1 1 1 1 1 External Machine Interface (EMI) A protocol primarily used to connect to short message service centres for mobile telephones. EMI is an extension to Universal Computer Protocol (UCP). EMI was was developed by CMG, now a part of LogicaCMG, the current SMSC market leader. Each byte of the message is encoded as two hexadecimal characters using an encoding not quite like ASCII. EMI specification (http://www.netfunitalia.it/downloads/SMSC_EMI_Specification.PDF) (2007-09-10) 1 1 1 1 1 external memory A vague term for slower, non-volatile storage, usually magnetic disk, in contrast to main memory which is usually volatile semiconductor RAM. [Jargon File] (1997-02-17) 1 1 1 1 1 EXTRA Object-oriented, Pascal style, handles sets. "A Data Model and Query Language for EXODUS", M.J. Carey et al, SIGMOD 88 Conf Proc, pp.413- 423, ACM SIGMOD Record 17:3 (Sept 1988). 1 1 1 1 1 extranet The extension of a company's intranet out onto the Internet, e.g. to allow selected customers, suppliers and mobile workers to access the company's private data and applications via the web. This is in contrast to, and usually in addition to, the company's public website which is accessible to everyone. The difference can be somewhat blurred but generally an extranet implies real-time access through a firewall of some kind. Such facilities require very careful attention to security but are becoming an increasingly important means of delivering services and communicating efficiently. [Did Marc Andreessen invent the term in September 1996?] (1997-12-17) 1 1 1 1 1 extrapolate extrapolation 1 1 1 1 1 extrapolation A mathematical procedure which estimates values of a function for certain desired inputs given values for known inputs. If the desired input is outside the range of the known values this is called extrapolation, if it is inside then it is called interpolation. The method works by fitting a "curve" (i.e. a function) to two or more given points and then applying this function to the required input. Example uses are calculating trigonometric functions from tables and audio waveform sythesis. The simplest form of interpolation is where a function, f(x), is estimated by drawing a straight line ("linear interpolation") between the nearest given points on either side of the required input value: f(x) ~ f(x1) + (f(x2) - f(x1))(x-x1)/(x2 - x1) There are many variations using more than two points or higher 1 1 1 1 1 EXUG European X User Group 1 1 1 1 1 eyeball search (Or vgrep) To look for something in a mass of code or data with one's own native optical sensors, as opposed to using some sort of pattern matching software like grep or any other automated search tool. Compare vdiff, desk check. [Jargon File] (1997-12-17) 1 1 1 1 1 EZ High-level string-processing language derived from SNOBOL4, SL5 and Icon. ["The EZ Reference Manual", C.W. Fraser et al, CS TR 84-1, U Arizona, 1984]. 1 1 1 1 1 ezd (Easy drawing) A graphics server that sits between an application program and an X server and allows both existing and new programs easy access to structured graphics. Ezd users have been able to have their programs produce interactive drawings within hours of reading the manual page. Ezd supports structured graphics - application defined graphical objects are ordered into drawings by the application. Unlike most X tools, ezd does not require any event handling by the application. The ezd server maintains the window contents. When an event occurs an application supplied Scheme expression is evaluated. Latest version: 15mar93 (as of 1993-03-10). (ftp://gatekeeper.dec.com/pub/DEC/ezd/). Contact: Joel Bartlett. (2000-03-25) 1 1 1 1 1 e-zine electronic magazine 1 1 1 1 1 F100-L Ferranti F100-L 1 1 1 1 1 f2c A Fortran 77 to C translator by S. I. Feldman, D. M. Gay, M. W. Maimone and N. L. Schryer. Produces ANSI C or C++. (ftp://netlib.bell-labs.com/netlib/f2c). E-mail: <dmg@bell-labs.com>. Latest version: 1997.07.24. (1997-08-01) 1 1 1 1 1 F2F face-to-face 1 1 1 1 1 F68K A portable Forth system for Motorola 680x0 computers by Joerg Plewe <joerg.plewe@mpi-dortmund.mpg.de>. Ported to Atari ST, Atari TT, Amiga, Sinclair QL and OS9. Easily ported to Motorola 68000 based systems. (ftp://archive.umich.edu/atari/Languages/). (1992-12-14) 1 1 1 1 1 FAC Functional Array Calculator. An APL-like language, but purely functional and lazy. It allows infinite arrays. ["FAC: A Functional APL Language", H.-C. Tu and A.J. Perlis, IEEE Trans Soft Eng 3(1):36-45 (Jan 1986)]. 1 1 1 1 1 facebook.com One of the most popular social networking websites. FaceBook home (http://facebook.com/). (2007-11-16) 1 1 1 1 1 face time Time spent interacting with somebody face-to-face (as opposed to via electronic links). "Oh, yeah, I spent some face time with him at the last Usenix." [Jargon File] 1 1 1 1 1 face-to-face (F2F, IRL) Used to describe personal interaction in real life as opposed to via some digital or electronic communications medium. (1997-01-31) 1 1 1 1 1 Facile A concurrent extension of ML from ECRC. (http://ecrc.de/facile/facile_home.html). ["Facile: A Symmetric Integration of Concurrent and Functional Programming", A. Giacalone et al, Intl J Parallel Prog 18(2):121-160, Apr 1989]. (1994-12-01) 1 1 1 1 1 facsimile ("fax") A process by which fixed graphic material including pictures, text, or images is scanned and the information converted into electrical signals which are transmitted via telephone to produce a paper copy of the graphics on the receiving fax machine. Some modems can be used to send and receive fax data. V.27 ter and V.29 protocols are used. [Details? Standards?] (2004-07-26) 1 1 1 1 1 FACT Fully Automated Compiling Technique 1 1 1 1 1 fact The kind of clause used in logic programming which has no subgoals and so is always true (always succeeds). E.g. wet(water). male(denis). This is in contrast to a rule which only succeeds if all its subgoals do. Rules usually contain logic variables, facts rarely do, except for oddities like "equal(X,X).". (1996-10-20) 1 1 1 1 1 factor A quantity which is multiplied by another quantity. See also divisor. [Jargon File] 1 1 1 1 1 factorial The mathematical function that takes a natural number, N, and returns the product of N and all smaller positive integers. This is written N! = N * (N-1) * (N-2) * ... * 1. The factorial of zero is one because it is an empty product. Factorial can be defined recursively as 0! = 1 N! = N * (N-1)! , N > 0 The gamma function is the equivalent for real numbers. For example, the number of ways of shuffling 52 playing cards is 52! or nearly 10^68. 52 Factorial 1 1 1 1 1 FAD ["FAD, A Simple and Powerful Database Language", F. Bancilon et al, Proc 13th Intl Conf on VLDB, Brighton, England, Sep 1987]. 1 1 1 1 1 failback failover 1 1 1 1 1 failover Automatically switching to a different, redundant system upon failure or abnormal termination of the currently active system. Failover can be applied to a cluster of servers, to network or storage components or any other set of redundant devices that must provide high availability because down-time would be expensive or inconvenient. It may be implemented in hardware, software or a combination. A "hot standby" is continuously active at the same time as the failed system, using some kind of load balancing to share the work, whereas a "warm standby" is ready to become active at short notice. When the failed system is operational again it may "failback", i.e. become (one of) the active system(s) or it may become a warm standby. (2008-01-15) 1 1 1 1 1 failure The inability of a system or system component to perform a required function within specified limits. A failure may be produced when a fault is encountered. (1996-05-13) 1 1 1 1 1 failure-directed testing (Or "heuristics testing") Software testing based on the knowledge of the types of errors made in the past that are likely for the system under test. (1996-05-16) 1 1 1 1 1 FAIR An early system on the IBM 705. [Listed in CACM 2(5):1959-05-16]. (1996-05-13) 1 1 1 1 1 Fairchild F8 An 8-bit microprocessor. The processor itself had no address bus - program and data memory access were contained in separate units, which reduced the number of pins and the associated cost. It also featured 64 registers, accessed by the ISAR register in cells (register windows) of eight, which meant external RAM wasn't always needed for small applications. In addition, the 2-chip processor didn't need support chips, unlike others which needed seven or more. The F8 inspired other similar CPUs, such as the Intel 8048. The use of the ISAR register allowed a subroutine to be entered without saving a bunch of registers, speeding execution - the ISAR would just be changed. Special purpose registers were stored in the second cell (regs 9-15), and the first eight registers were accessed directly. The windowing concept was useful, but only the register pointed to by the ISAR could be accessed - to access other registers the ISAR was incremented or decremented through the window. 1 1 1 1 1 fall back A feature of a modem protocol where two modems which experience data corruption, e.g. due to line noise, can renegotiate to use a lower speed connection, possibly applying fall forward if the channel improves. (2004-07-30) 1 1 1 1 1 fall forward A feature of a modem protocol where two modems which fall back to a lower speed because of data corruption can later return to the higher speed if the connection improves. (2004-07-30) 1 1 1 1 1 fall over [IBM] Yet another synonym for crash or lose. "Fall over hard" equates to crash and burn. [Jargon File] 1 1 1 1 1 fall through (The American misspelling "fall thru" is also common) 1. To exit a loop by exhaustion, i.e. by having fulfilled its exit condition rather than via a break or exception condition that exits from the middle of it. This usage appears to be *really* old, dating from the 1940s and 1950s. 2. To fail a test that would have passed control to a subroutine or some other distant portion of code. 3. In C, "fall-through" occurs when the flow of execution in a switch statement reaches a "case" label other than by jumping there from the switch header, passing a point where one would normally expect to find a "break". A trivial example: switch (colour) 1 1 1 1 1 fall thru fall through 1 1 1 1 1 FALSE A small, compiled extensible language with lambda abstractions by W. van Oortmerssen. For Amiga (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/ff885). 1 1 1 1 1 fandango on core (Unix/C, from the Mexican dance) In C, a wild pointer that runs out of bounds, causing a core dump, or corrupts the malloc arena in such a way as to cause mysterious failures later on, is sometimes said to have "done a fandango on core". On low-end personal machines without an MMU, this can corrupt the operating system itself, causing massive lossage. Other frenetic dances such as the rhumba, cha-cha, or watusi, may be substituted. See aliasing bug, precedence lossage, smash the stack, memory leak, memory smash, overrun screw, core. [Jargon File] (1994-12-16) 1 1 1 1 1 fan-out The number of logic gate inputs that can be driven from a single gate output of the same type. Circuit designers need to add extra buffers if a signal goes to more inputs than the fan-out of the gate that produces it allows. (2007-05-16) 1 1 1 1 1 FAP The assembly language for Sperry-Rand 1103 and 1103A. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-16) 1 1 1 1 1 FAQ frequently asked question 1 1 1 1 1 FAQL frequently asked question 1 1 1 1 1 FAQ list frequently asked question 1 1 1 1 1 faradise /far'*-di:z/ [US Geological Survey] To start any hyper-addictive process or trend, or to continue adding current to such a trend. Telling one user about a new octo-tetris game you compiled would be a faradising act - in two weeks you might find your entire department playing the faradic game. 1 1 1 1 1 farkled /far'kld/ (From DeVry Institute of Technology, Atlanta) A synonym for hosed. Possibly related to Yiddish farblondjet and/or the "Farkle Family" skits on Rowan & Martin's Laugh-In. [Jargon File] (1998-09-07) 1 1 1 1 1 farm processor farm 1 1 1 1 1 farming (From Adelaide University, Australia) What the heads of a disk drive are said to do when they plow little furrows in the magnetic media during a head crash. Typically used as follows: "Oh no, the machine has just crashed; I hope the hard drive hasn't gone farming again." [Jargon File] (2001-03-26) 1 1 1 1 1 FARNET A non-profit corporation, established in 1987, whose mission is to advance the use of computer networks to improve research and education. 1 1 1 1 1 fas 1. Frankenstein Cross Assemblers. A reconfigurable assembler package, especially suited for 8-bit processors, consisting of a base assembler module and a yacc parser, for each microprocessor, to handle mnemonics and addressing. Second party parser modules available from many sites. Base assembler and yacc parser modules by Mark Zenier. FTP: ftp.njit.edu/pub/msdos/frankasm/frankasm.zoo. 2. FAS. A general purpose language sponsored by the Finnish government in the 70's and 80's. 1 1 1 1 1 FASBOL ["FASBOL. A SNOBOL4 Compiler", P.J. Santos, Memo ERL-M134, UC Berkeley 1971]. 1 1 1 1 1 fascist Said of a computer system with excessive or annoying security barriers, usage limits, or access policies. The implication is that said policies are preventing hackers from getting interesting work done. The variant "fascistic" seems to have been preferred at MIT. In the design of languages and other software tools, "the fascist alternative" is the most restrictive and structured way of capturing a particular function; the implication is that this may be desirable in order to simplify the implementation or provide tighter error checking. Compare bondage-and-discipline language, although that term is global rather than local. [Jargon File] (2003-07-29) 1 1 1 1 1 FASE Fundamentally Analyzable Simplified English. L.E. McMahon, Bell Labs. [Sammet 1969, p.720]. (1994-11-09) 1 1 1 1 1 FAST 1. <body> Federation Against Software Theft. 2. <language> Fortran Automatic Symbol Translator. (1996-05-19) 1 1 1 1 1 Fast ATA Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 Fast ATA-2 Advanced Technology Attachment Interface with Extensions 1 1 1 1 1 Faster LEX (FLEX) A reimplementation of the Lex scanner generator, by Vern Paxson <vern@ee.lbl.gov>. Flex++ produces C++ and aflex produces Ada. FTP flex-2.3.8.tar.Z from a GNU archive site or (ftp://ftp.ee.lbl.gov/pub/flex-2.4.3.tar.Z). ["The FLEX Scanner Generator", Vern Paxson <vern@ee.lbl.gov>, Systems Engineering, LBL, CA]. [Home? Current version?] (2003-12-16) 1 1 1 1 1 Fast Ethernet A version of Ethernet developed in the 1990s(?) which can carry 100 Mbps compared with standard Ethernet's 10 Mbps. It requires upgraded network cards and hubs. The relevant standards are 100BaseT, 100BaseFX and 100BaseVG. (1998-03-23) 1 1 1 1 1 Fast Fourier Transform (FFT) An algorithm for computing the Fourier transform of a set of discrete data values. Given a finite set of data points, for example a periodic sampling taken from a real-world signal, the FFT expresses the data in terms of its component frequencies. It also solves the essentially identical inverse problem of reconstructing a signal from the frequency data. The FFT is a mainstay of numerical analysis. Gilbert Strang described it as "the most important algorithm of our generation". The FFT also provides the asymptotically fastest known algorithm for multiplying two polynomials. Versions of the algorithm (in C and Fortran) can be found on-line from the GAMS server here (http://gams.nist.gov/cgi-bin/gams-serve/class/J1.html). ["Numerical Methods and Analysis", Buchanan and Turner]. (1994-11-09) 1 1 1 1 1 Fast Packet Asynchronous Transfer Mode 1 1 1 1 1 Fast Page Mode Dynamic Random Access Memory Is this the same as Page Mode Dynamic Random Access Memory? (1996-10-06) 1 1 1 1 1 Fast SCSI A variant on the SCSI-2 bus. It uses the same 8-bit bus as the original SCSI-1 but runs at up to 10MB/s - double the speed of SCSI-1. (1994-11-24) 1 1 1 1 1 FAT File Allocation Table 1 1 1 1 1 FAT32 File Allocation Table 1 1 1 1 1 fatal Resulting in termination of the program. (1997-08-03) 1 1 1 1 1 fatal error Any error which causes abrupt termination of the program. The program may be terminated either by itself or by the operating system (a fatal exception). In the former instance, the program contains code which catches the error and, as a result, returns to the operating system or calls an operating system service to terminate the program. (1997-08-03) 1 1 1 1 1 fatal exception A program execution error which is trapped by the operating system and which results in abrupt termination of the program. It may be possible for the program to catch some such errors, e.g. a floating point underflow; others, such as an invalid memory access (an attempt to write to read-only memory or an attempt to read memory outside of the program's address space), may always cause control to pass to the operating system without allowing the program an opportunity to handle the error. The details depend on the language's run-time system and the operating system. See also: fatal error. (1997-08-03) 1 1 1 1 1 fat binary An executable file containing code for more than one CPU. The correct code is selected automatically at run time. This is convenient for distributing software and sharing it between multiple platforms. NEXTSTEP supports fat binaries, e.g. for Motorola 68000, Intel 80486 and SPARC ("triple fat"). Mac OS supports fat binaries for both 680x0 and PowerPC native code. [Other OSes?] (1995-09-23) 1 1 1 1 1 fat client Opposite of "thin client". (1996-12-08) 1 1 1 1 1 fat electrons Old-time hacker David Cargill's theory on the cause of computer glitches. Your typical electricity company draws its line current out of the big generators with a pair of coil taps located near the top of the dynamo. When the normal tap brushes get dirty, they take them off line to clean them up, and use special auxiliary taps on the *bottom* of the coil. Now, this is a problem, because when they do that they get not ordinary or "thin" electrons, but the fat sloppy electrons that are heavier and so settle to the bottom of the generator. These flow down ordinary wires just fine, but when they have to turn a sharp corner (as in an integrated-circuit via), they're apt to get stuck. This is what causes computer glitches. [Obviously, fat electrons must gain mass by bogon absorption - ESR] Compare bogon, magic smoke. [Jargon File] 1 1 1 1 1 fault 1. <programming> A manifestation of an error in software. A fault, if encountered, may cause a failure. 2. <architecture> page fault. (1996-05-14) 1 1 1 1 1 fault-based testing Software testing using test data designed to demonstrate the absence of a set of pre-specified faults; typically, frequently occurring faults. For example, to demonstrate that the software handles or avoids divide by zero correctly, the test data would include zero. (1996-05-15) 1 1 1 1 1 fault tolerance 1. The ability of a system or component to continue normal operation despite the presence of hardware or software faults. This often involves some degree of redundancy. 2. The number of faults a system or component can withstand before normal operation is impaired. (1995-04-06) 1 1 1 1 1 fault tolerant fault tolerance 1 1 1 1 1 fault tree analysis A form of safety analysis that assesses hardware safety to provide failure statistics and sensitivity analyses that indicate the possible effect of critical failures. (1996-05-15) 1 1 1 1 1 fax facsimile 1 1 1 1 1 Fax over IP (FoIP) Transmission of a facsimile over an IP networking instead of PSTN, analogous to Voice over IP. (1999-04-26) 1 1 1 1 1 FC A functional language. ["FC Manual", L. Augustsson, Memo 13, Programming Methodology Group, Chalmers U, Sweden 1982]. (1995-03-22) 1 1 1 1 1 FC-AL Fibre Channel-Arbitrated Loop. 1 1 1 1 1 FCB file control block. 1 1 1 1 1 F-code The code for the FP/M abstract machine. ["FP/M Abstract Syntax Description", Roger Bailey, Dept Computing, Imperial College, U London, 1985]1w. (1994-12-01) 1 1 1 1 1 FCP Flat Concurrent Prolog. ["Design and Implementation of Flat Concurrent Prolog", C. Mierowsky, TR CS84-21 Weizmann Inst, Dec 1984]. (1994-10-20) 1 1 1 1 1 FC-PGA Flip Chip Pin Grid Array 1 1 1 1 1 FCS Frame Check Sequence 1 1 1 1 1 FDC floppy disk controller 1 1 1 1 1 FDD disk drive 1 1 1 1 1 FDDI Fiber Distributed Data Interface 1 1 1 1 1 FDISK (Fixed disk utility) An MS-DOS utility program which prepares a hard disk so that it can be used as a boot disk and file systems can be created on it. OS/2, NT, Windows 95, Linux, and other Unix versions all have this command or something similar. (1996-12-23) 1 1 1 1 1 fd leak file descriptor leak 1 1 1 1 1 fdlibm A new version of the C maths library, libm, by Dr. K-C Ng. It is the basis for the bundled /usr/lib/libm.so in Solaris 2.3 for SPARC and for future Solaris 2 releases for x86 and PowerPC. It provides the standard functions necessary to pass the usual test suites. This new libm can be configured to handle exceptions in accordance with various language standards or in the spirit of IEEE 754. The C source code should be portable to any IEEE 754 system. E-mail: <netlib@research.att.com> ("send all from fdlibm"), <fdlibm-comments@sunpro.eng.sun.com> (comments and bug reports). (ftp://netlib.att.com/netlib). (1993-12-18). 1 1 1 1 1 FDMA frequency division multiple access 1 1 1 1 1 FDSE full-duplex Switched Ethernet 1 1 1 1 1 FDSP full-duplex speaker phone 1 1 1 1 1 FDT Formal Description Technique 1 1 1 1 1 fdx full-duplex 1 1 1 1 1 FEA finite element analysis 1 1 1 1 1 fear and loathing (Hunter S. Thompson) A state inspired by the prospect of dealing with certain real-world systems and standards that are totally brain-damaged but ubiquitous - Intel 8086s, COBOL, EBCDIC, or any IBM machine except the Rios (also known as the RS/6000). [Jargon File] (1994-12-06) 1 1 1 1 1 fear-driven development When project management adds more pressure (fires someone or something). A play on test-driven development. [arnis-l, Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-09-04) 1 1 1 1 1 feasibility study Part of the systems develpment life cycle which aims to determine whether it is sensible to develop some system. The most popular model of feasibility study is TELOS, standing for Technical, Economic, Legal, Operational, Schedule. Technical Feasibility: does the technology exist to implement the proposed system? Is it a practical proposition? Economic Feasibility: is the system cost-effective? Do benefits outweigh costs? Legal Feasibility: is there any conflict between the proposed system and legal requirements, e.g. the Data Protection Act? Operational Feasibility: are the current work practices and procedures adequate to support the new system? Schedule Feasibility: can the system be developed in time? After the feasibility study, the requirements analysis should be carried out. (2006-07-11) 1 1 1 1 1 feasible A description of an algorithm that takes polynomial time (that is, for a problem set of size N, the resources required to solve the problem can be expressed as some polynomial involving N). Problems that are "feasible" are said to be "in P" where P is polynomial time. Problems that are "possible" but not feasible are said to be "in NP". (2001-04-12) <systems analysis> A description of a project or system for which a feasibility study gives a positive answer. (2006-07-11) 1 1 1 1 1 feature 1. A good property or behaviour (as of a program). Whether it was intended or not is immaterial. 2. An intended property or behaviour (as of a program). Whether it is good or not is immaterial (but if bad, it is also a misfeature). 3. A surprising property or behaviour; in particular, one that is purposely inconsistent because it works better that way - such an inconsistency is therefore a feature and not a bug. This kind of feature is sometimes called a miswart. 4. A property or behaviour that is gratuitous or unnecessary, though perhaps also impressive or cute. For example, one feature of Common LISP's "format" function is the ability to print numbers in two different Roman-numeral formats (see bells, whistles, and gongs). 5. A property or behaviour that was put in to help someone else but that happens to be in your way. 6. A bug that has been documented. To call something a 1 1 1 1 1 feature creature [Possibly from slang "creature feature" for a horror movie] 1. One who loves to add features to designs or programs, perhaps at the expense of coherence, concision or taste. 2. Alternately, a mythical being that induces otherwise rational programmers to perpetrate such crocks. See also feeping creaturism, creeping featurism. [Jargon File] 1 1 1 1 1 feature creep creeping featurism 1 1 1 1 1 featurectomy /fee"ch*r-ek"t*-mee/ The act of removing a feature from a program. Featurectomies come in two flavours, the "righteous" and the "reluctant". Righteous featurectomies are performed because the remover believes the program would be more elegant without the feature, or there is already an equivalent and better way to achieve the same end. (Doing so is not quite the same thing as removing a misfeature.) Reluctant featurectomies are performed to satisfy some external constraint such as code size or execution speed. [Jargon File] (1994-10-20) 1 1 1 1 1 feature key (Or "flower", "pretzel", "clover", "propeller", beanie (from propeller beanie), splat, "command key") The Macintosh modifier key with the four-leaf clover graphic on its keytop. The feature key is the Mac's equivalent of a control key (and so labelled on some Mac II keyboards). The proliferation of terms for this creature may illustrate one subtle peril of iconic interfaces. Macs also have an "Option" modifier key, equivalent to Alt. The cloverleaf-like symbol's oldest name is "cross of St. Hannes", but it occurs in pre-Christian Viking art as a decorative motif. In Scandinavia it marks sites of historical interest. An early Macintosh developer who happened to be Swedish introduced it to Apple. Apple documentation gives the translation "interesting feature". The symbol has a Unicode character called "PLACE OF INTEREST SIGN" (U+2318), previously known as "command key". 1 1 1 1 1 feature shock (From Alvin Toffler's "Future Shock") A user's confusion when confronted with a package that has too many features and poor introductory material. [Jargon File] (2005-09-15) 1 1 1 1 1 FEC Forward Error Correction 1 1 1 1 1 FED field emission display 1 1 1 1 1 Federal Geographic Data Committee (FGDC) (ftp://fgdc.er.usgs.gov/gdc/html/fgdc.html). [Summary?] (1995-03-06) 1 1 1 1 1 Federal Information Exchange (FIX) One of the connection points between the American governmental internets and the Internet. (2001-05-14) 1 1 1 1 1 Federal Information Processing Standards (FIPS) United States Government technical standards published by the National Institute of Standards and Technology (NIST). NIST develops FIPS when there are compelling Federal government requirements such as for security and interoperability but no acceptable industry standards or solutions. Computer-related products bought by the US Government must conform to FIPS. (2003-06-04) 1 1 1 1 1 Federal Networking Council (FNC) The coordinating group of representatives from federal agencies involved in the development and use of federal networking, especially those networks using TCP/IP and the Internet. Current members include representatives from DOD, DOE, DARPA, NSF, NASA, and HHS. (1994-11-17) 1 1 1 1 1 federation The establishment of some or all of business agreements, cryptographic trust and user identifiers or attributes across security and policy domains to enable more seamless business interaction. As web services promise to enable integration between business partners through loose coupling at the application and messaging layer, federation does so at the identity management layer, insulating each domain from the details of the others' authentication and authorization. Key to this loose coupling at the identity management layer are standardized mechanisms and formats for the communication of identity information between the domains. SAML is one such standard. (2011-05-12) 1 1 1 1 1 Federation Against Software Theft Limited (FAST) A non-profitmaking organisation, formed in 1984 by the software industry with the aim of eradicating software theft in the UK. FAST was the world's first anti-piracy organisation to work to protect the intellectual property rights of software publishers. Initially concentrating on lobbying parliament to revise Copyright law, FAST also prosecutes organisations and individuals for software theft on behalf of its members and publicises the legal penalties and security risks. FAST Corporate Services Limited runs the FAST Standard for Software Compliance (FSSC-1:2004). This was developed in collaboration with the British Standards Institution as an independent standard of excellence in software compliance. In 1995 FAST proposed to merge with the Business Software Alliance created by Microsoft and which has a world-wide influence. However, the talks fell through and in 1996, Novell and Adobe Systems, Inc. defected to BSA. 1 1 1 1 1 Fedora An open source project, sponsored by Red Hat, Inc., and potentially feeding into their products. Fedora Home (http://fedora.redhat.com/). (2005-12-27) 1 1 1 1 1 feed 1. <data> data feed. 2. Rich Site Summary. 1 1 1 1 1 feedback Part of a system output presented at its input. Feedback may be unintended. When used as a design feature, the output is usually transformed by passive components which attenuate it in some manner; the result is then presented at the system input. Feedback is positive or negative, depending on the sign with which a positive change in the original input reappears after transformation. Negative feedback was invented by Black to stabilise vacuum tube amplifiers. The behaviour becomes largely a function of the feedback transformation and only minimally a function of factors such as transistor gain which are imperfectly known. Positive feedback can lead to instability; it finds wide application in the construction of oscillators. Feedback can be used to control a system, as in feedback control. (1996-01-02) 1 1 1 1 1 feedback control A control system which monitors its effect on the system it is controlling and modifies its output accordingly. For example, a thermostat has two inputs: the desired temperature and the current temperature (the latter is the feedback). The output of the thermostat changes so as to try to equalise the two inputs. Computer disk drives use feedback control to position the read/write heads accurately on a recording track. Complex systems such as the human body contain many feedback systems that interact with each other; the homeostasis mechanisms that control body temperature and acidity are good examples. (1996-01-02) 1 1 1 1 1 feed-forward A multi-layer perceptron network in which the outputs from all neurons (see McCulloch-Pitts) go to following but not preceding layers, so there are no feedback loops. 1 1 1 1 1 Feel (Free and Eventually Eulisp) An initial implementation of an EuLisp interpreter by Pete Broadbery <pab@maths.bath.ac.uk>. Version 0.75 features an integrated object system, modules, parallelism, interfaces to PVM library, TCP/IP sockets, futures, Linda and CSP. Portable to most Unix systems. Can use shared memory and threads if available. (ftp://ftp.bath.ac.uk/pub/eulisp/). (1992-09-14) 1 1 1 1 1 feep /feep/ 1. The soft electronic "bell" sound of a display terminal (except for a VT-52); a beep (in fact, the microcomputer world seems to prefer beep). 2. To cause the display to make a feep sound. ASR-33s (the original TTYs) do not feep; they have mechanical bells that ring. Alternate forms: beep, "bleep", or just about anything suitably onomatopoeic. (Jeff MacNelly, in his comic strip "Shoe", uses the word "eep" for sounds made by computer terminals and video games; this is perhaps the closest written approximation yet.) The term "breedle" was sometimes heard at SAIL, where the terminal bleepers are not particularly soft (they sound more like the musical equivalent of a raspberry or Bronx cheer; for a close approximation, imagine the sound of a Star Trek communicator's beep lasting for five seconds). The feeper on a VT-52 has been compared to the sound of a '52 Chevy stripping its gears. See also ding. [Jargon File] 1 1 1 1 1 feeper /fee'pr/ The device in a terminal or workstation (usually a loudspeaker of some kind) that makes the feep sound. 1 1 1 1 1 feeping creature [feeping creaturism] An unnecessary feature; a bit of chrome that, in the speaker's judgment, is the camel's nose for a whole horde of new features. [Jargon File] 1 1 1 1 1 feeping creaturism /fee'ping kree"ch*r-izm/ A deliberate spoonerism for creeping featurism, meant to imply that the system or program in question has become a misshapen creature of hacks. This term isn"t really well defined, but it sounds so neat that most hackers have said or heard it. It is probably reinforced by an image of terminals prowling about in the dark making their customary noises. 1 1 1 1 1 FEL Function Equation Language. Programs are sets of definitions. Sequences are lists stored in consecutive memory. "FEL Programmer's Guide", R. M. Keller, AMPS TR 7, U Utah, March 1982 1 1 1 1 1 femto- prefix 1 1 1 1 1 fence 1. A sequence of one or more distinguished (out-of-band) characters (or other data items), used to delimit a piece of data intended to be treated as a unit (the computer-science literature calls this a "sentinel"). The NUL (ASCII 0000000) character that terminates strings in C is a fence. Hex FF is also (though slightly less frequently) used this way. See zigamorph. 2. An extra data value inserted in an array or other data structure in order to allow some normal test on the array's contents also to function as a termination test. For example, a highly optimised routine for finding a value in an array might artificially place a copy of the value to be searched for after the last slot of the array, thus allowing the main search loop to search for the value without having to check at each pass whether the end of the array had been reached. 3. [among users of optimising compilers] Any technique, usually exploiting knowledge about the compiler, that blocks 1 1 1 1 1 fencepost error 1. (Rarely "lamp-post error") A problem with the discrete equivalent of a boundary condition, often exhibited in programs by iterative loops. From the following problem: "If you build a fence 100 feet long with posts 10 feet apart, how many posts do you need?" (Either 9 or 11 is a better answer than the obvious 10). For example, suppose you have a long list or array of items, and want to process items m through n; how many items are there? The obvious answer is n - m, but that is off by one; the right answer is n - m + 1. The "obvious" formula exhibits a fencepost error. See also zeroth and note that not all off-by-one errors are fencepost errors. The game of Musical Chairs involves a catastrophic off-by-one error where N people try to sit in N - 1 chairs, but it's not a fencepost error. Fencepost errors come from counting things rather than the spaces between them, or vice versa, or by neglecting to consider whether one should 1 1 1 1 1 fepped out /fept owt/ The Symbolics 3600 LISP Machine has a Front-End Processor (FEP). When the main processor gets wedged, the FEP takes control of the keyboard and screen. Such a machine is said to have "fepped out" or "dropped into the fep". [Jargon File] (1994-12-01) 1 1 1 1 1 FEPROM Flash Erasable Programmable Read-Only Memory 1 1 1 1 1 Fermat prime A prime number of the form 2^2^n + 1. Any prime number of the form 2^n+1 must be a Fermat prime. Fermat conjectured in a letter to someone or other that all numbers 2^2^n+1 are prime, having noticed that this is true for n=0,1,2,3,4. Euler proved that 641 is a factor of 2^2^5+1. Of course nowadays we would just ask a computer, but at the time it was an impressive achievement (and his proof is very elegant). No further Fermat primes are known; several have been factorised, and several more have been proved composite without finding explicit factorisations. Gauss proved that a regular N-sided polygon can be constructed with ruler and compasses if and only if N is a power of 2 times a product of distinct Fermat primes. (1995-04-10) 1 1 1 1 1 Fermat's Last Post A post to a bug tracker, mailing list or forum in which the author claims to have found a simple fix or workaround for a bug, but never says what it is and never shows up again to explain it (even after others have been puzzling over the bug for years). [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-02-19) 1 1 1 1 1 Ferranti F100-L A processor, with 16-bit addressing, registers and data paths and a 1-bit serial ALU. The F100-L could only access 32K of memory (one address bit was used for indirection). It was designed by a British company for the British Military. The unique feature of the F100-L was that it had a complete control bus available for a coprocessor. Any instruction the F100-L couldn't decode was sent directly to the coprocessor for processing. Applications for coprocessors at the time were limited, but the design is still used in modern processors, such as the National Semiconductor 32000 series. The disk operating system was written by Alec Cawley. (2007-05-19) 1 1 1 1 1 ferrite core memory (Or "core") An early form of non-volatile storage built (by hand) from tiny rings of magnetisable material threaded onto very fine wire to form large (e.g. 13"x13" or more) rectangluar arrays. Each core stored one bit of data. These were sandwiched between printed circuit boards(?). Sets of wires ran horizontally and vertically and where a vertical and horizontal wire crossed, a core had both wires threaded through it. A single core could be selected and magnetised by passing sufficient current through its horizontal and vertical wires. A core would retain its magnetisation until it was re-magnetised. The two possible polarities of magnetisation were used to represent the binary values zero and one. A third "sense" wire, passed through the core and, if the magnetisation of the core was changed, a small pulse would be induced in the sense wire which could be detected and used to deduce the core's original state. 1 1 1 1 1 Ferroelectric RAM Ferroelectric Random Access Memory 1 1 1 1 1 Ferroelectric Random Access Memory (FRAM) A type of non-volatile read/write random access semiconductor memory. FRAM combines the advantages of SRAM - writing is roughly as fast as reading, and EPROM - non-volatility and in-circuit programmability. Current (Feb 1997) disadvantages are high cost and low density, but that may change in the future. Density is currently at most 32KB on a chip, compared with 512KB for SRAM, 1MB for EPROM and 8MB for DRAM. A ferroelectric memory cell consists of a ferroelectric capacitor and a MOS transistor. Its construction is similar to the storage cell of a DRAM. The difference is in the dielectric properties of the material between the capacitor's electrodes. This material has a high dielectric constant and can be polarized by an electric field. The polarisation remains until it gets reversed by an opposite electrical field. This makes the memory non-volatile. Note that ferroelectric material, despite its name, does not 1 1 1 1 1 Fetch A Macintosh program by Jim Matthews <Fetch@Dartmouth.edu> for transferring files using File Transfer Protocol (FTP). Fetch requires a Mac 512KE, System 4.1, and either KSP 1.03 or MacTCP. Latest version: 2.1.2. Fetch is Copyright 1992, Trustees of Dartmouth College. (ftp://ftp.Dartmouth.edu/pub/mac/Fetch_2.1.2.sit.hqx). (ftp://src.doc.ic.ac.uk/computing/systems/mac/info-mac/comm/tcp). (1994-11-30) 1 1 1 1 1 fetch-execute cycle The sequence of actions that a central processing unit performs to execute each machine code instruction in a program. At the beginning of each cycle the CPU presents the value of the program counter on the address bus. The CPU then fetches the instruction from main memory (possibly via a cache and/or a pipeline) via the data bus into the instruction register. From the instruction register, the data forming the instruction is decoded and passed to the control unit which sends a sequence of control signals to the relevant function units of the CPU to perform the actions required by the instruction such as reading values from registers, passing them to the ALU to add them together and writing the result back to a register. The program counter is then incremented to address the next instruction and the cycle is repeated. 1 1 1 1 1 Feynman, Richard P. Richard P. Feynman 1 1 1 1 1 FF form feed 1 1 1 1 1 ffccc Floppy Fortran coding convention checker. 1 1 1 1 1 FFP Formal FP. A language similar to FP, but with regular sugarless syntax, for machine execution. See also FL. ["Can Programming be Liberated From the von Neumann Style? A Functional Style and Its Algebra of Programs", John Backus, 1977 Turing Award Lecture, CACM 21(8):165-180 (Aug 1978)]. (1994-10-24) 1 1 1 1 1 FFT Fast Fourier Transform 1 1 1 1 1 FGDC Federal Geographic Data Committee 1 1 1 1 1 FGHC Flat GHC. A flat variant of GHC in which guard calls can be only to primitives. See also KL1. (1994-10-24) 1 1 1 1 1 FGL 1. Flow Graph Lisp. A distributed dataflow language for AMPS (Applicative Multi-Processing System). "A Loosely-Coupled Applicative Multi-Processing System", R. Keller et al, NCC, AFIPS June 1979, pp.613- 622. 2. Function Graph Language. Related to FEL. 1 1 1 1 1 FGL+LV ["Functional Programming and the Logical Variable", G. Lindstrom, POPL 1985, pp. 266-280]. (1994-11-30) 1 1 1 1 1 FGRAAL Fortran extended GRAph Algorithmic Language. A Fortran extension for handling sets and graphs. "On a Programming Language for Graph Algorithms", W.C. Rheinboldt et al, BIT 12(2) 1972. 1 1 1 1 1 fgrep A variant of the Unix grep command which searches for fixed (uninterpreted) strings rather than regular expressions. Surprisingly, this is not always faster. (1996-10-27) 1 1 1 1 1 FhG Fraunhofer Gesellschaft 1 1 1 1 1 FHS Filesystem Hierarchy Standard 1 1 1 1 1 FHSS Frequency-Hopping Spread Spectrum 1 1 1 1 1 fi The country code for Finland. (1999-01-27) 1 1 1 1 1 Fiber Distributed Data Interface (FDDI) A 100 Mbit/s ANSI standard local area network architecture, defined in X3T9.5. The underlying medium is optical fibre (though it can be copper cable, in which case it may be called CDDI) and the topology is a dual-attached, counter-rotating token ring. FDDI rings are normally constructed in the form of a "dual ring of trees". A small number of devices, typically infrastructure devices such as routers and concentrators rather than host computers, are connected to both rings - these are referred to as "dual-attached". Host computers are then connected as single-attached devices to the routers or concentrators. The dual ring in its most degenerate form is simply collapsed into a single device. In any case, the whole dual ring is typically contained within a computer room. This network topology is required because the dual ring actually passes through each connected device and requires 1 1 1 1 1 Fiber Optic InterRepeater Link (FOIRL) An older standard of fiber optic guides used for carrying 10 MBps Ethernet. The maximum length of a segment is 1 km. A FOIRL multiport repeater and transceivers are necessary to carry the signal to multiple devices. The more recent version of Ethernet over fiber optic cables is 10baseFL with a maximum segment length of 2 km. (1998-06-28) 1 1 1 1 1 fiber optics US spelling of "fibre optics". See optical fibre. (1997-03-31) 1 1 1 1 1 Fibonacci sequence The infinite sequence of numbers beginning 1, 1, 2, 3, 5, 8, 13, ... in which each term is the sum of the two terms preceding it. The ratio of successive Fibonacci terms tends to the golden ratio, namely (1 + sqrt 5)/2. [Why not "Fibonacci series"?] (2002-10-15) 1 1 1 1 1 Fibre Channel An ANSI standard originally intended for high-speed SANs connecting servers, disc arrays, and backup devices, also later adapted to form the physical layer of Gigabit Ethernet. Development work on Fibre channel started in 1988 and it was approved by the ANSI standards committee in 1994, running at 100Mb/s. More recent innovations have seen the speed of Fibre Channel SANs increase to 10Gb/s. Several topologies are possible with Fibre Channel, the most popular being a number of devices attached to one (or two, for redundancy) central Fibre Channel switches, creating a reliable infrastructure that allows servers to share storage arrays or tape libraries. One common use of Fibre Channel SANs is for high availability databaseq clusters where two servers are connected to one highly reliable RAID array. Should one server fail, the other server can mount the array itself and continue operations with minimal downtime and loss of data. 1 1 1 1 1 Fibre Channel-Arbitrated Loop (FC-AL) A fast serial bus interface standard intended to replace SCSI on high-end servers. FC-AL has a number of advantages over SCSI. It offers higher speed: the base speed is 100 megabytes per second, with 200, 400, and 800 planned. Many devices are dual ported, i.e., can be accessed through two independent ports, which doubles speed and increases fault tolerance. Cables can be as long as 30 m (coaxial) or 10 km (optical). FC-AL enables self-configuring and hot swapping and the maximum number of devices on a single port is 126. Finally, it provides software compatibility with SCSI. Despite all these features FC-AL is unlikely to appear on desktops anytime soon, partly because its price, partly because typical desktop computers would not take advantage of many of the advanced features. On these systems FireWire has more potential. [Current status? Reference?] 1 1 1 1 1 fibre optics optical fibre 1 1 1 1 1 FIDIL Based on "maps", generalised arrays whose index sets ("domains") are arbitrary D-dimensional sets. Domains are first-class objects and may be constructed by union, intersection, etc. ["Fidil: A Language for Scientific Programming", P.N. Hilfinger et al, TR UCRL-98057, LLNL Jan 1988]. 1 1 1 1 1 FIDO (FInite DOmains) A constraint language implemented on top of Prolog. (ftp://ftp.uni-kl.de/pub1/Unix/languages/fido/). (2014-11-08) 1 1 1 1 1 FidoNet A worldwide hobbyist network of personal computers which exchanged e-mail, discussion groups, and files. Founded in 1984 and originally consisting only of IBM PCs and compatibles, FidoNet grew to include such diverse machines as Apple IIs, Ataris, Amigas and Unix systems. Though much younger than Usenet, by early 1991 FidoNet had reached a significant fraction of Usenet's size at some 8000 systems. [Jargon File] (2014-11-08) 1 1 1 1 1 Fidonews The weekly official on-line newsletter of FidoNet, also known as "'Snooz". As the editorial policy of Fidonews was "anything that arrives, we print", there were often large articles completely unrelated to FidoNet, which in turn tend to elicit flamage in subsequent issues. [Jargon File] (2014-11-08) 1 1 1 1 1 field An area of a database record, or graphical user interface form, into which a particular item of data is entered. Example usage: "The telephone number field is not really a numerical field", "Why do we need a four-digit field for the year?". A database column is the set of all instances of a given field from all records in a table. (1999-04-26) 1 1 1 1 1 field circus A derogatory pun on "field service". The field service organisation of any hardware manufacturer, but especially DEC. There is an entire genre of jokes about DEC field circus engineers: Q: How can you recognise a DEC field circus engineer with a flat tire? A: He's changing one tire at a time to see which one is flat. Q: How can you recognise a DEC field circus engineer who is out of gas? A: He's changing one tire at a time to see which one is flat. See Easter egging for additional insight on these jokes. There is also the "Field Circus Cheer" (from the plan file for DEC on MIT-AI): Maynard! Maynard! Don't mess with us! We're mean and we're tough! If you get us confused 1 1 1 1 1 field effect transistor (FET) A transistor with a region of donor material with two terminals called the "source" and the drain, and an adjoining region of acceptor material between, called the "gate". The voltage between the gate and the substrate controls the current flow between source and drain by depleting the donor region of its charge carriers to greater or lesser extent. There are two kinds of FET's, Junction FETs and MOSFETs. Because no current (except a minute leakage current) flows through the gate, FETs can be used to make circuits with very low power consumption. Contrast bipolar transistor. (1995-10-05) 1 1 1 1 1 field emission display (FED) A type of flat panel display in which field emitting cathodes bombard a phosphor coating causing it to emit light. A field emission display is similar to a cathode ray tube but only a few millimeters thick. They use a large array of fine metal tips or carbon nanotubes (which are the most efficient electron emitters known), to emit electrons through a process known as field emission. Many of these are behind each phosphor dot so FEDs do not display dead pixels like LCDs even if 20% of the emitters fail. Sony is researching FED because it is the flat-panel technology that comes closest to matching the picture of a CRT. (2007-10-10) 1 1 1 1 1 field mouse wireless mouse 1 1 1 1 1 field-programmable gate array (FPGA) A gate array where the logic network can be programmed into the device after its manufacture. An FPGA consists of an array of logic elements, either gates or lookup table RAMs, flip-flops and programmable interconnect wiring. Most FPGAs are reprogrammable, since their logic functions and interconnect are defined by RAM cells. The Xilinx LCA, Altera FLEX and AT&T ORCA devices are examples. Others can only be programmed once, by closing "antifuses". These retain their programming permanently. The Actel FPGAs are the leading example of such devices. Atmel FPGAs are currently (July 1997) the only ones in which part of the array can be reprogrammed while other parts are active. As of 1994, FPGAs have logic capacity up to 10K to 20K 2-input-NAND-equivalent gates, up to about 200 I/O pins and can run at clock rates of 50 MHz or more. FPGA designs must be prepared using CAD software tools, usually provided by 1 1 1 1 1 field servoid /fee'ld ser'voyd/ A play on "android", a derogatory term for a representative of a field service organisation (see field circus), suggesting an unintelligent rule-driven approach to servicing computer hardware. [Jargon File] (2003-02-03) 1 1 1 1 1 FIFO first-in first-out 1 1 1 1 1 Fifth An enhanced version of FORTH. M.S. Dissertation, Cliff Click <cliff@cs.rice.edu>, Texas A&M, 1985. Available from the Software Construction Co, (409)696-5432. 1 1 1 1 1 Fifth Dimension Technologies (5DT) Manufacturers of the 5th Glove. (1995-04-04) 1 1 1 1 1 fifth generation language A myth the Japanese spent a lot of money on. In about 1982, MITI decided it would spend ten years and a lot of money applying artificial intelligence to programming, thus solving the software crisis. The project spent its money and its ten years and in 1992 closed down with a wimper. (1996-11-06) 1 1 1 1 1 fifth normal form database normalisation 1 1 1 1 1 Fight-o-net A distortion of FidoNet, often applied after a flurry of flamage in a particular echo, especially the SYSOP echo or Fidonews. [Jargon File] (1996-11-04) 1 1 1 1 1 file An element of data storage in a file system. The history of computing is rich in varied kinds of files and file systems, whether ornate like the Macintosh file system or deficient like many simple pre-1980s file systems that didn't have directories. However, a typical file has these characteristics: * It is a single sequence of bytes (but consider Macintosh resource forks). * It has a finite length, unlike, e.g., a Unix device. * It is stored in a non-volatile storage medium (but see ramdrive). * It exists (nominally) in a directory. * It has a name that it can be referred to by in file operations, possibly in combination with its path. Additionally, a file system may support other file attributes, such as permissions; timestamps for creation, last modification, and last access and revision numbers (a` la 1 1 1 1 1 File Allocation Table (FAT) The component of an MS-DOS or Windows 95 file system which describes the files, directories, and free space on a hard disk or floppy disk. A disk is divided into partitions. Under the FAT file system each partition is divided into clusters, each of which can be one or more sectors, depending on the size of the partition. Each cluster is either allocated to a file or directory or it is free (unused). A directory lists the name, size, modification time and starting cluster of each file or subdirectory it contains. At the start of the partition is a table (the FAT) with one entry for each cluster. Each entry gives the number of the next cluster in the same file or a special value for "not allocated" or a special value for "this is the last cluster in the chain". The first few clusters after the FAT contain the root directory. The FAT file system was originally created for the CP/M[?] 1 1 1 1 1 File Attach [FidoNet] 1. A file sent along with a mail message from one BBS to another. 2. Sending someone a file by using the File Attach option in a BBS mailer. [Jargon File] 1 1 1 1 1 File Composition A typesetting language. ["File Composition System Reference Manual", No. 90388, Information Intl]. 1 1 1 1 1 file compression The compression of data in a file, usually to reduce storage requirements. (1995-04-06) 1 1 1 1 1 file control block (FCB) An MS-DOS data structure that stores information about an open file. The number of FCBs is configured in CONFIG.SYS with a command FCBS=x,y where x (between 1 and 255 inclusive, default 4) specifies the number of file control blocks to allocate and therefore the number of files that MS-DOS can have open at one time. y (not needed from DOS 5.0 onward) specifies the number of files to be closed automatically if all x are in use. (1995-03-21) 1 1 1 1 1 file descriptor An integer that identifies an open file within a process. This number is obtained as a result of opening a file. Operations which read, write, or close a file would take the file descriptor as an input parameter. In many operating system implementations, file descriptors are small integers which index a table of open files. In Unix, file descriptors 0, 1 and 2 correspond to the standard input, standard output and standard error files respectively. See file descriptor leak. (1998-02-06) 1 1 1 1 1 file descriptor leak (Or "fd leak" /F D leek/) A kind of programming bug analogous to a core leak, in which a program fails to close file descriptors ("fd"s) after file operations are completed, and thus eventually runs out of them. See leak. (1994-11-30) 1 1 1 1 1 file extension filename extension 1 1 1 1 1 FileMaker A database application developed by Claris. It is currently the leading database application for the Macintosh and is the second most popular standalone package for Windows. (1998-02-18) 1 1 1 1 1 FileMaker, Inc. The company that distributes the FileMaker database. FileMaker, Inc. was previously known as Claris and was renamed after a restructuring in January 1998. (http://filemaker.com/). (1998-02-18) 1 1 1 1 1 filename extension The portion of a filename, following the final point, which indicates the kind of data stored in the file - the file type. Many operating systems use filename extensions, e.g. Unix, VMS, MS-DOS, Microsoft Windows. They are usually from one to three letters (some sad old OSes support no more than three). Examples include "c" for C source code, "ps" for PostScript, "txt" for arbitrary text. NEXTSTEP and its descendants also use extensions on directories for a similar purpose. Apart from informing the user what type of content the file holds, filename extensions are typically used to decide which program to launch when a file is "run", e.g. by double-clicking it in a GUI file browser. They are also used by Unix's make to determine how to build one kind of file from another. Compare: MIME type. 1 1 1 1 1 FileNet A system for storage of images on laser disk using COLD. (1995-11-09) 1 1 1 1 1 File Request 1. The FidoNet equivalent of FTP, in which one BBS system automatically dials another and snarfs one or more files. Often abbreviated "FReq"; files are often announced as being "available for FReq" in the same way that files are announced as being "available for/by anonymous FTP" on the Internet. 2. The act of getting a copy of a file by using the File Request option of the BBS mailer. [Jargon File] (1995-01-05) 1 1 1 1 1 File Separator (FS) ASCII character 28. (1996-06-28) 1 1 1 1 1 file server Hardware and software that together provide file-handling and storage functions for multiple users on a local area network. The most common choices for file server software are Sun Microsystems' Network File System for Unix and Novell Netware for IBM PC compatibles. There is also a version of NFS for PCs called PC-NFS. Storing files on a file server saves having multiple copies stored on individual computers, thus economising on disk space and also makes administrating and updating the files easier. 1 1 1 1 1 File Service Protocol (FSP) A protocol, similar to FTP, for copying files between computers. It's designed for anonymous archives, and has protection against server and network overloading. It doesn't use connections so it can survive interruptions in service. Until 1993-08-12, FSP didn't stand for anything. Wen-King was responsible for the initials and Michael Grubb <mg@ac.duke.edu> for their eventual expansion. Other suggestions were "File Slurping Protocol", "Flaky Stream Protocol" and "FTP's Sexier Partner". FAQ (ftp://ftp.germany.eu.net/pub/networking/inet/fsp/fsp-faq/). [fsp-faq, 1993-08-12]. (1997-12-07) 1 1 1 1 1 file signature A magic number. [Jargon File] 1 1 1 1 1 file system (FS, or "filesystem") 1. A system for organizing directories and files, generally in terms of how it is implemented in the disk operating system. E.g., "The Macintosh file system is just dandy as long as you don't have to interface it with any other file systems." 2. The collection of files and directories stored on a given drive (floppy drive, hard drive, disk partition, logical drive, RAM drive, etc.). E.g., "mount attaches a named file system to the file system hierarchy at the pathname location directory [...]" -- Unix manual page for "mount(8)". As an extension of this sense, "file system" is sometimes used to refer to the representatation of the file system's organisation (e.g. its file allocation table) as opposed the actual content of the files in the file system. Unix manual page: fs(5), mount(8). (1997-04-10) 1 1 1 1 1 Filesystem Hierarchy Standard (FHS) A standard designed to be used by Unix distribution developers, package developers, and system implementors. FHS consists of a set of requirements and guidelines for file and directory placement under UNIX-like operating systems. The guidelines are intended to support interoperability of applications, system administration tools, development tools, and scripts. These systems should also be supported with greater documentation uniformity. The standard is primarily intended to be a reference and is not a tutorial on how to manage a Unix filesystem or directory hierarchy. (http://pathname.com/fhs/). RedHat deviation (http://redhat.com/corp/support/manuals/RHL-6.0-Manual/install-guide/manual/doc084.html). (2001-05-24) 1 1 1 1 1 file transfer Copying a file from one computer to another over a computer network. See also File Transfer Protocol, Kermit, Network File System, rcp, uucp, XMODEM, ZMODEM. (1997-04-10) 1 1 1 1 1 File Transfer Protocol (FTP) A client-server protocol which allows a user on one computer to transfer files to and from another computer over a TCP/IP network. Also the client program the user executes to transfer files. It is defined in STD 9, RFC 959. See also anonymous FTP, FSP, TFTP. Unix manual page: ftp(1). (1994-12-01) 1 1 1 1 1 file type The kind of data stored in a file. Most modern operating systems use the filename extension to determine the file type though others store this information elsewhere in the file system. The file type is used to choose an appropriate icon to represent the file in a GUI and the correct application with which to view, edit, run, or print the file. Different operating systems support different sets of file types though most agree on a large common set and allow arbitrary new types to be defined. See also MIME. FileInfo.com - The File Extensions Resource (http://fileinfo.com/) (2009-03-27) 1 1 1 1 1 filing system file system 1 1 1 1 1 filk /filk/ [SF fandom, where a typo for "folk" was adopted as a new word] A popular or folk song with lyrics revised or completely new lyrics, intended for humorous effect when read, and/or to be sung late at night at SF conventions. There is a flourishing subgenre of these called "computer filks", written by hackers and often containing rather sophisticated technical humour. See double bucky for an example. Compare grilf, hing and newsfroup. [Jargon File] 1 1 1 1 1 fill-out form A type of user interface used, for example, on the web, to organise a set of questions or options for the user so that it resembles a traditional paper form that is filled out. Typical query types are: fill-in-the-blank (text), menu of options, select zero or more, or select exactly one ("radio buttons"). Most web browsers support fill-out forms. Overview (http://ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/overview.html). (1998-03-24) 1 1 1 1 1 film at 11 (MIT, in parody of US TV newscasters) 1. Used in conversation to announce ordinary events, with a sarcastic implication that these events are earth-shattering. "ITS crashes; film at 11." "Bug found in scheduler; film at 11." 2. Also widely used outside MIT to indicate that additional information will be available at some future time, *without* the implication of anything particularly ordinary about the referenced event. For example, "The mail file server died this morning; we found garbage all over the root directory. Film at 11." would indicate that a major failure had occurred but that the people working on it have no additional information about it as yet; use of the phrase in this way suggests gently that the problem is liable to be fixed more quickly if the people doing the fixing can spend time doing the fixing rather than responding to questions, the answers to which will appear on the normal "11:00 news", if people will just be patient. 1 1 1 1 1 FILO stack 1 1 1 1 1 Filtabyte An Ethernet controller card made by LRT based on the LANCE and SIA. It uses DMA. Its Ethernet address can be changed by software. (1994-12-01) 1 1 1 1 1 filter 1. (Originally Unix, now also MS-DOS) A program that processes an input data stream into an output data stream in some well-defined way, and does no I/O to anywhere else except possibly on error conditions; one designed to be used as a stage in a pipeline (see plumbing). Compare sponge. 2. (functional programming) A higher-order function which takes a predicate and a list and returns those elements of the list for which the predicate is true. In Haskell: filter p [] = [] filter p (x:xs) = if p x then x : rest else rest where 1 1 1 1 1 filter promotion In a generate and test algorithm, combining part of the filter with the generator in order to reduce the number of potential solutions generated. A trivial example: filter (< 100) [1..1000] ==> [1..99] where [1..n] generates the list of integers from 1 to n. Here the filter has been combined completely with the generator. This is an example of fusion. (2005-03-18) 1 1 1 1 1 FIMS Form Interface Management System 1 1 1 1 1 Finagle's Law The generalised or "folk" version of Murphy's Law, fully named "Finagle's Law of Dynamic Negatives" and usually rendered "Anything that can go wrong, will". One variant favoured among hackers is "The perversity of the Universe tends toward a maximum". The label "Finagle's Law" was popularised by SF author Larry Niven in several stories depicting a frontier culture of asteroid miners; this "Belter" culture professed a religion and/or running joke involving the worship of the dread god Finagle and his mad prophet Murphy. [Jargon File] (1995-12-14) 1 1 1 1 1 Financial Information eXchange (FIX) A standard messaging protocol for the real-time electronic exchange of securities transactions. [Reference?] (2001-05-14) 1 1 1 1 1 Finder The part of the Macintosh Operating System and GUI that simulates the desktop. The multitasking version of Finder was called "MultiFinder" until multitasking was integrated into the core of the OS with the introduction of System 7.0 in 1990. (2005-03-18) 1 1 1 1 1 fine adjuster A tool used for percussive maintenance, also known as a "hammer". (1999-01-15) 1 1 1 1 1 fine grain granularity 1 1 1 1 1 finger A Unix program that displays information about a particular user or all users logged on the system, or a remote system. Finger typically shows full name, last login time, idle time, terminal line, and terminal location (where applicable). It may also display a plan file left by the user (see also Hacking X for Y). Some versions take a "-l" (long) argument which yields more information. [Jargon File] (2002-10-06) 1 1 1 1 1 finger-pointing syndrome All-too-frequent result of bugs, especially in new or experimental configurations. The hardware vendor points a finger at the software. The software vendor points a finger at the hardware. All the poor users get is the finger. [Jargon File] (1995-12-14) 1 1 1 1 1 finite compact 1 1 1 1 1 Finite Automata Finite State Machine 1 1 1 1 1 Finite Automaton Finite State Machine 1 1 1 1 1 finite differencing strength reduction 1 1 1 1 1 Finite Impulse Response (FIR) A type of digital signal filter, in which every sample of output is the weighted sum of past and current samples of input, using only some finite number of past samples. (2001-06-06) 1 1 1 1 1 Finite State Automata Finite State Machine 1 1 1 1 1 Finite State Automaton Finite State Machine 1 1 1 1 1 Finite State Machine (FSM or "Finite State Automaton", "transducer") An abstract machine consisting of a set of states (including the initial state), a set of input events, a set of output events, and a state transition function. The function takes the current state and an input event and returns the new set of output events and the next state. Some states may be designated as "terminal states". The state machine can also be viewed as a function which maps an ordered sequence of input events into a corresponding sequence of (sets of) output events. A deterministic FSM (DFA) is one where the next state is uniquely determinied by a single input event. The next state of a nondeterministic FSM (NFA) depends not only on the current input event, but also on an arbitrary number of subsequent input events. Until these subsequent events occur it is not possible to determine which state the machine is in. It is possible to automatically translate any nondeterministic 1 1 1 1 1 finn To pull rank on somebody based on the amount of time one has spent on IRC. The term derives from the fact that IRC was originally written in Finland in 1987. [Jargon File] (2000-08-05) 1 1 1 1 1 FIPS Federal Information Processing Standards 1 1 1 1 1 FIR 1. <electronics> Finite Impulse Response (filter). 2. <standard> Fast Infrared. Infrared standard from IrDA, part of IrDA Data. FIR supports synchronous communications at 4 Mbps (and 1.115 Mbps?), at a distance of up to 1 metre. (1999-10-14) 1 1 1 1 1 firebottle electron tube 1 1 1 1 1 firefighting 1. What sysadmins have to do to correct sudden operational problems. An opposite of hacking. "Been hacking your new newsreader?" "No, a power glitch hosed the network and I spent the whole afternoon fighting fires." 2. The act of throwing lots of manpower and late nights at a project, especially to get it out before deadline. See also gang bang, Mongolian Hordes technique; however, the term firefighting connotes that the effort is going into chasing bugs rather than adding features. (1994-12-01) 1 1 1 1 1 Firefox A complete free, open-source web browser from the Mozilla Foundation and therefore a true code descendent of Netscape Navigator. The first non-beta release was in late 2004. Firefox Home (http://mozilla.org/products/firefox). (2005-01-26) 1 1 1 1 1 firehose syndrome An absence, failure or inadequacy of flow control mechanisms causing the sender to overwhelm the receiver. The implication is that, like trying to drink from a firehose, the consequenses are worse than just loss of data, e.g. the receiver may crash. See ping-flood. [Jargon File] (2007-03-12) 1 1 1 1 1 firewall 1. firewall code. 2. firewall machine. 1 1 1 1 1 firewall code 1. The code you put in a system (say, a telephone switch) to make sure that the users can't do any damage. Since users always want to be able to do everything but never want to suffer for any mistakes, the construction of a firewall is a question not only of defensive coding but also of interface presentation, so that users don't even get curious about those corners of a system where they can burn themselves. 2. Any sanity check inserted to catch a can't happen error. Wise programmers often change code to fix a bug twice: once to fix the bug, and once to insert a firewall which would have arrested the bug before it did quite as much damage. [Jargon File] 1 1 1 1 1 firewall machine A dedicated gateway server with special security precautions on it, used to service external connections (typically from the public Internet). The firewall machine protects servers and networks hidden behind it from crackers. The typical firewall is an inexpensive microprocessor-based Unix machine with no critical data, with public network ports on it, but just one carefully watched connection back to the rest of the cluster. The special precautions may include threat monitoring, call-back, and even a complete iron box keyable to particular incoming IDs or activity patterns. The type of network and security environment of a firewall machine is often called a De-Militarised Zone (DMZ). It may contain other servers such as e-mail servers or proxy gateways - machines that need to be publicly accessible but also need some access to internal systems. Also known as a (Venus) flytrap after the insect-eating plant. (2014-07-15) 1 1 1 1 1 FireWire High Performance Serial Bus 1 1 1 1 1 fireworks mode The mode a machine is sometimes said to be in when it is performing a crash and burn operation. [Jargon File] 1 1 1 1 1 Firmware Software stored in read-only memory (ROM) or programmable ROM (PROM). Easier to change than hardware but harder than software stored on disk. Firmware is often responsible for the behaviour of a system when it is first switched on. A typical example would be a "monitor" program in a microcomputer which loads the full operating system from disk or from a network and then passes control to it. 1 1 1 1 1 firmy stiffy 1 1 1 1 1 first class module A module that is a first class data object of the programming language, e.g. a record containing functions. In a functional language, it is standard to have first class programs, so program building blocks can have the same status. Claus Reinke's Virtual Bookshelf (http://informatik.uni-kiel.de/~cr/bib/bookshelf/Modules.html). (2004-01-26) 1 1 1 1 1 first fit A resource allocation scheme that searches a list of free resources and returns the first one that can satisfy the request. For example, when allocating memory from a list of free blocks (a heap), first fit scans the list from the beginning until it finds a block which is big enough to satisfy the request. The requested size is allocated from this block and the rest of the block returned to the free pool. First fit is faster than a best fit scheme, but results in more fragmentation of the free space because it is more likely to split up a large free block when a smaller block could have been used. (2015-01-31) 1 1 1 1 1 first generation 1. <architecture> first generation computer. 2. <language> first generation language. 1 1 1 1 1 first generation computer A prototype computer based on vacuum tubes and other esoteric technologies. Chronologically, any computer designed before the mid-1950s. Examples include Howard Aiken's Mark 1 (1944), Maunchly and Eckert's ENIAC (1946), and the IAS computer. (1996-11-22) 1 1 1 1 1 first generation language Raw machine code. When computers were first "programmed" from an input device, rather than by being rewired, they were fed input in the form of numbers, which they then interpreted as commands. This was really low level, and a program fragment might look like "010307 010307". Almost no one programs in machine language anymore, because translators are nearly trivial to write. (1994-12-01) 1 1 1 1 1 first-in first-out (FIFO, or "queue") A data structure or hardware buffer from which items are taken out in the same order they were put in. Also known as a "shelf" from the analogy with pushing items onto one end of a shelf so that they fall off the other. A FIFO is useful for buffering a stream of data between a sender and receiver which are not synchronised - i.e. not sending and receiving at exactly the same rate. Obviously if the rates differ by too much in one direction for too long then the FIFO will become either full (blocking the sender) or empty (blocking the receiver). A Unix pipe is a common example of a FIFO. A FIFO might be (but isn't ever?) called a LILO - last-in last-out. The opposite of a FIFO is a LIFO (last-in first-out) or "stack". (1999-12-06) 1 1 1 1 1 first normal form database normalisation 1 1 1 1 1 first-order Not higher-order. (1995-03-06) 1 1 1 1 1 first-order logic The language describing the truth of mathematical formulas. Formulas describe properties of terms and have a truth value. The following are atomic formulas: True False p(t1,..tn) where t1,..,tn are terms and p is a predicate. If F1, F2 and F3 are formulas and v is a variable then the following are compound formulas: F1 ^ F2 conjunction - true if both F1 and F2 are true, F1 V F2 disjunction - true if either or both are true, F1 => F2 implication - true if F1 is false or F2 is 1 1 1 1 1 First Party DMA bus mastering 1 1 1 1 1 fish (Adelaide University, Australia) 1. Another metasyntactic variable. See foo. Derived originally from the Monty Python skit in the middle of "The Meaning of Life" entitled Find the Fish. 2. <storage> microfiche. A microfiche file cabinet may be referred to as a "fish tank". [Jargon File] (1994-12-01) 1 1 1 1 1 FISH queue (By analogy with FIFO - first-in, first-out) first in, still here. A joking way of pointing out that processing of a particular sequence of events or requests has stopped dead. Also "FISH mode" and "FISHnet"; the latter may be applied to any network that is running really slowly or exhibiting extreme flakiness. [Jargon File] (1994-12-01) 1 1 1 1 1 FITNR (Thinking Machines, Inc.) Fixed In the Next Release. A written-only notation attached to bug reports. Often wishful thinking. [Jargon File] (1994-12-01) 1 1 1 1 1 FITS Flexible Image Transport System. The standard data interchange and archive format of the astronomy community. (1994-12-01) 1 1 1 1 1 FIX 1. <networking> Federal Information Exchange. 2. <business, protocol> Financial Information eXchange. (2001-05-14) 1 1 1 1 1 fix 1. <mathematics> The fixed point combinator. Called Y in combinatory logic. Fix is a higher-order function which returns a fixed point of its argument (which is a function). fix :: (a -> a) -> a fix f = f (fix f) Which satisfies the equation fix f = x such that f x = x. Somewhat surprisingly, fix can be defined as the non-recursive lambda abstraction: fix = \ h . (\ x . h (x x)) (\ x . h (x x)) Since this involves self-application, it has an infinite type. A function defined by 1 1 1 1 1 fixed disk A hard disk which is not a removable disk. 1 1 1 1 1 fixed point The fixed point of a function, f is any value, x for which f x = x. A function may have any number of fixed points from none (e.g. f x = x+1) to infinitely many (e.g. f x = x). The fixed point combinator, written as either "fix" or "Y" will return the fixed point of a function. See also least fixed point. (1995-04-13) 1 1 1 1 1 fixed-point A number representation scheme where a number, F is represented by an integer I such that F=I*R^-P, where R is the (assumed) radix of the representation and P is the (fixed) number of digits after the radix point. On computers with no floating-point unit, fixed-point calculations are significantly faster than floating-point as all the operations are basically integer operations. Fixed-point representation also has the advantage of having uniform density, i.e., the smallest resolvable difference of the representation is R^-P throughout the representable range, in contrast to floating-point representations. For example, in PL/I, FIXED data has both a precision and a scale-factor (P above). So a number declared as 'FIXED DECIMAL(7,2)' has a precision of seven and a scale-factor of two, indicating five integer and two fractional decimal digits. The smallest difference between numbers will be 0.01. (2006-11-15) 1 1 1 1 1 fixed point combinator (Y) The name used in combinatory logic for the fixed point function, also written as "fix". (1994-10-20) 1 1 1 1 1 fixed-radio access Wireless Local Loop 1 1 1 1 1 fixed-width record 1 1 1 1 1 FIXME A standard tag often put in comments near a piece of code that needs work. The point of doing so is that a grep or a similar pattern-matching tool can find all such places quickly. This is common in GNU code. Compare XXX. [Jargon File] (2001-03-16) 1 1 1 1 1 fixpoint fixed point 1 1 1 1 1 fj The country code for Fiji. (1999-01-27) 1 1 1 1 1 Fjolnir An Icelandic programming language for the IBM PC from the University of Iceland. [Pall Haraldsson <pallha@rhi.hi.is>]. (1995-03-17) 1 1 1 1 1 fk The country code for the Falkland Islands (Malvinas). (1999-01-27) 1 1 1 1 1 FL Function Level. John Backus's successor to FP, developed ca. 1985. FL is dynamically typed and adds higher-order functions, exceptions, user-defined types and other features. ["FL Language Manual, Parts 1 & 2", J. Backus et al, IBM Research Report RJ 7100 (1989)]. (1994-10-20) 1 1 1 1 1 F+L Functions plus Logic. Equational clauses within function definitions to solve for logic variable bindings. ["Functions plus Logic in Theory and Practice", R.B. Kieburtz, Feb 1987, unpublished]. (1994-10-20) 1 1 1 1 1 flag 1. <programming> A variable or quantity that can take on one of two values; a bit, particularly one that is used to indicate one of two outcomes or is used to control which of two things is to be done. "This flag controls whether to clear the screen before printing the message." "The program status word contains several flag bits." See also hidden flag, mode bit. 2. command line option. [Jargon File] (1998-05-02) 1 1 1 1 1 flag day A software change that is neither forward- nor backward-compatible, and which is costly to make and costly to reverse. E.g. "Can we install that without causing a flag day for all users?" This term has nothing to do with the use of the word flag to mean a variable that has two values. It came into use when a massive change was made to the Multics time-sharing system to convert from the old ASCII code to the new one; this was scheduled for Flag Day (a US holiday), June 14, 1966. See also backward combatability, lock-in. [Jargon File] (1998-01-15) 1 1 1 1 1 FLAIR An early system on the IBM 650. [Listed in CACM 2(5):16 (May 1959)]. (1995-03-17) 1 1 1 1 1 flaky (Or "flakey") Subject to frequent lossage. This use is of course related to the common slang use of the word to describe a person as eccentric, crazy, or just unreliable. A system that is flaky is working, sort of - enough that you are tempted to try to use it - but fails frequently enough that the odds in favour of finishing what you start are low. Commonwealth hackish prefers dodgy. [Jargon File] (1996-01-05) 1 1 1 1 1 flamage flame 1 1 1 1 1 flame To rant, to speak or write incessantly and/or rabidly on some relatively uninteresting subject or with a patently ridiculous attitude or with hostility toward a particular person or group of people. "Flame" is used as a verb ("Don't flame me for this, but..."), a flame is a single flaming message, and "flamage" /flay'm*j/ the content. Flamage may occur in any medium (e.g. spoken, electronic mail, Usenet news, web). Sometimes a flame will be delimited in text by marks such as "<flame on>...<flame off>". The term was probably independently invented at several different places. Mark L. Levinson says, "When I joined the Harvard student radio station (WHRB) in 1966, the terms flame and flamer were already well established there to refer to impolite ranting and to those who performed it. Communication among the students who worked at the station was by means of what today 1 1 1 1 1 flame bait A Usenet posting or other message intended to trigger a flame war, or one that invites flames in reply. [Jargon File] (1998-05-27) 1 1 1 1 1 flame off flame on 1 1 1 1 1 flame on To begin or continue to flame. The punning reference to Marvel Comics's Human Torch is no longer widely recognised. The phrase "flame on" may actually precede the flame, in which case "flame off" will follow it. See rave, burble. [Jargon File] (1996-10-29) 1 1 1 1 1 flamer (Or "pain in the net") One who habitually flames. Said especially of obnoxious Usenet personalities. [Jargon File] (1996-08-26) 1 1 1 1 1 flame war An acrimonious dispute conducted on a public electronic forum such as Usenet. See flame. [Jargon File] (1998-05-27) 1 1 1 1 1 flaming flame 1 1 1 1 1 FLAP A symbolic mathematics package for IBM 360. ["FLAP Programmer's Manual", A.H. Morris Jr., TR-2558 (1971) US Naval Weapons Lab]. [Sammet 1969, p. 506]. [Jargon File] (1994-10-17) 1 1 1 1 1 flap 1. <storage, jargon> To unload a DECtape (so it goes flap, flap, flap). Old-time hackers at MIT tell of the days when the disk was device 0 and microtapes were 1, 2, etc. and attempting to flap device 0 would instead start a motor banging inside a cabinet near the disk. The term is used, by extension, for unloading any magnetic tape. See also macrotape. Modern cartridge tapes no longer actually flap, but the usage has remained. The term could well be re-applied to DEC's TK50 cartridge tape drive, a spectacularly misengineered contraption which makes a loud flapping sound, almost like an old reel-type lawnmower, in one of its many tape-eating failure modes. 2. <networking> See flapping router. [Jargon File] (1997-06-17) 1 1 1 1 1 flapping router A router that transmits routing updates alternately advertising a destination network first via one route, then via a different route. Flapping routers are identified on more advanced protocol analysers such as the Network General (TM) Sniffer. (1999-08-24) 1 1 1 1 1 flarp /flarp/ [Rutgers University] Yet another metasyntactic variable (see foo). Among those who use it, it is associated with a legend that any program not containing the word "flarp" somewhere will not work. The legend is discreetly silent on the reliability of programs which *do* contain the magic word. [Jargon File] 1 1 1 1 1 Flash (Or "Shockwave Flash") A file format for delivering interactive vector graphics and animation on the web, developed by Macromedia. (http://macromedia.com/software/flash/). (1998-07-07) 1 1 1 1 1 flash 1. <file format> Adobe Flash. 2. <storage> flash memory. 2. <chat> A program to flood a Unix user's terminal with garbage by exploiting a security hole in the talk daemon. (1996-09-08) 1 1 1 1 1 flash drive Any of various kinds of device using sold-state memory ("flash memory") with an interface like a hard disk drive, often a USB interface. (2009-07-28) 1 1 1 1 1 Flash EPROM Flash Erasable Programmable Read-Only Memory 1 1 1 1 1 Flash Erasable Programmable Read-Only Memory (FEPROM, "flash memory") A kind of non-volatile storage device similar to EEPROM, but where erasing can only be done in blocks or the entire chip. In 1995 this relatively new technology started to replace EPROMs because reprogramming could be done with the chip installed. At that time FEPROMs could be rewritten about 1000 times. Like EAPROM and ferro-magnetic material, FEPROMs rely on FN tunnelling. Some flash memory supports block erase. (1995-04-22) 1 1 1 1 1 Flash Lights Impressively (FLI) /FLY/ A joke assembly language instruction first documented in the late 1970s in "The Hackers Dictionary". The FLI instruction was frequently referred to by engineers when minicomputers such as the DEC PDP-8, PDP-11 and some early microcomputers such as the IMSAI and Altair had dozens of front panel lights. "When the computer is about to do some long I/O operation, stick in a FLI so the accountants won't think the machine has hung again." (2004-08-23) 1 1 1 1 1 flash memory Originally, Flash Erasable Programmable Read-Only Memory but commonly used for various kinds of solid-state memory. (2009-07-28) 1 1 1 1 1 Flash ROM Flash Erasable Programmable Read-Only Memory 1 1 1 1 1 flat 1. Lacking any complex internal structure. "That bitty box has only a flat file system, not a hierarchical one." The verb form is flatten. Usually used pejoratively (at least with respect to file systems). 2. Said of a memory architecture like that of the VAX or Motorola 680x0 that is one big linear address space (typically with each possible value of a processor register corresponding to a unique address). This is a Good Thing. The opposite is a "segmented" architecture like that of the Intel 80x86 in which addresses are composed from a base-register/offset pair. Segmented designs are generally considered cretinous. 3. A flat domain is one where all elements except bottom are incomparable (equally well defined). E.g. the integers. [Jargon File] 1 1 1 1 1 flat address space The memory architecture in which any memory location can be selected from a single contiguous block by a single integer offset. Almost all popular processors have a flat address space, but the Intel x86 family has a segmented address space. A flat address space greatly simplifies programming because of the simple correspondence between addresses (pointers) and integers. (1996-09-10) 1 1 1 1 1 flat ASCII (Or "plain ASCII") Said of a text file that contains only 7-bit ASCII characters and uses only ASCII-standard control characters (that is, has no embedded codes specific to a particular text formatter markup language, or output device, and no meta-characters). Compare flat file. [Jargon File] (1996-01-26) 1 1 1 1 1 flat file A single file containing flat ASCII representing or encoding some structure, e.g. a database, tree or network. Flat files can be processed with general purpose tools such as Perl and text editors but are less efficient than binary files if they must be parsed repeatedly by a program. Flat files are more portable between different operating systems and application programs than binary files, and are more easily transmitted in electronic mail. See also flatten, sharchive. [Jargon File] (1996-01-26) 1 1 1 1 1 flat file database A database containing a single table, stored in a single flat file, often in a human-readable format such as comma-separated values or fixed-width columns. (2008-06-16) 1 1 1 1 1 flatten To remove structural information, especially to filter something with an implicit tree structure into a simple sequence of leaves; also tends to imply mapping to flat ASCII. "This code flattens an expression with parentheses into an equivalent canonical form." [Jargon File] 1 1 1 1 1 flat thunk A software mechanism that allows a Win32 application to load and call a 16-bit DLL, or a 16-bit application to load and call a Win32 DLL. See also generic thunk, universal thunk. (1999-04-05) 1 1 1 1 1 Flavors A Lisp variant for the LISP Machine, with object-oriented features, developed by D. Weinreb and D.A. Moon <moon@cambridge.apple.com> in 1980. "Classes" were called Flavors in the language. Though the Flavors design was superseded (notably by the Common LISP CLOS facility), the term "flavor" persisted as a general synonym for "class". ["Object-Oriented Programming with Flavors", D.A. Moon, SIGPLAN Notices 21(11):1-8 (OOPSLA '86), Nov 1986]. (1994-12-01) 1 1 1 1 1 Fleng A parallel logic language. ["Massively Parallel Implementation of Flat GHC on the Connection Machine", M. Nilsson, Proc Intl Conf on 5th Gen Comp Sys, 1988, pp.1031-1040]. 1 1 1 1 1 FLEX 1. Faster LEX. 2. A real-time language for dynamic environments. ["FLEX: Towards Flexible Real-Time Programs", K. Lin et al, Computer Langs 16(1):65-79, Jan 1991]. 3. An early object-oriented language developed for the FLEX machine by Alan Kay in about 1967. The FLEX language was a simplification of Simula and a predecessor of Smalltalk. (1995-03-29) 1 1 1 1 1 Flex A system developed by Ian Currie (Iain?) at the (then) Royal Signals and Radar Establishment at Malvern in the late 1970s. The hardware was custom and microprogrammable, with an operating system, (modular) compiler, editor, garbage collector and filing system all written in Algol-68. Flex was also re-implemented on the Perq(?). [I. F. Currie and others, "Flex Firmware", Technical Report, RSRE, Number 81009, 1981]. [I. F. Currie, "In Praise of Procedures", RSRE, 1982]. (1997-11-17) 1 1 1 1 1 Flex++ GNU's Flex scanner generator retargeted to C++ by Alain Coetmeur <coetmeur@icdc.fr>. Version 3.0. (ftp://iecc.com/pub/file/flex++.tar.gz). (ftp://iecc.com/pub/file/misc++.tar.gz). (ftp://ftp.th-darmstadt.de/pub/programming/languages/C++/tools/flex++-3.0.tar.gz). (1993-07-08) 1 1 1 1 1 Flex 2 A preprocessor designed to make Fortran look more like Pascal, developed in about 1980. [DECUS?] (2004-08-23) 1 1 1 1 1 FLI Flash Lights Impressively. 1 1 1 1 1 flib /flib/ (WPI) A meta-number, said to be an integer between 3 and 4. See grix, N. (1995-01-31) 1 1 1 1 1 FLIC Functional Language Intermediate Code. An intermediate language used in the Chalmers LML compiler. ["FLIC - A Functional Language Intermediate Code", S. Peyton Jones <simonpj@dcs.gla.ac.uk> et al, RR 148, U Warwick, Sep 1989]. (1995-01-31) 1 1 1 1 1 FLIP 1. An early assembly language on the G-15. [Listed in CACM 2(5):16 (May 1959)]. 2. ["FLIP User's Manual", G. Kahn, TR 5, INRIA 1981]. 3. Formal LIst Processor. An early language for pattern-matching on Lisp structures, similar to CONVERT. ["FLIP, A Format List Processor", W. Teitelman, Memo MAC-M-263, MIT 1966]. (1995-01-31) 1 1 1 1 1 Flip Chip Pin Grid Array (FC-PGA) The package of certain Intel Celeron and Pentium III processors. FC-PGA processors fit into Socket 370 motherboard sockets. The Flip Chip Pin Grid Array is similar to PPGA, except that the silicon core is facing up and the heat slug is exposed. FC-PGA packaging is used by Pentium III processors, and Celeron 566 processors onward. Earlier Celeron processors used PPGA packaging. Celeron processors are also available in Slot 1 SEPP packaging and Pentium III processors in Slot 1 SECC2 packaging. Adapters are available to allow a PPGA Celeron to plug into a Slot 1 connector. (2000-08-26) 1 1 1 1 1 flip-flop A digital logic circuit that can be in one of two states which it switches (or "toggles") between under control of its inputs. It can thus be considered as a one bit memory. Three types of flip-flop are common: the SR flip-flop, the JK flip-flop and the D-type flip-flop (or latch). Early literature refers to the "Eccles-Jordan circuit" and the Eccles-Jordan binary counter, using two vacuum tubes as the active (amplifying) elements for each bit of information storage. Later implementations using bipolar transistors could operate at up to 20 million state transitions per second as early as 1963. (1995-11-11) 1 1 1 1 1 flippy /flip'ee/ A single-sided floppy disk altered for double-sided use by addition of a second write-notch, so called because it must be flipped over for the second side (the "flip side") to be accessible. Used in the Commodore 1541 and elsewhere. No longer common. [Jargon File] (2000-03-07) 1 1 1 1 1 FLIP-SPUR An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 1 1 1 1 1 float The usual keyword for the floating-point data type, e.g. in the C programming language. The keyword "double" usually also introduces a floating-point type, but with twice the precession of a float. (2008-06-13) 1 1 1 1 1 floater A report in a bug tracking system that floats at the top of the queue but never gets assigned to a developer, maybe because there is a workaround. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-04-25) 1 1 1 1 1 floating-point A number representation consisting of a mantissa, M, an exponent, E, and a radix (or base). The number represented is M*R^E where R is the radix. In science and engineering, exponential notation or scientific notation uses a radix of ten so, for example, the number 93,000,000 might be written 9.3 x 10^7 (where ^7 is superscript 7). In computer hardware, floating point numbers are usually represented with a radix of two since the mantissa and exponent are stored in binary, though many different representations could be used. The IEEE specify a standard representation which is used by many hardware floating-point systems. Non-zero numbers are normalised so that the binary point is immediately before the most significant bit of the mantissa. Since the number is non-zero, this bit must be a one so it need not be stored. A 1 1 1 1 1 floating-point accelerator (FPA) Additional hardware to perform functions on floating point numbers such as addition, multiplication, logarithms, exponentials, trigonometric functions and various kinds of rounding and error detection. A floating point accelerator often functions as a co-processor to the CPU. The term "floating-point accelerator" suggests a physically larger system, often an extra circuit board, whereas a floating-point unit is probably a single chip or even part of a chip. (1994-12-01) 1 1 1 1 1 Floating-Point SPECbaserate SPECrate_base_fp92 1 1 1 1 1 Floating-Point SPECbaseratio SPECbase_fp92 1 1 1 1 1 Floating-Point SPECrate SPECrate_fp92 1 1 1 1 1 Floating-Point SPECratio SPECfp92 1 1 1 1 1 floating point underflow underflow 1 1 1 1 1 Floating-Point Unit (FPU) A floating-point accelerator, usually in a single integrated circuit, possible on the same IC as the central processing unit. (1994-10-27) 1 1 1 1 1 floating underflow underflow 1 1 1 1 1 F-Logic An object-oriented language and deductive database system. ["F-Logic: A Higher-Order Language for Reasoning about Objects, Inheritance and Scheme", ACM SIGMOD May 1989, pp. 134-146]. (1994-10-20) 1 1 1 1 1 flood On a real-time network (whether at the level of TCP/IP, or at the level of, say, IRC), to send a huge amount of data to another user (or a group of users, in a channel) in an attempt to annoy him, lock his terminal, or to overflow his network buffer and thus lose his network connection. The basic principles of flooding are that you should have better network bandwidth than the person you're trying to flood, and that what you do to flood them (e.g., generate ping requests) should be *less* resource-expensive for your machine to produce than for the victim's machine to deal with. There is also the corrolary that you should avoid being caught. Failure to follow these principles regularly produces hilarious results, e.g., an IRC user flooding himself off the network while his intended victim is unharmed, the attacker's flood attempt being detected, and him being banned from the network in semi-perpetuity. 1 1 1 1 1 FLOP 1. An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-14) 2. Erroneous singular of FLOPS. (2005-06-17) 1 1 1 1 1 Floppy A Fortran coding convention checker. A later version can generate HTML. See also Flow. ffccc posted to comp.sources.misc volume 12. (1996-08-23) 1 1 1 1 1 floppy floppy disk 1 1 1 1 1 floppy disc It's "floppy disk", not like "compact disc". (2004-11-08) 1 1 1 1 1 floppy disk (Or "floppy", "diskette") A small, portable plastic disk coated in a magnetisable substance used for storing computer data, readable by a computer with a floppy disk drive. The physical size of disks has shrunk from the early 8 inch, to 5 1/4 inch ("minifloppy") to 3 1/2 inch ("microfloppy") while the data capacity has risen. These disks are known as "floppy" disks (or diskettes) because the disk is flexible and the read/write head is in physical contact with the surface of the disk in contrast to "hard disks" (or winchesters) which are rigid and rely on a small fixed gap between the disk surface and the heads. Floppies may be either single-sided or double-sided. 3.5 inch floppies are less floppy than the larger disks because they come in a stiff plastic "envelope" or case, hence the alternative names "stiffy" or "crunchy" sometimes used to distinguish them from the floppier kind. The following formats are used on IBM PCs and elsewhere: 1 1 1 1 1 floppy disk drive disk drive 1 1 1 1 1 floppy drive disk drive 1 1 1 1 1 FLOPS Floating-point operations per second. 1 1 1 1 1 Flops The MFLOPS benchmark. 1 1 1 1 1 floptical (From "floppy disk" and "optical") A floppy disk which uses an optical tracking mechanism to improve the positioning accuracy of an ordinary magnetic head, thereby allowing more tracks and greater density. Storage media FAQ (http://cis.ohio-state.edu/hypertext/faq/usenet/arch-storage/part1/faq.html). (1995-03-15) 1 1 1 1 1 Flow A companion utility to Floppy by Julian James Bunn <julian@vxcrna.cxern.ch>. Flow allows the user to produce various reports on the structure of Fortran 77 code, such as flow diagrams and common block tables. It runs under VMS, Unix, CMS. Posted to comp.sources.misc volume 31. (1995-03-14) 1 1 1 1 1 flow chart An archaic form of visual control-flow specification employing arrows and "speech balloons" of various shapes. Hackers never use flow charts, consider them extremely silly, and associate them with COBOL programmers, card wallopers, and other lower forms of life. This attitude follows from the observations that flow charts (at least from a hacker's point of view) are no easier to read than code, are less precise, and tend to fall out of sync with the code (so that they either obfuscate it rather than explaining it, or require extra maintenance effort that doesn't improve the code). See also Program Design Language. [Jargon File] (1994-12-01) 1 1 1 1 1 flow control The collection of techniques used in serial communications to stop the sender sending data until the receiver can accept it. This may be either software flow control or hardware flow control. The receiver typically has a fixed size buffer into which received data is written as soon as it is received. When the amount of buffered data exceeds a "high water mark", the receiver will signal to the transmitter to stop transmitting until the process reading the data has read sufficient data from the buffer that it has reached its "low water mark", at which point the receiver signals to the transmitter to resume transmission. (1995-03-22) 1 1 1 1 1 flower key feature key 1 1 1 1 1 FLOW-MATIC or FLOWMATIC (Originally B-0) Possibly the first English-like DP language. Developed at Remington Rand in 1958 for the UNIVAC I. [Sammet 1969, pp. 316-324]. (1994-10-24) 1 1 1 1 1 flow of control control flow 1 1 1 1 1 FLPL Fortran List Processing Language. A package of Fortran subroutines for handling lists by H. Gelernter et al, ca 1960. [Sammet 1969, p. 388]. (1994-10-24) 1 1 1 1 1 FLUB The abstract machine for bootstrapping STAGE2. [Mentioned in Machine Oriented Higher Level Languages, W. van der Poel, N-H 1974, p. 271]. (1995-03-13) 1 1 1 1 1 Fluegelman, Andrew Andrew Fluegelman 1 1 1 1 1 flush To delete something, usually superfluous, or to abort an operation. Flush was standard ITS terminology for aborting an output operation. One spoke of the text that would have been printed, but was not, as having been flushed. It is speculated that this term arose from a vivid image of flushing unwanted characters by hosing down the internal output buffer, washing the characters away before they could be printed. Compare drain. 2. To force temporarily buffered data to be written to more permanent memory. E.g. flushing buffered disk writes to disk, as with C's standard I/O library "fflush(3)" call. This sense was in use among BLISS programmers at DEC and on Honeywell and IBM machines as far back as 1965. Another example of this usage is flushing a cache on a context switch where modified data stored in the cace which belongs to one processes must be written out to main memory so that 1 1 1 1 1 Flynn's taxonomy A classification of computer architectures based on the number of streams of instructions and data: Single instruction/single data stream (SISD) - a sequential computer. Multiple instruction/single data stream (MISD) - unusual. Single instruction/multiple data streams (SIMD) - e.g. an array processor. Multiple instruction/multiple data streams (MIMD) - multiple autonomous processors simultaneously executing different instructions on different data. [Flynn, M. J., "Some Computer Organizations and Their Effectiveness", IEEE Transactions on Computing C-21, No. 9, Sep 1972, pp 948-960]. ["A Survey of Parallel Computer Architectures", Duncan, Ralph, IEEE Computer, Feb 1990, pp 5-16]. (2003-05-29) 1 1 1 1 1 fly page banner 1 1 1 1 1 Flyspeck 3 A standard name for any font that is so tiny as to be unreadable, by analogy with names like "Helvetica 10" for 10-point Helvetica. Legal boilerplate is usually printed in Flyspeck 3. (1994-11-08) 1 1 1 1 1 flytrap firewall machine 1 1 1 1 1 FM 1. <communications> Frequency Modulation. 2. <jargon> Fucking Manual, a back-formation from RTFM. Used to refer to the manual itself. 3. <jargon> Fucking Magic, in the sense of black magic. (2001-04-30) 1 1 1 1 1 fm The country code for the Federated States of Micronesia. Heavily used for vanity domains by FM radio stations. (1999-01-27) 1 1 1 1 1 FMPL Frobozz Magic Programming Language 1 1 1 1 1 FMQ A BNF-based paser generator with an error corrector generator, by Jon Mauney. (ftp://csczar.ncsu.edu/). (1990-03-31) 1 1 1 1 1 FMS Flexible Manufacturing System (factory automation). 1 1 1 1 1 FMV video 1 1 1 1 1 FNAL Fermi National Accelerator Laboratory (Illinois, USA). 1 1 1 1 1 FNC Federal Networking Council 1 1 1 1 1 fnord 1. <convention> A word used in electronic mail and news messages to tag utterances as surrealist mind-play or humour, especially in connection with Discordianism and elaborate conspiracy theories. "I heard that David Koresh is sharing an apartment in Argentina with Hitler. (Fnord.)" "Where can I fnord get the Principia Discordia from?" 2. <programming> A metasyntactic variable, commonly used by hackers with ties to Discordianism or the Church of the SubGenius. The word "fnord" was invented in the "Illuminatus!" trilogy by Robert Shea and Robert Anton Wilson. [Jargon File] (1995-02-28) 1 1 1 1 1 FN tunnelling Fowler-Nordheim tunnelling 1 1 1 1 1 fo The country code for the Faroe Islands. (1999-01-27) 1 1 1 1 1 FOAD fuck off and die. (1998-01-18) 1 1 1 1 1 FOAF [Usenet] Friend Of A Friend. The source of an unverified, possibly untrue story. This term was not originated by hackers (it is used in Jan Brunvand's books on urban folklore), but is much better recognised on Usenet and elsewhere than in mainstream English. [Jargon File] 1 1 1 1 1 FOCAL 1. FOrmula CALculator. An interactive system written by Rick Merrill of DEC in 1969 for PDP-5 and PDP-8. It was a descendant of AID/JOSS. Versions: FOCAL-69, FOCAL-1971, FOCAL-11 (for PDP-11 under RT-11). (1994-12-21) 2. Forty-One CAlculator Language. The programming language of the HP-41 calculator line. (1994-12-21) 1 1 1 1 1 FOCL An expert system shell and backward chaining rule interpreter for the Macintosh. (ftp://ics.uci.edu/pub/machine-learning-programs/KR-FOCL-ES.cpt.hqx). E-mail: <pazzani@ics.uci.edu>. (1994-12-21) 1 1 1 1 1 FOCUS A hierarchical database language from Information Builders, Inc. (1994-12-21) 1 1 1 1 1 focus group An event where market researchers meet (potential) users of a product to try to plan how to improve it. (1999-02-24) 1 1 1 1 1 FOD /fod/ [Abbreviation for "Finger of Death", originally a spell-name from fantasy gaming] To terminate with extreme prejudice and with no regard for other people. From MUDs where the wizard command "FOD <player>" results in the immediate and total death of <player>, usually as punishment for obnoxious behaviour. This usage migrated to other circumstances, such as "I'm going to fod the process that is burning all the cycles." Compare gun. In aviation, FOD means Foreign Object Damage, e.g. what happens when a jet engine sucks up a rock on the runway or a bird in flight. Finger of Death is a distressingly apt description of what this generally does to the engine. [Jargon File] 1 1 1 1 1 FOIL File Oriented Interpretive Language. CAI language. ["FOIL - A File Oriented Interpretive Language", J.C. Hesselbart, Proc ACM 23rd National Conf (1968)]. 1 1 1 1 1 FoIP Fax over IP 1 1 1 1 1 FOIRL Fiber Optic InterRepeater Link 1 1 1 1 1 fold case case sensitivity 1 1 1 1 1 folder directory 1 1 1 1 1 fold function In functional programming, fold or "reduce" is a kind of higher-order function that takes as arguments a function, an initial "accumulator" value and a data structure (often a list). In Haskell, the two flavours of fold for lists, called foldl and foldr are defined like this: foldl :: (a -> b -> a) -> a -> [b] -> a foldl f z [] = z foldl f z (x:xs) = foldl f (f z x) xs foldr :: (a -> b -> b) -> b -> [a] -> b foldr f z [] = z 1 1 1 1 1 FOLDOC Free On-line Dictionary of Computing 1 1 1 1 1 FOLDOC New Terms (/new.html) 1 1 1 1 1 followup On Usenet, a posting generated in response to another posting (as opposed to a reply, which goes by e-mail rather than being broadcast). Followups include the ID of the parent message in their headers; smart news-readers can use this information to present Usenet news in "conversation" sequence rather than order-of-arrival. See thread. [Jargon File] 1 1 1 1 1 font A set of glyphs (images) representing the characters from some particular character set in a particular size and typeface. The image of each character may be encoded either as a bitmap (in a bitmap font) or by a higher-level description in terms of lines and areas (an outline font). There are several different computer representations for fonts, the most widely known are Adobe Systems, Inc.'s PostScript font definitions and Apple's TrueType. Window systems can display different fonts on the screen and print them. [Other types of font?] (2001-04-27) 1 1 1 1 1 fontology (XEROX PARC) The body of knowledge dealing with the construction and use of new fonts (e.g. for window systems and typesetting software). It has been said that fontology recapitulates file-ogeny. Unfortunately, this reference to the embryological dictum that "Ontogeny recapitulates phylogeny" is not merely a joke. On the Macintosh, for example, System 7 has to go through contortions to compensate for an earlier design error that created a whole different set of abstractions for fonts parallel to "files" and "folders" - ESR [Jargon File] (1994-12-01) 1 1 1 1 1 foo /foo/ A sample name for absolutely anything, especially programs and files (especially scratch files). First on the standard list of metasyntactic variables used in syntax examples. See also bar, baz, qux, quux, corge, grault, garply, waldo, fred, plugh, xyzzy, thud. The etymology of "foo" is obscure. When used in connection with "bar" it is generally traced to the WWII-era Army slang acronym FUBAR, later bowdlerised to foobar. However, the use of the word "foo" itself has more complicated antecedents, including a long history in comic strips and cartoons. FOO often appeared in the "Smokey Stover" comic strip by Bill Holman. This surrealist strip about a fireman appeared in various American comics including "Everybody's" between about 1930 and 1952. FOO was often included on licence plates of cars and in nonsense sayings in the background of some 1 1 1 1 1 foobar Another common metasyntactic variable; see foo. Hackers do *not* generally use this to mean FUBAR in either the slang or jargon sense. According to a german correspondent, the term was coined during WW2 by allied troops who could not pronounce the german word "furchtbar" (horrible, terrible, awful). [Jargon File] (2003-07-03) 1 1 1 1 1 foogol A tiny ALGOL-like language by Per Lindberg, based on the VALGOL I compiler, G.A. Edgar, DDJ May 1985. Runs on vaxen. Posted to comp.sources.Unix archive volume 8. (ftp://ftp.wustl.edu/systems/amiga/fish/fish/ff066). 1 1 1 1 1 FOOL Fool's Lisp. A small Scheme interpreter. (ftp://scam.berkeley.edu/src/local/fools.tar.Z). (1994-10-04) 1 1 1 1 1 fool file A term found on Usenet for a notional repository of all the most dramatically and abysmally stupid utterances ever. An entire subgenre of sig blocks consists of the header "From the fool file:" followed by some quote the poster wishes to represent as an immortal gem of dimwittery; for this usage to be really effective, the quote has to be so obviously wrong as to be laughable. More than one Usenetter has achieved an unwanted notoriety by being quoted in this way. (2001-01-05) 1 1 1 1 1 Fools' Lisp A small Scheme interpreter by Jonathan Lee <jonathan@scam.berkeley.edu>. Version 1.3.2 is R4RS conformant. It runs on Sun-3, Sun-4, Decstation, VAX (Ultrix), Sequent, Apollo. (ftp://scam.berkeley.edu/src/local/fools.tar.Z). (1991-10-31) 1 1 1 1 1 Foonly 1. The PDP-10 successor that was to have been built by the Super Foonly project at the Stanford Artificial Intelligence Laboratory along with a new operating system. The intention was to leapfrog from the old DEC time-sharing system SAIL was then running to a new generation, bypassing TENEX which at that time was the ARPANET standard. ARPA funding for both the Super Foonly and the new operating system was cut in 1974. Most of the design team went to DEC and contributed greatly to the design of the PDP-10 model KL10. 2. The name of the company formed by Dave Poole, one of the principal Super Foonly designers, and one of hackerdom's more colourful personalities. Many people remember the parrot which sat on Poole's shoulder and was a regular companion. 3. Any of the machines built by Poole's company. The first was the F-1 (a.k.a. Super Foonly), which was the computational engine used to create the graphics in the movie TRON. The F-1 was the fastest PDP-10 ever built, but only 1 1 1 1 1 FOOP OBJ2 plus object-orientation. "Extensions and Foundations for Object-Oriented Programming", J. Goguen et al, in Research Directions in Object-Oriented Programming, B. Shriver et al eds, MIT Press 1987. 1 1 1 1 1 foot-net sneakernet 1 1 1 1 1 footprint 1. <jargon, hardware> The floor or desk area taken up by a piece of hardware. 2. <jargon, storage> The amount of disk or RAM taken up by a program or file. 3. (IBM) The audit trail left by a crashed program (often footprints). See also toeprint. [Jargon File] (1995-04-25) 1 1 1 1 1 for for loop 1 1 1 1 1 fora forum 1 1 1 1 1 FORC Early system on IBM 704. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 Force A dBASE dialect for MS-DOS. 1 1 1 1 1 ForceOne A programming language by Andrew K. Wright. ["Polymorphism in the Compiled Language ForceOne", G.V. Cormack et al, Proc 20th Annual Hawaii Intl Conf on System Sciences, 1987, pp.284-292]. ["Design of the Programming Language ForceOne", A.K. Wright, MS Thesis, U Waterloo 1987]. (1994-10-24) 1 1 1 1 1 ForceTwo An unofficial successor to ForceOne by Andrew K. Wright. 1 1 1 1 1 foreground (Unix) On a time-sharing system, a task executing in foreground is one able to accept input from and return output to the user in contrast to one running in the background. Nowadays this term is primarily associated with Unix, but it appears first to have been used in this sense on OS/360. Normally, there is only one foreground task per terminal (or terminal window). Having multiple processes simultaneously reading the keyboard is confusing. [Jargon File] (1994-10-24) 1 1 1 1 1 Foreign eXchange Office (FXO) An analog telephone plug on a handset that receives POTS service from the telephone exchange ("central office") via a Foreign eXchange Subscriber socket and provides on-hook/off-hook indication to the exchange. (2008-01-17) 1 1 1 1 1 Foreign eXchange Subscriber (FXS) A socket that provides analog telephone service (POTS) from the telephone exchange ("central office") to a handset with an Foreign eXchange Office plug. The socket provides dial tone, power and a ring signal. (2008-01-17) 1 1 1 1 1 foreign key A column in a database table containing values that are also found in some primary key column (of a different table). By extension, any reference to entities of a different type. Some RDBMSs allow a column to be explicitly labelled as a foreign key and only allow values to be inserted if they already exist in the relevant primary key column. [Is it still a foreign key if the primary key is in a different column in the __same__ table?] (2005-01-14) 1 1 1 1 1 Foresight A software product from Nu Thena providing graphical modelling tools for high level system design and simulation. (1994-10-24) 1 1 1 1 1 for free Said of a capability of a programming language or hardware equipment that is available by its design without needing cleverness to implement: "In APL, we get the matrix operations for free." "And owing to the way revisions are stored in this system, you get revision trees for free." The term usually refers to a serendipitous feature of doing things a certain way (compare big win), but it may refer to an intentional but secondary feature. [Jargon File] (1994-12-14) 1 1 1 1 1 fork A Unix system call used by a process (the "parent") to make a copy (the "child") of itself. The child process is identical to the parent except it has a different process identifier and a zero return value from the fork call. It is assumed to have used no resources. A fork followed by an exec can be used to start a different process but this can be inefficient and some later Unix variants provide vfork as an alternative mechanism for this. See also fork bomb. (1996-12-08) 1 1 1 1 1 fork bomb A particular species of wabbit that can be written in one line of C: main() for(;;)fork(); or shell: $0 & $0 & on any Unix system, or occasionally created by an egregious coding bug. A fork bomb process "explodes" by recursively spawning copies of itself using the Unix system call fork(2). Eventually it eats all the process table entries and effectively wedges the system. Fortunately, fork bombs are relatively easy to spot and kill, so creating one deliberately seldom accomplishes more than to bring the just wrath of the gods down upon the perpetrator. See also logic bomb. [Jargon File] 1 1 1 1 1 forked (Unix; probably after "fucked") Terminally slow, or dead. Originated when one system was slowed to a snail's pace by an inadvertent fork bomb. [Jargon File] (1994-12-14) 1 1 1 1 1 for loop A loop construct found in many procedural languages which repeatedly executes some instructions while a condition is true. In C, the for loop is written in the form; for (INITIALISATION; CONDITION; AFTER) STATEMENT; where INITIALISATION is an expression that is evaluated once before the loop, CONDITION is evaluated before each iteration and the loop exits if it is false, AFTER is evaluated after each iteration, and STATEMENT is any statement, including a compound statement within braces "..", that is executed if CONDITION is true. For example: int i; for (i = 0; i < 10; i++) printf("Hello\n"); 1 1 1 1 1 FORM A system written by Jos Vermaseren <t68@nikhefh.nikhef.nl> in 1989 for fast handling of very large-scale symbolic mathematics problems. FORM is a descendant of Schoonschip and is available for many personal computers and workstations. (ftp://acm.princeton.edu/), (ftp://nikhefh.nikhef.nl/). Mailing list: <form@can.nl>. (1995-04-12) 1 1 1 1 1 FORMAC FORmula MAnipulation Compiler. J. Sammet & Tobey, IBM Boston APD, 1962. An extension of Fortran for symbolic mathematics. Versions: PL/I-FORMAC and FORMAC73. ["Introduction to FORMAC", J.E. Sammet et al, IEEE Trans Elec Comp (Aug 1964)]. [Sammet 1969, pp. 474-491]. 1 1 1 1 1 FORMAL 1. FORmula MAnipulation Language. An early Fortran extension for symbolic mathematics. ["FORMAL, A Formula Manipulation Language", C.K. Mesztenyi, Computer Note CN-1, CS Dept, U Maryland (Jan 1971)]. 2. A data manipulation language for nonprogrammers from IBM LASC. ["FORMAL: A Forms-Oriented and Visual-Directed Application System", N.C. Shu, IEEE Computer 18(8):38-49 (1985)]. (1994-12-06) 1 1 1 1 1 formal argument (Or "parameter") A name in a function or subroutine definition that is replaced by, or bound to, the corresponding actual argument when the function or subroutine is called. In many languages formal arguments behave like local variables which get initialised on entry. See: argument. (2002-07-02) 1 1 1 1 1 Formal Description Technique (FDT) A formal method for developing telecomunications services and protocols. FDTs range from abstract to implementation-oriented descriptions. All FDTs offer the means for producing unambiguous descriptions of OSI services and protocols in a more precise and comprehensive way than natural language descriptions. They provide a foundation for analysis and verification of a description. The target of analysis and verification may vary from abstract properties to concrete properties. Natural language descriptions remain an essential adjunct to formal description, enabling an unfarmiliar reader to gain rapid insight into the structure and function of services and protocols. Examples of FDTs are LOTOS, Z, SDL, and Estelle. [ISO/IEC DTR10167: "Guidelines for the application of Estelle, LOTOS and SDL"]. (1994-12-06) 1 1 1 1 1 formal methods Mathematically based techniques for the specification, development and verification of software and hardware systems. Referentially transparent languages are amenable to symbolic manipulation allowing program transformation (e.g. changing a clear inefficient specification into an obscure but efficient program) and proof of correctness. Oxford FM archive (http://comlab.ox.ac.uk/archive/formal-methods.html). (1996-05-15) 1 1 1 1 1 Formal Object Role Modeling Language (FORML) A CASE language? (1997-04-12) 1 1 1 1 1 formal review A technical review conducted with the customer including the types of reviews called for in DOD-STD-2167A (Preliminary Design Review, Critical Design Review, etc.) (1996-05-15) 1 1 1 1 1 format 1. <storage> disk format - to prepare a new, blank disk for writing. 2. <operating system> file format - how data is arranged in a specific type of file. (2007-09-04) 1 1 1 1 1 FORMAT-Fortran Fortran Matrix Abstraction Technique Fortran 1 1 1 1 1 Formatting Output Specification Instance (FOSI) An old SGML DTD standard for document management in the US military, to be replaced (soon after Oct 1996?) by the ISO standard DSSSL. (1996-10-07) 1 1 1 1 1 Formes An object-oriented language for music composition and synthesis, written in VLISP. ["Formes: Composition and Scheduling of Processes", X. Rodet & P. Cointe, Computer Music J 8(3):32-50 (Fall 1984)]. (1996-06-24) 1 1 1 1 1 form factor The type of packaging of a processor integrated circuit, e.g. PPGA, FC-PGA. More generally, a term popular among marketroids in 1998, denoting the shape of something designed. (2000-08-26) 1 1 1 1 1 form feed (FF, Control-L, ASCII 12) The character used to start a new page on a printer. This is done by "feeding" a new page (or "form") through the printer. (1996-06-24) 1 1 1 1 1 form function The shape of something designed. This term is currently (Feb 1998) in vogue among marketroids. (1998-02-11) 1 1 1 1 1 FORML 1. <language> Formal Object Role Modeling Language. 2. <event> Forth Modification Lab. (1997-04-12) 1 1 1 1 1 forms 1. <programming> fill-out form. 2. <library> (Xforms) A GUI component library for X11. (1998-03-24) 1 1 1 1 1 formula 1. In logic, a sequence of symbols representing terms, predicates, connectives and quantifiers which is either true or false. 2. <language, music> FORTH Music Language. An extension of FORTH with concurrent note-playing processes. Runs on Macintosh and Atari ST with MIDI output. ["Formula: A Programming Language for Expressive Computer Music", D.P. Anderson et al Computer 24(7):12 (Jul 1991)]. 3. Preprocessor language for the Acorn Archimedes, allowing inline high-level statements to be entered in an assembly program. Written in nawk. 1 1 1 1 1 Formula ALGOL An ALGOL extension for symbolic mathematics, strings and lists, developed by A.J. Perlis and R. Iturriaga at Carnegie for the CDC G-20 in 1962. ["An Extension of ALGOL for Manipulating Formulae", A.J. Perlis et al, CACM 7(2):127-130 (Feb 1964)]. [Sammet 1969, p. 583]. (1995-02-15) 1 1 1 1 1 Forsythe A descendent of Algol 60, intended to be as uniform and general as possible, while retaining the basic character of its progenitor. Forsythe features higher-order procedures and intersection types. (ftp://e.ergo.cs.cmu.edu/). ["Preliminary Design of the Programming Language Forsythe", J.C. Reynolds, CMU-CS-88-159, 1988]. 1 1 1 1 1 FORTH 1. <language> An interactive extensible language using postfix syntax and a data stack, developed by Charles H. Moore in the 1960s. FORTH is highly user-configurable and there are many different implementations, the following description is of a typical default configuration. Forth programs are structured as lists of "words" - FORTH's term which encompasses language keywords, primitives and user-defined subroutines. Forth takes the idea of subroutines to an extreme - nearly everything is a subroutine. A word is any string of characters except the separator which defaults to space. Numbers are treated specially. Words are read one at a time from the input stream and either executed immediately ("interpretive execution") or compiled as part of the definition of a new word. The sequential nature of list execution and the implicit use of the data stack (numbers appearing in the lists are pushed to the stack as they are encountered) imply postfix syntax. 1 1 1 1 1 for The Rest Of Them for The Rest Of Us 1 1 1 1 1 for The Rest Of Us (From the Macintosh slogan "The computer for the rest of us") 1. Used to describe a spiffy product whose affordability shames other comparable products, or (more often) used sarcastically to describe spiffy but very overpriced products. 2. Describes a program with a limited interface, deliberately limited capabilities, non-orthogonality, inability to compose primitives, or any other limitation designed to not confuse a naïve user. This places an upper bound on how far that user can go before the program begins to get in the way of the task instead of helping accomplish it. Used in reference to Macintosh software which doesn't provide obvious capabilities because it is thought that the poor luser might not be able to handle them. Becomes "the rest of *them*" when used in third-party reference; thus, "Yes, it is an attractive program, but it's designed for The Rest Of Them means a program that superficially looks neat" but has no depth beyond the surface flash. 1 1 1 1 1 Forth Modification Lab (FORML) A Forth conference held every November on the West coast of the USA (). (1997-04-12) 1 1 1 1 1 Fortran (Formula Translation) The first and, for a long time, the most widely used programming language for numerical and scientific applications. The original versions lacked recursive procedures and block structure and had a line-oriented syntax in which certain columns had special significance. There have been a great many versions. The name is often written "FORTRAN", harking back to the days before computers were taught about lower case, but ANSI decreed, in about 1985 via the ANSI FORTRAN Technical Committee TC, that it should be "Fortran". See also: Fortrash. [Was Fortran I the first version?] (2000-07-07) 1 1 1 1 1 Fortran 66 Fortran IV standardised. ASA X3.9-1966. 1 1 1 1 1 Fortran 77 A popular version of Fortran with Block IF, PARAMETER and SAVE statements added, but still no WHILE. It has fixed-length character strings, format-free I/O, and arrays with lower bounds. [ANSI X3.9-1978]. GNU version (ftp://gnu.org/pub/gnu/g77). Amiga version (ftp://ftp.cso.uiuc.edu/amiga/fish/ff470/BCF). (1994-12-16) 1 1 1 1 1 Fortran 90 (Previously "Fortran 8x" and "Fortran Extended") An extensive enlargement of Fortran 77. Fortran 90 has derived types, assumed shape arrays, array sections, functions returning arrays, case statement, module subprograms and internal subprograms, optional and keyword subprogram arguments, recursion, and dynamic allocation. It is defined in ISO 1539:1991, soon to be adopted by ANSI. ["Fortran 90 Explained", M. Metcalf et al, Oxford University Press 1990]. (1994-12-16) 1 1 1 1 1 Fortran Automatic Symbol Translator (FAST) An assembly language for the IBM 650 by MITRE Corporation. [CACM 2(5):16 (May 1959)]. [Sammet 1969, p.526]. (1994-11-09) 1 1 1 1 1 Fortran D A data-parallel Fortran developed by Ken Kennedy at Rice University. ["Fortran D Language Specification", G. Fox et al, TR 90079, Rice U, March 1991]. E-mail: Theresa Chapman <tlc@cs.rice.edu>. (1994-12-16) 1 1 1 1 1 Fortran I An early version of Fortran designed by John Backus at IBM for the IBM 704. The design was begun in 1954 and a compiler released in April 1957. [Was this the first Fortran?] (1995-02-15) 1 1 1 1 1 Fortran II 1958. Added subroutines. 1 1 1 1 1 Fortran III This was only distributed to ca. 20 sites. See Wexelblat. 1 1 1 1 1 Fortran IV IBM 1962. For the IBM 7090/94. Many implementations went well beyond the original definition. 1 1 1 1 1 Fortran-Linda Scientific Computer Assocs <linda@sca.com>. 1 1 1 1 1 Fortran M Parallel extensions to Fortran with processes and channels by Ian Foster <fortran-m@mcs.anl.gov>. ["Fortran M: A Language for Modular Parallel Programming", I. Foster et al, MCS-P327-0992, ANL, 1992]. (1994-10-26) 1 1 1 1 1 Fortran Matrix Abstraction Technique Fortran (FORMAT-Fortran) A language for manipulation, printing and plotting of large matrices. ["FORMAT-FORTRAN Matrix Abstraction Technique (Vol. V)" AFFDL-TR-66-207, Douglas Aircraft Co. Oct 1968]. (1996-09-29) 1 1 1 1 1 Fortran-Plus Fortran for the DAP parallel machine, implements many Fortran 90 features. 1 1 1 1 1 FORTRANSIT Fortran Internal Translator. A subset of Fortran translated into IT on the IBM 650. It was in use in the late 1950s and early 1960s. Compilation took place in several steps (using punched cards as the only input/output media). FORTRANSIT was converted to IT Internal Translator which was converted into SOAP and thence to machine code. In the SOAP -> machine code step, the user had to include card decks for all the subroutines used in his FORTRANSIT program (including e.g. square root, sine, and even basic floating point routines). [Sammet 1969, p. 141]. (1995-03-30) 1 1 1 1 1 Fortran V Preliminary work on adding character handling to Fortran by IBM ca. 1962. This name as never really used. (1994-10-26) 1 1 1 1 1 Fortran VI IBM's internal name for early PL/I work ca. 1963. [Sammet 1969, p. 540]. (1994-10-25) 1 1 1 1 1 Fortrash /for'trash/ Hackerism for the Fortran language, referring to its primitive design, gross and irregular syntax, limited control constructs, and slippery, exception-filled semantics. [Jargon File] (1994-10-26) 1 1 1 1 1 FORTRUNCIBLE A cross between Fortran and RUNCIBLE for the IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 fortune cookie (WAITS, via the Unix "fortune" program) A quotation, item of trivia, joke, or maxim selected at random from a collection (the "cookie file") and printed to the user's tty at login time or (less commonly) at logout time. There was a fortune program on TOPS-20. [First program?] [Jargon File] (1995-02-14) 1 1 1 1 1 forum (Plural "fora" or "forums") Any discussion group accessible through a dial-in BBS (e.g. GEnie, CI$), a mailing list, or a Usenet newsgroup (see network, the). A forum functions much like a bulletin board; users submit postings for all to read and discussion ensues. Contrast real-time chat or point-to-point personal e-mail. [Jargon File] (1998-01-18) 1 1 1 1 1 for values of A common rhetorical maneuver at MIT is to use any of the canonical random numbers as placeholders for variables. "The max function takes 42 arguments, for arbitrary values of 42". "There are 69 ways to leave your lover, for 69 = 50". This is especially likely when the speaker has uttered a random number and realises that it was not recognised as such, but even "non-random" numbers are occasionally used in this fashion. A related joke is that pi equals 3 - for small values of pi and large values of 3. This usage probably derives from the programming language MAD (Michigan Algorithm Decoder), an ALGOL-like language that was the most common choice among mainstream (non-hacker) users at MIT in the mid-1960s. It had a control structure FOR VALUES OF X = 3, 7, 99 DO ... that would repeat the indicated instructions for each value in the list (unlike the usual FOR that generates an arithmetic sequence of values). MAD is long extinct, but similar for-constructs still flourish 1 1 1 1 1 forward (verb) To send (a copy of) an electronic mail message that you have received on to one or more other addressees. Most e-mail systems can be configured to do this automatically to all or certain messages, e.g. Unix sendmail looks for a ".forward" file in the recipient's home directory. A mailing list server (or "mail exploder") is designed to forward messages automatically to lists of people. Unix manual page: aliases(5). (2000-03-22) 1 1 1 1 1 forward analysis An analysis which determines properties of the output of a program from properties of the inputs. 1 1 1 1 1 forward chaining A data-driven technique used in constructing goals or reaching inferences derived from a set of facts. Forward chaining is the basis of production systems. Oppose backward chaining. (1994-10-28) 1 1 1 1 1 forward compatibility The ability to accept input from later versions of itself. Forward compatibility is harder to achieve than backward compatibility, since, in the backward case, the input format is know whereas a forward compatible system needs to cope gracefully with unknown future features. An example of future compatibility is the stipulation that a web browser should ignore HTML tags it does not recognise. See also extensible. (2003-06-23) 1 1 1 1 1 forward compatible forward compatibility 1 1 1 1 1 forward delta The delta which, when combined with a version, creates a child version. See change management 1 1 1 1 1 forward engineering The traditional process of moving from high-level abstractions and logical, implementation-independent designs to the physical implementation of a system. Contrast reverse engineering. (1996-10-02) 1 1 1 1 1 Forward Error Correction (FEC) A class of methods for controling errors in a one-way communication system. FEC sends extra information along with the data, which can be used by the receiver to check and correct the data. A CPU writing data to RAM is a kind of one-way communication - see error correcting memory and error checking and correction. (1996-10-02) 1 1 1 1 1 forwards compatibility forward compatible 1 1 1 1 1 forwards compatible forward compatible 1 1 1 1 1 FORWISS Bayerische Forschungszentrum fuer Wissensbasierte Systeme (Bavarian research centre for knowledge-based systems) in Passau. 1 1 1 1 1 For Your Information (FYI) A subseries of RFCs that are not technical standards or descriptions of protocols. FYIs convey general information about topics related to TCP/IP or the Internet. See also STD. (1994-10-26) 1 1 1 1 1 FOSI Formatting Output Specification Instance 1 1 1 1 1 FOSIL Fredette's Operating System Interface Language 1 1 1 1 1 FOSS free open-source software 1 1 1 1 1 fossil 1. In software, a misfeature that becomes understandable only in historical context, as a remnant of times past retained so as not to break compatibility. Example: the retention of octal as default base for string escapes in C, in spite of the better match of hexadecimal to ASCII and modern byte-addressable architectures. See dusty deck. 2. More restrictively, a feature with past but no present utility. Example: the force-all-caps (LCASE) bits in the V7 and BSD Unix tty driver, designed for use with monocase terminals. (In a perversion of the usual backward-compatibility goal, this functionality has actually been expanded and renamed in some later USG Unix releases as the IUCLC and OLCUC bits.) 3. The FOSSIL (Fido/Opus/Seadog Standard Interface Level) driver specification for serial-port access to replace the brain-dead routines in the IBM PC ROMs. Fossils are used by most MS-DOS BBS software in preference to the "supported" 1 1 1 1 1 foundation The axiom of foundation states that the membership relation is well founded, i.e. that any non-empty collection Y of sets has a member y which is disjoint from Y. This rules out sets which contain themselves (directly or indirectly). 1 1 1 1 1 FOundation for Research and Technology - Hellas (FORTH) A small Greek software and research company associated with the Institute of Computer Science, Address: Science and Technology Park of Crete, Vassilika Vouton, P.O.Box 1385 GR 711 10 Heraklion, Crete, Greece. Telephone: +30 (81) 39 16 00, Fax: +30 (81) 39 16 01. (1997-04-12) 1 1 1 1 1 four-colour glossies 1. Literature created by marketroids that allegedly contains technical specs but which is in fact as superficial as possible without being totally content-free. "Forget the four-colour glossies, give me the tech ref manuals." Often applied as an indication of superficiality even when the material is printed on ordinary paper in black and white. Four-colour-glossy manuals are *never* useful for finding a problem. 2. [rare] Applied by extension to manual pages that don't contain enough information to diagnose why the program doesn't produce the expected or desired output. 1 1 1 1 1 four colour map theorem (Or "four colour theorem") The theorem stating that if the plane is divided into connected regions which are to be coloured so that no two adjacent regions have the same colour (as when colouring countries on a map of the world), it is never necessary to use more than four colours. The proof, due to Appel and Haken, attained notoriety by using a computer to check tens of thousands of cases and is thus not humanly checkable, even in principle. Some thought that this brought the philosophical status of the proof into doubt. There are now rumours of a simpler proof, not requiring the use of a computer. See also chromatic number (1995-03-25) 1 1 1 1 1 four colour theorem four colour map theorem 1 1 1 1 1 Fourier transform A technique for expressing a waveform as a weighted sum of sines and cosines. Computers generally rely on the version known as discrete Fourier transform. Named after J. B. Joseph Fourier (1768 -- 1830). See also wavelet, discrete cosine transform. (1997-03-9) 1 1 1 1 1 fourth generation computer A computer built using Very Large Scale Integration (VLSI) integrated circuits, especially a microcomputer based on a microprocesseor, or a parallel processor containing two to thousands of CPUs. VLSI made it routine to fabricate an entire CPU, main memory, or similar device with a single integrated circuit that can be mass produced at very low cost. This has resulted in new classes of machines such as personal computers, and high performance parallel processors that contains thousands of CPUs. (1996-11-22) 1 1 1 1 1 fourth generation language (4GL, or "report generator language") An application specific language, one with built-in knowledge of an application domain, in the way that SQL has built-in knowledge of the relational database domain. The term was invented by Jim Martin to refer to non-procedural high level languages built around database systems. Fourth generation languages are close to natural language and were built with the concept that certain applications could be generalised by adding limited programming ability to them. When given a description of the data format and the report to generate, a 4GL system produces COBOL (or other 3GL) code, that actually reads and processes the data and formats the results. Some examples of 4GL are: database query language e.g.SQL; Focus, Metafont, PostScript, S, IDL-PV, WAVE, 1 1 1 1 1 fourth normal form database normalisation 1 1 1 1 1 Fowler-Nordheim tunnelling (US: "tunneling") The quantum mechanical effect exploited in EAPROM and Flash Erasable Programmable Read Only Memory. It differs from Frenkel-Pool Tunnelling in that it does not rely on defects in the semiconductor. [More detail?] (2001-09-27) 1 1 1 1 1 Fox Free Objects for Crystallography 1 1 1 1 1 FoxBASE+ Fox Software's dBASE III+-like product which later became FoxPRO. It used the Xbase programming language. [Features? Dates? Status?] (2004-09-01) 1 1 1 1 1 FoxPRO A dBASE IV-like product originally from Fox Software which (well before 2000) mutated into Microsoft Visual FoxPro. [Features? Dates?] (2000-08-06) 1 1 1 1 1 Fox Software Developers of FoxBASE+ and FoxPRO. Fox Software merged with Microsoft around 1992. Addresss: Perrysburg, OH, USA. [More details?] (1997-11-18) 1 1 1 1 1 Fox Wiki A wiki for the Fox (Free Objects for Crystallography) software. Fox Wiki (http://vincefn.net/Fox/). (2014-01-20) 1 1 1 1 1 FP 1. functional programming. 2. floating-point. 3. Functional Programming. A combinator-based functional language by John Backus stressing the use of higher-order functions. Implementation by Andy Valencia. (ftp://apple.com/comp.sources.Unix/volume13). See also FFP, FL, IFP, Berkeley FP. ["Can Programming be Liberated From the von Neumann Style? A Functional Style and Its Algebra of Programs", John Backus, 1977 Turing Award Lecture, CACM 21(8):165-180 (Aug 1978)]. 4. <programming> Function Point. (1995-03-12) 1 1 1 1 1 FP2 Functional Parallel Programming. A term rewriting language which unifies functional programming and parallel programming. Every object is a term and every computation is done by rewriting. Rewrite rules are used to specify algebraic data types and parallel processes. ["Term Rewriting as a Basis for the Design of a Functional and Parallel Programming Language. A Case Study: The Language FP2", Ph. Jorrand in Fundamentals of Artificial Intelligence, LNCS 258, Springer 1986, pp. 221-276]. (1994-10-20) 1 1 1 1 1 FPA 1. <hardware> floating-point accelerator. 2. <programming> Function Point Analysis. 1 1 1 1 1 fpc A translator from Backus's FP to C. (ftp://apple.com/comp.sources.Unix/Volume20). 1 1 1 1 1 FPGA Field-Programmable Gate Array 1 1 1 1 1 FPLMTS Future Public Land Mobile Telecommunications System. 1 1 1 1 1 FPM Fast Page Mode Dynamic Random Access Memory 1 1 1 1 1 FP/M An abstract machine and intermediate language for functional languages, used to implement Hope. FP/M is an optimisation of the SECD machine. ["The Compilation of FP/M Programs into Conventional Machine Code", A.J. Field, Imperial College, London, 1985]. ["Functional Programming", A.J. Field & P.G. Harrison, A-W 1988]. (1994-10-20) 1 1 1 1 1 FPM DRAM Fast Page Mode Dynamic Random Access Memory 1 1 1 1 1 fprintf Variant of the C library routine printf which prints to a given stream. E.g. fprintf(stderr, "%s: can't open file \"%s\".", argv[0], argv[1]); which prints to the "standard error" output stream. (1995-04-25) 1 1 1 1 1 fps frames per second 1 1 1 1 1 FPU floating-point unit 1 1 1 1 1 FQDN fully qualified domain name 1 1 1 1 1 FQL A functional database language. ["An Implementation Technique for Database Query Languages", O.P. Buneman et al, ACM Trans Database Sys 7(2):164-186 (June 1982)]. (1995-04-27) 1 1 1 1 1 fr The country code for France. (1999-01-27) 1 1 1 1 1 FRA Wireless Local Loop 1 1 1 1 1 fractal A fractal is a rough or fragmented geometric shape that can be subdivided in parts, each of which is (at least approximately) a smaller copy of the whole. Fractals are generally self-similar (bits look like the whole) and independent of scale (they look similar, no matter how close you zoom in). Many mathematical structures are fractals; e.g. Sierpinski triangle, Koch snowflake, Peano curve, Mandelbrot set and Lorenz attractor. Fractals also describe many real-world objects that do not have simple geometric shapes, such as clouds, mountains, turbulence, and coastlines. Benoit Mandelbrot, the discoverer of the Mandelbrot set, coined the term "fractal" in 1975 from the Latin fractus or to break. He defines a fractal as a set for which the Hausdorff Besicovich dimension strictly exceeds the topological dimension. However, he is not satisfied with this definition as it excludes sets one would consider 1 1 1 1 1 fractal compression A technique for encoding images using fractals. Yuval Fisher's fractal image compression site (http://inls.ucsd.edu/y/Fractals/). [Summary?] (1998-03-27) 1 1 1 1 1 fractal dimension A common type of fractal dimension is the Hausdorff-Besicovich Dimension, but there are several different ways of computing fractal dimension. Fractal dimension can be calculated by taking the limit of the quotient of the log change in object size and the log change in measurement scale, as the measurement scale approaches zero. The differences come in what is exactly meant by object size and what is meant by "measurement scale" and how to get an average number out of many different parts of a geometrical object. Fractal dimensions quantify the static *geometry* of an object. For example, consider a straight line. Now blow up the line by a factor of two. The line is now twice as long as before. Log 2 / Log 2 = 1, corresponding to dimension 1. Consider a square. Now blow up the square by a factor of two. The square is now 4 times as large as before (i.e. 4 original squares can be placed on the original square). Log 4 / log 2 1 1 1 1 1 FRAD Frame Relay Access Device. 1 1 1 1 1 fragile brittle 1 1 1 1 1 fragment fragmentation 1 1 1 1 1 fragmentation 1. <networking> segmentation. 2. The process, or result, of splitting a large area of free memory (on disk or in main memory) into smaller non-contiguous blocks. This happens after many blocks have been allocated and freed. For example, if there is 3 kilobytes of free space and two 1k blocks are allocated and then the first one (at the lowest address) is freed, then there will be 2k of free space split between the two 1k blocks. The maximum size block that could then be allocated would be 1k, even though there was 2k free. The solution is to "compact" the free space by moving the allocated blocks to one end (and thus the free space to the other). As modern file systems are used and files are deleted and created, the total free space becomes split into smaller non-contiguous blocks (composed of "clusters" or "sectors" or some other unit of allocation). Eventually new files being created, and old files being extended, cannot be stored each 1 1 1 1 1 FRAM Ferroelectric Random Access Memory 1 1 1 1 1 frame 1. <networking> A data link layer "packet" which contains the header and trailer information required by the physical medium. That is, network layer packets are encapsulated to become frames. See also datagram, encapsulation, packet, Maximum Transmission Unit. 2. <programming> (language implementation) See activation record. 3. <hardware> One complete scan of the active area of a display screen. Each frame consists of a number N of horizontal scan lines, each of which, on a computer display, consists of a number M of pixels. N is the vertical resolution of the display and M is the horizontal resolution. The rate at which the displayed image is updated is the refresh rate in frames per second. (2000-10-07) 1 1 1 1 1 frame buffer Part of a video system in which an image is stored, pixel by pixel and which is used to refresh a raster image. The term "video memory" suggests a fairly static display whereas a frame buffer holds one frame from a sequence of frames forming a moving image. Frame buffers are found in frame grabbers and time base correction systems, for example. (1997-10-03) 1 1 1 1 1 Frame Check Sequence (FCS) The extra characters added to a frame for error detection and correction(?). FCS is used in X.25, HDLC, Frame Relay, and other data link layer protocols. (1998-02-27) 1 1 1 1 1 frame grabber A device that captures a single frame from an analog video signal (from a video camera or VCR) and stores it as a digital image under computer control. (1997-07-11) 1 1 1 1 1 FrameKit A frame language. ["The FrameKit User's Guide", E. Nyberg, TR CMU- CMT-88-MEMO, CMU 1988]. (1994-10-20) 1 1 1 1 1 FrameMaker A commercial document preparation program produced by Frame Technology Corporation who were taken over by Adobe Systems, Inc. in 1995/6. FrameMaker is available for a wide variety of workstations and is designed for technical and scientific documents. It uses a powerful system of templates and paragraph styles to control WYSIWYG formatting. It supports graphics, tables, and contents pages among other things. Version: FrameMaker 6, due April 2000. See also Maker Interchange Format. (2000-04-04) 1 1 1 1 1 frame pointer A pointer to the current activation record in an implementation of a block structured language. (1994-10-20) 1 1 1 1 1 frame rate The number of frames of an animation which are displayed every second, measured in frames per second (fps). The higher the frame rate, the smoother the animation will appear but the more processing power and system bandwidth is required. At less than 30 fps, the human eye can see the new pictures coming onto the screen. (2000-02-02) 1 1 1 1 1 Frame Relay A DTE-DCE interface specification based on LAPD (Q.921), the Integrated Services Digital Network version of LAPB (X.25 data link layer). A common specification was produced by a consortium of StrataCom, Cisco, Digital, and Northern Telecom. Frame Relay is the result of wide area networking requirements for speed; LAN-WAN and LAN-LAN internetworking; "bursty" data communications; multiplicity of protocols and protocol transparency. These requirements can be met with technology such as optical fibre lines, allowing higher speeds and fewer transmission errors; intelligent network end devices (personal computers, workstations, and servers); standardisation and adoption of ISDN protocols. Frame Relay could connect dedicated lines and X.25 to ATM, SMDS, BISDN and other "fast packet" technologies. Frame Relay uses the same basic data link layer framing and 1 1 1 1 1 Frame Relay Access Device (FRAD) Hardware and software that turns packets from TCP, SNA, IPX, etc into frames that can be sent over a Frame Relay wide area network. FRADs are a hot topic in data comms because companies like Netlink, Motorola, Stratacom are making lots of money out of them. (1995-11-17) 1 1 1 1 1 frames per second (fps) The unit of measurement of the frame rate of a moving image. (2000-02-02) 1 1 1 1 1 Frame Technology Corporation The company which developed FrameMaker, taken over by Adobe Systems, Inc. in late 1995/early 1996. (1995-01-30) 1 1 1 1 1 framework In object-oriented systems, a set of classes that embodies an abstract design for solutions to a number of related problems. (1995-01-30) 1 1 1 1 1 Framework 4 A European Union funding programme, the information technology portion of which replaced ESPRIT. (1994-09-19) 1 1 1 1 1 framing specification A specification of the "protocol bits" that surround the data bits on a communications channel to allow the data to be "framed" into chunks, like start and stop bits in EIA-232. It allows a receiver to synchronize at points along the data stream. (1995-01-13) 1 1 1 1 1 FRANK ["Using BINS for Interprocess Communication", P.C.J. Graham, SIGPLAN Notices 20(2):32-41 (Feb 1985)]. (1995-01-13) 1 1 1 1 1 Franz Lisp A MacLisp-like dialect of Lisp, developed primarily for work in symbolic algebra by R. Fateman et al at Ucb in about 1980. It was named after the Hungarian composer Franz Liszt (1811-1886). Franz Lisp was written in C and includes a compiler called "Liszt". ["The FRANZ LISP Manual", J.K. Foderaro et al. UC Berkeley 1980]. Version: Opus 38.22. Liszt 8.08. (ftp://ted.cs.uidaho.edu/pub/hol/franz.tar.Z). (2001-12-04) 1 1 1 1 1 Fraps A Windows application that can be used with games using DirectX or OpenGL to display the current screen redraw rate in frames per second (FPS). Fraps can also measure the frame rate between any two points and can capture stills, audio and video to disk. Latest version: 2.7.4 (2006-06-18), as of 2006-07-12. Fraps Home (http://fraps.com/). (2006-07-12) 1 1 1 1 1 Fraunhofer Gesellschaft (FhG, FhG IIS, Institut für Integrierte Schaltungen) A german company, named after the physicist. IIS is Integrated Circuit Institute. FhG are known for their research on audio compression, especially MPEG-1 Layer-3 (MP3). (2001-12-04) 1 1 1 1 1 FRED Robert Carr. Language used by Framework, Ashton-Tate. [Jargon File] 1 1 1 1 1 fred 1. The personal name most frequently used as a metasyntactic variable (see foo). Allegedly popular because it's easy for a non-touch-typist to type on a standard QWERTY keyboard. Unlike J. Random Hacker or "J. Random Loser", this name has no positive or negative loading (but see Mbogo, Dr. Fred). See also barney. 2. An acronym for "Flipping Ridiculous Electronic Device"; other F-verbs may be substituted for "flipping". 1 1 1 1 1 Fredette's Operating System Interface Language (FOSIL) A portable job control language for IBM OS360, UNIVAC EXEC 8 and Honeywell GCOS. ["Fredette's Operating System Interface Language (FOSIL)", G.N. Baird in Command Languages, C. Unger ed, N-H 1973]. (2000-08-06) 1 1 1 1 1 frednet /fred'net/ Used to refer to some random and uncommon protocol encountered on a network. "We're implementing bridging in our router to solve the frednet problem." [Jargon File] 1 1 1 1 1 free See free software, free variable. 1 1 1 1 1 FreeBSD A free operating system based on the BSD 4.4-lite release from Computer Systems Research Group at the University of California at Berkeley. FreeBSD requires an ISA, EISA, VESA, or PCI based computer with an Intel 80386SX to Pentium CPU (or compatible AMD or Cyrix CPU) with 4 megabytes of RAM and 60MB of disk space. Some of FreeBSD's features are: preemptive multitasking with dynamic priority adjustment to ensure smooth and fair sharing of the computer between applications and users. Multiuser access - peripherals such as printers and tape drives can be shared between all users. Complete TCP/IP networking including SLIP, PPP, NFS and NIS. Memory protection, demand-paged virtual memory with a merged VM/buffer cache design. FreeBSD was designed as a 32 bit operating system. X Window System (X11R6) provides a graphical user interface. Binary compatibility with many 1 1 1 1 1 FreeHEP An organisation offering a repository of software and related information for high energy physics applications. 1 1 1 1 1 Freenet Community-based bulletin board system with e-mail, information services, interactive communications, and conferencing. Freenets are funded and operated by individuals and volunteers #NAME? National Public Telecomputing Network (NPTN), an organisation based in Cleveland, Ohio, devoted to making computer telecommunication and networking services as freely available as public libraries. 1 1 1 1 1 Free Objects for Crystallography (Fox) A free, open-source program for ab initio structure determination from powder diffraction. Fox Wiki (http://vincefn.net/Fox/). (2014-01-21) 1 1 1 1 1 Free On-line Dictionary Free On-line Dictionary of Computing 1 1 1 1 1 free open-source software free software 1 1 1 1 1 FreePPP The latest incarnation of MacPPP. FreePPP continues to be used by many MacOS users as an alternative to Apple's TCP/IP stack. (http://rockstar.com/ppp.shtml). (2000-11-25) 1 1 1 1 1 freerexx REXX interpreters for Unix in C++. (ftp://rexx.uwaterloo.ca/pub/freerexx/rx102.tar.Z). 1 1 1 1 1 free software Software that everyone is free to copy, redistribute and modify. That implies free software must be available as source code, hence "free open source software" - "FOSS". It is usually also free of charge, though anyone can sell free software so long as they don't impose any new restrictions on its redistribution or use. The widespread acceptance of this definition and free software itself owes a great deal to Richard Stallman and the Free Software Foundation. There are many other kinds of "free software" in the sense of free of charge. See "-ware". This dictionary is free in both senses, though since it is documentation not software it is distributed under the GFDL. (2007-02-09) 1 1 1 1 1 Free Software Foundation (FSF) An organisation devoted to the creation and dissemination of free software, i.e. software that is free from licensing fees or restrictions on use. The Foundation's main work is supporting the GNU project, started by Richard Stallman (RMS), partly to proselytise for his position that information is community property and all software source should be shared. The GNU project has developed the GNU Emacs editor and a C compiler, gcc, replacements for many Unix utilities and many other tools. A complete Unix-like operating system (HURD) is in the works (April 1994). Software is distributed under the terms of the GNU General Public License, which also provides a good summary of the Foundation's goals and principles. The Free Software Foundation raises most of its funds from distributing its software, although it is a charity rather than a company. Although the software is freely available (e.g. by FTP - see 1 1 1 1 1 free variable 1. A variable referred to in a function, which is not an argument of the function. In lambda-calculus, x is a bound variable in the term M = \ x . T, and a free variable of T. We say x is bound in M and free in T. If T contains a subterm \ x . U then x is rebound in this term. This nested, inner binding of x is said to "shadow" the outer binding. Occurrences of x in U are free occurrences of the new x. Variables bound at the top level of a program are technically free variables within the terms to which they are bound but are often treated specially because they can be compiled as fixed addresses. Similarly, an identifier bound to a recursive function is also technically a free variable within its own body but is treated specially. A closed term is one containing no free variables. See also closure, lambda lifting, scope. 2. In logic, a variable which is not quantified (see quantifier). 1 1 1 1 1 freeware Software, often written by enthusiasts and distributed at no charge by users' groups, or via the web, electronic mail, bulletin boards, Usenet, or other electronic media. At one time, "freeware" was a trademark of Andrew Fluegelman. It wasn't enforced after his death. Freeware should not be confused with "free software" (roughly, software with unrestricted redistribution) or shareware (software distributed without charge for which users can pay voluntarily). Jim Knopf's story (http://freewarehof.org/sstory.html). [Jargon File] (2003-07-26) 1 1 1 1 1 freeze To lock an evolving software distribution or document against changes so it can be released with some hope of stability. Carries the strong implication that the item in question will unfreeze at some future date. There are more specific constructions on this term. A feature freeze, for example, locks out modifications intended to introduce new features but still allows bugfixes and completion of existing features; a "code freeze" connotes no more changes at all. At Sun Microsystems and elsewhere, one may also hear references to "code slush" - that is, an almost-but-not-quite frozen state. [Jargon File] 1 1 1 1 1 Frege, Gottlob Gottlob Frege 1 1 1 1 1 frequency division multiple access frequency division multiplexing 1 1 1 1 1 frequency division multiplexing (FDM) The simultaneous transmission of multiple separate signals through a shared medium (such as a wire, optical fibre, or light beam) by modulating, at the transmitter, the separate signals into separable frequency bands, and adding those results linearly either before transmission or within the medium. While thus combined, all the signals may be amplified, conducted, translated in frequency and routed toward a destination as a single signal, resulting in economies which are the motivation for multiplexing. Apparatus at the receiver separates the multiplexed signals by means of frequency passing or rejecting filters, and demodulates the results individually, each in the manner appropriate for the modulation scheme used for that band or group. Bands are joined to form groups, and groups may then be joined into larger groups; this process may be considered recursively, but such technique is common only in large and 1 1 1 1 1 Frequency-Hopping Spread Spectrum (FH, FHSS) A variation of spread spectrum communications in which a sequence of pseudo random numbers control a frequency synthesizer, generating different carrier frequencies that "hop around" in the desired frequency range. The receiver tunes to the same sequence of carrier frequencies in synchronisation with the transmitter. Frequency hopping spread spectrum was invented by Hedy Lamarr ("the most beautiful girl in the world", Samson and Delilah etc.) and the composer George Antheil. They held a patent filed in 1942. (2009-07-01) 1 1 1 1 1 Frequency Modulation (FM) A method of encoding data by varying the frequency of a constant amplitude carrier signal. Contrast Amplitude Modulation. (2001-04-02) 1 1 1 1 1 Frequency Shift Keying (FSK) The use of frequency modulation to transmit digital data, i.e. two different carrier frequencies are used to represent zero and one. FSK was originally used to transmit teleprinter messages by radio (RTTY) but can be used for most other types of radio and land-line digital telegraphy. More than two frequencies can be used to increase transmission rates. (1997-07-14) 1 1 1 1 1 frequently asked question (FAQ, or rarely FAQL, FAQ list) A document provided for many Usenet newsgroups (and, more recently, web services) which attempts to answer questions which new readers often ask. These are maintained by volunteers and posted regularly to the newsgroup. You should always consult the FAQ list for a group before posting to it in case your question or point is common knowledge. The collection of all FAQ lists is one of the most precious and remarkable resources on the Internet. It contains a huge wealth of up-to-date expert knowledge on many subjects of common interest. Accuracy of the information is greatly assisted by its frequent exposure to criticism by an interested, and occasionally well-informed, audience (the readers of the relevant newsgroup). The main FTP archive for FAQs is on a computer called RTFM at MIT, where they can be accessed either by group (ftp://rtfm.mit.edu/pub/usenet-by-group/comp.answers/) or by 1 1 1 1 1 Fresco 1. <standard, programming> An object-oriented API for graphical user interfaces, under development by the X Consortium as an open, multi-vendor standard. 2. <language, specification> An object-oriented specification language. ["Refinement in Fresco", in Object Oriented Specification Case Studies, K. Lano et al eds, P-H 1993]. (1996-04-28) 1 1 1 1 1 Fresh ["Fresh: A Higher-Order Language Based on Unification", G. Smolka, in Logic Programming: Functions, Relations and Equations", D. DeGroot et al, P-H 1986, pp. 469-524]. (1996-04-28) 1 1 1 1 1 friction feed A method some printers and plotters use to move paper by rotating one or both of a pair of spring-loaded rubber-coated rollers with the paper sandwiched between them. Friction feed printers are notorious for slipping when the rollers wear out, but can take standard typing paper. For printers with a sheet feeder, friction feed is more appropriate than sprocket feed which requires the holes in the paper to engage with the sprockets of the feed mechanism. (1997-07-09) 1 1 1 1 1 fried 1. <hardware> Non-working due to hardware failure; burnt out. Especially used of hardware brought down by a "power glitch" (see glitch), drop-outs, a short, or some other electrical event. (Sometimes this literally happens to electronic circuits! In particular, resistors can burn out and transformers can melt down, emitting noxious smoke - see friode, SED and LER. However, this term is also used metaphorically.) Compare frotzed. 2. <jargon> Of people, exhausted. Said particularly of those who continue to work in such a state. Often used as an explanation or excuse. "Yeah, I know that fix destroyed the file system, but I was fried when I put it in." Especially common in conjunction with "brain": "My brain is fried today, I'm very short on sleep." [Jargon File] (1996-04-28) 1 1 1 1 1 Friend Relationship between classes in the language C++. 1 1 1 1 1 FRINGE C. Katz, GE, 1961. Subcomponent of GE-255 GECOM system. Sorting and merging of data, reports and file maintenance. 1 1 1 1 1 frink /frink/ The unknown ur-verb, fill in your own meaning. Found especially on the Usenet newsgroup news:alt.fan.lemurs, where it is said that the lemurs know what "frink" means, but they aren't telling. Compare gorets. [Jargon File] (1994-12-16) 1 1 1 1 1 friode /fri:'ohd/ (TMRC) A reversible (that is, fused, blown, or fried) diode. A friode may have been a SED at some time. See also LER. [Jargon File] (1996-04-28) 1 1 1 1 1 fritterware An excess of capability that serves no productive end. The canonical example is font-diddling software on the Mac (see macdink); the term describes anything that eats huge amounts of time for quite marginal gains in function but seduces people into using it anyway. See also window shopping. [Jargon File] 1 1 1 1 1 FRL Frame Representation Language. MIT. ["The FRL Manual", R. Roberts et al, AI Memo 409, MIT AI Lab, 1977]. (1994-12-16) 1 1 1 1 1 FRMT-FTRN Scientific language. 1976. 1 1 1 1 1 frob /frob/ 1. [MIT] The TMRC definition was "FROB = a protruding arm or trunnion"; by metaphoric extension, a "frob" is any random small thing; an object that you can comfortably hold in one hand; something you can frob (sense 2). See frobnitz. 2. Abbreviated form of frobnicate. 3. [MUD] A command on some MUDs that changes a player's experience level (this can be used to make wizards); also, to request wizard privileges on the "professional courtesy" grounds that one is a wizard elsewhere. The command is actually "frobnicate" but is universally abbreviated to the shorter form. [Jargon File] 1 1 1 1 1 frobnicate /frob'ni-kayt/ (Possibly from frobnitz, and usually abbreviated to frob, but "frobnicate" is recognised as the official full form). To manipulate or adjust, to tweak. One frequently frobs bits or other 2-state devices. Thus: Please frob the light switch (that is, flip it), but also Stop frobbing that clasp; you'll break it. One also sees the construction "to frob a frob". Usage: frob, twiddle, and tweak sometimes connote points along a continuum. "Frob" connotes aimless manipulation; twiddle connotes gross manipulation, often a coarse search for a proper setting; "tweak" connotes fine-tuning. If someone is turning a knob on an oscilloscope, then if he's carefully adjusting it, he is probably tweaking it; if he is just turning it but looking at the screen, he is probably twiddling it; but if he's just doing it because turning a knob is fun, he's frobbing it. The variant "frobnosticate" has also been reported. 1 1 1 1 1 frobnitz /frob'nits/, plural "frobnitzem" /frob'nit-zm/ or "frobni" /frob'ni:/ (TMRC) An unspecified physical object, a widget. Also refers to electronic black boxes. This rare form is usually abbreviated to "frotz", or more commonly to frob. Also used are "frobnule" (/frob'n[y]ool/) and "frobule" (/frob'yool/). Starting perhaps in 1979, "frobozz" /fr*-boz'/ (plural: "frobbotzim" /fr*-bot'zm/) has also become very popular, largely through its exposure as a name via Zork. These variants can also be applied to nonphysical objects, such as data structures. Pete Samson, compiler of the original TMRC lexicon, adds,q "Under the TMRC (railway) layout were many storage boxes, managed (in 1958) by David R. Sawyer. Several had fanciful designations written on them, such as Frobnitz Coil Oil""." Perhaps DRS intended Frobnitz to be a proper name, but the name was quickly taken for the thing". This was almost certainly the origin of the term. [Jargon File] (1994-12-16) 1 1 1 1 1 Frobozz Magic Programming Language (FMPL of Accardi). A prototype-based, object-oriented, event-driven (mainly I/O events) interpreted language with functional features. Developed at the Experimental Computing Facility, University of California, Berkeley. There is an interpreter by Jon Blow <blojo@xcf.berkeley.edu>. Latest version: 1, as of 1992-06-02. (ftp://xcf.berkeley.edu/src/local/fmpl). Mailing list: <fmpl@xcf.berkeley.edu>. E-mail: Jack Hsu <tcl-archive@barkley.berkeley.edu>. (1992-06-02) 1 1 1 1 1 frogging (University of Waterloo) 1. Partial corruption of a text file or input stream by some bug or consistent glitch, as opposed to random events like line noise or media failures. Might occur, for example, if one bit of each incoming character on a tty were stuck, so that some characters were correct and others were not. See terminak for a historical example. 2. By extension, accidental display of text in a mode where the output device emits special symbols or mnemonics rather than conventional ASCII. This often happens, for example, when using a terminal or comm program on a device like an IBM PC with a special "high-half" character set and with the bit-parity assumption wrong. A hacker sufficiently familiar with ASCII bit patterns might be able to read the display anyway. [Jargon File] 1 1 1 1 1 Frolic A Prolog system in Common Lisp. (ftp://ftp.cs.utah.edu/pub/frolic.tar.Z). (1991-11-23) 1 1 1 1 1 front end 1. An intermediary computer that does set-up and filtering for another (usually more powerful but less friendly) machine (a back end). 2. Software that provides an interface to another program behind it, which may not be as user-friendly. Probably from analogy with hardware front-ends that interfaced with mainframes. [Jargon File] 1 1 1 1 1 front-end processor (FEP) 1. A small computer necessary to enable an IBM mainframe using SNA to communicate beyond the limits of the dinosaur pen. 2. A small computer controlling the screen and keyboard of a Symbolics 3600 LISP Machine. 1 1 1 1 1 front side bus (FSB) The bus via which a processor communicates with its RAM and chipset; one half of the Dual Independent Bus (the other half being the backside bus). The L2 cache is usually on the FSB, unless it is on the same chip as the processor [example?]. In PCI systems, the PCI bus runs at half the FSB speed. Intel's Pentium 60 ran the bus and processor at 60 MHz. All later processors have used multipliers to increase the internal clock speed while maintaining the same external clock speed, e.g. the Pentium 90 used a 1.5x multiplier. Modern Socket 370 motherboards support multipliers from 4.5x to 8.0x, and FSB speeds from 50 MHz to a proposed 83 MHz standard. These higher speeds may cause problems with some PCI hardware. Altering the FSB speed and the multiplier ratio are the two main ways of overclocking processors. Toms Hardware - The Bus Speed Guide 1 1 1 1 1 frotzed /frotst/ down because of hardware problems. Compare fried. A machine that is merely frotzed may be fixable without replacing parts, but a fried machine is more seriously damaged. (2010-05-16) 1 1 1 1 1 frowney (Or "frowney face") See emoticon. [Jargon File] 1 1 1 1 1 fry 1. To fail. Said especially of smoke-producing hardware failures. More generally, to become non-working. Usage: never said of software, only of hardware and humans. See fried, magic smoke. 2. To cause to fail; to roach, toast, or hose a piece of hardware. Never used of software or humans, but compare fried. 1 1 1 1 1 FS 1. <file system> file system. 2. <character> File Separator. 1 1 1 1 1 FSB front side bus 1 1 1 1 1 fsck 1. <operating system> file system check. The Unix program that checks a file system for internal consistency and bad blocks etc. and can repair some faults. fsck is often used after a crash when the file system has been left in an inconsistent state, e.g. due to incomplete flushing of buffers. (1998-03-06) 2. <jargon> Used on Usenet newsgroup alt.sysadmin.recovery as substitute for "fuck" and became more main-stream after the Communications Decency Act. (1998-03-06) 1 1 1 1 1 FSF Free Software Foundation 1 1 1 1 1 FSK Frequency Shift Keying 1 1 1 1 1 FSL Formal Semantics Language. A language for compiler writing. ["A Formal Semantics for Computer Languages and its Application in a Compiler-Compiler", J.A. Feldman, CACM 9(1) (Jan 1966)]. [Sammet 1969, p. 641]. (1995-01-23) 1 1 1 1 1 FSM 1. <mathematics, algorithm, theory> Finite State Machine. 2. <networking> FDDI Switching Module. (3Com implements this device on its LAN switches). [What is it?] (1997-05-16) 1 1 1 1 1 FSP File Service Protocol 1 1 1 1 1 fsplit A tool to split up monolithic Fortran programs. 1 1 1 1 1 FT fault tolerant 1 1 1 1 1 FTAM File Transfer, Access, and Management: an application layer protocol for file transfer and remote manipulation (ISO 8571). 1 1 1 1 1 FTP File Transfer Protocol 1 1 1 1 1 FTP archive archive site 1 1 1 1 1 FTP by mail A service offered by DEC to allow people without Internet access to get copies of files which are available by anonymous FTP. Send a message with just the word "help" in the body to <ftpmail@decwrl.dec.com>. 1 1 1 1 1 FTP server A network server program or computer which responds to requests for files via FTP. A busy Internet archive site may have one or more computers dedicated to running FTP server software. These will typically have hostnames beginning with "ftp.", e.g. ftp.denet.dk. (1998-07-02) 1 1 1 1 1 FTP Software, Inc. Developers of the original PC/TCP Packet Driver specification. Address: 26 Princess St. Wakefield, MA 01880-3004. Telephone: +1 (617) 246 0900. (1994-12-05) 1 1 1 1 1 FTTP Do you mean FTP or HTTP? 1 1 1 1 1 FTW An ambiguous acronym which might stand for any of "For The Win" (the thing just referred to will help you succeed), Forever Two Wheels (biker slang), WTF backwards, "Fuck The World", "Fuck This War", "Fun To Watch" or something else. (2008-09-12) 1 1 1 1 1 FTX Stratus' Unix operating system. (1998-07-06) 1 1 1 1 1 FUBAR 1. (WWII military slang) Fucked up beyond all recognition (or repair). See foobar. 2. <hardware> The Failed UniBus Address Register in a VAX. A good example of how jargon can occasionally be snuck past the suits. Larry Robinson <lrobins@indiana.edu> reports the following nonstandard use for FUBAR: One day somebody got mad at the card reader (or card eater that day) on our Univac 3200. He taped a sign, "This thing is FUBAR", on the metal weight that sits on the stack of unread cards. The sign stayed there for over a year. One day, somebody said, "Don't forget to put the fubar on top of the stack". It stuck! We called that weight the fubar until they took away the machine. The replacement card reader had two spring loaded card clamps, one for the feed and one for the return, and we called THOSE fubars until we dumped punch 1 1 1 1 1 FUD /fuhd/ An acronym invented by Gene Amdahl after he left IBM to found his own company: "FUD is the fear, uncertainty, and doubt that IBM sales people instill in the minds of potential customers who might be considering [Amdahl] products." The idea, of course, was to persuade them to go with safe IBM gear rather than with competitors' equipment. This implicit coercion was traditionally accomplished by promising that Good Things would happen to people who stuck with IBM, but Dark Shadows loomed over the future of competitors' equipment or software. [Jargon File] (1995-05-23) 1 1 1 1 1 fudge 1. To perform in an incomplete but marginally acceptable way, particularly with respect to the writing of a program. "I didn't feel like going through that pain and suffering, so I fudged it - I'll fix it later." 2. The resulting code. [Jargon File] 1 1 1 1 1 fudge factor A value or parameter that is varied in an ad hoc way to produce the desired result. The terms "tolerance" and slop are also used, though these usually indicate a one-sided leeway, such as a buffer that is made larger than necessary because one isn't sure exactly how large it needs to be, and it is better to waste a little space than to lose completely for not having enough. A fudge factor, on the other hand, can often be tweaked in more than one direction. A good example is the "fuzz" typically allowed in floating-point calculations: two numbers being compared for equality must be allowed to differ by a small amount; if that amount is too small, a computation may never terminate, while if it is too large, results will be needlessly inaccurate. Fudge factors are frequently adjusted incorrectly by programmers who don't fully understand their import. 1 1 1 1 1 Fudgets (From "functional widgets") Graphical user interface widgets available as The Fudget library - a toolkit for concurrent programming of graphical user interfaces, client/servers and more written in Haskell by Thomas Hallgren <hallgren@cs.chalmers.se> and Magnus Carlsson <magnus@cs.chalmers.se>. Version: h9 1995-07-04 (Baastad Spring School Release). (http://cs.chalmers.se/Fudgets/). (ftp://ftp.cs.chalmers.se/pub/haskell/chalmers). (1996-03-17) 1 1 1 1 1 FUDGIT A double-precision multi-purpose fitting program by Thomas Koenig <ig25@rz.uni-karlsruhe.de>. It can manipulate complete columns of numbers in the form of vector arithmetic. FUDGIT is also an expression language interpreter understanding most of C grammar except pointers. Morever, FUDGIT is a front end for any plotting program supporting commands from stdin, e.g. Gnuplot. Version 2.27 runs on AIX, HP-UX, Linux, IRIX, NeXT, SunOS, Ultrix. (ftp://tsx-11.mit.edu/pub/linux/sources/usr.bin/). (1993-03-22) 1 1 1 1 1 FUD wars /fuhd worz/ Political posturing, intended to create FUD, engaged in by hardware and software vendors ostensibly committed to standardisation but actually willing to fragment the market to protect their own shares. The Unix International vs. OSF conflict is but one outstanding example. [Jargon File] (1994-12-01) 1 1 1 1 1 Fuel-can A derogatory term for the Atari Falcon. (1994-12-22) 1 1 1 1 1 Fugue A music language implemented in Xlisp. ["Fugue: A Functional Language for Sound Synthesis", R.B. Dannenberg et al, Computer 24(7):36-41 (Jul 1991)]. (1994-12-01) 1 1 1 1 1 Fujitsu A Japanese elecronics corporation. Fujitsu owns ICL, Amdahl Corporation, and DMR. Home USA (http://fujitsu.com/), Japan (http://fujitsu.co.jp/index-e.html). (2000-04-03) 1 1 1 1 1 full-custom Design of integrated circuits at the transistor or polygon level. This is in contrast to the use of libraries of components. Full-custom design requires considerable skill and experience and is usually only feasible for simple circuits, especially ones with much repetition, such as memory device, where a small saving in the size and power consumption of a component will yield a large overall saving. (1994-12-01) 1 1 1 1 1 full-duplex (fdx, from telegraphy) 1. A type of duplex communications channel which carries data in both directions at once. On purely digital connections, full-duplex communication requires two pairs of wires. On analog networks or in digital networks using carriers, it is achieved by dividing the bandwidth of the line into two frequencies, one for sending, and the other for receiving. 2. An obsolete term for remote echo. Compare simplex, half-duplex, double-duplex. (2001-07-21) 1 1 1 1 1 full-duplex Switched Ethernet (FDSE) A Switched Ethernet link which can carry data in both directions simultaneously, doubling transmission capacity from the usual 10 to 20 megabits per second. (1996-06-20) 1 1 1 1 1 full laziness A transformation, described by Wadsworth in 1971, which ensures that subexpressions in a function body which do not depend on the function's arguments are only evaluated once. E.g. each time the function f x = x + sqrt 4 is applied, (sqrt 4) will be evaluated. Since (sqrt 4) does not depend on x, we could transform this to: f x = x + sqrt4 sqrt4 = sqrt 4 We have replaced the dynamically created (sqrt 4) with a single shared constant which, in a graph reduction system, will be evaluated the first time it is needed and then updated with its value. See also fully lazy lambda lifting, let floating. 1 1 1 1 1 full-motion video (FMV) Any kind of video that is theoretically capable of changing the entire content on the screen fast enough that the transitions are not obvious to the human eye, i.e. about 24 times a second or more. In practise most video encoding relies on the fact that in most video there is relatively little change from one frame to the next. This allows for compression of the video data. The term is used, chiefly in computer games, in contrast to techniques such as the use of sprites that move against a more-or-less fixed background. (2011-01-04) 1 1 1 1 1 full outer join outer join 1 1 1 1 1 fully associative cache A type of cache in which data from any address can be stored in any cache location. The whole address must be used as the tag (the value that identifies a block of data in the cache). All tags must be compared simultaneously (associatively) with the requested address and if one matches then its associated data is accessed. This requires an associative memory to hold the tags which makes this form of cache more expensive. It does however solve the problem of contention for cache locations (cache conflict) since a block need only be flushed when the whole cache is full and then the block to flush can be selected in a more efficient way. The alternatives are direct mapped cache or set associative cache. (2013-08-09) 1 1 1 1 1 Fully Automated Compiling Technique (FACT, "Honeywell-800 Business Compiler") A pre-COBOL English-like business data processing language for the Honeywell 800, developed ca. 1959. [Sammet 1969, p. 327]. (1994-12-01) 1 1 1 1 1 fully lazy lambda lifting John Hughes's optimisation of lambda lifting to give full laziness. Maximal free expressions are shared to minimise the amount of recalculation. Each inner sub-expression is replaced by a function of its maximal free expressions (expressions not containing any bound variable) applied to those expressions. E.g. f = \ x . (\ y . (+) (sqrt x) y) ((+) (sqrt x)) is a maximal free expression in (\ y . (+) (sqrt x) y) so this inner abstraction is replaced with (\ g . \ y . g y) ((+) (sqrt x)) Now, if a partial application of f is shared, the result of evaluating (sqrt x) will also be shared rather than re-evaluated on each application of f. As Chin notes, the same benefit could be achieved without introducing the new 1 1 1 1 1 fully qualified domain name (FQDN) The full name of a system, consisting of its local hostname and its domain name, including a top-level domain (tld). For example, "venera" is a hostname and "venera.isi.edu" is an FQDN. An FQDN should be sufficient to determine a unique Internet address for any host on the Internet. This process, called "name resolution", uses the Domain Name System (DNS). With the explosion of interest in the Internet following the advent of the web, domain names (especially the most significant two components, e.g. "sun.com", and especially in the ".com" tld) have become a valuable part of many companies' "brand". The allocation of these, overseen by ICANN, has therefore become highly political and is performed by a number of different registrars. There are different registries for the different tlds. A final dot on the end of a FQDN can be used to tell the DNS that the name is fully qualified and so needs no extra 1 1 1 1 1 fum At Xerox PARC, often the third standard metasyntactic variable after foo and bar. baz is more common outside PARC. [Jargon File] (2003-09-24) 1 1 1 1 1 Fun A typed lambda-calculus, similar to SOL[2]. "On Understanding Types, Data Abstractions and Polymorphism", L. Cardelli et al, ACM Comp Surveys 17(4) (Dec 1985). 1 1 1 1 1 function 1. <mathematics> (Or "map", "mapping") If D and C are sets (the domain and codomain) then a function f from D to C, normally written "f : D -> C" is a subset of D x C such that: 1. For each d in D there exists some c in C such that (d,c) is an element of f. I.e. the function is defined for every element of D. 2. For each d in D, c1 and c2 in C, if both (d,c1) and (d,c2) are elements of f then c1 = c2. I.e. the function is uniquely defined for every element of D. See also image, inverse, partial function. 2. <programming> Computing usage derives from the mathematical term but is much less strict. In programming (except in functional programming), a function may return different values each time it is called with the same argument values and may have side effects. A procedure is a function which returns no value but has only side-effects. The C language, for example, has no 1 1 1 1 1 functional 1. Working correctly. 2. Pertaining to functional programming. 3. higher-order function. 1 1 1 1 1 functional database A database which uses a functional language as its query language. Databases would seem to be an inappropriate application for functional languages since, a purely functional language would have to return a new copy of the entire database every time (part of) it was updated. To be practically scalable, the update mechanism must clearly be destructive rather than functional; however it is quite feasible for the query language to be purely functional so long as the database is considered as an argument. One approach to the update problem would use a monad to encapsulate database access and ensure it was single threaded. Alternative approaches have been suggested by Trinder, who suggests non-destructive updating with shared data structures, and Sutton who uses a variant of a Phil Wadler's linear type system. There are two main classes of functional database languages. 1 1 1 1 1 functional dependency Given a relation R (in a relational database), attribute Y of R is functionally dependent on attribute X of R and X of R functionally determines Y of R (in symbols R.X -> R.Y) if and only if each X in R has associated with it precisely one Y in R (at any one time). Attributes X and Y may be composite. This is very close to a function in the mathematical sense. (1997-09-01) 1 1 1 1 1 functionality Waffle for "features" or "function". The capabilities or behaviours of a program, part of a program, or system, seen as the sum of its features. Roughly, "the things it can do". Generally used in a comparative sense, e.g. "The latest update adds some useful functionality". (1997-07-14) 1 1 1 1 1 functional language A language that supports and encourages functional programming. (1995-11-08) 1 1 1 1 1 functional program A program employing the functional programming approach or written in a functional language. (1995-11-07) 1 1 1 1 1 functional programming (FP) A program in a functional language consists of a set of (possibly recursive) function definitions and an expression whose value is output as the program's result. Functional languages are one kind of declarative language. They are mostly based on the typed lambda-calculus with constants. There are no side-effects to expression evaluation so an expression, e.g. a function applied to certain arguments, will always evaluate to the same value (if its evaluation terminates). Furthermore, an expression can always be replaced by its value without changing the overall result (referential transparency). The order of evaluation of subexpressions is determined by the language's evaluation strategy. In a strict (call-by-value) language this will specify that arguments are evaluated before applying a function whereas in a non-strict (call-by-name) language arguments are passed unevaluated. 1 1 1 1 1 functional programming language A language that supports and encourages functional programming. (1995-11-08) 1 1 1 1 1 functional requirements What a system should be able to do, the functions it should perform. This term is used at both the user requirements analysis and software requirements specifications phases in the software life-cycle. An example of a non-functional requirement is an initialisation sequence incorporated into the software that is specific to a given customer. (2001-05-22) 1 1 1 1 1 functional specification A description of what a system (e.g. a piece of software) does or should do (but not how it should do it). The functional specification is one of the inputs to the design process. See IEEE/ANSI Std. 610.12-1990. (1999-04-07) 1 1 1 1 1 functional testing (Or "black-box testing", "closed-box testing") The application of test data derived from functional requirements without regard to how the system is implemented. (1996-05-15) 1 1 1 1 1 functional unit A subsystem of the central processing unit of a computer. E.g. arithmetic and logic unit, memory address register, barrel shifter, register file. (1995-02-10) 1 1 1 1 1 function application A function applied to (some of) its arguments. If it is not applied to all its argument then it is a "partial application". Application is usually written in the form f(x) but some languages such as command-line interpreters and many functional languages use juxtaposition: f x. Lisp places the parentheses around the whole application: (f x). 1 1 1 1 1 function complete State of a software component or system such that each function described by the software's functional specification can be reached by at least one functional path, and attempts to operate as specified. (1999-04-07) 1 1 1 1 1 Function Graph Language (FGL) The machine language for the AMPS (Applicative Multi-Processing System) proposed by Robert Keller, Gary Lindstrom and Suhas Patil at the University of Utah. (2007-03-22) 1 1 1 1 1 function inlining Defining a member function's implementation within the class where it was also declared. This is usually reserved for small functions since the inline function must be re-compiled for every instance of the class. (2007-03-22) 1 1 1 1 1 function key (From the IBM 3270 terminal's Programmed Function Keys (PF keys)) One of a set of special keys on a computer or terminal keyboard which can be programmed so as to cause an application program to perform certain actions. Function keys on a terminal may either generate short fixed sequences of characters, often beginning with the escape character (ASCII 27), or the characters they generate may be configured by sending special character sequences to the terminal. On a microcomputer keyboard, the function keys may generate a fixed, single byte code, outside the normal ASCII range, which is translated into some other configurable sequence by the keyboard device driver or interpreted directly by the application program. (1995-02-07) 1 1 1 1 1 Function Point Analysis (FPA) A standard metric for the relative size and complexity of a software system, originally developed by Alan Albrecht of IBM in the late 1970s. Functon points (FPs) can be used to estimate the relative size and complexity of software in the early stages of development #NAME? the components of the system as seen by the end-user: the inputs, outputs, inquiries, interfaces to other systems, and logical internal files. The components are classified as simple, average, or complex. All of these values are then scored and the total is expressed in Unadjusted FPs (UFPs). Complexity factors described by 14 general systems characteristics, such as reusability, performance, and complexity of processing can be used to weight the UFP. Factors are also weighted on a scale of 0 - not present, 1 - minor influence, to 5 - strong influence. The result of these computations is a number that correlates to system size. 1 1 1 1 1 functor In category theory, a functor F is an operator on types. F is also considered to be a polymorphic operator on functions with the type F : (a -> b) -> (F a -> F b). Functors are a generalisation of the function "map". The type operator in this case takes a type T and returns type list of T. The map function takes a function and applies it to each element of a list. (1995-02-07) 1 1 1 1 1 funky Said of something that functions, but in a slightly strange, klugey way. It does the job and would be difficult to change, so its obvious non-optimality is left alone. Often used to describe interfaces. The more bugs something has that nobody has bothered to fix because workarounds are easier, the funkier it is. TECO and UUCP are funky. The Intel i860's exception handling is extraordinarily funky. Most standards acquire funkiness as they age. "The new mailer is installed, but is still somewhat funky; if it bounces your mail for no reason, try resubmitting it." "This UART is pretty funky. The data ready line is active-high in interrupt mode and active-low in DMA mode." [Jargon File] 1 1 1 1 1 FUNLOG Functional programming plus unification. "Lazy" in the sense that expressions are reduced only if they are not unifiable. ["FUNLOG: A Computational Model Integrating Logic Programming and Functional Programming", P.A. Subrahmanyam et al, in Logic Programming: Functions, Relations and Equations, D. DeGroot et al eds, P-H 1986]. 1 1 1 1 1 FunnelWeb A literate-programming tool by Ross Williams <ross@spam.adelaide.edu.au>. It emphasises simplicity and reliability. It provides a macro facility and assists in the production of typeset documentation. It is independent of the input programming language. Posted to comp.sources.unix volume 26 under CopyLeft. Runs on Sun, Vax, Macintosh and IBM PC. (1993-04-11) 1 1 1 1 1 funny money Notional units of computing time and/or storage handed to students at the beginning of a computer course; also called play money or "purple money" (in implicit opposition to real or "green" money). In New Zealand and Germany the odd usage "paper money" has been recorded; in Germany, the particularly amusing synonym transfer ruble commemorates the funny money used for trade between COMECON countries back when the Soviet Bloc still existed. When your funny money ran out, your account froze and you needed to go to a professor to get more. Fortunately, the plunging cost of time-sharing cycles has made this less common. The amounts allocated were almost invariably too small, even for the non-hackers who wanted to slide by with minimum work. In extreme cases, the practice led to small-scale black markets in bootlegged computer accounts. By extension, phantom money or quantity tickets of any kind used 1 1 1 1 1 furigana (Or "rubi") Small hiragana, written above kanji (and these days sometimes above Latin characters) as a phonetic comment and reading aid. The singular and plural are both "furigana". (2000-12-30) 1 1 1 1 1 furrfu Written-only rot13 "Sheesh!". "furrfu" evolved in mid-1992 as a response to postings repeating urban myths on newsgroup news:alt.folklore.urban, after some posters complained that "Sheesh!" as a response to newbies was being overused. (1995-10-25) 1 1 1 1 1 FUSE A DEC software development environment for ULTRIX, offering an integrated toolkit for developing, testing, debugging and maintenance. 1 1 1 1 1 FUSION Software package supplied by Network Research Corporation claiming to connect various different configurations of LAN. 1 1 1 1 1 fusion A program transformation where a composition of two functions is replaced by in-lining them and combining their bodies. E.g. f x = g (h x) ==> f x = g (2 * x) g x = x + 1 f x = 2 * x + 1 h x = 2 * x This has the beneficial effect of reducing the number of function calls. It can be especially useful where the intermediate result is a large data structure which can be eliminated. 1 1 1 1 1 FutureBasic A BASIC compiler for the Macintosh. (http://stazsoftware.com/futurebasic/). [Summary? Version?] (2002-08-28) 1 1 1 1 1 future date testing The process of setting a computer's date to a future date to test a program's (expected or unexpected) date sensitivity. Future date testing only shows the effects of dates on the computer(s) under scrutiny, it does not take into account knock-on effects of dates on other connected systems. (2000-09-11) 1 1 1 1 1 futz ("futzing around") To waste time on activity that is often experimental and may or may not be productive. Not normally used for game playing. (2008-11-27) 1 1 1 1 1 fuzzball A DEC LSI-11 running a particular suite of homebrewed software written by Dave Mills and assorted co-conspirators, used in the early 1980s for Internet protocol testbedding and experimentation. These were used as NSFnet backbone sites in its early 56KB-line days. A few were still active on the Internet in early 1991, doing odd jobs such as network time service. [Jargon File] (1994-12-05) 1 1 1 1 1 fuzzy computing fuzzy logic 1 1 1 1 1 fuzzy logic A superset of Boolean logic dealing with the concept of partial truth -- truth values between "completely true" and completely false. It was introduced by Dr. Lotfi Zadeh of UCB in the 1960's as a means to model the uncertainty of natural language. Any specific theory may be generalised from a discrete (or crisp) form to a continuous (fuzzy) form, e.g. "fuzzy calculus", "fuzzy differential equations" etc. Fuzzy logic replaces Boolean truth values with degrees of truth which are very similar to probabilities except that they need not sum to one. Instead of an assertion pred(X), meaning that X definitely has the property associated with predicate pred, we have a truth function truth(pred(X)) which gives the degree of truth that X has that property. We can combine such values using the standard definitions of fuzzy logic: truth(not x) = 1.0 - truth(x) 1 1 1 1 1 fuzzy subset In fuzzy logic, a fuzzy subset F of a set S is defined by a membership function which gives the degree of membership of each element of S belonging to F. 1 1 1 1 1 fweep (WPI) One step below a gweep, a person who uses the system solely to play games and use electronic mail. Compare dweeb, twink, terminal junkie, tourist, weenie. (1995-01-31) 1 1 1 1 1 FWIW For what it's worth. 1 1 1 1 1 fx The country code for metropolitan France. Apprently not widely used. (1999-01-27) 1 1 1 1 1 FX-87 Effects. A polymorphic language based on Scheme, allowing side effects and first-class functions. It attempts to integrate functional and imperative programming. Expressions have types, side effects (e.g. reading, writing or allocating) and regions (stating where the effects may occur). Versions: FX-89, FX-90. (ftp://brokaw.lcs.mit.edu/). ["The FX-87 Reference Manual", D.K. Gifford <gifford@lcs.mit.edu> et al, MIT/LCS/TR-407, Oct 1987]. (1995-01-31) 1 1 1 1 1 FX-90 A language with partial type and effect reconstruction and first-class modules. (1995-01-31) 1 1 1 1 1 FXO Foreign eXchange Office 1 1 1 1 1 FXS Foreign eXchange Subscriber 1 1 1 1 1 FYA For your amusement. 1 1 1 1 1 FYI For Your Information 1 1 1 1 1 FYI4 [Malkin, G., and A. Marine, "FYI on Questions and Answers: Answers to Commonly asked "New Internet User" Questions", FYI 4, RFC 1325, Xylogics, SRI, May 1992.] 1 1 1 1 1 G 1. <unit> The abbreviated form of giga-. 2. <language> ["G: A Functional Language with Generic Abstract Data Types", P.A.G. Bailes, Computer Langs 12(2):69-94, 1987]. 3. <language> A language developed at Oregon State University in 1988 which combines functional programming, object-oriented programming, relational, imperative programming and logic programming (you name it we got it). ["The Multiparadigm Language G", J. Placer, Computer Langs 16:235-258, 1991]. [Jargon File] (1996-08-12) 1 1 1 1 1 G2 A real-time expert system from Gensym Corporation. 1 1 1 1 1 G3 1. <protocol, compression> Group 3 fax. 2. <hardware, processor> PowerPC G3. (1998-09-10) 1 1 1 1 1 G4 Group 4 1 1 1 1 1 GA genetic algorithm 1 1 1 1 1 ga The country code for Gabon. (1999-01-27) 1 1 1 1 1 Gabriel A graphical DSP language for simulation and real systems. ["A Design Tool for Hardware and Software for Multiprocessor DSP Systems," E.A. Lee, E. Goei, J. Bier & S. Bhattacharya, DSP Systems, Proc ISCAS-89, 1989]. [Jargon File] (1994-12-23) 1 1 1 1 1 gabriel /gay'bree-*l/ (After Richard Gabriel) An unnecessary (in the opinion of the opponent) stalling tactic, e.g. tying one's shoelaces or combing one's hair repeatedly, asking the time, etc. Also used to refer to the perpetrator of such tactics. Also, "pulling a Gabriel", "Gabriel mode". [Jargon File] (1999-10-12) 1 1 1 1 1 Gabriel, Richard Richard Gabriel 1 1 1 1 1 GADS Picture retrieval language. "Integrated Geographical Databases: The GADS Experience", P.E. Mantey et al, in Database Techniques for Pictorial Applications, A. Blaser ed, pp.193-198. 1 1 1 1 1 Gaelic For automated test programs. Used in military, essentially replaced by ATLAS. 1 1 1 1 1 gag Equivalent to choke, but connotes more disgust. "Hey, this is Fortran code. No wonder the C compiler gagged." See also barf. [Jargon File] 1 1 1 1 1 GAIA GUI Application Interoperability Architecture. An OSF project. 1 1 1 1 1 GAL Generic Array Logic. (1995-12-09) 1 1 1 1 1 Galaxy An extensible language in the vein of EL/1 and RCC. ["Introduction to the Galaxy Language", Anne F. Beetem et al, IEEE Software 6(3):55-62]. (1995-12-09) 1 1 1 1 1 Galileo ["Galileo: A Strongly Typed Interactive Conceptual Language", A. Albano et al, ACM Trans Database Sys 10(2):230-260 (June 1985)]. 1 1 1 1 1 Gambit A variant of Scheme R3.99 supporting the future construct of Multilisp by Marc Feeley <feeley@iro.umontreal.ca>. Implementation includes optimising compilers for Macintosh (with Toolbox and built-in editor) and Motorola 680x0 Unix systems and HP300, BBN GP100 and NeXT. Version 2.0 conforms to the IEEE Scheme standard. Gambit used PVM as its intermediate language. (ftp://acorn.cs.brandeis.edu/dist), (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f7/ff764/Gambit_Terp). (ftp://ftp.iro.umontreal.ca/pub/parallele/gambit/). Mailing list: gambit@trex.umontreal.ca. (1998-02-10) 1 1 1 1 1 games "The time you enjoy wasting is not time wasted." -- Bertrand Russell. Here are some games-related pages on the Web: Imperial Nomic (http://mit.edu:8001/people/achmed/fascist/), Thoth's games and recreations page (http://cis.ufl.edu/~thoth/library/recreation.html), Games Domain (http://wcl-rs.bham.ac.uk/GamesDomain), Zarf's List of Games on the Web (http://leftfoot.com/games.html), Dave's list of pointers to games resources (http://wcl-rs.bham.ac.uk/~djh/index.html), Collaborative Fiction (http://asylum.cid.com/fiction/fiction.html). See also 3DO, ADL, ADVENT, ADVSYS, alpha/beta pruning, Amiga, CHIP-8, Core Wars, DROOL, empire, I see no X here., Infocom, Inglish, initgame, life, 1 1 1 1 1 game tree A tree representing contingencies in a game. Each node in a game tree represents a possible position (e.g., possible configuration of pieces on a chessboard) in the game, and each branching ("edge" in graph terms) represents a possible move. (1998-11-14) 1 1 1 1 1 GAMMA 1. A language for matrices and generation of mathematical programming reports. ["GAMMA 3.3 for MPS/MPSX, IBM System:/360", Bonnor & Moore Assocs (Mar 1975)]. 2. A high-level parallel language. [Research Directions in High-Level Parallel Languages, LeMetayer ed, Springer 1992]. (1994-11-29) 1 1 1 1 1 gamma correction Adjustments applied during the display of a digital representation of colour on a screen in order to compensate for the fact that the Cathode Ray Tubes used in computer monitors (and televisions) produce a light intensity which is not proportional to the input voltage. The light intensity is actually proportional to the input voltage raised to the inverse power of some constant, called gamma. Its value varies from one display to another, but is usually around 2.5. Because it is more intuitive for the colour components (red, green and blue) to be varied linearly in the computer, the actual voltages sent to the monitor by the display hardware must be adjusted in order to make the colour component intensity on the screen proportional to the value stored in the computer's display memory. This process is most easily achieved by a dedicated module in the display hardware which simply scales the outputs of the display memory before 1 1 1 1 1 GAMS Guide to Available Mathematical Software 1 1 1 1 1 gamut The gamut of a monitor is the set of colours it can display. There are some colours which can't be made up of a mixture of red, green and blue phosphor emissions and so can't be displayed by any monitor. [Examples?] (1994-11-29) 1 1 1 1 1 GAN Generating and Analyzing Networks. "GAN - A System for Generating and Analyzing Activity Networks", A. Schurmann, CACM 11(10) (Oct 1968). 1 1 1 1 1 GANDALF A software development environment from Carnegie Mellon University. 1 1 1 1 1 gang bang The use of large numbers of loosely coupled programmers in an attempt to wedge a great many features into a product in a short time. Though there have been memorable gang bangs (e.g. that over-the-weekend assembler port mentioned in Steven Levy's "Hackers"), most are perpetrated by large companies trying to meet deadlines; the inevitable result is enormous buggy masses of code entirely lacking in orthogonality. When market-driven managers make a list of all the features the competition has and assign one programmer to implement each, the probability of maintaining a coherent (or even functional) design goes infinitesimal. See also firefighting, Mongolian Hordes technique, Conway's Law. [Jargon File] 1 1 1 1 1 GAP Groups Algorithms and Programming. A system for symbolic mathematics for computational discrete algebra, especially group theory, by Johannes Meier, Alice Niemeyer, Werner Nickel, and Martin Schonert of Aachen. GAP was designed in 1986 and implemented 1987. Version 2.4 was released in 1988 and version 3.1 in 1992. Sun version (ftp://ftp.math.rwth-aachen.de/pub/gap). ["GAP 3.3 Manual, M. Schonert et al, Lehrstuhl D Math, RWTH Aachen, 1993]. (1995-04-12) 1 1 1 1 1 GAPLog General Amalgamated Programming with Logic. LOGPRO group, Linkoping Sweden. A restricted version of constraint logic programming, using S-unification but not restricted to a single domain. [Chapter in forthcoming Springer book on ESPRIT] 1 1 1 1 1 garbageabetical order 1. The result of using an insertion sort to merge data into an unsorted list. 2. The state of any file or list that is supposed to be sorted, but is not. (1997-02-11) 1 1 1 1 1 garbage collect garbage collection 1 1 1 1 1 garbage collection (GC) The process by which dynamically allocated storage is reclaimed during the execution of a program. The term usually refers to automatic periodic storage reclamation by the garbage collector (part of the run-time system), as opposed to explicit code to free specific blocks of memory. Automatic garbage collection is usually triggered during memory allocation when the amount free memory falls below some threshold or after a certain number of allocations. Normal execution is suspended and the garbage collector is run. There are many variations on this basic scheme. Languages like Lisp represent expressions as graphs built from cells which contain pointers and data. These languages use automatic dynamic storage allocation to build expressions. During the evaluation of an expression it is necessary to reclaim space which is used by subexpressions but which is no longer pointed to by anything. This reclaimed memory is returned to the free memory pool for subsequent 1 1 1 1 1 Garbage In, Garbage Out (GIGO) /gi:'goh/ Wilf Hey's maxim expressing the fact that computers, unlike humans, will unquestioningly process nonsensical input data and produce nonsensical output. Of course a properly written program will reject input data that is obviously erroneous but such checking is not always easy to specify and is tedious to write. GIGO is usually said in response to lusers who complain that a program didn't "do the right thing" when given imperfect input or otherwise mistreated in some way. Also commonly used to describe failures in human decision making due to faulty, incomplete, or imprecise data. The expansion "Garbage In, Gospel Out" is an ironic comment on the tendency to put excessive trust in "computerised" data. [Jargon File] (2004-10-03) 1 1 1 1 1 Gargoyle A language for compiler writing. [J.V. Garwick, CACM 7(1):16-20, (Jan 1964)]. (1994-11-04) 1 1 1 1 1 Garnet 1. A graphical object editor and Macintosh environment. 2. A user interface development environment for Common Lisp and X11 from The Garnet project team. It helps you create graphical, interactive user interfaces. Version 2.2 includes the following: a custom object-oriented programming system which uses a prototype-instance model. automatic constraint maintenance allowing properties of objects to depend on properties of other objects and be automatically re-evaluated when the other objects change. The constraints can be arbitrary Lisp expressions. Built-in, high-level input event handling. Support for gesture recognition. Widgets for multi-font, multi-line, mouse-driven text editing. Optional automatic layout of application data into lists, tables, trees or graphs. Automatic generation of PostScript for printing. Support for large-scale applications and data visualisation. Also supplied are: two complete widget sets, one with a 1 1 1 1 1 GARP A graphical language for concurrent programming. ["Visual Concurrent Programmint in GARP", S.K. Goering er al, PARLE '89 v.II, LNCS 366, pp. 165-180]. (1994-11-03) 1 1 1 1 1 garply /gar'plee/ A metasyntactic variable like foo, once popular among SAIL hackers. [Jargon File] (1994-11-03) 1 1 1 1 1 Gartner Group One of the biggest IT industry research firms. Address: Connecticut, USA. [URL?] (1997-09-30) 1 1 1 1 1 gas GNU assembler 1 1 1 1 1 GASP 1. <library> Graph Algorithm and Software Package. 2. <simulation> General Activities Simulation Program. 3. <simulation> General Aerodynamic Simulation Program. 1 1 1 1 1 gas plasma display A type of display containing super-energised neon gas, used mostly in flat monitor and television screens. Each pixel has a transistor that controls its colour and brightness. Plasma (http://kipinet.com/mmp/mmp_apr96/dep_techwatch.html). Flat Screen Technology (http://montegonet.com/plasma.html). More about Gas Plasma (http://advancedplasma.com/whatis.html). [How does it work?] (1998-04-30) 1 1 1 1 1 GAT Generalized Algebraic Translator. Improved version of IT. On IBM 650 RAMAC. [Sammet 1969, p. 142]. 1 1 1 1 1 GATE GAT Extended? Based on IT. [Sammet 1969, p. 139]. 1 1 1 1 1 gate A low-level digital logic component. Gates perform Boolean functions (e.g. AND, NOT), store bits of data (e.g. a flip-flop), and connect and disconnect various parts of the overall circuit to control the flow of data (tri-state buffer). In a CPU, the term applies particularly to the buffers that route data between the various functional units. Each gate allows data to flow from one unit to another or enables data from one output onto a certain bus. (1999-09-02) 1 1 1 1 1 gated /gayt-dee/ Gate daemon. A program which supports multiple routing protocols and protocol families. It may be used for routing, and makes an effective platform for routing protocol research. (ftp://gated.cornell.edu). See also Exterior Gateway Protocol, Open Shortest Path First, Routing Information Protocol, routed. (1994-12-07) 1 1 1 1 1 Gates Bill Gates 1 1 1 1 1 gateway 1. <networking> A deprecated term for a device that enables data to flow between different networks (forming an internet). Preferred terms are "protocol converter" (connects networks that use different protocols), "router" (connects two broadcast networks at layer 3 (network layer). Another example is a mail gateway, which is a layer 7 (application layer) gateway. 2. <hypertext> An interface between an information source and a web server. Common Gateway Interface is a standard for such interfaces. The information source can be any system that can be accessed by a program running on the web server. A typical example is a relational database. (2000-05-24) 1 1 1 1 1 Gateway 2000 One of the lagest US manufacturers of IBM compatibles, founded by CEO Ted Waitt in September 1985, in Sioux City, Iowa. In 1990 the company moved to North Sioux City, South Dakota. In August 1994, quarterly profits were $4 million on sales of $617 million. Sales for the first quarter of 1997 were $1.42 billion. On 1997-05-15 Gateway bought the Amiga brand. (http://gw2k.com/). (1998-07-30) 1 1 1 1 1 Gauss 1. <person> Carl Friedrich Gauss. 2. <statistics> Gaussian distribution. See normal distribution. 3. <unit> The unit of magnetic field strength. 1 gauss = 1 Maxwell / cm^2. A good loudspeaker coil magnet flux density is of the order of 10000 gauss. 4. <language> A powerful matrix programming language by Aptech Systems. Gauss is very popular with econometricians. (http://rhkoning.xs4all.nl/gauss/index.htm). (2003-10-25) 1 1 1 1 1 Gaussian distribution normal distribution 1 1 1 1 1 gawk GNU awk. Gawk is a superset of standard awk and includes some Plan 9 features. David Trueman and Arnold Robbins of Georgia Institute of Technology were developing it in 1993. It has been ported to Unix, MS-DOS, Macintosh, and Archimedes. Latest version: 2.15.3, as of 1993-11-08. Available by FTP from your nearest GNU archive site. Mac version (ftp://archive.umich.edu/mac/utilities/developerhelps/macgawk2.11.cpt.hqx). (2000-10-21) 1 1 1 1 1 GB gigabytes or gigabits - see MB. Giga stands for 10^9 - a US billion, or in computing for 2^30. The text of a thirty volume encyclopaedia would require about one gigabyte of ASCII storage. (1997-03-27) 1 1 1 1 1 Gb Gigabit. 10^9 bits. Might also be wrongly used for gigabyte (GB). (1997-03-27) 1 1 1 1 1 gb (Great Britain) A country code for United Kingdom. "uk" is generally used instead. (1999-01-27) 1 1 1 1 1 g-bell bell 1 1 1 1 1 GBIP General Purpose Interface Bus 1 1 1 1 1 GBML Genetics Based Machine Learning 1 1 1 1 1 gbps gigabits per second 1 1 1 1 1 GC 1. garbage collection. 2. A storage allocator with garbage collection by Hans-J. Boehm and Alan J. Demers. Gc is a plug-in replacement for C's malloc. Since the collector does not require pointers to be tagged, it does not attempt to ensure that all inaccessible storage is reclaimed. Version 3.4 has been ported to Sun-3, Sun-4, Vax/BSD, Ultrix, Intel 80386/Unix, SGI, Alpha/OSF/1, Sequent (single threaded), Encore (single threaded), RS/600, HP-UX, Sony News, A/UX, Amiga, NeXT. (ftp://parcftp.xerox.com/pub/russell/gc3.4.tar.Z). (2000-04-19) 1 1 1 1 1 GCAL The Cambridge Phoenix equivalent of troff. So called because all Cambridge utilities were named after birds, GCAL was a "run off" equivalent, and Geococcyx californianus is the Latin name of the roadrunner. GCAL was eventually obsoleted by TeX. It is believed that even more obscure puns lurked in the depths of Phoenix. Perhaps it is better they stayed there. (2003-12-05) 1 1 1 1 1 GCC The GNU Compiler Collection, which currently contains front ends for C, C++, Objective-C, Fortran, Java, and Ada, as well as libraries for these languages (libstdc++, libgcj, etc). GCC formerly meant the GNU C compiler, which is a very high quality, very portable compiler for C, C++ and Objective C. The compiler supports multiple front-ends and multiple back-ends by translating first into Register Transfer Language and from there into assembly code for the target architecture. (http://gcc.gnu.org/). Bug Reports (http://gcc.gnu.org/bugzilla/). FTP gcc-2.X.X.tar.gz from your nearest GNU archive site. MS-DOS (ftp://oak.oakland.edu/pub/msdos/djgpp/). Mailing lists: gcc-help@gcc.gnu.org, gcc-announce@gcc.gnu.org (announcements). 1 1 1 1 1 GCL General Control Language. A portable job control language. ["A General Control Interface for Satellite Systems", R.J. Dakin in Command Languages, C. Unger ed, N-H 1973]. 1 1 1 1 1 G-Code 1. Johnsson & Augustsson, Chalmers Inst Tech. Intermediate language used by the G-machine, an implementation of graph reduction based on supercombinators. "Efficient Compilation of Lazy Evaluation", T. Johnsson, SIGPLAN Notices 19(6):58-69 (June 1984). 2. A machine-like language for the representation and interpretation of attributed grammars. Used as an intermediate language by the Coco compiler generator. "A Compiler Generator for Microcomputers", P. Rechenberg et al, P-H 1989. 1 1 1 1 1 GCOS /jee'kohs/ An operating system developed by General Electric from 1962; originally called GECOS (the General Electric Comprehensive Operating System). The GECOS-II operating system was developed by General Electric for the 36-bit GE-635 in 1962-1964. Contrary to rumour, GECOS was not cloned from System/360 [DOS/360?] - the GE-635 architecture was very different from the IBM 360 and GECOS was more ambitious than DOS/360. GE Information Service Divsion developed a large special multi-computer system that was not publicised because they did not wish time sharing customers to challenge their bills. Although GE ISD was marketing DTSS - the first commercial time sharing system - GE Computer Division had no license from Dartmouth and GE-ISD to market it to external customers, so they designed a time-sharing system to sell as a standard part of GECOS-III, which replaced GECOS-II in 1967. GECOS TSS was more general purpose than DTSS, it was more a programmer's 1 1 1 1 1 GCOS Macro Assembler Program (GMAP) The macro assembler for the GCOS 8 operating system on Honeywell/Bull DPS-8 computers. ["GCOS8 OS GMAP User's Guide", Bull]. (2009-01-14) 1 1 1 1 1 GCR Group Code Recording 1 1 1 1 1 GCT A test-coverage tool by Brian Marick <marick@testing.com>, based on GNU C. Version 1.4 was ported to Sun-3, Sun-4, RS/6000, 68000, 88000, HP-PA, IBM 3090, Ultrix, Convex, SCO but not Linux, Solaris, or Microsoft Windows. Commercial support is available from the author (+1 217 351 7228). (ftp://cs.uiuc.edu/pub/testing/gct.file/). (1999-07-08) 1 1 1 1 1 gd The country code for Grenada. (1999-01-27) 1 1 1 1 1 GDA (Genetic Data Analysis) A program by Paul O. Lewis and Dmitri Zaykin, designed to accompany the referenced book, that computes linkage and hardy-weinberg disequilibrium and some genetic distances, and provides method-of-moments estimators for hierarchical F-statistics. A command-line version by Chris Basten runs under Mac OS. ["Genetic Data Analysis" by Bruce S. Weir, 1996, Sinaur Associates]. (2009-10-15) 1 1 1 1 1 GDB GNU debugger. The FSF's source-level debugger for C, C++ and other languages. Developed by many people but most recently Fred Fish <fnf@cygnus.com>, Stu Grossman <grossman@cygnus.com> and John Gilmore <gnu@cygnus.com> all of Cygnus Support. GDB fills the same niche as dbx. Programs must be compiled to include debugging symbols. Version 4.11. Distributed under GNU CopyLeft. It runs on most Unix variants, VMS, VXWorks, Amiga and MS-DOS. FTP gdb-*.tar.[zZ] from a GNU archive site. E-mail: <bug-gdb@gnu.org> (bug reports). (1993-10-29) 1 1 1 1 1 GDBPSK Gaussian Differential Binary Phase-Shift Keying 1 1 1 1 1 Gödel, Kurt Kurt Gödel 1 1 1 1 1 GDI Graphic Display Interface 1 1 1 1 1 GDMO Guidelines for the Definition of Managed Objects. A standard (ISO/IEC 10165-4) for defining data models on ASN.1 1 1 1 1 1 GDPL Generalized Distributed Programming Language. "GDPL - A Generalized Distributed Programming Language", K. Ng et al, Proc 4th Intl Conf Distrib Comp Sys, IEEE 1984, pp.69-78. 1 1 1 1 1 GE General Electric 1 1 1 1 1 ge The country code for Georgia. (1999-01-27) 1 1 1 1 1 GE-645 A computer built by General Electric, the successor to the GE-635, designed to provide the extra CPU features required by the Multics project. The GE-645 was designed in 1965 by John Couleur and Edward Glaser at MIT. It had several security levels and instructions for handling virtual memory. Addressing used an 18-bit segment in addition to the 18-bit address, dramatically increasing the theoretical memory size and making virtual memory easier to support. Design of the GE-645's successor, the GE-655, started in 1967. (2006-09-24) 1 1 1 1 1 GEA Graph Extended ALGOL. Extension of ALGOL 60 for graph manipulation, on UNIVAC 1108. "A Language for Treating Graphs", S. Crespi-Reghizzi et al, CACM 13(5) (May 1970). 1 1 1 1 1 GEANT A simulation, tracking and drawing package for HEP. 1 1 1 1 1 GECOM A language for the GE-255 series, like COBOL with some ALGOL features added, in use around 1964-5. GECOM included many of the early COBOL constructs including report writer and TABSOL (programming by truth table). Another (planned but unimplemented?) component was FRINGE. [Sammet 1969, p. 329]. [Dates?] (1996-09-15) 1 1 1 1 1 GECOS GCOS 1 1 1 1 1 Gedanken John Reynolds, 1970. "GEDANKEN - A Simple Typeless Language Based on the Principle of Completeness and the Reference Concept", J.C. Reynolds, CACM 13(5):308-319 (May 1970). [Jargon File] 1 1 1 1 1 gedanken /g*-dahn'kn/ Ungrounded; impractical; not well-thought-out; untried; untested. Gedanken is a German word for "thought". A thought experiment is one you carry out in your head. In physics, the term "gedanken experiment" is used to refer to an experiment that is impractical to carry out, but useful to consider because it can be reasoned about theoretically. (A classic gedanken experiment of relativity theory involves thinking about a man in an elevator accelerating through space.) Gedanken experiments are very useful in physics, but must be used with care. It's too easy to idealise away some important aspect of the real world in constructing the "apparatus". Among hackers, accordingly, the word has a pejorative connotation. It is typically used of a project, especially one in artificial intelligence research, that is written up in grand detail (typically as a Ph.D. thesis) without ever being implemented to any great extent. Such a project is usually 1 1 1 1 1 geef (Ostensibly from "gefingerpoken") mung. See also blinkenlights. [Jargon File] (1995-01-18) 1 1 1 1 1 geek computer geek 1 1 1 1 1 geek out To temporarily enter techno-nerd mode while in a non-hackish context, for example at parties held near computer equipment. Especially used when you need to do or say something highly technical and don't have time to explain: "Pardon me while I geek out for a moment." See computer geek, propeller head. [Jargon File] (1995-01-18) 1 1 1 1 1 GEI A German software engineering company. 1 1 1 1 1 GE Information Services One of the leading on-line services, started on 1st October 1985, providing subscribers with hundreds of special interest areas, computer hardware and software support, award-winning multi-player games, the most software files in the industry (over 200 000), worldwide news, sports updates, business news, investment strategies, and Internet electronic mail and fax (GE Mail). Interactive conversations (Chat Lines) and bulletin boards (Round Tables) with associated software archives are also provided. GEnie databases (through the ARTIST gateway) allow users to search the full text of thousands of publications, including Dun & Bradstreet Company Profiles; a GEnie NewsStand with more than 900 newspapers, magazines, and newsletters; a Reference Center with information ranging from Agriculture to World History; the latest in medical information from MEDLINE; and patent and trademark registrations. (http://genie.com/). Shopping 2000 1 1 1 1 1 GEM One of the first commercially available GUIs. Borrowing heavily from the Macintosh WIMP-style interface it was available for both the IBM compatible market (being packaged with Amstrad's original PC series) and more successfully for the Atari ST range. The PC version was produced by Digital Research (more famous for DR-DOS, their MS-DOS clone), and was not developed very far. The Atari version, however, continued to be developed until the early 1990s and the later versions supported 24-bit colour modes, full colour icons and a nice looking sculpted 3D interface. (1997-01-10) 1 1 1 1 1 gen generate 1 1 1 1 1 gender mender (Or "gender bender", "gender blender", "sex changer", and even "homosexual adaptor") A cable connector shell with either two male or two female connectors on it, used to correct the mismatches that result when some loser didn't understand the EIA-232C specification and the distinction between DTE and DCE. Used especially for EIA-232C parts in either the original D-25 or the IBM PC's D-9 connector. There appears to be some confusion as to whether a "male homosexual adaptor" has pins on both sides (is doubly male) or sockets on both sides (connects two males). [Jargon File] (1995-04-16) 1 1 1 1 1 Gene Amdahl A former IBM engineer who founded Amdahl Corporation. (1995-05-23) 1 1 1 1 1 General Activities Simulation Program (GASP) A set of discrete system simulation subroutines for Fortran. (2003-09-27) 1 1 1 1 1 General Aerodynamic Simulation Program (GASP) (http://aerosft.com/Gasp/References/main.php3). [Summary?] (2003-09-27) 1 1 1 1 1 General Dynamics Canada Ltd A Canadian defence electronics company that makes direct and indirect fire control systems, vehicle electronics, reconnaissance vehicle surveillance systems, computerised laser sight for anti-tank weapons, tactical communication systems, headquarters information distribution system, tactical voice and distribution systems, acoustic signal processing, ASW mission systems, sonobuoy processors, active sonar systems, towed array sonar systems, tactical acoustic trainer, Mil-Spec electroluminiscent displays, large multi-sensor displays, coastal intrusion detection systems and fibre-optic distribution systems. The company was founded in 1948 as "Computing Devices Canada Ltd.", part of the Ceridian group of companies. It was renamed General Dynamics Canada Ltd. on 2002-01-01. General Dynamics Canada (http://www.gdcanada.com/). (2013-01-20) 1 1 1 1 1 General Electric (GE) A US company that manufactured computers from 1956 until 1970, when it sold its computer division to Honeywell and left the computer business. Notable GE computers were the GE-265, which supported the Dartmouth Time-sharing System (DTSS), and the GE-645 used for Multics development. See also GCOS. Not to be confused with the General Electric Company (GEC) in the UK (where FOLDOC's first seeds were sown). (2002-02-27) 1 1 1 1 1 General Electric Comprehensive Operating System GCOS 1 1 1 1 1 General Magic A software company based in Mountain View, California. Products released in 1994 after four years in development include: Telescript - a communications-oriented programming language; Magic Cap - an OOPS designed for PDAs; and a new, third generation GUI. Motorola's Envoy, due for release in the third quarter of 1994, will use Magic Cap as its OS. What PostScript did for cross-platform, device-independent documents, Telescript aims to do for cross-platform, network-independent messaging. Telescript protects programmers from many of the complexities of network protocols. Competitors for Magic Cap include Microsoft's Windows for Pens/Winpad, PenPoint, Apple Computer's Newton Intelligence and GEOS by GeoWorks. (http://genmagic.com/). (1995-02-23) 1 1 1 1 1 General Packet Radio Service (GPRS) A GSM data transmission technique that does not set up a continuous channel from a portable terminal for the transmission and reception of data, but transmits and receives data in packets. It makes very efficient use of available radio spectrum, and users pay only for the volume of data sent and received. See also: packet radio. (1999-09-12) 1 1 1 1 1 General Protection Failure (GPF, or General Protection Fault) An addressing error, caught by the processor's memory protection hardware, that cannot be attributed to any expected condition such as a page fault. (1995-03-28) 1 1 1 1 1 General Protection Fault General Protection Failure 1 1 1 1 1 General Public Licence It's spelled "General Public License". (In the UK, "licence" is a noun and "license" is a verb (like advice/"advise") but in the US both are spelled "license"). (1995-05-12) 1 1 1 1 1 General Public License (GPL, note US spelling) The licence applied to most software from the Free Software Foundation and the GNU project and other authors who choose to use it. The licences for most software are designed to prevent users from sharing or changing it. By contrast, the GNU General Public License is intended to guarantee the freedom to share and change free software - to make sure the software is free for all its users. The GPL is designed to make sure that anyone can distribute copies of free software (and charge for this service if they wish); that they receive source code or can get it if they want; that they can change the software or use pieces of it in new free programs; and that they know they can do these things. The GPL forbids anyone to deny others these rights or to ask them to surrender the rights. These restrictions translate to certain responsibilities for those who distribute copies of the software or modify it. See also General Public Virus. 1 1 1 1 1 General Public Virus A pejorative name for some versions of the GNU project copyleft or General Public License (GPL), which requires that any tools or application programs incorporating copylefted code must be source-distributed on the same terms as GNU code. Thus it is alleged that the copyleft "infects" software generated with GNU tools, which may in turn infect other software that reuses any of its code. Copyright law limits the scope of the GPL to "programs textually incorporating significant amounts of GNU code" so GPL is only passed on if actual GNU source is transmitted. This used to be the case with the Bison parser skeleton until its licence was fixed. (http://org.gnu.de/manual/bison/html_chapter/bison_2.html#SEC2). [Jargon File] (1999-07-14) 1 1 1 1 1 General Purpose Graphic Language ["A General Purpose Graphic Language", H.E. Kulsrud, CACM 11(4) (Apr 1968)]. 1 1 1 1 1 General Purpose Interface Bus IEEE 488 1 1 1 1 1 General Purpose Language (GPL) An ALGOL 60 variant with user-definable types and operators. [Sammet 1969, p. 195]. ["The GPL Language", J.V. Garwick et al, TER-05, CDC, Palo Alto 1969]. 1 1 1 1 1 General Purpose Macro-generator (GPM) An early text-processing language similar to TRAC, implemented on the Atlas 2 by Christopher Strachey. ["A General Purpose Macrogenerator", C. Strachey, Computer J 8(3):225-241, Oct 1965]. (2006-07-21) 1 1 1 1 1 General Recursion Theorem Cantor's theorem, originally stated for ordinals, which extends inductive proof to recursive construction. The proof is by pasting together "attempts" (partial solutions). [Better explanation?] (1995-06-15) 1 1 1 1 1 generate To produce something according to an algorithm or program or set of rules, or as a (possibly unintended) side effect of the execution of an algorithm or program. The opposite of parse. [Jargon File] (1995-06-15) 1 1 1 1 1 generation An attempt to classify the degree of sophistication of programming languages. See First generation language -- Fifth generation language. (1995-06-15) 1 1 1 1 1 Generic Array Logic (GAL) A newer kind of Programmable Array Logic based on EEPROM storage cells, been pioneered by Lattice. GALs can be erased and reprogrammed and usually replace a whole set of different PALs (hence the name). (1995-12-09) 1 1 1 1 1 Generic Expert System Tool (GEST) An expert system shell for Symbolics Lisp machine, with frames, forward chaining, backward chaining and fuzzy logic; written by John Gilmore(?) at GA Tech. Latest version: 4.0, as of 1995-04-16. (ftp://ftp.gatech.edu/pub/ai/gest.tar.Z). (1995-04-16) 1 1 1 1 1 generic identifier A string constituting the name of a element in an SGML document. (2001-01-31) 1 1 1 1 1 genericity The possibility for a language to provided parameterised modules or types. E.g. List(of:Integer) or List(of:People). (1996-05-19) 1 1 1 1 1 generic markup In computerised document preparation, a method of adding information to the text indicating the logical components of a document, such as paragraphs, headers or footnotes. SGML is an example of such a system. Specific instructions for layout of the text on the page do not appear in the markup. (1996-05-19) 1 1 1 1 1 generic programming A programming technique which aims to make programs more adaptable by making them more general. Generic programs often embody non-traditional kinds of polymorphism; ordinary programs are obtained from them by suitably instantiating their parameters. In contrast with normal programs, the parameters of a generic programs are often quite rich in structure. For example they may be other programs, types or type constructors or even programming paradigms. (1997-11-22) 1 1 1 1 1 Generic Routing Encapsulation (GRE) A protocol which allows an arbitrary network protocol A to be transmitted over any other arbitrary network protocol B, by encapsulating the packets of A within GRE packets, which in turn are contained within packets of B. Defined in RFC 1701 and RFC 1702 (GRE over IP). (1998-07-19) 1 1 1 1 1 Generic Security Service Application Programming Interface (GSS-API) An application level interface (API) to system security services. It provides a generic interface to services which may be provided by a variety of different security mechanisms. Vanilla GSS-API supports security contexts between two entities (known as principals). GSS-API is a draft internet standard which is being developed in the Common Authentication Technology Working Group (cat-wg) of the Internet Engineering Task Force (IETF). Initial specifications for GSS-API appeared in RFC 1508 and RFC 1509. Subsequent revisions appeared in several draft standards documents. (http://dstc.qut.edu.au/~barton/work/project.html). (1996-05-19) 1 1 1 1 1 generic thunk A software mechanism that allows a 16-bit Windows application to load and call a Win32 DLL under Windows NT and Windows 95. See also flat thunk, universal thunk. (1999-04-05) 1 1 1 1 1 generic type variable (Also known as a "schematic type variable"). Different occurrences of a generic type variable in a type expression may be instantiated to different types. Thus, in the expression let id x = x in (id True, id 1) id's type is (for all a: a -> a). The universal quantifier for all a: means that a is a generic type variable. For the two uses of id, a is instantiated to Bool and Int. Compare this with let id x = x in let f g = (g True, g 1) in 1 1 1 1 1 Genesia An expert system developed by Electricite de France and commercialised by STERIA (Paris). 1 1 1 1 1 genetic algorithm (GA) An evolutionary algorithm which generates each individual from some encoded form known as a "chromosome" or genome. Chromosomes are combined or mutated to breed new individuals. "Crossover", the kind of recombination of chromosomes found in sexual reproduction in nature, is often also used in GAs. Here, an offspring's chromosome is created by joining segments choosen alternately from each of two parents' chromosomes which are of fixed length. GAs are useful for multidimensional optimisation problems in which the chromosome can encode the values for the different variables being optimised. Illinois Genetic Algorithms Laboratory (http://GAL4.GE.UIUC.EDU/illigal.home.html) (IlliGAL). (1995-02-03) 1 1 1 1 1 genetic algorithms genetic algorithm 1 1 1 1 1 genetic programming (GP) A programming technique which extends the genetic algorithm to the domain of whole computer programs. In GP, populations of programs are genetically bred to solve problems. Genetic programming can solve problems of system identification, classification, control, robotics, optimisation, game playing, and pattern recognition. Starting with a primordial ooze of hundreds or thousands of randomly created programs composed of functions and terminals appropriate to the problem, the population is progressively evolved over a series of generations by applying the operations of Darwinian fitness proportionate reproduction and crossover (sexual recombination). (1995-03-31) 1 1 1 1 1 GEnie Services GE Information Services 1 1 1 1 1 Genken Programming Language (GPL) A variant of PL360 by K. Asai of the Japan Atomic Energy Research Institute. ["Experience With GPL", K. Asai, in Machine Oriented Higher Level Languages, W. van der Poel, N-H 1974, pp. 371-376]. (1995-04-13) 1 1 1 1 1 GENOVA An old statistical package still in use on some VM computers. (1995-11-28) 1 1 1 1 1 gensym /jen'sim/ (From the MacLISP for "generated symbol") To invent a new name for something temporary, in such a way that the name is almost certainly not in conflict with one already in use. The canonical form of a gensym is "Gnnnn" where nnnn represents a number; any LISP hacker would recognise G0093 (for example) as a gensym. Gensymmed names are useful for storing or uniquely identifying crufties. [Jargon File] (1999-10-31) 1 1 1 1 1 Gensym Corporation A company that supplies software and services for intelligent operations management. Common applications include quality management, process optimisation, dynamic scheduling, network management, energy and environmental management, and process modelling and simulation. Their products include G2. (http://gensym.com/). (1999-10-31) 1 1 1 1 1 Gensym Standard Interface (GSI) A set of C libraries and programming tools used to interface G2 to external systems. Commercially available bridges are available to SCADA systems and PLCs. (1997-02-11) 1 1 1 1 1 Gentleman's Portable Coroutine System A coroutine package in Fortran. ["A Portable Coroutine System", W.M. Gentleman, Info Proc 71, C.V. Freiman ed, 1972]. (1995-02-01) 1 1 1 1 1 GEN-X An expert system developed by General Electric. 1 1 1 1 1 Geographical Information System Geographic Information System [Which is more common?] (1995-12-21) 1 1 1 1 1 Geographic Information System (GIS) A computer system for capturing, storing, checking, integrating, manipulating, analysing and displaying data related to positions on the Earth's surface. Typically, a GIS is used for handling maps of one kind or another. These might be represented as several different layers where each layer holds data about a particular kind of feature (e.g. roads). Each feature is linked to a position on the graphical image of a map. Layers of data are organised to be studied and to perform statistical analysis (i.e. a layer of customer locations could include fields for Name, Address, Contact, Number, Area). Uses are primarily government related, town planning, local authority and public utility management, environmental, resource management, engineering, business, marketing, and distribution. GIS dictionary (http://geo.ed.ac.uk/root/agidict/html/welcome.html). 1 1 1 1 1 geometric mean The Nth root of the product of N numbers. If each number in a list of numbers was replaced with their geometric mean, then multiplying them all together would still give the same result. The geometric mean thus gives an average "factor" in a context where numbers are multiplied together, e.g. compound interest. Wolfram (http://mathworld.wolfram.com/GeometricMean.html). (2007-03-16) 1 1 1 1 1 GEORGE One of the earliest programming languages, developed by Charles Hamblin in 1957. GEORGE was a stack oriented language, using reverse Polish notation. It was implemented on the English Electric DEUCE. ["GEORGE: A Semi-Translation Programming Scheme for the DEUCE, Programming and Operations Manual", C. L. Hamblin, U New S Wales, 1958]. ["Computer Languages", C.L. Hamblin, Aust J Sci 20(5):135-139, Dec 1957 and Aust Comp J 17(4):195-198, Nov 1985] (2007-03-18) 1 1 1 1 1 GEORGE 3 The operating system for the ICL 1900 mainframe. Lots of two-letter commands. (2003-09-20) 1 1 1 1 1 George Boole 1815-11-02 - 2008-05-11 22:58 best known for his contribution to symbolic logic (Boolean Algebra) but also active in other fields such as probability theory, algebra, analysis, and differential equations. He lived, taught, and is buried in Cork City, Ireland. The Boole library at University College Cork is named after him. For centuries philosophers have studied logic, which is orderly and precise reasoning. George Boole argued in 1847 that logic should be allied with mathematics rather than with philosophy. Demonstrating logical principles with mathematical symbols instead of words, he founded symbolic logic, a field of mathematical/philosophical study. In the new discipline he developed, known as Boolean algebra, all objects are divided into separate classes, each with a given property; each class may be described in terms of the presence or absence of the same property. An electrical circuit, for example, is either 1 1 1 1 1 Georg Simon Ohm (1789-1854) A German physicist who became Professor of Physics at Munich University, after whom the unit of electrical resistance was named. (2003-12-02) 1 1 1 1 1 GEOS A small windowing, microkernel (less than 64 kbytes long) operating system written in heavily bummed assembly language for MS-DOS computers. It multitasks rather nicely on a 6 Mhz Intel 80286 with at least 512K memory. It was adapted to PDAs by adding pen recognition, which doesn't work very well. Usenet newsgroup: news:comp.os.geos. (1995-01-21) 1 1 1 1 1 GEPURS An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-21) 1 1 1 1 1 Gerald ["Gerald: An Exceptional Lazy Functional Programming Language", A.C. Reeves et al, in Functional Programming, Glasgow 1989, K. Davis et al eds, Springer 1990]. (1995-01-10) 1 1 1 1 1 Gerald Sussman (Gerald J. Sussman, Jerry) A noted hacker at MIT and one of the developers of SCHEME and 6.001. (http://martigny.ai.mit.edu/~gjs/gjs.html). (1996-11-29) 1 1 1 1 1 German \j*r'mn\ A human language written (in latin alphabet) and spoken in Germany, Austria and parts of Switzerland. German writing normally uses four non-ASCII characters: "ä", "ö" and "ü" have "umlauts" (two dots over the top) and "ß" is a double-S ("scharfes S") which looks like the Greek letter beta (except in capitalised words where it should be written "SS"). These can be written in ASCII in several ways, the most common are ae, oe ue AE OE UE ss or sz and the TeX versions "a "o "u "A "O U s. See also ABEND, blinkenlights, DAU, DIN, gedanken, GMD, kluge. Usenet newsgroup: news:soc.culture.german. (ftp://src.doc.ic.ac.uk/usenet/news-info/soc.answers/german-faq), (ftp://alice.fmi.uni-passau.de/pub/dictionaries/german.dat.Z). (1995-03-31) 1 1 1 1 1 GEST Generic Expert System Tool 1 1 1 1 1 Get a life! Standard way of suggesting that someone has succumbed to terminal geekdom. Often heard on Usenet, especially as a way of suggesting that the target is taking some obscure issue of theology too seriously. This exhortation was popularised by William Shatner on a "Saturday Night Live" episode in a speech that ended "Get a *life*!", but some respondents believe it to have been in use before then. It was certainly in wide use among hackers for at least five years before achieving mainstream currency in early 1992. [Jargon File] (1995-01-18) 1 1 1 1 1 Get a real computer! A typical hacker response to news that somebody is having trouble getting work done on a toy system or bitty box. The threshold for "real computer" rises with time. As of mid-1993 it meant multi-tasking, with a hard disk, and an address space bigger than 16 megabytes. At this time, according to GLS, computers with character-only displays were verging on "unreal". In 2001, a real computer has a one gigahertz processor, 128 MB of RAM, 20 GB of hard disk, and runs Linux. [Jargon File] (2001-06-22) 1 1 1 1 1 get.com A command which can be created using debug in MS DOS to set the errorlevel according to which key is pressed. The errorlevel can then be interrogated from a batch file by a series of commands like this: get if errorlevel 118 goto E118 if errorlevel 117 goto E117 if errorlevel 116 goto E116 if errorlevel 115 goto E115 if errorlevel 114 goto E114 where E118 etc. are labels in the batch file. (1996-02-01) 1 1 1 1 1 getty A Unix program which sets terminal type, modes, speed and line discipline for a serial port, and is used in the login process. (1996-12-08) 1 1 1 1 1 gf The country code for French Guiana. (1999-01-27) 1 1 1 1 1 GFDL GNU Free Documentation License 1 1 1 1 1 g file (General file) A mid 1980s term for text files, usually short and unpublished found on BBSs. The g-files section on BBSs contain text files of general interest, viewable on-line; this is as opposed to files in the file transfer section, which are generally downloadable but not viewable on-line. When used on the Internet, this term generally refers to the types of file most often associated with old BBSs such as instructions on phreaking or making bombs. (1996-06-20) 1 1 1 1 1 GFLOPS gigaflops 1 1 1 1 1 GFR Grim File Reaper 1 1 1 1 1 GFS Grandfather, Father, Son 1 1 1 1 1 gh The country code for Ghana. (1999-01-27) 1 1 1 1 1 GHC 1. Guarded horn clauses. 2. Glasgow Haskell Compiler. (1999-01-05) 1 1 1 1 1 ghetto code A particularly inelegant and obviously suboptimal section of code that still meets the original requirements. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-05-14) 1 1 1 1 1 ghost (Or "zombie") The image of a user's session on IRC and similar systems, left when the session has been terminated (properly or, often, improperly) but the server (or the network at large) believes the connection is still active and belongs to a real user. Compare clonebot. (1997-04-07) 1 1 1 1 1 Ghostscript The GNU interpreter for PostScript and PDF, with previewers for serval systems and many fonts. Ghostscript was originally written by L. Peter Deutsch <ghost@aladdin.com> of Aladdin Enterprises. The first public release was v1.0 on 1988-08-11. Latest version: 8.11, as of 2003-08-29. GNU Home (http://gnu.org/software/ghostscript/). News & community (http://ghostscript.com/). (2003-09-24) 1 1 1 1 1 ghostview An X Window System interface to the ghostscript PostScript interpreter. 1 1 1 1 1 GHz GigaHertz 1 1 1 1 1 GI generic identifier 1 1 1 1 1 gi The country code for Gibraltar. (1999-01-27) 1 1 1 1 1 Gibson, William William Gibson 1 1 1 1 1 gid 1. <operating system> group identifier. 2. <filename extension> global index. (1997-01-30) 1 1 1 1 1 GIF Graphics Interchange Format 1 1 1 1 1 GIF89 Graphics Interchange Format 1 1 1 1 1 GIF89a animated GIF 1 1 1 1 1 GIFF Do you mean GIF or is this some kind of IFF? 1 1 1 1 1 gig gigabyte 1 1 1 1 1 giga- prefix 1 1 1 1 1 gigabit 2^30 bits, 1,073,741,824 bits. See prefix. (1995-11-12) 1 1 1 1 1 gigabits per second (Gbps) A unit of information transfer rate equal to one billion bits per second. Note that, while a gigabit is defined as a power of two (2^30 bits), a gigabit per second is defined as a power of ten (10^9 bits per second, which is slightly less) than 2^30). (2004-02-10) 1 1 1 1 1 gigabyte (GB or colloquially "gig") A unit of data equal to one billion bytes but see binary prefix for other definitions. A gigabyte is 1000^3 bytes or 1000 megabytes. A human gene sequence (including all the redundant codons) contains about 1.5 gigabytes of data. 1000 gigabytes are one terabyte. See prefix. Human genome data content (http://bitesizebio.com/articles/how-much-information-is-stored-in-the-human-genome/). (2013-11-03) 1 1 1 1 1 gigaflop gigaflops 1 1 1 1 1 gigaflops (GFLOPS) One thousand million (10^9) floating point operations per second. One of them is strictly "one gigaflops" in the same way that one mile per hour isn't 1 MP. See prefix. (1998-04-19) 1 1 1 1 1 GigaHertz (GHz) Billions of cycles per second. The unit of frequency used to measure the clock rate of modern digital logic, including microprocessors. (2001-05-14) 1 1 1 1 1 GIGO Garbage In, Garbage Out 1 1 1 1 1 gilley (Usenet) The unit of analogical bogosity. According to its originator, the standard for one gilley was "the act of bogotoficiously comparing the shutting down of 1000 machines for a day with the killing of one person. The" milligilley has been found to suffice for most normal conversational exchanges. (1995-03-17) 1 1 1 1 1 gillion /gil'y*n/ or /jil'y*n/ (From giga- by analogy with mega/million and tera/trillion) 10^9. Same as an American billion or a British "milliard". How one pronounces this depends on whether one speaks giga- with a hard or soft "g". [Jargon File] (1995-03-17) 1 1 1 1 1 Gilmore, John John Gilmore 1 1 1 1 1 GIM-1 Generalized Information Management Language. Nelson, Pick, Andrews. Proc SJCC 29:169-73, AFIPS (Fall 1966). 1 1 1 1 1 GIN A special-purpose macro assembler used to build the GEORGE 3 operating system for ICL1900 series computers. (1994-11-02) 1 1 1 1 1 GINA Generic Interactive Application. An application framework based on Common Lisp and OSF/Motif, designed to simplify the construction of graphical interactive applications. GINA consists of CLM - a language binding for OSF/Motif in Common Lisp; the GINA application framework - a class library in CLOS; the GINA interface builder - an interactive tool implemented with GINA to design Motif windows. Version 2.2 requires OSF/Motif 1.1 or better, Common Lisp with CLX, CLOS, PCL and processes. It runs with Franz Allegro, Lucid, CMU CL and Symbolics Genera. Germany (ftp://ftp.gmd.de/gmd/gina). N. America (ftp://export.lcs.mit.edu/contrib/). Mailing list: gina-users-request@gmdzi.gmd.de. (1994-11-02) 1 1 1 1 1 Ginger A simple functional language from the University of Warwick with parallel constructs. (1994-11-02) 1 1 1 1 1 GIP 1. General Interpretive Programme. A 1956 interpreted language for the English Electric DEUCE, with array operations and an extensive library of numerical methods. ["Interpretive and Brick Schemes, with Special Reference to Matrix Operations", English Electric COmpany, DEUCE News No. 10 (1956)]. (1994-11-02) 2. An erroneous singular of GIPS. 1 1 1 1 1 GIPS /gips/ or /jips/ [Analogy with MIPS] Giga-Instructions per Second (or possibly "Gillions of Instructions per Second"; see gillion). In 1991, this was used of only a handful of highly parallel machines and one sequential processor built with Josephson devices. DEC's Alpha AXP 21164 processor was the first commercially available 1 GIPS sequential processor (7 Sep 1994). Compare KIPS. ["A 1-GIPS Josephson Data Processor", Yuji Hatano et al, IEEE J Solid State Circuits, vol 26, 6, June 1991] [Jargon File] (1994-11-02) 1 1 1 1 1 GIRL Graph Information Retrieval Language. A language for handling directed graphs. ["Graph Information Retrieval Language", S. Berkowitz, Report 76-0085, Naval Ship Res Dev Center, (Feb 1976)]. (1994-11-02) 1 1 1 1 1 GIS Geographical Information System 1 1 1 1 1 Giuseppe Peano (1858-08-27 - 1932-04-20) An Italian mathematician who wrote over 200 books and papers, was a founder of mathematical logic and set theory and taught at the University of Turin. He contributed to mathematical analysis, logic, the teaching of calculus, differential equations, vector analysis and the axiomatization of mathematics. The standard axiomatization of the natural numbers is named Peano arithmetic or the Peano axioms after him. He also invented the Peano curve, an early example of a fractal. (2013-03-23) 1 1 1 1 1 GIYF Google Is Your Friend. See STFW. (2014-05-23) 1 1 1 1 1 GKS Graphical Kernel System 1 1 1 1 1 GKS-3D The three-dimensional version of GKS, a standard for graphics I/O (ISO 8805). (1994-11-02) 1 1 1 1 1 GL Graphics Language. A graphics package from Silicon Graphics. 1 1 1 1 1 gl The country code for Greenland. (1999-01-27) 1 1 1 1 1 Glammar A pattern transformation language for text-to-text translation. Used for compiler writing and linguistics. (ftp://phoibos.cs.kun.nl/pub/GLASS/glammar.tar.Z). 1 1 1 1 1 glark /glark/ To figure something out from context. "The System III manuals are pretty poor, but you can generally glark the meaning from context." Interestingly, the word was originally glork; the context was "This gubblick contains many nonsklarkish English flutzpahs, but the overall pluggandisp can be glorked [sic] from context" (David Moser, quoted by Douglas Hofstadter in his "Metamagical Themas" column in the January 1981 "Scientific American"). It is conjectured that hackish usage mutated the verb to "glark" because glork was already an established jargon term. Compare grok, zen. [Jargon File] 1 1 1 1 1 Glasgow Haskell Compiler (GHC) A Haskell 1.2 compiler written in Haskell by the AQUA project at Glasgow University, headed by Simon Peyton Jones <simonpj@dcs.glasgow.ac.uk> throughout the 1990's [started?]. GHC can generate either C or native code for SPARC, DEC Alpha and other platforms. It can take advantage of features of gcc such as global register variables and has an extensive set of optimisations. GHC features an extensible I/O system based on a "monad", in-line C code, fully fledged unboxed data types, incrementally-updatable arrays, mutable reference types, generational garbage collector, concurrent threads. Time and space profiling is also supported. It requires GNU gcc 2.1+ and Perl. GHC runs on Sun-4, DEC Alpha, Sun-3, NeXT, DECstation, HP-PA and SGI. Latest version: 4.01, as of 1998-11-30. Glasgow FTP 1 1 1 1 1 GLASS General LAnguage for System Semantics. An Esprit project at the University of Nijmegen. (ftp://phoibos.cs.kun.nl/pub/GLASS). (1995-01-25) 1 1 1 1 1 glass (IBM) silicon. [Jargon File] 1 1 1 1 1 glass box testing white box testing 1 1 1 1 1 glassfet /glas'fet/ [Analogy with MOSFET] (or "firebottle") A humorous way to refer to a vacuum tube. [Jargon File] 1 1 1 1 1 glass tty /glas T-T-Y/ or /glas ti'tee/ A terminal that has a display screen but which, because of hardware or software limitations, behaves like a teletype or some other printing terminal, thereby combining the disadvantages of both: like a printing terminal, it can't do fancy display hacks, and like a display terminal, it doesn't produce hard copy. An example is the early "dumb" version of Lear-Siegler ADM 3 (without cursor control). See tube, tty; compare dumb terminal, smart terminal. See "TV Typewriters" for an interesting true story about a glass tty. 1 1 1 1 1 GLB greatest lower bound 1 1 1 1 1 glibc GNU C Library 1 1 1 1 1 Glish Glish is an interpretive language for building loosely-coupled distributed systems from modular, event-oriented programs. Written by Vern Paxson <vern@ee.lbl.gov>. These programs are written in conventional languages such as C, C++, or Fortran. Glish scripts can create local and remote processes and control their communication. Glish also provides a full, array-oriented programming language (similar to S) for manipulating binary data sent between the processes. In general Glish uses a centralised communication model where interprocess communication passes through the Glish interpreter, allowing dynamic modification and rerouting of data values, but Glish also supports point-to-point links between processes when necessary for high performance. Version 2.4.1 includes an interpreter, C++ class library and user manual. It requires C++ and there are ports to SunOS, Ultrix, an HP/UX (rusty). (ftp://ftp.ee.lbl.gov/glish/glish-2.4.1.tar.Z). 1 1 1 1 1 Glisp Generalized LISP. D.C. Smith, Aug 1990. A coordinated set of high-level syntaxes for Common LISP. Contains Mlisp, Plisp and ordinary LISP, with an extensible framework for adding others. Written in Plisp. (ftp://bric-a-brac.apple.com/dts/mac/lisp). 1 1 1 1 1 glitch /glich/ [German "glitschen" to slip, via Yiddish "glitshen", to slide or skid] 1. (Electronics) When the inputs of a circuit change, and the outputs change to some random value for some very brief time before they settle down to the correct value. If another circuit inspects the output at just the wrong time, reading the random value, the results can be very wrong and very hard to debug (a glitch is one of many causes of electronic heisenbugs). 2. A sudden interruption in electric service, sanity, continuity, or program function. Sometimes recoverable. An interruption in electric service is specifically called a power glitch (or power hit), of grave concern because it usually crashes all the computers. See also gritch. 2. [Stanford] To scroll a display screen, especially several lines at a time. WAITS terminals used to do this in order to avoid continuous scrolling, which is distracting to the eye. 1 1 1 1 1 glob /glob/ A mechanism that returns a list of pathnames that match a pattern containing wild card characters. Globbing was available in early versions of Unix and, in more limited form, in Microsoft Windows. The characters are: * = zero or more characters, e.g. "probab*" would match probabilistic, probabilistically, probabilities, probability, probable, probably. ? = any single character, e.g. "b?g" would match bag, big, bog, bug. [] any of the enclosed characters, e.g. "b[ao]g" would match bag, bog (not on Windows). These have become sufficiently pervasive that hackers use them in written messages. E.g. "He said his name was [KC]arl" (expresses ambiguity). "I don't read talk.politics.*" (any of the talk.politics subgroups on Usenet). Other examples are given under the entry for X. 1 1 1 1 1 global index (gid) The filename extension of a Windows 95 "global index" file. .gid files are created by the help browser internal to Windows 95 (also available for other Windows versions) for WinHelp files (hlp), as well as for storing user preferences, such as window position. (1997-01-30) 1 1 1 1 1 globalisation internationalisation 1 1 1 1 1 Global Network Navigator (GNN) A collection of free services provided by O'Reilly & Associates. The Whole Internet Catalog describes the most useful Net resources and services with live links to those resources. The GNN Business Pages list companies on the Internet. The Internet Help Desk provides help in starting Internetq exploration. NetNews is a weekly publication that reports on the news of the Internet, with weekly articles on Internet trends and special events, sports, weather, and comics. There are also pages aobut travel and personal finance. Home page (http://gnn.com/). E-mail: <support@gnn.com>. Telephone: (800) 998 9938 (USA), +1 (707) 829 0515 (outside USA). (1995-01-10) 1 1 1 1 1 Global Positioning System (GPS) A system for determining postion on the Earth's surface by comparing radio signals from several satellites. When completed the system will consist of 24 satellites equipped with radio transmitters and atomic clocks. Depending on your geographic location, the GPS receiver samples data from up to six satellites, it then calculates the time taken for each satellite signal to reach the GPS receiver, and from the difference in time of reception, determines your location. ["Global Positioning by Satellite"? Precison? Coverage? Web page?] (1998-02-10) 1 1 1 1 1 Global System for Mobile Communications (GSM, originally "Groupe de travail Sp?ciale pour les services Mobiles") One of the major standards for digital cellular communications, in use in over 60 countries and serving over one billion subscribers. The GSM standard is currently used in the 900 MHz, 1800 MHz and 1900 MHz bands. GPRS allows circuit switched data communications over GSM, and is widely used for World Wide Web and electronic mail access from cellular devices. GSM World (http://gsmworld.com/). (2005-01-26) 1 1 1 1 1 glork /glork/ 1. Used as a name for just about anything. See foo. 2. Similar to glitch, but usually used reflexively. "My program just glorked itself." See also glark. [Jargon File] 1 1 1 1 1 GLOS Graphics Language Object System. 1 1 1 1 1 GLOW A POP-11 variant with lexical scope. Available from Andrew Arnblaster, Bollostraat 6, B-3140 Keerbergen, Belgium, for Mac or MS-DOS. [Byte's UK edition, May 1992, p.84UK-8]. (1997-02-07) 1 1 1 1 1 GLS Guy Lewis Steele, Jr. 1 1 1 1 1 GLU A practical coarse grain implementation of the Lucid dataflow language for networks. (1998-03-07) 1 1 1 1 1 glue A generic term for any interface logic or protocol that connects two component blocks. For example, Blue Glue is IBM's SNA protocol, and hardware designers call anything used to connect large VLSI's or circuit blocks "glue logic". [Jargon File] (1999-02-22) 1 1 1 1 1 glue language Any language, usually a scripting language, used to write glue to integrate tools and other programs to solve some problem. (1999-02-22) 1 1 1 1 1 glyph An image used in the visual representation of characters; roughly speaking, how a character looks. A font is a set of glyphs. In the simple case, for a given font (typeface and size), each character corresponds to a single glyph but this is not always the case, especially in a language with a large alphabet where one character may correspond to several glyphs or several characters to one glyph (a character encoding). Usually used in reference to outline fonts, in particular TrueType. (1998-05-31) 1 1 1 1 1 Glypnir 1966. An ALGOL-like language with parallel extensions. Similar to Actus. "GLYPNIR - A Programming Language for the Illiac IV", D.H. Lawrie et al, CACM 18(3) (Mar 1975). 1 1 1 1 1 gm The country code for Gambia. (1999-01-27) 1 1 1 1 1 GMAP GCOS Macro Assembler Program 1 1 1 1 1 GMD Full name: "GMD - Forschungszentrum Informationstechnik GmbH" (German National Research Center for Information Technology). Before April 1995, GMD stood for "Gesellschaft für Mathematik und Datenverarbeitung" - National Research Center for Computer Science, it is retained for historical reasons. (http://gmd.de/GMDHome.english.html). Address: D-53754 Sankt Augustin, Germany. (1995-04-10) 1 1 1 1 1 GMD Toolbox for Compiler Construction (Or Cocktail) A huge set of compiler building tools for MS-DOS, Unix and OS/2. parser generator (LALR -> C, Modula-2), documentation, parser generator (LL(1) -> C, Modula-2), tests, scanner generator (-> C, Modula-2), tests translator (Extended BNF -> BNF), translator (Modula-2 -> C), translator (BNF (yacc) -> Extended BNF), examples abstract syntax tree generator, attribute-evaluator generator, code generator Latest version: 9209. The MS-DOS version requires DJ Delorie's DOS extender (go32) and the OS/2 version requires the emx programming environment. (ftp://ftp.karlsruhe.gmd.de/pub/cocktail/dos). OS/2 FTP (ftp://ftp.eb.ele.tue.nl/pub/src/cocktail/dos-os2.zoo). Mailing list: listserv@eb.ele.tue.nl (subscribe to Cocktail). E-mail: Josef Grosch <grosch@karlsruhe.gmd.de>, Willem Jan Withagen <wjw@eb.ele.tue.nl> (OS/2). 1 1 1 1 1 GMT Universal Time 1 1 1 1 1 1 gn The country code for Guinea. (1999-01-27) 1 1 1 1 1 gnarly /nar'lee/ Both obscure and hairy. "Yow! - the tuned assembler implementation of BitBlt is really gnarly!" From a similar but less specific usage in surfer slang. [Jargon File] (1996-09-17) 1 1 1 1 1 Gnat An Ada compiler written in Ada using the gcc code generator to allow easy porting to a variety of platforms. Gnat is the only Ada compiler that completely implements the Ada standard, including all the annexes. The compiler is released under the GNU license and is currently maintained by Ada Core Technologies (ACT). (http://gnat.com/). (1999-06-24) 1 1 1 1 1 GNATS GNU Problem Report Management System 1 1 1 1 1 GNN Global Network Navigator 1 1 1 1 1 GNOME GNU Network Object Model Environment 1 1 1 1 1 Gnome Computers A small UK hardware and software company. They make transputer boards for the Acorn Archimedes among other things. E-mail: Chris Stenton <chris@gnome.co.uk>. (1994-09-30) 1 1 1 1 1 GNU /g*noo/ 1. A recursive acronym: GNU's Not Unix!. The Free Software Foundation's project to provide a freely distributable replacement for Unix. The GNU Manifesto was published in the March 1985 issue of Dr. Dobb's Journal but the GNU project started a year and a half earlier when Richard Stallman was trying to get funding to work on his freely distributable editor, Emacs. Emacs and the GNU C compiler, gcc, two tools designed for this project, have become very popular. GNU software is available from many GNU archive sites. See also Hurd. 2. <person> John Gilmore. [Jargon File] (1997-04-12) 1 1 1 1 1 GNU archive site The main GNU FTP archive is on gnu.org but copies ("mirrors") of some or all of the files there are also held on many other computers around the world. To avoid overloading gnu.org and the Internet you should FTP files from the machine closest to yours. Look for a directory like /pub/gnu, /mirrors/gnu, /systems/gnu or /archives/gnu. GNU Project FTP server (https://ftp.gnu.org/). (2014-12-04) 1 1 1 1 1 GNU assembler (GAS) A Unix assembler for the GNU project. Many CPU types are handled and COFF and IEEE-695 formats are supported as well as standard a.out. Current version 2.2 ported to Sun-3, Sun-4, i386, 386BSD, BSD/386, Linux, PS/2-AIX, VAX, Ultrix, BSD, VMS. The assembler has been merged with GNU Binutils. E-mail: <bug-gnu-utils@gnu.org>. (1995-04-18) 1 1 1 1 1 GNU awk gawk 1 1 1 1 1 GNU BC A GNU version of BC which is self-contained and internally executes its own compiled code rather than acting as a front-end to DC like the standard Unix bc. Version 1.02 parser (yacc), interpreter, BC math library Philip A. Nelson <phil@cs.wwu.edu> FTP bc-1.02.tar.Z from a GNU archive site. requires: vsprintf and vfprintf routines ports: Unix (BSD, System V, MINIX, POSIX) Superset of POSIX BC (P10003.2/D11), with a POSIX-only mode. 1 1 1 1 1 GNU C The extension of C compiled by gcc. (1997-09-30) 1 1 1 1 1 GNU C Library (glibc) The run-time library for the GNU C compiler, gcc, and others. glibc is the source code for libc.a. It is maintained separately from the compilers and is a superset of ANSI C and POSIX.1 and a large subset of POSIX.2. Latest version: 2.1.3, as of 2000-04-29 (http://gnu.org/glibc). Mailing list: <bug-glibc@gnu.org> (bugs). (2000-05-31) 1 1 1 1 1 GNU DC GNU Desktop Calculator. An interpreter for a subset of the standard Unix DC that handles all its operations, except the (undocumented) array operations. Integration with GNU BC is being attempted. Version 0.2. FTP dc-0.2.tar.Z from your nearest GNU archive site. (1993-05-21) 1 1 1 1 1 GNU E A persistent C++ variant Version 2.3.3 compiler (ftp://ftp.cs.wisc.edu/exodus/E/). GNU E is a persistent, object oriented programming language developed as part of the Exodus project. GNU E extends C++ with the notion of persistent data, program level data objects that can be transparently used across multiple executions of a program, or multiple programs, without explicit input and output operations. GNU E's form of persistence is based on extensions to the C++ type system to distinguish potentially persistent data objects from objects that are always memory resident. An object is made persistent either by its declaration (via a new persistent storage class qualifier) or by its method of allocation (via persistent dynamic allocation using a special overloading of the new operator). The underlying object 1 1 1 1 1 GNU Emacs Emacs 1 1 1 1 1 GNU Free Documentation License (GFDL) The Free Software Foundation's license designed to ensure the same freedoms for documentation that the GPL gives to software. This dictionary is distributed under the GFDL, see the copyright notice in the Free On-line Dictionary of Computing section (at the start of the source file). The full text follows. Version 1.1, March 2000 Copyright 2000 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or 1 1 1 1 1 GNU General Public License General Public License 1 1 1 1 1 GNUMACS /gnoo'maks/ [contraction of "GNU Emacs"] Often-heard abbreviated name for the GNU project's flagship tool, Emacs. Used especially in contrast with GOSMACS. [Jargon File] 1 1 1 1 1 GNU mirror site GNU archive site 1 1 1 1 1 GNU Network Object Model Environment (GNOME) A project to build a complete, user-friendly desktop based entirely on free software. GNOME is part of the GNU project and part of the OpenSource movement. The desktop will consist of small utilities and larger applications which share a consistent look and feel. GNOME uses GTK+ as the GUI toolkit for applications. GNOME is intended to run on any modern and functional Unix-like system. The current version runs on Linux, FreeBSD, IRIX and Solaris. (http://gnome.org/). (1998-10-17) 1 1 1 1 1 Gnuplot A command-driven interactive graphing program. Gnuplot can plot two-dimensional functions and data points in many different styles (points, lines, error bars); and three-dimensional data points and surfaces in many different styles (contour plot, mesh). It supports complex arithmetic and user-defined functions and can label title, axes, and data points. It can output to several different graphics file formats and devices. Command line editing and history are supported and there is extensive on-line help. Gnuplot is copyrighted, but freely distributable. It was written by Thomas Williams, Colin Kelley, Russell Lang, Dave Kotz, John Campbell, Gershon Elber, Alexander Woo and many others. Despite its name, gnuplot is not related to the GNU project or the FSF in any but the most peripheral sense. It was designed completely independently and is not covered by the General Public License. However, the FSF has decided to distribute gnuplot as part of the GNU system, because it 1 1 1 1 1 GNU Privacy Guard tool, cryptography (GPG) GNU's encryption and digital signature tool intended to be a free replacement for PGP. (2003-04-12) 1 1 1 1 1 GNU Problem Report Management System (GNATS) GNU's bug tracking system. Users who experience problems use electronic mail, web-based or other clients communicating with the GNATS network daemon running at the support site, or direct database submissions to communicate these problems to maintainers at that Support Site. (http://gnu.org/software/gnats). (2002-06-12) 1 1 1 1 1 GNU public licence Properly known as the General Public License. Improperly known as the General Public Virus. (1995-05-04) 1 1 1 1 1 GNUS GNU news. A GNU Emacs subsystem for reading and sending Usenet news, written by Masanobu Umeda <umerin@mse.kyutech.ac.jp>. You can use GNUS to browse through news groups, look at summaries of articles in a specific group, and read articles of interest. You can respond to authors or write articles or replies to all the readers of a news group. GNUS can be configured to use the NNTP protocol to get news from a remove server or it can read it from local news spool files. Usenet newsgorup: news:gnu.emacs.gnus. (1995-05-04) 1 1 1 1 1 GNU sed A GNU version of the standard Unix Sed stream editor. GNU sed was written by Tom Lord <lord+@andrew.cmu.edu>. Version 2.03. FTP from your nearest GNU archive site. E-mail: <bug-gnu-utils@gnu.org> (bugs). (1993-08-09) 1 1 1 1 1 GNU Smalltalk A GNU version of Smalltalk, by Steven Byrne <sbb@eng.sun.com>. Version 1.1.1, FTP from your nearest GNU archive site. msgGUI is a graphical user interface library for GNU Smalltalk. (1991-09-15) 1 1 1 1 1 GNUStep A GNU implementation of OpenStep. Work has started on an implementation using an existing library written in Objective-C. Much work remains to be done to bring this library close to the OpenStep specifications. Adam Fedor is head of the project. (http://gnustep.org/). [Current status? Newsgroup?] (1999-11-25) 1 1 1 1 1 GNU style An obsolete and deprecated source code indent style used throughout GNU Emacs and the Free Software Foundation code, and just about nowhere else. Indents are always four spaces per level, with "" and "" halfway between the outer and inner indent levels. if (cond) <body> (2014-09-24) 1 1 1 1 1 GNU superoptimiser (GSO) A function sequence generator that uses an exhaustive generate-and-test approach to find the shortest instruction sequence for a given function. Written by Torbjorn Granlund <tege@gnu.ai.mit.edu> and Tom Wood. You have to tell the superoptimiser which function and which CPU you want to get code for. This is useful for compiler writers. FTP superopt-2.2.tar.Z from a GNU archive site. Generates code for DEC Alpha, SPARC, Intel 80386, 88000, RS/6000, 68000, 29000 and Pyramid (SP, AP and XP). (1993-02-16) 1 1 1 1 1 Go A thinking game with an oriental origin estimated to be around 4000 years old. Nowadays, the game is played by millions of people in (most notably) China, Japan, Korea and Taiwan. In the Western world the game is practised by a yearly increasing number of players. On the Internet Go players meet, play and talk 24 hours/day on the Internet Go Server (IGS). (http://cwi.nl/~jansteen/go/go.html). Usenet newsgroup: news:rec.games.go. (1995-03-17) 1 1 1 1 1 goal In logic programming, a predicate applied to its arguments which the system attempts to prove by matching it against the clauses of the program. A goal may fail or it may succeed in one or more ways. (1997-07-14) 1 1 1 1 1 goal seek what-if analysis 1 1 1 1 1 Go Back N A data link layer protocol. [Details?] (2010-01-19) 1 1 1 1 1 gobble 1. To consume, usually used with "up". "The output spy gobbles characters out of a tty output buffer." 2. To obtain, usually used with "down". "I guess I'll gobble down a copy of the documentation tomorrow." See also snarf. [Jargon File] (2010-01-19) 1 1 1 1 1 GObject Introspection A GNOME project that defines a syntax for introspection annotation pragmas to be used in the GObject library source code. Rather than actual introspection, these are intended to allow automatic generation of bindings (APIs) to expose the library to higher-level languages. The sort of information provided is the type and direction (in, out, inout) of function parameters and the responsibility for freeing memory used by data structures. GObject Introspection Home (http://live.gnome.org/GObjectIntrospection/). (2010-01-19) 1 1 1 1 1 Godwin's Law "As a Usenet discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one." There is a tradition in many groups that, once this occurs, that thread is over, and whoever mentioned the Nazis has automatically lost whatever argument was in progress. Godwin's Law thus practically guarantees the existence of an upper bound on thread length in those groups. However there is also a widely recognised codicil that any intentional triggering of Godwin's Law in order to invoke its thread-ending effects will be unsuccessful. [Jargon]. (2003-10-06) 1 1 1 1 1 Godzillagram /god-zil'*-gram/ (From Japan's national hero and datagram) 1. A network packet that in theory is a broadcast to every machine in the universe. The typical case is an IP datagram whose destination IP address is [255.255.255.255]. Fortunately, few gateways are foolish enough to attempt to implement this case! 2. A network packet of maximum size. An IP Godzillagram has 65,536 octets. Compare super source quench. (2003-10-07) 1 1 1 1 1 Goedel (After the mathematician Kurt Gödel) A declarative, general-purpose language for artificial intelligence based on logic programming. It can be regarded as a successor to Prolog. The type system is based on many-sorted logic with parametric polymorphism. Modularity is supported, as well as infinite precision arithmetic and finite sets. Goedel has a rich collection of system modules and provides constraint solving in several domains. It also offers metalogical facilities that provide significant support for metaprograms that do analysis, transformation, compilation, verification, and debugging. A significant subset of Goedel has been implemented on top of SISCtus Prolog by Jiwei Wang <jiwei@lapu.bristol.ac.uk>. FTP Bristol, UK (ftp://ftp.cs.bris.ac.uk/goedel), FTP K U Leuven (ftp://ftp.cs.kuleuven.ac.be/pub/logic-prgm/goedel). E-mail: <goedel@compsci.bristol.ac.uk>. 1 1 1 1 1 go-faster stripes chrome. Mainstream in some parts of UK. [Jargon File] (1998-07-05) 1 1 1 1 1 Gofer A lazy functional language designed by Mark Jones <mpj@cs.nott.ac.uk> at the Programming Research Group, Oxford, UK in 1991. It is very similar to Haskell 1.2. It has lazy evaluation, higher order functions, pattern matching, and type classes, lambda, case, conditional and let expressions, and wild card, "as" and irrefutable patterns. It lacks modules, arrays and standard classes. Gofer comes with an interpreter (in C), a compiler which compiles to C, documentation and examples. Unix Version 2.30 (1994-06-10) Mac_Gofer version 0.16 beta. Ported to Sun, Acorn Archimedes, IBM PC, Macintosh, Atari, Amiga. Version 2.30 added support for contexts in datatype and member function definitions, Haskell style arrays, an external function calling mechanism for gofc, an experimental implementation of Launchbury/Peyton Jones style lazy 1 1 1 1 1 Goffin A definitional constraint language for declarative parallel programming. Goffin systematically integrates equational constraints and functions within a uniform framework of concurrent programming. Goffin is an embedding of a functional language kernel (Haskell) into a layer of constraint logic, which allows logical variables inside functional expressions. In order to preserve referential transparency, functional reduction suspends until logical variables become bound. Logical variables are bound by equational constraints, which impose relations over expressions. Hence, constraints are the means to structure the concurrent reduction of functional expressions. (1995-02-21) 1 1 1 1 1 go flatline [Cyberpunk SF, refers to flattening of EEG traces upon brain-death] also "flatlined". 1. To die, terminate, or fail, especially irreversibly. In hacker parlance, this is used of machines only, human death being considered somewhat too serious a matter to employ jargon-jokes about. 2. To go completely quiescent; said of machines undergoing controlled shutdown. "You can suffer file damage if you shut down Unix but power off before the system has gone flatline." 3. Of a video tube, to fail by losing vertical scan, so all one sees is a bright horizontal line bisecting the screen. [Jargon File] 1 1 1 1 1 GO-GO ALPS 1 1 1 1 1 go gold The point in the life of a software product where it is declared ready to release for sale. This may be because it has reached sufficiently high quality (freedom from bugs, etc.), or because it is financially expedient. (2004-08-02) 1 1 1 1 1 GOL General Operating Language. Subsystem of DOCUS. [Sammet 1969, p.678]. 1 1 1 1 1 golden [Probabaly from folklore's "golden egg"] When used to describe a magnetic medium (e.g. "golden disk", "golden tape"), describes one containing a tested, up-to-spec, ready-to-ship software version. Compare platinum-iridium. [Jargon File] 1 1 1 1 1 golf ball printer IBM 2741 1 1 1 1 1 GOM Good Old MAD. Don Boettner, U Mich. MAD for the IBM 360. Parts of the MTS time-sharing system were written in GOM. 1 1 1 1 1 gonk /gonk/ 1. To prevaricate or to embellish the truth beyond any reasonable recognition. In German the term is (mythically) "gonken"; in Spanish the verb becomes "gonkar". "You're gonking me. That story you just told me is a bunch of gonk. In German, for example, ""Du gonkst mir"" (You're" pulling my leg). See also gonkulator. 2. (British) To grab some sleep at an odd time. Compare gronk out. [Jargon File] (1995-03-07) 1 1 1 1 1 gonkulator /gon'kyoo-lay-tr/ (From "Hogan's Heroes", the TV series) A pretentious piece of equipment that actually serves no useful purpose. Usually used to describe one's least favourite piece of computer hardware. See gonk. [Jargon File] (1995-03-07) 1 1 1 1 1 GOOD Graph-Oriented Object Database 1 1 1 1 1 Good Thing (From the 1930 Sellar and Yeatman parody "1066 And All That") Often capitalised; always pronounced as if capitalised. 1. Self-evidently wonderful to anyone in a position to notice: "The Trailblazer's 19.2 Kbaud PEP mode with on-the-fly Lempel-Ziv compression is a Good Thing for sites relaying netnews." 2. Something that can't possibly have any ill side-effects and may save considerable grief later: "Removing the self-modifying code from that shared library would be a Good Thing". 3. When said of software tools or libraries, as in "Yacc is a Good Thing", specifically connotes that the thing has drastically reduced a programmer's work load. Opposite: Bad Thing, compare big win. [Jargon File] (1995-05-07) 1 1 1 1 1 Google The web search engine that indexes the greatest number of web pages - over two billion by December 2001 and provides a free service that searches this index in less than a second. The site's name is apparently derived from "googol", but note the difference in spelling. The "Google" spelling is also used in "The Hitchhikers Guide to the Galaxy" by Douglas Adams, in which one of Deep Thought's designers asks, "And are you not," said Fook, leaning anxiously foward, "a greater analyst than the Googleplex Star Thinker in the Seventh Galaxy of Light and Ingenuity which can calculate the trajectory of every single dust particle throughout a five-week Dangrabad Beta sand blizzard?" (http://google.com/). (2001-12-28) 1 1 1 1 1 googol The number represented in base-ten by a one with a hundred zeroes after it. According to Webster's Dictionary, the name was coined in 1938 by Milton Sirotta, the nine-year-old nephew of American mathematician, Edward Kasner. See also googolplex. (2001-03-29) 1 1 1 1 1 googolplex The number represented in base-ten by a one with a googol zeroes after it. (2001-03-29) 1 1 1 1 1 gopher A distributed document retrieval system which started as a Campus Wide Information System at the University of Minnesota, and which was popular in the early 1990s. Gopher is defined in RFC 1436. The protocol is like a primitive form of HTTP (which came later). Gopher lacks the MIME features of HTTP, but expressed the equivalent of a document's MIME type with a one-character code for the Gopher object type. At time of writing (2001), all Web browers should be able to access gopher servers, although few gopher servers exist anymore. Tim Berners-Lee, in his book "Weaving The Web" (pp.72-73), related his opinion that it was not so much the protocol limitations of gopher that made people abandon it in favor of HTTP/HTML, but instead the legal missteps on the part of the university where it was developed: "It was just about this time, spring 1993, that the University of Minnesota decided that it would ask for a license fee from certain classes of users who wanted to use gopher. Since the gopher software being picked up so widely, the university was going to charge an annual fee. The browser, and the act of browsing, would be free, and the server software would remain free to nonprofit and educational institutions. But any other users, notably companies, would have to pay to use gopher server software. This was an act of treason in the academic community and the" 1 1 1 1 1 Gopher client A program which runs on your local computer and provides a user interface to the Gopher protocol and to gopher servers. Web browsers can act as Gopher clients and simple Gopher-only clients are available for ordinary terminals, the X Window System, GNU Emacs, and other systems. (ftp://boombox.micro.umn.edu/). (2001-03-31) 1 1 1 1 1 Gopher object type A character specifying how to display a Gopher document. Current types are: 0 document 1 menu 2 CSO phone book entity 3 error 4 binhex binary 5 DOS binary (deprecated) 6 UU binary (deprecated) 7 index search 8 telnet connection 9 binary + duplicate server for previous object I image M MIME document T tn3270 based telnet connection c cal 1 1 1 1 1 Gopherspace The sum of all files that can be reached using gopher. (2005-06-08) 1 1 1 1 1 gorets /gor'ets/ The unknown ur-noun, fill in your own meaning. Found especially on the Usenet newsgroup alt.gorets, which seems to be a running contest to redefine the word by implication in the funniest and most peculiar way, with the understanding that no definition is ever final. [A correspondent from the Former Soviet Union informs me that gorets is Russian for "mountain dweller" - ESR] Compare frink. [Jargon File] 1 1 1 1 1 gorilla arm The side-effect that destroyed touch-screens as a mainstream input technology despite a promising start in the early 1980s. It seems the designers of all those spiffy touch-menu systems failed to notice that humans aren't designed to hold their arms in front of their faces making small motions. After more than a very few selections, the arm begins to feel sore, cramped, and oversized - the operator looks like a gorilla while using the touch screen and feels like one afterward. This is now considered a classic cautionary tale to human-factors designers; "Remember the gorilla arm!" is shorthand for "How is this going to fly in *real* use?". 1 1 1 1 1 go root [Unix] To temporarily enter root mode in order to perform a privileged operation. This use is deprecated in Australia, where the verb "root" refers to animal sex. See su. [Jargon File] 1 1 1 1 1 gorp /gorp/ (CMU, perhaps from the canonical hiker's food, Good Old Raisins and Peanuts) Another metasyntactic variable, like foo and bar. 1 1 1 1 1 GOSIP Government OSI Profile 1 1 1 1 1 Gosling, James James Gosling 1 1 1 1 1 GOSMACS /goz'maks/ Gosling Emacs. The first Emacs implementation in C, predating but now largely eclipsed by GNU Emacs. Originally freeware; a commercial version is now modestly popular as UniPress Emacs. The author (James Gosling) went on to invent NeWS. [Jargon File] 1 1 1 1 1 Gosperism /gos'p*r-izm/ A hack, invention, or saying due to arch-hacker R. William (Bill) Gosper. This notion merits its own term because there are so many of them. Many of the entries in HAKMEM are Gosperisms. See also life. 1 1 1 1 1 GOSPL Graphics-Oriented Signal Processing Language. A graphical DSP language for simulation. ["Graphic Oriented Signal Processing Language - GOSPL", C.D. Covington et al, Proc ICASSP-87, 1987]. 1 1 1 1 1 gotcha A misfeature of a system, especially a programming language or environment, that tends to breed bugs or mistakes because it both enticingly easy to invoke and completely unexpected and/or unreasonable in its outcome. For example, a classic gotcha in C is the fact that if (a=b) code; is syntactically valid and sometimes even correct. It puts the value of "b" into "a" and then executes "code" if "a" is non-zero. What the programmer probably meant was if (a==b) code; which executes "code" if "a" and "b" are equal. [Jargon File] (1995-04-17) 1 1 1 1 1 goto (Or "GOTO", "go to", "GO TO", "JUMP", "JMP") A construct and keyword found in several higher-level programming languages (e.g. Fortran, COBOL, BASIC, C) to cause an unconditional jump or transfer of control from one point in a program to another. The destination of the jump is usually indicated by a label following the GOTO keyword. In some languages, a label is a line number, in which case every statement may be labelled, in others a label is an optional alphanumeric identifier. Use of the GOTO instruction in high level language programming fell into disrepute with the development and general acceptance of structured programming, and especially following the famous article "GOTO statement considered harmful". Since a GOTO is effectively an assignment to the program counter, it is tempting to make the generalisation assignment considered harmful and indeed, this is the basis 1 1 1 1 1 Gottlob Frege (1848-1925) A mathematician who put mathematics on a new and more solid foundation. He purged mathematics of mistaken, sloppy reasoning and the influence of Pythagoras. Mathematics was shown to be a subdivision of formal logic. [Where?] (1997-07-14) 1 1 1 1 1 gov The top-level domain for US government bodies. (1999-01-26) 1 1 1 1 1 governance information technology governance 1 1 1 1 1 Government OSI Profile (GOSIP) A subset of OSI standards specific to US Government procurements, designed to maximize interoperability in areas where plain OSI standards are ambiguous or allow excessive options. (1995-12-13) 1 1 1 1 1 go voice When two or more parties stop communicating digitally and resuming the conversation via voice communication over the telephone. Prototypically this is used (e.g., "Wanna go voice?") between two modem users to denote the action of picking up the phone while shutting off the modem, in order to use the same line for voice communication as had was being used for data transmission. Compare: Voice-Net. (1997-01-31) 1 1 1 1 1 GP Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 gp The country code for Guadeloupe. (1999-01-27) 1 1 1 1 1 GPF General Protection failure/fault 1 1 1 1 1 GPIB IEEE 488 1 1 1 1 1 GPL 1. General Purpose Language. 2. ["A Sample Management Application Program in a Graphical Data-driven Programming language", A.L. Davis et al, Digest of Papers, Compcon Spring 81, Feb 1981, pp. 162-167]. 3. Genken Programming Language. 4. General Public License. [Jargon File] 1 1 1 1 1 GPM General Purpose Macro-generator 1 1 1 1 1 GPRS General Packet Radio Service 1 1 1 1 1 GPS Global Positioning System 1 1 1 1 1 GPSS General Purpose Systems Simulator. Geoffrey Gordon, 1960. Discrete simulations. "The Application of GPSS V to Discrete System Simulation", G. Gordon, P-H 1975. Versions include GPSS II (1963), GPSS III (1965), GPS/360 (1967), and GPSS V (1970). 1 1 1 1 1 GPV General Public Virus 1 1 1 1 1 GPX Early system on UNIVAC II. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 gq The country code for Equatorial Guinea. (1999-01-27) 1 1 1 1 1 gr The country code for Greece. (1999-01-27) 1 1 1 1 1 GRAAL ("Grail") General Recursive Applicative and Algorithmic Language. FP with polyadic combinators. "Graal: A Functional Programming System with Uncurryfied Combinators and its Reduction Machine", P. Bellot in ESOP 86, G. Goos ed, LNCS 213, Springer 1986. 1 1 1 1 1 grabber pointer A mouse pointer sprite in the shape of a small hand that closes when a mouse button is clicked, indicating that the object on the screen under the pointer has been selected. (2012-07-08) 1 1 1 1 1 Grace Hopper US Navy Rear Admiral Grace Brewster Hopper (1906-12-09 to 1992-01-01), née Grace Brewster Murray. Hopper is believed to have concieved the concept of the compiler with the A-0 in 1952. She also developed the first commercial high-level language, which eventually evolved into COBOL. She worked on the Mark I computer with Howard Aiken and with BINAC in 1949. She is credited with having coined the term "debug", and the adage "it is always easier to ask forgiveness than it is to get permission" (with various wordings), which has been the guiding principle in sysadmin decisions ever since. See also the entries debug and bug. Hopper is buried at Arlington National Cemetery. In 1994, the US Navy named a new ship, the guided-missile destroyer USS Hopper (http://hopper.navy.mil/), after her. (1999-06-29) 1 1 1 1 1 GRAF GRaphic Additions to Fortran. Fortran plus graphic data types. ["GRAF: Graphic Additions to Fortran", A. Hurwitz et al, Proc SJCC 30 (1967)]. [Sammet 1969, p. 674]. (1995-01-23) 1 1 1 1 1 Graffiti Handwriting recognition software for the Newton and Zoomer which recognises symbols that aren't necessarily letters. This gives greater speed and accuracy. It was written by Berkeley Softworks. (1995-01-24) 1 1 1 1 1 GRAIL Graphical Input Language. A flow chart language entered on a graphics tablet. The graphical follow-on to JOSS. ["The GRAIL Language and Operations", T.O. Ellis et al, RM-6001-ARPA, RAND, Sept 1969]. (1995-01-23) 1 1 1 1 1 GRAIN A pictorial query language. ["Pictorial Information Systems", S.K. Chang et al eds, Springer 1980]. (1995-01-23) 1 1 1 1 1 grain granularity 1 1 1 1 1 GRAM An extension of BNF used by the SIS compiler generator. ["SIS - Semantics Implementation System", P.D. Mosses, TR DAIMI MD-30, Aarhus U, Denmark]. (1995-01-23) 1 1 1 1 1 grammar A formal definition of the syntactic structure (the syntax) of a language. A grammar is normally represented as a set of production rules which specify the order of constituents and their sub-constituents in a sentence (a well-formed string in the language). Each rule has a left-hand side symbol naming a syntactic category (e.g. "noun-phrase" for a natural language grammar) and a right-hand side which is a sequence of zero or more symbols. Each symbol may be either a terminal symbol or a non-terminal symbol. A terminal symbol corresponds to one "lexeme" - a part of the sentence with no internal syntactic structure (e.g. an identifier or an operator in a computer language). A non-terminal symbol is the left-hand side of some rule. One rule is normally designated as the top-level rule which gives the structure for a whole sentence. A parser (a kind of recogniser) uses a grammar to parse a 1 1 1 1 1 grammar analysis A program written in ABC for answering such questions as "what are the start symbols of all rules", "what symbols can follow this symbol", "which rules are left recursive", and so on. Includes a grammar of ISO Pascal. Version 1 by Steven Pemberton <Steven.Pemberton@cwi.nl>. Ports to Unix, MS-DOS, Atari, Macintosh. FTP: ftp.eu.net, ftp.nluug.net programming/languages/abc/examples/grammar/. (1993-07-05) 1 1 1 1 1 grammatical inference Deducing a grammar from given examples. Also known as inductive inference and recently as "computational learning". 1 1 1 1 1 Grandfather, Father, Son (GFS) A backup rotation scheme in which a grandfather backup is performed on the first Monday of each month, a "father" backup is performed on every other Monday and a "son" backup is performed on every other day of the week. Grandfather tapes are kept for a year, father tapes for a month and son tapes for a week. The exact schedule (and thus the number of tapes required) may vary, as may the choice of full backup or incremental backup, but the idea is that it should be possible to restore versions of any file of different ages: e.g. yesterday's, last week's or last year's version. (2004-10-11) 1 1 1 1 1 granularity The size of the units of code under consideration in some context. The term generally refers to the level of detail at which code is considered, e.g. "You can specify the granularity for this profiling tool". The most common computing use is in parallelism or concurrency where "fine grain parallelism" means individual tasks are relatively small in terms of code size and execution time, "coarse grain" is the opposite. You talk about the "granularity" of the parallelism. The smaller the granularity, the greater the potential for parallelism and hence speed-up but the greater the overheads of synchronisation and communication. (1997-05-08) 1 1 1 1 1 Grapes A Modula-like system description language. E-mail: <peter@cadlab.cadlab.de>. ["GRAPES Language Description. Syntax, Semantics and Grammar of GRAPES-86", Siemens Nixdorf Inform, Berlin 1991, ISBN 3-8009-4112-0]. 1 1 1 1 1 Grapevine A distributed system project. [Who? Where? Why?] 1 1 1 1 1 graph 1. <mathematics> A collection of nodes and edges. See also connected graph, degree, directed graph, Moore bound, regular graph, tree. 2. <graphics> A visual representation of algebraic equations or data. (1996-09-22) 1 1 1 1 1 Graph Algorithm and Software Package (GASP) A PL/I extension for programming graph algorithms. ["GASP - Gprah Algorithm Software Package", S. Chase, TR CS Dept, U Illinois, Dec 1969]. (1998-02-27) 1 1 1 1 1 graph coloring graph colouring 1 1 1 1 1 graph colouring A constraint-satisfaction problem often used as a test case in research, which also turns out to be equivalent to certain real-world problems (e.g. register allocation). Given a connected graph and a fixed number of colours, the problem is to assign a colour to each node, subject to the constraint that any two connected nodes cannot be assigned the same colour. This is an example of an NP-complete problem. See also four colour map theorem. 1 1 1 1 1 Graphic ALGOL A extension of ALGOL 60 for real-time generation of shaded perspective pictures. ["An Extended ALGOL 60 for Shaded Computer Graphics", B. Jones, Proc ACM Symp on Graphic Languages, Apr 1976]. (2011-03-08) 1 1 1 1 1 Graphical Kernel System (GKS) The widely recognised standard ANSI X3.124 for graphical input/output. GKS is worked on by the ISO/IEC group JTC1/SC24. It provides applications programmers with standard methods of creating, manipulating, and displaying or printing computer graphics on different types of computer graphics output devices. It provides an abstraction to save programmers from dealing with the detailed capabilities and interfaces of specific hardware. GKS defines a basic two-dimensional graphics system with: uniform input and output primitives; a uniform interface to and from a GKS metafile for storing and transferring graphics information. It supports a wide range of graphics output devices including such as printers, plotters, vector graphics devices, storage tubes, refresh displays, raster displays, and microfilm recorders. (1999-04-01) 1 1 1 1 1 Graphical User Interface (GUI) The use of pictures rather than just words to represent the input and output of a program. A program with a GUI runs under some windowing system (e.g. The X Window System, MacOS, Microsoft Windows, Acorn RISC OS, NEXTSTEP). The program displays certain icons, buttons, dialogue boxes, etc. in its windows on the screen and the user controls it mainly by moving a pointer on the screen (typically controlled by a mouse) and selecting certain objects by pressing buttons on the mouse while the pointer is pointing at them. This contrasts with a command line interface where communication is by exchange of strings of text. Windowing systems started with the first real-time graphic display systems for computers, namely the SAGE Project [Dates?] and Ivan Sutherland's Sketchpad (1963). Douglas Engelbart's Augmentation of Human Intellect project at SRI in the 1960s developed the On-Line System, which 1 1 1 1 1 Graphic Display Interface (GDI) graphics adaptor. (1995-03-16) 1 1 1 1 1 Graphic Language For specifying graphic operations. ["A Problem Oriented Graphic Language", P.J. Schwinn, proc ACM 22nd Natl Conf, 1967]. [Sammet 1969, p. 677]. 1 1 1 1 1 graphics Any kind of visible output including text, images, movies, line art and digital photographs; stored in bitmap or vector graphic form. Most modern computers can display non-text data and most use a graphical user interface (GUI) for virtually all interaction with the user. Special hardware, typically some kind of graphics adaptor, is required to allow the computer to display graphics (as opposed to, say, printing text on a teletype) but since GUIs became ubiquitous this has become the default form of visual output. The most demanding applications for computer graphics are those where the computer actually generates moving images in real time, especially in video games. There are many kinds of software devoted to manipulating graphical data, including image editing (e.g. Photoshop), drawing (e.g. Illustrator), user interface toolkits (e.g. X Window System), CAD, CGI. 1 1 1 1 1 graphics accelerator Hardware (often an extra circuit board) to perform tasks such as plotting lines and surfaces in two or three dimensions, filling, shading and hidden line removal. (1997-07-14) 1 1 1 1 1 graphics adapter graphics adaptor 1 1 1 1 1 graphics adaptor (Or "graphics adapter", "graphics card", video adaptor, etc.) A circuit board fitted to a computer, especially an IBM PC, containing the necessary video memory and other electronics to provide a bitmap display. Adaptors vary in the resolution (number of pixels) and number of colours they can display, and in the refresh rate they support. These parameters are also limited by the monitor to which the adaptor is connected. A number of such display standards, e.g. SVGA, have become common and different software requires or supports different sets. (1996-09-16) 1 1 1 1 1 graphics card graphics adaptor 1 1 1 1 1 Graphics Interchange Format /gif/, occasionally /jif/ (GIF, GIF 89A) A standard for digitised images compressed with the LZW algorithm, defined in 1987 by CompuServe (CIS). Graphics Interchange Format and GIF are service marks of CompuServe Incorporated. This only affects use of GIF within Compuserve, and pass-through licensing for software to access them, it doesn't affect anyone else's use of GIF. It followed from a 1994 legal action by Unisys against CIS for violating Unisys's LZW software patent. The CompuServe Vice President has stated that "CompuServe is committed to keeping the GIF 89A specification as an open, fully-supported, non-proprietary specification for the entire on-line community including the web". Filename extension: .gif. File format (ftp://peipa.essex.ac.uk/ipa/info/file-formats). GIF89a specification (http://asterix.seas.upenn.edu/~mayer/lzw_gif/gif89a.html). 1 1 1 1 1 Graphics Interface Format You mean "Graphics Interchange Format". (1999-10-11) 1 1 1 1 1 Graphics Language Object System (GLOS) A language with statements for describing graphics objects (line, circle, polygon, etc.), written by Michael J McLean and Brian Hicks at the University of Queensland, St. Lucia in 1978. New objects are defined using procedures. 2-D transformations are context dependent and may be nested. [M.J. McLean, "The Semantics of Computer Drafting Languages", PhD thesis, University of Queensland, 1978]. [Hicks, B.W., and McLean, M.J. "A Graphic Language for Describing Line Objects", Proceedings of the DECUS-Australia August 1973 Symposium, Melbourne, 1973]. (2002-06-01) 1 1 1 1 1 graphic workstation A workstation specifically configured for graphics works such as image manipulation, bitmap graphics ("paint"), and vector graphics ("draw") type applications. Such work requires a powerful CPU and a high resolution display. A graphic workstation is very similar to a CAD workstation and, given the typical specifications of personal computers currently available in 1999, the distinctions are very blurred and are more likely to depend on availability of specific software than any detailed hardware requirements. (1999-05-04) 1 1 1 1 1 Graph-Oriented Object Database (GOOD) A graph manipulation language for use as a database query language. ["A Graph-Oriented Object Database Model", M. Gyssens et al, Proc ACM Symp Princs of Database Sys, Mar 1990]. (1995-03-07) 1 1 1 1 1 graph plotter plotter 1 1 1 1 1 graph reduction A technique invented by Chris Wadsworth where an expression is represented as a directed graph (usually drawn as an inverted tree). Each node represents a function call and its subtrees represent the arguments to that function. Subtrees are replaced by the expansion or value of the expression they represent. This is repeated until the tree has been reduced to a value with no more function calls (a normal form). In contrast to string reduction, graph reduction has the advantage that common subexpressions are represented as pointers to a single instance of the expression which is only reduced once. It is the most commonly used technique for implementing lazy evaluation. 1 1 1 1 1 graph rewriting system An extension of a term rewriting system which uses graph reduction on terms represented by directed graphs to avoid duplication of work by sharing expressions. 1 1 1 1 1 GRAPPLE GRAPh Processing LanguagE. 1968. ["A Directed Graph Representation for Computer Simulation of Belief Systems", L.G. Tesler et al, Math Biosciences 2:19-40 (1968)]. 1 1 1 1 1 GRAS A public domain graph-oriented database system for software engineering applications from RWTH Aachen. 1 1 1 1 1 GRASP/Ada Graphical Representation of Algorithms, Structures and Processes. ["A Graphically Oriented Specification Language for Automatic Code Generation", J.H. Cross, Auburn U, NASA CR-183212, 1989]. 1 1 1 1 1 GRASPIN An Esprit project to develop a personal software engineering environment to support the construction and verification of distributed and non-sequential software systems. 1 1 1 1 1 grault /grawlt/ Yet another metasyntactic variable, invented by Mike Gallaher and propagated by the GOSMACS documentation. See corge. [Jargon File] 1 1 1 1 1 Gray A parser generator written in Forth by Martin Anton Ertl <anton@mips.complang.tuwien.ac.at>. Gray takes grammars in an extended BNF and produces executable Forth code for recursive descent parsers. There is no special support for error handling. Version 3 runs under Tile Forth Release 2 by Mikael Patel. (1992-05-22) 1 1 1 1 1 graybar land The place you go while you're staring at a computer that's processing something very slowly (while you watch the grey bar creep across the screen). "I was in graybar land for hours, waiting for that CAD rendering." (1997-04-17) 1 1 1 1 1 Gray code A binary sequence with the property that only one bit changes between any two consecutive elements (the two codes have a Hamming distance of one). The Gray code originated when digital logic circuits were built from vacuum tubes and electromechanical relays. Counters generated tremendous power demands and noise spikes when many bits changed at once. E.g. when incrementing a register containing 11111111, the back-EMF from the relays' collapsing magnetic fields required copious noise suppression. Using Gray code counters, any increment or decrement changed only one bit, regardless of the size of the number. Gray code can also be used to convert the angular position of a disk to digital form. A radial line of sensors reads the code off the surface of the disk and if the disk is half-way between two positions each sensor might read its bit from both positions at once but since only one bit differs between the two, the value read is guaranteed to be one of the two valid 1 1 1 1 1 gray-scale US spelling of "grey-scale". 1 1 1 1 1 GRE Generic Routing Encapsulation 1 1 1 1 1 greater than ">" ASCII character 62. Common names: ITU-T: greater than; ket ("<" = bra); right angle; right angle bracket; right broket. Rare: into, toward; write to; blow ("<" = suck); gozinta; out; zap (all from Unix I/O redirection); INTERCAL: right angle. See also less than. (1995-03-17) 1 1 1 1 1 greatest common divisor (GCD) A function that returns the largest positive integer that both arguments are integer multiples of. See also Euclid's Algorithm. Compare: lowest common multiple. (1999-11-02) 1 1 1 1 1 greatest lower bound (glb, meet, infimum) The greatest lower bound of two elements, a and b is an element c such that c <= a and c <= b and if there is any other lower bound c' then c' <= c. The greatest lower bound of a set S is the greatest element b such that for all s in S, b <= s. The glb of mutually comparable elements is their minimum but in the presence of incomparable elements, if the glb exists, it will be some other element less than all of them. glb is the dual to least upper bound. (In LaTeX "<=" is written as \sqsubseteq, the glb of two elements a and b is written as a \sqcap b and the glb of set S as \bigsqcap S). (1995-02-03) 1 1 1 1 1 Great Renaming The flag day in 1986 on which all of the non-local groups on the Usenet had their names changed from the net.- format to the current multiple-hierarchies scheme. Used especially in discussing the history of newsgroup names. "The oldest sources group is comp.sources.misc; before the Great Renaming, it was net.sources." FAQ (http://vrx.net/usenet/history/rename.html). [Jargon File] (2000-07-14) 1 1 1 1 1 Great Runes Uppercase-only text or display messages. Some archaic operating systems still emit these. See also runes, smash case, fold case. Decades ago, back in the days when it was the sole supplier of long-distance hardcopy transmittal devices, the Teletype Corporation was faced with a major design choice. To shorten code lengths and cut complexity in the printing mechanism, it had been decided that teletypes would use a monocase font, either ALL UPPER or all lower. The Question Of The Day was therefore, which one to choose. A study was conducted on readability under various conditions of bad ribbon, worn print hammers, etc. Lowercase won; it is less dense and has more distinctive letterforms, and is thus much easier to read both under ideal conditions and when the letters are mangled or partly obscured. The results were filtered up through management. The chairman of Teletype killed the proposal because it failed one incredibly important criterion: 1 1 1 1 1 Great Worm Internet Worm 1 1 1 1 1 greek 1. <text, graphics> To display text as abstract dots and lines in order to give a preview of layout without actually being legible. This is faster than drawing the characters correctly which may require scaling or other transformations. Greeking is particularly useful when displaying a reduced image of a document where the text would be too small to be legible on the display anyway. A related technique is lorem ipsum. (2006-09-18) 1 1 1 1 1 greeking greek 1 1 1 1 1 Green A language proposed by Cii Honeywell-Bull to meet the DoD Ironman requirements which led to Ada. This language won in 1979. ["On the GREEN Language Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices 13(10):16-21 (Oct 1978)]. (1994-12-02) 1 1 1 1 1 Green Book 1. <publication> Informal name for one of the four standard references on PostScript. The other three official guides are known as the Blue Book, the Red Book, and the White Book. ["PostScript Language Program Design", Adobe Systems, Addison-Wesley, 1988 (ISBN 0-201-14396-8)]. 2. <publication> Informal name for one of the three standard references on SmallTalk. Also associated with blue and red books. ["Smalltalk-80: Bits of History, Words of Advice", by Glenn Krasner (Addison-Wesley, 1983; QA76.8.S635S58; ISBN 0-201-11669-3)]. 3. <publication> The "X/Open Compatibility Guide", which defines an international standard Unix environment that is a proper superset of POSIX/SVID. It also includes descriptions of a standard utility toolkit, systems administrations features, and the like. This grimoire is 1 1 1 1 1 Green Book CD-ROM A standard CD-ROM format developed by Philips for CD-i. It is ISO 9660 compliant and uses mode 2 form 2 addressing. It can only be played on drives which are XA (Extended Architecture) compatible. Many Green Book discs contain CD-i applications which can only be played on a CD-i player but many others contain films or music videos. Video CDs in Green Book format are normally labelled "Digital Video on CD" Green Book was obsoleted by White book CD-ROM in March 1994. (1994-11-02) 1 1 1 1 1 green bytes (Or "green words") Meta-information embedded in a file, such as the length of the file or its name; as opposed to keeping such information in a separate description file or record. By extension, the non-data bits in any self-describing format. "A GIF file contains, among other things, green bytes describing the packing method for the image." At a meeting of the SHARE Systems Division, November 22, 1964, in Washington, DC, George Mealy of IBM described the new block tape format for FORTRAN in which unformatted binary records had a Control Word. George used green chalk to describe it. No one liked the contents of the Green Word (not information, wrong location, etc.) so Conrad Weisert and Channing Jackson made badges saying "Stamp out Green Words". This was the first computer badge. Compare out-of-band, zigamorph, fence. Button 251 (http://mxg.com/thebuttonman/search.asp). [Jargon File] 1 1 1 1 1 green card [after the "IBM System/360 Reference Data" card] A summary of an assembly language, even if the colour is not green. Less frequently used now because of the decrease in the use of assembly language. "I'll go get my green card so I can check the addressing mode for that instruction." Some green cards are actually booklets. The original green card became a yellow card when the System/370 was introduced, and later a yellow booklet. An anecdote from IBM refers to a scene that took place in a programmers' terminal room at Yorktown in 1978. A luser overheard one of the programmers ask another "Do you have a green card?" The other grunted and passed the first a thick yellow booklet. At this point the luser turned a delicate shade of olive and rapidly left the room, never to return. [Jargon File] 1 1 1 1 1 green lightning [IBM] 1. Apparently random flashing streaks on the face of 3278-9 terminals while a new symbol set is being downloaded. This hardware bug was left deliberately unfixed, as some genius within IBM suggested it would let the user know that something is happening. That, it certainly does. Later microprocessor-driven IBM colour graphics displays were actually *programmed* to produce green lightning! 2. [proposed] Any bug perverted into an alleged feature by adroit rationalisation or marketing. "Motorola calls the CISC cruft in the 88000 architecture "compatibility logic", but I call it green lightning". See also feature. 1 1 1 1 1 green machine A computer or peripheral device that has been designed and built to military specifications for field equipment (that is, to withstand mechanical shock, extremes of temperature and humidity, and so forth). Comes from the olive-drab "uniform" paint used for military equipment. [Jargon File] 1 1 1 1 1 green monitor Advanced Power Management 1 1 1 1 1 Green's Theorem (TMRC) For any story, in any group of people there will be at least one person who has not heard the story. A refinement of the theorem states that there will be *exactly* one person (if there were more than one, it wouldn't be as bad to re-tell the story). The name of this theorem is a play on a fundamental theorem in calculus. [Jargon File] (1994-12-16) 1 1 1 1 1 Greenwich Mean Time (GMT) The local time on the Greenwich meridian, based on the hypothetical mean sun (which averages out the effects of the Earth's elliptical orbit and its tilted axis). GMT is the basis of the civil time for the UK. In 1925 the reference point was changed from noon to midnight and it was recommended that the term "Universal Time" should be used for the new GMT. Authorities disagreed on whether GMT equates with UT0 or UT1, however the differences between the two are of the order of thousandths of a second. GMT is no longer used for scientific purposes. (2001-08-02) 1 1 1 1 1 green words green bytes 1 1 1 1 1 Greg Olson President and CEO of Sendmail Inc.. Olson is an industry veteran who worked on distributed systems at Summit Systems Inc. then at Britton Lee Inc., Sybase Inc. and Integrated Systems Inc.. (1998-08-25) 1 1 1 1 1 Gregorian calendar The system of dates used by most of the world. The Gregorian calendar was proposed by the Calabrian doctor Aloysius Lilius and was decreed by, and named after, Pope Gregory XIII on 1582-02-24. It corrected the Julian calendar whose years were slightly longer than the solar year. It also replaced the lunar calendar which was also out of time with the seasons. The correction was achieved by skipping several days as a one-off resynchronisation and then dropping three leap days every 400 hundred years. In the revised system, leap years are all years divisible by 4 but excluding those divisible by 100 but including those divisible by 400. This gives a mean calendar year of 365.2425 days = 52.1775 weeks = 8,765.82 hours = 525,949.2 minutes = 31,556,952 seconds. leap seconds are occasionally added to this to correct for irregularities in the Earth's rotation. (2007-01-10) 1 1 1 1 1 grep <tool> A Unix command for searching files for lines matching a given regular expression (RE). Named after the qed/ed editor subcommand "g/re/p", where re stands for a regular expression, to Globally search for the Regular Expression and Print the lines containing matches to it. There are two other variants, fgrep which searches only for fixed strings and egrep which accepts extended REs but is usually the fastest of the three. Used by extension to mean "to look for something by pattern". When browsing through a large set of files, one may speak of grepping around. "Grep the bulletin board for the system backup schedule, would you?" See also vgrep. [Jargon File] 1 1 1 1 1 grey-scale (US "gray-scale") 1. Composed of (discrete) shades of grey. If the pixels of a grey-scale image have N bits, they may take values from zero, representing black up to 2^N-1, representing white with intermediate values representing increasingly light shades of grey. If N=1 the image is not called grey-scale but could be called monochrome. 2. A range of acurately known shades of grey printed out for use in calibrating those shades on a display or printer. (1995-03-17) 1 1 1 1 1 Greystone Technologies The producers of the GT/M MUMPS compiler and GT/SQL pre-processor for VAX and DEC Alpha. [Address?] (1995-01-10) 1 1 1 1 1 GRG A computer algebra system for differential geometry, gravitation and field theory. Version 3.1 works with PSL-based REDUCE 3.3 or 3.4. E-mail: V.V. Zhytnikov <vvzhy@phy.ncu.edu.tw>. (1994-12-16) 1 1 1 1 1 GRIB GRid In Binary. The World Meteorological Organization's data format. (1995-01-10) 1 1 1 1 1 grick /grik/ (WPI, first used by Tim Haven to describe "grick trigonometry", a shortcut method of determing attack angles in grid-based games like Star Trek) Any integral increment of measurement. E.g. "Please turn the stereo up a few gricks". (1995-01-31) 1 1 1 1 1 grilf Girl-friend. Like newsfroup and filk, a typo incarnated as a new word. Seems to have originated sometime in 1992. [Jargon File] (1995-01-31) 1 1 1 1 1 Grim File Reaper (GFR) An ITS and LISP Machine utility to remove files according to some program-automated or semi-automatic manual procedure, especially one designed to reclaim mass storage space or reduce name-space clutter (the original GFR actually moved files to tape). See also prowler, reaper. Compare GC, which discards only provably worthless stuff. (1996-06-20) 1 1 1 1 1 GRIND GRaphical INterpretive Display. A graphics input language for the PDP-9. ["GRIND: A Language and Translator for Computer Graphics", A.P. Conn, Dartmouth, June 1969]. [Jargon File] (1995-01-31) 1 1 1 1 1 grind 1. (MIT and Berkeley) To prettify hardcopy of code, especially LISP code, by reindenting lines, printing keywords and comments in distinct fonts (if available), etc. This usage was associated with the MacLISP community and is now rare; prettyprint was and is the generic term for such operations. 2. (Unix) To generate the formatted version of a document from the nroff, troff, TeX, or Scribe source. 3. To run seemingly interminably, especially (but not necessarily) if performing some tedious and inherently useless task. Similar to crunch or grovel. Grinding has a connotation of using a lot of CPU time, but it is possible to grind a disk, network, etc. See also hog. 4. To make the whole system slow. "Troff really grinds a PDP-11." 5. "grind grind" excl. Roughly, "Isn't the machine slow today!" 1 1 1 1 1 grind crank A mythical accessory to a terminal. A crank on the side of a monitor, which when operated makes a zizzing noise and causes the computer to run faster. Usually one does not refer to a grind crank out loud, but merely makes the appropriate gesture and noise. See grind. Historical note: At least one real machine actually had a grind crank - the R1, a research machine built toward the end of the days of the great vacuum tube computers, in 1959. R1 (also known as "The Rice Institute Computer" (TRIC) and later as "The Rice University Computer" (TRUC)) had a single-step/free-run switch for use when debugging programs. Since single-stepping through a large program was rather tedious, there was also a crank with a cam and gear arrangement that repeatedly pushed the single-step button. This allowed one to "crank" through a lot of code, then slow down to single-step for a bit when you got near the code of interest, poke at some registers using the console typewriter, 1 1 1 1 1 GRIP Graph Reduction In Parallel. Simon Peyton Jones's GRIP machine built at UCL, now at the University of Glasgow. It has many processors (Motorola 68020 or other) on Futurebus with intelligent memory units. (1994-12-14) 1 1 1 1 1 gripenet [IBM] A wry (and thoroughly unofficial) name for IBM's internal VNET system, deriving from its common use by IBMers to voice pointed criticism of IBM management that would be taboo in more formal channels. [Jargon File] 1 1 1 1 1 gritch /grich/ 1. A complaint (often caused by a glitch). 2. To complain. Often verb-doubled: "Gritch gritch". 3. A synonym for glitch (as verb or noun). (1995-01-31) 1 1 1 1 1 grix /griks/ (WPI) A meta-number, said to be an integer between 6 and 7. Used either alone or with flib or suffixes such as -ty, -teen, etc. to denote an arbitrary integer (see N). "This system will bomb if there are grixty-flib users on it." (1995-01-31) 1 1 1 1 1 groff GNU roff. GNU's implementation of roff in C++. See also nroff, troff. Version 1.07 by James J. Clark <jjc@jclark.com>. FTP groff-1.07.tar.z from a GNU archive site. (1993-03-03) 1 1 1 1 1 grok /grok/, /grohk/ (From the novel "Stranger in a Strange Land", by Robert A. Heinlein, where it is a Martian word meaning literally "to drink" and metaphorically "to be one with") 1. To understand, usually in a global sense. Connotes intimate and exhaustive knowledge. Contrast zen, which is similar supernal understanding experienced as a single brief flash. See also glark. 2. Used of programs, may connote merely sufficient understanding. "Almost all C compilers grok the "void" type these days." [Jargon File] (1995-01-31) 1 1 1 1 1 gronk /gronk/ Popularised by Johnny Hart's comic strip "B.C." but the word apparently predates that. 1. To clear the state of a wedged device and restart it. More severe than "to frob" (sense 2). 2. [TMRC] To cut, sever, smash, or similarly disable. 3. The sound made by many 3.5-inch diskette drives. In particular, the microfloppies on a Commodore Amiga go grink, gronk. [Jargon File] 1 1 1 1 1 gronked 1. Broken. "The teletype scanner was gronked, so we took the system down." 2. Of people, the condition of feeling very tired or (less commonly) sick. "I've been chasing that bug for 17 hours now and I am thoroughly gronked!" Compare broken, which means about the same as gronk used of hardware, but connotes depression or mental/emotional problems in people. 1 1 1 1 1 group A group G is a non-empty set upon which a binary operator * is defined with the following properties for all a,b,c in G: Closure: G is closed under *, a*b in G Associative: * is associative on G, (a*b)*c = a*(b*c) Identity: There is an identity element e such that a*e = e*a = a. Inverse: Every element has a unique inverse a' such that a * a' = a' * a = e. The inverse is usually written with a superscript -1. (1998-10-03) 1 1 1 1 1 Group 3 (G3) The CCITT fax protocol which uses data compression and allows a variety of file types (e.g. electronic mail, pictures, PostScript) to be transmitted over analogue telephone lines. The Group 3 protocol was published by CCITT in 1993. Full details of the protocol are available from ITU-T. See also Group 4. (1998-10-03) 1 1 1 1 1 Group 4 (G4) The CCITT fax protocol which uses data compression and allows a variety of file types (e-mail, pictures, PostScript, etc.) to be transmitted over digital (ISDN) telephone lines. The Group 4 protocol was published by CCITT in 1993. Full details of the protocol are available from ITU-T. See also Group 3. (1998-09-10) 1 1 1 1 1 Group Code Recording (GCR) A recording method used for 6250 BPI magnetic tapes. GCR typically uses a group of five bits of code to represent four bits of data. The encoding ensures no more than two or three zeros occur in a row, and no more than eight or so ones occur in a row, where zeros represent an absense of magnetic change. GCR is also used on Commodore Business Machines diskette drives; the 4040, 8050, 154x, 157x and 158x series of 5.25" and 3.5" low and high density diskette drives used with 8-bit home computers circa 1977 to 1992. It was also supported on Amiga internal and external drives but only used for reading non-Amiga disks. Compare NRZI, PE. (2004-06-01) 1 1 1 1 1 group identifier (gid) A unique number, between 0 an 32767, identifying a set of users under Unix. Gids are found in the /etc/passwd and /etc/group databases (or their NIS equivalents) and one is also associated with each file, indicating the group to which its group permissions apply. (1996-12-01) 1 1 1 1 1 Group Separator (GS) ASCII character 29. (1996-06-28) 1 1 1 1 1 Group-Sweeping Scheduling (GSS) A disk scheduling strategy in which requests are served in cycles, in a round-robin manner. To reduce disk arm movements ("seeking"), the set of streams is divided into groups that are served in fixed order. Streams within a group are served according to "SCAN". If all clients are assigned to one group, GSS reduces to SCAN, and if all clients are assigned to separate groups, GSS effectively becomes round-robin scheduling. The service order within one group is not fixed, and a stream may in fact be first in one cycle while last in the next. This variation has to be masked by extra buffering but whereas SCAN requires buffer space for all streams, GSS can reuse the buffer for each group and effect a trade-off between seek optimisation and buffer requirements. (1995-11-12) 1 1 1 1 1 Groupware CSCW 1 1 1 1 1 Groupwise A workgroup application suite offering electronic mail and diary scheduling from Novell, Inc.. It can operate on a number of platforms. Groupwise was previously known as WordPerfect Office, and is an extensible system suitable for LAN or WAN operation. Mail gateway software is available for a number of protocols including SMTP, allowing the exchange of mail with the Internet. (1995-09-23) 1 1 1 1 1 grovel 1. To work interminably and without apparent progress. Often used transitively with "over" or "through". "The file scavenger has been groveling through the /usr directories for 10 minutes now." Compare grind and crunch. Emphatic form: "grovel obscenely". 2. To examine minutely or in complete detail. "The compiler grovels over the entire source program before beginning to translate it." "I grovelled through all the documentation, but I still couldn't find the command I wanted." [Jargon File] 1 1 1 1 1 grunge /gruhnj/ 1. That which is grungy, or that which makes it so. 2. [Cambridge] Code which is inaccessible due to changes in other parts of the program. The preferred term in North America is dead code. 1 1 1 1 1 gry The suffix referred to in the following puzzle: Question: "Angry" and "hungry" are two words that end in "gry". What is the third word. Everyone knows what it means and everyone uses it every day. Look closely and I have already given you the third word. What is it? Answer: "what". Variants of this puzzle have circulated widely on the Internet for some years, usually in a corrupted form such as "Name three common English words ending in 'gry'", which has no third answer. (http://www.worldwidewords.org/articles/gry.htm). (http://word-detective.com/gry.html). (2007-04-04) 1 1 1 1 1 GS Group Separator 1 1 1 1 1 gs The country code for South Georgia and the South Sandwich Islands. (1999-01-27) 1 1 1 1 1 GSBL ["GSBL: An Algebraic Specification Language Based on Inheritance", S. Clerici et al in ECOOP '88, S. Gjessing et al eds, LNCS 322, Springer 1988, pp.78-92]. (2003-06-02) 1 1 1 1 1 GSI Gensym Standard Interface 1 1 1 1 1 GSL Grenoble System Language. M. Berthaud, IBM, Grenoble. "GSL Language Reference Manual", M. Berthaud et al, March 1973. "A MOL-Based Software Construction System", M. Berthaud et al, in Machine Oriented Higher Level Languages, W. van der Poel, N-H 1974, pp.151-157. 1 1 1 1 1 GSM Global System for Mobile Communications 1 1 1 1 1 GSPL Greenberg's System Programming Language. Bernard Greenberg. (1995-05-09) 1 1 1 1 1 GSS Group-Sweeping Scheduling. (1995-11-12) 1 1 1 1 1 GSS-API Generic Security Service Application Programming Interface 1 1 1 1 1 gt The country code for Guatemala. (1999-01-27) 1 1 1 1 1 gtg Got to go. The user is about to stop chatting. (1999-06-07) 1 1 1 1 1 GTK+ ("The GIMP ToolKit", or incorrectly "Gnu ToolKit" or "Generic ToolKit") A multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off projects to complete application suites. GTK+ consists of the three parts; GLib, providing basic data structures, event handling, threads, etc., Pango, for layout and rendering of text, and ATK, providing interfaces for accessibility. GTK+ Home (http://gtk.org/). (2003-12-03) 1 1 1 1 1 GTL Gunning Transceiver Logic 1 1 1 1 1 GT/SQL An SQL pre-processor from Greystone Technologies which combines MUMPS code with SQL code and generates code that can work with a database from both the MUMPS and SQL perspectives. This is often done when a database is to be made available in a client/server environment, where the MUMPS database serves one or more SQL clients. (1995-01-10) 1 1 1 1 1 gu The country code for Guam. (1999-01-27) 1 1 1 1 1 guaranteed scheduling A scheduling algorithm used in multitasking operating systems that guarantees fairness by monitoring the amount of CPU time spent by each user and allocating resources accordingly. [How does it allocate resources?] (1998-04-26) 1 1 1 1 1 guard 1. In functional programming, a Boolean expression attached to a function definition specifying when (for what arguments) that definition is appropriate. 2. In (parallel) logic programming, a Boolean expression which is used to select a clause from several alternative matching clauses. See Guarded Horn Clauses. 3. In parallel languages, a Boolean expression which specifies when an message may be sent or received. (1995-05-09) 1 1 1 1 1 Guarded Horn Clauses (GHC) A parallel dialect of Prolog by K. Ueda in which each clause has a guard. GHC is similar to Parlog. When several clauses match a goal, their guards are evaluated in parallel and the first clause whose guard is found to be true is used and others are rejected. It uses committed-choice nondeterminism. See also FGHC, KL1. (1995-05-09) 1 1 1 1 1 gubbish /guhb'*sh/ (A portmanteau of "garbage" and "rubbish" which may have originated with SF author Philip K. Dick) Garbage; crap; nonsense. "What is all this gubbish?" The opposite portmanteau "rubbage" is also reported. [Jargon File] (1995-05-09) 1 1 1 1 1 guest book The electronic equivalent of the physical notebooks found in some small hotels, in which visitors can write their names, comments and suggestions for the benefit of the proprietors and future visitors or purely for posterity. The electronic version is a form on a website into which users can enter similar details for display on the site. (2009-01-15) 1 1 1 1 1 GUI Graphical User Interface 1 1 1 1 1 GUIDE Graphical User Interface Development Environment from Sun. 1 1 1 1 1 Guide A hypertext system from the University of Kent (GB) and OWL for displaying on-line documentation. 1 1 1 1 1 Guide to Available Mathematical Software (http://gams.nist.gov/). (1995-04-28) 1 1 1 1 1 guiltware /gilt'weir/ 1. A piece of freeware decorated with a message telling one how long and hard the author worked on it and intimating that one is a no-good freeloader if one does not immediately send the poor suffering martyr gobs of money. 2. Shareware that works. [Jargon File] 1 1 1 1 1 gun (ITS, from the ":GUN" command) To forcibly terminate a program or job (computer, not career). "Some idiot left a background process running soaking up half the cycles, so I gunned it." Compare can. (1995-02-27) 1 1 1 1 1 gunch /guhnch/ <jargon> (TMRC) To push, prod, or poke at a device that has almost (but not quite) produced the desired result. Implies a threat to mung. [Jargon File] (1995-02-27) 1 1 1 1 1 Gunning Transceiver Logic (GTL) A standard for electrical signals in CMOS circuits used to provide higher data transfer speeds with smaller voltage swings [compared with what?]. The GTL signal swings between 0.4 volts and 1.2 volts with a reference voltage of about 0.8 volts. Only a small deviation of 0.4 volts (or thereabouts) from the reference voltage is required to switch between on and off states. Therefore, a GTL signal is said to be a low voltage swing logic signal. Gunning Transceiver Logic has several advantages. The resistive termination of a GTL signal provides a clean signalling environment [what?]. Moreover, the low terminating voltage of 1.2 volts results in reduced voltage drops across the resistive elements. GTL has low power dissipation and can operate at high frequency and causes less electromagnetic interference (EMI). GTL/BTL: A Low-Swing Solution for High-Speed Digital Logic 1 1 1 1 1 gunzip The decompression utility corresponding to gzip. In operating systems with links, gunzip is just a link to gzip and its function can be invoked by passing a "-d" flag to gzip. (1996-01-03) 1 1 1 1 1 Gupta Corporation The vendor of SQLWindows. Gupta Corporation provides application development and deployment software for client-server applications, consisting of a relational database, application development tools and transparent connectivity software. Gupta employs 400 people in 15 offices worldwide, including the United States, Europe and Asia. Gupta's 1993 fiscal year income was $5.6 million and their revenue was $56.1 million. Gupta sells client-server system components for networks of personal computers. (http://wji.com/gupta/htmls/homepage.html). Address: 1060 Marsh Road, Menlo Park, CA 94025, USA. Telephone: +1 (415) 321 9500. Fax: +1 (415) 321 5471. (1997-04-28) 1 1 1 1 1 gurfle /ger'fl/ An expression of shocked disbelief. "He said we have to recode this thing in Fortran by next week. Gurfle!" Compare weeble. [Jargon File] (1996-06-01) 1 1 1 1 1 guru An expert, especially in "Unix guru". Implies not only wizard skill but also a history of being a knowledge resource for others. Less often, used (with a qualifier) for other experts on other systems, as in "VMS guru". See source of all good bits. [Jargon File] (1996-06-01) 1 1 1 1 1 guru meditation The Amiga equivalent of Unix's panic (sometimes just called a "guru" or "guru event"). When the system crashes, a cryptic message of the form "GURU MEDITATION #XXXXXXXX.YYYYYYYY" may appear, indicating what the problem was. An Amiga guru can figure things out from the numbers. In the earliest days of the Amiga, there was a device called a Joyboard which was basically a plastic board built onto a joystick-like device; it was sold with a skiing game cartridge for the Atari game machine. It is said that whenever the prototype OS crashed, the system programmer responsible would concentrate on a solution while sitting cross-legged, balanced on a Joyboard, resembling a meditating guru. Sadly, the joke was removed in AmigaOS 2.04. The Jargon File claimed that a guru event had to be followed by a Vulcan nerve pinch but, according to a correspondent, a mouse click was enough to start a reboot. (2002-06-25) 1 1 1 1 1 Guy Lewis Steele, Jr. (GLS) A software engineer whose most notable contributions to the art of computing include the design of Scheme (in cooperation with Gerald Sussman) and the design of the original command set of Emacs. He is also known for his contribution to the Jargon File and for being the first to port TeX (from WAITS to ITS). He wrote the book Common Lisp, which virtually defines the language. He was working at Sun Microsystems, Inc. from 1996 to the present (June 2001). (2001-06-14) 1 1 1 1 1 Guy Steele Guy Lewis Steele, Jr. 1 1 1 1 1 GVL Graphical View Language. A visual language for specifying interactive graphical output by T.C.N. Graham & J.R. Cordy, Queen's University, Canada. ["GVL: A Graphical, Functional Language for the Specification of Output in Programming Languages", J.R. Cordy & T.C.N. Graham, Proc IEEE Intl Conf on Comp Lang ICCL'90 (March 1990)]. 1 1 1 1 1 gw The country code for Guinea-Bissau. (1999-01-27) 1 1 1 1 1 GW-Ada A new version of Ada/Ed? MS-DOS version (ftp://wuarchive.wustl.edu/languages/ada/compiler/adaed/gwu/9309/dos), Macintosh version (ftp://wuarchive.wustl.edu/languages/ada/compilers/adaed/gwu/mac). (1993-09-01) 1 1 1 1 1 GW-BASIC An early version of MS-BASIC. (1995-05-12) 1 1 1 1 1 gweep /gweep/ To hack, usually at night, or one who does so. At WPI, from 1977 onward, gweeps could often be found at the College Computing Center punching cards or crashing the PDP-10 or, later, the DEC-20. The term has survived the demise of those technologies, however, and is still alive in late 1991. "I'm going to go gweep for a while. See you in the morning." "I gweep from 8 PM till 3 AM during the week." Gweep originated as an onomatopeiac term, evoking the sound of the (once-ubiquitous) Hazeltine 9000 terminals' bell on WPI campus. A gweep is one step above a fweep. [Jargon File] (1995-01-31) 1 1 1 1 1 GWHIS A commercial version of NCSA Mosaic for MS Windows 3.x and Windows for Workgroups. GWHIS was released by Quadralay Corporation on 30 September 1994. GWHIS Viewer for Microsoft Windows differs from NCSA Mosaic for Microsoft Windows in several ways including: A hotlist similiar to the X Window System version. Edit Annotation and Delete Annotation work. All Buttons and Menu Items are "greyed out" while files are being retreived and processed. This prevents the user from queing up requests to the TCP/IP stack which causes many crashes. Look and Feel are similiar to the X version. On-line help is complete. Functional Setup program. Greater overall stability. (1994-12-16) 1 1 1 1 1 GWM Generic Window Manager. An extensible window manager for the X Window System. It is built on top of an interpreter for the WOOL language. (ftp://export.lcs.mit.edu/contrib/gwm), (ftp://avahi.inria.fr/contrib/gwm). 1 1 1 1 1 gy The country code for Guyana. (1999-01-27) 1 1 1 1 1 Gypsy Specification and verification of concurrent systems software. Message passing using named mailboxes. Separately compilable units: routine (procedure, function, or process), type and constant definition, each with a list of access rights. ["Report on the Language Gypsy", A.L. Ambler et al, UT Austin ICSCS-CMP-1976-08-1]. 1 1 1 1 1 gz gzip 1 1 1 1 1 gzip GNU compression utility. Gzip reduces the size of the named files using Lempel-Ziv LZ77 compression. Whenever possible, each file is replaced by one with the filename extension ".gz". Compressed files can be restored to their original form using gzip -d or gunzip or zcat. The Unix "compress" utility is patented (by two separate patents, in fact) and is thus shunned by the GNU Project since it is not free software. They have therefore chosen gzip, which is free of any known software patents and which tends to compress better anyway. All compressed files in the GNU anonymous FTP area (gnu.org/pub/gnu) are in gzip format and their names end in ".gz" (as opposed to compress-compressed files, which end in ".Z"). Gzip can uncompress "compress"-compressed files and "pack" files (which end in ".z"). The decompression algorithms are not patented, only compression is. 1 1 1 1 1 h 1. A simple markup language intended for quick conversion of existing text to hypertext. 2. A method of marking common words to call attention to the fact that they are being used in a nonstandard, ironic, or humorous way. Originated in the fannish catchphrase "Bheer is the One True Ghod!" from decades ago. H-infix marking of Ghod and other words spread into the 1960s counterculture via underground comix, and into early hackerdom either from the counterculture or from SF fandom (the three overlapped heavily at the time). More recently, the h infix has become an expected feature of benchmark names (Dhrystone, Rhealstone, etc.); this follows on from the original Whetstone (the name of a laboratory) but may have been influenced by the fannish/counterculture h infix. [Jargon File] (1994-11-04) 1 1 1 1 1 H.261 A video compression standard developed by ITU-T before 1992 to work with integrated service digital network. Data is compressed at the rate of 64P kilobits per second, where P can range from 1 to 30 depending on the number of ISDN channels used. This standard was developed primarily to support video phones and video conferencing. See also ivs. (http://crs4.it/~luigi/MPEG/mpeggloss-h.html#H.261). [Date? Details?] (1994-11-03) 1 1 1 1 1 H.264 (Or Advanced Video Coding, AVC) A low bit rate visual communication standard used in video conferencing. H.264 was developed by MPEG and ITU-T VCEG to replace H.263. Video and image compression resources and research (http://www.vcodex.fsnet.co.uk/h264.html). (2007-03-16) 1 1 1 1 1 H.323 The ITU-T standard for sending voice (audio) and video using IP on a LAN without QoS. H.323 includes Q.931 for call setup, H.225 for call signalling, H.245 for exchanging terminal capabilities, RTP/RTCP for packet streaming, G.711/G.712 for CODECs, and several other protcols, many of which need to be negotiated to setup a simple voice call. The complexity of H.323 has lead to the IETF proposing the simpler alternatives SIP and MGCP/Megaco. (2003-11-30) 1 1 1 1 1 Habitat The original term for on-line graphical virtual communities or worlds. Created at Lucasfilm in 1985 by Randy Farmer and Chip Morningstar. (http://communities.com/habitat.html). (1996-06-12) 1 1 1 1 1 hack 1. Originally, a quick job that produces what is needed, but not well. 2. An incredibly good, and perhaps very time-consuming, piece of work that produces exactly what is needed. 3. To bear emotionally or physically. "I can't hack this heat!" 4. To work on something (typically a program). In an immediate sense: "What are you doing?" "I'm hacking TECO." In a general (time-extended) sense: "What do you do around here?" "I hack TECO." More generally, "I hack "foo"" is roughly equivalent to ""foo" is my major interest (or project)". "I hack solid-state physics." See Hacking X for Y. 5. To pull a prank on. See hacker. 6. To interact with a computer in a playful and exploratory rather than goal-directed way. "Whatcha up to?" "Oh, just hacking." 1 1 1 1 1 hackathon A planned hacking run that is intended to last for about a week with lots of hackers. The term was used in 2005 by the Apache Foundation and the OpenBSD Project, among others. (2005-01-26) 1 1 1 1 1 hack attack (Possibly by analogy with "Big Mac Attack" from advertisements for the McDonald's fast-food chain; the variant big hack attack is reported) Nearly synonymous with hacking run, though the latter more strongly implies an all-nighter. [Jargon File] (1996-08-26) 1 1 1 1 1 hacked off (Analogous to "pissed off") Said of system administrators who have become annoyed, upset, or touchy owing to suspicions that their sites have been or are going to be victimised by crackers, or used for inappropriate, technically illegal, or even overtly criminal activities. For example, having unreadable files in your home directory called worm, "lockpick", or "goroot" would probably be an effective (as well as impressively obvious and stupid) way to get your sysadmin hacked off at you. [Jargon File] (1996-08-26) 1 1 1 1 1 hacked up Sufficiently patched, kluged, and tweaked that the surgical scars are beginning to crowd out normal tissue (compare critical mass). Not all programs that are hacked become "hacked up"; if modifications are done with some eye to coherence and continued maintainability, the software may emerge better for the experience. Contrast hack up. [Jargon File] (1996-08-26) 1 1 1 1 1 hacker (Originally, someone who makes furniture with an axe) 1. A person who enjoys exploring the details of programmable systems and how to stretch their capabilities, as opposed to most users, who prefer to learn only the minimum necessary. 2. One who programs enthusiastically (even obsessively) or who enjoys programming rather than just theorizing about programming. 3. A person capable of appreciating hack value. 4. A person who is good at programming quickly. 5. An expert at a particular program, or one who frequently does work using it or on it; as in "a Unix hacker". (Definitions 1 through 5 are correlated, and people who fit them congregate.) 6. An expert or enthusiast of any kind. One might be an astronomy hacker, for example. 7. One who enjoys the intellectual challenge of creatively 1 1 1 1 1 hacker ethic 1. The belief that information-sharing is a powerful positive good, and that it is an ethical duty of hackers to share their expertise by writing free software and facilitating access to information and to computing resources wherever possible. 2. The belief that system-cracking for fun and exploration is ethically OK as long as the cracker commits no theft, vandalism, or breach of confidentiality. Both of these normative ethical principles are widely, but by no means universally, accepted among hackers. Most hackers subscribe to the hacker ethic in sense 1, and many act on it by writing and giving away free software. A few go further and assert that *all* information should be free and *any* proprietary control of it is bad; this is the philosophy behind the GNU project. Sense 2 is more controversial: some people consider the act of cracking itself to be unethical, like breaking and entering. 1 1 1 1 1 hacker humour A distinctive style of shared intellectual humour found among hackers, having the following marked characteristics: 1. Fascination with form-vs.-content jokes, paradoxes, and humour having to do with confusion of metalevels (see meta). One way to make a hacker laugh: hold a red index card in front of him/her with "GREEN" written on it, or vice-versa (note, however, that this is funny only the first time). 2. Elaborate deadpan parodies of large intellectual constructs, such as specifications (see write-only memory), standards documents, language descriptions (see INTERCAL), and even entire scientific theories (see quantum bogodynamics, computron). 3. Jokes that involve screwily precise reasoning from bizarre, ludicrous, or just grossly counter-intuitive premises. 4. Fascination with puns and wordplay. 5. A fondness for apparently mindless humour with subversive currents of intelligence in it - for example, old Warner 1 1 1 1 1 hacking run (Analogy with "bombing run" or "speed run") A hack session extended long outside normal working times, especially one longer than 12 hours. May cause you to "change phase the hard way". [Jargon File] (1996-08-26) 1 1 1 1 1 Hacking X for Y [ITS] Ritual phrasing of part of the information which ITS made publicly available about each user. This information (the INQUIR record) was a sort of form in which the user could fill out various fields. On display, two of these fields were always combined into a project description of the form Hacking X for Y (e.g. ""Hacking perceptrons for Minsky""). This form of description became traditional and has since been carried over to other systems with more general facilities for self-advertisement (such as Unix plan files). [Jargon File] 1 1 1 1 1 Hackintosh 1. <jargon, computer> An Apple Lisa that has been hacked into emulating a Macintosh (also called a "Mac XL"). 2. <jargon, computer> A Macintosh assembled from parts theoretically belonging to different models in the line. (1995-03-08) 1 1 1 1 1 hackish /hak'ish/ 1. Said of something that is or involves a hack. 2. Of or pertaining to hackers or the hacker subculture. See also true-hacker. [Jargon File] (1995-03-08) 1 1 1 1 1 hackishness The quality of being or involving a hack. This term is considered mildly silly. Synonym hackitude. [Jargon File] (1995-03-08) 1 1 1 1 1 hackitude An even sillier word for hackishness. [Jargon File] (1995-03-08) 1 1 1 1 1 hack mode Engaged in hacking. A Zen-like state of total focus on The Problem that may be achieved when one is hacking (this is why every good hacker is part mystic). Ability to enter such concentration at will correlates strongly with wizardliness; it is one of the most important skills learned during larval stage. Sometimes amplified as "deep hack mode". Being yanked out of hack mode (see priority interrupt) may be experienced as a physical shock, and the sensation of being in hack mode is more than a little habituating. The intensity of this experience is probably by itself sufficient explanation for the existence of hackers, and explains why many resist being promoted out of positions where they can code. See also cyberspace. Some aspects of hackish etiquette will appear quite odd to an observer unaware of the high value placed on hack mode. For example, if someone appears at your door, it is perfectly okay 1 1 1 1 1 hack on To hack; implies that the subject is some pre-existing hunk of code that one is evolving, as opposed to something one might hack up. [Jargon File] 1 1 1 1 1 hack together To throw something together so it will work. Unlike kluge together or "cruft together", this does not necessarily have negative connotations. (2003-09-02) 1 1 1 1 1 hack up To hack, but generally implies that the result is a quick hack. Contrast this with hack on. To "hack up on" implies a quick-and-dirty modification to an existing system. Contrast hacked up; compare kluge up, monkey up, cruft together. [Jargon File] (2003-09-02) 1 1 1 1 1 hack value Often adduced as the reason or motivation for expending effort toward a seemingly useless goal, the point being that the accomplished goal is a hack. For example, MacLISP had features for reading and printing Roman numerals, which were installed purely for hack value. See display hack for one method of computing hack value, but this cannot really be explained, only experienced. As Louis Armstrong once said when asked to explain jazz: "Man, if you gotta ask you'll never know." (Feminists please note Fats Waller's explanation of rhythm: "Lady, if you got to ask you ain't got it.") 1 1 1 1 1 ha ha only serious (SF fandom, originally as mutation of HHOK, "Ha Ha Only Kidding") A phrase (often seen abbreviated as HHOS) that aptly captures the flavour of much hacker discourse. Applied especially to parodies, absurdities, and ironic jokes that are both intended and perceived to contain a possibly disquieting amount of truth, or truths that are constructed on in-joke and self-parody. The Jargon File contains many examples of ha-ha-only-serious in both form and content. Indeed, the entirety of hacker culture is often perceived as ha-ha-only-serious by hackers themselves; to take it either too lightly or too seriously marks a person as an outsider, a wannabee, or in larval stage. For further enlightenment on this subject, consult any Zen master. See also AI koan. [Jargon File] 1 1 1 1 1 hair [back-formation from hairy] The complications that make something hairy. "Decoding TECO commands requires a certain amount of hair." Often seen in the phrase "infinite hair", which connotes extreme complexity. Also in "hairiferous" (tending to promote hair growth): "GNUMACS elisp encourages lusers to write complex editing modes." "Yeah, it's pretty hairiferous all right." (Or just: "Hair squared!") 1 1 1 1 1 hairy 1. Annoyingly complicated. "DWIM is incredibly hairy." 2. Incomprehensible. "DWIM is incredibly hairy." 3. Of people, high-powered, authoritative, rare, expert, and/or incomprehensible. Hard to explain except in context: "He knows this hairy lawyer who says there's nothing to worry about. See also hirsute." The adjective "long-haired" is well-attested to have been in slang use among scientists and engineers during the early 1950s; it was equivalent to modern "hairy" and was very likely ancestral to the hackish use. In fact the noun "long-hair" was at the time used to describe a hairy person. Both senses probably passed out of use when long hair was adopted as a signature trait by the 1960s counterculture, leaving hackish hairy as a sort of stunted mutant relic. 4. <topology> hairy ball. [Jargon File] (2001-03-29) 1 1 1 1 1 hairy ball A result in topology stating that a continuous vector field on a sphere is always zero somewhere. The name comes from the fact that you can't flatten all the hair on a hairy ball, like a tennis ball, there will always be a tuft somewhere (where the tangential projection of the hair is zero). An immediate corollary to this theorem is that for any continuous map f of the sphere into itself there is a point x such that f(x)=x or f(x) is the antipode of x. Another corollary is that at any moment somewhere on the Earth there is no wind. (2002-01-07) 1 1 1 1 1 HAKMEM /hak'mem/ MIT AI Memo 239 (February 1972). A legendary collection of neat mathematical and programming hacks contributed by many people at MIT and elsewhere. (The title of the memo really is "HAKMEM", which is a 6-letterism for "hacks memo".) Some of them are very useful techniques, powerful theorems, or interesting unsolved problems, but most fall into the category of mathematical and computer trivia. Here is a sampling of the entries (with authors), slightly paraphrased: Item 41 (Gene Salamin): There are exactly 23,000 prime numbers less than 2^18. Item 46 (Rich Schroeppel): The most *probable* suit distribution in bridge hands is 4-4-3-2, as compared to 4-3-3-3, which is the most *evenly* distributed. This is because the world likes to have unequal numbers: a thermodynamic effect saying things will not be in the state of lowest energy, but in the state of lowest disordered energy. 1 1 1 1 1 hakspek /hak'speek/ A shorthand method of spelling found on many British academic bulletin boards and chat systems. Syllables and whole words in a sentence are replaced by single ASCII characters the names of which are phonetically similar or equivalent, while multiple letters are usually dropped. Hence, "for" becomes "4"; "two", "too", and "to" become "2"; ck becomes "k". "Before I see you tomorrow" becomes "b4 i c u 2moro". First appeared in London about 1986, and was probably caused by the slowness of available talk systems, which operated on archaic machines with outdated operating systems and no standard methods of communication. Has become rarer since. See also chat, B1FF, ASCIIbonics. [Jargon File] (1998-01-25) 1 1 1 1 1 HAL 1. <computer> HAL 9000, the murdering computer on the spaceship in the science fiction classic "2001, A Space Odyssey" by Arthur C. Clark. HAL is "IBM" with each letter changed to the one before and there is an unconfirmed rumour that 9000 is the sum of the various IBM computer numbers that were in service at the time. However, in the sequel "2010", Clarke emphatically denies that HAL's name is supposed to be "one step ahead of IBM". It is, rather, short for "heuristic algorithm". 2. <operating system> Hardware Abstraction Layer. (1995-11-09) 1 1 1 1 1 half-duplex (hdx, from telegraphy) 1. A type of communication channel using a single circuit which can carry data in either direction but not both directions at once. Compare: simplex, full-duplex. 2. An obsolete term for local echo. (2001-07-21) 1 1 1 1 1 halftone The reproducion of greyscale images using dots of a single shade but varying size to simulate the different shades of grey. Laser printers that cannot print different sized dots, halftones are produced by varying the numbers of dots in a given area. This process is also used to produce a black and white version of a colour original using shades of grey in place of colours. See also device independent bitmap. (1996-09-20) 1 1 1 1 1 HALGOL A simple language from Hewlett-Packard for communicating with devices such as modems and X.25 PADs. (1995-04-12) 1 1 1 1 1 HALMAT Intermediate language used by HAL/S. 1 1 1 1 1 Hal/S (Hal/Shuttle) A real-time high-level language for flight control applications. Hal was developed for NASA by Intermetrics, Inc. in the 1970s for on-board software. The initial version was a Fortran preprocessor, written in Fortran. In 1972, as the space shuttle project advanced, the language was renamed Hal/S and made more adaptable to architecture of different computers by using XPL. In all, 11 different implementations, mostly based on IBM 360, were created. Applications also included projects by JPL (Galileo probe, Deep Space network). ["Two-Dimensional Characteristics of HAL, A Language for Spaceflight Applications", J.S. Miller, SIGPLAN Notices 7(10), Oct 1972]. ["Space Station Flight Software: Hal/S or Ada?", Allan R. Klumpp, "Computer", March 1985]. (2002-07-13) 1 1 1 1 1 Halt and Catch Fire (HCF) Any of several undocumented and semi-mythical machine instructions with destructive side-effects, supposedly included for test purposes on several well-known architectures going as far back as the IBM 360. The Motorola 6800 microprocessor was the first for which an HCF opcode became widely known. This instruction caused the processor to read every memory location sequentially until reset. [Gerry Wheeler, Byte, December 1977, p46, "Undocumented M6800 Instructions" (https://archive.org/details/byte-magazine-1977-12)]. (2014-09-20) 1 1 1 1 1 halting problem The problem of determining in advance whether a particular program or algorithm will terminate or run forever. The halting problem is the canonical example of a provably unsolvable problem. Obviously any attempt to answer the question by actually executing the algorithm or simulating each step of its execution will only give an answer if the algorithm under consideration does terminate, otherwise the algorithm attempting to answer the question will itself run forever. Some special cases of the halting problem are partially solvable given sufficient resources. For example, if it is possible to record the complete state of the execution of the algorithm at each step and the current state is ever identical to some previous state then the algorithm is in a loop. This might require an arbitrary amount of storage however. Alternatively, if there are at most N possible different states then the algorithm can run for at most N steps without 1 1 1 1 1 Hamilton William Hamilton 1 1 1 1 1 Hamiltonian cycle Hamiltonian problem 1 1 1 1 1 Hamiltonian path Hamiltonian problem 1 1 1 1 1 Hamiltonian problem (Or "Hamilton's problem") A problem in graph theory posed by William Hamilton: given a graph, is there a path through the graph which visits each vertex precisely once (a "Hamiltonian path")? Is there a Hamiltonian path which ends up where it started (a "Hamiltonian cycle" or Hamiltonian tour)? Hamilton's problem is NP-complete. It has numerous applications, sometimes completely unexpected, in computing. (http://ing.unlp.edu.ar/cetad/mos/Hamilton.html). (1997-07-18) 1 1 1 1 1 Hamiltonian tour Hamiltonian problem 1 1 1 1 1 Hamilton's problem Hamiltonian problem 1 1 1 1 1 hammer Commonwealth hackish synonym for bang on. [Jargon File] (1995-02-16) 1 1 1 1 1 Hamming code Extra, redundant bits added to stored or transmitted data for the purposes of error detection and correction. Named after the mathematician Richard Hamming, Hamming codes greatly improve the reliability of data, e.g. from distant space probes, where it is impractical, because of the long transmission delay, to correct errors by requesting retransmission. [Detail? Connection with Hamming Distance?] (2002-07-02) 1 1 1 1 1 Hamming distance The minimum number of bits that must be changed in order to convert one bit string into another. Named after the mathematician Richard Hamming. [Connection with Hamming code?]. (2002-07-02) 1 1 1 1 1 Hamming, Richard Richard Hamming 1 1 1 1 1 hamster 1. <programming> (From Fairchild) A particularly slick little piece of code that does one thing well; a small, self-contained hack. The image is of a hamster happily spinning its exercise wheel. 2. <hardware> A tailless mouse; that is, one with an infrared link to a receiver on the machine, as opposed to the conventional cable. 3. <product> (UK) Any item of hardware made by Amstrad, a company famous for its cheap plastic PC-almost-compatibles. [Jargon File] (1995-02-16) 1 1 1 1 1 Han character (From the Han dynasty, 206 B.C.E to 25 C.E.) One of the set of glyphs common to Chinese (where they are called "hanzi"), Japanese (where they are called kanji), and Korean (where they are called hanja). Han characters are generally described as "ideographic", i.e., picture-writing; but see the reference below. Modern Korean, Chinese and Japanese fonts may represent a given Han character as somewhat different glyphs. However, in the formulation of Unicode, these differences were folded, in order to conserve the number of code positions necessary for all of CJK. This unification is referred to as "Han Unification", with the resulting character repertoire sometimes referred to as "Unihan". Unihan reference at the Unicode Consortium (http://charts.unicode.org/unihan.html). [John DeFrancis, "The Chinese Language: Fact and Fantasy", University of Hawaii Press, 1984]. 1 1 1 1 1 HAND Have A Nice Day. Often used sarcastically and in connection with HTH, as in: > Where's the point of alt.stupidity? Between the 't' and the 's'. HTH. HAND. (1998-03-06) 1 1 1 1 1 hand cruft (After "hand craft") To write something by hand that would be better done automatically, e.g. writing assembly language instead of using a compiler (see hand hacking). [Jargon File] (2006-01-19) 1 1 1 1 1 Handel An imperative language with primitives for controlling parallel programs. Used by Wayne Luk for work in compilation of programs to hardware (FPGAs). (1995-02-28) 1 1 1 1 1 hand hack 1. (Or "hand cruft") To Translate a hot spot of a program in a HLL into assembly language by hand, as opposed to trying to coerce the compiler into generating better code. Both the term and the practice are becoming uncommon. See tune, bum. 2. More generally, manual construction or patching of data sets that would normally be generated by a translation utility and interpreted by another program, and aren't really designed to be read or modified by humans. [Jargon File] (1995-02-16) 1 1 1 1 1 Hand-held Personal Computer palmtop 1 1 1 1 1 handle 1. <programming, operating system> A simple item of data that identifies a resource. For example, a Unix file handle identifies an open file and associated data such as whether it was opened for read or write and the current read/write position. On the Macintosh, a handle is a pointer to a pointer to some dynamically-allocated memory. The extra level of indirection allows on-the-fly memory compaction or garbage collection without invalidating application program references to the allocated memory. 2. <jargon> An alias used intended to conceal a user's true identity in an electronic message. The term is common on Citizen's Band and other amateur radio but, in that context usually means the user's real name as FCC rules forbid concealing one's identity. Use of grandiose handles is characteristic of crackers, weenies, spods, and other lower forms of network life; true hackers travel on their own reputations. 1 1 1 1 1 handoff handover 1 1 1 1 1 handover (HO, or "handoff") the mechanism by which an on going cellular connection between a mobile terminal (MT, typically a mobile phone) or mobile host (MH) and a corresponding terminal or host is transferred from one point of access of the fixed network to another. Handover may occur because the phone is leaving its current cell, to balance demand between cells, to reduce interference or to transfer a user who has stopped moving to a nearby cell with shorter range. (2010-05-07) 1 1 1 1 1 hand-roll (From mainstream slang "hand-rolled cigarette" in opposition to "ready-made") To perform a normally automated software installation or configuration process by hand; implies that the normal process failed due to bugs or was defeated by something exceptional in the local environment. "The worst thing about being a gateway between four different nets is having to hand-roll a new sendmail configuration every time any of them upgrades." [Jargon File] (1995-02-28) 1 1 1 1 1 handshake handshaking 1 1 1 1 1 handshaking 1. Predetermined hardware or software activity designed to establish or maintain two machines or programs in synchronisation. Handshaking often concerns the exchange of messages or packets of data between two systems with limited buffers. A simple handshaking protocol might only involve the receiver sending a message meaning "I received your last message and I am ready for you to send me another one." A more complex handshaking protocol might allow the sender to ask the receiver if he is ready to receive or for the receiver to reply with a negative acknowledgement meaning "I did not receive your last message correctly, please resend it" (e.g. if the data was corrupted en route). Hardware handshaking uses voltage levels or pulses on wires to carry the handshaking signals whereas software handshaking uses data units (e.g. ASCII characters) carried by some underlying communication medium. Flow control in bit-serial data transmission such as 1 1 1 1 1 handwave [possibly from gestures characteristic of stage magicians] To gloss over a complex point; to distract a listener; to support a (possibly actually valid) point with blatantly faulty logic. If someone starts a sentence with "Clearly..." or Obviously... or "It is self-evident that...", it is a good bet he is about to handwave (alternatively, use of these constructions in a sarcastic tone before a paraphrase of someone else's argument suggests that it is a handwave). The theory behind this term is that if you wave your hands at the right moment, the listener may be sufficiently distracted to not notice that what you have said is wrong. Failing that, if a listener does object, you might try to dismiss the objection with a wave of your hand. The use of this word is often accompanied by gestures: both hands up, palms forward, swinging the hands in a vertical plane pivoting at the elbows and/or shoulders (depending on the magnitude of the handwave); alternatively, holding the 1 1 1 1 1 hang 1. To wait for an event that will never occur. "The system is hanging because it can't read from the crashed drive". See wedged, hung. 2. To wait for some event to occur; to hang around until something happens. "The program displays a menu and then hangs until you type a character." Compare block. 3. To attach a peripheral device, especially in the construction "hang off": "We're going to hang another tape drive off the file server." Implies a device attached with cables, rather than something that is strictly inside the machine's chassis. 1 1 1 1 1 hanja Han characters 1 1 1 1 1 Hanoi Towers of Hanoi 1 1 1 1 1 Han Unification Han character 1 1 1 1 1 hanzi Han characters 1 1 1 1 1 happily Of software, used to emphasise that a program is unaware of some important fact about its environment, either because it has been fooled into believing a lie, or because it doesn't care. The sense of "happy" here is not that of elation, but rather that of blissful ignorance. "The program continues to run, happily unaware that its output is going to /dev/null." [Jargon File] 1 1 1 1 1 Happy A dyslexic acronym for "A Yacc-like Haskell Parser generator". An LALR1 grammar parser generator for Haskell. Happy is written in Haskell, uses a parser generated by itself, and can be compiled using ghc, hbc or gofer. Happy uses an implementation of monadic IO built on top of stream IO, but this should change when the Haskell 1.3 standard has been implemented. Version: 0.9 (1996-02-28). Happy is covered by the General Public License. (http://dcs.gla.ac.uk/fp/software/happy.html). (ftp://ftp.dcs.gla.ac.uk/pub/haskell/happy/). E-mail: <andy@dcs.gla.ac.uk>, <simonm@dcs.gla.ac.uk>. (1996-03-21) 1 1 1 1 1 haptic interface A touch interface to a computer that provides feedback, such as a data glove. (2003-10-17) 1 1 1 1 1 haptics The science of applying tactile sensation to human interaction with computers. Haptics Community (http://haptic.mech.northwestern.edu/). (2003-10-17) 1 1 1 1 1 haque /hak/ (Usenet) A variant spelling of hack, used only for the noun form and connoting an elegant hack. [Jargon File] (1995-02-22) 1 1 1 1 1 hard boot A boot which resets the entire system. The phrase has connations of hostility toward, or frustration with, the computer being booted. For example, "I'll have to hard boot this losing Sun", or "I recommend booting it hard". Hard boots are often performed with a power cycle. Contrast soft boot. See also cold boot and reboot [Jargon File] (1995-11-27) 1 1 1 1 1 hard-coded (By analogy with "hard-wired") Said of a data value or behaviour written directly into a program, possibly in multiple places, where it cannot be easily modified. There are several alternatives, depending on how often the value is likely to change. It may be replaced with a compile-time constant, such as a C "#define" macro, in which case a change will still require recompilation; or it may be read at run time from a profile, resource (see de-rezz), or environment variable that a user can easily modify; or it may be read as part of the program's input data. To change something hard-coded requires recompilation (if using a compiled language of course) but, more seriously, it requires sufficient understanding of the implementation to be sure that the change will not introduce inconsistency and cause the program to fail. For example, "The line terminator is hard-coded as newline; who in their right mind would use anything else?" 1 1 1 1 1 hardcopy A paper printout of data displayed on a screen. Contrast softcopy. (1995-08-31) 1 1 1 1 1 hard crash When a program stops running completely and unexpectedly, often due to external events, e.g. the CPU overheating or an unrecoverable memory error. See also disk crash. (2009-07-01) 1 1 1 1 1 hard disk (In contrast to floppy disk) A magnetic disk data storage device where the disks are rigid and fixed to a central axle. They are usually packaged with associated read/write heads and electronics. Most hard disks are permanently connected to the drive (fixed disks) though there are also removable hard disks. See magnetic disk. (2007-06-14) 1 1 1 1 1 hard disk drive (HDD) A disk drive used to read and write hard disks. (1995-03-14) 1 1 1 1 1 hard drive hard disk drive 1 1 1 1 1 hard link One of several directory entries which refer to the same Unix file. A hard link is created with the "ln" (link) command: ln <old name> <new name> where <old name> and <new name> are pathnames within the same file system. Hard links to the same file are indistinguishable from each other except that they have different pathnames. They all refer to the same inode and the inode contains all the information about a file. The standard ln command does not usually allow you to create a hard link to a directory, chiefly because the standard rm and rmdir commands do not allow you to delete such a link. Some systems provide link and unlink commands which give direct access to the system calls of the same name, for which no such restrictions apply. Normally all hard links to a file must be in the same file 1 1 1 1 1 hard linking hard link 1 1 1 1 1 hard sector An archaic floppy disk format employing multiple synchronisation holes in the media to define the sectors. (1995-01-24) 1 1 1 1 1 hardware The physical, touchable, material parts of a computer or other system. The term is used to distinguish these fixed parts of a system from the more changeable software or data components which it executes, stores, or carries. Typical computer hardware consists of electronic devices (CPU, memory, display) with some electromechanical parts (keyboard, printer, disk drives, tape drives, loudspeakers) for input, output and storage. Completely non-electronic (mechanical, electromechanical, hydraulic, biological) computers have also been conceived of and built. See also firmware, wetware. (1997-01-23) 1 1 1 1 1 Hardware Abstraction Layer (HAL) The layer of Microsoft Windows NT where they have isolated their assembly language code. (1995-04-17) 1 1 1 1 1 hardware circular buffer digital signal processors which support hardware circular buffers automatically generate and increment pointers for memory accesses which wrap to the beginning of the buffer when its end is reached, thus saving the time and instructions otherwise needed to ensure that the address pointer stays within the boundary of the buffer, and speeding the execution of repetitive DSP algorithms. Digital Signal Processor For Digital Audio Applications (http://analog.com/publications/documentation/21065L_Audio_Tutorial.PDF). (2000-06-17) 1 1 1 1 1 Hardware Description Language (HDL) A kind of language used for the conceptual design of integrated circuits. Examples are VHDL and Verilog. (1995-04-18) 1 1 1 1 1 hardware handshaking A technique for regulating the flow of data across an interface by means of signals carried on separate wires. A common example is the RTS (Request to Send) and CTS (Clear to Send) signals on an EIA-232 serial line. The alternative, software handshaking, uses two special characters inserted into the data stream to carry the same information. (1995-01-23) 1 1 1 1 1 hardware register (Or "hardware log") A list of all hardware, both internal and external, that is attached to a particular computer. (2006-09-07) 1 1 1 1 1 hardwarily /hard-weir'*-lee/ In a way pertaining to hardware. "The system is hardwarily unreliable." The adjective "hardwary" is *not* traditionally used, though it has recently been reported from the U.K. See softwarily. [Jargon File] (1995-01-23) 1 1 1 1 1 hard-wired 1. <electronics> An aspect of an electronic circuit which is determined by the wiring of the hardware, as opposed to being programmable in software or controlled by a switch. 2. <software, jargon> In software, a synonym for hard-coded. 3. By extension, anything that is not modifiable, especially in the sense of customisable to one's particular needs or tastes. [Jargon File] (1999-10-18) 1 1 1 1 1 Harris Semiconductor Ltd. Address: Riverside Way, Camberley, Surrey, CU15 3YQ, UK. Telephone: +44 (1276) 686 886. Fax: +44 (1276) 682 323. (1995-11-21) 1 1 1 1 1 Harvard architecture A computer architecture in which program instructions are stored in different memory from data. Each type of memory is accessed via a separate bus, allowing instructions and data to be fetched in parallel. Contrast: von Neumann architecture. [Why Harvard?] (2004-01-14) 1 1 1 1 1 Harvard Graphics A presentation graphics product by Software Publishing Corporation (SPC) for creating presentations, speeches, slides, etc.. (1998-07-20) 1 1 1 1 1 Harvard Mark II Machine A relay-based computer designed and built by Howard Aiken, with support from IBM, for the United States Navy's Naval Proving Ground, between 1942 - 1947. The Harvard Mark II was the second in a series of four electro-mechanical computers that were forerunners of the ENIAC. Harvard machines (http://hoc.co.umist.ac.uk/storylines/compdev/electromechanical/harvardmarkmachines.html). (2003-09-13) 1 1 1 1 1 Harvest A highly scalable, customisable system for discovering resources on the Internet. Version: 1.3. (http://tardis.ed.ac.uk/harvest/). (1999-01-16) 1 1 1 1 1 Harvest C A C compiler, assembler and linker for the Macintosh by Eric W. Sink. The parts of the system are integrated in a single application, which manages a "project" composed by several C source files and resource files (which contain data). Version 1.3. (ftp://archive.umich.edu/mac/development/languages/). (1992-05-26) 1 1 1 1 1 hash 1. <character> hash character. 2. <programming> hash coding. 3. The preferred term for a Perl associative array. (1995-03-06) 1 1 1 1 1 hash bucket hash coding 1 1 1 1 1 hash character "#", ASCII character 35. Common names: number sign; pound; pound sign; hash; sharp; crunch; hex; INTERCAL: mesh. Rare: grid; crosshatch; octothorpe; flash; ITU-T: square, pig-pen; tictactoe; scratchmark; thud; thump; splat. The pronunciation of "#" as "pound" is common in the US but a bad idea; Commonwealth Hackish has its own, rather more apposite use of "pound sign" (confusingly, on British keyboards the pound graphic happens to replace "#"; thus Britishers sometimes call "#" on a US-ASCII keyboard "pound", compounding the American error). The US usage derives from an old-fashioned commercial practice of using a "#" suffix to tag pound weights on bills of lading. The character is usually pronounced "hash" outside the US. The name "octothorpe" was made up by a Bell Labs supervisor, Don Macpherson. Octothorpe story 1 1 1 1 1 hash coding (Or "hashing") A scheme for providing rapid access to data items which are distinguished by some key. Each data item to be stored is associated with a key, e.g. the name of a person. A hash function is applied to the item's key and the resulting hash value is used as an index to select one of a number of "hash buckets" in a hash table. The table contains pointers to the original items. If, when adding a new item, the hash table already has an entry at the indicated location then that entry's key must be compared with the given key to see if it is the same. If two items' keys hash to the same value (a "hash collision") then some alternative location is used (e.g. the next free location cyclically following the indicated one). For best performance, the table size and hash function must be tailored to the number of entries and range of keys to be used. The hash function usually depends on the table size so if the table needs to be enlarged it must usually be 1 1 1 1 1 hash collision (Or "hash clash") When two different keys hash to the same value, i.e. to the same location in a hash table. ESR once asked a friend what he expected Berkeley to be like. The friend replied, "Well, I have this mental picture of naked women throwing Molotov cocktails, but I think that's just a collision in my hash tables." [Jargon File] (1995-01-23) 1 1 1 1 1 hash function A hash coding function which assigns a data item distinguished by some "key" into one of a number of possible "hash buckets" in a hash table. The hash function is usually combined with another more precise function. For example a program might take a string of letters and put it in one of twenty six lists depending on its first letter. Ideally, a hash function should distribute items evenly between the buckets to reduce the number of hash collisions. If, for example, the strings were names beginning with "Mr.", Miss or "Mrs." then taking the first letter would be a very poor hash function because all names would hash the same. (1997-08-03) 1 1 1 1 1 hashing hash coding 1 1 1 1 1 hash table hash coding 1 1 1 1 1 Haskell (Named after the logician Haskell Curry) A lazy purely functional language largely derived from Miranda but with several extensions. Haskell was designed by a committee from the functional programming community in April 1990. It features static polymorphic typing, higher-order functions, user-defined algebraic data types, and pattern-matching list comprehensions. Innovations include a class system, systematic operator overloading, a functional I/O system, functional arrays, and separate compilation. Haskell 1.3 added many new features, including monadic I/O, standard libraries, constructor classes, labeled fields in datatypes, strictness annotations, an improved module system, and many changes to the Prelude. Gofer is a cut-down version of Haskell with some extra features. Filename extension: .hs, .lhs (literate programming). 1 1 1 1 1 Haskell B An early version of Haskell by Lennart Augustsson <augustss@cs.chalmers.se> from Chalmers. Haskell B evolved into a full-featured implementation of Haskell 1.2, with quite a few extensions. Ports exist for many platforms including Sun, DEC, Sequent, IBM PC, Symmetry and unsupported versions for NS32000, IBM RT/PC, Cray, Sun-3, Vax, ARM, and RS/6000. Version 0.999.5 included a compiler, interpreter, library, documentation, and examples. (ftp://ftp.cs.chalmers.se/pub/haskell/chalmers/). Mailing list: <haskell-request@cs.yale.edu>. E-mail: <hbc@cs.chalmers.se>. (1996-08-21) 1 1 1 1 1 Haskell Curry Haskell Brooks Curry (1900-09-12 - 1982-09-01). The logician who re-invented and developed combinatory logic. The functional programming language Haskell was named after him. Biography (http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Curry.html). (1999-01-08) 1 1 1 1 1 Haskell User's Gofer System (HUGS) An implementation of Haskell derived from Gofer 2.30b with an interactive development environment much like Gofer's. Almost all of the features of Haskell 1.2 are implemented with the exception of the module system. Hugs supports Haskell style type classes, a full prelude, derived instances, defaults, overloaded numeric literals and pattern matching, and bignum arithmetic. Home (http://cs.nott.ac.uk/Department/Staff/mpj/hugs.html). (ftp://ftp.cs.nott.ac.uk/pub/haskell/hugs). E-mail: Mark P. Jones <mpj@cs.nott.ac.uk>. (1995-02-14) 1 1 1 1 1 HASL SASL plus conditional unification. ["A Prological Definition of HASL, A Purely Functional Language with Unification Based Conditional Binding Expressions", H. Abramson in Logic Programming: Functions, Relations and Equations, D. DeGroot et al eds, P-H 1986]. (1996-08-21) 1 1 1 1 1 HASP Houston Automatic Spooling Program 1 1 1 1 1 has the X nature (From Zen Buddhist koans of the form "Does an X have the Buddha-nature?") Common hacker construction for "is an X", used for humorous emphasis. "Anyone who can't even use a program with on-screen help embedded in it truly has the loser nature!" See also the X that can be Y is not the true X. [Jargon File] (1995-01-11) 1 1 1 1 1 hat A common (spoken) name for the circumflex ("^", ASCII 94) character. See ASCII for other synonyms. [Jargon File] 1 1 1 1 1 hate-driven development A play on test-driven development for use when a piece of code is not necessarily broken but you hate the way it is written so much that you feel compelled to rewrite it. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)] (2014-09-30) 1 1 1 1 1 Hayes A modem manufacturer. (gopher://leapfrog.almac.co.uk:70/00/business/comms/hayes/corporat.txt). Address: Atlanta, Georgia, USA. (1995-01-30) 1 1 1 1 1 Hayes-compatible A description of a modem which understands the same set of commands as one made by Hayes. [What are the commands?] (1996-12-08) 1 1 1 1 1 Haze An X Window System window manager designed to be light-weight and look like MacOS. Haze is based on mlvwm. It support virtual desktops, configurable menu bar and shaded windows. Haze home (http://www.escomposlinux.org/jes/description.html). (2010-05-03) 1 1 1 1 1 HBOOK A histogramming package in the CERN program library. 1 1 1 1 1 hc The compiler for the h hyperbook language. 1 1 1 1 1 HC-900 A hybrid controller made by Honeywell. Honeywell (http://honeywell.silverw.com/docs/51-52-03-31.pdf). [Hybrid of what and what?] (2004-03-31) 1 1 1 1 1 HCF 1. <operating system> Host Command Facility. 2. <architecture> Halt and Catch Fire. [Jargon File] (1999-01-24) 1 1 1 1 1 HCI 1. Human-Computer Interaction. 2. Human-Computer Interface. 3. Host Control Interface. (2002-06-21) 1 1 1 1 1 HCLP Hierarchical CLP. ["Constraint Hierarchies and Logic Programming", A. Borning et al, in Proc Sixth Intl Logic Prog Conf, June 1989, pp. 149-164]. 1 1 1 1 1 HCPRVR HCPRVR: An Interpreter for Logic Programs, D. Chester in Proc First Natl Conf on AI, Stanford, 1980. 1 1 1 1 1 HCS Heterogeneous Computer System A distributed system project. [Where? When? What?] (1995-02-01) 1 1 1 1 1 HD high density 1 1 1 1 1 HD6309 Hitachi 6309 1 1 1 1 1 HDA Head Disk Assembly 1 1 1 1 1 HDC Disk Controller 1 1 1 1 1 HDD hard disk drive 1 1 1 1 1 HDF Hierarchical Data Format 1 1 1 1 1 HDFL A single assignment language. ["Methods for Handling Structures in Data-Flow Systems", J.L. Gaudiot, Proc 12th Intl Symp Comp Arch, June 1985]. 1 1 1 1 1 HDL Hardware Description Language 1 1 1 1 1 HDLC High-level Data Link Control 1 1 1 1 1 HDM Hierarchical Design Methodology 1 1 1 1 1 HDMI High-Definition Multimedia Interface 1 1 1 1 1 HDSL High bit-rate Digital Subscriber Line 1 1 1 1 1 HDTV High Definition Television 1 1 1 1 1 hdx half-duplex 1 1 1 1 1 Head Disk Assembly (HDA) A sealed, high capacity mainframe hard disk with integral heads, as opposed to a removable disk. (1999-01-13) 1 1 1 1 1 header 1. The portion of a packet, preceding the actual data, containing source and destination addresses, error checking and other fields. 2. The part of an electronic mail message or news article that precedes the body of a message and contains, among other things, the sender's name and e-mail address and the date and time the message was sent. 1 1 1 1 1 Head Normal Form (HNF) A term describing a lambda expression whose top level is either a variable, a data value, a built-in function applied to too few arguments, or a lambda abstraction whose body is not reducible. I.e. the top level is neither a redex nor a lambda abstraction with a reducible body. An expression in HNF may contain redexes in argument postions whereas a normal form may not. Compare Weak Head Normal Form. (2003-01-08) 1 1 1 1 1 head normalisation theorem Under the typed lambda-calculus, beta/delta reduction of the left-most redex (normal order reduction) is guaranteed to terminate with a head normal form if one exists. See also Church-Rosser theorem. 1 1 1 1 1 heads down [Sun] Concentrating, usually so heavily and for so long that everything outside the focus area is missed. See also hack mode and larval stage, although this mode is hardly confined to fledgling hackers. [Jargon File] 1 1 1 1 1 head-strict A head-strict function will not necessarily evaluate every cons cell of its (list) argument, but whenever it does evaluate a cons cell it will also evaluate the element in the head of that cell. An example of a head-strict function is beforeZero :: [Int] -> [Int] beforeZero [] = [] beforeZero (0:xs) = [] beforeZero (x:xs) = x : beforeZero xs which returns a list up to the first zero. This pattern of evaluation is important because it is common in functions which operate on a list of inputs. See also tail-strict, hyperstrict. (1995-05-11) 1 1 1 1 1 heap 1. <programming> An area of memory used for dynamic memory allocation where blocks of memory are allocated and freed in an arbitrary order and the pattern of allocation and size of blocks is not known until run time. Typically, a program has one heap which it may use for several different purposes. Heap is required by languages in which functions can return arbitrary data structures or functions with free variables (see closure). In C functions malloc and free provide access to the heap. Contrast stack. See also dangling pointer. 2. <programming> A data structure with its elements partially ordered (sorted) such that finding either the minimum or the maximum (but not both) of the elements is computationally inexpensive (independent of the number of elements), while both adding a new item and finding each subsequent smallest/largest element can be done in O(log n) time, where n is the number of elements. 1 1 1 1 1 heartbeat 1. <networking> The signal emitted by a Level 2 Ethernet transceiver at the end of every packet to show that the collision-detection circuit is still connected. 2. A periodic synchronisation signal used by software or hardware, such as a bus clock or a periodic interrupt. 3. The "natural" oscillation frequency of a computer's clock crystal, before frequency division down to the machine's clock rate. 4. A signal emitted at regular intervals by software to demonstrate that it is still alive. Sometimes hardware is designed to reboot the machine if it stops hearing a heartbeat. See also breath-of-life packet, watchdog. [Jargon File] (1996-03-12) 1 1 1 1 1 heatseeker (IBM) A customer who can be relied upon to buy, without fail, the latest version of an existing product (not quite the same as a member of the lunatic fringe). A 1993 example of a heatseeker is someone who, owning a 286 PC and Windows 3.0, goes out and buys Windows 3.1 (which offers no worthwhile benefits unless you have a 386). If all customers were heatseekers, vast amounts of money could be made by just fixing the bugs in each release (n) and selling it to them as release (n+1). [Jargon File] (1996-03-12) 1 1 1 1 1 heat sink /heet sink/ (from "sink", electronics jargon for something which takes in current) A piece of thermally conductive metal attached to a semiconductor or other electronic device and designed to prevent it from overheating by conducting heat away from it and radiating it to the environment. Heat sinks often have fins to increase their surface area. They occasionally have fans attached. Heat sink compound can be smeared between the device and the heat sink to improve thermal conduction. (1997-06-10) 1 1 1 1 1 heat slug A metal plate that helps dissipate heat away from the silicon core of a processor to the packaging or heat-sink. (2000-08-26) 1 1 1 1 1 heavy metal big iron 1 1 1 1 1 heavyweight High-overhead; baroque; code-intensive; featureful, but costly. Especially used of communication protocols, language designs, and any sort of implementation in which maximum generality and/or ease of implementation has been pushed at the expense of mundane considerations such as speed, memory use and startup time. Emacs is a heavyweight editor; X is an *extremely* heavyweight window system. This term isn't pejorative, but one hacker's heavyweight is another's elephantine and a third's monstrosity. Opposite: "lightweight". Usage: now borders on technical especially in the compound "heavyweight process". (1994-12-22) 1 1 1 1 1 heavy wizardry Code or designs that trade on a particularly intimate knowledge or experience of a particular operating system or language or complex application interface. Distinguished from deep magic, which trades more on arcane *theoretical* knowledge. Writing device drivers is heavy wizardry; so is interfacing to X (sense 2) without a toolkit. Especially found in source-code comments of the form "Heavy wizardry begins here". Compare voodoo programming. [Jargon File] 1 1 1 1 1 Hebbian learning The most common way to train a neural network; a kind of unsupervised learning; named after canadian neuropsychologist, Donald O. Hebb. The algorithm is based on Hebb's Postulate, which states that where one cell's firing repeatedly contributes to the firing of another cell, the magnitude of this contribution will tend to increase gradually with time. This means that what may start as little more than a coincidental relationship between the firing of two nearby neurons becomes strongly causal. Despite limitations with Hebbian learning, e.g., the inability to learn certain patterns, variations such as Signal Hebbian Learning and Differential Hebbian Learning are still used. (http://neuron-ai.tuke.sk/NCS/VOL1/P3_html/node14.html). (2003-11-07) 1 1 1 1 1 heisenbug /hi:'zen-buhg/ (From Heisenberg's Uncertainty Principle in quantum physics) A bug that disappears or alters its behaviour when one attempts to probe or isolate it. (This usage is not even particularly fanciful; the use of a debugger sometimes alters a program's operating environment enough that buggy code, such as that which relies on the values of uninitialised memory, behaves quite differently.) In C, nine out of ten heisenbugs result from uninitialised auto variables, fandango on core phenomena (especially corruption of the malloc arena) or errors that smash the stack. Opposite: Bohr bug. See also mandelbug, schroedinbug. [Jargon File] (1995-02-28) 1 1 1 1 1 Helen Keller mode 1. State of a hardware or software system that is deaf, dumb, and blind, i.e. accepting no input and generating no output, usually due to an infinite loop or some other excursion into deep space. (Unfair to the real Helen Keller, whose success at learning speech was triumphant.) See also go flatline, catatonic. 2. On IBM PCs under MS-DOS, refers to a specific failure mode in which a screen saver has kicked in over an ill-behaved application which bypasses the very interrupts the screen saver watches for activity. Your choices are to try to get from the program's current state through a successful save-and-exit without being able to see what you're doing, or to re-boot the machine. This isn't (strictly speaking) a crash. [Jargon File] 1 1 1 1 1 Helix A hardware description language from Silvar-Lisco. 1 1 1 1 1 hello hello, world 1 1 1 1 1 hello packet An OSPF packet sent periodically on each network interface, real or virtual, to discover and test connections to neighbours. Hello packets are multicast on physical networks capable of multicasting or broadcasting to enable dynamic router discovery. They include the parameters that routers connected to a common network must agree on. Hello packets increase network resilience by, e.g., allowing a router to establish a secondary connection when a primary connection fails. (1999-11-02) 1 1 1 1 1 hello, sailor! Occasional West Coast equivalent of hello, world; seems to have originated at SAIL, later associated with the game Zork (which also included "hello, aviator" and "hello, implementor"). Originally from the traditional hooker's greeting to a swabbie fresh off the boat, of course. [Jargon File] (2007-10-30) 1 1 1 1 1 hello, world The canonical, minimal, first program that a programmer writes in a new programming language or development environment. The program just prints "hello, world" to standard output in order to verify that the programmer can successfully edit, compile and run a simple program before embarking on anything more challenging. Hello, world is the first example program in the C programming book, K&R, and the tradition has spread from there to pretty much every other language and many of their textbooks. Environments that generate an unreasonably large executable for this trivial test or which require a hairy compiler-linker invocation to generate it are considered bad. Hello, World in over 400 programming languages (http://www.roesler-ac.de/wolfram/hello.htm). (2013-10-27) 1 1 1 1 1 HELP 1. <language, robotics> DEA. A Language for industrial robots. 2. (Help Est un Lisp Paresseux - Help Is a Lazy Lisp). A lazy version of Scheme with strictness annotations, by Thomas Schiex <schiex@europe.cert.fr>. 1 1 1 1 1 Helvetica One of the most widely used sans-serif typefaces, developed in 1957 by Swiss typeface designer Max Miedinger with Eduard Hoffmann. Originally called Neue Haas Grotesk, it was renamed Helvetica for the international market. Helvetica is very similar to the common Arial typeface. The name is Latin for Swiss. Linotype (http://www.linotype.com/526/helvetica-family.html). (2013-09-19) 1 1 1 1 1 henry (H) The SI unit of inductance: one henry is the inductance of a closed loop in which the induced voltage is one volt if the current flowing through it changes by one ampere each second, i.e., 1 H = 1 Vs/A. Named after the American physicist Joseph Henry (1797-1878). (1997-03-16) 1 1 1 1 1 HENSA Higher Education National Software Archive 1 1 1 1 1 HEP High Energy (Particle) Physics. 1 1 1 1 1 HEPDB A database management system for HEP. 1 1 1 1 1 HEPiX A recently formed collaboration among various HEP institutes aiming at providing "compatible" versions of the Unix operating system at their sites. 1 1 1 1 1 HEPnet An association concerned with networking requirements for high energy physicists. 1 1 1 1 1 HEPVM A collaboration among various HEP institutes to implement compatible versions of IBM's VM-CMS operating system at their sites. 1 1 1 1 1 HEQS E. Derman. Constraint language for financial modelling. Uses an extension of the equation solver in IDEAL. "A Simple Equation Solver and Its Application to Financial Modeling", E. Derman et al, Soft Prac & Exp 14(12):1169-1181 (Dec 1984). 1 1 1 1 1 HERA An electron-proton collider at DESY, W. Germany. 1 1 1 1 1 HERAKLIT A distributed object-oriented language. ["Definition einer objektorientierten Programmiersprache mit hierarchischem Typkonzept", B. Hindel, diss U Erlangen-Nuernberg, Dec 1987]. (1995-03-16) 1 1 1 1 1 here document Data included in a Unix shell script or Perl script using the "<<" syntax. (1995-04-19) 1 1 1 1 1 Herman Hollerith The promulgator of the punched card. Hollerith was born on 1860-02-29 and died on 1929-11-17. He graduated from Columbia University, NewYork, NY, USA. He joined the US Census Bureau as a statistician where he used a punched card device to help analyse the 1880 US census data. This punched card system stored data in 80 columns. This "80-column" concept has carried forward in various forms into modern applications. In 1896, Hollerith founded the Tabulating Machine Company to exploit his invention and in 1924 his firm became part of IBM. The Hollerith system was used for the 1911 UK census. A correspondant writes: Wasn't Hollerith's original machine first used for the 1990 US census? And I think I am right in saying that the physical layout was a 20x12 grid of round holes. The one I have seen (picture only, unfortunately, not the real thing) did not use 'columns' as such but holes were grouped into 1 1 1 1 1 Hermes An experimental, very high level, integrated language and system from the IBM Watson Research Centre, produced in June 1990. It is designed for implementation of large systems and distributed applications, as well as for general-purpose programming. It is an imperative language, strongly typed and is a process-oriented successor to NIL. Hermes hides distribution and heterogeneity from the programmer. The programmer sees a single abstract machine containing processes that communicate using calls or sends. The compiler, not the programmer, deals with the complexity of data structure layout, local and remote communication, and interaction with the operating system. As a result, Hermes programs are portable and easy to write. Because the programming paradigm is simple and high level, there are many opportunities for optimisation which are not present in languages which give the programmer more direct control over 1 1 1 1 1 Hesiod The name server of the Athena project. [Details?] (1997-10-27) 1 1 1 1 1 heterogeneous Composed of unrelated parts, different in kind. Often used in the context of distributed systems that may be running different operating systems or network protocols (a heterogeneous network). For examples see: interoperable database, middleware. Constrast homogeneous. (1999-05-06) 1 1 1 1 1 heterogeneous network A network running multiple network layer protocols such as DECnet, IP, IPX, XNS. (1997-10-27) 1 1 1 1 1 heterogenous It's spelled heterogeneous. (1999-06-10) 1 1 1 1 1 heuristic 1. <programming> A rule of thumb, simplification, or educated guess that reduces or limits the search for solutions in domains that are difficult and poorly understood. Unlike algorithms, heuristics do not guarantee optimal, or even feasible, solutions and are often used with no theoretical guarantee. 2. <algorithm> approximation algorithm. (2001-04-12) 1 1 1 1 1 heuristics testing failure-directed testing 1 1 1 1 1 Hewlett-Packard (HP) Hewlett-Packard designs, manufactures and services electronic products and systems for measurement, computation and communications. The company's products and services are used in industry, business, engineering, science, medicine and education in approximately 110 countries. HP was founded in 1939 and employs 96600 people, 58900 in the USA. They have manufacturing and R&D establishments in 54 cities in 16 countries and approximately 600 sales and service offices in 110 countries. Their revenue (in 1992/1993?) was $20.3 billion. The Chief Executive Officer is Lewis E. Platt. HP's stock is traded on the New York Stock Exchange and the Pacific, Tokyo, London, Frankfurt, Zurich and Paris exchanges. Quarterly sales $6053M, profits $347M (Aug 1994). (http://hp.com/home.html). (1994-09-26) 1 1 1 1 1 Hewlett-Packard Graphics Language (HP-GL) A vector graphics language used by HP plotters. [Details? On-line spec?] (1994-10-27) 1 1 1 1 1 Hewlett-Packard Interface Bus IEEE 488 1 1 1 1 1 Hewlett Packard Multi Processing Executive (HP-MPE) The standard operating system on all HP3000 minicomputers, in the same way that HP9000 computers run HP-UX. Latest version: MPE/IX Version 5.5.04, as of 1998-02-17. (1998-02-17) 1 1 1 1 1 Hewlett Packard Precision Architecture (HP-PA) Hewlett Packard's range of RISC processors. [Details?] (1995-02-22) 1 1 1 1 1 Hewlett-Packard Visual Engineering Environment (HP VEE) A package similar in intention to LabVIEW, running on Unix workstations under OSF/Motif. (1997-05-12) 1 1 1 1 1 hex 1. hexadecimal. 2. A 6-pack of anything (compare quad). Neither usage has anything to do with magic or black art, though the pun is appreciated and occasionally used by hackers. True story: As a joke, some hackers once offered some surplus ICs for sale to be worn as protective amulets against hostile magic. The chips were, of course, hex inverters. 3. <character> The hash character, used to introduce hexadecimal constants in some assembly languages. [Jargon File] (1995-03-06) 1 1 1 1 1 hexadecimal (Or "hex") Base 16. A number representation using the digits 0-9, with their usual meaning, plus the letters A-F (or a-f) to represent hexadecimal digits with values of (decimal) 10 to 15. The right-most digit counts ones, the next counts multiples of 16, then 16^2 = 256, etc. For example, hexadecimal BEAD is decimal 48813: digit weight value B = 11 16^3 = 4096 11*4096 = 45056 E = 14 16^2 = 256 14* 256 = 3584 A = 10 16^1 = 16 10* 16 = 160 D = 13 16^0 = 1 13* 1 = 13 1 1 1 1 1 hexidecimal Mis-spelling of "hexadecimal". (1998-03-03) 1 1 1 1 1 hexit /hek'sit/ A hexadecimal digit (0-9, and A-F or a-f). Used by people who claim that there are only *ten* digits, sixteen-fingered human beings being rather rare, despite what some keyboard designs might seem to imply (see space-cadet keyboard). [Jargon File] (1996-03-09) 1 1 1 1 1 HFC 1. <networking> Hybrid Fiber Coax. 2. <hardware> hydrofluorocarbon. (1999-11-02) 1 1 1 1 1 HHCP Host Host Copy 1 1 1 1 1 HHOJ ha ha only joking. Contrast ha ha only serious. (1998-01-18) 1 1 1 1 1 HHOK ha ha only kidding. See ha ha only serious. [Jargon File] 1 1 1 1 1 HHOS ha ha only serious 1 1 1 1 1 hi hmake interactive 1 1 1 1 1 HIBOL A variant of DIBOL, used in Infotec computers. HIBOL was considered to be a very high level language and significantly easier to maintain than COBOL. It uses a single type of data object, called a flow, which is an indexed stream of data values. Computation is expressed as operations acting on flows. Language List (http://people.ku.edu/~nkinners/LangList/Langs/H/HIBOL.htm). Translation of COBOL to HIBOL (http://dl.acm.org/citation.cfm?id=889862). ["HIBOL: a language for fast prototyping in data processing environments", Roland T. Mittermeir, Technische Universitaet Wien, Vienna, Austria, Proceedings of the workshop on Rapid Prototyping, ACM New York, NY, USA 1982, ISBN:0-89791-094-X, (http://dl.acm.org/citation.cfm?id=1006282)]. [R. T. Mittermeir, "HIBOL - A very High Level Business Oriented Language, User Manual", TR DA 81/04/04, Institut fuer 1 1 1 1 1 HID Human Interface Device 1 1 1 1 1 hidden flag (scientific computation) An extra option added to a routine without changing the calling sequence. For example, instead of adding an explicit input variable to instruct a routine to give extra diagnostic output, the programmer might just add a test for some otherwise meaningless feature of the existing inputs, such as a negative mass. The use of hidden flags can make a program very hard to debug and understand, but is all too common wherever programs are hacked in a hurry. [Jargon File] (1994-11-24) 1 1 1 1 1 hierarchical database A kind of database management system that links records together like a family tree such that each record type has only one owner, e.g. an order is owned by only one customer. Hierarchical structures were widely used in the first mainframe database management systems. However, due to their restrictions, they often cannot be used to relate structures that exist in the real world. 1 1 1 1 1 Hierarchical Data Format (HDF) A library and multi-object file format for the transfer of graphical and numerical data between computeres. The freely available HDF distribution consists of the library, command line utilities, test suite source, Java interface, and the Java-based HDF Viewer (JHV). HDF supports several different data models, including multidimensional arrays, raster images, and tables. Each defines a specific aggregate data type and provides an API for reading, writing, and organising the data and metadata. New data models can be added by the HDF developers or users. HDF is self-describing, allowing an application to interpret the structure and contents of a file without any outside information. One HDF file can hold a mixture of related objects which can be accessed as a group or as individual objects. Users can create their own grouping structures called "vgroups". HDF files can be shared across most common platforms, 1 1 1 1 1 Hierarchical Design Methodology (HDM) A method for specifying software and systems using hierarchies of abstract machines, developed by Larry Robinson at SRI International circa 1975-1976. The specifications were written in SPECIAL. (2012-07-08) 1 1 1 1 1 hierarchical file system A file system in which the files are organised into a hierarchy. The nodes of the hierarchy are called directories while the leaves are the files themselves. See also root directory. Compare flat file system. (1996-11-21) 1 1 1 1 1 Hierarchical Music Specification Language (HMSL) A programming language for experimental music composition and performance. It is a set of object-oriented extensions to Forth. (Its near-total unintelligibility to people unfamiliar with Forth has led some to expand "HMSL" as "Her Majesty's Secret Language".) Phil Burk (who also later developed pForth), Larry Polansky, and David Rosenboom started developing HMSL in 1980 while working at the Mills College Center for Contemporary Music (http://mills.edu/LIFE/CCM/CCM.homepage.html). As of June 1998, development is ongoing. (http://softsynth.com/hmsl/). (1998-09-07) 1 1 1 1 1 hierarchical navigation On a web page, any type of menu whose hierarchical structure matches that of the site to which the page belongs. A hierarchical navigation menu allows the user to jump ("navigate") directly to a section of the site several levels below the top. The menu may present only a fixed number of levels rather than the whole structure. (2003-10-01) 1 1 1 1 1 Hierarchical Object Oriented Design (HOOD) An architectural design method, primarily for Ada, leading to automated checking, documentation and source code generation. (2009-01-14) 1 1 1 1 1 hierarchical routing The complex problem of routing on large networks can be simplified by breaking a network into a hierarchy of smaller networks, where each level is responsible for its own routing. The Internet has, basically, three levels: the backbones, the mid-levels, and the stub networks. The backbones know how to route between the mid-levels, the mid-levels know how to route between the sites, and each site (being an autonomous system) knows how to route internally. See also Exterior Gateway Protocol, Interior Gateway Protocol, transit network. 1 1 1 1 1 hierarchy An organisation with few things, or one thing, at the top and with several things below each other thing. An inverted tree structure. Examples in computing include a directory hierarchy where each directory may contain files or other directories; a hierarchical network (see hierarchical routing), a class hierarchy in object-oriented programming. (1994-10-11) 1 1 1 1 1 Higgs Bugson A hypothetical bug predicted to exist based on a small number of possibly related event log entries and vague anecdotal user reports. The Higgs Bugson is difficult to reproduce because you don't really know if it's there, and if it is there what is causing it. To find one you will need a Large Hadron Debugger. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-08-31) 1 1 1 1 1 high bit (Or "high-order bit") The most significant bit in a byte. See also meta bit, hobbit, dread high bit disease. [Jargon File] (2012-08-31) 1 1 1 1 1 High bit-rate Digital Subscriber Line (HDSL) A form of Digital Subscriber Line, providing T1 or E1 connections over two or three twisted-pair copper lines, respectively. Unlike most other forms of DSL HDSL is not a typical consumer service, it's used mostly to replace traditional T1/E1 connections, such as connecting PBXes to telco offices. The advantage of HDSL over the Alternate Mark Inversion line coding scheme traditionally used on T1/E1 lines is that it requires about an order of magnitude lower bandwidth to carry the same traffic. (1998-05-18) 1 1 1 1 1 high colour A colour depth of 16 (or 15) bits per pixel. Compare true colour. (1999-08-01) 1 1 1 1 1 High-Definition Multimedia Interface (HDMI) an industry standard for connecting digital audio and video devices via a single cable. HDMI can connect any audio/video source, such as a set-top box, DVD player, or A/V receiver to an audio and/or video output device such as a digital television (DTV). HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio. It transmits all ATSC HDTV standards and supports 8-channel, 192kHz, uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS), HDMI 1.3 adds additional support for new lossless digital audio formats Dolby TrueHD and DTS-HD Master Audio with bandwidth to spare to accommodate future enhancements. HDMI 1.4 incorporates connection via Ethernet. HDMI was created by Hitachi, Panasonic Corporation, Philips, Sony, Thomson (RCA), Toshiba and Silicon Image and has the support of several major motion picture 1 1 1 1 1 high density floppy disk 1 1 1 1 1 Higher Education National Software Archive (HENSA) (http://hensa.ac.uk/). (1995-01-06) 1 1 1 1 1 higher-order function (HOF) A function that can take one or more functions as argument and/or return a function as its value. E.g. map in (map f l) which returns the list of results of applying function f to each of the elements of list l. See also curried function. 1 1 1 1 1 higher-order macro A means of expressing certain higher-order functions in a first order language. Proposed by Phil Wadler. Higher-order macros cannot be recursive at the top level but they may contain recursive definitions. E.g. map f l = m l where m [] = [] m (x:xs) = f x : m xs Expanding a call to this macro is equivalent to specialising a 1 1 1 1 1 High-level Data Link Control (HDLC) A general-purpose data link control protocol defined by ISO for use on both point-to-point and multipoint (multidrop) data links. It supports full-duplex, transparent-mode operation. It is used extensively in both multipoint and computer networks. Some manufacturers and other standards bodies still use their own acronyms, e.g. IBM's SDLC (Synchronous Data Link Control), the forerunner of HDLC and ANSI's ADCCP (Advanced Data Communications Control Procedure). [Fred Halsall, "Data Communications, Computer Networks and Open Systems" 4th edition, 1996, p.237, Addison-Wesley Publishing Co. Reading, Mass., USA]. (1997-11-09) 1 1 1 1 1 high-level language (HLL) A programming language which provides some level of abstraction above assembly language. These normally use statements consisting of English-like keywords such as "FOR", PRINT or "GOTO", where each statement corresponds to several machine language instructions. It is much easier to program in a high-level language than in assembly language though the efficiency of execution depends on how good the compiler or interpreter is at optimising the program. Rarely, the variants "VHLL" and "MLL" are found. See also languages of choice, generation. (1994-12-07) 1 1 1 1 1 high memory area (HMA) The first 64 kilobytes (minus 16 byte) of the extended memory on an IBM PC. By a strange design glitch the Intel 80x86 processors can actually address 17*64 kbyte minus 16 byte of memory (from 0000:0000 to ffff:ffff) in real mode. In the Intel 8086 and Intel 8088 processors, unable to handle more than 1 megabyte of memory, addressing wrapped around, that is, address ffff:0010 was equivalent to 0000:0000. For compatibility reasons, later processors still wrapped around by default, but this feature could be switched off. Special programs called A20 handlers can control the addressing mode dynamically, thereby allowing programs to load themselves into the 1024--1088 kbyte region and run in real mode. From version 5.0 parts of MS-DOS can be loaded into HMA as well freeing up to 46 kbytes of conventional memory. (1995-01-10) 1 1 1 1 1 high moby /hi:' mohb'ee/ The high half of a 512K PDP-10's physical address space; the other half was of course the low moby. This usage has been generalised in a way that has outlasted the PDP-10; for example, at the 1990 Washington D.C. Area Science Fiction Conclave (Disclave), when a miscommunication resulted in two separate wakes being held in commemoration of the shutdown of MIT's last ITS machines, the one on the upper floor was dubbed the "high moby" and the other the "low moby". All parties involved grokked this instantly. See moby. [Jargon File] 1 1 1 1 1 High Performance Computing and Communications (HPCC) High performance computing includes scientific workstations, supercomputer systems, high speed networks, special purpose and experimental systems, the new generation of large scale parallel systems, and application and systems software with all components well integrated and linked over a high speed network. ["Grand Challenges 1993: High Performance Computing and Communications", Committee on Physical, Mathematical and Engineering Sciences of the Federal Coordinating Council for Science, Engineering and Technology.] 1 1 1 1 1 High Performance File System (HPFS) The native file system for IBM's OS/2. (1995-03-06) 1 1 1 1 1 High Performance Fortran (HPF) A data parallel language extension to Fortran 90 which provides a portable programming interface for a wide variety of target platforms. The original HPF language specification was produced by the High Performance Fortran Forum, a broad consortium of industry and academia, which met regularly throughout 1992 and early 1993. HPF compilers are now available on most commonly-used computing systems, and users are beginning to gain first hand experience with this language. The Forum has continued to meet in order to address advanced topics. HPF+ at Vienna (http://par.univie.ac.at/hpf+/). ["High Performance Fortran: Status Report", G.L. Steele Jr <gls@think.com>, SIGPLAN Notices 28(1):1-4 (Jan 1993)]. (1996-09-09) 1 1 1 1 1 High Performance Parallel Interface (HIPPI, previously HPPI) A connection-oriented, point-to-point networking standard using circuit-switching technology at a speed of 800 Mbits/s or 1.6 Gbits/s (simplex or full-duplex). HIPPI is often used for short distances (up to 10km depending on cable type) to connect a supercomputer to routers, frame buffers, mass-storage peripherals and other computers. HIPPI was developed at Los Alamos National Laboratory and is now ANSI standard X3T9/88-127. Standards for interconnecting with ATM, SONet, and fibre channel are in development. HIPPI Networking Forum (http://esscom.com/hnf). (1997-06-29) 1 1 1 1 1 High Performance Routing (HPR) Routing designed to work in conjunction with APPN Intermediate Session Routing (ISR) network nodes. HPR nodes perform many of the same functions as ISR nodes. For example, HPR nodes use the same method of calculating routes based on the Topology Routing Service database and class of service tables. HPR nodes also supports such APPN features as connection networks and support for parallel transmission groups (TGs). In the HPR architecture, both partner nodes must support HPR for RTP connections to take place between the nodes. If one node supports HPR and the partner node does not, then the link will support ISR functionality only. ["APPN Architecture and Product Implementations Tutorial", IBM, GG24-3669-92]. (1997-05-08) 1 1 1 1 1 High Performance Serial Bus (Or "IEEE 1394") A 1995 Macintosh/IBM PC serial bus interface standard offering isochronous real-time data transfer. 1394 can transfer data between a computer and its peripherals at 100, 200, or 400 Mbps, with a planed increase to 2 Gbps. Cable length is limited to 4.5 m but up to 16 cables can be daisy-chained yielding a total length of 72 m. It can daisy-chain together up to 63 peripherals in a tree-like structure (as opposed to SCSI's linear structure). It allows peer-to-peer communication, e.g. between a scanner and a printer, without using system memory or the CPU. It is designed to support plug-and-play and hot swapping. Its six-wire cable is not only more convenient than SCSI cables but can supply up to 60 watts of power, allowing low-consumption devices to operate without a separate power cord. Some expensive camcorders included this bus from 1995. It is expected to be used to carry SCSI, with possible application to 1 1 1 1 1 High Speed Circuit Switched Data (HSCSD) A planned feature of GSM Phase 2 defining a standard for circuit switched data transmission over a GSM link at up to 57.6 (78.8?) kbps. This is achieved by concatenating up to four consecutive GSM timeslots, each of which is capable of 14.4 kbit/s. It uses multiplexing and compression or filtering. The following services toward the fixed network are supported: V.34 up to 28.8 kbps and V.110 with rate adaptation up to 38.4 kbps. HSCSD is aimed at mobile workstation users. As it is circuit switched, it is suited to streaming applications such as video conferencing and multimedia. Bursty applications like electronic mail, are more suited to packet switched data (as in GPRS). Ericsson (http://ericsson.com/wireless/products/mobsys/gsm/subpages/wise/subpages/hscsd.shtml). (http://gsmworld.com/). 1 1 1 1 1 High Speed Connect (HSC) A Hewlett-Packard bus like EISA. [HP9000 Configuration Guide, January 1996]. [Details?] (1996-06-06) 1 1 1 1 1 High-speed Net Connect (HNC) A network interface unit for BS2000 mainframes based on Novell NetWare, supporting Ethernet and FDDI. (2005-02-11) 1 1 1 1 1 high speed serial interface (HSSI) A serial port which supports serial transmit speeds of up to 52 megabits per second. It is typically used for leased lines such as DS3 (44.736 Mbps) and E3 (34 Mbps) and for Wide Area Network devices such as routers. (1995-11-20) 1 1 1 1 1 High Voltage Differential (HVD) Differential SCSI scheme that has been in use for years. The terminators run on 5 Volts DC. See also LVD. (1999-02-16) 1 1 1 1 1 HIGZ High Level Interface to Graphics and Zebra. Part of the PAW system. 1 1 1 1 1 hill climbing A graph search algorithm where the current path is extended with a successor node which is closer to the solution than the end of the current path. In simple hill climbing, the first closer node is chosen whereas in steepest ascent hill climbing all successors are compared and the closest to the solution is chosen. Both forms fail if there is no closer node. This may happen if there are local maxima in the search space which are not solutions. Steepest ascent hill climbing is similar to best first search but the latter tries all possible extensions of the current path in order whereas steepest ascent only tries one. (1995-12-09) 1 1 1 1 1 HiLog A higher-order logic programming language. An extension of normal logic programming where predicate symbols may be variable or structured. This allows unification to be performed on the predicate symbols themselves in addition to their arguments. (ftp://sbcs.sunysb.edu/SB-hilog). ["HiLog as a Platform for Database Languages (Or Why Predicate Calculus is Not Enough)", W. Chen et al, Stony Brook, 2nd Intl Workshop on Database Prog Langs, Morgan Kaufmann, 1989]. (1994-12-07) 1 1 1 1 1 HIMEM An IBM PC extended memory manager, part of MS-DOS version 5.00 or higher. HIMEM can also act as an A20 handler. (1996-01-10) 1 1 1 1 1 Hindenbug A catastrophic, data-destroying bug, after the 1937 Hindenburg airship disaster. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-10-20) 1 1 1 1 1 hing (IRC) Fortuitous typo for "hint", now in wide intentional use among players of initgame. Compare newsfroup, filk. [Jargon File] (1994-12-07) 1 1 1 1 1 HINT Hierarchical Information NeTs. A language for the CDC 3600. ["HINT: A Graph Processing Language", R.D. Hart, Michigan State U, Apr 1970]. (1994-12-07) 1 1 1 1 1 HiPAC An active DBMS from Xerox Advanced Information Technology. 1 1 1 1 1 HIPPI High Performance Parallel Interface 1 1 1 1 1 hiragana The cursive formed Japanese kana syllabary. Hiragana is mostly used for grammatical particles, verb-inflection, and Japanese words which are not written in kanji or which are too difficult for an educated person to read or write in kanji. Hiragana are also used for furigana. (2001-03-18) 1 1 1 1 1 hirsute Occasionally used as a humorous synonym for hairy. [Jargon File] 1 1 1 1 1 HISTORIAN A source code management system sold by OPCODE, Inc. 1 1 1 1 1 history 1. <history> Virginia Tech history of computing (http://ei.cs.vt.edu/~history/index.html). IT Rentals computing timeline (http://www.itrentals.com/historyofcomputing/). 2. <operating system> A record of previous user inputs (e.g. to a command interpreter) which can be re-entered without re-typing them. The major improvement of the C shell (csh) over the Bourne shell (sh) was the addition of a command history. This was still inferior to the history mechanism on VMS which allowed you to recall previous commands as the current input line. You could then edit the command using cursor motion, insert and delete. These sort of history editing facilities are available under tcsh and GNU Emacs. 3. The history of the world was once discussed in Usenet newsgroups news:soc.history and news:alt.history. (2013-08-04) 1 1 1 1 1 hit 1. <architecture> cache hit. 2. <web> A request to a web server from a web browser or other client (e.g. a robot). The number of hits on a server may be important for determining advertising revenue. In the course of loading a single web page, a browser may hit a web server many times e.g. to retrieve the page itself and each image on the page. In contrast, caching by browsers and web proxies reduces the number of hits on the server because some requests are satisfied from the cache. 3. <jargon> To press and release a key on the keyboard. Some prefer the less aggressive "tap". (2000-02-20) 1 1 1 1 1 Hitachi 6309 (HD6309) Hitachi's version of the Motorola 6809 microprocessor. Compatible with the 6809, it added two new eight-bit registers that could be added to form a second 16-bit register, and all four eight-bit registers could form a 32-bit register. It also featured division, and some 32-bit arithmetic and was generally 30% faster in native mode. This information, surprisingly, was never published by Hitachi. Technical reference (http://sandelman.ottawa.on.ca/People/Alan_DeKok/interests/6309.techref). (1997-03-21) 1 1 1 1 1 Hitachi HD64180 A processor family which adds peripherals and an MMU to the Zilog Z80. (1995-10-06) 1 1 1 1 1 HITL Human Interface Technology Laboratory 1 1 1 1 1 hit rate The fraction of all memory reads which are satisfied from the cache. (1997-01-21) 1 1 1 1 1 hk The country code for Hong Kong. (1999-01-27) 1 1 1 1 1 HL7 An information exchange protocol used in medicine, and possibly elsewhere. It is different from DICOM. [Details?] (1998-12-23) 1 1 1 1 1 HLISP Monocopy and Associative Algorithms in an Extended Lisp, E. Goto, U Tokyo May 1974. 1 1 1 1 1 HLL high-level language 1 1 1 1 1 HLLAPI High Level Language Application Programming Interface 1 1 1 1 1 hlp A Microsoft Windows filename extension for hypertext WinHelp files. These are in a proprietary format, and are compiled from source files written in a dialect of RTF. See also gid. Usenet newsgroup: news:comp.os.ms-windows.programmer.winhelp. (1997-01-30) 1 1 1 1 1 hm The country code for the Heard and McDonald Islands. (1999-01-27) 1 1 1 1 1 HMA High Memory Area 1 1 1 1 1 HMAC Keyed-Hashing Message Authentication 1 1 1 1 1 hmake A compilation manager for Haskell. hmake recompiles a given module or program by extracting dependencies between source modules and issuing appropriate compiler commands to rebuild only changed modules. hmake can use whatever Haskell compilers and preprocessors you have installed. If an .hi interface file is unchanged then changes in the corresponding implementation code will not trigger recompilation of calling code. hmake interactive is an interactive development environment built on hmake. Malcolm Wallace of the York Functional Programming Group developed hmake in 2005 based on Thomas Hallgren's hbcmake and nhc13make. hmake home (http://www.cs.york.ac.uk/fp/hmake/hmake.html). (2009-11-24) 1 1 1 1 1 HMP hybrid multiprocessing 1 1 1 1 1 HMSL Hierarchical Music Specification Language 1 1 1 1 1 HMTL Do you mean HTML? (1998-06-30) 1 1 1 1 1 hn The country code for Honduras. (1999-01-27) 1 1 1 1 1 HNC High-speed Net Connect 1 1 1 1 1 HO handover 1 1 1 1 1 Hoare powerdomain powerdomain 1 1 1 1 1 Hobbit A Scheme to C compiler by Tanel Tammet <tammet@cs.chalmers.se>. Hobbit attempts to retain most of the original Scheme program structure, making the output C program readable and modifiable. Hobbit is written in Scheme and is able to self-compile. Hobbit release 1 works together with the scm release scm4b3. Future releases of scm and hobbit will be coordinated. Latest version: release 2. (ftp://altdorf.ai.mit.edu/archive/scm/hobbit2.tar.Z). (1993-04-25) 2. The non-ITS name of <vad@ai.mit.edu> (*Hobbit*), master of lasers. 1 1 1 1 1 hobbit High order bit. The most significant bit (of a byte). Also known as the meta bit or high bit. [Jargon File] 1 1 1 1 1 hog A term used to describe programs, hardware or people that use more than their share of a system's resources, especially those which noticeably degrade interactive response. The term is usually qualified, e.g. "memory hog", "core hog", "hog the processor", "hog the disk". E.g. "A controller that never gives up the I/O bus gets killed after the bus-hog timer expires." User also hog resources, particularly disk, where it seems that 10% of the people use 90% of the disk, no matter how big the disk is or how many people use it. Once a disk hog fills up one file system, he typically finds a new one to consume, claiming to the sysadmin that they have an important new project to complete. (2014-08-16) 1 1 1 1 1 HOL Higher Order Logic. A proof-generating system for higher order logic based on LCF. Implementations include HOL-88 and HOL-90. (ftp://ted.cs.uidaho.edu/pub/hol). Mailing list: info-hol@ted.cs.uidaho.edu. ["HOL: A Machine Oriented Formulation of Higher Order Logic", M.J.C. Gordon, Report 68, Comp Lab U Cambridge (1985)]. ["Introduction to HOL", M.J.C. Gordon et al, Cambridge U Press 1993 ISBN 0-521-441897]. 1 1 1 1 1 HOL-88 An implementation of HOL built on ML by Mike Gordon <mjcg@cl.cam.ac.uk>. 1 1 1 1 1 HOL-90 An implementation of HOL built on SML/NJ by Brian Graham <graham@cpsc.ucalgary.ca>. Runs on Sun-4. (ftp://fsa.cpsc.ucalgary.ca/pub/hol90.tar.Z). Mailing list: info-hol@clover.ucdavis.edu. 1 1 1 1 1 hole 1. <electronics> In the hole model of current flow, the absence of an electron, e.g. in a semiconductor material. In the electron model, a hole can be thought of as an incomplete outer electron shell in a doping substance. Considering holes as positive charge carriers is a useful abstraction. 2. <security> A security vulnerability, particularly one which allows an attacker to gain unauthorised access to a system (by analogy with a hole in a wall). (2014-10-25) 1 1 1 1 1 hole model A model of semiconductor behaviour in which donors contribute a positive charge equal in magnitude to the charge of an electron, and acceptors contribute space for such a charge within the crystal lattice. The hole model was proposed well before electrons were discovered and described. Much of electronics, especially at the engineering level, continues to consider current as flowing from positive to negative. (1995-10-05) 1 1 1 1 1 Hollerithabetical order Sorted into the order a standard Hollerith card sorting machine produces, with special characters interleaved within the alphabet. (1997-02-11) 1 1 1 1 1 Hollerith, Herman Herman Hollerith 1 1 1 1 1 Hollywired Siliwood 1 1 1 1 1 HOL-UNITY A verification tool for UNITY? Version 2.1. E-mail: Flemming Andersen <fa@tfl.dk>? 1 1 1 1 1 holy wars [Usenet, but may predate it] flame wars over religious issues. The paper by Danny Cohen that popularised the terms big-endian and little-endian was entitled "On Holy Wars and a Plea for Peace". Other perennial Holy Wars have included Emacs vs. vi, my personal computer vs. everyone else's personal computer, ITS vs. Unix, Unix vs. VMS, BSD Unix vs. USG Unix, C vs. Pascal, C vs. Fortran, etc., ad nauseam. The characteristic that distinguishes holy wars from normal technical disputes is that in a holy wars most of the participants spend their time trying to pass off personal value choices and cultural attachments as objective technical evaluations. See also theology. [Jargon File] 1 1 1 1 1 home 1. <file system> home directory. 2. <web> home page. 3. <hardware> home keys. 1 1 1 1 1 home box A hacker's personal machine, especially one he or she owns. "Yeah? Well, *my* home box runs a full 4.2BSD, so there!" (2006-12-01) 1 1 1 1 1 home keys The eight keys on a typewriter or computer keyboard on which a touch-typist positions their eight finger tips when starting to type or when resting between words or phrases. Typists learn the position of all keys on the keyboard in relation to the home keys. On a standard english keyboard layout, the home keys are ASDF for the left hand and JKL; for the right. Most keyboards have small raised bumps on the left and right index finger keys (F and J) so you can find the home keys by touch without looking. (2006-12-01) 1 1 1 1 1 home machine 1. Synonym home box. 2. The machine that receives your e-mail. These senses might be distinct, for example, for a hacker who owns one computer at home, but reads e-mail at work. [Jargon File] (2006-12-01) 1 1 1 1 1 home page 1. The top-level entry point web page relating to an individual or institution, or possibly a subject area. This often has a URL consisting of just a hostname, e.g. http://ncsa.uiuc.edu/. All other pages on a website are usually accessible by following links from the home page. 2. The web page a user's web browser is configured to load each time it is started. This will typically default to the home page (sense 1) of the organisation that produced or distributed the browser. (1999-03-21) 1 1 1 1 1 Home Phoneline Networking Alliance (HomePNA) A non-profit association of more than 100 technology companies working together to ensure adoption of a phone line networking standard which should provide high-speed, affordable home networking. The Home Phoneline Networking Alliance (HomePNA) was founded in June 1998 by 3Com, AMD, AT&T Wireless Services, Compaq, Conexant, Epigram, Hewlett-Packard, IBM, Intel, Lucent Technologies, Rockwell Semiconductor Systems, and Tut Systems. The membership now spans the networking, telecommunications, hardware, software, and consumer electronics industries. The alliance was originally formed because of the increasing demand for home networking caused by the growing number of homes with multiple PCs (and other devices) to connect together to provide facilities such as shared Internet access, networked gaming, and sharing of peripherals, 1 1 1 1 1 HomePNA Home Phoneline Networking Alliance 1 1 1 1 1 home row keys home keys 1 1 1 1 1 homogeneous (Or "homogenous") Of uniform nature, similar in kind. 1. In the context of distributed systems, middleware makes heterogeneous systems appear as a homogeneous entity. For example see: interoperable network. Constrast heterogeneous. 2. <mathematics> (Of a polynomial) containing terms of the same degree with respect to all the variables, as in x^2 + 2xy #NAME? 3. <mathematics> (Of a function) containing a set of variables such that when each is multiplied by a constant, this constant can be eliminated without altering the value of the function, as in cos x/y + x/y. 4. <mathematics> (of an equation) containing a homogeneous function made equal to 0. (1999-05-06) 1 1 1 1 1 homogenous homogeneous 1 1 1 1 1 homomorphism A map f between groups A and B is a homomorphism of A into B if f(a1 * a2) = f(a1) * f(a2) for all a1, a2 in A. where the *s are the respective group operations. (2009-01-14) 1 1 1 1 1 Honeywell A US company known for its mainframes and operating systems. The company's history is long and tortuous, with many mergers, acquisitions and name changes. A company formed on 1886-04-23 to make furnace regulators eventually merged in 1927 with another company formed in 1904 by a young plumbing and heating engineer named Mark Honeywell who was perfecting the heat generator. A 1955 joint venture with Raytheon Corp., called Datamatic Corporation, marked Honeywell's entry into the computer business. Their first computer was the D-1000. In 1960 Honeywell bought out Raytheon's interest and the name changed to Electronic Data Processing (EDP) then in 1963 it was officially renamed Honeywell Inc. In 1970 Honeywell merged its computer business with General Electric's to form Honeywell Information Systems. In 1986 a joint venture with the french company Bull and japanese NEC 1 1 1 1 1 Honeywell-800 Business Compiler Fully Automated Compiling Technique 1 1 1 1 1 HOOD Hierarchical Object Oriented Design 1 1 1 1 1 HOOK ? Object Oriented Kernel. Delphia. An object-oriented extension of Delphia Prolog. [Jargon File] 1 1 1 1 1 hook A software or hardware feature included in order to simplify later additions or changes by a user. For example, a simple program that prints numbers might always print them in base 10, but a more flexible version would let a variable determine what base to use; setting the variable to 5 would make the program print numbers in base 5. The variable is a simple hook. An even more flexible program might examine the variable and treat a value of 16 or less as the base to use, but treat any other number as the address of a user-supplied routine for printing a number. This is a hairy but powerful hook; one can then write a routine to print numbers as Roman numerals, say, or as Hebrew characters, and plug it into the program through the hook. Often the difference between a good program and a superb one is that the latter has useful hooks in judiciously chosen places. Both may do the original job about equally well, but the one with the hooks is much more flexible for future 1 1 1 1 1 hop 1. <messaging> One point-to-point transmission in a series required to get a message from point A to point B on a store and forward network. On such networks (including UUCPNET and FidoNet), an important inter-machine metric is the hop count of the shortest path between them. This can be more significant than their geographical separation. Each exclamation mark in a bang path represents one hop. 2. <networking> One direct host-to-host connection forming part of the route between two hosts in a routed network such as the Internet. Some protocols place an upper limit on the hop count in order to detect routing loops. 3. <jargon, networking> To log in to a remote computer, especially via rlogin or telnet. "I'll hop over to foovax to FTP that." [Jargon File] (1997-06-25) 1 1 1 1 1 Hope A functional programming language designed by R.M. Burstall, D.B. MacQueen and D.T. Sanella at University of Edinburgh in 1978. It is a large language supporting user-defined prefix, infix or distfix operators. Hope has polymorphic typing and allows overloading of operators which requires explicit type declarations. Hope has lazy lists and was the first language to use call-by-pattern. It has been ported to Unix, Macintosh, and IBM PC. See also Hope+, Hope+C, Massey Hope, Concurrent Massey Hope. (ftp://brolga.cc.uq.oz.au/pub/hope). [R.M.Burstall, D.B.MacQueen, D.T.Sanella, "HOPE: An experimental applicative language", Proc. 1980 Lisp conf., Stanford, CA, p.136-143, Aug 1980]. ["A HOPE Tutorial", R. Bailey, BYTE Aug 1985, pp.235-258]. ["Functional Programming with Hope", R. Bailey, Ellis Horwood 1990]. 1 1 1 1 1 Hope+ An extension of Hope implemented in the Alvey Flagship project at Imperial College. Hope+ has vectors, real numbers, best fit pattern matching, lazy data constructors, absolute set abstractions and constraints. It has a continuation-based I/O system with referential transparency and is capable of handling all common I/O tasks such as terminal and file I/O, signal handling and interprocess communications. It has modules and separate compilation. See also Hope+C, Massey Hope, Concurrent Massey Hope. ["Hope+", N. Perry, Imperial College, IC/FPR/LANG/2.5.1/7, 1988.] (1999-08-24) 1 1 1 1 1 Hope+C A further evolution of Hope+ with continuation-based I/O, coroutines, and RFCs. Hope+C was developed as part of the Flagship project at Imperial College. It has been implemented for Sun-3s with Motorola FPUs. See also Massey Hope, Concurrent Massey Hope. E-mail: John Darlington <jd@doc.ic.ac.uk>. [What kind of RFCs?] (1999-06-23) 1 1 1 1 1 Hopfield model Hopfield network 1 1 1 1 1 Hopfield network (Or "Hopfield model") A kind of neural network investigated by John Hopfield in the early 1980s. The Hopfield network has no special input or output neurons (see McCulloch-Pitts), but all are both input and output, and all are connected to all others in both directions (with equal weights in the two directions). Input is applied simultaneously to all neurons which then output to each other and the process continues until a stable state is reached, which represents the network output. (1997-10-11) 1 1 1 1 1 horizontal application An application program common to different business processes, e.g. office automation. Compare vertical application. (1994-12-12) 1 1 1 1 1 horizontal encoding An instruction set where each field (a bit or group of bits) in an instruction word controls some functional unit or gate directly, as opposed to vertical encoding where instruction fields are decoded (by hard-wired logic or microcode) to produce the control signals. Horizontal encoding allows all possible combinations of control signals (and therefore operations) to be expressed as instructions whereas vertical encoding uses a shorter instruction word but can only encode those combinations of operations built into the decoding logic. An instruction set may use a mixture of horizontal and vertical encoding within each instruction. Because an architecture using horizontal encoding typically requires more instruction word bits it is sometimes known as a very long instruction word (VLIW) architecture. (1995-04-23) 1 1 1 1 1 horizontal loop combination tupling 1 1 1 1 1 horizontal microcode Microcode using horizontal encoding. (1995-04-23) 1 1 1 1 1 horizontal scan rate (HSR) The measure of how many scan lines of pixels a monitor can display in one second, expressed in kHz (generally somewhere between 20 and 100 kHz). The HSR is controlled by the horizontal sync signal generated by the video controller, but is limited by the speed with which the monitor can scan the electron beam horizontally across the screen and then return it to the beginning of the next line. (1996-02-09) 1 1 1 1 1 horizontal tabulation (tab, Control-I, HT, ASCII 9) A character which when displayed or printed causes the following character to be placed at the next "tabstop" - the column whose number is a multiple of the current tab width. Commonly (especially in Unix(?)) the tab width is eight, so, counting from the left margin (column zero), the tab stops are at columns 8, 16, 24, up to the width of the screen or page. A tab width of four or two is often preferred when indenting program source code to conserve indentation. Represented as "\t" in C, Unix, and derivatives. (1999-07-05) 1 1 1 1 1 Horn clause A set of atomic literals with at most one positive literal. Usually written L <- L1, ..., Ln or <- L1, ..., Ln where n>=0, "<-" means "is implied by" and comma stands for conjuction ("AND"). If L is false the clause is regarded as a goal. Horn clauses can express a subset of statements of first order logic. The name "Horn Clause" comes from the logician Alfred Horn, who first pointed out the significance of such clauses in 1951, in the article "On sentences which are true of direct unions of algebras", Journal of Symbolic Logic, 16, 14-21. A definite clause is a Horn clause that has exactly one positive literal. 1 1 1 1 1 hose 1. To make non-functional or greatly degraded in performance. That big ray-tracing program really hoses the system. See hosed. 2. A narrow channel through which data flows under pressure. Generally denotes data paths that represent performance bottlenecks. 3. Cabling, especially thick Ethernet cable. This is sometimes called "bit hose" or "hosery" (a play on "hosiery") or "etherhose". See also washing machine. [Jargon File] 1 1 1 1 1 hosed A somewhat humorous variant of "down", used primarily by Unix hackers. "Hosed" implies a condition thought to be relatively easy to reverse. It is also widely used of people in the mainstream sense of "in an extremely unfortunate situation". The term was popularised by fighter pilots refering to being hosed by machine gun fire (date?). Usage in hackerdom dates back to CMU in the 1970s or earlier. "Acronyms and Abbreviations" from UCC, Ireland (http://ucc.ie/cgi-bin/acronym) expands it as "Hardware Or Software Error Detected", though this is probably a back-formation. The Jargon File version 4.1.4 1999-06-17 says that it was probably derived from the Canadian slang "hoser" (meaning "a man, esp. one who works at a job that uses physical rather than mental skills and whose habits are slightly offensive but amusing"). 1 1 1 1 1 HOS-STPL Hospital Operating System - STructured Programming Language. A Fortran-like language with structured extensions. ["HOS-STPL User Manual", Health Services Research, US Public Health Service (Jan 1975)]. 1 1 1 1 1 host 1. <networking> A computer connected to a network. The term node includes devices such as routers and printers which would not normally be called "hosts". 2. <communications> A computer to which one connects using a terminal emulator. (1995-02-16) 1 1 1 1 1 host adaptor SCSI adaptor 1 1 1 1 1 Host Command Facility (HCF) Used to access IBM S/36 and AS/400 computers from a mainframe. [What is it?] (1999-01-24) 1 1 1 1 1 Host Control Interface (HCI) A network layer in the Bluetooth Core Protocol Stack, lying between the software and the hardware stacks and serving as the interface through which the software controls two of Bluetooth's four core protocols. (2002-06-28) 1 1 1 1 1 host-host layer transport layer 1 1 1 1 1 hosting web hosting 1 1 1 1 1 hostname 1. (Or "sitename"). The unique name by which a computer is known on a network, used to identify it in electronic mail, Usenet news, or other forms of electronic information interchange. On the Internet the hostname is an ASCII string, e.g. "foldoc.doc.ic.ac.uk" which, consists of a local part (foldoc) and a domain name (doc.ic.ac.uk). The hostname is translated into an Internet address either via the hosts file, NIS or by the Domain Name System (DNS) or resolver. It is possible for one computer to have several hostnames (aliases) though one is designated as its canonical name. It is often possible to guess a hostname for a particular institution. This is useful if you want to know if they operate network services like anonymous FTP, World-Wide Web or finger. First try the institution's name or obvious abbreviations thereof, with the appropriate domain appended, 1 1 1 1 1 host number The host part of an Internet address. The rest is the network number. (1994-10-27) 1 1 1 1 1 hosts file A text file on a networked computer used to associate host names with IP addresses. A hosts file contains lines consisting of whitespace-separated fields giving an IP address followed by list of host names or aliases associated with that address. The name resolution library software can use this file to look up the IP address for a host name. The hosts file is "/etc/hosts" on Unix and C:\Windows\System32\drivers\etc\hosts or "lmhosts" on Microsoft Windows, In most cases, hosts files have now been almost entirely replaced by DNS, in which distributed servers provide the same information. A hosts file can still be used to override DNS for testing purposes or other special situations. (2007-05-09) 1 1 1 1 1 Hot Fix Novell, Inc.'s term for the feature of their network file server operating system, Novell NetWare, which handles errors in disk write operations. The OS re-reads every block it writes to disk while it holds the data to be written in memory. In the case of an error, the data block is written to a spare area on the disk. The feature lost much of its importance with the widespread use of hard disk drives with built-in error correction and bad block re-mapping. (1997-05-27) 1 1 1 1 1 HotJava A modular, extensible web browser from Sun Microsystems that can execute programs written in the Java programming language. These programs, known as "applets", can be included (like images) in HTML pages. Because Java programs are compiled into machine independent bytecodes, applets can run on any platform on which HotJava runs - currently (December 1995) SPARC/Solaris 2 and Intel 80x86/Windows 95, Windows NT. (http://java.sun.com/hotjava.html). (1995-12-10) 1 1 1 1 1 Hotline 1. <company> Hotline Communications Ltd.. 2. <messaging> Hotline Connect. (1999-12-07) 1 1 1 1 1 Hotline Communications Ltd. The company that developes and distributes Hotline Connect. (http://BigRedH.com/index2.html). (1999-12-07) 1 1 1 1 1 Hotline Connect A suite of communication products developed by Hotline Communications Ltd. Hotline Connect is a real-time, multi-platform Internet/Intranet communication suite, that operates independent of the web. It provides easy-to-use private and public virtual community building and live interaction with real-time chat, conferencing, messaging, data warehousing, file transfer, and viewing. Version: 1.7.2, as of 1999-12-07. (1999-12-07) 1 1 1 1 1 hotlink A mechanism for sharing data between two application programs where changes to the data made by one application appear instantly in the other's copy. Under System 7 on the Macintosh the users establishes a hotlink by doing a "Create Publisher" on the server and Subscribe on the client. Under Windows 3 it's "Cut Special"(?) and "Paste Special" (as opposed to the normal Cut and Paste). (1995-02-16) 1 1 1 1 1 hotlist (From hypertext "hot spot") A document on the web or a user's browser configuration file containing hypertext links, often unorganised and undocumented, to notable pages on the Web. Compare the 19th century notion of a commonplace book (http://c.gp.cs.cmu.edu:5103/prog/webster?commonplace+book). (1995-04-16) 1 1 1 1 1 Hotmail A web mail service bought by Microsoft. (http://hotmail.com/). (2006-10-30) 1 1 1 1 1 hot spot 1. (primarily used by C/Unix programmers, but spreading) It is received wisdom that in most programs, less than 10% of the code eats 90% of the execution time; if one were to graph instruction visits versus code addresses, one would typically see a few huge spikes amidst a lot of low-level noise. Such spikes are called "hot spots" and are good candidates for heavy optimisation or hand-hacking. The term is especially used of tight loops and recursions in the code's central algorithm, as opposed to (say) initial set-up costs or large but infrequent I/O operations. See tune, bum, hand-hacking. 2. The active location of a cursor on a bit-map display. "Put the mouse's hot spot on the "ON" widget and click the left button." 3. A screen region that is sensitive to mouse clicks, which trigger some action. Hypertext help screens are an example, in which a hot spot exists in the vicinity of any word for 1 1 1 1 1 Hot Standby Routing Protocol (HSRP) A CISCO standard, defined in RFC 2281, that calls for a mirrored router in passive mode to send hello packets, wait for a lead router to die and, without dropping a packet, take over from that router. Note: "standby", not "swappable" (and certainly not swapable). (2005-01-26) 1 1 1 1 1 Hot Swapable Routing Protocol Incorrect spelling of incorrect expansion of HSRP - Hot Standby Routing Protocol. (2005-01-26) 1 1 1 1 1 Hot Swappable Routing Protocol Incorrect expansion of HSRP - Hot Standby Routing Protocol. (2005-01-26) 1 1 1 1 1 hot swapping The connection and disconnection of peripherals or other components without interrupting system operation. This facility may have design implications for both hardware and software. [More detail?] (1997-03-15) 1 1 1 1 1 HOTT (Hot Off The Tree) An Internet-based electronic magazine edited by David Scott Lewis <d.s.lewis@ieee.org> and distributed by electronic mail. (1994-12-23) 1 1 1 1 1 house wizard (Probably from ad-agency tradetalk, "house freak") A hacker occupying a technical-specialist, R&D, or systems position at a commercial shop. A really effective house wizard can have influence out of all proportion to his/her ostensible rank and still not have to wear a suit. Used especially of Unix wizards. The term "house guru" is equivalent. [Jargon File] (1995-02-16) 1 1 1 1 1 Houston Automatic Spooling Program (HASP) A program developed by IBM for NASA in the 1960s to SPOOL output on OS/MFT and OS/MVT to improve job processing performance. (2003-05-19) 1 1 1 1 1 Howe, Denis Denis Howe 1 1 1 1 1 how many nibbles are in a byte how many nibbles in a byte 1 1 1 1 1 how many nibbles in a byte There are two nibbles in a byte. (2009-09-17) 1 1 1 1 1 HP Hewlett-Packard 1 1 1 1 1 hp2ps An HP-GL interpreter written in PostScript by Alun Jones. hp2ps runs on the printer itself. Version 1.9c. (1999-11-23) 1 1 1 1 1 H/PC Hand-held Personal Computer 1 1 1 1 1 HPCC High Performance Computing and Communications 1 1 1 1 1 HPcode Stack-based intermediate language used by HP in many of its compilers for RISC and stack-based architectures. Supports Fortran, Ada, Pascal, COBOL and C++. Descended from Stanford's U-code. 1 1 1 1 1 HPCode-Plus A descendant of HPcode with data types, developed to be an ANDF language. ["ANDF: Finally an UNCOL After 30 Years", M.E. Benitez, Jack Davidson <jwd@virginia.edu> et al, CS TR-91-05 U Virginia (Mar 1991)]. (1995-03-16) 1 1 1 1 1 HPF High Performance Fortran 1 1 1 1 1 HPFS High Performance File System 1 1 1 1 1 HP-GL Hewlett-Packard Graphics Language 1 1 1 1 1 HP-GL/2 HP-GL/2 Programmer's Guide, No. 5959-9733, HP. (See PCL.) 1 1 1 1 1 HP-IB IEEE 488 1 1 1 1 1 HPL Language used in HP9825A/S/T "Desktop Calculators", 1978(?) and ported to the early Series 200 family (9826 and 9836, 68000). Fairly simple and standard, but with extensive I/O support for data acquisition and control (BCD, Serial, 16 bit custom and IEEE 488 interfaces), including interrupt handling. Currently owned by Structured Software Systems. "HPL Operating Manual for Series 200, Models 216, 226 and 235\6, HP 98614-90010, Jan 1984." 1 1 1 1 1 HPLOT A graphical output facility for HBOOK. (1995-02-22) 1 1 1 1 1 HP-MPE Hewlett Packard Multi Processing Executive 1 1 1 1 1 HP-PA Hewlett Packard Precision Architecture 1 1 1 1 1 HPPI High Performance Parallel Interface 1 1 1 1 1 HPR High Performance Routing 1 1 1 1 1 HP-SUX /H-P suhks/ An unflattering hackerism for HP-UX which features some truly unique bogosities in the file system internals and elsewhere (these occasionally create portability problems). HP-UX is often referred to as "hockey-pux" inside HP, and one respondent claims that the proper pronunciation is /H-P ukkkhhhh/ as though one were about to spit. Another such alternate spelling and pronunciation is "H-PUX" /H-puhks/. Hackers at HP/Apollo (the former Apollo Computers which was swallowed by HP in 1989) have been heard to complain that Mr. Packard should have pushed to have his name first, if for no other reason than the greater eloquence of the resulting acronym. Compare AIDX, buglix, Telerat, Open DeathTrap, ScumOS, sun-stools. [Jargon File] (1997-05-12) 1 1 1 1 1 HP-UX The version of Unix running on Hewlett-Packard workstations. HP-UX conforms to X/Open's Portability Guide Issue 4 (XPG4), Federal Information Processing Specification (FIPS) 151.1, POSIX 1003.1, POSIX 1003.2, AT&T's System V Interface Definition 2 (SVID 2). HP-UX incorporates selected features from the University of California at Berkeley Software Distribution 4.3 (4.3BSD). It is known by some as "HP-SUX". [Features?] (1997-05-12) 1 1 1 1 1 HP VEE Hewlett-Packard Visual Engineering Environment 1 1 1 1 1 hqx binhex 1 1 1 1 1 hr The country code for Croatia. (1999-01-27) 1 1 1 1 1 href (hypertext reference) The attribute of an HTML "a" (anchor or link) tag, whose value gives the URL of the web page or other resource that the link points to. For example, <a href="http://foldoc.org/">FOLDOC href definition</a> would display an anchor pointing to this dictionary. (2008-02-22) 1 1 1 1 1 hs Haskell 1 1 1 1 1 HSB hue, saturation, brightness 1 1 1 1 1 HSC High Speed Connect 1 1 1 1 1 HSCSD High Speed Circuit Switched Data 1 1 1 1 1 HSL-FX Hierarchical Specification Language - Function Extension 1 1 1 1 1 HSM Hierarchical Storage Management 1 1 1 1 1 HSRP Hot Standby Routing Protocol 1 1 1 1 1 HSSI high speed serial interface 1 1 1 1 1 HSV hue, saturation, value 1 1 1 1 1 HT horizontal tabulation 1 1 1 1 1 ht The country code for Haiti. (1999-01-27) 1 1 1 1 1 HTH Hope This Helps. Often used sarcastically, see HAND. (1998-03-06) 1 1 1 1 1 HTLM Do you mean HTML? 1 1 1 1 1 HTML Hypertext Markup Language 1 1 1 1 1 HTML+ A proposed successor to HTML. HTML+ was a superset of HTML designed to extend the capabilities of the language to incorporate better support for multimedia objects in documents. (1994-10-27) 1 1 1 1 1 htmlcommentbox.com A service for adding a comment box to any web page, allowing visitors to leave comments and the site owner to review them. (http://htmlcommentbox.com/) (2013-03-20) 1 1 1 1 1 HTTL Do you mean HTTP or HTML? 1 1 1 1 1 HTTP Hypertext Transfer Protocol 1 1 1 1 1 HTTP/1.0 Hypertext Transfer Protocol version 1.0. 1 1 1 1 1 HTTP cookie A small string of information sent by a web server to a web browser that will be sent back by the browser each time it accesses that server. Cookies were invented by Netscape to make it easier to maintain state between HTTP transactions. They can contain any arbitrary information the server chooses to put in them. The most common use of cookies is to identify and authenticate a user who has logged in to a website, so they don't have to sign in every time they visit. Other example uses are maintaining a shopping basket of goods you have selected to purchase during a session at an online shop or site personalisation (presenting different pages to different users). The browser limits the size of each cookie and the number each server can store. This prevents a malicious site consuming lots of disk space on the user's computer. The only information that cookies can return to the server is what that server previously sent out. 1 1 1 1 1 HTTPd (Hypertext transfer protocol daemon). An HTTP/1.0-compatible server, written by Rob McCool <robm@ncsa.uiuc.edu> of NCSA, for making hypertext and other documents available to web browsers. HTTPd is designed to be small and fast and to work with most HTTP/0.9 and HTTP/1.0 browsers. You can customise your server to execute searches and handle HTML forms. It also supports server side include files, allowing you to include the output of commands or other files in HTML documents. The current (1994-08-08) version is 1.3. (http://hoohoo.ncsa.uiuc.edu/docs/Overview.html). E-mail: <httpd@ncsa.uiuc.edu>. (1995-01-16) 1 1 1 1 1 HTTP proxy server A proxy server for HTTP requests. Typically an HTTP proxy or "web proxy" accepts HTTP requests containing URLs with a special prefix. The proxy removes the prefix and looks for the resulting URL in its local cache (if it is a caching proxy). If found, it returns the document immediately, otherwise it fetches it from the remote server, saves a copy in its cache and returns it to the requester. The cache will usually have an expiry algorithm which flushes documents according to their age, size and access history. The purpose is to reduce the amount of data flowing over the proxy's Internet connection and to speed up clients' access to frequently requested pages, e.g. at an ISP or on a large company's firewall. The proxy may also reject requests where the URL or content matches certain conditions. The Apache HTTP server can be configured to act as a proxy server. Another popular software proxy is Squid. 1 1 1 1 1 HTTPS HyperText Transmission Protocol, Secure 1 1 1 1 1 HTTP server (Or "web server") A server process running at a website which sends out web pages in response to HTTP requests from remote browsers. If one site runs more than one server they must use different port numbers. Alternatively, several hostnames may be mapped to the same computer in which case they are known as virtual servers. Apache and NCSA HTTPd are two popular web servers. There are many others including some for practically every platform. Servers differ mostly in the "server-side" features they offer such as server-side include, and in their authentication and access control mechanisms. All decent servers support CGI and most have some binary API as well. (1997-02-05) 1 1 1 1 1 hu The country code for Hungary. (1999-01-27) 1 1 1 1 1 hub (By analogy with the hub of a wheel) A device connected to several other devices. In ARCnet, a hub is used to connect several computers together. In a message handling service, a number of local computers might exchange messages solely with a hub computer. The hub would be responsible for exchanging messages with other hubs and non-local computers. (1995-01-16) 1 1 1 1 1 Hubnet A 50 Mb/s optical fibre network developed at Toronto University. Network topology is a rooted tree with a maximum of 65536 hosts with maximum separation of 2 km. The protocol is multiple access, collision avoidance, echo detect and retry. [Computer Systems Equipment Design, Jan 85]. (1994-11-22) 1 1 1 1 1 hubs hub 1 1 1 1 1 hue (Or "tint") The coordinate in the HSB colour model that determines the frequency of light or the position in the spectrum or the relative amounts of red, green and blue. Hue corresponds to the common definition of colour, e.g. "red", "orange", "violet" etc. The other coordinates are saturation and brightness. (1999-07-05) 1 1 1 1 1 hue, saturation, brightness (HSB) A colour model that describes colours in terms of hue, saturation, and brightness. In the tables below, a hue is a "pure" colour, i.e. one with no black or white in it. A shade is a "dark" colour, i.e. one produced by mixing a hue with black. A tint is a "light" colour, i.e. one produced by mixing a hue with white. A tone is a colour produced by mixing a hue with a shade of grey. Microsoft Windows colour dialogs, PagePlus, and Paint Shop Pro use HSB but call the third dimension "luminosity" or "lightness". It ranges from 0% (black) to 100% (white). A pure hue is 50% luminosity, 100% saturation. Colour type S L Black Any 0% White Any 100% Grey 0% 1-99% Hue 100% 50% Shade 100% 1-49% 1 1 1 1 1 hue, saturation, value (HSV) A colour model that describes colours in terms of hue (or "tint"), saturation (or "shade") and value (or "tone" or "luminance"). [Same as HSB?] (1999-07-05) 1 1 1 1 1 huff To compress data using Huffman coding. Various programs that use such methods have been called "HUFF" or some variant thereof. Opposite: puff. Compare crunch, compress. [Jargon File] (1994-12-23) 1 1 1 1 1 Huffman Huffman coding 1 1 1 1 1 Huffman code Huffman coding 1 1 1 1 1 Huffman coding A data compression technique which varies the length of the encoded symbol in proportion to its information content, that is the more often a symbol or token is used, the shorter the binary string used to represent it in the compressed stream. Huffman codes can be properly decoded because they obey the prefix property, which means that no code can be a prefix of another code, and so the complete set of codes can be represented as a binary tree, known as a Huffman tree. Huffman coding was first described in a seminal paper by D.A. Huffman in 1952. (1994-12-23) 1 1 1 1 1 Huffman encoding Huffman coding 1 1 1 1 1 Hugh Loebner Dr. Hugh Gene Loebner, the instigator of the Loebner Prize in artificial intelligence. (http://loebner.net/). E-mail address: Hugh Loebner <hugh@loebner.net>. (2003-11-30) 1 1 1 1 1 HUGO A bytecode-interpreted transaction handler from Geac. (1994-12-23) 1 1 1 1 1 HUGS Haskell User's Gofer System 1 1 1 1 1 Human-Computer Interaction (HCI) The study of how humans interact with computers, and how to design computer systems that are easy, quick and productive for humans to use. See also Human-Computer Interface. HCI Sites (http://acm.org/sigchi/hci-sites/). (1999-05-09) 1 1 1 1 1 Human-Computer Interface (HCI) Any software or hardware that allows a user to interact with a computer. Examples are WIMP, command-line interpreter, or virtual reality. See also Human-Computer Interaction. (1999-05-09) 1 1 1 1 1 Human Interface Device (HID) Any device to interact directly with humans (mostly input) like keyboard, mouse, joystick, or graphics tablet. (2001-03-29) 1 1 1 1 1 Human Interface Technology Laboratory (HITL) The Human Interface Technology Laboratory at the University of Washington was founded in 1990. It is a centre for research and development of advanced interface technology. Located on the university campus, HITL forms a bridge between academia and industry. It maintains its industrial focus via the Virtual Worlds Consortium and maintains contacts with academia by training students and teaching courses. The lab has access to faculty and students throughout the State of Washington. Address: Human Interface Technology Laboratory, University of Washington, Seattle, USA. (1995-02-13) 1 1 1 1 1 humanist technology Technology centered around the interests, needs, and well-being of humans. (2002-07-16) 1 1 1 1 1 humma A filler word used on various "chat" and "talk" programs when you had nothing to say but felt that it was important to say something. The word apparently originated (at least with this definition) on the MECC Timeshare System (MTS, a now-defunct educational time-sharing system running in Minnesota during the 1970s and the early 1980s) but was later sighted on early Unix systems. [Jargon File] (1999-02-27) 1 1 1 1 1 humor hacker humour 1 1 1 1 1 humour hacker humour 1 1 1 1 1 hung ["hung up"] Equivalent to wedged, but more common at Unix/C sites. Not generally used of people. Synonym with locked up, wedged; compare hosed. See also hang. A hung state is distinguished from crashed or down, where the program or system is also unusable but because it is not running rather than because it is waiting for something. However, the recovery from both situations is often the same. [Jargon File] 1 1 1 1 1 Hungarian Notation A linguistic convention requiring one or more letters to be added to the start of variable names to denote scope and/or type. Hungarian Notation is mainly confined to Microsoft Windows programming environments, such as Microsoft C, C++ and Visual Basic. It was originally devised by Charles Simonyi, a Hungarian, who was a senior programmer at Microsoft for many years. He disliked the way that names in C programs gave no clue as to the type, leading to frequent programmer errors. According to legend, fellow programmers at Microsoft, on seeing the convoluted, vowel-less variable names produced by his scheme, said, "This might as well be in Greek - or even Hungarian!". They made up the name "Hungarian notation" (possibly with "reverse Polish notation" in mind). Hungarian Notation is not really necessary when using a modern strongly-typed language as the compiler warns the 1 1 1 1 1 Hungry Programmers A group of programmers producing free software. (http://hungry.com/). (1995-03-20) 1 1 1 1 1 hungry puppy Synonym slopsucker. [Jargon File] 1 1 1 1 1 Hungry ViewKit A C++ class library for developing Motif application programs (although this restriction will be lifted once LessTif is finished). It follows the API of the Iris(tm) ViewKit, put out by SGI. The Hungry ViewKit is a superset of the Iris ViewKit, so any code developed for the Iris version will work with the Hungry version, but possibly not vice versa. (http://hungry.com/products/viewkit/). (1995-03-20) 1 1 1 1 1 hungus /huhng'g*s/ (Perhaps related to slang "humongous") Large, unwieldy, usually unmanageable. E.g. "TCP is a hungus piece of code." [Jargon File] (1999-01-26) 1 1 1 1 1 Hunt the Wumpus (Or "Wumpus") /wuhm'p*s/ A famous fantasy computer game, created by Gregory Yob in about 1973. Hunt the Wumpus appeared in Creative Computing, Vol 1, No 5, Sep - Oct 1975, where Yob says he had come up with the game two years previously, after seeing the grid-based games Hurkle, Snark and Mugwump at People's Computing Company (PCC). He later delivered Wumpus to PCC who published it in their newsletter. ESR says he saw a version including termites running on the Dartmouth Time-Sharing System in 1972-3. Magnus Olsson, in his 1992-07-07 USENET article <9207071854.AA21847@thep.lu.se>, posted the BASIC source code of what he believed was pretty much the version that was published in 1973 in David Ahl's "101 Basic Computer Games", by Digital Equipment Corporation. The wumpus lived somewhere in a cave with the topology of an dodecahedron's edge/vertex graph (later versions supported 1 1 1 1 1 Hurd The GNU project's replacement for the Unix kernel. The Hurd is a collection of servers that run on the Mach microkernel to implement file systems, network protocols, file access control, and other features that are implemented by the Unix kernel or similar kernels such as Linux. The GNU C Library provides the Unix system call interface, and calls the Hurd for services it can't provide itself. The Hurd aims to establish a framework for shared development and maintenance, allowing a broad range of users to share projects without knowing much about the internal workings of the system - projects that might never have been attempted without freely available source, a well-designed interface, and a multi-server-based design. Currently there are free ports of the Mach kernel to the Intel 80386 IBM PC, the DEC PMAX workstation, the Luna 88k, with more in progress, including the Amiga and 1 1 1 1 1 HVD High Voltage Differential 1 1 1 1 1 Hybrid A concurrent object-oriented language. ["Active Objects in Hybrid", O.M. Nierstrasz, SIGPLAN Notices 22(12):243-253 (OOPSLA '87) (Dec 1987)]. (1994-12-07) 1 1 1 1 1 Hybrid Fiber Coax (HFC) A kind of physical connection used in networks for audio, video, and data. DVB (Digital Video Broadcast) is used in Europe and DOCSIS is used in N America. [What is the relationship between HFC, DVB, DOCSIS?] (1999-11-02) 1 1 1 1 1 hybrid multiprocessing (HMP) The kind of multitasking which OS/2 supports. HMP provides some elements of symmetric multiprocessing, using add-on IBM software called MP/2. OS/2 SMP was planned for release in late 1993. (1995-03-19) 1 1 1 1 1 hybrid testing A combination of top-down testing with bottom-up testing of prioritised or available components. (1996-05-22) 1 1 1 1 1 hydra code Code that cannot be fixed because each time a bug is remove, two new bugs grow in its place. Named after the many-headed Hydra of Greek mythology. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-01-04) 1 1 1 1 1 hydrofluorocarbon (HFC) A suggested replacement for the chlorofluorocarbon (CFC) coolant gas used in chillers and air conditioners. (1996-11-05) 1 1 1 1 1 HyperBase An experimental active multi-user database for hypertext systems from the University of Aalborg, written in C++. It is built on the client-server model enabling distributed, concurrent, and shared access from workstations in a local area network. See also EHTS. (1995-03-19) 1 1 1 1 1 Hyper-C A data parallel extension of C from HyperParallel Tech, France, for PVM, CM and Maspar. It is available from Fortunel Systems <fortunel@vnet.net>, +1 (919) 319 1624. E-mail: <hyperc-support@hyperparallel.polytechnique.fr>. (1994-11-17) 1 1 1 1 1 HyperCard A software package by Bill Atkinson for storage and retrieval of information on the Macintosh. It can handle images and is designed for browsing. The powerful customisable interactive user interface allows new applications to be easily constructed by manipulating objects on the screen, often without conventional programming, though the language HyperTalk can be used for more complex tasks. Usenet newsgroup: news:comp.sys.mac.hypercard. ["Apple Macintosh HyperCard User Guide", Apple Computer 1987]. (1995-02-10) 1 1 1 1 1 hypercube A cube of more than three dimensions. A single (2^0 = 1) point (or "node") can be considered as a zero dimensional cube, two (2^1) nodes joined by a line (or "edge") are a one dimensional cube, four (2^2) nodes arranged in a square are a two dimensional cube and eight (2^3) nodes are an ordinary three dimensional cube. Continuing this geometric progression, the first hypercube has 2^4 = 16 nodes and is a four dimensional shape (a "four-cube") and an N dimensional cube has 2^N nodes (an "N-cube"). To make an N+1 dimensional cube, take two N dimensional cubes and join each node on one cube to the corresponding node on the other. A four-cube can be visualised as a three-cube with a smaller three-cube centred inside it with edges radiating diagonally out (in the fourth dimension) from each node on the inner cube to the corresponding node on the outer cube. Each node in an N dimensional cube is directly connected to N other nodes. We can identify each node by a set of N 1 1 1 1 1 Hyperion An MS-DOS personal computer that was manufactured in Kanata (near Ottawa, Ontario, Canada) in the mid-1980s. It received considerable government subsidies and, while it was considered well-designed and manufactured and a real threat to the Compaq Portable, the Ottawa firm that designed it was unable to beat Compaq. (1997-07-21) 1 1 1 1 1 hyperlink hypertext link 1 1 1 1 1 Hyper-Man A browser available with Epoch giving hypertext access to the Unix manual. 1 1 1 1 1 hypermedia hypertext 1 1 1 1 1 HyperNeWS A Hypertext system from the Turing Institute Glasgow, based on NeWS. 1 1 1 1 1 Hyperscript Informix. The object-based programming language for Wingz, used for creating charts, graphs, graphics, and customised data entry. 1 1 1 1 1 hyperspace /hi:'per-spays/ A memory location that is *far* away from where the program counter should be pointing, often inaccessible because it is not even mapped in. (Compare jump off into never-never land.) This usage is from the SF notion of a spaceship jumping "into hyperspace", that is, taking a shortcut through higher-dimensional space - in other words, bypassing this universe. The variant "east hyperspace" is recorded among CMU and Bliss hackers. [Jargon File] (1994-11-23) 1 1 1 1 1 HyperSPARC The successor to the SuperSPARC processor, based on the SPARC ISA. The HyperSPARC has smaller caches than the SuperSPARC: 8kb on-chip and 256kb off-chip (compared with 36kb and 1Mb). The HyperSPARC's memory management is optimised for more efficient out-of-cache addressing which means quicker access to external (slower, cheaper) memory. (1994-11-23) 1 1 1 1 1 Hyperstrict A function which is hyperstrict in some argument will fully evaluate that argument. To fully evaluate an object, evaluate it to WHNF and if it is a constructed data object (e.g. a list or tuple) then fully evaluate every component and so on recursively. Thus a hyperstrict function will fail to terminate if its argument or any component or sub-component of its argument fails to terminate (i.e. if its argument is not total). 1 1 1 1 1 HyperTalk A verbose semicompiled language by Bill Atkinson and Dan Winkler, with loose syntax and high readability. HyperTalk uses HyperCard as an object management system, development environment and interface builder. Programs are organised into "stacks" of "cards", each of which may have buttons and "fields". All data storage is in zero-terminated strings in fields, local, or global variables; all data references are through "chunk expressions" of the form: 'last item of background field Name List of card ID 34217'. Flow of control is event-driven and uses message-passing among scripts that are attached to stack, background, card, field and button objects. Apple Computer has taken back distribution and maintenance of 1 1 1 1 1 hypertext A term coined by Ted Nelson around 1965 for a collection of documents (or "nodes") containing cross-references or "links" which, with the aid of an interactive browser program, allow the reader to move easily from one document to another. The extension of hypertext to include other media - sound, graphics, and video - has been termed "hypermedia", but is usually just called "hypertext", especially since the advent of the web and HTML. (2000-09-10) 1 1 1 1 1 hypertext link (Or "hyperlink", "button", formerly "span", region, "extent") A pointer from within the content of one hypertext node (e.g. a web page) to another node. In HTML (the language used to write web pages), the source and destination of a link are known as "anchors". A source anchor may be a word, phrase, image or the whole node. A destination anchor may be a whole node or some position within the node. A hypertext browser displays source anchors in some distinctive way. When the user activates the link (e.g. by clicking on it with the mouse), the browser displays the destination anchor to which the link refers. Anchors should be recognisable at all times, not, for example, only when the mouse is over them. Originally links were always underlined but the modern preference is to use bold text. In HTML, anchors are created with <a..>..</a> anchor elements. The opening "a" tag of a source anchor has an 1 1 1 1 1 Hypertext Markup Language (HTML) A hypertext document format used on the web. HTML is built on top of SGML. "Tags" are embedded in the text. A tag consists of a "<", a "directive" (in lower case), zero or more parameters and a ">". Matched pairs of directives, like <title> and "</title>" are used to delimit text which is to appear in a special place or style. Links to other documents are in the form <a href="http://machine.edu/subdir/file.html">foo</a> where "<a>" and "</a>" delimit an "anchor", "href" introduces a hypertext reference, which is most often a Uniform Resource Locator (URL) (the string in double quotes in the example above). The link will be represented in the browser by the text "foo" (typically shown underlined and in a different colour). A certain place within an HTML document can be marked with a named anchor, e.g.: 1 1 1 1 1 Hypertext Transfer Protocol (HTTP) The client-server TCP/IP protocol used on the web for the exchange of HTML documents. It conventionally uses port 80. Latest version: HTTP 1.1, defined in RFC 2068, as of May 1997 See also Uniform Resource Locator. (1994-10-27) 1 1 1 1 1 HyperText Transmission Protocol, Secure (HTTPS) A variant of HTTP used by Netscape for handling secure transactions. The Netscape Navigator supports a URL access method, https, for connecting to HTTP servers using SSL. https is a unique protocol that is simply SSL underneath HTTP. You need to use "https://" for HTTP URLs with SSL, whereas you continue to use "http://" for HTTP URLs without SSL. The default "https" port number is 443, as assigned by the Internet Assigned Numbers Authority. (http://netscape.com/info/security-doc.html). (1995-01-16) 1 1 1 1 1 hyperware Software that implements or uses hypertext. (2000-09-11) 1 1 1 1 1 hypotenuse The side of a right-angled triangle opposite the right angle. (2004-02-15) 1 1 1 1 1 hysterical reasons (Or "hysterical raisins") A variant on the stock phrase "for historical reasons", indicating specifically that something must be done in some stupid way for backward compatibility, and moreover that the feature it must be compatible with was the result of a bad design in the first place. "All IBM PC video adaptors have to support MDA text mode for hysterical reasons." Compare bug-for-bug compatible. [Jargon File] 1 1 1 1 1 Hytelnet A hypertext database of publicly accessible Internet sites created and maintained by Peter Scott <scottp@moondog.usask.ca>. Hytelnet currently lists over 1400 sites, including Libraries, Campus-Wide Information Systems, Gopher, WAIS, WWW and Freenets. Hytelnet software is available for the IBM PC, Macintosh, Unix and VMS systems. (ftp://ftp.usask.ca/pub/hytelnet) (128.233.3.11). Telnet (telnet://access.usask.ca/), login: hytelnet. Mailing list: listserv@library.berkeley.edu (no subject, body: subscribe hytelnet FirstName LastName). (1995-10-18) 1 1 1 1 1 HyTime Hypermedia/Time-based Structuring Language: an emerging ANSI/ISO Standard from the SGML Users' Group's Special Interest Group on Hypertext and Multimedia (SIGhyper). A hypermedia extension of SGML. ["The HyTime Hypermedia/Time-based Document Structuring Language", S. Newcomb et al, CACM 34(11):67-83 (Nov 1991)]. 1 1 1 1 1 i18n internationalisation 1 1 1 1 1 I2O Intelligent Input/Output 1 1 1 1 1 i386 Intel 80386 1 1 1 1 1 i486 Intel 486 1 1 1 1 1 i487 Intel 487SX 1 1 1 1 1 i860 A 32/64-bit superscalar RISC microprocessor from Intel, released in 1989. Originally codenamed "N10". It has a 32-bit integer ALU and a 64-bit floating-point unit. It has a 64-bit data bus with an initialisation mode which only uses eight bits of the data bus to allow the use of a small boot ROM. It has a 32-bit wide instruction cache and a separate 64-bit wide data cache. It uses register scoreboarding and register bypassing. The clock rate is 33 MHz with a clock-doubled version available. (1998-03-28) 1 1 1 1 1 IA Information Appliance 1 1 1 1 1 IA32 The processor chip architecture and instruction set used by Intel in its Pentium processors. (2007-06-17) 1 1 1 1 1 IAB Internet Architecture Board 1 1 1 1 1 IAD A dynamic analyser from IBM giving information on run-time performance and code use. 1 1 1 1 1 IAL ALGOL 58 1 1 1 1 1 IAM Interactive Algebraic Manipulation. Interactive symbolic mathematics for PDP-10. ["IAM, A System for Interactive Algebraic Manipulation", C. Christensen et al, Proc Second Symp Symb Alg Manip, ACM Mar 1971]. 1 1 1 1 1 IANA Internet Assigned Numbers Authority 1 1 1 1 1 IANAL I Am Not A Lawyer (but my legal opinion is...). (1998-07-28) 1 1 1 1 1 IAP Internet Access Provider 1 1 1 1 1 I-APL A version of APL. (ftp://watserv1.waterloo.edu/languages/apl/). (1992-07-06) 1 1 1 1 1 IAR Instruction Address Register. The IBM name for program counter. (1995-03-21) 1 1 1 1 1 IAS 1. <computer> The first modern computer. It had main registers, processing circuits, information paths within the central processing unit, and used Von Neumann's fetch-execute cycle. The IAS machine's basic unit of information was a 40-bit word and the memory had 4096 words. A word stored in memory could represent either an instruction or data. Each IAS instruction was twenty bits long, so that two instructions could be stored in each 40-bit memory location. Each instruction consisted of an 8-bit operation code and a 12-bit address that could identify any of 2^12 locations that may be used to store an operand of the instruction. The CPU consisted of a data processing unit and a program control unit. It contained various processing and control circuits along with a set of high-speed registers for the temporary storage of instructions, memory addresses, and data. The main actions specified by instructions were performed by 1 1 1 1 1 IAW inactive window. Used in talk systems to mean that that person will not be taking part in the conversation for a while. The sadly mispelled alternative, "unactive window" (UAW) has also been reported. (1994-12-05) 1 1 1 1 1 IAYSDAH I acknowledge your strangely depressing attempt at humour. (2004-03-04) 1 1 1 1 1 IBEX The command language for Honeywell's CP-6 operating system. (1994-12-06) 1 1 1 1 1 IBM International Business Machines 1 1 1 1 1 IBM 1130 A computer introduced by IBM in 1965. It was their cheapest computer to date, and was aimed at price-sensitive, computing-intensive technical markets like education and engineering. It notably included inexpensive disk storage. Non-IBM clones were produced. IBM 1130 Enthusiasts (http://ibm1130.org/). (2005-01-17) 1 1 1 1 1 IBM 1403 A printer used with the IBM 360 mainframe, a successor to the 1401. (1999-01-11) 1 1 1 1 1 IBM 1620 A computer built by IBM and released in late 1959. The 1620 cost from around $85,000(?) up to hundreds of thousands of dollars(?) according to the configuration. It was billed as a "small scientific computer" to distinguish it from the business-oriented IBM 1401. It was regarded as inexpensive, and many schools started out with one. It was either developed for the US Navy to teach computing, or as a replacement for the very successful IBM 650 which did quite well in the low end scientific market. Rumour has it that the Navy called this computer the CADET - Can't Add, Doesn't Even Try. The ALU used lookup tables to add, subtract and multiply but it could do address increments and the like without the tables. You could change the number base by adjusting the tables, which were input during the boot sequence from Hollerith cards. The divide instruction required additional hardware, as did floating point operations. 1 1 1 1 1 IBM 1710 An IBM 1620 with additional features useful for industrial process control: A/D convertors, D/A convertors, general-purpose I/O lines, and interrupts. [Date?] (1997-07-20) 1 1 1 1 1 IBM 2741 A slow, letter-quality printing device and terminal based on the IBM Selectric typewriter. The print head was a little sphere resembling a golf ball, bearing reversed embossed images of 88 different characters arranged on four parallels of latitude; one could change the font by changing the golf ball. The device communicated at 134.5 bits per second, half duplex. When the computer transmitted, it physically locked the keyboard. This was the technology that enabled APL to use a non-EBCDIC, non-ASCII, and in fact completely non-standard character set. This put it 10 years ahead of its time - where it stayed, firmly rooted, for the next 20, until character displays gave way to programmable bit-mapped devices with the flexibility to support other character sets. (2006-08-04) 1 1 1 1 1 IBM 3270 A class of terminals made by IBM known as Display Devices, normally used to talk to IBM mainframes. The 3270 attempts to minimise the number of I/O interrupts required by accepting large blocks of data, known as datastreams, in which both text and control (or formatting functions) are interspersed allowing an entire screen to be "painted" as a single output operation. The concept of "formatting" in these devices allows the screen to be divided into clusters of contiguous character cells for which numerous attributes (color, highlighting, character set, protection from modification) can be set. Further, using a technique known as 'Read Modified' the changes from any number of formatted fields that have been modified can be read as a single input without transferring any other data, another technique to enhance the terminal throughput of the CPU. The 3270 had twelve, and later twenty-four, special Programmed 1 1 1 1 1 IBM 360 System/360 1 1 1 1 1 IBM 370 System/370 1 1 1 1 1 IBM 370ESA (Enterprise System Architecture) An IBM mainframe computer introduced in 1988. Successor to the IBM 370XA had enhanced access registers that allowed access to other forms of virtual memory. This enhancement allowed more data storage in main and virtual memory, reducing I/O operating and improving speed and efficiency. The IBM 370ESA was rebranded as the IBM390, and later as the zSeries. (2004-06-06) 1 1 1 1 1 IBM 370XA An IBM mainframe computer introduced in 1983. Successor to the System/370, this machine had an enhanced address space. (2004-05-27) 1 1 1 1 1 IBM 3720 A communications controller made by IBM, suitable for use in an IBM S/390. Official service support was withdrawn in 1999 in favour of the IBM 3745. (http://ibm.com/search?q=3720&realm=Networking). (2000-02-21) 1 1 1 1 1 IBM390 IBM 370ESA 1 1 1 1 1 IBM 650 A computer, produced ca. 1955 and in use in the late 1950s, with rotating magnetic drum storage and punched card input. Its memory words could store 10-digit decimal numbers and each instruction had two addresses, one for the operand and one for address of the next instruction on the drum. SOAP was its (optimising) assembler. Languages used on it included BACAIC, BALITAC, BELL, CASE SOAP III, DRUCO I, EASE II, ELI, ESCAPE, FAST, FLAIR, FORTRANSIT, FORTRUNCIBLE, GAT, IPL, Internal Translator, KISS, MITILAC, MYSTIC, OMNICODE, PIT, RELATIVE, RUNCIBLE, SIR, SOAP, Speedcoding, SPIT, SPUR. [More details?] (1995-03-30) 1 1 1 1 1 IBM 700 series A family of computers made by IBM, including the IBM 701, IBM 702, IBM 704, IBM 705 and IBM 709. (2005-06-20) 1 1 1 1 1 IBM 701 ("Defense Calculator") The first of the IBM 700 series of computers. The IBM 701 was annouced internally on 1952-04-29 as "the most advanced, most flexible high-speed computer in the world". Known as the Defense Calculator while in development at IBM Poughkeepsie Laboratory, it went public on 1953-04-07 as the IBM 701 Electronic Data Processing Machines (plural because it consisted of eleven connected units). The 701 was the first IBM large-scale electronic computer manufactured in quantity and their first commercial scientific computer. It was the first IBM machine in which programs were stored in an internal, addressable, electronic memory. It was developed and produced in less than two years from "first pencil on paper" to installation. It was key to IBM's transition from punched card machines to electronic computers. It consisted of four magnetic tape drives, a magnetic drum 1 1 1 1 1 IBM 704 A large, scientific computer made by IBM and used by the largest commercial, government and educational institutions. The IBM 704 had 36-bit memory words, 15-bit addresses and instructions with one address. A few index register instructions had the infamous 15-bit decrement field in addition to the 15-bit address. The 704, and IBM 709 which had the same basic architecture, represented a substantial step forward from the IBM 650's magnetic drum storage as they provided random access at electronic speed to core storage, typically 32k words of 36 bits each. [Or did the 704 actually come *before* the 650?] A typical 700 series installation would be in a specially built room of perhaps 1000 to 2000 square feet, with cables running under a raised floor and substantial air conditioning. There might be up to eight magnetic tape transports, each 1 1 1 1 1 IBM 7040 A scaled down version of the IBM 7090. (1997-02-23) 1 1 1 1 1 IBM 705 A business-oriented counterpart of the IBM 704. The 705 was a decimal machine with a circular register which could hold several values at the same time. Languages incuded ACOM, Autocode, ELI, PRINT, PRINT I, SOHIO, SYMBOLIC ASSEMBLY. (2000-06-01) 1 1 1 1 1 IBM 709 A computer made by IBM oriented toward scientific work. The 709 had the same basic architecture as the IBM 704 but with many I/O and performance refinements over the 704. The IBM 709 (like the 704) had 36-bit memory words, 15-bit addresses and instructions with one address. A few index register instructions had the infamous 15-bit decrement field in addition to the 15-bit address. The IBM 7090 was a transistorised version of the 709. [Difference between 704 and 709?] (1999-01-19) 1 1 1 1 1 IBM 7090 A transistorised version of the IBM 709 which was a very popular high end computer in the early 1960s. The 7090 had 32Kbytes of 36-bit core memory and a hardware floating point unit. Fortran was its most popular language, but it supported many others. It was later upgraded to the IBM 7094, and a scaled down version, the IBM 7040 was also introduced. IBM 7090s controlled the Mercury and Gemini space flights, the Balistic Missile Early Warning System (until well into the 1980s), and the CTSS time sharing system at MIT. The 7090 was not good at unit record I/O, so in small configurations an IBM 1401 was used for SPOOL I/O and in large configurations (such as a 7090/94) a 7040/44 would be directly coupled and dedicated to handling printers and card readers. (See the film Dr Strangelove). (1999-01-19) 1 1 1 1 1 IBM 7094 A faster version of the IBM 7090 with more index registers. (1997-02-23) 1 1 1 1 1 IBM 801 The original IBM RISC processor, developed as a research project. It was named after the building in which it was designed. [Features? Dates?] (1995-03-01) 1 1 1 1 1 IBM compatible A computer which can use hardware and software designed for the IBM PC (or, less often, IBM mainframes). This was once a key phrase in marketing a new PC clone but now in 1998 is rarely used, the non-IBM wintel personal computer manufacturers such as Compaq, Dell and Gateway 2000 and OS vendor Microsoft having taken control of the market, marginalising IBM. (1998-07-30) 1 1 1 1 1 IBM Customer Engineer (CE) A hardware guy from IBM. [Are/were any CEs female?] (1998-07-08) 1 1 1 1 1 IBM discount A price increase. Outside IBM, this derives from the common perception that IBM products are generally overpriced (see clone); inside, it is said to spring from a belief that large numbers of IBM employees living in an area cause prices to rise. [Jargon File] (1995-02-07) 1 1 1 1 1 IBM PC International Business Machines Personal Computer. IBM PCs and compatible models from other vendors are the most widely used computer systems in the world. They are typically single user personal computers, although they have been adapted into multi-user models for special applications. Note: "IBM PC" is used in this dictionary to denote IBM and compatible personal computers, and to distinguish these from other personal computers, though the phrase "PC" is often used elsewhere, by those who know no better, to mean "IBM PC or compatible". There are hundreds of models of IBM compatible computers. They are based on Intel's microprocessors: Intel 8086, Intel 8088, Intel 80286, Intel 80386, Intel 486 or Pentium. The models of IBM's first-generation Personal Computer (PC) series have names: IBM PC, IBM PC XT, IBM PC AT, Convertible and Portable. The models of its second generation, the Personal System/2 (PS/2), are known by model 1 1 1 1 1 IBM PC AT ("Advanced Technology") A version of the IBM PC, released in Aug 1984 with an Intel 80286 processor, a 16-bit bus, a medium-speed hard disk and a 1.2 megabyte floppy disk drive. It had a larger case than the PC, which allowed it to accept "tall cards". The AT keyboard corrected the PC's non-standard placement of the return and left shift keys but shortened the backspace key, making it harder to reach. (1995-03-01) 1 1 1 1 1 IBM PCjr (IBM PC Junior) A floppy disk-based home computer with an Intel 8088 CPU and a chiclet keyboard, released in November 1983. The PCjr could be expanded to have two floppy drives and 640 kilobytes of RAM using sidecars. Some even had a mouse and could run drawing programs with popup menus. (1995-10-06) 1 1 1 1 1 IBM PC XT An IBM PC with a (slow) hard disk. The XT was released in March 1983. It had an Intel 8088 CPU. The XT/370, released in October 1983, added IBM 370 mainframe emulation, and the XT 286 followed in September 1986 with an Intel 80286 CPU [Why?]. (1996-05-21) 1 1 1 1 1 IBM System/36 A mid-range computer introduced in 1983, which remained popular in the 1990s because of its low cost and high performance. Prices started in the $20k range for the small 5362 to $100+k for the expanded 5360. In 1994, IBM introduced the Advanced 36 for $9,000. The largest 5360 had 7MB of RAM and 1432MB of hard disk. The smallest 5362 had 256K of RAM and 30MB of hard disk. The Advanced 36 had 64MB of RAM and 4300MB of hard disk, but design issues limit the amount of storage that can actually be addressed by the operating system; underlying microcode allowed additional RAM to cache disk reads and writes, allowing the Advanced 36 to outperform the S/36 by 600 to 800%. There was only one operating system for the S/36: SSP (System Support Product). SSP consumed about 7-10MB of hard drive space. Computer programs on the S/36 reside in "libraries," and the SSP itself resides in a special system library called 1 1 1 1 1 IBM Systems Engineer (SE) A software person from IBM. (1998-07-08) 1 1 1 1 1 IBM zSeries IBM 370ESA 1 1 1 1 1 Ibpag2 Icon-Based Parser Generation System 2 1 1 1 1 1 Iburg A program by Christopher W. Fraser <cwf@research.att.com>, David R. Hanson <drh@princeton.edu> and Todd A. Proebsting <todd@cs.arizona.edu> that generates a fast tree parser. Iburg is compatible with Burg. Both programs accept a cost-augmented tree grammar and emit a C program that discovers an optimal parse of trees in the language described by the grammar. They have been used to construct fast optimal instruction selectors for use in code generation. Burg uses BURS. Iburg's matchers do dynamic programming at compile time. (ftp://ftp.cs.princeton.edu/pub/iburg.tar.Z). (1993-02-10) 1 1 1 1 1 IC 1. <hardware> integrated circuit. 2. Independent Carrier. 3. Imperial College. (1997-04-12) 1 1 1 1 1 ICA Independent Computing Architecture 1 1 1 1 1 ICAM Integrated Computer Aided Manufacturing 1 1 1 1 1 ICANN Internet Corporation for Assigned Names and Numbers 1 1 1 1 1 I-CASE Integrated CASE. Another term for an IPSE. 1 1 1 1 1 ICBM address (Or "missile address") The form used to register a site with the Usenet mapping project includes a space for longitude and latitude, preferably to seconds-of-arc accuracy. This is actually used for generating geographically-correct maps of Usenet links on a plotter; however, it has become traditional to refer to this as one's ICBM address or "missile address", and many people include it in their sig block with that name. (A real missile address would include target altitude.) [Jargon File] (1994-12-15) 1 1 1 1 1 ICE 1. <electronics> in-circuit emulator. 2. <security, jargon> Intrusion Countermeasure Electronics. (2000-03-18) 1 1 1 1 1 icebreaker A program designed for cracking security on a system. See also: ICE. [Jargon File] (2000-03-18) 1 1 1 1 1 ICES Integrated Civil Engineering System. Subsystems include COGO, STRUDL, BRIDGE, LEASE, PROJECT, ROADS and TRANSET. Internal languages include ICETRAN and CDL. "An Integrated Computer System for Engineering Problem Solving", D. Roos, Proc SJCC 27(2), AFIPS (Spring 1965). Sammet 1969, pp.615-620. 1 1 1 1 1 ICETRAN An extension of Fortran IV and a component of ICES. [Sammet 1969, p. 617]. 1 1 1 1 1 ICI An extensible, interpretated language by Tim Long with syntax similar to C. ICI adds high-level garbage-collected associative data structures, exception handling, sets, regular expressions, and dynamic arrays. Libraries provide additional types and functions to support common needs such as I/O, simple databases, character based screen handling, direct access to system calls, safe pointers, and floating-point. ICI runs on Microsoft Windows, MS-DOS, Unix, and Linux and in embedded environments. (http://zeta.org.au/~atrn/ici/). (ftp://ftp.research.canon.com.au/pub/misc/ici). E-mail: Andy Newman <andy@research.canon.com.au>. Mailing list: ici@research.canon.com.au. (1999-12-07) 1 1 1 1 1 ICL International Computers Limited. 1 1 1 1 1 ICMP Internet Control Message Protocol 1 1 1 1 1 ICMP Router Discovery Protocol (IRDP) A routing protocol used by Microsoft Windows DHCP clients and various Unix flavors. Vulnerability (http://securiteam.com/securitynews/Most_DHCP_clients_are_vulnerable_to_an_IRDP_attack.html). [Details? Reference?] (1999-10-31) 1 1 1 1 1 I-Comm A graphical web browser for IBM PCs with a window system (Windows 95, Windows NT or OS/2). I-Comm does NOT require a SLIP or PPP connection, just a modem. It is available as a shareware program. Version: 1.15 Beta1. (http://talentcom.com/icomm/icomm.htm), mirror (http://best.com:80/~icomm/icomm/icomm.htm). FTP netcom.com (ftp://ftp.netcom.com/pub/ic/icomm/), FTP best.com (ftp://ftp.best.com/pub/icomm/icomm/). E-Mail: <icomm@talentcom.com>. (1996-03-22) 1 1 1 1 1 iCOMP Intel Comparative Microprocessor Performance index 1 1 1 1 1 Icon A descendant of SNOBOL4 with Pascal-like syntax, produced by Griswold in the 1970's. Icon is a general-purpose language with special features for string scanning. It has dynamic types: records, sets, lists, strings, tables. If has some object oriented features but no modules or exceptions. It has a primitive Unix interface. The central theme of Icon is the generator: when an expression is evaluated it may be suspended and later resumed, producing a result sequence of values until it fails. Resumption takes place implicitly in two contexts: iteration which is syntactically loop-like ('every-do'), and goal-directed evaluation in which a conditional expression automatically attempts to produce at least one result. Expressions that fail are used in lieu of Booleans. Data backtracking is supported by a reversible assignment. Icon also has co-expressions, which can be explicitly resumed at any time. 1 1 1 1 1 icon A small picture intended to represent something (a file, directory, or action) in a graphical user interface. When an icon is clicked on, some action is performed such as opening a directory or aborting a file transfer. Icons are usually stored as bitmap images. Microsoft Windows uses a special bitmap format with file name extension .ico as well as embedding icons in executable (".exe") and Dynamically Linked Library (DLL) files. The term originates from Alan Kay's theory for designing interfaces which was primarily based on the work of Jerome Bruner. Bruner's second developmental stage, iconic, uses a system of representation that depends on visual or other sensory organization and upon the use of summarising images. IEEE publication (http://ieee.org/organizations/history_center/cht_papers/Barnes.pdf). [What MS tool can create .ico files?] (2003-08-01) 1 1 1 1 1 Icon-Based Parser Generation System 2 (Ibpag2) A parser generator for Icon by Richard L. Goerwitz <goer@midway.uchicago.edu>. It can handle both SLR1 grammars and even GLR grammars (Tomita grammars). Ibpag2 runs under Unix. Latest version: 1.0 (beta), as of 1993-07-13. (2004-06-06) 1 1 1 1 1 Iconicode 1990-1992. Visual dataflow language, token-based with hierarchical, recursive and iterative constructs. Version: IDF with extensions for image processing. ["IDF: A Graphical Data Flow Programming Language for Image Processing and Computer Vision", Neil Hunt, Proc IEEE Conf on Systems Man & Cybernetics, IEEE, Nov 1990. Available from Iconicon <icon@teleos.com>]. 1 1 1 1 1 ICONIX Software Engineering, Inc. Makers of ICONIX PowerTools, software development tools, and the first CD-ROM training course in object-oriented methods. ICONIX started operating in 1984. (http://biap.com/iconix/). Address: 2800 28th Street, Suite 320, Santa Monica, CA 90405, USA. Telephone: +1 (310) 458 0092 (1995-04-30) 1 1 1 1 1 IC-Prolog Clark & McCabe, Imperial College 1979. Logic language with coroutining. ["IC-Prolog Language Features", K.L. Clark <klc@doc.ic.ac.uk> et al in Logic Programming, K.L. Clark et al eds, pp.253-266, Academic Press 1982]. 1 1 1 1 1 IC Prolog II Imperial College Prolog. A Prolog with multi-threading, TCP primitives for interprocess communication, mailboxes, and an interface to Parlog. (ftp://doc.ic.ac.uk/computing/programming/languages). ["IC Prolog II: A Language for Implementing Multi-Agent Systems", Y. Cosmadopoulos et al, in Tutorial and Workshop on Cooperating Knowledge Based Systems, Keele U 1992]. (1994-11-01) 1 1 1 1 1 ICQ 1. Abbreviation for "I seek you". 2. A proprietary chat system created by a couple of israeli guys, who later founded "mirabilis". ICQ was sold to America On-Line around 1998. The name "ICQ" is a play on "cq", the radio signal for seeking conversation. (http://icq.com/). [Confirm derivation? TCP? Summary?] (2000-04-03) 1 1 1 1 1 ICSI International Computer Science Institute at Berkeley, CA. 1 1 1 1 1 ICT 1. <education> Information and Communication Technology. 2. <testing> In Circuit Test. (2000-04-04) 1 1 1 1 1 ICW Interactive CourseWare 1 1 1 1 1 ICWS International Core War Society. 1 1 1 1 1 Id Irvine Dataflow 1 1 1 1 1 id The country code for Indonesia. (1999-01-27) 1 1 1 1 1 I-D Internet-Draft 1 1 1 1 1 ID10T /I D ten T/ A grade of user problem somewhere between PEBCAK and UBD. Considered friendlier than saying, "You called me down here to exit a modal dialog box for you?" (2003-06-07) 1 1 1 1 1 IDAMS A pictorial retrieval language implemented in APL. ["Concept of the Diagnostic Image Workstation", D. Meyer-Ebrecht, Proc 2nd Conf on Picture Archiving (PACS II), SPIE 418, pp.180-183 (1983)]. 1 1 1 1 1 IDD international direct dialing 1 1 1 1 1 IDE 1. <storage> Integrated Drive Electronics, see Advanced Technology Attachment. 2. <programming, tool> integrated development environment. 3. <company> Interactive Development Environments. (2002-04-14) 1 1 1 1 1 IDEA 1. <language> Interactive Data Entry/Access. 2. <algorithm> International Data Encryption Algorithm. (1996-02-16) 1 1 1 1 1 IDEAL 1. Ideal DEductive Applicative Language. A language by Pier Bosco and Elio Giovannetti combining Miranda and Prolog. Function definitions can have a guard condition (introduced by ":-") which is a conjunction of equalities between arbitrary terms, including functions. These guards are solved by normal Prolog resolution and unification. It was originally compiled into C-Prolog but was eventually to be compiled to K-leaf. 2. A numerical constraint language written by Van Wyk of Stanford in 1980 for typesetting graphics in documents. It was inspired partly by Metafont and is distributed as part of Troff. ["A High-Level Language for Specifying Pictures", C.J. Van Wyk, ACM Trans Graphics 1(2):163-182 (Apr 1982)]. (1994-12-15) 1 1 1 1 1 ideal In domain theory, a non-empty, downward closed subset which is also closed under binary least upper bounds. I.e. anything less than an element is also an element and the least upper bound of any two elements is also an element. (1997-09-26) 1 1 1 1 1 Idealized CSP A programming language combining simply typed, call-by-name procedures with asynchronous communicating processes, assuming fair parallel execution. Idealized CSP generalises Anthony Hoare's original CSP and Kahn's networks of deterministic processes, and is closely related to Parallel Algol by Stephen Brookes of CMU. Procedures permit the encapsulation of common protocols and parallel programming idioms. Local variables and local channel declarations provide a way to delimit the scope of interference between parallel agents, and allow a form of concurrent object-oriented programming. [Was this language also designed by Brookes?] (1997-09-26) 1 1 1 1 1 Idealized Instruction Set (IIS) The assembly language for the Flagship parallel machine. ["An Idealized Instruction Set for a Packet Rewrite Machine", J. Sargeant, Manchester U, 1988]. (1994-11-07) 1 1 1 1 1 IDEF ICAM Definition. 1 1 1 1 1 IDEF0 A minor elaboration on SADT. IDEF Home (http://www.idef.com/idef0.html). (2007-02-12) 1 1 1 1 1 idempotent 1. A function f : D -> D is idempotent if f (f x) = f x for all x in D. I.e. repeated applications have the same effect as one. This can be extended to functions of more than one argument, e.g. Boolean & has x & x = x. Any value in the image of an idempotent function is a fixed point of the function. 2. This term can be used to describe C header files, which contain common definitions and declarations to be included by several source files. If a header file is ever included twice during the same compilation (perhaps due to nested #include files), compilation errors can result unless the header file has protected itself against multiple inclusion; a header file so protected is said to be idempotent. 3. The term can also be used to describe an initialisation subroutine that is arranged to perform some critical action exactly once, even if the routine is called several times. 1 1 1 1 1 identifier 1. <programming, operating system> A formal name used in source code to refer to a variable, function, procedure, package, etc. or in an operating system to refer to a process, user, group, etc. Each different type of entity may have a different range of valid identifiers or "name space". For example, an identifier in C is a series of one or more letters, digits and underscores that does not begin with a digit. An identifier has a type, e.g. integer variable, hash, variant and a scope, e.g. block, global. (2006-05-29) 2. <database> (id) A primary key. The column containing a table's primary key is frequently named after the table with _id appended, e.g. "customer_id". (2006-05-29) 1 1 1 1 1 ideogram A symbol representing a concept. Nearly all ideograms are pictograms - pictures of the thing represented, others are merely conventional. An example of non-pictorial ideogram might be the degree symbol (a superfix circle) when used for temperature. (2014-07-30) 1 1 1 1 1 I didn't change anything! An aggrieved cry often heard as bugs manifest during a regression test. The canonical reply to this assertion is Then it works just the same as it did before, doesn't it? See also one-line fix. This is also heard from applications programmers trying to blame an obvious applications problem on an unrelated systems software change, for example a divide-by-0 fault after terminals were added to a network. Usually, their statement is found to be false. Upon close questioning, they will admit some major restructuring of the program that shouldn't have broken anything, in their opinion, but which actually hosed the code completely. [Jargon File] 1 1 1 1 1 idk I don't know. (2003-09-23) 1 1 1 1 1 IDL 1. Interactive Data analysis Language (Xerox). 2. Interface Description Language (Snodgrass, UNC, Arizona). 3. Interface Definition Language (SunSoft, OMG). 4. Interactive Data Language (Research Systems). (2004-05-07) 1 1 1 1 1 IDMS 1. <language, database> A pictorial query language, an extension of Sequel2. ["A Management System for an Integrated Database of Pictures and Alphanumeric Data", G.Y. Tang, Computer Graphics Image Processing 16:270-286 (1981)]. 2. <database> Integrated Database Management System. (2002-06-10) 1 1 1 1 1 IDMSX IDMS extended. (1995-04-19) 1 1 1 1 1 Id Nouveau A dataflow language by Arvind <arvind@lcs.mit.edu> and R.S. Nikhil <nikhil@crl.dec.com>, MIT LCS, ca. 1986. Id Nouveau began as a functional language, added streams, resource managers and I-structures (mutable arrays). Loops are syntactic sugar for tail recursion. See also Id. ["Id Nouveau Reference Manual", R.S. Nikhil, CS TR, MIT, March 1988]. ["Id (Version 90.1) Reference Manual", R.S. Nikhil, CSG Memo 284-2, LCS MIT, July 15, 1991]. 1 1 1 1 1 IDOL Icon-Derived Object Language. An object-oriented preprocessor for Icon. (ftp://src.doc.ic.ac.uk/pub/languages/icon/idol.tar.Z). ["Programming in Idol: An Object Primer", C.L. Jeffery, U Arizona CS TR #90-10]. 1 1 1 1 1 IDS/I Integrated Data Store. An extension to COBOL involving chains (circular lists), for General Electric computers. ["A General Purpose Programming System for Random Access Memories", C.W. Bachman et al, Proc FJCC 26(1), AFIPS (Fall 1964)]. [Sammet 1969, p. 376]. 1 1 1 1 1 IDSN ISDN 1 1 1 1 1 id Software Creators and publishers of the DOOM game for IBM PCs. E-mail: <help@idsoftware.com>. Telephone: +1 800-ID-GAMES (Orders only). 1 1 1 1 1 IDSS Intelligent Decision Support Systems 1 1 1 1 1 IE Internet Explorer 1 1 1 1 1 ie The country code for Ireland. (1999-01-27) 1 1 1 1 1 IEC International Electrotechnical Commission 1 1 1 1 1 IEC 559 IEEE Floating Point Standard 1 1 1 1 1 IEEE Institute of Electrical and Electronics Engineers 1 1 1 1 1 IEEE 1076 The IEEE standard for VHDL. 1 1 1 1 1 IEEE 1394 High Performance Serial Bus 1 1 1 1 1 IEEE 488 (GPIB, General-Purpose Interface Bus, HP-IB, Hewlett-Packard Interface Bus) An 8-bit parallel bus common on test equipment. The IEEE-488 standard was proposed by Hewlett-Packard in the late 1970s and has undergone a couple of revisions. HP documentation (including data sheets and manuals) calls it HP-IB, or Hewlett-Packard Interface Bus. It allows up to 15 intelligent devices to share a single bus, with the slowest device participating in the control and data transfer handshakes to drive the speed of the transaction. The maximum data rate is about one megabit per second. Other standards committees have adopted HP-IB (American Standards Institute with ANSI Standard MC 1.1 and International Electro-technical Commission with IEC Publication 625-1). To paraphrase from the HP 1989 Test & Measurement Catalog (the 50th Anniversary version): The HP-IB has a party-line 1 1 1 1 1 IEEE 754 IEEE Floating Point Standard 1 1 1 1 1 IEEE 802 The IEEE standards for local area networks. The spanning tree algorithm is defined in IEEE 802.1 (under consideration), Logical Link Control (LLC, the upper portion of the data link layer) in IEEE 802.2, Ethernet in IEEE 802.3, Token Bus in IEEE 802.4 and IBM Token Ring in IEEE 802.5. The equivalent ISO standard is IS 8802. (1995-02-15) 1 1 1 1 1 IEEE 802.1 An IEEE working group concerned with the IEEE 802 family of networking standards, specifically bridging and network management. The spanning tree protocol is standardised as 802.1D. (2010-09-26) 1 1 1 1 1 IEEE 802.2 (Networks) The IEEE standard defining Logical Link Control (LLC, the upper portion of the data link layer) for local area networks. (1995-02-14) 1 1 1 1 1 IEEE 802.3 The IEEE standard defining the hardware layer and transport layer of (a varient of) Ethernet. The maximum segment length is 500m and the maximum total length is 2.5km. The maximum number of hosts is 1024. The maximum packet size is 1518 bytes. If the upper layer protocol submits a PDU less than 64 bytes, 802.3 will pad the LLC Info field to achieve the minimum 64 bytes. Although it is not technically correct, the terms "packet" and frame are used interchangeably. The ISO/IEC 8802-3 ANSI/IEEE 802.3 Standards refer to MAC sub-layer frames consisting of the Destination Address, Source Address, Length, LLC Info., and FCS fields. The Preamble and SFD are (usually) considered a header to the MAC Frame. This header plus the MAC Frame constitute a "Packet". (1995-07-09) 1 1 1 1 1 IEEE 802.3u The IEEE committee working on standards for Fast Ethernet. (1998-06-30) 1 1 1 1 1 IEEE 802.3z The IEEE committee working on standards for Gigabit Ethernet. (1998-06-30) 1 1 1 1 1 IEEE 802.4 The IEEE Token Bus standard. (1996-12-12) 1 1 1 1 1 IEEE 802.5 The IEEE token ring standard. The most common type of token ring. (1994-10-27) 1 1 1 1 1 IEEE Computer Society The society of the IEEE which publishes the journal Computer. (http://computer.org/). (1995-03-10) 1 1 1 1 1 IEEE Floating Point Standard (IEEE 754) "IEEE Standard for Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985)" or IEC 559: "Binary floating-point arithmetic for microprocessor systems". A standard, used by many CPUs and FPUs, which defines formats for representing floating-point numbers; representations of special values (e.g. infinity, very small values, NaN); five exceptions, when they occur, and what happens when they do occur; four rounding modes; and a set of floating-point operations that will work identically on any conforming system. IEEE 754 specifies formats for representing floating-point values: single-precision (32-bit) is required, double-precision (64-bit) is optional. The standard also mentions that some implementations may include single-extended precision (80-bit) and double-extended precision (128-bit) formats. [On-line document?] 1 1 1 1 1 IEEE Standard 1149.1 Joint Test Action Group 1 1 1 1 1 IEF Advantage Gen 1 1 1 1 1 IEN Internet Experiment Note 1 1 1 1 1 IEPG Internet Engineering and Planning Group 1 1 1 1 1 IESG Internet Engineering Steering Group 1 1 1 1 1 IETF Internet Engineering Task Force 1 1 1 1 1 IF1 A graph language used as an intermediate language for dataflow hardware. Used by the OSC SISAL compiler. ["The Manchester Prototype Dataflow Computer", J.R. Gurd et al, CACM 28(1):34-52, Jan 1985]. (1996-01-05) 1 1 1 1 1 IF2 S graph language used by the OSC SISAL compiler, a superset of IF1. ["IF2: An Applicative Language Intermediate Form with Explicit Memory Management", M. L. Welcome et al, UC-LLNL, Nov 1986]. (1996-01-05) 1 1 1 1 1 IFAC International Federation of Automatic Control, involved in informatics related to control systems. 1 1 1 1 1 IFC Internet Foundation Classes 1 1 1 1 1 ifdef out /if'def owt/ v. Synonym for condition out, specific to C. [Jargon File] 1 1 1 1 1 IFDL Independent Form Description Language. DEC's language for describing form-based human interfaces in DECforms. (1995-04-21) 1 1 1 1 1 IFF 1. <file format> Interchange File Format. 2. Identify friend or foe (radar). 1 1 1 1 1 iff if and only if, i.e. necessary and sufficient. For example, two figures are congruent iff one can be placed over the other so that they coincide. (2002-12-28) 1 1 1 1 1 IFIP 1. International Federation for Information Processing. 2. A subset of ALGOL. [Sammet 1969, p. 180]. 1 1 1 1 1 IFP Illinois Functional Programming 1 1 1 1 1 IFS 1. <operating system> internal field separators. 2. <operating system> Installable File System. 3. <graphics> Iterated Function System. (1999-04-07) 1 1 1 1 1 IFX ["Type Reconstruction with First-Class Polymorphic Values", J. O'Toole et al, SIGPLAN Notices 24(7):207-217 (Jul 1989)]. 1 1 1 1 1 If you want X, you know where to find it. There is a legend that Dennis Ritchie, inventor of C, once responded to demands for features resembling those of what at the time was a much more popular language by observing "If you want PL/I, you know where to find it." Ever since, this has been hackish standard form for fending off requests to alter a new design to mimic some older (and, by implication, inferior and baroque) one. The case X = Pascal manifests semi-regularly on Usenet's news:comp.lang.c newsgroup. Indeed, the case X = X has been reported in discussions of graphics software (see X Window System). [Jargon File] (1995-10-25) 1 1 1 1 1 IGC Institute for Global Communications 1 1 1 1 1 IGES Initial Graphics Exchange Specification: an ASME/ANSI standard for the exchange of CAD data. 1 1 1 1 1 IGL Interactive Graphic Language. Used primarily by Physics Dept at Brooklyn Poly, uses numerical methods on vectors to approximate continuous function problems that don't have closed form solutions. [Is this being confused with Tektronix's graphics library by the same name?] 1 1 1 1 1 IGMP Internet Group Management Protocol 1 1 1 1 1 IGP Interior Gateway Protocol 1 1 1 1 1 IGPL Interest Group in Pure and Applied Logics 1 1 1 1 1 IGS Internet Go Server. 1 1 1 1 1 IGU I Give Up. Often found appended to documents, e-mail, programs that don't work, etc. (1999-09-30) 1 1 1 1 1 IHS Integrated Home System 1 1 1 1 1 IHV Independent Hardware Vendor 1 1 1 1 1 IIcx Apple IIcx 1 1 1 1 1 IIDMS/R Integrated database management system 1 1 1 1 1 IIL Integrated Injection Logic 1 1 1 1 1 IINREN Interagency Interim National Research and Education Network 1 1 1 1 1 IIOP Internet Inter-ORB Protocol 1 1 1 1 1 IIR Infinite Impulse Response 1 1 1 1 1 IIRC If I recall/remember correctly. (1996-11-28) 1 1 1 1 1 IIS 1. <web> Internet Information Server. 2. <language> Idealized Instruction Set. (1999-08-26) 1 1 1 1 1 IIT Integrated Information Technology 1 1 1 1 1 IITF Information Infrastructure Task Force 1 1 1 1 1 IITRAN Simple PL/I-like language for students, on IBM 360. ["The IITRAN Programming Language", R. Dewar et al, CACM 12(10):569-575 (Oct 1969)]. 1 1 1 1 1 il The country code for Israel. (1999-01-27) 1 1 1 1 1 ILBM interleaved bit-map 1 1 1 1 1 ILF Independent Logical File 1 1 1 1 1 ILIAD A real-time language. ["On the Design of a Language for Programming Real-Time Concurrent Processes", H.A. Schutz, IEEE Trans Soft Eng SE-5(3):248-255, May 1979]. (2000-09-03) 1 1 1 1 1 I-Link High Performance Serial Bus 1 1 1 1 1 ILISP A somewhat LISP Machine-like interface to lisp listeners from Emacs. Version 5.0 Emacs interface by ? Ivan Vazquez <ivan@haldane.bu.edu>. (ftp://haldane.bu.edu/) (128.197.54.25). E-mail: <ilisp-bug@darwin.bu.edu>, <ilisp-bugs@darwin.bu.edu>, <ilisp-request@darwin.bu.edu> (discussion). (1993-06-28) 1 1 1 1 1 ill-behaved 1. [numerical analysis] Said of an algorithm or computational method that tends to blow up because of accumulated roundoff error or poor convergence properties. 2. Software that bypasses the defined operating system interfaces to do things (like screen, keyboard, and disk I/O) itself, often in a way that depends on the hardware of the machine it is running on or which is nonportable or incompatible with other pieces of software. In the IBM PC/mess-dos world, there is a folk theorem (nearly true) to the effect that (owing to gross inadequacies and performance penalties in the OS interface) all interesting applications are ill-behaved. See also bare metal. Opposite: well-behaved, compare PC-ism. [Jargon File] 1 1 1 1 1 ILLIAC Assembly language for the ILLIAC computer. Listed in CACM 2(5):16, (May 1959) p.16. 1 1 1 1 1 Illiac IV One of the most infamous supercomputers ever. It used early ideas on SIMD (single instruction stream, multiple data streams). The project started in 1965, it used 64 processors and a 13MHz clock. In 1976 it ran its first sucessfull application. It had 1MB memory (64x16KB). Its actual performance was 15 MFLOPS, it was estimated in initial predictions to be 1000 MFLOPS. It totally failed as a computer, only a quarter of the fully planned machine was ever built, costs escalated from the $8 million estimated in 1966 to $31 million by 1972, and the computer took three more years of enginering before it was operational. The only good it did was to push research forward a bit, leading way for machines such as the Thinking Machines CM-1 and CM-2. (1995-04-28) 1 1 1 1 1 Illinois Functional Programming (IFP) An interpreter written in portable C by Arch D. Robison for a variant of Backus's FP with syntax like ALGOL or Modula-2. IFP Runs under Unix, CTSS (Cray) and MS-DOS. Version: 0.5. (ftp://a.cs.uiuc.edu/pub/ifp). Posted to comp.sources.unix volume 10. ["The Illinois Functional Programming Interpreter", A.D. Robison, Proc 1987 SIGPLAN Conf on Interpreters and Interpretive Techniques (June 1987), pp. 64-73]. ["Illinois Functional Programming: A Tutorial", A.D. Robison, BYTE Feb 1987, pp. 115-125]. (1994-10-24) 1 1 1 1 1 ILOC Rice U. Register-oriented intermediate language targeted to PC/RT. Source languages include Fortran and Russell. 1 1 1 1 1 Ilog Solver A commercial constraint programming system. (1994-11-15) 1 1 1 1 1 iMac One of the trademark/brand names that Apple Inc use for their Mac family of personal computers. (2009-05-05) 1 1 1 1 1 image 1. <data, graphics> Data representing a two-dimensional scene. A digital image is composed of pixels arranged in a rectangular array with a certain height and width. Each pixel may consist of one or more bits of information, representing the brightness of the image at that point and possibly including colour information encoded as RGB triples. Images are usually taken from the real world via a digital camera, frame grabber, or scanner; or they may be generated by computer, e.g. by ray tracing software. See also image formats, image processing. (1994-10-21) 2. <mathematics> The image (or range) of a function is the set of values obtained by applying the function to all elements of its domain. So, if f : D -> C then the set f(D) = \ f(d) | d in D \ is the image of D under f. The image is a subset of C, the codomain. (2000-01-19) 1 1 1 1 1 image formats There are many formats used to store images in files. GIF, TIFF and JPEG are very common. Others are BIFF, bmp, Clear, FITS, IFF, NFF, OFF, PCX, PNG, TGA, XBM. Some of these are documented on-line at the following sites: The Graphics File Format Page (http://dcs.ed.ac.uk/~mxr/gfx/). The NCSA file formats archive (ftp://ftp.ncsa.uiuc.edu/misc/file.formats/graphics.formats). The Avalon repository (ftp://avalon.viewpoint.com/pub/format_specs). [Others?] (1997-08-07) 1 1 1 1 1 image map An image in an HTML document with "hot spots" which when clicked on in a suitable browser, act as anchors or links to other information. For example, an image of a map of the world might provide links to resources related to different countries. Clicking on a country would take the user to the relevant information. [Documentation URL?] (1995-12-05) 1 1 1 1 1 image processing Computer manipulation of images. Some of the many algorithms used in image processing include convolution (on which many others are based), FFT, DCT, thinning (or skeletonisation), edge detection and contrast enhancement. These are usually implemented in software but may also use special purpose hardware for speed. Image processing contrasts with computer graphics, which is usually more concerned with the generation of artificial images, and visualisation, which attempts to understand (real-world) data by displaying it as an artificial image (e.g. a graph). Image processing is used in image recognition and computer vision. Silicon Graphics manufacture workstations which are often used for image processing. There are a few programming languages designed for image processing, e.g. CELIP, VPL. See also Pilot European Image Processing Archive. 1 1 1 1 1 image recognition The identification of objects in an image. This process would probably start with image processing techniques such as noise removal, followed by (low-level) feature extraction to locate lines, regions and possibly areas with certain textures. The clever bit is to interpret collections of these shapes as single objects, e.g. cars on a road, boxes on a conveyor belt or cancerous cells on a microscope slide. One reason this is an AI problem is that an object can appear very different when viewed from different angles or under different lighting. Another problem is deciding what features belong to what object and which are background or shadows etc. The human visual system performs these tasks mostly unconsciously but a computer requires skillful programming and lots of processing power to approach human performance. (1997-07-20) 1 1 1 1 1 imaging The production of graphic images, either from a video camera or from digitally generated data (see visualisation), or the recording of such images on microfilm, videotape or laser disk. See also scanner. (1997-07-20) 1 1 1 1 1 Imago Europe plc A UK Internet provider. There sevice is called Imago On-line. E-mail: <info@imago.com>. 1 1 1 1 1 Imago On-line An Internet electronic mail and news service in the United Kingdom provided by Imago Europe plc. A one year subscription to the service costs just seventy five pounds plus VAT and offers dial-up access with a graphical user interface for users of Macintosh and Microsoft Windows PCs and the Apple Newton MessagePad PDA family. 1 1 1 1 1 imake A tool which generates Makefiles from a template, a set of cpp macros, and a per-directory input file called an Imakefile. This allows machine dependencies (such has compiler options, alternate command names, and special make rules) to be kept separate from the descriptions of the various items to be built. imake is distributed with, and used extensively by, the X Window System. (1995-02-21) 1 1 1 1 1 IMAO IMHO 1 1 1 1 1 IMAP Internet Message Access Protocol 1 1 1 1 1 imc A REXX interpreter for SunOS. Current version 1.3 [?]. (ftp://rexx.uwaterloo.ca/pub/freerexx/imc/). (2000-11-07) 1 1 1 1 1 IMD intermodulation distortion 1 1 1 1 1 IMHO (From SF fandom via Usenet) In My Humble Opinion. Also seen in variant forms such as IMO, IMNSHO (In My Not-So-Humble Opinion) and IMAO (In My Arrogant Opinion). [Jargon File] (1998-09-24) 1 1 1 1 1 IML Initial Microprogram Load 1 1 1 1 1 immediate version child version 1 1 1 1 1 Imminent Death Of The Net Predicted! Since Usenet first got off the ground in 1980-81, it has grown exponentially, approximately doubling in size every year. On the other hand, most people feel the signal-to-noise ratio of Usenet has dropped steadily. These trends led, as far back as mid-1983, to predictions of the imminent collapse (or death) of the net. Ten years and numerous doublings later, enough of these gloomy prognostications have been confounded that the phrase Imminent Death Of The Net Predicted! has become a running joke, hauled out any time someone grumbles about the S/N ratio or the huge and steadily increasing volume, or the possible loss of a key node or link, or the potential for lawsuits when ignoramuses post copyrighted material etc. [Jargon File] (1998-09-24) 1 1 1 1 1 IMNSHO IMHO 1 1 1 1 1 IMO IMHO 1 1 1 1 1 IMP 1. <language> IMProved Mercury autocode. 2. <language> An extensible dialect of ALGOL 60, for CDC 1604. ["Experience with an Extensible Language", Edgar T. Irons, CACM 13(1):31-39, Jan 1970]. 3. <language> Interpretive Menu Processor. 4. <language> IMPlementation language. 5. <networking> Interface Message Processor. (1996-04-07) 1 1 1 1 1 impact printer The earlier, noisier kind of printer where part of the mechanism comes into contact with the paper. The term would only be only used in contrast to "non-impact printer". Examples include line printer, daisy wheel printer, golf ball printer, dot matrix printer, Braille printer. (1998-10-13) 1 1 1 1 1 impedance Opposition to flow of alternating current. Impedance consists of resistance plus reactance (capacitive or inductive). Measured in Ohms. (2003-12-02) 1 1 1 1 1 imperative imperative language 1 1 1 1 1 imperative language Any programming language that specifies explicit manipulation of the state of the computer system, not to be confused with a procedural language, which specifies an explicit sequence of steps to perform. An example of an imperative (but non-procedural) language is a data manipulation language for a relational database management system. This specifies changes to the database but does not necessarily require anyone to specify a sequence of steps. Both contrast with declarative languages, which specify neither explicit state manipulation nor a sequence of steps. (2007-10-02) 1 1 1 1 1 imperative programming imperative language 1 1 1 1 1 Imperial College of Science, Technology and Medicine (IC, ICST&M) One of the colleges of London University. The Department of Computing is the home of FOLDOC. IC Home (http://ic.ac.uk/). (2005-05-09) 1 1 1 1 1 Imperial Software Technology A software engineering company which emerged from Imperial College in about 1982. It enjoys a world-wide reputation for technical excellence as a software product and technology provider in the Open Systems market. Its flagship product is X-Designer, the award-winning graphical user interface builder. It also has considerable expertise in the Z language and Formal Methods. (http://ist.co.uk/). (1995-11-23) 1 1 1 1 1 IMPlementation language (IMP) An extension of B with floating-point operations, developed by W. Davidsen at General Electric in 1970 for the GE 600. It was also cross-compiled to VAX and Intel 8080. (1996-04-07) 1 1 1 1 1 implication implies 1 1 1 1 1 implicit parallelism A feature of a programming language for a parallel processing system which decides automatically which parts to run in parallel. The best way of providing implicit parallelism is still (1995) an active research topic. The problem is to generate the right number of parallel tasks of the right size (or granularity). Too many tasks and the system gets bogged down in house-keeping, or memory for waiting tasks runs out, too few tasks and processors are left idle. The best performance is usually achieved with explicit parallelism where the programmer can annotate his program to indicate which parts should be executed as independent parallel tasks. (1995-02-16) 1 1 1 1 1 implicit type conversion (Or "coercion") The abilty of some compilers to automatically insert type conversion functions where an expression of one type is used in a context where another type is expected. A common example is coercion of integers to reals so that an expression like sin(1) is compiled as sin(integerToReal(1)) where sin is of type Real -> Real. A coercion is usually performed automatically by the compiler whereas a cast is an explicit type conversion inserted by the programmer. See also subtype. (1997-07-28) 1 1 1 1 1 implies (=> or a thin right arrow) A binary Boolean function and logical connective. A => B is a true implication unless A is true and B is false. The truth table is A B | A => B ----+------- F F | T F T | T T F | F T T | T It is surprising at first that A => B is always true if A is false, but if X => Y then we would expect that (X & Z) => Y 1 1 1 1 1 imply implies 1 1 1 1 1 import To read data that is not in the native format of the application. For example, a web browser will have its own way of storing bookmarks but it will usually provide a function to import bookmarks from Internet Explorer. The alternative is to provide an independent external conversion utility but this is usually less convenient for the user. (2004-11-15) 1 1 1 1 1 imprecise probability A probability that is represented as an interval (as opposed to a single number) included in [0,1]. (2001-02-21) 1 1 1 1 1 IMProved Mercury autocode (IMP) A version of Autocode used to program the Edinburgh Multi Access System (EMAS), one of the first operating systems written in a high-level language, apparently predating Unix. Luis Damas' Prolog interpreter in IMP for EMAS led to C-Prolog. [Papers in J. British Computer Society]. (1996-04-07) 1 1 1 1 1 IMR Internet Monthly Report 1 1 1 1 1 IMS Information Management System 1 1 1 1 1 IMS 6100 Intersil 6100 1 1 1 1 1 Imsai One of the companies that made very early microprocessor systems. [Where? When? Who? What?] (1995-05-12) 1 1 1 1 1 IMS/Data Base (IMS/DB) A hierarchical high performance database for IBM mainframes, part of IMS. IMS/DB is implemented on top of VSAM and uses its underlying data structures. (1999-01-11) 1 1 1 1 1 IMS/Data Communications (IMS/DC) The teleprocessing monitor/transaction processing sytem in IMS from IBM. (1999-01-11) 1 1 1 1 1 IMSE Integrated Modelling Support Environment 1 1 1 1 1 IMTC International Multimedia Teleconferencing Consortium 1 1 1 1 1 in 1. <networking> The country code for India. (1999-01-27) 2. The typical type or "mode" of function parameter that passes information in one direction - from the caller to the function. Other modes are out and inout. (2010-01-19) 1 1 1 1 1 Ina Jo [FDM?] ["The Ina Jo Specification Language Reference Manual", J. Scheid et al, TR TM-(L)-6021/001/00, SDC Mar 1985]. (2000-02-24) 1 1 1 1 1 InARP Inverse Address Resolution Protocol 1 1 1 1 1 in-band signaling in-band signalling 1 1 1 1 1 in-band signalling (Or CAS, channel associated signaling) Transmission of control signals in the same channel as data. This is commonly used in the Public Switched Telephone Network where the same pair of wires carry both voice and control signals (e.g. dialling, ringing). Another example is the use on a computer serial line of Control-S and Control-Q characters for flow control as opposed to hardware flow control which would be out-of-band signalling. In digital communications, in-band signalling often uses bit-robbing where, for example, one bit in each frame is used for signalling instead of data. This is the reason why a D1 channel in the T-carrier system can only carry 56 Kbps of usable data instead of the 64 Kbps carried by the D0 channel in the E-carrier system. (2007-01-26) 1 1 1 1 1 inc /ink/ increment, i.e. increase by one. Especially used by assembly programmers, as many assembly languages have an inc mnemonic. Antonym: dec. [Jargon File] 1 1 1 1 1 incantation Any particularly arbitrary or obscure command that one must mutter at a system to attain a desired result. Not used of passwords or other explicit security features. Especially used of tricks that are so poorly documented that they must be learned from a wizard. "This compiler normally locates initialised data in the data segment, but if you mutter the right incantation they will be forced into text space." 1 1 1 1 1 include [Usenet] 1. To duplicate a portion (or whole) of another's message (typically with attribution to the source) in a reply or followup, for clarifying the context of one's response. See the discussion of inclusion styles under "Hacker Writing Style". 2. [C] "#include <disclaimer.h>" has appeared in sig blocks to refer to a notional "standard disclaimer file". [Jargon File] 1 1 1 1 1 include war Excessive multi-leveled including within a discussion thread, a practice that tends to annoy readers. In a forum with high-traffic newsgroups, such as Usenet, this can lead to flames and the urge to start a kill file. 1 1 1 1 1 inclusive In domain theory, a predicate P : D -> Bool is inclusive iff For any chain C, a subset of D, and for all c in C, P(c) => P(lub C) In other words, if the predicate holds for all elements of an increasing sequence then it holds for their least upper bound. ("lub is written in LaTeX as \sqcup). (1995-02-03) 1 1 1 1 1 incomparable Two elements a, b of a set are incomparable under some relation <= if neither a <= b, nor b <= a. (1995-09-21) 1 1 1 1 1 incremental analysis Partial analysis of an incomplete product to allow early feedback on its development. (1996-05-22) 1 1 1 1 1 incremental backup A kind of backup that copies all files which have changed since the date of the previous backup. The first backup of a file system should include all files - a full backup. Call this level 0. The next backup could also be a full level 0 backup but it is usually much quicker to do a level 1 backup which will include only those files which have changed since the level 0 backup. Together the level 0 and level 1 backups will include the latest version of every file. Level 1 backups can be made until, say, the backup tape is nearly full, after which we can switch to level 2. Each level includes those files which have changed since the last backup at a lower level. The more levels you use, the longer it will take to restore the latest version of a file (or all files) if you don't know when it was last modified. Compare differential backup. (2004-03-01) 1 1 1 1 1 incremental constraint solver A system in which a constraint solver is given constraints one at a time by an inference engine (as is found in Prolog). The solver adds the new constraint to an initially empty set of solved constraints. If the new constraint is consistent with the solved constraints it will be added to the set. If it was inconsistent, the inference engine backtracks. This is the basis of Constraint Logic Programming. (1994-11-01) 1 1 1 1 1 Incremental Prototyping Technology for Embedded Realtime Systems An Esprit project. [Partners? Results?] (1998-11-27) 1 1 1 1 1 indent indentation 1 1 1 1 1 indentation Space and/or tab characters added at the beginning of a line to indicate structure, e.g. indenting a quotation to make it stand out or indenting a block of code controlled by an if statement. Indentation is important in source code for readability. There are a number of different indent styles. Some programming languages go further and use indentation as the main method to represent block structure to the compiler or interpreter, see off-side rule. (2008-10-23) 1 1 1 1 1 indent style Rules for formatting code to make it easier to visually match up the beginning and end of a block of statements, particularly one controlled by a control statement such as "if", "else", "for", "while", "do". This becomes important with large, nested blocks of code. Indent styles vary in the placement of "" and "" with respect to the statement(s) they enclose and the controlling statement. The normal style is "Allman style", named after Eric Allman, a Berkeley hacker who wrote many BSD utilities in it. It is sometimes called "BSD style". It resembles normal indent style in Pascal and ALGOL. Basic indent per level is eight or four spaces. This is the only indent style to clearly associate the controlling statement and the beginning and the end of the block by aligning them vertically, which probably explains its widespread adoption. if (cond) 1 1 1 1 1 Independent Computing Architecture (ICA) Citrix's proprietary protocol that allows client desktop computers to run applications on application servers. Originally used between Windows systems, ICA is now also suported on Unix and Macintosh desktops and servers as well as some thin client hardware. (2012-07-08) 1 1 1 1 1 Independent Logical File (ILF) One kind of dynamic database management system. Examples of ILF databases are INQUIRE, ADABAS, NOMAD, FOCUS and DATACOM. [More details?] (1998-10-07) 1 1 1 1 1 Independent Verification and Validation (IV&V) The verification and validation of a software product by an organisation that is both technically and managerially separate from the organisation responsible for developing the product. (1996-12-27) 1 1 1 1 1 index (Plural "indices" or "indexes") 1. <programming> A number used to select an element of a list, vector, array or other sequence. Such indices are nearly always non-negative integers but see associative array. 2. <database> See inverted index. [Other kinds?] 3. <web> A search engine. 4. <web> A subject index. [Jargon File] (1997-04-09) 1 1 1 1 1 Index Data A Danish company who have released a lot of ANSI Z39.50 related source under GPL. (http://130.228.5.168). (1996-07-22) 1 1 1 1 1 IndexedDB A transactional, JavaScript-based object-oriented database for use in web browsers. IndexedDB stores and retrieves objects that are indexed with a key. Using the structured clone algorithm, it can serialise complex data structures that may contain cyclic references. IndexedDB is supported by Chrome, Firefox, Opera, Safari and even Internet Explorer. MDN (https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API), W3C Proposal (http://www.w3.org/TR/IndexedDB/). (2014-12-01) 1 1 1 1 1 Indexed Sequential Access Method (ISAM) An IBM file management system allowing records to be accessed either sequentially (in the order they were entered) or via an index. Each index orders the records on a different key. ISAM was followed by VSAM (Virtual Storage Access Method) and pre-dated relational databases. (2003-07-13) 1 1 1 1 1 index.htm index.html 1 1 1 1 1 index.html The default HTML page served by most web servers in response to a request for a directory. The name suggests that the page will contain some kind of index of the contents of the requested directory. For example, if the content for website example.com is stored in the file system in directory /var/www/example.com, then a request for http://example.com/products would return the contents of file /var/www/example.com/products/index.html. A website's home page follows the same logic. For the above example, a request for http://example.com/ would return the contents of /var/www/example.com/index.html. It is often possible, and occasionally necessary, to specify index.html explicitly in the URL, as in http://example.com/index.html, though modern practice is to omit it. If you're looking for FOLDOC's home page (/) at http://foldoc.org/index.html, then you followed an out-of-date 1 1 1 1 1 index register A register found in some CPUs, whose contents can be added to the address operand to give the effective address. Incrementing the index register then allows the program to access the next location in memory and so on, making it very useful for working with arrays or blocks of memory. Index registers first appeared around April 1949 in the Manchester Mark I. The Mark I's index register's contents were simply added to the entire instruction, thus potentially changing the opcode (see The story of Mel)! (2006-09-20) 1 1 1 1 1 indices A plural of "index". 1 1 1 1 1 indirect address An addressing mode found in many processors' instruction sets where the instruction contains the address of a memory location which contains the address of the operand (the "effective address") or specifies a register which contains the effective address. In the first case (indirection via memory), accessing the operand requires two memory accesses - one to fetch the effective address and another to read or write the actual operand. Register indirect addressing requires only one memory access. An indirect address may be indicated in assembly language by an operand in parentheses, e.g. in Motorola 68000 assembly MOV D0,(A0) writes the contents of register D0 to the location pointed to by the address in register A0. Indirect addressing is often combined with pre- or post- increment or decrement addressing, allowing the address of the 1 1 1 1 1 indirect addressing indirect address 1 1 1 1 1 indirection Manipulating data via its address. Indirection is a powerful and general programming technique. It can be used for example to process data stored in a sequence of consecutive memory locations by maintaining a pointer to the current item and incrementing it to point to the next item. Indirection is supported at the machine language level by indirect addressing. Many processor and operating system architectures use vectors which are also an instance of indirection, being locations which hold the address of a routine to handle a particular event. The event handler can be changed simply by pointing the vector at a new piece of code. C includes operators "&" which returns the address of a variable and its inverse "*" which returns the variable at a given address. (1997-02-06) 1 1 1 1 1 indirect jump A jump via an indirect address, i.e. the jump instruction contains the address of a memory location that contains the address of the next instruction to execute. The location containing the address to jump to is sometimes called a vector. Indirect jumps make normal code hard to understand because the jump target is a run-time property of the program that depends on the execution history. They are useful for, e.g. allowing user code to replace operating system code or setting up event handlers. (2010-01-01) 1 1 1 1 1 induction A method of proving statements about well-ordered sets. If S is a well-ordered set with ordering "<", and we want to show that a property P holds for every element of S, it is sufficient to show that, for all s in S, IF for all t in S, t < s => P(t) THEN P(s) I.e. if P holds for anything less than s then it holds for s. In this case we say P is proved by induction. The most common instance of proof by induction is induction over the natural numbers where we prove that some property holds for n=0 and that if it holds for n, it holds for n+1. (In fact it is sufficient for "<" to be a well-founded partial order on S, not necessarily a well-ordering of S.) (1999-12-09) 1 1 1 1 1 inductive inference grammatical inference 1 1 1 1 1 inductive relation A relation R between domains D and E is inductive if for all chains d1 .. dn in D and e1 .. en in E, For all i, di R ei => lub(d) R lub(e) 1 1 1 1 1 Industrial Programming, Inc. The company which developed MTOS. (http://ipi.com). E-mail: <info@ipi.com>. Telephone: +1 (516) 938 6600. Address: 100 Jericho Quadrangle, Jericho, NY 11753, USA. (1997-07-23) 1 1 1 1 1 Industrial Robot Language (IRL) A high-level language for programming industrial robots. ["IRL, Industrial Robot Language", DIN 66312, Beuth-Verlag 1992]. (1996-11-28) 1 1 1 1 1 Industry Standard Architecture (ISA) A bus standard for IBM compatibles that extends the XT bus architecture to 16 bits. It also allows for bus mastering although only the first 16 MB of main memory is available for direct access. In reference to the XT bus architecture it is sometimes referred to as "AT bus architecture". Compare EISA, MCA. (1996-06-25) 1 1 1 1 1 inetd Berkeley daemon program that listens for connection requests or messages for certain ports and starts server programs to perform the services associated with those ports. Sometimes known as netd. Unix manual page: inetd(8). (1995-03-20) 1 1 1 1 1 inews A Unix program for posting Usenet news articles, written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. inews reads an article (perhaps with headers) from a file or standard, adds some headers and possibly a signature, and, if the article passes some consistency checks (too much quoting, non-existent newsgroup) then inews sends the article to the local news server for distribution. If an unapproved posting is made to a moderated newsgroup, inews will try to send the article to the moderator (specified in a configuration file) by electronic mail. Version: 1.25, dated 1993/03/18. Unix manual page: inews(1). (1996-02-27) 1 1 1 1 1 infant mortality It is common lore among hackers (and in the electronics industry at large) that the chances of sudden hardware failure drop off exponentially with a machine's time since first use (that is, until the relatively distant time at which enough mechanical wear in I/O devices and thermal-cycling stress in components has accumulated for the machine to start going senile). Up to half of all chip and wire failures happen within a new system's first few weeks; such failures are often referred to as "infant mortality" problems (or, occasionally, as "sudden infant death syndrome"). See bathtub curve, burn-in period. [Jargon File] (1995-03-20) 1 1 1 1 1 infeasible path dead code 1 1 1 1 1 inference The logical process by which new facts are derived from known facts by the application of inference rules. See also symbolic inference, type inference. (1995-03-20) 1 1 1 1 1 inference engine A program that infers new facts from known facts using inference rules. Commonly found as part of a Prolog interpreter, expert system or knowledge based system. (1994-11-01) 1 1 1 1 1 inference rule A procedure which combines known facts to produce ("infer") new facts. For example, given that 1. Socrates is a man and that 2. all men are motal, we can infer that Socrates is mortal. This uses the rule known as "modus ponens" which can be written in Boolean algebra as (A & A => B) => B (if proposition A is true, and A implies B, then B is true). Or given that, 1. Either Denis is programming or Denis is sad and 2. Denis is not sad, 1 1 1 1 1 infimum greatest lower bound 1 1 1 1 1 infinite 1. Bigger than any natural number. There are various formal set definitions in set theory: a set X is infinite if (i) There is a bijection between X and a proper subset of X. (ii) There is an injection from the set N of natural numbers to X. (iii) There is an injection from each natural number n to X. These definitions are not necessarily equivalent unless we accept the Axiom of Choice. 2. The length of a line extended indefinitely. See also infinite loop, infinite set. [Jargon File] (1995-03-29) 1 1 1 1 1 Infinite Impulse Response A type of digital signal filter, in which every sample of output is the weighted sum of past and current samples of input, using all past samples, but the weights of past samples are an inverse function of the sample age, approaching zero for old samples. (2001-06-06) 1 1 1 1 1 infinite loop (Or "endless loop") Where a piece of program is executed repeatedly with no hope of stopping. This is nearly always because of a bug, e.g. if the condition for exiting the loop is wrong, though it may be intentional if the program is controlling an embedded system which is supposed to run continuously until it is turned off. The programmer may also intend the program to run until interrupted by the user. An endless loop may also be used as a last-resort error handler when no other action is appropriate. This is used in some operating system kernels following a panic. A program executing an infinite loop is said to spin or buzz forever and goes catatonic. The program is "wound around the axle". A standard joke has been made about each generation's exemplar of the ultra-fast machine: "The Cray-3 is so fast it can execute an infinite loop in under 2 seconds!" See also black hole, recursion, infinite loop. 1 1 1 1 1 Infinite Monkey Theorem "If you put an infinite number of monkeys at typewriters, eventually one will bash out the script for Hamlet." (One may also hypothesise a small number of monkeys and a very long period of time.) This theorem asserts nothing about the intelligence of the one random monkey that eventually comes up with the script (and note that the mob will also type out all the possible *incorrect* versions of Hamlet). It may be referred to semi-seriously when justifying a brute force method; the implication is that, with enough resources thrown at it, any technical challenge becomes a one-banana problem. This theorem was first popularised by the astronomer Sir Arthur Eddington. It became part of the idiom through the classic short story "Inflexible Logic" by Russell Maloney, and many younger hackers know it through a reference in Douglas Adams's "Hitchhiker's Guide to the Galaxy". See also: RFC 2795. 1 1 1 1 1 infinite set A set with an infinite number of elements. There are several possible definitions, e.g. (i) ("Dedekind infinite") A set X is infinite if there exists a bijection (one-to-one mapping) between X and some proper subset of X. (ii) A set X is infinite if there exists an injection from N (the set of natural numbers) to X. In the presence of the Axiom of Choice all such definitions are equivalent. (1995-03-27) 1 1 1 1 1 infinity 1. <mathematics> The size of something infinite. Using the word in the context of sets is sloppy, since different infinite sets aren't necessarily the same size cardinality as each other. See also aleph 0 2. <programming> The largest value that can be represented in a particular type of variable (register, memory location, data type, whatever). See also minus infinity. [Jargon File] (1994-11-18) 1 1 1 1 1 infix notation One of the possible orderings of functions and operands: in infix notation the functions are placed between their operands, such as "1+2". Although infix notation is limited to binary functions most languages mix infix notation with prefix or postfix notation, as a form of syntactic sugar. (1997-01-17) 1 1 1 1 1 infix syntax infix notation 1 1 1 1 1 inflate deflate 1 1 1 1 1 INFN Istituto Nazionale di Fisica Nucleare: an Italian State research organisation. 1 1 1 1 1 Infobahn (After the German "Autobahn") Information Superhighway. 1 1 1 1 1 Info BASIC Variant of Pick BASIC used with PRIME's PRIMOS. 1 1 1 1 1 infobot A bot that serves as a common database of information (often noteworthy URLs) for users on a chat system. Infobots often have a simple chatbot interface, responding to key-phrases, as well as to direct queries. Here, in a real conversation, the bot Purl's first response is triggered by the phrase "just tell me", and its second response is triggered by being directly asked "perlfunc?": <eesh> can someone tell me what: $num9 = substr($number,9,1); means <Tkil> eesh -- man perlfunc, look at "substr". <eesh> just tell me <purl> Didn't your momma ever tell you, "Go look it up in the dictionary"?! <Tkil> eesh -- no. that's all we'll tell you. read the documentation. <Tkil> eesh -- if you haven't man pages or perldoc, you can read them on the 'net. 1 1 1 1 1 Informatics Corporation Renamed to Sterling Software Corp. [When?] (1998-10-30) 1 1 1 1 1 information The result of applying data processing to data, giving it context and meaning. Information can then be further processed to yeild knowledge. People or computers can find patterns in data to perceive information, and information can be used to enhance knowledge. Since knowledge is prerequisite to wisdom, we always want more data and information. But, as modern societies verge on information overload, we especially need better ways to find patterns. 1234567.89 is data. Your bank balance has jumped 8087% to $1234567.89 is information. Nobody owes me that much money is knowledge. "I'd better talk to the bank before I spend it, because of what has happened to other people is wisdom." (2007-09-10) 1 1 1 1 1 Information Algebra Theoretical formalism for DP, never resulted in a language. Language Structure Group of CODASYL, ca. 1962. Sammet 1969, 709 1 1 1 1 1 Information and Communication Technology (ICT) The study of the technology used to handle information and aid communication. The phrase was coined by [?] Stevenson in his 1997 report to the UK government and promoted by the new National Curriculum documents for the UK in 2000. In addition to the subjects included in Information Technology (IT), ICT emcompasses areas such as telephony, broadcast media and all types of audio and video processing and transmission. (http://rubble.ultralab.anglia.ac.uk/stevenson/ICTUKIndex.html). (2008-09-19) 1 1 1 1 1 Information Appliance (IA) A consumer device that performs only a few targeted tasks and is controlled by a simple touch-screen interface or push buttons on the device's enclosure. [How does this differ from a PDA?] (1998-02-24) 1 1 1 1 1 Information Builders Distributors of LEVEL5 OBJECT. Telephone +1 800 969 INFO. 1 1 1 1 1 Information Engineering Facility Advantage Gen 1 1 1 1 1 information highway information superhighway 1 1 1 1 1 Information Infrastructure Task Force (IITF) A US government body created in 1993 by President Clinton to control and oversee the NII project. The IITF consists of representatives of the federal agencies involved in information technology. They work with the private sector to develop policy. Various IITF committees work on telecommunications, IPR, privacy, government information and applications. In 2013, the IITF does not appear to have any presence on the WWW, which strongly suggests that it no longer exists (or that it is pretty out of touch with modern information infrastructure). (http://itlaw.wikia.com/wiki/Information_Infrastructure_Task_Force). [Did it ever achieve anything? What happened to it?] (2013-11-16) 1 1 1 1 1 Information Innovation A group of companies with offices in Amsterdam and New York which acts as an information filter for the web. They analyse what happens in the Web community and organise the Web's information so that it is accessible and efficient to use. Information Innovation provides: The Management Guide - a guide for managers in the information age. The Guide consists of 22 parts, each concentrating on a particular technology or issue facing managers. Topics range from Artificial Intelligence and Telecommunications to Finance and Marketing. Each part contains references to additional valuable information, including CD ROMs, conferences, magazines, articles and books. The Hypergraphic Matrix - a "hypergraphic" matrix of 250 graphics discussing the interrelationships between technology, change, business functions and specific industries. 1 1 1 1 1 information island A body of information (i.e. electronic files) that needs to be shared but has no network connection. (1995-03-16) 1 1 1 1 1 Information Management The planning, budgeting, control and exploitation of the information resources in an organisation. The term encompasses both the information itself and the related aspects such as personnel, finance, marketing, organisation and technologies and systems. Information Managers are responsible for the coordination and integration of a wide range of information handling activities within the organisation. These include the formulation of corporate information policy, design, evaluation and integration of effective information systems and services, the exploitation of IT for competitive advantage and the integration of internal and external information and data. 1 1 1 1 1 Information Management System (IMS, IMS/VS, IMS/ESA) A database system from IBM consisting of IMS/Data Base and IMS/Data Communications. (1999-01-11) 1 1 1 1 1 information overload When a person feels unable to read all the information that is presented or available to them, particularly where they need to make decisions based on that information but can't because there is just too much to take in in the time available. (2005-01-09) 1 1 1 1 1 Information Processing Language (IPL) Said to be the first list-processing language, also the first language to support recursion. Written by Allen Newell, J.C. Shaw and H. Simon at Carnegie ca. 1956. It was very low level. Versions: IPL-I (never implemented), IPL-II (1957 for JOHNNIAC), IPL-III (existed briefly), IPL-IV, IPL-V (1958, for IBM 650, IBM 704, IBM 7090, many others. Widely used), IPL-VI. [Sammet 1969, pp. 388-400]. ["Information Processing Language-V Manual", A. Newell ed, P-H 1965]. (1994-11-04) 1 1 1 1 1 Information Resource Management (IRM) A philosophical and practical approach to managing government information. Information is regarded as a valuable resource which should be managed like other resources, and should contribute directly to accomplishing organisational goals and objectives. IRM provides an integrated view for managing the entire life-cycle of information, from generation, to dissemination, to archiving and/or destruction, for maximising the overall usefulness of information, and improving service delivery and program management. IRM views information and Information Technology as an integrating factor in the organisation, that is, the various organisational positions that manage information are coordinated and work together toward common ends. Further, IRM looks for ways in which the management of information and the management of Information Technology are interrelated, and fosters that interrelationship and organisational integration. IRM includes the management of (1) the broad range of 1 1 1 1 1 information superhighway (Or "Infobahn", "Info Strada") The name coined by US Vice-president Al Gore in the early 1990s for the emerging high-speed global communications network capable of carrying voice, data, video, and other services around the world. These services use satellite, copper cable, optical fibre, cellular telecommunications, and are accessible via set-top boxes or suitably equipped computers. See also National Information Infrastructure. (2001-03-31) 1 1 1 1 1 Information Systems Factory (ISF) An equivalent to an SEE. [Simultaneous Engineering Environment or Software Engineering Environment?] (2000-12-30) 1 1 1 1 1 information technology (IT) Applied computer systems - both hardware and software, and often including networking and telecommunications, usually in the context of a business or other enterprise. Often the name of the part of an enterprise that deals with all things electronic. The term "computer science" is usually reserved for the more theoretical, academic aspects of computing, while the vaguer terms "information systems" (IS) or "information services" may include more of the human activities and non-computerised business processes like knowledge management. Others say that IT includes computer science. (2000-10-02) 1 1 1 1 1 information technology governance The structure, oversight and management processes which ensure the delivery of the expected benefits of IT in a controlled way to help enhance the long term sustainable success of the enterprise. (2009-04-27) 1 1 1 1 1 Information Technology Infrastructure Library (ITIL) A method of organising the system and network management departments of large organisations. ITIL defines the (work) processes involved and the interfaces between them. (1995-06-27) 1 1 1 1 1 Informix A relational DBMS vendor. 1 1 1 1 1 InfoSeek A company providing InfoSeek Net Search, a free web search service which, in August 1995, indexed the full text of over 400,000 web pages. Net Search was rated as the fourth most popular site on the web by Interactive Age magazine. The also sell a commercial service, InfoSeek Search, that offers access to all the Usenet news groups, daily newswires, business and computer periodicals, and more. (http://www2.infoseek.com/). (1995-11-09) 1 1 1 1 1 InfoStreet, Inc. An Internet consulting and development company dedicated to assisting companies in establishing an Internet presence. InfoStreet develope Internet strategies, design and create web pages, and host and maintain websites. InfoStreet, has been recognized by PC/Computing as the "Best of the Top Home Page Services" (August 1996) and has been featured in Netguide magazine and the Wiley and Son's Electronic Marketing book. (http://InfoStreet.com/). Home page hosting service (http://instantweb.com). (1997-01-30) 1 1 1 1 1 infotainment Interactive services or software that provides some combination of information and entertainment. (2010-03-02) 1 1 1 1 1 InfoWord Office A suite of applications for Unix including a word processor, spreadsheet and database. Light Infocon S.A. (http://light.com.br/). (1998-07-21) 1 1 1 1 1 infrared (IR) Electromagnetic waves in the frequency range just below visible light corresponding to radiated heat. IR waves can be generated by a kind of LED and are often used for remote controls for televisions etc. and in some docking stations. (1997-01-30) 1 1 1 1 1 Infrared Data Association (IrDA) A non-profit trade association providing standards to ensure the quality and interoperability of infrared (IR) hardware. The association currently has a membership of over 160 companies from around the world, representing computer and telecommunications hardware, software, components and adapters. IrDA typically uses direct infrared i.e. point-to-point, line-of-sight, one-to-one communications. The standards include: IrDA Data (SIR, FIR, VFIR), IrDA Control, and AIR. Ports built to the above standards can be found in products such as PDAs, Palm devices, printers, desktop adapters, notebooks, and digital cameras. (http://irda.org). IrDA Serial Infrared Interface (http://cesdis1.gsfc.nasa.gov/linux/misc/irda.html). 1 1 1 1 1 infrastructure Basic support services for computing, particularly national networks. See also information superhighway. (1995-06-27) 1 1 1 1 1 Inglish An English-like language used for Adventure games like "The Hobbit". Inglish could distinguish between "take the rope and axe" and "take the money and run". (1995-06-27) 1 1 1 1 1 INGRES A relational DBMS vendor. 1 1 1 1 1 inheritance In object-oriented programming, the ability to derive new classes from existing classes. A derived class (or "subclass") inherits the instance variables and methods of the "base class" (or "superclass"), and may add new instance variables and methods. New methods may be defined with the same names as those in the base class, in which case they override the original one. For example, bytes might belong to the class of integers for which an add method might be defined. The byte class would inherit the add method from the integer class. See also Liskov substitution principle, multiple inheritance. (2000-10-10) 1 1 1 1 1 initgame /in-it'gaym/ [IRC] An IRC version of the venerable trivia game "20 questions", in which one user changes his nick to the initials of a famous person or other named entity, and the others on the channel ask yes or no questions, with the one to guess the person getting to be "it" next. As a courtesy, the one picking the initials starts by providing a 4-letter hint of the form sex, nationality, life-status, reality-status. For example, MAAR means "Male, American, Alive, Real" (as opposed to "fictional"). Initgame can be surprisingly addictive. See also hing. [Jargon File] 1 1 1 1 1 initialise To give a variable its first value. This may be done automatically by some languages or it may require explicit code by the programmer. Some languages allow initialisation to be combined with variable definition, e.g. in C: int i = 0; Failing to initialise a variable before using it is a common programming error, but one which compilers and automatic checkers like lint can easily detect. (1997-06-08) 1 1 1 1 1 Initial Microprogram Load (IML) Loading microcode into microcode memory. (1997-08-31) 1 1 1 1 1 Initial Operational Test and Evaluation (IOT&E) The first phase of operational test and evaluation conducted on pre-protectional items, prototypes, or pilot production items and normally completed prior to the first major production decision. Conducted to provide a valid estimate of expected system operational effectiveness and suitability. (1996-12-27) 1 1 1 1 1 Initial Program Load (IPL) The procedure used to (re-)start a computer system by copying the operating system kernel into main memory and running it. Part of the boot sequence. (1997-08-31) 1 1 1 1 1 Initial Program Loader (IPL) A bootstrap loader which loads the part of an operating system needed to load the remainder of the operating system. (1997-08-31) 1 1 1 1 1 initiator SCSI initiator 1 1 1 1 1 injection 1. <mathematics> A function, f : A -> B, is injective or one-one, or is an injection, if and only if for all a, b in A, f(a) = f(b) => a = b. I.e. no two different inputs give the same output (contrast many-to-one). This is sometimes called an embedding. Only injective functions have left inverses f' where f'(f(x)) = x, since if f were not an injection, there would be elements of B for which the value of f' was not unique. If an injective function is also a surjection then is it a bijection. 2. <reduction> An injection function is one which takes objects of type T and returns objects of type C(T) where C is some type constructor. An example is f x = (x, 0). The opposite of an injection function is a projection function which extracts a component of a constructed object, 1 1 1 1 1 inkjet printer A class of printer in which small ink droplets are sprayed electrostatically from a nozzle onto the paper. Inkjet printers are very quiet in comparison to impact printers. A popular example is the Olivetti BJ10. (1995-03-14) 1 1 1 1 1 ink printer A retronym used by Blind users to refer to all printers which are not Braille printers, regardless of whether they actually use ink. (1998-10-13) 1 1 1 1 1 inline (Or "unfold") To replace a function call with an instance of the function's body. Actual argument expressions are substituted for formal parameters as in beta reduction. Inlining is usually done as a compile-time transformation. If done recklessly (e.g. attempting to inline a recursive function) the compiler will fail to terminate. If done over-enthusiastically the code size may increase exponentially, e.g. if function f calls g twice, and g calls h twice and h is inlined in g which is inlined in f (in either order) then there will be four copies of h's body in f. See also linear argument, unfold/fold. (1994-11-03) 1 1 1 1 1 inline element Any HTML element that is rendered in the same position as normal plain text, i.e. to the right of the preceding text (for left-to-right scripts). This contrasts with a block-level elements that is always placed below the preceding text line. Inline elements typically specify formatting, e.g. <B> (bold), <SMALL> or the kind of content, e.g. <CODE>, <KBD>, though they also include things like inline images (<IMG>) and text areas (<TEXTAREA>). (http://htmlhelp.com/reference/html40/inline.html) (2011-01-04) 1 1 1 1 1 inline image An image that appears within the body of a web page. Most graphical web browsers display images inline (with an option to turn off inline images, to speed up the display of web pages). Other image formats may have to be displayed in a separate window and/or by another application program. An inline image in a web page is specified with the <IMG> HTML tag, which can take many attributes, the most important of which is the SRC attribute that gives the URL from which to fetch the image. The ALT attribute gives text to display in place of the image for users with images disabled or who are using text-only browsers or text-to-speech convertors (e.g. blind users). (2011-01-04) 1 1 1 1 1 INMOS transputer transputer 1 1 1 1 1 inner class In Java, a non-static, nested class. (2006-11-18) 1 1 1 1 1 inner join (Commonly "join", but see also "outer join") A relational database operation which selects rows from two tables such that the value in one column of the first table also appears in a certain column of the second table. An example in SQL: select * from A, B where A.x = B.y The column names (x and y in this example) are often, but not necessarily, the same. (1998-11-23) 1 1 1 1 1 inner product In linear algebra, any linear map from a vector space to its dual defines a product on the vector space: for u, v in V and linear g: V -> V' we have gu in V' so (gu): V -> scalars, whence (gu)(v) is a scalar, known as the inner product of u and v under g. If the value of this scalar is unchanged under interchange of u and v (i.e. (gu)(v) = (gv)(u)), we say the inner product, g, is symmetric. Attention is seldom paid to any other kind of inner product. An inner product, g: V -> V', is said to be positive definite iff, for all non-zero v in V, (gv)v > 0; likewise negative definite iff all such (gv)v < 0; positive semi-definite or non-negative definite iff all such (gv)v >= 0; negative semi-definite or non-positive definite iff all such (gv)v <= 0. Outside relativity, attention is seldom paid to any but positive definite inner products. Where only one inner product enters into discussion, it is generally elided in favour of some piece of syntactic sugar, 1 1 1 1 1 InnovAda An object-oriented extension to Ada, said to be Lisp-like. Implemented as an Ada preprocessor. (1994-11-03) [Where? Who? When?] 1 1 1 1 1 inode A data structure holding information about files in a Unix file system. There is an inode for each file and a file is uniquely identified by the file system on which it resides and its inode number on that system. Each inode contains the following information: the device where the inode resides, locking information, mode and type of file, the number of links to the file, the owner's user and group ids, the number of bytes in the file, access and modification times, the time the inode itself was last modified and the addresses of the file's blocks on disk. A Unix directory is an association between file leafnames and inode numbers. A file's inode number can be found using the "-i" switch to ls. Unix manual page: fs(5). See also /usr/include/ufs/inode.h. 1 1 1 1 1 in-order traversal traverse 1 1 1 1 1 inout A type or "mode" of function parameter that passes information in both directions - from the caller to the function and back to the caller, combining the in and out modes. An "inout" parameter might be used where the function needs to read and update some data belonging to the caller as a side effect of its main purpose. (2010-01-19) 1 1 1 1 1 IN point (l'Imprimerie nationale point) A variant of the point equal to 0.4 mm. (2002-03-11) 1 1 1 1 1 Inprise Corporation Borland Software Corporation. 1 1 1 1 1 Input ALPHA 1 1 1 1 1 input Data transferred from the outside world into a computer system via some kind of input device. Opposite: output. (1997-04-28) 1 1 1 1 1 input device A peripheral used to transfer data from the outside world into a computer system. Some input devices are operated directly by the user, e.g. keyboard, mouse, touch screen, joystick, digitising tablet, microphone; others are sensors or transducers which convert external signals into data, e.g. using an ananlog to digital converter (this would also be true of a microphone). Other kinds of inputs are really one half of a bidirectional link with another computer or storage device, e.g. serial line, SCSI interface. (1996-11-03) 1 1 1 1 1 input/output (I/O) Communication between a computer and its users, its storage devices, other computers (via a network) or the outside world. The devices the computer uses to do this are called "peripherals". What actually counts as I/O depends on what level of detail you are considering, e.g. communication between processors would not be considered I/O when considering a multiprocessor as a single system. Important aspects of I/O are throughput, latency, and whether the communications is synchronous or asynchronous (using some kind of buffer). (2003-12-04) 1 1 1 1 1 input/output redirection In Unix, to send ouput from a process to different file or device or to another process via a pipe, or to have a process read its input from a different file, device or pipe. Some other operating systems have similar facilities. To redirect input to come from a file instead of the keyboard, use "<": myprog < myfile Similarly to redirect output to a file instead of the screen: ls > filelist A pipe redirects the output of one process directly into the input of another who | wc -l A common misuse by beginners is 1 1 1 1 1 inquiry/response system Any computer system in which data is entered offline and processed in batch form, but information can be retrieved on-line. An example is the checking of credit cards. ["Computer Information Systems for Business V", Thomas Dock and James C Wetherbe, West Publishing Company 1988]. (1996-06-24) 1 1 1 1 1 INRIA Institut National de Recherche en Informatique et Automatique 1 1 1 1 1 insanely great (Macintosh community, from Steve Jobs; also BSD Unix people via Bill Joy) Something so incredibly elegant that it is imaginable only to someone possessing the most puissant of hacker-natures. [Jargon File] (1994-12-06) 1 1 1 1 1 insertion sort A sorting algorithm that inserts each item in the proper place into an initially empty list by comparing it with each item in the list until it finds the new element's successor or the end of the list. Compare bubble sort. (1997-02-12) 1 1 1 1 1 INSIGHT A simulation and modelling language especially for health care problems. ["Simulation Modeling with INSIGHT", S.D. Roberts Proc 1983 Winter Sim Conf, S.D. Roberts et al eds, pp.7-16]. (1995-03-03) 1 1 1 1 1 Insignia Solutions, Inc. /in-sig'nee-* s*-loosh'nz/ A company that made its name as a provider of software that allows users to run Microsoft Windows and MS-DOS application programs on Digital, HP, IBM, Motorola, NeXT, Silicon Graphics and Sun/SPARC workstations, X terminals, Java desktops, and Apple Computer's Power Mac and Motorola 68000-based computers. Insignia Solutions was founded in 1986. Their first product, SoftPC 1.0 for Sun workstations, was introduced in 1988. Also in 1988, Insignia shipped its first version of SoftPC for Apple Computer's Macintosh. As the demand to run Windows and MS-DOS applications on non-Intel computers grew, Insignia signed OEM agreements with several companies including Data General, Digital, Fujitsu, HP, Intergraph Corp., Motorola, Silicon Graphics, and Sun Microsystems. Insignia Solutions sold its SoftWindows and RealPC product lines to FWB Software [when?]. Its major product in 2000 is 1 1 1 1 1 inspection A formal evaluation technique in which software requirements, design, or code are examined in detail by a person or group other than the author to detect faults, violations of development standards, and other problems. (1996-05-22) 1 1 1 1 1 installable file system (IFS or "File System Driver", "FSD") An API that allows you to extend OS/2 to access files stored on disk in formats other than FAT and HPFS, and access files that are stored on a network file server. For example an IFS could provide programs running under OS/2 (including DOS and Windows programs) with access to files stored under Unix using the Berkeley fast file system. The other variety of IFS (a "remote file system" or redirector) allows file sharing over a LAN, e.g. using Unix's Network File System protocol. In this case, the IFS passes a program's file access requests to a remote file server, possibly also translating between different file attributes used by OS/2 and the remote system. Documentation on the IFS API has been available only by special request from IBM. An IFS is structured as an ordinary 16-bit DLL with entry points for opening, closing, reading, and writing files, the 1 1 1 1 1 installed user base user base 1 1 1 1 1 installer A utility program to ease the installation of another, probably larger, application. It is also possible for hardware to have an installer accompany it, to install any low level device drivers required. The installer commonly asks the user to enter desired configuration options for the main program or hardware, and sets up various initialisation files accordingly, as well as copying the main program to a hard disc. Some badly designed operating systems require applications to provide an uninstaller because of the number of different files modified or created during the installation process. (1998-02-09) 1 1 1 1 1 instance An individual object of a certain class. While a class is just the type definition, an actual usage of a class is called "instance". Each instance of a class can have different values for its instance variables, i.e. its state. (1998-03-06) 1 1 1 1 1 instance variable In object-oriented programming, one of the variables of a class template which may have a different value for each object of that class. Instance variables hold the state of an object. (1998-01-16) 1 1 1 1 1 instantiate instantiation 1 1 1 1 1 instantiation Producing a more defined version of some object by replacing variables with values (or other variables). 1. In object-oriented programming, producing a particular object from its class template. This involves allocation of a structure with the types specified by the template, and initialisation of instance variables with either default values or those provided by the class's constructor function. 2. In logic programming, when unification binds a logic variable to some value. 3. In type checking, when type inference binds a type variable to some type. 4. <multimedia> A specific representation of an object or artifact. Examples of instantiations would be different images of an object, text translated into English and French or a video and a still image of a museum piece. (2015-02-08) 1 1 1 1 1 Institute for Global Communications (IGC) Provider of computer networking tools for international communications and information exchange. The IGC Networks -- PeaceNet, EcoNet, ConflictNet and LaborNet -- comprise the world's only computer communications system dedicated solely to environmental preservation, peace, and human rights. New technologies are helping these worldwide communities cooperate more effectively and efficiently. Address: 18 De Boom Street, San Francisco, CA 94107 USA. A division of the Tides Foundation, a 501(c)(3) tax-exempt organisation. A founding member of the world-wide Association of Progressive Communications (APC). (ftp://igc.apc.org). E-mail: <support@igc.apc.org>. (1996-06-24) 1 1 1 1 1 Institute of Electrical and Electronics Engineers, Inc. (IEEE) The world's largest technical professional society, based in the USA. Founded in 1884 by a handful of practitioners of the new electrical engineering discipline, today's Institute has more than 320,000 members who participate in its activities in 147 countries. The IEEE sponsors technical conferences, symposia and local meetings worldwide, publishes nearly 25% of the world's technical papers in electrical, electronics and computer engineering and computer science, provides educational programs for its members and promotes standardisation. Areas covered include aerospace, computers and communications, biomedical technology, electric power and consumer electronics. (http://ieee.org/). Gopher (gopher://gopher.ieee.org/). (ftp://ftp.ieee.org/). E-mail file-server: <fileserver-help@info.ieee.org>. IEEE Standards Process Automation (SPA) System 1 1 1 1 1 Institut National de Recherche en Informatique et Automatique (INRIA) A French research institute for computer science, control theory, and applied mathematics. INRIA has research units in Rocquencourt (near Paris), Sophia-Antipolis (near Nice), Grenoble, Nancy (also known as LORIA) and Rennes (known as IRISA), the last two in partnership with CNRS and local universities. INRIA works on various projects, including the development of free software such as SciLab, Objective Caml, Bigloo, and projects such as GNU MP. (2003-07-13) 1 1 1 1 1 instruction machine instruction 1 1 1 1 1 Instruction Address Register (IAR) The IBM name for program counter. The IAR can be accessed by way of a supervisor call in supervisor state, but cannot be directly addressed in problem state. (1995-03-21) 1 1 1 1 1 instructional technology Design, development, use, management and evaluation of process and resources for learning. Instructional technology aims to promote the application of validated, practical procedures in the design and delivery of instruction. It is often defined either in terms of media and other technology used (e.g. audiovisual media and equipment and computers), or in terms of a systematic process which encompasses instructional design, development, delivery and evaluation. ["Instructional Technology: The Definition and Domains of the Field", 1994, Barbara Seels and Rita Richey, Washington, D.C., Association for Educational Communications and Technology]. (2010-01-29) 1 1 1 1 1 instruction mnemonic A word or acronym used in assembly language to represent a binary machine instruction operation code. Different processors have different instruction sets and therefore use a different set of mnemonics to represent them. E.g. ADD, B (branch), BLT (branch if less than), SVC, MOVE, LDR (load register). (1997-02-18) 1 1 1 1 1 instruction prefetch A technique which attempts to minimise the time a processor spends waiting for instructions to be fetched from memory. Instructions following the one currently being executed are loaded into a prefetch queue when the processor's external bus is otherwise idle. If the processor executes a branch instruction or receives an interrupt then the queue must be flushed and reloaded from the new address. Instruction prefetch is often combined with pipelining in an attempt to keep the pipeline busy. By 1995 most processors used prefetching, e.g. Motorola 680x0, Intel 80x86. [First processors using prefetch?] (1998-03-29) 1 1 1 1 1 instruction scheduling The compiler phase that orders instructions on a pipelined, superscalar, or VLIW architecture so as to maximise the number of function units operating in parallel and to minimise the time they spend waiting for each other. Examples are filling a delay slot; interspersing floating-point instructions with integer instructions to keep both units operating; making adjacent instructions independent, e.g. one which writes a register and another which reads from it; separating memory writes to avoid filling the write buffer. Norman P. Jouppi and David W. Wall, "Available Instruction-Level Parallelism for Superscalar and Superpipelined Processors" (ftp://gatekeeper.dec.com/archive/pub/DEC/WRL/research-reports/WRL-TR-89.7.ps.Z), Proceedings of the Third International Conference on Architectural Support for Programming Languages and Operating Systems, pp. 272--282, 1989. 1 1 1 1 1 instruction set The collection of machine language instructions that a particular processor understands. The term is almost synonymous with "instruction set architecture" since the instructions are fairly meaningless in isolation from the registers etc. that they manipulate. (1999-07-05) 1 1 1 1 1 instruction set architecture (ISA) The parts of a processor's design that need to be understood in order to write assembly language, such as the machine language instructions and registers. Parts of the architecture that are left to the implementation, such as number of superscalar functional units, cache size and cycle speed, are not part of the ISA. The definition of SPARC, for example, carefully distinguishes between an implementation and a specification. (1999-01-16) 1 1 1 1 1 Instruction Set Processor (ISP) A family of languages for describing the instruction sets of computers. ["Computer Structures: Readings and Examples", D.P. Siewiorek et al, McGraw-Hill 1982]. (1995-10-12) 1 1 1 1 1 instrument To install devices or instructions into hardware or software to monitor the operation of a system or component. (1996-05-22) 1 1 1 1 1 int 1. <programming> A common name for the integer data type. In C for example, it means a (signed) integer of the computer's native word length. 2. <networking> The top-level domain for international organisations. (1999-01-26) 1 1 1 1 1 INTCODE A low-level interpreted language used in bootstrapping the BCPL compiler. The INTCODE machine has six control registers and eight functions. OCODE was used as the intermediate language. ["INTCODE - An Interpretive Machine Code for BCPL", M. Richards, Computer Lab, U Cambridge 1972]. ["BCPL - The Language and its Compiler", Martin Richards & Colin Whitby-Stevens, Cambridge U Press 1979]. (2014-08-21) 1 1 1 1 1 integer (Or "whole number") One of the numbers in the set ..., -3, -2, -1, 0, 1, 2, 3, ... There are an infinite number of integers, though each one is finite. An inductive definition of an integer is a number that is either zero or an integer plus or minus one. An integer has no fractional part. If written as a real number, e.g. 42.0, the part after the decimal point will be zero. A natural number is a non-negative integer. Computers usually store integers in binary. Natural numbers can be stored as unsigned integers and integers that may be negative require a sign bit and typically use twos complement representation. Other representations have been used, such as binary-coded decimal. (2002-04-07) 1 1 1 1 1 Integer SPECbaserate SPECrate_base_int92 1 1 1 1 1 Integer SPECbaseratio SPECbase_int92 1 1 1 1 1 Integer SPECrate SPECrate_int92 1 1 1 1 1 Integer SPECratio SPECint92 1 1 1 1 1 integrated circuit (IC, or "chip") A microelectronic semiconductor device consisting of many interconnected transistors and other components. ICs are constructed ("fabricated") on a small rectangle (a "die") cut from a Silicon (or for special applications, Sapphire) wafer. This is known as the "substrate". Different areas of the substrate are "doped" with other elements to make them either "p-type" or "n-type" and polysilicon or aluminium tracks are etched in one to three layers deposited over the surface. The die is then connected into a package using gold wires which are welded to "pads", usually found around the edge of the die. Integrated circuits can be classified into analogue, digital and hybrid (both analogue and digital on the same chip). Digital integrated circuits can contain anything from one to millions of logic gates - inverters, AND, OR, NAND and NOR gates, flip-flops, multiplexors etc. on a few square millimeters. The small size of these circuits allows 1 1 1 1 1 Integrated Database Management System (IDMS) A network DBMS written by the staff of B.F.Goorich (Akron, Ohio, USA) circa 1972 and sold to Cullinet (Originally Cullinane, now part of Computer Associates). IDMS was licensed to ICL in 1976 for porting to, and subsequent development on, their computers. It was implemented on the ICL 1900 Series (DME George 2, George 3, CME, TME), System 4, and ICL 2900 Series (later Series 39 Corporate Servers). The latest version runs on Series 39 OpenVME as IDMSX (IDMS extended). [Was it a relational database?] (1995-04-19) 1 1 1 1 1 integrated development environment interactive development environment 1 1 1 1 1 Integrated Drive Electronics Advanced Technology Attachment 1 1 1 1 1 Integrated Information Technology (IIT) A Santa Clara based company producing a programmable, single chip H.261 and MPEG system. The chip contains a RISC processor, originally based on the MIPS architecture but now called RISCit, and a "Pixel Processor". (1994-11-03) 1 1 1 1 1 Integrated Modelling Support Environment (IMSE) An Esprit programme. [Details?] (1999-04-26) 1 1 1 1 1 Integrated Project Support Environment (IPSE) A set of management and technical tools to support software development, usually integrated in a coherent framework, equivalent to a Software Engineering Environment. (1999-04-26) 1 1 1 1 1 Integrated Services Digital Network (ISDN) A set of communications standards allowing a single wire or optical fibre to carry voice, digital network services and video. ISDN is intended to eventually replace the plain old telephone system. ISDN was first published as one of the 1984 ITU-T Red Book recommendations. The 1988 Blue Book recommendations added many new features. ISDN uses mostly existing Public Switched Telephone Network (PSTN) switches and wiring, upgraded so that the basic "call" is a 64 kilobits per second, all-digital end-to-end channel. Packet and frame modes are also provided in some places. There are different kinds of ISDN connection of varying bandwidth (see DS level): DS0 = 1 channel PCM at 64 kbps T1 or DS1 = 24 channels PCM at 1.54 Mbps T1C or DS1C = 48 channels PCM at 3.15 Mbps 1 1 1 1 1 Integrated Systems Architecture (ISA for ODP) An Esprit 2 project continuing the ANSA project. (1995-02-21) 1 1 1 1 1 Integrated Systems Laboratory A joint project of Control Data Corporation and NCR Corporation, established in 1973 and dissolved in 1976. Integrated Systems Laboratory developed Software Writer's Language. Address: Escondidio, California, USA. (2003-12-31) 1 1 1 1 1 integration Combining software or hardware components or both into an overall system. (1996-05-22) 1 1 1 1 1 integration testing A type of testing in which software and/or hardware components are combined and tested to confirm that they interact according to their requirements. Integration testing can continue progressively until the entire system has been integrated. (2003-09-24) 1 1 1 1 1 integrity 1. <data> data integrity. 2. <database> referential integrity. 1 1 1 1 1 integrity constraint A constraint (rule) that must remain true for a database to preserve data integrity. Integrity constraints are specified at database creation time and enforced by the database management system. Examples from a genealogical database would be that every individual must be their parent's child or that they can have no more than two natural parents. (1995-11-11) 1 1 1 1 1 Intel Intel Corporation 1 1 1 1 1 Intel 4004 The world's first microprocessor, released in 1971. The 4004 contained 2300 transistors (compared with 5.5 million in the 1996 Pentium Pro) and was intended for use in a calculator. It processed data in 4 bits, but its instructions were 8 bits long. Program and Data memory were separate, it had 1 kilobyte of data memory and a 12-bit PC for 4K of program memory (in the form of a 4 level stack, used for CALL and RET instructions). There were also sixteen 4-bit (or eight 8-bit) general purpose registers. The 4004 had 46 instructions. (1997-03-30) 1 1 1 1 1 Intel 4040 An enhanced version of the Intel 4004, adding 14 instructions, larger (8 level) stack, 8 kbyte program memory and interrupt abilities (including shadows of the first 8 registers). The 4040 was similar to the Intel 8008. (1994-10-31) 1 1 1 1 1 Intel 486 (Or "i486", "iAPX 80486", and "Intel DX4" but usually just "486"). A range of Intel CISC microprocessors which is part of the Intel 80x86 family of processors. The 486s are very similar to their immediate predecessor, the Intel 80386DX. The main differences are that the 486 has an optimised instruction set, has an on-chip unified instruction and data cache, an optional on-chip floating-point unit (FPU), and an enhanced bus interface unit. These improvements yield a rough doubling in performance over an Intel 80386 at the same clock rate. There are several suffixes and variants including: Intel 486SX - a 486DX with a faulty FPU that has been disabled in the factory. Intel 486DX - 486SX with a working FPU. 486DX-2 - runs at twice the external clock rate. 486SX-2 - runs at twice the external clock rate. 1 1 1 1 1 Intel 486DX One of Intel's Intel 486 family of microprocessors (one of the last before the Pentium). The 486DX has a working built-in floating point unit (FPU). The Intel 486SX is effectively a DX with the FPU disabled. The DX has a pin to select the external data bus width (16 or 32). The Intel 487SX is a 486DX with a 486SX pinout. (1995-05-09) 1 1 1 1 1 Intel 486SX An Intel 486DX microprocessor with its floating-point unit disconnected. All 486SX chips were fabricated with FPUs. If testing showed that the CPU was OK but the FPU was defective, the FPU's power and bus connections were destroyed with a laser and the chip was sold cheaper as an SX, if the FPU worked it was sold as a DX. [Was this true of all 486SX chips?] Some systems, e.g. Aopen 486SX, allowed a DX to be plugged into an expansion socket. A board jumper would disable the SX which was hard to remove because it was surface mounted. Some SX chips only had a 16-bit wide external data bus. The DX has a pin to select the data bus width (16 or 32). On the smaller SX, that line is hard-wired to 16 inside the package. This is similar to the 286 SX, which was a 16-bit processor with an 8-bit external data bus. The Jargon File claimed that the SX was deliberately disabled crippleware. The German computer magazine, "c't", 1 1 1 1 1 Intel 487SX A version of the Intel 486DX microprocessor with an extra pin, for use in the coprocessor socket of an Intel 486SX system. The 487SX provides the FPU which is missing in the 486SX. Although the 486SX is completely disabled when you install a 487SX, the 487SX design requires that you leave the 486SX in your PC [why?], rather than use it elsewhere. Intel admits that in some systems you can unplug the 486SX and fit a 487SX in its place but they don't guarantee that it will always work. See Intel 486. (1995-05-10) 1 1 1 1 1 Intel 8008 A microprocessor intended for use as a terminal controller, and similar to the Intel 4040. The 8008 had a 14-bit PC and addressing and an eight level internal stack. It was followed by the Intel 8080. [Date?] (1994-10-31) 1 1 1 1 1 Intel 80186 A microprocessor developed by Intel circa 1982. The 80186 was an improvement on the Intel 8086 and Intel 8088. As with the 8086, it had a 16-bit external bus and was also available as the Intel 80188, with an 8-bit external data bus. The initial clock rate of the 80186 and 80188 was 6 MHz. They were not used in many computers, but one notable exception was the Mindset, a very advanced computer for the time. They were used as embedded processors. One major function of the 80186/80188 series was to reduce the number of chips required. "To satisfy this market, we defined a processor with a significant performance increase over the 8086 that also included such common peripheral functions as software-controlled wait state and chip select logic, three timers, priority interrupt controller, and two channels of DMA (direct memory access). This processor, the 80186, could replace up to 22 separate VLSI (very large scale integration) and TTL (transistor-transistor logic) packages and sell for less than the cost of the parts it replaced." -- Paul Wells of Intel Corporation writing in Byte (reference below) New instructions were also introduced as follows: ENTER Make stcak frame for procedure parameters 1 1 1 1 1 Intel 80188 A version of the Intel 80186 with an 8 bit external data bus (instead of 16 bit). This makes it cheaper to connect to peripherals. (1995-01-13) 1 1 1 1 1 Intel 80286 (Or "286", "i286") A microprocessor developed by Intel. THe 80286 processor has a 16-bit data bus and incorporates a memory management unit that allowed a limited amount of multitasking. The 80286 only has a segmented MMU while the later processors add a paged MMU "behind" the segmented one. The 80286 was the processor in the IBM PC AT personal computer. (1995-02-21) 1 1 1 1 1 Intel 80386 (Commonly abbreviated to "386", trademark Intel386) The successor to the Intel 80286 microprocessor. It was the first Intel processor with 32-bit data and address busses. It can address four gigabytes (2^32 bytes) of memory; however, 16 megabytes is a typical maximum in IBM PCs. The 386 allows multiple application programs to run at the same time (when running under 386-specific operating systems) using "protected mode". The first IBM compatible to use the 386 was the Compaq 386, before IBM used it in high-end models of their PS/2 series. It is also used in HP's RS series and many others. It does not require special EMS memory boards to expand MS-DOS memory limits. With the 386, the EMS standard can be simulated in normal extended memory, and many DOS add-ons provide this "Expanded Memory Manager" feature. 1 1 1 1 1 Intel 80386DX A version of the Intel 80386 with a 32-bit data bus and 32-bit address bus, a BGA. The 386DX was clocked at 16 to 33 MHz by Intel and up to 40 MHz by AMD. It comes in a BGA package. (2003-07-05) 1 1 1 1 1 Intel 80386SX A lower-speed version of the Intel 80386. It uses a 16-bit data bus instead of a 32-bit data bus. It has a 24-bit address bus. It is faster than the 286, and more importantly, like the full-size 386, provides more flexibility in running existing DOS applications. Intel's version runs at 16 MHz, while AMD's can run at up to 33 MHz. It comes in a PFP package. (2003-07-05) 1 1 1 1 1 Intel 8048 The microcontroller used in IBM PC keyboards. The 8048 was inspired by, and similar to, the Fairchild F8 microprocessor but, being a microcontroller, was designed for low cost and small size. The 8048 has a modified Harvard architecture, with program ROM on chip and 64 to 256 bytes of RAM also on chip. I/O is mapped in its own address space. Though the 8048 was eventually replaced by the very popular but bizarre Intel 8051 and Intel 8052, even in 2000 it is still very popular due to its low cost, wide availability, and development tools. [Was it really __the_first__ microcontroller? Are the ROM and RAM both on-chip?] (2000-06-01) 1 1 1 1 1 Intel 80486 Intel 486 1 1 1 1 1 Intel 8051 A microcontroller developed by Intel in 1980 for use in embedded products and still (1999) one of the most popular microcontrollers. The 8051/8031 cores are used in over 100 devices from 10 independent manufacturers such as Dallas and Philips. [What is the difference between the 8031/8051/8052?] See also CAS 8051 Assembler, as31 assembler, 51forth. 8051 FAQ (http://ece.orst.edu/~pricec/8051/faq/index.html). The 8031/51 series microcontroller (http://rehn.org/YAM51/). Intel MCS51 series microcontrollers (http://intel.com/design/mcs51/). (1999-11-21) 1 1 1 1 1 Intel 8080 The successor to the Intel 8008. The 8080 had a 16-bit address bus and an 8-bit data bus. It had seven 8-bit registers (six which could also be combined as three 16-bit registers), a 16-bit stack pointer to memory which replaced the 8008's internal stack and a 16-bit program counter. It also had 256 I/O ports (so I/O devices could be connected without needing to allocate any addressing space as is required for memory mapped devices) and a signal pin that allowed the stack to occupy a separate bank of memory. Shortly after the 8080, the Motorola 6800 was introduced. [Date?] (1994-10-31) 1 1 1 1 1 Intel 8085 A microprocessor intended to be an improved Intel 8080, as was the Zilog Z80. (1994-10-31) 1 1 1 1 1 Intel 8086 A sixteen bit microprocessor chip used in early IBM PCs. The Intel 8088 was a version with an eight-bit external data bus. The Intel 8086 was based on the design of the Intel 8080 and Intel 8085 (it was source compatible with the 8080) with a similar register set, but was expanded to 16 bits. The Bus Interface Unit fed the instruction stream to the Execution Unit through a 6 byte prefetch queue, so fetch and execution were concurrent - a primitive form of pipelining (8086 instructions varied from 1 to 4 bytes). It featured four 16-bit general registers, which could also be accessed as eight 8-bit registers, and four 16-bit index registers (including the stack pointer). The data registers were often used implicitly by instructions, complicating register allocation for temporary values. It featured 64K 8-bit I/O (or 32K 16 bit) ports and fixed vectored interrupts. There were also four segment 1 1 1 1 1 Intel 8088 An Intel 8086 with 16-bit registers and an 8-bit data bus. The 8088 was the processor used in the original IBM PC. (1995-02-21) 1 1 1 1 1 Intel 80x86 (x86) One of the family of Intel microprocessors including the Intel 80186, Intel 80286, Intel 80386, Intel 486, in a more general sense also Intel 8086, Pentium, Pentium Pro, and Pentium II. The abbreviation "x86" also includes compatible processors, e.g. from Cyrix or AMD. (2004-02-27) 1 1 1 1 1 Intel 8751 A microcontroller from Intel including a CPU, two timers. 128 bytes of RAM, 4 kBytes of EEPROM, four eight-bit biderectional I/O ports and an EIA-232 port. The 8751 belongs to the Intel i51 Microcontroller family. It was designed by Intel but is now manufactured by Intel, Philips, Siemens, AMD and others. Motorola's microcontroller families (68HC05, 68HC08 and 68HC11) are meant to compete with the i51 family. (1995-04-22) 1 1 1 1 1 Intel Comparative Microprocessor Performance index (iCOMP) A unit used by Intel to indicate the relative performance of their 80x86 microprocessors. (http://134.134.214.1/procs/perf/icomp/). (1997-06-07) 1 1 1 1 1 Intel Corporation A US microelectronics manufacturer. They produced the Intel 4004, Intel 8080, Intel 8086, Intel 80186, Intel 80286, Intel 80386, Intel 486 and Pentium microprocessor families as well as many other integrated circuits and personal computer networking and communications products. Gordon Moore and Robert Noyce founded Intel in 1968 to design, manufacture, and market semiconductor computer memory to replace magnetic core memory, the dominant computer memory at that time. Dr. Andrew S. Grove joined Intel soon after its incorporation. Three years later, in 1971, Intel introduced the world's first microprocessor, the Intel 4004. Intel has design, development, production, and administration facilities throughout the western US, Europe and Asia. In 1995 nearly 75% of the world's personal computers use Intel architecture. Annual revenues are rapidly approaching $10 billion. In March, 1994, "Business Week" named Intel one of 1 1 1 1 1 IntelDX4 Essentially an Intel 486DX microprocessor with a 16 kilobyte on-chip cache. The DX4 is the fastest member of the Intel 486 family. 75 and 100MHz versions are available. At an iCOMP index rating of 435, the 100 MHz DX4 performs up to 50% faster than the 66 MHz Intel DX2. The DX4's clock multiplier allows the processor to run three times faster than the system clock. This performance is achieved in part by a 16K on-chip cache (double that of the other 486s). The DX4 has an integrated floating point unit. Like the other 486s, the DX4 achieves performance through a RISC integer core that executes frequently used instructions in a single clock cycle (the Pentium's can execute multiple instructions in a single clock cycle). Low power consumption has been achieved with SL Technology and a 0.6 micron manufacturing process, giving 1.6 million transistors on a single chip operating at only 3.3 Volts. 1 1 1 1 1 Intel i960 A superscalar 32-bit RISC microprocessor from Intel intended for embedded applications. The i960 CA variant can reach 66 native MIPS peak performance with a sustained execution of two instructions per clock cycle. The i960 CF has an on-chip, four kilobyte two-way set-associative instruction cache and a one kilobyte data cache. Both the CA and CF processors have on-chip RAM; a four-channel DMA unit; and integrated peripherals. (1996-05-23) 1 1 1 1 1 INTELLECT A query language written by Larry Harris in 1977, close to natural English. (1995-04-14) 1 1 1 1 1 intellectual property (IP) The ownership of ideas and control over the tangible or virtual representation of those ideas. Use of another person's intellectual property may or may not involve royalty payments or permission, but should always include proper credit to the source. (1997-03-27) 1 1 1 1 1 intelligent backtracking An improved backtracking algorithm for Prolog interpreters, which records the point at which each logic variable becomes bound and, when a given set of bindings leads to failure, ignores any choice point which does not bind any of those variables. No choice from such a choice point can succeed since it does not change the bindings which caused the failure. (1996-04-06) 1 1 1 1 1 intelligent database A database management system which performs data validation and processing traditionally done by application programs. Most DBMSs provide some data validation, e.g. rejecting invalid dates or alphabetic data entered into money fields, but often most processing is done by application programs. There is however no limit to the amount of processing that can be done by an intelligent database as long as the process is a standard function for that data. Examples of techniques used to implement intelligent databases are constraints, triggers and stored procedures. Moving processing to the database aids data integrity because it is guaranteed to be consistent across all uses of the data. Mainframe databases have increasingly become more intelligent and personal computer database systems are rapidly following. (1998-10-07) 1 1 1 1 1 Intelligent Input/Output /i:-too-oh/ (I2O) A specification which aims to provide an I/O device driver architecture that is independent of both the specific device being controlled and the host operating system. The Hardware Device Module (HDM) manages the device and the OS Services Module (OSM) interfaces to the host operating system. The HDM is portable across multiple operating systems, processors and busses. The HDM and OSM communicate via a two layer message passing protocol. A Message Layer sets up a communications session and runs on top of a Transport Layer which defines how the two parties share information. I2O is also designed to facilitate intelligent I/O subsystems, with support for message passing between multiple independent processors. By relieving the host of interrupt intensive I/O tasks required by the various layers of a driver architecture, the I2O intelligent I/O architecture greatly improves I/O performance. I2O systems will be able to more 1 1 1 1 1 Intelligent I/O Intelligent Input/Output 1 1 1 1 1 intelligent key A relational database key which depends wholly on one or more other columns in the same table. An intelligent key might be identified for implementation convenience, where there is no good candidate key. For example, if the three-letter initials of a group of people are known to be unique but only their full names are recorded, a three letter acronym for their names (e.g. John Doe Smith -> JDS) would be an intelligent key. Intelligent keys are a Bad Thing because it is hard to guarantee uniqueness, and if the value on which an intelligent key depends changes then the key must either stay the same, creating an inconsistency within the containing table, or change, requiring changes to all other tables in which it appears as a foreign key. The correct solution is to use a surrogate key. (1999-12-07) 1 1 1 1 1 intelligent terminal (or "smart terminal", "programmable terminal") A terminal that often contains not only a keyboard and screen, but also comes with a disk drive and printer, so it can perform limited processing tasks when not communicating directly with the central computer. Some can be programmed by the user to perform many basic tasks, including both arithmetic and logic operations. In some cases, when the user enters data, the data will be checked for errors and some type of report will be produced. In addition, the valid data that is entered may be stored on the disk, it will be transmitted over communication lines to the central computer. An intelligent terminal may have enough computing capability to draw graphics or to offload some kind of front-end processing from the computer it talks to. The development of workstations and personal computers has made this term and the product it describes semi-obsolescent, but one may still hear variants of the phrase "act like a 1 1 1 1 1 IntelliMouse Microsoft IntelliMouse Explorer 1 1 1 1 1 Intel Literature Sales Address: PO Box 58130, Santa Clara, CA 95052, USA. Telephone: +1 800 548 4725. (1995-01-12) 1 1 1 1 1 Intelsat A private satellite communications company that provides telephony, corporate network, video and Internet solutions around the globe via capacity on 25 geosynchronous satellites. (2003-05-13) 1 1 1 1 1 Intel x86 Intel 80x86 1 1 1 1 1 intensional A description of properties, e.g. intensional equality, that relate to how an object is implemented as opposed to extensional properties which concern only how its output depends on its input. (1995-01-12) 1 1 1 1 1 Intent to Package (ITP) A notice, posted to the Debian developer mailing list, announcing a developer's intent to make a new Debian package, including a brief description of the package and its license. (2000-05-31) 1 1 1 1 1 INTERACTIVE A network simulation language. ["Design and Implementation of a Pascal Based Interactive Network Simulation Language", R. Lakshmanan, PhD Thesis, Oakland U, Rochester MI 1983]. (1995-01-12) 1 1 1 1 1 interactive A term describing a program whose input and output are interleaved, like a conversation, allowing the user's input to depend on earlier output from the same run. The interaction with the user is usually conducted through either a text-based interface or a graphical user interface. Other kinds of interface, e.g. using speech recognition and/or speech synthesis, are also possible. This is in contrast to batch processing where all the input is prepared before the program runs and so cannot depend on the program's output. (1996-06-21) 1 1 1 1 1 Interactive CourseWare (ICW) A training program controlled by a computer that relies on trainee input to determine the order and pace of instruction delivery. The trainee advances through the sequence of instructional events by making decisions and selections. The instruction branches according to the trainee's responses. ICW is a US military term which includes computer-aided instruction and computer-based training. (1995-11-08) 1 1 1 1 1 Interactive Data analysis Language (IDL) A language from Xerox, built on Interlisp-D. (2004-05-07) 1 1 1 1 1 Interactive Data Entry/Access (IDEA) A language from Data General in which you designed the screen first, and then wrote the program around the predefined fields. IDEA was a precursor to the DG COBOL Screen Section. (1996-02-16) 1 1 1 1 1 Interactive Data Language (IDL) A commercial array-oriented language with numerical analysis and display features, first released in 1977. It supports interactive reduction, analysis, and visualisation of scientific data. It is sold by Research Systems, Inc. Version: 3.6.1 runs under Unix, MS-DOS, MS Windows, VAX/VMS and Macintosh. Not to be confused with any of the other IDLs. (ftp://gateway.rs.inc.com/pub/idl). E-mail: <info@rsinc.com>. (1994-10-07) 1 1 1 1 1 interactive development environment (IDE, integrated development environment) A system for supporting the process of writing software. Such a system may include a syntax-directed editor, graphical tools for program entry, and integrated support for compiling and running the program and relating compilation errors back to the source. Such systems are typically both interactive and integrated, hence the ambiguous acronym. They are interactive in that the developer can view and alter the execution of the program at the level of statements and variables. They are integrated in that, partly to support the above interaction, the source code editor and the execution environment are tightly coupled, e.g. allowing the developer to see which line of source code is about to be executed and the current values of any variables it refers to. Examples include Visual C++ and Visual Basic. (2002-09-21) 1 1 1 1 1 Interactive Development Environments (IDE) A US software engineering company. (1996-03-04) 1 1 1 1 1 Interactive Software Engineering (ISE) The company set up by Bertrand Meyer, now its president, to develop and distribute Eiffel, the language which he created. ISE also organises the TOOLS conference (Technology of Object-Oriented Languages and Systems). (http://eiffel.com/). E-mail: info@eiffel.com. Telephone: +1 (805) 685 1006. Address: Santa Barbara, Goleta CA, USA. (1995-12-28) 1 1 1 1 1 Interactive System Productivity Facility (ISPF) Something to do with IBM's OS/390. (http://s390.ibm.com/bookmgr-cgi/bookmgr.cmd/BOOKS/ISPDGD02/COVER?SHELF=ISP5BK01). [Summary?] (1999-07-14) 1 1 1 1 1 Interactive Voice Response (IVR) <communications> A telecommunications system, prevelant with PBX and voice mail systems, that uses a prerecorded database of voice messages to present options to a user, typically over telephone lines. User input is retrieved via DTMF tone key presses. When used in conjunction with voice mail, for example, these systems typically allow users to store, retrieve, and route messages, as well as interact with an underlying database server which may allow for automated transactions and data processing. (15 Sept 1997) (1997-09-21) 1 1 1 1 1 Interagency Interim National Research and Education Network (IINREN) An evolving operating network system. Near term (1992-1996) research and development activities will provide for the smooth evolution of this networking infrastructure into the future gigabit NREN. (1994-12-06) 1 1 1 1 1 InterBase A commercial active DBMS. 1 1 1 1 1 INTERCAL /in't*r-kal/ (Said by the authors to stand for "Compiler Language With No Pronounceable Acronym"). Possibly the most elaborate and long-lived joke in the history of programming languages. It was designed on 1972-05-26 by Don Woods and Jim Lyons at Princeton University. INTERCAL is purposely different from all other computer languages in all ways but one; it is purely a written language, being totally unspeakable. The INTERCAL Reference Manual, describing features of horrifying uniqueness, became an underground classic. An excerpt will make the style of the language clear: It is a well-known and oft-demonstrated fact that a person whose work is incomprehensible is held in high esteem. For example, if one were to state that the simplest way to store a value of 65536 in a 32-bit INTERCAL variable is: DO :1 <- #0$#256 any sensible programmer would say that that was absurd. Since 1 1 1 1 1 Interchange File Format (IFF, full name "EA IFF 1985") A generic file format published by Electronic Arts as an open standard. IFF is chunk-based and hierarchical so files can include other files. It is easily extensible and an all round Good Idea. An IFF file starts with one of the following "group IDs": 'FORM', 'LIST' or 'CAT '. This is followed by an unsigned 32-bit number of bytes in the remainder of the file. Then comes an ID that indicates which type of IFF file this is. The main image type is ILBM, audio is either AIFF or 8SVX, animations are ANIM etc. An IFF file will probably have a filename extension related to this file type stored in the file. The rest of the file is divided into chunks each of which also has a four-byte header and byte count. Microsoft WAV and AVI are all based around an almost identical scheme to IFF called RIFF. The main difference is that, in RIFF files, numbers are little-endian as on Intel 1 1 1 1 1 INTERCOM The assembly language for the G-15. Versions: INTERCOM 101, INTERCOM 1000. [Listed in CACM 2(5):16, May 1959]. (1997-07-23) 1 1 1 1 1 Interdata A computer manufacturer. Interdata became Perkin-Elmer, then Concurrent. (2004-05-12) 1 1 1 1 1 Interest Group in Pure and Applied Logics (IGPL) A body of 700 researchers in various aspects of logic (symbolic, mathematical, computational, philosophical, etc.) from all over the world. The group's main rôle is as a research and information clearing house. The group also: supports exchange of information about research problems, references and common interest among group members; helps to obtain photocopies of papers; supplies review copies of books through the Journals on which some members are editors; organises exchange visits and workshops; advises on papers for publication; edits and distributes a Newsletter and an electronic Bulletin; keeps an FTP archive of papers, abstracts; obtains reductions on group purchases of logic books from publishers. (http://theory.doc.ic.ac.uk/tfm/igpl.html). E-mail: <igpl-request@doc.ic.ac.uk>. (1995-02-10) 1 1 1 1 1 interesting In hacker parlance, this word has strong connotations of annoying, or "difficult", or both. Hackers relish a challenge, and enjoy wringing all the irony possible out of the ancient Chinese curse "May you live in interesting times". [Jargon File] 1 1 1 1 1 inter-exchange carrier (IXC) A company allowed to handle long-distance calls following the break-up of the Bell system in the US by anti-trust regulators. Local Exchange Carriers (LEC) are not allowed to handle long-distance traffic and Inter Exchange carriers are not allowed to handle local calls. (2002-08-28) 1 1 1 1 1 interface A boundary across which two systems communicate. An interface might be a hardware connector used to link to other devices, or it might be a convention used to allow communication between two software systems. Often there is some intermediate component between the two systems which connects their interfaces together. For example, two EIA-232 interfaces connected via a serial cable. See also graphical user interface, Application Program Interface. (1996-05-22) 1 1 1 1 1 interface analysis A software test which checks the interfaces between program elements for consistency and adherence to predefined rules or axioms. (1996-07-09) 1 1 1 1 1 Interface Architect An interface builder for Motif distributed by Hewlett-Packard (see UIMX). 1 1 1 1 1 Interface Definition Language (IDL) 1. An OSF standard for defining RPC stubs. [Details?] 2. Part of an effort by Project DOE at SunSoft, Inc. to integrate distributed object technology into the Solaris operating system. IDL provides the standard interface between objects, and is the base mechanism for object interaction. The Object Management Group's CORBA 1.1 (Common Object Request Broker Architecture) specifies the interface between objects. IDL (Interface Definition Language) is the base mechanism for object interaction. The SunSoft OMG IDL CFE (Compiler Front End) version 1.2 provides a complete framework for building CORBA 1.1-compliant preprocessors for OMG IDL. To use it you write a back-end. A complete compiler of IDL would translate IDL into client side and server side routines for remote communication in the same manner as Sun's current RPCL compiler. The IDL 1 1 1 1 1 Interface Description Language (IDL) A language designed by Nestor, Lamb and Wulf of CMU in 1981 for describing the data structures passed between parts of an application, to provide a language-independent intermediate representation. It forms part of Richard Snodgrass <rts@cs.arizona.edu>'s Scorpion environment development system. Not to be confused with any of the other IDLs. Mailing list: info-idl@sei.cmu.edu. ["The Interface Description Language: Definition and Use," by Richard Snodgrass, Computer Science Press, 1989, ISBN 0-7167-8198-0]. [SIGPLAN Notices 22(11) (Nov 1987) special issue]. (1994-11-11) 1 1 1 1 1 Interface Message Processor (IMP) The original message switching node on the ARPANET. [More details?] (1996-04-07) 1 1 1 1 1 Interior Gateway Protocol (IGP) An Internet protocol which distributes routing information to the routers within an autonomous system. The term "gateway" is historical, "router" is currently the preferred term. See also Exterior Gateway Protocol, Open Shortest Path First, Routing Information Protocol. (1994-11-09) 1 1 1 1 1 interlace progressive coding 1 1 1 1 1 interlaced image progressive coding 1 1 1 1 1 interlacing 1. <hardware> A video display system which builds an image on the VDU in two phases, known as "fields", consisting of even and odd horizontal lines. The complete image (a "frame") is created by scanning an electron beam horizontally across the screen, starting at the top and moving down after each horizontal scan until the bottom of the screen is reached, at which point the scan starts again at the top. On an interlaced display, even numbered scan lines are displayed in the first field and then odd numbered lines in the second field. For a given screen resolution, refresh rate (frames per second) and phosphor persistence, interlacing reduces flicker because the top and bottom of the screen are redrawn twice as often as if the scan simply proceded from top to bottom in a single vertical sweep. 2. <graphics> progressive coding. (1998-02-25) 1 1 1 1 1 Interlan A brand of Ethernet card. (1994-11-09) 1 1 1 1 1 Interleaf A document preparation system for Sun, VAX, Apollo and other workstations. (1994-11-09) 1 1 1 1 1 interleave interleaving 1 1 1 1 1 interleaving sector interleave 1 1 1 1 1 INTERLINK A commercial product comprising hardware and software for file transfer between IBM and VAX computers. 1 1 1 1 1 Interlisp A dialect of Lisp developed in 1967 by Bolt, Beranek and Newman (Cambridge, MA) as a descendant of BBN-Lisp. It emphasises user interfaces. It is currently[?] supported by Xerox PARC. Interlisp was one of two main branches of LISP (the other being MACLISP). In 1981 Common LISP was begun in an effort to combine the best features of both. Interlisp includes a Lisp programming environment. It is dynamically scoped. LAMBDA functions evaluate their arguments, NLAMBDA functions do not. Any function could be called with optional arguments. See also AM, CLISP, Interlisp-10, Interlisp-D. ["Interlisp Programming Manual", W. Teitelman, TR, Xerox Rec Ctr 1975]. (2004-05-07) 1 1 1 1 1 Interlisp-10 An Interlisp with shallow binding. 1 1 1 1 1 Interlisp-D Xerox's Interlisp with deep binding. 1 1 1 1 1 Intermedia A hypertext system developed by a research group at IRIS (Brown University) to support education and research. Intermedia was a "shell" over A/UX 1.1, programmed using an object-oriented toolkit and standard DBMS functions. The data model and architecture were designed for flexibility and consistency. Intermedia consisted of several applications sharing an event-driven gui. These included a text editor (InterText), graphics editor (InterDraw), picture viewer (InterPix), timeline editor (InterVal), 3D model viewer (InterSpect), animation editor (InterPlay) and video editor (InterVideo). [Yankelovich et al, "Intermedia: The Concept and the Construction of a Seamless Information Environment" (http://research.microsoft.com/en-us/um/people/sdrucker/papers/intermedia1.pdf)] (http://elab.eserver.org/hfl0032.html). (2014-11-02) 1 1 1 1 1 Intermedia Interchange Format A Standard Hypertext Interchange format from IRIS. 1 1 1 1 1 intermediate code intermediate language 1 1 1 1 1 Intermediate Distribution Frame (IDF) A network closet containing a secondary hub, fed from the main hub. (1995-05-05) 1 1 1 1 1 Intermediate Programming Language A very early attempt by Arthur W. Burks to express machine language at a higher level of abstraction. Like Plankalkul, it used a right-handed style of assignment, in which the location appears on the right. (1995-05-09) 1 1 1 1 1 Intermediate System (IS) An Open Systems Interconnection system which performs network layer forwarding. It is analogous to an IP router. (1994-11-29) 1 1 1 1 1 Intermediate System-Intermediate System (IS-IS) The OSI Interior Gateway Protocol. (2003-07-12) 1 1 1 1 1 intermercial interstitial 1 1 1 1 1 Intermetrics, Inc. AverStar 1 1 1 1 1 intermodulation distortion (IMD) Nonlinear distortion in a system or transducer, characterised by the appearance in the output of frequencies equal to the sums and differences of integral multiples of the two or more component frequencies present in the input waveform. (2000-08-21) 1 1 1 1 1 internal field separators ($IFS) A predefined environment variable in the Unix Bourne shell whose default value is the three-character string containing space, tab and line feed. Any string of one or more of these characters separates the command and each of its arguments in a command line. $IFS also tells the shell's built-in read command where to split an input line when reading into multiple variables. E.g. setting IFS=: would be appropriate for reading a file with ':'-separated fields, such as /etc/passwd. (1999-04-07) 1 1 1 1 1 Internal Translator (IT) An early compiler for mathematics developed by A.J. Perlis et al at Carnegie Tech ca 1957. IT was originally written for the Burroughs 205, then the IBM 650. IT was the forerunner of RUNCIBLE, GATE, CORRELATE and GAT. IT source code was converted to PIT, thence to SPIT. IT-2 produced machine language directly, IT-3 developed at Carnegie added double-precision floating-point. [Sammet 1969, pp. 139-141]. [CACM 1(5):22 1958]. (1994-11-30) 1 1 1 1 1 International Algebraic Language ALGOL 58 1 1 1 1 1 International Atomic Time (TAI) An international standard measurement of time based on the comparison of many atomic clocks. TAI is maintained by the Bureau International des Poids et Mesures (BIPM), the world's governing body for civil atomic time measurement. TAI is the basis for Coordinated Universal Time. BIPM (http://www.bipm.org/enus/5_Scientific/c_time/time_1.html). (2001-08-02) 1 1 1 1 1 International Business Machines (IBM) The best known American computer manufacturer, founded by Thomas J. Watson (born 1874-02-17), known as "Big Blue" after the colour of its logo. IBM makes everything from mainframes to personal computers (PCs) and has been immensely successful in selling them, chiefly to business. It has often been said that "Nobody has ever been sacked for buying IBM". The IBM PC in its various versions has been so successful that unqualified reference to a "PC" almost certainly means a PC from IBM, or one of the many brands of clone produced by other manufacturers to cash in on IBM's original success. Alternative expansions of "IBM" such as Inferior But Marketable; It's Better Manually; Insidious Black Magic; It's Been Malfunctioning; Incontinent Bowel Movement, illustrate the considerable antipathy most hackers have long felt toward the "industry leader" (see fear and loathing). Quarterly sales $15351M, profits $689M (Aug 1994). 1 1 1 1 1 International Computers Limited plc (ICL) A UK hardware and software manufacturer specialising in systems integration in selected markets, supported by its service and technology businesses. ICL operates in over 80 countries worldwide, with 24000 employees and revenues of £2.6 billion in 1993. ICL produced George 2, George 3, VME, OpenVME, Series 39, DME, CME, the ICL 1900 and ICL 2900 series. (http://icl.co.uk/). Usenet newsgroup: news:alt.sys.icl. (1995-04-19) 1 1 1 1 1 International Core War Society (ICWS) The official standards body for Core War. (1996-02-16) 1 1 1 1 1 International Data Encryption Algorithm (IDEA) A conventional encryption algorithm, written by Xuejia Lai and James Massey, in 1992. It is a block cipher, considered to be the best and most secure available, and operates on 64-bit blocks with a 128 bit key. It is used by Pretty Good Privacy. (1996-03-07) 1 1 1 1 1 International Electrotechnical Commission (IEC) A standardisation body at the same level as ISO. [Relationship? Why separate?] (1995-04-21) 1 1 1 1 1 International Federation for Information Processing A multinational federation of professional and technical organisations (or national groupings of such organisations) concerned with information processing. From any one country, only one such organisation - which must be representative of the national activities in the field of information processing #NAME? group of developing countries can be admitted as a Full Member. On 1 October 1993, 46 organisations were Full Members of the Federation, representing 66 countries. IFIP was founded under the auspices of UNESCO and advises them and the ITU-T. (http://dit.upm.es/~cdk/ifip.html). (1995-03-10) 1 1 1 1 1 International Function Point Users Group (IFPUG) A forum for the exchange of ideas about Function Point Analysis. IFPUG's membership now includes over 500 companies on four continents. Telephone: +1 (614) 8957130. (1995-03-10) 1 1 1 1 1 internationalisation (i18n, globalisation, enabling, software enabling) The process and philosophy of making software portable to other locales. For successful localisation, products must be technically and culturally neutral. Effective internationalisation reduces the time and resources required for localisation, improving time-to-market abroad and allowing simultaneous shipment. In orther words, internationalisation abstracts out local details, localisation specifies those details for a particular locale. Technically this may include allowing double-byte character sets such as unicode or Japanese, local numbering, date and currency formats, and other local format conventions. It also includes the separation of user interface text e.g. in dialog boxes and menus. All the text used by an application may be kept in a separate file or directory, so that it can be translated all at once. User interfaces may 1 1 1 1 1 internationalization internationalisation 1 1 1 1 1 International Multimedia Teleconferencing Consortium (IMTC) A non-profit corporation formed in September 1994 comprising more than 150 companies from around the world. The IMTC encourages the development and implementation of interoperable multimedia teleconferencing systems based on international open standards. (http://imtc.org/). (1999-03-17) 1 1 1 1 1 International Olympiad in Informatics (IOI) An annual competition in computing science for senior pupils at secondary schools all over the world. (http://win.tue.nl/win/ioi/). (1996-12-07) 1 1 1 1 1 International Organisation for Standardisation International Organization for Standardization 1 1 1 1 1 International Organization for Standardization (ISO) A voluntary, nontreaty organisation founded in 1946, responsible for creating international standards in many areas, including computers and communications. Its members are the national standards organisations of 89 countries, including the American National Standards Institute. ISO produced the OSI seven layer model for network architecture. The term "ISO" is not actually an acronym for anything. It is a pun on the Greek prefix "iso-", meaning "same". Some ISO documents say ISO is not an acronym even though it is an anagram of the initials of the organisation's name. (http://iso.ch/). (1999-06-22) 1 1 1 1 1 International Phonetic Alphabet (IPA) A system of symbols for representing pronunciation. There is no commonly agreed way to represent IPA in ASCII characters though it can be represented in Unicode. [Reference?] (1998-12-30) 1 1 1 1 1 International Programmable Airline Reservation System (IPARS) The international version of PARS, designated by IBM for use in all IBM World trade countries (i.e. outside domestic USA). (1999-01-18) 1 1 1 1 1 International Smalltalk Association (ISA) A user group which published newsletters on Smalltalk-related issues, technical and general information. Its goal was to champion Smalltalk and its uses. It was disbanded around 1991. (1995-02-16) 1 1 1 1 1 International Standard The series of standards from ISO and its subcommitees. [List? Text?] (1995-04-21) 1 1 1 1 1 International Telecommunications Union (ITU) ITU-T, the telecommunication standardisation sector of ITU, is responsible for making technical recommendations about telephone and data (including fax) communications systems for PTTs and suppliers. Before 1993-03-01 ITU-T was known as CCITT. Every four years they hold plenary sessions where they adopt new standards; there was one in 1992. ITU works closely with all standards organisations to form an international uniform standards system for communication. Study Group XVII is responsible for recommending standards for data communications over telephone networks. They publish the V.XX standards and X.n protocols. V.21 is the same as EIA's EIA-232. V.24 is the same as EIA's EIA-232C. V.28 is the same as EIA's EIA-232D. Address: International Telecommunication Union, Information Services Department, Place des Nations, 1211 Geneva 20, Switzerland. 1 1 1 1 1 International Traffic in Arms Regulation (ITAR) Now called the Defense Trade Regulations. 1 1 1 1 1 Internaut (From "Internet" + "astronaut") A person who explores the Internet (or "cyberspace"), normally searching for information. (2002-06-30) 1 1 1 1 1 Internet 1. With a lower-case "i", any set of networks interconnected with routers. 2. With an upper-case "I", the world's collection of interconnected networks. The Internet is a three-level hierarchy composed of backbone networks, mid-level networks, and stub networks. These include commercial (.com or .co), university (.ac or .edu) and other research networks (.org, .net) and military (.mil) networks and span many different physical networks around the world with various protocols, chiefly the Internet Protocol. Until the advent of the web in 1990, the Internet was almost entirely unknown outside universities and corporate research departments and was accessed mostly via command line interfaces such as telnet and FTP. Since then it has grown to become a ubiquitous aspect of modern information systems, becoming highly commercial and a widely accepted medium for all sort of customer 1 1 1 1 1 Internet Access Provider (IAP) A company or other origanisation which provides access to the Internet to businesses and/or consumers. An IAP purchases an Internet link from another company that has a direct link to the Internet and resells portions of that bandwidth to the general public. For example, an IAP may purchase a T1 link (1.544Mb/s) and resell that bandwidth in chunks consisting of ISDN (64Kb/s, 128Kb/s) and analog modems (14.4Kb/s, 28.8Kb/s). The IAP's customer base is likely to include both businesses and individuals. Individual customers usually connect to the IAP via a modem and telephone line to a (preferably local) point of presence. An IAP may also be an Internet Service Provider. (1996-06-25) 1 1 1 1 1 Internet Adapter The Internet Adapter (TIA). A program from Cyberspace Development which runs on a Unix shell account and acts as a SLIP emulator. A TIA emulated SLIP account is not quite the same as a real SLIP account but TIA's SLIP emulation is completely standard in terms of working with MacTCP-based software on the Macintosh (or WinSock on a Microsoft Windows machine). You do not get your own Internet Address as you do with a real SLIP account, instead, TIA uses the IP number of the machine it runs on and "redirects" traffic back to you. You cannot set up your machine as an FTP server, for instance, since there's no IP number for an FTP client elsewhere to connect to. TIA's performance is reportedly good, faster than normal SLIP in fact, and about as fast as Compressed SLIP. Future releases will support CSLIP and even PPP. Cyberspace Development has ported TIA to several versions of 1 1 1 1 1 Internet address IP address 1 1 1 1 1 internet address (Note lower case "i"). An IP address that uniquely identifies a node on an internet. [Jargon File] (1995-04-12) 1 1 1 1 1 Internet Architecture Board (IAB) The technical body that oversees the development of the Internet suite of protocols. It has two task forces: the Internet Engineering Task Force and the Internet Research Task Force. IAB previously stood for Internet Activities Board. (1994-12-06) 1 1 1 1 1 Internet Assigned Numbers Authority (IANA) The central registry for various assigned numbers: Internet Protocol parameters, such as port, protocol, and enterprise numbers; and options, codes, and types. The currently assigned values are listed in the "Assigned Numbers" document STD 2. To request a number assignment, e-mail <iana@isi.edu>. (1994-12-06) 1 1 1 1 1 Internet backbone High-speed networks that carry Internet traffic. These communications networks are provided by companies such as AT&T, GTE, IBM, MCI, Netcom, Sprint, UUNET and consist of high-speed links in the T1, T3, OC1 and OC3 ranges. The backbones carry Internet traffic around the world and meet at Network Access Points (NAPs). Internet Service Providers (ISPs) connect either directly to a backbone, or they connect to a larger ISP with a connection to a backbone. The topology of the "backbone" and its interconnections may once have resembled a spine with ribs connected along its length but is now almost certainly more like a fishing net wrapped around the world with many circular paths. [Map?] (1998-07-02) 1 1 1 1 1 Internet Chess Server An interactive meeting-place on the Internet where people can play chess against each other. Usenet newsgroup: news:alt.chess.ics. [Server address?] (1995-03-25) 1 1 1 1 1 Internet Control Message Protocol (ICMP) An extension to the Internet Protocol (IP) that allows for the generation of error messages, test packets, and informational messages related to IP. It is defined in STD 5, RFC 792. (1999-09-18) 1 1 1 1 1 Internet Corporation for Assigned Names and Numbers (ICANN) The non-profit corporation that was formed to assume responsibility for IP address allocation, protocol parameter assignment, domain name system management, and root server system management functions now performed under U.S. Government contract by IANA and other entities. ICANN Home (http://icann.org/). (2002-01-09) 1 1 1 1 1 Internet-Draft (I-D) A draft working document of the Internet Engineering Task Force, its Areas, and its Working Groups. As the name implies, Internet-Drafts are purely discussion documents with no formal status. They are valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. Very often, an I-D is a precursor to a Request For Comments. (1994-12-08) 1 1 1 1 1 Internet Engineering and Planning Group (IEPG) (http://iepg.org/). 1 1 1 1 1 Internet Engineering Steering Group (IESG) A body composed of the Internet Engineering Task Force Area Directors and the IETF Chair. It provides the first technical review of Internet standards and is responsible for day-to-day "management" of the IETF. (1994-12-08) 1 1 1 1 1 Internet Engineering Task Force (IETF) The IETF is a large, open international community of network designers, operators, vendors and researchers whose purpose is to coordinate the operation, management and evolution of the Internet and to resolve short- and mid-range protocol and architectural issues. It is a major source of proposals for protocol standards which are submitted to the Internet Architecture Board (IAB) for final approval. The IETF meets three times a year and extensive minutes are included in the IETF Proceedings. The IETF Secretariat, run by The Corporation for National Research Initiatives with funding from the US government, maintains an index of Internet-Drafts whereas RFCs are maintained by The Internet Architecture Board. (http://ietf.org). (1999-01-27) 1 1 1 1 1 Internet Experiment Note (IEN) A series of reports pertinent to the Internet. IENs were published in parallel to RFCs and are no longer active. See also Internet-Draft, Request For Comments. (1994-12-08) 1 1 1 1 1 Internet Explorer (IE, MSIE) Microsoft's free World-Wide Web browser for Microsoft Windows, Windows 95, Windows NT, and Macintosh. Internet Explorer is the main rival to Netscape Navigator (which runs on many more platforms). Both support the same core features and offer incompatible extensions. Microsoft combined later versions of IE with their file system browser, "Explorer" and bundled it with Windows 95 in an attempt to use their dominance of the desktop operating system market to force users to abandon Netscape's browser, which they perceived as a potential threat. This, and other dubious business moves, became the subject of a US Department of Justice antitrust trial in late 1998/early 1999. (http://microsoft.com/ie/). (1999-01-31) 1 1 1 1 1 Internet Express An Internet provider in Colorado Springs, USA. Formerly called the Community News Service. They provide SLIP accounts at no extra charge. (1994-12-08) 1 1 1 1 1 Internet Foundation Classes (IFC) A library of classes used in the creation of Java applets with GUIs. Created by Netscape, the Internet Foundation Classes provide GUI elements, as well as classes for Applications Services, Security, Messaging, and Distributed Objects. The IFC code, which is exclusively Java, is layered on top of the Java Abstract Windowing Toolkit (AWT), thus preserving platform independence. The AWT and IFC collectively form the Java Foundation Classes, which provide a standardised framework for developing powerful Java applications. IFC download (http://wp.netscape.com/eng/ifc/download.html). (2003-08-17) 1 1 1 1 1 Internet Go Server (IGS) A place for Go players to meet and play via the Internet. IGS Home (http://pandanet.co.jp/English/). (1995-03-17) 1 1 1 1 1 Internet Group Management Protocol (IGMP) An extension to the Internet Protocol, used by IP hosts to report their host group memberships to immediately-neighbouring multicast routers. See also MBONE. Version 1 of IGMP is defined in Appendix 1 of RFC 1112. Version 2 is proposed in RFC 2236. (1999-11-08) 1 1 1 1 1 Internet Information Server (IIS) Microsoft's web server and FTP server for Windows NT. IIS is intended to meet the needs of a range of users: from workgroups and departments on a corporate intranet to ISPs hosting websites that receive millions of hits per day. Features include innovative web publishing, customisable tools, wizards, customisable management tools, flexible administration options, and analysis tools. IIS makes it easy to share documents and information across a company intranet or the Internet, and is completely integrated with Windows NT Directory Services. IIS 1.0 was released for Windows NT 3.51 and had a limited feature set. IIS 2.0 was released with Windows NT 4.0 with a similar feature set to IIS 1.0. IIS 3.0 quickly followed with many additions including Active Server Pages (ASP), ISAPI and ADO 1.0. 1 1 1 1 1 Internet Inter-ORB Protocol (IIOP) A protocol which will be mandatory for all CORBA 2.0 compliant platforms. The initial phase of the project is to build an infrastructure consisting of: an IIOP to HTTP gateway which allows CORBA clients to access WWW resources; an HTTP to IIOP gateway to let WWW clients access CORBA resources; a web server which makes resources available by both IIOP and HTTP; web browsers which can use IIOP as their native protocol. (http://ansa.co.uk/ANSA/ISF/wwwCorba_1.html). (1996-04-01) 1 1 1 1 1 Internet Message Access Protocol (IMAP) A protocol allowing a client to access and manipulate electronic mail messages on a server. It permits manipulation of remote message folders (mailboxes), in a way that is functionally equivalent to local mailboxes. IMAP includes operations for creating, deleting, and renaming mailboxes; checking for new messages; permanently removing messages; searching; and selective fetching of message attributes, texts, and portions thereof. It does not specify a means of posting mail; this function is handled by a mail transfer protocol such as SMTP. Latest version: 4. See RFC 2060, RFC 2061, and others. Compare: POP. (1999-03-14) 1 1 1 1 1 Internet Monthly Report (IMR) Publication designed to communicate to the Internet Research Group the accomplishments, milestones reached, or problems discovered by the participating organisations. (1994-12-08) 1 1 1 1 1 Internet Network Information Center (InterNIC) An umbrella entity created by the National Science Foundation in Spring 1992, in cooperation with the Internet community, consisting of Network Information Service Managers who provided and/or coordinated NSFNet services. General Atomics provided information services, AT&T provided directory and database services, and Network Solutions, Inc. (NSI) provided registration services. In 1999 Internic was replaced by ICANN. (http://internic.net/). (http://nic.net/). (2003-04-16) 1 1 1 1 1 internet number internet address 1 1 1 1 1 Internet Open Trading Protocol (IOTP, Formerly "Open Trading Protocol", OTP) A specification that provides an interoperable framework for Internet commerce. It is optimised for the case where the buyer and the merchant do not have a prior acquaintance and is payment system independent. It will be able to encapsulate and support payment systems such as SET, Mondex, CyberCash's CyberCoin, DigiCash's e-cash, GeldKarte, etc. IOTP is able to handle cases where such merchant roles as the shopping site, the payment handler, the deliverer of goods or services, and the provider of customer support are performed by different Internet sites. The IOTP specification is maintained by the IETF Internet Open Trading Protocol (trade) Working Group (http://ietf.org/html.charters/trade-charter.html). (http://otp.org/). (2001-09-22) 1 1 1 1 1 Internet Protocol (IP) The network layer for the TCP/IP protocol suite widely used on Ethernet networks, defined in STD 5, RFC 791. IP is a connectionless, best-effort packet switching protocol. It provides packet routing, fragmentation and re-assembly through the data link layer. IPv4 is the version in widespread use and IPv6 was just beginning to come into use in 2000 but is still not widespread by 2008. [Other versions? Dates?] (2000-12-19) 1 1 1 1 1 Internet Protocol Control Protocol (IPCP) The Control Protocol for Internet Protocol. [Details?] (2002-06-29) 1 1 1 1 1 Internet Protocol version 4 The version of Internet Protocol in widespread use in 2000. (2000-12-19) 1 1 1 1 1 Internet Protocol version 6 (IPv6, IPng, IP next generation) The most viable candidate to replace the current Internet Protocol. The primary purpose of IPv6 is to solve the problem of the shortage of IP addresses. The following features have been purposed: 16-byte addresses instead of the current four bytes; embedded encryption - a 32-bit Security Association ID (SAID) plus a variable length initialisation vector in packet headers; user authentication (a 32-bit SAID plus variable length authentication data in headers); autoconfiguration (currently partly handled by Dynamic Host Configuration Protocol); support for delay-sensitive traffic - a 24 bit flow ID field in headers to denote voice or video, etc. One possible solution is based on the TUBA protocol (RFC 1347, 1526, 1561) which is itself based on the OSI Connectionless Network Protocol (CNLP). Another is TP/IX (RFC 1475) which changes TCP and UDP headers to give a 1 1 1 1 1 Internet provider Internet Service Provider 1 1 1 1 1 Internet Public Library (IPL) A project at the University of Michigan School of Information and Library Studies to provide an on-line, 24 hour public library, chaired by an assemblage of librarians and information industry professionals. The library aims to provide library services to a target audience estimated to number 1/4 of the entire American population by the end of the century. The Internet Public Library is scheduled to go on-line in March 1995. Among the first services will be on-line reference; youth services; user education; and professional services for librarians. (http://ipl.sils.umich.edu/). (telnet://ipl.sils.umich.edu/). Mailing list: majordomo@sils.umich.edu. (1995-07-20) 1 1 1 1 1 Internet Registry (IR) The Internet Assigned Numbers Authority has the discretionary authority to delegate portions of its responsibility and, with respect to network address and Autonomous System identifiers, has lodged this responsibility with the IR. The IR function is performed by the Defense Data Network Network Information Center. 1 1 1 1 1 Internet Relay Chat (IRC) /I-R-C/, occasionally /*rk/ A client-server chat system of large (often worldwide) networks. IRC is structured as networks of Internet servers, each accepting connections from client programs, one per user. The IRC community and the Usenet and MUD communities overlap to some extent, including both hackers and regular folks who have discovered the wonders of computer networks. Some Usenet jargon has been adopted on IRC, as have some conventions such as emoticons. There is also a vigorous native jargon (see the entry for "chat"). The largest and first IRC network is EFNet, with a smaller breakaway network called the Undernet having existed since 1992, and dozens of other networks having appeared (and sometimes disappeared) since. See also nick, bot, op. Yahoo's IRC index 1 1 1 1 1 Internet Research Steering Group (IRSG) The "governing body" of the Internet Research Task Force. (1994-12-08) 1 1 1 1 1 Internet Research Task Force (IRTF) The IRTF is chartered by the Internet Architecture Board to consider long-term Internet issues from a theoretical point of view. It has Research Groups, similar to Internet Engineering Task Force Working Groups, which are each tasked to discuss different research topics. Multi-cast audio/video conferencing and privacy enhanced mail are samples of IRTF output. (1994-12-08) 1 1 1 1 1 Internet Security Association and Key Management Protocol (ISAKMP) The definitions and procedures for authenticating communication between 2 peers. This includes the creation and management of Security Associations, key generation techniques, and threat mitigation. ISAKMP is proposed in RFC 2408. (2000-02-08) 1 1 1 1 1 Internet Server Application Programming Interface (ISAPI) Microsoft's programming interface between applications and their Internet Server. Active Servers created with ISAPI extensions can be complete in-process applications themselves, or can "connect" to other services. ISAPI is used for the same sort of functions as CGI but uses Microsoft Windows dynamic link libraries (DLL) for greater efficiency. The server loads the DLL the first time a request is received and the DLL then stays in memory, ready to service other requests until the server decides it is no longer needed. This minimises the overhead associated with executing such applications many times. An HTTP server can unload ISAPI application DLLs to free memory or preload them to speed up the first access. Applications can also be enhanced by ISAPI filters (1997-01-06) 1 1 1 1 1 Internet Service Provider (ISP) A company which provides other companies or individuals with access to, or presence on, the Internet. Most ISPs are also Internet Access Providers; extra services include help with design, creation and administration of websites, training and administration of intranets and domain name registration. (2005-06-19) 1 1 1 1 1 Internet Society (ISOC) A non-profit, professional membership organisation which facilitates and supports the technical evolution of the Internet, stimulates interest in and educates the scientific and academic communities, industry and the public about the technology, uses and applications of the Internet, and promotes the development of new applications for the system. The Society provides a forum for discussion and collaboration in the operation and use of the global Internet infrastructure. The Internet Society publishes a quarterly newsletter, the Internet Society News, and holds an annual conference, INET. The development of Internet technical standards takes place under the auspices of the Internet Society with substantial support from the Corporation for National Research Initiatives under a cooperative agreement with the US Federal Government. (http://info.isoc.org/). 1 1 1 1 1 Internet Telephony IP Telephony 1 1 1 1 1 Internet Telephony Service Providers (ITSP) Companies providing IP Telephony. (1999-04-26) 1 1 1 1 1 internetworking The interconnection of two or more networks, usually local area networks so that data can pass between hosts on the different networks as though they were one network. This requires some kind of router or gateway. (1994-11-30) 1 1 1 1 1 Internetwork Packet eXchange (IPX) A network layer protocol initially developed at XEROX Corporation and made popular by Novell, Inc. as the basic protocol in its Novell NetWare file server operating system. A router with IPX routing can interconnect Local Area Networks so that Netware clients and servers can communicate. The SPX transport layer protocol runs on top of IPX. (1997-03-04) 1 1 1 1 1 Internet Worm The November 1988 worm perpetrated by Robert T. Morris. The worm was a program which took advantage of bugs in the Sun Unix sendmail program, Vax programs, and other security loopholes to distribute itself to over 6000 computers on the Internet. The worm itself had a bug which made it create many copies of itself on machines it infected, which quickly used up all available processor time on those systems. Some call it "The Great Worm" in a play on Tolkien (compare elvish, elder days). In the fantasy history of his Middle Earth books, there were dragons powerful enough to lay waste to entire regions; two of these (Scatha and Glaurung) were known as "the Great Worms". This usage expresses the connotation that the RTM hack was a sort of devastating watershed event in hackish history; certainly it did more to make non-hackers nervous about the Internet than anything before or since. 1 1 1 1 1 Internex On-Line A rather cheap Internet service provider in Toronto, Canada. (http://io.org/). (1994-11-30) 1 1 1 1 1 InterNIC Internet Network Information Center 1 1 1 1 1 interoperability The ability of software and hardware on multiple machines from multiple vendors to communicate. 1 1 1 1 1 interoperable database A database front-end which communicates with multiple heterogenous databases and makes them appear as a single homogenous entity with semantic calls. See ODBC. (1995-02-06) 1 1 1 1 1 inter-packet gap A time delay between successive data packets mandated by the network standard for protocol reasons. In Ethernet, the medium has to be "silent" (i.e., no data transfer) for a few microseconds before a node can consider the network idle and start to transmit. This is necessary for fairness reasons. The delay time, which approximately equals the signal propagation time on the cable, allows the "silence" to reach the far end so that all nodes consider the net idle. (1995-11-11) 1 1 1 1 1 interpolation extrapolation 1 1 1 1 1 Interpress Interpreted FORTH-like graphics language, possibly the first page description language, predating PostScript. Both are descendants of JaM. Used on Xerox printers. ["Interpress, The Source Book", Steven Harrington et al, P-H 1988.] 1 1 1 1 1 interpreted interpreter 1 1 1 1 1 interpreter A program which executes other programs. This is in contrast to a compiler which does not execute its input program (the "source code") but translates it into executable "machine code" (also called "object code") which is output to a file for later execution. It may be possible to execute the same source code either directly by an interpreter or by compiling it and then executing the machine code produced. It takes longer to run a program under an interpreter than to run the compiled code but it can take less time to interpret it than the total required to compile and run it. This is especially important when prototyping and testing code when an edit-interpret-debug cycle can often be much shorter than an edit-compile-run-debug cycle. Interpreting code is slower than running the compiled code because the interpreter must analyse each statement in the program each time it is executed and then perform the desired 1 1 1 1 1 Interpretive Menu Processor (IMP) The language used to implement much of the user interface of the Alis office automation package from Applix, Inc. (1996-04-07) 1 1 1 1 1 Inter-process Communication (IPC) Exchange of data between one process and another, either within the same computer or over a network. It implies a protocol that guarantees a response to a request. Examples are Unix sockets, RISC OS's messages, OS/2's Named Pipes, Microsoft Windows' DDE, Novell's SPX and Macintosh's IAC. Although IPC is performed automatically by programs, an analogous function can be performed interactively when users cut and paste data from one process to another using a clipboard. (1995-12-14) 1 1 1 1 1 interrupt 1. An asynchronous event that suspends normal processing and temporarily diverts the flow of control through an "interrupt handler" routine. Interrupts may be caused by both hardware (I/O, timer, machine check) and software (supervisor, system call or trap instruction). In general the computer responds to an interrupt by storing the information about the current state of the running program; storing information to identify the source of the interrupt; and invoking a first-level interrupt handler. This is usually a kernel level privileged process that can discover the precise cause of the interrupt (e.g. if several devices share one interrupt) and what must be done to keep operating system tables (such as the process table) updated. This first-level handler may then call another handler, e.g. one associated with the particular device which generated the interrupt. 1 1 1 1 1 interrupt handler A routine which is executed when an interrupt occurs. Interrupt handlers typically deal with low-level events in the hardware of a computer system such as a character arriving at a serial port or a tick of a real-time clock. Special care is required when writing an interrupt handler to ensure that either the interrupt which triggered the handler's execution is masked out (inhibitted) until the handler exits, or the handler is re-entrant so that multiple concurrent invocations will not interfere with each other. If interrupts are masked then the handler must execute as quickly as possible so that important events are not missed. This is often arranged by splitting the processing associated with the event into "upper" and "lower" halves. The lower part is the interrupt handler which masks out further interrupts as required, checks that the appropriate event has occurred (this may be necessary if several events share the 1 1 1 1 1 interrupt list [MS-DOS] The list of all known software interrupt calls (both documented and undocumented) for IBM PCs and compatibles, maintained and made available for free redistribution by Ralf Brown <ralf@cs.cmu.edu>. As of late 1992, it had grown to approximately two megabytes in length. 1 1 1 1 1 interrupt priority level The Motorola 68000 family of processors can be at an interrupt priority level from 0 (no interrupt in progress) up to 7. While the processor is handling an interrupt at one level, it will ignore other interrupts at that level or lower. (1994-11-23) 1 1 1 1 1 interrupt request (IRQ) The name of an input found on many processors which causes the processor to suspend normal instruction execution temporarily and to start executing an interrupt handler routine. Such an input may be either "level sensitive" - the interrupt condition will persist as long as the input is active or "edge triggered" - an interrupt is signalled by a low-to-high or high-to-low transition on the input. Some processors have several interrupt request inputs allowing different priority interrupts. (1994-12-08) 1 1 1 1 1 interrupts interrupt 1 1 1 1 1 Intersil 6100 (IMS 6100) A single chip design of the DEC PDP-8 minicomputer. The old PDP-8 design was very strange, and if it hadn't been popular, an awkward CPU like the 6100 would never been designed. The 6100 was a 12-bit processor, which had three registers: the PC, AC (accumulator), and MQ. All 2-operand instructions read AC and MQ and wrote back to AC. It had a 12-bit address bus, limiting RAM to only 4K. Memory references were 7-bit, offset either from address 0, or from the PC page base address (PC AND 7600 oct). It had no stack. Subroutines stored the PC in the first word of the subroutine code itself, so recursion required fancy programming. 4K RAM was pretty much hopeless for general purpose use. The 6102 support chip (included in the 6120) added 3 address lines, expanding memory to 32K the same way that the PDP-8/E expanded the PDP-8. Two registers, IFR and DFR, held the page 1 1 1 1 1 Intersil 6120 (IMS 6120) An improved version of the Intersil 6100. The 6120 was used in the DECmate. [Details?] (1994-11-23) 1 1 1 1 1 interstitial A web page that appears before the expected content page. Interstitials can be used for advertising (intermercial, transition ad) or to confirm that the user is old enough to view the requested page, etc.. (2003-07-11) 1 1 1 1 1 Intertec The computer manufacturer that built the Superbrain. All Intertec systems were sold, installed and serviced by dealers. Intertec manufactured the entire product including designing and producing the circuit boards and molding the cabinets. Intertec's first products were terminals - a dumb terminal called "Intertube" and a smart terminal that emulated various common terminals (VT100 etc.) called "The Emulator". The terminals looked similar to the Superbrain, but smaller. (http://www.old-computers.com/museum/computer.asp?st=1&c=204). (2013-12-30) 1 1 1 1 1 interupt It's spelled "interrupt". (1996-12-13) 1 1 1 1 1 interval A set of real numbers bounded by two real numbers - the endpoints or bounds. The set may or may not include either endpoint, leading to four possibilities: closed [a, b] a <= x <= b open (a, b) a < x < b left-open, right-closed (a, b] a < x <=b left-closed, right-open [a, b) a <= x < b See closed interval, open interval. (2015-04-26) 1 1 1 1 1 InterViews An object-oriented toolkit developed at Stanford University for building graphical user interfaces. It is implemented in C++ and provides a library of objects and a set of protocols for composing them. 1 1 1 1 1 interworking Systems or components, possibly from different origins, working together to perform some task. Interworking depends crucially on standards to define the interfaces between the components. The term implies that there is some difference between the components which, in the absence of common standards, would make it unlikely that they could be used together. For example, software from different companies, running on different hardware and operating systems can interwork via standard network protocols. (1998-11-22) 1 1 1 1 1 intranet Any network which provides similar services within an organisation to those provided by the Internet outside it but which is not necessarily connected to the Internet. The commonest example is the use by a company of one or more web servers on an internal TCP/IP network for distribution of information within the company. Since about 1995, intranets have become a major growth area in corporate computing due to the availability of cheap or free commercial browser and web server software which allows them to provide a simple, uniform hypertext interface to many kinds of information and application programs. Some companies give limited access to their intranets to other companies or the general public. This is known as an extranet. (1997-07-14) 1 1 1 1 1 Intrinsics A library package on top of Xlib, extending the basic functions of the X Window System. It provides mechanisms for building widget sets and application environments. (1996-08-26) 1 1 1 1 1 introspection A feature of some programming languages that allows a running program to obtain information about its own implementation. For example, the Lisp function, "symbol-function" takes a Lisp symbol and returns the function definition associated with that symbol. Lisp is particularly suited to introspection because its source code uses the same underlying representation as its data. Another example is Perl's "can" method which returns true if a given object's class provides a given method. (2010-01-19) 1 1 1 1 1 introspection annotation A kind of pragma that makes information about the implementation of a program available to the program at run-time, allowing it to do introspection. For example, gtk-doc defines a GObject Introspection syntax for annotations that give machine readable information about function parameters and return values, though these don't appear to be intended for actual introspection. (2010-01-19) 1 1 1 1 1 Intrusion Countermeasure Electronics (ICE) A contrived acronym for security software, coined by Usenetter Tom Maddox and popularised by William Gibson's cyberpunk SF novels. In Gibson's novels ICE software responds to intrusion by attempting to literally kill the intruder. The term is not in serious use as of 2000 apart from the commercial software product, BlackICE and a growing number of others. See also: icebreaker. [Jargon File] (2000-03-18) 1 1 1 1 1 Intrusive Testing Testing that collects timing and processing information during program execution that may change the behaviour of the software from its behavior in a real environment. Intrusive testing usually involves additional code embedded in the software being tested or additional processes running concurrently with software being tested on the same processor. (1996-12-01) 1 1 1 1 1 Intuition The Amiga windowing system (a shared-code library). (1997-08-01) 1 1 1 1 1 intuitionism intuitionistic logic 1 1 1 1 1 intuitionistic logic Brouwer's foundational theory of mathematics which says that you should not count a proof of (There exists x such that P(x)) valid unless the proof actually gives a method of constructing such an x. Similarly, a proof of (A or B) is valid only if it actually exhibits either a proof of A or a proof of B. In intuitionism, you cannot in general assert the statement (A or not-A) (the principle of the excluded middle); (A or not-A) is not proven unless you have a proof of A or a proof of not-A. If A happens to be undecidable in your system (some things certainly will be), then there will be no proof of (A or not-A). This is pretty annoying; some kinds of perfectly healthy-looking examples of proof by contradiction just stop working. Of course, excluded middle is a theorem of classical logic (i.e. non-intuitionistic logic). History 1 1 1 1 1 intuitionistic probability Florentin Smarandache's representation of the probability of an event occuring, given by T, I, F which are real subsets representing the truth, indeterminacy, and falsity percentages respectively, and n_sup = sup(T) + sup(I) + sup(F) < 100 Related to intuitionistic logic. [Florentin Smarandache, "A Unifying Field in Logics. / Neutrosophy: Neutrosophic Probability, Set, and Logic", American Research Press, Rehoboth 1999]. (2001-03-18) 1 1 1 1 1 intuitionist logic Incorrect term for "intuitionistic logic". (1999-11-24) 1 1 1 1 1 invariant A rule, such as the ordering of an ordered list or heap, that applies throughout the life of a data structure or procedure. Each change to the data structure must maintain the correctness of the invariant. (1996-03-12) 1 1 1 1 1 inverse Given a function, f : D -> C, a function g : C -> D is called a left inverse for f if for all d in D, g (f d) = d and a right inverse if, for all c in C, f (g c) = c and an inverse if both conditions hold. Only an injection has a left inverse, only a surjection has a right inverse and only a bijection has inverses. The inverse of f is often written as f with a -1 superscript. (1996-03-12) 1 1 1 1 1 Inverse Address Resolution Protocol (InARP) Additions to ARP typically used for Frame Relay. [Any other examples of its use?] Frame Relay stations route frames of a higher level protocol between LANs, across a Permanent Virtual Circuit. These stations are identified by their Data Link Control Identifier (DLCI), equivalent to an Ethernet address in a LAN itself. InARP allows a station to determine a protocol address (e.g. IP address) from a DLCI. This is useful if a new virtual circuit becomes available. Signalling messages announce its DLCI, but without the corresponding protocol address it is unusable: no frames can be routed to it. Reverse ARP (RARP) performs a similar task on an Ethernet LAN, however RARP answers the question "What is my IP Address?" whereas InARP answers the question "What is your protocol address?". See RFC 2390. 1 1 1 1 1 inverse comment convention A kind of literate programming where the program code is marked to distinguish it from the text, rather than the other way around as in normal programs. (2003-09-24) 1 1 1 1 1 inverted index A sequence of (key, pointer) pairs where each pointer points to a record in a database which contains the key value in some particular field. The index is sorted on the key values to allow rapid searching for a particular key value, using e.g. binary search. The index is "inverted" in the sense that the key value is used to find the record rather than the other way round. For databases in which the records may be searched based on more than one field, multiple indices may be created that are sorted on those keys. An index may contain gaps to allow for new entries to be added in the correct sort order without always requiring the following entries to be shifted out of the way. (1995-02-08) 1 1 1 1 1 invoking a method method invocation 1 1 1 1 1 InWorld VR Manufacturers of the CyberWand. (1995-04-04) 1 1 1 1 1 IO Idiotic operator. (2003-05-15) 1 1 1 1 1 io The country code for British Indian Ocean territory. (1999-01-27) 1 1 1 1 1 I/O Input/Output 1 1 1 1 1 IOI International Olympiad in Informatics 1 1 1 1 1 Iomega Corporation A storage device manufacturer whose major products are the Zip and Jaz removable disk drives and Ditto tape drives. They became popular with an early product called the Bernoulli Box. These products fall in line with their focus set in 1994 "to help people manage their stuff". The company's stated aim is to create portable, fast, large and cheap storage solutions. Iomega's major competitor in the growing market for removable disks is SyQuest, who seem to always be a few weeks behind them. In general, Iomega target the Small Office/Home Office. They are also investigating the growing digital photography market which also needs large removable storage devices. Iomega's president and CEO is Kim Edwards. They have nearly 2000 employees in offices world-wide. Revenue for the quarter ending Dec 1996 was $371 million and net income was $20 million. 1 1 1 1 1 I-OOA A tool, developed and sold by the Kennedy-Carter company, that supports the Schlaer Mellor design method, and that generates code in C and C++. This tool can be modified to generate code of different styles, and also, to generate code in different programming languages. (1995-01-31) 1 1 1 1 1 I/O redirection input/output redirection 1 1 1 1 1 IOS Internetworking Operating System 1 1 1 1 1 Iota A specification language. ["The Iota Programming System", R. Nakajima er al, Springer 1983]. (1994-12-08) 1 1 1 1 1 IOT&E Initial Operational Test and Evaluation 1 1 1 1 1 IOW in other words. (1997-05-26) 1 1 1 1 1 IP Internet Protocol 1 1 1 1 1 IPA International Phonetic Alphabet 1 1 1 1 1 iPad A tablet computer announced by Apple Computer, Inc. on 2010-01-27 to be released in March 2010. The iPad runs iPhone OS 3.2, providing multi-touch interaction and multimedia processing. Like Apple's iPhone and iPod, it uses a virtual keyboard for text input and runs most iPhone apps. It adds the iBooks application for reading text in ePub format. It has a 1GHz Apple A4 SoC processor, up to 64GB of flash memory, a 250mm LED-backlit colour LCD display (resolution 1024x768 pixels) and a 25 Wh lithium-polymer battery. Internet access will be Wi-Fi in early models with HSDPA 3G available soon after using a micro-SIM. It weighs 730g. Features it lacks include a camera, the ability to multitask and an open developement environment. The iPad is the culmination of a series of attempts by Apple to produce a tablet device, starting with the Newton MessagePad 100 in 1993 and including collaboration with 1 1 1 1 1 IP address (Internet address) The 32-bit number uniquely identifying a node on a network using Internet Protocol, as defined in STD 5, RFC 791. An IP address is normally displayed in dotted decimal notation, e.g. 128.121.4.5. The address can be split into a network number (or network address) and a host number unique to each host on the network and sometimes also a subnet address. The way the address is split depends on its "class", A, B or C (but see also CIDR). The class is determined by the high address bits: Class A - high bit 0, 7-bit network number, 24-bit host number. n1.a.a.a 0 <= n1 <= 127 Class B - high 2 bits 10, 14-bit network number, 16-bit host number. n1.n2.a.a 128 <= n1 <= 191 Class C - high 3 bits 110, 21-bit network number, 8-bit host number. n1.n2.n3.a 192 <= n1 <= 223 DNS translates a node's fully qualified domain name to an 1 1 1 1 1 IPARS International Programmable Airline Reservation System 1 1 1 1 1 I-Pay A Dutch only payment system for the Internet. [Reference?] (1998-04-28) 1 1 1 1 1 IPC Inter-Process Communication 1 1 1 1 1 ipconfig A Microsoft Windows program to display information about the the computer's Internet Protocol settings, including IP address, DHCP lease information, network card Ethernet address, and DNS information. [Was it ever "winipcfg"?] (2006-02-12) 1 1 1 1 1 IPCP Internet Protocol Control Protocol 1 1 1 1 1 IPE Integrated Programming Environment 1 1 1 1 1 Iperf A tool to measure maximum TCP bandwidth, allowing the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, and datagram loss. An IPv6 version is also available. Latest version: 1.7.0, as of 2004-01-18. Iperf Home (http://dast.nlanr.net/Projects/Iperf/). (2004-01-18) 1 1 1 1 1 IPL 1. Information Processing Language. 2. Internet Public Library. 3. Initial Program Load. 4. Initial Program Loader. (1997-08-31) 1 1 1 1 1 IP next generation Internet Protocol Version 6 1 1 1 1 1 IPng Internet Protocol Version 6 1 1 1 1 1 IP number Internet address 1 1 1 1 1 IPS A threaded language. ["IPS, An Unorthodox High Level Language", K. Meinzer, BYTE pp. 146-159 (Jan 1979)]. (1994-11-04) 1 1 1 1 1 IPSE Integrated Project Support Environment 1 1 1 1 1 IPsec ("IP Secure"?) A protocol that provides security for transmission of sensitive information over unprotected networks such as the Internet. IPsec acts at the network layer, protecting and authenticating IP packets between participating devices ("peers"), such as Cisco routers. IETF IPsec (http://ietf.org/ids.by.wg/ipsec.html). (2002-05-06) 1 1 1 1 1 IPT IP Telephony 1 1 1 1 1 IP Telephony (IPT, Internet Telephony) Use of IP data connections to exchange voice and fax data that have traditionally been carried over the public switched telephone network. During the late 1990s, an increasing number of telephone calls have been routed over the Internet. Calls made in this way avoid PSTN charges. Unlike traditional telephony, IP telephony is relatively unregulated. Companies providing these services are known as Internet Telephony Service Providers (ITSPs). They include telephone companies, cable TV companies and Internet Service Providers (ISPs). There are still many problems with voice quality, latency, compression algorithms, and quality of service. Voice over IP is an organised effort to standardise IP telephony. See also Computer Telephone Integration. 1 1 1 1 1 IPv4 Internet Protocol version 4 1 1 1 1 1 IPv6 Internet Protocol version 6 1 1 1 1 1 IPX Internetwork Packet eXchange 1 1 1 1 1 IPXCP Internetwork Packet eXchange Control Protocol. (1995-09-27) 1 1 1 1 1 IQ Pictorial query language, implemented in Ratfor. ["Structured Implementation of an Image Query Language", Y.E. Lien et al, in Database Techniques for Pictorial Applications, A. Blaser ed, pp.416-430]. 1 1 1 1 1 iq The country code for Iraq. (1999-01-27) 1 1 1 1 1 IQL An object-oriented deductive language/database system. 1 1 1 1 1 IR 1. <networking> Internet Registry. 2. <electronics> infrared. (1997-01-30) 1 1 1 1 1 ir The country code for Iran. (1999-01-27) 1 1 1 1 1 IrBUS IrDA Control 1 1 1 1 1 IRC Internet Relay Chat 1 1 1 1 1 ircop /*r'-kop/ ("IRC" + "op", but with the, presumably intentional, alternate analysis "IRC" + "cop") Someone who is endowed with privileges on IRC, not limited to a particular channel. These privileges include channel op privileges in any channel, but also notably include the ability to disconnect a user from the IRC network. Ircops are generally people who are in charge of the IRC server at their particular site. Compare op. (1997-12-12) 1 1 1 1 1 IRC penis war penis war 1 1 1 1 1 IrDA Infrared Data Association 1 1 1 1 1 IrDA-C IrDA Control 1 1 1 1 1 IrDA Control (IrDA-C, formerly IrBUS) Infrared standard from IrDA. IrDA Control is a low speed communication standard that allows cordless peripherals such as keyboards, mice, game pads, and joysticks to interact with intelligent host devices. Host devices include PCs, home appliances, game machines, and television and web set-top boxes. IrDA Control supports data rates of 75 Kbps at up to 8 metres, and is designed to integrate with devices that use USB HID. Parts and products featuring IrDA Control are expected in 1998. See also IrDA Data, AIR. (1999-10-14) 1 1 1 1 1 IrDA Data (IrDA-D) Infrared standards from IrDA. IrDA Data is designed for data transfer over a distance of up to 1 metre, acting as a point-to-point cable replacement. Several IrDA Data standards exist, supporting data rates from 9600 bps - 50 Mbps, namely SIR, FIR, and VFIR. See also IrDA Control, AIR. (1999-10-14) 1 1 1 1 1 IRDATA Industrial Robot DATA. A standardised robot control code. "IRDATA, Industrial Robot Data", DIN 66313, Beuth-Verlag 1991. 1 1 1 1 1 IRDP ICMP Router Discovery Protocol 1 1 1 1 1 IRDS Information Resource Dictionary System. A set of ISO standards for CASE repositories. It governs the definition of data dictionaries to be implemented on top of relational databases (see repository, data dictionary). 1 1 1 1 1 IRET Return from interrupt 1 1 1 1 1 IRIS Institute for Research in Information and Scholarship of Brown University (Providence RI). (1994-11-04) 1 1 1 1 1 Iris An object-oriented DBMS. (1994-11-04) 1 1 1 1 1 IRISA INRIA 1 1 1 1 1 IRIS Explorer Numerical Algorithms Group (NAG)'s tool for developing visualisation applications via a visual programming environment. IRIS Explorer has a range of visualisation techniques, from simple graphs to multidimensional animation, that can help show trends and relationships in data. IRIS Explorer uses standard Open Inventor, ImageVision and OpenGL libraries as well as NAG's own numerical libraries. It is available for Windows, Unix and Linux. It has a point-and-click interface and a library of "modules" (software routines). IRIS Explorer home (http://www.nag.co.uk/Welcome_IEC.asp). (2008-09-04) 1 1 1 1 1 IRIX /ir'iks/ The main operating system used by Silicon Graphics workstations and servers. IRIX is multiprocessor and multi-threaded. It incorporates substantial functionality from UNIX System V, Release 4.1 and 4.2. (1997-06-17) 1 1 1 1 1 IRL 1. <jargon, chat> In real life. Generally synonymous with f2f. 2. <language, robotics> Industrial Robot Language. (1997-01-31) 1 1 1 1 1 IRM Information Resource Management 1 1 1 1 1 iron Hardware, especially older and larger hardware of mainframe class with big metal cabinets housing relatively low-density electronics (but the term is also used of modern supercomputers). Often in the phrase big iron. Oppose silicon. See also dinosaur. [Jargon File] (1994-11-04) 1 1 1 1 1 Iron Age In the history of computing, 1961-1971 - the formative era of commercial mainframe technology, when ferrite core memory dinosaurs ruled the earth. The Iron Age began, ironically enough, with the delivery of the first minicomputer (the PDP-1) and ended with the introduction of the first commercial microprocessor (the Intel 4004) in 1971 See also Stone Age; compare elder days. [Jargon File] (2003-09-27) 1 1 1 1 1 iron box [Unix/Internet] A special environment set up to trap a cracker logging in over remote connections long enough to be traced. May include a modified shell restricting the cracker's movements in unobvious ways, and "bait" files designed to keep him interested and logged on. See also back door, firewall machine, Venus flytrap, and Clifford Stoll's account in "The Cuckoo's Egg" of how he made and used one. Compare padded cell. [Jargon File] 1 1 1 1 1 Ironman HOLWG, DoD, Jan 1977, revised Jul 1977. Fourth of the series of DoD requirements that led to Ada. "Department of Defense Requirements for High Order Computer Programming Languages", SIGPLAN Notices 12(12):39-54 (Dec 1977). "Revised Ironman Requirements for High Order Computer Programming Languages", US Dept of Defense, Jul 1977. (See Strawman, Woodenman, Tinman, Steelman). 1 1 1 1 1 ironmonger [IBM] A hardware specialist (derogatory). Compare sandbender, polygon pusher. [Jargon File] 1 1 1 1 1 IRQ interrupt request 1 1 1 1 1 irrational number A real number which is not a rational number, i.e. it is not the ratio of two integers. The decimal expansion of an irrational is infinite but does not end in an infinite repeating sequence of digits. Examples of irrational numbers are pi, e and the square root of two. (1995-04-12) 1 1 1 1 1 irrefutable The opposite of refutable. 1 1 1 1 1 IRSG Internet Research Steering Group 1 1 1 1 1 IRTF Internet Research Task Force 1 1 1 1 1 IRUS Irvine Research Unit in Software 1 1 1 1 1 Irvine Dataflow (Always called "Id") A non-strict, single assignment language and incremental compiler developed by Arvind and Gostelow and used on MIT's Tagged-Token Dataflow Architecture and planned to be used on Motorola's Monsoon. See also Id Nouveau. ["An Asynchronous Programming Language for a Large Multiprocessor Machine", Arvind et al, TR114a, Dept ISC, UC Irvine, Dec 1978]. ["The U-Interpreter", Arvind et al, Computer 15(2):42-50, 1982]. (1998-02-14) 1 1 1 1 1 Irvine Research Unit in Software (IRUS) The University of California, Irvine. [Details?] (1995-04-18) 1 1 1 1 1 IS 1. <standard> International Standard. 2. Intermediate System. 1 1 1 1 1 is The country code for Iceland. (1999-01-27) 1 1 1 1 1 IS-11172 The International Standard for MPEG-1 compression. (1999-01-06) 1 1 1 1 1 IS-13818 The International Standard for MPEG-2 compression. (1999-01-06) 1 1 1 1 1 ISA 1. <architecture> Integrated Systems Architecture. 2. <body> International Smalltalk Association. 3. <architecture> instruction set architecture. 4. <architecture> Industry Standard Architecture. (1997-02-13) 1 1 1 1 1 Isabelle A generic theorem prover with support for several object-logics, developed by Lawrence C. Paulson <Larry.Paulson@cl.cam.ac.uk> in collaboration with Tobias Nipkow (http://in.tum.de/~nipkow/) at the Technical University of Munich. A system of type classes allows polymorphic object-logics with overloading and automatic type inference. Isabelle supports first-order logic - constructive and classical versions; higher-order logic, similar to Gordon's HOL; Zermelo Fränkel set theory; an extensional version of Martin Löf's type theory, the classical first-order sequent calculus, LK; the modal logics T, S4, and S43; and Logic for Computable Functions. An object logic's syntax and inference rules are specified declaratively allowing single-step proof construction. Proof procedures can be expressed using "tactics" and tacticals. Isabelle provides control structures for 1 1 1 1 1 Isabelle-92 Isabelle 1 1 1 1 1 Isabelle-93 Isabelle 1 1 1 1 1 ISA bus Industry Standard Architecture 1 1 1 1 1 ISAKMP Internet Security Association and Key Management Protocol 1 1 1 1 1 ISAM Indexed Sequential Access Method 1 1 1 1 1 ISAPI Internet Server Application Programming Interface 1 1 1 1 1 ISAPI filter A replaceable DLL which the server calls whenever there is an HTTP request. When the filter is first loaded, it communicates to the server what sort of notifications will be accepted. After that, whenever a selected event occurs, the filter is called to process the event. Example applications of ISAPI filters include custom authentication schemes, compression, encryption, logging, traffic analysis or other request analyses. (1997-01-06) 1 1 1 1 1 ISBL A mathematical query language. [Stands for? Details?] (1997-01-06) 1 1 1 1 1 ISDE Integrated Software Development Environment: equivalent to an IPSE. 1 1 1 1 1 ISDN Integrated Services Digital Network 1 1 1 1 1 ISE Interactive Software Engineering 1 1 1 1 1 ISEE Integrated Software Engineering Environment - equivalent to SEE. 1 1 1 1 1 I see no X here. Hackers (and the interactive computer games they write) traditionally favour this slightly marked usage over other possible equivalents such as "There's no X here!" or "X is missing." or "Where's the X?". This goes back to the original PDP-10 ADVENT, which would respond in this wise if you asked it to do something involving an object not present at your location in the game. [Jargon File] 1 1 1 1 1 ISETL Interactive SETL by Gary Levin <gary@clutx.clarkson.edu>. Latest version: 3.0. Binaries (ftp://sun.soe.clarkson.edu/) and source for MS-DOS, Macintosh, Unix, VAX/VMS. [Clarkson U. "An Introduction to ISETL Version 1.9", G.M. Levin, Dept MCS, Clarkson U]. ["Learning discrete mathematics with ISETL", Nancy Baxter. Ed. Gary Levin Dubinsky. Springer-Verlag, c.1989.] (Apr 1994) 1 1 1 1 1 ISF Information Systems Factory 1 1 1 1 1 ISINDEX An HTML tag which tells the browser to display a text entry box on the current page. Any text entered in the box by the user is appended as a URL-encoded query string to the current URL and sent to the server using a GET method. This is a simple way of making a website searchable or allowing other kinds of simple user input. It relies on the server mapping the query URL to an appropriate process, probably depending on the page in which the ISINDEX appeared. More complex input can be catered for using the FORM tag, or Java. (1996-12-22) 1 1 1 1 1 ISIS 1. A toolkit for implementing fault-tolerant distributed systems, developed at Cornell and now available commercially 2. A dialect of JOSS. [Sammet 1969, p. 217]. 1 1 1 1 1 IS-IS Intermediate System-Intermediate System 1 1 1 1 1 ISL Interface Specification Language. Xerox PARC. Interface description language used by the ILU (Inter-Language Unification) system. Includes descriptions of multiple inheritance, exceptions and garbage collection. E-mail: Bill Janssen <janssen@parc.xerox.com>. 1 1 1 1 1 ISLisp International Standard Lisp. An object-oriented Lisp intended as an international replacement for Common Lisp, EuLisp, Le-Lisp and Scheme. The standard's goals are object orientation, extensibility, efficiency, and suitability for non-academic use. The standard is defined in ISO WG 16, draft Dec 1992. (ftp://ma2s2.mathematik.uni-karlsruhe.de/pub/lisp/islisp/). (1995-02-14) 1 1 1 1 1 ISMAP (web) An attribute of the HTML tag <IMG> (inline image) which specifies that if the image is selected, the browser will generate a request indicating the coordinates of the point which was clicked. This request is then interpreted by the server by mapping certain regions of the image to certain actions. Documentation (http://utirc.utoronto.ca/HTMLdocs/NewHTML/image.html). (1995-02-14) 1 1 1 1 1 ISO International Organization for Standardization 1 1 1 1 1 ISO 10646 Universal Character Set 1 1 1 1 1 ISO 3166 country code 1 1 1 1 1 ISO 639-1 language code 1 1 1 1 1 ISO 639-2 language code 1 1 1 1 1 ISO 8072 transport layer 1 1 1 1 1 ISO 8073 transport layer 1 1 1 1 1 ISO 8208 X.25 1 1 1 1 1 ISO 8326 session layer 1 1 1 1 1 ISO 8327 session layer 1 1 1 1 1 ISO 8485 A Programming Language 1 1 1 1 1 ISO 8613 Open Document Architecture 1 1 1 1 1 ISO 8649 Association Control Service Element 1 1 1 1 1 ISO 8650 Association Control Service Element 1 1 1 1 1 ISO 8805 GKS-3D 1 1 1 1 1 ISO 8807 LOTOS 1 1 1 1 1 ISO 8822 presentation layer 1 1 1 1 1 ISO 8823 presentation layer 1 1 1 1 1 ISO 8825 Basic Encoding Rules 1 1 1 1 1 ISO 8859 ISO/IEC's set of 8-bit coded graphic character sets for European languages. Part 1 (full name: "ISO 8859-1:1987 Information processing -- 8-bit single-byte coded graphic character sets -- Part 1: Latin alphabet No. 1") is a common extension of, and replacement for, ASCII. ISO shop (http://iso.ch/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=28245). (2001-12-28) 1 1 1 1 1 ISO 8859-1 ISO 8859 1 1 1 1 1 ISO 8879 The ISO standard defining SGML. (1995-05-03) 1 1 1 1 1 ISO 9000 A set of international standards for both quality management and quality assurance that has been adopted by over 90 countries worldwide. The ISO 9000 standards apply to all types of organisations, large and small, and in many industries. The standards require: standard language for documenting quality processes; system to manage evidence that these practices are instituted throughout an organisation; and third-party auditing to review, certify, and maintain certification of organisations. The ISO 9000 series classifies products into generic product categories: hardware, software, processed materials, and services. Documentation is at the core of ISO 9000 conformance. In fact, the standards have been paraphrased as: Say what you do. Do what you say. Write it down. In Britain it is associated with BS5750 which may become obsolete. 1 1 1 1 1 ISO 9072 Remote Operations Service Element 1 1 1 1 1 ISO 9660 The ISO standard file system for CD-ROMs, later extended by the Joliet standard to allow Unicode characters. (2006-09-25) 1 1 1 1 1 ISO 9735 (Or "EDIFACT") ISO's 1988 standard for Electronic data interchange for administration, commerce and transport. It defines application layer syntax. It was amended and reprinted in 1990. (http://iso.ch/cate/d17592.html). (1995-03-10) 1 1 1 1 1 ISOC Internet Society 1 1 1 1 1 ISO C ANSI C 1 1 1 1 1 isochronous /i:-sok'rn-*s/ A form of multiplexing that guarantees to provide a certain minimum data rate, as required for time-dependent data such as video or audio. Isochronous transmission transmits asynchronous data over a synchronous data link so that individual characters are only separated by a whole number of bit-length intervals. This is in contrast to asynchronous transmission, in which the characters may be separated by arbitrary intervals, and with synchronous transmission [which does what?]. An isochronous message protocol assigns each data source a fixed amount of time to transmit (its "slot") within each cycle through the sources. That guarantees that each source will have regular opportunities to transmit the latest information. If a source has no more data to transmit, then the rest of its time slot is wasted. If it has more to send than will fit in its slot, it has to either store the excess data and transmit it in its next slot, or discard it. 1 1 1 1 1 isochronous transfer isochronous 1 1 1 1 1 ISODE ISO Development Environment 1 1 1 1 1 ISO Development Environment (ISODE) /eye-so-dee-eee/ Software that implements a set of OSI upper-layer services. It supports OSI applications on top of OSI and TCP/IP networks. (1994-12-15) 1 1 1 1 1 ISO/IEC 10646-1 Universal Character Set 1 1 1 1 1 ISO/IEC 26300 OpenDocument 1 1 1 1 1 isolated compact 1 1 1 1 1 ISO Latin 1 ISO 8859 1 1 1 1 1 isometric joystick Any kind of joystick where the input depends on the force exerted rather than the position of the control, e.g. TrackPoint. (2003-06-26) 1 1 1 1 1 isometry A mapping of a metric space onto another or onto itself so that the distance between any two points in the original space is the same as the distance between their images in the second space. For example, any combination of rotation and translation is an isometry of the plane. (1997-12-13) 1 1 1 1 1 isomorphic Two mathematical objects are isomorphic if they have the same structure, i.e. if there is an isomorphism between them. For every component of one there is a corresponding component of the other. (1995-03-25) 1 1 1 1 1 isomorphism A bijective map between two objects which preserves, in both directions, any structure under consideration. Thus a `group isomorphism' preserves group structure; an order isomorphism (between posets) preserves the order relation, and so on. Usually it is clear from context what sort of isomorphism is intended. (1995-03-25) 1 1 1 1 1 isomorphism class A collection of all the objects isomorphic to a given object. Talking about the isomorphism class (of a poset, say) ensures that we will only consider its properties as a poset, and will not consider other incidental properties it happens to have. (1995-03-25) 1 1 1 1 1 ISO Pascal A Lex scanner and Yacc parser are in the comp.sources.unix volume 13 archive. [More detail?] 1 1 1 1 1 ISO seven layer model Open Systems Interconnect 1 1 1 1 1 ISP 1. Internet Service Provider. 2. Instruction Set Processor. 1 1 1 1 1 ISPBX Integrated Services Digital Network PBX. 1 1 1 1 1 ISPF Interactive System Productivity Facility 1 1 1 1 1 ISPL Instruction Set Processor Language. The original ISP language, written in BLISS ca 1971. ["Computer Structures: Readings and Examples", D.P. Siewiorek et al, McGraw-Hill 1982]. 1 1 1 1 1 ISPS Instruction Set Processor Specifications. Operational hardware specification language. Successor to ISPL. ["Instruction Set Processor Specifications", M.R. Barbacci et al, IEEE Trans Computers, C-30(1):24-80 (Jan 1981)]. [Bell, Newell, Siewiorek, Barbacci 1982?] 1 1 1 1 1 IST Imperial Software Technology. (1995-10-12) 1 1 1 1 1 ISTAR An experimental IPSE from Imperial Software Technology. (1995-10-12) 1 1 1 1 1 ISTM It seems to me. (2000-07-06) 1 1 1 1 1 ISV Independent Software Vendor (not a hardware manufacturer). 1 1 1 1 1 ISWIM (If You See What I Mean) An influential but unimplemented computer programming language described in the article by Peter J. Landin cited below. Landin attempted to capture all known programming language concepts, including assignment and control operators such as goto and coroutines, within a single lambda calculus based framework. ISWIM is an imperative language with a functional core, consisting of sugared lambda calculus plus mutable variables and assignment. A powerful control mechanism, Landin's J operator, enables capture of the current continuation (the call/cc operator of Scheme is a simplified version). Being based on lambda calculus ISWIM had higher order functions and lexically scoped variables. The operational semantics of ISWIM are defined using Landin's SECD machine and use call-by-value (eager evaluation). To make ISWIM look more like mathematical 1 1 1 1 1 IT 1. <business, jargon> Information Technology. 2. <language, mathematics, history> Internal Translator. (2000-10-02) 1 1 1 1 1 it The country code for Italy. (1999-01-27) 1 1 1 1 1 ITAR International Traffic in Arms Regulation 1 1 1 1 1 Iterated Function System (IFS) A class of fractals that yield natural-looking forms like ferns or snowflakes. Iterated Function Systems use a very easy transformation that is done recursively. (1998-04-04) 1 1 1 1 1 iteration Repetition of a sequence of instructions. A fundamental part of many algorithms. Iteration is characterised by a set of initial conditions, an iterative step and a termination condition. A well known example of iteration in mathematics is Newton-Raphson iteration. Iteration in programs is expressed using a loop, e.g. in C: new_x = n/2; do x = new_x; new_x = 0.5 * (x + n/x); 1 1 1 1 1 iterative deepening A graph search algorithm that will find the shortest path with some given property, even when the graph contains cycles. When searching for a path through a graph, starting at a given initial node, where the path (or its end node) has some desired property, a depth-first search may never find a solution if it enters a cycle in the graph. Rather than avoiding cycles (i.e. never extend a path with a node it already contains), iterative deepening explores all paths up to length (or "depth") N, starting from N=0 and increasing N until a solution is found. (2004-01-26) 1 1 1 1 1 iterator An object or routine for accessing items from a list, array or stream one at a time. By extension, the term can be used for an object or routine for accesing items from any data structure that can be viewed as a list. For example, a traverser is an iterator for tree-shaped data structures. (2001-10-04) 1 1 1 1 1 Iternet It's spelled "Internet". (1997-04-07) 1 1 1 1 1 IT governance information technology governance 1 1 1 1 1 ITHACA An Esprit project to put a 4th generation object-oriented system to practical use in an industrial environment. The ITHACA environment offered an application support system incorporating advanced technologies in the fields of object-oriented programming, programming languages, databases, user interfaces and software development tools. (2009-04-27) 1 1 1 1 1 ITIL Information Technology Infrastructure Library 1 1 1 1 1 ITP Intent to Package 1 1 1 1 1 ITS 1. Incompatible time-sharing System An influential but highly idiosyncratic operating system written for the PDP-6 and PDP-10 at MIT and long used at the MIT AI Lab. Much AI-hacker jargon derives from ITS folklore, and to have been "an ITS hacker" qualifies one instantly as an old-timer of the most venerable sort. ITS pioneered many important innovations, including transparent file sharing between machines and terminal-independent I/O. After about 1982, most actual work was shifted to newer machines, with the remaining ITS boxes run essentially as a hobby and service to the hacker community. The shutdown of the lab's last ITS machine in May 1990 marked the end of an era and sent old-time hackers into mourning nationwide (see high moby). The Royal Institute of Technology in Sweden is maintaining one "live" ITS site at its computer museum (right next to the only TOPS-10 system still on the Internet), so ITS is still alleged to hold the record for OS in longest 1 1 1 1 1 it's a feature From the adage "It's not a bug, it's a feature." Used sarcastically to describe an unpleasant experience that you wish to gloss over. (1997-04-29) 1 1 1 1 1 ITSP Internet Telephony Service Providers 1 1 1 1 1 ITU International Telecommunications Union 1 1 1 1 1 ITU-T International Telecommunications Union 1 1 1 1 1 ITU-T X.680 Coordinated Universal Time 1 1 1 1 1 ITU X.209 Basic Encoding Rules 1 1 1 1 1 Ivan A Diana-like language making up part of VHDL. ["VHDL - The Designer Environment", A. Gilman, IEEE Design & Test 3, (Apr 1986)]. 1 1 1 1 1 Ivan Sutherland Ivan E. Sutherland is widely known for his pioneering contributions. His 1963 MIT PhD thesis, Sketchpad, opened the field of computer graphics. His 1966 work, with Sproull, on a head-mounted display anticipated today's virtual reality by 25 years. He co-founded Evans and Sutherland, which manufactures the most advanced computer image generators now in use. As head of Computer Science Department of Caltech he helped make integrated circuit design an acceptable field of academic study. Dr. Sutherland is on the boards of several small companies and is a member of the National Academy of Engineering and the National Academy of Sciences, the ACM and IEEE. He received the ACM's Turing Award in 1988. He is now Vice President and Fellow of Sun Microsystems Laboratories in Mountain View, CA, USA. (1994-11-16) 1 1 1 1 1 Iverson's Language APL, which went unnamed for many years. [Sammet 1969, p.770]. (1994-11-16) 1 1 1 1 1 IVR Interactive Voice Response 1 1 1 1 1 ivs INRIA Videoconferencing System. A video-conferencing tool for the Internet based on the H.261 video compression standard. (http://zenon.inria.fr:8003/rodeo/personnel/Thierry.Turletti/ivs.html). (1994-11-16) 1 1 1 1 1 IVTRAN Parallel Fortran for the Illiac IV. 1966. 1 1 1 1 1 IV&V Independent Verification and Validation 1 1 1 1 1 IVY A language with a more pleasant syntax than Perl, tcl or Lisp. It has nice features like low punctuation count, blocks indicated by indentation, and similarity to normal procedural languages. This language started out as an idea for an extension language for the editor JOE. An experimental interpreter by Joseph H Allen <jhallen@world.std.com> was posted to alt.sources on 28 Sep 1993 1 1 1 1 1 IWay Information Superhighway 1 1 1 1 1 IWBNI It Would Be Nice If. Compare WIBNI. [Jargon File] (1994-11-24) 1 1 1 1 1 IXC IntereXchange Carrier 1 1 1 1 1 IXI Limited A Cambridge, England company who were the leading supplier of Unix System windowing software when they were acquired by SCO in February 1993. (1994-12-12) 1 1 1 1 1 IXO Telocator Alphanumeric Protocol 1 1 1 1 1 IYFEG (Usenet) Insert Your Favourite Ethnic Group. Used as a meta-name when telling ethnic jokes on the net to avoid offending anyone. See also JEDR. [Jargon File] (1994-11-24) 1 1 1 1 1 J A derivative and redesign of APL with added features and control structures. J is purely functional with lexical scope and more conventional control structures, plus several new concepts such as function rank and function arrays. J was designed and developed by Kennneth E. Iverson and Roger Hui <hui@yrloc.ipsa.reuter.com>. J uses only the ASCII character set but has a spelling scheme that retains the advantages of APL's special alphabet. J is a conventional procedural programming language but can be used as a purely functional language. Version 4.1 for MS-DOS, Sun, Mac, Archimedes. Source available in C from Iverson Software, +1 (416) 925 6096. Version 6 package from ISI includes an interpreter and tutorial. Ported to DEC, NeXT, SGI, Sun-3, Sun-4, Vax, RS/6000, MIPS, Macintosh, Acorn Archimedes, IBM PC, Atari, 3b1, Amiga. (ftp://watserv1.waterloo.edu/languages/apl/j). 1 1 1 1 1 J2EE Java 2 Platform, Enterprise Edition 1 1 1 1 1 J2ME Java 2 Platform, Micro Edition 1 1 1 1 1 J2SE Java 2 Platform, Standard Edition 1 1 1 1 1 J3 A dialect of JOVIAL. ["Military Standard JOVIAL (J3)", MIL-STD-1588 (USAF), June 1976]. (1994-12-07) 1 1 1 1 1 J73 A dialect of JOVIAL. ["Military Standard JOVIAL (J73)", MIL-STD-1589 (USAF), Feb 1977]. (1994-12-07) 1 1 1 1 1 jabber When a network node transmits a packet longer than the maximum permissible length, usually due to a fault condition. (1996-05-10) 1 1 1 1 1 JACAL JAffer's Canonical ALgebra 1 1 1 1 1 jaccl An LR1 grammar parser generator written by Dave Jones at Megatest. (1989-09-08) 1 1 1 1 1 jack in To log on to a machine or connect to a network or BBS, especially for purposes of entering a virtual reality simulation such as a MUD or IRC (leaving is "jacking out"). This term derives from cyberpunk SF, in which it was used for the act of plugging an electrode set into neural sockets in order to interface the brain directly to a virtual reality. It is primarily used by MUD and IRC fans and younger hackers on BBS systems. [Jargon File] 1 1 1 1 1 Jack Kilby (1924 - 2005-06-20) The electronics engineer who invented the integrated circuit in 1958 at Texas Instruments. TI Biography (http://ti.com/corp/docs/kilbyctr/jackstclair.shtml). [Was the JK flip-flop named after him?] (2005-06-22) 1 1 1 1 1 Jackson method A proprietary structured method for software analysis, design and programming. (2005-06-22) 1 1 1 1 1 Jacquard, Joseph-Marie Joseph-Marie Jacquard 1 1 1 1 1 Jacquard loom /zhah-kar'/ A mechanical loom, invented by Joseph-Marie Jacquard in 1801, which used the holes punched in pasteboard punch cards (which see) to control the weaving of patterns in fabric. It was the first machine to use punch cards, although it did no computation based on them. (http://history.rochester.edu/steam/hollerith/loom.htm). (1998-10-19) 1 1 1 1 1 JAD Joint Application Design Or "Joint Application Development". [What is it?] (1995-11-15) 1 1 1 1 1 JADE James' DSSSL Engine 1 1 1 1 1 Jade 1. U Washington, late 80's. A strongly-typed language, object-oriented but without classes. For type research. The compiler output is Smalltalk. [Submitter claimed that Jade has exactly one user!] 2. Implicit coarse-grained concurrency. The constructs 'with', 'withonly' and 'without' create tasks with specified side effects to shared data objects. Implemented as a C preprocessor. "Coarse-Grain Parallel Programming in Jade", M.S. Lam et al, SIGPLAN Notices 26(7):94-105 (Jul 1991). 1 1 1 1 1 jadeTeX A program which uses TeX as a back-end for producing DVI (or PDF) printable output from James' DSSSL Engine. (ftp://ftp.tug.org/tex-archive/macros/jadetex/). (1997-11-20) 1 1 1 1 1 JAffer's Canonical ALgebra (JACAL) A symbolic mathematics program, most of which was written in Scheme by Aubrey Jaffer. (http://swissnet.ai.mit.edu/~jaffer/JACAL.html). (1999-06-27) 1 1 1 1 1 jaggies /jag'eez/ (Or "staircase") The "staircase" effect observable when an edge (especially a linear edge of very shallow or steep slope) is rendered on a bitmap display (as opposed to a vector display). The effect is even more pronounced when a bitmap image or text in a bitmap font is enlarged. Outline fonts and anti-aliasing are two techniques used to solve this problem with text. [Jargon File] (1997-12-01) 1 1 1 1 1 JaM John and Martin. An interpreted FORTH-like graphics language by John Warnock and Martin Newell, Xerox PARC, 1978. JaM was the forerunner of both Interpress and PostScript. It is mentioned in PostScript Language reference Manual, Adobe Systems, A-W 1985. 1 1 1 1 1 jam A condition on a network where two nodes transmitting simultaneously detect the collision and continue to transmit for a certain time (4 to 6 bytes on Ethernet) to ensure that the collision has been detected by all nodes involved. (1994-12-12) 1 1 1 1 1 James Clark Dr. James H. Clark 1 1 1 1 1 James' DSSSL Engine (JADE) A DSSSL tool by James J. Clark. Jade is an implementation of the DSSSL style language for Unix and Microsoft Windows. It can turn the SGML source of the DSSSL standard into an RTF file of about 200 pages using a fairly complex DSSSL specification. (http://jclark.com/). (1996-10-13) 1 1 1 1 1 James Gosling The software engineer who wrote GOSMACS, and served as Sun Microsystems, Inc. project leader for both NeWS, and Java. He is currently (1997) a Vice President and Distinguished Engineer at Sun. (http://java.sun.com:80/people/jag/). Biography (http://sun.com/sunergy/Bios/gosling_bio.html). (1997-03-12) 1 1 1 1 1 James H. Clark Dr. James H. Clark 1 1 1 1 1 JAM Programming Language (JPL) A string-based imperative language from JYACC Corporation, part of the JAM tool for developing screen (non-window) applications. (2007-10-02) 1 1 1 1 1 JANET Joint Academic NETwork 1 1 1 1 1 JANET IP Service (JIPS) Joint Academic NETwork Internet Protocol. E-mail: <jips-nosc@nic.ja.net>. [Details?] (1994-12-12) 1 1 1 1 1 Janus 1. Distributed language with an ask/tell constraint system. qdjanus is a Janus-to-Prolog compiler for Sicstus Prolog and jc is compiles to C. ["Janus: A Step Towards Distributed Constraint Programming", V. Saraswat <saraswat@parc.xerox.com> et al in Logic Programming: Proc 1990 North Am Conf, S. Debray et al eds, MIT Press 1990]. ["Programming in Janus", Saraswat, Kahn, and Levy]. 2. W.M. Waite, U Colorado. Intermediate language, claimed as an implementation of UNCOL. Used on CDC 6600. ["Experience with the Universal Intermediate Language Janus", B.K. Haddon et al, Soft Prac & Exp 8(5):601- 616 (Sep 1978)]. 1 1 1 1 1 japh A Perl program which prints "Just another Perl hacker" using extremely obfuscated methods, typically ones based on obscure behaviours of sometimes rarely-used functions, in the spirit of the Obfuscated C Contest. The obfuscation can result from the code being total gibberish, e.g.: $_="krJhruaesrltre c a cnp,ohet";$_.=$1,print$2while s/(..)(.)//; or from having "Just another Perl hacker" embedded in opaque code: $_='987;s/^(\d+)/$1-1/e;$1?eval:print"Just another Perl hacker,"';eval or from looking like it does something simple and completely unrelated to printing "Just another Perl hacker": $_ = "wftedskaebjgdpjgidbsmnjgc"; tr/a-z/oh, turtleneck Phrase Jar!/; print; Examples (http://perl.com/CPAN/misc/japh). (1997-09-14) 1 1 1 1 1 jar Java archive 1 1 1 1 1 jargon Language specific to some field of human endeavour, in this case, computing, that might not be understood by those outside that area. This dictionary contains many examples of jargon (/contents/jargon.html). The Jargon File is the definitive collection of computing jargon. (2014-09-01) 1 1 1 1 1 Jargon File The on-line hacker Jargon File maintained by Eric S. Raymond. A large collection of definitions of computing terms, including much wit, wisdom, and history. Many definitions (/contents/jargon.html) in this dictionary are from v3.0.0 of 1993-07-27. Jargon File Home (http://catb.org/~esr/jargon/). See also Yellow Book, Jargon. (2014-08-14) 1 1 1 1 1 Java An object-oriented, distributed, interpreted, architecture-neutral, portable, multithreaded, dynamic, buzzword-compliant, general-purpose programming language developed by Sun Microsystems in the early 1990s (initially for set-top television controllers) and released to the public in 1995. Java was named after the Indonesian island, a source of programming fluid. Java first became popular as the earliest portable dynamic client-side content for the web in the form of platform-independent Java applets. In the late 1990s and into the 2000s it also became very popular on the server side, where an entire set of APIs defines the J2EE. Java is both a set of public specifications (controlled by Oracle, who bought Sun Microsystems, through the JCP) and a series of implementations of those specifications. Java is syntactially similar to C++ without user-definable 1 1 1 1 1 Java 2 Java 2 Platform, Standard Edition 1 1 1 1 1 Java 2 Platform Java 2 Platform, Standard Edition 1 1 1 1 1 Java 2 Platform, Enterprise Edition (J2EE) Sun's Java platform for multi-tier server-oriented enterprise applications. The basis of J2EE is Enterprise JavaBeans (EJB). See also the Standard edition J2SE and the Micro edition J2ME. (http://java.sun.com/j2ee/). (2000-04-20) 1 1 1 1 1 Java 2 Platform, Micro Edition (J2ME) Sun's Java platform for consumer devices. J2ME defines Configurations and Profiles for different classes of small memory device, from smart cards to pagers to set-top boxes. It can run on various Java virtual machines including KVM. Related products include PersonalJava and EmbeddedJava. See also the Standard edition J2SE and the Enterprise edition J2EE. (Home (http://javasoft.com/j2me/). (2000-04-20) 1 1 1 1 1 Java 2 Platform, Standard Edition (J2SE) Sun's Java programming platform aimed at network-oriented enterprise applications. J2SE comprises the Java 2 Software Development Kit (SDK) and the Java 2 Run-Time Environment. See also the Micro edition J2ME and the Enterprise edition J2EE. Java 2 Platform (http://javasoft.com/j2se/). (2000-04-20) 1 1 1 1 1 Java 2 SDK Java 2 Software Development Kit 1 1 1 1 1 Java 2 Software Development Kit (Java 2 SDK) Sun's tools to develop Java applications, part of the Java 2 Platform. Latest version: Java 2 SDK version 1.2.2, as of April 2000. Versions prior to 1.2 were known as the Java Development Kit (JDK). (http://javasoft.com/j2se/). (2000-04-20) 1 1 1 1 1 Java archive (jar) A compressed archive file containing Java class files, filename extension: .jar. The Java Development Kit contains a tool called jar for creating .jar files, similar to the standard Unix tar command. As well as archiving and compressing the Java class files, it also inserts a "manifest" file which can contain information about the class files, such as a digital signature. Combining class files into a single archive file makes it possible to download them in a single HTTP transaction. This, and the compression, speeds up execution of Java programs delivered via the Internet. (2001-02-03) 1 1 1 1 1 JavaBeans A component architecture for the Java programming language, developed initially by Sun, but now available from several other vendors. JavaBeans components are called "beans". JavaBeans allows developers to create reusable software components that can then be assembled together using visual application builder tools including Sybase's PowerJ, Borland's JBuilder, IBM's Visual Age for Java, SunSoft's Java Workshop and Symantec's Visual Cafe. JavaBeans support Introspection (a builder tool can analyze how a Bean works), Customisation (developers can customise the appearance and behaviour of a Bean), Events (Beans can communicate), Properties (developers can customise and program with Beans(?)) and Persistence (customised Beans can be stored and reused). (http://javasoft.com/beans/). (1997-11-20) 1 1 1 1 1 Java Community Process (JCP) An organization controlled by Sun Microsystems to further the growth of the Java language and runtime. The JCP produces standards called Java Standard Requests, which are "requests" in the same sense as RFCs. (2005-01-21) 1 1 1 1 1 Java Database Connectivity (JDBC) Part of the Java Development Kit which defines an application programming interface for Java for standard SQL access to databases from Java programs. Home (http://java.sun.com/products/jdk/1.1/docs/guide/jdbc/index.html). FAQ (http://yoyoweb.com/Javanese/JDBC/FAQ.html). See also Open Database Connectivity. (1997-09-04) 1 1 1 1 1 Java Development Kit (JDK) A free Sun Microsystems product which provides the environment required for programming in Java. The JDK is available for a variety of platforms, but most notably Sun Solaris and Microsoft Windows. (http://java.sun.com/products/jdk/1.1/index.html). [Version?] (1997-09-04) 1 1 1 1 1 Java Message Service (JMS) An API for accessing enterprise messaging systems from Java programs. Java Message Service, part of the J2EE suite, provides standard APIs that Java developers can use to access the common features of enterprise message systems. JMS supports the publish/subscribe and point-to-point models and allows the creation of message types consisting of arbitrary Java objects. JMS provides support for administration, security, error handling, and recovery, optimisation, distributed transactions, message ordering, message acknowledgment, and more. (http://java.sun.com/products/jms). Overview (http://developer.java.sun.com/developer/technicalArticles/Networking/messaging/). (2001-06-22) 1 1 1 1 1 Java Native Interface (JNI) A native programming interface for Java that allows Java code running inside a Java Virtual Machine to interoperate with applications and libraries written in other programming languages such as C, C++ and assembly language. (1997-12-07) 1 1 1 1 1 Java Open Language Toolkit (JOLT) A project aimed at providing a freely available and redistributale implementation of Sun Microsystems's Java language and tools. (http://redhat.com/linux-info/jolt/). (1996-12-17) 1 1 1 1 1 Java Remote Method Protocol (JRMP) A proprietary wire-level protocol designed by Sun Microsystems to transport Java RMI. JRMP serves the same function as IIOP, but also supports object passing. Sun plans to offer IIOP as an alternative to JRMP. Sun do not appear to use this term any longer, simply referring to the "RMI transport protocol". (http://java.sun.com/j2se/1.3.0/docs/guide/rmi/spec/rmi-protocol3.html). Comparison (http://execpc.com/~gopalan/misc/compare.html). (2001-07-21) 1 1 1 1 1 Java Run-Time Environment (JRE) The part of the Java Development Kit required to run Java programs. The JRE consists of the Java Virtual Machine, the Java platform core classes and supporting files. It does not include the compiler, debugger or other tools present in the JDK. The JRE is the smallest set of executables and files that constitute the standard Java platform. (1998-11-30) 1 1 1 1 1 JavaScript (Formerly "LiveScript") Netscape's simple, cross-platform, web scripting language, only very vaguely related to Java (which is a Sun trademark). JavaScript is intimately tied to the web, and currently runs in only three environments - as a server-side scripting language, as an embedded language in server-parsed HTML, and as an embedded language run in web browsers where it is the most important part of DHTML. JavaScript has a simplified C-like syntax and is tightly integrated with the browser Document Object Model. It is useful for implementing enhanced forms, simple web database front-ends, and navigation enhancements. It is unusual in that the scope of variables extends throughout the function in which they are declared rather than the smallest enclosing block as in C. JavaScript originated from Netscape and, for a time, only their products supported it. Microsoft now supports a 1 1 1 1 1 JavaScript Object Notation (JSON) Syntax for serialising JavaScript objects, often used as a data carrier format. JSON is based on a subset of the JavaScript programming language. It uses a file extension of .json and is considered a language-independent data format. (2008-05-28) 1 1 1 1 1 Java servelet Java servlet 1 1 1 1 1 JavaServer Faces (JSF) A system for building web applications by assembling reusable user interface components in a web page, connecting these components to a data source and passing client events to server handlers. (http://java.sun.com/j2ee/javaserverfaces/overview.html). (2006-07-21) 1 1 1 1 1 JavaServer Pages (JSP) A freely available specification for extending the Java Servlet API to generate dynamic web pages on a web server. The JSP specification was written by industry leaders as part of the Java development program. JSP assists developers in creating HTML or XML pages that combine static (fixed) page templates with dynamic content. Separating the user interface from content generation allows page designers to change the page layout without having to rewrite program code. JSP was designed to be simpler than pure servlets or CGI scripting. JSP uses XML-like tags and scripts written in Java to generate the page content. HTML or XML formatting tags are passed back to the client. Application logic can live on the server, e.g. in JavaBeans. JSP is a cross-platform alternative to Microsoft's Active Server Pages, which only runs in IIS on Windows NT. 1 1 1 1 1 Java servlet (By analogy with "applet") A Java program that runs as part of a network service, typically an HTTP server and responds to requests from clients. The most common use for a servlet is to extend a web server by generating web content dynamically. For example, a client may need information from a database; a servlet can be written that receives the request, gets and processes the data as needed by the client and then returns the result to the client. Applets are also written in Java but run inside the JVM of a HTML browser on the client. Servlets and applets allow the server and client to be extended in a modular way by dynamically loading code which communicates with the main program via a standard programming interface. Servlets are more flexible than CGI scripts and, being written in Java, more portable. The spelling "servelet" is occasionally seen but JavaSoft 1 1 1 1 1 Java Servlet Development Kit (JSDK) A suite of software for easing the development of Java servlets. JavaSoft Servlet Development Kit (http://javasoft.com/products/jdk/1.2/docs/ext/servlet/). (1998-05-26) 1 1 1 1 1 Java Virtual Machine (JVM) A specification for software which interprets Java programs that have been compiled into byte-codes, and usually stored in a ".class" file. The JVM instruction set is stack-oriented, with variable instruction length. Unlike some other instruction sets, the JVM's supports object-oriented programming directly by including instructions for object method invocation (similar to subroutine call in other instruction sets). The JVM itself is written in C and so can be ported to run on most platforms. It needs thread support and I/O (for dynamic class loading). The Java byte-code is independent of the platform. There are also some hardware implementations of the JVM. Specification (http://javasoft.com/docs/books/vmspec/html/VMSpecTOC.doc.html). Sun's Java chip (http://news.com/News/Item/0,4,9328,00.html). 1 1 1 1 1 Java VM Java Virtual Machine 1 1 1 1 1 JAZ An early system on the LGP-30. [CACM 2(5):16, May 1959]. (1997-05-16) 1 1 1 1 1 Jaz Jaz Drive 1 1 1 1 1 Jaz Drive Iomega Corporation's drive which takes removable one or two gigabyte disk cartridges which contain conventional hard disks. Internal and external drives are available claiming an average transfer rate of 330 megabytes per minute - though that is dependent on the SCSI adapter, the parallel port adapter is unlikely to reach anything like this speed. The Jaz drive was the successor to the company's more establistablished Zip Drive. (1998-08-28) 1 1 1 1 1 JAZELLE A data management system for High Energy Physics from Stanford Linear Accelerator. (1995-02-22) 1 1 1 1 1 JBIG Joint Bi-level Image Experts Group 1 1 1 1 1 JBOD Just a Bunch Of Disks 1 1 1 1 1 JBOPS A nickname for the major ERP and enterprise software application companies: JD Edwards, Baan, Oracle, PeopleSoft, and SAP. (1999-07-27) 1 1 1 1 1 jc Version 1.50 alpha compiler(->C) David Gudeman <gudeman@cs.arizona.edu> (ftp://cs.arizona.edu/janus/jc/). A janus-to-C compiler (considerably faster than qdjanus). jc is a sequential implementation of a concurrent language. bugs: <jc-bugs@cs.arizona.edu> ports: sun-4, sun-3, Sequent Symmetry jc is an experimental system, undergoing rapid development. Mailing list: janusinterest-request@parc.xerox.com (1992-06-09) 1 1 1 1 1 JCL Job Control Language 1 1 1 1 1 JCOOL A version of the COOL C++ class library that uses real C++ templates. (2007-10-14) 1 1 1 1 1 JCP Java Community Process 1 1 1 1 1 JCS-13 An early system on the IBM 701. [Listed in CACM 2(5):16, May 1959]. (1997-06-16) 1 1 1 1 1 JDBC Java Database Connectivity 1 1 1 1 1 JDK Java Development Kit 1 1 1 1 1 JEAN A dialect of JOSS. [Details?] (1997-09-14) 1 1 1 1 1 Jean E. Sammet Author of several surveys of early programming languages, refererred to in many entries in this dictionary. E-mail: sammet@vtvm1.cc.vt.edu Relevant publications include: [Sammet, Jean E., "Programming Languages: History and Fundamentals", P-H 1969. QA76.5 .S213]. The definitive work on early computer language development. [Sammet, Jean E., "Programming Languages: History and Future", CACM 15(7):601-610, Jul 1972]. [Sammet, Jean E., "Roster of Programming Languages" Computers & Automation 16(6):80-82, June 1967; Computers & Automation 17(6):120-123, June 1968; Computers & Automation 18(7):153-158, June 1969; Computers & Automation 19(6B):6-11, 30 Nov 1970; Computers & Automation 20(6B):6-13, 30 Jun, 1971; Computers & Automation 21(6B), 30 Aug 1972; Computing Reviews 15(4): 147-160, April 1974; 1 1 1 1 1 Jean-Maurice-Émile Baudot (1845-1903) The inventor of the Baudot code. Baudot joined the French Post & Telegraph Administration in 1869 as a telegraph operator. In his own time he developed a code for sending several messages at once. In 1874 Baudot patented his first printing telegraph where signals were translated onto paper tape. The Baudot code was adopted first in France and then by other nations for <telegraph> and <teletype> transmissions. The unit of transmission speed, baud, is named after him. (2013-01-12) 1 1 1 1 1 JEDR Synonymous with IYFEG. At one time, people in the Usenet newsgroup news:rec.humor.funny tended to use "JEDR" instead of IYFEG or "<ethnic>"; this stemmed from a public attempt to suppress the group once made by a loser with initials JEDR after he was offended by an ethnic joke posted there. (The practice was retconned by expanding these initials as "Joke Ethnic/Denomination/Race".) After much sound and fury JEDR faded away; this term appears to be doing likewise. JEDR's only permanent effect on the net.culture was to discredit "sensitivity" arguments for censorship so thoroughly that more recent attempts to raise them have met with immediate and near-universal rejection. [Jargon File] (1994-11-22) 1 1 1 1 1 Jef Raskin The person who started the Macintosh project at Apple Computer, Inc. but left the company before the product was launched. (1999-08-24) 1 1 1 1 1 Jenga Code A style of programming which results in the whole thing collapsing when you touch a single block of code. Named after the game where players try to remove wooden blocks from a tower without it falling down. Also known as Crispy Noodle Code. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. [Why crispy noodle?] (2013-12-25) 1 1 1 1 1 Jerry Sussman Gerald Sussman 1 1 1 1 1 JES job entry system 1 1 1 1 1 JES2 One of IBM's job entry systems for MVS. (1995-08-16) 1 1 1 1 1 JES3 One of IBM's job entry systems for MVS. (1995-08-16) 1 1 1 1 1 JFCL /jif'kl/, /jaf'kl/, /j*-fi'kl/ (obsolete) To cancel or annul something. "Why don't you jfcl that out?" The fastest do-nothing instruction on older models of the PDP-10 happened to be JFCL, which stands for "Jump if Flag set and then CLear the flag"; this does something useful, but is a very fast no-operation if no flag is specified. Geoff Goodfellow, one of the jargon-1 co-authors, had JFCL on the licence plate of his BMW for years. Usage: rare except among old-time PDP-10 hackers. [Jargon File] (1994-11-22) 1 1 1 1 1 JFDI Just fucking do it. (2008-04-18) 1 1 1 1 1 JFET Junction Field Effect Transistor 1 1 1 1 1 JFGI Just Fucking Google It. See STFW. (2014-05-23) 1 1 1 1 1 JFIF JPEG File Interchange Format 1 1 1 1 1 jiffy 1. The duration of one tick of the computer's system clock. Often one AC cycle time (1/60 second in the US and Canada, 1/50 most other places), but more recently 1/100 sec has become common. 2. Confusingly, the term is sometimes also used for a 1-millisecond wall time interval. Even more confusingly, physicists semi-jokingly use "jiffy" to mean the time required for light to travel one foot in a vacuum, which turns out to be close to one *nanosecond*. [Jargon File] (2002-03-02) 1 1 1 1 1 Jim Clark Dr. James H. Clark 1 1 1 1 1 Jini /jee'nee/ Sun's Java-based system for networking home appliances, desktop computers and other kinds of consumer electronics. (http://java.sun.com/products/jini/). [Details?] (1998-11-14) 1 1 1 1 1 JIPS JANET IP Service 1 1 1 1 1 JIT dynamic translation 1 1 1 1 1 jitter Random variation in the timing of a signal, especially a clock. (1995-01-16) 1 1 1 1 1 JK flip-flop An edge triggered SR flip-flop with extra logic such that only one of the R and S inputs is enabled at any time. This prevents a race condition which can occur when both inputs of an RS flip-flop are active at the same time. In a JK flip-flop the R and S inputs are renamed J and K. The set input (J) is only enabled when the flip-flop is reset and K when it is set. If both J and K inputs are held active then the outputs will change ("togle") on each falling edge of the clock. JK flip-flops can be used to build a binary counter with a reset input. (http://play-hookey.com/digital/logic7.html). [Was it named after Jack Kilby?] (2004-07-17) 1 1 1 1 1 jm The country code for Jamaica. (1999-01-27) 1 1 1 1 1 J.M.E. Baudot Jean-Maurice-Émile Baudot 1 1 1 1 1 JMHO Just My Humble Opinion. (1999-02-18) 1 1 1 1 1 JMS Java Message Service 1 1 1 1 1 JNI Java Native Interface 1 1 1 1 1 JNT Association A non-profit company funded by the UK's advisory committee to manage and develop the UK national research network backbone. In 1970, the United Kingdom Computer Board commissioned Professor Mike Wells to report on UK university networking. As a result, on 1976-11-01, the Network Unit was created which in turn led to the creation in 1979 of a full-time Joint Network Team (JNT) and in 1982 to the creation of JANET. On 1993-12-10, the JNT Association was formed to develop and manage JANET for the education and research community. ICANN wiki entry (http://icannwiki.com/UKERNA). (2016-04-12) 1 1 1 1 1 jo The country code for Jordan. (1999-01-27) 1 1 1 1 1 job All activities involved in completing any project on a computer from start to finish. A job may involve several processes and several programs. This term originates from a time when a user would manually submit a job as a deck of punched cards which would typically include source code interspersed with job control language instructions to guide phases of the job such as compilation, linking, execution and printing. (2005-03-16) 1 1 1 1 1 Job Control Language (JCL) IBM's supremely rude script language, used to control the execution of programs in IBM OS/360's batch systems. JCL has a very fascist syntax, and some versions will, for example, barf if two spaces appear where it expects one. Most programmers confronted with JCL simply copy a working file (or card deck), changing the file names. Someone who actually understands and generates unique JCL is regarded with the mixed respect one gives to someone who memorises the phone book. It is reported that hackers at IBM itself sometimes sing "Who's the breeder of the crud that mangles you and me? I-B-M, J-C-L, M-o-u-s-e" to the tune of the "Mickey Mouse Club" theme to express their opinion of the beast. As with COBOL, JCL is often used as an archetype of ugliness even by those who haven't experienced it. However, no self-respecting mainframe MVS programmer would admit ignorance of JCL. 1 1 1 1 1 Job Entry System (JES) An IBM mainframe term. There are really two JESs. JES2 is smaller and simpler, and can handle 99.99% of most jobs that run on IBM's MVS operating system. JES3 is much bigger and requires really big iron to run. (1996-03-23) 1 1 1 1 1 Jobs Stephen Jobs 1 1 1 1 1 job security When some piece of code is written in a particularly obscure fashion, and no good reason (such as time or space optimisation) can be discovered, it is often said that the programmer was attempting to increase his job security (i.e. by making himself indispensable for maintenance). This sour joke seldom has to be said in full; if two hackers are looking over some code together and one points at a section and says job security, the other one may just nod. [Jargon File] (1996-09-17) 1 1 1 1 1 jock 1. A programmer who is characterised by large and somewhat brute-force programs. 2. When modified by another noun, describes a specialist in some particular computing area. The compounds "compiler jock" and "systems jock" seem to be the best-established examples. [Jargon File] (1995-01-19) 1 1 1 1 1 joe A computer account whose user name and password are the same. Joes are considered harmful, as are any passwords which are easy to guess. (1995-06-21) 1 1 1 1 1 joe code /joh' kohd"/ 1. Code that is overly tense and unmaintainable. "Perl may be a handy program, but if you look at the source, it's complete joe code." 2. Badly written, possibly buggy code. Correspondents wishing to remain anonymous have fingered a particular Joe at the Lawrence Berkeley Laboratory and observed that usage has drifted slightly; the original sobriquet "Joe code" was intended in sense 1. [Jargon File] 1 1 1 1 1 John Atanasoff John Vincent Atanasoff 1 1 1 1 1 John Gilmore A noted Unix hacker who cofounded Usenet's anarchic alt.* newsgroup hierarchy with Brian Reid. He also worked on GDB. E-mail: John Gilmore <gnu@toad.com>. (1995-04-18) 1 1 1 1 1 John Mauchly /jon W mok'*-lee/ (rhymes with "broccoli") Dr. John W. Mauchly, one of the developers of ENIAC. (2002-10-06) 1 1 1 1 1 John McCarthy A pioneer of artificial intelligence (he coined ther term). He invented Lisp at MIT in the late 1950s and later worked at SAIL. (ftp://www-formal.stanford.edu/jmc). E-mail: <jmc@cs.stanford.edu>. (2003-08-06) 1 1 1 1 1 Johnniac A mainframe computer based on a design by John von Neuman built at the Institute for Advanced Study, USA. The Johnniac went live in 1953 and was decommissioned in 1966. Its memory consisted of 80 special "Selectron" vacuum tubes, each of which held 256 bits of data. (2003-06-07) 1 1 1 1 1 JOHNNIAC Open Shop System (JOSS) An early, simple, interactive calculator language developed by Charles L. Baker at Rand in 1964. There were two versions: JOSS I and JOSS II. [Connection with Johnniac?] ["JOSS Users' Reference Manual", R.L. Clark, Report F-1535/9, RAND Corp (Jan 1975)]. [Sammet 1969, pp. 217-226]. (2004-07-11) 1 1 1 1 1 John Ousterhout /oh'st*r-howt/ John K. Ousterhout, the designer of Tcl and Tk, and founder of Scriptics. See also: Ousterhout's dichotomy. E-mail: john.ousterhout@scriptics.com. (1999-02-21) 1 1 1 1 1 John Tukey The eminent statistician credited with coining the term "bit" in 1949. (http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Tukey.html). (2003-02-28) 1 1 1 1 1 John Vincent Atanasoff John Vincent Atanasoff, 1903-10-04 - 1995-06-15. An American mathemetical physicist, and the inventor of the electronic digital computer. Between 1937 and 1942 he built the Atanasoff-Berry Computer with Clifford Berry, at the Iowa State University. Atanasoff was born on 1903-10-04 in Hamilton, New York. In 1925, he got a Bachelor of Science degree in Electrical Engineering from the University of Florida. In 1926 he received a Master's degree in Maths from Iowa State University. He received a PhD as a theoretical physicist from the University of Wisconsin in 1930. While an associate professor of mathematics and physics at Iowa State University, Atanasoff began to envision a digital computational device, believing analogue devices to be too restrictive. Whilst working on his electronic digital computer, Atanasoff was introduced to a graduate student named Clifford Berry, who helped him build the computer. 1 1 1 1 1 John von Neumann /jon von noy'mahn/ Born 1903-12-28, died 1957-02-08. A Hungarian-born mathematician who did pioneering work in quantum physics, game theory, and computer science. He contributed to the USA's Manhattan Project that built the first atomic bomb. von Neumann was invited to Princeton University in 1930, and was a mathematics professor at the Institute for Advanced Studies from its formation in 1933 until his death. From 1936 to 1938 Alan Turing was a visitor at the Institute and completed a Ph.D. dissertation under von Neumann's supervision. This visit occurred shortly after Turing's publication of his 1934 paper "On Computable Numbers with an Application to the Entscheidungs-problem" which involved the concepts of logical design and the universal machine. von Neumann must have known of Turing's ideas but it is not clear whether he applied them to the design of the IAS Machine ten years later. 1 1 1 1 1 join 1. <database> inner join (common) or outer join (less common). 2. <theory> least upper bound. (1998-11-23) 1 1 1 1 1 Joint Academic NETwork (JANET) The wide area network which links UK academic and research institutes. JANET is controlled by the Joint Network Team (JNT) and Network Executive (NE). It is an internet (a large number of interconnected sub-networks) that provides connectivity within the community as well as access to external services and other communities. The hub is the JANET subnetwork, a private X.25 packet-switched network that interconnects over 100 sites. At the majority of sites, local area networks (LANs) are connected to JANET allowing off-site access for the computers and terminals connected to these networks. The Coloured Book protocol architecture is used to support interactive terminal access to computers (for both character terminals and screen terminals), inter-host file transfers, electronic mail and remote batch job submission. (http://nic.ja.net/). See also JIPS, SuperJanet. 1 1 1 1 1 Joint Bi-level Image Experts Group (JBIG) An experts group of ISO, IEC and ITU-T (JTC1/SC2/WG9 and SGVIII) working to define a compression standard for lossless image coding. Their proposed algorithm features compatible progressive coding and sequential coding and is lossless - the image is unaltered after compression and decompression. JBIG can handle images with from one to 255 bits per pixel. Better compression algorithms exist for more than about eight bits per pixel. With multiple bits per pixel, Gray code can be used to reduce the number of bit changes between adjacent decimal values (e.g. 127 and 128), and thus improve the compression which JBIG does on each bitplane. JBIG uses discrete steps of detail by successively doubling the resolution. The sender computes a number of resolution layers and transmits these starting at the lowest resolution. Resolution reduction uses pixels in the high resolution layer and some already computed low resolution pixels as an index 1 1 1 1 1 Joint Photographic Experts Group (JPEG) The original name of the committee that designed the standard image compression algorithm. JPEG is designed for compressing either full-colour or grey-scale digital images of natural, real-world scenes. It does not work so well on non-realistic images, such as cartoons or line drawings. JPEG does not handle compression of black-and-white (1 bit-per-pixel) images or moving pictures. Standards for compressing those types of images are being worked on by other committees, named JBIG and MPEG. (http://jpeg.org/). Filename extension: .jpg, .jpeg. See also PJPEG. (2000-09-11) 1 1 1 1 1 Joint Technical Committee (JTC) A standards body straddling ISO and IEC. (1995-04-21) 1 1 1 1 1 Joint Test Action Group (JTAG, or "IEEE Standard 1149.1") A standard specifying how to control and monitor the pins of compliant devices on a printed circuit board. Each device has four JTAG control lines. There is a common reset (TRST) and clock (TCLK). The data line daisy chains one device's test data out (TDO) pin to the test data in (TDI) pin on the next device. The protocol contains commands to read and set the values of the pins (and, optionally internal registers) of devices. This is called "boundary scanning". The protocol makes board testing easier as signals that are not visible at the board connector may be read and set. The protocol also allows the testing of equipment, connected to the JTAG port, to identify components on the board (by reading the device identification register) and to control and monitor the device's outputs. 1 1 1 1 1 Joliet An extension of the ISO 9660:1988 ISO standard file system for CD-ROMs that allows Unicode characters in file names and other enhancements. Version 1 of Joliet was released on 1995-05-22. Joiliet supports file and directory names up to 128 bytes (64 unicode characters) long, directory names with file name extensions, a directory hierarchy deeper than 8 levels and the volume recognition sequence supports multisession. Joliet uses ISO 9660's "supplementary volume descriptor" (SVD) to specify Unicode files. Use of the previously unused escape sequence ISO 2022 means that Joliet is backward compatible with ISO 9660.. (http://www-plateau.cs.berkeley.edu/people/chaffee/jolspec.html). (2006-09-25) 1 1 1 1 1 jolix 386BSD 1 1 1 1 1 JOLT Java Open Language Toolkit 1 1 1 1 1 Jonathan's Own Version Of Emacs (jove) A version of the GNU Emacs editor. Similar to MicroGnuEmacs. (2008-05-29) 1 1 1 1 1 Jon Postel (Jonathan Bruce Postel, 1943 - 1998-10-16) /p*-stel'/ One of the Internet's founding fathers. Jon's name is prominent on many of the fundamental standards on which the Internet is built, such as UDP. He ran IANA for as long as anybody could remember, in fact for most of the time he *was* IANA. He wrote STD 1, STD 2 and several dozen other RFCs. His friend Vinton Cerf noted his passing in RFC 2468. (1998-10-21) 1 1 1 1 1 JOOP Journal of Object-Oriented Programming 1 1 1 1 1 Joseph-Marie Jacquard /zhoh-zef' mah-ree' zhah-kar'/ (1752-07-07 to 1834-08-07) The inventor of the Jacquard loom. (1998-10-19) 1 1 1 1 1 Josephson Junction A type of electronic circuit capable of switching at very high speeds when operated at temperatures approaching absolute zero. The low power dissipation of a Josepshson Junction makes it useful in high density computer circuits. (2004-06-28) 1 1 1 1 1 JOSS JOHNNIAC Open Shop System 1 1 1 1 1 Jossle A type checked language with separate compilation using a program library. Mentioned in ["Rationale for the Design of Ada", J. Ichbiah, Cambridge U Press, 1986, p.192]. (2005-02-19) 1 1 1 1 1 journal An on-going record of transactions, such as database updates, file system writes, procedure calls or message transmissions. A journal differs from a simple log in that the contents of the journal can be used to reconstruct the state of the system after a failure by re-applying the transactions in the journal to a snapshot of the system previous state. (2008-05-29) 1 1 1 1 1 journalling journal 1 1 1 1 1 jove Jonathan's Own Version Of Emacs. 1 1 1 1 1 JOVIAL (Jule's Own Version of IAL) A version of IAL produced by Jules I. Schwartz in 1959-1960. JOVIAL was based on ALGOL 58, with extensions for large scale real-time programming. It saw extensive use by the US Air Force. The data elements were items, entries (records) and tables. Versions include JOVIAL I (IBM 709, 1960), JOVIAL II (IBM 7090, 1961) and JOVIAL 3 (1965). Dialects: J3, JOVIAL J73, JS, JTS. Ada/Jovial Newsletter, Dale Lange +1 (513) 255-4472. [CACM 6(12):721, Dec 1960]. (1996-07-19) 1 1 1 1 1 Joy A functional programming language by Manfred von Thun. Joy is unusual because it is not based on lambda calculus, but on the composition of functions. Functions take a stack as argument, consume any number of parameters from it, and return it with any number of results on it. The concatenation of programs denotes the composition of functions. One of the datatypes of Joy is that of quoted programs, of which lists are a special case. Joy Home (http://latrobe.edu.au/philosophy/phimvt/joy.html). (2003-06-13) 1 1 1 1 1 Joyce A distributed language based on Pascal and CSP, by Per Brinch Hansen. ["Joyce - A Programming Language for Distributed Systems", Per Brinch Hansen, Soft Prac & Exp 17(1):29-50 (Jan 1987)]. (1994-12-06) 1 1 1 1 1 joystick A device consisting of a hand held stick that pivots about one end and transmits its angle in two dimensions to a computer. Joysticks are often used to control games, and usually have one or more push-buttons whose state can also be read by the computer. Most I/O interface cards for IBM PCs have a joystick (game control) port. (1995-03-08) 1 1 1 1 1 Joy, William William Joy 1 1 1 1 1 jp The country code for Japan. (1999-01-27) 1 1 1 1 1 JPEG Joint Photographic Experts Group 1 1 1 1 1 JPEG-2000 A potential successor to JPEG with better compression and multiresolution images. JPEG-2000 gives reasonable quality down to 0.1 bits/pixel (JPEG quality drops dramatically below about 0.4 bits/pixel). (2001-12-02) 1 1 1 1 1 JPEG File Interchange Format (JFIF) The technical name for the file format better known as JPEG. This term is used only when the difference between the JPEG file format and the JPEG image compression algorithm is crucial. (1998-02-10) 1 1 1 1 1 jpg JPEG 1 1 1 1 1 JPL JAM Programming Language. 1 1 1 1 1 JPLDIS Jet Propulsion Laboratory Display Information System. Query system for UNIVAC 1108 [or PDP's?] written in Fortran, based on Tymshare's "Retrieve". Indirectly led to Vulcan which led to dBASE II. Jack Hatfield, George Masters, W. Van Snyder, Jeb Long et al, JPL. 1 1 1 1 1 J. Presper Eckert One of the developers of ENIAC. Biography (http://www-groups.dcs.st-and.ac.uk/~history/ShortBiogs/E.html). [Summary?] (1995-11-14) 1 1 1 1 1 J. Random /J rand'm/ (Generalised from J. Random Hacker) Arbitrary; ordinary; any one; any old. "J. Random" is often prefixed to a noun to make a name out of it. It means roughly some particular or "any specific one". "Would you let J. Random Loser marry your daughter?" The most common uses are "J. Random Hacker", "J. Random Loser", and "J. Random Nerd" ("Should J. Random Loser be allowed to gun down other people?"), but it can be used simply as an elaborate version of random in any sense. [Jargon File] 1 1 1 1 1 J. Random Hacker /J rand'm hak'r/ MIT jargon for a mythical figure; the archetypal hacker nerd. This may originally have been inspired by "J. Fred Muggs", a show-biz chimpanzee whose name was a household word back in the early days of TMRC, and was probably influenced by J. Presper Eckert (one of the co-inventors of the electronic computer). See random, Suzie COBOL. (1996-10-16) 1 1 1 1 1 JRE Java Run-Time Environment 1 1 1 1 1 JRL J. Random Loser. The names JRL and JRN were sometimes used as example names when discussing a kind of user ID used under TOPS-10 and WAITS. They were understood to be the initials of (fictitious) programmers named "J. Random Loser" and "J. Random Nerd". For example, if one said "To log in, type log one comma jay are en" (that is, "log 1,JRN"), the listener would have understood that he should use his own computer ID in place of "JRN". 1 1 1 1 1 JRMP Java Remote Method Protocol 1 1 1 1 1 JRN J. Random Nerd. See JRL. 1 1 1 1 1 JRST /jerst/ [based on the PDP-10 jump instruction, obsolete] To suddenly change subjects, with no intention of returning to the previous topic. Usage: rather rare except among PDP-10 diehards, and considered silly. See also AOS. [Jargon File] 1 1 1 1 1 JS Dialect of JOVIAL. [Sammet 1969, p.639]. 1 1 1 1 1 JSA Japanese Standards Association. 1 1 1 1 1 JSDK Java Servlet Development Kit 1 1 1 1 1 JSF JavaServer Faces 1 1 1 1 1 JSON JavaScript Object Notation 1 1 1 1 1 JSP JavaServer Pages 1 1 1 1 1 JSTL JSP Standard Tag Library 1 1 1 1 1 JTAG Joint Test Action Group 1 1 1 1 1 JTB jump trace buffer 1 1 1 1 1 JTC Joint Technical Committee. 1 1 1 1 1 JTC1/SC24 The ISO/IEC group which has worked on standards like GKS, PHIGS, CGM, and is now also involved in the area of standardisation in Multimedia Presentation. (http://cwi.nl/JTC1SC24/). (1995-01-04) 1 1 1 1 1 JTS A simple dialect of JOVIAL. [Sammet 1969, p. 528]. (1995-01-04) 1 1 1 1 1 juggling eggs Keeping a lot of state in your head while modifying a program. "Don't bother me now, I'm juggling eggs", means that an interrupt is likely to result in the program's being scrambled. In the classic first-contact SF novel "The Mote in God's Eye", by Larry Niven and Jerry Pournelle, an alien describes a very difficult task by saying "We juggle priceless eggs in variable gravity." See also hack mode. [Jargon File] 1 1 1 1 1 Jughead Jughead is a tool for Gopher administrators to get menu information from various gopher servers, and is an acronym for: Jonzy's Universal Gopher Hierarchy Excavation And Display. Jughead was written in ANSI C. Gopher: gopher.cc.utah.edu, About U of U Gopher/Gopher Tools/jughead. (ftp://ftp.cc.utah.edu/pub/gopher/GopherTools). Mailing list: jughead-news@lists.utah.edu. 1 1 1 1 1 jukebox A hardware mechanism for allowing access to one of a group of discs, especially CD-ROMs or other optical media. [Or magnetic tapes?] (1996-12-10) 1 1 1 1 1 jump (Or "branch") The term for a goto instruction, usually in a context of machine languages. "Branch" may be synonymous with "jump", or may refer to jumps that depend on a condition. (1998-11-14) 1 1 1 1 1 jumper A removable wire or small plug whose presence or absence is used to determine some aspect of hardware configuration. (1995-03-14) 1 1 1 1 1 jump off into never-never land [J. M. Barrie's "Peter Pan"] Same as branch to Fishkill, but more common in technical cultures associated with non-IBM computers that use the term "jump" rather than "branch". Compare hyperspace. [Jargon File] (1994-12-15) 1 1 1 1 1 jump trace buffer (JTB) A feature of some pipelined processors (e.g. Amulet, Pentium?) which stores the source and destination addresses of the last few branch instuctions executed. When a branch instruction is fetched, its source is looked for in the JTB. If found, the next instuction fetch will be from the previous destination of that branch. If it turns out that the branch shouldn't have been taken this time, then the pipeline is flushed. This means that in a tight loop it is not necessary to flush the pipeline every time you jump back to the start. (1994-12-15) 1 1 1 1 1 Junction FET Junction Field Effect Transistor 1 1 1 1 1 Junction Field Effect Transistor (JFET, Junction FET) A Field Effect Transistor in which the conducting channel lies between pn junctions in the silicon material. A pn junction acts as a diode, so it becomes conductive if the gate voltage gets reversed. (1997-02-24) 1 1 1 1 1 Juno A numerical constraint-oriented language for graphics applications. It solves its constraints using Newton-Raphson relaxation. It was inspired partly by Metafont. ["Juno, a Constraint-Based Graphics System", G. Nelson in SIGGRAPH '85 Conf Readings, B.A. Barsky ed, Jul 1985, pp. 235-243]. (1994-11-23) 1 1 1 1 1 jupiter To kill an IRC robot or user and then take its place by adopting its nick so that it cannot reconnect. Named after a particular IRC user who did this to NickServ, the robot in charge of preventing people from inadvertently using a nick claimed by another user. [Jargon File] (1994-11-23) 1 1 1 1 1 Just a Bunch Of Disks (JBOD, or "Just a Bunch of Drives") A storage subsystems using multiple independent disk drives, as opposed to one form of RAID or another. For example, Unisys open storage provides JBOD in both SCSI and fibre channel interfaces. Unisys JBOD (http://marketplace.unisys.com/storage/jbod.html). (1998-12-21) 1 1 1 1 1 just-in-time dynamic translation 1 1 1 1 1 JVM Java Virtual Machine 1 1 1 1 1 Jym A predecessor to Graal by Patrick Bellot, France. 1 1 1 1 1 K kilo-, a kilobyte. Used both as a spoken word and a written suffix, like meg and gig for megabyte and gigabyte. See prefix. [Jargon File] (1995-09-29) 1 1 1 1 1 K5 An early system on the Larc computer. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-23) 1 1 1 1 1 K56flex A modem standard developed by Rockwell for 56 kbps communications. K56flex Became more popular than the rival X2 but will be superseded by the official V.90 standard. [Already superseded?] (1998-09-08) 1 1 1 1 1 K6 A Pentium II class microprocessor, manufactured by AMD. [100% Compatible? Speed?] (1998-02-27) 1 1 1 1 1 K7 Athlon 1 1 1 1 1 KA9Q A popular implementation of TCP/IP and associated protocols for amateur packet radio systems and personal computers connected via serial lines. It was named after the call-sign of Phil Karn - the radio ham who first wrote it for MS-DOS on the IBM PC. KA9Q is currently maintained by Anthony Frost <vulch@kernow.demon.co.uk> (call-sign G8UDV) and Adam Goodfellow <tcpip2@comptech.demon.co.uk>. It has been ported to the Archimedes by Jonathan Naylor (G4KLX). [FTP?] (1994-11-08) 1 1 1 1 1 KADS Knowledge Analysis and Design System 1 1 1 1 1 kahuna /k*-hoo'n*/ (From the Hawaiian title for a shaman) An IBM synonym for wizard or guru. [Jargon File] (1994-11-09) 1 1 1 1 1 Kaleidoscope An object-oriented language which mixes imperative programming and constraint-oriented features. Kaleidoscope was written by Freeman-Benson of the University of Washington, Universite de Nantes, 1989; University of Victoria, 1992. It is similar to Siri and vaguely related to Prose. Versions: Kaleidoscope '90 and Kaleidoscope '91. ["Kaleidoscope: Mixing Objects, Constraints and Imperative Programming", B.N. Freeman-Benson, SIGPLAN Notices 25(10):77-88 (OOPSLA/ECOOP '90) (Oct 1990)]. ["Constraint Imperative Programming", B.N. Freeman-Benson, Ph.D. Thesis, TR 91-07-02, U Wash (1991)]. ["Constraint Imperative Programming", Freeman-Benson et al, IEEE Conf on Comp Lang, Apr 1992]. (1994-11-09) 1 1 1 1 1 Kali A data parallel language. ["Supporting Shared Data Structures on Distributed Memory Architectures", C. Koelbel et al in Second ACM SIGPLAN Symp on Princ and Prac of Parallel Programming, pp.177-186, Mar 1990]. (1994-11-09) 1 1 1 1 1 kamikaze packet Christmas tree packet 1 1 1 1 1 Kamin's interpreters A set of interpreters for Pascal, Lisp, APL, Scheme, SASL, CLU, Smalltalk, and Prolog. Tim Budd <budd@cs.orst.edu> implemented them as subclasses in C++ sometime before 1991-09-12. (ftp://cs.orst.edu/pub/budd/kamin/). ["Programming Languages, An Interpreter-Based Approach", Samuel Kamin]. (2002-03-14) 1 1 1 1 1 kana The two Japanese syllabaries, hiragana and katakana. (2001-03-18) 1 1 1 1 1 kangaroo code spaghetti code 1 1 1 1 1 kanji /kahn'jee/ (From the Japanese kan - the Chinese Han dynasty, and "ji" - glyph or letter of the alphabet. Not capitalised. Plural "kanji") The Japanese word for a Han character used in Japanese. Kanji constitute a part of the writing system used to represent the Japanese language in written, printed and displayed form. The term is also used for the collection of all kanji letters. US-ASCII doesn't include kanji characters, but some character encodings, including Unicode, do. The Japanese writing system also uses hiragana, katakana, and sometimes romaji (Roman alphabet letters). These characters are distinct from, though commonly used in combination with, kanji. Furigana are also added sometimes. (2000-12-30) 1 1 1 1 1 KAOS Kent Applicative Operating System 1 1 1 1 1 KAP Kernel Andorra Prolog. The predecessor of AKL. ["Kernel Andorra Prolog and its Computation Model", S. Haridi <seif@sics.se> et al, in Logic Programming: Proc 7th Intl Conf, MIT Press 1990]. (1994-11-02) 1 1 1 1 1 Karel Language featured in Karel the Robot: A Gentle Introduction to Computer Programming, Richard E. Pattis, Wiley 1981. (ftp://ftp.wustl.edu/mirrors/Unix-c/languages/pascal/karel.tar-z). 1 1 1 1 1 katakana The square-formed Japanese kana syllabary. Katakana is mostly used to write foreign names, foreign words, and loan words as well as many onomatopeia, plant and animal names. (2001-03-18) 1 1 1 1 1 Katmai New Instructions Streaming SIMD Extensions 1 1 1 1 1 KB kilobyte 1 1 1 1 1 KBMS An expert system. 1 1 1 1 1 kbps kilobits per second 1 1 1 1 1 KBS Knowledge-Based System 1 1 1 1 1 KC-85/1 A commercial home computer from East Germany. The KC-85/1 runs at 2.45 MHz and uses a Z80 clone CPU. The computer allows for only semigraphics. (2004-03-31) 1 1 1 1 1 KC85/2 A commercial home computer introduced in East Germany in 1984. The KC85/2 has 32 KB of RAM and uses a Z80 clone CPU. (2004-03-31) 1 1 1 1 1 KC85/3 A commercial home computer introduced in East Germany in 1986. The KC85/3 has 32 KB of RAM and uses a Z80 clone CPU. (2004-03-31) 1 1 1 1 1 KC85/4 The last commercial home computer from East Germany in the KC series. The KC85/4 was introduced in 1988. It runs at 1.77 MHz, has 64 KB of RAM and uses a Z80 clone CPU. It displays graphics at a resolution of 320x256. (2004-03-31) 1 1 1 1 1 KCL Kyoto Common Lisp 1 1 1 1 1 ke The country code for Kenya. (1999-01-27) 1 1 1 1 1 KEE Knowledge Engineering Environment. Frame-based expert system. Supports dynamic inheritance, multiple inheritance, polymorphism. Classes, meta-classes and objects are all treated alike. A class is an instance of a meta-class. Can control rules for merging of each field when multiple inheritance takes place. Methods are written in LISP. Actions may be triggered when fields are accessed or modified. Extensive GUI integrates with objects. Can easily make object updates to be reflected on display or display selections to update fields. This can in turn trigger other methods or inference rules which may then update other parts of the display. Intellicorp, for TI Explorer. "The Role of Frame-Based Representation in Reasoning", R. Fikes et al, CACM 28(9):904- 920 (Sept 1985). 1 1 1 1 1 keep-alive A short message sent periodically on a communication channel that would otherwise time out and close due to inactivity. (2012-07-18) 1 1 1 1 1 Keldysh Institute of Applied Mathematics Address: Russian Academy of Sciences Miusskaya Pl. 4, 125047 Moscow, Russia. (1994-12-12) 1 1 1 1 1 ken /ken/ 1. Ken Thompson 2. A flaming user. This was originated by the Software Support group at Symbolics because the two greatest flamers in the user community were both named Ken. [Jargon File] 1 1 1 1 1 Ken Thompson The principal inventor of the Unix operating system and author of the B language, the predecessor of C. In the early days Ken used to hand-cut Unix distribution tapes, often with a note that read "Love, ken". Old-timers still use his first name (sometimes uncapitalised, because it's a login name and mail address) in third-person reference; it is widely understood (on Usenet in particular) that without a last name "Ken" refers only to Ken Thompson. Similarly, Dennis without last name means Dennis Ritchie (and he is often known as dmr). Ken was first hired to work on the Multics project, which was a huge production with many people working on it. Multics was supposed to support hundreds of on-line logins but could barely handle three. In 1969, when Bell Labs withdrew from the project, Ken got fed up with Multics and went off to write his own operating 1 1 1 1 1 Kent Applicative Operating System (KAOS) A functional operating system concept using dynamic process creation and inter-process communication. KAOS was described in 1989 by Dr. John Cupitt in his PhD thesis at the University of Kent. It was based on earlier work by Will R. Stoye. KAOS allowed dynamic creation of "functional processes" - functions that transform an input stream to an output stream. Process scheduling is based on evaluation on demand. Inter-process communication is by message passing based on Stoye's sorting office concept. (2015-05-30) 1 1 1 1 1 Kent Recursive Calculator (KRC) A lazy functional language developed by David Turner in 1981, based on SASL, with pattern matching and ZF expressions. ["Functional Programming and its Applications", David A. Turner, Cambridge U Press 1982]. See also continental drift. (2011-11-30) 1 1 1 1 1 Kerberos The authentication system of MIT's Project Athena. It is based on symmetric key cryptography. Adopted by OSF as the basis of security for DME. (1997-02-04) 1 1 1 1 1 Kermit A popular packet-oriented protocol from Columbia University for transferring text files and binary files on both full-duplex and half-duplex 8 bit and 7-bit serial connections in a system- and medium-independent fashion, and implemented on hundreds of different computer and operating system platforms. On full-duplex connections a sliding window protocol with selective retransmission provides excellent performance and error recovery characteristics. On 7-bit connections, locking shifts provide efficient transfer of 8-bit data. When properly implemented, as in the Columbia University Kermit Software collection, performance is equal to or better than other protocols such as ZMODEM, YMODEM, and XMODEM, especially on poor connections. Kermit is an open protocol - anybody can base their own program on it, but some Kermit software and source code is copyright by Columbia University. 1 1 1 1 1 kernal kernel 1 1 1 1 1 kernel (Note: NOT "kernal"). 1. <operating system> The essential part of Unix or other operating systems, responsible for resource allocation, low-level hardware interfaces, security etc. See also microkernel. 2. <language> An essential subset of a programming language, in terms of which other constructs are (or could be) defined. Also known as a core language. (1996-06-07) 1 1 1 1 1 Kernel Parlog A modeless intermediate language for Parlog compilation. ["Notes on the Implementation of Parlog", K.L. Clark et al, J Logic Prog 2(1):17-42 1985]. (1996-06-07) 1 1 1 1 1 kernel style K&R style 1 1 1 1 1 Kernel User Interface Package (KUIP) The human interface to Physics Analysis Workbench (PAW). (1994-11-11) 1 1 1 1 1 kerning In typography, the process of adjusting the spacing between certain pairs of characters to improve the appearance of the text. Roughly speaking, this can be thought of as equalising the area of space between adjacent characters. Each character of a proportional font has a width that includes some space on either side so that adjacent letters don't touch. Some pairs of characters such as A and V, look better if the spaces overlap slightly, bringing the characters closer together (but still not touching). In most cases, kerning reduces the spacing ("negative kerning") but some pairs like "r" and "y" look better with extra space ("positive kerning"). See also tracking, leading. (2014-01-14) 1 1 1 1 1 Kevo A prototype-based object-oriented language written for Macintosh by Antero Taivalsaari at UTA, Finland. Kevo is built around a threaded code interpreter and features a unique prototype-based object model (which is based neither on classes nor Self-style delegation), pre-emptive multitasking, cooperative multitasking, dynamic memory management, an icon-based object browser and editor modelled loosely after Mac Finder. Kevo's syntax is close to Forth and its semantics resembles Self and Omega. Latest version: 0.9b6. (ftp://cs.uta.fi/pub/kevo/). E-mail: <kevo-interest@ursamajor.uvic.ca>. [TR DCS-197-19, U Victoria, June 1992]. (1993-05-18) 1 1 1 1 1 key 1. <database> A value used to identify a record in a database, derived by applying some fixed function to the record. The key is often simply one of the fields (a column if the database is considered as a table with records being rows, see "key field"). Alternatively the key may be obtained by applying some function, e.g. a hash function, to one or more of the fields. The set of keys for all records forms an index. Multiple indexes may be built for one database depending on how it is to be searched. 2. <cryptography> A value which must be fed into the algorithm used to decode an encrypted message in order to reproduce the original plain text. Some encryption schemes use the same (secret) key to encrypt and decrypt a message, but public key encryption uses a "private" (secret) key and a "public" key which is known by all parties. 3. <hardware> An electromechanical keyboard button. (2003-07-04) 1 1 1 1 1 keyboard A hardware device consisting of a number of mechanical buttons (keys) which the user presses to input characters to a computer. Keyboards were originally part of terminals which were separate peripheral devices that performed both input and output and communicated with the computer via a serial line. Today a keyboard is more likely to be connected more directly to the processor, allowing the processor to scan it and detect which key or keys are currently pressed. Pressing a key sends a low-level key code to the keyboard input driver routine which translates this to one or more characters or special actions. Keyboards vary in the keys they have, most have keys to generate the ASCII character set as well as various function keys and special purpose keys, e.g. reset or volume control. (2003-07-04) 1 1 1 1 1 Keyboard Commando A bulletin board user who posts authoritatively on military or combat topics, but who has never served in uniform or heard a shot fired in anger. A poseur. (1997-04-25) 1 1 1 1 1 keyboard plaque The disgusting buildup of dirt and crud found on computer keyboards. "Are there any other terminals I can use? This one has a bad case of keyboard plaque." (1997-04-30) 1 1 1 1 1 Keyboard Send Receive (KSR) Part of a designation for a hard-copy terminal, manufactured by Teletype Corporation. The KSR range were lower cost versions of the ASR models. (1995-11-23) 1 1 1 1 1 Keyboard Video Mouse (KVM) Used to describe a "KVM switch" that allows one keyboard, one video display and one mouse to be switched between two or more computers. (2007-03-22) 1 1 1 1 1 Keyed-Hashing Message Authentication (HMAC) A mechanism for message authentication using cryptographic hash functions. HMAC can be used with any iterative cryptographic hash function, e.g., MD5, SHA-1, in combination with a secret shared key. The cryptographic strength of HMAC depends on the properties of the underlying hash function. [RFC 2104]. (1997-05-10) 1 1 1 1 1 Keyed Sequenced Data Set (KSDS) One of the access methods used by VSAM. KSDS has indexes and data split into CI (Control Interval) in CA (Control Area) and multi index levelled. Forward and backward compression is applied to key values. (1999-01-11) 1 1 1 1 1 key escrow A controversial arrangement where the keys needed to decrypt encrypted data must be held in escrow by a third party so that government agencies can obtain them to decrypt messages which they suspect to be relevant to national security. (1999-12-14) 1 1 1 1 1 key field A field of a database (typically a relational database) table which together form a unique identifier for a record (a table entry). The aggregate of these fields is usually referred to simply as "the key". (1997-08-03) 1 1 1 1 1 key frame A frame in an animated sequence of frames which was drawn or otherwise constructed directly by the user rather than generated automatically, e.g. by tweening. (1995-04-06) 1 1 1 1 1 KeyNote Software A company which offers software-based business contact directories for people who develop, manufacture, market, or distribute software or multimedia products. E-mail: <server@netmail.com> (Subject: SEND INDEX). 1 1 1 1 1 keypad An input device with a small array of push buttons labeled with numbers or other symbols, designed to allow rapid entry of characters from a small set, e.g. decimal digits 0-9 or, historically, hexadecimal digits. The most common form of keypad is the numeric keypad found on a standard PC keyboard. (2008-10-10) 1 1 1 1 1 keypal The electronic mail equivalent of a pen pal - someone with whom to exchange electronic mail for the simple joy of communicating. Request for keypals (gopher://wealaka.okgeosurvey1.gov/11/K12/keypals). [Is there some kind of central clearing-house for requests on the net?] 1 1 1 1 1 KeySpell A spell checker and teaching aid from UK company KeySpell Limited for Microsoft Windows. KeySpell offers a selection of phonetically similar words, phrases, confusable terms, and examples in context. Even correctly spelt homophones can be checked. KeySpell can be run with Microsoft Word 97 or stand-alone. It includes 225,000 words and phrases and can use subsets of these. (http://keyspell.com). (1999-05-21) 1 1 1 1 1 keyword 1. One of a fixed set of symbols built into the syntax of a language. Typical keywords would be if, then, else, print, goto, while, switch. There are usually restrictions about reusing keywords as names for user-defined objects such as variables or procedures. Languages vary as to what is provided as a keyword and what is a library routine, for example some languages provide keywords for input/output operations whereas in others these are library routines. 2. A small set of words designed to convey the subject of a technical article. Some publications specify a fixed set of keywords from which those for a particular article should be chosen. 1 1 1 1 1 keyword in context (KWIC) A document search method that creates indexes of document text or titles. Each keyword is stored in the resulting index along with some surrounding text, usually the word or phrase that precedes or follows the keyword in the text or title. (2004-02-17) 1 1 1 1 1 KFX The kernel language of FX-87. ["Polymorphic Effect Systems", J.M. Lucassen et al, Proc 15th Ann ACM Conf POPL, ACM 1988, pp.47-57]. (1995-02-15) 1 1 1 1 1 kg The country code for Kyrgyzstan. (1999-01-27) 1 1 1 1 1 kgbvax kremvax 1 1 1 1 1 kh The country code for Cambodia (formerly Kampuchea). (1999-01-27) 1 1 1 1 1 Khornerstone A multipurpose benchmark from Workstation Labs used in various periodicals. The source is not free. Results are published in "UNIX Review". (1993-04-15) 1 1 1 1 1 Khwarizmi Muhammad ibn Musa al-Khwarizmi 1 1 1 1 1 ki The country code for Kiribati. (1999-01-27) 1 1 1 1 1 kibibyte The official ISO[?] name for 1024 bytes, to distinguish it from 1000 bytes which they call a kilobyte. Mebibyte, "Gibibyte", etc, are prefixes for other powers of 1024. Although this new naming standard has been widely reported in 2003, it seems unlikely to catch on. (2003-09-27) 1 1 1 1 1 KIBO /ki:'boh/ 1. [acronym] Knowledge In, Bullshit Out. A summary of what happens whenever valid data is passed through an organisation (or person) that deliberately or accidentally disregards or ignores its significance. Consider, for example, what an advertising campaign can do with a product's actual specifications. Compare GIGO; see also SNAFU principle. 2. James Parry <kibo@world.std.com>, a Usenetter infamous for various surrealist net.pranks and an uncanny, machine-assisted knack for joining any thread in which his nom de guerre is mentioned. (http://kibo.com/). [Jargon File] (2003-05-20) 1 1 1 1 1 kiboze [Usenet] To grep the Usenet news for a string, especially with the intention of posting a follow-up. This activity was popularised by Kibo. 1 1 1 1 1 kick [IRC] To cause somebody to be removed from a IRC channel, an option only available to CHOPs. This is an extreme measure, often used to combat extreme flamage or flooding, but sometimes used at the chop's whim. Compare gun. [Jargon File] 1 1 1 1 1 kicking dead whales down the beach A simile for a slow, difficult, and disgusting process. First popularised by a famous quote about the difficulty of getting work done under one of IBM's mainframe OSes. "Well, you *could* write a C compiler in COBOL, but it would be like kicking dead whales down the beach." [Jargon File] (2012-09-21) 1 1 1 1 1 Kid Kernel language for Id. A refinement of P-TAC, used as an intermediate language for Id. Lambda-calculus with first-class let-blocks and I-structures. ["A Syntactic Approach to Program Transformations", Z. Ariola et al, SIGPLAN Notices 26(9):116-129 (Sept 1991)]. (1996-07-22) 1 1 1 1 1 KIDASA Software A company which develops project management software for Microsoft Windows. (http://kidasa.com). (1996-07-22) 1 1 1 1 1 killer micro [Popularised by Eugene Brooks] A microprocessor-based machine that infringes on mini, mainframe, or supercomputer performance turf. Often heard in "No one will survive the attack of the killer micros!", the battle cry of the downsizers. Used especially of RISC architectures. The popularity of the phrase "attack of the killer micros" is doubtless reinforced by the movie title "Attack Of The Killer Tomatoes" (one of the canonical examples of so-bad-it's-wonderful among hackers). This has even more flavour now that killer micros have gone on the offensive not just individually (in workstations) but in hordes (within massively parallel computers). [Jargon File] 1 1 1 1 1 killer poke A recipe for inducing hardware damage on a machine via insertion of invalid values (see poke) into a memory-mapped control register; used especially of various fairly well-known tricks on bitty boxes without hardware memory management (such as the IBM PC and Commodore PET) that can overload analog electronics in the monitor. See also HCF. (1994-11-04) 1 1 1 1 1 kill file [Usenet] Per-user file(s) used by some Usenet reading programs (originally Larry Wall's rn) to discard summarily (without presenting for reading) articles matching some particularly uninteresting (or unwanted) patterns of subject, author, or other header lines. Thus to add a person (or subject) to one's kill file is to arrange for that person to be ignored by one's newsreader in future. By extension, it may be used for a decision to ignore the person or subject in other media. See also plonk. [Jargon File] 1 1 1 1 1 kilo- prefix 1 1 1 1 1 kilobaud 1000 baud. (1996-02-12) 1 1 1 1 1 kilobit 2^10 = 1024 bits of storage (1 Kb). Compare kilobits per second. (2002-03-23) 1 1 1 1 1 kilobits per second (kbps, kb/s) A unit of data rate where 1 kb/s = 1000 bits per second. This contrasts with units of storage where 1 Kb = 1024 bits (note upper case K). (2002-03-23) 1 1 1 1 1 kilobyte (KB) A unit of data equal to 1000 bytes (but see binary prefix for other definitions). One kilobyte is the amount of data in 1000 ASCII (or UTF-8) characters or about 250 English words (whose average length is about four characters). 1000 kilobytes are one megabyte. (2014-07-21) 1 1 1 1 1 kiloflops 1000 FLOPS. See prefix. (1998-09-07) 1 1 1 1 1 kiosk A stall set up in a public place where one can obtain information, e.g. tourist information. The information may be provided by a human or by a computer. In the latter case, the data may be stored locally (e.g. on CD-ROM) or accessed via a network using some kind of distributed information retreival system such as Gopher or web. (1998-09-07) 1 1 1 1 1 KIPS /kips/ [by analogy with MIPS] Thousands (*not* 1024s) of instructions per second. Usage: rare. [Jargon File] 1 1 1 1 1 KIS Knowbot Information Service 1 1 1 1 1 KISS Early system on IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 KISS Principle /kis' prin'si-pl/ Keep It Simple, Stupid. A maxim often invoked when discussing design to fend off creeping featurism and control complexity of development. Possibly related to the marketroid maxim on sales presentations, "Keep It Short and Simple". See also Occam's Razor. [Jargon File] (1994-11-18) 1 1 1 1 1 kit (Usenet, possibly from DEC) Slang for a full software distribution, as opposed to a patch or upgrade. A source software distribution that has been packaged in such a way that it can (theoretically) be unpacked and installed according to a series of steps using only standard Unix tools, and entirely documented by some reasonable chain of references from the top-level README file. The more general term distribution may imply that special tools or more stringent conditions on the host environment are required. [Jargon File] (1994-11-18) 1 1 1 1 1 KL0 Kernel Language 0. A sequential logic language based on Prolog, used in the Japanese ICOT project. (1994-11-18) 1 1 1 1 1 KL1 Kernel Language 1. An experimental AND-parallel version of KL0 for the ICOT project in Japan. KL1 is an implementation of FGHC. Not to be confused with KL-ONE. ["Design of the Kernel Language for the Parallel Inference Machine", U. Kazunori et al, Computer J (Dec 1990)]. (1994-10-24) 1 1 1 1 1 Klamath The pre-release "code name" for Intel's Pentium II microprocessor. (1998-09-07) 1 1 1 1 1 KLB Known Lazy Bastard 1 1 1 1 1 Kleene closure Kleene star 1 1 1 1 1 Kleene star (Or "Kleene closure", named after Stephen Kleene) The postfix "*" operator used in regular expressions, Extended Backus-Naur Form, and similar formalisms to specify a match for zero or more occurrences of the preceding expression. For example, the regular expression "be*t" would match the string "bt", "bet", "beet", "beeeeet", and so on. (2000-07-26) 1 1 1 1 1 Kleene, Stephen Cole Stephen Kleene 1 1 1 1 1 Klerer-May System Early system from Columbia University with special mathematics symbols. Its reference manual was two pages long! ["Further Advances in Two-Dimensional Input-Output by Typewriter Terminals", M. Klerer et al, Proc FJCC 31 (1967)]. [Sammet 1969, pp. 284-294]. (1994-10-24) 1 1 1 1 1 KLOC Thousand (kilo-) Lines of code. (1995-03-12) 1 1 1 1 1 klone /klohn/ clone. [Jargon File] 1 1 1 1 1 KL-ONE A frame language. Not to be confused with KL1. ["An Overview of the KL-ONE Knowledge Representation System", R.J. Brachman and J. Schmolze, Cognitive Sci 9(2), 1985]. (1994-11-18) 1 1 1 1 1 kludge /kluhj/ (From the old Scots "kludgie" meaning an outside toilet) A Scottish engineering term for anything added in an ad hoc (and possibly unhygenic!) manner. At some point during the Second World War, Scottish engineers met Americans and the meaning, spelling and pronunciation of kludge became confused with that of "kluge". The spelling "kludge" was apparently popularised by the Datamation cited below which defined it as "An ill-assorted collection of poorly matching parts, forming a distressing whole." The result of this tangled history is a mess; in 1993, many (perhaps even most) hackers pronounce the word /klooj/ but spell it "kludge" (compare the pronunciation drift of mung). Some observers consider this appropriate in view of its meaning. ["How to Design a Kludge", Jackson Granholme, Datamation, February 1962, pp. 30-31]. 1 1 1 1 1 kluge /klooj/, /kluhj/ (From German "klug" /kloog/ - clever and Scottish "kludge") 1. A Rube Goldberg (or Heath Robinson) device, whether in hardware or software. The spelling "kluge" (as opposed to "kludge") was used in connection with computers as far back as the mid-1950s and, at that time, was used exclusively of *hardware* kluges. 2. <programming> A clever programming trick intended to solve a particular nasty case in an expedient, if not clear, manner. Often used to repair bugs. Often involves ad-hockery and verges on being a crock. In fact, the TMRC Dictionary defined "kludge" as "a crock that works". 3. Something that works for the wrong reason. 4. (WPI) A feature that is implemented in a rude manner. In 1947, the "New York Folklore Quarterly" reported a classic shaggy-dog story "Murgatroyd the Kluge Maker" then current in the Armed Forces, in which a "kluge" was a complex and puzzling artifact with a trivial function. Other sources 1 1 1 1 1 kluge around To avoid a bug or difficult condition by inserting a kluge. Compare workaround. [Jargon File] (1995-03-10) 1 1 1 1 1 km The country code for Comoros. (1999-01-27) 1 1 1 1 1 KMODEL An ancestor of Model-K. "Preliminary Results on the BEHAVIOUR Specifications Language KMODEL-0", BEHAVIOUR Memo 5-91, 1991, GMD, Sankt Augustin, Germany 1 1 1 1 1 KMS Knowledge Management System 1 1 1 1 1 kn The country code for Saint Kitts and Nevis. (1999-01-27) 1 1 1 1 1 knapsack problem Given a set of items, each with a cost and a value, determine the number of each item to include in a collection so that the total cost is less than some given cost and the total value is as large as possible. The 0/1 knapsack problem restricts the number of each items to zero or one. Such constraint satisfaction problems are often solved using dynamic programming. The general knapsack problem is NP-hard, and this has led to attempts to use it as the basis for public-key encryption systems. Several such attempts failed because the knapsack problems they produced were in fact solvable by polynomial-time algorithms. [Are there any trusted knapsack-based public-key cryptosystems?]. (1995-04-10) 1 1 1 1 1 KNI Streaming SIMD Extensions 1 1 1 1 1 Knights of the Lambda-Calculus A semi-mythical organisation of wizardly LISP and Scheme hackers. The name refers to a mathematical formalism invented by Alonzo Church, with which LISP is intimately connected. There is no enrollment list and the criteria for induction are unclear, but one well-known LISPer has been known to give out buttons and, in general, the *members* know who they are. [Jargon File] 1 1 1 1 1 knowbot A kind of bot that collects information by automatically gathering certain specified information from websites. (1999-06-19) 1 1 1 1 1 Knowbot Information Service (KIS) Also known as netaddress. The Knowbot Information Service (KIS) provides a uniform user interface to a variety of remote directory services such as whois, finger, X.500, MCIMail. By submitting a single query to KIS, a user can search a set of remote white pages services and see the results of the search in a uniform format. There are several interfaces to the KIS service including electronic mail and telnet. Another KIS interface imitates the Berkeley whois command. KIS consists of two distinct types of modules which interact with each other (typically across a network) to provide the service. One module is a user agent module that runs on the KIS mail host machine. The second module is a remote server module (possibly on a different machine) that interrogates various database services across the network and provides the results to the user agent module in a uniform fashion. 1 1 1 1 1 knowledge The objects, concepts and relationships that are assumed to exist in some area of interest. A collection of knowledge, represented using some knowledge representation language is known as a knowledge base and a program for extending and/or querying a knowledge base is a knowledge-based system. Knowledge differs from data or information in that new knowledge may be created from existing knowledge using logical inference. If information is data plus meaning then knowledge is information plus processing. A common form of knowledge, e.g. in a Prolog program, is a collection of facts and rules about some subject. For example, a knowledge base about a family might contain the facts that John is David's son and Tom is John's son and the rule that the son of someone's son is their grandson. From this knowledge it could infer the new fact that Tom is David's grandson. 1 1 1 1 1 Knowledge Analysis and Design System (KADS) A structured way of developing knowledge-based systems (expert systems). KADS was developed as an alternative to an evolutionary approach and is now accepted as the European standard for knowledge based systems. (http://cse.unsw.edu.au/~timm/pub/slides/kltut/index.html). ["Knowledge Based Systems Analysis and Design: A KADS Developers Handbook", Tansley and Hayball] (1998-03-12) 1 1 1 1 1 knowledge base A collection of knowledge expressed using some formal knowledge representation language. A knowledge base forms part of a knowledge-based system (KBS). (1994-10-19) 1 1 1 1 1 knowledge-based system (KBS) A program for extending and/or querying a knowledge base. The related term expert system is normally used to refer to a highly domain-specific type of KBS used for a specialised purpose such as medical diagnosis. The Cyc project is an example of a large KBS. (1999-09-07) 1 1 1 1 1 knowledge level A level of description of the knowledge of an agent that is independent of the agent's internal symbol-level representation. Knowledge can be attributed to agents by observing their actions. An agent knows something if it acts as if it had the information and is acting rationally to achieve its goals. The "actions" of agents, including knowledge base servers and knowledge-based systems, can be seen through a "tell and ask" functional interface, where a client interacts with an agent by making logical assertions (tell), and posing queries (ask). (1994-10-19) 1 1 1 1 1 Knowledge Management System (KMS) A distributed hypermedia system for managing knowledge in organisations. KMS is a commercial system from Knowledge Systems, Inc. running on workstations, based on previous research with ZOG at Carnegie Mellon University. (1994-10-28) 1 1 1 1 1 Knowledge Query and Manipulation Language (KQML) A language and protocol, based on SGML, for exchanging information and knowledge, proposed in 1993(?). Work on KQML is led(?) by Tim Finin <finin@umbc.edu> of the University of Maryland Baltimore County, Lab for Advanced Information Technology. It is part of the ARPA Knowledge Sharing Effort. The KQML message format and protocol can be used to interact with an intelligent system, either by an application program, or by another intelligent system. KQML's performatives are operations that agents perform on each other's knowledge and goal stores. Higher-level interactions such as contract nets and negotiation are built using these. KQML's "communication facilitators" coordinate the interactions of other agents to support knowledge sharing. Experimental prototype systems support concurrent engineering, intelligent design, intelligent planning, and scheduling. 1 1 1 1 1 knowledge representation The subfield of artificial intelligence concerned with designing and using systems for storing knowledge - facts and rules about some subject. A body of formally represented knowledge is based on a conceptualisation - an abstract view of the world that we wish to represent. In order to manipulate this knowledge we must specify how the abstract conceptualisation is represented as a concrete data structure. An ontology is an explicit specification of a conceptualisation. (1994-10-19) 1 1 1 1 1 Knowledge Sharing Effort An ARPA project developing techniques and methods for building large-scale knowledge bases which are sharable and reusable. KQML is part of it. (1999-09-28) 1 1 1 1 1 Knowledge Systems Laboratory (KSL) An artificial intelligence research laboratory within the Department of Computer Science at Stanford University. Current work focuses on knowledge representation for sharable engineering knowledge bases and systems, computational environments for modelling physical devices, architectures for adaptive intelligent systems, and expert systems for science and engineering. (1994-12-06) 1 1 1 1 1 Known Lazy Bastard (KLB) A term, used among technical support staff, for a user who repeatedly asks for help with problems whose solutions are clearly explained in the documentation, and persists in doing so after having been told to RTFM. KLBs are singled out for special treatment (i.e. ridicule), especially if they have been heard to say "It's so boring to read the manual! Why don't you just tell me?". The deepest pit in Hell is reserved for KLBs whose questions reveal total ignorance of the basic concepts (e.g., "How do I make a font in Excel?", "Where do I turn on my RAM?"), and who refuse to accept that their questions are neither simple nor well-formed. (1998-09-07) 1 1 1 1 1 Knuth /knooth/ 1. Donald Knuth. 2. ["The Art of Computer Programming", Donald E. Knuth] Mythically, the reference that answers all questions about data structures or algorithms. A safe answer when you do not know: "I think you can find that in Knuth." Contrast literature. See also bible. [Jargon File] 1 1 1 1 1 Kodak The photographic company responsible for Photo CD. (http://kodak.com/). (1995-12-13) 1 1 1 1 1 Kohonen T. Kohonen 1 1 1 1 1 KOMPILER An early system on the IBM 701. Versions: KOMPILER 2 for IBM 701, KOMPILER 3 for IBM 704. [Listed in CACM 2(5):16, May 1959]. (2005-06-20) 1 1 1 1 1 Konrad Zuse The designer of the first programming language, Plankalkül, and the first fully functional program-controlled electromechanical digital computer in the world, the Z3. He died on 1995-12-18 in Huenfeld, Germany. Biography (http://ei.cs.vt.edu/~history/Zuse.html). ["Konrad Zuse: Mein Leben" (My Life), published 1956]. ["Konrad Zuse: The Computer my Life, Springer, 1993]. (1999-02-18) 1 1 1 1 1 Korf, Richard Richard Korf 1 1 1 1 1 Korn Shell (ksh) A command interpreter for Unix. SKsh is an AmigaDos-specific version and pdksh is a free Unix version. [More details?] 1 1 1 1 1 kp The country code for North Korea. (1999-01-27) 1 1 1 1 1 KQML Knowledge Query and Manipulation Language 1 1 1 1 1 KR knowledge representation 1 1 1 1 1 kr The country code for South Korea. [Jargon File] (1999-01-27) 1 1 1 1 1 K&R Kernighan and Ritchie. Brian Kernighan and Dennis Ritchie's book, cited below, describing the basis of K&R C, especially the classic and influential first edition. Synonyms: White Book, Old Testament. See also New Testament. [Jargon File] [Brian Kernighan, Dennis Ritchie, "The C Programming Language", Prentice-Hall 1978; ISBN 0-113-110163-3]. (2011-11-30) 1 1 1 1 1 KRC Kent Recursive Calculator 1 1 1 1 1 K&R C (C Classic) The C programming language as defined in the first edition of K&R, with some small additions. The name "C Classic", a play on "Coke Classic", came into use while ANSI C was being standardised by the ANSI X3J11 committee. See also classic. [Jargon File] (2006-09-26) 1 1 1 1 1 kremvax /krem-vaks/ (Or kgbvax) Originally, a fictitious Usenet site at the Kremlin, named like the then large number of Usenet VAXen with names of the form foovax. Kremvax was announced on April 1, 1984 in a posting ostensibly originated there by Soviet leader Konstantin Chernenko. The posting was actually forged by Piet Beertema as an April Fool's joke. Other fictitious sites mentioned in the hoax were moskvax and kgbvax. This was probably the funniest of the many April Fool's forgeries perpetrated on Usenet (which has negligible security against them), because the notion that Usenet might ever penetrate the Iron Curtain seemed so totally absurd at the time. In fact, it was only six years later that the first genuine site in Moscow, demos.su, joined Usenet. Some readers needed convincing that the postings from it weren't just another prank. Vadim Antonov, senior programmer at Demos and the major poster from there up to mid-1991, was quite aware of 1 1 1 1 1 KRL Knowledge Representation Language. A frame-based language. ["An Overview of KRL, a Knowledge Representation Language", D.G. Bobrow and T. Winograd, Cognitive Sci 1:1 (1977)]. 1 1 1 1 1 KRS A frame-based language built on Common LISP. (2011-12-05) 1 1 1 1 1 K&R style An ugly, obsolete, deprecated source code indent style that looks like this: if (cond) <body> The basic indent is eight spaces (or one tab) per level; less commonly four. It is named after Kernighan & Ritchie because the examples in K&R are formatted this way. It is also called "kernel style" (because the Unix kernel was written in it) or Egyptian brackets. This style was popular when programmers worked on small displays, or when printing code on paper, becuase it saves vertical space. It should be avoided because the opening brace is easy to miss at the end of a long condition in an "if" or "while" statement and it makes it hard to pair up braces. 1 1 1 1 1 KRYPTON A frame language. ["An Essential Hybrid Reasoning System: Knowledge and Symbol Level Accounts of KRYPTON", R.J. Brachman et al, Proc IJCAI-85, 1985]. (2011-12-05) 1 1 1 1 1 ksh Korn Shell 1 1 1 1 1 KSL Knowledge Systems Laboratory 1 1 1 1 1 KSR 1. Keyboard Send Receive. 2. <company> Kendall Square Research. (1995-11-23) 1 1 1 1 1 KTH Kungliga Tekniska Högskolan 1 1 1 1 1 kthx OK, thanks. Can be used as a (sarcastic) prefix, as in plz2stfukthx. (2008-03-14) 1 1 1 1 1 KUIP Kernel User Interface Package 1 1 1 1 1 Kungliga Tekniska Högskolan (KTH, Royal Institute of Art and Technology) A Swedish university founded in 1827 that is strong in engineering and computing (e.g. AI, Virtual Reality). In 1998 KTH had nearly 11,000 undergraduate students, 1,300 postgraduate students, and 2,900 staff, making it the largest of Sweden's six universitites of technology. (http://kth.se/index-eng.html). Address: Stockholm, Sweden. (2001-03-18) 1 1 1 1 1 KUTGW Keep up the good work. (1999-03-08) 1 1 1 1 1 Kvatro Telecom AS The company that maintains Mary. Address: Trondheim, Norway. (http://kvatro.no/). (1998-11-10) 1 1 1 1 1 Kvikkalkul /kveek`kahl-kool'/ A deliberately cryptic programming language said to have been devised by the Swedish Navy in the 1950s as part of their abortive attempt at a nuclear weapons program. What little is known about it comes from a series of an anonymous posts to Usenet in 1994. The poster described the language, saying that he had programmed in Kvikkalkul when he worked for the Swedish Navy in the 1950s. It is an open question whether the posts were a troll, a subtle parody or truth stranger than fiction could ever be. Assuming it existed, Kvikkalkul is so much a bondage-and-discipline language that it is, in its own ways, even more bizarre than the deliberate parody language INTERCAL. Among its notable "features", all symbols in Kvikkalkul, including variable names and program labels, can consist only of digits. Operators consist entirely of the punctuation symbols (, ), -, and :. Kvikkalkul allows no 1 1 1 1 1 KVM Keyboard Video Mouse 1 1 1 1 1 kw The country code for Kuwait. (1999-01-27) 1 1 1 1 1 KWIC keyword in context 1 1 1 1 1 ky The country code for the Cayman Islands. (1999-01-27) 1 1 1 1 1 Kyoto Common Lisp (KCL) An implementation of Common Lisp by T. Yuasa <yuasa@tutics.tut.ac.jp> and M. Hagiya <hagiya@is.s.u-tokyo.ac.jp>, written in C to run under Unix-like operating systems. KCL is compiled to ANSI C. It conforms to Common Lisp as described in Guy Steele's book and is available under a licence agreement. (ftp://rascal.ics.utexas.edu/pub/kcl.tar.Z). E-mail: <kcl@cli.com> (bug reports). Mailing list: kcl-request@cli.com, kcl@rascal.ics.utexas.edu. ["Design and Implementation of Kyoto Common Lisp", T. Yuasa <yuasa@tutics.tut.ac.jp>, J Info Proc 13(3):284-295 (1990)]. ["Kyoto Common Lisp Report", T. Yuasa & M. Hagiya]. (1987-06-01) 1 1 1 1 1 kyrka feature key 1 1 1 1 1 kz The country code for Kazakhstan. (1999-01-27) 1 1 1 1 1 L0 A low-level language developed at the Technical University of Munich. L0 was typed and had the usual flow control, but only 3-address expressions. Higher level languages, L1 and L2 were planned. ["Brief Survey of L0", H. Scheidig, in Machine Oriented Higher Level Languages, W. van der Poel ed, N-H 1974, pp. 239-247]. (2003-06-12) 1 1 1 1 1 L0pht /loft/ An Internet security organisation that merged with @stake in January 2000. (2003-06-12) 1 1 1 1 1 l10n localisation 1 1 1 1 1 L1 cache primary cache 1 1 1 1 1 L2 cache secondary cache 1 1 1 1 1 L2CAP Logical Link Control and Adaptation Protocol 1 1 1 1 1 L2TP Layer Two Tunneling Protocol 1 1 1 1 1 L6 Bell Telephone Laboratories Low-Level Linked List Language. Ken Knowlton, 1965. List processing language, typeless. ["A Programmer's Description of L6, Bell Telephone Laboratories' Low-Level Linked List Language", K. Knowlton CACM 9(8):616-625 (Aug 1966). Sammet 1969, pp.400- 405]. 1 1 1 1 1 la The country code for Laos. (1999-01-27) 1 1 1 1 1 label 1. <programming> An identifier used to mark a position in a program so that it can be the destination of a goto statement. 2. <networking> The identifier assigned to a datagram for label switching. (2007-10-17) 1 1 1 1 1 label edge router (LER) A device that sits at the edge of an MPLS domain, that uses routing information to assign labels to datagrams and then forwards them into the MPLS domain. (1999-06-14) 1 1 1 1 1 Label Forwarding Information Base (LFIB) A label switching scheme used in MultiProtocol Label Switching (MPLS). [Details?] (2007-06-25) 1 1 1 1 1 label switched path (LSP) The specific path through a network that a datagram follows, based on its MPLS labels. (1999-06-14) 1 1 1 1 1 label switching A routing technique that uses information from existing IP routing protocols to identify IP datagrams with labels and forwards them to a modified switch or router, which then uses the labels to switch the datagrams through the network. Label switching combines the best attributes of data link layer (layer two) switching (as in ATM and Frame Relay) with the best attributes of network layer (layer three) routing (as in IP). Prior to the formation of the MPLS Working Group in 1997, a number of vendors had announced and/or implemented proprietary label switching. (2007-10-17) 1 1 1 1 1 Label Switching Router (LSR) A device that typically resides somewhere in the middle of a network and is capable of forwarding datagrams by label switching. In many cases, especially early versions of MPLS networks, a LSR will typically be a modified ATM switch that forwards datagrams based upon a label in the VPI/VCI field. (1999-06-14) 1 1 1 1 1 Lab for Computer Science MIT. (http://lcs.mit.edu/). 1 1 1 1 1 Laboratoire lorrain de recherche en informatique et ses applications (LORIA) A French research institute associated with INRIA. (2007-06-01) 1 1 1 1 1 Laboratory INstrument Computer (LINC) A computer which was originally designed in 1962 by Wesley Clark, Charles Molnar, Severo Ornstein and others at the Lincoln Laboratory Group, to facilitate scientific research. With its digital logic and stored programs, the LINC is accepted by the IEEE Computer Society to be the World's first interactive personal computer. The machine was developed to fulfil a need for better laboratory tools by doctors and medical researchers. It would supplant the 1958 Average Response Computer, and was designed for individual use. Led by William N. Papian and mainly funded by the National Institute of Health, Wesley Clark designed the logic while Charles Molnar did the engineering. The first LINC was finished in March 1962. In January 1963, the project moved to MIT, and then to Washington University (in St. Louis) in 1964. The LINC had a simple operating system, four "knobs" (which 1 1 1 1 1 Laboratory Virtual Instrument Engineering Workbench (LabVIEW) A package from National Instruments Corp originally developed to provide a graphical user interface to instruments connected by the IEEE 488 (GPIB) bus. It has powerful graphical editing facilities for defining and interconnecting "virtual instruments". (1996-04-24) 1 1 1 1 1 LaborNet An IGC network serving groups, unions and labour advocates interested in information sharing and collaboration with the intent of enhancing the human rights and economic justice of workers. Issues covered include workplace and community health and safety issues, trade issues and international union solidarity and collaboration. 1 1 1 1 1 Labtech Notebook Commercial data aquisition software. (1995-03-08) 1 1 1 1 1 LabVIEW Laboratory Virtual Instrument Engineering Workbench 1 1 1 1 1 Lace Language for Assembling Classes in Eiffel. Specifies how to assemble an Eiffel system : in which directories to find the clusters, which class to use as the root, permits class renaming to avoid name clashes. "Eiffel: The Language", Bertrand Meyer, P-H 1992. 1 1 1 1 1 lace card (Obsolete) A punched card with all holes punched (also called a "whoopee card" or "ventilator card"). Card readers tended to jam when they got to one of these, as the resulting card had too little structural strength to avoid buckling inside the mechanism. Card punches could also jam trying to produce these things owing to power-supply problems. When some practical joker fed a lace card through the reader, you needed to clear the jam with a "card knife" - which you used on the joker first. [Jargon File] 1 1 1 1 1 ladder logic Source code formatted in two columns with conditions on the left that lead to outputs on the right: if (c1) s1 else if (c2) s2 else if (c3) s3 ... (2007-03-15) 1 1 1 1 1 LADY ["Key Concepts in the INCAS Multicomputer Project", J. Nehmer et al IEEE Trans Soft Eng SE-13(8):913-923 (Aug 1987)]. (1996-06-21) 1 1 1 1 1 lag netlag 1 1 1 1 1 Lakota Scripting language, extends existing OS commands. E-mail: Richard Harter <rh@smds.UUCP>, SMDS, Inc. 1 1 1 1 1 LALR Look Ahead Left-to-right parse, Rightmost-derivation 1 1 1 1 1 lalr.ss An LALR1 grammar parser generator written in, and outputting, Scheme by Mark Johnson <mj@cs.brown.edu>. Version 0.9 (before 1995-10-30). FTP new/lalr.shar from the Scheme Repository. (1993-05-24) 1 1 1 1 1 Lambada-Calculus (A pun on "lambda-calculus") Teaching logic thru spanish dance steps. Invented by P. van der Linden <linden@eng.sun.com>. (1996-08-10) 1 1 1 1 1 LAMBDA A version of typed lambda-calculus, used to describe semantic domains. ["Outline of a Mathematical Theory of Computation", D.S. Scott, TM PRG-2, PRG, Oxford U, 1971]. 1 1 1 1 1 lambda abstraction A term in lambda-calculus denoting a function. A lambda abstraction begins with a lower-case lambda (represented as \ in this document), followed by a variable name (the "bound variable"), a full stop and a lambda expression (the body). The body is taken to extend as far to the right as possible so, for example an expression, \ x . \ y . x+y is read as \ x . (\ y . x+y). A nested abstraction such as this is often abbreviated to: \ x y . x + y The lambda expression (\ v . E) denotes a function which takes an argument and returns the term E with all free occurrences of v replaced by the actual argument. Application is 1 1 1 1 1 lambda-calculus (Normally written with a Greek letter lambda). A branch of mathematical logic developed by Alonzo Church in the late 1930s and early 1940s, dealing with the application of functions to their arguments. The pure lambda-calculus contains no constants - neither numbers nor mathematical functions such as plus - and is untyped. It consists only of lambda abstractions (functions), variables and applications of one function to another. All entities must therefore be represented as functions. For example, the natural number N can be represented as the function which applies its first argument to its second N times (Church integer N). Church invented lambda-calculus in order to set up a foundational project restricting mathematics to quantities with "effective procedures". Unfortunately, the resulting system admits Russell's paradox in a particularly nasty way; Church couldn't see any way to get rid of it, and gave the project up. 1 1 1 1 1 lambda expression A term in the lambda-calculus denoting an unnamed function (a "lambda abstraction"), a variable or a constant. The pure lambda-calculus has only functions and no constants. (1995-04-13) 1 1 1 1 1 lambda lifting A program transformation to remove free variables. An expression containing a free variable is replaced by a function applied to that variable. E.g. f x = g 3 where g y = y + x x is a free variable of g so it is added as an extra argument: f x = g 3 x where g y x = y + x Functions like this with no free variables are known as supercombinators and are traditionally given upper-case names beginning with "$". This transformation tends to produce many supercombinators of the form f x = g x which can be eliminated by eta reduction and substitution. Changing the order of the parameters may also allow more optimisations. References to global (top-level) constants and functions are not transformed to function parameters though they are technically free variables. 1 1 1 1 1 LambdaMOO The most frequently used server software for running a MOO and also the nerve-center (of sorts) of the MOO community. (ftp://ftp.lambda.moo.mud.org/pub/MOO/). Telnet (telnet://lambda.moo.mud.org:8888). (1999-05-25) 1 1 1 1 1 Lambda Prolog An extension of standard Prolog defined by Dale A. Miller and Gopalan Nadathur in 1986, in which terms are strongly typed lambda terms. Clauses are higher order hereditary Harrop formulas. The main novelties are universal quantification on goals and implication. The Prolog/Mali compiler compiles Lambda Prolog for the MALI abstract memory system. Teyjus (http://teyjus.cs.umn.edu/) is an implementation of Lambda Prolog. Lambda Prolog home (http://cse.psu.edu/~dale/lProlog/). Mailing list: lprolog@cs.umn.edu. ["Higher-order logic programming", Miller D.A. and Nadathur G., 3rd International Conference on Logic Programming, pp 448-462, London 1986]. [Nadathur G. "A Higher-Order Logic as a Basis for Logic Programming", Thesis, University of Pennsylvania, 1987]. (2002-10-15) 1 1 1 1 1 lamer A hopelessly clueless luser. (1997-01-31) 1 1 1 1 1 LAMINA A concurrent object-oriented language. ["Experiments with a Knowledge-based System on a Multiprocessor", Third Intl Conf Supercomputing Proc, 1988]. ["ELINT in LAMINA, Application of a Concurrent Object language", Delagi et al, KSL-88-3, Knowledge Sys Labs, Stanford U]. 1 1 1 1 1 lamp-post error fencepost error 1 1 1 1 1 LAN local area network 1 1 1 1 1 LAN administrator A person who installs and maintains LAN hardware and software. A LAN administrator troubleshoots network usage and computer peripherals. He installs new users, performs system backups and data recovery, and resolves LAN communications problems. (2004-03-12) 1 1 1 1 1 LANCE Local Area Network Controller for Ethernet. The alternative name for the Am7990 integrated circuit used in a Filtabyte Ethernet controller card. (1995-02-15) 1 1 1 1 1 language 1. <language, programming> programming language. 2. <human language> natural language. (1998-09-07) 1 1 1 1 1 language-based editor language-sensitive editor 1 1 1 1 1 language code A set of standard names and abbreviations maintained by ISO for identifying human languages, natural and invented, past and present. Each language has a list of English and French names and an ISO 639-2 three-letter code. Some also have an ISO 639-1 two-letter code. The list even includes the Klingon language from the Star Trek science fiction series. Latest list (http://www.loc.gov/standards/iso639-2/php/English_list.php). There are also country codes. (2006-12-11) 1 1 1 1 1 Language for Communicating Systems (LCS) A concurrent SML by Bernard Berthomieu with behaviours and processes, based upon higher order CCS. LCS is implemented as a bytecode interpreter and runs on Sun SPARC, SGI MIPS, and Linux. Latest version: 5.1, as of 2000-03-17. (http://laas.fr/~bernard/lcs.html). E-mail: Bernard Berthomieu <Bernard.Berthomieu@laas.fr>. Mailing list: lcs@laas.fr (2000-03-28) 1 1 1 1 1 Language for the On-Line Investigation and Transformation of Abstractions (LOLITA) An extension of the Culler-Fried System for symbolic mathematics. ["An On- line Symbol Manipulation System", F.W. Blackwell, Proc ACM 22nd Natl Conf, 1967]. [Sammet 1969, p. 464]. (2003-07-29) 1 1 1 1 1 Language H An early business-oriented language from NCR. 1 1 1 1 1 language lawyer A person, usually an experienced or senior software engineer, who is intimately familiar with many or most of the numerous restrictions and features (both useful and esoteric) applicable to one or more computer programming languages. A language lawyer is distinguished by the ability to show you the five sentences scattered through a 200-page manual that together imply the answer to your question "if only you had thought to look there". Compare wizard, legal, legalese. [Jargon File] (1995-02-15) 1 1 1 1 1 Language Of Temporal Ordering Specification (LOTOS) A formal specification language based on temporal ordering used for protocol specfication in ISO OSI standards. It is published as ISO 8807 in 1990 and describes the order in which events occur. ["The Formal Description Technique LOTOS", P.H.J. van Eijk et al eds, N-H 1989]. (1995-03-18) 1 1 1 1 1 Language Sensitive Editor (LSE) A language-sensitive editor from DEC. (1995-02-15) 1 1 1 1 1 language-sensitive editor An editor that is aware of the syntactic, semantic and in some cases the structural rules of a specific programming language and provides a framework for the user to enter source code. Programs or changes to previously stored programs are incrementally parsed into an abstract syntax tree and automatically checked for correctness. (1995-02-15) 1 1 1 1 1 languages of choice C and Lisp. Nearly every hacker knows one of these, and most good ones are fluent in both. Smalltalk and Prolog are also popular in small but influential communities. There is also a rapidly dwindling category of older hackers with Fortran, or even assembler, as their language of choice. They often prefer to be known as Real Programmers, and other hackers consider them a bit odd (see "The Story of Mel"). Assembler is generally no longer considered interesting or appropriate for anything but HLL implementation, glue, and a few time-critical and hardware-specific uses in systems programs. Fortran occupies a shrinking niche in scientific programming. Most hackers tend to frown on languages like Pascal and Ada, which don't give them the near-total freedom considered necessary for hacking (see bondage-and-discipline language), and to regard everything even remotely connected with COBOL or other traditional card walloper languages as a total and 1 1 1 1 1 Laning and Zierler Possibly the first true working algebraic compiler. Written by J.H. Laning Jr and N. Zierler in 1953-1954 to run on MIT's Whirlwind computer. [Sammet 1969, pp. 131-132]. [Did the language have a name?] (1994-11-01) 1 1 1 1 1 Lan Kanal Adapter (LKA) A sort of external LAN interface for a BS200 computer. (2005-02-11) 1 1 1 1 1 LANL Los Alamos National Laboratory, Los Alamos, NM, USA. 1 1 1 1 1 Lan Manager Microsoft's OS/2-based network operating system. Developed in conjunction with 3Com, Lan Manager runs as a task under OS/2. Because of this, a file server may concurrently be used for other tasks, such as database services. It offers good mulitasking. (1997-03-19) 1 1 1 1 1 LANtastic A trademarked name for numerous products of Artisoft, Inc.. (1995-04-16) 1 1 1 1 1 LAP LISP Assembly Program. The assembly language embedded into early Lisp. LAP was also used by the Liar compiler for MIT Scheme and MACLISP. [Sammet 1969, p. 597]. (1994-11-01) 1 1 1 1 1 LAP4 Early assembly language for Linc-8 machine. 1 1 1 1 1 LAPB Link Access Protocol Balanced 1 1 1 1 1 LAPD 1. Link Access Procedure on the D channel. 2. Los Angeles Police Department. 1 1 1 1 1 LAPM Link Access Protocol for Modems 1 1 1 1 1 LAPSE A single assignment language for the Manchester dataflow machine. ["A Single Assignment Language for Data Flow Computing", J.R.W. Glauert, M.Sc Diss, Victoria U Manchester, 1978]. (1994-12-21) 1 1 1 1 1 laptop portable computer 1 1 1 1 1 laptop computer portable computer 1 1 1 1 1 LaQuey [LaQuey, T. (with J. Ryer), "The Internet Companion: A Beginner's Guide to Global Networking", Addison-Wesley, Reading, MA, 1992] (2007-09-27) 1 1 1 1 1 Larch The Larch Project develops aids for formal specifications. Each Larch specification has two components: an interface containing predicates written in the LIL (Larch Interface Language) designed for the target language and a 'trait' containing assertions about the predicates written in LSL, the Larch Shared Language common to all. ["The Larch Family of Specification Languages", J. Guttag et al, IEEE Trans Soft Eng 2(5):24-365 (Sep 1985)]. 1 1 1 1 1 Larch/C++ An interface specification language which can be used to formally specify C++ program modules. 1 1 1 1 1 LARCH/CLU The Larch specification language for CLU. Used in "Abstraction and Specification in Program Development", B. Liskov & J. Guttag, MIT Press 1986. (1996-01-02) 1 1 1 1 1 Large Installation Systems Administration (LISA) The USENIX systems administration conference. It is now more general that its title suggests. It is sponsored and organised by SAGE, the USENIX Systems Administrators Guild. (ftp://ftp.sage.usenix.org/pub/sage/). (1996-01-02) 1 1 1 1 1 Larry Wall A demigod, the author of Perl, patch, and rn. In the Perl README, he says, "I want you to know that I create nice things like this because it pleases the Author of my story. If this bothers you, then your notion of Authorship needs some revision. But you can use Perl anyway." E-mail: Larry Wall <lwall@sems.com>. (1996-06-04) 1 1 1 1 1 LART Luser Attitude Re-adjustment Tool 1 1 1 1 1 larval stage Describes a period of monomaniacal concentration on coding apparently passed through by all fledgling hackers. Common symptoms include the perpetration of more than one 36-hour hacking run in a given week; neglect of all other activities including usual basics like food, sleep, and personal hygiene; and a chronic case of advanced bleary-eye. Can last from 6 months to 2 years, the apparent median being around 18 months. A few so afflicted never resume a more "normal" life, but the ordeal seems to be necessary to produce really wizardly (as opposed to merely competent) programmers. See also wannabee. A less protracted and intense version of larval stage (typically lasting about a month) may recur when one is learning a new OS or programming language. [Jargon File] 1 1 1 1 1 lase /layz/ To print a given document via a laser printer. "OK, let's lase that sucker and see if all those graphics-macro calls did the right things." 1 1 1 1 1 laser (Light Amplification by Stimulated Emission of Radiation) The type of light source used in a laser printer. (2003-05-08) 1 1 1 1 1 laser printer A non-impact high-resolution printer which uses a rotating disk to reflect laser beams to form an electrostatic image on a selenium imaging drum. The developer drum transfers toner from the toner bin to the charged areas of the imaging drum, which then transfers it onto the paper into which it is fused by heat. Toner is dry ink powder, generally a plastic heat-sensitive polymer. Print resolution currently (2001) ranges between 300 and 2400 dots per inch (DPI). Laser printers using chemical photoreproduction techniques can produce resolutions of up to 2400 DPI. Print speed is limited by whichever is slower - the printer hardware (the "engine speed"), or the software rendering process that converts the data to be printed into a bit map. The print speed may exceed 21,000 lines per minute, though printing speed is more often given in pages per minute. If a laser printer is rated at 12 pages per minute (PPM), this 1 1 1 1 1 Lasherism (Harvard) A program that solves a standard problem (such as the Eight Queens Puzzle or implementing the life algorithm) in a deliberately nonstandard way. Distinguished from a crock or kluge by the fact that the programmer did it on purpose as a mental exercise. Such constructions are quite popular in exercises such as the Obfuscated C contest, and occasionally in retrocomputing. Lew Lasher was a student at Harvard around 1980 who became notorious for such behaviour. [Jargon File] (1994-12-07) 1 1 1 1 1 last call optimisation (Or "tail call optimisation") Discarding the immediate calling context (call stack frame) when the last action of a function or procedure, A, is to call another function or procedure, B. B will then return directly to A's caller, or possibly further up the call stack if the optimisation has been applied to several consecutive calls. Last call optimisation allows arbitrarily deep nesting of procedure calls without consuming memory to store useless environments. This is particularly useful in the special case of tail recursion optimisation, where a procedure's last action is to call itself (possibly indirectly). (2007-03-16) 1 1 1 1 1 last-in first-out stack 1 1 1 1 1 LAT Local Area Transport 1 1 1 1 1 latch A digital logic circuit used to store one or more bits. A latch has a data input, a clock input and an output. When the clock input is active, data on the input is "latched" or stored and transfered to the output either immediately or when the clock input goes inactive. The output will then retain its value until the clock goes active again. See also flip-flop. (1995-02-03) 1 1 1 1 1 latency 1. The time it takes for a packet to cross a network connection, from sender to receiver. 2. The period of time that a frame is held by a network device before it is forwarded. Two of the most important parameters of a communications channel are its latency, which should be low, and its bandwidth, which should be high. Latency is particularly important for a synchronous protocol where each packet must be acknowledged before the next can be transmitted. (2000-02-27) 1 1 1 1 1 LaTeX (Lamport TeX) Leslie Lamport <lamport@pa.dec.com>'s document preparation system built on top of TeX. LaTeX was developed at SRI International's Computer Science Laboratory and was built to resemble Scribe. LaTeX adds commands to simplify typesetting and lets the user concentrate on the structure of the text rather than on formatting commands. BibTeX is a LaTeX package for bibliographic citations. Lamport's LaTeX book has an exemplary index listing every symbol, concept and example in the book. The index in the, now obsolete, first edition includes (on page 221) the mysterious entry Gilkerson, Ellen, 221. The second edition (1994) has an entry for "infinite loop" instead. ["LaTeX, A Document Preparation System", Leslie Lamport, A-W 1986, ISBN 0-201-15790-X (first edition, now obsolete)]. (1997-11-17) 1 1 1 1 1 Latin 1 ISO 8859 1 1 1 1 1 lattice A partially ordered set in which all finite subsets have a least upper bound and greatest lower bound. This definition has been standard at least since the 1930s and probably since Dedekind worked on lattice theory in the 19th century; though he may not have used that name. See also complete lattice, domain theory. (1999-12-09) 1 1 1 1 1 LAU Langage a Assignation Unique. A single assignment language for the LAU dataflow machine, Toulouse. ["Pipelining, Parallelism and Asynchronism in the LAU System", J.C. Syre et al, Proc 1977 Intl Conf Parallel Proc, pp. 87-92]. 1 1 1 1 1 laundromat Synonym disk farm; see washing machine. [Jargon File] (1998-02-01) 1 1 1 1 1 LAURE A language for knowledge representation combining object-oriented features and logic programming. It has set operations, object-oriented exception handling and a polymorphic type system. ["An Object-Oriented Language for Advanced Applications", in Proc TOOLS 5, Santa Barbara 1991, P-H]. (1998-02-01) 1 1 1 1 1 LAVA A language for VLSI that deals with "sticks", i.e. wires represented as lines with thickness. ["A Target Language for Silicon Compilers", R.J. Matthews et al, IEEE COMPCON, 1982, pp. 349-353]. (1994-12-07) 1 1 1 1 1 law software law 1 1 1 1 1 LAWN wireless local area network 1 1 1 1 1 Lawrence Livermore Labs Lawrence Livermore National Laboratory 1 1 1 1 1 Lawrence Livermore National Laboratory (LLNL) A research organaisatin operated by the University of California under a contract with the US Department of Energy. LLNL was founded on 2 September 1952 at the site of an old World War II naval air station. The Lab employs researchers from many scientific and engineering disciplines. Some of its departments are the National Ignition Facility, the Human Genome Center, the ASCI Tera-Scale Computing partnership, the Computer Security Technology Center, and the Site 300 Experimental Test Facility. Other research areas are Astronomy and Astrophysics, Atmospheric Science, Automation and Robotics, Biology, Chemistry, Computing, Energy Research, Engineering, Environmental Science, Fusion, Geology and Geophysics, Health, Lasers and Optics, Materials Science, National Security, Physics, Sensors and Instrumentation, Space Science. LLNL also works with industry in research and licensing projects. At the end of fiscal year 1995, the lab had signed 1 1 1 1 1 LAX LAnguage eXample. A toy language used to illustrate compiler design. ["Compiler Construction", W.M. Waite et al, Springer 1984]. (1994-12-07) 1 1 1 1 1 layer protocol layer 1 1 1 1 1 layer 1 physical layer 1 1 1 1 1 layer 2 data link layer 1 1 1 1 1 layer 3 network layer 1 1 1 1 1 layer 4 transport layer 1 1 1 1 1 layer 5 session layer 1 1 1 1 1 layer 6 presentation layer 1 1 1 1 1 layer 7 application layer 1 1 1 1 1 Layer Two Tunneling Protocol (L2TP) An IETF standard protocol for creating Virtual Private Networks. L2TP is an open standard with mutlivendor interoperability and acceptance. Compare: PPTP. [Sponsored by Cisco Systems, Inc.?] (1998-09-24) 1 1 1 1 1 laziness lazy evaluation 1 1 1 1 1 lazy evaluation An evaluation strategy combining normal order evaluation with updating. Under normal order evaluation (outermost or call-by-name evaluation) an expression is evaluated only when its value is needed in order for the program to return (the next part of) its result. Updating means that if an expression's value is needed more than once (i.e. it is shared), the result of the first evaluation is remembered and subsequent requests for it will return the remembered value immediately without further evaluation. This is often implemented by graph reduction. An unevaluated expression is represented as a closure - a data structure containing all the information required to evaluate the expression. Lazy evaluation is one evaluation strategy used to implement non-strict functions. Function arguments may be infinite data structures (especially lists) of values, the components of which are evaluated as needed. 1 1 1 1 1 lazy list A list which is built using a non-strict constructor. Any head or tail of the list may be an unevaluated closure. Also known as streams since they may be used to carry a sequence of values from the output of one function to an input of another. See also Lazy evaluation. 1 1 1 1 1 Lazy SML Lazy Standard ML 1 1 1 1 1 lazy sml2c A lazy version sml2c. Portable, written in SML. Language extensions include first-class continuations, asynchronous signal handling. E-mail: <david.tarditi@cs.cmu.edu>. (ftp://dravido.soar.cs.cmu.edu/usr/nemo/sml2c). 1 1 1 1 1 Lazy Standard ML (LSML) A lazy varient of SML, allowing cyclic val definitions, by Prateek Mishra <mishra@sbcs.sunysb.edu>. Latest version: 0.43-1, as of 1993-11-15. Not to be confused with LML. (ftp://sbcs.sunysb.edu/pub/lsml). (1999-08-30) 1 1 1 1 1 lb The country code for Lebanon. (1999-01-27) 1 1 1 1 1 LBA Logical Block Addressing 1 1 1 1 1 LBE Language-Based Editor 1 1 1 1 1 LBL Lawrence Berkeley Laboratory, Berkeley, CA, USA. 1 1 1 1 1 LBX Low Bandwidth X. 1 1 1 1 1 lc The country code for Saint Lucia. (1999-01-27) 1 1 1 1 1 LCC Language for Conversational Computing. Written at CMU in the 1960's. Similar to JOSS, with declarations, pointers and block structure from ALGOL 60. Implemented for IBM 360/IBM 370 under TSS. ["LCC Reference Manual", H.R. Van Zoeren, CMU 196]9. 1 1 1 1 1 lcc A hand-coded, retargetable compiler for ANSI C written by Dave Hanson <drh@cs.princeton.edu>. lcc's parser is faster than yacc and the code it generates is as good as GCC. Version 1.8 includes a compiler, test suite and documentation. lcc has been ported to Vax, commercial backends for MIPS, SPARC, 68000 are cheap for universities. Chop is a code generator for use with lcc. (http://cs.princeton.edu/software/lcc/). E-mail: <lcc-requests@princeton.edu>. ["A Retargetable C Compiler: Design and Implementation", Addison-Wesley, 1995, ISBN 0-8053-1670-1]. (1998-03-20) 1 1 1 1 1 LCD liquid crystal display 1 1 1 1 1 LCF Logic for Computable Functions 1 1 1 1 1 LCL 1. The Larch interface language for ANSI standard C. [J.V. Guttag et al, TR 74, DEC SRC, Palo Alto CA, 1991]. 2. Liga Control Language. Controls the attribute evaluator generator LIGA, part of the Eli compiler-compiler. ["LCL: Liga Control Language", U. Kastens <uwe@uni-paderborn.de>, U Paderborn]. (1995-01-23) 1 1 1 1 1 lclint A lint-like ANSI C source checker from MIT. If formal specifications are supplied (in a separate file), lclint can do more powerful checking to detect inconsistencies between specifications and code. Adding specifications enables further checking, types can be defined as abstract and lclint can detect inconsistent use of global variables; undocumented modification of client-visible state; inconsistent use of an uninitialised formal parameter; or failure to initialise an actual parameter. (http://larch-www.lcs.mit.edu:8001/larch/lclint.html). (1995-05-11) 1 1 1 1 1 LCP Link Control Protocol 1 1 1 1 1 LCS Language for Communicating Systems 1 1 1 1 1 ld 1. <programming, tool> (Load) Unix's linker. 2. <mathematics> logarithmus dualis. (1999-03-19) 1 1 1 1 1 LDAP Lightweight Directory Access Protocol 1 1 1 1 1 LDB /l*'d*b/ [PDP-10 instruction] To extract from the middle. LDB me a slice of cake, please. This usage has been kept alive by Common LISP's function of the same name. Considered silly. See also DPB. [Jargon File] 1 1 1 1 1 LDL ["LDL: A Logic-Based Data-Language", S. Tsur et al, Proc VLDB 1986, Kyoto Japan, Aug 1986, pp.33-41]. 1 1 1 1 1 LDL1 Successor of LDL. "Sets and Negation in a Logic Database Language", C. Beeri et al, in Proc 6th Ann ACM Symp Princs Database Sys (1987), pp.21- 37. 1 1 1 1 1 LDP Linux Documentation Project 1 1 1 1 1 LDT Logic Design Translator. Computer system design analysis. [Sammet 1969, p. 621]. (1994-12-01) 1 1 1 1 1 LE/1 Langage External. ["An Evaluation of the LE/1 Network Command Language Designed for the SOC Network", J. du Masle, in Command Languages, C. Unger ed, N-H 1973]. (1994-12-01) 1 1 1 1 1 leading /ledding/ The spacing between lines of text. This is defined when a font is designed but can often be altered in order to change the appearance of the text or for special effects. It is measured in points and is normally 120% of the height of the text. See also kerning, tracking. (1996-06-07) 1 1 1 1 1 LEAF 1. LISP Extended Algebraic Facility. 2. "LEAF: A Language which Integrates Logic, Equations and Functions", R. Barbuti et al in Logic Programming, Functions Relations and Equations, D. DeGroot et al eds, P-H 1986, pp.201-238. 1 1 1 1 1 leaf (Or "terminal node") In a tree, a node which has no daughter. (1998-11-14) 1 1 1 1 1 Leaf Distribution Limited A UK connectivity software supplier which also provides SERVELAN, a country-wide Internet access service. E-mail: <sales@leaf.co.uk>. Address: 7 Elmwood, Chineham Business Park, Crockford Lane, BASINGSTOKE RG24 0WG. Telephone: +44 (1256) 707 777. Fax: +44 (1256) 707 555. (1995-01-04) 1 1 1 1 1 leaf site A machine that merely originates and reads Usenet news or mail, and does not relay any third-party traffic. Often uttered in a critical tone; when the ratio of leaf sites to backbone, rib, and other relay sites gets too high, the network tends to develop bottlenecks. Compare backbone site, rib site. [Jargon File] 1 1 1 1 1 League for Programming Freedom (LPF) A grass-roots organisation of professors, students, businessmen, programmers and users dedicated to bringing back the freedom to write programs. Once programmers were allowed to write programs using all the techniques they knew, and providing whatever features they felt were useful. Monopolies, software patents and interface copyrights have taken away freedom of expression and the ability to do a good job. Look and feel lawsuits attempt to monopolise well-known command languages; some have succeeded. Copyrights on command languages enforce gratuitous incompatibility, close opportunities for competition and stifle incremental improvements. Software patents are even more dangerous; they make every design decision in the development of a program carry a risk of a lawsuit, with draconian pre-trial seizure. It is difficult and expensive to find out whether the techniques you 1 1 1 1 1 leak With a qualifier, one of a class of resource-management bugs that occur when resources are not freed properly after operations on them are finished, so they effectively disappear (leak out). This leads to eventual exhaustion as new allocation requests come in. One might refer to, say, a "window handle leak" in a window system. See memory leak, fd leak. [Jargon File] (1995-04-18) 1 1 1 1 1 leaky heap memory leak 1 1 1 1 1 Lean An experimental language from the University of Nijmegen and University of East Anglia, based on graph rewriting and useful as an intermediate language. Lean is descended from Dactl0. Clean is a subset of Lean. ["Towards an Intermediate Language Based on Graph Rewriting", H.P. Barendregt et al in PARLE: Parallel Architectures and Languages Europe, G. Goos ed, LNCS 259, Springer 1987, pp.159-175]. (1995-01-25) 1 1 1 1 1 LEAP Language for the Expression of Associative Procedures. ALGOL-based formalism for sets and associative retrieval, for TX-2. Became part of SAIL. An ALGOL-based Associative Language, J.A. Feldman et al, CACM 12(8):439-449 (Aug 1969). 1 1 1 1 1 leapfrog attack Use of userid and password information obtained illicitly from one host (e.g. downloading a file of account IDs and passwords, tapping TELNET, etc.) to compromise another host. Also, the act of TELNETting through one or more hosts in order to confuse a trace (a standard cracker procedure). [Jargon File] 1 1 1 1 1 leap second Coordinated Universal Time 1 1 1 1 1 learning curve A graph showing some measure of the cost of performing some action against the number of times it has been performed. The term probably entered engineering via the aircraft industry in the 1930s, where it was used to describe plots showing the cost of making some particular design of aeroplane against the number of units made. The term is also used in psychology to mean a graph showing some measure of something learned against the number of trials. The psychology graphs normally slope upward whereas the manufacturing ones normally slope downward but they are both usually steep to start with and then level out. Marketroids often misuse the term to mean the amount of time it takes to learn to use something ("reduce the learning curve") or the ease of learning it ("easy learning curve"). The phrase "steep learning curve" is sometimes used incorrectly to mean "hard to learn" whereas of course it implies rapid learning. 1 1 1 1 1 leased line A private telephone circuit permanently connecting two points, normally provided on a lease by a local PTT. (1998-03-24) 1 1 1 1 1 least fixed point A function f may have many fixed points (x such that f x = x). For example, any value is a fixed point of the identity function, (\ x . x). If f is recursive, we can represent it as f = fix F where F is some higher-order function and fix F = F (fix F). The standard denotational semantics of f is then given by the least fixed point of F. This is the least upper bound of the infinite sequence (the ascending Kleene chain) obtained by repeatedly applying F to the totally undefined value, bottom. I.e. fix F = LUB bottom, F bottom, F (F bottom), .... The least fixed point is guaranteed to exist for a 1 1 1 1 1 least recently used (operating systems) (LRU) A rule used in a paging system which selects a page to be paged out if it has been used (read or written) less recently than any other page. The same rule may also be used in a cache to select which cache entry to flush. This rule is based on temporal locality - the observation that, in general, the page (or cache entry) which has not been accessed for longest is least likely to be accessed in the near future. (1995-02-15) 1 1 1 1 1 least significant bit (LSB) Bit zero, the bit of a binary number giving the number of ones, the last or rightmost bit when the number is written in the usual way. (1995-07-13) 1 1 1 1 1 least upper bound (lub or "join", "supremum") The least upper bound of two elements a and b is an upper bound c such that a <= c and b <= c and if there is any other upper bound c' then c <= c'. The least upper bound of a set S is the smallest b such that for all s in S, s <= b. The lub of mutually comparable elements is their maximum but in the presence of incomparable elements, if the lub exists, it will be some other element greater than all of them. Lub is the dual to greatest lower bound. (In LaTeX, "<=" is written as \sqsubseteq, the lub of two elements a and b is written a \sqcup b, and the lub of set S is written as \bigsqcup S). (1995-02-03) 1 1 1 1 1 leaves leaf 1 1 1 1 1 LEC Local Exchange Carrier 1 1 1 1 1 LECOM Version of COMIT on GE 225 ca. 1966. Sammet 1969, p.419. 1 1 1 1 1 LED Light-Emitting Diode. 1 1 1 1 1 LEDA Library of Efficient Data types and Algorithms 1 1 1 1 1 Leda A multi-paradigm language supporting imperative programming, declarative programming, procedural programming, functional programming, logic programming and object-oriented programming developed by Tim Budd <budd@cs.orst.edu> at Oregon State University in 1990-1993. ["Blending Imperative and Relational Programming", Tim Budd, IEEE Software 8(1):58-65 (Jan 1991)]. Forthcoming book. (ftp://cs.orst.edu/pub/budd/leda/). (2007-10-02) 1 1 1 1 1 LED page printer LED printer 1 1 1 1 1 LED printer (Or "LED page printer") A printer which is similar in operation to a laser printer, but where an array of LEDs is used in place of the laser. (1996-12-08) 1 1 1 1 1 leech Someone who downloads files but provides nothing for others to download. The term is common on BitTorrent, which relies on having multiple sources for files to improve download speed. (2007-03-27) 1 1 1 1 1 leet elite 1 1 1 1 1 left arrow The graphic which the 1963 version of ASCII had in place of the underscore character, ASCII 95. (1995-03-06) 1 1 1 1 1 left brace "". ASCII character 123. Common names: open brace; left brace; left squiggly; left squiggly bracket/brace; left curly bracket/brace; ITU-T: opening brace. Rare: brace ("" = unbrace); curly ("" = uncurly); leftit ("" = rytit); left squirrelly; INTERCAL: embrace ("" = bracelet). Paired with right brace (""). (1995-03-16) 1 1 1 1 1 left bracket "[". ASCII character 91. Common: left square bracket; ITU-T: opening bracket; bracket. Rare: square; INTERCAL: U turn. Paired with right bracket ("]"). (1995-03-16) 1 1 1 1 1 left join outer join 1 1 1 1 1 left outer join outer join 1 1 1 1 1 left parenthesis "(". ASCII character 40. Common names: left paren; left parenthesis; left; open; paren (")" = thesis); open paren; open parenthesis; left parenthesis; left banana. Rare: so (")" = already); lparen; ITU-T: opening parenthesis; open round bracket, left round bracket, INTERCAL: wax (")" = wane); parenthisey (")" = unparenthisey); left ear. Paired with right parenthesis (")"). (1995-03-06) 1 1 1 1 1 LeFun Logic, Equations and Functions. An integration of logic programming and functional programming by H. Ait-Kaci et al of MCC, Austin TX. ["LeFun: Logic, Equations and Functions", H. Ait-Kaci et al, Proc 1987 Symp on Logic Programming, San Francisco]. (1994-10-21) 1 1 1 1 1 legacy legacy system 1 1 1 1 1 legacy code legacy system 1 1 1 1 1 legacy software legacy system 1 1 1 1 1 legacy system A computer system or application program which continues to be used because of the cost of replacing or redesigning it and often despite its poor competitiveness and compatibility with modern equivalents. The implication is that the system is large, monolithic and difficult to modify. If legacy software only runs on antiquated hardware the cost of maintaining this may eventually outweigh the cost of replacing both the software and hardware unless some form of emulation or backward compatibility allows the software to run on new hardware. (1998-08-09) 1 1 1 1 1 legal Loosely used to mean "in accordance with all the relevant rules", especially in connection with some set of constraints defined by software. "The older =+ alternate for += is no longer legal syntax in ANSI C." "This parser processes each line of legal input the moment it sees the trailing linefeed." Hackers often model their work as a sort of game played with the environment in which the objective is to maneuver through the thicket of "natural laws" to achieve a desired objective. Their use of "legal" is flavoured as much by this game-playing sense as by the more conventional one having to do with courts and lawyers. Compare language lawyer, legalese. [Jargon File] 1 1 1 1 1 legalese Dense, pedantic verbiage in a language description, product specification, or interface standard; text that seems designed to obfuscate and requires a language lawyer to parse it. Though hackers are not afraid of high information density and complexity in language (indeed, they rather enjoy both), they share a deep and abiding loathing for legalese; they associate it with deception, suits, and situations in which hackers generally get the short end of the stick. 1 1 1 1 1 LEGOL Application of MP/3 to the Design and Implementation of LEGOL, A Legally Oriented Language, S.H. Mandil et al, Intl Symp Programming, Paris 1974. 1 1 1 1 1 Le-Lisp Jerome Chailloux and Emmanuel St James, INRIA, France. A LISP dialect close to Common Lisp, lexically scoped, with a CLOS-like object system. Uses both packages and modules. le-lisp: A Portable and Efficient Lisp System, J. Chailloux et al, Proc 1984 ACM Symp on Lisp and Functional Programming, ACM. Version v.16, available from ILOG, France. 1 1 1 1 1 lemma A result already proved, which is needed in the proof of some further result. (1995-03-25) 1 1 1 1 1 Lempel-Ziv compression Substitutional compression schemes proposed by Jakob Ziv and Abraham Lempel in 1977 and 1978. There are two main schemes, LZ77 and LZ78. Lempel-Ziv Welch compression is a variant of LZ78. 1 1 1 1 1 Lempel-Ziv Welch compression (LZW) The algorithm used by the Unix compress command to reduce the size of files, e.g. for archival or transmission. LZW was designed by Terry Welch in 1984 for implementation in hardware for high-performance disk controllers. It is a variant of LZ78, one of the two Lempel-Ziv compression schemes. The LZW algorithm relies on reoccurrence of byte sequences (strings) in its input. It maintains a table mapping input strings to their associated output codes. The table initially contains mappings for all possible strings of length one. Input is taken one byte at a time to find the longest initial string present in the table. The code for that string is output and then the string is extended with one more input byte, b. A new entry is added to the table mapping the extended string to the next unused code (obtained by incrementing a counter). The process repeats, starting from byte b. The number of bits in an output code, and hence the 1 1 1 1 1 Lenat, Doug Doug Lenat 1 1 1 1 1 lenient evaluation An evaluation strategy, described in [Traub, FPCA 89], under which all redexes are evaluated in parallel except inside the arms of conditionals and inside lambda abstractions. Lenient evaluation is an example of an eager evaluation strategy. (2004-01-22) 1 1 1 1 1 LEO Low Earth Orbit 1 1 1 1 1 Leo 1. <language> A general-purpose systems language, syntactically like Pascal and Y, semantically like C. ["The Leo Programming Language", G. Townsend, CS TR 84-7, U Arizona 1984]. (1996-02-06) 2. <application> A general data management environment which can show user-created relationships among any kind data. It can also be used as an outlining editor as it embeds the noweb and CWEB markup languages in an outline context. Leo is written in pure Python using Tk/tcl and so runs on Windows, Linux and MacOS X. It isdistributed under the Python License. (2006-07-12) 1 1 1 1 1 LER 1. <networking> Label Edge Router. 2. <electronics, humour> Light-Emitting Resistor. [Jargon File] (1999-06-30) 1 1 1 1 1 LERP /lerp/ vi., Quasi-acronym for Linear Interpolation, used as a verb or noun for the operation. "Bresenham's algorithm lerps incrementally between the two endpoints of the line." [Jargon File] 1 1 1 1 1 less than "<" ASCII character 60. Common names: ITU-T: less than; bra (">" = ket); left angle; left angle bracket; left broket. Rare: from; read from; suck (">" = blow); comes-from; in; crunch (all from Unix); INTERCAL: angle. See also greater than. (1995-03-20) 1 1 1 1 1 LessTif The Hungry Programmers' version of OSF/Motif. It will be source code compatible with Motif, meaning that the same source will compile with both libraries and work exactly the same. All the programming is being done with no reference to the header files for the motif widgets, so that LessTif can be distributed as free software. (http://hungry.com/products/lesstif). (1995-03-20) 1 1 1 1 1 let floating A program transformation used in functional programming to implement full laziness. E.g. the function f x = x + sqrt 4 can be expressed as f x = let t = sqrt 4 in x + t but note that t does not depend on the argument x so we can automatically transform this to t = sqrt 4 f x = x + t Making t into a global constant which need only be evaluated at most once, rather than every time f is called. The general idea is to float each subexpression as far out (toward the top level) as possible to maximise sharing. 1 1 1 1 1 letterbomb 1. An e-mail message containing live data intended to do nefarious things to the recipient's computer or terminal. It is possible, for example, to send letterbombs that will lock up some specific kinds of terminals when they are viewed, so thoroughly that the user must turn the terminal off to unwedge it. Under Unix, a letterbomb can also try to get part of its contents interpreted as a shell command. The results of this could range from silly to tragic. See also Trojan horse; compare nastygram, talk bomb. 2. Loosely, a mailbomb. [Jargon File] (1998-01-16) 1 1 1 1 1 level 1 cache primary cache 1 1 1 1 1 level 2 cache secondary cache 1 1 1 1 1 LEVEL5 OBJECT From Information Builders. [What is it?] 1 1 1 1 1 level one cache primary cache 1 1 1 1 1 level-sensitive scan design (circuit design) (LSSD) A kind of scan design which uses separate system and scan clocks to distinguish between normal and test mode. Latches are used in pairs, each has a normal data input, data output and clock for system operation. For test operation, the two latches form a master/slave pair with one scan input, one scan output and non-overlapping scan clocks A and B which are held low during system operation but cause the scan data to be latched when pulsed high during scan. ____ | | Sin ----|S | A ------|> | | Q|---+--------------- Q1 1 1 1 1 1 level two cache secondary cache 1 1 1 1 1 Lex 1. <tool> A lexical analyser generator for Unix and its input language. There is a GNU version called flex and a version written in, and outputting, SML/NJ called ML-lex. A version, by David Poole at Montana has been retargeted to Turbo Pascal, (ftp://iecc.com/pub/file/lyprg.zip). ["Lex - A Lexical Analyzer Generator", M.E. Lesk, CS TR 39, Bell Labs, Oct 1975]. 2. <language, specification> The lexical specification language for COPS. ["Metalanguages of the Compiler Production System COPS", J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed W. Henhapl, Tech Hochs Darmstadt 1978, pp.122-159]. (2000-11-15) 1 1 1 1 1 lexeme A minimal lexical unit of a language. Lexical analysis converts strings in a language into a list of lexemes. For a programming language these word-like pieces would include keywords, identifiers, literals and punctutation. The lexemes are then passed to the parser for syntactic analysis. (1996-04-06) 1 1 1 1 1 lexer lexical analyser 1 1 1 1 1 lexical analyser (Or "scanner") The initial input stage of a language processor (e.g. a compiler), the part that performs lexical analysis. (1995-04-05) 1 1 1 1 1 lexical analysis (Or "linear analysis", "scanning") The first stage of processing a language. The stream of characters making up the source program or other input is read one at a time and grouped into lexemes (or "tokens") - word-like pieces such as keywords, identifiers, literals and punctutation. The lexemes are then passed to the parser. ["Compilers - Principles, Techniques and Tools", by Alfred V. Aho, Ravi Sethi and Jeffrey D. Ullman, pp. 4-5] (1995-04-05) 1 1 1 1 1 lexical scope (Or "static scope") When the scope of an identifier is fixed at compile time to some region in the source code containing the identifier's declaration. This means that an identifier is only accessible within that region (including procedures declared within it). This contrasts with dynamic scope where the scope depends on the nesting of procedure and function calls at run time. Statically scoped languages differ as to whether the scope is limited to the smallest block (including begin/end blocks) containing the identifier's declaration (e.g. C, Perl) or to whole function and procedure bodies (e.g. ECMAScript), or some larger unit of code (e.g. ?). The former is known as static nested scope. (2005-07-28) 1 1 1 1 1 lexical scoping lexical scope 1 1 1 1 1 lexiphage /lek'si-fayj"/ A notorious word chomper, implemented and named by John Doty in late 1972 on and HP calculator and later on ITS. The lexiphage program would draw on a selected victim's bitmapped terminal the words THE BAG in ornate letters, followed a pair of jaws biting pieces of it off. http://lexiphage.com/). [Jargon File] (2002-06-12) 1 1 1 1 1 LF Line Feed 1 1 1 1 1 LFIB Label Forwarding Information Base 1 1 1 1 1 LG Simple language for analytic geometry, with graphic output. LG: A Language for Analytic Geometry, J. Reymond, CACM 12(8) (Aug 1969). 1 1 1 1 1 LGDF Large-Grain DataFlow. ["A Large-grain Data Flow Scheduler for Parallel Processing on Cyberplus", R.G. Babb et al, Proc 1986 Intl Conf on Parallel Proc, Aug 1986]. (2000-07-07) 1 1 1 1 1 LGEN A logic language for VLSI implementation by S.C. Johnson of Bell Labs. [S.C. Johnson, "Code Generation for Silicon", Proc 10th POPL, 1983]. (1995-02-15) 1 1 1 1 1 LGN Linear Graph Notation 1 1 1 1 1 lha 1. <filename extension> The filename extension for a file produced by the shareware compression and archive software LHARC. 2. <tool> A compression program for MS-DOS. Output files have the extension ".lzh". [Does it use LZH compression?] (2002-07-28) 1 1 1 1 1 LHARC A compression program developed by Rahul Dhesi. LHARC was later replaced with LHA, which produces files with extension ".lzh". (2002-07-28) 1 1 1 1 1 lhs The filename extension for literate Haskell source files. (1995-02-15) 1 1 1 1 1 li The country code for Liechtenstein. (1999-01-27) 1 1 1 1 1 Liana A C-like, interpretive, object-oriented programming language, class library, and integrated development environment designed specifically for development of application programs for Microsoft Windows and Windows NT. Designed by Jack Krupansky <Jack@BaseTechnology.com> of Base Technology, Liana was first released as a commercial product in August 1991. The language is designed to be as easy to use as BASIC, as concise as C, and as flexible as Smalltalk. The OOP syntax of C++ was chosen over the less familiar syntax of Smalltalk and Objective-C to appeal to C programmers and in recognition of C++ being the leading OOP language. The syntax is a simplified subset of C/C++. The semantics are also a simplified subset of C/C++, but extended to achieve the flexibility of Smalltalk. Liana is a typeless language (like Lisp, Snobol and Smalltalk), which means that the datatypes of variables, 1 1 1 1 1 Liar MIT Scheme 1 1 1 1 1 liar paradox A sentence which asserts its own falsity, e.g. "This sentence is false" or "I am lying". These paradoxical assertions are meaningless in the sense that there is nothing in the world which could serve to either support or refute them. Philosophers, of course, have a great deal more to say on the subject. ["The Liar: an Essay on Truth and Circularity", Jon Barwise and John Etchemendy, Oxford University Press (1987). ISBN 0-19-505944-1 (PBK), Library of Congress BC199.P2B37]. (1995-02-22) 1 1 1 1 1 lib Library. In Unix, the directories /lib and /usr/lib traditionally contain files with filename extension ".lib" that are special archives containing modules of standard object code. In modern Unixes the same directories contain ".so" (shared object) files, which are similar except that the object code they contain is designed to be loaded once and shared by all application code that needs it, thus saving memory. (2008-11-25) 1 1 1 1 1 libg++ The run-time library for the GNU C++ compiler, g++. Version: 2.5.1 is a superset of ANSI and POSIX.1. libg++ is no longer maintained, use libstd++ instead if possible. Available by FTP from a GNU archive site. Bug reports: <bug-lib-g++@gnu.org>. (2000-04-24) 1 1 1 1 1 library A collection of subroutines and functions stored in one or more files, usually in compiled form, for linking with other programs. Libraries are one of the earliest forms of organised code reuse. They are often supplied by the operating system or software development environment developer to be used in many different programs. The routines in a library may be general purpose or designed for some specific function such as three dimensional animated graphics. Libraries are linked with the user's program to form a complete executable. The linking may be static linking or, in some systems, dynamic linking. (1998-11-21) 1 1 1 1 1 Library of Efficient Data types and Algorithms (LEDA) A class library for C++ of efficient data types (e.g. graph classes) and algorithms by Stefan N"aher <stefan@mpi-sb.mpg.de> of the University of Saarbruecken. Version 3.0 includes both template and non-template versions. (ftp://ftp.mpi-sb.mpg.de/pub/LEDA). (1996-04-15) 1 1 1 1 1 librery It's spelled "library". (1996-12-13) 1 1 1 1 1 LIDO An input language for the attribute evaluator generator LIGA (a successor of GAG and a subsystem of the Eli compiler-compiler). LIDO is derived from GAG's input language ALADIN. ["LIDO: A Specification Language for Attribute Grammars", U. Kastens <uwe@uni-paderborn.de>, Fab Math-Inf, U Paderborn (Oct 1989)]. (1994-10-20) 1 1 1 1 1 LiE A symbolic mathematics package aimed at Lie groups. ["LiE, a Package for Lie Group Computations", M.A.A. van Leeuwen et al, in Computer Algebra Nederland, 1992 (ISBN 90-741160-02-7)]. (1994-10-20) 1 1 1 1 1 LIF 1. <hardware> Low Insertion Force. 2. <file format> Logical Interchange Format. (2003-10-15) 1 1 1 1 1 life 1. <simulation> Conway's Game of Life. 2. <jargon> The opposite of Usenet/the Internet/video games/whatever the speaker considers a waste of time. As in Get a life! 3. <language> Logic of Inheritance, Functions and Equations (LIFE) An object-oriented, functional, constraint-based language by Hassan Ait-Kacy <hak@prl.dec.com> et al of MCC, Austin TX, 1987. LIFE integrates ideas from LOGIN and LeFun. See also Wild_LIFE. ["Is There a Meaning to LIFE?", H. Ait-Kacy et al, Intl Conf on Logic Prog, 1991]. (2015-05-04) 1 1 1 1 1 life-cycle software life-cycle 1 1 1 1 1 LIFIA Laboratoire d'Informatique Fondamentale et d'Intelligence Artificielle. 1 1 1 1 1 LIFO stack 1 1 1 1 1 lifted domain In domain theory, a domain with a new bottom element added. Given a domain D, the lifted domain, lift D contains an element lift d corresponding to each element d in D with the same ordering as in D and a new element bottom which is less than every other element in lift D. In functional languages, a lifted domain can be used to model a constructed type, e.g. the type data LiftedInt = K Int contains the values K minint .. K maxint and K bottom, corresponding to the values in Int, and a new value bottom. This denotes the fact that when computing a value v = (K n) the computation of either n or v may fail to terminate yielding the values (K bottom) or bottom respectively. (In LaTeX, a lifted domain or element is indicated by a subscript \perp). See also tuple. 1 1 1 1 1 LIGHT LIfecycle Global HyperText. A project in the CERN ECP/TP group whereby documents resulting from the software life cycle are available as hypertext. (1995-02-03) 1 1 1 1 1 light client thin client 1 1 1 1 1 light-emitting diode (LED) a type of diode that emits light when current passes through it. Depending on the material used the colour can be visible or infrared. LEDs have many uses, visible LEDs are used as indicator lights on all sorts of electronic devices and in moving-message panels, while infrared LEDs are the heart of remote control devices. See also smoke-emitting diode. (1996-01-05) 1 1 1 1 1 light-emitting resistor (LER, from "light-emitting diode") A resistor in the final stages of burning up. (Though intended as purely humorous, the term could sensibly describe the filament of a common incandescent electric light bulb). See also SED. (1996-02-06) 1 1 1 1 1 light pen An early pointing device which the user pointed at a raster-scanned display screen. A photocell in the pen detected the flying spot of the raster scan. The position of the spot at that instant, obtained from the scanning electronics, was made available to software as (x, y) co-ordinates. (2003-12-02) 1 1 1 1 1 light pipe optical fibre 1 1 1 1 1 light-weight Opposite of heavy-weight; usually found in combining forms such as "light-weight process". [Jargon File] (1996-02-22) 1 1 1 1 1 Lightweight Directory Access Protocol (LDAP) A protocol for accessing on-line directory services. LDAP was defined by the IETF in order to encourage adoption of X.500 directories. The Directory Access Protocol (DAP) was seen as too complex for simple internet clients to use. LDAP defines a relatively simple protocol for updating and searching directories running over TCP/IP. LDAP is gaining support from vendors such as Netscape, Novell, Sun, HP, IBM/Lotus, SGI, AT&T, and Banyan An LDAP directory entry is a collection of attributes with a name, called a distinguished name (DN). The DN refers to the entry unambiguously. Each of the entry's attributes has a type and one or more values. The types are typically mnemonic strings, like "cn" for common name, or "mail" for e-mail address. The values depend on the type. For example, a mail attribute might contain the value 1 1 1 1 1 light-weight process (LWP) A single-threaded sub-process which, unlike a thread, has its own process identifier and may also differ in its inheritance and controlling features. Several operating systems, e.g. SunOS 5.x, provide system calls for creating and controlling LWPs. (1996-02-22) 1 1 1 1 1 like kicking dead whales down the beach kicking dead whales down the beach 1 1 1 1 1 like nailing jelly to a tree Used to describe a task thought to be impossible, especially one in which the difficulty arises from poor specification or inherent slipperiness in the problem domain. "Trying to display the "prettiest" arrangement of nodes and arcs that diagrams a given graph is like nailing jelly to a tree, because nobody's sure what "prettiest" means algorithmically." [Jargon File] (1997-12-23) 1 1 1 1 1 like this You weren't supposed to follow that link, it was just an example of what a link looks like. 1 1 1 1 1 Lila Patrick Salle'<salle@geocub.greco-prog.fr>. A small assembly-like language used for implementation of Actor languages. [Plasma perhaps?]. 1 1 1 1 1 Lilith The workstation for which Modula-2 was developed as the system language. [Details?] (1995-10-25) 1 1 1 1 1 LILLIAC IV A supercomputer designed in the late 1960s at the University of Illinois which had 64 separate CPUs all supervised by a common control unit and all capable of operating simultaneously. (1996-11-25) 1 1 1 1 1 lilo 1. <operating system> Linux Loader. 2. first-in first-out. (2001-03-26) 1 1 1 1 1 Lily (LIsp LibrarY) A C++ class library by Roger Sheldon <sheldon@kong.gsfc.nasa.gov> which gives C++ programmers the capability to write Lisp-style code. Lily's garbage collection mechanism is not sufficient for commercial use however and the documentation is incomplete. It is distributed under the GNU Library General Public License. Version: 0.1. (ftp://sunsite.unc.edu/uploads/lily-0.1.tar.gz). (1993-11-08) 1 1 1 1 1 LIMDEP A linear programming language used by economists. 1 1 1 1 1 LIM EMS Expanded Memory Specification 1 1 1 1 1 LIMP ["Messages in Typed Languages", J. Hunt et al, SIGPLAN Notices 14(1):27-45 (Jan 1979)]. 1 1 1 1 1 Linc 1. <language> A Burroughs/Unisys 4GL designed in New Zealand. 2. Laboratory Instrument Computer. (1999-03-29) 1 1 1 1 1 Lincoln Reckoner An interactive mathematics program including matrix operations, written about 1965. It ran on the TX-2. ["The Lincoln Reckonere: An Operation-Oriented On-line Facility with Distributed Control", A.N. Stowe et al, Proc FJCC 29 (1966)]. [Sammet 1969, pp. 245-247]. 1 1 1 1 1 LINCtape A formatted, block-oriented, high-reliability, random access tape system used on the Laboratory Instrument Computer. The tape was 3/4" wide. The funny DECtape is actually a variant of the original LINCtape. According to Wesley Clark, DEC tried to "improve" the LINCtape system, which mechanically, was wonderfully simple and elegant. The DEC version had pressure fingers and tape guides to force alignment as well as huge DC servo motors and complex control circuitry. These literally shredded the tape to bits if not carefully adjusted, and required frequent cleaning to remove all the shedded tape oxide. That was amazing, because the tape had a micro-thin plastic layer OVER the oxide to protect it. What happened was that all the forced alignment stuff caused shredding at the edge. An independent company, Computer Operations[?], built LINCtape drives for use in nuclear submarines. This was based on the 1 1 1 1 1 Linda A "coordination language" from Yale, providing a model for concurrency with communication via a shared tuple space. Linda is usually implemented as a subroutine library for a specific base language, as in C-Linda, Fortran-Linda, LindaLISP and Prolog-Linda. It is available from Scientific Computing Associates, Inc. [What is?] (http://cs.yale.edu/HTML/YALE/CS/Linda/linda.html). There is a Multi-BinProlog Linda implementation available by (ftp://clement.info.umoncton.ca/). ["Generative Communication in Linda", D. Gelernter <gelernter@cs.yale.edu>, ACM TOPLAS 7(1):80-112 (1985)]. ["Linda in Context", N. Carreiro et al, Yale U., CACM 32(4):444-458, Apr 1989]. See also Ease, Lucinda, Melinda. (2000-07-07) 1 1 1 1 1 LindaLISP Linda for Lisp. 1 1 1 1 1 line 1. <hardware> An electrical conductor. For distances larger than a breadbox, a single line may consist of two electrical conductors in twisted, parallel, or concentric arrangement used to transport one logical signal. By extension, a (usually physical) medium such as an optical fibre which carries a signal. (1995-09-29) 1 1 1 1 1 line 666 (Christian eschatological myth) The notional line of source at which a program fails for obscure reasons, implying either that *somebody* is out to get it (when you are the programmer), or that it richly deserves to be got (when you are not). E.g. "It works when I trace through it, but seems to crash on line 666 when I run it." "What happens is that whenever a large batch comes through, mmdf dies on the Line of the Beast. Probably some twit hard-coded a buffer size." [Jargon File] (1999-03-01) 1 1 1 1 1 linear address space A memory addressing scheme used in processors where the whole memory can be accessed using a single address that fits in a single register or instruction. This contrasts with a segmented memory architecture, such as that used on the Intel 8086, where an address is given by an offset from a base address held in one of the "segment registers". Linear addressing greatly simplifies programming at the assembly language level but requires more instruction word bits to be allocated for an address. (1995-02-16) 1 1 1 1 1 linear argument A function argument which is used exactly once by the function. If the argument is used at most once then it is safe to inline the function and replace the single occurrence of the formal parameter with the actual argument expression. If the argument was used more than once this transformation would duplicate the argument expression, causing it to be evaluated more than once. If the argument is sure to be used at least once then it is safe to evaluate it in advance (see strictness analysis) whereas if the argument was not used then this would waste work and might prevent the program from terminating. (1994-11-03) 1 1 1 1 1 linear assignment assignment problem 1 1 1 1 1 linear function A recursive function is linear if it is of the form f x = if p x then q x else h f x where h is a "linear functional" which means that (1) for all functions, a, b c and some function ht h (if a then b else c) = if ht a then h b else h c Function ht is known as the "predicate transformer" of h. (2) If for some x, h (\ y . bottom) x /= bottom then for all g, ht g x = True. I.e. if h g x terminates despite g x not terminating then ht g x doesn't depend on g. See also linear argument. 1 1 1 1 1 Linear Graph Notation (LGN) A linearised representation of TCOL trees. [B.W. Leverett et al, "An Overview of the Production Quality Compiler-Compiler Projects", TR CMU-CS-79-105, Carnegie Mellon 1979]. (1995-01-23) 1 1 1 1 1 linear logic A logic invented by Girard in 1987 that can be used in proofs related to resource usage. (http://brics.dk/LS/96/6/BRICS-LS-96-6/BRICS-LS-96-6.html). [Wadler, P., "Is there a use for linear logic", ACM/IFIP PEPM Conference, 1991]. [Summary?] (2003-05-02) 1 1 1 1 1 linear map (Or "linear transformation") A function from a vector space to a vector space which respects the additive and multiplicative structures of the two: that is, for any two vectors, u, v, in the source vector space and any scalar, k, in the field over which it is a vector space, a linear map f satisfies f(u+kv) = f(u) + kf(v). (1996-09-30) 1 1 1 1 1 linear programming A procedure for finding the maximum or minimum of a linear function where the arguments are subject to linear constraints. The simplex method is one well known algorithm. (1995-04-06) 1 1 1 1 1 linear space A vector space where all linear combinations of elements are also elements of the space. This is easy for spaces of numbers but not for a space of functions. Roughly, this is to say that multiplication by numbers, and addition of elements is defined in the space. (2000-03-10) 1 1 1 1 1 linear topology A linear topology on a left A-module M is a topology on M that is invariant under translations and admits a fundamental system of neighborhood of 0 that consists of submodules of M. If there is such a topology, M is said to be linearly topologized. If A is given a discrete topology, then M becomes a topological A-module with respect to a linear topology. [Wikipedia] (2014-06-30) 1 1 1 1 1 linear transformation linear map 1 1 1 1 1 linear type 1. <theory, programming> An attribute of values which are used exactly once: they are neither duplicated nor destroyed. Such values require no garbage collection, and can safely be updated in place, even if they form part of a data structure. Linear types are related to the linear logic of J.-Y Girard. They extend Schmidt's notion of single threading, provide an alternative to Hudak and Bloss' update analysis, and offer a practical complement to Lafont and Holmström's elegant linear languages. ['Use-Once' Variables and Linear Objects - Storage Management, Reflection and Multi-Threading, Henry Baker. (http://home.pipeline.com/~hbaker1/Use1Var.html)]. ["Linear types can change the world!", Philip Wadler, Programming Concepts and Methods, April 1990, eds. M. Broy, C. Jones, pub. North-Holland, IFIP TC2 Working Conference on Programming Concepts and Methods, Sea of Galilee, Israel]. (1995-03-03) 1 1 1 1 1 line conditioning The adjustment of electrical characteristics of, e.g., twisted pair telephone lines by insertion of components such as resistors, capacitors, transformers or (commonly) inductors. Lines intended for analogue voice signals usually have inductors inserted every few miles; such a line is said to be "loaded". The special purpose lines which have neither inductors nor the DC voltage which powers ordinary telephones are said to be dry, and are much better for data transmission. (1996-04-07) 1 1 1 1 1 line eater 1. A bug in some now-obsolete versions of the Usenet software that used to eat up to BUFSIZ bytes of the article text. The bug was triggered by having the text of the article start with a space or tab. This bug was quickly personified as a mythical creature called the "line eater", and postings often included a dummy line of "line eater food". Ironically, line eater "food" not beginning with a space or tab wasn't actually eaten, since the bug was avoided; but if there *was* a space or tab before it, then the line eater would eat the food *and* the beginning of the text it was supposed to be protecting. The practice of "sacrificing to the line eater" continued for some time after the bug had been nailed to the wall, and is still humorously referred to. The bug itself is still (in mid-1991) occasionally reported to be lurking in some mail-to-netnews gateways. 2. NSA line eater. (1996-04-09) 1 1 1 1 1 line editor An early kind of text editor suited to use on a teletype. The user enters editing commands which apply to the current line or some given range of lines. These include moving forward and backward through the buffer, inserting and deleting lines, substituting a string for a pattern match, and printing lines. Visual feedback is restricted to explicitly requesting the display of one or more lines, in contrast to a screen editor. ed is Unix's line editor. (1999-03-01) 1 1 1 1 1 line feed (LF, control-J, ASCII 10) The ASCII character meaning move the cursor down to the same column on the next line. Originally this would have been done by "feeding" paper through the printer. Unix uses line feed as its text line terminator (newline character). (1997-07-14) 1 1 1 1 1 line noise 1. Spurious characters due to electrical noise in a communications link, especially an EIA-232 serial connection. Line noise may be induced by poor connections, interference or crosstalk from other circuits, electrical storms, cosmic rays, or (notionally) birds crapping on the phone wires. 2. Any chunk of data in a file or elsewhere that looks like the results of electrical line noise. 3. Text that is theoretically a readable text or program source but employs syntax so bizarre that it looks like line noise. Yes, there are languages this ugly. The canonical example is TECO, whose input syntax is often said to be indistinguishable from line noise. Other non-WYSIWYG editors, such as Multics "qed" and Unix "ed", in the hands of a real hacker, also qualify easily, as do deliberately obfuscated languages such as INTERCAL. [Jargon File] 1 1 1 1 1 line printer A printer that prints one entire line at a time. Print quality is low compared with a laser printer. Line printers typically use sprocket feed and wide fanfold paper. Line printer speed is usually measured in lines per minute (lpm). 1200 lpm is a good rate for a line printer like a 3205 m5. 66 lines per page is typical, giving 18 pages per minute (ppm). This assumes all upper case, if a mixed case print train is used, throughput is halved. By comparison, a fast laser printer can output 100+ ppm (1999-01-13) 1 1 1 1 1 line probing A feature of some V.34 modems that will allow them to identify the capacity and quality of the phone line and adjust themselves to allow, for each individual connection, for maximum throughput using the highest possible data transmission rate. (1994-06-09) 1 1 1 1 1 lines of code (LOC) A common measure of the size or progress of a programming project. For example, one can describe a completed project as consisting of 100,000 LOC; or one can characterise a week's progress as 5000 LOC. Using LOC as a metric of progress encourages programmers to reinvent the wheel or split their code into lots of short lines. (2001-05-28) 1 1 1 1 1 lines per minute (lpm) A unit used to measure line printer throughput. (1999-01-13) 1 1 1 1 1 line starve (MIT, opposite of line feed) 1. To feed paper through a printer the wrong way by one line (most printers can't do this). On a display terminal, to move the cursor up to the previous line of the screen. "To print "X squared", you just output "X", line starve, "2", line feed." (The line starve causes the "2" to appear on the line above the "X", and the line feed gets back to the original line.) 2. A character (or character sequence) that causes a terminal to perform this action. ASCII 26, also called SUB or control-Z, was one common line-starve character in the days before microcomputers and the X3.64 terminal standard. Unlike "line feed", "line starve" is *not* standard ASCII terminology. Even among hackers it is considered silly. 3. (Proposed) A sequence such as \c (used in System V echo, as well as nroff and troff) that suppresses a newline or other character(s) that would normally be emitted. 1 1 1 1 1 Lingo An animation scripting language. [MacroMind Director V3.0 Interactivity Manual, MacroMind 1991]. 1 1 1 1 1 LINGOL LINguistics Oriented Language. Natural language processing. ["A Linguistics Oriented Programming Language", V.R. Pratt, Third Intl Joint Conf on AI, 1973]. 1 1 1 1 1 link 1. <file system> hard link or symbolic link. 2. <hypertext> hypertext link. (1997-10-22) 1 1 1 1 1 Link Access Procedure on the D channel (LAPD) (Q.921). An Integrated Services Digital Network data link layer protocol. 1 1 1 1 1 Link Access Protocol Balanced (LAPB) X.25 layer 2 (data link layer) protocol. [Details?] (1996-01-22) 1 1 1 1 1 Link Access Protocol for Modems (LAPM) The Automatic Repeat Request system used in the V.42 protocol. 1 1 1 1 1 linkage editor linker 1 1 1 1 1 Link Control Protocol A protocol used to automatically agree upon encapsulation format options, handle varying packet size limits, authenticate the identity of its peer on the link, determine when a link is functioning properly and when it is defunct, detect a looped-back link and other common misconfiguration errors, and terminate the link. [RFC 1570]. (1997-05-10) 1 1 1 1 1 link-dead Said of a MUD character who has frozen in place because of a dropped network connection. [Jargon File] (1995-01-24) 1 1 1 1 1 link editor linker 1 1 1 1 1 linked list A data structure in which each element contains a pointer to the next element, thus forming a linear list. A doubly linked list contains pointers to both the next and previous elements. (1995-03-28) 1 1 1 1 1 linker (link editor, linkage editor, link loader) A program that combines one or more files containing object code from separately compiled program modules into a single file containing loadable or executable code This process involves resolving references between the modules and fixing the relocation information used by the operating system kernel when loading the file into memory to run it. Under Unix, the linker is called "ld" and object files have filename extension .o (object), .so (shared object), or .lib (library), and the resulting executable is called a.out by default. (2001-10-13) 1 1 1 1 1 link farm A directory tree that contains mostly symbolic links to files in a master directory tree of files. Link farms save space when one is maintaining several nearly identical copies of the same source tree - for example, when the only difference is architecture-dependent object files. They also mean that changes to the master tree are instantly visible in the link farm. Good text editors provide the option to replace a link with a new version of the target file when saving thus allowing the farm to have its own versions of just those files that differ from the master tree. E.g. "Let's freeze the source and then rebuild the FROBOZZ-3 and FROBOZZ-4 link farms." Link farms may also be used to get around restrictions on the number of "-I" (include-file directory) arguments on older C preprocessors. However, they can also get completely out of hand, becoming the file system equivalent of spaghetti code. [Jargon File] 1 1 1 1 1 link loader linker 1 1 1 1 1 link rot The process by which links on a web page became unusable as the pages they point to change location or are removed. (1997-03-29) 1 1 1 1 1 links link 1 1 1 1 1 Link State Routing Protocol A routing protocol such as OSPF which permits routers to exchange information with one another about the reachability of other networks and the cost or metric to reach the other networks. The cost/metric is based on number of hops, link speeds, traffic congestion, and other factors as determined by the network designer. Link state routers use Dijkstra's algorithm to calculate shortest (lowest cost) paths, and normally update other routers with whom they are connected only when their own routing tables change. Link state routing is an improvement over distance-vector routing protocols such as RIP which normally use only a single metric (such as hop count) and which exchange all of their table information with all other routers on a regular schedule. Link state routing normally requires more processing but less transmission overhead. (2000-03-14) 1 1 1 1 1 LINPACK 1. A package of linear algebra routines. 2. The kernel benchmark developed from the "LINPACK" package of linear algebra routines. It was written by Jack Dongarra <dongarra@cs.utk.edu> in Fortran and is commonly used in that language but there is also a C version. Source Code by FTP: single precision Fortran (ftp://netlib.att.com/netlib/benchmark/linpacks.Z), double precision Fortran (ftp://netlib.att.com/netlib/benchmark/linpackd.Z), C (ftp://netlib.att.com:/netlib/benchmark/linpackc.Z). Results (http://performance.netlib.org/performance/html/linpack.data.col0.html). (1994-11-14) 1 1 1 1 1 lint A Unix C language processor which carries out more thorough checks on the code than is usual with C compilers. Lint is named after the bits of fluff it supposedly picks from programs. Judging by references on Usenet this term has become a shorthand for desk check at some non-Unix shops, even in languages other than C. Also used as delint. [Jargon File] (1994-11-14) 1 1 1 1 1 Linux ("Linus Unix") /li'nuks/ (but see below) An implementation of the Unix kernel originally written from scratch with no proprietary code. The kernel runs on Intel and Alpha hardware in the general release, with SPARC, PowerPC, MIPS, ARM, Amiga, Atari, and SGI in active development. The SPARC, PowerPC, ARM, PowerMAC - OSF, and 68k ports all support shells, X and networking. The Intel and SPARC versions have reliable symmetric multiprocessing. Work on the kernel is coordinated by Linus Torvalds, who holds the copyright on a large part of it. The rest of the copyright is held by a large number of other contributors (or their employers). Regardless of the copyright ownerships, the kernel as a whole is available under the GNU General Public License. The GNU project supports Linux as its kernel until the research Hurd kernel is completed. This kernel would be no use without application programs. 1 1 1 1 1 Linux Documentation Project (LDP) A team of volunteers developing documentation for the Linux operating system. The LDP aims to handle all of the issues of Linux documentation, ranging from on-line documentation to printed manuals, covering topics such as installing, using, and running Linux. The LDP has no central organisation; anyone can join in. (http://metalab.unc.edu/LDP/). (1999-06-10) 1 1 1 1 1 Linux Loader (LILO) A boot loader for Linux. LILO does not depend on a specific file system, it can boot Linux kernel images from floppy disks and hard disks and can even boot other operating systems. One of up to sixteen differernt images can be selected at boot time. Various parameters, such as the root device, can be set independently for each kernel. LILO can even be used as the master boot record. (2006-09-12) 1 1 1 1 1 Linux Network Administrators' Guide (NAG) A book on setting up and running Unix networks. NAG is freely available in electronic form. It was produced by Olaf Kirch, <okir@monad.swb.de> and others as part of the Linux Documentation Project with help from O'Reilly and Associates. It includes the following sections: Introduction to Networking, Issues of TCP/IP Networking, Configuring the Networking Hardware, Setting up the Serial Hardware, Configuring TCP/IP Networking, Name Service and Resolver Configuraton, Serial Line IP, The Point-to-Point Protocol, Various Network Applications, The Network Information System, The Network File System, Managing Taylor UUCP, Electronic Mail, Getting smail Up and Running, Sendmail+IDA, Netnews, C News, A Description of NNTP, Newsreader Configuration, Glossary, Annotated Bibliography. FTP from UNC (ftp://sunsite.unc.edu/pub/Linux/docs/LDP). FTP from MIT (ftp://tsx-11.mit.edu/pub/linux/docs/LDP). 1 1 1 1 1 Linux User Group (LUG) Any organisation of Linux users in a local area, university, etc., that offers mutual technical support, companionship with people of similar interests and promotes the use of Linux among computer users generally. LUGs often hold Install Fests for the general public, in which experienced Linux users explain and supervise the installation of Linux on new users' systems. (2003-09-14) 1 1 1 1 1 lion food (IBM) Middle management or HQ staff, or, by extension, administrative drones in general. The term derives from an old joke: Two lions escape from the zoo and split up to increase their chances. When they finally meet after two months, one is skinny and the other overweight. The thin one says, "How did you manage? I ate a human just once and they turned out a small army to chase me with guns and nets, it was terrible. Since then I've been reduced to eating mice, insects, even grass." The fat one replies: "Well, *I* hid near an IBM office and ate a manager every day. Nobody even noticed!" [Jargon File] (1994-12-01) 1 1 1 1 1 Lions Book "Source Code and Commentary on Unix level 6", by John Lions. The two parts of this book contained the entire source listing of the Unix Version 6 kernel, and a commentary on the source discussing the algorithms. These were circulated internally at the University of New South Wales beginning 1976-77, and were, for years after, the *only* detailed kernel documentation available to anyone outside Bell Labs. Because Western Electric wished to maintain trade secret status on the kernel, the Lions book was never formally published and was only supposed to be distributed to affiliates of source licensees (it is still possible to get a Bell Labs reprint of the book by sending a copy of a V6 source licence to the right person at Bellcore, but *real* insiders have the UNSW edition). In spite of this, it soon spread by samizdat to a good many of the early Unix hackers. (http://peer-to-peer.com/catalog/history/lions.html). 1 1 1 1 1 LIPL Linear IPL. A linearised (i.e. horizontal format) version of IPL-V. [Sammet 1969, p. 394]. [R. Dupchak, "LIPL - Linear Information Processing Language", Rand Memo RM-4320-PR, Feb 1965]. (1994-12-01) 1 1 1 1 1 liquid crystal display (LCD) An electro-optical device used to display digits, characters or images, commonly used in digital watches, calculators, and portable computers. The heart of the liquid crystal display is a piece of liquid crystal material placed between a pair of transparent electrodes. The liquid crystal changes the phase of the light passing through it and this phase change can be controlled by the voltage applied between the electrodes. If such a unit is placed between a pair of plane polariser plates then light can pass through it only if the correct voltage is applied. Liquid crystal displays are formed by integrating a number of such cells, or more usually, by using a single liquid crystal plate and a pattern of electrodes. The simplest kind of liquid crystal displays, those used in digital watches and calculators, contain a common electrode plane covering one side and a pattern of electrodes on the other. These electrodes can be individually controlled to 1 1 1 1 1 LIS Langage Implementation Systeme. A predecessor of Ada developed by Ichbiah in 1973. It was influenced by Pascal's data structures and Sue's control structures. A type declaration can have a low-level implementation specification. ["The System Implementation Language LIS", J.D. Ichbiah et al, CII Honeywell-Bull, TR 4549 E/EN, Louveciennes France (Dec 1974)]. ["The Two-Level Approach to Data Independent Programming in LIS", J.D. Ichbiah et al, in Machine Oriented Higher Level Languages, W. van der Poel ed, N-H 1974, pp.161-169]. (1994-12-01) 1 1 1 1 1 LISA 1. <computer> Local Integrated Software Architecture. A personal computer introduced by Apple Computer, Inc. in 1983. The LISA was a predecessor of the Macintosh and was the first personal computer on the market with a graphical user interface. It was origionally named after Steve Jobs's daughter. The acronym was applied later. [Spec?] 2. <tool> A system for statistical data analysis, similar to S. FTP MIT (ftp://dolphin.mit.edu/). 3. <event> Large Installation Systems Administration. (2001-10-16) 1 1 1 1 1 Liskov, Barbara Barbara Liskov 1 1 1 1 1 Liskov substitution principle (LSP) The principle that object-oriented functions that use pointers or references to a base class must be able to use objects of a derived class without knowing it. Barbara Liskov first wrote it as follows: If for each object o1 of type S there is an object o2 of type T such that for all programs P defined in terms of T, the behaviour of P is unchanged when o1 is substituted for o2 then S is a subtype of T. A function that violates the LSP uses a reference to a base class and must know about all the derivatives of that base class. Such a function violates the open/closed principle because it must be modified whenever a new derivative of the base class is created. [Liskov, B. Data Abstraction and Hierarchy, SIGPLAN Notices. 23(5), May 1988]. (2001-09-14) 1 1 1 1 1 Lisp LISt Processing language. (Or mythically "Lots of Irritating Superfluous Parentheses"). Artificial Intelligence's mother tongue, a symbolic, functional, recursive language based on the ideas of lambda-calculus, variable-length lists and trees as fundamental data types and the interpretation of code as data and vice-versa. Data objects in Lisp are lists and atoms. Lists may contain lists and atoms. Atoms are either numbers or symbols. Programs in Lisp are themselves lists of symbols which can be treated as data. Most implementations of Lisp allow functions with side-effects but there is a core of Lisp which is purely functional. All Lisp functions and programs are expressions that return values; this, together with the high memory use of Lisp, gave rise to Alan Perlis's famous quip (itself a take on an Oscar Wilde quote) that "Lisp programmers know the value of 1 1 1 1 1 LISP 1 The original Lisp. Invented by John McCarthy et al at MIT in the late 50's. Followed by LISP 1.5. 1 1 1 1 1 LISP 1.5 The second version of Lisp, successor to LISP 1. Developed at MIT in 1959. Followed by LISP 1.75, LISP 1.9, Lisp 2 and many other versions. 1 1 1 1 1 LISP 2 LISP 1.5 with an ALGOL 60-like surface syntax. Also optional type declarations, new data types including integer-indexed arrays and character strings, partial-word extraction/insertion operators and macros. A pattern-matching facility similar to COMIT was proposed. Implemented for the Q-32 computer. ["The LISP 2 Programming Language and System", P.W. Abrahams et al, Proc FJCC 29:661-676, AFIPS (Fall 1966).] 1 1 1 1 1 LISP70 A Lisp dialect descended from MLISP and MLISP2. Also known as PLISP and VEL. Useful for parsing. Only the pattern-matching system was published and fully implemented. According to Alan Kay, LISP70 had an influence on Smalltalk-72. "The LISP70 Pattern Matching System, Larry Tesler et al, IJCAI 73. 1 1 1 1 1 LISP A LISP A: A LISP-like System for Incremental Computing, E.J. Sandewall, Proc SJCC 32 (1968). 1 1 1 1 1 LISP Extended Algebraic Facility (LEAF) ["An Algebraic Extension to LISP", P.H. Knowlton, Proc FJCC 35 1969]. (1996-06-07) 1 1 1 1 1 Lispkit A functional programming language designed by Peter Henderson with Lisp syntax. Designed for portability. The Lispkit implementation is an extension to Landin's SECD machine that supports lazy evaluation. See also Stack environment control dump machine. 1 1 1 1 1 Lispkit Lisp Purely functional version of LISP. "Functional Programming, Application and Implementation", P. Henderson, P-H 1980. 1 1 1 1 1 Lisp-Linda P. Dourish, U Edinburgh 1988. 1 1 1 1 1 Lisp Machine 1. <architecture> Any machine (whether notional or actual) whose instruction set is Lisp. 2. <hardware, operating system> A line of workstations made by Symbolics, Inc. from the mid-1970s (having grown out of the MIT AI Lab) to late 1980s. All system code for Symbolics Lisp Machines was written in Lisp Machine Lisp. Symbolics Lisp Machines were also notable for having had space-cadet keyboards. [More details and historical background?] Lisp Machine Museum (http://kogs-www.informatik.uni-hamburg.de/~moeller/symbolics-info/symbolics.html). (2003-07-03) 1 1 1 1 1 LISP Machine LISP An extension of Maclisp, now called Zetalisp. (1998-12-13) 1 1 1 1 1 Lisp Object-Oriented Programming System (LOOPS) An object-oriented extension of Lisp from the Intelligent Systems Laboratory at Xerox Palo Alto Research Center. It is used in the development of knowledge-based systems. See also CommonLoops. ["The LOOPS Manual", D.G. Bobrow & M. Stefik, Xerox Corp 1983]. 1 1 1 1 1 LISP, Objects, and Symbolic Programming A book with compiler included by Robert R. Kessler and Amy R. Petajan, published by Scott, Foresman and Company, Glenview, IL, USA. (1988). 1 1 1 1 1 Lisptalk Concurrent Programming Language Lisptalk, C. Li, SIGPLAN Notices 23(4):71-80 (Apr 1988). 1 1 1 1 1 LispView CLOS based windowing system on OpenWindows. 1 1 1 1 1 list A data structure holding many values, possibly of different types, which is usually accessed sequentially, working from the head to the end of the tail - an "ordered list". This contrasts with a (one-dimensional) array, any element of which can be accessed equally quickly. Lists are often stored using a cell and pointer arrangement where each value is stored in a cell along with an associated pointer to the next cell. A special pointer, e.g. zero, marks the end of the list. This is known as a (singly) "linked list". A doubly linked list has pointers from each cell to both next and previous cells. An unordered list is a set. (1998-11-12) 1 1 1 1 1 list comprehension An expression in a functional language denoting the results of some operation on (selected) elements of one or more lists. An example in Haskell: [ (x,y) | x <- [1 .. 6], y <- [1 .. x], x+y < 10] This returns all pairs of numbers (x,y) where x and y are elements of the list 1, 2, ..., 10, y <= x and their sum is less than 10. A list comprehension is simply "syntactic sugar" for a combination of applications of the functions, concat, map and filter. For instance the above example could be written: filter p (concat (map (\ x -> map (\ y -> (x,y)) [1..x]) [1..6])) 1 1 1 1 1 List Enhanced An MS-DOS file browsing utility written by Vern Buerg in 1983. A former mainframe systems programmer, Buerg wrote DOS utilities when he began using an IBM PC and missed the file-scanning ability he had on mainframes. The software became an instant success, and his list utility was in use on an estimated 5 million PCs. shareware version (http://buerg.com/ftp.html). (1997-05-16) 1 1 1 1 1 listless In functional programming, a property of a function which allows it to be combined with other functions in a way that eliminates intermediate data structures, especially lists. Phil Wadler's thesis gives the conditions for a function to be in listless form: each input list is traversed only once, one element at a time, from left to right. Each output list is generated once, one element at a time, from left to right. No other lists are generated or traversed. Not all functions can be expressed in listless form (e.g. reverse). (1995-02-22) 1 1 1 1 1 Listproc A mailing list processor owned and developed by BITNET which runs under Unix. See also Listserv, Majordomo. [Details?] (1995-02-22) 1 1 1 1 1 lists list 1 1 1 1 1 Listserv An automatic mailing list server, initially written to run under IBM's VM operating system by Eric Thomas. Listserv is a user name on some computers on BITNET/EARN which processes electronic mail requests for addition to or deletion from mailing lists. Examples are listserv@ucsd.edu, listserver@nysernet.org. Some listservs provide other facilities such as retrieving files from archives and database search. Full details of available services can usually be obtained by sending a message with the word HELP in the subject and body to the listserv address. Eric Thomas, has recently formed an international corporation, L-Soft, and has ported Listserv to a number of other platforms including Unix. Listserv has simultaneously been enhanced to use both the Internet and BITNET. Two other major mailing list processors, both of which run 1 1 1 1 1 Liszt A Franz Lisp compiler in C which emits C, by Jeff W. Dalton <jeff@festival.ed.ac.uk>. Mailing list: franz-friends-request@berkeley.edu. (1994-10-20) 1 1 1 1 1 lite (Misspelling of "light", when used to mean lightweight) A suffix denoting a scaled-down or crippled product, often designed to be distributed without charge, e.g. on a magazine coverdisk. An example is pklite. (1995-10-06) 1 1 1 1 1 literal A constant made available to a process, by inclusion in the executable text. Most modern systems do not allow texts to modify themselves during execution, so literals are indeed constant; their value is written at compile-time and is read-only at run time. In contrast, values placed in variables or files and accessed by the process via a symbolic name, can be changed during execution. This may be an asset. For example, messages can be given in a choice of languages by placing the translation in a file. Literals are used when such modification is not desired. The name of the file mentioned above (not its content), or a physical constant such as 3.14159, might be coded as a literal. Literals can be accessed quickly, a potential advantage of their use. (1996-01-23) 1 1 1 1 1 literate programming Combining the use of a text formatting language such as TeX and a conventional programming language so as to maintain documentation and source code together. Literate programming may use the inverse comment convention. Perl's literate programming system is called pod. (2003-09-24) 1 1 1 1 1 literature The literature. Computer-science journals and other publications, vaguely gestured at to answer a question that the speaker believes is trivial. Thus, one might answer an annoying question by saying "It's in the literature." Oppose Knuth, which has no connotation of triviality. (1994-11-04) 1 1 1 1 1 LITHE Object-oriented with extensible syntax. LITHE: A Language Combining a Flexible Syntax and Classes, D. Sandberg, Conf Rec 9th Ann ACM Sym POPL, ACM 1982, pp.142-145. 1 1 1 1 1 lithium lick NeXT employees who have had too much attention from their esteemed founder, Steve Jobs, are said to have "lithium lick" when they begin to show signs of Jobsian fervour and repeat the most recent catch phrases in normal conversation, e.g. "It just works, right out of the box!" [Jargon File] 1 1 1 1 1 LitProg literate programming 1 1 1 1 1 LITTLE A typeless language used to produce machine-independent software. LITTLE has been used to implement SETL. Guide to the LITTLE Language, D. Shields, LITTLE Newsletter 33, Courant Inst (Aug 1977). 1 1 1 1 1 little-endian A computer architecture in which, within a given 16- or 32-bit word, bytes at lower addresses have lower significance (the word is stored "little-end-first"). The PDP-11 and VAX families of computers and Intel microprocessors and a lot of communications and networking hardware are little-endian. The term is sometimes used to describe the ordering of units other than bytes; most often, bits within a byte. Compare big-endian, middle-endian. See NUXI problem. [Jargon File] (1995-08-16) 1 1 1 1 1 Little Smalltalk A line-oriented near-subset of Smalltalk-80 written in C by Tim Budd <budd@cs.orst.edu>. Version 3 runs on Unix, IBM PC, Atari and VMS. (ftp://cs.orst.edu/pub/budd/). ["A Little Smalltalk", Timothy Budd, A-W 1987]. 1 1 1 1 1 live data 1. Data that is written to be interpreted and takes over program flow when triggered by some un-obvious operation, such as viewing it. One use of such hacks is to break security. For example, some smart terminals have commands that allow one to download strings to program keys; this can be used to write live data that, when listed to the terminal, infects it with a security-breaking virus that is triggered the next time a hapless user strikes that key. For another, there are some well-known bugs in vi that allow certain texts to send arbitrary commands back to the machine when they are simply viewed. 2. In C, data that includes pointers to functions (executable code). 3. An object, such as a trampoline, that is constructed on the fly by a program and intended to be executed as code. 4. Actual real-world data, as opposed to "test data". For example, "I think I have the record deletion module finished." 1 1 1 1 1 Live Free Or Die! 1. The state motto of New Hampshire, which appears on that state's automobile licence plates. 2. A slogan associated with Unix in the romantic days when Unix aficionados saw themselves as a tiny, beleaguered underground tilting against the windmills of industry. The free referred specifically to freedom from the fascist design philosophies and crufty misfeatures common on commercial operating systems. Armando Stettner, one of the early Unix developers, used to give out fake licence plates bearing this motto under a large Unix, all in New Hampshire colours of green and white. These are now valued collector's items. 1 1 1 1 1 livelock /li:v'lok/ When two or more processes continuously change their state in response to changes in the other process(es) without doing any useful work. This is similar to deadlock in that no progress is made but differs in that neither process is blocked or waiting for anything. A human example of livelock would be two people who meet face-to-face in a corridor and each moves aside to let the other pass, but they end up swaying from side to side without making any progress because they always move the same way at the same time. [Jargon File] (1998-07-05) 1 1 1 1 1 LiveScript JavaScript 1 1 1 1 1 liveware /li:v'weir/ 1. A less common synonym for wetware 2. (Cambridge) Vermin. "Waiter, there's some liveware in my salad." [Jargon File] (1995-10-30) 1 1 1 1 1 lk The country code for Sri Lanka. (1999-01-27) 1 1 1 1 1 LKA Lan Kanal Adapter 1 1 1 1 1 LL A class of language grammars, which can be parsed without backtracking. The first L stands for Left-to-right scan, the second for Leftmost derivation. Often found in the form LL(k) where k is the number of tokens of look-ahead required when parsing a sentence of the language. In particular, LL(1) is a fairly restrictive class of grammar, but allows simple top-down parsing (e.g. recursive-descent) to be used without wasteful backtracking. A number of programming languages are LL(1) (or close). (1995-10-30) 1 1 1 1 1 LLC Logical Link Control 1 1 1 1 1 LLGen A BNF-based LL1 parser generator by Fischer and LeBlanc. It conforms to a subset of FMQ. (ftp://csczar.ncsu.edu/). ["Crafting A Compiler", Fischer and LeBlanc]. (1990-03-31) 1 1 1 1 1 LLM3 /el el em trwa/ The assembly language for a virtual machine used as the implementation language for Le-Lisp. Developed by J. Chailloux of INRIA. 1 1 1 1 1 LLNL Lawrence Livermore National Laboratory 1 1 1 1 1 LLP Lower Layer Protocol 1 1 1 1 1 LM3 The Larch interface language for Modula-3. ["LM3: A Larch/Modula-3 Interface Language", Kevin D. Jones, TR 72, DEC SRC, Palo Alto CA]. 1 1 1 1 1 LMAO laughed my ass off. Seen on Compuserve. (1996-02-04) 1 1 1 1 1 LMDS Local Multipoint Distribution System 1 1 1 1 1 lmgtfy.com A somewhat sarcastic web service that animates the action of searching on Google. Instead of displaying the search results, the site creates a self-referential URL like (http://lmgtfy.com/?q=GIYF) that takes you to a page showing an animation of the actions of clicking in the Google search box, entering some text and clicking the submit button. It then takes you to the results on Google. The link is intended be sent to in answer to a question that could easily have been answered by Google. It is a more polite, if long-winded, way of saying JFGI or STFW. In the belief that it is better to teach a man to fish than to give him a fish, the service helps the recipient to help himself while succinctly conveying the message that he is too stupid to use Google. (2014-05-23) 1 1 1 1 1 LML 1. Lazy ML. A lazy, purely functional variant of ML designed by Thomas Johnson and Lennart Augustsson at the Chalmers University of Technology, Gothenburg, Sweden in 1984. LML is implemented on the G-machine, and was used to implement the first Haskell B compiler. There is a compiler (lmlc) and interpreter. (ftp://ftp.cs.chalmers.se/pub/haskell/chalmers). (1994-12-14) 2. Logical ML. Adds to Lazy ML a data type of "theories" whose objects represent logic programs. ["Logic Programming within a Functional Framework", A. Brogi et al, in Programming Language Implementation and Logic Programming, P. Deransart et al eds, LNCS 456, Springer 1990]. (1994-12-14) 1 1 1 1 1 LM-Prolog Lisp Machine Prolog. A Prolog interpreter in Zetalisp for the Lisp Machine developed by Ken Kahn and Mats Carlsson in 1983. (ftp://sics.se/archive/lm-prolog.tar.Z). ["LM-Prolog User Manual", M. Carlsson et al, Uppsala Dec 1983]. (1994-12-14) 1 1 1 1 1 LMTP Local Mail Transfer Protocol 1 1 1 1 1 LNF ["A Fully Lazy Higher Order Purely Functional Programming Language With Reduction Semantics", K.L. Greene, CASE Center TR 8503, Syracuse U 1985]. 1 1 1 1 1 LO Linear Objects. A concurrent logic programming language based on linear logic, an extension of Horn logic with a new kind of OR-concurrency. ["LO and Behold! Concurrent Structured Processes", J. Andreoli et al, SIGPLAN Notices 25(10):44-56 (OOPSLA/ECOOP '90) (Oct 1990)]. 1 1 1 1 1 L&O Logic and Objects. A front end for IC Prolog. (ftp://src.doc.ic.ac.uk/computing/programming/languages/pd-ICP-0,90.tar.Z). E-mail: Zacharias Bobolakis <zb@doc.ic.ac.uk>. ["Logic and Objects", Frank McCabe, Prentice-Hall]. 1 1 1 1 1 load 1. To copy data (often program code to be run) into memory, possibly parsing it somehow in the process. E.g. "WordPerfect can't load this RTF file - are you sure it didn't get corrupted in the download?" Opposite of save. 2. The degree to which a computer, network, or other resource is used, sometimes expressed as a percentage of the maximum available. E.g. "What kind of CPU load does that program give?", "The network's constantly running at 100% load". Sometimes used, by extension, to mean "to increase the level of use of a resource". E.g. "Loading a spreadsheet really loads the CPU". See also: load balancing. 3. To install a piece of software onto a system. E.g. "The computer guy is gonna come load Excel on my laptop for me". This usage is widely considered to be incorrect. (2002-07-02) 1 1 1 1 1 load balancing Techniques which aim to spread tasks among the processors in a parallel processor to avoid some processors being idle while others have tasks queueing for execution. Load balancing may be performed either by heavily loaded processors (with many tasks in their queues) sending tasks to other processors; by idle processors requesting work from others; by some centralised task distribution mechanism; or some combination of these. Some systems allow tasks to be moved after they have started executing ("task migration") others do not. It is important that the overhead of executing the load balancing algorithm does not contribute significantly to the overall processing or communications load. Distributed scheduling algorithms may be static, dynamic or preemptive. Static algorithms allocate processes to processors at run time while taking no account of current network load. Dynamic algorithms are more flexible, though 1 1 1 1 1 load-bearing printf The kind of bug present in a program which works correctly when producing debug output but fails when the debugging is turned off. The expression combines load-bearing wall (http://en.wikipedia.org/wiki/The_Builders) and printf as used in debugging by printf. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-05-10) 1 1 1 1 1 lobotomy 1. What a hacker subjected to formal management training is said to have undergone. At IBM and elsewhere this term is used by both hackers and low-level management; the latter doubtless intend it as a joke. 2. The act of removing the processor from a microcomputer in order to replace or upgrade it. Some very cheap clone systems are sold in "lobotomised" form - everything but the brain. [Jargon File] 1 1 1 1 1 LOC lines of code 1 1 1 1 1 local area network (LAN) A data communications network which is geographically limited (typically to a 1 km radius) allowing easy interconnection of terminals, microprocessors and computers within adjacent buildings. Ethernet and FDDI are examples of standard LANs. Because the network is known to cover only a small area, optimisations can be made in the network signal protocols that permit data rates up to 100Mb/s. See also token ring, wide area network, metropolitan area network.. Usenet newsgroup: news:comp.dcom.lans.misc. (1995-03-13) 1 1 1 1 1 Local Area Terminal (LAT) A DECnet-related, non-routable network protocol. [Details?] (1999-01-14) 1 1 1 1 1 local bus A bus connecting a processor to memory, usually on the same circuit board as opposed to a backplane and therefore faster. Various proprietary local busses for personal computers are still in use. The most common are Vesa local bus (VLB or VL), and Peripheral Component Interconnect (PCI). Some computers, e.g. notebook computers, use a local bus with no expansion slots. Previous non-local bus standards include ISA, EISA and MCA. (1997-08-25) 1 1 1 1 1 locale A geopolitical place or area, especially in the context of configuring an operating system or application program with its character sets, date and time formats, currency formats etc. Locales are significant for internationalisation and localisation. (1999-06-09) 1 1 1 1 1 local echo (Obsolete: "half-duplex") A mode of operation of a communications program or device in which it displays the characters the user enters at the same time as it sends them to the remote system. In communications between computers or computing processes, particularly those involving human keyboarding and/or reading, duplex came to mean the re-transmission of a keyboard character to the output display. Early input device such as the Teletype ASR-33 teleprinter, being descended from the electric typewriter, printed all input characters as they were typed (i.e. they did local echo). Local echo was typically optional on the video terminals that replaced them, and usually disabled in favour of remote echo. A disadvantage of local echo is that it will continue, even when the communication circuit has failed, which can be misleading. (2000-03-30) 1 1 1 1 1 local exchange carrier (LEC) A company allowed to handle local calls following the break-up of the Bell system in the US by anti-trust regulators. These vary from Regional Bell Operating Companies (RBOC) through to small independents such as Farmers Cooperative. Local exchange carriers are not allowed to handle long-distance traffic. This is handled by inter-exchange carriers (IXC) who are not allowed to handle local calls. (2002-08-28) 1 1 1 1 1 localisation (l10n) Adapting a product to meet the language, cultural and other requirements of a specific target market locale. Localisation includes the translation of the user interface, on-line help and documentation, and ensuring the images and concepts are culturally appropriate and sensitive. There may be subtle cross-cultural considerations, e.g. do the icons make sense in other parts of the world? Internationalisation is the process that occurs during application development that makes localisation easier by separating the details that differ between locales from the rest of the program that stays the same. If internationalisation is thorough, localisation will require no programming. The abbreviation l10n means "L - 10 letters - N". (1999-06-09) 1 1 1 1 1 localised localisation 1 1 1 1 1 locality 1. In sequential architectures programs tend to access data that has been accessed recently (temporal locality) or that is at an address near recently referenced data (spatial locality). This is the basis for the speed-up obtained with a cache memory. 2. In a multi-processor architecture with distributed memory it takes longer to access the memory attached to a different processor. This overhead increases with the number of communicating processors. Thus to efficiently employ many processors on a problem we must increase the proportion of references which are to local memory. (1995-02-28) 1 1 1 1 1 local loop The circuits between a telephone subscriber's residence or business and the switching equipment at the local central office. (1995-03-17) 1 1 1 1 1 local loopback addresses The special Internet address, 127.0.0.1, defined by the Internet Protocol. A host can use local the loopback address to send messages to itself. (1995-03-21) 1 1 1 1 1 Local Mail Transfer Protocol (LMTP) A protocol designed as an alternative to ESMTP for cases where the mail receiver does not manage a queue. LMTP is an application level protocol that runs on top of TCP/IP. It was initially defined in RFC 2033, and uses (with a few changes) the syntax and semantics of ESMTP. It should be used only by specific prior arrangement and configuration, and it must not be used on TCP port 25 (the SMTP port). (2002-03-09) 1 1 1 1 1 Local Multipoint Distribution System (LMDS) A broadband wireless technology. [Details?] 1 1 1 1 1 locals The users on one's local network (as opposed, say, to people one reaches via public Internet or UUCP connections). The marked thing about this usage is how little it has to do with real-space distance. "I have to do some tweaking on this mail utility before releasing it to the locals." (1994-11-29) 1 1 1 1 1 Local Shared Resources (LSR) A way of controlling VSAM buffers in OS/390. (2002-02-17) 1 1 1 1 1 LocalTalk An Apple Computer network standard using Apple Computer's own networking hardware. Compare EtherTalk. (1994-11-29) 1 1 1 1 1 local variable A variable with lexical scope, i.e. one which only exists in some particular part of the source code, typically within a block or a function or procedure body. This contrasts with a global variable, which is defined throughout the whole program. Code is easier to understand and modify when the scope of variables is as small as possible because it is easier to see how the variable is set and used. Code containing global variables is harder to modify because its behaviour may depend on and affect other sections of code that refer to that variable. (2009-12-14) 1 1 1 1 1 location memory location 1 1 1 1 1 Loch Ness Monster Bug (Or "Bugfoot") A bug which cannot be reproduced or has only been sighted by one person. Named after the mythical creature claimed to inhabit Loch Ness in Scotland. (2012-12-29) 1 1 1 1 1 locked and loaded [Military slang for an M-16 rifle with magazine inserted and prepared for firing] Said of a removable disk volume properly prepared for use - that is, locked into the drive and with the heads loaded. Ironically, because their heads are loaded whenever the power is up, this description is never used of Winchester drives (which are named after a rifle). [Jargon File] 1 1 1 1 1 locked up Synonym for hung, wedged. 1 1 1 1 1 lock-in When an existing standard becomes almost impossible to supersede because of the cost or logistical difficulties involved in convincing all its users to switch something different and, typically, incompatible. The common implication is that the existing standard is notably inferior to other comparable standards developed before or since. Things which have been accused of benefiting from lock-in in the absence of being truly worthwhile include: the QWERTY keyboard; any well-known operating system or programming language you don't like (e.g., see "Unix conspiracy"); every product ever made by Microsoft Corporation; and most currently deployed formats for transmitting or storing data of any kind (especially the Internet Protocol, 7-bit (or even 8-bit) character sets, analog video or audio broadcast formats and nearly any file format). Because of network effects outside of just computer 1 1 1 1 1 Locus A distributed system project supporting transparent access to data through a network-wide file system. 1 1 1 1 1 Loebner Prize An annual competition in artificial intelligence started by Dr. Hugh Loebner of New York City in 1991. A $100,000 prize is offered to the author of the first computer program to pass an unrestricted Turing test. Annual competitions are held each year with a $2000 prize for the best program on a restricted Turing test. Sponsors of previous competitions include: Apple Computer, Computerland, Crown Industries, GDE Systems, IBM Personal Computer Company's Center for Natural Computing, Greenwich Capital Markets, Motorola, the National Science Foundation, The Alfred P. Sloan Foundation, and The Weingart Foundation. The 1995 and 1996 events were unrestricted Turing Tests, requiring computer entries to converse indefinitely with no topic restrictions. So far, even the best programs give themselves away almost immediately, either by simple grammatical mistakes or by repetition. 1 1 1 1 1 log 1. <mathematics, programming> logarithm. 2. <operating system, programming> A record of the activity of some system, often stored in a particular file. Different operating systems have different conventions and support for storing logs. Unix has the syslog system and the /var/log directory hierarchy, Microsoft Windows has event logs. Web servers, for example, typically record information about every page accessed in one or more "web logs". (2009-05-29) 1 1 1 1 1 logarithmus dualis (ld) Latin for logarithm base two. More commonly written as "log" with a subscript "2". Roughly the number of bits required to represent an integer. (1999-03-19) 1 1 1 1 1 LogC A C extension incorporating rule-oriented programming, for AI application programs. Production rules are encapsulated into functional components called rulesets. LogC uses a search network algorithm similar to RETE. Version 1.6. ["LogC: A Language and Environment for Embedded Rule Based Systems", F. Yulin et al, SIGPLAN Notices 27(11):27-32 (Nov 1992)]. 1 1 1 1 1 logic 1. <philosophy, logic> A branch of philosophy and mathematics that deals with the formal principles, methods and criteria of validity of inference, reasoning and knowledge. Logic is concerned with what is true and how we can know whether something is true. This involves the formalisation of logical arguments and proofs in terms of symbols representing propositions and logical connectives. The meanings of these logical connectives are expressed by a set of rules which are assumed to be self-evident. Boolean algebra deals with the basic operations of truth values: AND, OR, NOT and combinations thereof. Predicate logic extends this with existential and universal quantifiers and symbols standing for predicates which may depend on variables. The rules of natural deduction describe how we may proceed from valid premises to valid conclusions, where the premises and conclusions are expressions in predicate logic. 1 1 1 1 1 logical (From the technical term "logical device", wherein a physical device is referred to by an arbitrary "logical" name) Having the role of. If a person (say, Les Earnest at SAIL) who had long held a certain post left and were replaced, the replacement would for a while be known as the "logical" Les Earnest. (This does not imply any judgment on the replacement). Compare virtual. At Stanford, "logical" compass directions denote a coordinate system in which "logical north" is toward San Francisco, logical west is toward the ocean, etc., even though logical north varies between physical (true) north near San Francisco and physical west near San Jose. (The best rule of thumb here is that, by definition, El Camino Real always runs logical north-and-south.) In giving directions, one might say: "To get to Rincon Tarasco restaurant, get onto El Camino Bignum going logical north." Using the word "logical" helps to 1 1 1 1 1 logical address virtual address 1 1 1 1 1 Logical Block Addressing (LBA) A hard disk sector addressing scheme used on all SCSI hard disks, and on ATA-2 conforming IDE hard disks. The addressing conversion is performed by the hard disk firmware. Prior to LBA, combined limitations of IBM PC BIOS and ATA restricted the useful capacity of IDE hard disks on IBM PCs and compatibles to 1024 cylinders * 63 sectors per track * 16 heads * 512 bytes per sector = 528 million bytes = 504 megabytes. Modern BIOSes select LBA mode automatically, and work around the 1024-cylinder BIOS limit by representing a hard disk to the OS as having e.g. half as many cylinders and twice as many heads. However, there is still an unbreakable BIOS disk size limit of 1024 cylinders * 63 sectors per track * 256 heads * 512 bytes per sector = 8 gigabytes, but modern OSes (including Windows 9x, Windows NT and Linux) are not affected by it, since they issue direct LBA-based calls, bypassing the BIOS hard disk services completely. 1 1 1 1 1 logical complement In Boolean algebra, the logical complement or negation of a Boolean value is the opposite value, given by the following truth table: A | -A --+--- T | F F | T #NAME? vertical line hanging from the right-hand end of the "-" (LaTeX \neg) or as A'. In the C programming language, it is !A and in digital circuit design, /A. (1995-01-24) 1 1 1 1 1 Logical Interchange Format (LIF) A Hewlett-Packard simple file system format used to boot HP-PA machines and to interchange files between older HP machines. A LIF file system is a header, containing a single directory, with 10-character case sensitive filenames and 2-byte file types, followed by the files. LIF Utilities for linux (http://hpcc.org/hpil/lif_utils.html). (2003-10-09) 1 1 1 1 1 Logical Link Control (LLC) The upper portion of the data link layer, as defined in IEEE 802.2. The LLC sublayer presents a uniform interface to the user of the data link service, usually the network layer. Beneath the LLC sublayer is the Media Access Control (MAC) sublayer. (1995-02-14) 1 1 1 1 1 Logical Link Control and Adaptation Protocol (L2CAP) A Bluetooth protocol in the Core Protocol Stack providing data services to higher layer Bluetooth protocols. L2CAP Layer Tutorial (http://palowireless.com/infotooth/tutorial/l2cap.asp). (2002-06-28) 1 1 1 1 1 logical relation A relation R satisfying f R g <=> For all a, b, a R b => f a R g b This definition, by Plotkin, can be used to extend the definition of a relation on the types of a and b to a relation on functions. 1 1 1 1 1 logical shift (Either shift left logical or shift right logical) Machine-level operations available on nearly all processors which move each bit in a word one or more bit positions in the given direction. A left shift moves the bits to more significant positions (like multiplying by two), a right shift moves them to less significant positions (like dividing by two). The comparison with multiplication and division breaks down in certain circumstances - a logical shift may discard bits that are shifted off either end of the word and does not preserve the sign of the word (positive or negative). Logical shift is approriate when treating the word as a bit string or a sequence of bit fields, whereas arithmetic shift is appropriate when treating it as a binary number. The word to be shifted is usually stored in a register, or possibly in memory. (1996-07-02) 1 1 1 1 1 logical shift left logical shift 1 1 1 1 1 logical shift right logical shift 1 1 1 1 1 Logical Unit (LU) A primary component of SNA, an LU is a type of NAU that enables end users to communicate with each other and gain access to SNA network resources. (1997-04-30) 1 1 1 1 1 Logical Unit 6.2 (LU6.2) A type of logical unit that governs peer-to-peer SNA communications. LU6.2 supports general communication between programs in a distributed processing environment. LU6.2 is characterised by a peer relationship between session partners, efficient use of a session for multiple transactions, comprehensive end-to-end error processing and a generic application program interface consisting of structured verbs that are mapped into a product inplementation. LU6.2 is used by IBM's TPF operating system. [IBM Dictionary of Computing, McGraw-Hill 1993]. (1996-08-26) 1 1 1 1 1 Logical Unit Number (LUN) A 3-bit identifier used on a SCSI bus to distinguish between up to eight devices (logical units) with the same SCSI ID. (1999-02-11) 1 1 1 1 1 logic bomb Code surreptitiously inserted into an application or operating system that causes it to perform some destructive or security-compromising activity whenever specified conditions are met. Compare back door. [Jargon File] (1996-07-02) 1 1 1 1 1 Logic Design Language A language for computer design. ["A System Description Language Using Parametric Text Generation", R.H. Williams, TR 02.487, IBM San Jose, Aug 1970]. (1994-11-29) 1 1 1 1 1 logic emulator A system of FPGAs, programmable interconnect and software which automatically configures itself into an operating prototype of a large-scale logic design, such as a microprocessor. An emulated design can be connected into the target system and really operated and tested before the design is made into an integrated circuit. Quickturn is the leading logic emulation system. (1994-11-29) 1 1 1 1 1 Logic for Computable Functions (LCF) Part of the Edinburgh proof assistant. [What is it? Address?] (1995-01-06) 1 1 1 1 1 logic gate An integrated circuit or other device whose inputs and outputs represent Boolean or binary values as voltages (TTL uses 0V for False or 0, +5V for True or 1). Different gates implement different Boolean functions: AND, OR, NAND, NOR (these may take two or more inputs) NOT (one input), XOR (two inputs). NOT, NAND and NOR are often constructed from single transistors and the other gates made from combinations of these basic ones. These functions are all combinatorial logic functions, i.e. their outputs depend only on their inputs and there is no internal state. Gates with state, such as latches and flip-flops, are constructed by feeding some of their outputs back to their inputs. (1995-02-08) 1 1 1 1 1 logic programming A declarative, relational style of programming based on first-order logic. The original logic programming language was Prolog. The concept is based on Horn clauses. The programmer writes a "database" of "facts", e.g. wet(water). ("water is wet") and "rules", e.g. mortal(X) :- human(X). ("X is mortal is implied by X is human"). Facts and rules are collectively known as "clauses". The user supplies a "goal" which the system attempts to prove using "resolution" or "backward chaining". This involves matching the current goal against each fact or the left hand side of each rule using "unification". If the goal matches a fact, the goal succeeds; if it matches a rule 1 1 1 1 1 Logic Replacement Technology (LRT) Reading, BERKS. Tel: (0734) 751087. Marketing Director Bob Barrett. Manufacturers of the Ethernet hardware including the Filtabyte Ethernet controller card and EtherGate open access gateway. 1 1 1 1 1 logic variable A variable in a logic programming language which is initially undefined ("unbound") but may get bound to a value or another logic variable during unification of the containing clause with the current goal. The value to which it is bound may contain other variables which may themselves be bound or unbound. For example, when unifying the clause sad(X) :- computer(X, ibmpc). with the goal sad(billgates). the variable X will become bound to the atom "billgates" yielding the new subgoal "computer(billgates, ibmpc)". (1995-03-14) 1 1 1 1 1 LOGIN 1. An object-oriented deductive language and database system integrating logic programming and inheritance. ["LOGIN: A Logic Programming Language with Built-In Inheritance", H. Ait-Kaci et al, J Logic Programming 3(3):185-215 (1986)]. 1 1 1 1 1 log in (Or "login", "log on", "logon") To start a session with a system, usually by giving a user name and password as a means of user authentication. The term is also used to mean the ability to access a service (also called an account), e.g. "Have you been given a login yet?" Log in/on is occasionally misused to refer to starting a session where no authorisation is involved, or to access where there is no session involved. E.g. "Log on to our Web site!" login is also the Unix program which reads and verifies a user's user name and password and starts an interactive session. The noun forms are usually written as a single word whereas the verb forms are often written as two words. To end a session is to "log out" or "off". (2006-07-10) 1 1 1 1 1 LOGISCOPE Software quality analysis tools from Verilog SA, used to evaluate the quality of software, both statically (based on software metrics) and dynamically. 1 1 1 1 1 Loglan An artificial human language designed by James Cooke Brown in the late 1950s. Most artificial human languages devised in the 19th and 20th centuries (e.g. Esperanto) were designed to be easy to learn. Loglan, however, is unique in that its chief design goal was to avoid synactic ambiguity -- the kind that arises when trying to parse sentences like "The blind man picked up the hammer and saw". Loglan is thus the only human language unambiguously parseable by a formal grammar (assuming you count Loglan as a human language; its grammar is not at all like that of any natural human language). Most later development on Loglan continued under the name Lojban. The Loglan Institute, Inc. is a non-profit research corporation. Loglan is unrelated to the programming languages Loglan'82 1 1 1 1 1 Loglan'82 A teaching language including all the programming tools used in object-oriented programming, modular programming, and structured programming as well as programming by rules and functional programming. Supported object-oriented programming features include classes, objects, coroutines, processes (in Loglan'82 processes are objects which are able to act in parallel), inheritance, exception handling, and dynamic arrays. Loglan'82 is apparently unrelated to Loglan. (http://univ-pau.fr/~salwicki/loghome.html). A cross-compiler to C is here (ftp://infpc1.univ-pau.fr/pub/Loglan82). [Related to Loglan-88?] (1999-07-02) 1 1 1 1 1 Loglan-88 An object-oriented language from the Institute of Informatics at Warsaw University. Loglan-88 is apparently unrelated to Loglan. [Loglan-88, "Report on the Programming Language, LNCS 414, Springer-Verlag, 1990, ISBN 3-540-52325-1]. [Related to Loglan'82?] (1997-08-01) 1 1 1 1 1 LOGLISP A version of Prolog implemented by Robinson in Lisp which allows Prolog programs to call Lisp and vice versa. ["LOGLISP: An Alternative to Prolog", J. Alan Robinson et al in Machine Intelligence 10, D. Michie ed, Ellis Horwood 1982]. 1 1 1 1 1 LOGO A Lisp-like language for teaching programming, noted for its "turtle graphics" used to draw geometric shapes. LOGO was developed in 1966-1968 by a group at Bolt, Beranek & Newman (now "BBN Technologies") headed by Wally Fuerzeig <fuerzeig@bbn.com> (who still works there in 2003) and including Seymour Papert <seymour@media.mit.edu>. There are Logo interpreters for Macintosh, Unix, IBM PC, X Window System, and many PCs. Implmentations include Berkeley Logo, MswLogo. (2000-03-28) 1 1 1 1 1 log off log out 1 1 1 1 1 LOGOL Strings are stored on cyclic lists or 'tapes', which are operated upon by finite automata. J. Mysior et al, "LOGOL, A String manipulation Language", in Symbol Manipulations Languages and Techniques, D.G. Bobrow ed, N-H 1968, pp.166-177. 1 1 1 1 1 logon 1. <jargon> login. 2. <networking> In ACF/VTAM, an unformatted session-initiation request for a session between two logical units. (1996-03-07) 1 1 1 1 1 log out (Or "log off") To end an authenticated session, undoing what happens when you log in. This is primarily to prevent other users gaining access to your logged in session, e.g. at an unattended computer, but typically also terminates any processes and network connections started as part of your session. (2004-11-16) 1 1 1 1 1 Lojban /lozh'bahn/ A language for humans developed by former members of the Loglan project. Helsinki Lojban (http://xiron.pc.helsinki.fi/lojban/). (2007-02-18) 1 1 1 1 1 LOL "laughing out loud", or "lots of love" or "luck". (2003-07-29) 1 1 1 1 1 LOLITA Language for the On-Line Investigation and Transformation of Abstractions 1 1 1 1 1 Lolli (Named after the "lollipop" operator "-o") An interpreter for logic programming based on linear logic, written by Josh Hodas <hodas@saul.cis.upenn.edu>. Lolli can be viewed as a refinement of the Hereditary Harrop formulas of Lambda-Prolog. All the operators (though not the higher order unification) of Lambda-Prolog are supported, but with the addition of linear variations. Thus a Lolli program distinguishes between clauses which can be used as many, or as few, times as desired, and those that must be used exactly once. Lolli is implemented in SML/NJ. (ftp://ftp.cis.upenn.edu/pub/Lolli/Lolli-0.7.tar.Z). [Josh Hodas et al, "Logic Programming in a Fragment of Intuitionistic Linear Logic", Information and Computation, to appear]. (1992-11-18) 1 1 1 1 1 LOM A programming language developed in Toulouse in the early 1980s for data processing. (1996-03-01) 1 1 1 1 1 longitudinal parity An extra byte (or word) appended to a block of data in order to reveal corruption of the data. Bit n of this byte indicates whether there was an even or odd number of "1" bits in bit position n of the bytes in the block. The parity byte is computed by XORing the data bytes in the block. Longitudinal parity allows single bit errors to be detected. (1996-03-01) 1 1 1 1 1 Longitudinal Redundancy Check (LRC, Block Redundancy Check) An error checking method that generates a longitudinal parity byte from a specified string or block of bytes on a longitudinal track. The longitudinal parity byte is created by placing individual bytes of a string in a two-dimensional array and performing a Vertical Redundancy Check vertically and horizontally on the array, creating an extra byte. This is an improvement over the VRC because it will catch two errors in the individual characters of the string, beyond the odd errors. (2004-01-26) 1 1 1 1 1 LOOK A specification language. ["A Look at Algebraic Specifications", S.N. Zilles et al, IBM RR, 1982]. (1994-11-16) 1 1 1 1 1 Look Ahead Left-to-right parse, Rightmost-derivation (LALR, Look ahead LR) A type of LR parser that can deal with more context-free grammars than SLR parsers but less than LR[1] parsers. LALR parsers are popular because they give a good trade-off between the number of grammars they can deal with and the size of the parsing table required. Compiler compilers like yacc and Bison generate LALR parsers. Wikipedia (http://wikipedia.org/wiki/LALR_parser). (2003-05-13) 1 1 1 1 1 Look ahead LR Look Ahead Left-to-right parse, Rightmost-derivation 1 1 1 1 1 look and feel The appearance and function of a program's user interface. The term is most often applied to graphical user interfaces (GUI) but might also be used by extension for a textual command language used to control a program. Look and feel includes such things as the icons used to represent certain functions such as opening and closing files, directories and application programs and changing the size and position of windows; conventions for the meaning of different buttons on a mouse and keys on the keyboard; and the appearance and operation of menus. A user interface with a consistent look and feel is considered by many to be an important factor in the ease of use of a computer system. The success of the Macintosh user interface was partly due to its consistency. Because of the perceived importance of look and feel, there have been several legal actions claiming breech of copyright 1 1 1 1 1 Looking Glass A desktop manager for Unix from Visix. 1 1 1 1 1 LOOKS ["LOOKS: Knowledge-Representation System for Designing Expert Systems in a Logical Programming Framework", F. Mizoguchi, Proc Intl Conf 5th Gen Comp Sys, ICOT 1984]. 1 1 1 1 1 loop A sequence of instructions in a program that the processor repeats, either until some condition is met, or indefinitely (an infinite loop). In an structured language (e.g. C, Pascal, BASIC, or Fortran), a loop is usually achieved with for loop, while loop or repeat loop constructs. In other languages these constructs may be synthesised with a jump (assembly language) or a GOTO (early Fortran or BASIC). To "loop through" a list means to process each element in turn. Hackers might use this for everyday iterative actions, e.g. "I've got to loop through my paper mail." (2014-12-20) 1 1 1 1 1 loop combination A program transformation where the bodies of two loops are merged into one thus reducing the overhead of manipulating and testing the control variable and branching. Further optimisation of the merged code may then become possible. In horizontal loop combination the bodies of the loops are largely independent so only the loop overhead is saved. Vertical loop combination applies where the results of the first loop are used by the second. Combining the two allows the intermediate results to be used immediately (in registers) rather than requiring them to be stored in an array. The functional equivalent of horizontal and vertical loop combination are tupling and fusion. 1 1 1 1 1 loop fusion loop combination 1 1 1 1 1 LOOPN A compiler, simulator, and associated source control for an object-oriented Petri net language developed by Charles Lakos <Charles.Lakos@adelaide.edu.au> at the University of Tasmania. In LOOPN, a Petri net is an extension of a coloured timed Petri net. The extension means firstly that token types are classes. In other words, they consist of both data fields and functions, they can be declared by inheriting from other token types, and they can be used polymorphically. The object-oriented extensions also mean that module or subnet types are classes. LOOPN has been developed over a period of about five years at the University of Tasmania, where it has been used in teaching computer simulation and the modelling of network protocols. (ftp://ftp.cs.adelaide.edu.au/pub/OPN/loopn/). (2000-09-02) 1 1 1 1 1 LOOPS Lisp Object-oriented Programming System 1 1 1 1 1 loop through loop 1 1 1 1 1 loose bytes Commonwealth hackish term for the padding bytes or shims many compilers insert between members of a record or structure to cope with alignment requirements imposed by the machine architecture. 1 1 1 1 1 LOP A language based on first-order logic. ["SETHEO - A High-Perormance Theorem Prover for First-Order Logic", Reinhold Letz et al, J Automated Reasoning 8(2):183-212 (1992)]. 1 1 1 1 1 lord high fixer [Primarily British, from Gilbert & Sullivan's "Lord High Executioner"] The person in an organisation who knows the most about some aspect of a system. See wizard. [Jargon File] 1 1 1 1 1 Lore 1. Object-oriented language for knowledge representation. Etude et Realisation d'un Language Objet: LORE, Y. Caseau, These, Paris-Sud, Nov 1987. 2. CGE, Marcoussis, France. Set-based language [same as 1?] E-mail: Christophe Dony <chd.ibp.fr> 1 1 1 1 1 Lorem ipsum A common piece of text used as mock-content when testing a given page layout or font. The following text is often used: "Lorem ipsum dolor sit amet, consectetaur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum." This continues at length and variously. The text is not really Greek, but badly garbled Latin. It started life as extracted phrases from sections 1.10.32 and 1.10.33 of Cicero's "De Finibus Bonorum et Malorum" ("The Extremes of Good and Evil"), which read: Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non 1 1 1 1 1 Lorenz attractor (After Edward Lorenz, its discoverer) A region in the phase space of the solution to certain systems of (non-linear) differential equations. Under certain conditions, the motion of a particle described by such as system will neither converge to a steady state nor diverge to infinity, but will stay in a bounded but chaotically defined region. By chaotic, we mean that the particle's location, while definitely in the attractor, might as well be randomly placed there. That is, the particle appears to move randomly, and yet obeys a deeper order, since is never leaves the attractor. Lorenz modelled the location of a particle moving subject to atmospheric forces and obtained a certain system of ordinary differential equations. When he solved the system numerically, he found that his particle moved wildly and apparently randomly. After a while, though, he found that while the momentary behaviour of the particle was chaotic, the 1 1 1 1 1 LORIA Laboratoire lorrain de recherche en informatique et ses applications 1 1 1 1 1 lose (MIT) 1. To fail. A program loses when it encounters an exceptional condition or fails to work in the expected manner. 2. To be exceptionally unesthetic or crocky. 3. Of people, to be obnoxious or unusually stupid (as opposed to ignorant). 4. Refers to something that is losing, especially in the phrases "That's a lose!" and "What a lose!" [Jargon File] (1995-04-19) 1 1 1 1 1 loser An unexpectedly bad situation, program, programmer, or person. Someone who habitually loses. (Even winners can lose occasionally). Someone who knows not and knows not that he knows not. Emphatic forms are "real loser", "total loser", and "complete loser" (but not **"moby loser", which would be a contradiction in terms). See luser. [Jargon File] (1995-04-19) 1 1 1 1 1 losing Said of anything that is or causes a lose or lossage. [Jargon File] 1 1 1 1 1 loss Something (not a person) that loses; a situation in which something is losing. Emphatic forms include "moby loss", and "total loss", "complete loss". Common interjections are "What a loss!" and "What a moby loss!" Note that "moby loss" is OK even though **"moby loser" is not used; applied to an abstract noun, moby is simply a magnifier, whereas when applied to a person it implies substance and has positive connotations. Compare lossage. (1995-04-19) 1 1 1 1 1 lossage /los'*j/ The result of a bug or malfunction. This is a mass or collective noun. "What a loss!" and "What lossage!" are nearly synonymous. The former is slightly more particular to the speaker's present circumstances; the latter implies a continuing lose of which the speaker is currently a victim. Thus (for example) a temporary hardware failure is a loss, but bugs in an important tool (like a compiler) are serious lossage. [Jargon File] (1995-04-19) 1 1 1 1 1 lossless A term describing a data compression algorithm which retains all the information in the data, allowing it to be recovered perfectly by decompression. Unix compress and GNU gzip perform lossless compression. Opposite: lossy. (1995-03-29) 1 1 1 1 1 lossless audio compression Any kind of audio compression in which the original signal and the decoded signal are bitwise identical. Lossless audio compression algorithms are usually based on a data compression algorithm like PKzip or gzip but specialized for PCM audio data. The signal is divided into predictable tonal components and unpredictable noisy components. Tonal components are stored as coefficients of a predictor, the remaining signal is coded by Rice coding, Huffman coding or arithmetic coding. (2001-12-24) 1 1 1 1 1 Lossless Predictive Audio Compression (LPAC) A lossless audio compression algorithm with compression ratios from 1.5 to 4, depending on the input. Software is available for Microsoft Windows, Linux and Solaris. LPAC files (*.pac) can be played with a Winamp plug-in. (http://www-ft.ee.tu-berlin.de/~liebchen/lpac.html). (2001-12-17) 1 1 1 1 1 lossy A term describing a data compression algorithm which actually reduces the amount of information in the data, rather than just the number of bits used to represent that information. The lost information is usually removed because it is subjectively less important to the quality of the data (usually an image or sound) or because it can be recovered reasonably by interpolation from the remaining data. MPEG and JPEG are examples of lossy compression techniques. Opposite: lossless. (1995-03-29) 1 1 1 1 1 lossy audio compression Any audio compression algorithm which does not retain every bit of data but only reproduces a signal that sounds more or less like the original. Examples are MP1, MP2, MP3, AAC. (2001-12-24) 1 1 1 1 1 lost in the noise Synonym lost in the underflow. This term is from signal processing, where signals of very small amplitude cannot be separated from low-intensity noise in the system. Though popular among hackers, it is not confined to hackerdom; physicists, engineers, astronomers, and statisticians all use it. [Jargon File] 1 1 1 1 1 lost in the underflow Too small to be worth considering; more specifically, small beyond the limits of accuracy or measurement. This is a reference to "floating point underflow". The Hacker's Jargon File claimed that it is also a pun on undertow (a kind of fast, cold current that sometimes runs just offshore and can be dangerous to swimmers). "Well, sure, photon pressure from the stadium lights alters the path of a thrown baseball, but that effect gets lost in the underflow." Compare epsilon, epsilon squared; see also overflow bit. (1997-09-05) 1 1 1 1 1 LOTIS LOgic, TIming, Sequencing. A language which describes a computer via its data flow. [Sammet 1969, p. 620]. 1 1 1 1 1 LOTOS Language Of Temporal Ordering Specification 1 1 1 1 1 lots of MIPS but no I/O Used to describe a person who is technically brilliant but can't seem to communicate with human beings effectively. Technically it describes a machine that has lots of processing power but is bottlenecked on input-output (in 1991, the IBM Rios, a.k.a. RS/6000, is a notorious recent example). [Jargon File] 1 1 1 1 1 Lotus 1-2-3 A spreadsheet for MS-DOS from Lotus Development Corporation. It can be programmed using macros and comes with a separate program to produce graphs and charts but this cannot be run at the same time as the spreadsheet. It has keyboard-driven pop-up menus as well as one-key commands, making it fast to operate. Lotus 1-2-3 supported EGA and later VGA graphics. Early versions used the filename extension "WK1". Version: 4. Lotus 1-2-3 has been the subject of several user interface copyright court cases in the US. (http://nyweb.com/lotus/123.html). 1-2-3's successor, Symphony, had simultaneous update of spreadsheet, graph and word processor windows. (1995-11-28) 1 1 1 1 1 Lotus Development Corporation A software company who produced Lotus 1-2-3, the Symphony spreadsheet and Lotus Notes for the IBM PC. Disliked by the League for Programming Freedom on account of their lawsuits. Quarterly sales $224M, profits $10M (Aug 1994). Telephone: +1 (617) 225 1284. [Where are they? Founded when? Other products? E-mail? Internet?] (1994-11-16) 1 1 1 1 1 Lotus Notes A group of application programs from Lotus Development Corporation which allows organisations to share documents and exchange electronic mail messages. Notes supports replication. (1994-10-27) 1 1 1 1 1 Lotus Notes Formula Language A macro language for Lotus Notes that uses commands starting with @, e.g. @If, @Left, @Right, @Username. Many Notes applications are built with just this language. (2003-10-06) 1 1 1 1 1 LotusScript A Visual BASIC-like scripting language for Lotus Notes and Lotus SmartSuite. LotusScript is object-oriented and can be used for complex Notes programming, although Java is also available. LotusScript Documentation (http://lotus.com/products/lotusscript.nsf). (2003-10-06) 1 1 1 1 1 loudspeaker An electromechanical device for converting an electrical signal into sound. (2008-10-09) 1 1 1 1 1 Lout Lout is a batch text formatting system and an embedded language by Jeffrey H. Kingston <jeff@cs.su.oz.au>. The language is procedural, with Scribe-like syntax. Lout features equation formatting, tables, diagrams, rotation and scaling, sorted indexes, bibliographic databases, running headers and odd-even pages and automatic cross-referencing. Lout is easily extended with definitions which are very much easier to write than troff of TeX macros because Lout is a high-level language, the outcome of an eight-year research project that went back to the beginning. Version 2.05 includes a translator from Lout to PostScript and documentation. and runs under Unix and on the Amiga. Author's site (ftp://ftp.cs.su.oz.au/jeff/lout.2.03.tar.Z), (ftp://ftp.uu.net/tmp/lout.tar.Z). Amiga (ftp://ftp.wustl.edu/pub/aminet/text/dtp/loutBin203.lha). (1993-07-30) 1 1 1 1 1 love What some users feel for computers. "There is no truth in the rumour that I love computers, it's just what I tell them to get them to bed." #NAME? [What did you expect in a computing dictionary?] (2007-05-11) 1 1 1 1 1 low-bandwidth [communication theory] Used to indicate a talk that, although not content-free, was not terribly informative. "That was a low-bandwidth talk, but what can you expect for an audience of suits!" Compare zero-content, bandwidth, math-out. [Jargon File] 1 1 1 1 1 Low Bandwidth X (LBX) An implementation of the X Window System designed to improve performance over ISDN, WAN, and serial lines. [Details?] (2003-07-09) 1 1 1 1 1 low earth orbit (LEO) The kind of orbit used by communications satellites that will offer high bandwidth for video on demand, television, and Internet communications. A satellite in LEO, in contrast to one in a geostationary orbit, is not in a fixed position relative to the Earth's surface so several satellites are required to provide continuous service. [Ovum report, "Applications for the superhighway", John Moroney]. (1996-02-06) 1 1 1 1 1 Lower Layer Protocol (LLP, or lower-layer protocol) Any protocol residing in OSI layers one to four. These protocols package, route, verify and transmit datagrams. A prime example would be TCP/IP. Lower layer protocols support the upper layer protocols. (1999-02-17) 1 1 1 1 1 lower set A finite non-empty downward closed subset of a partial order. (1999-03-17) 1 1 1 1 1 Low Insertion Force (LIF) PGA/SPGA sockets with no handle. The integrated circuit is simply pushed into the socket, and levered out to remove. Most motherboard processor sockets are now ZIF rather than LIF. (1999-08-05) 1 1 1 1 1 LOWL The abstract machine for bootstrapping ML/1, developed by P.J. Brown of the University of Kent at Canterbury. ["Macro Processors and Techniques for Portable Software", P.J. Brown, published by Wiley, ISBN 0.471.11005.1]. [Mentioned in "Machine Oriented Higher Level Languages", W. van der Poel, N-H 1974, p. 271]. [What does LOWL stand for?] (1997-11-04) 1 1 1 1 1 low-level language Any programming language which either is assembly language, or which is meant to be closely related to, and easily translated into, machine language. Low-level languages lack the amenities of high-level languages but it may be possible to write more efficient code in them. (2000-08-10) 1 1 1 1 1 low pass filter A filter that attenuates high frequency components of a signal. In image processing, a low pass filter might be used to remove noise from an image. (2000-04-19) 1 1 1 1 1 Low Voltage Differential (LVD) A method of driving SCSI cables that will be formalised in the SCSI-3 specifications. LVD uses less power than the current differential drive (HVD), is less expensive and will allow the higher speeds of Ultra-2 SCSI. LVD requires 3.3 Volts DC instead of 5 Volts DC for HVD. (1999-02-16) 1 1 1 1 1 LPAC 1. <audio, compression> Lossless Predictive Audio Compression. 2. London Parallel Applications Centre. (2001-12-17) 1 1 1 1 1 LPC A variant of C designed ca 1988 to program LP MUDs. (1995-04-18) 1 1 1 1 1 LPF League for Programming Freedom 1 1 1 1 1 LPG 1. Linguaggio Procedure Grafiche (Italian for "Graphical Procedures Language"). dott. Gabriele Selmi. Roughly a cross between Fortran and APL, with graphical-oriented extensions and several peculiarities. Underlies the products of CAD.LAB Spa. "Graphical Procedure Language User's Guide and Reference Manual", CAD.LAB, Bologna, Italy, 1989, order code GO89/9. 2. Langage de Programmation Generique. An applicative language, both specification and functional. Special emphasis on parametrised declarations. "Design and Implementation of a Generic, Logic and Functional Programming Language", D. Bert et al, ESOP 86, LNCS 213, Springer 1986. 1 1 1 1 1 LPI A PL/I interpreter for IBM PCs and workstations. (ftp://ftp.wustl.edu/mirrors/msdos/pli/runpli1a.arc). E-mail: <rcg@lpi.liant.com>. (1999-09-03) 1 1 1 1 1 LPL List Programming Language. LISP-like language with ALGOL-like syntax, for IBM 360. "LPL - LISP Programming Language", F.W. Blair et al, RC 3062, IBM TJWRC, Sep 1970. 1 1 1 1 1 lpm lines per minute 1 1 1 1 1 LP MUD A kind of player-programmable multi-user adventure game. [More details?] See MUD. 1 1 1 1 1 lpr Line printer. The Unix print command. This does not actually print files but rather copies (or links) them to a spool area from where a daemon copies them to the printer. 1 1 1 1 1 LPS Sets with restricted universal quantifiers. ["Logic Programming with Sets", G. Kuper, J Computer Sys Sci 41:44-64 (1990)]. 1 1 1 1 1 lp spooler A line printer spooler. (2000-04-03) 1 1 1 1 1 LPT /L-P-T/ or /lip'it/ or /lip-it'/ Line printer. Rare under Unix, more common among hackers who grew up with ITS, MS-DOS, CP/M and other operating systems that were strongly influenced by early DEC conventions. [Jargon File] 1 1 1 1 1 lr The country code for Liberia. (1999-01-27) 1 1 1 1 1 LRC Longitudinal Redundancy Check 1 1 1 1 1 LRLTRAN Lawrence Radiation Laboratory TRANslator. A Fortran extension with vector arithmetic and dynamic storage, used for scientific work and systems programming, including the LTSS operating system. ["The LRLTRAN Compiler", S.F. Mendicino, CACM 11(11):747-775 (Nov 1969)]. 1 1 1 1 1 LRU Least Recently Used 1 1 1 1 1 ls 1. <file system, tool> The Unix command for listing a directory. Unix manual page: ls(1). 2. <networking> The country code for Lesotho. (2000-03-18) 1 1 1 1 1 LSA Link State Advertisement 1 1 1 1 1 LSB 1. Least Significant Bit. 2. (Rarely) Least Significant Byte. 1 1 1 1 1 LSE Language Sensitive Editor 1 1 1 1 1 LSL 1. Larch Shared Language. An assertion language. (See Larch). 2. Link and Selector Language. Graphic query language. "LSL: A Link and Selector Language", D.C. Tsichritzis, Proc Intl Conf Management of Data, ACM 1976, pp.123-134. 1 1 1 1 1 LSML Lazy Standard ML 1 1 1 1 1 L-Soft An international corporation formed by Eric Thomas, the author of Listserv, to develop it and port it to platforms other than the IBM VM operating system, including Unix. Listserv has been enhanced to use both the Internet and BITNET. (1995-02-22) 1 1 1 1 1 LSP Label Switched Path 1 1 1 1 1 LSR 1. <networking> Label Switching Router. 2. <operating system> Local Shared Resources. (2002-02-17) 1 1 1 1 1 LSSD level-sensitive scan design 1 1 1 1 1 LSYD Language for SYstems Development. A PL/I-like language with data structure and character extensions. ["Systems Programming Languages", R.D. Bergeron et al, in Advances in Computers 1971, A-P]. (1995-01-31) 1 1 1 1 1 lt The country code for Lithuania. (1999-01-27) 1 1 1 1 1 LT-2 An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-31) 1 1 1 1 1 LTL Linear Temporal Logic 1 1 1 1 1 LTPS Low Temperature Polysilicon 1 1 1 1 1 LTR Langage Temps-Réel. (French for "real-time language") A French predecessor to Ada, LTR is Modula-like with a set of special-purpose real-time constructs based on an event model. It was mentioned in the reference below. ["An Overview of Ada", J.G.P. Barnes, Soft Prac & Exp 10:851-887 (1980)]. (1995-01-31) 1 1 1 1 1 LTR3 Version three of LTR, by A. Parayre of Delegation Generale pour l'Armement, France. LTR3 was widely used by the French military and avionics companies. ["The LTR3 Reference Manual", A. Parayre, Delegation Generale pour l'Armement, France]. (1995-01-31) 1 1 1 1 1 lu The country code for Luxembourg. (1999-01-27) 1 1 1 1 1 LU6.2 Logical Unit 6.2 1 1 1 1 1 lub least upper bound 1 1 1 1 1 Lubarsky's Law of Cybernetic Entomology There is always one more bug. [Jargon File] (2001-07-12) 1 1 1 1 1 Lucent Technologies The former systems and equipment portion of AT&T (including Bell Laboratories), split off in 1996. Lucent Home (http://lucent.com/). (2002-06-23) 1 1 1 1 1 LUCID 1. Early query language, ca. 1965, System Development Corp, Santa Monica, CA. [Sammet 1969, p.701]. 2. A family of dataflow languages descended from ISWIM, lazy but first-order. Ashcroft & Wadge <wwadge@csr.uvic.ca>, 1981. They use a dynamic demand driven model. Statements are regarded as equations defining a network of processors and communication lines, through which the data flows. Every data object is thought of as an infinite stream of simple values, every function as a filter. Lucid has no data constructors such as arrays or records. Iteration is simulated with 'is current' and 'fby' (concatenation of sequences). Higher-order functions are implemented using pure dataflow and no closures or heaps. ["Lucid: The Dataflow Language" by Bill Wadge <wwadge@csr.UVic.CA> and Ed Ashcroft, c. 1985]. ["Lucid, the Dataflow Programming Language", W. Wadge, Academic Press 1 1 1 1 1 Lucid Emacs Xemacs 1 1 1 1 1 Lucinda A language which combines Russell-like polymorphism with Linda-like concurrency. Lucinda is implemented as a threaded interpreter written in C, for a Sun network and a Meiko Computing Surface. ["Lucinda - An Overview", P. Butcher, U York et al, SIGPLAN Notices 26(8):90-100, Aug 1991]. E-mail: Alan Wood <wood@cs.york.ac.uk>. (1996-08-20) 1 1 1 1 1 Lucy A distributed constraint programming language, which is an actor subset of Janus. ["Actors as a Special Case of Concurrent Constraint Programming", K. Kahn <kahn@parc.xerox.com> et al, SIGPLAN Notices 25(10):57-66 (OOPSLA/ ECOOP '90), Oct 1990]. (2001-03-04) 1 1 1 1 1 LUG Linux User Group 1 1 1 1 1 luminance brightness 1 1 1 1 1 lump uncurrying Chin's generalisation of uncurrying. A curried function taking several tuples as arguments can be transformed to take a single tuple containing all the components of the original tuples. 1 1 1 1 1 LUN Logical Unit Number 1 1 1 1 1 lunatic fringe [IBM] Customers who can be relied upon to accept release 1 versions of software. [Jargon File] 1 1 1 1 1 Lund Simula A version of SIMULA from Lund Software House. Version 4.07. (FTP: rascal.ics.utexas.edu/misc/mac/programming/ no longer exists). (1995-03-29) 1 1 1 1 1 Lund Software House AB The company who produced Lund Simula. Address: Box 7056, S-22007 Lund, Sweden. (1995-03-29) 1 1 1 1 1 lurk lurking 1 1 1 1 1 lurker lurking 1 1 1 1 1 lurking The activity of one of the "silent majority" in a electronic forum such as Usenet; posting occasionally or not at all but reading the group's postings regularly. This term is not pejorative and indeed is casually used reflexively: "Oh, I'm just lurking". Often used in "the lurkers", the hypothetical audience for the group's flamage-emitting regulars. Lurking and reading the FAQ are recommended netiquette for beginners who need to learn the history and practises of the group before posting. (1997-06-14) 1 1 1 1 1 luser /loo'zr/ A user; especially one who is also a loser. (luser and loser are pronounced identically.) This word was coined around 1975 at MIT. Under ITS, when you first walked up to a terminal at MIT and typed Control-Z to get the computer's attention, it printed out some status information, including how many people were already using the computer; it might print "14 users", for example. Someone thought it would be a great joke to patch the system to print "14 losers" instead. There ensued a great controversy, as some of the users didn't particularly want to be called losers to their faces every time they used the computer. For a while several hackers struggled covertly, each changing the message behind the back of the others; any time you logged into the computer it was even money whether it would say "users" or "losers". Finally, someone tried the compromise "lusers", and it stuck. Later one of the ITS machines supported "luser" as a 1 1 1 1 1 Luser Attitude Re-adjustment Tool (LART) Something large, heavy and painful, used to respond appropriately to particularly annoying lusers. The alt.sysadmin.recovery FAQ recommends the following LARTs. A 2x4 works fine, but a real professional needs something a little more effective. Unfortunately, this is a very personal thing, and no consensus has yet been reached on the group. Everything from a simple, 7.65mm Walther (for the Bond fans only, it's not a very good gun) to a 155mm with depleted Uranium rounds has been suggested, some even going for exotic things like Thermite, nukes or flamethrowers. For further info, look at the rec.guns home page. alt.sysadmin.recovery FAQ (http://ctrl-c.liu.se/~ingvar/asr/overview.html). (1998-12-09) 1 1 1 1 1 LUSTRE (A French acronym for Synchronous real-time Lucid). Real-time dataflow language for synchronous systems, especially automatic control and signal processing. A Lucid subset, plus timing operators and user-defined clocks. Designed for automatic control applications. It is based on the idea that automatic control engineers use to analyse, and specify their systems in terms of functions over sequences (sampled signals). It thus seems both safe and cost effective to try to compile directly those descriptions into executable code. A lot of work has been done, so as to get efficient compilation, and also in formal verification. The language has been used in nuclear plant control, and will be used in aircraft control. ["Outline of a Real-Time Data-Flow Language", J.-L. Bergerand et al, Proc IEE-CS Real Time Systems Symp, San Diego, IEEE Dec 1985, pp. 33-42]. ["LUSTRE: A Declarative Language for Programming Synchronous 1 1 1 1 1 lv The country code for Latvia. (1999-01-27) 1 1 1 1 1 lvalue A reference to a location, an expression which can appear as the destination of an assignment operator indicating where a value should be stored. For example, a variable or an array element are lvalues but the constant 42 and the expression i+1 are not. A constant string may or may not be an lvalue (it usually is in C). (1995-04-28) 1 1 1 1 1 LVD Low Voltage Differential 1 1 1 1 1 LWP light-weight process. (1996-02-22) 1 1 1 1 1 ly The country code for Libya. (1999-01-27) 1 1 1 1 1 LYaPAS (Russian acronym for "Logical Language for the Representation of Synthesis Algorithms") A language for the URAL-1 computer. It was coded in octal! ["LYaPAS: A Programming Language for Logic and Coding Algorithms", M.A. Gavrilov et al eds, Academic Press 1969]. (1995-02-16) 1 1 1 1 1 Lycos A web index, served by Carnegie Mellon University. It allows you to search on document title and content for a list of keywords. Lycos is probably the biggest such index on the web. By April 1995, the Lycos database contained 2.95 million unique documents. The Lycos database is built by a Web crawler that can bring in 5000 documents per day. The index searches document title, headings, links, and keywords it locates in these documents. The Lycos servers are efficient but overloaded. Failure to connect or "please try later" messages are common. (http://lycos.cs.cmu.edu/). (1995-04-06) 1 1 1 1 1 lylafklc Love you like a fat kid loves cake. (2006-12-12) 1 1 1 1 1 lynix Misspelling of "Linux" (the Unix clone), or possibly "lynx" (the web browser). (1995-04-06) 1 1 1 1 1 LYNX A language for large distributed networks, using remote procedure calls, developed by the University of Wisconsin in 1984. ["The Lynx Distributed Programming Language: Motivation, Design and Experience", M.L. Scott, Computer Langs 16:209-233 (1991)]. (1994-10-12) 1 1 1 1 1 Lynx 1. A WWW browser from the University of Kansas for use on cursor-addressable, character cell terminals or terminals emulators under Unix or VMS. Lynx is a product of the Distributed Computing Group within Academic Computing Services of The University of Kansas. Lynx was originally developed by Lou Montulli, Michael Grobe and Charles Rezac. Garrett Blythe created DosLynx and later joined the Lynx effort as well. Foteos Macrides ported much of Lynx to VMS and is now maintaining it. Version: 2.4-FM (1995-10-25). (http://cc.ukans.edu/about_lynx/about_lynx.html). Mailing list: lynx-dev@ukanaix.cc.ukans.edu (send "subscribe lynx-dev <your-name>" in the message body to listserv@ukanaix.cc.ukans.edu). (1994-12-07) 2. Lynx Real-Time Systems. (1996-03-25) 1 1 1 1 1 LynxOS A POSIX compliant real-time operating system from Lynx Real-Time Systems. It has a Unix-like interface to application programs. (1994-10-12) 1 1 1 1 1 Lynx Real-Time Systems A company in Los Gatos, California who distribute LynxOS. (http://lynx.com/). E-mail: <sales@lynx.com>, <support@lynx.com>. Address: 16780 Lark Avenue, Los Gatos, CA 95030, USA. Telephone:: +1 (408) 354 7770, +1 (800) 255 LYNX. Fax: +1 (408) 354 7085. (1995-01-18) 1 1 1 1 1 LYRIC Language for Your Remote Instruction by Computer. A CAI language implemented as a Fortran preprocessor. ["Computer Assisted Instruction: Specification of Attributes for CAI Programs and Programmers", G.M. Silvern et al, Proc ACM 21st Natl Conf (1966)]. (1994-10-12) 1 1 1 1 1 LZ77 compression The first algorithm to use the Lempel-Ziv substitutional compression schemes, proposed in 1977. LZ77 compression keeps track of the last n bytes of data seen, and when a phrase is encountered that has already been seen, it outputs a pair of values corresponding to the position of the phrase in the previously-seen buffer of data, and the length of the phrase. In effect the compressor moves a fixed-size "window" over the data (generally referred to as a "sliding window"), with the position part of the (position, length) pair referring to the position of the phrase within the window. The most commonly used algorithms are derived from the LZSS scheme described by James Storer and Thomas Szymanski in 1982. In this the compressor maintains a window of size N bytes and a "lookahead buffer", the contents of which it tries to find a match for in the window: while (lookAheadBuffer not empty) 1 1 1 1 1 LZ78 compression A substitutional compression scheme which works by entering phrases into a dictionary and then, when a reoccurrence of that particular phrase is found, outputting the dictionary index instead of the phrase. Several algorithms are based on this principle, differing mainly in the manner in which they manage the dictionary. The most well-known Lempel-Ziv scheme is Terry Welch's Lempel-Ziv Welch variant of LZ78. [comp.compression FAQ]. 1 1 1 1 1 LZ compression Lempel-Ziv compression 1 1 1 1 1 lzexe An executable file compression utility for MS-DOS. It adds a minimal header to the executable to decompress it when it is executed. See also pklite. 1 1 1 1 1 lzh The filename extension for a file produced by the LHA program. (1995-04-03) 1 1 1 1 1 LZH compression (After Lempel-Ziv and Haruyasu, the inventors) A compression algorithm derived from the LZSS scheme with a sliding window and additional compression applied to the output of the LZSS compressor by dynamic Huffman coding. (1995-04-07) 1 1 1 1 1 LZW compression Lempel-Ziv Welch compression 1 1 1 1 1 M 1. Alternative name for MUMPS. 2. A C-like language from Silicon Compiler Systems for multilevel hardware description. It is currently available in the GDT package from Mentor Graphics. [Jargon File] (1994-10-26) 3. <unit> The abbreviated for of mega-. (1995-01-10) 1 1 1 1 1 m2 A Modula-2 compiler for VAX and MIPS. A Pascal compiler for VAX is also included. The Pascal compiler accepts a language that is almost identical to Berkeley Pascal. It was originally designed and built by Michael L. Powell in 1984. Joel McCormack made it faster, fixed lots of bugs, and swiped/wrote a User's Manual. Len Lattanzi ported it to the MIPS. It has the following extensions: foreign function and data interface, dynamic array variables, subarray parameters, multi-dimensional open array parameters, inline procedures, longfloat type, type-checked interface to C library I/O routines. It runs on VAX (Ultrix, BSD) and MIPS (Ultrix). (ftp://gatekeeper.dec.com/pub/DEC/Modula-2/m2.tar.Z). E-mail: <modula-2@decwrl.pa.dec.com>. (1992-07-06) 1 1 1 1 1 M2toM3 A simple Modula-2 to Modula-3 translator by Peter Klein <pk@i3.informatik.rwth-aachen.de> which covers most of the syntactic differences between those languages. No context sensitive analysis is done, so WITH statements, local modules, enumeration type literals and variant RECORDs have to be dealt with by hand. Part of the Sun Modula 2 library is emulated by the Modula 3 library. Version 1.01. (ftp://martha.informatik.rwth-aachen.de/pub/Modula3). (1992-12-01) 1 1 1 1 1 M3 A macro processor, forerunner of M4, for the AP-3 minicomputer. 1 1 1 1 1 m4 A macro processor for Unix and GCOS which is more flexible than cpp. m4 copies its input to the output, expanding macros which can be either built-in or user-defined. m4 has built-in functions for including files, running Unix commands, doing integer arithmetic, manipulating text in various ways and recursing. m4 can be used either as a front-end to a compiler or as a stand-alone tool. sendmail's configuration file (/etc/sendmail.cf) is writen in m4 macros. There is a GNU m4 v1.1 (ftp://gnu.org/pub/gnu/m4-1.0.tar.Z) by Francois Pinard <pinard@iro.umontreal.ca> and a public domain version by Ozan Yigit <oz@sis.yorku.ca> and Richard A. O'Keefe <ok@goanna.cs.rmit.OZ.AU> (FTP from any 386BSD, NetBSD or FreeBSD archive). A Macintosh version is here (ftp://nic.switch.ch/pub/software/mac/src/mpw-c/). See also m3, m5. 1 1 1 1 1 M5 Macro processor, a generalisation of M4 by A. Dain, U Cincinnati, 1992. For Unix and DOS. (ftp://thor.exe.u.edu/pub/dain/m5). 1 1 1 1 1 ma The country code for Morocco. (1999-01-27) 1 1 1 1 1 MAC 1. Media Access Control. 2. Early system on Ferranti Mercury. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 Mac The line of computers manufactured by Apple Inc. Mac is not primarily a nickname or an abbreviation, but a brand name and trademark in its own right. Apple currently (2009) refer to the brand as any of "Mac", "iMac" or Macintosh (all registered trademarks). The Mac was Apple's successor to the Lisa. The project was proposed by Jef Raskin some time before Steve Jobs's famous visit to Xerox PARC. Jobs tried to scuttle the Macintosh project and only joined it later because he wasn't trusted to manage the Lisa project. The Macintosh user interface was notable for popularising the graphical user interface, with its easy to learn and easy to use desktop metaphor. The first Macintosh, introduced in January 1984, had a Motorola 68000 CPU, 128K of RAM, a small monochrome screen, and one built-in floppy disk drive with an external slot for one more, two serial ports and a four-voice sound 1 1 1 1 1 Mac-1 The assembly language used in the book cited below. See Mic-1. ["Structured Computer Organization", A.S. Tanenbaum, 3rd Edition, P-H 1989, Sect. 4.3]. (1996-04-07) 1 1 1 1 1 MAC-360 A system for solving numerical problems using equation-like input. Developed around 1967. ["User's Guide to MAC-360", Charles Stark Draper Lab, Cambridge MA (Aug 1973)]. [Sammet 1969, p. 264]. 1 1 1 1 1 MACA Multiple Access with Colision Avoidance 1 1 1 1 1 MAC address The hardware address of a device connected to a shared network medium. See also Media Access Control. 1 1 1 1 1 MACAnalyst An analysis CASE tool for the Macintosh from Excel Software, Inc. 1 1 1 1 1 Macaulay A symbolic mathematics package for commutative algebra, algebraic geometry and cohomology, written in C by Mike Stillman <mike@mssun7.msi.cornell.edu> and Dave Bayer <bayer@cUnixa.columbia.edu> in 1977. Version 3 runs on Sun, Macintosh and Amiga. (ftp://zariski.harvard.edu/). (1994-10-12) 1 1 1 1 1 MacBinary An eight-bit wide representation of the data and resource forks of an Macintosh file and of relevant Finder information. MacBinary files are recognised as special by several MacIntosh terminal emulators. These emulators, using Kermit or XMODEM or any other file transfer protocol, can separate the incoming file into forks and appropriately modify the Desktop to display icons, types, creation dates, and the like. (1995-03-08) 1 1 1 1 1 MACDesigner A design CASE tool for the Mac from Excel Software, Inc. 1 1 1 1 1 macdink /mak'dink/ To make many incremental and unnecessary cosmetic changes to a program or file. Often the subject of the macdinking would be better off without them. The Macintosh is said to encourage such behaviour. See also fritterware, window shopping. [Jargon File] (1994-11-22) 1 1 1 1 1 MACE A concurrent object-oriented language. 1 1 1 1 1 Mach An operating system kernel under development at Carnegie-Mellon University to support distributed and parallel computation. Mach is designed to support computing environments consisting of networks of uniprocessors and multiprocessors. Mach is the kernel of the OSF/1. 1 1 1 1 1 Machiavelli An extension of Standard ML developed by Peter Buneman & Atsushi Ohori of the University of Pennsylvania in 1989, based on orthogonal persistence. ["Database Programming in Machiavelli: A Polymorphic Language with Static Type Inference", A. Ohori, Proc SIGMOD Conf, ACM, June 1989]. (1995-02-21) 1 1 1 1 1 machinable Machine-readable. Having the softcopy nature. [Jargon File] 1 1 1 1 1 machine Common term for "computer", usually when considered at the hardware level. The Turing Machine, an early example of this usage, was however neither hardware nor software, but only an idea. [Earlier use?] (1995-02-15) 1 1 1 1 1 machine code The representation of a computer program that is read and interpreted by the computer hardware (rather than by some other machine code program). A program in machine code consists of a sequence of "instructions" (possibly interspersed with data). An instruction is a binary string, (often written as one or more octal, decimal or hexadecimal numbers). Instructions may be all the same size (e.g. one 32-bit word for many modern RISC microprocessors) or of different sizes, in which case the size of the instruction is determined from the first word (e.g. Motorola 68000) or byte (e.g. Inmos transputer). The collection of all possible instructions for a particular computer is known as its "instruction set". Each instruction typically causes the Central Processing Unit to perform some fairly simple operation like loading a value from memory into a register or adding the numbers in two registers. An instruction consists of an op code and 1 1 1 1 1 machine cycle The four steps which the CPU carries out for each machine language instruction: fetch, decode, execute, and store. These steps are performed by the control unit, and may be fixed in the logic of the CPU or may be programmed as microcode which is itself usually fixed (in ROM) but may be (partially) modifiable (stored in RAM). The fetch cycle places the current program counter contents (the address of the next instruction to execute) on the address bus and reads in the word at that location into the instruction register (IR). In RISC CPUs instructions are usually a single word but in other architectures an instruction may be several words long, necessitating several fetches. The decode cycle uses the contents of the IR to determine which gates should be opened between the CPU's various functional units and busses and what operation the ALU(s) should perform (e.g. add, bitwise and). Each gate allows 1 1 1 1 1 MAchine INdependent SAIL (MAINSAIL) From XIDAK, Palo Alto CA, +1 (415) 855 9271. (2006-12-06) 1 1 1 1 1 machine instruction The smallest element of a machine code program. (2009-06-23) 1 1 1 1 1 machine language machine code 1 1 1 1 1 machine learning The ability of a machine to improve its performance based on previous results. Neural networks are one kind of machine learning. [More examples? Net resources? Web page?] (1995-02-15) 1 1 1 1 1 Mach Interface Generator (MIG) An implementation of a subset of Matchmaker that generates C and C++ remote procedure call interfaces for interprocess communication between Mach tasks. ["MIG - The Mach Interface Generator", R.P. Draves et al, CS CMU, (1989-08-4)]. (1994-11-22) 1 1 1 1 1 machoflops /mach'oh-flops/ A pun on "megaflops" referring to the inflated performance figures often quoted by computer manufacturers. Real application programs are lucky to get half the quoted speed. See Your mileage may vary, benchmark. [Jargon File] (1995-02-15) 1 1 1 1 1 Mac II Macintosh II 1 1 1 1 1 Mac IIcx Macintosh IIcx 1 1 1 1 1 Macintosh One of the trademark/brand names that Apple Inc use for their Mac family of personal computers. (2009-05-05) 1 1 1 1 1 Macintosh Common Lisp (MCL) Common Lisp for the Apple Macintosh. Guillaume Cartier, of the Mathematics Department at UQAM, Canada, has written some libraries. Latest version: 1.2. (ftp://cambridge.apple.com/pub/mcl2/contrib/). (1992-11-30) 1 1 1 1 1 Macintosh file system A file on the Macintosh consists of two parts, called forks. The "data fork" contains the data which would normally be stored in the file on other operating systems. The "resource fork" contains a collection of arbitrary attribute/value pairs, including program segments, icon bitmaps, and parametric values. Yet more information regarding Macintosh files is stored by the Finder in a hidden file, called the "Desktop Database". Because of the complications in storing different parts of a Macintosh file in non-Macintosh file systems that only handle consecutive data in one part, it is common to only send the Data fork or to convert the Macintosh file into some other format before transferring it. (1996-03-03) 1 1 1 1 1 Macintosh II (Mac II) A version of Apple's Macintosh personal computer, released in March 1987, using the Motorola 68020 CPU, which runs at a higher clock rate than the Motorola 68000 used in the original Mac. The Mac II has a full 32-bit data bus instead of a 16-bit bus. Mac II models have built-in 40 to 160 megabyte hard disks and can take up to eight megabytes of RAM (and more as denser memory chips arive). The Mac II was the first Macintosh to provide a colour graphics option, with up to 256 colours on screen at a 640x480 resolution. Mac II models are designed for expandability with three (Macintosh IIcx) or six (II & IIx) built-in NuBus expansion slots for additional peripheral and coprocessor boards. (1996-05-25) 1 1 1 1 1 Macintosh IIcx (Mac IIcx) A version of Apple's Macintosh II personal computer, introduced in 1989, with a Motorola 68030 processor running at 16 MHz and up to 128 MB of RAM (120 ns, 30-pin DRAM chips). The IIcx requires System 6.0.3 or later and requires "Mode 32" or "32-bit Enabler" to use more than 8MB of RAM. It was discontinued 1991, and in 1996 is still considered one of the best-designed Macs ever. (1996-05-25) 1 1 1 1 1 Macintosh Operating System (Mac OS) Apple Computer, Inc.'s proprietary operating system for their Macintosh family of personal computers. The part of the operating system that simulates the desktop is called "Finder." The multitasking version of Finder was called "MultiFinder" until multitasking was integrated into the core of the OS with the introduction of System 7.0 in 1990 The Macintosh series provides a built-in graphics language, called "QuickDraw", which provides a standard for software developers. Mac OS 8, scheduled for delivery in July 1997, included new human-interface features, increased system stability and performance, a PowerPC processor-native Finder, tighter integration of Internet access through panel-based assistants, Personal Web Sharing and the ability to run Java applets and programs through Mac OS Run Time for 1 1 1 1 1 Macintosh user interface The graphical user interface used by Apple Computer's Macintosh family of personal computers, based on graphical representations of familiar office objects (sheets of paper, files, wastepaper bin, etc.) positioned on a two-dimensional "desktop" workspace. Programs and data files are represented on screen by small pictures (icons). An object is selected by moving a mouse over the real desktop which correspondingly moves the pointer on screen. When the pointer is over an icon on screen, the icon is selected by pressing the button on the mouse. A hierarchical file system is provided that lets a user drag a document (a file) icon into and out of a folder (directory) icon. Folders can also contain other folders and so on. To delete a document, its icon is dragged into a trash can icon. For people that are not computer enthusiasts, managing files on the Macintosh is easier than 1 1 1 1 1 Macintoy /mak'in-toy/ The Apple Macintosh, considered as a toy. Less pejorative than Macintrash. [Jargon File] 1 1 1 1 1 Macintrash /mak'in-trash"/ The Apple Macintosh, as described by a hacker who doesn"t appreciate being kept away from the *real computer* by the interface. The term maggotbox has been reported in regular use in the Research Triangle area of North Carolina. Compare Macintoy. See also beige toaster, WIMP environment, point-and-drool interface, drool-proof paper, user-friendly. (1995-05-02) 1 1 1 1 1 MACL Macintosh Allegro CL. E-mail: <info-macl@cambridge.apple.com>. 1 1 1 1 1 MacLisp A dialect of Lisp developed at MIT AI Lab in 1966, known for its efficiency and programming facilities. MacLisp was later used by Project MAC, Mathlab and Macsyma. It ran on the PDP-10. It introduced the LEXPR (a function with variable arity), macros, arrays, and CATCH/THROW. MacLisp was one of two main branches of LISP (the other being Interlisp). In 1981 Common LISP was begun in an effort to combine the best features of both. ["MACLISP Reference Manual", D.A. Moon <moon@cambridge.apple.com>, TR Project MAC, MIT 1974]. (2004-05-07) 1 1 1 1 1 MacMinix The Macintosh version of MINIX. [Details? URL?] (1997-06-17) 1 1 1 1 1 Mac OS Macintosh Operating System 1 1 1 1 1 Mac OS X /mak oss ten/ Version 10 of the Macintosh Operating System, based on FreeBSD unlike prevoius versions. Apple released the kernel of Mac OS X Server as darwin, under an open source license. Mac OS X incldues a code framework called the "Core Foundation" and an Application Kit framework for GUI and widgets strongly derived from NEXTSTEP. (2007-03-15) 1 1 1 1 1 Mac Playmate An early (~1985) example of a pornographic computer game. Mac Playmate runs on the Macintosh and involves trying to stimulate a simulated woman to orgasm by applying various implements to her erogenous zones. (2002-03-08) 1 1 1 1 1 MacPPP An implementation of PPP for the Macintosh developed by Larry J. Blunk and others at Merit Network, Inc. MacPPP was revised in 1993 with the release of MacPPP 2.0.1. The latest incarnation of MacPPP is FreePPP. (2000-11-25) 1 1 1 1 1 MACRO 1. Assembly language for VAX/VMS. 2. PL/I-like language with extensions for string processing. MACRO: A Programming Language, S.R. Greenwood, SIGPLAN Notices 14(9):80-91 (Sep 1979). [Jargon File] 1 1 1 1 1 macro A name (possibly followed by a formal argument list) that is equated to a text or symbolic expression to which it is to be expanded (possibly with the substitution of actual arguments) by a macro expander. The term "macro" originated in early assemblers, which encouraged the use of macros as a structuring and information-hiding device. During the early 1970s, macro assemblers became ubiquitous, and sometimes quite as powerful and expensive as HLLs, only to fall from favour as improving compiler technology marginalised assembly language programming (see languages of choice). Nowadays the term is most often used in connection with the C preprocessor, Lisp, or one of several special-purpose languages built around a macro-expansion facility (such as TeX or Unix's troff suite). Indeed, the meaning has drifted enough that the collective macros is now sometimes used for code in any special-purpose 1 1 1 1 1 macro- Prefix large. Opposite of micro-. In the mainstream and among other technical cultures (for example, medical people) this competes with the prefix mega-, but hackers tend to restrict the latter to quantification. [Jargon File] 1 1 1 1 1 macrology /mak-rol'*-jee/ 1. Set of usually complex or crufty macros, e.g. as part of a large system written in Lisp, TECO, or (less commonly) assembler. 2. The art and science involved in comprehending a macrology. Sometimes studying the macrology of a system is not unlike archaeology, ecology, or theology, hence the sound-alike construction. See also boxology. (2003-09-02) 1 1 1 1 1 Macromedia A company supplying multimedia and interactive television services and digital arts software tools in the US and worldwide. They produce products for Microsoft Windows and the Macintosh including: Macromedia FreeHand, a tool for design and illustration; Macromedia Director, an animation and authoring tool for multimedia production; Authorware Professional, a multiplatform authoring tool for interactive learning; MacroModel, a 3D modelling tool for multimedia, graphics and product design; SoundEdit 16, a digital sound recording and editing system; Fontographer, a typeface editing programme; and Action!, a multimedia presentation application. Chief Executive Officer: Bud Colligan. (1995-01-10) 1 1 1 1 1 macro preprocessor preprocessor 1 1 1 1 1 Macro SAP Macro processing modification of SAP. D.E. Eastwood and D.M. McIlroy, unpublished memorandum, Bell Labs 1959. Led to TRAC. 1 1 1 1 1 macrotape /mak'roh-tayp/ An industry-standard reel of magnetic tape, as opposed to a microtape. See also round tape. [Jargon File] (1994-10-20) 1 1 1 1 1 MACSYMA Project MAC's SYmbolic MAnipulator. The first comprehensive symbolic mathematics system, written in Lisp by Joel Moses <moses@larch.lcs.mit.edu> of MIT in 1969, later Symbolics, Inc. Versions include Symbolics Macsyma, DOE Maxima (ANL, in Common LISP) and Vaxima. (ftp://rascal.ics.utexas.edu/pub/maxima-4-155.tar.Z). E-mail: <macsyma-service@symbolics.com>. ["MACSYMA - The Fifth Year", J. Moses, SIGSAM Bulletin 8(3) (Aug 1974)]. (1994-11-01) 1 1 1 1 1 MacTCP Part of earlier versions of MacOS that provided access to TCP/IP services. Apple removed MacTCP from MacOS in revision 7.5.3 in favor of the new OpenTransport (OT) TCP/IP stack. However, MacTCP lives on as a community development effort. See also MacPPP. [How did it work? Where was it from?] (2000-06-25) 1 1 1 1 1 MacX A package allowing the Macintosh to be used as an X server. 1 1 1 1 1 MAD 1. Michigan Algorithm Decoder. 2. A data flow language. ["Implementation of Data Structures on a Data Flow Computer", D.L. Bowen, Ph.D. Thesis, Victoria U Manchester, Apr 1981]. (1999-12-10) 1 1 1 1 1 Mad/1 A later, much enhanced version of Michigan Algorithm Decoder (MAD), for the IBM 360. Mad/1 was University of Michigan's answer to PL/I. (1999-12-10) 1 1 1 1 1 Madaline A structure of many ADALINE units. 1 1 1 1 1 MADCAP Math and set problems, for the Maniac II and CDC 6600. "MADCAP - A Scientific Compiler for a Displayed Formula Texbook Language, M.B. Wells, CACM 4(1):31-36 (Jan 1961)." Sammet 1969, pp.271-281. Versions: Madcap 5 (1964), Madcap 6. The Unified Data Structure Capability in Madcap 6, M.B. Wells et al, Intl J Comp Info Sci 1(3) (sep 1972). 1 1 1 1 1 MADTRAN Early preprocessor that translated Fortran to MAD, for gain in speed. 1 1 1 1 1 maggotbox /mag'*t-boks/ An even more derogatory term than Macintrash. [Jargon File] (1995-01-25) 1 1 1 1 1 MAGIC An early system on the Midac computer. [Listed in CACM 2(5):16 (May 1959)]. [Jargon File] (1995-01-25) 1 1 1 1 1 magic 1. As yet unexplained, or too complicated to explain; compare automagically and (Arthur C.) Clarke's Third Law: Any sufficiently advanced technology is indistinguishable from magic. TTY echoing is controlled by a large number of magic bits. "This routine magically computes the parity of an 8-bit byte in three instructions." 2. Characteristic of something that works although no one really understands why (this is especially called black magic). 3. (Stanford) A feature not generally publicised that allows something otherwise impossible or a feature formerly in that category but now unveiled. Compare wizardly, deep magic, heavy wizardry. For more about hackish "magic" see Magic Switch Story. 4. magic number. 1 1 1 1 1 magic bullet (Or "silver bullet" from vampire legends) A term widely used in software engineering for a supposed quick, simple cure for some problem. E.g. "There's no silver bullet for this problem". (1999-01-13) 1 1 1 1 1 magic cookie 1. Something passed between routines or programs that enables the receiver to perform some operation; a capability ticket or opaque identifier. Especially used of small data objects that contain data encoded in a strange or intrinsically machine-dependent way. E.g. on non-Unix operating systems with a non-byte-stream model of files, the result of "ftell" may be a magic cookie rather than a byte offset; it can be passed to "fseek", but not operated on in any meaningful way. The phrase "it hands you a magic cookie" means it returns a result whose contents are not defined but which can be passed back to the same or some other program later. 2. An in-band code for changing graphic rendition (e.g. inverse video or underlining) or performing other control functions. Some older terminals would leave a blank on the screen corresponding to mode-change magic cookies; this was also called a glitch (or occasionally a "turd"; compare mouse droppings). 1 1 1 1 1 magic number 1. In source code, some non-obvious constant whose value is significant to the operation of a program and that is inserted inconspicuously in-line (hard-coded), rather than expanded in by a symbol set by a commented "#define". Magic numbers in this sense are bad style. 2. A number that encodes critical information used in an algorithm in some opaque way. The classic examples of these are the numbers used in hash or CRC functions or the coefficients in a linear congruential generator for pseudorandom numbers. This sense actually predates, and was ancestral to, the more common sense 1. 3. Special data located at the beginning of a binary data file to indicate its type to a utility. Under Unix, the system and various applications programs (especially the linker) distinguish between types of executable file by looking for a magic number. Once upon a time, these magic 1 1 1 1 1 Magic Paper An early interactive symbolic mathematics system. [Sammet 1969, p. 510]. (1995-01-25) 1 1 1 1 1 magic smoke A substance trapped inside integrated circuit packages that enables them to function (also called blue smoke; this is similar to the archaic "phlogiston" hypothesis about combustion). Its existence is demonstrated by what happens when a chip burns up - the magic smoke gets let out, so it doesn't work any more. See Electing a Pope, smoke test. Usenetter Jay Maynard tells the following story: "Once, while hacking on a dedicated Zilog Z80 system, I was testing code by blowing EPROMs and plugging them in the system then seeing what happened. One time, I plugged one in backward. I only discovered that *after* I realised that Intel didn't put power-on lights under the quartz windows on the tops of their EPROMs - the die was glowing white-hot. Amazingly, the EPROM worked fine after I erased it, filled it full of zeros, then erased it again. For all I know, it's still in service. Of course, this is because the magic smoke didn't get let out." Compare the original phrasing of Murphy's Law. [Jargon File] (1995-01-25) 1 1 1 1 1 Magic Switch Story Some years ago, I was snooping around in the cabinets that housed the MIT AI Lab's PDP-10, and noticed a little switch glued to the frame of one cabinet. It was obviously a homebrew job, added by one of the lab's hardware hackers (no-one knows who). You don't touch an unknown switch on a computer without knowing what it does, because you might crash the computer. The switch was labelled in a most unhelpful way. It had two positions, and scrawled in pencil on the metal switch body were the words "magic" and "more magic". The switch was in the "more magic" position. I called another hacker over to look at it. He had never seen the switch before either. Closer examination revealed that the switch had only one wire running to it! The other end of the wire did disappear into the maze of wires inside the computer, but it's a basic fact of electricity that a switch can't do anything unless there are two wires connected to it. 1 1 1 1 1 Magma A program used for heavy duty algebraic computation in many branches of mathematics. Magma, developed by John Cannon and associates at the University of Sydney, succeeded Cayley. It runs at several hundred sites. E-mail: <magma@maths.usyd.edu.au>. (http://maths.usyd.edu.au:8000/u/magma/). [W. Bosma, J. Cannon and C. Playoust, The Magma algebra system I: The user language, J. Symb. Comp., 24, 3/4, 1997, 235-265]. (2000-12-21) 1 1 1 1 1 Magma2 A language that allows programmability of the control environment, e.g. recursion, backtracking, coroutines, nondeterminism, etc. Magma2 was the successor to MagmaLISP. ["Magma2: A Language Oriented Toward Experiments in Control", Franco Turini, ACM TOPLAS 6(4):468-486 (Oct 1984)]. (1995-07-30) 1 1 1 1 1 MagmaLISP The predecessor of Magma2. ["MagmaLISP: A Machine Language for Artificial Intelligence", C. Mantagero et al, Proc 4th Intl Joint Conf Artif Intell, 1975, pp. 556-561]. (1995-07-30) 1 1 1 1 1 magnetic disk A flat rotating disc covered on one or both sides with magnetisable material. The two main types are the hard disk and the floppy disk. Data is stored on either or both surfaces of discs in concentric rings called "tracks". Each track is divided into a whole number of "sectors". Where multiple (rigid) discs are mounted on the same axle the set of tracks at the same radius on all their surfaces is known as a "cylinder". Data is read and written by a disk drive which rotates the discs and positions the read/write heads over the desired track(s). The latter radial movement is known as "seeking". There is usually one head for each surface that stores data. To reduce rotational latency it is possible, though expensive, to have multiple heads at different angles. The head writes binary data by magnetising small areas or zones of the disk in one of two opposing orientations. It reads data by detecting current pulses induced in a coil as 1 1 1 1 1 Magnetic Ink Character Recognition (MICR) A character recognition system using special ink and characters which can be magnetised and read automatically. MICR is used almost exclusively in the banking industry where it is used to print details on cheques to enable automatic processing. (1995-04-13) 1 1 1 1 1 magnetic stripe A black stripe, printed on the back of a credit card or similar, that stores a machine-readable copy of the information on the card. The stripe contains iron particles about 500 nanometers long that can be magnetised like magnetic tape. The data can be read by swiping the card through a card reader. (2007-06-04) 1 1 1 1 1 magnetic tape (Or "magtape", "tape" - paper tape is now obsolete) A data storage medium consisting of a magnetisable oxide coating on a thin plastic strip, commonly used for backup and archiving. Early industry-standard magnetic tape was half an inch wide and wound on removable reels 10.5 inches in diameter. Different lengths were available with 2400 feet and 4800 feet being common. DECtape was a variation on this "round tape". In modern magnetic tape systems the reels are much smaller and are fixed inside a cartridge to protect the tape and for ease of handling ("square tape" - though it's really rectangular). Cartridge formats include QIC, DAT, and Exabyte. Tape is read and written on a tape drive (or "deck") which winds the tape from one reel to the other causing it to move past a read/write head. Early tape had seven parallel tracks 1 1 1 1 1 magnetic tape drive (Or "tape drive") A peripheral device that reads and writes magnetic tape. (1996-05-25) 1 1 1 1 1 magneto-optical disk (MO) A plastic or glass disk coated with a compound (often TbFeCo) with special optical, magnetic and thermal properties. The disk is read by bouncing a low-intensity laser off the disk. Originally the laser was infrared, but frequencies up to blue may be possible giving higher storage density. The polarisation of the reflected light depends on the polarity of the stored magnetic field. To write, a higher intensity laser heats the coating up to its Curie point, allowing its magnetisation to be altered in a way that is retained when it has cooled. Although optical, they appear as hard drives to the operating system and do not require a special filesystem (they can be formatted as FAT, HPFS, NTFS, etc.). The initial 5.25" MO drives, introduced at the end of the 1980s, were the size of a full-height 5.25" hard drive (like in IBM PC XT) and the disks looked like a CD-ROM enclosed in an old-style cartridge 1 1 1 1 1 magneto-optical drive magneto-optical disk 1 1 1 1 1 magnetostrictive delay line An early storage device that used tensioned wires of nickel alloy carrying longitudinal waves produced and detected electromagnetically. They had better storage behaviour than mercury delay lines. [H. Epstein and O.B. Stram, "A High Performance Magnetostriction-Sonic Delay Line," Transactions, Institute of Radio Engineers, Professional Group on Ultrasonic Engineering, 1957, pp. 1-24]. (2002-11-08) 1 1 1 1 1 MAGNUM A database language for DEC-10's, used internally by Tymshare, Inc.. MAGNUM was designed in the late 1970's by Dale Jordan, Rich Strauss and Dave McQuoid originally, and was written in BLISS-10. It was the world's first commercial relational database. It was in the process of being written in 1976. (1995-01-25) 1 1 1 1 1 Magritte A constraint language for interactive graphical layout by J. Gosling. It solves constraints using algebraic transformations. ["Algebraic Constraints", J. Gosling, PhD Thesis, TR CS-83-132, CMU, May 1983]. (1994-10-20) 1 1 1 1 1 mail 1. electronic mail. 2. The Berkeley Unix program for composing and reading electronic mail. It normally uses sendmail to handle delivery. Unix manual page: mail(1) (1997-12-03) 1 1 1 1 1 Mail Application Programming Interface Messaging Application Programming Interface 1 1 1 1 1 mail bomb To send, or urge others to send, massive amounts of electronic mail to a single system or person, with intent to crash or spam the recipient's system. A successful mail bomb may cause the victim's disk quota to be exhausted, the disk holding his mailbox to fill up, or his computer to spend a large proportion of its time processing mail. Mail-bombing is sometimes done in retaliation against someone persistently abusing Usenet and violating netiquette. While it may inconvenience the intended victim (if they gave their real address), it will probably also inconvenience other users and administrators of the computers and networks involved. Mailbombing is thus a serious offense itself. See netiquette for the correct way to respond to perceived violations. Compare letterbomb, nastygram. [Jargon File] (1995-04-04) 1 1 1 1 1 mailbox 1. <messaging> A file belonging to a particular user on a particular computer in which received electronic mail messages are stored ready for the user to read them. A mailbox may be just an electronic mail address to which messages are sent and may not actually correspond to a file if the messages are processed automatically, e.g. a mail server or mailing list. 2. <programming> A destination for interprocess messages in a message passing system. A mailbox is a message queue, usually stored in the memory of the processor on which the receiving process is running. Primitives are provided for sending a message to a named mailbox and for reading messages from a mailbox. (1994-10-20) 1 1 1 1 1 mail bridge A mail gateway that forwards electronic mail messages between two or more networks if they meet certain administrative criteria. (1996-02-26) 1 1 1 1 1 mail exchanger A server running SMTP Message Transfer Agent software that accepts incoming electronic mail and either delivers it locally or forwards it to another server. The mail exchanger to use for a given domain can be discovered by querying DNS for Mail Exchange Records. (2007-01-29) 1 1 1 1 1 Mail Exchange Record (MX Record) A DNS resource record type that says which SMTP server handles electronic mail for a particular domain. E.g. the MX record foo.co.uk. 1054 IN MX 10 mail.foo.co.uk. means that mail for an address like "denis@foo.co.uk" should be sent to "mail.foo.co.uk". There can be several servers for a domain. The "10" is a priority - the server with the lowest number will be tried first. (2007-01-29) 1 1 1 1 1 mail exploder Part of an electronic mail delivery system which allows a message to be delivered to a list of addresses. Mail exploders are used to implement mailing lists. Users send messages to a single address and the mail exploder takes care of delivery to the individual mailboxes in the list. (1996-02-26) 1 1 1 1 1 mail filter A program which sorts and processes incoming mail based on patterns found in the mail headers. procmail is an example for Unix. (1996-12-09) 1 1 1 1 1 mail gateway A machine that connects two or more electronic mail systems (including dissimilar mail systems) and transfers messages between them. Sometimes the mapping and translation can be quite complex, and it generally requires a store and forward scheme whereby the message is received from one system completely before it is transmitted to the next system, after suitable translations. (1996-02-26) 1 1 1 1 1 mail hub mail server 1 1 1 1 1 mailing list (Often shortened in context to "list") An electronic mail address that is an alias (or macro, though that word is never used in this connection) which is expanded by a mail exploder to yield many other e-mail addresses. Some mailing lists are simple "reflectors", redirecting mail sent to them to the list of recipients. Others are filtered by humans or programs of varying degrees of sophistication; lists filtered by humans are said to be "moderated". The term is sometimes used, by extension, for the people who receive e-mail sent to such an address. Mailing lists are one of the primary forms of hacker interaction, along with Usenet. They predate Usenet, having originated with the first UUCP and ARPANET connections. They are often used for private information-sharing on topics that would be too specialised for or inappropriate to public Usenet groups. Though some of these maintain almost purely technical content (such as the 1 1 1 1 1 mail merge A function of some word processing software (e.g. Microsoft Word) that produces multiple instances of a document by substituting different text strings from a database in place of certain field markers. This is often done with envelopes, resumes, spam, and various other mass mailings. (http://mtroyal.ab.ca/programs/academserv/ADC/workshops/staff/mail_merge/mail_merge_tutorial.html). (2002-07-26) 1 1 1 1 1 mail path source route 1 1 1 1 1 mail server 1. <tool, messaging> A program that distributes files or information in response to requests sent via electronic mail. Examples on the Internet include Almanac and netlib. Mail servers are also used on Bitnet. In the days before Internet access was widespread and UUCP mail links were common, mail servers could be used to provide remote services which might now be provided via FTP or WWW. 2. <messaging> (Or "mail hub") A computer used to store and/or forward electronic mail. (1995-05-05) 1 1 1 1 1 Mail Transfer Agent Message Transfer Agent 1 1 1 1 1 Mail Transport Agent Message Transfer Agent 1 1 1 1 1 mail user agent (MUA) The program that allows the user to compose and read electronic mail messages. The MUA provides the interface between the user and the Message Transfer Agent. Outgoing mail is eventually handed over to an MTA for delivery while the incoming messages are picked up from where the MTA left it (although MUA's running on single-user machines may pick up mail using POP). Popular MUAs for Unix include elm, mush, pine, and RMAIL. FAQ (http://cis.ohio-state.edu/hypertext/faq/usenet/mail/setup/unix/part2/faq-doc-3.html). (1996-03-21) 1 1 1 1 1 Mail Users' Shell (mush) A MUA for Unix and MS-DOS. It has both line-mode and full-screen interfaces as well as a SunView interface. mush provides a very powerful shell interface with a csh-like scripting language, plenty of environment variables, command-line aliases, filename completion, conditionals, and command piping. z-mail is a more recent commercial version of mush. Usenet newsgroup: news:comp.mail.mush. (1996-02-26) 1 1 1 1 1 main The name of the subroutine called by the run-time system (RTS) when it executes a C program. The RTS passes the program's command-line arguments to main as a count and an array of pointers to strings. If the main subroutine returns then the program exits. Java has inheritted the name "main" from C but in Java it's more complicated of course. The main routine must have a signature of exactly public static void main(String []) And it must be inside a public class with the same name as the source file where it is defined. (2008-11-12) 1 1 1 1 1 MAINBOL MAcro ImplementatioN of SNOBOL4. (1997-09-14) 1 1 1 1 1 Main Distribution Frame (MDF) The network closet containing the main hub. (1995-05-05) 1 1 1 1 1 mainframe A term originally referring to the cabinet containing the central processor unit or "main frame" of a room-filling Stone Age batch machine. After the emergence of smaller "minicomputer" designs in the early 1970s, the traditional big iron machines were described as "mainframe computers" and eventually just as mainframes. The term carries the connotation of a machine designed for batch rather than interactive use, though possibly with an interactive time-sharing operating system retrofitted onto it; it is especially used of machines built by IBM, Unisys and the other great dinosaurs surviving from computing's Stone Age. It has been common wisdom among hackers since the late 1980s that the mainframe architectural tradition is essentially dead (outside of the tiny market for number crunching supercomputers (see Cray)), having been swamped by the recent huge advances in integrated circuit technology and 1 1 1 1 1 mainframe programmer/analyst A peson who writes and maintains business applications. He develops and supports large-scale batch or high-volume transaction environments that require IBM/MVS mainframe processing power or equivalent. He programs in business-oriented languages such as COBOL, CICS, or fourth-generation languages. (2004-03-12) 1 1 1 1 1 main loop The top-level control flow construct in an input- or event-driven program, the one which receives and acts or dispatches on the program's input events. See also driver. [Jargon File] (2004-03-12) 1 1 1 1 1 main memory The storage device used by a computer to hold the currently executing program and its working data. A modern computer's main memory is built from random-access memory integrated circuits. In the old days ferrite core memory was one popular form of main memory, leading to the use of the term "core" for main memory. Computers have several other sorts of memory, distinguished by their access time, storage capicity, cost, and the typical lifetime or rate of change of the data they hold. Registers in the CPU are fast, few, expensive and typically change every few machine instructions. Other kinds are cache, PROM, magnetic disk (which may be used for virtual memory) and magnetic tape. (1996-11-04) 1 1 1 1 1 MAINSAIL MAchine INdependent SAIL. 1 1 1 1 1 main store main memory 1 1 1 1 1 maintainer The person responsible for coordinating changes to a package of software and arranging the distribution of updates. The term usually applies only to free software where the maintainer (often the author) is doing it as a free public service. (2001-01-27) 1 1 1 1 1 maintainer script One of the scripts (preinst, prerm, postinst, postrm) that may be included in a Debian binary package. These scripts may create and/or remove symlinks, files or directories that, for some reason, could not be done directly by dpkg. Maintainer scripts frequently create or update the symlinks in the /etc/rc?.d directories and start, stop, or restart daemons. (2000-05-31) 1 1 1 1 1 maintenance The modification of a software product, after delivery, to correct faults, to improve performance or other attributes, or to adapt the product to a changed environment. Maintenance is an important part of the software life-cycle. It is expensive in manpower and resources, and one of the aims of software engineering is to reduce its cost. (1996-12-27) 1 1 1 1 1 Maisie A C-based parallel programming language by Wen-Toh Liao <wentoh@may.CS.UCLA.EDU>. Maisie extends C with asynchronous typed message passing and lightweight processes. Programs can define, create and destroy processes, send and receive messages and manipulate the system clock. Maisie has been ported to PVM/3.1, Cosmic Environment and SUN sockets. Version 2.1.1.3 (ftp://cs.ucla.edu/pub/maisie.2.1.1.3.tar.Z). (1993-06-14) 1 1 1 1 1 major delivery A (chiefly British) synonym for major release. E.g, the ninth major release of a piece of software might be called MD9. The release notation would be "v9.0". (1996-08-04) 1 1 1 1 1 Majordomo A popular freeware mailing list processor written in Perl which runs under Unix. Majordomo is a "groupware" project which evolved from code by Brent Chapman <brent@greatcircle.com>, with maintenance by John Rouillard <rouilj@cs.umb.edu>. The current Majordomo maintainer is Chan Wilson <cwilson@sgi.com>. A majordomo is a person who speaks, makes arrangements, or takes charge for another; from Latin "major domus" - "master of the house". (http://greatcircle.com/majordomo/). (2001-04-27) 1 1 1 1 1 major release A release of a piece of software which is not merely a revision or a bug fix release but which contains substantial changes (e.g., an overhaul of the interface, change in compatibility). Traditionally, major releases are numbered as X.0; for example, WordPerfect 6.0 is a major release, significantly different from any previous version; whereas WordPerfect 6.1 has only minor changes, and is, thus, only a revision. See also major delivery. (1996-08-04) 1 1 1 1 1 Make The Unix tool to automate the recompilation, linking etc. of programs, taking account of the interdependencies of modules and their modification times. Make reads instructions from a "makefile" which specifies a set of targets to be built, the files they depend on and the commands to execute in order to produce them. Most C systems come with a make. There is also one produce by GNU. ["Make - A Program for Maintaining Computer Programs", A.I. Feldman, TR No 57, Bell Labs Apr 1977]. (1995-01-05) 1 1 1 1 1 Makedoc A program from Carleton University, Ottawa that generates documentation for Objective C programs. It will also generate a class hierarchy diagram. The output format is similar to that used by StepStone. 1 1 1 1 1 makefile A script which tells the Unix program "make" how to build a particular computer program or set of programs. A makefile contains variable assignments and rules of the form target: inputs commands which say if any of the files in "inputs" has been modified more recently than file "target" (or if the target does not exist) then execute "commands", which will normally bulid target from "inputs". If make is run with no arguments, it looks for a makefile called "Makefile" or "makefile". (1995-01-05) 1 1 1 1 1 Maker Interchange Format (MIF) A language used to describe a FrameMaker document in a text file. MIF is used to exchange information between FrameMaker and other applications. ["Using FrameMaker 4," Windows and Macintosh Version, c. 1986-1993 Frame Technology Corporation]. (1995-01-30) 1 1 1 1 1 MAL Micro Assembly Language 1 1 1 1 1 Malamud The book: [Malamud, C., "Analyzing Sun Networks", Van Nostrand Reinhold, New York, NY, 1992.] (1995-04-10) 1 1 1 1 1 MALI A hardware memory device for logic programming computers with real time garbage collection. 1 1 1 1 1 mall A collection of web documents featuring commercial products and services, usually served by one particualr Internet access provider. (1995-04-10) 1 1 1 1 1 malloc C's standard library routine for storage allocation. It takes the number of bytes required and returns a pointer to a block of that size. Storage is allocated from a heap which lies after the end of the program and data areas. Memory allocated with malloc must be freed explicitly using the free routine before it can be re-used. gc is a storage allocator with garbage collection that is intended to be used as a plug-in replacement for malloc. 1 1 1 1 1 malware Any software designed to do something that the user would not wish it to do, hasn't asked it to do, and often has no knowledge of until it's too late. Types of malware include backdoor, virus, worm, Trojan horse. Malware typically affects the system on which it is run, e.g. by deleting or corrupting files on the local disks. Since Internet connections became common, malware has increasingly targeted remote systems. An early example was malware consisting of a malicious e-mail attachment that targeted security flaws in Microsoft Outlook (the most common e-mail client) to send itself to all the user's contacts. A more recent kind of malware "recruits" the infected computer to become part of a botnet consisting of thousands of infected computers that can then be remotely controlled and used to launch DDoS attacks. (2007-11-15) 1 1 1 1 1 malware as a service A kind of cybercrime as a service in which the service provider operates or distributes malware on behalf of others for money. (2015-02-23) 1 1 1 1 1 MAN Metropolitan Area Network 1 1 1 1 1 man Unix manual page 1 1 1 1 1 managed code Code that is executed by the .NET common language runtime (CLR). VB.NET code is always managed code but C++ .NET can optionally use unmanaged code. Managed code provides metadata allowing the CLR to manage security (role-based as well as new approaches to code access security). The CLR also handles errors, manages the program stack and finds methods in assembly modules. Managed data is memory that's subject to garbage collection. There are additional restrictions to permit interoperability of different languages, for example, Visual Basic arrays must be zero-based. (2007-07-13) 1 1 1 1 1 management 1. Corporate power elites distinguished primarily by their distance from actual productive work and their chronic failure to manage (see also suit). Spoken derisively, as in *Management* decided that .... 2. Mythically, a vast bureaucracy responsible for all the world's minor irritations. Hackers' satirical public notices are often signed "The Mgt"; this derives from the Illuminatus! novels. [Jargon File] (1995-02-28) 1 1 1 1 1 Management Information Base (MIB) A database of managed objects acessed by network management protocols. An SNMP MIB is a set of parameters which an SNMP management station can query or set in the SNMP agent of a network device (e.g. router). SNMP has two standard MIBs. The first, MIB I, was established in RFC 1156, was defined to manage TCP/IP-based internets. MIB II, defined in RFC 1213, is an update. Standard minimal MIBs have been defined, and many hardware (and certain software, e.g. DBMS) providers have developed private MIBs in ASN.1 format allowing them to be compiled for use in a Network Management System. In theory, any SNMP manager can talk to any SNMP agent with a properly defined MIB. See also client-server model. (2004-07-22) 1 1 1 1 1 Management Information System (MIS) A computer system, usually based on a mainframe or minicomputer, designed to provide management personnel with up-to-date information on an organisation's performance, e.g. inventory and sales. These systems output information in a form that is useable by managers at all levels of the organisation: strategic, tactical, and operational. A good example of an MIS report is an annual report for a stockholder (a scheduled report). [Que's Computer User's Dictionary Second Edition, 1992]. (2001-04-01) 1 1 1 1 1 Manager of Business Applications A person who plans and oversees multiple projects and project managers. He works with the CIO and senior management to determine systems development strategy and standards. He administers the department budget and reviews project managers. (2004-03-18) 1 1 1 1 1 Manchester Autocode The predecessor of Mercury Autocode. ["The Programming Strategy Used with the Manchester University Mark I Computer", R.A. Brooker, Proc IEE 103B Suppl:151-157, 1956]. (2000-10-02) 1 1 1 1 1 Manchester encoding A method of transmitting bits which enables the receiver to easily synchronise with the sender. A simple way of signalling bits might be to transmit a high voltage for some period for a 1-bit and a low voltage for a 0 bit: Bits Sent: 1 1 0 0 Signal: High ___________ Low |___________ Time: -> . . . . . However, when several identical bits are sent in succession, this provides no information to the receiver about when each bit starts and stops. Manchester encoding splits each bit period into two, and ensures that there is always a transition between the signal levels in the middle of each bit. This allows the receiver to synchronise with the sender. 1 1 1 1 1 Mandala A system based on Concurrent Prolog, developed at ICOT, Japan. ["Mandala: A Logic Based Knowledge Programming System", K. Furukawa et al, Intl Conf 5th Gen Comp Sys 1984]. (1995-11-23) 1 1 1 1 1 Mandelbrot, Benoit Benoit Mandelbrot 1 1 1 1 1 Mandelbrot set (After its discoverer, Benoit Mandelbrot) The set of all complex numbers c such that | z[N] | < 2 for arbitrarily large values of N, where z[0] = 0 z[n+1] = z[n]^2 + c The Mandelbrot set is usually displayed as an Argand diagram, giving each point a colour which depends on the largest N for which | z[N] | < 2, up to some maximum N which is used for the points in the set (for which N is infinite). These points are traditionally coloured black. The Mandelbrot set is the best known example of a fractal - it includes smaller versions of itself which can be explored to arbitrary levels of detail. 1 1 1 1 1 mandelbug /man'del-buhg/ (From the Mandelbrot set) A bug whose underlying causes are so complex and obscure as to make its behaviour appear chaotic or even nondeterministic. This term implies that the speaker thinks it is a Bohr bug, rather than a heisenbug. See also schroedinbug. [Jargon File] (1995-02-08) 1 1 1 1 1 Mandy Rice-Davis Applies (MRDA) An acronym used to imply that someone is lying to protect their own interests. During the trial of Stephen Ward (who was charged with living off the immoral earnings of Christine Keeler and Rice-Davies), the prosecuting counsel pointed out that Lord Astor denied any involvement with her and Rice-Davies replied, "Well, he would, wouldn't he?" (2010-01-01) 1 1 1 1 1 manged /mahnjd/ [probably from the French "manger" or Italian mangiare, to eat; perhaps influenced by English "mange", mangy] Refers to anything that is mangled or damaged, usually beyond repair. "The disk was manged after the electrical storm." Compare mung. [Jargon File] 1 1 1 1 1 mangle Used similarly to mung or scribble, but more violent in its connotations; something that is mangled has been irreversibly and totally trashed. 1 1 1 1 1 mangler [DEC] A manager. Compare mango; see also management. Note that system mangler is somewhat different in connotation. [Jargon File] 1 1 1 1 1 mango /mang'go/ (Originally in-house jargon at Symbolics) A manager. Compare mangler. See also devo and doco. (1995-03-21) 1 1 1 1 1 MANIAC Mathematical Analyzer, Numerical Integrator and Computer 1 1 1 1 1 man page Unix manual page 1 1 1 1 1 MANTIS A structured, full-function procedural 4GL and application development system from Cincom. MANTIS enables the developer to design prototypes, create transaction screens and reports, define logical data views, write structured procedures, and dynamically test, correct, document, secure, and release applications for production in a single, integrated, interactive session. MANTIS applications can be enhanced with gOOi, the graphical object-oriented interface, which creates graphical Windows representations of existing MANTIS screens. (http://cincom.com/products/mantis/). (2003-08-08) 1 1 1 1 1 mantissa 1. <programming> The part of a floating point number which, when multiplied by its radix raised to the power of its exponent, gives its value. The mantissa may include the number's sign or this may be considered to be a separate part. 2. <mathematics> The fractional part of a logarithm. (1996-06-15) 1 1 1 1 1 manual testing That part of software testing that requires human input, analysis, or evaluation. (1996-12-27) 1 1 1 1 1 Manufacturer Resource Planning (MRP II) A system based on MRP which allows manufacturers to optimise materials, procurement, manufacturing processes, etc., and provide financial and planning reports. In the late 1970s and early 1980s, manufacturers integrated MRP and other manufacturing and business functions. This renaissance is commonly known as Manufacturing Resource Planning (MRP II). According to the American Production and Inventory Control Society, Inc. (APICS), MRP II is a method for the effective planning of all resources of a manufacturing company. Ideally, it addresses operational planning in units, financial planning in dollars, and has a simulation capability to answer "what if" questions. It includes business planning, sales and operations planning, production scheduling, material requirements planning (MRP), capacity requirements planning, and the execution support systems for capacity and material. Output from these systems is integrated with financial reports 1 1 1 1 1 Manufacturers Automation Protocol Manufacturing Automation Protocol 1 1 1 1 1 Manufacturing Automation Protocol (MAP) A set of protocols developed by General Motors based on Token Bus (IEEE 802.4) and giving predictable real-time response. (1994-10-21) 1 1 1 1 1 manularity /man"yoo-la"ri-tee/ ("manual" + "granularity") A notional measure of the manual labor required for some task, particularly one of the sort that automation is supposed to eliminate. "Composing English on paper has much higher manularity than using a text editor, especially in the revising stage." Hackers tend to consider manularity a symptom of primitive methods; in fact, a true hacker confronted with an apparent requirement to do a computing task by hand will inevitably seize the opportunity to build another tool (see toolsmith). [Jargon File] (1994-10-26) 1 1 1 1 1 Many Integrated Core Architecture (MIC) Intel's name for integrated circuits with around 50 processing cores on a single chip, fabricated with a 22-nanometer IC manufacturing process. The Intel Xeon Phi coprocessor, the first product based on Intel MIC Architecture, is targeted at high-performance computing applications. intel.com (http://www.intel.com/content/www/us/en/architecture-and-technology/many-integrated-core/intel-many-integrated-core-architecture.html). (2014-10-14) 1 1 1 1 1 MAO An early symbolic mathematics system. [A. Rom, Celest Mech 1:309-319 (1969)]. (1995-02-10) 1 1 1 1 1 MAP 1. <protocol> Manufacturing Automation Protocol. 2. Mathematical Analysis without Programming. (1996-12-01) 1 1 1 1 1 map 1. <mathematics> function. 2. <programming> In functional programming, the most common higher-order function over lists. Map applies its first argument to each element of its second argument (a list) and returns the list of results. map :: (a -> b) -> [a] -> [b] map f [] = [] map f (x:xs) = f x : map f xs This can be generalised to types other than lists. (1997-11-05) 1 1 1 1 1 MAPI Messaging Application Programming Interface 1 1 1 1 1 Maple A symbolic mathematics package by B. Char, K. Geddes, G. Gonnet, M. Monagan and S. Watt of the University of Waterloo, Canada and ETH Zurich, Switzerland in 1980. Version: Maple V. E-mail: <wmsi@daisy.waterloo.edu>. Mailing list: glabahn@daisy.waterloo.edu. (1994-10-21) 1 1 1 1 1 mapping function 1 1 1 1 1 marbles (From the mainstream "lost his marbles") The minimum needed to build your way further up some hierarchy of tools or abstractions. After a bad system crash, you need to determine if the machine has enough marbles to come up on its own, or enough marbles to allow a rebuild from backups, or if you need to rebuild from scratch. "This compiler doesn't even have enough marbles to compile hello, world." [Jargon File] (1998-05-21) 1 1 1 1 1 Marc Andreessen The man who founded Netscape Communications Corporation in April 1994 with Dr. James H. Clark. Andreessen has been a director since September 1994. As an undergraduate at the University of Illinois in Champaign, Andreessen created the Mosaic web browser prototype with a team of students and staff at the university's National Center for Supercomputing Applications (NCSA). With a friendly, point-and-click method for navigating the Internet and free distribution to network users, NCSA Mosaic gained an estimated two million users worldwide in just over one year. Andreessen earned his Bachelor of Science degree in Computer Science at the University of Illinois in 1993. Home (http://netscape.com/columns/techvision/index.html). (1999-04-12) 1 1 1 1 1 Margaret Hamilton (born 1936-08-17) A computer scientist, systems engineer and business owner, credited with coining the term software engineering. Margaret Hamilton published over 130 papers, proceedings and reports about the 60 projects and six major programs in which she has been involved. In 1965 she became Director of Software Programming at MIT's Charles Stark Draper Laboratory and Director of the Software Engineering Division of the MIT Instrumentation Laboratory, which developed on-board flight software for the Apollo space program. At NASA, Hamilton pioneered the Apollo on-board guidance software that navigated to and landed on the Moon and formed the basis for software used in later missions. At the time, programming was a hands-on, engineering descipline; computer science and software engineering barely existed. Hamilton produced innovations in system design and software 1 1 1 1 1 marginal 1. Extremely small. "A marginal increase in core can decrease GC time drastically." In everyday terms, this means that it is a lot easier to clean off your desk if you have a spare place to put some of the junk while you sort through it. 2. Of extremely small merit. "This proposed new feature seems rather marginal to me." 3. Of extremely small probability of winning. "The power supply was rather marginal anyway; no wonder it fried." [Jargon File] (1994-10-21) 1 1 1 1 1 Marginal Hacks Margaret Jacks Hall, a building into which the Stanford AI Lab was moved near the beginning of the 1980s (from the D.C. Power Lab). [Jargon File] (1998-05-21) 1 1 1 1 1 Maril Machine description language used by the Marion code generator. ["The Marion System for Retargetable Instruction Scheduling", D.G. Bradlee et al, SIGPLAN Notices 26(6):229-240 (June 1991)]. 1 1 1 1 1 Mark I (Or "Automatic Sequence Controlled Calculator", ASCC) A first generation computer that was designed by Howard Aiken of Harvard University, taking inspiration from Charles Babbage's Analytical Engine. The Mark I, as the Harvard University staff called it, was built by IBM between 1939 to 1944. It was delivered to Harvard University and became operational in March 1944. The Mark I is considered to be the first full-sized digital computer. It was built from clutches, relays, rotating shafts and switches. It read its instructions from one paper tape and data from another. It could store 72 numbers, each of 23 decimal digits. It weighed about 4500 Kg, had 800 Km of wiring, was used only for numeric calculations, and took three seconds to carry out one multiplication. The IBM archives call it the, "...industry's largest electromechanical calculator." One of the Mark I's first programers was John von Neumann. 1 1 1 1 1 marketroid /mar'k*-troyd/ (Or "marketing slime", "marketeer", "marketing droid", "marketdroid") A member of a company's marketing department, especially one who promises users that the next version of a product will have features that are not actually scheduled for inclusion, are extremely difficult to implement, and/or are in violation of the laws of physics; and/or one who describes existing features (and misfeatures) in ebullient, buzzword-laden adspeak. Derogatory. [Jargon File] (1995-02-23) 1 1 1 1 1 Markov See Andrei Markov, Markov chain, Markov model, Markov process. (1995-02-23) 1 1 1 1 1 Markov chain (Named after Andrei Markov) A model of sequences of events where the probability of an event occurring depends upon the fact that a preceding event occurred. A Markov process is governed by a Markov chain. In simulation, the principle of the Markov chain is applied to the selection of samples from a probability density function to be applied to the model. Simscript II.5 uses this approach for some modelling functions. [Better explanation?] (1995-02-23) 1 1 1 1 1 Markov model A model or simulation based on Markov chains. (2000-10-29) 1 1 1 1 1 Markov process A process in which the sequence of events can be described by a Markov chain. (1995-02-23) 1 1 1 1 1 Markowitz The author of the original Simscript language. 1 1 1 1 1 mark-sweep garbage collection Each cell has a bit reserved for marking which is clear initially. During garbage collection all active cells are traced from the root and marked. Then all cells are examined. Unmarked cells are freed. 1 1 1 1 1 markup In computerised document preparation, a method of adding information to the text to indicate the logical components of a document, instructions for layout of the text on the page or other information which can be interpreted by some automatic system. For example, HTML (Hypertext Markup Language) adds tags to the text to indicate the appearance and behaviour it should have when displayed by a web browser. E.g.: <b>This is bold text.</b> <a href="http://foldoc.org/">This is a link to FOLDOC</a>. Other examples of markup languages are troff, SGML (on which HTML was based) and XML. (2012-12-14) 1 1 1 1 1 Marlais A simple-minded interpreter by Brent Benson at Harris for a programming language strongly resembling Dylan. Marlais version 0.2a is a "hackers release" for education, experimentation, porting, extension, and bug fixing. It has been ported to Sun-3, Sun-4, VAX/BSD, OS/2, Linux, Sequent Symmetry, Encore, HP-UX, Ultrix, SGI, Sony News, and A/UX. (ftp://travis.csd.harris.com/pub/marlais-0.2a.tar.gz). (1993-09-23) 1 1 1 1 1 Mars A legendary tragic failure, the archetypal Hacker Dream Gone Wrong. Mars was the code name for a family of PDP-10 compatible computers built by Systems Concepts (now, The SC Group): the multi-processor SC-30M, the small uniprocessor SC-25M, and the never-built superprocessor SC-40M. These machines were marvels of engineering design; although not much slower than the unique Foonly F-1, they were physically smaller and consumed less power than the much slower DEC KS10 or Foonly F-2, F-3, or F-4 machines. They were also completely compatible with the DEC KL10, and ran all KL10 binaries (including the operating system) with no modifications at about 2--3 times faster than a KL10. When DEC cancelled the Jupiter project in 1983, Systems Concepts should have made a bundle selling their machine into shops with a lot of software investment in PDP-10s, and in fact their spring 1984 announcement generated a great deal of excitement in the PDP-10 world. TOPS-10 was running on the 1 1 1 1 1 Marseille Prolog One of the two main dialects of Prolog, the other being Edinburgh Prolog. The difference is largely syntax. The original Marseille Interpreter (1973) was written in Fortran. [Developed by?] (1998-03-16) 1 1 1 1 1 marshaling Alternative US spelling of "marshalling". (1998-03-16) 1 1 1 1 1 marshalling (US -ll- or -l-) The process of packing one or more items of data into a message buffer, prior to transmitting that message buffer over a communication channel. The packing process not only collects together values which may be stored in non-consecutive memory locations but also converts data of different types into a standard representation agreed with the recipient of the message. (2000-06-09) 1 1 1 1 1 MARSYAS MARshall SYstem for Aerospace Simulation. A software system for digital simulation of large physical systems. ["MARSYAS - A Software System for the Digital Simulation of Physical Systems", H. Trauboth et al, Proc SJCC, 36 (1970)]. (1994-12-02) 1 1 1 1 1 Martian Packets that turn up unexpectedly on the wrong network because of bogus routing entries. Also a packet which has an altogether bogus (non-registered or ill-formed) internet address, such as the test loopback interface [127.0.0.1]. Such a packet will come back labelled with a source address that is clearly not of this earth. "The domain server is getting lots of packets from Mars. Does that gateway have a martian filter?" [Jargon File] 1 1 1 1 1 Martin Marietta Laboratories Moorestown (http://atlgw.atl.ge.com/). Address: Building 145, Moorestown Corporate Center, Moorestown, NJ 08057, USA. (1995-02-06) 1 1 1 1 1 MARVIN U Dortmund, 1984. Applicative language based on Modula-2, enhanced by signatures (grammars) terms (trees) and attribute couplings (functions on trees). Used for specification of language translators. ["MARVIN - A Tool for Applicative and Modular Compiler Specification", H. Ganziger et al, Forsch 220, U Dortmund, Jul 1986]. 1 1 1 1 1 Mary An extensible, machine-oriented superset of ALGOL68 developed by Mark Rain. Mary is maintained (and used) by Kvatro Telecom AS. Although dated, it still offers a nice strongly typed 3GL with macros but without most of C's flaws. It runs on SPARC and x86 computers. Hidden on the back cover of the manual: MARY HAD A LITTLE LAMB #NAME? ["Mary Programmer's Reference Manual", M. Rain et al, R Unit, Trondheim Norway, 1974]. ["Operator Expressions in Mary", M. Rain, SIGPLAN Notices 8(1), Jan 1973]. (1998-11-10) 1 1 1 1 1 MAS Modula-2 Algebra System. Runs on IBM PC, Atari, Amiga. (ftp://alice.fmi.uni-passau.de). ["Modula-2 Algebra System", H. Kredel, Proc DISCO 90 Capri, LNCS 429, Springer 1990, pp270-271]. 1 1 1 1 1 MASCOT Modular Approach to Software Construction Operation and Test: a method for software design aimed at real-time embedded systems from the Royal Signals and Research Establishment, UK. 1 1 1 1 1 Mask Read-Only Memory (MROM) A kind of ROM in which the memory contents are determined by one of the masks used to manufacture the integrated circuit. MROM can give high storage density (bits per millimeter squared) making it a cheap solution for high volume applications. [Other ROM types?] (1995-04-22) 1 1 1 1 1 MASM Microsoft Assembler for MS-DOS. (1995-04-22) 1 1 1 1 1 MasPar Unity A translator from UNITY to MPL by Martin Huber, University of Karlsruhe, Germany. Version 1.0. (ftp://SanFrancisco.ira.uka.de/pub/maspar/maspar_unity.tar.Z). E-mail: Lutz Prechelt <prechelt@ira.uka.de>. 1 1 1 1 1 masquerading 1. <networking> "NAT" (Linux kernel name). 2. <messaging> Hiding the names of internal e-mail client and gateway machines from the outside world by rewriting the From address and other headers as the message leaves the organisation. This is good practise because external users do not need to know about internal changes in message routing. The external mail gateway needs to know how to route incoming replies back to the original sender. (1998-03-03) 1 1 1 1 1 Massachusetts Institute of Technology (MIT) An independent, coeducational university located in Cambridge, MA, USA. Its best-known computer-related labs are the Artificial Intelligence Lab, the Lab for Computer Science and the Media Lab. It is also known for its hacks or practical jokes, such as The Great Dome Police Car Hack (http://the-tech.mit.edu/Bulletins/hack.html). Resident computer hackers include Richard Stallman, Gerald Sussman and Tom Knight. See also 6.001. (http://web.mit.edu/). 1 1 1 1 1 massage Vague term used to describe "smooth" transformations of a data set into a different form, especially transformations that do not lose information. Connotes less pain than munch or crunch. "He wrote a program that massages X bitmap files into GIF format." Compare slurp. [Jargon File] 1 1 1 1 1 Massey Hope A refinement of Hope+C by Nigel Perry <N.Perry@massey.ac.nz> of Massey University, NZ, with improved syntax. Concurrent Massey Hope is derived directly from Massey Hope. (1999-08-04) 1 1 1 1 1 Massively Multiplayer Online Game (MMOG, MMO) Any game that allows dozens, hundreds or even thousands of players to interact with a game via the Internet. Typically the game runs on a central server farm and players access it via a personal computer, game console or mobile phone. The most popular genre is the Massively Multiplayer Online Role Playing Game (MMORPG), of which World of Warcraft is probably the most popular example. Note that an MMOG is not necessarily a _massive_ game (though often they are based in large, complex worlds), their distinguishing characteristic is the number of players. (2012-05-30) 1 1 1 1 1 Massively Multiplayer Online Role-Playing Game Massively Multiplayer Online Game 1 1 1 1 1 master botmaster 1 1 1 1 1 master boot record A special area on a computer's main hard disk that gives the location of the disk's boot block or bootable partition where the operating system is installed. (2009-05-19) 1 1 1 1 1 Matchmaker A language for specifying and automating the generation of multi-lingual interprocess communication interfaces. MIG is an implementation of a subset of Matchmaker. (1994-11-22) 1 1 1 1 1 Material Requirements Planning (MRP) A system for effectively managing material requirements in a manufacturing process. Information systems have long been an important part of the manufacturing environment. In the 1960s, manufacturers developed Material Requirements Planning (MRP). According to the American Production and Inventory Control Society, Inc. (APICS), MRP is a set of techniques that uses bill of material data, inventory data, and the master production schedule to calculate requirements for materials. It makes recommendations to reorder materials. Furthermore, because it is time-phased, it makes recommendations to reschedule open orders when due dates and need dates are not in phase. Time-phased MRP begins with the items listed on the Master Production Schedule and determines the quantity of all components and materials required to fabricate those items and the date that the components and material are required. Time-phased MRP is accomplished by exploding the bill of 1 1 1 1 1 Mathcad A symbolic mathematics environment. 1 1 1 1 1 Mathematica A popular symbolic mathematics and graphics system, developed in 1988 by Stephen Wolfram and sold by Wolfram Research. The language emphasises rules and pattern-matching. The name was suggested by Steve Jobs. (http://wri.com/mathematica/). Stanford FTP (ftp://otter.stanford.edu/), NCSA FTP (ftp://ftp.ncsa.uiuc.edu/). Mailing list: mathgroup-request@yoda.ncsa.uiuc.edu. Usenet newsgroup: news:comp.soft-sys.math.mathematica. ["Mathematica: A System for Doing Mathematics by Computer", Stephen Wolfram, A-W 1988]. (1995-05-01) 1 1 1 1 1 Mathematical Analysis without Programming (MAP) An On-line system for mathematics under CTSS. [Sammet 1969, p. 240]. (1995-02-10) 1 1 1 1 1 Mathematical Analyzer, Numerical Integrator and Computer (MANIAC, Or "Mathematical Analyzer, Numerator, Integrator, and Computer") An early computer, built for the Los Alamos Scientific Laboratory. MANIAC began operation in March 1952. Typical of early computers, it ran its own propriatery language. It was succeeded by MANIAC II in 1957. A MANIAC III was built at the University of Chicago in 1964. Contrary to legend, MANIAC did not run MAD (Michigan Algorithm Decoder), which was not invented until 1959. (2013-05-05) 1 1 1 1 1 Mathematics in Recognizable Form Automatically Compiled (MIRFAC) An early interactive system resembling BASIC using typewriter output with special mathematical symbols. [Sammet 1969, pp. 281-284]. (1997-08-01) 1 1 1 1 1 MATHLAB Symbolic math system, MITRE, 1964. Later version: MATHLAB 68 (PDP-6, 1967). ["The Legacy of MATHLAB 68", C. Engelman, Proc 2nd Symp on Symbolic and Algebraic Manip, ACM (Mar 1971)]. [Sammet 1969, p. 498]. 1 1 1 1 1 MATH-MATIC or MATHMATIC Alternate name for AT-3. Early, pre-Fortran language for UNIVAC I or II. Sammet 1969. 1 1 1 1 1 math-out (Possibly from "white-out", the blizzard variety) A paper or presentation so encrusted with mathematical or other formal notation as to be incomprehensible. This may be a device for concealing the fact that it is actually content-free. See also numbers, social science number. [Jargon File] (1994-12-14) 1 1 1 1 1 MathWorks The MathWorks, Inc. 1 1 1 1 1 MATLAB A high-level language and interactive program from The MathWorks for numeric computation and visualisation. MATLAB supports numerical analysis, matrix computation, signal processing, linear algebra, statistics, Fourier analysis, filtering, optimisation and numerical integration. It can output two and three dimensional graphics and can be integrated with C, C++, Fortran, Java, COM and Microsoft Excel. (http://mathworks.com/products/matlab/). Latest version: 7.0.4, as of 2005-08-13. (2005-08-13) 1 1 1 1 1 Matrix [FidoNet] 1. What the Opus BBS software and sysops call FidoNet. 2. Fanciful term for a cyberspace expected to emerge from current networking experiments (see network, the). 3. The totality of present-day computer networks. [Jargon File] 1 1 1 1 1 Matrix Compiler Early matrix computations on UNIVAC. Sammet 1969, p.642. 1 1 1 1 1 MATRIX MATH An early system on the UNIVAC I or II. [Listed in CACM 2(5):1959-05-16]. (1997-02-27) 1 1 1 1 1 Matrix Math eXtensions (MMX) (NOT an acronym for "MultiMedia eXtension", according to Intel, but an Intel brand name) A set of 57 extra instructions built into some versions of Intel's Pentium microprocessors for supporting SIMD operations on multimedia and communications data types. MMX-enhanced processors are due to be released early in 1997. They will be fully compatible with previous Intel processors and software but software will only benefit if it is written to use the new instructions. They can handle many common multimedia operations, such as digital signal processing, normally handled by a separate sound card or video card. (1996-12-21) 1 1 1 1 1 MAU Media Access Unit 1 1 1 1 1 Mauchly, John W. John Mauchly 1 1 1 1 1 mawk An faster implementation of nawk written by Mike Brennan at Boeing in 1991 and distributed under GPL but distinct from GNU's gawk. Interpreter version 1.1.3 has been ported to Sun-3, Sun-4/SunOS 4.0.3; Vax/BSD 4.3, ULTRIX 4.1; Stardent 3000/SYSVR3; DECStation/ULTRIX 4.1, MS-DOS/Turbo C++. (ftp://oxy.edu/public/mawk). (2000-05-04) 1 1 1 1 1 maximal free expression (MFE) A free expression is sub-expression of a lambda abstraction not containing the bound variable. A maximal free expression is a free expression not contained within any other free expression. See full laziness. 1 1 1 1 1 maximin minimax 1 1 1 1 1 MAXIMOP Job Control Languages: MAXIMOP and CAFE, J. Brandon, Proc BCS Symp on Job Control Languages--Past Present and Future, NCC, Manchester, ENgland 1974. 1 1 1 1 1 maximum Maytag mode (From the US brand of washing machine) What a washing machine or, by extension, any hard disk is in when it's being used so heavily that it's shaking like an old Maytag with an unbalanced load. If prolonged for any length of time, can lead to disks becoming walking drives. [Jargon File] (1997-07-22) 1 1 1 1 1 maximum seek time (Or full stroke seek time) The time it takes to seek over all tracks, i.e., from the innermost to the outermost or vice versa. The maximum seek time gives a worst-case measure of the speed of the drive which is useful in some real-time applications where it is important that data flows continuously (such as video editing or CD recording). (1997-07-15) 1 1 1 1 1 maximum segment size (MSS) The maximum amount of TCP data that a node can send in one segment. This should be the size of the receiver's reassembly buffer to try to avoid fragmentation. The equivalent at the physical layer is "Maximum Transmission Unit". (1998-03-06) 1 1 1 1 1 Maximum Transmission Unit (MTU) The largest number of bytes of "payload" data a frame can carry, not counting the frame's header and trailer. A frame is a single unit of transportation on the data link layer. It consists of header data plus data which was passed down from the network layer (e.g. an IP datagram) plus sometimes trailer data. An Ethernet (V2) frame has a MTU of 1500 bytes but the size of the frame can be up to 1526 bytes (22 byte header, 4 byte CRC trailer). See also fragmentation. (2000-10-07) 1 1 1 1 1 Maxis Software The developers of SimCity and SimCity 2000. (http://maxis.com/). Address: 2 Theatre Square, Suite 230, Orinda, CA 94563-3346, USA. Telephone: +1 (800) 33-MAXIS. (1995-02-08) 1 1 1 1 1 MB (Or "Mb") megabytes or megabits. When referring to the size or data transfer rate of a storage device which is accessed in multiples of eight bits (e.g. RAM, hard disk) this almost certainly means megabytes, but when referring to the data transfer rate of a communications system it probably means megabits. Some years ago, it is claimed, "MB" always meant megabytes and "Mb" meant megabits but recently this useful distinction has been lost. (1996-09-22) 1 1 1 1 1 MBASIC Microsoft BASIC. 1 1 1 1 1 Mbogo, Dr. Fred /*m-boh'goh, dok'tr fred/ [Stanford] The archetypal man you don't want to see about a problem, especially an incompetent professional; a shyster. "Do you know a good eye doctor?" Sure, try Mbogo Eye Care and Professional Dry Cleaning. The name comes from synergy between "bogus" and the original Dr. Mbogo, a witch doctor who was Gomez Addams' physician on the old "Addams Family" TV show. Compare Bloggs Family, the, see also fred. [Jargon File] (2002-04-14) 1 1 1 1 1 MBONE Virtual Internet Backbone for Multicast IP. IP-Multicast is the class-D addressing scheme in IP implemented by Steve Deering at Xerox PARC. It was adopted at the IETF March 1992 meeting and acquired the name MBONE after the July 1992 IETF meeting. IP Multicast-based routing allows distributed applications to achieve real-time communication over IP wide area networks through a lightweight, highly threaded model of communication. Each network-provider participant in the MBONE provides one or more IP multicast routers to connect with tunnels to other participants and to customers. The multicast routers are typically separate from a network's production routers since most production routers don't yet support IP multicast. Most sites use workstations running the mrouted program, but the experimental MOSPF software for Proteon routers is an alternative. 1 1 1 1 1 MBps megabytes per second 1 1 1 1 1 mbps megabits per second 1 1 1 1 1 MBS mobile broadband services 1 1 1 1 1 MC An extension of C with modules. Symbols in other modules can be referenced using a dot notation. ["Design and Implementation of a C-Based Language for Distributed Real-Time Systems", A. Rizk et al, SIGPLAN Notices 22(6):83-96 (June 1987)]. (1995-10-06) 1 1 1 1 1 mc The country code for Monaco. (1999-01-27) 1 1 1 1 1 MC68000 Motorola 68000 1 1 1 1 1 MC68010 Motorola 68010 1 1 1 1 1 MC68020 Motorola 68020 1 1 1 1 1 MC68030 Motorola 68030 1 1 1 1 1 MC68040 Motorola 68040 1 1 1 1 1 MC6809 Motorola 6809 1 1 1 1 1 MCA Micro Channel Architecture 1 1 1 1 1 MCAD Microsoft Certified Application Developer 1 1 1 1 1 MCC 1. Mosaic Communications Corporation. 2. The Microelectronics and Computer Technology Corporation. 1 1 1 1 1 McCulloch-Pitts neuron The basic building block of artificial neural networks. It receives one or more inputs and produces one or more identical outputs, each of which is a simple non-linear function of the sum of the inputs to the neuron. The non-linear function is typically a threshhold or step function which is usually smoothed (i.e. a sigmoid) to facilitate learning. (1997-10-11) 1 1 1 1 1 MCDBA Microsoft Certified Database Administrator 1 1 1 1 1 MCDST Microsoft Certified Desktop Support Technician 1 1 1 1 1 McG360 Interactive, similar to PAL[5], for IBM 360. McG360 Programmer's Guide, RC 2693, IBM TJWRC, Nov 1969. 1 1 1 1 1 MCGA Multi-Color Graphics Array 1 1 1 1 1 MCI A United States long-distance telecommunications company. Recently bought from British Telecom [by ?]. (1998-05-18) 1 1 1 1 1 MCI Mail The first commercial Internet electronic mail service, launched by MCI in about 1981. Vint Cerf was the chief engineer. Reading mail was free but you had to pay to send. Users discovered you could communicate for free by sharing an account. One user would save a message as a draft and the other would read it and replace it with his response. (2004-08-25) 1 1 1 1 1 MCL Macintosh Common LISP 1 1 1 1 1 M-Code 1. Intermediate language produced by some Modula-2 compilers. [Which compilers?] 2. The intermediate language for an SECD-like machine, used by the Concert implementation of MultiLISP. (1996-01-22) 1 1 1 1 1 MCP motion compensated prediction 1 1 1 1 1 MCP-1600 A processor made by Western Digital, consisting of at least four separate integrated circuits, including the control circuitry unit, the ALU, two or four ROM chips with microcode, and timing circuitry. The ALU chip contained twenty-six 8-bit registers and an 8-bit ALU, while the control unit supervised the moving of data, memory access, and other control functions. The ROM allowed the chip to function as either an 8- or 16-bit chip, with clever use of the 8-bit ALU. Further, microcode allowed the addition of floating-point routines (40 + 8 bit format), simplifying programming (and possibly producing a floating-point coprocessor). Two standard microcode ROMs were available. This flexibility was one reason it was also used to implement the DEC LSI-11 processor as well as the WD Pascal Microengine. (1994-11-18) 1 1 1 1 1 MCPD Microsoft Certified Professional Developer 1 1 1 1 1 MCS Meta Class System 1 1 1 1 1 MCSA 1. Microsoft Certified Systems Administrator. 2. Microsoft Certified Solutions Associate. (2013-09-02) 1 1 1 1 1 MCSD Microsoft Certified Solution Developer 1 1 1 1 1 MCSE 1. <education> Microsoft Certified System Engineer. 2. <humour> Minesweeper, Chess, Solitaire Expert. (2013-03-16) 1 1 1 1 1 mcvax mcvax.cwi.nl used to be the international backbone node of EUnet, the European Unix network. It was located in Amsterdam, Netherlands and belonged to "Centrum voor Wiskunde en Informatica" (Centre for Mathematics and Computer Science) which is an institute belonging to a foundation called Mathematisch Centrum. Since the first mcvax was on of the first VAXen in Europe and one of it's first uucp connections was to a machine called decvax it was quickly christened mcvax. Some also say this was done to give Jim McKie a nice mail address: mcvax!mckie. But this is certainly not true at all. The function of EUnet international backbone moved to another VAX later but the name moved with it, because in those days of mainly uucp based mail and before widespread use of pathalias it was simply not feasible to rename the machine to "europa" as was suggested at one stage. Mcsun (or relay.eu.net or net.eu.relay in some parts of Europe) replaced the international backbone host of EUnet 1 1 1 1 1 mcvert A Unix program for reading and writing Apple Computer Macintosh binary files. It was written by Doug Moore, now at Rice University (Jan 1990). See BinHex, HQX, MacBinary. (1995-04-22) 1 1 1 1 1 MD 1. <audio, storage> Mini Disk. 2. <programming> major delivery. 3. message digest function. (2001-12-02) 1 1 1 1 1 md The country code for Moldova. (1999-01-27) 1 1 1 1 1 MD5 Message Digest 5 1 1 1 1 1 MDA Monochrome Display Adapter 1 1 1 1 1 MDAC Microsoft Data Access Components 1 1 1 1 1 MDCT Modified Discrete Cosine Transform 1 1 1 1 1 MDF Main Distribution Frame 1 1 1 1 1 MDI Multiple Document Interface 1 1 1 1 1 MDL (Originally "Muddle"). C. Reeve, Carl Hewitt and Gerald Sussman, Dynamic Modeling Group, MIT ca. 1971. Intended as a successor to Lisp, and a possible base for Planner-70. Basically LISP 1.5 with data types and arrays. Many of its features were advanced at the time (I/O, interrupt handling and coroutining), and were incorporated into later LISP dialects ("optional", "rest" and "aux" markers). In the mid 80's there was an effort to use bytecoding to make the language portable. CLU was first implemented in MDL. Infocom wrote Zork in MDL, and used it as the basis for the ZIL interpreter. Implementations exist for ITS, TOPS-20, BSD 4.3, Apollo Domain, SunOS and A/UX. ["The MDL Programming Language", S.W. Galley et al, Doc SYS.11.01, Project MAC, MIT (Nov 1975)]. 1 1 1 1 1 Mean Time Between Failures (MTBF, or "Mean Time Between Faults") The average time (usually expressed in hours) that a component works without failure. It is calculated by dividing the total number of failures into the total number of operating hours observed. The term can also mean the length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs. See also Mean Time To Recovery. (1998-05-01) 1 1 1 1 1 Mean Time Between Faults Mean Time Between Failures 1 1 1 1 1 Mean Time To Recovery (MTTR) The average time that a device will take to recover from a non-terminal failure. Examples of such devices range from self-resetting fuses (where the MTTR would be very short, probably seconds), up to whole systems which have to be replaced. The MTTR would usually be part of a maintenance contract, where the user would pay more for a system whose MTTR was 24 hours, than for one of, say, 7 days. This means the supplier is guaranteeing to have the system up and running again within 24 hours (or 7 days) of being notified of the failure. Some devices have a MTTR of zero, which means that they have redundant components which can take over the instant the primary one fails, see RAID for example. See also Mean Time Between Failures. (1998-05-01) 1 1 1 1 1 measure To ascertain or appraise by comparing to a standard; to apply a metric. (1996-12-27) 1 1 1 1 1 measurement The act or process of measuring; a figure, extent, or amount obtained by measuring. (1996-12-27) 1 1 1 1 1 meatspace The physical world (as opposed virtual reality) where you might spend facetime with the carbon community. (1999-01-15) 1 1 1 1 1 meatware Less common synonym for wetware. [Was it Marvin Minsky who described brains as machines?/computers? made of meat?] [Jargon File] (1994-10-21) 1 1 1 1 1 media 1. <data> Any kind of data including graphics, images, audio and video, though typically excluding raw text or executable code. The term multimedia suggests a collection of different types of media or the ability to handle such collections. 2. <storage> The physical object on which data is stored, as opposed to the device used to read and write it. 3. <networking> The object at the physical layer that carries data, typically an electrical or optical cable, though, in a wireless network, the term refers to the space through which radio waves propagate. Most often used in the context of Media Access Control (MAC). (2010-01-07) 1 1 1 1 1 Media Access Control (MAC) The lower sublayer of the OSI data link layer. The interface between a node's Logical Link Control and the network's physical layer. The MAC differs for various physical media. See also MAC Address, Ethernet, IEEE 802.3, token ring. [What does it do? Examples?] (1996-01-29) 1 1 1 1 1 Media Access Unit (MAU or Multistation Access Unit, MSAU) In a Token Ring network, a device to attach multiple network stations in a star topology, internally wired to connect the stations into a logical ring. The MAU contains relays to short out nonoperating stations. Multiple MAUs can be connected into a larger ring through their Ring In/Ring Out connectors. (1997-05-27) 1 1 1 1 1 Media Converter A component used in Ethernet, although it is not part of the IEEE standard. The IEEE standard states that all segments must be linked with repeaters. Media converters were developed as a simpler, cheaper alternative to repeaters. However, in the 1990s the cost difference between the two is negligible. (1996-12-09) 1 1 1 1 1 Media Gateway Control Protocol (MGCP) A protocol used within a Voice over IP system. MGCP is an IETF work in progress, it superseded SGCP. MGCP is an internal protocol used within a distributed system that appears to the outside world as a single VoIP gateway. This system is composed of a Call Agent, and a set of gateways, including at least one "media gateway" that performs the conversion of media signals between circuits and packets, and at least one "signalling gateway" when connected to an SS7 controlled network. IETF MGCP draft (http://ietf.org/internet-drafts/draft-huitema-megaco-mgcp-v0r1-05.txt). (1999-03-17) 1 1 1 1 1 Medium Access Control Media Access Control 1 1 1 1 1 meeces /mees'*z/ (TMRC) Occasional furry visitors who are not urchins; that is, mice. This may no longer be in live use. According to ESR it derives from the refrain of the early-1960s cartoon character Mr. Jinx: "I hate meeces to *pieces*!" [Jargon File] (1996-12-09) 1 1 1 1 1 Meet greatest lower bound 1 1 1 1 1 meg megabyte 1 1 1 1 1 mega- prefix 1 1 1 1 1 megabits per second (Mbps, Mb/s) Millions of bits per second. A unit of data rate. 1 Mb/s = 1,000,000 bits per second (not 1,048,576). E.g. Ethernet can carry 10 Mbps. (2002-03-23) 1 1 1 1 1 megabyte (MB, colloquially "meg") A Unit of data equal to one million bytes but see binary prefix for other definitions. A megabyte is 1000^2 bytes or 1000 kilobytes. The text of a six hundred page paperback book stored as ASCII characters contains about one megabyte of data. The complete King James bible is 5.2 megabytes. 1000 megabytes are one gigabyte. See prefix. (2013-11-04) 1 1 1 1 1 megabytes per second (MBps, MB/s) Millions of bytes per second. A unit of data rate. 1 MB/s = 1,000,000 bytes per second (not 1,048,576). (2007-02-20) 1 1 1 1 1 megaflop Etymologically incorrect singular of "megaflops". (1995-02-28) 1 1 1 1 1 megaflops One million floating-point operations per second. A common unit of measurement of performance of computers used for numerical work. (2000-08-03) 1 1 1 1 1 MegaHertz (MHz) Millions of cycles per second. The unit of frequency used to measure the clock rate of modern digital logic, including microprocessors. (1994-10-27) 1 1 1 1 1 megapenny /meg'*-pen"ee/ $10,000 (1 cent * 10^6). Used semi-humorously as a unit in comparing computer cost and performance figures. [Jargon File] 1 1 1 1 1 MEGO /me"goh/ or /mee'goh/ ["My Eyes Glaze Over", often "Mine Eyes Glazeth (sic) Over", attributed to the futurologist Herman Kahn] Also "MEGO factor". 1. A handwave intended to confuse the listener and hopefully induce agreement because the listener does not want to admit to not understanding what is going on. MEGO is usually directed at senior management by engineers and contains a high proportion of TLAs. 2. excl. An appropriate response to MEGO tactics. 3. Among non-hackers, often refers not to behaviour that causes the eyes to glaze, but to the eye-glazing reaction itself, which may be triggered by the mere threat of technical detail as effectively as by an actual excess of it. 1 1 1 1 1 Mei A set of class libraries by Atsushi Aoki <aoki@sra.co.jp> and others for Objectworks Smalltalk Release 4.1. Mei includes: Grapher Library for drawing diagrams; Meta Grapher Library (grapher to develop grapher); Drawing tools and painting tools (structured diagram editors and drawing editors); GUI builder; Lisp interpreter; Prolog interpreter; Pluggable gauges; Extended browser; (package, history, recover, etc.) Mei is available under General Public License and requires Objectworks Smalltalk Release 4.1. Latest version: 0.50, as of 1993-01-20. Home (http://sra.co.jp/people/aoki/htmls/FreeSoftwareForSmalltalk.html). E-mail: Watanabe Katsuhiro <katsu@sran14.sra.co.jp> (1999-12-08) 1 1 1 1 1 Mel The story of Mel 1 1 1 1 1 MELD A concurrent, object-oriented, dataflow, modular and fault-tolerant language! MELD is comparable to SR. ["MELDing Multiple Granularities of Parallelism", G. Kaiser et al, ECOOP '89, pp. 147-166, Cambridge U Press 1989]. (1994-11-11) 1 1 1 1 1 MELDC A reflective object-oriented concurrent programming language developed in 1990 by the MELD Project of the Programming Systems Laboratory at Columbia University. MELDC is a redesign of MELD based on C. The core of the architecture is a micro-kernel (the MELDC kernel), which encapsulates a minimum set of entities that cannot be modelled as objects. All components outside of the kernel are implemented as objects in MELDC itself and are modularised in the MELDC libraries. MELDC is reflective in three dimensions: structural, computational and architectural. The structural reflection indicates that classes and meta-classes are objects, which are written in MELDC. The computational reflection means that object behaviours can be computed and extended at run time. The architectural reflection indicates that new features/properties (e.g. persistency and remoteness) can be constructed in MELDC. Version 2.0 runs on Sun-4/SunOS 4.1 and DECstation and 1 1 1 1 1 Melinda ["Melinda: Linda with Multiple Tuple Spaces", S. Hupfer, <hupfer-susanne@yale.edu> YALEU/DCS/RR-766, Yale U Feb 1990]. (1994-11-11) 1 1 1 1 1 Mel Kaye The hero of The Story of Mel, a Real Programmer. The preface to the manuals for the Royal McBee LGP-30 ACT 1 (Algebraic Compiler and Translator) compiler (dated 1959) contain the following attribution from Clay S. Boswell, Jr. (apparently ACT 1's designer): I wish to acknowledge my appreciation to the many people who offered suggestions and criticisms of the ACT 1 System. In particular, Mel Kaye of Royal McBee who did the bulk of the programming. (2008-08-04) 1 1 1 1 1 Mellor Schlaer-Mellor 1 1 1 1 1 meltdown network meltdown 1 1 1 1 1 Melvin Conway An early proto-hacker who wrote an assembler for the Burroughs 220 called SAVE and (probably) formulated Conway's Law. [Jargon File] (2015-12-30) 1 1 1 1 1 member function A method in C++. 1 1 1 1 1 membership function fuzzy subset 1 1 1 1 1 meme /meem/ [By analogy with "gene"] Richard Dawkins's term for an idea considered as a replicator, especially with the connotation that memes parasitise people into propagating them much as viruses do. Memes can be considered the unit of cultural evolution. Ideas can evolve in a way analogous to biological evolution. Some ideas survive better than others; ideas can mutate through, for example, misunderstandings; and two ideas can recombine to produce a new idea involving elements of each parent idea. The term is used especially in the phrase "meme complex" denoting a group of mutually supporting memes that form an organised belief system, such as a religion. However, "meme" is often misused to mean "meme complex". Use of the term connotes acceptance of the idea that in humans (and presumably other tool- and language-using sophonts) cultural evolution by selection of adaptive ideas has become more important than biological evolution by selection of 1 1 1 1 1 meme plague The spread of a successful but pernicious meme, especially one that parasitises the victims into giving their all to propagate it. Astrology, BASIC, and the other guy's religion are often considered to be examples. This usage is given point by the historical fact that "joiner" ideologies like Naziism or various forms of millennarian Christianity have exhibited plague-like cycles of exponential growth followed by collapses to small reservoir populations. [Jargon File] (1996-08-11) 1 1 1 1 1 memetic algorithm A genetic algorithm or evolutionary algorithm which includes a non-genetic local search to improve genotypes. The term comes from the Richard Dawkin's term meme. One big difference between memes and genes is that memes are processed and possibly improved by the people that hold them - something that cannot happen to genes. It is this advantage that the memetic algorithm has over simple genetic or evolutionary algorithms. These algorithms are useful in solving complex problems, such as the "Travelling Salesman Problem," which involves finding the shortest path through a large number of nodes, or in creating artificial life to test evolutionary theories. Memetic algorithms are one kind of metaheuristic. UNLP memetic algorithms home page (http://ing.unlp.edu.ar/cetad/mos/memetic_home.html). (07 July 1997) 1 1 1 1 1 memetics /me-met'iks/ The study of memes. As of mid-1993, this is still an extremely informal and speculative endeavor, though the first steps toward at least statistical rigor have been made by H. Keith Henson and others. Memetics is a popular topic for speculation among hackers, who like to see themselves as the architects of the new information ecologies in which memes live and replicate. [Jargon File] (2000-01-09) 1 1 1 1 1 Memex Vannevar Bush's original name for hypertext, which he invented in the 1930s. Fantastic article (http://jefferson.village.virginia.edu/elab/hfl0051.html). (2000-01-09) 1 1 1 1 1 memo function (Or "memoised function") A function that remembers which arguments it has been called with and the result returned and, if called with the same arguments again, returns the result from its memory rather than recalculating it. Memo functions were invented by Professor Donald Michie of Edinburgh University. The idea was further developed by Robin Popplestone in his Pop2 language long before it was ever worked into LISP. This same principle is found at the hardware level in computer architectures which use a cache to store recently accessed memory locations. A Common Lisp package by Marty Hall <hall@aplcenmp.apl.jhu.edu> (ftp://archive.cs.umbc.edu/pub/Memoization). ["'Memo' functions: and machine learning", Donald Michie, Nature, 218, 19-22, 1968]. 1 1 1 1 1 memoisation memo function 1 1 1 1 1 memoised function memo function 1 1 1 1 1 memoization memo function 1 1 1 1 1 memoized function memo function 1 1 1 1 1 memory These days, usually used synonymously with Random Access Memory or Read-Only Memory, but in the general sense it can be any device that can hold data in machine-readable format. (1996-05-25) 1 1 1 1 1 memory address space 1. Any part of a processor's address space that is occupied by memory. 2. The range of addresses seen by a memory device relative to the base address at which it is mapped into the processor's address space. (1999-11-01) 1 1 1 1 1 memory dump (Or "core dump") A file on hard disk (traditionally called "core") containing a copy of the contents of a process's memory, produced when a process is aborted by certain kinds of internal error or signal. Debuggers like adb and gdb can load the dump file and display the information it contains about the state of the running program. This can be related to the program code, both object code and, in a source-level debugger, the source code. Information includes the contents of registers, the call stack and all other program data. (2007-05-09) 1 1 1 1 1 memory farts The flatulent sounds that some MS-DOS box BIOSes (most notably AMI's) make when checking memory at boot time. [Jargon File] (1994-11-02) 1 1 1 1 1 memory leak A leak in a program's dynamic store allocation logic that causes it to fail to reclaim memory in the heap after it has finished using it, eventually causing the program to fail due to lack of memory. These problems were severe on older machines with small, fixed-size address spaces, and special "leak detection" tools were written to diagnose them. The introduction of virtual memory made memory leaks a less serious problem, although if you run out of virtual memory, it means you've got a *real* leak! See aliasing bug. [Jargon File] (2003-10-07) 1 1 1 1 1 memory location A byte, word or other small unit of storage space in a computer's main memory that is identified by its starting address (and size). (1999-04-19) 1 1 1 1 1 memory management A collection of techniques for providing sufficient memory to one or more processes in a computer system, especially when the system does not have enough memory to satisfy all processes' requirements simultaneously. Techniques include swapping, paging and virtual memory. Memory management is usually performed mostly by a hardware memory management unit. (1995-01-23) 1 1 1 1 1 Memory Management Unit (MMU, "Paged Memory Management Unit", PMMU) A hardware device or circuit that supports virtual memory and paging by translating virtual addresses into physical addresses. The virtual address space (the range of addresses used by the processor) is divided into pages, whose size is 2^N, usually a few kilobytes. The bottom N bits of the address (the offset within a page) are left unchanged. The upper address bits are the (virtual) page number. The MMU contains a page table which is indexed (possibly associatively) by the page number. Each page table entry (PTE) gives the physical page number corresponding to the virtual one. This is combined with the page offset to give the complete physical address. A PTE may also include information about whether the page has been written to, when it was last used (for a least recently used replacement algorithm), what kind of processes (user 1 1 1 1 1 memory mapped I/O The use of the same instructions and bus to communicate with both main memory and input/output devices. This is in contrast to processors that have a separate I/O bus and special instructions to access it. The I/O devices are addressed at certain reserved address ranges on the main memory bus. These addresses cannot therefore be used for RAM. Motorola and Mostec architectures, among others, use memory mapped I/O. Video cards and other cards with on-board memory might be accessed in this way though the term applies not just to devices containing memory but to any device connected to the memory bus. Accessing the devices usually consists of reading and writing certain built-in registers though sometimes the mere presence of a particular address can trigger the device. (1997-04-14) 1 1 1 1 1 memory protection A system to prevent one process corrupting the memory (or other resources) of any other, including the operating system. Memory protection usually relies on a combination of hardware (a memory management unit) and software to allocate memory to processes and handle exceptions. The effectiveness of memory protection varies from one operating system to another. In most versions of Unix it is almost impossible to corrupt another process' memory, except in some archaic implementations and Lunix (not Linux!). Under Microsoft Windows (version? hardware?) any 16 bit application(?) can circumvent the memory protection, often leading to one or more GPFs. Currently (April 1996) neither Microsoft Windows 3.1, Windows 95, nor Mac OS offer memory protection. Windows NT has it, and Mac OS System 8 will offer a form of memory protection. [MS DOS EMM386 relevant?] 1 1 1 1 1 memory smash A Xerox PARC term for writing to the location addressed by a dangling pointer. [Jargon File] (1994-11-02) 1 1 1 1 1 Memory Type Range Registers (MTRR) Registers in the Pentium Pro and Pentium II processors that can be used to specify a strategy for communication with the external memory and caches for a number of physical address ranges. Strategies include write-through, write-back, or uncached(?). Such control is useful where the memory is located on a device and is accessed via some kind of device bus, e.g. a PCI or AGP graphics card, where caching would be of no benefit. (1999-07-02) 1 1 1 1 1 MEMS microelectromechanical system 1 1 1 1 1 Mentat (After the human computers in Frank Herbert's SF classic, "Dune") An object-oriented distributed language developed at the University of Virginia some time before Dec 1987. Mentat is an extension of C++ and is portable to a variety of MIMD architectures. By 1994 Mentat was available for Sun-3, Sun-4, iPSC/2 with plans for Mach, iPSC860, RS/6000 and Iris. The language is now (May 1998) supported in a new project, Legion. E-mail: <mentat@uvacs.cs.virginia.edu>. ["Mentat: An Object-Oriented Macro Data Flow System", A. Grimshaw <grimshaw@cs.virginia.edu> et al, SIGPLAN Notices 22(12):35-47, Dec 1987, OOPSLA '87]. (1998-05-15) 1 1 1 1 1 MENTOR CAI language. "Computer Systems for Teaching Complex Concepts", Report 1742, BBN, Mar 1969. 1 1 1 1 1 menu A list from which the user may select an operation to be performed. This is often done with a mouse or other pointing device under a graphical user interface but may also be controlled from the keyboard. Menus are very convenient for beginners because they show what commands are available and make experimentating with a new program easy, often reducing the need for user documentation. Experienced users however, often prefer keyboard commands, especially for frequently user operations, because they are faster to use. In situations such as text entry where the keyboard must be used anyway, having to move your hand to the mouse to invoke a menu operation is slow. There are many different ways of presenting menus but the most common are the menu bar (with pull-down menus) and the context-sensitive menu. The term "menu" tends to be reserved for a list of actions or global options, whereas a "list box" or other graphical 1 1 1 1 1 menu bar A permanently displayed menu spread horizontally across the top of the screen or window. When the mouse is pressed over an item on the menu bar, a pull-down menu appears. (1999-09-22) 1 1 1 1 1 menuitis /men"yoo-i:"tis/ A notional disease suffered by software with an obsessively simple-minded menu interface and no escape. Hackers find this intensely irritating and much prefer the flexibility of command-line or language-style interfaces, especially those customisable via macros or a special-purpose language in which one can encode useful hacks. See user-obsequious, drool-proof paper, WIMP, for the rest of us. [Jargon File] (1994-12-02) 1 1 1 1 1 MENYMA/S ["A Message Oriented Language for System Applications", A. Koch et al, Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982, pp. 824-832]. (1994-12-02) 1 1 1 1 1 Mercury Autocode Autocode for the Ferranti Mercury machine. 1 1 1 1 1 mercury delay line An archaic first-in first-out fixed time period data storage device using acoustic transducers to transmit data as waves in a trough or tube of mercury. EDSAC (Cambridge) and UNIVAC I used delay lines. (2002-06-12) 1 1 1 1 1 MERISE Methode d'Etude et de Realisation Informatique pour les Systemes d'Enteprise. A software engineering method popular in France; many IPSEs are based on it. (1995-01-24) 1 1 1 1 1 Merlin OS/2 1 1 1 1 1 MEROON An object-oriented system built on Scheme. [What kind of system?] (ftp://nexus.yorku.ca/pub/scheme/new/). (1997-05-05) 1 1 1 1 1 Mesa Xerox PARC, 1977. System and application programming for proprietary hardware: Alto, Dolphin, Dorado and Dandelion. Pascal-like syntax, ALGOL68-like semantics. An early version was weakly typed. Mesa's modules with separately compilable definition and implementation parts directly led to Wirth's design for Modula. Threads, coroutines (fork/join), exceptions, and monitors. Type checking may be disabled. Mesa was used internally by Xerox to develop ViewPoint, the Xerox Star, MDE, and the controller of a high-end copier. It was released to a few universitites in 1985. Succeeded by Cedar. ["Mesa Language Manual", J.G. Mitchell et al, Xerox PARC, CSL-79-3 (Apr 1979)]. ["Early Experience with Mesa", Geschke et al, CACM 20(8):540-552 (Aug 1977)]. 1 1 1 1 1 mesh The INTERCAL name for hash. 1 1 1 1 1 MESI protocol Modified, Exclusive, Shared, Invalid. A cache coherency protocol where each cache line is marked with one of the four states. The MESI protocol is used by the Pentium processor. (1995-05-05) 1 1 1 1 1 message In object-oriented programming sending a message to an object (to invoke a method) is equivalent to calling a procedure in traditional programming languages, except that the actual code executed may only be selected at run time depending on the class of the object. Thus, in response to the message "drawSelf", the method code invoked would be different if the target object were a circle or a square. (1995-02-16) 1 1 1 1 1 message board bulletin board system 1 1 1 1 1 Message Digest 5 The message digest function defined in RFC 1321. (1996-08-04) 1 1 1 1 1 message digest function one-way hash function 1 1 1 1 1 Message Handling System (MHS) The standard defined by ITU-T as X.400 and by ISO as Message-Oriented Text Interchange Standard (MOTIS). MHS is the X.400 family of services and protocols that provides the functions for global electronic mail transfer among local mail systems and MTAs. It is used by CompuServe, among others. (1996-09-25) 1 1 1 1 1 message passing One of the two techniques for communicating between parallel processes (the other being shared memory). A common use of message passing is for communication in a parallel computer. A process running on one processor may send a message to a process running on the same processor or another. The actual transmission of the message is usually handled by the run-time support of the language in which the processes are written, or by the operating system. Message passing scales better than shared memory, which is generally used in computers with relatively few processors. This is because the total communications bandwidth usually increases with the number of processors. A message passing system provides primitives for sending and receiving messages. These primitives may by either synchronous or asynchronous or both. A synchronous send will not complete (will not allow the sender to proceed) until the receiving process has received the message. This allows 1 1 1 1 1 Message Passing Interface A de facto standard for communication among the nodes running a parallel program on a distributed memory system. MPI is a library of routines that can be called from Fortran and C programs. MPI's advantage over older message passing libraries is that it is both portable (because MPI has been implemented for almost every distributed memory architecture) and fast (because each implementation is optimised for the hardware it runs on). [Address?] (1997-06-09) 1 1 1 1 1 message switching store and forward 1 1 1 1 1 Message Transfer Agent (MTA, Mail Transfer Agent) Any program responsible for delivering e-mail messages. Upon receiving a message from a Mail User Agent or another MTA, often by SMTP over the Internet, it stores it temporarily locally and analyses the recipients and delivers it to any local addressees and/or forwards it to other remote MTAs (routing) for delivery to remote recipients. In either case it may edit and/or add to the message headers. The most widely used MTA for Unix is sendmail, which communicates using SMTP. [Other OSes?] RFC 2821 (SMTP) expands MTA as "Mail Transfer Agent" though this is less common. Alternatives with "Transport" are also seen but less correct. (2007-06-01) 1 1 1 1 1 Message Transport Agent Message Transfer Agent 1 1 1 1 1 Messaging Application Programming Interface (MAPI) A messaging architecture and a client interface component for applications such as electronic mail, scheduling, calendaring and document management. As a messaging architecture, MAPI provides a consistent interface for multiple application programs to interact with multiple messaging systems across a variety of hardware platforms. MAPI provides better performance and control than Simple MAPI, Common Messaging Calls (CMC) or the Active Messaging Library. It has a comprehensive, open, dual-purpose interface, integrated with Microsoft Windows. MAPI can be used by all levels and types of client application and service providers - driver-like components that provide a MAPI interface to a specific messaging system. For example, a word processor can send documents and a workgroup application can share and store different types of data using MAPI. MAPI separates the programming interfaces used by the client 1 1 1 1 1 Messaging Applications Programming Interface Messaging Application Programming Interface 1 1 1 1 1 mess-dos /mes-dos/ (Or MS-DOG, Messy-DOS, mess-dross, mess-loss, mush-dos) Derisory term for MS-DOS. Often followed by the ritual banishing "Just say No!" Most hackers (even many MS-DOS hackers) loathe MS-DOS for its single-tasking nature, its limits on application size, its nasty primitive interface, and its ties to IBMness (see fear and loathing). In Ireland and the UK it is sometimes called "Domestos" after a brand of toilet cleanser. [Jargon File] (1994-11-16) 1 1 1 1 1 META The assembly language for the CYBER 200, developed at CDC ca 1977. [CDC Pub 60256020]. [Jargon File] (1994-11-16) 1 1 1 1 1 meta /me't*/ or /may't*/ or (Commonwealth) /mee't*/ A prefix meaning one level of description higher. If X is some concept then meta-X is data about, or processes operating on, X. For example, a metasyntax is syntax for specifying syntax, metalanguage is a language used to discuss language, metadata is data about data, and meta-reasoning is reasoning about reasoning. This is difficult to explain briefly, but much hacker humour turns on deliberate confusion between meta-levels. [Jargon File] (1999-04-06) 1 1 1 1 1 META 5 Early syntax-directed compiler-compiler, used for translating one high-level language to another. Versions: META II, META-3. ["META 5: A Tool to Manipulate Strings of Data", D.K. Oppenheim et al, Proc 21st Natl Conf, ACM 1966]. [Sammet 1969, p. 638]. (1995-01-23) 1 1 1 1 1 meta bit The most-signigicant bit of an 8-bit character, which is on in character values 128--255. Also called the high bit, "alt bit" (alternate bit) or hobbit. Some terminals and consoles (see space-cadet keyboard) have a META shift key. Others (including, *mirabile dictu*, keyboards on IBM PC-class machines) have an ALT key. See also bucky bits. Historical note: although, in modern usage shaped by a universe of 8-bit bytes, the meta bit is invariably hex 80 (octal 0200), things were different on earlier machines with 36-bit words and 9-bit bytes. The MIT and Stanford keyboards (see space-cadet keyboard) generated hex 100 (octal 400) from their meta keys. [Jargon File] (2014-10-05) 1 1 1 1 1 MetaCard A commercial human interface and hypertext system for Unix and the X Window System, similar to Hypercard. (1994-11-17) 1 1 1 1 1 Meta-CASE tool A term sometimes used for software packages (like TBK or VSF) which allow users to develop or customise their own CASE tools. 1 1 1 1 1 metaclass The class of a class in an object-oriented programming language. A metaclass is a class whose instances are themselves classes. Typically there will only be one metaclass, called "Class" or similar, which is the class of all classes including itself. In some languages there will be no metaclass. The idea of a metaclass is closely associated with introspection #NAME? itself or other programs. (2013-09-02) 1 1 1 1 1 Meta Class System (MCS) A portable object-oriented extension of Common Lisp from GMD. It integrates the functionality of CLOS and TELOS. (ftp://gmdzi.gmd.de/pub/lisp/mcs). (1994-10-21) 1 1 1 1 1 Meta-Crystal A language for transformations of Crystal programs. Implemented in T. ["Meta-Crystal - A Metalanguage for Parallel-Program Optimisation", J.A. Yang et al, TR YALEU/DCS/TR-786, Yale Apr 1990]. (2016-01-19) 1 1 1 1 1 metadata /me't*-day`t*/, or combinations of /may'-/ or (Commonwealth) /mee'-/; /-dah`t*/ (Or "meta-data") Data about data. In data processing, metadata is definitional data that provides information about or documentation of other data managed within an application or environment. For example, metadata would document data about data elements or attributes, (name, size, data type, etc) and data about records or data structures (length, fields, columns, etc) and data about data (where it is located, how it is associated, ownership, etc.). Metadata may include descriptive information about the context, quality and condition, or characteristics of the data. A collection of metadata, e.g. in a database, is called a data dictionary. Myers of The Metadata Company claims to have coined the term in 1969 though it appears in the book, "Extension of programming language concepts" published in 1968, by Philip 1 1 1 1 1 Metadata Information Partners The Metadata Company 1 1 1 1 1 META element An HTML element, with tag name of "META", expressing metadata about a given HTML document. HTML standards do not require that documents have META elements but if META elements occur, they must be inside the document's HEAD element. The META element can be used to identify properties of a document (e.g., author, expiration date, a list of key words, etc.) and assign values to those properties, typically by specifying a NAME attribute (to name the property) and a CONTENT attribute (to assign a value for that property). The HTML 4 specification doesn't standardise particular NAME properties or CONTENT values; but it is conventional to use a Description property to convey a short summary of the document, and a "Keywords" property to provide a list of keywords relevant to the document, as in: <META NAME="Description" CONTENT="Information from around the world on kumquat farming techniques and current kumquat 1 1 1 1 1 metafile 1. An image file format for transport between different machines, often as a device independent bitmap. 2. A functional specification for encoding computer graphics for later display on some suitable device. (1996-09-20) 1 1 1 1 1 METAFONT A system for the design of raster-based alphabets by Donald Knuth. A companion to TeX. ["The METAFONT Book," Donald Knuth, A-W 1986. Version 2.0, March 1990]. (1994-11-04) 1 1 1 1 1 metaheuristic A top-level general strategy which guides other heuristics to search for feasible solutions in domains where the task is hard. Metaheuristics have been most generally applied to problems classified as NP-Hard or NP-Complete by the theory of computational complexity. However, metaheuristics would also be applied to other combinatorial optimisation problems for which it is known that a polynomial-time solution exists but is not practical. Examples of metaheuristics are Tabu Search, simulated annealing, genetic algorithms and memetic algorithms. (1997-10-30) 1 1 1 1 1 Meta-II An early compiler-compiler. ["Meta-II: a Syntax Oriented Compiler Writing Language", V. Schorre, Proc 19th ACM Natl Conf 1964]. (1995-01-23) 1 1 1 1 1 metainformation metadata 1 1 1 1 1 Meta-IV Vienna Development Method Specification Language 1 1 1 1 1 METAL 1. Mega-Extensive Telecommunications Applications Language. BBS language for PRODOS 8 on Apple II. 2. The syntax-definition formalism of the Mentor system. Metal specifications are compiled to specifications for a scanner/parser generator such as Lex/Yacc. "Metal: A Formalism to Specify Formalisms", G. Kahn et al, Sci Comp Prog 3:151-188 (1983). 1 1 1 1 1 metalanguage 1. [theorem proving] A language in which proofs are manipulated and tactics are programmed, as opposed to the logic itself (the "object language"). The first ML was the metalanguage for the Edinburgh LCF proof assistant. 2. [logic] A language in which to discuss the truth of statements in another language. 1 1 1 1 1 Metal Oxide Semiconductor (MOS) The three materials used to form a gate in the most common kind of Field Effect Transistor - a MOSFET. [Other MOS devices?] (1996-05-27) 1 1 1 1 1 Metal Oxide Semiconductor Field Effect Transistor (MOSFET) A Field Effect Transistor in which the conducting channel is insulated from the gate terminal by a layer of oxide. Therefore it does not conduct even if a reverse voltage is applied to the gate. (1997-02-24) 1 1 1 1 1 metaphone An algorithm for encoding a word so that similar sounding words encode the same. It's similar to soundex in purpose, but as it knows the basic rules of English pronunciation it's more accurate. The higher accuracy doesn't come free, though, metaphone requires more computational power as well as more storage capacity, but neither of these requirements are usually prohibitive. It is in the public domain so it can be freely implemented. Metaphone was developed by Lawrence Philips <lphilips@verity.com>. It is described in ["Practical Algorithms for Programmers", Binstock & Rex, Addison Wesley, 1995]. (1998-12-22) 1 1 1 1 1 metaprogram A program which modifies or generates other programs. A compiler is an example of a metaprogram: it takes a program as input and produces another (compiled) one as output. (1994-10-24) 1 1 1 1 1 metasyntactic variable Strictly, a variable used in metasyntax, but often used for any name used in examples and understood to stand for whatever thing is under discussion, or any random member of a class of things under discussion. The word foo is the canonical example. To avoid confusion, hackers never (well, hardly ever) use "foo" or other words like it as permanent names for anything. In filenames, a common convention is that any filename beginning with a metasyntactic-variable name is a scratch file that may be deleted at any time. To some extent, the list of one's preferred metasyntactic variables is a cultural signature. They occur both in series (used for related groups of variables or objects) and as singletons. Here are a few common signatures: foo, bar, baz, quux, quuux, quuuux...: MIT/Stanford usage, now found everywhere. At MIT (but not at Stanford), baz dropped out of use for a while in the 1970s and '80s. A common recent 1 1 1 1 1 metasyntax Syntax used to describe syntax. The best known example is BNF and its variants such as EBNF. A metasyntactic variable is a variable used in metasyntax. (1999-04-06) 1 1 1 1 1 META tag META element 1 1 1 1 1 Meta-Vlisp An innovative Lisp dialect by E. St.James of IBP, France. (2000-12-19) 1 1 1 1 1 Met-English A Fortran-like language designed at Metropolitan Life in the early 1960s. It had support for variable-length bit fields. Most MetLife DP in the 1960s and 1970s was in Met-English. It was originally developed for Honeywell machines, but many programs still run under IBM MVS via a Honeywell emulator. (1995-02-15) 1 1 1 1 1 METEOR A version of COMIT with Lisp-like syntax, written in MIT Lisp 1.5 for the IBM 7090. "METEOR - A List Interpreter for String Transformation", D.G. Bobrow in The Programming Language LISP and its Interpretation, E.D. and D.G. Bobrow eds, 1964. 1 1 1 1 1 meter US spelling of "metre". (1998-02-07) 1 1 1 1 1 method In object-oriented programming, a function that can be called on an object of a given class. When a method is called (or invoked (method invocation)) on an object, the object is passed as an implicit argument to the method, usually referred to by the special variable "this". If the method is not defined in the object's class, it is looked for in that class's superclass, and so on up the class hierarchy until it is found. A subclass thus inherits inheritance all the methods of its superclasses. Different classes may define methods with the same name (i.e. methods may be polymorphic). Methods are sometimes called "object methods" or "instance methods". "Class methods" are methods that operate on objects of class "class". "Static methods" are not methods but normal functions packaged with the class. (2000-03-22) 1 1 1 1 1 method invocation In object-oriented programming, the way the program looks up the right code to run when a method with a given name is called ("invoked") on an object. The method is first looked for in the object's class, then that class's superclass and so on up the class hierarchy until a method with the given name is found (the name is "resolved"). Generally, method lookup cannot be performed at compile time because the object's class is not known until run time. This is the case for an object method whereas a class method is just an ordinary function (that is bundled with a given class) and can be resolved at compile time (or load time in the case of a dynamically loaded library). (2014-09-06) 1 1 1 1 1 methodology 1. <programming> An organised, documented set of procedures and guidelines for one or more phases of the software life cycle, such as analysis or design. Many methodologies include a diagramming notation for documenting the results of the procedure; a step-by-step "cookbook" approach for carrying out the procedure; and an objective (ideally quantified) set of criteria for determining whether the results of the procedure are of acceptable quality. An example is The Yourdon methodology. 2. A pretentious way of saying "method". (1995-04-10) 1 1 1 1 1 Methods A line-oriented Smalltalk for PC's, produced by Digitalk ca 1985. Methods was the predecessor of Smalltalk/V. (1995-04-16) 1 1 1 1 1 me too A functional language for executable specifications developed by Peter Henderson in 1984. It is like LispKit Lisp, but with sets, maps and sequences to describe the specification. ["Functional Programming, Formal Specification and Rapid Prototyping", IEEE Trans Soft Eng, SE-12(2):241-250 (Feb 1986)]. (1994-10-21) 1 1 1 1 1 metre (US "meter") The fundamental SI unit of length. From 1889 to 1960, the metre was defined to be the distance between two scratches in a platinum-iridium bar kept in the vault beside the Standard Kilogram at the International Bureau of Weights and Measures near Paris. This replaced an earlier definition as 10^-7 times the distance between the North Pole and the Equator along a meridian through Paris; unfortunately, this had been based on an inexact value of the circumference of the Earth. From 1960 to 1984 it was defined to be 1650763.73 wavelengths of the orange-red line of krypton-86 propagating in a vacuum. It is now defined as the length of the path traveled by light in a vacuum in the time interval of 1/299,792,458 of a second. (1998-02-07) 1 1 1 1 1 metric software metric 1 1 1 1 1 metric space A set of points together with a function, d, called a metric function or distance function. The function assigns a positive real number to each pair of points, called the distance between them, such that: 1. For any point x, d(x,x)=0; 2. For any two distinct points x and y, d(x,y)>0; 3. For any two points x and y, not necessarily distinct, d(x,y) = d(y,x). 4. For any three points x, y, and z, that are not necessarily distinct, d(x,z) <= d(x,y) + d(y,z). The distance from x to z does not exceed the sum of the distances from x to y and from y to z. The sum of the lengths of two sides of a triangle is equal to or exceeds the length of the third side. 1 1 1 1 1 Metropolitan Area Network (MAN) A data network intended to serve an area the size of a large city. Such networks are being implemented by innovative techniques, such as running optical fibre through subway tunnels. A popular example of a MAN is SMDS. See also Local Area Network, Wide Area Network. (1994-11-22) 1 1 1 1 1 M-expression LISP (MLISP) The original "meta-language" syntax of Lisp, designed by John McCarthy in 1962. MLISP was intended for external use in place of the parenthesised S-expression syntax. ["LISP 1.5 Programmer's Manual", J. McCarthy et al, MIT Press 1962]. (1994-11-22) 1 1 1 1 1 MFC Microsoft Foundation Class (1995-11-16) 1 1 1 1 1 MFE maximal free expression 1 1 1 1 1 MFLOPS 1. <unit> megaflops. 2. <benchmark> A benchmark which attemps to estimate a system's floating-point "MFLOPS" rating for specific FADD, FSUB, FMUL and FDIV instruction mixes. C Source (ftp://ftp.nosc.mil/pub/aburto/flops20.c). Results (http://performance.netlib.org/performance/html/flops.html), (ftp://ftp.nosc.mil/pub/aburto/flops_1.tbl), (ftp://ftp.nosc.mil/pub/aburto/flops_2.tbl), (ftp://ftp.nosc.mil/pub/aburto/flops_3.tbl), (ftp://ftp.nosc.mil/pub/aburto/flops_4.tbl). (1994-11-14) 1 1 1 1 1 MFM Modified Frequency Modulation 1 1 1 1 1 MFTL My Favourite Toy Language 1 1 1 1 1 mg The country code for Madagascar. <text, tool> MicroGnuEmacs. 1 1 1 1 1 MGCP Media Gateway Control Protocol 1 1 1 1 1 mh The country code for Marshall Islands. (1999-01-27) 1 1 1 1 1 MHDL 1. MIMIC Hardware Description Language. 2. Microwave Hardware Description Language. 1 1 1 1 1 MHEG Multimedia and Hypermedia information coding Expert Group 1 1 1 1 1 MHS message handling system 1 1 1 1 1 MHz MegaHertz 1 1 1 1 1 MIB Management Information Base 1 1 1 1 1 MIB Variable A managed object that is defined in a Management Information Base (MIB). The object is defined by a textual name and a corresponding object identifier, a syntax, an access mode, a status, and a description of the semantics of the managed object. The MIB Variable contains pertinent management information that is accessible as defined by the access mode. (1995-03-22) 1 1 1 1 1 MIC Many Integrated Core Architecture 1 1 1 1 1 Mic-1 Microprogramming language, used in Andrew Tanenbaum's book. See Mac-1. [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H 1989, Sect 4.4, 4.5]. 1 1 1 1 1 Mic-2 Microprogramming language, used in Tanenbaum's book. See Mac-1. [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H 1989, Sect 4.4, 4.5]. 1 1 1 1 1 MICE Multimedia Integrated Conferencing for European Researchers 1 1 1 1 1 mice mouse 1 1 1 1 1 Michigan Algorithm Decoder (MAD) An early programming language, based on IAL, developed at the University of Michigan by R. Graham, Bruce Arden, and Bernard Galler in 1959. MAD was one of the first extensible languages: the user could define his own operators and data types. MAD ran on the IBM 704, IBM 709 and IBM 7090. It was ported to the IBM 7040 at the City College of New York by Robert Teitel and also to Philco, Univac and CDC computers. Mad/1 was a later version. ["Michigan Algorithm Decoder (The MAD Manual)", U Michigan Computing Center, 1966]. [Sammet 1969, p. 205]. (2005-02-09) 1 1 1 1 1 mickey The unit of resolution of mouse movement. It has been suggested that the "disney" will become a benchmark unit for animation graphics performance. [Jargon File] (1999-06-30) 1 1 1 1 1 mickey mouse program The North American equivalent of a "noddy program", i.e. trivial. The term doesn't necessarily have the belittling connotations of mainstream slang "Oh, that's just mickey mouse stuff!"; sometimes trivial programs can be very useful. [Jargon File] (1995-04-10) 1 1 1 1 1 MICR Magnetic Ink Character Recognition 1 1 1 1 1 micro microprocessor 1 1 1 1 1 micro- prefix 1 1 1 1 1 microarray A technique for performing many DNA experiments in parallel. Nothing to do with computers. (2007-05-14) 1 1 1 1 1 Micro Assembly Language (MAL) A microprogramming language with high-level syntax, used in the reference below. See also Mic-1, Mac-1. [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H 1989, Sect 4.4]. (1995-04-10) 1 1 1 1 1 microcentury One CS professor used to characterise the standard length of his lectures as a microcentury - that is, about 52.6 minutes (see also attoparsec, nanoacre, and especially microfortnight). 1 1 1 1 1 Micro Channel Architecture (MCA) IBM's proprietary 32-bit bus, used in high-end PS/2 personal computers. Micro Channel is designed for multiprocessing. It eliminates potential conflicts that arise when installing new peripheral devices. MCA is *not* compatible with either EISA or XT bus architecture so older cards cannot be used with it. As with the ROM BIOS in the first IBM PCs, figuring out the Micro Channel's secrets has been an arduous task of reverse engineering ever since the PS/2 line was announced. Consequently, the MCA has never become as wide spread as the competing EISA standard. (1996-08-16) 1 1 1 1 1 microchip art (chip art, chip graffiti) Images etched on integrated circuits purely for decoration, visible only under a microscope. Smithsonian Institute Chip Art (http://smithsonianchips.si.edu/chipfun/graff.htm). 1 1 1 1 1 microcode A technique for implementing the instruction set of a processor as a sequence of microcode instructions ("microinstructions"), each of which typically consists of a (large) number of bit fields and the address of the next microinstruction to execute. Each bit field controls some specific part of the processor's operation, such as a gate which allows some functional unit to drive a value onto the bus or the operation to be performed by the ALU. Several microinstructions will usually be required to fetch, decode and execute each machine code instruction ("macroinstruction"). The microcode may also be responsible for polling for hardware interrupts between each macroinstruction. Writing microcode is known as microprogramming. Microcode may be classified as "horizontally encoded" or vertically encoded. Horizontal microcode is as described above where there is a fairly direct correspondence between 1 1 1 1 1 Microcom Networking Protocol (MNP) One of the most common modem protocols with compression. Also the name of a product. [Details? On-line spec?] (1995-01-31) 1 1 1 1 1 microcomputer A computer based on a microprocessor. Contrast with minicomputer, mainframe. (1995-02-07) 1 1 1 1 1 microcontroller A microprocessor on a single integrated circuit intended to operate as an embedded system. As well as a CPU, a microcontroller typically includes small amounts of RAM and PROM and timers and I/O ports. An example is the Intel 8751. (1995-04-22) 1 1 1 1 1 MicroDroid [Usenet] A Microsoft employee, especially one who posts to various operating-system advocacy newsgroups. MicroDroids post follow-ups to any messages critical of Microsoft's operating systems, and often end up sounding like visiting Mormon missionaries. [Jargon File] 1 1 1 1 1 microelectromechanical system (MEMS) The integration of mechanical structures (moving parts) with microelectronics. MEMS devices are custom designed for a purpose which requires a mechanical action to be controlled by a computer. Applications include sensors, medical devices, process controls. (http://mems.mcnc.org/). See also nanotechnology. (1999-03-25) 1 1 1 1 1 Microelectronics and Computer Technology Corporation (MCC) One of the first, and now one of the largest, US computer industry research and development consortia. Founded in late 1982 by major computer and semiconductor manufacturers, MCC's membership has diversified to include a broad range of high-profile corporations from electronics, computers, aerospace, semiconductors, and related industries, reflecting the full range of companies vital to the life cycle of Information Technology products. Active involvement of small- and medium-sized firms and technology users, along with well-established alliances with government research and development agencies and leading universities, allows MCC's partners to maximise the benefit of scarce research and development resources. Some of the technical areas in which MCC has distinguished itself are: System Architecture and Design (optimise hardware and software design, provide for scalability and interoperability, allow 1 1 1 1 1 MicroEmacs (uemacs) A simple, portable text editor with versions for most microcomputers and many other computers. It is both relatively easy for the novice to use, but also very powerful in the hands of an expert. MicroEmacs can be extensibly customised. Most versions use only a screen and keyboard - mouse and windowing facilities are not standard. MicroEmacs was written by Dave G Conroy, Steve Wilhite, George Jones, and for nearly ten years: Daniel Lawrence. Version: 3.11. (ftp://midas.mgmt.purdue.edu/dist/). [FTP? Differences from GNU Emacs?] (1995-01-05) 1 1 1 1 1 microfloppies 3.5-inch floppies, as opposed to 5.25-inch vanilla or mini-floppies and the now-obsolete 8-inch variety. This term may be headed for obsolescence as 5.25-inchers pass out of use, only to be revived if anybody floats a sub-3-inch floppy standard. See stiffy, minifloppies. [Jargon File] 1 1 1 1 1 microfortnight One millionth of the fundamental unit of time in the Furlong/Firkin/Fortnight system of measurement; 1.2096 sec. (A furlong is 1/8th of a mile; a firkin is 1/4th of a barrel; the mass unit of the system is taken to be a firkin of water). The VMS operating system has a lot of tuning parameters that you can set with the SYSGEN utility, and one of these is TIMEPROMPTWAIT, the time the system will wait for an operator to set the correct date and time at boot if it realises that the current value is bogus. This time is specified in microfortnights! Multiple uses of the millifortnight (about 20 minutes) and nanofortnight have also been reported. 1 1 1 1 1 MicroGnuEmacs (mg) A Public Domain Emacs-style editor modified from MicroEmacs to be more compatible with GNU Emacs. mg is essentially free, it is not associated with the GNU project, and does not have the GNU copyright restrictions. It is a small, fast, portable editor for people who can't run real Emacs thing for one reason or another. It has few if any of the MicroEmacs features that were incompatible with GNU Emacs and adds missing features that seemed essential. MicroGnuEmacs is derived from, and aims to replace, v30 of MicroEmacs, the latest version from the original MicroEmacs author Dave Conroy. The chief contributors were Mike Meyer <mwm@ucbopal.berkeley.edu>, Mic Kaczmarczik <mic@ngp.utexas.edu>, Bob Larson, and Dave Brower <rtech!daveb@sun.com>. mg version 1a of 1986-11-16 works with 4.2BSD, 4.3BSD, Ultrix-32, OS9/68k, VMS, Amiga, System V, Eunice. It is included in base OpenBSD. It should also support 1 1 1 1 1 Micro Instrumentation and Telemetry Systems (MITS) The company which made the Altair 8800 micrcomputer kit. They also made instrumentation kits for model rockets and RC vehicles. Ed Roberts owned MITS for a few years until he sold out, moved to Georgia, and went to med school. Address: Albuquerque NM, USA. (2002-06-17) 1 1 1 1 1 Micro Interpreter for Knowledge Engineering (MIKE) An expert system shell for teaching purposes, with forward chaining, backward chaining, and user-definable conflict resolution strategies. MIKE is written in Edinburgh Prolog. Version 2.03. [BYTE, Oct 1990]. (ftp://hcrl.open.ac.uk/pub/software/src/MIKE-v2.03). Contact: Marc Eisenstadt, HCRL, Open University. (1995-01-10) 1 1 1 1 1 microkernel An approach to operating system design emphasising small modules that implement the basic features of the system kernel and can be flexibly configured. (1999-08-02) 1 1 1 1 1 microLenat /mi:"-kroh-len"-*t/ The unit of bogosity, written uL; the consensus is that this is the largest unit practical for everyday use. The microLenat, originally invented by David Jefferson, was promulgated as an attack against noted computer scientist Doug Lenat by a tenured graduate student at CMU. Doug had failed the student on an important exam for giving only "AI is bogus" as his answer to the questions. The slur is generally considered unmerited, but it has become a running gag nevertheless. Some of Doug's friends argue that *of course* a microLenat is bogus, since it is only one millionth of a Lenat. Others have suggested that the unit should be redesignated after the grad student, as the microReid. [Jargon File] 1 1 1 1 1 microlog A section of non-volitile memory used to record state information. Often used for retaining crash information after a reboot in embedded systems. ["before" a reboot?] (2004-02-24) 1 1 1 1 1 micrometre (Or "micron") One millionth of a metre. The symbol is a Greek letter mu followed by "m". Features on modern integrated circuits are typically measured in microns. The smallest features in 1999 are around 0.1 microns across. (1999-09-28) 1 1 1 1 1 Micro ML (uML) An interpreter for a subset of SML. Runs on MS-DOS. Written at the University of Umea, Sweden. (ftp://ftp.cs.umu.se/pub/umlexe01.zoo). 1 1 1 1 1 Micron Micron Electronics, Inc. 1 1 1 1 1 micron micrometre 1 1 1 1 1 Micron Electronics, Inc. An electronics company that develops, markets, manufactures, and supports high-performance notebook computers, desktop personal computers, PC servers and related hardware and software products. (1997-03-10) 1 1 1 1 1 Micronetics Standard MUMPS (MSM) A version of MUMPS for the IBM PC RT and R6000. [Address?] (1995-01-10) 1 1 1 1 1 Micro$oft Microsoft written with a dollar sign, as though there was any doubt that they are a money-making enterprise. This little witticism was probably created before Microsoft's founder, Bill Gates established the philanthropic Bill & Melinda Gates Foundation. Why I hate Microsoft (http://www.vanwensveen.nl/rants/microsoft/IhateMS.html). (2013-12-30) 1 1 1 1 1 microperation An elementary operation performed on data stored in registers or in memory. Microperations are classified as transfer, arithmetic, logic, or shift/rotate. [Relationship with microcode?] (2003-12-29) 1 1 1 1 1 microphone Any electromechanical device designed to convert sound into an electrical signal. A microphone converts an acoustic waveform consisting of alternating high and low air pressure travelling through the air into a voltage. To do this it uses some kind of pressure or movement sensor. The simplest kind of microphone is actually very similar in construction to a loudspeaker. The analogue electrical signal can be fed into a computer's sound card where it is amplified and sampled to convert it into a digital waveform for storage or transmission. (2002-11-04) 1 1 1 1 1 microPLANNER A subset of PLANNER, implemented in Lisp by Gerald Sussman et al at MIT. Its important features were goal-oriented, pattern-directed procedure invocation, an embedded knowledge base, and automatic backtracking. microPLANNER was superseded by Conniver. ["microPLANNER Reference Manual", G.J. Sussman et al, AI Memo 203, MIT AI Lab, 1970]. (1995-01-10) 1 1 1 1 1 microprocesor It's spelled microprocessor. (1997-02-13) 1 1 1 1 1 microprocessor (Or "micro") A computer whose entire CPU is contained on one (or a small number of) integrated circuits. The important characteristics of a microprocessor are the widths of its internal and external address bus and data bus (and instruction), its clock rate and its instruction set. Processors are also often classified as either RISC or CISC. The first commercial microprocessor was the Intel 4004 which appeared in 1971. This was the CPU member of a set of four LSI integrated circuits called the MCS-4, which was originally designed for use in a calculator but was marketed as "programmable controller for logic replacement". The 4004 is referred to as a 4-bit microprocessor since it processed only 4 bits of data at a time. This very short word size is due mainly to the limitations imposed by the maximum integrated circuit density then achievable. As integrated circuit densities increased with the rapid 1 1 1 1 1 Microprocessor without Interlocked Pipeline Stages (MIPS) A project at Stanford University intended to simplify processor design by eliminating hardware interlocks between the five pipeline stages. This means that only single execution cycle instructions can access the thirty two 32-bit general registers, so that the compiler can schedule them to avoid conflicts. This also means that LOAD/STORE and branch instructions have a one-cycle delay to account for. However, because of the importance of multiply and divide instructions, a special HI/LO pair of multiply/divide registers exist which do have hardware interlocks, since these take several cycles to execute and complicate instruction scheduling. The project eventually lead to the commercial MIPS R2000 processor. (1995-02-09) 1 1 1 1 1 microprogramming microcode 1 1 1 1 1 microReid /mi:'kroh-reed/ See bogosity. [Jargon File] 1 1 1 1 1 MICRO SAINT A general purpose simulation tool from US company Micro Analysis and Design. (2007-03-22) 1 1 1 1 1 microsecond One millionth (10^-6) of a second. (1995-03-14) 1 1 1 1 1 Microserf Wired magazine's term for a Microsoft employee. (1995-03-02) 1 1 1 1 1 Microslop A derisive synonym for Microsoft Corporation. It refers to the sloppy, bug-ridden "x.0" versions of MS-DOS, Microsoft Windows and other Microsoft products. (1995-12-28) 1 1 1 1 1 Microsloth Windows /mi:'kroh-sloth" win"dohz/ (Or Windoze, /win'dohz/) A derogatory term for Microsoft Windows which is so limited by bug-for-bug compatibility with mess-dos that it is agonisingly slow on anything less than a fast 486. Also called just "Windoze", with the implication that you can fall asleep waiting for it to do anything; the latter term is extremely common on Usenet. Compare X, sun-stools. [Jargon File] (1996-10-08) 1 1 1 1 1 Microsoft Microsoft Corporation 1 1 1 1 1 Microsoft Access 1. <database> A relational database running under Microsoft Windows. Data is stored as a number of "tables", e.g. "Stock". Each table consists of a number of "records" (e.g. for different items) and each record contains a number of "fields", e.g. "Product code", "Supplier", "Quantity in stock". Access allows the user to create "forms" and "reports". A form shows one record in a user-designed format and allows the user to step through records one at a time. A report shows selected records in a user-designed format, possibly grouped into sections with different kinds of total (including sum, minimum, maximum, average). There are also facilities to use links ("joins") between tables which share a common field and to filter records according to certain criteria or search for particular field values. Version: 2 (date?). 1 1 1 1 1 Microsoft Basic (MS-BASIC) A dialect of BASIC from Microsoft, originally developed by Bill Gates in a garage back in the CP/M days. It was originally known as GWBasic, then QBASIC and finally MS-BASIC. When the MS-DOS operating system came out, it incorporated the GWBASIC.EXE or BASICA.EXE interpreters. GWBASIC ("Gee Whiz") incorporated graphics and a screen editor and was compatible with earlier BASICs. QBASIC was more sophisticated. Version 4.5 had a full screen editor, debugger and compiler. The compiler could also produce executable files but to run these a utility program (BRUN44.EXE) had to be present. Thus source code could be kept private. From DOS 5.0 or 6.0 onward, MS-BASIC was standard. Latest version: 1.1, also produces stand-alone executables and can display graphics. Usenet newsgroup: news:comp.lang.basic.misc. 1 1 1 1 1 Microsoft Certified Application Developer (MCAD) Microsoft's qualification signifying ability to build applications with Microsoft Visual Studio .NET and web services on Microsoft .NET Framework 1.0 and 1.1. MCAD can no longer be earned. (http://www.microsoft.com/learning/en/in/certification/mcad.aspx) (2013-04-21) 1 1 1 1 1 Microsoft Certified Database Administrator (MCDBA) Microsoft's certification of ability to design, implement and manage SQL Server 2000 databases. The qualification was retired on 2012-09-30. (http://www.microsoft.com/learning/en/us/mcdba-certification.aspx). (2013-06-15) 1 1 1 1 1 Microsoft Certified Desktop Support Technician (MCDST) Microsoft's qualification signifying ability to troubleshoot Windows XP desktop environments and to solve hardware and software operation and application problems on Windows XP. MCDST can no longer be earned. (2013-05-23) 1 1 1 1 1 Microsoft Certified Professional Developer (MCPD) Microsoft's certification intended to show comprehensive skills designing, developing and deploying applications for a particular job role. (2013-07-21) 1 1 1 1 1 Microsoft Certified Solution Developer (MCSD) A course for the VAR or software developer. Candidates must pass three core exams and an elective exam. The core exams cover systems analysis, and desktop and distributed development. (http://microsoft.com/mcsd). (2001-05-20) 1 1 1 1 1 Microsoft Certified System Engineer (MCSE) A qualification obtained by passing Microsoft's system engineer certification exams. (http://microsoft.com/mcse). (2002-07-02) 1 1 1 1 1 Microsoft Certified Systems Administrator (MCSA) Microsoft's qualification for people who administer network and system environments based on Windows operating systems. Specializations include Messaging and Security. Replaced by Microsoft Certified Solutions Associate. (2013-09-02) 1 1 1 1 1 Microsoft Certified Systems Developer Do you mean Microsoft Certified Solution Developer or Microsoft Certified System Engineer? (2001-05-20) 1 1 1 1 1 Microsoft Corporation The biggest supplier of operating systems and other software for IBM PC compatibles. Software products include MS-DOS, Microsoft Windows, Windows NT, Microsoft Access, LAN Manager, MS Client, SQL Server, Open Data Base Connectivity (ODBC), MS Mail, and SNA Server for Windows NT. Microsoft was founded as "Micro-soft" in 1975 by Bill Gates (now CEO) and his high school pal Paul Allen. Their first product was a version of BASIC for the new Altair computer [which one?]. In 1980, IBM chose Microsoft to supply the operating system for the IBM PC. On the UK television program "The Net" in May 1994, Bill Gates said he was betting his company on the information highway". Quarterly sales $1293M, profits $362M (Aug 1994). (http://microsoft.com/). (ftp://ftp.microsoft.com/). 1 1 1 1 1 Microsoft Data Access Components (MDAC) Microsoft's umbrella term for their ActiveX Data Objects (ADO), OLE DB, and Open Database Connectivity (ODBC) libraries. Together, these provide access to a variety of data sources, both relational (SQL) and nonrelational. MDAC is the technology that supports Universal Data Access, Microsoft's strategy for providing access to information across the enterprise. (http://msdn.microsoft.com/library/en-us/mdacsdk/htm/mdacstartpage1.asp). (2004-02-17) 1 1 1 1 1 Microsoft Disc Operating System Microsoft Disk Operating System 1 1 1 1 1 Microsoft Disk Operating System /M S doss/ (Or "MS-DOS", "PC-DOS", MS-DOG, "mess-dos") Microsoft Corporation's clone of the CP/M disk operating system for the 8088 crufted together in 6 weeks by hacker Tim Paterson, who is said to have regretted it ever since. MS-DOS is a single user operating system that runs one program at a time and is limited to working with one megabyte of memory, 640 kilobytes of which is usable for the application program. Special add-on EMS memory boards allow EMS-compliant software to exceed the 1 MB limit. Add-ons to DOS, such as Microsoft Windows and DESQview, take advantage of EMS and allow the user to have multiple applications loaded at once and switch between them. Numerous features, including vaguely Unix-like but rather broken support for subdirectories, I/O redirection and pipelines, were hacked into MS-DOS 2.0 and subsequent versions; as a result, there are two or more incompatible 1 1 1 1 1 Microsoft DOS Microsoft Disk Operating System 1 1 1 1 1 Microsoft Excel A spreadsheet program from Microsoft, part of their Microsoft Office suite of productivity tools for Microsoft Windows and Macintosh. Excel is probably the most widely used spreadsheet in the world. Latest version: Excel 97, as of 1997-01-14. (http://microsoft.com/msexcel/). [Feature summary? History?] (1997-01-14) 1 1 1 1 1 Microsoft Exchange Microsoft's messaging and enterprise collaboration server. Exchange's primary role is as an electronic mail message store but it can also store calendars, task lists, contact details, and other data. [Better descripton? URL?] (1999-09-17) 1 1 1 1 1 Microsoft Extended (MSX) A Range of computers created in an attempt by the industry to create a standard for home computers, similar to VHS did with home video. The basic MSX machine contained a Z80 CPU working at 3.58MHz. MSX machines were produced by such giants as Sony, Yamaha, Panasonic, Toshiba, Daewoo, and Philips. The MSX standard was designed by a company called ASCII in cooperation with Microsoft who provided a firmware version of its BASIC for the machine. Because this BASIC version was an extended version of MicroSoft Basic, it was called MicroSoft eXtended BASIC; Hence "MSX". Microsoft also produced MSX-DOS - a stripped-down version of MS-DOS. Extensions to the MSX included MSX2, MSX2+ and TurboR. FAQ (http://faq.msxnet.org/). (1999-02-26) 1 1 1 1 1 Microsoft Foundation Classes (MFC) Software structures in C++, the Windows base classes which can respond to messages, make windows, and from which application specific classes can be derived. (1995-11-17) 1 1 1 1 1 Microsoft IIS Internet Information Server 1 1 1 1 1 Microsoft IntelliMouse Explorer An optical mouse from Microsoft. (http://microsoft.com/presspass/features/1999/04-19mouse.htm). (1999-07-21) 1 1 1 1 1 Microsoft Internet Information Server Internet Information Server 1 1 1 1 1 Microsoft Mail (MS Mail) A Microsoft Windows electronic mail program. [Features? Version?] (1996-08-26) 1 1 1 1 1 Microsoft Mail Application Program Interface Messaging Application Programming Interface 1 1 1 1 1 Microsoft Network The Microsoft Network 1 1 1 1 1 Microsoft Networking Microsoft's name for the networking subsystems of Windows 95 and later. Not to be confused with The Microsoft Network. Microsoft networking uses the SMB file sharing protocol. It is implemented as file system drivers i.e. "installable file systems" (IFS). The network redirector "Client for Microsoft Networks", is implemented in the VREDIR.VXD virtual device driver. Peer resource sharing is provided by "File and Printer Sharing for Microsoft Networks" (VSERVER.VXD). Windows 95's support for Netware (NCP) networks is provided in a similar way via NWREDIR.VXD and NWSERVER.VXD. (1999-08-08) 1 1 1 1 1 Microsoft Office Microsoft's bundles of productivity tools including Microsoft Word, Microsoft Excel, Microsoft Powerpoint, Microsoft Outlook, Microsoft Access, Microsoft Publisher, Microsoft Front Page, Microsoft Team Manager, Microsoft Project, Microsoft Schedule+, Microsoft Internet Explorer, Small Business Financial Manager, Automap Streets Plus. Editions of Office include Microsoft Office Professional Edition, Microsoft Office Standard Edition, Microsoft Office Small Business Edition, Microsoft Office Developer Edition. Different editions contain different subsets of the above applications. Current version, as of 2004-08-30: Office 2003. (http://microsoft.com/office). (2004-08-30) 1 1 1 1 1 Microsoft Office Small Business Edition (SBE) Editions of Microsoft Office 97, 2003, and probably other versions, targetted at small businesses. Small Business Edition includes Microsoft Word, Microsoft Excel, Microsoft PowerPoint, Microsoft Outlook with Business Contact Manager and Microsoft Publisher. SBE 2003 doesn't include Microsoft Access or the addtional XML, IRM and Visual Studio support found in Microsoft Office Professional Edition, though the new user price is the same. Office Editions (http://microsoft.com/office/editions/howtobuy/compare.mspx). (2004-08-31) 1 1 1 1 1 Microsoft Point to Point Encryption (MPPE) An encryption protocol that may be used with PPTP to provide an encrypted connection. (1998-09-24) 1 1 1 1 1 Microsoft Project A Microsoft Windows program offering various project management tools. (http://microsoft.com/office/project/). (2003-07-02) 1 1 1 1 1 Microsoft SQL Server A relational database management system (RDBMS) which is part of Microsoft's BackOffice family of servers. SQL Server was designed for client/server use and is accessed by applications using SQL. It runs on Windows NT version 3.5 or higher and is compliant with the ANSI SQL-92 and FIPS 127-2 SQL standards. SQL Server supports symmetric multiprocessing hardware; SNMP, ODBC, and major open standard communications protocols. It has Internet integration, data replication, and data warehousing features. Microsoft SQL Server was originally developed by Sybase Corporation but the cooperation was broken sometime [when?] before version 6.0. Latest version: 7.0. [Or is it 2000?] (http://microsoft.com/sql). Usenet newsgroup: news:comp.databases.ms-sqlserver. (2001-04-27) 1 1 1 1 1 Microsoft Windows Microsoft's proprietary window system and user interface software released in 1985 to run on top of MS-DOS. Widely criticised for being too slow (hence Windoze, "Microsloth Windows") on the machines available then. The 1996 market share of operating systems was: DOS/Windows 70% Windows 95 15% Windows NT 2% Other 13% Versions include 1985 Windows 1, 1987 Windows 2, 1987 Windows/386, 1990 Windows 3.0, 1992 Windows 3.1, 1992 Windows for Workgroups 3.1, 1993 Windows 3.11, 1993 Windows for Workgroups 3.11, 1993 Windows NT 3.1, 1994 Windows NT 3.5, 1995 Windows 95, 199? Windows NT 4, 1998 Windows 98, Windows NT 5, Windows XP, Windows 7, Windows 8. (2015-03-07) 1 1 1 1 1 Microsoft Word A popular word processor, part of the Microsoft Office suite. The original Word (versions 1.0 to 4.?/5.0?) was originally text-based (non-GUI) and ran under MS-DOS. Then Microsoft released Word for Windows 1.0 and 2.0. Later they produced new versions for each OS, both numbered 6.0. (http://microsoft.com/catalog/products/word/). [Features?] (1997-02-11) 1 1 1 1 1 MicroStation A full-featured 2-D and 3-D CAD program for MS-DOS, Microsoft Windows, Macintosh, and Unix workstations from Bentley Systems, Inc. Created in 1984, MicroStation is a high-end package used worldwide in environments where many designers work on large, complex projects. MicroStation Modeler is a superset of MicroStation that provides solid modelling, and MasterPiece is MicroStation's rendering and animation program. (2001-04-19) 1 1 1 1 1 microtape /mi:'kroh-tayp/ Occasionally used to mean a DECtape, as opposed to a macrotape. Apparently the term "microtape" was actually the official term used within DEC for these tapes until someone coined the word DECtape, which, of course, sounded sexier to the marketroids. Another version of the story holds that someone discovered a conflict with another company's microtape trademark. [Jargon File] (1995-03-16) 1 1 1 1 1 Microware Corporation Authors of OS-9. Address: Des Moines, Iowa, USA. (1995-02-02) 1 1 1 1 1 Microwave Hardware Description Language (MHDL) A Hardware Description Language by David Barton[?] from Intermetrics incorporating Haskell 1.2. Not to be confused with other MHDLs. (2000-11-14) 1 1 1 1 1 MIDAS A digital simulation language. [Sammet 1969, p.627]. 1 1 1 1 1 Midas A Motif-based toolkit for interactive data analysis by T. Johnson, SLAC. The basis for the Midas-WWW browser. 1 1 1 1 1 Midas-WWW A Motif-based browser for WWW based on the Midas toolkit. (1998-08-09) 1 1 1 1 1 middle-endian Neither big-endian nor little-endian. Used of perverse byte orders such as 3-4-1-2 or 2-1-4-3, occasionally found in the packed decimal formats of some minicomputer manufacturers. See -endian. [Jargon File] (1998-08-09) 1 1 1 1 1 middleware Software that mediates between an application program and a network. It manages the interaction between disparate applications across the heterogeneous computing platforms. The Object Request Broker (ORB), software that manages communication between objects, is an example of a middleware program. 1 1 1 1 1 MIDI Musical Instrument Digital Interface 1 1 1 1 1 mid-level network (Or "regional network"). The kind of networks which make up the second level of the Internet hierarchy. They are the transit networks which connect the stub networks to the backbone networks. 1 1 1 1 1 MIF Maker Interchange Format 1 1 1 1 1 MIG Mach Interface Generator 1 1 1 1 1 MIGRAINES A graphical user interface for evaluating and interacting with the Aspirin neural network simulation. Utilities exist for moving quickly from an Aspirin description of a network directly to an executable program for simulating and evaluating that network. MIGRAINES has been kept separate from Aspirin so that its limitations do not restrict the performance of Aspirin. However, in practice, they are used together. This combination allows for simple specification and creation of efficient neural network systems that can be graphically analysed and tested. [Aspirin/MIGRAINES Neural Network Software User's Manual, Release v6.0 MP-91W00050, Copyright 1992 by Russel Leighton and the MITRE Corporation]. (1995-03-07) 1 1 1 1 1 MII 1. <body> A consortium of Microsoft, IBM, and Intel. [When? What did it do?] 2. <storage> A broadcast component video tape format licensed by Panasonic. (1998-11-15) 1 1 1 1 1 MIIS /Meese/ An interpreted language with one-letter keywords. [Details? Similar to MUMPS?] (1995-01-10) 1 1 1 1 1 MIKE Micro Interpreter for Knowledge Engineering 1 1 1 1 1 mil The top-level domain for entities affiliated with US armed forces. (1999-01-26) 1 1 1 1 1 Milarepa A Perl BNF parser generator by Jeffrey Kegler <jeffrey@netcom.com>. Milarepa takes a source grammar written in a mixture of BNF and Perl and generates Perl source, which, when enclosed in a simple wrapper, parses the language described by the grammar. Milarepa is not restricted to LRn grammars, and the parse logic follows directly from the BNF. It handles ambiguous grammars, ambiguous tokens (tokens which were not positively identified by the lexer) and allows the programmer to change the start symbol. The grammar may not be left recursive. The input must be divided into sentences of a finite maximum length. There is no fixed distinction between terminals and non-terminals, that is, a symbol can both match the input AND be on the left hand side of a production. Multiple Marpa grammars are allowed in a single Perl program. Version: Prototype 1.0. Posted to comp.lang.perl. 1 1 1 1 1 MILITRAN A discrete simulation system for military applications produced by the Sys Res Group at ONR in 1964. [Sammet 1969, p. 657]. (1994-11-11) 1 1 1 1 1 mill Arithmetic and Logic Unit 1 1 1 1 1 millennium bug Year 2000 1 1 1 1 1 millennium meltdown Year 2000 1 1 1 1 1 milli- prefix 1 1 1 1 1 millihelen The amount of beauty required to launch one ship. (2002-03-19) 1 1 1 1 1 milliLampson /mil'*-lamp"sn/ A unit of talking speed, abbreviated mL. Most people run about 200 milliLampsons. The eponymous Butler Lampson (a CS theorist and systems implementor highly regarded among hackers) goes at 1000. A few people speak faster. This unit is sometimes used to compare the (sometimes widely disparate) rates at which people can generate ideas and actually emit them in speech. For example, noted computer architect C. Gordon Bell (designer of the PDP-11) is said, with some awe, to think at about 1200 mL but only talk at about 300; he is frequently reduced to fragments of sentences as his mouth tries to keep up with his speeding brain. [Jargon File] 1 1 1 1 1 millisecond (ms) One thousandth of a second, one thousand microseconds. A long time for a modern computer. (1995-08-18) 1 1 1 1 1 MILNET Military Network. Part of the Defense Data Network (DDN) and of the Internet. Managed by the Defense Information Systems Agency (DISA). [Location? Number of hosts? Purpose?] 1 1 1 1 1 MIMD Multiple Instruction/Multiple Data 1 1 1 1 1 MIME Multipurpose Internet Mail Extensions 1 1 1 1 1 mimencode (Originally distributed as "mmencode"). A replacement for uuencode for use in electronic mail and news. Part of MIME. uuencode uses characters that don"t translate well across all mail gateways (particularly those which convert between ASCII and EBCDIC). Also, different variants of uuencode encode data in different and incompatible ways, with no standard. Finally, few uuencode variants work well in a pipe. Mimencode implements the encodings which were defined for MIME as uuencode replacements, and should be considerably more robust for e-mail use. Written by Nathaniel S. Borenstein of Bell Communications Research, Inc. (Bellcore) in 1991. 1 1 1 1 1 Mimer SQL A relational database management system, free for non-commercial use, developed by the Swedish company Upright Database Technology AB. Mimer Home (http://developer.mimer.com). (2002-06-03) 1 1 1 1 1 MIME type The unique identifier used for different file types when conveyed across a MIME-based protocol such as MIME e-mail or HTTP. Registration of MIME types is explained in RFC 2048. Official MIME types (ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/media-types). (1998-02-10) 1 1 1 1 1 MIMIC An early language designed by J.H. Andrews of the NIH in 1967 for solving engineering problems such as differential equations that would otherwise have been done on an analog computer. ["MIMIC, An Alternative Programming Language for Industrial Dynamics, N.D. Peterson, Socio-Econ Plan Sci. 6, Pergamon 1972]. (1995-01-19) 1 1 1 1 1 MIMOLA Operational hardware specification language. ["A Retargetable Compiler for a High-Level Microprogramming Language", 17th Ann Workshop on Microprogramming, P. Marwedel, IEEE 1984, pp. 267-274]. 1 1 1 1 1 mind mouse A pointing device (unlike a mouse in design, but serving the same purpose) which works via sensors in contact with the user's skin. The sensors are built into a plastic base which fits on one finger and which is similar in shape to a finger cast. The principle of operation is presumably myoelectric, not psionic, contrary to what the name implies. As of the time of writing (1996), mind mice are not accurate enough to be anything but novelties. [Availability?] (1997-04-07) 1 1 1 1 1 mind uploading The science fiction concept of copying one's mind into an artificial body or computer. Home (http://sunsite.unc.edu/jstrout/uploading/MUHomePage.html). (1995-04-10) 1 1 1 1 1 Minerva software A company producing software for the Acorn Archimedes. (http://zynet.co.uk/minerva/). (1995-01-31) 1 1 1 1 1 Minesweeper, Chess, Solitaire Expert (MCSE) A humourous expansion of MCSE suggesting a more realistic summary of a person's computer expertise. (2013-03-16) 1 1 1 1 1 minicomputer A computer built between about 1963 and 1987, smaller and less powerful than a mainframe, typically about the size and shape of a wardrobe, mounted in a single tall rack. Minicomputers were characterised by short word lengths of 8 to 32 bits, limited hardware and software facilities and small physical size. Their low cost made them suitable for a wide variety of applications such as industrial control, where a small, dedicated computer which is permanently assigned to one application, is needed. In recent years, improvements in device technology have resulted in minicomputers which are comparable in performance to large second generation computers and greatly exceed the performance of first generation computers. The processor was typically built using low integration logic integrated circuits - TTL or maybe ECL, thus distinguishing it from a microcomputer which is built around 1 1 1 1 1 Mini Disc A music medium designed by Sony as a portable replacement for music Compact Discs. In 1994 Sony announced a data version which can hold 140 MB or about 100 MB using error correction. These will be competitive with 128 MB magneto-optical disks. Mini Discs may be either a re-writable or mass-produced read-only type. Sony have also announced a standard data format. The transfer rate is similar to CD-ROM which is slow compared to the current magneto-optical drives (which are similar to an old hard disk, with writing noticeably slower than reading). Pre-recorded read-only Mini Discs can be mass manufactured on a modified CD press - this and the standard format mean it could take off as a software distribution medium. An article in the December 1994 PCW quotes access times of about 300 ms and data transfer rate of about 150 kb/s (i.e. about single spin CD rate). 1 1 1 1 1 minifloppy 5.25-inch vanilla floppy disks, as opposed to 3.5-inch or microfloppies and the now-obsolescent 8-inch variety. At one time, this term was a trademark of Shugart Associates for their SA-400 minifloppy drive. Nobody paid any attention. See stiffy. (1996-05-03) 1 1 1 1 1 minimal automaton An automaton possessing with redundant states. (1996-05-03) 1 1 1 1 1 minimax An algorithm for choosing the next move in a two player game. A player moves so as to maximise the minimum value of his opponent's possible following moves. If it is my turn to move, I give a value to each legal move I might make. If the result of a move is an immediate win for me I give it positive infinity and, if it is an immediate win for you, negative infinity. The value to me of any other move is the minimum of the values resulting from each of your possible replies. The above algorithm will give every move a value of positive or negative infinity since the value of every move will be the value of some final winning or losing move. This can be extended if we can supply a heuristic evaluation function which gives values to non-final game states without considering all possible following complete sequences. We can then limit the minimax algorithm to look only a certain number of moves ahead. This number is called the "look-ahead" or 1 1 1 1 1 Mini-ML ["A Simple Applicative Language: Mini-ML", D. Clement et al, Proc 1986 ACM Conf on LISP and Functional Prog, (Aug 1986)]. 1 1 1 1 1 minimum seek time (Or track-to-track seek time) The time it takes to move the head of a disk drive from one track to the next. The minimum seek time gives a good measure of the speed of the drive in a single-user/single-process environment where successive read/write request are largely correlated and thus if correlated data is stored in nearby cylinders most seeks are from one cylinder to the next. (1997-07-15) 1 1 1 1 1 Mini PL/I A commercial PL/I subset for the Olivetti Audit 7 minicomputer. 1 1 1 1 1 MINITAB II A system for interactive solution of small statistical problems. ["MINITAB Student Handbook", T.A. Ryan et al, Duxbury Press 1976]. (1994-10-31) 1 1 1 1 1 MINIX /MIN-ix/ A small operating system that is very similar to UNIX. MINIX was written for educational purposes by Prof. Andrew S. Tanenbaum of Vrije Universiteit, Amsterdam. MINIX has been written from scratch and contains no AT&T code -- neither in the kernel, the compiler, the utilities, nor the libraries. Although copyrighted by Prentice-Hall, all sources, binaries and documentation can be obtained via Internet for educational or research purposes. Current versions as of 1996-11-15: MINIX 2.0 - Intel CPUs from Intel 8088 to Pentium MINIX 1.5 - Intel, Macintosh (MacMinix), Amiga, Atari ST, Sun SPARC. (http://cs.vu.nl/~ast/minix.html). (1997-06-16) 1 1 1 1 1 Minnesota Internet Users Essential Tool (Minuet) An integrated package for IBM PC that includes modules for electronic mail (using the POP protocol), Gopher, telnet, Usenet news and FTP. Minuet provides an easy-to-use, mouse-driven graphical user interface via the TurboVision libraries. It is a TCP/IP client that runs over any type of TCP/IP network including Ethernet and SLIP. It will work with either static IP addresses or dynamic IP addresses (bootp). FAQ (http://micro.umn.edu/products/minuet/minuet-1.html). (ftp://boombox.micro.umn.edu/pub/pc/minuet/beta16/minuarc.exe). (1995-04-10) 1 1 1 1 1 MINT Mint Is Not TRAC 1 1 1 1 1 MiNT (MinT is not TOS - a recursive acronym) A freeware, open source operating system for the Atari ST range of computers. MiNT was originally based on a port of BSD to Atari ST computers by Eric R. Smith. MiNT gave the Atari access to BSD's many network applications. A short (1992-94) romance between MiNT and Atari Corp., who decided to convert the system to the MultiTOS kernel, produced a unique TOS/Unix hybrid, which provides simultaneous access to both GEM and BSD application libraries. Since MiNT is MultiTOS's kernel, it has kept all the features described above and, if an AES replacement is installed, it can show you a new face of MultiTOS. Unlike MultiTOS however, MiNT is based on a different file system, that is faster and more flexible than TOS's. Furthermore, thanks to the network support, MiNT allows an Atari to be an Internet server that can still run GEM and TOS applications! This has won MiNT many devotees ("MiNTquisitors"), making it the main 1 1 1 1 1 Mint Is Not TRAC (MINT) A version of TRAC used as the extension language in the Freemacs editor. (ftp://sun.soe.clarkson.edu/pub/freemacs). (1994-10-31) 1 1 1 1 1 Minuet Minnesota Internet Users Essential Tool. 1 1 1 1 1 MINUIT A program for function minimisation and error analysis. (1994-10-31) 1 1 1 1 1 minus - Common: dash; ITU-T: hyphen; ITU-T: minus. Rare: INTERCAL: worm; option; dak; bithorpe. 1 1 1 1 1 minus infinity The most negative value, not necessarily or even usually the simple negation of plus infinity. In N bit twos-complement arithmetic, infinity is 2^(N-1) - 1 but minus infinity is -(2^(N-1)), not -(2^(N-1) - 1). 1 1 1 1 1 MIPS 1. <unit, benchmark> Million instructions per second. The unit commonly used to give the rate at which a processor executes instructions. Often rendered by hackers as "Meaningless Indication of Processor Speed" or in other unflattering ways. This expresses a nearly universal attitude about the value of most benchmark claims, said attitude being one of the great cultural divides between hackers and marketroids. The etymologically incorrect singular "1 MIP" is sometimes heard. See also KIPS and GIPS. 2. VAX MIPS. 3. <processor> Microprocessor without Interlocked Pipeline Stages. 4. <company> MIPS Technologies, Inc. [Jargon File] (1996-03-01) 1 1 1 1 1 MIPS project Microprocessor without Interlocked Pipeline Stages 1 1 1 1 1 MIPS R2000 The R2000 design came, in about 1987, from the Stanford MIPS project, which stood for Microprocessor without Interlocked Pipeline Stages. Like the AMD 29000, the R2000 has no condition code register considering it a potential bottleneck. The program counter can be read like other registers. The CPU includes an MMU that can also control a cache, and the CPU can operate as big-endian or little-endian. There is a FPU, the R2010. Versions include the MIPS R3000 and MIPS R4000. (1995-02-09) 1 1 1 1 1 MIPS R2010 A FPU for the MIPS R2000. (1995-02-09) 1 1 1 1 1 MIPS R3000 A version of the MIPS R2000 with improved cache control. (1995-02-09) 1 1 1 1 1 MIPS R4000 A 64-bit version of the MIPS R3000 with has more pipeline stages for a higher clock rate and performance. (1995-02-09) 1 1 1 1 1 MIPS Technologies, Inc. A company which designs, develops, and licenses reduced instruction set computer (RISC) microprocessors and compilers. MIPS Technologies, Inc. is a wholly-owned subsidiary of Silicon Graphics, Inc. and operates as an independent unit. MIPS is the successor to the processor business of MIPS Computer Systems which was founded in 1984 and merged with Silicon Graphics on 29 June 1992. MIPS Technologies developed the world's first RISC VLSI microprocessors (1985) (or was it the ARM?), the first commercial 64-bit microprocessor (MIPS R4000, 1992), announced MIPS R4300i - the first 64-bit RISC processor designed for interactive consumer applications (April 1995). They announced the MIPS R10000 - the next generation general-purpose MIPS microprocessor and the most powerful processor in the world (October 1994). MIPS' semiconductor company partners participate in the design and development of MIPS processors and software and then 1 1 1 1 1 Miracula An implementation of a subset of Miranda by Stefan Kahrs <smk@ed.ac.uk>, LFCS, no modules or files. Can be interactively switched between eager and lazy evaluation. Portable source in C from the author. 1 1 1 1 1 Miranda (From the Latin for "admirable", also the heroine of Shakespeare's "Tempest") A lazy purely functional programming language and interpreter designed by David Turner of the University of Kent in the early 1980s and implemented as a product of his company, Research Software Limited. Miranda combines the main features of KRC and SASL with strong typing similar to that of ML. It features terse syntax using the offside rule for indentation. The type of an expression is inferred from the source by the compiler but explicit type declarations are also allowed. It has nested pattern-matching, list comprehensions and modules. It uses operator sections rather than lambda abstractions. User types are algebraic, and in early versions could be constrained by laws. It is implemented using SKI combinator reduction. Originally implemented for Unix, there are versions for most UNIX-like platforms including Intel PC under Linux. The 1 1 1 1 1 MIRFAC Mathematics in Recognizable Form Automatically Compiled 1 1 1 1 1 mirror 1. <hardware, storage> Writing duplicate data to more than one device (usually two hard disks), in order to protect against loss of data in the event of device failure. This technique may be implemented in either hardware (sharing a disk controller and cables) or in software. It is a common feature of RAID systems. Several operating systems support software disk mirroring or disk-duplexing, e.g. Novell NetWare. See also Redundant Array of Independent Disks. Interestingly, when this technique is used with magnetic tape storage systems, it is usually called "twinning". A less expensive alternative, which only limits the amount of data loss, is to make regular backups from a single disk to magnetic tape. 2. mirror site. (1998-06-11) 1 1 1 1 1 mirroring mirror 1 1 1 1 1 mirror site An archive site or website which keeps a copy of some or all files at another site so as to make them more quickly available and to reduce the load on the source site. It is generally best to use the mirror that is physically closest to you as this will usually give the fastest download. Such mirroring is usually done for specific whole directories or files on a specific remote server as opposed to a cache or proxy server which keeps copies of everything that is requested via it. For example, src.doc.ic.ac.uk is the main UK mirror for the GNU archive at gnu.org. (2006-10-16) 1 1 1 1 1 MIS Management Information System 1 1 1 1 1 misbug /mis-buhg/ [MIT] An unintended property of a program that turns out to be useful; something that should have been a bug but turns out to be a feature. Usage: rare. Compare green lightning. See miswart. [Jargon File] 1 1 1 1 1 MIS Director Chief Information Officer 1 1 1 1 1 misfeature /mis-fee'chr/ or /mis'fee"chr/ A feature that eventually causes lossage, possibly because it is not adequate for a new situation that has evolved. Since it results from a deliberate and properly implemented feature, a misfeature is not a bug. Nor is it a simple unforeseen side effect; the term implies that the feature in question was carefully planned, but its long-term consequences were not accurately or adequately predicted (which is quite different from not having thought ahead at all). A misfeature can be a particularly stubborn problem to resolve, because fixing it usually involves a substantial philosophical change to the structure of the system involved. Many misfeatures (especially in user-interface design) arise because the designers/implementors mistake their personal tastes for laws of nature. Often a former feature becomes a misfeature because trade-offs were made whose parameters subsequently change (possibly only in the judgment of the 1 1 1 1 1 MISHAP An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 1 1 1 1 1 Missed'em-five (Or "SysVile" /sis-vi:l'/) A pejorative hackerism for AT&T System V Unix, generally used by BSD partisans in a bigoted mood. See software bloat, Berzerkeley. [Jargon File] (1998-07-01) 1 1 1 1 1 missile address ICBM address 1 1 1 1 1 missing Missing definition 1 1 1 1 1 miswart /mis-wort/ [By analogy with misbug] A feature that superficially appears to be a wart but has been determined to be the Right Thing. For example, in some versions of the Emacs text editor, the "transpose characters" command exchanges the character under the cursor with the one before it on the screen, *except* when the cursor is at the end of a line, in which case the two characters before the cursor are exchanged. While this behaviour is perhaps surprising, and certainly inconsistent, it has been found through extensive experimentation to be what most users want. This feature is a miswart. [Jargon File] 1 1 1 1 1 MIT Massachusetts Institute of Technology 1 1 1 1 1 MIT AI Lab (Massachusetts Institute of Technology artificial intelligence laboratory) Workplace of many famous AI researchers at MIT including GLS and RMS. (http://ai.mit.edu/). Address: 545 Technology Sq., Cambridge, MA 02139, USA. (2003-02-28) 1 1 1 1 1 MITI SQRIBE 1 1 1 1 1 MITILAC An early system on the IBM 650. [Listed in CACM 2(5):16, May 1959]. (1998-09-24) 1 1 1 1 1 MIT Licence It's american and they spell the noun and the verb license, so MIT License. (2014-11-27) 1 1 1 1 1 MIT License A popular open source software license. The MIT License is very permissive, allowing "any person ... to deal in the Software without restriction" as long as they preserve the copyright notice and the license itself. It also includes the usual disclaimers. MIT License home (http://opensource.org/licenses/MIT). (2014-11-27) 1 1 1 1 1 MIT Lisp Machine Lisp Machine 1 1 1 1 1 MITRE Corporation A US federally funded R&D center, spun off in 1958 from the MIT Lincoln Laboratory (also an FFRDC). MITRE is a non-profit corporation chartered to do R&D in the public interest. MITRE were responsible for system engineering and implementation oversight of SAGE. MITRE does not stand for MIT Research and Engineering, though it could have. (http://mitre.org/). (1999-12-16) 1 1 1 1 1 MIT Research Laboratory for Electronics See also Jay Forrester, core memory, the Whirlwind computer, MIT Lincoln Laboratory. [Summary?] (1999-12-16) 1 1 1 1 1 MITS Micro Instrumentation and Telemetry Systems 1 1 1 1 1 MIT Scheme (Previously "C-Scheme") A Scheme implementation by the MIT Scheme Team (Chris Hanson, Jim Miller, Bill Rozas, and many others) with a rich set of utilities, a compiler called Liar and an editor called Edwin. MIT Scheme includes an interpreter, large run-time library, Emacs macros, native-code compiler, emacs-like editor, and a source-level debugger. Latest version: 7.7.1, as of 2002-06-18. MIT Scheme conforms fully with R4RS and almost with the IEEE Scheme standard. It runs on Motorola 68000: HP9000, Sun-3, NeXT; MIPS: Decstation, Sony, SGI; HP-PA: 600, 700, 800; VAX: Ultrix, BSD, DEC Alpha: OSF; Intel i386: MS-DOS, MS Windows, and various other Unix systems. See also: LAP, Schematik, Scode. (http://gnu.org/software/mit-scheme/). Usenet newsgroup: news:comp.lang.scheme.c. 1 1 1 1 1 MIX Knuth's hypothetical machine, used in The Art of Computer Programming v.1, Donald Knuth, A-W 1969. 1 1 1 1 1 MIXAL MIX Assembly Language. The assembly language for Donald Knuth's hypothetical MIX machine. (1995-01-05) 1 1 1 1 1 MIX Communications (MIX) Providers of Internet access and presentation services for businesses and individuals in the Milwaukee, WI, USA metropolitan area. MIX started providing Internet access services to the Milwaukee area in 1990. It was the first business in Milwaukee to provide Internet access services to the public. MIX Communications is owned and operated by Dean Roth. (http://mixcom.com/). E-mail: <info@mixcom.com>. Telephone: +1 (414) 351 1868 (Office), +1 (414) 351 1139 (BBS). Address: MIX Communications, P.O. Box 17166, Milwaukee, WI 53217, USA. (1995-01-05) 1 1 1 1 1 M-JPEG Moving JPEG 1 1 1 1 1 MJS An early system on the UNIVAC I or II. [Listed in CACM 2(5):1959-05-16]. (1996-12-15) 1 1 1 1 1 mk The country code for the Former Yugoslav Republic of Macedonia. (1999-01-27) 1 1 1 1 1 ML 1. <robotics> Manipulator Language. IBM language for handling robots. 2. Meta Language. R. Milner <rm@lfcs.edinburgh.ac.uk> et al, 1973. A strict higher-order functional language. It was the first language to include polymorphic typing which was statically-checked. It also had garbage collection and a formal semantics. It began as the metalanguage for the Edinburgh LCF proof assistant. (LCF="Logic for Computable Functions") People soon noticed that ML could be a useful general programming language and stand-alone versions were implemented. Standard ML (SML) is a descendant of these (and related languages such as Hope). The "metalanguage" aspect has long since disappeared from the language itself (although there are some systems that still use it that way). The historical name is now so inappropriate that asking what ML stands for is like asking what C or 1 1 1 1 1 ml The country code for Mali. (1999-01-27) 1 1 1 1 1 ML-2000 An extension and redesign of Standard ML. Under development. 1 1 1 1 1 MLAB Modeling LABoratory. An interactive mathematical modelling system. ["MLAB, An On-Line Modeling Laboratory", NIH (Mar 1975)]. (1994-10-13) 1 1 1 1 1 ML/I An early macro language first implemented by Peter Brown at the Cambridge University in 1966. ML/I has been maintained by Bob Eager since 1973. ML/I Home (http://ml1.org.uk/). [P.J. Brown, CACM 10(10):618-623, Oct 1967]. (2006-07-21) 1 1 1 1 1 MLISP 1. M-expression LISP. 2. Meta-LISP. D.C. Smith & H. Enea. LISP variant with ALGOL-like syntax. Not just a surface syntax, a full language. MLISP, D.C. Smith, TR CS-179, CS Dept, Stanford (Oct 1970). Version: MLISP2. 3. A hybrid of M-expression LISP and Scheme. M-LISP: Its Natural Semantics and Equational Logic, R. Muller, SIGPLAN Notices 26(9):234-242 (Sept 1991) (PEPM '91). 1 1 1 1 1 ML Kit The ML Kit is a straight translation of the Definition of Standard ML into a collection of Standard ML modules. For example, every inference rule in the Definition is translated into a small piece of Standard ML code which implements it. The translation has been done with as little originality as possible - even variable conventions from the Definition are carried straight over to the Kit. The Kit is intended as a tool box for those people in the programming language community who may want a self-contained parser or type checker for full Standard ML but do not want to understand the clever bits of a high-performance compiler. We have tried to write simple code and modular interfaces. Version 1 interpreter, documentation Nick Rothwell, David N. Turner, Mads Tofte <tofte@diku.dk>, and Lars Birkedal at Edinburgh and Copenhagen Universities. (ftp://ftp.diku.dk/diku/users/birkedal/). UK: ftp 1 1 1 1 1 MLL Medium-Level Language. Sometimes used half-jokingly to describe C, alluding to its structured-assembler image. (1994-12-07) 1 1 1 1 1 ML-lex A version of lex in SML/NJ which outputs a lexical analyser in SML/NJ. (ftp://research.att.com/dist/ml/75.tools.tar.Z). 1 1 1 1 1 ML-Linda U Edinburgh, under development. 1 1 1 1 1 ML Threads SML/NJ with mutual exclusion primitives similar to those in Modula-2+ and Mesa. Written by Greg Morrisett <jgmorris@cs.cmu.edu>. Lightweight threads are created using fork. They are pre-emptively scheduled and communicate via shared memory which can be protected by a "mutex" (monitor). Implementations for Motorola 68020, SPARC and MIPS and VAX- and MIPS-based multiprocessors. ["Adding Threads to Standard ML", E. Cooper et al, CMU-CS-90-186, CMU Dec 1990]. 1 1 1 1 1 ML-Twig A variant of TWIG in SML, by Jussi Rintanen <jur@cs.hut.fi>, which comes with SML/NJ. (1995-02-14) 1 1 1 1 1 mm The country code for Myanmar (Burma). (1999-01-27) 1 1 1 1 1 Mma A fast Mathematica-like system, in Allegro CL by R. Fateman, 1991. (ftp://peoplesparc.berkeley.edu/pub/mma.tar.Z). 1 1 1 1 1 mmap The Unix system call which establishes a mapping between a range of addresses in a user process's address space and a portion of some "memory object" (typically a file, one of the special "devices" /dev/mem or /dev/kmem or some memory-mapped peripheral). This allows the process to access a file at random byte offsets without using the seek system call or to access physical addresses or kernel's virtual address space. It can also be used as an alternative to writing a device driver since it is usually simpler to code and faster to use. (1995-02-14) 1 1 1 1 1 MMCD MultiMedia Compact Disc. (1995-11-23) 1 1 1 1 1 MMDF Multi-channel Memorandum Distribution Facility 1 1 1 1 1 MMI 1. Man-Machine Interface. 2. <company> The company which developed the first Programmable Array Logic devices. MMI was bought by AMD. [Dates?] (1995-12-09) 1 1 1 1 1 MML Human-Machine Language. A language from ITU-T for telecommunications applications. It has a complex natural-language syntax. [CCITT Recommendations Z.311-Z.318, Z-341, Nov 1984]. (1995-01-31) 1 1 1 1 1 MMO Massively Multiplayer Online Game 1 1 1 1 1 MMOG Massively Multiplayer Online Game 1 1 1 1 1 MMORPG Massively Multiplayer Online Game 1 1 1 1 1 MMS Multimedia Messaging Services 1 1 1 1 1 MMU Memory Management Unit 1 1 1 1 1 MMX Matrix Math eXtensions 1 1 1 1 1 MMX technology Matrix Math eXtensions 1 1 1 1 1 mn The country code for Mongolia. (1999-01-27) 1 1 1 1 1 mnemonic A word or string which is intended to be easier to remember than the thing it stands for. Most often used in instruction mnemonic which are so called because they are easier to remember than the binary patterns they stand for. Non-printing ASCII characters also have mnemonics like NAK, ESC, DEL intended to evoke their meaning on certain systems. (1995-05-11) 1 1 1 1 1 MNP Microcom Networking Protocol 1 1 1 1 1 mo The country code for Macau. (1999-01-27) 1 1 1 1 1 Mobile Subscriber Integrated Services Directory Number A number string used to uniquely identify a mobile telephone subscriber in GSM, CDMA and UMTS cellular networks. The number is formatted according to the E.164 numbering plan, consisting of a country code (CC), national destination code (NDC) and subscriber number (SN). See also: IMSI, IMEI, The GSM Specifications (http://www.etsi.org/services_products/freestandard/home.htm). (2006-12-28) 1 1 1 1 1 Mobile Triton (Official name 82430MX) A version of Intel's Triton I processor chip set intended for mobile computers. Mobile Triton consists of one 82437MX and two 82438MX. [Special features?] (1996-04-03) 1 1 1 1 1 mobo motherboard 1 1 1 1 1 MOBSSL-UAF Merritt and Miller's Own Block-Structured Simulation Language-Unpronounceable Acronym For. A l for interactive continuous simulation. ["MOBSSL - An Augmented Block Structured Continuous System Simulation Language for Digital and Hybrid Computers", M.J. Merritt et al, Proc FJCC 35, AFIPS (Fall 1969)]. (1995-01-31) 1 1 1 1 1 moby /moh'bee/ (From MIT, seems to have been in use among model railroad fans years ago. Derived from Melville's Moby Dick, some say from "Moby Pickle") 1. Large, immense, complex, impressive. "A Saturn V rocket is a truly moby frob." "Some MIT undergrads pulled off a moby hack at the Harvard-Yale game." 2. (Obsolete) The maximum address space of a computer (see below). For a 680[234]0 or VAX or most modern 32-bit architectures, it is 4,294,967,296 8-bit bytes (four gigabytes). 3. A title of address (never of third-person reference), usually used to show admiration, respect, and/or friendliness to a competent hacker. "Greetings, moby Dave. How's that address-book thing for the Mac going?" 4. In backgammon, doubles on the dice, as in "moby sixes", moby ones, etc. Compare this with bignum: double sixes are both bignums and moby sixes, but moby ones are not bignums 1 1 1 1 1 mockingbird Software that intercepts communications (especially login transactions) between users and hosts and provides system-like responses to the users while saving their responses (especially account IDs and passwords). A special case of Trojan horse. [Jargon File] 1 1 1 1 1 Mockingboard A sound and speech board for the Apple II computer, on sale in 1978. See also zxnrbl. (1997-03-18) 1 1 1 1 1 Mock Lisp The Lisp used by the Gosling Emacs editor. 1 1 1 1 1 mod 1. <filename extension, application, file format, music> (module) The filename extension for a sampled music file format that originated on the Commodore Amiga. A .MOD file is composed of digitised sound samples, arranged in patterns to create a song. There are .MOD players for most personal computers including Amiga, Archimedes, IBM PC, and Macintosh. An IBM PC will require a sound card capable of handling digitised samples (Sound Blaster, Sound Blaster Pro, GUS) and slower Intel 80386-based PCs may not be able to do anything else while playing a module. .MOD files differ from .MID (MIDI) files in that they contain sound samples. This allows each song to use different sounds but it also puts more load on the CPU than playing a MIDI file, since more data must be processed for each note. A slow CPU would benefit from a sound card with wavetable synthesis which handles samples instead of the CPU. 1 1 1 1 1 modal 1. (Of an interface) Having modes. Modeless interfaces are generally considered to be superior because the user does not have to remember which mode he is in. 2. See modal logic. 3. In MS Windows programming, A window with the label WS_MODAL will stay on the screen and claim all the user-input. Other windows can only be accessed if the MODAL window is closed. Such a window would typically be used for an error dialog box to warn the user for something important, like "Critical error, shut down the system and restart". (1995-02-07) 1 1 1 1 1 modal logic An extension of propositional calculus with operators that express various "modes" of truth. Examples of modes are: necessarily A, possibly A, probably A, it has always been true that A, it is permissible that A, it is believed that A. It is necessarily true that A means that things being as they are, A must be true, e.g. It is necessarily true that x=x is TRUE while It is necessarily true that x=y is FALSE even though "x=y" might be TRUE. Adding modal operators [F] and [P], meaning, respectively, henceforth and hitherto leads to a "temporal logic". Flavours of modal logics include: Propositional Dynamic Logic (PDL), Propositional Linear Temporal Logic (PLTL), 1 1 1 1 1 modam Do you mean modem? (2008-05-08) 1 1 1 1 1 MODCAL A version of HP-PASCAL enhanced with system programming constructs, used internally by HP. (1995-02-07) 1 1 1 1 1 Mode An object-oriented language. ["The Programming Language Mode: Language Definition and User Guide", J. Vihavainen, C-1987-50, U Helsinki, 1987]. [Jargon File] (1994-10-21) 1 1 1 1 1 mode 1. A general state, usually used with an adjective describing the state. Use of the word "mode" rather than "state" implies that the state is extended over time, and probably also that some activity characteristic of that state is being carried out. "No time to hack; I'm in thesis mode." In its jargon sense, "mode" is most often attributed to people, though it is sometimes applied to programs and inanimate objects. In particular, see hack mode, day mode, night mode, demo mode, fireworks mode, and yoyo mode; also chat. 2. More technically, a mode is a special state that certain user interfaces must pass into in order to perform certain functions. For example, in order to insert characters into a document in the Unix editor "vi", one must type the "i" key, which invokes the "Insert" command. The effect of this command is to put vi into "insert mode", in which typing the i key has a quite different effect (to wit, it inserts an 1 1 1 1 1 mode bit A flag, usually in hardware, that selects between two (usually quite different) modes of operation. The connotations are different from flag bit in that mode bits are mainly written during a boot or set-up phase, are seldom explicitly read, and seldom change over the lifetime of an ordinary program. The classic example was the EBCDIC-vs.-ASCII bit (#12) of the Program Status Word of the IBM 360. Another was the bit on a PDP-12 that controlled whether it ran the PDP-8 or the LINC instruction set. [Jargon File] 1 1 1 1 1 MODEF Pascal-like language with polymorphism and data abstraction. Definition of the Programming Language MODEF, J. Steensgard-Madsen et al, SIGPLAN Notices 19(2):92-110 (Feb 1984). 1 1 1 1 1 MODEL A Pascal-like language with extensions for large-scale system programming and interface with Fortran applications. MODEL includes generic procedures, and a static macro-like approach to data abstraction. It produces P-code and was used to implement the DEMOS operating system on the Cray-1. ["A Manual for the MODEL Programming Language", J.B. Morris, Los Alamos 1976]. (1996-05-29) 1 1 1 1 1 model 1. <simulation> A description of observed or predicted behaviour of some system, simplified by ignoring certain details. Models allow complex systems, both existent and merely specified, to be understood and their behaviour predicted. A model may give incorrect descriptions and predictions for situations outside the realm of its intended use. A model may be used as the basis for simulation. Note: British spelling: "modelling", US: "modeling". (2008-04-28) 2. <programming> The core part of a Model-View-Controller or similar software architecture; the part that stores the data and runs the business rules or algorithms. (2014-11-27) 1 1 1 1 1 model checking To algorithmically check whether a program (the model) satisfies a specification. The model is usually expressed as a directed graph consisting of nodes (or vertices) and edges. A set of atomic propositions is associated with each node. The nodes represents states of a program, the edges represent possible executions which alters the state, while the atomic propositions represent the basic properties that hold at a point of execution. A specification language, usually some kind of temporal logic, is used to express properties. The problem can be expressed mathematically as: given a temporal logic formula p and a model M with initial state s, decide if M,s \models p. ["Automatic verification of finite state concurrent systems using temporal logic", E.M. Clarke, E.A. Emerson, and A.P. Sisla, ACM Trans. on Programming Languages and Systems 1 1 1 1 1 modeling US spelling of "modelling". (1999-12-10) 1 1 1 1 1 modeling language modelling language 1 1 1 1 1 modelling model 1 1 1 1 1 modelling language Possibly a kind of programming language designed for describing models and their behaviour. See also data modelling, object relational model, simulation, UML, VRML. (2009-05-11) 1 1 1 1 1 Modelsim A simulation tool for programming VLSI ASICs, FPGAs, CPLDs, and SoCs. Manual by Arnd Riebartsch (http://arieba.net/simulators.htm#ModelSim). (2003-07-19) 1 1 1 1 1 Model-View-Controller (MVC) A way of partitioning the design of interactive software; a software architecture pattern. The model is the internal workings of the program (the data objects and algorithms), the "view" is how the user sees the state of the model and the "controller" is how the user changes the state or provides input. MVC was the original kind of what is now sometimes called an MV* pattern. Trygve Reenskaug introduced it into Smalltalk-76 while visiting Xerox PARC in the 1970s. (2014-11-27) 1 1 1 1 1 Model-View-Presenter (MVP) A user interface architectural pattern where functions are separated between the model, view and presenter. The model defines the data to be displayed or otherwise acted upon in the user interface. The view displays data from the model and routes user commands (events) to the presenter to act upon that data. The presenter retrieves data from the model and displays it in the view. The implementation of MVP can vary as to how much presentation logic is handled by the presenter and the view. In a web application most presentation logic is usually in the view which runs in the web browser. MVP is one of the MV* variations of the MVC pattern. (2014-11-27) 1 1 1 1 1 modem (Modulator/demodulator) An electronic device for converting between serial data (typically EIA-232) from a computer and an audio signal suitable for transmission over a telephone line connected to another modem. In one scheme the audio signal is composed of silence (no data) or one of two frequencies representing zero and one. Modems are distinguished primarily by the maximum data rate they support. Data rates can range from 75 bits per second up to 56000 and beyond. Data from the user (i.e. flowing from the local terminal or computer via the modem to the telephone line) is sometimes at a lower rate than the other direction, on the assumption that the user cannot type more than a few characters per second. Various data compression and error correction algorithms are required to support the highest speeds. Other optional features are auto-dial (auto-call) and auto-answer which 1 1 1 1 1 MODEM7 A batch file transfer protocol. See also XMODEM. (1995-05-02) 1 1 1 1 1 moderator A person, or small group of people, who manages a moderated mailing list or Usenet newsgroup. Moderators are responsible for determining which email submissions are passed on to the list or newsgroup. 1 1 1 1 1 Modified Frequency Modulation (MFM, Modified FM, or sometimes "Multiple Frequency Modulation") A modification to the original frequency modulation scheme for encoding data on magnetic disks. MFM allows more than 1 symbol per flux transition (up to 3), giving greater density of data. It is used with a data rate of between 250-500 kbit/s on industry standard 3.5" and 5.25" low and high density diskettes, and up to 5 Mbit/s on ST-506 hard disks. Except for 1.44 MB floppy disks, this encoding is obsolete. Other data encoding schemes include GCR, FM, RLL. See also: PRML. (2002-06-24) 1 1 1 1 1 modifier An operation that alters the state of an object. Modifiers often have names that begin with "set" and corresponding selector functions whose names begin with get. (1998-01-12) 1 1 1 1 1 M O drive magneto-optical disk 1 1 1 1 1 MODSIM A general-purpose, modular, block-structured language from CACI, which provides support for object-oriented programming and discrete event simulation. It is intended for building large process-based discrete event simulation models through modular and object-oriented mechanisms similar to those of Modula-2. MODSIM is descended from Modula-2 and Simula. It supports multiple inheritance, templates, reference types, polymorphism, and process-oriented simulation with synchronous and asynchronous activities using explicit simulation time. See also MODSIM II, USAModSim. (1994-11-11) 1 1 1 1 1 MODSIM II 1986. Object-oriented modular language for discrete simulation, with multiple inheritance, strong typing, integrated 2D and 3D graphics. Compiles to C. CACI, La Jolla, (619) 457-9681. list: palmer@world.std.com 1 1 1 1 1 Modula MODUlar LAnguage 1 1 1 1 1 Modula-2 A high-level programming language designed by Niklaus Wirth at ETH in 1978. It is a derivative of Pascal with well-defined interfaces between modules, and facilities for parallel computation. Modula-2 was developed as the system language for the Lilith workstation. The central concept is the module which may be used to encapsulate a set of related subprograms and data structures, and restrict their visibility from other portions of the program. Each module has a definition part giving the interface, and an implementation part. The language provides limited single-processor concurrency (monitors, coroutines and explicit transfer of control) and hardware access (absolute addresses and interrupts). It uses name equivalence. DEC FTP archive (ftp://gatekeeper.dec.com/.1/DEC/Modula-2/m2.tar.Z). ["Programming in Modula-2", N. Wirth, Springer 1985]. 1 1 1 1 1 Modula-2* An extension of Modula-2 by M. Philippsen <philipp@ira.uka.de> of the University of Karlsruhe. It uses a superset of data parallelism, allowing both synchronous and asynchronous programs, both SIMD and MIMD. Parallelism may be nested to any depth. There are version for MasPar and a simulator for the SPARC. (ftp://iraun1.ira.uka.de/pub/programming/modula2star). E-mail: Ernst Heinz <heinz@ira.uka.de>. ["Modula-2*: An Extension of Modula-2 for Highly Parallel, Portable Programs", W. Tichy et al, TR 4/90, U Karlsruhe, Jan 1990]. (1994-10-21) 1 1 1 1 1 Modula-2+ Modula-2 plus exceptions and threads developed by P. Rovner et al of DEC SRC, Palo Alto CA in 1984. ["Modula-2+ User's Manual", M-C van Leunen]. ["Extending Modula-2 to Build Large, Integrated Systems", P. Rovner, IEEE Software 3(6):46-57 (Nov 1986)]. (1994-10-21) 1 1 1 1 1 Modula-3 L. Cardelli et al, DEC and Olivetti, 1988. A descendant of Modula-2+ and Cedar, designed for safety and simplicity. Objects, generics, threads, exceptions and garbage collection. Modules are explicitly safe or unsafe. As in Mesa, any set of variables can be monitored. No multiple inheritance, no operator overloading. Uses structural equivalence. "Modula-3 Report", Luca Cardelli et al, TR 52, DEC SRC, and Olivetti Research Center, Aug 1988 (revised Oct 1989). The changes are described in "System Programming with Modula-3", Greg Nelson ed, P-H 1991, ISBN 0-13-590464-1. "Modula-3", Sam Harbison, P-H 1992. Version: SRC Modula-3 V1.5. (ftp://gatekeeper.dec.com/pub/DEC/Modula-3/release/). See also SRC Modula-3. 1 1 1 1 1 Modula-3* Incorporation of Modula-2* ideas into Modula-3. ["Modula-3*: An Efficiently Compilable Extension of Modula-3 for Problem-Oriented Explicitly Parallel Programming", E. Heinz <heinze@ira.uka.de>, 1993]. 1 1 1 1 1 Modula-3pi Machine-independent intermediate language for compilation of Modula-3*. "Modula-3pi Language Definition", E.A. Heinz, TR, U Karlsruhe 1993. 1 1 1 1 1 Modula-P Modula-P: A Language for Parallel Programming Definition and Implementation on a Transputer Network, R. Hoffart et al, IEEE Conf Comp Langs 1992. 1 1 1 1 1 Modula-Prolog Adds a Prolog layer to Modula-2. "Modula-Prolog: A Software Development Tool", C. Muller IEEE Software pp.39-45 (Nov 1986). 1 1 1 1 1 Modula/R Modula with relational database constructs added. LIDAS Group (J. Koch, M. Mall, P. Putfarken, M. Reimer, J.W. Schmidt, C.A. Zehnder) "Modula/R Report", LIDAS Memo 091-83, ETH Zurich, Sep 1983. 1 1 1 1 1 modular arithmetic (Or "clock arithmetic") A kind of integer arithmetic that reduces all numbers to one of a fixed set [0..N-1] (this would be "modulo N arithmetic") by effectively repeatedly adding or subtracting N (the "modulus") until the result is within this range. The original mathematical usage considers only __equivalence__ modulo N. The numbers being compared can take any values, what matters is whether they differ by a multiple of N. Computing usage however, considers modulo to be an operator that returns the remainder after integer division of its first argument by its second. Ordinary "clock arithmetic" is like modular arithmetic except that the range is [1..12] whereas modulo 12 would be [0..11]. (2003-03-28) 1 1 1 1 1 Modular C A preprocessor-based extension to C allowing modules. [Article by Stowe Boyd, Azrex Inc, SIGPLAN Notices, ca 1980]. (1994-10-25) 1 1 1 1 1 MODUlar LAnguage (Modula) Wirth's 1977 predecessor of Modula-2. The original Modula was, more oriented toward concurrent programming, but otherwise quite similar. ["Modula - A Language for Modular Multiprogramming", N. Wirth, Soft Prac & Exp 7(1):3-35, Jan 1977]. (1999-07-12) 1 1 1 1 1 Modular Prolog An interpreter for SB-Prolog version 3.1 extended with ML-style modules. Runs on SPARC. Distributed under GNU General Public License. (ftp://ftp.dcs.ed.ac.uk/pub/dts/mod-prolog.tar.Z). E-mail: Brian Paxton <mprolog@dcs.ed.ac.uk>. ["A Calculus for the Construction of Modular Prolog Programs", D. Sannella et al, J Logic Prog 12:147-177 (1992)]. (1994-10-25) 1 1 1 1 1 Modular SB-Prolog Modular Prolog 1 1 1 1 1 module 1. <programming> An independent piece of software which forms part of one or more larger programs. Different languages have different concepts of a module but there are several common ideas. Modules are usually compiled seperately (in compiled languages) and provide an abstraction or information hiding mechanism so that a module's implementation can be changed without requiring any change to other modules. In this respect they are similar to objects in an object-oriented language, though a module may contain many procedures and/or functions which would correspond to many objects. A module often has its own name space for identifiers so the same identifier may be used to mean different things in different modules. [Difference from package?]. 2. <hardware> An independent assembly of electronic components with some distinct function, e.g. a RAM module consisting of 1 1 1 1 1 Modulex Based on Modula-2. Mentioned by M.P. Atkinson & J.W. Schmidt in a tutorial in Zurich, 1989. 1 1 1 1 1 modulo /mod'yu-loh/ 1. <mathematics> modular arithmetic. 2. <mathematics> modulo operator. (1999-07-12) 1 1 1 1 1 modulo arithmetic modular arithmetic 1 1 1 1 1 modulo operator (mod) The operator that returns the remainder after integer division of its first argument by its second. Written as "%" in C and some other languages. Where the second argument is a power of two, the result can be calculated much more quickly using bitwise and with the appropriate bit-mask. (1999-07-12) 1 1 1 1 1 Mohammed Al-Khawarizmi Muhammad ibn Musa al-Khwarizmi 1 1 1 1 1 molly-guard /mol'ee-gard/ [University of Illinois] A shield to prevent tripping of some Big Red Switch by clumsy or ignorant hands. Originally used of the plexiglass covers improvised for the BRS on an IBM 4341 after a programmer's toddler daughter (named Molly) frobbed it twice in one day. Later generalised to covers over stop/reset switches on disk drives and networking equipment. [Jargon File] 1 1 1 1 1 monad /mo'nad/ A technique from category theory which has been adopted as a way of dealing with state in functional programming languages in such a way that the details of the state are hidden or abstracted out of code that merely passes it on unchanged. A monad has three components: a means of augmenting an existing type, a means of creating a default value of this new type from a value of the original type, and a replacement for the basic application operator for the old type that works with the new type. The alternative to passing state via a monad is to add an extra argument and return value to many functions which have no interest in that state. Monads can encapsulate state, side effects, exception handling, global data, etc. in a purely lazily functional way. A monad can be expressed as the triple, (M, unitM, bindM) where M is a function on types and (using Haskell notation): 1 1 1 1 1 monadic 1. <programming> unary, when describing an operator or function. The term is part of the dyadic, niladic sequence. 2. <theory> See monad. (1998-07-24) 1 1 1 1 1 Mongolian Hordes technique (Or "Chinese Army technique") Assigning a large number of inexperienced programmers to a job which would better performed by a few skilled ones. The term was first used by Dr. Fred Brooks in his book "The Mythical Man-Month", Chapter 3. According to Dr. Brooks, he had in mind the vision of the Mongol Hordes sweeping across Asia and Europe when he created the term. [Jargon File] (1996-06-20) 1 1 1 1 1 moniter It's spelled "monitor". (1996-11-28) 1 1 1 1 1 monitor 1. A cathode-ray tube and associated electronics connected to a computer's video output. A monitor may be either monochrome (black and white) or colour (RGB). Colour monitors may show either digital colour (each of the red, green and blue signals may be either on or off, giving eight possible colours: black, white, red, green, blue, cyan, magenta and yellow) or analog colour (red, green and blue signals are continuously variable allowing any combination to be displayed). Digital monitors are sometimes known as TTL because the voltages on the red, green and blue inputs are compatible with TTL logic chips. See also gamut, multisync, visual display unit. 2. A programming language construct which encapsulates variables, access procedures and initialisation code within an abstract data type. The monitor's variable may only be accessed via its access procedures and only one process may be actively accessing the monitor at any one time. The access 1 1 1 1 1 monkey, scratch scratch monkey 1 1 1 1 1 monkey sort bogo-sort 1 1 1 1 1 monkey up To hack together hardware for a particular task, especially a one-shot job. Connotes an extremely crufty and consciously temporary solution. Compare hack up, kluge up. 1 1 1 1 1 Mono An open source .NET framework for Unix. Mono Home (http://go-mono.com/). (2003-09-24) 1 1 1 1 1 monochrome Literally "one colour". Usually used for a black and white (or sometimes green or orange) monitor as distinct from a color monitor. Normally, each pixel on the display will correspond to a single bit of display memory and will therefore be one of two intensities. A grey-scale display requires several bits per pixel but might still be called monochrome. Compare: bitonal. (1994-11-24) 1 1 1 1 1 Monochrome Display Adapter (MDA) One of IBM's earliest hardware video display standards for use in IBM PC. MDA can display only monochrome 80*25 text (IBM PC video mode 7). It is now obsolete. (2011-03-20) 1 1 1 1 1 monoid An operator * and a value x form a monoid if * is associative and x is its left and right identity. 1 1 1 1 1 monotonic In domain theory, a function f : D -> C is monotonic (or monotone) if for all x,y in D, x <= y => f(x) <= f(y). ("<=" is written in LaTeX as \sqsubseteq). (1994-11-24) 1 1 1 1 1 MONSTR A term graph rewriting language from Manchester University(?), designed to be easily implementable on distributed architectures and featuring limited synchronisation facilities. (1995-03-20) 1 1 1 1 1 Montage An object-relational database management system from Montage Software, the commercialisation of POSTGRES. (1995-02-23) 1 1 1 1 1 Monte Carlo (After Monte Carlo, Monaco - a gambling mecca) Any one of various methods involving statistical techniques for finding the solutions to mathematical or physical problems. For example, to calculate pi: draw a square then draw the biggest circle that fits exactly inside it. Pick random points on the square. The proportion of these that lie within the circle should tend to pi/4. (2005-04-05) 1 1 1 1 1 monty /mon'tee/ Any program with a ludicrously complex user interface that performs a trivial task. An example would be a menu-driven, button clicking, pulldown, pop-up windows program for listing directories. The original monty was a weather reporting program, Monty the Amazing Weather Man, written at the USGS. Monty had a widget-packed X-window interface with over 200 buttons; and all it actually *did* was FTP files off the network. [Jargon File] (2005-04-05) 1 1 1 1 1 MOO MUD Object Oriented 1 1 1 1 1 Moof /moof/ [MAC users] 1. A semi-legendary creature, also called the "dogcow", that lurks in the depths of the Macintosh Technical Notes Hypercard stack V3.1; specifically, the full story of the dogcow is told in technical note #31 (the particular Moof illustrated is properly named "Clarus"). Option-shift-click will cause it to emit a characteristic Moof! or "!fooM" sound. *Getting* to tech note 31 is the hard part; to discover how to do that, one must needs examine the stack script with a hackerly eye. Clue: rot13 is involved. A dogcow also appears if you choose "Page Setup..." with a LaserWriter selected and click on the "Options" button. 2. Used to flag software that's a hack, something untested and on the edge. On one Apple Computer CD-ROM, certain folders such as "Tools & Apps (Moof!)" and "Development Platforms (Moof!)", are so marked to indicate that they contain software not fully tested or sanctioned by the powers that be. When you open these folders you cross the boundary into hackerland. 1 1 1 1 1 Moore bound An upper limit on the number of nodes in a regular graph of degree d>2 and diameter k: N(d,k) <= d(d-1)^k - 2 ------------ d-2 1 1 1 1 1 Moore graph A graph which achieves the Moore bound. These are complete graphs, polygon graphs (regular graphs of degree 2) and three others: (nodes, degree, diameter) = (10,3,2), (50,7,2) and the possible but undiscovered (3250,57,2). 1 1 1 1 1 Moore's Law /morz law/ The observation, made in 1965 by Intel co-founder Gordon Moore while preparing a speech, that each new memory integrated circuit contained roughly twice as much capacity as its predecessor, and each chip was released within 18-24 months of the previous chip. If this trend continued, he reasoned, computing power would rise exponentially with time. Moore's observation still holds in 1997 and is the basis for many performance forecasts. In 24 years the number of transistors on processor chips has increased by a factor of almost 2400, from 2300 on the Intel 4004 in 1971 to 5.5 million on the Pentium Pro in 1995 (doubling roughly every two years). Date Chip Transistors MIPS clock/MHz ----------------------------------------------- Nov 1971 4004 2300 0.06 1 1 1 1 1 moose call whalesong 1 1 1 1 1 MooZ An object-oriented extension of Z. ["Object Orientation in Z", S. Stepney et al eds, Springer 1992]. (1997-07-09) 1 1 1 1 1 Mops Like Yerk, Mops is descended from the ex-commercial object-oriented language Neon. It was developed by Michael Hore <mikeh@kralizec.zeta.org.au>. Mops features an optimising native-code compiler; it is much faster than Yerk, but less compatible with Neon. Mops includes extensions such as multiple inheritance. Version 2.3.1 includes a compiler, documentation and an editor. A Macintosh version is available. (ftp://oddjob.uchicago.edu/pub/Yerk). 1 1 1 1 1 MORAL Mentioned in "An Overview of Ada", J.G.P. Barnes, Soft Prac & Exp 10:851-887 (1980). 1 1 1 1 1 more The standard Unix pager program. See also: less. (2008-09-08) 1 1 1 1 1 moria /mor'ee-*/ Like nethack and rogue, one of the large PD Dungeons and Dragons-like simulation games, available for a wide range of machines and operating systems. The name is from Tolkien's Mines of Moria; compare elder days, elvish. The game is extremely addictive and a major consumer of time better used for hacking. [Jargon File] 1 1 1 1 1 morphing The animated transformation of one image into another by gradually distorting the first image so as to move certain chosen points to the position of corresponding points in the second image. Compare tweening. (1995-04-03) 1 1 1 1 1 Morse code A coding system invented by Samuel A. Morse, for use in sending character data over extremely low-quality pathways -- such as telegraphs and low-quality radio. Morse code expresses characters as pulses of different durations. Short signals are called "dots" and long signals are calles dashes. The coding assigns shorter sequences to the most frequently used characters. American Morse code is the first and original Morse code character set. Character sets adapted to other languages were developed later. American Morse Code: A . __ J . . S . . . 1 . __ __ . B __ . . . K __ . __ T __ 2 . . __ . . C . . . L ___ U . . __ 3 . . . __ . D __ . . M __ __ V . . . __ 4 . . . . __ E . N __ . W . __ __ 5 __ __ __ F . __ . O . . X . __ . . 6 . . . . . . 1 1 1 1 1 MORTRAN A public domain Fortran preprocessor for structured programming. (1995-09-20) 1 1 1 1 1 MOS Metal Oxide Semiconductor 1 1 1 1 1 Mosaic NCSA's browser (client) for the web. Mosaic has been described as "the killer application of the 1990s" because it was the first program to provide a slick multimedia graphical user interface to the Internet's burgeoning wealth of distributed information services (formerly mostly limited to FTP and Gopher) at a time when access to the Internet was expanding rapidly outside its previous domain of academia and large industrial research institutions. NCSA Mosaic was originally designed and programmed for the X Window System by Marc Andreessen and Eric Bina at NCSA. Version 1.0 was released in April 1993, followed by two maintenance releases during summer 1993. Version 2.0 was released in December 1993, along with version 1.0 releases for both the Apple Macintosh and Microsoft Windows. An Acorn Archimedes port is underway (May 1994). 1 1 1 1 1 Mosaic Communications Corporation Netscape Communications Corporation 1 1 1 1 1 Moscow ML A light-weight implementation of Standard ML written by Sergei Romanenko <sergei-romanenko@refal.msk.su> of the Keldysh Institute of Applied Mathematics with assistance from Peter Sestoft <sestoft@dina.kvl.dk>, Royal Veterinary and Agricultural University. Moscow ML is based on CAML Light. Version: 1.20 implements the Standard ML Core language. The sublanguage of Modules implemented by Moscow ML contains signatures and non-nested structures, and identifies structures with source files. It is certainly less expressive than the full Standard ML Modules language, but the type-safe separate compilation facility is simple, useful, and easy to use. It is the intention to implement the full Standard ML Modules language (including functors) in due course. Compilation of a signature produces a compiled interface file, which is used when compiling other signatures and 1 1 1 1 1 MOSFET Metal Oxide Semiconductor Field-Effect Transistor 1 1 1 1 1 Mosiac Do you mean Mosaic? 1 1 1 1 1 MOS Technologies MOS Technology 1 1 1 1 1 MOS Technology A microprocessor design company started by some ex-Motorola designers, shortly after the Intel 8080 and Motorola 6800 appeared, in about 1975. MOS Technology introduced the 650x series, based on the Motorola 6800 design, though they were not exact clones for legal reasons. The design goal was a low-cost (smaler chip) design, realized by simplifying the decoder stage. There were no instructions with the value xxxxxx11, reducing the 1-of-4 decoder to a single NAND gate. Instructions with the value xxxxxx11 actually executed two instructions in paralell, some of them useful. The 6501 was pin-compatible with the 6800 for easier market penetration. The 650x-series had an on-chip clock oscillator while the 651x-series had none. The 6510 was used in the Commodore 64, released September 1981 and MOS made almost all the ICs for Commodore's pocket calculators. 1 1 1 1 1 most general unifier If U is the most general unifier of a set of expressions then any other unifier, V, can be expressed as V = UW, where W is another substitution. See also unification. (2000-03-07) 1 1 1 1 1 Most Significant Bit (MSB) Bit n-1 in an n bit binary number, the bit with the greatest weight (2^(n-1)). The first or leftmost bit when the number is written in the usual way. (1995-07-13) 1 1 1 1 1 motd message of the day 1 1 1 1 1 mother parent 1 1 1 1 1 motherboard (mobo) The main printed circuit board in an electronic device, particularly a computer, which may contain sockets that accept additional boards ("daughter-boards"). In a personal computer, the motherboard contains the bus, the microprocessor, and integrated circuits used for controlling any built-in peripherals such as the keyboard, text and graphics display, serial ports and parallel ports, joystick, and mouse interfaces. (2000-08-10) 1 1 1 1 1 Motif The standard graphical user interface and window manager from OSF, running on the X Window System. 1 1 1 1 1 Motion JPEG Moving JPEG 1 1 1 1 1 Motion Picture Experts Group Incorrect expansion of MPEG, which stands for Moving Picture Experts Group. (2000-05-31) 1 1 1 1 1 Motorola Motorola, Inc. 1 1 1 1 1 Motorola 14500B (MC14500B) A 1-bit ICU from Motorola. Probably the limit in small processors, the 14500B had a 4-bit instruction and controlled a single data read/write line, used for application control. It had no address bus - that was an external unit that was added on. Another CPU could be used to feed control instructions to the 14500B in an application. It had only 16 pins, less than a typical RAM chip, and ran at 1 MHz. (1994-11-30) 1 1 1 1 1 Motorola 6800 A microprocessor released shortly after the Intel 8080, in about 1975. It had 78 instructions, including the undocumented HCF (Halt and Catch Fire) bus test instruction. The 6800 evolved into the Motorola 6801 and 6803. The 6502 was based on the design of the 6800 but had one less data register and one more index register. (1994-10-31) 1 1 1 1 1 Motorola 68000 (MC68000) The first member of Motorola, Inc.'s family of 16- and 32-bit microprocessors. The successor to the Motorola 6809 and followed by the Motorola 68010. The 68000 has 32-bit registers but only a 16-bit ALU and external data bus. It has 24-bit addressing and a linear address space, with none of the evil segment registers of Intel's contemporary processors that make programming them unpleasant. That means that a single directly accessed array or structure can be larger than 64KB in size. Addresses are computed as 32 bit, but the top 8 bits are cut to fit the address bus into a 64-pin package (address and data share a bus in the 40 pin packages of the 8086 and Zilog Z8000). The 68000 has sixteen 32-bit registers, split into data and address registers. One address register is reserved for the Stack Pointer. Any register, of either type, can be used for any function except direct addressing. Only address 1 1 1 1 1 Motorola 6801 (And 6803) A version of the Motorola 6800 with ROM, some RAM, a serial I/O port and other functions on the chip. It was meant for embedded controllers, where the part count was to be minimised. The 6803 led to the 68HC11 and that was extended to 16 bits as the 68HC16. (1994-11-07) 1 1 1 1 1 Motorola 68010 A microprocessor from Motorola. It was the successor to the Motorola 68000 and was followed by the Motorola 68020. Some instructions which were previously user mode were made system mode, which necessitated patches to a few programs. The 68010's main advantage over the 68000 was that it could recover from a bus fault. The 68000 microcode didn't save enough state to restart all instructions; the 68010 corrected this fault. This allowed it to use paged virtual memory. The 68010's DBxx (decrement and branch) instructions could hold and execute the preceding instruction in the prefetch buffer, allowing some two-instruction loops to execute without refetching instructions. At one time there was a 68010 variant that was pin-for-pin compatible with the 68000. Early Amiga hackers replaced their 68000s with 68010s in order to get a small performance increase. 1 1 1 1 1 Motorola 68020 A microprocessor from Motorola. It was the successor to the Motorola 68010 and was followed by the Motorola 68030. The 68020 has 32-bit internal and external data and address buses and a 256-byte instruction buffer, arranged as 64 direct-mapped 4-byte entries[?]. The 68020 added many improvements to the 68010 including a 32-bit ALU and external data bus and address bus, and new instrucitons and addressing modes. The 68020 (and 68030) had a proper three-stage pipeline. The new instructions included some minor improvements and extensions to the supervisor state, some support for high-level languages which didn't get used much (and was removed from future 680x0 processors[?]), bigger (32 x 32-bit) multiply and divide instructions, and bit field manipulations. The new adderessing modes added another level of indirection to many of the pre-existing modes, and added quite a bit of flexibility to various indexing modes and operations. 1 1 1 1 1 Motorola 68030 A 32-bit microprocessor in Motorola's Motorola 68000 family, with on-chip split instruction and data cache of 256 bytes each. The 68030 has an on-chip MMU (except in the 680EC30 version). The 68881 and the faster 68882 FPU chips could be used with the 68030. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. The 68030 is used in many models of the Apple Macintosh II series of personal computers. (2001-01-08) 1 1 1 1 1 Motorola 68040 (MC68040) A microprocessor from Motorola. It was the successor to the Motorola 68030 and was followed by the Motorola 68060. The 68040 was the first 680x0 family member with an on-chip FPU. It also had split instruction and data caches of 4 kilobytes(?) each. It was fully pipelined, with six stages. The 68040 was used in the Apple Macintosh Quadra series of personal computers. The MC68LC040 is an MC68040 without a built-in FPU, and the MC68EC040 is an MC68040 without an MMU or FPU. (2003-10-25) 1 1 1 1 1 Motorola 68050 There was no 68050. The successor to the Motorola 68040 was the Motorola 68060. The even numbers (68000, 68020, 68060) were reserved for major revisions to the 680x0 core. The odd numbers (68010, 68030, 68050) were minor upgrades from the previous chip. For example, the Motorola 68010 was a Motorola 68000 with some minor enhancements and modifications to some user/superuser instruction assignments. The Motorola 68030 was a Motorola 68020 with an MMU and more minor enhancements. The 68050 would have been a 68040 with some bugs fixed, which didn't really warrant a new name so it was sold as a 68040. (1995-11-29) 1 1 1 1 1 Motorola 68060 A 32-bit microprocessor from Motorola, the successor to the Motorola 68040. The 68060 is the highest performance 680x0 family processor currently (April 1995) available. It has 2 to 3 times the performance of the 68040 The 68060 is probably the last development from Motorola in the high performacnce 680x0 series. They don't want to compete with their own PowerPC chips. The 680x0 series is intended more for embedded systems, where it is already very popular. New developments here seem to integrate more peripheral functions on chip rather than increasing processing power. (1995-04-22) 1 1 1 1 1 Motorola 6809 (MC6809) An eight-bit microprocessor from Motorola, Inc.. The 6809 was a major advance over both its predecessor, the Motorola 6800 and the 6502. The 6809 had two 8-bit accumulators, rather than one in the 6502, and could combine them into a single 16-bit register. It also featured two index registers and two stack pointers, which allowed for some very advanced addressing modes. The 6809 was source compatible with the 6800, even though the 6800 had 78 instructions and the 6809 only had around 59 (including a SEX instruction). Some instructions were replaced by more general ones which the assembler would translate and some were replaced by addressing modes. The 6809 had one of the first multiplication instructions of the time, 16-bit arithmetic and a special fast interrupt. But it was also highly optimised, gaining up to five times the speed of the 6800 series CPU. Like the 6800, it included the undocumented 1 1 1 1 1 Motorola 680x0 Shorthand for any member for the Motorola 68000 family of microprocessors from Motorola, Inc. The "x" stands for 0, 1, 2, 3, 4 or 6. (1993-05-01) 1 1 1 1 1 Motorola 68HC11 A microcontroller family from Motorola descended from the Motorola 6800 microprocessor. The 68HC11 devices are more powerful and more expensive than the 68HC05 family. FAQ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/comp.answers/microcontroller-faq/68hc11). There is an opcode simulator for the 68HC11, by Ted Dunning <ted@nmsu.edu>. Interrupts, hardware I/O, and half carries are still outside the loop. Adding interrupts may require simulating at the clock phase level. Version 1. (ftp://crl.nmsu.edu/pub/non-lexical/6811/sim6811.shar). (1995-04-28) 1 1 1 1 1 Motorola 68LC040 A version of the Motorola 68040 with no MMU or FPU, making it more like an enhanced Motorola 68020. A Power Macintosh can emulate a Motorola 68LC040. (1999-01-11) 1 1 1 1 1 Motorola 88000 A family of RISC microprocessors from Motorola. [Details?] (1995-03-01) 1 1 1 1 1 Motorola, Inc. One of the world's leading providers of wireless communications, semiconductors and advanced electronic systems and services. Major equipment businesses include cellular telephone, two-way radio, paging and data communications, personal communications, automotive, defense and space electronics, computers, satellite communications systems, police and emergency service radio systems, taxicab dispatching (radio) systems. Communication devices, computers and millions of consumer products are powered by Motorola semiconductors. They are probably best known in the computing world for their microprocessors, including the Motorola 6800 and Motorola 68000 CISC families and Motorola 88000 RISCs, the Motorola DSP56000 digital signal processors and the PowerPC on which they collaborated. They also led the development of VMEbus. Quarterly sales $5400M, profits $367M (Aug 1994). 1 1 1 1 1 mount To make a file system available for access. Unix does this by associating the file system with a directory (the "mount point") within a currently mounted file system. The "root" file system is mounted on the root directory, "/" early in the boot sequence. "mount" is also the Unix command to do this, "unmount" breaks the association. E.g., "mount attaches a named file system to the file system hierarchy at the pathname location directory [...]" -- Unix manual page mount(8). File systems are usually mounted either at boot time under control of /etc/rc (or one of its subfiles) or on demand by an automounter daemon. Other operating systems such as VMS and DOS mount file systems as separate directory hierarchies without any common ancestor or root directory. Apparently derived from the physical sense of "mount" meaning 1 1 1 1 1 Mouse A mighty small macro language developed by Peter Grogono in 1975 ["Mouse, A Language for Microcomputers", P. Grogono <grogono@concour.cs.concordia.ca> Petrocelli Books, 1983]. (1994-10-31) 1 1 1 1 1 mouse The most commonly used computer pointing device, first introduced by Douglas Engelbart in 1968. The mouse is a device used to manipulate an on-screen pointer that's normally shaped like an arrow. With the mouse in hand, the computer user can select, move, and change items on the screen. A conventional roller-ball mouse is slid across the surface of the desk, often on a mouse mat. As the mouse moves, a ball set in a depression on the underside of the mouse rolls accordingly. The ball is also in contact with two small shafts set at right angles to each other inside the mouse. The rotating ball turns the shafts, and sensors inside the mouse measure the shafts' rotation. The distance and direction information from the sensors is then transmitted to the computer, usually through a connecting wire - the mouse's tail. The computer then moves the mouse pointer on the screen to follow the movements of the mouse. This may be done 1 1 1 1 1 mouse ahead The point-and-click analog of "type ahead". To manipulate a computer's pointing device (almost always a mouse in this usage, but not necessarily) and its selection or command buttons before a computer program is ready to accept such input, in anticipation of the program accepting the input. Handling this properly is rare, but it can help make a WIMP environment much more usable, assuming the users are familiar with the behaviour of the user interface. [Jargon File] (1994-12-05) 1 1 1 1 1 mouse around To explore public portions of a large system, especially a network such as Internet via FTP or TELNET, looking for interesting stuff to snarf. [Jargon File] (1994-12-05) 1 1 1 1 1 mouse arrest Getting busted for violating an on-line service's rule of conduct. "Sorry I couldn't get back to you. AOL put me under mouse arrest." (1997-03-30) 1 1 1 1 1 mouse belt rat belt 1 1 1 1 1 mouse droppings 1. <graphics, operating system, jargon> Pixels (usually single) that are not properly restored when the mouse pointer moves away from a particular location on the screen, producing the appearance that the mouse pointer has left droppings behind. The major causes for this problem are MS-DOS programs that write to the screen memory corresponding to the mouse pointer's current location without hiding the mouse pointer first, and mouse drivers that do not quite support the graphics mode in use. 2. <web, jargon> The client address recorded in a web server's log whenever a client connects to a site. Users may be unaware that their activity is being logged in this way but the potential for misuse of the information is limited. [March 1996 Macworld, p260, Viewpoint article by Larry Irving]. (1994-12-05) 1 1 1 1 1 mouse elbow A tennis-elbow-like fatigue syndrome resulting from excessive use of a WIMP. Similarly, "mouse shoulder". GLS reports that he used to get this a lot before he taught himself to be ambimoustrous. [Jargon File] (1994-12-05) 1 1 1 1 1 mouse mat (U.S.: "mouse pad") A small sheet with a special surface for a rolling ball mouse to move on. Most mouse mats are sheets of rubber or foam about 20cm by 25cm and about 5mm thick with one side covered with cloth or sometimes hard plastic. Deluxe versions come combined with a wrist rest. It is rare to find a mouse mat which does not carry some form of advertisement for some company or other. They are such a common free gift that few people actually have to buy one. Mats are supposed to provide better traction and a clean, lint-free surface over which to move but it debatable whether they are useful at all, or whether any appropriate surface (preferably hard, even, flat, and clean) is as good. Howevever, some mice which use optical (e.g. Sun) or radio-frequency sensors (e.g. ?) to detect motion (instead of using a rolling ball) will only work on specially designed mouse mats. Critics may consider this to be part of the connector conspiracy, though the designers would claim 1 1 1 1 1 mouse pad mouse mat 1 1 1 1 1 mouse trails A feature (usually of Graphical User Interfaces) which causes the mouse pointer to leave a trail across the screen. This is done by keeping track of the last eight or so (maybe configurable) pointer positions, and only erasing the oldest. This means that at any time, there may be up to eight pointers on the screen, but if the mouse is still, they will all be in the same position, and so only one will be visible. When the mouse moves, it appears to leave a trail of pointers behind it, and this can dramatically increase the visibility of the pointer when using LCD screens. The older ones had such long persistence that a single mouse pointer, when moving, tended to be completely invisible, and on a cluttered screen, was very difficult to find. (1996-07-08) 1 1 1 1 1 mouso /mow'soh/ (By analogy with "typo") An error in mouse usage resulting in an inappropriate selection or graphic garbage on the screen. Compare thinko. [Jargon File] (1996-04-21) 1 1 1 1 1 Moving JPEG (M-JPEG) A compression technique for moving images which applies JPEG still image compression to each frame of a moving picture sequence. Play-back requires a machine capable of decompressing and displaying each JPEG image quickly enough to sustain the required frame rate of the picture sequence. There is no standard for Moving JPEG as with JPEG, but there are JPEG compression chips (for example see Zoran (http://zoran.com/)) which are designed to work at television frame rates and resolutions. See also MPEG and MPEG2. (1996-12-15) 1 1 1 1 1 Moving Picture Expert Group Incorrect expansion of MPEG, which stands for Moving Picture Experts Group. (2000-05-31) 1 1 1 1 1 Moving Picture Experts Group (MPEG, ISO/IEC JTC1/SC29 WG11) An ISO committee that generates standards for digital video compression and audio. Also the name of their algorithms. MPEG-1 is optimised for CD-ROM and is the basis for MP3. MPEG-2 is aimed at broadcast quality video for applications such as digital television set-top boxes and DVD. MPEG-4 is a standard for low bandwidth video telephony and multimedia on the web. MPEG-3 was merged into MPEG-2. (http://cselt.it/mpeg/). MPEG.org (http://mpeg.org/). MPEG decoder (ftp://toe.cs.berkeley.edu/pub/multimedia/mpeg/). MPEG routines (ftp://ftp.mni.mcgill.ca/pub/mpeg/). (2000-05-31) 1 1 1 1 1 Moving Pictures Experts Group Incorrect expansion of MPEG, which stands for Moving Picture Experts Group. (2000-05-31) 1 1 1 1 1 Moxie A language for real-time computer music synthesis, written in XPL. ["Moxie: A Language for Computer Music Performance", D. Collinge, Proc Intl Computer Music Conf, Computer Music Assoc 1984, pp.217-220]. (1994-12-05) 1 1 1 1 1 Mozilla The open source web browser, designed for standards-compliance, performance, and portability, whose development is coordinated by the Mozilla Foundation. The Mozilla project started in March 1998 when Netscape Communications Corporation released the source code of Netscape Communicator. The now abandoned version based on that code is referred to as "Mozilla Classic". Since then, much has been rewritten, including the layout engine, the networking library, and the front-end. Mozilla 1.0 was finally released on 2002-06-05. Much of the code was used to build Firefox. Although a lot of Mozilla code is under the original Netscape Public License, some parts of the code are under the Mozilla Public License or dual MPL/GPL. Mozilla was the original project code name for Netscape Navigator and, according to some of the documentation, the 1 1 1 1 1 Mozilla Foundation The body set up by Netscape in January 1998 to coordinate development of the Mozilla browser and to provide a point of contact. Mozilla Home (http://mozilla.org/). (2005-01-26) 1 1 1 1 1 Mozilla Public License open source license 1 1 1 1 1 mp The country code for the Northern Mariana Islands. (1999-01-27) 1 1 1 1 1 MP1 MPEG-1 audio layer 1 1 1 1 1 1 MP-1 Assembly language for the MasPar computer. (1994-12-05) 1 1 1 1 1 MP2 MPEG-1 audio layer 2 1 1 1 1 1 MP3 MPEG-1 audio layer 3 1 1 1 1 1 MP3Pro An extention of MP3 using SBR, targetting data rates of 64-96 kbps. (2001-12-20) 1 1 1 1 1 MPC 1. <operating system> Memory Protection Check. [Origin?] 2. <computer> Multimedia Personal Computer. 3. Multiprocess Communications. 1 1 1 1 1 MPC Level 1 Specification The original Multimedia Personal Computer specification. Minimum requirements are a 16 MHz 386SX with 2 megabytes of RAM, a 30 MB hard disk drive, and a CD-ROM drive with a sustained data transfer rate of 150 KB/s at no more than 40% of CPU bandwidth and reading at least 16 KB blocks. The maximum average seek time is 1 second and the Mean Time Between Failure 10000 hours. Capability Mode 1. The computer must have 8-bit digital sound and an 8-note synthesizer with MIDI playback. Sample rates of 22.05 and 11.025 kHz must be supported by no more than 10% of CPU bandwidth, preferably 44.1 kHz at no more than 15% of CPU bandwidth. The synthesizer must support multi-voice, multi-timbral generation of six simultaneous melody notes and two simultaneous percussive notes with internal mixing capabilities to combine input from three sources and present the output as a stereo, line-level audio signal at the back 1 1 1 1 1 MPC Level 2 Specification An improved version of the MPC Level 1 Specification for Multimedia Personal Computers. Minimum requirements are a 25 Mhz 486SX with 4 MB of RAM and a 160 MB hard disk drive. The CD-ROM drive must support a sustained data transfer rate of 300 KB/s using at most 60% of CPU bandwidth on 16 KB minimum block read size. Its average seek time must be 400 milliseconds maximum. Capability Mode 1, Mode 2 form 1, Mode 2 form 2, Multisession. It must be CD-ROM XA-ready. The computer must have 16-bit digital sound, an 8-note synthesizer, and MIDI playback. A sample rate of 44.1 kHz must be available on stereo channels with more than 15% of CPU bandwidth. A video display with a resolution of 640 x 480 in 65,536 colours, and MIDI, I/O, and joystick ports must be provided. (1997-01-19) 1 1 1 1 1 MPEG Moving Picture Experts Group 1 1 1 1 1 MPEG-1 The first MPEG format for compressed video, optimised for CD-ROM. MPEG-1 was designed for the transmission rates of about 1.5 Mbps achievable with Video-CD and CD-i. It uses discrete cosine transform (DCT) and Huffman coding to remove spatially redundant data within a frame and block-based motion compensated prediction (MCP) to remove data which is temporally redundant between frames. Audio is compressed using subband encoding. These algorithms allow better than VHS quality video and almost CD quality audio to be compressed onto and streamed off a single speed (1x) CD-ROM drive. MPEG encoding can introduce blockiness, colour bleed and shimmering effects on video and lack of detail and quantisation effects on audio. The official name of MPEG-1 is International Standard IS-11172. 1 1 1 1 1 MPEG-1 audio layer 1 (MP1) A simple 32-subband audio compressor using a floating point representation for subband samples. Resolution and scale factor are stored for groups of 12 subsamples. MP1 is only used for Philips DCC Digital Compact cassette with data rates of 384 kbps. (2001-12-02) 1 1 1 1 1 MPEG-1 audio layer 3 (MP3) A digital audio compression algorithm that acheives a compression factor of about twelve while preserving sound quality. It does this by optimising the compression according to the range of sound that people can actually hear. MP3 is currently (July 1999) the most powerful algorithm in a series of audio encoding standards developed under the sponsorship of the Moving Picture Experts Group (MPEG) and formalised by the International Organization for Standardization (ISO). MP3 is very different from Layer 2, using an additional MDCT layer to increase frequency resolution. Its scale factor groups are more optimised for the human ear, and it uses nonlinear sample quantisation and Huffman coding. MP3 files (filename extension ".mp3") can be downloaded from many websites and can be played using software available for most operating systems (also downloadable), e.g. Winamp for PC, MacAmp for Macintosh, and mpeg123 for Unix. 1 1 1 1 1 MPEG-1 layer 3 MPEG-1 audio layer 3 1 1 1 1 1 MPEG-2 A variant of the MPEG video and audio compression algorithm and file format, optimised for broadcast quality video. MPEG-2 was designed to transmit images using progressive coding at 4 Mbps or higher for use in broadcast digital TV and DVD. An MPEG-2 player can handle MPEG-1 data as well. MPEG-2 has been approved as International Standard IS-13818. (1995-04-18) 1 1 1 1 1 MPEG-21 A file format designed to merge very different things in one object, so you can store interactive material in this format (audio, video, questions, answers, overlays, non-linear order, calculation from user inputs, etc.) [Technical details?] (2001-12-02) 1 1 1 1 1 MPEG-2.5 audio layer 3 A non-standard extention of MPEG-2 audio layer 3 by FhG for lowest sampling rates (8-12 kHz) targeting bit rates from 16-32 kbps (possibly 8-160 kbps). (2001-12-04) 1 1 1 1 1 MPEG-2 AAC Low Profile A successor of MP3 allowing transparent coding at data rates of 75-80% of that of MP3. It is very different from MP3, only used MDCT, no subband coding. (2001-12-08) 1 1 1 1 1 MPEG-2 audio layer 3 An extention of MPEG-1 audio layer 3 for lower sampling rates (16-24 kHz) targeting bit rates from 32-64 kbps (possibly 8-160 kbps). It is often combined with MPEG-2 LSF. (2001-12-04) 1 1 1 1 1 MPEG-2 Low Sampling Frequencies Extention (MPEG-2 LSF) An extension of MPEG-2, mostly used with MPEG-2 audio layer 3 because the aim was medium quality at low bit rates, not lower sampling frequencies. (2001-12-04) 1 1 1 1 1 MPEG-2 LSF MPEG-2 Low Sampling Frequencies Extention 1 1 1 1 1 MPEG-2 MC MPEG-2 Multi Channel Extention 1 1 1 1 1 MPEG-2 Multi Channel Extention (MPEG-2 MC) An extension of MPEG-2 that uses up to 5 channels and about 1200 kbps. (2001-12-08) 1 1 1 1 1 MPEG-3 A proposed variant of the MPEG video and audio compression algorithm and file format. MPEG-3 was intended as an extension of MPEG-2 to cater for HDTV but was eventually merged into MPEG-2. Not to be confused with MP3 - MPEG-1 layer 3. [Technical details?] (1999-01-06) 1 1 1 1 1 MPEG-4 A video compression standard planned for late 1998. MPEG-4 extends the earlier MPEG-1 and MPEG-2 algorithms with synthesis of speech and video, fractal compression, computer visualisation and artificial intelligence-based image processing techniques. [Technical details?] (1999-01-06) 1 1 1 1 1 MPEG-4 AAC Main Profile A successor of MP3 allowing transparent coding at data rates of 70-75% of that of MP3. It is very different from MP3, only used MDCT, no subband coding. It is much more complex that MP3 and MPEG-2 AAC Low Profile. (2001-12-08) 1 1 1 1 1 MPEG-4 AAC SSR MPEG-4 Advanced Audio Coding Scalable Sampling Rate 1 1 1 1 1 MPEG-4 Advanced Audio Coding Scalable Sampling Rate (MPEG-4 AAC SSR) An AAC flavour supporting different qualities for different targets. One stream can contain up to 3 streams for 11.025 kHz (Stream 1), 22.05 (Stream 1 and 2) and 44.1 kHz (all 3 Streams) sampling frequency. Quality is between Low Profile and Main profile. See also JPEG-2000. (2001-12-09) 1 1 1 1 1 MPEG-4 Harmonics, individual lines and noise (MPEG-4 HILN) An MPEG-4 variant using parametric encoding with a target bit rate of 30 kbps. (2001-12-09) 1 1 1 1 1 MPEG-4 Harmonic Vector eXCitation (MPEG-4 HVXC) An MPEG-4 variant using parametric encoding with a target bit rate of 20 kbps, for voice coding. (2001-12-09) 1 1 1 1 1 MPEG-4 HILN MPEG-4 Harmonics, individual lines and noise 1 1 1 1 1 MPEG-4 HVXC MPEG-4 Harmonic Vector eXCitation 1 1 1 1 1 MPEG-7 A successor to MPEG-4, not standardized yet. (2001-12-02) 1 1 1 1 1 MPEGplus A non-ISO standard compressed audio file format derived from MPEG-1 Layer 2. (2001-12-11) 1 1 1 1 1 MPG Miles per gallon, as in "Your MPG may vary", i.e. "Your mileage may vary". 1 1 1 1 1 mpg A filename extension for a file in MPEG format. (1995-03-07) 1 1 1 1 1 MPI Message Passing Interface 1 1 1 1 1 MPL 1. <language> An early possible name for PL/I. [Sammet 1969, p.542]. 2. MasPar data-parallel version of C. See also ampl. Compiler version 3.1 (ftp://maspar.maspar.com/put/). 3. Motorola Programming Language. A low-level PL/I-like language, similar to PL/M, but for the Motorola 6800. 4. MicroProgramming Language. Simple language for microprogramming. Statements on the same line represent register transfers caused by one microinstruction, and are executed in parallel. ["Structured Computer Organization", A.S. Tanenbaum, First Edition, P-H 1976. (Replaced in later editions by Mic-1)]. (1995-03-07) 1 1 1 1 1 MPL II [Burroughs VMS MPL II Language Reference Manual]. 1 1 1 1 1 MPLS Multiprotocol Label Switching 1 1 1 1 1 MPLS domain A portion of a network that contains devices that understand MPLS. (1999-06-14) 1 1 1 1 1 MP/M Multi-tasking Program for Microcomputers 1 1 1 1 1 MPP Multiple Parallel Processing 1 1 1 1 1 MPPE Microsoft Point to Point Encryption 1 1 1 1 1 MPPL An early possible name for PL/I. [Sammet 1969, p. 542]. (1995-03-07) 1 1 1 1 1 MPR II A green standard published by SWEDAC (the Swedish Board for Technical Accreditation) that limits the maximum amount of ELF and VLF electromagnetic radiation a computer monitor may emit. Most personal computer monitors comply with this standard or the more stringent European TCO requirement. (1996-02-19) 1 1 1 1 1 M-Prolog 1. Marseille Prolog. 2. An extension to Prolog involving modules. ["The MProlog System", J. Bendl et al, Proc Logic Prog Workshop, 1980]. (1994-10-31) 1 1 1 1 1 MPS III Solving matrices and producing reports. "MPS III DATAFORM User Manual", Management Science Systems (1976). 1 1 1 1 1 MPSX Mathematical Programming System Extended. Solution strategy for mathematical programming. "Mathematical Programming System Extended (MPSX) Control Language User's Manual", SH20-0932, IBM. Sammet 1978. 1 1 1 1 1 MPV An extension of the VRTX real-time operating system to support multi-processing. (1994-11-08) 1 1 1 1 1 MPX Multiplexor Channel 1 1 1 1 1 mq The country code for Martinique. (1999-01-27) 1 1 1 1 1 MQG Multi-threaded Query Gate 1 1 1 1 1 mr The country code for Mauritania. (1999-01-27) 1 1 1 1 1 MRAM Magnetic RAM 1 1 1 1 1 MRDA Mandy Rice-Davis Applies 1 1 1 1 1 MRDS Multics Relational Data Store 1 1 1 1 1 MRI 1. <application> Magnetic Resonance Imaging. 2. Measurement Requirements and Interface. 1 1 1 1 1 MROC Miniature Ruggedized Optical Correlator 1 1 1 1 1 MROM Mask Read-Only Memory 1 1 1 1 1 MRP Material Requirements Planning 1 1 1 1 1 MRP II Manufacturer Resource Planning 1 1 1 1 1 MRS Modifiable Representation System. An integration of logic programming into Lisp. ["A Modifiable Representation System", M. Genesereth et al, HPP 80-22, CS Dept Stanford U 1980]. (1994-11-08) 1 1 1 1 1 ms 1. <unit> millisecond. 2. <networking> The country code for Montserrat. (1999-01-27) 1 1 1 1 1 MS Access Microsoft Access 1 1 1 1 1 MSAU Media Access Unit 1 1 1 1 1 MSB Most Significant Bit 1 1 1 1 1 MS-BASIC Microsoft Basic 1 1 1 1 1 MS-DOG A pejorative name for MS-DOS. 1 1 1 1 1 MS-DOS Microsoft Disk Operating System 1 1 1 1 1 MSG.84 A language for the functional specification and module design phases of the software life cycle, first presented in Berzins and Gray's 1985 paper. Not unlike PDL. ["Analysis and design in MSG.84: formalizing functional specifications", Valdis Berzins, Michael Gray, Volume 11 Issue 8, IEEE Transactions on Software Engineering, Aug 1985]. (2003-05-15) 1 1 1 1 1 msgGUI A graphical user interface for GNU Smalltalk. The msgGUI package contains the basics for creating window applications in the manner available in other graphical Smalltalk implementations. Version 1.0 of the library was by Mark Bush, ECS, Oxford University, UK. (ftp://ftp.comlab.ox.ac.uk/pub/Packages/mst/mstGUI-1.0.tar.Z). (2000-06-14) 1 1 1 1 1 MSIE Internet Explorer 1 1 1 1 1 MSM Micronetics Standard MUMPS 1 1 1 1 1 MS Mail Microsoft Mail 1 1 1 1 1 MSN The Microsoft Network 1 1 1 1 1 MS Office Microsoft Office 1 1 1 1 1 MS Project Microsoft Project 1 1 1 1 1 MSS maximum segment size 1 1 1 1 1 MS-Windows Microsoft Windows 1 1 1 1 1 MswLogo A Microsoft Windows front-end for Berkeley Logo by George Mills <george.mills AT softronix DOT com>. MswLogo has 3D primitives and GUI support. It runs on every flavour of Windows from 16-bit to NT. (http://softronix.com/logo.html). (2006-02-28) 1 1 1 1 1 MS Word Microsoft Word 1 1 1 1 1 MSX Microsoft Extended 1 1 1 1 1 MSX-DOS Microsoft Extended 1 1 1 1 1 mt The country code for Malta. (1999-01-27) 1 1 1 1 1 MTA 1. <messaging> Message Transfer Agent. 2. <messaging> Message Transfer Architecture. (AT&T). 3. Multiple Terminal Access. 4. Maintenance Task Analysis. (1997-02-28) 1 1 1 1 1 MTBF Mean Time Between Failures 1 1 1 1 1 mtc A Modula-2 to C translator. (ftp://rusmv1.rus.uni-stuttgart.de/soft/Unixtools/compilerbau/mtc.tar.Z). (1991-10-25) 1 1 1 1 1 M Technology Association The MUMPS User's Group that disbanded some time between 1995 and 2003. Address: 1738 Elton Road, Suite 205, Silver Spring, MD 20903-1725, USA. Telephone: +1 301 431-4070. Fax: +1 301 431-0017. (2003-06-04) 1 1 1 1 1 MTOS 1. <operating system> A family of real-time operating systems for use in embedded systems. It is developed and marketed by Industrial Programming, Inc.. 2. <operating system> MultiTOS (1997-06-03) 1 1 1 1 1 MTS 1. Message Transport System. 2. <programming> Microsoft Transaction Server. (1999-03-29) 1 1 1 1 1 MTTR Mean Time To Recovery 1 1 1 1 1 MTU Maximum Transmission Unit 1 1 1 1 1 Mu (Greek letter). 1. <unit> /micro/ prefix denoting division by 10^6, e.g. mu m (micrometre, a millionth part of a metre). Sometimes written as a 'u', the ASCII character nearest in appearance. 2. <mathematics> /myoo/ In the theory of functions, mu x . E denotes the least value of x for which E = x, i.e. the least fixed point of the function \ x . E. The recursive function mu f . H f satisfies (and is defined by) the equation mu f . H f = H (mu f . H f) An alternative notation for the same function is fix H = H (fix H) See fixed point combinator. 3. <database> multiple value. [Jargon File] (1995-10-30) 1 1 1 1 1 mu 1. <networking> The country code for Mauritius. 2. <philosophy> /moo/ The correct answer to the classic trick question "Have you stopped beating your wife yet?". Assuming that you have no wife or you have never beaten your wife, the answer "yes" is wrong because it implies that you used to beat your wife and then stopped, but "no" is worse because it suggests that you have one and are still beating her. According to various Discordians and Douglas Hofstadter the correct answer is usually "mu", a Japanese word alleged to mean "Your question cannot be answered because it depends on incorrect assumptions". Hackers tend to be sensitive to logical inadequacies in language, and many have adopted this suggestion with enthusiasm. The word "mu" is actually from Chinese, meaning nothing; it is used in mainstream Japanese in that sense, but native speakers do not recognise the Discordian question-denying use. It almost certainly derives from 1 1 1 1 1 MUA Mail User Agent 1 1 1 1 1 MUCAL A language for playing music on the PDP-8. (1995-04-16) 1 1 1 1 1 MUD Multi-User Dimension or "Multi-User Domain". Originally "Multi-User Dungeon". [Jargon File] (1995-04-16) 1 1 1 1 1 muddie Synonym mudhead. More common in Great Britain, possibly because system administrators there like to mutter bloody muddies when annoyed at the species. [Jargon File] 1 1 1 1 1 Muddle Original name of MDL. 1 1 1 1 1 mudhead A MUD player who eats, sleeps, and breathes MUD. Mudheads have been known to fail their degrees, drop out, etc. with the consolation, however, that they made wizard level. When encountered in person, on a MUD or in a chat system, all a mudhead will talk about is three topics: the tactic, character, or wizard that is supposedly always unfairly stopping him/her from becoming a wizard or beating a favourite MUD; why the specific game he/she has experience with is so much better than any other; and the MUD he or she is writing or going to write because his/her design ideas are so much better than in any existing MUD. See also wannabee. To the anthropologically literate, this term may recall the Zuni/Hopi legend of the mudheads or "koyemshi", mythical half-formed children of an unnatural union. Figures representing them act as clowns in Zuni sacred ceremonies. [Jargon File] (1994-11-29) 1 1 1 1 1 MUD Object Oriented (MOO) One of the many MUD spin-offs (e.g. MUSH, MUSE, and MUX) created to diversify the realm of interactive text-based gaming. A MOO is similar to a MUSH in that the users themselves can create objects, rooms, and code to add to the environment. The most frequently used server software for running a MOO is LambdaMOO but alternatives include WinMOO (http://www-personal.umich.edu/~cunkel/WinMOO/) and MacGoesMOO (http://neon.ci.lexington.ma.us/SpamCentral/scaron/mgm.html). (1999-05-25) 1 1 1 1 1 muFP A functional language for hardware design, a predecessor of Ruby. 1 1 1 1 1 Muhammad al-Khwarizmi Muhammad ibn Musa al-Khwarizmi 1 1 1 1 1 Muhammad ibn Musa al-Khwarizmi An astronomer, geographer and mathematician, born around 780 CE in Khwarizm (modern Khiva), south of the Aral Sea. Khawarizmi founded algebra and algorithms (named after him), synthesised Greek and Hindu knowledge, introducing the Indian system of numerals (now known as Arabic numerals), developed operations on fractions, trigonometric tables containing the sine functions, the calculus of two errors and the decimal system, explained the use of zero, perfected the geometric representation of conic sections, collaborated in the degree measurements aimed at measuring of volume and circumference of the Earth and produced the first map of the known world in 830 CE. He died around 850 CE. Muslim Heritage.com (http://muslimheritage.com/day_life/default.cfm?ArticleID=317&Oldpage=1]). (2008-07-08) 1 1 1 1 1 mu-law The North America standard for nonuniform quantising logarithmic compression. [Equation?] (1995-02-21) 1 1 1 1 1 Mule A multi-lingual enhancement of GNU Emacs. Mule can handle not only ASCII characters (7 bit) and ISO Latin 1 characters (8 bit), but also 16-bit characters like Japanese, Chinese, and Korean. Mule can have a mixture of languages in a single buffer. Mule runs under the X window system, or on a Hangul terminal, mterm or exterm. Latest version: 2.3. (ftp://etlport.etl.go.jp/pub/mule). (1996-01-28) 1 1 1 1 1 Mul-T An implementation of Multilisp built on T, for the Encore Multimax. ["Mul-T: A High-Performance Parallel Lisp", SIGPLAN Notices 24(7):81-90 (Jul 1989)]. (1995-02-21) 1 1 1 1 1 Multi-BinProlog A multi-threaded Linda-style parallel extension to BinProlog for Solaris 2.3. Version: 3.30. (1995-04-04) 1 1 1 1 1 multiboot dual boot 1 1 1 1 1 multiC A data-parallel version of C from Wavetracer. (1995-04-04) 1 1 1 1 1 MultiCal System E-mail: Richard Snodgrass <rts@cs.arizona.edu>. (ftp://ftp.cs.arizona.edu/tsql/multical). [What is it?] (1994-11-11) 1 1 1 1 1 multicast addressing Ethernet addressing scheme used to send packets to devices of a certain type or for broadcasting to all nodes. The least significant bit of the most significant byte of a multi-cast address is one. 1 1 1 1 1 multicast backbone (MBONE) A virtual network on top of the Internet which supports routing of IP multicast packets, intended for multimedia transmission. MBONE gives public access desktop video communications. The quality is poor with only 3-5 frames per second instead of the 30 frames per second of commercial television. Its advantage is that it avoids all telecommunications costs normally associated with teleconferencing. An interesting innovation is the use of MBONE for audio communications and an electronic "whiteboard" where the computer screen becomes a shared workspace where two physically remote parties can draw on and edit shared documents in real-time. (1994-10-27) 1 1 1 1 1 Multi-channel Memorandum Distribution Facility (MMDF) An electronic mail system for Unix(?) which is much easier to configure than sendmail. The source is available. MMDF is a versatile and configurable mail routing system (MTA) which also includes user interface programs (MUA). It can be set up to route mail to different domains and hosts over different channels (e.g. SMTP, UUCP). On UNIX systems, its configuration begins with the /usr/mmdf/mmdftailor file, which defines the machine and domain names, various other configuration tables (alias, domain, channel) and other configuration information. [Home?] (1997-01-14) 1 1 1 1 1 multician /muhl-ti'shn/ A term coined at Honeywell, ca. 1970 for a competent user of Multics. Perhaps oddly, no one has ever promoted the analogous "Unician". [Jargon File] (1996-08-24) 1 1 1 1 1 Multi-Color Graphics Array (MCGA) One of IBM's less popular hardware video display standards for use in the IBM PS/2. MCGA can display 80*25 text in monochrome, 40*25 text in 256 colours or 320*200 pixel graphics in 256 colors. It is now obsolete. (2011-03-20) 1 1 1 1 1 Multics /muhl'tiks/ MULTiplexed Information and Computing Service. A time-sharing operating system co-designed by a consortium including MIT, GE and Bell Laboratories as a successor to MIT's CTSS. The system design was presented in a special session of the 1965 Fall Joint Computer Conference and was planned to be operational in two years. It was finally made available in 1969, and took several more years to achieve respectable performance and stability. Multics was very innovative for its time - among other things, it was the first major OS to run on a symmetric multiprocessor; provided a hierarchical file system with access control on individual files; mapped files into a paged, segmented virtual memory; was written in a high-level language (PL/I); and provided dynamic inter-procedure linkage and memory (file) sharing as the default mode of operation. Multics was the only 1 1 1 1 1 Multics Relational Data Store (MRDS) The first commercial relational database, implemented as part of Multics by Jim Weeldreyer and Oris Friesen of Honeywell Phoenix in about 1977. MRDS included a report writer called LINUS written by Jim Falksen. (1997-01-29) 1 1 1 1 1 Multiflow Computer A now-defunct computer company, best known for its work in Very Long Instruction Word processors. Address: New Haven, Conn. USA. (1995-03-01) 1 1 1 1 1 Multi-Garnet A better constraint system for Garnet. Version 2.1 by Michael Sannella <sannella@cs.washington.edu>. (ftp://a.gp.cs.cmu.edu/usr/garnet/alpha/src/contrib/multi-garnet). (1992-09-21) 1 1 1 1 1 multihomed host A host which has more than one connection to a network. The host may send and receive data over any of the links but will not route traffic for other nodes. 1 1 1 1 1 multilayer perceptron A network composed of more than one layer of neurons, with some or all of the outputs of each layer connected to one or more of the inputs of another layer. The first layer is called the input layer, the last one is the output layer, and in between there may be one or more hidden layers. 1 1 1 1 1 MultiLisp A parallel extension of Scheme with explicit concurrency. The form (future X) immediately returns a future, and creates a task to evaluate X. When the evaluation is complete, the future is resolved to be the value. ["MultiLisp: A Language for Concurrent Symbolic Computation", R. Halstead, TOPLAS pp.501-538 (Oct 1985)]. [Did MultiLisp use PVM as its intermediate language?] (1998-02-10) 1 1 1 1 1 multimedia Any collection of data including text, graphics, images, audio and video, or any system for processing or interacting with such data. Often also includes concepts from hypertext. This term was once almost synonymous with CD-ROM in the personal computer world because the large amounts of data involved were best supplied on CD-ROM. DVDs and broadband Internet connections have now largely replaced CDs as the means of delivery. A "multimedia PC" typically includes software for playing DVD video, 5.1 audio hardware and can display video on a television. It may also include a television receiver and software to record broadcast television to disk and play it back. The Multimedia Personal Computer (MPC) standard was an attempt to improve compatibility between such systems. Usenet newsgroup: news:comp.multimedia. (1994-12-02) 1 1 1 1 1 Multimedia and Hypermedia information coding Expert Group (MHEG) is an ISO standard encoding for multimedia and hypermedia information, designed to facilitate use and interchange of such information in varied domains such as games, electronic publishing and medical applications. MHEG Home (http://mheg.org/). (2002-12-30) 1 1 1 1 1 MultiMedia Compact Disc (MMCD) A CD-ROM standard for storing 4.7 GB of data including video. MMCD is being developed by a large numer of computer manufacturers and is expected to be shipped in late 1996 or early 1997. Initially it will be aimed at the consumer market, then perhaps in CD-ROM format for computers, and maybe later on erasble CD. (1995-11-23) 1 1 1 1 1 MultiMedia Extension Matrix Math eXtensions 1 1 1 1 1 Multimedia Integrated Conferencing for European Researchers (MICE) A project which aims to create a pilot (virtual) network between European researchers, and also to connect them to sites in the US. The MICE system currently allows multimedia conferencing (audio, video and shared workspace) between conference rooms and workstation-based facilities, hardware and software, packet-switched networks and ISDN, using both unicast (point-to-point) and multicast (multi-point) protocols. (http://www-mice.cs.ucl.ac.uk/mice). (1997-12-18) 1 1 1 1 1 Multimedia Internet Mail Extensions Called Multipurpose Internet Mail Extensions in the RFC. [Is this an old name for it?] 1 1 1 1 1 Multimedia Messaging Services (MMS) A feature of some mobile telephones that allows them to send messages including text, sound, images and video. (2007-06-25) 1 1 1 1 1 Multimedia PC multimedia 1 1 1 1 1 Multimedia Personal Computer (MPC) A specification published by the Multimedia PC Marketing Council in 1990 to encourage the adoption of a standard multimedia computing platform. In May 1993, the MPC Marketing Council published a new specification called MPC Level 2 Specification as an enhanced multimedia computer standard. The original MPC specification, now also known as the MPC Level 1 Specification, continues in full effect. The appearance of the MPC or MPC2 certification mark on a computer system or upgrade kit indicates that the hardware meets the corresponding (Level 1 or Level 2) MPC Marketing Council specification. Software bearing the Multimedia PC mark has been designed to work on Multimedia PC licensed hardware. By establishing a standard platform, certifying hardware compliance and providing inter-operability between software and hardware for the consumer, the MPC Marketing Council is encouraging widespread use of multimedia applications and hardware. 1 1 1 1 1 multimedia system multimedia 1 1 1 1 1 multi-part key compound key 1 1 1 1 1 Multi-Pascal An extension of Pascal-S with multiprocessing features. Used in "The Art of Parallel Programming", Bruce P. Lester, P-H 1993. 1 1 1 1 1 multiple access multiplexing 1 1 1 1 1 Multiple Access with Colision Avoidance (MACA) A protocol used as a basis for the IEEE 802.11 wireless LAN standards. [Details?] (2004-01-14) 1 1 1 1 1 multiple boot dual boot 1 1 1 1 1 Multiple Document Interface (MDI) The ability of an application program to show windows giving views of more than one document at a time. The opposite is Single Document Interface (SDI). (1999-03-30) 1 1 1 1 1 multiple inheritance In object-oriented programming, the possibility that a class may have more than one direct superclass in the class hierarchy. The opposite is single inheritance. (2014-09-06) 1 1 1 1 1 Multiple Instruction Multiple Data Multiple Instruction/Multiple Data 1 1 1 1 1 Multiple Instruction/Multiple Data (MIMD) The classification under Flynn's taxonomy of a parallel processor where many functional units perform different operations on different data. Examples would be a network of workstations or transputers. Compare SIMD. (1994-11-08) 1 1 1 1 1 Multiple Master (Or "Multiple Master Font") A font that is a mixture of two or more other fonts. A Multiple Master font is a single font containing from two to sixteen master designs (the current implementation limit). A weight factor specifies the contribution of each master design for the creation of a multiple master font instance. A Multiple Master instance is a single interpolation of a multiple master font as created by a user or application. ATM Glossary (http://adobe.com/supportservice/devrelations/typeforum/glossary.html). Useable fonts (http://susi.informatik.rwth-aachen.de/Mirror/winsite/win3/fonts_atm.html). (1998-05-31) 1 1 1 1 1 multiple perspective software development A decentralised approach to software development which, instead of adopting a monolithic representation and centralised control, models development in terms of collaboration between autonomous partial systems. Software development usually involves people with different goals, expertise, and backgrounds, and the use of a wide range of formalisms, tools, and environments. As information is exchanged between participants, dependencies may be established between information created by them. Multiple perspective software development may be mapped into the transaction model which can be used to prevent uncoordinated access to interdependent information causing inconsistency. [Fox Wai-Leung Poon] (1995-12-14) 1 1 1 1 1 multiple value (MU) A one-to-many relationship between entries in a database, for example a person may have an address field which spanned multiple records (with different indexes). Multiple values are a non-relational technique. MUs have recently been made available in DB2, despite the product being so heavily influenced by Codd's Laws of relational databases. [Confirm, clarify?] (1995-10-30) 1 1 1 1 1 Multiple Virtual Storage (MVS) Release 2 of OS/VS2, called MVS because it had multiple 16 MB virtual address spaces, in contrast to SVS. MVS ran on the IBM 390 series mainframes. It became MVS/SP, then MVS/XA (with 31-bit addressing) and then MVS/ESA. MVS/Open Edition (MVS/OE), aimed at the growing open systems market, added TCP/IP and Unix support in an MVS address space, allowing users to run IBM, CICS-type applications, batch applications and Unix. MVS/ESA was repackaged as OS/390 as a marketing exercise but it's basically the same thing. Version: 5.1. [Features? Dates?] (1999-01-20) 1 1 1 1 1 multiplexer multiplexor 1 1 1 1 1 multiplexing 1. <communications> (Or "multiple access") Combining several signals for transmission on some shared medium (e.g. a telephone wire). The signals are combined at the transmitter by a multiplexor (a "mux") and split up at the receiver by a demultiplexor. The communications channel may be shared between the independent signals in one of several different ways: time division multiplexing, frequency division multiplexing, or code division multiplexing. If the inputs take turns to use the output channel (time division multiplexing) then the output bandwidth need be no greater than the maximum bandwidth of any input. If many inputs may be active simultaneously then the output bandwidth must be at least as great as the total bandwidth of all simultaneously active inputs. In this case the multiplexor is also known as a concentrator. (1995-03-02) 2. <storage> Writing multiple logical copies of data 1 1 1 1 1 multiplexor multiplexing 1 1 1 1 1 Multiplexor Channel (MPX) mainframe terminology for a slow peripheral device connection, e.g. for a printer, operator console, or card reader. (1997-06-30) 1 1 1 1 1 multiplex printer A duplex circuit using time-division multiplexing to provide multiple duplex channels over one wire. For example, channels A, B, C, and D could be used for simultaneous transmission in both directions. (2000-04-02) 1 1 1 1 1 Multipop-68 An early time-sharing operating system developed in Edinburgh by Robin Popplestone and others. It was inspired by MIT' Project MAC, via a "MiniMac" project which was aborted when it became obvious that Elliot Brothers Ltd. could not supply the necessary disk storage. Multipop was highly efficient in its use of machine resources to support symbolic programming, and effective - e.g. in supporting the development of the Boyer-Moore theorem prover and of Burstall and Darlington's transformation work. It was not good at supporting the user programs which were then the standard fare of computing, e.g. matrix inversion. This arose from the fact that while the POP-2 compiler generated good code for function call (which is a lot of what layered systems like operating systems do) it did not generate efficient code for arithmetic or store access, because there was no way to police the generation of illegal objects statically. (Hindley-Milner type checking did not exist). 1 1 1 1 1 multiprocessing parallel processing 1 1 1 1 1 multiprocessor parallel processing 1 1 1 1 1 multiprogramming multitasking 1 1 1 1 1 Multiprotocol Label Switching (MPLS) A packet switching protocol developed by the IETF. Initially developed to improve switching speed, other benefits are now seen as being more important. MPLS adds a 32-bit label to each packet to improve network efficiency and to enable routers to direct packets along predefined routes in accordance with the required quality of service. The label is added when the packet enters the MPLS network, and is based on an analysis of the packet header. The label contains information on the route along which the packet may travel, and the forwarding equivalence class (FEC) of the packet. Packets with the same FEC are routed through the network in the same way. Routers make forwarding decisions based purely on the contents of the label. This simplifies the work done by the router, leading to an increase in speed. At each router, the label is replaced with a new label, which tells the next router 1 1 1 1 1 Multipurpose Internet Mail Extensions (MIME) A standard for multi-part, multimedia electronic mail messages and web hypertext documents on the Internet. MIME provides the ability to transfer non-textual data, such as graphics, audio and fax. It is defined in RFC 2045, RFC 2046, RFC 2047, RFC 2048, RFC 2049, and BCP0013. It uses mimencode to encode binary data into base 64 using a subset of ASCII. FAQ (http://cis.ohio-state.edu/hypertext/faq/usenet/mail/mime-faq/top.html). (1995-04-04) 1 1 1 1 1 multiscan A monitor that can synchronise to a variety of horizontal scan rates and refresh rates, allowing it to display images at different resolutions. (1996-02-09) 1 1 1 1 1 MultiScheme An implementation of Multilisp built on MIT's C-Scheme, for the BBN Butterfly. ["MultiScheme: A Paralled Processing System Based on MIT Scheme", J. Miller, TR-402, MIT LCS, Sept 1987]. (1995-04-04) 1 1 1 1 1 Multistation Access Unit Media Access Unit 1 1 1 1 1 multisync An NEC trademark term for multiscan. As NEC was the first to manufacture multiscan monitors the term is often used interchangeably with multiscan. (1996-02-09) 1 1 1 1 1 Multisystem eXtention Interface Bus (MXIbus) A high performance communication link that interconnects devices using round, flexible cable. MXIbus is used between a GPIB card and a VXI cage. (1999-10-12) 1 1 1 1 1 multitasking (Or "multi-tasking", "multiprogramming", concurrent processing, "concurrency", "process scheduling") A technique used in an operating system for sharing a single processor between several independent jobs. The first multitasking operating systems were designed in the early 1960s. Under "cooperative multitasking" the running task decides when to give up the CPU and under "pre-emptive multitasking" (probably more common) a system process called the scheduler suspends the currently running task after it has run for a fixed period known as a "time-slice". In both cases the scheduler is responsible for selecting the next task to run and (re)starting it. The running task may relinquish control voluntarily even in a pre-emptive system if it is waiting for some external event. In either system a task may be suspended prematurely if a hardware interrupt occurs, especially if a higher priority 1 1 1 1 1 Multi-tasking Program for Microcomputers (MP/M) An operating system, written by Gary Kildal, very similar to CP/M, also written by Kildal. MP/M allowed virtual terminals, each of which could execute an application while another terminal was called to the screen with a special key combination. See also Control Program for Microcomputers. (1996-09-08) 1 1 1 1 1 multithreaded multithreading 1 1 1 1 1 multithreading Sharing a single CPU between multiple tasks (or threads) in a way designed to minimise the time required to switch threads. This is accomplished by sharing as much as possible of the program execution environment between the different threads so that very little state needs to be saved and restored when changing thread. Multithreading differs from multitasking in that threads share more of their environment with each other than do tasks under multitasking. Threads may be distinguished only by the value of their program counters and stack pointers while sharing a single address space and set of global variables. There is thus very little protection of one thread from another, in contrast to multitasking. Multithreading can thus be used for very fine-grain multitasking, at the level of a few instructions, and so can hide latency by keeping the processor busy after one thread issues a long-latency instruction on which subsequent instructions in that 1 1 1 1 1 MultiTOS (MTOS) A new version of TOS. MultiTOS's main advantage was support for pre-emptive multitasking and memory protection. It also supported the latest (and far superior) versions of GEM. MultiTOS was supplied with the Falcon030 range of computers from Atari. It is a little known fact that the MultiTOS kernel was based heavily on the freeware OS MinT which was developed long before Atari got MultiTOS working. (1997-01-10) 1 1 1 1 1 multi-user A term describing an operating system or application program that can be used by several people concurrently; opposite of single-user. Unix is an example of a multi-user operating system, whereas most (but not all) versions of Microsoft Windows are intended to support only one user at a time. A multi-user system, by definition, supports concurrent processing of multiple tasks (once known as "time-sharing") or true parallel processing if it has multiple CPUs. While batch processing systems often ran jobs for serveral users concurrently, the term "multi-user" typically implies interactive access. Before Ethernet networks were commonplace, multi-user systems were accessed from a terminal (e.g. a vt100) connected via a serial line (typically RS-232). This arrangement was eventually superseded by networked personal computers, perhaps sharing files on a file server. With 1 1 1 1 1 Multi-User Dimension (MUD) (Or Multi-User Domain, originally "Multi-User Dungeon") A class of multi-player interactive game, accessible via the Internet or a modem. A MUD is like a real-time chat forum with structure; it has multiple "locations" like an adventure game and may include combat, traps, puzzles, magic and a simple economic system. A MUD where characters can build more structure onto the database that represents the existing world is sometimes known as a "MUSH". Most MUDs allow you to log in as a guest to look around before you create your own character. Historically, MUDs (and their more recent progeny with names of MU- form) derive from a hack by Richard Bartle and Roy Trubshaw on the University of Essex's DEC-10 in 1979. It was a game similar to the classic Colossal Cave adventure, except that it allowed multiple people to play at the same time and interact with each other. Descendants of that game still exist today and are sometimes generically called 1 1 1 1 1 Multi-User Dungeon Multi-User Dimension 1 1 1 1 1 Multi-User Shared Hallucination (MUSH) A user-extendable MUD. A MUSH provides commands which the players can use to construct new rooms or make objects and puzzles for other players to explore. (http://cis.upenn.edu/~lwl/muds.html). (1995-03-16) 1 1 1 1 1 Multi-Version Concurrency Control (MVCC) An advanced technique for improving multi-user database performance. The main difference between multiversion and lock models is that in MVCC locks acquired for querying (reading) data don't conflict with locks acquired for writing data and so reading never blocks writing and writing never blocks reading. This technique is used in the free software database PostgreSQL. (1999-06-18) 1 1 1 1 1 multi-way branch switch statement 1 1 1 1 1 MuMath A symbolic mathematics package for the IBM PC, written in MuSimp. (1995-04-12) 1 1 1 1 1 mumblage /muhm'bl*j/ The topic of one's mumbling (see mumble). "All that mumblage" is used like "all that stuff" when it is not quite clear how the subject of discussion works, or like "all that crap" when "mumble" is being used as an implicit replacement for pejoratives. [Jargon File] 1 1 1 1 1 mumble 1. Said when the correct response is too complicated to enunciate, or the speaker has not thought it out. Often prefaces a longer answer, or indicates a general reluctance to get into a long discussion. "Don't you think that we could improve LISP performance by using a hybrid reference-count transaction garbage collector, if the cache is big enough and there are some extra cache bits for the microcode to use?" Well, mumble ... I'll have to think about it. 2. Yet another metasyntactic variable, like foo. 3. Sometimes used in "public" contexts on-line as a placefiller for things one is barred from giving details about. For example, a poster with pre-released hardware in his machine might say "Yup, my machine now has an extra 16M of memory, thanks to the card I'm testing for Mumbleco." 4. A conversational wild card used to designate something one doesn't want to bother spelling out, but which can be glarked from context. Compare blurgle. 1 1 1 1 1 mumble mode The mode a program, piece of hardware, or other system is said to be in when it is still running and perhaps reacting to input and/or occasionally producing output (especially if it shouldn't), but in a way that appears wildly inappropriate to the task it is supposed to perform. Compare "off the trolley" and "deep space". (1997-03-27) 1 1 1 1 1 MUMPS (Or "M") Massachusetts General Hospital Utility Multi-Programming System. A programming language with extensive tools for the support of database management systems. MUMPS was originally used for medical records and is now widely used where multiple users access the same databases simultaneously, e.g. banks, stock exchanges, travel agencies, hospitals. Early MUMPS implementations for PDP-11 and IBM PC were complete operating systems, as well as programming languages, but current-day implementations usually run under a normal host operating system. A MUMPS program hardly ever explicitly performs low-level operations such as opening a file - there are programming constructs in the language that will do so implicitly, and most MUMPS programmers are not even aware of the operating system activity that MUMPS performs. Syntactically MUMPS has only one data-type: strings. 1 1 1 1 1 munch To transform information in a serial fashion, often requiring large amounts of computation. To trace down a data structure. Related to crunch and nearly synonymous with grovel, but connotes less pain. Often confused with mung. [Jargon File] (1995-01-10) 1 1 1 1 1 munching Exploration of security holes of someone else's computer for thrills, notoriety or to annoy the system manager. Compare cracker. See also hacked off. [Jargon File] 1 1 1 1 1 munching squares A display hack dating back to the PDP-1 (ca. 1962, reportedly discovered by Jackson Wright), which employs a trivial computation (repeatedly plotting the graph Y = X XOR T for successive values of T - see HAKMEM items 146--148) to produce an impressive display of moving and growing squares that devour the screen. The initial value of T is treated as a parameter, which, when well-chosen, can produce amazing effects. Some of these, later (re)discovered on the LISP Machine, have been christened "munching triangles" (try AND for XOR and toggling points instead of plotting them), munching w's, and "munching mazes". More generally, suppose a graphics program produces an impressive and ever-changing display of some basic form, foo, on a display terminal, and does it using a relatively simple program; then the program (or the resulting display) is likely to be referred to as munching foos. [This is a good example of the use of the word foo as a metasyntactic variable.] 1 1 1 1 1 munchkin /muhnch'kin/ [Squeaky-voiced little people in L. Frank Baum's The Wizard of Oz] A teenage-or-younger micro enthusiast hacking BASIC or something else equally constricted. A term of mild derision - munchkins are annoying but some grow up to be hackers after passing through a larval stage. The term urchin is also used. See also wannabee, bitty box. [Jargon File] 1 1 1 1 1 mundane Someone outside some group that is implicit from the context, such as the computer industry or science fiction fandom. The implication is that those in the group are special and those outside are just ordinary. (2000-07-22) 1 1 1 1 1 mung /muhng/ (MIT, 1960) Mash Until No Good. Sometime after that the derivation from the recursive acronym "Mung Until No Good" became standard. 1. To make changes to a file, especially large-scale and irrevocable changes. See BLT. 2. To destroy, usually accidentally, occasionally maliciously. The system only mungs things maliciously; this is a consequence of Finagle's Law. See scribble, mangle, trash, nuke. Reports from Usenet suggest that the pronunciation /muhnj/ is now usual in speech, but the spelling "mung" is still common in program comments (compare the widespread confusion over the proper spelling of kluge). 3. The kind of beans of which the sprouts are used in Chinese food. (That's their real name! Mung beans! Really!) Like many early hacker terms, this one seems to have 1 1 1 1 1 munge /muhnj/ 1. A derogatory term meaning to imperfectly transform information. 2. A comprehensive rewrite of a routine, data structure or the whole program. This term is often confused with mung and may derive from it, or possibly vice-versa. One correspondent believes it derives from the french "mange" /monzh/, eat. [Jargon File] (2002-04-15) 1 1 1 1 1 MUP Multiple Universal naming convention Provider 1 1 1 1 1 MU-Prolog Prolog with "wait" declarations for coroutining, developed by L. Naish of the Univeristy of Melbourne in 1982. ["Negation and Control in Prolog", L. Naish, TR 85/12, U Melbourne (1985)]. See NU-Prolog. (1998-02-14) 1 1 1 1 1 Murphy's Law (Or "Sod's Law") The correct, *original* Murphy's Law reads: "If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it." This is a principle of defensive design, cited here because it is usually given in mutant forms less descriptive of the challenges of design for lusers. For example, you don't make a two-pin plug symmetrical and then label it "THIS WAY UP"; if it matters which way it is plugged in, then you make the design asymmetrical (see also the anecdote under magic smoke). Edward A. Murphy, Jr. was one of the engineers on the rocket-sled experiments that were done by the US Air Force in 1949 to test human acceleration tolerances (USAF project MX981). One experiment involved a set of 16 accelerometers mounted to different parts of the subject's body. There were two ways each sensor could be glued to its mount, and somebody methodically installed all 16 the wrong way around. Murphy 1 1 1 1 1 Muse OR-parallel logic programming. [Details?] (1995-03-16) 1 1 1 1 1 museum Museums on the Web (http://comlab.ox.ac.uk/archive/other/museums.html). (http://galaxy.einet.net/GJ/museums.html). (1995-03-16) 1 1 1 1 1 MUSH 1. <games> Multi-User Shared Hallucination. 2. <messaging> Mail Users' Shell. 1 1 1 1 1 Music A series of languages for musical sound synthesis from Bell Labs, 1960's. Versions: Music I through Music V. ["An Acoustical Compiler for Music and Psychological Stimuli", M.V. Mathews, Bell Sys Tech J 40 (1961)]. [Jargon File] (1999-06-04) 1 1 1 1 1 Musical Instrument Digital Interface (MIDI /mi'-dee/, /mee'-dee/) A hardware specification and protocol used to communicate note and effect information between synthesisers, computers, music keyboards, controllers, and other electronic music devices. It is basically a high-speed serial connection with separate connections for MIDI in, MIDI out and MIDI through (to allow devices to be chained). The basic unit of information is a "note on/off" event which includes a note number (pitch) and key velocity (loudness). There are many other message types for events such as pitch bend, patch changes and synthesizer-specific events for loading new patches etc. There is a file format for expressing MIDI data which is like a dump of data sent over a MIDI port. The MIME type "audio/midi" isn't actually registered so it should probably be "audio/x-midi". Filename extension: .mid or .midi 1 1 1 1 1 Musicam A name for MPEG-1 Layer 2 used for broadcasting. Common data rates are 192, 224, and 256 kbps. (2001-12-13) 1 1 1 1 1 MuSimp A Lisp variant used as the programming language for the IBM PC symbolic mathematics package MuMath. (1995-04-12) 1 1 1 1 1 MUSL Manchester University Systems Language 1 1 1 1 1 mutant Microsoft's term for a mutex which is generally used in user mode but can also be used in kernel mode. According to this terminology a mutex is only used in kernel mode. ["Microsoft Windows NT Workstation Resource Kit"]. (1997-07-30) 1 1 1 1 1 Mutation Testing A method to determine test set thoroughness by measuring the extent to which a test set can discriminate the program from slight variants of the program. (1996-12-27) 1 1 1 1 1 MuTeX An extension of TeX for typesetting music. (ftp://nic.stolaf.edu/pub/mutex/MuTeX.tar.Z). (1995-02-06) 1 1 1 1 1 mutex A mutual exclusion object that allows multiple threads to synchronise access to a shared resource. A mutex has two states: locked and unlocked. Once a mutex has been locked by a thread, other threads attempting to lock it will block. When the locking thread unlocks (releases) the mutex, one of the blocked threads will acquire (lock) it and proceed. If multiple threads or tasks are blocked on a locked mutex object, the one to take it and proceed when it becomes available is determined by some type of scheduling algorithm. For example, in a priority based system, the highest priority blocked task will acquire the mutex and proceed. Another common set-up is put blocked tasks on a first-in-first-out queue. See also: priority inversion (2002-03-14) 1 1 1 1 1 mutter To quietly enter a command not meant for the ears, eyes, or fingers of ordinary mortals. Often used in "mutter an incantation". See also wizard. [Jargon File] (1995-02-06) 1 1 1 1 1 mutual exclusion (Or "mutex", plural: "mutexes") A collection of techniques for sharing resources so that different uses do not conflict and cause unwanted interactions. One of the most commonly used techniques for mutual exclusion is the semaphore. (1995-04-08) 1 1 1 1 1 mutually recursive recursion 1 1 1 1 1 mutual recursion recursion 1 1 1 1 1 mux multiplexing 1 1 1 1 1 mv 1. operating system The Unix command to move or rename files or directories. 2. <networking> The country code for Maldives. (2014-11-27) 1 1 1 1 1 MV* A shorthand for a design pattern that may be either MVC or MVP or some other variation. (2014-11-27) 1 1 1 1 1 MVC 1. <programming> Model-View-Controller. 2. <filename extension> The filename extension of JPEG images output by Sony's Mavica range of digital cameras. (2002-05-28) 1 1 1 1 1 MVCC Multi-Version Concurrency Control 1 1 1 1 1 MVP Model-View-Presenter 1 1 1 1 1 MVS Multiple Virtual Storage 1 1 1 1 1 MVS/ESA Multiple Virtual Storage 1 1 1 1 1 MVS/OE Multiple Virtual Storage 1 1 1 1 1 MVS/Open Edition Multiple Virtual Storage 1 1 1 1 1 MVS/SP Multiple Virtual Storage 1 1 1 1 1 MVS/XA Multiple Virtual Storage 1 1 1 1 1 mw The country code for Malawi. (1999-01-27) 1 1 1 1 1 MX Mail Exchange Record 1 1 1 1 1 mx The country code for Mexico. (1999-01-27) 1 1 1 1 1 MXI Multisystem eXtention Interface Bus 1 1 1 1 1 MXIbus Multisystem eXtention Interface Bus 1 1 1 1 1 MX Record Mail Exchange Record 1 1 1 1 1 my The country code for Malaysia. (1999-01-27) 1 1 1 1 1 My Favourite Toy Language (MFTL) Describes a talk on a programming language design that is heavy on syntax (with lots of BNF), sometimes even talks about semantics (e.g. type systems), but rarely, if ever, has any content (see content-free). More broadly applied to talks - even when the topic is not a programming language --- in which the subject matter is gone into in unnecessary and meticulous detail at the sacrifice of any conceptual content. "Well, it was a typical MFTL talk". 2. A language about which the developers are passionate (often to the point of prosyletic zeal) but no one else cares about. Applied to the language by those outside the originating group. "He cornered me about type resolution in his MFTL." The first great goal in the mind of the designer of an MFTL is usually to write a compiler for it, then bootstrap the design away from contamination by lesser languages by writing a compiler for it in itself. Thus, the standard put-down 1 1 1 1 1 MYOB mind your own business. (2006-11-22) 1 1 1 1 1 MySpace A social networking website based in Beverly Hills, California, USA. MySpace home (http://myspace.com/). (2006-11-22) 1 1 1 1 1 MySQL /mi: S Q L/ The most popular open source relational database management system. MySQL is developed, distributed, and supported by MySQL AB. MySQL was named after co-founder Monty Widenius's daughter, My. It was originally written as a backwards compatible replacement for mSQL. It is written in C, C++ and yacc. It has become popular for use in web applications. MySQL supports a broad subset of ANSI SQL 99 and features views, stored procedures, triggers, cursors, replication, internationalisation and localisation, partitioning, ACID transactions. MySQL can be embedded in other systems or run on a cluster for fault tolerance. A commercial version, MySQL Enterprise is available. Latest version: 6.0, as of 2009-05-11. MySQL Home (http://mysql.com/). (2009-05-11) 1 1 1 1 1 MySQL AB The Swedish company that developes, distributes and supports the MySQL open source rdbms. MySQL AB is a subsidiary of Sun Microsystems, themselves acquired by Oracle Corporation on 2009-04-20. (2009-05-11) 1 1 1 1 1 MYSTIC An early system on the IBM 704, IBM 650, IBM 1103 and 1103A. [Listed in CACM 2(5):16, May 1959]. (1995-03-07) 1 1 1 1 1 MZ The file signature of an MS-DOS executable (.EXE) file (0x4d 5a), always the first two bytes of the file. It was reportedly invented by, and named after, a Microsoft programmer, Mark Zbikowski. In Unix systems, the string MZ is the magic number that identifies an MS-DOS EXE file. (2003-06-10) 1 1 1 1 1 mz The country code for Mozambique. (1999-01-27) 1 1 1 1 1 N A variable typically used to stand for a number of objects. Used unqualified in speech it suggests a large, undetermined number, e.g. "There were N bugs in that crock!", or a number implied by context, e.g. "Let's get pizza for N + 1". [Jargon File] (2006-04-18) 1 1 1 1 1 N10 Original codename of the Intel i860 microprocessor. 1 1 1 1 1 na The country code for Namibia. (1999-01-27) 1 1 1 1 1 nadger /nad'jr/ [Great Britain] To modify software or hardware in a hidden manner, generally so that it conforms better to some format. For instance, an assembly code string printing subroutine that takes its string argument from the instruction stream would be called like this: jsr print:"Hello world" The print routine would use the saved instruction pointer (its return address) to find its argument and would have to "nadger" it so that the processor returns to the instruction after the string. [Jargon File] (2014-07-09) 1 1 1 1 1 NAG 1. Numerical Algorithms Group. 2. The Linux Network Administrators' Guide. 1 1 1 1 1 Nagling Coalescence An algorithm for improving TCP/IP network performance by combining small packets ("tinygrams") into larger ones, thus reducing the per-packet overhead. The server transmits the packet either when it has reached a preset size or when it receives an acknowledgment of the previous packet. [Who was Nagling?] (1998-11-06) 1 1 1 1 1 nagware /nag'weir/ A term, originally from Usenet, for the variety of shareware that displays a message on start-up and/or termination reminding you to register, pay or donate (see guiltware). Sometimes user interaction is required to dismiss the nag in order to use the program, making it useless in batch mode. Nagware may also be crippleware, with a message nagging you pay to upgrade to the full or "pro" version. [Jargon File] (2015-01-17) 1 1 1 1 1 nailed to the wall [like a trophy] Said of a bug finally eliminated after protracted, and even heroic, effort. 1 1 1 1 1 nailing jelly like nailing jelly to a tree 1 1 1 1 1 naive Untutored in the perversities of some particular program or system; one who still tries to do things in an intuitive way, rather than the right way (in really good designs these coincide, but most designs aren't "really good" in the appropriate sense). This trait is completely unrelated to general maturity or competence or even competence at any other specific program. It is a sad commentary on the primitive state of computing that the natural opposite of this term is often claimed to be "experienced user" but is really more like cynical user. (1994-11-29) 1 1 1 1 1 naive user A luser. Tends to imply someone who is ignorant mainly owing to inexperience. When this is applied to someone who *has* experience, there is a definite implication of stupidity. [Jargon File] 1 1 1 1 1 NAK Negative Acknowledgement 1 1 1 1 1 name capture In beta reduction, when a term containing a free occurrence of a variable v is substituted into another term where v is bound the free v becomes spuriously bound or captured. E.g. (\ x . \ y . x y) y --> \ y . y y (WRONG) This problem arises because two distinct variables have the same name. The most common solution is to rename the bound variable using alpha conversion: (\ x . \ y' . x y') y --> \ y' . y y' Another solution is to use de Bruijn notation. Note that the argument expression, y, contained a free variable. The whole expression above must therefore be notionally contained within the body of some lambda abstraction which binds y. If we never reduce inside the 1 1 1 1 1 named Name Daemon. <networking> A Unix background process that converts hostnames to Internet addresses for the TCP/IP protocol. Unix manual page: named(8). See also DNS. (1995-03-28) 1 1 1 1 1 named pipe A Unix pipe with a filename created using the "mknod" command. Named pipes allow unrelated processes to communicate with each other whereas the normal (un-named) kind can only be used by processes which are parent and child or siblings (forked from the same parent). (1996-12-01) 1 1 1 1 1 name resolution The process of mapping a name into its corresponding address. The Domain Name System is the system which does name resolution on the Internet. (1997-12-15) 1 1 1 1 1 name service switching Domain Name System 1 1 1 1 1 namespace The set of all possible identifiers for some kind of object. From the definition of a set, all names in a namespace are unique and there is some rule to determine whether a potential name is an element of the set. For example, the Domain Name System includes rules for determining what constitutes a valid host name. (2008-12-09) 1 1 1 1 1 naming convention 1. <programming> variable naming convention. 2. <networking> Universal Naming Convention. 1 1 1 1 1 NaN Not-a-Number 1 1 1 1 1 NAND Not AND. The Boolean function which is true unless both its arguments are true, the logical complement of AND: A NAND B = NOT (A AND B) = (NOT A) OR (NOT B) Its truth table is: A | B | A NAND B --+---+--------- F | F | T F | T | T T | F | T 1 1 1 1 1 nano- /nan'oh/ 1. <unit> A prefix meaning 10^-9 or one billionth. Used loosely to mean "small", e.g. nanotechnology, or (rarely), following "nanosecond", to mean a short time, e.g. "I'll be with you in a nano". [Jargon File] (2002-03-02) 1 1 1 1 1 nanoacre /nan'oh-ay"kr/ A unit (about 2 mm square) of real estate on a VLSI integrated circuit. VLSI nanoacres have costs in the same range as real acres once one allows for design and fabrication setup costs. [Jargon File] (1995-09-20) 1 1 1 1 1 nanobot /nan"oh-bot/ A robot of microscopic proportions, presumably built by means of nanotechnology. As yet, only used informally (and speculatively!). Also called a nanoagent. [Jargon File] (1999-07-19) 1 1 1 1 1 nanocomputer /nan'oh-k*m-pyoo'tr/ A computer with molecular-sized switching elements. Designs for mechanical nanocomputers which use single-molecule sliding rods for their logic have been proposed. The controller for a nanobot would be a nanocomputer. Some nanocomputers can also be called quantum computers because quantum physics plays a major role in calculations. Richard P. Feynman is still cited today for his work in this area. ["Feynman Lectures on Computation", Richard P. Feynman (Editor, Author), Robin W. Allen (Editor), Tony Hey (Author)] [Jargon File] (2008-01-14) 1 1 1 1 1 nanofortnight (Adelaide University) 10^-9 fortnights or about 1.2 milliseconds. This unit was used largely by students doing undergraduate practicals. See microfortnight, attoparsec, and micro-. (1996-11-15) 1 1 1 1 1 nanometre 10^-9 metres; one thousand millionth part of a metre. The wavelength of visible light and dimensions in nanotechnology are typically measured in nanometres. (2003-05-02) 1 1 1 1 1 nanosecond (ns) 10^-9 seconds; one thousand millionth part of a second. This is the unit in which the fundamental logical operations of modern digital circuits are typically measured. For example, a microprocessor with a clock frequency of 100 megahertz will have a 10 nanosecond clock period. (1996-11-15) 1 1 1 1 1 nanotechnology /nan'-oh-tek-no"l*-jee/ Any fabrication technology in which objects are designed and built by the specification and placement of individual atoms or molecules or where at least one dimension is on a scale of nanometers. The first unequivocal nanofabrication experiments took place in 1990, for example with the deposition of individual xenon atoms on a nickel substrate to spell the logo of a certain very large computer company. Richard P. Feynman's initial public discussion in 1959-12-29 (http://www.zyvex.com/nanotech/feynman.html) lead to the Feynman Prize for Nanotechnology (http://www.foresight.org/FI/fi_spons.html). Erik Drexler coined the term about 30 years later in his book "Engines of Creation", where he predicted that nanotechnology could give rise to replicating assemblers, permitting an exponential growth of productivity and personal wealth. See also nanobot. 1 1 1 1 1 Napier Atkinson & Morrison, St Andrews U; design began ca. 1985, first implementation Napier88, 1988. Based on orthogonal persistence, permits definition and manipulation of namespaces. ["The Napier88 Reference Manual", R. Morrison et al, CS Depts St Andrews U and U Glasgow, Persistent Programming Research Report PPRR-77-89, 1989]. 1 1 1 1 1 NAPLPS North American Presentation-Level-Protocol Syntax. Format for sending text and graphics over communication lines. Used by videotex systems. 1 1 1 1 1 NAPSS Numerical Analysis Problem Solving System. Purdue ca. 1965. ["NAPSS - A Numerical Analysis Problem Solving System", J.R. Rice et al, Proc ACM 21st Natl Conf, 1966. Sammet 1969, p.299]. 1 1 1 1 1 narrowband A communication channel with a low data rate. [More specific?] The term is sometimes used for an Internet connection via a dial-up modem, typically at 56 kbaud, in contrast to broadband. (2003-10-15) 1 1 1 1 1 narrowing Unification followed by unfolding. The left-hand side of a rule is unified with some term, resulting in a set of variable bindings. The term is then replaced by the right-hand side of the rule with values substituted for bound variables. (2015-01-23) 1 1 1 1 1 NAS 1. Network Application Support. 2. <storage> Network Attached Storage. 3. <company> National Advanced Systems. (2003-07-20) 1 1 1 1 1 nasal demons Recognised shorthand on the Usenet group comp.std.c for any unexpected behaviour of a C compiler on encountering an undefined construct. During a discussion on that group in early 1992, a regular remarked "When the compiler encounters [a given undefined construct] it is legal for it to make demons fly out of your nose" (the implication is that the compiler may choose any arbitrarily bizarre way to interpret the code without violating the ANSI C standard). Someone else followed up with a reference to "nasal demons", which quickly became established. [Jargon File] 1 1 1 1 1 NASI NetWare Asynchronous Services Interface Novell NetWare. 1 1 1 1 1 nastistical A description of a method, thought by the programmer to be correct statistics, but which is not. An example is averaging together several averages of samples of different sizes. The correct way to do this is to average together all of the individual samples. (1997-02-12) 1 1 1 1 1 NASTRAN NAsa STRess ANalysis program. A program for solving large stress analysis problems. ["The NASTRAN User's Manual", SP-222(C3), NASA, 1976]. 1 1 1 1 1 nastygram /nas'tee-gram/ 1. A network packet or e-mail message (the latter is also called a letterbomb) that takes advantage of misfeatures or security holes on the target system to do untoward things. 2. Disapproving e-mail, especially from a net.god, pursuant to a violation of netiquette or a complaint about failure to correct some mail- or news-transmission problem. Compare shitogram, mailbomb. 3. A status report from an unhappy, and probably picky, customer. "What did Corporate say in today's nastygram?" 4. [deprecated] An error reply by mail from a daemon; in particular, a bounce message. [Jargon File] (2004-02-17) 1 1 1 1 1 NAT Network Address Translation 1 1 1 1 1 Nathan Hale An asterisk ("*", see also splat, ASCII). Notionally, from "I regret that I have only one asterisk for my country!" ("life to give" -> "ass to risk" -> "asterisk"), a misquote of the famous remark uttered by Nathan Hale just before he was hanged. Hale was a (failed) spy for the rebels in the American War of Independence. [Jargon File] (1996-09-22) 1 1 1 1 1 National Advanced Systems (NAS) A company, previously known as ITEL, that made IBM plug-compatible hardware and was bought by Hitachi. [Is this correct? Dates? US?] (2003-07-20) 1 1 1 1 1 National Bureau of Standards National Institute of Standards and Technology 1 1 1 1 1 National Center for Supercomputing Applications (NCSA) The birthplace of the first version of the Mosaic web browser. Address: Urbana, IL, USA. (http://ncsa.uiuc.edu/). [Summary?] (1994-10-27) 1 1 1 1 1 national characters Characters with accents and other diacritical marks that are used in certain written languages (that are based on the Roman alphabet) but not in others, particularly not in English. A standard list is ISO Latin 1. (1996-06-24) 1 1 1 1 1 National Database Language (NDL) A US standard for portability of database definitions and application programs. (1996-06-24) 1 1 1 1 1 National Information Infrastructure (NII, or "information superhighway") Future integrated communications in the USA. The NII will be based on a nationwide network of networks, and will supposedly allow all Americans to take advantage of the country's information, communication, and computing resources. The NII will include current and future public and private high-speed, interactive, narrow-band and broadband networks. It is the satellite, terrestrial, and wireless communications systems that deliver content to homes, businesses, and other public and private institutions. It is the information and content that flows over the infrastructure whether in the form of databases, the written word, a film, a piece of music, a sound recording, a picture, or computer software. It is the computers, televisions, telephones, radios, and other products that people will employ to access the infrastructure. It is the people who will provide, manage, and generate new information, and those that will help 1 1 1 1 1 National Information Services and Systems (NISS) An information archive service at Bath University, intended primarily for UK eductional institutions. (http://niss.ac.uk/). (1994-11-23) 1 1 1 1 1 National Institute of Standards and Technology (NIST, formerly the National Bureau of Standards) A United States governmental body that helps develop standards including FIPS. NIST Home (http://nist.gov/). (2003-06-04) 1 1 1 1 1 National Research and Education Network (NREN) The realisation of an interconnected gigabit computer network devoted to High Performance Computing and Communications. See also HPPC, IINREN. (1994-11-23) 1 1 1 1 1 National Science Foundation (NSF) A US government agency that promotes the advancement of science by funding science researchers, scientific projects and infrastructure to improve the quality of scientific research. The NSFNET is funded by NSF. (http://nsf.org/). (1999-01-15) 1 1 1 1 1 National Science Foundation Network (NSFNET) A high speed hierarchical "network of networks" in the US, funded by the National Science Foundation. At the highest level, it is a backbone network comprising 16 nodes connected to a 45Mb/s facility which spans the continental United States. Attached to that are mid-level networks and attached to the mid-levels are campus and local networks. NSFNET also has connections out of the US to Canada, Mexico, Europe, and the Pacific Rim. The NSFNET is part of the Internet. (1993-01-01) 1 1 1 1 1 National Semiconductor A semiconductor manufacturer, responsible for the SC/MP, National Semiconductor 16000 and National Semiconductor 32000 series of microprocessors. (2005-06-09) 1 1 1 1 1 National Semiconductor 32000 (NS32000) <processor> The first of a series of microprocessors from National Semiconductor. The 320xx processors have an interface which allows coprocessors such as FPUs and MMUs to be attached in a chain. The 320xx was the predecessor of the Swordfish processor. [Details?] (1994-11-17) 1 1 1 1 1 National Software Reuse Directory (NSRD) A directory of reusable software in the ASSET system. (1995-02-03) 1 1 1 1 1 National Spatial Data Infrastructure (NSDI) (http://fgdc.er.usgs.gov/nsdiover.html). [Summary?] (1995-03-06) 1 1 1 1 1 National Television Standards Committee (NTSC) The body defining the television video signal format used in the USA. The UK equivalent is PAL. Also, humorously, "Never Twice the Same Colour". (1997-07-17) 1 1 1 1 1 native compiler A compiler which runs on the computer for which it is producing machine code, in contrast to a cross-compiler, which produces code for a different computer. (1995-11-04) 1 1 1 1 1 Native Language System (NLS) A set of interfaces specified by X/Open for developing applications to run in different natural language environments. (1995-02-03) 1 1 1 1 1 NATURAL An integrated 4GL from Software AG, Germany. The menu-driven version is SUPER/NATURAL. Natural 2 is a major upgrade to Natural 1. Version 2.1.7 in the MVS environment (June 1995, also available for Unix). Natural works with DB2 and various other databases, but Natural and Adabas normally go together. There are many products available in the "Natural" family, including SuperNatural, Natural for Windows, Entire Connection (enables up/downloading and interaction with Excel) and Esperant. (1995-11-14) 1 1 1 1 1 natural deduction A set of rules expressing how valid proofs may be constructed in predicate logic. In the traditional notation, a horizontal line separates premises (above) from conclusions (below). Vertical ellipsis (dots) stand for a series of applications of the rules. "T" is the constant "true" and "F" is the constant false (sometimes written with a LaTeX \perp). ^ is the AND (conjunction) operator, "v" is the inclusive OR (disjunction) operator and "/" is NOT (negation or complement, normally written with a LaTeX \neg). P, Q, P1, P2, etc. stand for propositions such as "Socrates was a man". P[x] is a proposition possibly containing instances of the variable x, e.g. "x can fly". A proof (a sequence of applications of the rules) may be enclosed in a box. A boxed proof produces conclusions that are only valid given the assumptions made inside the box, however, the proof demonstrates certain relationships which 1 1 1 1 1 Natural English Programming in normal, spoken English. [Sammet 1969, p.768]. 1 1 1 1 1 natural language A language spoken or written by humans, as opposed to a language use to program or communicate with computers. Natural language understanding is one of the hardest problems of artificial intelligence due to the complexity, irregularity and diversity of human language and the philosophical problems of meaning. See also Pleuk grammar development system, proof, MIT Start Project (http://start.csail.mit.edu/), New York U (http://nyu.edu/pages/linguistics/ling.html). (2011-01-30) 1 1 1 1 1 Natural Language Information Analysis Method (NIAM, or Nijssen IAM) A method for data modelling. ["Conceptual Scheme and Relational Database Design", Nijssen and Halpin, Prentice-Hall, 1989]. (1995-03-31) 1 1 1 1 1 natural language processing (NLP) Computer understanding, analysis, manipulation, and/or generation of natural language. This can refer to anything from fairly simple string-manipulation tasks like stemming, or building concordances of natural language texts, to higher-level AI-like tasks like processing user queries in natural language. (1997-09-12) 1 1 1 1 1 natural number An integer greater than or equal to zero. A natural number is an isomorphism class of a finite set. (1995-03-25) 1 1 1 1 1 nature has the X nature 1 1 1 1 1 NAU 1. Network Addressable Unit. 2. Network Access Unit. (1997-05-10) 1 1 1 1 1 nav bar navigation bar 1 1 1 1 1 navigating navigation 1 1 1 1 1 navigation Finding your way around a website. Many sites have some kind of navigation bar. One of the first web browsers was called Netscape Navigator. (2008-11-17) 1 1 1 1 1 navigation bar (Always abbreviated "nav bar") On a website, a prominently displayed set of links to important sections of the site. (2008-11-17) 1 1 1 1 1 Navigator Netscape Navigator 1 1 1 1 1 Nawk New AWK. AT&T. Pattern scanning and processing language. An enhanced version of AWK, with dynamic regular expressions, additional built-ins and operators, and user-defined functions. 1 1 1 1 1 NB C 1 1 1 1 1 NBFCP NetBIOS Frames Control Protocol 1 1 1 1 1 NBS National Bureau of Standards: part of the US Department of Commerce, now NIST. 1 1 1 1 1 NBT NetBios over TCP/IP 1 1 1 1 1 NC Network Computer 1 1 1 1 1 nc The country code for New Caledonia. (1999-01-27) 1 1 1 1 1 NCD Network Computing Devices 1 1 1 1 1 NCP 1. IBM Advanced Communication Function/Network Control Program. 2. Novell, Inc. NetWare Core Protocol. (1999-01-20) 1 1 1 1 1 NCR Corporation Electronics company mainly active in the midrange server market. NCR was founded 1884 as National Cash Register Company. It joint the computer industry in th 1950s. In 1991 it was absorbed by AT&T (see dinosaurs mating), only to be spat out again in 1996. NCR mainframes of the 1960's are remembered by some for their hardware incompatibility with IBM mainframes: NCR punched round holes in their punched cards while IBM punched rectangular ones. The codes and machines were not compatible and information could not be easily shared between NCR and IBM customers. (http://ncr.com/). (1997-03-10) 1 1 1 1 1 NCRL Software Writer's Language 1 1 1 1 1 NCR Language Software Writer's Language 1 1 1 1 1 NCS Network Computing System: Apollo's RPC system used by DEC and Hewlett-Packard.The protocol has been adopted by OSF. 1 1 1 1 1 NCSA National Center for Supercomputing Applications 1 1 1 1 1 ND natural deduction 1 1 1 1 1 NDIS Network Device Interface Specification 1 1 1 1 1 NDL 1. National Database Language. 2. Network Definition Language. 1 1 1 1 1 NDS Netware Directory Services 1 1 1 1 1 ne The country code for Niger. (1999-01-27) 1 1 1 1 1 neat hack 1. A clever technique. 2. A brilliant practical joke, where neatness is correlated with cleverness, harmlessness, and surprise value. Example: the Caltech Rose Bowl card display switch. See also hack. [Jargon File] 1 1 1 1 1 neats vs. scruffies The label used to refer to one of the continuing holy wars in artificial intelligence research. This conflict tangles together two separate issues. One is the relationship between human reasoning and AI; neats tend to try to build systems that "reason" in some way identifiably similar to the way humans report themselves as doing, while "scruffies" profess not to care whether an algorithm resembles human reasoning in the least as long as it works. More importantly, neats tend to believe that logic is king, while scruffies favour looser, more ad-hoc methods driven by empirical knowledge. To a neat, scruffy methods appear promiscuous, successful only by accident and not productive of insights about how intelligence actually works; to a scruffy, neat methods appear to be hung up on formalism and irrelevant to the hard-to-capture "common sense" of living intelligences. (1994-11-29) 1 1 1 1 1 Nebula An early business-oriented language from ICL for the Ferranti Orion computer. ["NEBULA - A Programming Language for Data Processing", T.G. Braunholtz et al, Computer J 4(3):197-201 (1961)]. (1994-11-29) 1 1 1 1 1 NEC Nippon Electronics Corporation 1 1 1 1 1 NEC 780-C A copy of the Zilog Z80A microprocessor, running at 3.25 MHz. The NEC 780-C was the processor used in the Sinclair ZX-80. (2002-03-11) 1 1 1 1 1 needs assessment A systematic process to acquire an accurate, thorough picture of a system's strengths and weaknesses, in order to improve it and meet existing and future challenges. (2007-11-24) 1 1 1 1 1 neep-neep /neep neep/ [onomatopoeic, from New York SF fandom] One who is fascinated by computers. Less specific than hacker, as it need not imply more skill than is required to boot games on a personal computer. The derived noun "neeping" applies specifically to the long conversations about computers that tend to develop in the corners at most SF-convention parties (the term "neepery" is also in wide use). Fandom has a related proverb to the effect that "Hacking is a conversational black hole!". [Jargon File] (1994-11-29) 1 1 1 1 1 negation by failure An extralogical feature of Prolog and other logic programming languages in which failure of unification is treated as establishing the negation of a relation. For example, if Ronald Reagan is not in our database and we asked if he was an American, Prolog would answer "no". (1994-11-29) 1 1 1 1 1 negative acknowledgement 1. <character> (NAK) The mnemonic for ASCII character 21. Sometimes used as the response to receipt of a corrupted packet of information. Opposite of acknowledgement. 2. <communications> (NAK) Any message transmitted to indicate that some data has been received incorrectly, for example it may have a checksum or message length error. A NAK message allows the sender to distinguish a message which has been received in a corrupted state from one which is not received at all. An alternative is to use only ACK messages, in which case the non-receipt of an ACK after a certain time is counted as a NAK but gives no information about the integrity of the communications channel. See also ACK. (1997-01-07) 1 1 1 1 1 neighborhood bike code A piece of code that every programmer at the company has touched. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. [Urban Dictionary: neighborhood bike (http://www.urbandictionary.com/define.php?term=neighborhood+bike)]. (2014-07-12) 1 1 1 1 1 NELIAC Navy Electronics Laboratory International ALGOL Compiler. An Algol variant designed for numeric and logical computations and based on IAL. 1958-1959. Version: BC NELIAC. ["Neliac - A Dialect of Algol", H.D. Huskey et al, CACM 3(8):463-468 (Aug 1960)]. (1994-11-29) 1 1 1 1 1 Neon Charles Duff. An object-oriented extension of FORTH, for the Mac. Inheritance, SANE floating-point, system classes and objects for Mac interfacing, overlays. Sold by Kriya Systems, 1985-1988. Modified, made PD and renamed Yerk. 1 1 1 1 1 neophilia /nee"oh-fil"-ee-*/ The trait of being excited and pleased by novelty. Common among most hackers, SF fans, and members of several other connected leading-edge subcultures, including the pro-technology "Whole Earth" wing of the ecology movement, space activists, many members of Mensa, and the Discordian/neo-pagan underground. All these groups overlap heavily and (where evidence is available) seem to share characteristic hacker tropisms for science fiction, music, and oriental food. The opposite tendency is "neophobia". [Jargon File] (1999-06-04) 1 1 1 1 1 Neptune A hypertext system for computer assisted software engineering, developed at Tektronix. 1 1 1 1 1 nerd A generally pejortive term for any person who is socially inept and studious or demonstrates obsessive knowledge of something. For example, a computer nerd. The term first appeared in print in "If I Ran the Zoo", 1950 by Dr. Seuss. Compare: geek. (2010-02-28) 1 1 1 1 1 Nerd pride The Nerd Pride movement, modeled on the Gay Pride movement, was started at MIT by Professors Gerald Sussman and Hal Abelson. Nerd pride paraphernalia includes baseball hats, buttons and - of course - pocket protectors. "My idea is to present an image to children that it is good to be intellectual, and not to care about the peer pressures to be anti-intellectual. I want every child to turn into a nerd - where that means someone who prefers studying and learning to competing for social dominance." -- Gerald Sussman, quoted by Katie Hafner, "New York Times", 1994-08-29. (1994-11-11) 1 1 1 1 1 NERECO NEtwork REmote COmmunications. CSP with extensions to allow asymmetrical and asynchronous communications and fault handling. It is implemented on a network of Suns. ["A Concurrent Programming Support for Distributed Systems", G. Spezzano et al, in Computing Systems vol 3, pp.423-447, U Cal Press, 1990]. (1994-11-11) 1 1 1 1 1 NESL A parallel language loosely based on ML, developed at Carnegie Mellon University by the SCandAL project. NESL integrates parallel algorithms, functional languages and implementation techniques from the system's community. Nested data parallelism offers concise code that is easy to understand and debug and suits irregular data structures such as trees, graphs or sparse matrices. NESL's language based performance model is a formal way to calculate the "work" and "depth" of a program. These measures can be related to running time on a parallel computer. NESL was designed to make parallel programming easy and portable. Algorithms are typically more concise in NESL than in most other parallel programming languages and the code resembles high-level pseudocode. This places more responsibility on the compiler and run-time system for achieving good efficiency. 1 1 1 1 1 nested class In Java, a class defined within an enclosing class definition. A static nested class has no direct access to the members of its enclosing class whereas a non-static nested class, known as an "inner class", is associated with an instance of the enclosing class and an instance of the inner class has direct access to the members of its enclosing instance. Java Tutorial (http://java.sun.com/docs/books/tutorial/java/javaOO/nested.html). [Other languages?] (2006-11-19) 1 1 1 1 1 net 1. <networking> network. 2. <networking> network, the. 3. <architecture> neural network. 4. <networking> The top-level domain originally for networks, although it sees heavy use for vanity domains of all types. [Jargon File] (1999-01-26) 1 1 1 1 1 net.- /net dot/ A prefix used to describe people and events related to Usenet and the Internet. The convention dates from the time before the Great Renaming, when most non-local Usenet newsgroups had names beginning "net.". Includes net.gods, "net.goddesses" (various charismatic net.women with circles of on-line admirers), "net.lurkers" (see lurker), "net.person", net.parties (a synonym for boink), and many similar constructs. See also net.police. [Jargon File] (1995-03-21) 1 1 1 1 1 netaddress Knowbot Information Service 1 1 1 1 1 NetBEUI NetBIOS Extended User Interface. The network transport protocol used by all of Microsoft's network systems and IBM's LAN Server based systems. NetBEUI is often confused with NetBIOS. NetBIOS is the applications programming interface and NetBEUI is the transport protocol. 1 1 1 1 1 NetBIOS An applications programming interface (API) which activates network operations on IBM PC compatibles running under Microsoft's DOS. It is a set of network commands that the application program issues in order to transmit and receive data to another host on the network. The commands are interpreted by a network control program or network operating system that is NetBIOS compatible. See NetBOLLIX. 1 1 1 1 1 NetBIOS Frames Control Protocol (NBFCP, NBF protocol, originally "NetBEUI protocol") [RFC 2097] [What is it?] (1997-05-10) 1 1 1 1 1 NetBios over TCP/IP (NBT) A protocol supporting NetBIOS services in a TCP/IP environment, defined by RFCs 1001 and 1002. (1997-07-04) 1 1 1 1 1 NetBOLLIX ["bollix": to bungle] IBM's NetBIOS, an extremely brain-damaged network protocol that, like Blue Glue, is used at commercial shops that don't know any better. [Jargon File] 1 1 1 1 1 NetBSD An open source Unix clone that aims for platform independance by a clean separation between the hardware and the the kernel. It has been ported to many platforms from embedded systems to 64-bit computers. NetBSD Home (http://netbsd.org/). (2004-10-08) 1 1 1 1 1 netbui It's spelled "NetBEUI". (1996-12-23) 1 1 1 1 1 netburp (Or "netsplit") When netlag gets really bad, and delays between IRC servers exceed a certain threshhold, the network effectively becomes partitioned for a period of time, and large numbers of people seem to be signing off at the same time and then signing back on again when things get better. An instance of this is called a "netburp" (or, sometimes, netsplit). [Jargon File] (1996-06-04) 1 1 1 1 1 netCDF Network Common Data Form. A machine-independent, self-describing file format for scientific data. 1 1 1 1 1 Netcom On-line Communication Services, Inc. A company providing Internet access on Sun Microsystems computers running Unix. Customers either log in to a shell running on a Netcom computer, or rent a SLIP or PPP connection and run their own net software. Most hosts are in San Jose, California, but they have Points of Presence all over the USA. (http://netcom.com/). Address: 3031 Tisch Way San Jose, CA 95128, USA. Telephone: +1 (408) 983 5950, +1 800 353 6600. Fax: +1 (408) 241 9145. (1996-04-23) 1 1 1 1 1 netdead The state of someone who signs off IRC, perhaps during a netburp, and doesn't sign back on until later. In the interim, he is "dead to the net". [Jargon File] (2007-09-02) 1 1 1 1 1 Netfind A research prototype that provides a simple Internet "white pages" user directory. It runs on SunOS 4.0 or more recent systems that are connected to the Internet (however, you can run Netfind on one server at your site, and let the others use Netfind on that server). Given the name of a person on the Internet and a rough description of where the person works, Netfind attempts to locate telephone and electronic mailbox information about the person. (ftp://ftp.cs.colorado.edu/pub/cs/distribs/netfind). 1 1 1 1 1 net.god /net god/ Accolade referring to anyone who satisfies some combination of the following conditions: has been visible on Usenet for more than 5 years, ran one of the original backbone sites, moderated an important newsgroup, wrote news software, or knows Gene, Mark, Rick, Mel, Henry, Chuq, and Greg personally. Net.goddesses such as Rissa or the Slime Sisters have (so far) been distinguished more by personality than by authority. See demigod. [Jargon File] (1996-01-07) 1 1 1 1 1 NetHack /net'hak/ (Unix) A dungeon game similar to rogue but more elaborate, distributed in C source over Usenet and very popular at Unix sites and on PC-class machines (nethack is probably the most widely distributed of the freeware dungeon games). The earliest versions, written by Jay Fenlason and later considerably enhanced by Andries Brouwer, were simply called "hack". The name changed when maintenance was taken over by a group of hackers originally organised by Mike Stephenson. Version: NetHack 3.2 (Apr 1996?). (http://win.tue.nl/games/roguelike/nethack/). FAQ (ftp://rtfm.mit.edu/pub/usenet/rec.games.roguelike.nethack/). FTP U Penn (ftp://linc.cis.upenn.edu/pub/NH3.1/) No large downloads between 9:00 and 18:00 local or the directory will be removed. Usenet newsgroup: news:rec.games.roguelike.nethack. 1 1 1 1 1 netiquette /net'ee-ket/ or /net'i-ket/ Network etiquette. The conventions of politeness recognised on Usenet and in mailing lists, such as not (cross-)posting to inappropriate groups and refraining from commercial advertising outside the biz groups. The most important rule of netiquette is "Think before you post". If what you intend to post will not make a positive contribution to the newsgroup and be of interest to several readers, don't post it! Personal messages to one or two individuals should not be posted to newsgroups, use private e-mail instead. When following up an article, quote the minimum necessary to give some context to your reply and be careful to attribute the quote to the right person. If the article you are responding to was posted to several groups, edit the distribution ("Newsgroups:") header to contain only those 1 1 1 1 1 NETL A semantic network language, for connectionist architectures. ["NETL: A System for Representing and Using Real-World Data", S.E. Fahlman, MIT Press 1979]. (1995-01-05) 1 1 1 1 1 netlag A condition that occurs when the delays in the IRC network, a MUD connection, a telnet connection, or any other networked interactive system, become severe enough that servers briefly lose and then reestablish contact, causing messages to be delivered in bursts, often with delays of up to a minute. (Note that this term has nothing to do with mainstream "jet lag"). [Jargon File] (1996-06-21) 1 1 1 1 1 NetLingo An on-line dictionary of more than 3000 terms, started in 1995 and updated monthly. NetLingo contains simple explanations and comprehensive coverage, including chat acronyms and smilies. It is also available in dead tree form. NetLingo Home (http://netlingo.com/). (2004-09-12) 1 1 1 1 1 netload A program to down-load Excelan TCP/IP software. The host's Ethernet address can be specified as netload -e aabbccddeeff where aabbccddeeff is a 12 hexadecimal digit number. (1994-12-14) 1 1 1 1 1 Netmarq Limited A small technical consultancy specialising in the testing of network components. They do performance tests of network interface cards, routers, hubs, file servers, etc. To reflect the marketplace, most tests are carried out in a Novell NetWare environment, although they can equally well use Lan server, Banyan Vines, NT Advanced Server, IBM PC Support. They claim to be Europe's leading such test lab and compete with US Labs such as LanQuest and NSTL. They also do some network design, installation, support, and troubleshooting. E-mail: <netmarq@cix.compulink.co.uk>. (1994-12-14) 1 1 1 1 1 netmask A 32-bit bit mask which shows how an Internet address is to be divided into network, subnet and host parts. The netmask has ones in the bit positions in the 32-bit address which are to be used for the network and subnet parts, and zeros for the host part. The mask should contain at least the standard network portion (as determined by the address's class), and the subnet field should be contiguous with the network portion. If a `+' (plus sign) is given for the netmask value, then the network number is looked up in the NIS netmasks.byaddr map (or in the /etc/netmasks) file if not running the NIS service. Unix manual page: ifconfig(8). (1995-01-30) 1 1 1 1 1 NetNanny A small program for children to block access to certain sites. [Company? Address?] (1997-02-12) 1 1 1 1 1 netnews /net'n[y]ooz/ 1. The software that makes Usenet run. 2. The content of Usenet. "I read netnews right after my mail most mornings." [Jargon File] (1994-12-14) 1 1 1 1 1 net.personality Someone who has made a name for him or herself on Usenet, through either longevity or attention-getting posts, but doesn't meet the other requirements of net.godhood. [Jargon File] 1 1 1 1 1 netpipes A package by Robert Forsman <thoth@cis.ufl.edu> to manipulate BSD Unix TCP/IP stream sockets. The netpipes package makes TCP/IP streams usable in shell scripts. It can also simplify client-server code by allowing the programmer to skip all the tedious programming related to sockets and concentrate on writing a filter/service. (http://cis.ufl.edu/~thoth/netpipes/). (1996-10-03) 1 1 1 1 1 net.police /net-p*-lees'/ (Or "net police", "net.cops") Those Usenet readers who feel it is their responsibility to pounce on and flame any posting which they regard as offensive or in violation of their understanding of netiquette. Generally used sarcastically or pejoratively. See also net.-, code police. [Jargon File] 1 1 1 1 1 netquette It's spelled "netiquette". (1999-09-30) 1 1 1 1 1 Netrek A 16-player graphical real-time battle simulation with a Star Trek theme. The game is divided into two teams of eight (or less), who dogfight each other and attempt to conquer each other's planets. There are several different types of ships, from fast, fragile scouts up to big, slow battleships; this allows a great deal of variance in play styles. Netrek is played using a client to connect to one of several Netrek servers on the Internet. There is a metaserver which distributes details of games in progress on other servers. See also ogg. [Dates? Versions? Authors? Addresses?] (1998-02-01) 1 1 1 1 1 netrock /net'rok/ (IBM) A flame; used especially on VNET, IBM's internal corporate network. [Jargon File] (1994-11-18) 1 1 1 1 1 Netscape 1. Netscape Navigator. 2. Netscape Communications Corporation. 1 1 1 1 1 Netscape Communications Corporation (Formlerly "Mosaic Communications Corporation", MCC) A company set up in April 1994 by Dr. James H. Clark and Marc Andreessen <marca@netcom.com> (creator of the NCSA Mosaic program) to market their version of Mosaic, known as Netscape or Mozilla. They changed their name (http://netscape.com/newsref/pr/newsrelease5.html) on 1994-11-14 to reflect their other activities rather than just their browser based on Mosaic. (http://netscape.com/). Address: 501 East Middlefield Road, Mountain View, CA 94043, USA. Telephone: +1 (415) 254 1900. Fax: +1 (415) 254 2601. (2000-02-08) 1 1 1 1 1 Netscape Navigator /Mozilla/ (Often called just Netscape) A web browser from Netscape Communications Corporation. The first beta-test version was released free to the Internet on 13 October 1994. Netscape evolved from NCSA Mosaic (with which it shares at least one author) and runs on the X Window System under various versions of Unix, on Microsoft Windows and on the Apple Macintosh. It features integrated support for sending electronic mail and reading Usenet news, as well as RSA encryption to allow secure communications for commercial applications such as exchanging credit card numbers with net retailers. It provides multiple simultaneous interruptible text and image loading; native inline JPEG image display; display and interaction with documents as they load; multiple independent windows. Netscape was designed with 14.4 kbps modem links in mind. 1 1 1 1 1 Netscape Public License open source license 1 1 1 1 1 netsplit netburp 1 1 1 1 1 netstat (Or "rstat") A Unix command to give statistics about the network including socket status, interfaces that have been auto-configured, memory statistics, routing tables. Unix manual pages: rstat(3), netstat(8). (1996-06-04) 1 1 1 1 1 netter 1. Loosely, anyone with a network address. 2. More specifically, a Usenet regular. Most often found in the plural. "If you post *that* in a technical group, you're going to be flamed by angry netters for the rest of time!" [Jargon File] 1 1 1 1 1 NetWare Novell NetWare 1 1 1 1 1 NetWare Core Protocol (NCP) A Novell trademark for the protocol used to access Novell NetWare file and print service functions. It uses an underlying IPX or IP transport protocol. (1995-11-11) 1 1 1 1 1 Netware Directory Services (NDS) Novell, Inc.'s directory services for Netware, Windows NT, and Unix. The NDS directory represents each network resource (user, hardware, or application) as an object of a certain class, where each class has certain properties. For example, User and Print Server are object classes and a user has over 80 properties such as name, login, password, department, and title. The directory is hierarchical, divided into branches by rules of containment. A given object can only belong to a given container (or branch). The rules governing classes, properties and, rules of containment are known as the schema. (2001-03-20) 1 1 1 1 1 Netware Input/Output Subsystem (NIOS) The lowest layer in the Novell NetWare client architecture. NIOS is the interface layer between the client operating system and the 32-bit client services provided by NetWare. (http://developer.novell.com/research/appnotes/1996/november/01/04.htm). (1999-04-24) 1 1 1 1 1 NetWare Link State Protocol (NLSP) A companion protocol to IPX for exchange of routing information in a Novell network. NLSP supersedes Novell's RIP. (1997-03-04) 1 1 1 1 1 network Hardware and software data communication systems. The OSI seven layer model attempts to provide a way of partitioning any computer network into independent modules from the lowest (physical) layer to the highest (application) layer. Many different specifications exist at each of these layers. Networks are often also classified according to their geographical extent: local area network (LAN), metropolitan area network (MAN), wide area network (WAN) and also according to the protocols used. See BITNET, Ethernet, Internet, Novell, PSTN, network, the. [Tanenbaum, A., "Computer Networks; 2nd ed.", Prentice Hall, Englewood Cliffs, NJ, 1989.] (1995-03-10) 1 1 1 1 1 network address 1. The network portion of an IP address. For a class A network, the network address is the first byte of the IP address. For a class B network, the network address is the first two bytes of the IP address. For a class C network, the network address is the first three bytes of the IP address. In each case, the remainder is the host address. In the Internet, assigned network addresses are globally unique. See also subnet address, Internet Registry. 2. (Or "net address") An electronic mail address on the network. In the 1980s this might have been a bang path but now (1997) it is nearly always a domain address. Such an address is essential if one wants to be to be taken seriously by hackers; in particular, persons or organisations that claim to understand, work with, sell to, or recruit from among hackers but *don't* display net addresses are quietly presumed to be clueless poseurs and mentally flushed. 1 1 1 1 1 Network Addressable Unit (NAU) The SNA term for an addressable entity. Examples include PUs, LUs, and SSCPs. (1997-05-10) 1 1 1 1 1 Network Address Translation (NAT, or Network Address Translator, Virtual LAN) A technique in which a router or firewall rewrites the source and/or destination Internet addresses in a packet as it passes through, typically to allow multiple hosts to connect to the Internet via a single external IP address. NAT keeps track of outbound connections and distributes incoming packets to the correct machine. NAT is an alternative to adopting IPv6 (IPng). It allows the same IP addresses (10.x.x.x is the conventional range) to be used on many private local networks while requiring only one of the increasingly scarce public addresses to be allocated to each private network. NAT does not however allow an external service to initiate a TCP connection to an internal host, nor does it support stateless protocols based on UDP well unless the router software has extensions to support each specific protocol. (2005-09-18) 1 1 1 1 1 Network Address Translator Network Address Translation 1 1 1 1 1 Network Administrator A person who manages a communications network within an organisation. Responsibilities include network security, installing new applications, distributing software upgrades, monitoring daily activity, enforcing licensing agreements, developing a storage management program and providing for routine backups. (2004-03-20) 1 1 1 1 1 Network Application Support (NAS) DEC's approach to applications integration across a distributed multivendor environment. (2003-06-30) 1 1 1 1 1 Network Attached Storage (NAS) Fixed disks, RAID arrays, and magnetic tape drives connected directly to a Storage Area Network (SAN) or other direct network connection. This is in contrast to a file server where the peripherals are connected to the network via a computer (the server). (2003-06-30) 1 1 1 1 1 network byte order The order in which the bytes of a multi-byte number are transmitted on a network - most significant byte first (as in "big-endian" storage). This may or may not match the order in which numbers are normally stored in memory for a particular processor. (http://sun.com/realitycheck/headsup980803.html). (http://hp.com/unixwork/whatsnew/fyi/bissue/aug98/article3.htm). (1998-11-15) 1 1 1 1 1 network card network interface controller 1 1 1 1 1 network closet The place where network hardware (other than cabling) is installed. The space should be used primarily for storage, be dry, and have electricity available. Since network equipment rarely needs attention once installed and tested, the network closet can have limited accessibility. (1995-05-05) 1 1 1 1 1 Network Computing Devices (NCD) Producer of X terminals, PC-Xware and Z-Mail. (http://ncd.com/). (1998-10-07) 1 1 1 1 1 network database A kind of database management system in which each record type can have multiple owners, e.g. orders are owned by both customers and products. This contrasts with a hierarchical database (one owner) or relational database (no explicit owner). (1998-10-07) 1 1 1 1 1 Network Definition Language (NDL) The language used to program the DCP (Data Communications Processor) on Burroughs Large System. Version: NDL II. (1994-12-12) 1 1 1 1 1 Network Device Interface Specification (NDIS) A Microsoft Windows device driver programming interface allowing multiple protocols to share the same network hardware. E.g. TCP/IP and IPX on the same NIC. NDIS can also be used by some ISDN adapters. A protocol manager accepts requests from the transport layer and passes them to the data link layer (routed to the correct network interface if there is more than one). NDIS was developed by Microsoft and 3COM. Novell offers a similar device driver for NetWare called Open Data-Link Interface (ODI). The NDIS 2.0 specification was 5000 lines. Latest version: NDIS 5.0, as of 2000-10-30. (http://microsoft.com/hwdev/devdes/ndis5.htm). cdrom.com NDIS archive (ftp://ftp.cdrom.com/pub/os2/network/ndis/). ["3TECH, The 3COM Technical Journal", Winter 1991]. 1 1 1 1 1 network engineer A high-level LAN/WAN technician who plans, implements and supports network solutions between multiple platforms. A network engineer installs and maintains local area network hardware and software, and troubleshoots network usage and computer peripherals. He may have CNE certification. (2004-03-20) 1 1 1 1 1 Network extensible Window System (NeWS) An elegant PostScript-based windowing environment, invented by James Gosling, the author of GOSMACS. NeWS would almost certainly have won the standards war with the X Window System if it hadn't been proprietary to Sun Microsystems. There is a lesson here that too many software vendors haven't yet heeded. Communication is based on PostScript and server functions can be extended. See also HyperNeWS, OpenWindows. (1994-12-12) 1 1 1 1 1 Network File System (NFS) A protocol developed by Sun Microsystems, and defined in RFC 1094, which allows a computer to access files over a network as if they were on its local disks. This protocol has been incorporated in products by more than two hundred companies, and is now a de facto standard. NFS is implemented using a connectionless protocol (UDP) in order to make it stateless. See Nightmare File System, WebNFS. (1994-12-12) 1 1 1 1 1 Network Filing System Misnomer for Network File System. 1 1 1 1 1 Network Information Center (NIC) A body that provides information, assistance and services to network users. These will typically include telephone and electronic mail "help desk" type services for users and network information services such as hostnames and addresses which are accessed automatically by computers using some client-server protocol (usually Sun's NIS). See also Network Operations Center. (1994-12-13) 1 1 1 1 1 Network Information Service (NIS) Sun Microsystems' Yellow Pages (yp) client-server protocol for distributing system configuration data such as user and host names between computers on a network. Sun licenses the technology to virtually all other Unix vendors. The name "Yellow Pages" is a registered trademark in the United Kingdom of British Telecommunications plc for their (paper) commercial telephone directory. Sun changed the name of their system to NIS, though all the commands and functions still start with "yp", e.g. ypcat, ypmatch, ypwhich. Unix manual pages: yp(3), ypclnt(3), ypcat(1), ypmatch(1). (1995-04-08) 1 1 1 1 1 Network Information System A mis-expansion of NIS. (1995-04-08) 1 1 1 1 1 networking network 1 1 1 1 1 network interface card network interface controller 1 1 1 1 1 network interface controller (NIC or "network interface card") An adapter circuit board installed in a computer to provide a physical connection to a network. [Examples? Attributes?] (1996-03-04) 1 1 1 1 1 network layer (communications subnet layer) The third lowest layer in the OSI seven layer model. The network layer determines routing of packets of data from sender to receiver via the data link layer and is used by the transport layer. The most common network layer protocol is IP. (1994-12-13) 1 1 1 1 1 network layer reachability information (NLRI) Keywords used for unicast and multicast database forwarding. For example, you would assign a user's NLRI so the user can receive multicast messages regarding hardware down time that will affect a specific user group. [Reference?] (2002-06-01) 1 1 1 1 1 network management The process of controlling a network so as to maximise its efficiency and productivity. ISO's model divides network management into five categories: fault management, accounting management, configuration management, security management and performance management. Fault management is the process of identifying and locating faults in the network. This could include discovering the existence of the problem, identifying the source, and possibly repairing (or at least isolating the rest of the network from) the problem. Configuration management is the process of identifying, tracking and modifying the setup of devices on the network. This category is extremely important for devices that come with numerous custom settings (e.g. routers and file servers). Security management is the process of controlling (granting, 1 1 1 1 1 network meltdown (By analogy with catastrophic failure of a nuclear reactor) An event that causes saturation, or near saturation, of a network. Network meltdown usually results from illegal or misrouted packets (see Chernobyl packet) and typically lasts only a short time. It may also be caused by a hardware fault. It is the network equivalent of thrashing. [Jargon File] (2004-02-17) 1 1 1 1 1 Network News Transfer Protocol (NNTP) A protocol defined in RFC 977 for the distribution, inquiry, retrieval and posting of Usenet news articles over the Internet. It is designed to be used between a news reader client such as nn or GNUS and a news server. It is normally used on a connection to TCP port 119 on the news server. NNTP is a simple ASCII text protocol so even if you don't have a news reader program, you can just connect to the server using telnet: telnet news 119 where news is the name of your server (e.g. news.doc.ic.ac.uk). Typing HELP will give a list of other commands. 1 1 1 1 1 network node (node) An addressable device attached to a computer network. If the node is a computer it is more often called a "host". (2004-08-25) 1 1 1 1 1 Network Node Interface (NNI) The ATM Forum's specification for connections between network nodes. NNI makes network routing possible. It typically refers to backbone trunk connections between ATM switching equipment. See also: UNI. (2001-03-26) 1 1 1 1 1 network number network address 1 1 1 1 1 Network Operating System (NOS) The operating system on Control Data Corporation's Cyber Computer. [Details?] (2002-11-22) 1 1 1 1 1 network operating system (NOS) An operating system which includes software to communicate with other computers via a network. This allows resources such as files, application programs, and printers to be shared between computers. Examples are Berkeley Software Distribution Unix, Novell, LAntastic, MS LAN Manager. [Is there a specific OS called "Network Operating System"?] (2001-03-13) 1 1 1 1 1 Network Operations Center (NOC) A location from which the operation of a network or internet is monitored. Additionally, this center usually serves as a clearinghouse for connectivity problems and efforts to resolve those problems. See also Network Information Center. (1994-12-01) 1 1 1 1 1 network operator A person who monitors and maintains the operation of a communications network. A network operator troubleshoots hardware (cables, routers, network switches, hubs, network adaptors), software, and transmission problems. (2004-03-09) 1 1 1 1 1 network redirector An operating system driver that sends data to and receives data from a remote device. A network redirector often provides mechanisms to locate, open, read, write, and delete files and submit print jobs. It also makes available application services such as named pipes and mailslots. When an application needs to send or receive data from a remote device, it sends a call to the redirector. The redirector provides the functionality of the Application layer and Presentation layer of the OSI model. In Microsoft Networking, the network redirectors are implemented as installable file systems (IFS). (1999-08-08) 1 1 1 1 1 network segment A part of an Ethernet or other network, on which all message traffic is common to all nodes, i.e. it is broadcast from one node on the segment and received by all others. This is normally because the segment is a single continuous conductor, though it may include repeaters(?). Since all nodes share the physical medium, collision detection or some other protocol is required to determine whether a message was transmitted without interference from other nodes. The receiving node inspects the destination address of a packet to tell if it was (one of) the intended recipient(s). Communication between nodes on different segments is via one or more routers. (1996-10-16) 1 1 1 1 1 Network Solutions, Inc. (NSI) One of the three companies that provide and coordinate InterNIC services for the NSFNet. NSI is responsible for registration. NSI has been bought by, and is now a wholly-owned subsidiary of, Science Applications International Corporation (SAIC). (1995-11-09) 1 1 1 1 1 network storm broadcast storm 1 1 1 1 1 Network Termination (NT, NT1) A device connecting the customer's data or telephone equipment to the local ISDN exchange carrier's line. The NT device provides a connection for terminal equipment (TE) and terminal adaptor (TA) equipment to the local loop. (1994-11-30) 1 1 1 1 1 network, the 1. <jargon, networking> (Or "the net") The union of all the major noncommercial, academic and hacker-oriented networks, such as Internet, the old ARPANET, NSFnet, BITNET, and the virtual UUCP and Usenet "networks", plus the corporate in-house networks and commercial time-sharing services (such as CompuServe) that gateway to them. A site was generally considered "on the network" if it could be reached by electronic mail through some combination of Internet-style (@-sign) and UUCP (bang-path) addresses. Since the explosion of the Internet in the mid 1990s, the term is now synonymous with the Internet. See network address. 2. <body> A fictional conspiracy of libertarian hacker-subversives and anti-authoritarian monkeywrenchers described in Robert Anton Wilson's novel "Schrödinger's Cat", to which many hackers have subsequently decided they belong (this is an example of ha ha only serious). 1 1 1 1 1 Network Time Protocol (NTP) A protocol built on top of TCP/IP that assures accurate local timekeeping with reference to radio, atomic or other clocks located on the Internet. This protocol is capable of synchronizing distributed clocks within milliseconds over long time periods. It is defined in STD 12, RFC 1119. 1 1 1 1 1 network topology The "shape" of a network, how the nodes are connected to each other. Common topologies are bus network, star network and ring network. (2009-07-16) 1 1 1 1 1 network transparency A feature of an operating system or other service which lets the user access a remote resource through a network without having to know if the resource is remote or local. For example NFS allow users to access remote files as if they were local files. (1996-12-21) 1 1 1 1 1 NetX A LukeCo Company that designs web pages and web software. Not to be confused with Net:X. (http://members.aol.com/netx11/index.html). (1996-12-15) 1 1 1 1 1 Net:X A Canadian company. Not to be confused with NetX. (http://netx.ca/). [Summary?] (1998-06-25) 1 1 1 1 1 neural nets artificial neural network 1 1 1 1 1 neural network artificial neural network 1 1 1 1 1 neuron artificial neural network 1 1 1 1 1 Neutral Interconnect Network infrastructure where network service providers can freely exchange traffic without policy restrictions. Examples are the GIX (Global Internet Exchange) at MAE-East (A Metropolitan Area Ethernet around Washington), and the Ebone (European Backbone). There is currently (November 1993) no UK Neutral Interconnect. 1 1 1 1 1 neutrosophic Neutrosophy 1 1 1 1 1 neutrosophic logic (Or "Smarandache logic") A generalisation of fuzzy logic based on Neutrosophy. A proposition is t true, i indeterminate, and f false, where t, i, and f are real values from the ranges T, I, F, with no restriction on T, I, F, or the sum n=t+i+f. Neutrosophic logic thus generalises: - intuitionistic logic, which supports incomplete theories (for 0<n<100 and i=0, 0<=t,i,f<=100); - fuzzy logic (for n=100 and i=0, and 0<=t,i,f<=100); - Boolean logic (for n=100 and i=0, with t,f either 0 or 100); - multi-valued logic (for 0<=t,i,f<=100); - paraconsistent logic (for n>100 and i=0, with both t,f<100); - dialetheism, which says that some contradictions are true (for t=f=100 and i=0; some paradoxes can be denoted this way). Compared with all other logics, neutrosophic logic introduces 1 1 1 1 1 neutrosophic probability An extended form of probability based on Neutrosophy, in which a statement is held to be t true, i indeterminate, and f false, where t, i, f are real values from the ranges T, I, F, with no restriction on T, I, F or the sum n=t+i+f. (http://gallup.unm.edu/~smarandache/NeutProb.txt). ["Neutrosophy / Neutrosophic Probability, Set, and Logic", Florentin Smarandache, American Research Press, 1998]. (1999-10-04) 1 1 1 1 1 neutrosophic set A generalisation of the intuitionistic set, classical set, fuzzy set, paraconsistent set, dialetheist set, paradoxist set, tautological set based on Neutrosophy. An element x(T, I, F) belongs to the set in the following way: it is t true in the set, i indeterminate in the set, and f false, where t, i, and f are real numbers taken from the sets T, I, and F with no restriction on T, I, F, nor on their sum n=t+i+f. The neutrosophic set generalises: - the intuitionistic set, which supports incomplete set theories (for 0<n<100 and i=0, 0<=t,i,f<=100); - the fuzzy set (for n=100 and i=0, and 0<=t,i,f<=100); - the classical set (for n=100 and i=0, with t,f either 0 or 100); - the paraconsistent set (for n>100 and i=0, with both t,f<100); - the dialetheist set, which says that the intersection of 1 1 1 1 1 neutrosophic statistics Analysis of events described by neutrosophic probability. ["Neutrosophy / Neutrosophic Probability, Set, and Logic", Florentin Smarandache, American Research Press, 1998]. (1999-07-05) 1 1 1 1 1 Neutrosophy (From Latin "neuter" - neutral, Greek "sophia" - skill/wisdom) A branch of philosophy, introduced by Florentin Smarandache in 1980, which studies the origin, nature, and scope of neutralities, as well as their interactions with different ideational spectra. Neutrosophy considers a proposition, theory, event, concept, or entity, "A" in relation to its opposite, "Anti-A" and that which is not A, "Non-A", and that which is neither "A" nor Anti-A, denoted by "Neut-A". Neutrosophy is the basis of neutrosophic logic, neutrosophic probability, neutrosophic set, and neutrosophic statistics. (http://gallup.unm.edu/~smarandache/NeutroSo.txt). ["Neutrosophy / Neutrosophic Probability, Set, and Logic", Florentin Smarandache, American Research Press, 1998]. (1999-07-29) 1 1 1 1 1 Never Offline (NOL) /noh-el/ A software service provided by America's Multimedia Online that allows Internet users to be constantly connected to the Internet. (http://neveroffline.com/). [But what *is* it?] (1999-11-03) 1 1 1 1 1 newbie /n[y]oo'bee/ (Sometimes shorted to "noob") Originally from British public-school and military slang variant of "new boy", an inexperienced user. This term surfaced in the newsgroup news:talk.bizarre but is now in wide use. Criteria for being considered a newbie vary wildly; a person can be called a newbie in one group while remaining a respected regular in another. The label newbie is sometimes applied as a serious insult to a person who has been around for a long time but who carefully hides all evidence of having a clue. See BIFF. [Jargon File] (2007-08-02) 1 1 1 1 1 New Flavors An object-oriented Lisp from Symbolics, the successor to Flavors, it led to CLOS. ["Reference Guide to Symbolics-Lisp", Symbolics, March 1985]. (1994-10-10) 1 1 1 1 1 newgroup wars /n[y]oo'groop worz/ [Usenet] The salvos of dueling newgroup and "rmgroup" messages sometimes exchanged by persons on opposite sides of a dispute over whether a newsgroup should be created net-wide, or (even more frequently) whether an obsolete one should be removed. These usually settle out within a week or two as it becomes clear whether the group has a natural constituency (usually, it doesn't). At times, especially in the completely anarchic alt hierarchy, the names of newsgroups themselves become a form of comment or humour; e.g. the spinoff of alt.swedish.chef.bork.bork.bork from alt.tv.muppets in early 1990, or any number of specialised abuse groups named after particularly notorious flamers, e.g. alt.weemba. [Jargon File] 1 1 1 1 1 New Jersey [Primarily Stanford/Silicon Valley] Brain-damaged or of poor design. This refers to the allegedly wretched quality of such software as C, C++ and Unix (which originated at Bell Labs in Murray Hill, New Jersey). "This compiler bites the bag, but what can you expect from a compiler designed in New Jersey?" Compare Berkeley Quality Software. See also Unix conspiracy. 1 1 1 1 1 newline /n[y]oo'li:n/ Line feed or other character sequence used to terminate a line of text. Unix uses line feed as its text line terminator - a Bell-Labs-ism rather than a Berkeleyism. Interestingly (and unusually for Unix jargon), it is said to have originally been an IBM usage. Though the term "newline" appears in ASCII standards, it never caught on in the general computing world before Unix. The encoding of line feed as \n in C and Unix strings comes from this name. The term has been used more generally for any end of line character, character sequence (e.g. crlf), or operation (like Pascal's writeln procedure or Lisp 1.5's terpri) required to terminate a text record or separate lines. [Jargon File] (1997-07-14) 1 1 1 1 1 NEWP NEW Programming language 1 1 1 1 1 NEW Programming language (NEWP) A language which replaced ESPOL on the Burroughs Large System. (1994-12-13) 1 1 1 1 1 NeWS /nee'wis/, /n[y]oo'is/ or /n[y]ooz/ Network extensible Window System. Many hackers insist on the two-syllable pronunciations above as a way of distinguishing NeWS from news (the netnews software). [Jargon File] 1 1 1 1 1 news netnews 1 1 1 1 1 NewsClip A very high level language designed for writing netnews filters. It translates into C. It includes support for various newsreaders. Version 1.01 includes a translator from NewsClip to C, examples and documentation. NewsClip was written by Looking Glass Software Ltd. and is distributed and used by ClariNet Communications Corporation It is only supported for ClariNet customers. Output of the filters may not be sold and donation for use of this program is hinted at. E-mail: <newsclip@clarinet.com>. (1992-10-25) 1 1 1 1 1 newsfroup A silly synonym for Usenet newsgroup, originally a typo but now in regular use on Usenet's news:talk.bizarre and other lunatic-fringe groups. Compare hing, grilf, and filk. [Jargon File] (1994-12-13) 1 1 1 1 1 newsgroup One of Usenet's huge collection of topic groups or fora. Usenet groups can be "unmoderated" (anyone can post) or "moderated" (submissions are automatically directed to a moderator, who edits or filters and then posts the results). Some newsgroups have parallel mailing lists for Internet people with no netnews access, with postings to the group automatically propagated to the list and vice versa. Some moderated groups (especially those which are actually gatewayed Internet mailing lists) are distributed as digests, with groups of postings periodically collected into a single large posting with an index. Among the best-known are comp.lang.c (the C-language forum), comp.arch (on computer architectures), comp.Unix.wizards (for Unix wizards), rec.arts.sf-lovers (for science-fiction fans), and talk.politics.misc (miscellaneous political discussions and flamage). Barry Shein <bzs@world.std.com> is alleged to have said, 1 1 1 1 1 newsletter A periodically published work containing news and announcements on some subject, typically with a small circulation. Newsletters are a common application for DTP and may be distributed by electronic mail. (1996-12-10) 1 1 1 1 1 Newspeak A language inspired by Scratchpad. [J.K. Foderaro. "The Design of a Language for Algebraic Computation", Ph.D. Thesis, UC Berkeley, 1983]. 1 1 1 1 1 Newsqueak A concurrent applicative language with synchronous channels. ["Newsqueak: A Language for Communicating with Mice", R. Pike CSTR143, Bell Labs (March 1989)]. ["The Implementation of Newsqueak", Rob Pike, Soft Prac & Exp 20(7):649-659 (July 1990)]. 1 1 1 1 1 news reader A browser program which enables a user to read articles posted to Usenet. Articles may be stored in a local (or NFS-mounted) spool directory, or retrieved via NNTP. Examples are rn, GNUS, and nn. (1996-04-09) 1 1 1 1 1 New Storage System (NSS) A major Multics implementation project during the 1970s. The initial Multics file system design had evolved from the one-huge-disk world of CTSS. When multiple disk units were used they were just assigned increasing ranges of disk addresses, so a segment could have pages scattered over all disks on the system. This provided good I/O parallelism but made crash recovery expensive. NSS redesigned the lower levels of the file system, introducing the concepts of logical volume and physical volume and a mapping from a Multics directory branch to a VTOC entry for each file. The new system had much better recovery performance in exchange for a small space and performance cost. (1997-01-29) 1 1 1 1 1 new talk ntalk 1 1 1 1 1 New Testament [C programmers] The second edition of K&R's "The C Programming Language" (Prentice-Hall, 1988; ISBN 0-13-110362-8), describing ANSI C. [Jargon File] 1 1 1 1 1 Newton 1. (Named after Isaac Newton (1642-1727)). Rapin et al, Swiss Federal Inst Tech, Lausanne 1981. General purpose expression language, syntactically ALGOL-like, with object-oriented and functional features and a rich set of primitives for concurrency. Used for undergraduate teaching at Lausanne (EPFL). Versions: Newton 2.6 for VAX/VMS and Newton 1.2 for DEC-Alpha/OSF-1. E-mail: J. Hulaas <hulaas@lcodec1.epfl.ch>. (ftp://ellc4.epfl.ch /pub/languages/Newton). ["Procedural Objects in Newton", Ch. Rapin, SIGPLAN Notices 24(9) (Sep 1989)]. ["The Newton Language", Ch. Rapin et al, SIGPLAN Notices 16(8):31-40 (Aug 1981)]. ["Programming in Newton", Wuetrich and Menu, EPFL 1982]. 2. Apple Newton. (2000-08-29) 1 1 1 1 1 Newton-Raphson iteration An iterative algorithm for solving equations. Given an equation, f x = 0 and an initial approximation, x(0), a better approximation is given by: x(i+1) = x(i) - f(x(i)) / f'(x(i)) where f'(x) is the first derivative of f, df/dx. Newton-Raphson iteration is an example of an anytime algorithm in that each approximation is no worse than the previous one. (2007-06-19) 1 1 1 1 1 Newton's method Newton-Raphson 1 1 1 1 1 NewWave A graphical user interface and object-oriented environment from Hewlett-Packard, based on Windows and available on Unix workstations. 1 1 1 1 1 NewYacc A parser generator by Jack Callahan <callahan@mimsy.cs.umd.edu>. Version 1.0. (ftp://flubber.cs.umd.edu/src/). [Dec 89 CACM, A brief overview of NewYacc]. (1992-02-10) 1 1 1 1 1 New York State Educational Reasearch ETwork (NYSERNET) A New York Internet access provider and regional network. NYSERNet has been in the Internet business since about 1985 and have recently upgraded to a T3 backbone (45 megabits per second). They work with Sprint, NYNEX and Rochester Telephone. NYSERNet, Inc., provides Internet Training provided through the NYSERNet Internet Training and Education Center (NITEC), a twenty-four station hands-on facility in Syracuse, NY. The Information Services Group supplies tools for marketing via the Internet and NYSERNET also provide Technical Consulting Services. (http://nysernet.org/). E-mail: <info@nysernet.org>. (1995-02-01) 1 1 1 1 1 New York University (NYU) Established in 1831, New York University today includes thirteen schools, colleges and divisions located in New York City's borough of Manhattan, as well as research centers and programs in the surrounding suburbs and abroad. (http://nyu.edu/). 1 1 1 1 1 NEXOR A technology company that specialises in providing electronic communication software products and services to a worldwide market. It is also the home of CUSI. (http://nexor.com/). (1997-11-10) 1 1 1 1 1 Nexpert Object An expert system. 1 1 1 1 1 NeXT, Inc. The company founded by Steve Jobs [in ?] following his involuntary departure from Apple Computer, Inc.. NeXT produced both the hardware and operating system (NEXTSTEP). They changed their name to "NeXT Software" when they stopped making hardware and released NEXTSTEP For Intel processors. The company was bought by Apple in 1997(?). (1999-11-25) 1 1 1 1 1 Next Program Counter (nPC) A register in a CPU that contains the address of the instruction to be executed next. (2000-07-12) 1 1 1 1 1 NEXTSTEP The original multitasking operating system that NeXT, Inc. developed to run on its proprietary NeXT computers (informally known as "black boxes"). NEXTSTEP includes a specific graphical user interface, an interface builder, object-oriented application builder, and several "kits" of prebuilt software objects such as the Indexing Kit for databases. This software runs on top of NeXT's version of the Mach operating system on NeXT, 486, Pentium, HP-PA, and Sun SPARC computers. The official spelling changed from "NeXTstep" to "NeXTStep" to NeXTSTEP, and finally "NEXTSTEP". The last release of NEXTSTEP was 3.3, which NeXT then developed into "OpenStep". TjL's Pages (http://peak.org/~luomat/). Peanuts (http://peanuts.org/peanuts/NEXTSTEP/). See also: GNUStep. (2003-05-23) 1 1 1 1 1 nf The country code for Norfolk Island. (1999-01-27) 1 1 1 1 1 NFA Finite State Machine 1 1 1 1 1 NFQL ["NFQL: The Natural Forms Query Language", D. Embley, Trans Database Sys 14(2):168-211 (June 1989)]. 1 1 1 1 1 NFS Network File System 1 1 1 1 1 NFT Network File Transfer. An INTERLINK command on CERNVM. 1 1 1 1 1 ng The country code for Nigeria. (1999-01-27) 1 1 1 1 1 NGL A dialect of IGL. 1 1 1 1 1 NHOH Never heard of him/her. Often used in initgame. (1998-01-18) 1 1 1 1 1 ni The country code for Nicaragua. (1999-01-27) 1 1 1 1 1 NIAL Nested Interactive Array Language. A high-level array-oriented language from Queen's University, Canada, based on Array Theory as developed by Trenchard More Jr. Q'NIAL is an implementation in C. ["Programming Styles in NIAL", M.A. Jenkins et al, IEEE Software 3(1):46-55 (Jan 1986)]. (1995-01-25) 1 1 1 1 1 NIAL Systems Ltd. Distributors of Q'NIAL. Address: Ottawa Canada. Telephone: Canada (613) 234 4188. (1995-01-25) 1 1 1 1 1 NIAM Natural Language Information Analysis Method (or Nijssen IAM). 1 1 1 1 1 nibble /nib'l/ (US "nybble", by analogy with "bite" -> "byte") Half a byte. Since a byte is nearly always eight bits, a nibble is nearly always four bits (and can therefore be represented by one hex digit). Other size nibbles have existed, for example the BBC Microcomputer disk file system used eleven bit sector numbers which were described as one byte (eight bits) and a nibble (three bits). Compare crumb, tayste, dynner; see also bit, nickle, deckle. The spelling "nybble" is uncommon in Commonwealth Hackish as British orthography suggests the pronunciation /ni:'bl/. (1997-12-03) 1 1 1 1 1 Nibble Mode DRAM A standard DRAM where four successive bits can be clocked out of the single data line by successive pulses on the CAS\ line while RAS\ is active. A column address is only required for the first bit. This mode is now unfashionable but can be found on some older 64 kilobit and 256 kilobit chips. (1997-12-03) 1 1 1 1 1 NIC 1. <networking> Network Information Center. 2. <hardware> Network Interface Card. (1996-02-13) 1 1 1 1 1 NIC.DDN.MIL Defense Data Network's Network Information Center. (1996-02-13) 1 1 1 1 1 NICE The Nonprofit International Consortium for Eiffel. 1 1 1 1 1 nick [IRC] nickname. On IRC, every user must pick a nick, which is sometimes the user's real name or login name, but is often more fanciful. Compare handle. [Jargon File] 1 1 1 1 1 nickle /ni'kl/ ["nickel", common name for the US 5-cent coin] A nibble + 1; 5 bits. Reported among developers for Mattel's GI 1600 (the Intellivision games processor), a chip with 16 bit-wide RAM but 10 bit-wide ROM. See also deckle. 1 1 1 1 1 NICOL I 1. Small subset of PL/I by (Massachusetts) Computer Assoc, ca. 1965. Version: NICOL II (1967). Sammet 1969, p.542. 2. ICL, 1968. [same as 1?] 1 1 1 1 1 NIFOC Naked in front of computer. Possibly also typing with one hand. (2001-03-11) 1 1 1 1 1 Nightmare File System Pejorative hackerism for Sun's Network File System (NFS). In any nontrivial network of Suns where there is a lot of NFS cross-mounting, when one Sun goes down, the others often freeze up. Some machine tries to access the down one, and (getting no response) repeats indefinitely. This causes it to appear dead to some messages (what is actually happening is that it is locked up in what should have been a brief excursion to a higher spl level). Then another machine tries to reach either the down machine or the pseudo-down machine, and itself becomes pseudo-down. The first machine to discover the down one is now trying both to access the down one and to respond to the pseudo-down one, so it is even harder to reach. This situation snowballs very quickly, and soon the entire network of machines is frozen - worst of all, the user can't even abort the file access that started the problem! Many of NFS's problems are excused by partisans as being an 1 1 1 1 1 night mode phase 1 1 1 1 1 NIH The United States National Institutes of Health. 1 1 1 1 1 NIHCL A class library for C++ from the US National Institutes of Health (NIH). 1 1 1 1 1 NII National Information Infrastructure 1 1 1 1 1 NIKL Frame language. ["Recent Developments in NIKL", T.R. Kaczmarek et al, Proc AAAI-86, 1986]. 1 1 1 1 1 Niklaus Wirth The designer of the Modula-2, Modula-3, and, in around 1970, Pascal programming languages. [More info?] (2001-09-22) 1 1 1 1 1 NIL /nil/ 1. New Implementation of Lisp. A language intended to be the successor of MacLisp. A large Lisp, implemented mostly in VAX assembly language. A forerunner of Common LISP. ["NIL: A Perspective", Jon L. White, MACSYMA Users' Conf Proc, 1979]. 2. Network Implementation Language. Strom & Yemini, TJWRC, IBM. Implementation of complex networking protocols in a modular fashion. ["NIL: An Integrated Language and System for Distributed Programming", R. Strom et al, SIGPLAN Notices 18(6):73-82 (June 1983)]. 3. Empty list or False. In Lisp, the empty list (or "nil list") is used to represent the Boolean value False. This is possible because Lisp is not typed. True is represented by the special atom "t". 4. Spoken in reply to a question, particularly one asked using 1 1 1 1 1 niladic A less common synonym for "nullary", presumably following the more common monadic, dyadic, etc. The term was in use as early as 1976, and probably originated in APL. [APL: An Interactive Approach, 1976]. (2001-01-27) 1 1 1 1 1 Ninety-Ninety Rule "The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time". An aphorism attributed to Tom Cargill of Bell Labs, and popularised by Jon Bentley's September 1985 "Bumper-Sticker Computer Science" column in "Communications of the ACM". It was there called the "Rule of Credibility", a name which seems not to have stuck. [Jargon File] (1995-07-14) 1 1 1 1 1 Nintendo A Japanese video game hardware manufacturer and software publisher. Nintendo started by making playing cards, but was later dominant in video games throughout the 1980s and early 1990s worldwide. They make lots of games consoles including the Gameboy, Gameboy Advance SP, DS, DS Lite and the Wii. Nintendo home (http://nintendo.com/). (2008-03-08) 1 1 1 1 1 NIOS Netware Input/Output Subsystem 1 1 1 1 1 nipple Trackpoint 1 1 1 1 1 NIS Network Information Service 1 1 1 1 1 NISO National Information Standards Organisation (USA). NISO Standards cover many aspects of library science, publishing, and information services, and address the application of both traditional and new technologies to information services. 1 1 1 1 1 NISS National Information Services and Systems 1 1 1 1 1 NIST National Institute of Standards and Technology 1 1 1 1 1 NJCL Network Job Control Language. ["NJCL - A Network Job Control Language", J. du Masle et al, IFIP Congress 1974]. (1995-02-03) 1 1 1 1 1 nl The country code for the Netherlands (Holland). (1999-01-27) 1 1 1 1 1 NLANR National Laboratory for Applied Network Research 1 1 1 1 1 NLM Netware Loadable Module 1 1 1 1 1 NLP 1. <application> Natural Language Processing. 2. <networking> Network Layer Protocol. 1 1 1 1 1 NLRI network layer reachability information 1 1 1 1 1 NLS Native Language System 1 1 1 1 1 NLSP NetWare Link State Protocol 1 1 1 1 1 NLX A low-profile, low TCO motherboard design created jointly by Intel Corp., IBM, DEC and other PC vendors. In contrast to the traditional single-board design, NLX uses a riser card to carry PCI, ISA and AGP bus data (despite Intel's stated intent to rid PC motherboards of the ISA bus by 2000). Version 1.2 of NLX is the final specification, and was frozen in March 1997. Minor modifications appear in the form of Engineering Change Requests. (http://teleport.com/~nlx/). Intel (http://intel.com/design/motherboard/nlx.htm). ["NLX Motherboard Specification", various, pub. Intel Corp. 1997] (1998-09-21) 1 1 1 1 1 NMI Non-Maskable Interrupt 1 1 1 1 1 nML A specification language for instruction sets, based on attribute grammars, for back-end generators. ["The nML Machine Description Formalism", M. Freericks <mfx@cs.tu-berlin.de> TR TU Berlin, FB20, Bericht 1991/15]. (1995-11-28) 1 1 1 1 1 NMU Non-Maintainer Upload 1 1 1 1 1 NN neural network 1 1 1 1 1 nn A terminal based program for reading Usenet news by Kim F. Storm <storm@texas.dk>, Texas Instruments A/S, Denmark. nn lets you decide which of the many news groups you are interested in, and unsubscribe to those which don't interest you. nn lets you select articles to read from a menu in each of the groups you subscribe. nn sorts and presents new articles very quickly because it uses its own local database to maintain all the necessary information (this database is built and maintained by the nnmaster program). The NNTP support was designed and implemented by Ren'e Seindal, Institute of Datalogy, University of Copenhagen, Denmark. E-mail: <nn-bugs@dkuug.dk> (bugs, fixes, suggestions, etc.) Usenet newgroup: news:news.software.nn. (1995-12-04) 1 1 1 1 1 NNI Network Node Interface 1 1 1 1 1 NNTP Network News Transfer Protocol. (1996-02-26) 1 1 1 1 1 no The country code for Norway. (1999-01-27) 1 1 1 1 1 NOC Network Operations Center 1 1 1 1 1 NODAL Interpreted language implemented on Norsk Data's NORD-10 computers. Used by CERN and DESY high energy physics labs to control their accelerator hardware, PADAC and SEDAC. Included trackball input, graphics. 1 1 1 1 1 Nodal Switching System (NSS) Main routing nodes in the NSFnet backbone. 1 1 1 1 1 noddy /nod'ee/ [UK: from the children's books] 1. Small and un-useful, but demonstrating a point. Noddy programs are often written by people learning a new language or system. The archetypal noddy program is hello, world. Noddy code may be used to demonstrate a feature or bug of a compiler. May be used of real hardware or software to imply that it isn't worth using. "This editor's a bit noddy." 2. A program that is more or less instant to produce. In this use, the term does not necessarily connote uselessness, but describes a hack sufficiently trivial that it can be written and debugged while carrying on (and during the space of) a normal conversation. "I'll just throw together a noddy awk script to dump all the first fields." In North America this might be called a mickey mouse program. See toy program. 3. A simple (hence the name) language to handle text and interaction on the Memotech home computer. Has died with the machine. 1 1 1 1 1 node 1. A point or vertex in a graph. 2. network node. 3. A hypertext document. 1 1 1 1 1 noise Any part of a signal that is not the true or original signal but is introduced by the communication mechanism. A common example would be an electrical signal travelling down a wire to which noise is added by inductive and capacitive coupling with other nearby signals (this kind of noise is known as "crosstalk"). A less obvious form of noise is quantisation noise, such as the error between the true colour of a point in a scene in the real world and its representation as a pixel in a digital image. (2003-07-05) 1 1 1 1 1 noise margin The voltage difference between the guaranteed output level and the required input voltage level of a logic gate. (2007-05-16) 1 1 1 1 1 noise shaping Spectral noise transformation in a quantisation processes. Noise is "colourised" in the time domain an/or frequency domain by adding parts of the previous sample. The SNR bandwidth and SNR time integral stay the same, so some noise decreases, some increases, but overall noise always increases. An example of noise shaping in the frequency domain is quantisation of samples on a Compact Disc to reduce noise below -98 dB. The are different algorithms with slightly different filters, e.g. Super Bitmapping, 4D Recording. A time domain example is MPEG-4 AAC TNS, which is a method to enhance quality by temporal forming of the noise in a transform block. (2003-07-19) 1 1 1 1 1 NOL Never Offline 1 1 1 1 1 NOMAD A database language. Version: NOMAD2 from Must Software International. ["NOMAD Reference Manual", Form 1004, National CSS Inc, Dec 1976]. (1995-04-01) 1 1 1 1 1 NOMEX underwear /noh'meks uhn'-der-weir/ [Usenet] Synonym asbestos longjohns, used mostly in auto-related mailing lists and newsgroups. NOMEX underwear is an actual product available on the racing equipment market, used as a fire resistance measure and required in some racing series. [Jargon File] 1 1 1 1 1 Nominal Semidestructor Slang for "National Semiconductor", found among other places in the 4.3BSD networking sources. During the late 1970s to mid-1980s this company marketed a series of microprocessors including the National Semiconductor 16000 and National Semiconductor 32000. At one point early in the great microprocessor race, the specs on these chips made them look like serious competition for the rising Intel 80x86 and Motorola 680x0 series. Unfortunately, the actual parts were notoriously flaky and never implemented the full instruction set promised in their literature, apparently because the company couldn't get any of the mask steppings to work as designed. They eventually sank without trace, joining the Zilog Z8000 and a few even more obscure also-rans in the graveyard of forgotten microprocessors. (1994-12-23) 1 1 1 1 1 non-algorithmic procedure heuristic 1 1 1 1 1 non-constructive proof (Or "existence proof") A proof that something exists that does not provide an example of that thing or a method for finding an example. (A constructive proof does provide such an example or method). For example, for any pair of finite real numbers n < 0 and p > 0 there exists a real number 0 < k < 1 such that f(k) = (1-k)*n + k*p = 0. A non-constructive proof might proceed by observing that as k changes continuously from 0 to 1, f(k) changes continuously from n to p and, since they lie either side of zero, f(k) must pass through zero for some intermediate value of k. This proof does not tell us what that value of k is, only that it exists. Cantor's proof that the real numbers are uncountable can be thought of as a non-constructive proof that irrational numbers exist. There are existence theorems with no known constructive proof. 1 1 1 1 1 nondeterminism A property of a computation which may have more than one result. One way to implement a nondeterministic algorithm is using backtracking, another is to explore (all) possible solutions in parallel. (1995-04-13) 1 1 1 1 1 nondeterministic Exhibiting nondeterminism. 1 1 1 1 1 nondeterministic automaton (Or "probabilistic automaton") An automaton in which there are several possible actions (outputs and next states) at each state of the computation such that the overall course of the computation is not completely determined by the program, the starting state, and the initial inputs. See also nondeterministic Turing Machine. (1996-05-07) 1 1 1 1 1 nondeterministic polynomial time (NP) A set or property of computational decision problems solvable by a nondeterministic Turing Machine in a number of steps that is a polynomial function of the size of the input. The word "nondeterministic" suggests a method of generating potential solutions using some form of nondeterminism or "trial and error". This may take exponential time as long as a potential solution can be verified in polynomial time. NP is obviously a superset of P (polynomial time problems solvable by a deterministic Turing Machine in polynomial time) since a deterministic algorithm can be considered as a degenerate form of nondeterministic algorithm. The question then arises: is NP equal to P? I.e. can every problem in NP actually be solved in polynomial time? Everyone's first guess is "no", but no one has managed to prove this; and some very clever people think the answer is "yes". If a problem A is in NP and a polynomial time algorithm for A 1 1 1 1 1 Nondeterministic Turing Machine A normal (deterministic) Turing Machine that has a "guessing head" - a write-only head that writes a guess at a solution on the tape first, based on some arbitrary internal algorithm. The regular Turing Machine then runs and returns "yes" or "no" to indicate whether the solution is correct. A nondeterministic Turing Machine can solve nondeterministic polynomial time computational decision problems in a number of steps that is a polynomial function of the size of the input (1995-04-27) 1 1 1 1 1 non-impact printer Any printer, such as a laser printer, ink-jet printer, LED page printer, that prints without striking the paper, unlike a dot matrix printer which hits the paper with small pins. Non-impact printers are quieter than impact printers, and also faster due the lack of moving parts in the print head. (1995-11-20) 1 1 1 1 1 non-interlaced interlace 1 1 1 1 1 nonintrusive testing Testing that is transparent to the software under test, i.e., does not change its timing or processing characteristics. Nonintrusive testing usually involves additional hardware that collects timing or processing information and processes that information on another platform. 1 1 1 1 1 nonlinear (Scientific computation) A property of a system whose output is not proportional to its input. For example, a transistor has a region of input voltages for which its output voltage is found by multiplying the input voltage by the gain of the transistor. Outside this region though, the transistor behaves non-linearly, meaning that it does not obey this simple equation. The behaviour of a system containing non-linear components is thus harder to model and to predict. [Jargon File] 1 1 1 1 1 Non-Maintainer Upload (NMU) A release of a Debian package by someone other than its usual maintainer. E.g. "The bug was fixed in a recent NMU." (2014-09-30) 1 1 1 1 1 Non-Maskable Interrupt (NMI) An IRQ 7 on the PDP-11 or 680x0 or the NMI line on an 80x86. In contrast with a priority interrupt (which might be ignored, although that is unlikely), an NMI is *never* ignored. (1994-12-13) 1 1 1 1 1 non-optimal solution (Or "sub-optimal solution") An astoundingly stupid way to do something. This term is generally used in deadpan sarcasm, as its impact is greatest when the person speaking looks completely serious. See also Bad Thing. [Jargon File] (1994-12-13) 1 1 1 1 1 Nonpareil One of five pedagogical languages based on Markov algorithms, used in ["Nonpareil, a Machine Level Machine Independent Language for the Study of Semantics", B. Higman, ULICS Intl Report No ICSI 170, U London (1968)]. The others were Brilliant, Diamond, Pearl and Ruby. 1 1 1 1 1 non parity parity 1 1 1 1 1 non-polynomial The set or property of problems for which no polynomial-time algorithm is known. This includes problems for which the only known algorithms require a number of steps which increases exponentially with the size of the problem, and those for which no algorithm at all is known. Within these two there are problems which are provably difficult and "provably unsolvable". (1995-04-10) 1 1 1 1 1 Non Return to Zero Inverted (NRZI) A recording method used for 9-track magnetic tapes (200 and 800 BPI) where a zero is represented by a change in the signal and a one by no change. NRZI is also used extensively in SDLC communications. VTAM has a parameter NRZI=YES|NO. Compare Phase Encoded, GCR. (1999-01-11) 1 1 1 1 1 nontrivial Requiring real thought or significant computing power. Often used as an understated way of saying that a problem is quite difficult or impractical, or even entirely unsolvable ("Proving P=NP is nontrivial"). The preferred emphatic form is "decidedly nontrivial". See uninteresting, interesting. [Jargon File] (1995-02-21) 1 1 1 1 1 Non-Uniform Memory Access (NUMA) A memory architecture, used in multiprocessors, where the access time depends on the memory location. A processor can access its own local memory faster than non-local memory (memory which is local to another processor or shared between processors). (1995-11-12) 1 1 1 1 1 non-uniform quantising logarithmic compression The kind of compression often applied to a sound waveform. Logarithmic compression is a good match for the human ear's sensitivity but cannot handle zero amplitude (for which the logarithm is negative infinity). There are two standard compression functions which give a smooth transition between the logarithmic function and a linear segment passing through the origin: mu-law (North America) and A-law (ITU-T). (1995-02-21) 1 1 1 1 1 Non-Uniform Rational B Spline (nurbs) A common term in Mechanical CAD. The NURBS has excellent continuity characteristics which make it useful for creating accurate models in 3D geometry generation and computer modelling. [What is a nurbs? an rbs? a bs? a s?] (1996-08-27) 1 1 1 1 1 non-volatile non-volatile storage 1 1 1 1 1 non-volatile memory non-volatile storage 1 1 1 1 1 Non-Volatile Random Access Memory (NVRAM) Static random-access memory which is made into non-volatile storage either by having a battery permanently connected or by saving its contents to EEPROM before turning the power off and reloading it when power is restored. (1995-04-22) 1 1 1 1 1 non-volatile storage (NVS, persistent storage, memory) A term describing a storage device whose contents are preserved when its power is off. Storage using magnetic media (e.g. magnetic disks, magnetic tape or bubble memory) is normally non-volatile by nature whereas semiconductor memories (static RAM and especially dynamic RAM) are normally volatile but can be made into non-volatile storage by having a (rechargable) battery permanently connected. Dynamic RAM is particularly volatile since it looses its data, even if the power is still on, unless it is refreshed. An acoustic delay line is a (very old) example of a volatile storage device. Other examples of non-volatile storage are EEPROM, CD-ROM, paper tape and punched cards. (2000-05-22) 1 1 1 1 1 noob newbie 1 1 1 1 1 no-op /noh'op/ alt. NOP /nop/ [no operation] 1. A machine instruction that does nothing (sometimes used in assembler-level programming as filler for data or patch areas, or to overwrite code to be removed in binaries). See also JFCL. 2. A person who contributes nothing to a project, or has nothing going on upstairs, or both. As in "He's a no-op." 3. Any operation or sequence of operations with no effect, such as circling the block without finding a parking space, or putting money into a vending machine and having it fall immediately into the coin-return box, or asking someone for help and being told to go away. "Oh, well, that was a no-op." Hot-and-sour soup that is insufficiently either is "no-op soup"; so is wonton soup if everybody else is having hot-and-sour. [Jargon File] (1994-12-02) 1 1 1 1 1 NOR Not OR. The Boolean function which is true if none of its inputs are true and false otherwise, the logical complement of inclusive OR. The binary (two-input) NOR function can be defined (written as an infix operator): A NOR B = NOT (A OR B) = (NOT A) AND (NOT B) Its truth table is: A | B | A NOR B --+---+--------- F | F | T F | T | F 1 1 1 1 1 NORC COMPILER Early system on NORC machine. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 NorCroft (Contraction of Norman + Mycroft) A company producing C compilers, set up by Arthur Norman and Alan Mycroft. Now sort of called Codemist. The original Norcroft compiler was written by Alan and Arthur to provide a platform for teaching languages and compilers on the Cambridge University mainframe. They then went on to develop versions for the transputer, ARM and others. [What is the relationship between NorCroft and Codemist?] (1994-10-25) 1 1 1 1 1 NORD PL Intermediate language for Norsk Data computers. Sintran III, the operating system of the ND 10 (late 1970's), was written in NORD PL. ["NORD PL User's Guide", ND-60.047.03]. 1 1 1 1 1 NORDUnet (Nordic Universities Network?) A collaboration between the national research networks in Denmark, Finland, Iceland, Norway and Sweden. It provides international access for these countries. (http://info.nordu.net/). (1998-07-05) 1 1 1 1 1 norm A real-valued function modelling the length of a vector. The norm must be homogeneous and symmetric and fulfil the following condition: the shortest way to reach a point is to go straight toward it. Every convex symmetric closed surface surrounding point 0 introduces a norm by means of Minkowski functional; all vectors that end on the surface have the same norm then. The most popular norm is the Euclidean norm. (2004-02-15) 1 1 1 1 1 normal distribution (Or "Gaussian distribution") The frequency distribution of many natural phenomena such as the height or intelligence of people of a certain age and sex. The formula looks something like: P(x) = e^(((x-m)/s)^2) where P(x) is the probability of a measurement x, m is the mean value of x and s is the standard deviation. Also known as a "bell curve" because of its shape. (2003-10-25) 1 1 1 1 1 normal form 1. <reduction> In reduction systems, the state of a term which contains no reducible expressions. Variants include head normal form, weak head normal form. 2. <database> See database normalisation. 1 1 1 1 1 normalisation 1. <data processing> A transformation applied uniformly to each element in a set of data so that the set has some specific statistical property. For example, monthly measurements of the rainfall in London might be normalised by dividing each one by the total for the year to give a profile of rainfall throughout the year. 2. <programming> Representation of a floating-point number so that its mantissa's left-most digit is non-zero. If the leftmost fraction digit are zeros, the number is said to be unnormalised. Unnormalised numbers are normalised by shifting the fraction left, one digit at a time, until the leftmost digit is nonzero and reducing the exponent by the number of shifts. 3. <database> database normalisation. (1998-04-15) 1 1 1 1 1 normalised normalisation 1 1 1 1 1 normal order reduction Under this evaluation strategy an expression is evaluated by reducing the leftmost outermost redex first. This method will terminate for any expression for which termination is possible, whereas applicative order reduction may not. This method is equivalent to passing arguments unevaluated because arguments are initially to the right of functions applied to them. See also computational adequacy theorem. 1 1 1 1 1 normed space A vector space with a function, ||F||, such that ||F|| = 0 if and only if F=0 ||aF|| = abs(a) * ||F|| ||F+G|| <= ||F|| + ||G|| Roughly, a distance between two elements in the space is defined. (2000-03-10) 1 1 1 1 1 northbridge The single integrated circuit in a core logic chip set that connects the CPU to the system memory and the AGP and PCI busses. Other functions are provided by the southbridge chip. (http://maximumpc.com/terminator/terminator_n.html). (2000-01-15) 1 1 1 1 1 NorthWestNet (NWNET) Kochmer, J., and NorthWestNet, "The Internet Passport: NorthWestNets Guide to Our World Online", NorthWestNet, Bellevue, WA, 1992. 1 1 1 1 1 NOS Network Operating System 1 1 1 1 1 NOT The Boolean function which is true only if its input is false. Its truth table is: A | NOT A --+------ F | T T | F (1996-11-04) 1 1 1 1 1 Not-a-Number (NaN) An IEEE floating point representation for the result of a numerical operation which cannot return a valid number value. A NaN can result from multiplying an infinity by a zero, or from subtracting one infinity from another [what else?]. NaN is encoded as a special bit pattern [what pattern?] which would otherwise represent a floating-point number. It is used to signal error returns where other mechanisms are not convenient, e.g. a hardware floating-point unit and to allow errors to propagate through a calculation. Similar bit patterns represent positive and negative overflow and underflow and the positive and negative infinities resulting from division by zero. Bit patterns (http://psc.edu/general/software/packages/ieee/ieee.html). [ANSI/IEEE Std 754-1985]. [Correct?] 1 1 1 1 1 notebook 1. <computer> laptop computer. 2. <tool> Labtech Notebook. (1998-01-05) 1 1 1 1 1 NoteCards An ambitious hypertext system developed at Xerox PARC, "designed to support the task of transforming a chaotic collection of unrelated thoughts into an integrated, orderly interpretation of ideas and their interconnections." 1 1 1 1 1 Notepad The very basic text editor supplied with Microsoft Windows. (1998-01-05) 1 1 1 1 1 Notes Lotus Notes 1 1 1 1 1 Nother A parallel symbolic mathematics system. E-mail: <karhu@cs.umu.se>. 1 1 1 1 1 not ready for prime time Usable, but only just so; not very robust; for internal use only. Said of a program or device. Often connotes that the thing will be made more solid Real Soon Now. This term comes from the ensemble name of the original cast of "Saturday Night Live", the "Not Ready for Prime Time Players". It has extra flavour for hackers because of the special (though now semi-obsolescent) meaning of prime time. Compare beta. [Jargon File] 1 1 1 1 1 notspot In contrast with wireless hotspot, a place where there is no means to connect to the Internet. While the term "hotspot" refers to a wireless local area network, "notspot" might also mean a place without decent DSL (broadband Internet) connection. (2009-05-28) 1 1 1 1 1 notwork /not'werk/ A network that is performing badly. Said at IBM to have originally referred to a particular period of flakiness on IBM's VNET corporate network ca. 1988; but there are independent reports of the term from elsewhere. The joke sounds better in Russian, where "nyet" means "no", hence nyetwork /nyet'werk/. (2009-05-28) 1 1 1 1 1 Nova A minicomputer(?) introduced by Data General in 1969, with four 16-bit accumulators, AC0 to AC3, and a 15-bit program counter. A later model also had a 15-bit stack pointer and frame pointer. AC2 and AC3 could be used for indexed addressing and AC3 was used to store the return address on a subroutine call. Apart from the small register set, the NOVA was an ordinary CPU design. Memory could be accessed indirectly through addresses stored in other memory locations. If locations 0 to 3 were used for this purpose, they were auto-incremented after being used. If locations 4 to 7 were used, they were auto-decremented. Memory could be addressed in 16-bit words up to a maximum of 32K words (64K bytes). The instruction cycle time was 500 nanoseconds(?). The Nova originally used core memory, then later dynamic RAM. Like the PDP-8, the Data General Nova was also copied, not just in one, but two implementations - the Data General 1 1 1 1 1 Novell Data Systems A small computer hardware company building CP/M Z80-based systems. They later went on to become Novell, Inc. and develop Novell Netware. (1995-09-23) 1 1 1 1 1 Novell DOS Novell's fully compatible alternative to MS-DOS. It is intended as an operating system for workstations on Novell networks. It features enhanced memory management that moves the operating system, network drivers, and memory-resident programs (TSRs) out of conventional memory on all systems with an Intel 80286 or later processor and extended memory or expanded memory. It supports preemptive multitasking and peer-to-peer networking using the same DOS Requester and VLMs for a common client with native Novell NetWare. A data compression utility effectively doubles storage capacity of the hard disk. It supports disk defragmentation, a read/write disk cache for better performance of both DOS and Microsoft Windows application programs. An undelete utility recovers erased files, even on network drives. It has a complete on-line reference guide, command help, and menu-driven install and setup utilities for 1 1 1 1 1 Novell, Inc. A software development company specialising in networking and workgroup applications. Novell started life as Novell Data Systems, a computer hardware business. The company was reorganised as Novell, Inc., and began to focus almost entirely on networking in 1983, with the release of Novell Netware 1, a Network Operating System for IBM PCs. Novell Netware's success has left Novell in a dominant position in the networking market. The product has evolved and now supports many hardware and software platforms together with WAN connectivity. The company has diversified in recent years, with the acquisition of several mainstream applications, including Wordperfect and Quattro Pro. Other products include UnixWare, AppWare, Personal NetWare, Groupwise and Novell Dos 7. (http://novell.com/). 1 1 1 1 1 Novell NetWare Novell, Inc.'s proprietary networking operating system for the IBM PC. NetWare uses the IPX/SPX, NetBEUI or TCP/IP network protocols. It supports MS-DOS, Microsoft Windows, OS/2, Macintosh and Unix clients. NetWare for Unix lets users access Unix hosts. NetWare 2.2 is a 16-bit operating system, versions 4.x and 3.x are 32-bit operating systems. (http://netware.novell.com/). Usenet newsgroup: news:comp.sys.novell. ["Netware", K. Siyan, pub. New Riders]. [LAN Magazine, Sep 1993]. (1996-01-13) 1 1 1 1 1 NOWEB A system of structured programming and documentation from M.Speh in DESY. See literate programming. (1996-01-13) 1 1 1 1 1 no-write allocation A cache policy where only processor reads are cached, thus avoiding the need for write-back or write-through. (1996-06-12) 1 1 1 1 1 NP nondeterministic polynomial time. [Jargon File] 1 1 1 1 1 np The country code for Nepal. (1999-01-27) 1 1 1 1 1 NPC 1. <complexity> NP-complete. 2. <architecture> Next Program Counter. (2000-07-12) 1 1 1 1 1 NP-complete (NPC, Nondeterministic Polynomial time complete) A set or property of computational decision problems which is a subset of NP (i.e. can be solved by a nondeterministic Turing Machine in polynomial time), with the additional property that it is also NP-hard. Thus a solution for one NP-complete problem would solve all problems in NP. Many (but not all) naturally arising problems in class NP are in fact NP-complete. There is always a polynomial-time algorithm for transforming an instance of any NP-complete problem into an instance of any other NP-complete problem. So if you could solve one you could solve any other by transforming it to the solved one. The first problem ever shown to be NP-complete was the satisfiability problem. Another example is Hamilton's problem. See also computational complexity, halting problem, Co-NP, NP-hard. 1 1 1 1 1 NP-hard A set or property of computational search problems. A problem is NP-hard if solving it in polynomial time would make it possible to solve all problems in class NP in polynomial time. Some NP-hard problems are also in NP (these are called NP-complete), some are not. If you could reduce an NP problem to an NP-hard problem and then solve it in polynomial time, you could solve all NP problems. See also computational complexity. [Examples?] (1995-04-10) 1 1 1 1 1 NP-hilarious An algorithm whose complexity is a joke, either literally, as in BogoSort, or metaphorically. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-06-28) 1 1 1 1 1 NPL 1. New Programming Language. IBM's original (temporary) name for PL/I, changed due to conflict with England's "National Physical Laboratory." MPL and MPPL were considered before settling on PL/I. Sammet 1969, p.542. 2. A functional language with pattern matching designed by Rod Burstall and John Darlington in 1977. The language allowed certain sets and logic constructs to appear on the right hand side of definitions, E.g. setofeven(X) <= <:x: x in X & even(x) :> The NPL interpreter evaluates the list of generators from left to right so conditions can mention any bound variables that occur to their left. These were known as set comprehensions. NPL eventually evolved into Hope but lost set comprehensions which were called list comprehensions in later functional languages. [John Darlington, "Program Transformation and Synthesis: 1 1 1 1 1 NPPL Network Picture Processing Language. An interactive language for manipulation of digraphs. ["A Graph Manipulator for On-line Network Picture Processing", H.A. DiGiulio, Proc FJCC 35 (1969)]. 1 1 1 1 1 N-Prolog Prolog extended with explicit negation. Dov Gabbay <dg@doc.ic.ac.uk>. [J Logic Programming]. 1 1 1 1 1 NP time nondeterministic polynomial time 1 1 1 1 1 NP tricky A play on NP hard describing an algorithm or piece of code that is too complicated for a mere mortal to understand. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-06-18) 1 1 1 1 1 NQS Batch processing software for Unix systems. 1 1 1 1 1 Nqthm The language used in the Boyer-Moore theorem prover. ["Proving Theorems About LISP Functions", R.S. Boyer et al JACM 22(1):129-144 (Jan 1975)]. 1 1 1 1 1 nr The country code for Nauru. (1999-01-27) 1 1 1 1 1 NREN National Research and Education Network 1 1 1 1 1 nroff /N'rof/ [Unix, from "new roff"] A text formatting language and interpreter, companion to the Unix typesetter troff, accepting identical input but preparing output for terminals and line printers. See also groff. [Jargon File] (2012-12-14) 1 1 1 1 1 NRZ Non Return to Zero 1 1 1 1 1 NRZI Non Return to Zero Inverted 1 1 1 1 1 ns nanosecond 1 1 1 1 1 NS16000 National Semiconductor 16000 1 1 1 1 1 NS32000 National Semiconductor 32000 1 1 1 1 1 NSA line eater The National Security Agency trawling program sometimes assumed to be reading the net for the US Government's spooks. Most hackers describe it as a mythical beast, but some believe it actually exists, more aren't sure, and many believe in acting as though it exists just in case. Some netters put loaded phrases like "KGB", "Uzi", "nuclear materials", "Palestine", "cocaine", and "assassination" in their sig blocks to confuse and overload the creature. The GNU version of Emacs actually has a command that randomly inserts a bunch of insidious anarcho-verbiage into your edited text. There is a mainstream variant of this myth involving a "Trunk Line Monitor", which supposedly used speech recognition to extract words from telephone trunks. This one was making the rounds in the late 1970s, spread by people who had no idea of then-current technology or the storage, signal-processing, or speech recognition needs of such a project. On the basis 1 1 1 1 1 NSAPI Netscape Application Programming Interface 1 1 1 1 1 NSDI National Spatial Data Infrastructure 1 1 1 1 1 NSE Network Software Environment: a proprietary CASE framework from Sun Microsystems. 1 1 1 1 1 NSF National Science Foundation 1 1 1 1 1 NSFIP NEXTSTEP For Intel Processor. (1999-11-25) 1 1 1 1 1 NSFNET National Science Foundation Network 1 1 1 1 1 NSI Network Solutions, Inc. 1 1 1 1 1 nslookup A Unix utility program, originally by Andrew Cherenson, for querying Internet domain name servers. The basic use is to find the IP address corresponding to a given hostname (or vice versa). By changing the query type (e.g. "set type=CNAME") other types of information can be obtained including CNAME - the canonical name for an alias; HINFO - the host CPU and operating system type; MINFO - mailbox or mail list information; MX - mail exchanger information; NS - the name server for the named zone; PTR - the hostname if the query is an IP address, otherwise the pointer to other information; SOA the domain's start-of-authority information; TXT - text information; UINFO - user information; WKS - supported well-known services. Other types (ANY, AXFR, MB, MD, MF, NULL) are described in RFC 1035. (ftp://src.doc.ic.ac.uk/computing/operating-systems/unix/bsd-sources/usr.sbin/named/tools/nslookup/). (1994-10-27) 1 1 1 1 1 NSRD National Software Reuse Directory 1 1 1 1 1 NSS 1. <networking> Nodal Switching System. 2. <operating system> New Storage System. (1997-01-29) 1 1 1 1 1 NT 1. Network Termination. 2. New Technology, as in Windows NT. 1 1 1 1 1 NT1 Network Termination 1 1 1 1 1 NT5 Windows 2000 1 1 1 1 1 ntalk ("new talk") An update of the Unix "talk" program, old versions of "talk" being referred to as "old talk". New talk and old talk are generally incompatible, and attempts to get them to communicate result in entirely unhelpful error messages. On most modern Unix systems, the program "talk" is new talk, with some SunOS versions being a notable and annoying exception to this. (1997-09-11) 1 1 1 1 1 NTAS NT Advanced Server 1 1 1 1 1 NT File System (NTFS) The native file system of Windows NT. (1995-03-06) 1 1 1 1 1 NTFS NT File System 1 1 1 1 1 n-tier three-tier 1 1 1 1 1 NTIS National Technical Information Service 1 1 1 1 1 NTMBS null-terminated multibyte string. (1995-10-02) 1 1 1 1 1 NTP Network Time Protocol 1 1 1 1 1 NTSC National Television Standards Committee 1 1 1 1 1 NTU Network Termination Unit 1 1 1 1 1 nu The country code for Niue. (1999-01-27) Because it sounds like "new", nu is heavily used for vanity domains. (1999-01-27) 1 1 1 1 1 NuBus The proprietary expansion bus used on Apple Macintosh personal computers. (1995-02-03) 1 1 1 1 1 nu-calculus An asynchronous version of pi-calculus. 1 1 1 1 1 NUCLEOL List processing language, influenced by EOL. J. Nievergelt, Computer J 13(3) (Aug 1970). 1 1 1 1 1 nude Said of machines delivered without an operating system (compare bare metal). "We ordered 50 systems, but they all arrived nude, so we had to spend a an extra weekend with the installation tapes." This usage is a recent innovation reflecting the fact that most PC clones are now delivered with DOS or Microsoft Windows pre-installed at the factory. Other kinds of hardware are still normally delivered without OS, so this term is particular to PC support groups. [Jargon File] (1994-12-13) 1 1 1 1 1 nuke /n[y]ook/ 1. To intentionally delete the entire contents of a given directory or storage volume. "On Unix, "rm -r /usr" will nuke everything in the usr file system." Never used for accidental deletion. 2. Synonym for dike, applied to smaller things such as files, features, or code sections. Often used to express a final verdict. "What do you want me to do with that 80-meg wallpaper file?" "Nuke it." 3. Used of processes as well as files; nuke is a frequent verbal alias for "kill -9" on Unix. 4. On IBM PCs, a bug that results in fandango on core can trash the operating system, including the FAT (the in-core copy of the disk block chaining information). This can utterly scramble attached disks, which are then said to have been "nuked". This term is also used of analogous lossages on Macintoshes and other micros without memory protection. [Jargon File] 1 1 1 1 1 null A special value used in several languages to represent the thing referred to by an uninitialised pointer. <database> A special value that may be stored in some database columns to represent an unknown, missing, not applicable, or undefined value. Nulls are treated completely differently from ordinary values when evaluating SQL expressions and there are several SQL constructs for dealing with nulls. (2003-06-17) 1 1 1 1 1 nullary A description of an operator or function which takes no arguments, e.g. a function that returns the current time. Nullary is part of the unary, binary, ternary sequence, and is more common than its synonym niladic. (2001-02-25) 1 1 1 1 1 null modem A cable, especially an EIA-232 cable, for connecting serial ports on two computers directly, rather than via modems. Since, according to the specification, both computers should transmit on pin three of their EIA-232 connectors and receive on pin two, a null modem cable needs to connect one computer's pin two to the other's pin three and vice versa. It also needs to have male connectors at both ends (again, according to the specification). (1996-05-17) 1 1 1 1 1 null-terminated multibyte string (NTMBS) (Defined in the ANSI C++ draft) [Different from null-terminated string?] (1995-10-02) 1 1 1 1 1 NUMA Non-Uniform Memory Access 1 1 1 1 1 Number 5 Electronic Switching System (5ESS) An electronic circuit switching product sold by Alcatel Lucent (formerly Western Electric/AT&T Network Systems/Lucent Technologies), used by many telephone exchange carriers and service providers. Succeeded the Number 4 Electronic Switching System (4ESS) and reached widespread use in the 1980s. Not to be confused with the Class 5 Switch. (2013-09-14) 1 1 1 1 1 number crunching Computations of a numerical nature, especially those that make extensive use of floating-point numbers. The only thing Fortrash is good for. This term is in widespread informal use outside hackerdom and even in mainstream slang, but has additional hackish connotations: namely, that the computations are mindless and involve massive use of brute force. This is not always evil, especially if it involves ray tracing or fractals or some other use that makes pretty pictures, especially if such pictures can be used as wallpaper. See also crunch. [Jargon File] (1995-03-17) 1 1 1 1 1 number keys keypad 1 1 1 1 1 numbers (Scientific computation) Output from a computation that may not be significant but at least indicates that the program is running. Numbers may be used to placate management, grant sponsors, etc. "Making numbers" means running a program because output - any output, not necessarily meaningful output #NAME? See pretty pictures, math-out, social science number. [Jargon File] (1995-01-13) 1 1 1 1 1 number sign hash. 1 1 1 1 1 numeric keypad A keypad that has become a standard feature of PC keyboards, consisting of a rectangular array of 17 extra keys at the right-hand end: 0-9, ., Num Lock, /, *, -, + and Enter. Apart from Num Lock, these typically duplicate the function of other keys but are designed to make entering basic numerical calculations as quick as on a digital calculator. It is often possible to assign completely different functions to these keys according to the needs of a particular application. (2007-01-31) 1 1 1 1 1 Numeris The name given by France Telecom, the french telephone network operator, to its ISDN network. (1995-01-31) 1 1 1 1 1 Nuprl /nyu p*rl/ Nearly Ultimate PRL. A system for interactive creation of formal mathematics, including definitions and proofs. It has an extremely rich type system, including dependent functions, products, sets, quotients and universes. Types are first-class citizens. It is built on Franz Lisp and Edinburgh ML. ["Implementing Mathematics in the Nuprl Proof Development System", R.L. Constable et al, P-H 1986]. (1994-12-13) 1 1 1 1 1 NU-Prolog L. Naish, U Melbourne. A Prolog with 'when' declarations, the successor to MU-Prolog. Type-checked. "NU-Prolog Reference Manual - Version 1.3", J.A. Thom et al eds, TR 86/10, U Melbourne (1988). Available (but not free). (See PNU-Prolog). E-mail: <jas@mulga.oz.au>. 1 1 1 1 1 nurbs Non-Uniform Rational B Spline 1 1 1 1 1 Nu Thena A software vendor specialising in rapid prototyping tools for real-time hardware and software systems and collaborating with DAZIX. 1 1 1 1 1 NUXI problem /nuk'see pro'bl*m/ The problem of transferring data between computers with differing byte order. The string "Unix" might look like "NUXI" on a machine with a different "byte sex" (e.g. when transferring data from a little-endian to a big-endian, or vice-versa). See also middle-endian, swab, and bytesexual. [Jargon File] (2001-06-12) 1 1 1 1 1 NVL A function in Oracle SQL called like NVL(X, Y) that returns X unless it is null, in which case it returns Y. This function is useful for supplying a default value where an expression might be null. (2010-01-28) 1 1 1 1 1 NVRAM Non-Volatile Random Access Memory 1 1 1 1 1 NVS Non-Volatile Storage 1 1 1 1 1 NWNET NorthWestNet 1 1 1 1 1 NYAP An early system on the IBM 704. [Listed in CACM 2(5):16, May 1959]. (1997-12-03) 1 1 1 1 1 nybble nibble 1 1 1 1 1 nyet.gif A file that crackers from Russia tied to upload to many web sites in 2014 to test whether the victim's web server software was configured to accepted HTTP PUT requests. (2014-11-23) 1 1 1 1 1 nyetwork notwork 1 1 1 1 1 nym 1. <tool, networking> /nim/ (From the third syllable of anonymous; or "nym server") A server that functions as an anonymous remailer. 2. A popular hostname for nym servers. 3. A mail-forwarding account on a nym server. (1999-02-26) 1 1 1 1 1 nym server nym 1 1 1 1 1 Nyquist frequency The highest frequency that can be represented in a digital signal of a specified sampling frequency. It is equal to one-half of the sampling rate. See Nyquist Theorem. (2001-06-06) 1 1 1 1 1 Nyquist Theorem A theorem stating that when an analogue waveform is digitised, only the frequencies in the waveform below half the sampling frequency will be recorded. In order to reconstruct (interpolate) a signal from a sequence of samples, sufficient samples must be recorded to capture the peaks and troughs of the original waveform. If a waveform is sampled at less than twice its frequency the reconstructed waveform will effectively contribute only noise. This phenomenon is called "aliasing" (the high frequencies are under an alias). This is why the best digital audio is sampled at 44,000 Hz - twice the average upper limit of human hearing. The Nyquist Theorem is not specific to digitised signals (represented by discrete amplitude levels) but applies to any sampled signal (represented by discrete time values), not just sound. Nyquist 1 1 1 1 1 NYSERNET New York State Educational Reasearch NETwork 1 1 1 1 1 NYU OMNIFAX Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 nz The country code for New Zealand. (1999-01-27) 1 1 1 1 1 O ASCII code 79, The letter of the alphabet, not to be confused with 0 (zero) the digit. (1999-02-07) 1 1 1 1 1 O2 Object-Oriented. Object-oriented database language used in the Altair project. Implemented as an interpreter. GIP Altair, Versailles, France. Francois Bancilhon et al, in Advances in Object-Oriented Database Systems, K.R. Dittrich ed, LNCS 334, Springer 1988. See CO2. 1 1 1 1 1 Oaklisp A portable object-oriented Scheme by K. Lang and Barak Perlmutter of Yale. Oaklisp uses a superset of Scheme syntax. It is based on generic operations rather than functions, and features anonymous classes, multiple inheritance, a strong error system, setters and locators for operations and a facility for dynamic binding. Version 1.2 includes an interface, bytecode compiler, run-time system and documentation. (ftp://f.gp.cs.cmu.edu/usr/bap/oak/ftpable/), for Amiga (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/ff519). ["Oaklisp: An Object-Oriented Scheme with First-Class Types", K. Lang et al, SIGPLAN Notices 21(11):30-37 (Nov 1986) (OOPSLA '86)]. (1992-05-01) 1 1 1 1 1 OAP Outside Awareness Port 1 1 1 1 1 OASIS Open Document Format for Office Applications OpenDocument 1 1 1 1 1 OATH Object-oriented Abstract Type Hierarchy, a class library for C++ from Texas Instruments. 1 1 1 1 1 Ob- /ob/ prefix Obligatory. A piece of netiquette acknowledging that the author has been straying from the newsgroup's charter topic. For example, if a posting in alt.sex is a response to a part of someone else's posting that has nothing particularly to do with sex, the author may append "ObSex" (or "Obsex") and toss off a question or vignette about some unusual erotic act. It is considered a sign of great winnitude when one's Obs are more interesting than other people's whole postings. [Jargon File] 1 1 1 1 1 OBDC Do you mean ODBC? (1996-06-30) 1 1 1 1 1 OBE Office By Example 1 1 1 1 1 Oberon A strongly typed procedural programming language and an operating environment evolved from Modula-2 by Nicklaus Wirth in 1988. Oberon adds type extension (inheritance), extensible record types, multidimensional open arrays, and garbage collection. It eliminates variant records, enumeration types, subranges, lower array indices and for loops. A successor called Oberon-2 by H. Moessenboeck features a handful of extensions to Oberon including type-bound procedures (methods). Seneca is a variant of Oberon focussing on numerical programming under development by R. Griesemer in April 1993 (to be renamed). See also Ceres workstation Oberon System. (http://oberon.ethz.ch). (http://math.tau.ac.il/~laden/Oberon.html). Free ETH Oberon (ftp://ftp.inf.ethz.ch/pub/Oberon). MS-DOS 1 1 1 1 1 Oberon-2 A superset of Oberon-1, developed by H. Moessenboeck in 1991 to add object-orientation. Oberon-2 was a redesign of Object Oberon. It included type-bound procedures (equivalent to methods), read-only export of variables and record fields, open array variables, and a with statement with variants. It reintroduced the "for" statement. There is an Oberon-2 Lex scanner and Yacc parser by Stephen J Bevan of Manchester University, UK, based on the one in the Mo"ssenbo"ck and Wirth reference. Version 1.4. (ftp://neptune.inf.ethz.ch/Oberon/). (ftp://ftp.psg.com/pub/oberon/). ["The Programming Language Oberon-2", H. Mo"ssenbo"ck, N. Wirth, Institut fu"r Computersysteme, ETH Zu"rich, January 1992]. ["Second International Modula-2 Conference", Sept 1991]. (1992-07-06) 1 1 1 1 1 Oberon-V (Formerly Seneca). R. Griesemer, 1990. Descendant of Oberon designed for numerical applications on supercomputers, especially vector or pipelined architectures. Includes array constructors and an ALL statement. "Seneca - A Language for Numerical Applications on Vectorcomputers", Proc CONPAR 90 - VAPP IV Conf. R. Griesemer, Diss Nr. 10277, ETH Zurich. 1 1 1 1 1 OBEX Object Exchange 1 1 1 1 1 obfuscated Made unclear, used to describe source code that has been transformed or written to make it as hard as possible to read, usually for fun, as in the Obfuscated C Contest. A japh is a kind of obfuscated Perl program. The term is not normally used for code that has been transformed for security purposes, e.g. to enforce some kind of licencing mechanism. (2009-05-14) 1 1 1 1 1 Obfuscated C Contest The International Obfuscated C Code Contest (IOCCC) is an annual contest run since 1984 over Usenet by Landon Curt Noll and friends. The overall winner is whoever produces the most unreadable, creative, and bizarre (but working) C program. Various other prizes are awarded at the judges' whim. C's terse syntax and macro-preprocessor facilities give contestants a lot of maneuvering room. The winning programs often manage to be simultaneously funny, breathtaking works of art and horrible examples of how *not* to code in C. This relatively short and sweet hello, world program demonstrates obfuscated C: /* HELLO WORLD program * by Jack Applin and Robert Heckendorn, 1985 */ main(v,c)char**c;for(v[c++]="Hello, world!\n)"; (!!c)[*c]&&(v--||--c&&execlp(*c,*c,c[!!c]+!!c,!c)); **c=!c)write(!!*c,*c,!!**c); 1 1 1 1 1 obi-wan error /oh'bee-won" er"*r/ (RPI, from "off-by-one" and the Obi-Wan Kenobi character in "Star Wars") A kind of off-by-one error. (2009-05-14) 1 1 1 1 1 OBJ Joseph Goguen 1976. A family of declarative "ultra high level" languages. Abstract types, generic modules, subsorts (subtypes with multiple inheritance), pattern-matching modulo equations, E-strategies (user control over laziness), module expressions (for combining modules), theories and views (for describing module interfaces). For the massively parallel RRM (Rewrite Rule Machine). ["Higher-Order Functions Considered Unnecessary for Higher-Order Programming", J.A. Goguen, in Research Topics in Functional Programming]. 1 1 1 1 1 OBJ0 Tardo. Based on unsorted equational logic. 1 1 1 1 1 OBJ2 Clear-like parametrised modules. A functional system based on equations. "Principles of OBJ2", K. Futatsugi et al, 12th POPL, ACM 1985, pp.52-66. 1 1 1 1 1 OBJ3 A version of OBJ based on order-sorted rewriting. OBJ3 is agent-oriented and runs on AKCL. E-mail: <obj3sys@crl.sri.com>, <obj3dist@csl.sri.com>. ["Introducing OBJ3", J. Goguen et al, SRI-CSL-88-9, SRI Intl, 1988]. (1995-03-16) 1 1 1 1 1 object In object-oriented programming, an instance of the data structure and behaviour defined by the object's class. Each object has its own values for the instance variables of its class and can respond to the methods defined by its class. For example, an object of the "Point" class might have instance variables "x" and "y" and might respond to the "plot" method by drawing a dot on the screen at those coordinates. (2004-01-26) 1 1 1 1 1 ObjectBroker A distributed object system from DEC based on the CORBA standard. (1999-01-14) 1 1 1 1 1 ObjectCenter A product offering similar facilities to CodeCenter for the C++ language, plus class browsing facilities etc (formerly Saber-C++). 1 1 1 1 1 Object CHILL ["Object CHILL - An Object Oriented Language for Systems Implementation", J. Winkler et al, ACM Comp Sci Conf 1992, pp. 139-147]. (1995-01-31) 1 1 1 1 1 object code The machine code generated by a source code language processor such as an assembler or compiler. A file of object code may be immediately executable or it may require linking with other object code files, e.g. libraries, to produce a complete executable program. (1995-01-31) 1 1 1 1 1 Object-code Buffer Overrun Evaluator (OBOE) A tool by R. Banfi, D. Bruschi, and E. Rosti for the automatic detection of buffer overflow vulnerabilities in object code. OBOE can be applied to operating system components as well as ordinary application programs. It was designed for the system administrator to identify vulnerable programs before they are exploited. Being automatic, OBOE can be run as a background process for the analysis of all potentially insecure programs installed on a Unix system. It runs on HP-UX, Linux, and Sun Solaris. (http://idea.sec.dsi.unimi.it/research.html). (2003-10-25) 1 1 1 1 1 Object Compatibility Standard (OCS) An 88open standard for compilers and linkers. 1 1 1 1 1 Object Constraint Language (OCL) A formal specification language extension to UML. The Object Constraint Language is a precise text language that provides constraint and object query expressions on an object-oriented model that cannot otherwise be expressed by diagrammatic notation. OCL supplements UML by providing expressions that have neither the ambiguities of natural language nor the inherent difficulty of using complex mathematics. OCL is a descendent of Syntropy, a second-generation object-oriented analysis and design method. The OCL 1.4 definition specified a constraint language. In OCL 2.0, the definition has been extended to include general object query language definitions. OMG UML Home (http://uml.org/). Rational UML Resource Center (http://rational.com/uml/index.jsp). OCL 2.0 Submission to UML 1 1 1 1 1 Object Database Management Group Object Data Management Group 1 1 1 1 1 Object Data Management Group (ODMG, previously ".. Database ..") An independent consortium that specifies universal object storage standards. ODMG's members include object-oriented database management system (ODBMS) vendors and other interested parties. They aim to increase portability of customer software across products. On 1998-04-27 ODMG changed its name from the Object Database Management Group to reflect the expansion of its efforts beyond merely setting storage standards for object databases. (http://odmg.org/). (2000-05-23) 1 1 1 1 1 Objecteering An object-oriented design tool from Softeam, based on the Class Relation Methodology, with C++ code generation. (1997-03-18) 1 1 1 1 1 Object Exchange (OBEX) A Bluetooth protocol in the Core Protocol Stack for data exchange. (2002-06-28) 1 1 1 1 1 objectfuscated code Object-oriented code which has been abstracted to so many levels that no-one can understand it anymore. A play on obfuscated code. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-08-01) 1 1 1 1 1 object identifier (OID) Generally an implementation-specific integer or pointer that uniquely identifies an object. (1999-07-10) 1 1 1 1 1 Objectionable-C A hackish take on "Objective C". Objectionable-C uses a Smalltalk-like syntax, but lacks the flexibility of Smalltalk method calls, and (like many such efforts) comes frustratingly close to attaining the Right Thing without actually doing so. [Jargon File] (1995-02-15) 1 1 1 1 1 Objective C An object-oriented superset of ANSI C by Brad Cox, Productivity Products. Its additions to C are few and are mostly based on Smalltalk. Objective C is implemented as a preprocessor for C. Its syntax is a superset of standard C syntax, and its compiler accepts both C and Objective C source code (filename extension ".m"). It has no operator overloading, multiple inheritance, or class variables. It does have dynamic binding. It is used as the system programming language on the NeXT. As implemented for NEXTSTEP, the Objective C language is fully compatible with ANSI C. Objective C can also be used as an extension to C++, which lacks some of the possibilities for object-oriented design that dynamic typing and dynamic binding bring to Objective C. C++ also has features not found in Objective C. Versions exist for MS-DOS, Macintosh, VAX/VMS and Unix workstations. Language versions by Stepstone, 1 1 1 1 1 Objective CAML (Originally "CAML" - Categorical Abstract Machine Language) A version of ML by G. Huet, G. Cousineau, Ascander Suarez, Pierre Weis, Michel Mauny and others of INRIA. CAML is intermediate between LCF ML and SML [in what sense?]. It has first-class functions, static type inference with polymorphic types, user-defined variant types and product types, and pattern matching. It is built on a proprietary run-time system. The CAML V3.1 implementation added lazy and mutable data structures, a "grammar" mechanism for interfacing with the Yacc parser generator, pretty-printing tools, high-performance arbitrary-precision arithmetic, and a complete library. in 1990 Xavier Leroy and Damien Doligez designed a new implementation called CAML Light, freeing the previous implementation from too many experimental high-level features, and more importantly, from the old Le_Lisp back-end. 1 1 1 1 1 Objective Modula-2 (Or "ObjM2") An extension to Modula-2 for Cocoa and GNUstep software development. Objective Modula-2 follows the Objective-C object model and retains the bracketed Smalltalk message passing syntax used in Objective-C. Classes written in ObjM2 can be used within ObjC and vice versa. ObjM2 also retains Modula-2's data encapsulation features, namely nested modules with explicit import and export lists. Due to the strict type checking in Modula-2, ObjM2 can be considered a much safer programming language than is ObjC, yet losing none of the capabilities of ObjC. (2005-08-15) 1 1 1 1 1 Objective PASCAL An extension of the PASCAL language which provides the possibility to use object-oriented programming constructs. 1 1 1 1 1 Object Linking and Embedding (OLE) A distributed object system and protocol from Microsoft, also used on the Acorn Archimedes. OLE allows an editor to "farm out" part of a document to another editor and then reimport it. For example, a desk-top publishing system might send some text to a word processor or a picture to a bitmap editor using OLE. (1998-12-17) 1 1 1 1 1 Object Lisp An object-oriented Lisp developed by Lisp Machines Inc. (LMI) in about 1987. Object Lisp was based on nested closures and operator shadowing. Several competing object-orientated extensions to Lisp were around at the time, such as Flavors, in use by Symbolics; Common Objects, developed by Hewlett-Packard; and CommonLoops in use by Xerox. LMI submitted the specification as a candidate for an object-oriented standard for Common Lisp, but it was defeated in favour of CLOS. ["ObjectLISP User Manual", G. Dreschere, LMI 1987]. (2008-03-19) 1 1 1 1 1 ObjectLOGO A variant of LOGO with object-oriented extensions. Lexical scope. Version 2.6, for the Mac. Paradigm Software <paradigm@applelink.apple.com> (617)576-7675. 1 1 1 1 1 Object Management Group (OMG) A consortium aimed at setting standards in object-oriented programming. In 1989, this consortium, which included IBM Corporation, Apple Computer Inc. and Sun Microsystems Inc., mobilised to create a cross-compatible distributed object standard. The goal was a common binary object with methods and data that work using all types of development environments on all types of platforms. Using a committee of organisations, OMG set out to create the first Common Object Request Broker Architecture (CORBA) standard which appeared in 1991. As of February 1998, the latest standard is CORBA 2.2. (http://omg.org/). [David S. Linthicum, DBMS, January 1997] (1999-02-02) 1 1 1 1 1 Object management system In an IPSE, the system which maintains information about the system under development. 1 1 1 1 1 object method In object-oriented programming, a function that is called ("invoked") on an object ?? is passed 1 1 1 1 1 Object Modelling Technique (OMT) An object-oriented methodology. [Details?] (1996-11-03) 1 1 1 1 1 Object Oberon Oberon plus classes and methods by H. Moessenboeck & J. Templ, 1989. See Oberon-2. ["Object Oberon - An Object-Oriented Extension of Oberon", H. Moessenboeck et al, ETH TR 109 (Apr 1990)]. ["Object Oberon - A Modest Object-Oriented Language", H. Moessenboeck & J. Templ, in Structured Programming 10(4), 1989]. 1 1 1 1 1 object-orientation object-oriented 1 1 1 1 1 object-oriented 1. <programming> (OO) Based on objects, classes and methods, as in object-oriented programming or object-oriented design. An object-oriented database applies the same concepts to the storage of objects. 2. <graphics> vector graphics. (2014-01-06) 1 1 1 1 1 object-oriented analysis (OOA) The first phase of object-oriented design. (2014-01-06) 1 1 1 1 1 object-oriented database (OODB) A system offering DBMS facilities in an object-oriented programming environment. Data is stored as objects and can be interpreted only using the methods specified by its class. The relationship between similar objects is preserved (inheritance) as are references between objects. Queries can be faster because joins are often not needed (as in a relational database). This is because an object can be retrieved directly without a search, by following its object id. The same programming language can be used for both data definition and data manipulation. The full power of the database programming language's type system can be used to model data structures and the relationship between the different data items. Multimedia applications are facilitated because the class methods associated with the data are responsible for its correct interpretation. 1 1 1 1 1 object-oriented design (OOD) A design method in which a system is modelled as a collection of cooperating objects and individual objects are treated as instances of a class within a class hierarchy. Four stages can be identified: identify the classes and objects, identify their semantics, identify their relationships and specify class and object interfaces and implementation. Object-oriented design is one of the stages of object-oriented programming. Schlaer-Mellor is one approach to OOD. ["Object-oriented analysis and design with applications", Grady Booch, 2nd ed., pub. Benjamin/Cummings, Redwood CA, 1994]. (1997-12-07) 1 1 1 1 1 Object-Oriented Fortran (OOF) An object-oriented extension of Fortran, in which data items can be grouped into objects, which can be instantiated and executed in parallel. It was available for Sun, Iris, iPSC, and nCUBE, but is no longer supported. E-mail: Donna Reese <dreese@cs.msstate.edu>. (2001-03-06) 1 1 1 1 1 object-oriented language object-oriented programming 1 1 1 1 1 Object-Oriented Pascal Object Pascal 1 1 1 1 1 object-oriented polymorphism The kind of polymorphism found in object-oriented programming languages where a variable can refer to an object whose class is not known exactly until run time. A method can use a variable of a given class - call other methods on it, pass it as an argument, etc. - without needing to know to which subclass it refers, as long as its actual class is compatible with those uses. (2014-01-05) 1 1 1 1 1 object-oriented programming (OOP) The use of a class of programming languages and techniques based on the concept of an "object" which is a data structure (abstract data type) encapsulated with a set of routines, called "methods", which operate on the data. Operations on the data can __only__ be performed via these methods, which are common to all objects that are instances of a particular "class". Thus the interface to objects is well defined, and allows the code implementing the methods to be changed so long as the interface remains the same. Each class is a separate module and has a position in a class hierarchy. Methods or code in one class can be passed down the hierarchy to a subclass or inherited from a superclass. This is called "inheritance". A procedure call is described as invoking a method on an object (which effectively becomes the procedure's first argument), and may optionally include other arguments. The 1 1 1 1 1 object-oriented programming language object-oriented programming 1 1 1 1 1 Object-oriented SQL (OSQL) A functional language, a superset of SQL, used in Hewlett-Packard's OpenODB database system. (1994-11-29) 1 1 1 1 1 Object-Oriented Turing An extension of Turing and a replacement for Turing Plus by R.C. Holt <holt@csri.toronto.edu>, U Toronto, 1991. Object-Oriented Turing supports imperative programming, object-oriented programming and concurrent programming. It has modules, classes, single inheritance, processes, exception handling and optional machine-dependent programming. There is an integrated environment under the X Window System and a demo version (ftp://turing.toronto.edu/pub/turing). Versions exist for Sun-4, MIPS, RS-6000 and others. E-mail: <ootinfo@turing.toronto.edu>. ["A Conceptual Framework for Software Development", Mancoridis et al, eds, ACM SIGSCE Conference, Feb 1993, Indianapolis]. ["Turing Reference Manual", 1992, ISBN 0-921598-15-7]. (2000-04-21) 1 1 1 1 1 Objectory An object-oriented methodology mostly created by Ivar Jacobson. (2003-07-11) 1 1 1 1 1 ObjectPAL Object-oriented database language, part of Borland's MS-Windows version of Paradox. 1 1 1 1 1 Object Pascal An object-oriented Pascal developed jointly by Apple Computer and Niklaus Wirth. ["Object Pascal Report", Larry Tesler, Structured Language World 9(3):10-17 (1985)]. (1994-10-28) 1 1 1 1 1 Object Persistence Framework (OPF) Any system for storing objects so they can be reloaded into a future session. Typically this will use a relational database along with some kind of object relational mapping. Another typical solution would store objects in XML files (a form of serialisation). One of the trickier problems to solve is how to maintain references between objects, e.g. replacing memory pointers with unique names or identifiers. Virtually identical considerations apply to transferring objects, or indeed any kind of data structure, from one process to another via some communications channel, e.g. a TCP/IP connection. Apple's Enterprise Objects Framework (EOF) is a mature and powerful example. (2009-01-15) 1 1 1 1 1 object relational mapping (ORM) The software development activity that defines a correspondence between objects in a program and rows in a database table. Atomic object properties correspond to columns in the table, non-atomic data types and relations between objects are represented as foreign keys referring to other tables. An object persistence mechanism is responsible for maintaining the correspondence between objects and the database contents at run-time. (2014-12-03) 1 1 1 1 1 object relational modelling object relational mapping 1 1 1 1 1 Object Request Broker (ORB) Part of the OMG CORBA specification, an ORB's basic function is to pass method invocation requests to the correct objects and return the results to the caller. To achieve this the ORB must be able must be able to identify and locate objects, handle connections from invoker and the data returned from methods. Communication between the ORB and applications are achieved through IDL stubs and skeletons whilst the OMG has specified IIOP as the protocol through which ORBs may communicate with each other. Using IIOP, an ORB may request method invocations from a remote object. (2003-11-21) 1 1 1 1 1 Object Role Modeling (ORM) A conceptual modelling approach that pictures the application world as a set of objects that play roles (parts in relationships, which may be unary, binary or higher order). ORM provides both graphical and textual languages that enable models to be expressed naturally. For data modelling purposes, its graphical language is more expressive than ER or UML. (http://orm.net/). (1999-08-27) 1 1 1 1 1 Object Value In industrial design, a measure of consumers' immediate desire for an object, even before they know or understand what it does. "Gassee may be nuts, but at least the BeBox has great object value." (1997-03-30) 1 1 1 1 1 Objectworks An object-oriented development environment developed by ParcPlace, available under Smalltalk and C++. (1994-10-28) 1 1 1 1 1 Object Z University of Queensland. ["Object Orientation in Z", S. Stepney et al eds, Springer 1992]. 1 1 1 1 1 Objlog A frame-based language combining objects and Prolog II from CNRS, Marseille, France. ["The Inheritance Processes in Prolog", C. Chouraki et al, GRTC/187bis/Mars 1987 (CNRS)]. E-mail: <somebody@grtc.cnrs-mrs.fr>. (1994-10-28) 1 1 1 1 1 OBJT Error algebras plus an image construct. Tardo. 1 1 1 1 1 ObjVlisp 1984. An object-oriented extension of Vlisp. Reflective architecture. ["Metaclasses are First Class: The ObjVlisp Model", P. Cointe, SIGPLAN Notices 22(121):156-167 (Dec 1987) (OOPSLA '87)]. 1 1 1 1 1 ObjVProlog Logic programming and object-orientation, an adaptation of the ObjVlisp model to Prolog. ["ObjVProlog: Metaclasses in Logic", J. Malenfant, ECOOP '89, Cambridge U Press 1989, pp.257-269]. 1 1 1 1 1 Obliq A small, statically scoped untyped language by Luca Cardelli, 1993. Obliq is object-oriented, higher order, concurrent, and distributed. State is local to an address space, while computation can migrate over the network. The distributed computation mechanism is based on Modula-3 network objects. (ftp://gatekeeper.dec.com/pub/DEC/Modula-3/contrib). 1 1 1 1 1 oblique stroke "/". Common names include: (forward) slash; stroke; ITU-T: slant; oblique stroke. Rare: diagonal; solidus; over; slak; virgule; INTERCAL: slat. Commonly used as the division operator in programming, and to separate the components in Unix pathnames, and hence also in URLs. Also used to delimit regular expressions in several languages. (1996-09-24) 1 1 1 1 1 Oblog A small, portable, Object-oriented extension to Prolog by Margaret McDougall of EdCAAD, Dept Arch, University of Edinburgh. (1995-12-29) 1 1 1 1 1 OBOE Object-code Buffer Overrun Evaluator 1 1 1 1 1 OBSCURE A Formal Description of the Specification Language OBSCURE, J. Loeckx, TR A85/15, U Saarlandes, Saarbrucken, 1985. [Jargon File] 1 1 1 1 1 observational equivalence Two terms M and N are observationally equivalent iff for all contexts C[] where C[M] is a valid term, C[N] is also a valid term with the same value. 1 1 1 1 1 Oc ("Oh see!") A parallel logic language. ["Self-Description of Oc and its Applications", M. Hirata, Proc 2nd Natl Conf Japan Soc Soft Sci Tech, pp. 153-156, 1984]. (1995-03-16) 1 1 1 1 1 OC-12 Optical Carrier 12 1 1 1 1 1 OC-3 Optical Carrier 3 1 1 1 1 1 OC-48 Optical Carrier 48 1 1 1 1 1 OCAL On-Line Cryptanalytic Aid Language. ["OCAS: On-line Cryptanalytic Aid System", D.J. Edwards, MAC-TR-27, MIT Project MAC, May 1966. Sammet 1969, p.642]. 1 1 1 1 1 occam (Note lower case) A language based on Anthony Hoare's CSP and David May's EPL. Named after the English philosopher, William of Occam (1300-1349) who propounded Occam's Razor. The occam language was designed by David May of INMOS to easily describe concurrent processes which communicate via one-way channels. It was developed to run on the INMOS transputer but compilers are available for VAX, Sun and Intel MDS, inter alia. The basic entity in occam is the process of which there are four fundamental types, assignment, input, output, and wait. More complex processes are constructed from these using SEQ to specify sequential execution, PAR to specify parallel execution and ALT where each process is associated with an input from a channel. The process whose channel inputs first is executed. The fourth constructor is IF with a list of conditions and associated processes. The process executed is the one with the first true condition in textual order. There 1 1 1 1 1 occam 2 An extension of occam produced in 1987. Occam 2 adds floating-point, functions and a type system. ["occam 2 Reference Manual", INMOS, P-H 1988, ISBN 0-13-629312-3]. (1994-11-18) 1 1 1 1 1 Occam's Razor The English philosopher, William of Occam (1300-1349) propounded Occam's Razor: Entia non sunt multiplicanda praeter necessitatem. (Latin for "Entities should not be multiplied more than necessary"). That is, the fewer assumptions an explanation of a phenomenon depends on, the better it is. For example, some claim that God caused himself to exist and also caused the universe to exist - he was the "first cause" - whereas Occam's Razor suggests that if one accepts the possibility of something causing itself then it is better to assume that it was the universe that caused itself rather than God because this explanation involves fewer entities. The negation of Occam's Razor would suggest that an arbitrarily complex explanation is just as good as the simplest one. (E.g. God and his cat created a robot called Sparky who built the universe from parts bought from a shop in another dimension). 1 1 1 1 1 occlude (Or "shadow") To make a variable inaccessible by declaring another with the same name within the scope of the first. (1995-12-14) 1 1 1 1 1 occurs check A feature of some implementations of unification which causes unification of a logic variable V and a structure S to fail if S contains V. Binding a variable to a structure containing that variable results in a cyclic structure which may subsequently cause unification to loop forever. Some implementations use extra pointer comparisons to avoid this. Most implementations of Prolog do not perform the occurs check for reasons of efficiency. Without occurs check the complexity of unification is O(min(size(term1), size(term2))) with occurs check it's O(max(size(term1), size(term2))) In theorem proving unification without the occurs check can lead to unsound inference. For example, in Prolog it is 1 1 1 1 1 OCL 1. Operator Control Language. 2. Object Constraint Language. (2003-01-18) 1 1 1 1 1 OCLC Online Computer Library Center 1 1 1 1 1 OC-n Optical Carrier n 1 1 1 1 1 OCODE An assembly language for a stack-based virtual machine, used as the intermediate language of the Cambridge BCPL compiler. ["The Portability of the BCPL Compiler", M. Richards, Soft Prac & Exp 1(2) (1971)]. (1995-01-30) 1 1 1 1 1 OCP Order Code Processor. 1 1 1 1 1 OCR Optical Character Recognition 1 1 1 1 1 OCS Object Compatibility Standard 1 1 1 1 1 octal Base 8. A number representation using the digits 0-7 only, with the right-most digit counting ones, the next counting multiples of 8, then 8^2 = 64, etc. For example, octal 177 is digital 127: digit weight value 1 8^2 = 64 1* 64 = 64 7 8^1 = 8 7* 8 = 56 7 8^0 = 1 7* 1 = 7 --- 1 1 1 1 1 octal forty Jargon for "I'm drawing a blank.", I can't work it out. Octal 40 (decimal 32) is the ASCII code for space character. By an odd coincidence, hex 40 is the EBCDIC space character. [Jargon File] (1995-03-06) 1 1 1 1 1 Octave A high-level interactive language by John W. Eaton, with help from many others, like MATLAB, primarily intended for numerical computations. Octave provides a convenient command line interface for solving linear and nonlinear problems numerically. Octave can do arithmetic for real and complex scalars and matrices, solve sets of nonlinear algebraic equations, integrate functions over finite and infinite intervals, and integrate systems of ordinary differential and differential-algebraic equations. Octave has been compiled and tested with g++ and libg++ on a SPARCstation 2 running SunOS 4.1.2, an IBM RS/6000 running AIX 3.2.5, DEC Alpha systems running OSF/1 1.3 and 3.0, a DECstation 5000/240 running Ultrix 4.2a, and Intel 486 systems running Linux. It should work on most other Unix systems with g++ and libg++. Octave is distributed under the GNU General Public 1 1 1 1 1 octet Eight bits. This term is used in networking, in preference to byte, because some systems use the term "byte" for things that are not 8 bits long. (1995-03-03) 1 1 1 1 1 octothorpe hash character 1 1 1 1 1 OCX OLE custom controls 1 1 1 1 1 OD390 A CICS Web interperter from IBM used for application development involving web interfaces to DB2 tables. (1998-06-21) 1 1 1 1 1 ODA Open Document Architecture (formerly Office Document Architecture). 1 1 1 1 1 ODBC Open DataBase Connectivity 1 1 1 1 1 ODC Open Distributed Computing 1 1 1 1 1 Ode An Object-Oriented Database from AT&T which extends C++ and supports fast queries, complex application modelling and multimedia. Ode uses one integrated data model (C++ classes) for both database and general purpose manipulation. An Ode database is a collection of persistent objects. It is defined, queried and manipulated using the language O++. O++ programs can be compiled with C++ programs, thus allowing the use of existing C++ code. O++ provides facilities for specifying transactions, creating and manipulating persistent objects, querying the database and creating and manipulating versions. The Ode object database provides four object compatible mechanisms for manipulating and querying the database. As well as O++ there are OdeView - an X Window System interface; OdeFS (a file system interface allowing objects to be treated and manipulated like normal Unix files); and CQL++, 1 1 1 1 1 ODI 1. Optical Digital Image. 2. Open Data-link Interface. 1 1 1 1 1 ODIF Open Document Interchange Format 1 1 1 1 1 ODMA Open Document Management API 1 1 1 1 1 ODMG Object Data Management Group 1 1 1 1 1 odometry The use of motion sensors to determine a robot's change in position relative to some known position. For example, if a robot is traveling in a straight line and if it knows the diameter of its wheels, then by counting the number of wheel revolutions it can determine how far it has traveled. Robots will often have shaft encoders attached to their drive wheels which emit a fixed number of pulses per revolution. By counting these pulses, the processor can estimate the distance traveled. (2006-09-11) 1 1 1 1 1 ODP Open Distributed Processing 1 1 1 1 1 ODS Operational Data Store 1 1 1 1 1 ODSA Open Distributed System Architecture 1 1 1 1 1 ODT Open Desktop 1 1 1 1 1 OEM original equipment manufacturer 1 1 1 1 1 OFA Optimal Flexible Architecture 1 1 1 1 1 off-by-one error (Or "Obi-Wan error") An exceedingly common error induced in many ways, such as by starting at zero when you should have started at one or vice-versa, or by writing "< N" instead of "<= N" or vice-versa. Often confounded with fencepost error, which is properly a particular subtype of it. The term zeroth corrects the linguistic off-by-one error of, e.g., referring to the "1st" element of an array whose indexes start from zero. [Jargon File] (1998-09-21) 1 1 1 1 1 Office Microsoft Office 1 1 1 1 1 office automation The use of computers or related data processing technology to do routine clerical work such as writing, filing and distributing documents. The term was used before computers in offices were the norm (1960s?). (2007-09-11) 1 1 1 1 1 Office By Example (OBE) A sequel to QBE, described in publications by Moshe Zloof of IBM in the early 1980s but apparently never implemented. (1998-03-14) 1 1 1 1 1 Office Workstations Limited (OWL) A UK software company, now a subsidiary of Matsushita (Panasonic, etc.). They previously supported the Guide hypertext system but that support is now provided by US company InfoAccess. E-mail: <postmaster@owl-uk.owl-uk.co.uk> [Correct address?] (1996-01-15) 1 1 1 1 1 Official Production System (OPS) The first production system (i.e. rule based) programming language, developed at CMU in 1970 and used for building expert systems. OPS was originally written in Franz Lisp and later ported to other LISP dialects. (2003-04-05) 1 1 1 1 1 off-line (Or "offline") 1. Not directly connected to the computer (e.g., an off-line tape drive), or with connection suspended ("take the printer off-line"). Contrast background, on-line. 2. Not now or not here. "Let's take this discussion off-line." Specifically used on Usenet to suggest that a discussion be moved off a public newsgroup to e-mail. See also off-line world. [Jargon File] (1996-02-02) 1 1 1 1 1 off-line world A die-hard nethead term for non-computer-related experience. See also big room. ["Internet", Feb 1996]. (1996-03-04) 1 1 1 1 1 offset An index or position in an array, string, or block of memory usually a non-negative integer. E.g. the Perl function splice(ARRAY, OFFSET, LENGTH, LIST) replaces LENGTH elements starting at index OFFSET in array with LIST, where offset zero means the start of the array. For an Intel x86 processor with a segmented address space the offset is the position of a byte relative to the start of the segment. (2004-02-27) 1 1 1 1 1 offshoring Transfer of a business process, e.g. manufacturing or customer service, from a company in one country to the same or another company in a different country. This overlaps partially with outsourcing, in which work is transferred to a different company in the same or a different country. (2008-12-12) 1 1 1 1 1 off-side rule A lexical convention due to Landin, allowing the scope of declarations in a program to be expressed by indentation. Any non-whitespace token to the left of the first such token on the previous line is taken to be the start of a new declaration. Used in, for example, Miranda and Haskell. [P.J. Landin "The Next 700 Programming Languages", CACM vol 9 pp157-165, March 1966] 1 1 1 1 1 off the trolley Describes the behaviour of a program that malfunctions and goes catatonic, but doesn't actually crash or abort. See glitch, bug, deep space. [Jargon File] 1 1 1 1 1 ogg /og/ (CMU) 1. In the multi-player space combat game Netrek, to execute kamikaze attacks against enemy ships which are carrying armies or occupying strategic positions. Named during a game in which one of the players repeatedly used the tactic while playing Orion ship G, showing up in the player list as "Og". This trick has been roundly denounced by those who would return to the good old days when the tactic of dogfighting was dominant, but as Sun Tzu wrote, "What is of supreme importance in war is to attack the enemy's strategy." However, the traditional answer to the newbie question "What does ogg mean?" is just "Pick up some armies and I'll show you." 2. In other games, to forcefully attack an opponent with the expectation that the resources expended will be renewed faster than the opponent will be able to regain his previous advantage. Taken more seriously as a tactic since it has gained a simple name. 1 1 1 1 1 Ogg Vorbis A patent-free audio compression algorithm. (http://xiph.org/). (2001-12-17) 1 1 1 1 1 OHCI Open Host Controller Interface 1 1 1 1 1 Ohm The MKS unit of electrical resistance. One Ohm is the resistance of a conductor across which a potential difference of one Volt produces a current of one Ampere. Named after Georg Simon Ohm. (2003-12-02) 1 1 1 1 1 Ohm, Georg Simon Georg Simon Ohm 1 1 1 1 1 ohnosecond (Presumably a play on "nanosecond") The miniscule time it takes to realize that you've just made a BIG mistake like typing rm -rf * in the wrong directory. Seen in Elizabeth P. Crowe's book, "The Electronic Traveller." (1998-08-27) 1 1 1 1 1 OIC oh, I see. (1998-01-18) 1 1 1 1 1 OID object identifier 1 1 1 1 1 OIL 1. ["The Architecture of the FAIM-1 Symbolic Multiprocessing System", A. Davis et al, 9th Intl Joint Conf in Artif Intell, 1985, pp.32-38]. 2. Operator Identification Language. Used for overloading resolution by the Eli compiler-writing system. 1 1 1 1 1 OLAP On-Line Analytical Processing 1 1 1 1 1 OLAP Council A body formed in early 1995 to work on a cross-product API for OLAP. After little success it was replaced by the Analytical Solutions Forum. (2005-05-28) 1 1 1 1 1 OLC On-Line Computer system 1 1 1 1 1 OLDAS On-line Digital Analog Simulator. An interactive version of MIMIC, for IBM 360. ["OLDAS: An On-line Continuous System Simulation Language", R.P. Cullen, in Interactive Systems for Experimental Applied Mathematics, A-P 1968]. 1 1 1 1 1 old fart Tribal elder. A title self-assumed with remarkable frequency by (especially) Usenetters who have been programming for more than about 25 years; often appears in sig blocks attached to Jargon File contributions of great archaeological significance. This is a term of insult in the second or third person but one of pride in first person. [Jargon File] 1 1 1 1 1 old talk The old implementations of talk. See "ntalk" for details. (1997-09-11) 1 1 1 1 1 Old Testament [C programmers] The first edition of K&R, the sacred text describing Classic C. [Jargon File] 1 1 1 1 1 OLE Object Linking and Embedding 1 1 1 1 1 OLE custom controls (OCX) An Object Linking and Embedding (OLE) custom control allowing infinite extension of the Microsoft Access control set. OCX is similar in purpose to VBX used in Visual Basic. Available OCX's include "Scroll Bar Control", "Calendar Control", and "Data Outline Control". [Details?] (1995-12-05) 1 1 1 1 1 OLE DB Microsoft's low-level application program interface (API) for access to data sources. OLE originally stood for Object Linking and Embedding and DB for database but Microsoft no longer ascribes these meanings. (2008-03-19) 1 1 1 1 1 OLE for Process Control (OPC) A set of seven open standards for connectivity and interoperability of industrial automation and the enterprise systems. Based on fundamental and evolving standards and technology of the general computing market, the OPC Foundation adapts and creates specifications that fill industry-specific needs. OPC Foundation (http://opcfoundation.org/). (2003-05-21) 1 1 1 1 1 OLGA Ouf! un Langage pour les Grammaires Attribuees. Inria, 1985. Language for specification of attribute grammars, used as the input language of the compiler writing system FNC-2. Applicative, strongly typed, polymorphic, pattern-matching, modules. 1 1 1 1 1 Olivetti A large Italian company producing office machinery, computers and printers. Olivetti took a controlling stake in Acorn Computers in September 1985. Olivetti computers were once marketed in USA with the ATT brand name. [Address? Other products?] (1995-03-14) 1 1 1 1 1 O-Logic An object-oriented deductive language/database system. 1 1 1 1 1 OLTP On-Line Transaction Processing 1 1 1 1 1 OLWM OpenLook Window Manager 1 1 1 1 1 om The country code for Oman. (1999-01-27) 1 1 1 1 1 OMA Object Management Architecture. A set of standards under study by the OMG. (1994-11-11) 1 1 1 1 1 Omega 1. <programming> A prototype-based object-oriented language from Austria. ["Type-Safe Object-Oriented Programming with Prototypes - The Concept of Omega", G. Blaschek, Structured Programming 12:217-225, 1991]. 2. <text, tool> A successor to TeX extended to handle the Unicode character set. (http://ens.fr/omega/). (1997-11-20) 1 1 1 1 1 Omega-algebraic In domain theory, a complete partial order is algebraic if every element is the lub of some chain of compact elements. If the set of compact elements is countable it is omega-algebraic. Usually written with a Greek letter omega (LaTeX \omega). (1995-02-03) 1 1 1 1 1 Omega test The Omega test is a system written by William Pugh <pugh@cs.umd.edu> and others for performing symbolic manipulations of conjunctions of linear constraints over integer variables. The Omega test dependence analyser is a system built on top of the Omega test to analyse array data dependences. Version 3.2.2 includes a fortran to tiny translator, a Tiny interpreter(?) and analysis tools. (ftp://ftp.cs.umd.edu/pub/omega). E-mail: <omega@cs.umd.edu>. (1992-11-13) 1 1 1 1 1 OMF Object Management Facility. Part of the DAA proposed by Hewlett-Packard and Sun. 1 1 1 1 1 OMG Object Management Group 1 1 1 1 1 OMNICODE Thompson, 1956. Ran on IBM 650. [Sammet 1969, p. 5]. 1 1 1 1 1 OMNIFAX Alternate name for NYU OMNIFAX? Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 OMNITAB Statistical analysis and desk calculator. Version: OMNITAB II. ["OMNITAB II User's Reference Manual", NBS Tech Note 552 (Oct 1971). Sammet 1969, pp. 296-299]. 1 1 1 1 1 OMR Optical Mark Reader 1 1 1 1 1 OMS Opportunity Management System 1 1 1 1 1 OMT Object Modelling Technique 1 1 1 1 1 OMTool A graphical tool from General Electric Advanced Concepts Center for design and analysis of systems with the OMT methodology. Generates C++ and SQL code. 1 1 1 1 1 ONC Open Network Computing 1 1 1 1 1 Ondine ["Concurrency Introduction to an Object-Oriented Language System Ondine", T. Ogihara et al, 3rd Natl Conf Record A-5-1, Japan Soc for Soft Sci Tech, Japan 1986]. (2012-12-31) 1 1 1 1 1 one The lowest positive integer and the basis for counting. Multiplication by one is an identity operator and, since one is its own reciprocal, so is division by one. One is the result of dividing any non-zero number by itself. One raised to any power is one and raising to the power one is also an identity operator. <data> The largest digit in binary, related to the value true in Boolean algebra. Digital computers typically represent one by a high voltage and zero by a low voltage. (2012-12-31) 1 1 1 1 1 one-banana problem At computer installations where the computers have operators for routine administrivia, the programmers and hardware people tend to look down on the operators and claim that a trained monkey could do their job. The incentives offered to said monkeys would then describe the difficulty of a task. A one-banana problem is simple; hence, "It's only a one-banana job at the most; what's taking them so long?" See also Infinite-Monkey Theorem. [Jargon File] (2010-03-20) 1 1 1 1 1 one-dimensional array An array with only one dimension; the simplest kind of array, consisting of a sequence of items ("elements"), all of the same type. An element is selected by an integer index that normally starts at zero for the first element and increases by one. The index of the last element is thus the length of the array minus one. A one-dimensional array is also known as a vector. It should not be confused with a list. In some languages, e.g. Perl, all arrays are one-dimensional and higher dimensions are represented as arrays of pointers to arrays (which can have different sizes and can themselves contain pointers to arrays and so on). A one-dimensional array maps simply to memory: the address of an element with index i is A(i) = A0 + i * s where A0 is the base address of the array and s is the size of 1 1 1 1 1 one-line fix Used (often sarcastically) of a change to a program that is thought to be trivial or insignificant right up to the moment it crashes the system. Usually "cured" by another one-line fix. See also I didn't change anything! 1 1 1 1 1 one-liner wars A game popular among hackers who code in the language APL (see write-only language and line noise). The objective is to see who can code the most interesting and/or useful routine in one line of operators chosen from APL's exceedingly hairy primitive set. A similar amusement was practiced among TECO hackers and is now popular among Perl aficionados. Ken Iverson, the inventor of APL, has been credited with a one-liner that, given a number N, produces a list of the prime numbers from 1 to N inclusive. It looks like this: (2 = 0 +.= T o.| T) / T <- iN where "o" is the APL null character, the assignment arrow is a single character, and "i" represents the APL iota. [Jargon File] (2000-03-19) 1 1 1 1 1 ones complement A system used in some computers to represent negative numbers. To negate a number, each bit of the number is inverted (zeros are replaced with ones and vice versa). This has the consequence that there are two reperesentations for zero, either all zeros or all ones. ... 000...00011 = +3 000...00010 = +2 000...00001 = +1 000...00000 = +0 111...11111 = -0 1 1 1 1 1 One-Time Password (OTP) A security system that requires a new password every time a user authenticates themselves, thus protecting against an intruder replaying an intercepted password. OTP generates passwords using either the MD4 or MD5 hashing algorithms. The equivalent term "S/Key", developed by Bellcore, is a trademark of Telcordia Technologies, so the name OTP is used increasingly. See RFC 1760 - "The S/KEY One-Time Password System" and RFC 1938 - "A One-Time Password System". (http://cs.umd.edu/~harry/jotp/). (2000-01-31) 1 1 1 1 1 One Time Programmable Read-Only Memory (OTPROM, EPROM OTP) A kind of storage device like an EPROM but with no quartz glass window in the package for erasing the contents. This reduces the packaging cost but means the device cannot be erased with UV and so can only be written once. Erasure is possible, but expensive, with X-rays. (1995-04-22) 1 1 1 1 1 one-way function A function which is easy to compute but whose inverse is very difficult to compute. Such functions have important applications in cryptography, specifically in public-key cryptography. See also: trapdoor function. (2001-05-10) 1 1 1 1 1 one-way hash function (Or "message digest function") A one-way function which takes a variable-length message and produces a fixed-length hash. Given the hash it is computationally infeasible to find a message with that hash; in fact one can't determine any usable information about a message with that hash, not even a single bit. For some one-way hash functions it's also computationally impossible to determine two messages which produce the same hash. A one-way hash function can be private or public, just like an encryption function. MD5, SHA and Snefru are examples of public one-way hash functions. A public one-way hash function can be used to speed up a public-key digital signature system. Rather than sign a long message, which can take a long time, compute the one-way hash of the message, and sign the hash. sci.crypt FAQ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/sci.crypt/). 1 1 1 1 1 on-line 1. Ready for use. E.g. "The graph plotter's fixed and on-line again". 2. Interactive as opposed to batch. Accessible via a computer (or terminal), rather than on paper or other medium. 3. Of a user, actively using a computer system, especially the Internet. E.g "I haven't been on-line for three days." On-line should be hyphenated because it is compounded from two words but the hyphen is often omitted in names of organisations or services. (1998-12-22) 1 1 1 1 1 On-Line Analytical Processing (OLAP) A category of database software which provides an interface such that users can transform or limit raw data according to user-defined or pre-defined functions, and quickly and interactively examine the results in various dimensions of the data. OLAP primarily involves aggregating large amounts of diverse data. OLAP can involve millions of data items with complex relationships. Its objective is to analyze these relationships and look for patterns, trends, and exceptions. The term was originally coined by Dr. Codd in 1993 with 12 rules. Since then, the OLAP Council, many vendors, and Dr. Codd himself have added new requirements and confusion. Richard Creeth and Nigel Pendse define OLAP as fast analysis of shared multidimensional information. Their definition requires the system to respond to users within about five seconds. It should support logical and statistical processing of results without the user having to program in a 4GL. It 1 1 1 1 1 Online Computer Library Center, Inc. (OCLC) A nonprofit membership organisation offering computer-based services and research to libraries, educational organisations, and their users. OCLC operates the OCLC Cataloging PRISM service for cataloging and resource sharing, provides on-line reference systems for both librarians and end-users, and distributes on-line electronic journals. OCLC's goals are to increase the availability of library resources and reduce library costs for the fundamental public purpose of furthering access to the world's information. The OCLC library information network connects more than 10,000 36,000 libraries worldwide. Libraries use the OCLC System for cataloguing, interlibrary loan, collection development, bibliographic verification, and reference searching. Their most visible feature is the OCLC Online Union Catalog (OLUC) WorldCat (the OCLC Online Union Catalog). (http://oclc.org/). (2000-03-23) 1 1 1 1 1 On-Line Computer system (OLC) A predecessor of the Culler-Fried System from UCSB ca. 1966. [Sammet 1969, p.253]. (1995-11-25) 1 1 1 1 1 Online Media Acorn Online Media 1 1 1 1 1 On-line Process Synthesizer (OPS) A system for discrete simulation under CTSS developed by M. Greenberger at MIT ca. 1964. [Sammet 1969, p.660. Versions: OPS-3, OPS-4. "On- line Computation and Simulation: The OPS-3 System", M. Greenberger et al, MIT Press 1965]. (2003-04-05) 1 1 1 1 1 Online Public Access Catalog (OPAC) A computerised system to catalogue and organise materials in a library (the kind that contains books). OPACs have replaced card-based catalogues in many libraries. An OPAC is available to library users (public access). (2000-07-17) 1 1 1 1 1 On-Line Transaction Processing (OLTP) The processing of transactions by computers in real time. [Details? Products?] (1997-05-14) 1 1 1 1 1 Ontic Object-oriented language for an inference system with a Lisp-like appearance, but based on set theory. ["Ontic: A Knowledge Representation System for Mathematics", D.A. McAllester, MIT Press 1989]. (1996-06-24) 1 1 1 1 1 onto surjection 1 1 1 1 1 ontology 1. <philosophy> A systematic account of Existence. 2. <artificial intelligence> (From philosophy) An explicit formal specification of how to represent the objects, concepts and other entities that are assumed to exist in some area of interest and the relationships that hold among them. For AI systems, what "exists" is that which can be represented. When the knowledge about a domain is represented in a declarative language, the set of objects that can be represented is called the universe of discourse. We can describe the ontology of a program by defining a set of representational terms. Definitions associate the names of entities in the universe of discourse (e.g. classes, relations, functions or other objects) with human-readable text describing what the names mean, and formal axioms that constrain the interpretation and well-formed use of these terms. Formally, an ontology is the statement of a logical theory. 1 1 1 1 1 OnX A graphics package from LAL Orsay. 1 1 1 1 1 OO object-oriented 1 1 1 1 1 OOA object-oriented analysis 1 1 1 1 1 OOD object-oriented design 1 1 1 1 1 OODB object-oriented database 1 1 1 1 1 OODBMS object-oriented database management system 1 1 1 1 1 OOF Object-Oriented Fortran 1 1 1 1 1 OOGL Object-Oriented Graphics Language. 1970's. 1 1 1 1 1 OOo OpenOffice.org 1 1 1 1 1 OOP object-oriented programming 1 1 1 1 1 OOPL object-oriented programming language 1 1 1 1 1 OOPS OOPS: A Knowledge Representation Language, D. Vermeir, Proc 19th Intl Hawaii Conf on System Sciences, IEEE (Jan 1986) pp.156-157. 1 1 1 1 1 OOPSLA Conference on Object-oriented Programming Systems, Languages and Applications. 1 1 1 1 1 OOSD Object-oriented structured design: a design method elaborated from structured design and incorporating the essential features of the object-oriented approach. 1 1 1 1 1 OOZE Object oriented extension of Z. "Object Orientation in Z", S. Stepney et al eds, Springer 1992. 1 1 1 1 1 op /op/ 1. In England and Ireland, a common verbal abbreviation for "operator", as in system operator. This is less common in the US, where sysop seems to be preferred. 2. The general term for an IRC channel op. Also, as a verb: to give someone channel op privileges. Compare ircop. [Jargon File] (1997-12-12) 1 1 1 1 1 OPAC Online Public Access Catalog 1 1 1 1 1 Opal 1. A DSP language. ["OPAL: A High Level Language and Environment for DSP boards on PC", J.P. Schwartz et al, Proc ICASSP-89, 1989]. 2. The language of the object-oriented database GemStone. ["Making Smalltalk a Database System", G. Copeland et al, Proc SIGMOD'84, ACM 1984, pp.316- 325]. 3. A simulation language with provision for stochastic variables. An extension of Autostat. ["C-E-I-R OPAL", D. Pilling, Internal Report, C.E.I.R. Ltd. (1963)]. 4. A language for compiler testing said to be used internally by DEC. 5. A functional programming language designed at the Technische Universitaet Berlin as a testbed for the development of functional programs. OPAL integrates concepts from Algebraic Specification and Functional Programming, which favour the (formal) development of (large) 1 1 1 1 1 OPC OLE for Process Control 1 1 1 1 1 op code operation code 1 1 1 1 1 open 1. <programming> To prepare to read or write a file. This usually involves checking whether the file already exists and that the user has the necessary authorisation to read or write it. The result of a successful open is usually some kind of capability (e.g. a Unix file descriptor) - a token that the user passes back to the system in order to access the file without further checks and finally to close the file. 2. <character> Abbreviation for "open (or left) parenthesis" - used when necessary to eliminate oral ambiguity. To read aloud the LISP form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun foo, open eks close, open, plus eks one, close close." <software> 3. Non-proprietary. An open standard is one which can be used without payment. 4. <mathematics> open interval. 1 1 1 1 1 open box testing white box testing 1 1 1 1 1 open brace left brace 1 1 1 1 1 OpenBSD A version of BSD Unix with an emphasis on security. A lot of security work that is ported to other free operating systems originates with OpenBSD and a lot of code review is done here. Sub-projects of OpenBSD include implementations of SSH (http://openssh.org/), ntpd (http://openntpd.org/), and CVS, to be called OpenCVS. OpenBSD Home (http://openbsd.org/). (2005-01-17) 1 1 1 1 1 open/closed principle A principle used in OOPL which states that a class must be open and closed where open means it has the ability to be extended and closed means it cannot be modified other than by extension. The idea is that once a class has been approved for use having gone through code reviews, unit tests, and other qualifying procedures, you don't want to change the class very much, just extend it. In practice the open/closed principle simply means making good use of abstraction and polymorphism. (1997-09-23) 1 1 1 1 1 open-collar worker Someone who works at home or telecommutes. (1997-04-17) 1 1 1 1 1 Open DataBase Connectivity (ODBC) A standard for accessing different database systems. There are interfaces for Visual Basic, Visual C++, SQL and the ODBC driver pack contains drivers for the Access, Paradox, dBase, Text, Excel and Btrieve databases. An application can submit statements to ODBC using the ODBC flavor of SQL. ODBC then translates these to whatever flavor the database understands. ODBC 1.0 was released in September 1992. ODBC is based on Call-Level Interface and was defined by the SQL Access Group. Microsoft was one member of the group and was the first company to release a commercial product based on its work (under Microsoft Windows) but ODBC is not a Microsoft standard (as many people believe). ODBC drivers and development tools are available now for Microsoft Windows, Unix, OS/2, and Macintosh. [On-line document?] 1 1 1 1 1 Open Data-link Interface (ODI) A Novell-developed network card API that provides media and protocol independence. It allows the sharing of a single card by multiple transport layer protocols and resolves conflicts. (1995-03-13) 1 1 1 1 1 Open DeathTrap An abusive hackerism for the Santa Cruz Operation's Open DeskTop. The funniest part is that this was coined by SCO's own developers. Compare AIDX, Macintrash Nominal Semidestructor, ScumOS, sun-stools, HP-SUX. [Jargon File] (1995-02-02) 1 1 1 1 1 Open Desktop A Motif-based graphical interface from the Santa Cruz Operation (SCO), built over their Unix environment, part of the ACE initiative. Also known as "Open DeathTrap". (1995-02-02) 1 1 1 1 1 Open Distributed Processing (ODP) An attempt to standardise an OSI application layer communications architecture. ODP is a natural progression from OSI, broadening the target of standardisation from the point of interconnection to the end system behaviour. The objective of ODP is to enable the construction of distributed systems in a multi-vendor environment through the provision of a general architectural framework that such systems must conform to. One of the cornerstones of this framework is a model of multiple viewpoints which enables different participants to observe a system from a suitable perspective and a suitable level of abstraction. (1995-03-10) 1 1 1 1 1 Open Distributed System Architecture (ODSA) A research program sponsored by the UK Department of Trade and Industry and the Engineering and Physical Sciences Research Council. [Details?] (1995-02-09) 1 1 1 1 1 OpenDoc A compound document architecture from CIL based on CORBA. It aims to enable embedding of features from different application programs into a single working document. (1997-02-21) 1 1 1 1 1 OpenDocument (ODF, ISO/IEC 26300, OASIS Open Document Format for Office Applications) An XML file format for office documents, such as spreadsheets, charts, presentations, databases and word processing. OpenDocument was developed by the Open Office XML technical committee of the Organization for the Advancement of Structured Information Standards (OASIS) consortium. It is based on the XML format originally created and implemented by the OpenOffice.org office suite. OpenDocument is an open standard, i.e. freely available and implementable. Compare OOXML. (2007-09-19) 1 1 1 1 1 Open Document Architecture (ODA) ISO standard (8613) for describing documents. It allows text, graphics, and facsimile documents to be transferred between different systems. ODIF is part of ODA. (1995-03-03) 1 1 1 1 1 Open Document Interchange Format (ODIF) Part of the ODA standard. (1996-10-16) 1 1 1 1 1 Open Document Management API An open standard allowing desktop applications to interface with document management systems. (http://activedoc.com). (1997-07-04) 1 1 1 1 1 OpenGL Open Graphics Library 1 1 1 1 1 Open Graphics Library (OpenGL) A multi-platform software interface to graphics hardware, supporting rendering and imaging operations. The OpenGL interface was developed by Silicon Graphics, who license it to other vendors. The OpenGL graphics interface consists of several hundred functions operating on 2D and 3D objects, supporting basic techniques, such as modelling and smooth shading, and advanced techniques, such as texture mapping and motion blur. Many operations require a frame buffer. OpenGL is network-transparent, and a common extension to the X Window System allows an OpenGL client to communicate across a network with a different vendor's OpenGL server. OpenGL is based on Silicon Graphics' proprietary IRIS GL. OpenGL WWW Center (http://sgi.com/Technology/openGL/). Mesa GL (http://ssec.wisc.edu/~brianp/Mesa.html) (PD implementation). (1996-09-30) 1 1 1 1 1 Open Group The Open Group 1 1 1 1 1 OpenInsight The workflow-enabled Windows 95/Windows NT version of Advanced Revelation, featuring native support for Lotus Notes, Microsoft SQL Server, Oracle and ODBC. OpenInsight is available from Revelation Software. (1997-04-25) 1 1 1 1 1 open interval A type of interval (range of numbers) that does not include either of its endpoints. For example, when mixing red and blue paint, the proportion of red lies in the interval 0% to 100% but can't be exactly 0% or 100% or it wouldn't be a mixture. (2015-04-26) 1 1 1 1 1 Open Look A graphical user interface and window manager from Sun and AT&T. Usenet newsgroup: news:comp.graphics.openlook. (1995-06-11) 1 1 1 1 1 Open Network Computing (ONC) Sun's network protocols. [more detail?] 1 1 1 1 1 OpenOffice.org (OOo) The group that produces a free (GPL) cross-platform office suite that provides much of the same functionality as Microsoft Office including word processing, spreadsheet, presentation and graphics. Each program can read and write both its own and Microsoft formats. OpenOffice Home (http://openoffice.org/). (2005-01-26) 1 1 1 1 1 open parenthesis left parenthesis 1 1 1 1 1 Open Prolog Prolog for the Macintosh by Michael Brady <brady@cs.tcd.ie>. (http://cs.tcd.ie/open-prolog/). [Details?] (2000-12-21) 1 1 1 1 1 Open Scripting Architecture (OSA) A CIL approach to the coexistence of multiple scripting systems. (1995-03-10) 1 1 1 1 1 Open Shortest-Path First Open Shortest-Path First Interior Gateway Protocol 1 1 1 1 1 Open Shortest-Path First Interior Gateway Protocol (OSPF) A link state routing protocol that is one of the Internet standard Interior Gateway Protocols defined in RFC 1247. There is no OSPF EGP, OSPF is an IGP only. [Relationship to Internet Protocol packet routing?] OSPF Design Guide (http://cisco.com/warp/public/104/1.html). (2002-06-29) 1 1 1 1 1 Open Software Foundation (OSF) A foundation created by nine computer vendors, (Apollo, DEC, Hewlett-Packard, IBM, Bull, Nixdorf, Philips, Siemens and Hitachi) to promote "Open Computing". It is planned that common operating systems and interfaces, based on developments of Unix and the X Window System will be forthcoming for a wide range of different hardware architectures. OSF announced the release of the industry's first open operating system - OSF/1 on 23 October 1990 (1994-11-23) 1 1 1 1 1 open source A method and philosophy for software licensing and distribution designed to encourage use and improvement of software written by volunteers by ensuring that anyone can copy the source code and modify it freely. The term "open source" is now more widely used than the earlier term "free software" (promoted by the Free Software Foundation) but has broadly the same meaning - free of distribution restrictions, not necessarily free of charge. There are various open source licenses available. Programmers can choose an appropriate license to use when distributing their programs. The Open Source Initiative promotes the Open Source Definition. The Cathedral and the Bazaar (http://tuxedo.org/~esr/writings/cathedral-bazaar/cathedral-bazaar.html). was a seminal paper describing the open source phenomenon. Open Sources - O'Reilly book with full text online 1 1 1 1 1 Open Source Definition (OSD) Definition of distribution terms for open source software, promoted by the Open Source Initiative. (http://opensource.org/osd.html). (1999-11-28) 1 1 1 1 1 Open Source Initiative (OSI) An organisation dedicated to managing and promoting the Open Source Definition for the good of the community. (http://opensource.org/). (1999-11-28) 1 1 1 1 1 Open source license Any document that attempts to specify open source usage and distribution of software. These licenses are usually drafted by experts and are likely to be more legally sound than one a programmer could write. However, loopholes do exist. Here is a non-exhaustive list of open source licenses: 1. Public Domain - No license. 2. BSD License - An early open source license 3. General Public License (GPL) - The copyleft license of the Free Software Foundation. Used for GNU software and much of Linux. 4. Artistic License (http://my-opensource.org/Artistic.txt) Less restrictive than the GPL, permitted by Perl in addition to the GPL. 5. Mozilla Public Licenses (http://mozilla.org/MPL/). (MPL, MozPL) and Netscape Public License (NPL). ["Open Sources", pub. O'Reilly, full text 1 1 1 1 1 OpenStep An object-oriented application programming interface (API) derived from NEXTSTEP and proposed as an open standard by NeXT in 1994. OpenStep is the specification of the object kits of NEXTSTEP. OPENSTEP/Mach was an implementation of this specification. The original, OPENSTEP version 4.0, and really was NEXTSTEP 4. Rhapsody was the codename for Apple's Mac OS X Server, which is really NEXTSTEP 5 (it calls itself "kernel 5.3" at boot time). OpenStep was designed to be implemented independently of the computer's operating system, hardware, and user interface. The API for Rhapsody will be a superset of OpenStep's. When the OpenStep API is implemented for a specific platform and made into a product, it is written in uppercase, e.g. OPENSTEP Developer 4.2 for Mach, or OPENSTEP Enterprise for Windows NT and Windows 95. Versions of OPENSTEP exist for Windows 95/NT, Solaris, HP/UX, and Mach. 1 1 1 1 1 open switch (IBM, probably from railways) An unresolved question, issue, or problem. [Jargon File] (1994-11-11) 1 1 1 1 1 Open System Architecture (OSA) A competitor to IBM's SNA. (2005-03-07) 1 1 1 1 1 Open Systems Interconnect Open Systems Interconnection 1 1 1 1 1 Open Systems Interconnection (OSI-RM, OSI Reference Model, seven layer model) A model of network architecture and a suite of protocols (a protocol stack) to implement it, developed by ISO in 1978 as a framework for international standards in heterogeneous computer network architecture. The OSI architecture is split between seven layers, from lowest to highest: 1 physical layer, 2 data link layer, 3 network layer, 4 transport layer, 5 session layer, 6 presentation layer, 7 application layer. Each layer uses the layer immediately below it and provides a service to the layer above. In some implementations a layer may itself be composed of sub-layers. OSI is the umbrella name for a series of non-proprietary protocols and specifications, comprising, among others, the OSI Reference Model, ASN.1 (Abstract Syntax Notation 1), BER (Basic Encoding Rules), CMIP and CMIS (Common Management Information Protocol and Services), X.400 (Message Handling 1 1 1 1 1 Open Telecom Platform (OTP) A set of standard, open source libraries and tools for use with Erlang. (http://erlang.org/faq/t1.html#AEN17). (2001-08-28) 1 1 1 1 1 Open Trading Protocol Internet Open Trading Protocol 1 1 1 1 1 OpenTransport (OT) A complete reimplementation of all levels of the Macintosh networking code including "Classic" AppleTalk and MacTCP. It appeared in MacOS revision 7.5.3 [or earlier? Date?]. (2000-08-13) 1 1 1 1 1 Open University (OU) The UK distance-learning organisation, established in 1969. It teaches degree-level courses in many subjects via BBC radio and television broadcasts and summer schools. (http://hcrl.open.ac.uk/ou/ouhome.html). (1999-07-13) 1 1 1 1 1 OpenVMS Virtual Memory System 1 1 1 1 1 OpenWindows A graphical user interface server for Sun workstations which handles SunView, NeWS and X Window System protocols. (1995-06-11) 1 1 1 1 1 operand An argument of an operator or of a machine language instruction. (1995-08-18) 1 1 1 1 1 operating 1. operating system. 2. operator. 1 1 1 1 1 operating system (OS) The low-level software which handles the interface to peripheral hardware, schedules tasks, allocates storage, and presents a default interface to the user when no application program is running. The OS may be split into a kernel which is always present and various system programs which use facilities provided by the kernel to perform higher-level house-keeping tasks, often acting as servers in a client-server relationship. Some would include a graphical user interface and window system as part of the OS, others would not. The operating system loader, BIOS, or other firmware required at boot time or when installing the operating system would generally not be considered part of the operating system, though this distinction is unclear in the case of a rommable operating system such as RISC OS. The facilities an operating system provides and its general design philosophy exert an extremely strong influence on 1 1 1 1 1 Operating System/360 (OS/360) An operating system developed by IBM for their System/360 computer (announced in 1964). After this experience, Frederick P. Brooks wrote his famous book, The Mythical Man-Month, giving OS/360 as an example of the second-system effect. [Features? Relatonship to DOS/360?] (2001-03-23) 1 1 1 1 1 Operating System/Multiprogramming of Fixed Tasks (OS/MFT) One of the IBM operating systems associated with the IBM 360, released in 1966 and targetted at mid-range IBM 360 users (typically 360/40, 360/50). OS/MFT was the juinior member of the main 'OS' series of IBM operating systems, the other being OS/MVT. Smaller 360 mainframes used DOS. OS/MFT shared JCL and utilities with OS/MVT but allocated memory differently. In OS/MFT, partitions of memory were of a fixed number and size, specified by the generation and configuration of the operating system. As this class of mainframe had typically less than 512K of main memory, partitions tended to be about 128K. With the advent of Virtual Storage and the System 370's Dynamic Address Translation (DAT), OS/MFT was improved to become OS/VS1, taking account of virtual storage in a single partition up to 16MB. (1999-01-22) 1 1 1 1 1 operational database A database containing up-to-date, modifiable data, in contrast to a decision support database. (1995-02-14) 1 1 1 1 1 Operational Data Store (ODS) A group of integrated databases designed to support the monitoring of operations. Unlike function oriented databases, an ODS contains subject-oriented, dynamic, current enterprise-wide information that is continually updated to show the current state of operations. ["Data Warehousing Architecture and Implementation"]. (2010-02-28) 1 1 1 1 1 operational requirements Qualitative and quantitative parameters that specify the desired capabilities of a system and serve as a basis for determining the operational effectiveness and suitability of a system prior to deployment. (1997-01-07) 1 1 1 1 1 operational semantics A set of rules specifying how the state of an actual or hypothetical computer changes while executing a program. The overall state is typically divided into a number of components, e.g. stack, heap, registers etc. Each rule specifies certain preconditions on the contents of some components and their new contents after the application of the rule. It is similar in spirit to the notion of a Turing machine, in which actions are precisely described in a mathematical way. Compuare axiomatic semantics, denotational semantics. (1996-08-21) 1 1 1 1 1 operational test and evaluation (OT&E) Formal testing conducted prior to deployment to evaluate the operational effectiveness and suitability of the system with respect to its mission. (1997-01-07) 1 1 1 1 1 operational testing A US DoD term for testing performed by the end-user on software in its normal operating environment. (1997-01-07) 1 1 1 1 1 operation code (Always "op code" when spoken) The part or parts of a machine language instruction which determines what kind of action the computer should take, e.g. add, jump, load, store. In any particular instruction set certain fixed bit positions within the instruction word contain the op code, others give parameters such as the addresses or registers involved. For example, in a 32-bit instruction the most significant eight bits might be the op code giving 256 possible operations. For some instruction sets, certain values in the fixed bit positions may select a group of operations and the exact operation may depend on other bits within instruction word or subsequent words. When programming in assembly language, the op code is represented by a readable name called an instruction mnemonic. (1997-02-14) 1 1 1 1 1 operations support technician A person who analyses and supports computer operations by controlling production applications, monitoring system resources and response time and providing first-line support for operational problems. (2004-03-20) 1 1 1 1 1 operator A symbol used as a function, with infix syntax if it has two arguments (e.g. "+") or prefix syntax if it has only one (e.g. Boolean NOT). Many languages use operators for built-in functions such as arithmetic and logic. (1995-04-30) 1 1 1 1 1 Operator Control Language (OCL) The batch language for the IBM System/36, used specifically with the RPG II compiler. See also CL. (1994-11-18) 1 1 1 1 1 operator overloading overloading 1 1 1 1 1 OPF Object Persistence Framework 1 1 1 1 1 Opportunity Management System (OMS) A system that stores sales opportunities and related information. Each sales lead can be tracked with information such as source, type, worth, status, likelihood of closure etc. An OMS can perform other related tasks such as prioritising sales calls and generating analyses that assist the fine-tuning of marketing strategies. See also Customer Relationship Management. (1999-08-20) 1 1 1 1 1 OPS 1. <simulation> On-line Process Synthesizer. 2. <language> Official Production System. 3. <database> Oracle Parallel Server. (2003-04-05) 1 1 1 1 1 OPS5 A programming language for rule-based production systems. A rule consists of pre-condition(s) and a resulting action. The system checks its working memory to see if there are rules whose pre-conditions are satisfied, if so, the action in one selected satisfied rule is executed. There is a public domain implementation of an OPS5 interpreter written by Charles L. Forgy <forgy@cs.cmu.edu> in 1977. It was first implemented in Lisp and later in BLISS. It was also ported to Common Lisp by George Wood and Jim Kowalski. CLIPS is a language for writing expert systems, with some of the capabilities of OPS5. See also C5, OPS83, OPS4, OPS5+, OPS83. Inference Engine Tech, Cambridge MA. An OPS5 interpreter in Common LISP (ftp://ftp.wustl.edu/mirrors/Unix-c/languages/ops5). 1 1 1 1 1 OPS83 A commercial version of OPS5. 1 1 1 1 1 Optical Carrier 12 (OC-12) A SONET rate of 12 * 51.84 = 622.08 megabits per second. [Matches STS-12]? (1997-05-26) 1 1 1 1 1 Optical Carrier 3 (OC-3) A SONET rate of 3 * 51.84 = 155.52 megabits per second, which matches STS-3. (1997-02-05) 1 1 1 1 1 Optical Carrier 48 (OC-48) A SONET rate of 48 * 51.84 = 2488.32 megabits per second. [Matches STS-48]? (1997-05-26) 1 1 1 1 1 Optical Carrier n (OC-n) A SONET rate of n times 51.84 megabits per second. (1997-02-05) 1 1 1 1 1 Optical Character Recognition (OCR, sometimes /oh'k*/) Recognition of printed or written characters by computer. Each page of text is converted to a digital using a scanner and OCR is then applied to this image to produce a text file. This involves complex image processing algorithms and rarely achieves 100% accuracy so manual proof reading is recommended. (1999-08-26) 1 1 1 1 1 optical computing (Or "Optical Signal Processing") Operating on data represented using electromagnetic radiation, e.g. visible light, instead of the electrical signals used in a conventional electronic digital computer. Electronic digital computers are built from transistors. These form components that store data and logic gates that perform the low-level Boolean operations such as AND, OR and NOT that are the basis of all digital computation. The optical equivalent requires material with a non-linear refractive index such that light beams can interact with each other to perform the same Boolean operations. Though the photons that carry optical signals offer some theoretical advantages over the electrons that carry electronic signals, there are many practical problems that would have to be overcome before optical computing could compete in terms of cost, power and speed. (2015-08-21) 1 1 1 1 1 optical diff vdiff 1 1 1 1 1 optical disc drive optical disk drive 1 1 1 1 1 optical disk drive (Or "optical disc drive", "optical storage") A generic term for any device that reads and/or writes optical media, i.e. compact discs, DVDs and/or Blu-ray discs or future media that uses light (from a small laser) to read data off a removable, rotating disk. At least one such drive is commonly installed in most personal computers to allow them to play and/or record audio and video media and load and store data such as program installers. The floppy disk has been replaced by optical media due to its vastly greater capacity, e.g. 50,000 megabytes for a dual-layer blu-ray disc compared with 1.5 megabytes for a floppy (over 30,000 times as much). (2014-04-27) 1 1 1 1 1 optical drive optical disk drive 1 1 1 1 1 optical fiber optical fibre 1 1 1 1 1 optical fibre (fibre optics, FO, US "fiber", light pipe) A plastic or glass (silicon dioxide) fibre no thicker than a human hair used to transmit information using infra-red or even visible light as the carrier (usually a laser). The light beam is an electromagnetic signal with a frequency in the range of 10^14 to 10^15 Hertz. Optical fibre is less susceptible to external noise than other transmission media, and is cheaper to make than copper wire, but it is much more difficult to connect. Optical fibres are difficult to tamper with (to monitor or inject data in the middle of a connection), making them appropriate for secure communications. The light beams do not escape from the medium because the material used provides total internal reflection. AT&T Bell Laboratories in the United States managed to send information at a rate of 420 megabits per second, over 161.5 km through an optical fibre cable. In Japan, 445.8 megabits per second was achieved over a shorter distance. At 1 1 1 1 1 optical grep vgrep 1 1 1 1 1 Optical Mark Reader (OMR) A special scanning device that can read carefully placed pencil marks on specially designed documents. OMR is frequenty used in forms, questionnaires, and answer-sheets. (1995-04-13) 1 1 1 1 1 optical mouse Any kind of mouse that uses visible light or infrared to detect changes in its position. (1999-07-21) 1 1 1 1 1 Optical Signal Processor optical computing 1 1 1 1 1 optical storage optical disk drive 1 1 1 1 1 Optical Storage Technology Association (OSTA) An industry consortium concerned with optical storage. OSTA wrote and maintains the UDF file system used on DVD video discs. OSTA Home (http://osta.org/). (2003-07-12) 1 1 1 1 1 Optical Time Domain Reflectometer A device used to perform Optical Time Domain Reflectometry. (1995-02-01) 1 1 1 1 1 Optical Time Domain Reflectometry Measurement of the elapsed time and intensity of light reflected on optical fibre using an optical time domain reflectometer. The reflectometer can compute the distance to problems on the fibre such as attenuation and breaks, making it a useful tool in optical network trouble-shooting. (1995-02-01) 1 1 1 1 1 optimal 1. <mathematics> Describes a solution to a problem which minimises some cost function. Linear programming is one technique used to discover the optimal solution to certain problems. 2. <programming> Of code: best or most efficient in time, space or code size. (1995-10-05) 1 1 1 1 1 Optimal Flexible Architecture (OFA) Recommendations for logical and physical allocation of database files to disks. The OFA principles can be summarised as: isolate redo, rollback, temp, data and index files as much as possible. OFA can be combined with SAME (Stripe And Mirror Everything). (2007-02-28) 1 1 1 1 1 optimise To perform optimisation. 1 1 1 1 1 optimising compiler compiler which attempts to analyse the code it produces and to produce more efficient code by performing program transformation such as branch elimination, partial evaluation, or peep-hole optimisation. Contrast pessimising compiler. (1995-02-01) 1 1 1 1 1 optimism What a programmer is full of after fixing the last bug and just before actually discovering the *next* last bug. Fred Brooks's book "The Mythical Man-Month" contains the following paragraph that describes this extremely well. All programmers are optimists. Perhaps this modern sorcery especially attracts those who believe in happy endings and fairy god-mothers. Perhaps the hundreds of nitty frustrations drive away all but those who habitually focus on the end goal. Perhaps it is merely that computers are young, programmers are younger, and the young are always optimists. But however the selection process works, the result is indisputable: "This time it will surely run," or "I just found the last bug.". See also Lubarsky's Law of Cybernetic Entomology. [Jargon File] 1 1 1 1 1 optimize optimisation 1 1 1 1 1 option command line option 1 1 1 1 1 OPTRAN Specification language for attributed tree transformation writetn by R. Wilhelm, U Saarlandes in the early 1980's. ["POPSY and OPTRAN Manual", ESPRIT PROSPECTRA Project Item S.1.6-R.3.0, U Saarlandes (Mar 1986)]. 1 1 1 1 1 Opus A Honeywell operating system promised as a sop to customers after canning Multics in 1985. Opus was to provide everything Multics had and more, plus total compatibility with the Level 6/DPS6 operating system. Opus was a code name, the system was officially named VS3 (short for HVS R3 or Honeywell Virtual System Release Three). It was to run on the DPS6-plus hardware known internally as the MRX and HRX, and be all things to all people. The hardware was a dud (though it did run the native DPS6 software just fine), and the goal was, shall we say, ambitious. The effort was cancelled by Bull in 1987, in favor of another project going on in France. 1 1 1 1 1 OR The Boolean function which is true if any of its arguments are true. Its truth table is: A | B | A OR B --+---+--------- F | F | F F | T | T T | F | T T | T | T (1996-11-04) 1 1 1 1 1 Oracle Oracle Corporation 1 1 1 1 1 Oracle 7 Version 7 of the Oracle relational database system software. (1996-11-05) 1 1 1 1 1 Oracle Card A Hypercard-like product from Oracle for constructing database applications. It runs on IBM PC and Macintosh. (1995-03-15) 1 1 1 1 1 Oracle*CASE A set of CASE tools from Oracle. 1 1 1 1 1 Oracle Co-operative Applications Packaged client/server software from Oracle for accounting, manufacturing, distribution, human resources and project control. 1 1 1 1 1 Oracle Corporation The world's leading supplier of information management software. The company, worth $2 billion, offers its products, along with related consulting, education and support services in more than 90 countries around the world. Oracle is best known for its database management systems vendor and relational DBMS products. Oracle develops and markets Oracle Media Server and the Oracle7 family of software products for database management; Co-operative Development Environment and Oracle Co-operative Applications Oracle software runs on personal digital assistants, set-top boxs, IBM PCs, workstations, minicomputers, mainframes and massively parallel computers. Oracle bought Sun Microsystems on 2009-04-20. See also Adaptable User Interface, Bookviewer, CASE*Method, Component Integration Laboratories, DDE Manager, Online Media, Oracle Card, Oracle*CASE, 1 1 1 1 1 Oracle Parallel Server (OPS) An Oracle configuration that allows for multiple Oracle servers running on seperate computers to access the same database files simultaneously. Normally used for high availability, running parallel servers can improve performance by spreading out CPU load, however, it requires data to be partitioned correctly. This feature is enabled with the Parallel Server Option (or PSO). Oracle Parallel Server Option FAQ (http://orafaq.com/faqops.htm). (2003-04-05) 1 1 1 1 1 Oracle Rdb A set of relational database products originally known as Rdb from Digital Equipment Corporation, but purchased by Oracle Corporation in 1994. The current (October 1996) versions are Oracle Rdb V7.0 for OpenVMS VAX, Oracle Rdb V7.0 for OpenVMS Alpha, and Oracle Rdb V7.0 for Digital UNIX. This release of Oracle Rdb includes advances in non-stop computing for business critical applications, improvements to OLTP performance, and easy client/server application development. It also includes an ODBC Driver. (1996-10-30) 1 1 1 1 1 Oracle Toolkit Adaptable User Interface 1 1 1 1 1 Orange Book A standard from the US Government National Computer Security Council (an arm of the U.S. National Security Agency), "Trusted Computer System Evaluation Criteria, DOD standard 5200.28-STD, December 1985" which defines criteria for trusted computer products. There are four levels, A, B, C, and D. Each level adds more features and requirements. D is a non-secure system. C1 requires user log-on, but allows group ID. C2 requires individual log-on with password and an audit mechanism. (Most Unix implementations are roughly C1, and can be upgraded to about C2 without excessive pain). Levels B and A provide mandatory control. Access is based on standard Department of Defense clearances. B1 requires DOD clearance levels. B2 guarantees the path between the user and the security system and provides assurances that the system can be tested 1 1 1 1 1 ORB Object Request Broker 1 1 1 1 1 Orbit A Scheme compiler. ["Orbit: An Optimising Compiler for Scheme", D.A. Kranz et al, SIGPLAN Notices 21(7):281-292 (Jul 1986)]. (1994-10-28) 1 1 1 1 1 Orca Vrije Universiteit, Amsterdam, 1986. Similar to Modula-2, but with support for distributed programming using shared data objects, like Linda. A 'graph' data type removes the need for pointers. Version for the Amoeba OS, comes with Amoeba. Orca: A Language for Distributed Processing, H.E. Bal <bal@cs.vu.nl> et al, SIGPLAN Notices 25(5):17-24 (May 1990). 1 1 1 1 1 Order Code Processor The ICL 2900, ICL 3900 and above term for CPU. (1995-05-06) 1 1 1 1 1 order-embedding A function f : D -> C is order-embedding iff for all x, y in D, f(x) <= f(y) <=> x <= y. I.e. arguments and results compare similarly. A function which is order-embedding is monotonic and one-to-one and an injection. ("<=" is written in LaTeX as \sqsubseteq). (1995-02-03) 1 1 1 1 1 ordering A relation. See partial ordering, pre-order, total ordering. 1 1 1 1 1 ordinal An isomorphism class of well-ordered sets. (1995-03-10) 1 1 1 1 1 ordinary differential equation (ODE) A differential equation that contains functions of only one independent variable, in contrast to a partial differential equation (PDE). (2009-03-11) 1 1 1 1 1 ordinate The y-coordinate on an (x,y) graph; the output of a function plotted against its input. x is the "abscissa". See Cartesian coordinates. (1997-07-08) 1 1 1 1 1 OREGANO ["On the Design and Specification of the Programming Language OREGANO", D.M. Berry. UCLA-ENG-7388, 1973]. 1 1 1 1 1 O'Reilly and Associates The leading publisher of information on the Internet, Unix, the X Window System and other open systems. They also provide the Global Network Navigator service. Home page(http://ora.com/). (1995-01-10) 1 1 1 1 1 org The top-level domain for organisations or individuals that don't fit any other top-level domain (national, com, edu, or gov). Though many have .org domains, it was never intended to be limited to non-profit organisations. RFC 1591. (2001-05-14) 1 1 1 1 1 Organic Mode A term used by COCOMO to describe a project that is developed in a familiar, stable environment. The product is similar to previously developed products. Most people connected with the project have extensive experience in working with related systems and have a thorough understanding of the project. The project contains a minimum of innovative data processing architectures or algorithms. The product requires little innovation and is relatively small, rarely greater than 50,000 DSIs. (1996-05-29) 1 1 1 1 1 Orient84/K ["A Concurrent Object-Oriented Knowledge Representation Language Orient84/K", Y. Ishikawa, Keio U, Yokohama, SIGPLAN Notices 21(11):232-241 OOPSLA '86, Nov 1986]. (1996-05-29) 1 1 1 1 1 Original Equipment Manufacturer (OEM) A misleading term for a company which repackages equipment, such as computers, made by other companies. Unlike a value added reseller, an OEM does not necessarily add anything except their name to the product. In some cases though they may integrate components into complete systems. OEM arrangements are often made for marketing reasons. [Origin?] (2001-04-09) 1 1 1 1 1 ORKID Open Real-time Kernel Interface Definition 1 1 1 1 1 ORM 1. <programming, database> object relational mapping. 2. <programming> Object Role Modeling. 1 1 1 1 1 orphaned i-node /or'f*nd i:'nohd/ [Unix] 1. A file that retains storage but no longer appears in the directories of a file system. [Jargon File] (2014-12-03) 1 1 1 1 1 orphan process A Unix process whose original parent has terminated and which has become a child of "init(1)". Compare zombie. (1996-05-29) 1 1 1 1 1 ORTHOCARTAN A system for symbolic mathematics, especially General Relativity, written by A. Krasinski of Warsaw in the early 1980s. (1995-04-12) 1 1 1 1 1 orthogonal At 90 degrees (right angles). N mutually orthogonal vectors span an N-dimensional vector space, meaning that, any vector in the space can be expressed as a linear combination of the vectors. This is true of any set of N linearly independent vectors. The term is used loosely to mean mutually independent or well separated. It is used to describe sets of primitives or capabilities that, like linearly independent vectors in geometry, span the entire "capability space" and are in some sense non-overlapping or mutually independent. For example, in logic, the set of operators "not" and "or" is described as orthogonal, but the set "nand", "or", and "not" is not (because any one of these can be expressed in terms of the others). Also used loosely to mean "irrelevant to", e.g. "This may be orthogonal to the discussion, but ...", similar to "going off at a tangent". 1 1 1 1 1 orthogonal instruction set An instruction set where all (or most) instructions have the same format and all registers and addressing modes can be used interchangeably - the choices of op code, register, and addressing mode are mutually independent (loosely speaking, the choices are orthogonal). This contrasts with some early Intel microprocessors where only certain registers could be used by certain instructions. Examples include the PDP-11, 680x0, ARM, VAX. (2002-06-26) 1 1 1 1 1 Orwell Lazy functional language, Miranda-like. List comprehensions and pattern matching. "Introduction to Orwell 5.00", P.L. Wadler et al, Programming Research Group, Oxford U, 1988. 1 1 1 1 1 OS 1. operating system. 2. [obsolete, ITS], an output spy. See "OS and JEDGAR". 3. <operating system> An operating system from IBM for their System/360 line of hardware announced in 1964. OS was planned with several flavours that were supposed to be compatible. OS was late, memory hungry and not able to reach the marketing objectives of IBM for the 360/30, the planned successor of the IBM 1401. IBM then decided to design a new operating system for the low end machines which they called DOS/360. [Jargon File] (1997-09-22) 1 1 1 1 1 OS2 Normally written "OS/2". [Jargon File] (1997-05-02) 1 1 1 1 1 OS/2 /O S too/ IBM and Microsoft's successor to the MS-DOS operating system for Intel 80286 and Intel 80386-based microprocessors. It is proof that they couldn't get it right the second time either. Often called "Half-an-OS". The design was so baroque, and the implementation of 1.x so bad, that 3 years after introduction you could still count the major application programs shipping for it on the fingers of two hands, in unary. Later versions improved somewhat, and informed hackers now rate them superior to Microsoft Windows, which isn't saying much. See second-system effect. On an Intel 80386 or better, OS/2 can multitask between existing MS-DOS applications. OS/2 is strong on connectivity and the provision of robust virtual machines. It can support Microsoft Windows programs in addition to its own native applications. It also supports the Presentation Manager graphical user interface. 1 1 1 1 1 OS/360 Operating System/360 1 1 1 1 1 OS/390 An IBM mainframe operating system, featuring integrated MVS, UNIX, LAN, distributed computing and application enablement services through its base elements. These base services enable open, distributed processing and offer a foundation for object-ready application development. The OS/390 base includes a Communication Server that includes VTAM, the VTAM AnyNet feature, TCP/IP and TIOC. It provides SNA (3270), APPC, High Performance Routing, ATM support, sockets and RPC. OS/390 is basically rebranded, repackaged MVS/OE, CMOS processors, RAMAC disk arrays and open systems extension to networking in VTAM, the principle being that if you can't compete, rebrand what you have and tell everyone it's something new. (http://204.146.133.206/os390/index.html). (1999-01-20) 1 1 1 1 1 OS-9 A real-time operating system written by Microware Corporation. The original version was written about 1978 for the Motorola 6809 and has since been ported to the Motorola 68000, Intel 80386, Intel 486, and the PowerPC. The kernel of OS-9 is ROMable, modular, with a unified file system, allowing it to easily be scaled up or down as required. FAQ (http://os9archive.rtsi.com/os9faq.html). User Group (http://cs.wisc.edu/~pruyne/os9ugfaq.html). Usenet newsgroup: news:comp.os.os9. (1996-04-03) 1 1 1 1 1 OSA 1. Open Scripting Architecture. 2. Open System Architecture. 1 1 1 1 1 OSA extension (OSAX) Any extension to Macintosh OSA. (1999-01-14) 1 1 1 1 1 OSAX OSA extension 1 1 1 1 1 Osborne 1 A portable computer that weighed 11 kg and cost $1795, produced by Osborne Computer Corporation in 1981. The Osborne 1 came with a five-inch screen, modem port, two 5 1/4 floppy drives and a battery pack. It came with the CP/M operating system, SuperCalc spreadsheet application, WordStar, word processing application, Microsoft MBASIC programming language and Digital Research CBASIC programming language. (http://oldcomputers.net/osborne.html) (2007-05-21) 1 1 1 1 1 Osborne, Adam Adam Osborne 1 1 1 1 1 Osborne Computer Corporation The unsucessful computer manufacturer founded by Adam Osborne that produced one of the first laptop computers, the Osborne 1. (2007-05-21) 1 1 1 1 1 OSCAR 1. Oregon State Conversational Aid to Research. Interactive numerical calculations, vectors, matrices, complex arithmetic, string operations, for CDC 3300. "OSCAR: A User's Manual with Examples", J.A. Baughman et al, CC, Oregon State U. 2. Object-oriented language used in the COMANDOS Project. OSCAR: Programming Language Manual, TR, COMANDOS Project, Nov 1988. 1 1 1 1 1 OSD Open Source Definition 1 1 1 1 1 OSE Open Systems Environment 1 1 1 1 1 OSF Open Software Foundation 1 1 1 1 1 OSI 1. <networking> Open Systems Interconnection. 2. Open Source Initiative. (1999-12-29) 1 1 1 1 1 OSI Model Open Systems Interconnect 1 1 1 1 1 OSI Reference Model Open Systems Interconnect 1 1 1 1 1 OSI-RM Open Systems Interconnect 1 1 1 1 1 OSI seven layer model Open Systems Interconnect 1 1 1 1 1 O'small A small, concise, formally defined object-oriented language intended for teaching, by Andreas Hense <ahense@ahense.de>. O'small requires sml-yacc, sml-lex and sml-noshare. Binaries are provided for SPARC and it is probably portable to other Unix systems. There is also an interpreter in Miranda. (http://ahense.de/). [Christoph Boeschen, "Christmas - An abstract machine for O'small". Master's thesis, Universit"at des Saarlandes, Fachbereich, 1993-06-14]. (2001-02-11) 1 1 1 1 1 OS/MFT Operating System/Multiprogramming of Fixed Tasks 1 1 1 1 1 OS/MVT One of the IBM operating systems associated with the IBM 360, later rereleased with the IBM S/370 as OS/VS2. [Details?] (1999-01-12) 1 1 1 1 1 OSP optical computing 1 1 1 1 1 OSPF Open Shortest-Path First Interior Gateway Protocol 1 1 1 1 1 OSQL Object-oriented SQL 1 1 1 1 1 OSSL Operating Systems Simulation Language. ["OSSL - A Specialized Language for Simulating Computer Systems", P.B. Dewan et al, Proc SJCC 40, AFIPS (Spring 1972)]. 1 1 1 1 1 OSTA Optical Storage Technology Association 1 1 1 1 1 OS/VS1 OS/MFT 1 1 1 1 1 OS/VS2 An operating system from IBM, released with the IBM S/370 and originally known as OS/MVT. OS/VS2 R1 was known as SVS (Single Virtual Storage) as it had a single 16 MB virtual address space. OS/VS2 R2 was known as MVS - Multiple Virtual Storage. (1999-01-13) 1 1 1 1 1 OT OpenTransport 1 1 1 1 1 OTDR Optical Time-Domain Reflectometry 1 1 1 1 1 OT&E operational test and evaluation 1 1 1 1 1 OTI Open Tool Interface 1 1 1 1 1 OTOH On the other hand. (2000-01-31) 1 1 1 1 1 OTP 1. <security> One-Time Password. 2. <protocol> Open Trading Protocol. 3. <storage, integrated circuit> One Time Programmable Read Only Memory. 4. <communications, library> Open Telecom Platform. (2001-08-28) 1 1 1 1 1 OTPROM One Time Programmable Read-Only Memory 1 1 1 1 1 OTT Over the top. Excessive or uncalled for. (1995-01-31) 1 1 1 1 1 Ottawa Euclid Euclid 1 1 1 1 1 Ousterhout, John K. John Ousterhout 1 1 1 1 1 Ousterhout's dichotomy John Ousterhout's division of high-level languages into "system programming languages" and "scripting languages". This distinction underlies the design of his language Tcl. System programming languages (or "applications languages") are strongly typed, allow arbitrarily complex data structures, and programs in them are compiled, and are meant to operate largely independently of other programs. Prototypical system programming languages are C and Modula-2. By contrast, scripting languages (or "glue languages") are weakly typed or untyped, have little or no provision for complex data structures, and programs in them ("scripts") are interpreted. Scripts need to interact either with other programs (often as glue) or with a set of functions provided by the interpreter, as with the file system functions provided in a UNIX shell and with Tcl's GUI functions. Prototypical scripting languages are AppleScript, C Shell, 1 1 1 1 1 Ousterhout's fallacy Ousterhout's dichotomy 1 1 1 1 1 Ousterhout's false dichotomy Ousterhout's dichotomy 1 1 1 1 1 out A type or "mode" of function parameter that passes information in one direction - from the function to the caller. An "out" parameter thus provides an additional return value, typically for languages that don't have good support for returning data structures like lists. Other modes are in and inout. (2010-01-19) 1 1 1 1 1 outer join A less commonly used variant of the inner join relational database operation. An inner join selects rows from two tables such that the value in one column of the first table also appears in a certain column of the second table. For an outer join, the result also includes all rows from the first operand ("left outer join"), or the second operand ("right outer join"), or both ("full outer join"). A field in a result row will be null if the corresponding input table did not contain a matching row. For example, if we want to list all employees and their employee number, but not all employees have a number, then we could say (in SQL-92 syntax, as used by Microsoft SQL Server): SELECT employee.name, empnum.number FROM employee 1 1 1 1 1 outline font (Or "vector font") A font defined as a set of lines and curves as opposed to a bitmap font. An outline font (e.g. PostScript, TrueType, RISC OS) can be scaled to any size and otherwise transformed more easily than a bitmap font, and with more attractive results, though this requires a lot of numerical processing. The result of transforming a character in an outline font in a particular way is often saved as a bitmap in a font cache to avoid repeating the calculations if that character is to be drawn again. (1995-03-16) 1 1 1 1 1 out-of-band 1. <communications> The exchange of call control information on a dedicated channel, separate from that used by the telephone call or data transmission. 2. Sometimes used to describe what communications people call shift characters, such as the ESC that leads control sequences for many terminals, or the level shift indicators in the old 5-bit Baudot codes. 3. In personal communication, using methods other than electronic mail, such as telephone or snail-mail. 4. <software> Values returned by a function that are not in its "natural" range of return values, but rather signal some kind of exception. Many C functions that normally return a non-negative integer return -1 to indicate failure. This use confuses "out-of-band" with "out-of-range". It is actually a clear example of in-band signalling since it uses the same "channel" for control and data. Compare hidden flag, green bytes, fence. 1 1 1 1 1 output Data transferred from a computer system to the outside world via some kind of output device. Opposite: input. (1997-04-28) 1 1 1 1 1 output device Electronic or electromechanical equipment connected to a computer and used to transfer data out of the computer in the form of text, images, sounds or other media to a display screen, printer, loudspeaker or storage device. Most modern storage devices such as disk drives and magnetic tape drives act as both input and output devices, others such as CD-ROM are input only. (1997-03-18) 1 1 1 1 1 Outside Awareness Port (OAP) A humorous IBM term for a window (the glass kind) rather than the GUI kind. 1 1 1 1 1 outside-in testing A strategy for integration testing where units handling program inputs and outputs are tested first, and units that process the inputs to produce output are incrementally included as the system is integrated. A form of hybrid testing. (1997-01-07) 1 1 1 1 1 outsourcing Paying another company to provide services which a company might otherwise have employed its own staff to perform, e.g. software development. (1995-03-28) 1 1 1 1 1 overclocking Any adjustments made to computer hardware, or less commonly software, to make its CPU run at a higher clock rate than intended by the original manufacturers. Typically this involves replacing the crystal in the clock generation circuitry with a higher frequency one or changing jumper settings or software configuration. If the clock rate is increased too far, eventually some component in the system will not be able to cope and the system will stop working. This failure may be intermittent (it works most of the time but fails more often than usual) continuous (the system never works at the higher frequency) or, in the worst case, irreversible (a component is damaged by overheating). Improved cooling may be needed to maintain the same level of reliability. (2014-07-12) 1 1 1 1 1 Overdrive An Intel Pentium processor which fits into a socket designed to accomodate an Intel 486, or into a special upgrade socket on the motherboard. (1995-03-27) 1 1 1 1 1 overflow The condition that occurs when the result of a calculation is too big to store in the intended format. For example, the result of adding one to 255 cannot be represented as an unsigned, eight-bit integer. In a signed integer representation, overflow can occur when an integer becomes either too positive or too negative. Overflow can also occur in the exponent of a floating point number representation. The term "underflow" is sometimes used for negative overflow of the exponent. Ignoring overflow will result in nonsensicle results such as 255 + 1 = 0. At the hardware level, the ALU typically indicates overflow by setting an overflow flag bit which the program can test. Programming languages will typically respond to overflow by raising some kind of signal or other error condition to halt normal execution. Some languages attempt to avoid overflow by providing (optional) variable length number representation 1 1 1 1 1 overflow bit A processor flag bit set by the ALU to indicate overflow. (2008-05-30) 1 1 1 1 1 overflow flag overflow bit 1 1 1 1 1 overflow pdl The place where you put things when your pdl is full. If you don't have one and too many things get pushed, you forget something. The overflow pdl for a person's memory might be a memo pad. This usage inspired the following doggerel: Hey, diddle, diddle The overflow pdl To get a little more stack; If that's not enough Then you lose it all, And have to pop all the way back. --The Great Quux The term pdl seems to be primarily an MITism; outside MIT this term is replaced by "overflow stack". 1 1 1 1 1 overhead 1. Resources (in computing usually processing time or storage space) consumed for purposes which are incidental to, but necessary to, the main one. Overheads are usually quantifiable "costs" of some kind. Examples: The overheads in running a business include the cost of heating the building. Keeping a program running all the time eliminates the overhead of loading and initialising it for each transaction. Turning a subroutine into inline code eliminates the call and return time overhead for each execution but introduces space overheads. 2. <communications> information, such as control, routing, and error checking characters, that is transmitted along with the user data. It also includes information such as network status or operational instructions, network routing information, and retransmissions of user data received in error. 3. Overhead transparencies or "slides" (usually 8-1/2" x 11") 1 1 1 1 1 overloading (Or "Operator overloading"). Use of a single symbol to represent operators with different argument types, e.g. "-", used either, as a monadic operator to negate an expression, or as a dyadic operator to return the difference between two expressions. Another example is "+" used to add either integers or floating-point numbers. Overloading is also known as ad-hoc polymorphism. User-defined operator overloading is provided by several modern programming languages, e.g. C++'s class system and the functional programming language Haskell's type classes. Ad-hoc polymorphism (better described as overloading) is the ability to use the same syntax for objects of different types, e.g. "+" for addition of reals and integers or "-" for unary negation or diadic subtraction. Parametric polymorphism allows the same object code for a function to handle arguments of many types but overloading only reuses syntax and requires 1 1 1 1 1 overriding Redefining in a child class a method or function member defined in a parent class. Not to be confused with "overloading". (1996-12-21) 1 1 1 1 1 overrun 1. A frequent consequence of data arriving faster than it can be consumed, especially in serial line communications. For example, at 9600 baud there is almost exactly one character per millisecond, so if a silo can hold only two characters and the machine takes longer than 2 milliseconds to get to service the interrupt, at least one character will be lost. 2. Also applied to non-serial-I/O communications. "I forgot to pay my electric bill due to mail overrun." "Sorry, I got four phone calls in 3 minutes last night and lost your message to overrun." When thrashing at tasks, the next person to make a request might be told "Overrun!" Compare firehose syndrome. 3. More loosely, may refer to a buffer overflow not necessarily related to processing time (as in overrun screw). [Jargon File] 1 1 1 1 1 overrun screw A variety of fandango on core produced by a C program scribbling past the end of an array (C implementations typically have no checks for this error). This is relatively benign and easy to spot if the array is static; if it is auto, the result may be to smash the stack - often resulting in heisenbugs of the most diabolical subtlety. The term "overrun screw" is used especially of scribbles beyond the end of arrays allocated with malloc; this typically overwrites the allocation header for the next block in the arena, producing massive lossage within malloc and often a core dump on the next operation to use stdio or malloc itself. See spam, overrun; see also memory leak, memory smash, aliasing bug, precedence lossage, fandango on core, secondary damage. (1995-01-19) 1 1 1 1 1 overuse strain injury (Or "repetitive strain injury", RSI, "repetitive strain disorder") Any tendon or muscle injury resulting from overuse, usually in the hand, wrist, or arm. Injury may be caused by any combination of repetitive, unacustomed, or prolonged movements, forcefulness, or an awkward position (often due to bad ergonomics). The symptoms are pain, tingling, weakness, numbness, swelling, cracking, stiffness, or reduced coordination. Common conditions are: Carpal tunnel syndrome, where swelling of the membrane linings in your wrist surrounding the tendons that bend your fingers compresses the median nerve. This may result in numbness and pain in the hand, arm, shoulder, and neck. Tennis elbow, where rotating your wrist and using force causes a form of epicondylitis. Tendinitis, where unacustomed exercise or repeated awkward movements inflame wrist, elbow, or shoulder tendons, often 1 1 1 1 1 OWHY An early functional language(?). ["A Type-Theoretical Alternative to CUCH, ISWIM, OWHY", Dana Scott, Oxford U 1969]. (1995-01-19) 1 1 1 1 1 OWL 1. <company> Office Workstations Limited. 2. <language> Object Windows Language. (1996-01-13) 1 1 1 1 1 Owl The original name of Trellis. (1995-01-19) 1 1 1 1 1 Ox A preprocessor, written by Kurt Bischoff of Iowa State University, that extends and generalises the syntax and semantics of Yacc, Lex, and C. Ox's support of LALR1 grammars generalises yacc in the way that attribute grammars generalise context-free grammars. It augments Yacc and Lex specifications with definitions of synthesised and inherited attributes written in C syntax. Ox checks these specifications for consistency and completeness, and generates a program that builds and decorates attributed parse trees. Ox accepts a most general class of attribute grammars. The user may specify postdecoration traversals for easy ordering of side effects such as code generation. Latest version: G1.01, as of 1993-11-14. (ftp://ftp.cs.iastate.edu/pub/ox/). Info: <ox-request@cs.iastate.edu>. ["User Manual for Ox: An Attribute-Grammar Compiling System 1 1 1 1 1 Oz An object-oriented concurrent constraint language from the University of Saarbrucken. Oz is based on constraint communication, a new form of asynchronous communication using logic variables. Partial information about the values of variables is imposed concurrently and incrementally. Supports higher order programming and object-orientation including multiple inheritance. (ftp:duck.dfki.uni-sb.de/pub/papers). ["Object-Oriented Concurrent Constraint Programming in Oz", G. Smolka et al]. 1 1 1 1 1 oz An old Australian top-level domain and network which got incorporated into the current one. The former Australian domains .oz, .edu and .com are now .oz.au, .edu.au and .com.au. (1994-10-04) 1 1 1 1 1 Oz-Email An Internet access provider. (http://ozemail.com.au/). Address: Sydney, Australia. (1995-03-02) 1 1 1 1 1 P+ ["Experience with Remote Procedure Calls in a Real-Time Control System", B. Carpenter et al, Soft Prac & Exp 14(9):901-907 (Sep 1984)]. 1 1 1 1 1 P1754 IEEE Std 1754-1994 "A 32-Bit Microprocessor Architecture". The IEEE standard defining a version of the SPARC microprocessor architecture. The P1754 standard (the first microprocessor standard) was approved after four years on 1994-03-17. It is compatible with, but distinct from, SPARC International's 32 bit version of the SPARC Architecture, SPARC V8, from which it is largely derived. It is possible for a processor to comply with neither, one, or both specifications. SI article (http://sparc.com/sparc.new/other/sflash/94-03.html). (1996-12-21) 1 1 1 1 1 p2c A Pascal to C translator by Dave Gillespie <daveg@synaptics.com>. Version 1.20 (ftp://csvax.cs.caltech.edu/). Supports ANSI/ISO standard Pascal as well as substantial subsets of HP Pascal, Turbo Pascal, VAX, and many other dialects. (1990-04-13) 1 1 1 1 1 P2P peer-to-peer 1 1 1 1 1 P3L (Superscript 3). A language with explicit parallelism including constructs for farms and geometric parallelism. P3L currently uses C++ as a host language. [S. Pelagatti, "A method for the development and the support of massively parallel programs. PhD Thesis - TD 11/93, University of Pisa, Mar 1993]. (1994-07-15) 1 1 1 1 1 P4 A macro/subroutine package for parallel programming by Rusty Lusk <lusk@anta.mcs.anl.gov>. P4 uses monitors on shared memory machines and message passing on distributed memory machines. It is implemented as a subroutine library for C and Fortran. An enhancement of the "Argonne macros", PARMACS. (ftp://info.mcs.anl.gov/pub/p4t1.2.tar.Z). E-mail: <p4@mcs.anl.gov>. 1 1 1 1 1 P6 ("P" from Pentium, 6 from 686, the successor to 586 which is what the Pentium would have been had it followed the naming scheme its predecessors) The name for the Pentium Pro during development. (1995-11-15) 1 1 1 1 1 pa The country code for Panama. (1999-01-27) 1 1 1 1 1 PABX Private Automatic Branch eXchange 1 1 1 1 1 PACE A CPU based on the Nova design, but with 16-bit addressing, more addressing modes and a 10 level stack (like the Intel 8008). (1994-11-30) 1 1 1 1 1 Packard Bell Electronics, Inc. A leading US computer vendor. As recently as 29 November 1995 the Wall Street Journal reported that the company was having financial difficulties and that one of its major suppliers of CPUs, Intel, was about to make a large cash loan, so as to prevent loss of a major customer. Packard Bell is a privately held company and the WSJ also reported that NEC has been rumored to have bought a large minority block of shares to help the company stay in business. Its computers are sold in major retail outlets in the USA and are available as a bundled package: desktop or tower 486 CPU, single 3.5 inch floppy disk drive, CD-ROM, sound card, 14 inch colour monitor, and 4-8MB of RAM. 1995 end-of-year prices in Computer Currents magazine (a California Bay Area bi-monthly giveaway publication) are US$1500 (approx. 1000 pounds) for a 486 desktop, with 8MB RAM, 420MB hard disk drive, single 3.5 inch floppy drive, 14 1 1 1 1 1 packed decimal binary coded decimal 1 1 1 1 1 Packed Encoding Rules (PER) ASN.1 encoding rules for producing a compact transfer syntax for data structures described in ASN.1, defined in 1994. PER provides a much more compact encoding then BER. It tries to represents the data units using the minimum number of bits. The compactness requires that the decoder knows the complete abstract syntax of the data structure to be decoded, however. Documents: ITU-T X.691, ISO 8825-2. (1998-05-19) 1 1 1 1 1 packet The unit of data sent across a network. "Packet" is a generic term used to describe a unit of data at any layer of the OSI protocol stack, but it is most correctly used to describe application layer data units ("application protocol data unit", APDU). See also datagram, frame. (1994-11-30) 1 1 1 1 1 Packet Assembler/Disassembler (PAD) Hardware or software device for splitting a data stream into discrete packets for transmission over some medium and then reforming the stream(s) at the receiver. The term is most often used for interfaces to X.25 lines. (1995-01-31) 1 1 1 1 1 packet driver IBM PC local area network software that divides data into packets which it routes to the network. It also handles incoming data, reassembling the packets so that application programs can read the data as a continuous stream. FTP Software created the specification for IBM PC packet drivers but Crynwr Software dominate the market and have done the vast majority of the implementations. Packet drivers provide a simple, common programming interface that allows multiple applications to share a network interface at the data link layer. Packet drivers demultiplex incoming packets among the applications by using the network media's standard packet type or service access point field(s). The packet driver provides calls to initiate access to a specific packet type, to end access to it, to send a packet, to get statistics on the network interface and to get 1 1 1 1 1 Packet in Plastic Grid Array (PPGA) The package used for Intel's Celeron Socket 370 CPU. [Description?] (1999-06-24) 1 1 1 1 1 Packet InterNet Groper ping 1 1 1 1 1 packet radio The use of packet switched communications protocols in large networks (i.e not wireless LANs or Bluetooth) having wireless links to terminals at least. Packet radio is split into amateur packet radio (AX25) and General Packet Radio Service (GRPS). (2001-05-12) 1 1 1 1 1 packet sniffer A network monitoring tool that captures data packets and decodes them using built-in knowledge of common protocols. Sniffers are used to debug and monitor networking problems. (1995-03-28) 1 1 1 1 1 packet switch packet switching 1 1 1 1 1 packet-switched packet switching 1 1 1 1 1 packet switching A communications paradigm in which packets (messages or fragments of messages) are individually routed between nodes, with no previously established communication path. Packets are routed to their destination through the most expedient route (as determined by some routing algorithm). Not all packets travelling between the same two hosts, even those from a single message, will necessarily follow the same route. The destination computer reassembles the packets into their appropriate sequence. Packet switching is used to optimise the use of the bandwidth available in a network and to minimise the latency. X.25 is an international standard packet switching network. Also called connectionless. Opposite of circuit switched or connection-oriented. See also virtual circuit, wormhole routing. (1999-03-30) 1 1 1 1 1 Packet Switch Node (PSN) A dedicated computer whose purpose is to accept, route and forward packets in a packet-switched network. (1994-11-30) 1 1 1 1 1 packet writing A technique for writing CD-Rs and CD-RWs that is more efficient in both disk space used and the time it takes to write the CD. Adaptec's DirectCD is a packet writing recorder for Windows 95 and Windows NT that uses the UDF version 1.5 file system. [Is this true? How does it work?] (1999-09-01) 1 1 1 1 1 PackIt A file format used on the Apple Macintosh to represent collections of Mac files, possibly Huffman compressed. Packing many small related files together before a MacBinary transfer or a translation to BinHex 4.0 is common practice. (1994-11-30) 1 1 1 1 1 PACT I An early system on the IBM 701. Version PACT IA was for the IBM 704. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-30) 1 1 1 1 1 PACTOLUS Digital simulation. [Sammet 1969, p. 627]. (1994-11-30) 1 1 1 1 1 PAD Packet Assembler/Disassembler 1 1 1 1 1 padded cell Where you put lusers so they can't hurt anything. A program that limits a luser to a carefully restricted subset of the capabilities of the host system (for example, the "rsh" utility on USG Unix). Note that this is different from an iron box because it is overt and not aimed at enforcing security so much as protecting others (and the luser) from the consequences of the luser's boundless naivet'e (see naive). Also "padded cell environment". [Jargon File] (1994-11-30) 1 1 1 1 1 Paddle A language for transformations leading from specification to program. Used in the POPART programming environment generator. (1994-11-30) 1 1 1 1 1 PAGE A typesetting language. ["Computer Composition Using PAGE-1", J.L. Pierson, Wiley 1972]. 1 1 1 1 1 page 1. <operating system> paging. 2. <web> web page. (1997-04-10) 1 1 1 1 1 paged paging 1 1 1 1 1 Page Description Language (PDL) A language such as Adobe Systems, Inc.'s PostScript or Xerox's Interpress which allows the appearance of a printed page to be described in a high-level, device-independent way. Printing then becomes a two-stage process: an application program produces a description in the language, which is then interpreted by a specific output device. Such a language can therefore serve as an interchange standard for transmission and storage of printable documents. (1995-02-20) 1 1 1 1 1 Paged Memory Management Unit Memory Management Unit 1 1 1 1 1 page fault In a paged virtual memory system, an access to a page (block) of memory that is not currently mapped to physical memory. When a page fault occurs the operating system either fetches the page in from secondary storage (usually disk) if the access was legitimate or otherwise reports the access as illegal. (1995-11-11) 1 1 1 1 1 page in What a paging system does when it copies part of a task's working memory from swap space on disk to RAM. [Jargon File] (1995-01-23) 1 1 1 1 1 pagelet A component of an HTML page, that contains directives, layout, and code in a single context. A pagelet may be a separate file or web page that contains information you want displayed across several pages. They are similar to server-side include files, as implemented in ASP+. Pagelets act like independent HTML frames and provide discrete access to content. They use Cascading Style Sheets as templates for defining their layout behavior in a single context. [.NET Framework Essentials, 2nd Edition, Thuan L. Thai and Lam Hoang, February 2002, 0-596-00302-1] (2004-02-19) 1 1 1 1 1 page mode 1. <hardware, storage> See page mode DRAM. 2. <hardware> An operation mode of video terminals like the IBM 3270, in which the terminal only sends a completed input screen (page) to the host instead of sending each character as the keys are pressed. (1995-03-28) 1 1 1 1 1 Page Mode DRAM Page Mode Dynamic Random Access Memory 1 1 1 1 1 Page Mode Dynamic Random Access Memory A technique used to support faster sequential access to DRAM by allowing any number of accesses to the currently open row to be made after supplying the row address just once. The RAS signal is kept active, and with each falling edge of the CAS\ signal a new column address can be supplied and the corresponding bits can be accessed. This is faster than a full RAS-CAS cycle because only the shorter Column Access Time needs to be obeyed. Note that strictly speaking such a DRAM is not a true random access memory since accesses to the open row are faster than to other locations. EDO RAM is replacing Page Mode DRAM in many new microcomputers. [Is "Fast Page Mode" the same as "Page Mode"?] (1996-10-06) 1 1 1 1 1 page out What a paging system does when it copies part of a task's working memory from RAM to swap space on disk. [Jargon File] (1995-01-23) 1 1 1 1 1 pager 1. <hardware, communications> (Or "beeper", "bleeper" (UK?)) A small wireless receiver that, when triggered (generally via phone), will beep or vibrate (un)pleasantly. The wearer will have been trained to respond to this signal by looking at a small screen on the device for an unimportant message. In recent years, pagers have grown more complex, allowing for long alphanumeric messages to be received and scrolled though (as opposed to earlier models, which supported only short numeric messages); at the same time as pager functions are integrated into some PDAs. If this trend continues, the distinction between PDAs and high-end pagers will disappear. Short Message Service allows a mobile phone to display a message, just like an alphanumeric pager. 2. <tool> A program for viewing a text file a screenful at a time via a text terminal, as opposed to scrolling through it in a GUI window, or catting it all at once to the 1 1 1 1 1 paging A technique for increasing the memory space available by moving infrequently-used parts of a program's working memory from RAM to a secondary storage medium, usually hard disk. The unit of transfer is called a page. A memory management unit (MMU) monitors accesses to memory and splits each address into a page number (the most significant bits) and an offset within that page (the lower bits). It then looks up the page number in its page table. The page may be marked as paged in or paged out. If it is paged in then the memory access can proceed after translating the virtual address to a physical address. If the requested page is paged out then space must be made for it by paging out some other page, i.e. copying it to disk. The requested page is then located on the area of the disk allocated for "swap space" and is read back into RAM. The page table is updated to indicate that the page is paged in and its physical address recorded. 1 1 1 1 1 PaiLisp A parallel Lisp built on Scheme in 1986. ["A Parallel Lisp Language PaiLisp and its Kernel Specification", T. Ito et al, in Parallel Lisp: Languages and Systems, T. Ito et al eds, LNCS 441, Springer 1989]. (1995-01-30) 1 1 1 1 1 pain in the net flamer 1 1 1 1 1 Paintbrush A Microsoft Windows tool for creating bitmap graphics. (1996-08-26) 1 1 1 1 1 PAISley An operational specification language from Bell Labs. ["An Operational Approach to Requirements Specification for Embedded Systems", P. Zave, IEEE Trans Soft Eng SE-8(3):250-269 (May 1982)]. (1995-01-30) 1 1 1 1 1 Pajek A program for analysing and visualising large networks. "Pajek" is Slovene for spider. The program runs on Windows and is free for noncommercial use. Pajek is developed by Vladimir Batagelj and Andrej Mrvar with contributions from Matjaž Zaveršnik. Pajek home (http://pajek.imfm.si/). (2014-04-24) 1 1 1 1 1 PAL 1. <language> Paradox Application Language. 2. For the AVANCE distributed persistent operating system. ["PAL Reference Manual", M. Ahlsen et al, SYSLAB WP-125, Stockholm 1987]. ["AVANCE: An Object Management System", A. Bjornerstedt et al, SIGPLAN Notices 23(11):206-221 (OOPSLA '88) (Nov 1988)]. [What is it?] 3. <language> An object-oriented Prolog-like language. ["Inheritance Hierarchy Mechanism in Prolog", K. Akama, Proc Logic Prog '86, LNCS 264, Springer 1986, pp. 12-21]. 4. <language> PDP Assembly Language. 5. <language> Pedagogic Algorithmic Language. 6. <hardware, integrated circuit> Programmable Array Logic. 7. <television> phase alternating line. (2001-04-02) 1 1 1 1 1 Palace A proprietary multi-user virtual reality-like talk system. The Palace is distinguished from most other VR-like systems in that it is only two-dimensional rather than three; rooms, avatars, and "props" are made up of relatively small 2D bitmap images. Palace is a crude hack, or lightweight, depending on your point of view. (http://thepalace.com/). (1997-09-14) 1 1 1 1 1 palette colour palette 1 1 1 1 1 palmtop (Or "pocket computer", "Hand-held Personal Computer", H/PC) A small general-purpose, programmable, battery-powered computer cabable of handling both numbers and text (in contrast to most pocket calculators) which can be operated comfortably while held in one hand. A palmtop is usually loaded with an operating system such as Windows CE. Data can be transferred between the palmtop and a desktop PC. A palmtop is very similar to a Personal Digital Assistant though a palmptop may have a larger keyboard and more RAM and is possibly more general purpose in concept, if not in practise. The Psion Organiser is one of the best known examples. [Was it the first?] (1998-04-19) 1 1 1 1 1 Palo Alto Research Center XEROX PARC 1 1 1 1 1 Palo Alto Research Centre XEROX PARC 1 1 1 1 1 PAM Pluggable Authentication Module 1 1 1 1 1 Pam A toy ALGOL-like language used in "Formal Specification of Programming Languages: A Panoramic Primer", F.G. Pagan, P-H 1981. (1996-12-23) 1 1 1 1 1 Pandora Parlog extended to allow don't-know nondeterminism. ["Pandora: Non-Deterministic Parallel Logic Programming", R. Bahgat et al, Proc 6th Intl Conf Logic Programming, MIT Press 1989 pp. 471-486]. (1995-04-27) 1 1 1 1 1 panic 1. <operating system> What Unix does when a critical internal consistency checks fails in such a way that Unix cannot continue. The kernel attempts to print a short message on the console and write an image of memory into the swap area on disk. This can be analysed later using adb. The kernel will then either wait in a tight loop until the machine is rebooted or will initiate an automatic reboot. Unix manual page: panic(8). 2. Action taken by software which discovers some fatal problem which prevents it from continuing to run. (1995-03-01) 1 1 1 1 1 PANON A family of pattern-directed string processing languages based on generalised Markov algorithms. PANON-1 is based on simple generalised Markov algorithms and PANON-2 on conditional functional generalised Markov algorithms. ["String Processing Languages and Generalized Markov Algorithms", A. C. Forino, Proc IFIP Working Conf on Symb Manip Languages, pp.141-206, Amsterdam 1968]. 1 1 1 1 1 PANS Pretty Amazing New Stuff. 1 1 1 1 1 Pansophic A US Software Engineering company. 1 1 1 1 1 Pantone A set of standard colours for printing, each of which is specified by a single number. You can buy a Pantone swatch book containing samples of each colour. Some computer graphics software allows colours to be specified as Pantone numbers. Even though a computer monitor can only show an approximation to some of the colours, the software can output a colour separation for each different Pantone colour, enabling a print shop to exactly reproduce the original desired colour. (1996-03-23) 1 1 1 1 1 PAP 1. <networking, protocol, security> Password Authentication Protocol. 2. <networking, protocol, printer> Printer Access Protocol. (1996-03-23) 1 1 1 1 1 Paper Feed Control Character (PFCC) An obscure mechanism used in Fortran run-time systems whereby the first character of a line of output to a line-printer caused various actions after the line was printed: space return newline 0 return newline return newline 1 form-feed + return 1 1 1 1 1 papermail snail mail 1 1 1 1 1 paper-net snail mail 1 1 1 1 1 paper tape Punched paper tape. An early input/output and storage medium borrowed from telegraph and teletype systems. Data entered at the keyboard of the teletype could be directed to a perforator or punch which punched a pattern of holes across the width of a paper tape to represent the characters typed. The paper tape could be read by a tape reader feeding the computer. Computer output could be similarly punched onto tape and printed off-line. As well as storage of the program and data, use of paper tape enabled batch processing. The first units had five data hole positions plus a sprocket hole (for the driving wheel) across the width of the tape. These used commercial telegraph code (ITA2 also known as Murray), Baudot code or proprietary codes such as Elliott which were more programmer-friendly. Later systems had eight data holes and used ASCII coding. 1 1 1 1 1 paraconsistent probability A notion introduced by Florentin Smarandache: The probability (T, I, F) that an event occurs is calculated from different sources which may be contradictory or may overlap information; here T, I, F are real subsets representing the truth, indeterminacy, and falsity percentages respectively, and n_sup = sup(T)+sup(I)+sup(F) > 100. ["Neutrosophy / Neutrosophic probability, set, and logic", F. Smarandache, American Research Press, 1998]. See neutrosophic probability (2001-01-20) 1 1 1 1 1 PARADE PARallel Applicative Database Engine. A project at Glasgow University to construct a transaction-processor in the parallel functional programming language Haskell to run on an ICL EDS+ database machine. 1 1 1 1 1 PARADIGM PLUS A configurable object-oriented CASE tool from Proto Soft. 1 1 1 1 1 Paradigms of AI Programming A book by Peter Norvig with Scheme and Prolog interpreters and compilers in Common Lisp. (ftp://Unix.sri.com/pub/norvig/). ["Paradigms of AI Programming", Peter Norvig]. 1 1 1 1 1 Paradise Paradise is a subsystem (a set of packages) developed to implement inter-processes, inter-tasks and inter-machine communication for Ada programs under Unix. This subsystem gives the user full access to files, pipes, sockets (both Unix and Internet) and pseudo-devices. Paradise has been ported to Sun, DEC, Sony MIPS, Verdex compiler, DEC compiler, Alsys/Systeam compiler. Version 2.0 of the library (ftp://cnam.cnam.fr/pub/Ada/Paradise). E-mail: <paradise-info@cnam.cnam.fr>. (1992-09-30) 1 1 1 1 1 Paradox A relational database for Microsoft Windows, originally from Borland. Paradox 5 ran on Microsoft Windows [version?] and provided a graphical environment, a debugger, a data modelling tool, and many "ObjectPAL" commands. Paradox 7 ran under Windows 95 and Windows NT. Latest version: Paradox 9, as of 2000-02-10 (a Corel product). (http://corel.com/paradox9/index.htm). [Update?] (1996-05-27) 1 1 1 1 1 paradox An apparently sound argument leading to a contradiction. Some famous examples are Russell's paradox and the liar paradox. Most paradoxes stem from some kind of self-reference. Smarandache Linguistic Paradox (http://gallup.unm.edu/~smarandache/Paradox.htm). (1999-11-05) 1 1 1 1 1 Paradox Application Language (PAL) The programming language for Paradox, Borland's relational database. (1995-01-26) 1 1 1 1 1 Paragon Mark Sherman. IEEE Software (Nov 1991). 1 1 1 1 1 Paralation PARALlel reLATION. Sabot, MIT 1987. A framework for parallel programming. A "field" is an array of objects, placed at different sites. A paralation is a group of fields, defining nearness between field elements. Operations can be performed in parallel on every site of a paralation. ["The Paralation Model: Architecture Independent Programming", G.W. Sabot <gary@think.com>, MIT Press 1988]. 1 1 1 1 1 Paralation C Paralation embedded in C. Under development. 1 1 1 1 1 Paralation LISP Embeds the paralation model in Common LISP. Available from MIT Press, (800)356-0343. 1 1 1 1 1 ParAlfl Hudak, Yale. Parallel functional language, a superset of Alfl. Used by the Alfalfa system on Intel iPSC and Encore Multimax. ["Para-Functional Programming", P. Hudak, Computer 19(8):60-70 (Aug 1986)]. ["Alfalfa: Distributed Graph Reduction on a Hypercube Multiprocessor", B. Goldberg & P. Hudak, TR, Yale U, Nov 1986]. 1 1 1 1 1 Parallaxis A procedural programming language developed by Thomas Braeunl <braunl@ee.uwa.edu.au> at the University of Stuttgart. It is based on Modula-2, but extended for data parallel (SIMD) programming. The main approach for machine independent parallel programming is to include a description of the virtual parallel machine with each parallel algorithm. There is a simulator and X Window System-based profiler for workstations, Macintosh, and IBM PC. Version 2.0 runs on MP-1, CM-2, Sun-3, Sun-4, DECstation, HP 700, RS/6000. (http://ee.uwa.edu.au/~braunl/parallaxis/). ["User Manual for Parallaxis Version 2.0", T. Braunl, U Stuttgart]. (2000-05-31) 1 1 1 1 1 parallel parallel processing 1 1 1 1 1 Parallel Advanced Technology Attachment (PATA, Parallel ATA) A back-formation introduced around 2003 to distinguish the original Advanced Technology Attachment (ATA) standards from the new Serial Advanced Technology Attachment (Serial ATA, SATA). (2010-02-20) 1 1 1 1 1 Parallel ATA Parallel Advanced Technology Attachment 1 1 1 1 1 Parallel C 1. <language, parallel> Never implemented, but influenced the design of C*. [Details?] 2. C for the transputer by 3L. 3. (PC) Extensions to C developed at the University of Houston providing a shared memory SIMD model on message passing computers. (ftp://karazm.math.uh.edu/pub/Parallel/Tools/pc.1.1.1.tar.Z). E-mail: Ridgway Scott <scott@uh.edu>. (1995-03-21) 1 1 1 1 1 parallel computer parallel processor 1 1 1 1 1 parallel computing parallel processing 1 1 1 1 1 Parallel FORTH Forth For the MPP. 1 1 1 1 1 Parallel Fortran (Pfortran) Extensions to Fortran by Ridgway Scott <scott@uh.edu> of Houston University. Pfortran provides a shared memory SIMD model on message passing computers. It was under development in 1994. ["Pfortran: A Parallel Dialect of Fortran", L.R. Scott, Fortran Forum 11(3):20-31, Sep 1992]. (1994-11-08) 1 1 1 1 1 Parallel Haskell (pH) A parallel variant of Haskell incorporating ideas from Id and Sisal. pH is under development. Mailing list: pH@abp.lcs.mit.edu. (1995-03-31) 1 1 1 1 1 parallelism 1. parallel processing. 2. <parallel> The maximum number of independent subtasks in a given task at a given point in its execution. E.g. in computing the expression (a + b) * (c + d) the expressions a, b, c and d can all be calculated in parallel giving a degree of parallelism of (at least) four. Once they have been evaluated then the expressions a + b and c #NAME? The Bernstein condition states that processes P and Q can be executed in parallel (or in either sequential order) only if: (i) there is no overlap between the inputs of P and the outputs of Q and vice versa and (ii) there is no overlap between the outputs of P, the outputs of Q and the inputs of any other task. If process P outputs value v which process Q reads then P must 1 1 1 1 1 Parallel Pascal A data-parallel language, similar to Actus and Glypnir. ["Parallel Pascal: An Extended Pascal for Parallel Computers", A. Reeves, J Parallel Dist Computing 1:64-80 (1984)]. (1995-05-07) 1 1 1 1 1 parallel port An interface from a computer system where data is transferred in or out in parallel, that is, on more than one wire. A parallel port carries one bit on each wire thus multiplying the transfer rate obtainable over a single wire. There will usually be some control signals on the port as well to say when data is ready to be sent or received. The commonest kind of parallel port is a printer port, e.g. a Centronics port which transfers eight bits at a time. Disks are also connected via special parallel ports, e.g. SCSI or IDE. (1995-01-24) 1 1 1 1 1 Parallel Presence Detect presence detect 1 1 1 1 1 parallel processing (Or "multiprocessing") The simultaneous use of more than one computer to solve a problem. There are many different kinds of parallel computer (or "parallel processor"). They are distinguished by the kind of interconnection between processors (known as "processing elements" or PEs) and between processors and memory. Flynn's taxonomy also classifies parallel (and serial) computers according to whether all processors execute the same instructions at the same time ("single instruction/multiple data" - SIMD) or each processor executes different instructions ("multiple instruction/multiple data" - MIMD). The processors may either communicate in order to be able to cooperate in solving a problem or they may run completely independently, possibly under the control of another processor which distributes work to the others and collects results from them (a "processor farm"). The difficulty of cooperative problem solving is aptly demonstrated by the following dubious 1 1 1 1 1 parallel processor A computer with more than one central processing unit, used for parallel processing. (1996-04-23) 1 1 1 1 1 parallel random-access machine (PRAM) An idealised parallel processor consisting of P processors, unbounded shared memory, and a common clock. Each processor is a random-access machine (RAM) consisting of R registers, a program counter, and a read-only signature register. Each RAM has an identical program, but the RAMs can branch to different parts of the program. The RAMs execute the program synchronously one instruction in one clock cycle. See also pm2. (1997-06-04) 1 1 1 1 1 parallel reduction A form of applicative order reduction in which all redexes in an expression are reduced simultaneously. Variants include parallel outermost reduction and lenient reduction. See normal order reduction. 1 1 1 1 1 Parallel Server Option Oracle Parallel Server 1 1 1 1 1 Parallel SML ["Parallel SML: A Functional Language and its Implementation in Dactl", Kevin Hammond, Pitman Press 1990]. 1 1 1 1 1 Parallel Sysplex A Sysplex that uses one or more coupling facilities. (http://s390.ibm.com/products/pso/psohp.html). (1996-11-21) 1 1 1 1 1 Parallel Virtual Machine (PVM) 1. A software system designed to allow a network of heterogeneous machines to be used as a single distributed parallel processor. PVM was developed by the University of Tennessee, The Oak Ridge National Laboratory and the Emory University. (http://epm.ornl.gov/pvm/). Usenet newsgroup: news:comp.parallel.pvm. 2. The intermediate language used by the Gambit compiler for Scheme. [And Multilisp?] (1995-01-30) 1 1 1 1 1 param formal argument 1 1 1 1 1 parameter formal argument 1 1 1 1 1 parameter RAM (PRAM) A small memory in a Macintosh with a battery power supply which stores system parameters (desktop pattern, selectable memory configuration, etc.) when the computer is turned off. (1995-10-08) 1 1 1 1 1 parametric polymorphism Polymorphism was first identified by Christopher Strachey in 1967 and developed by Hindley and Milner. For example we could specify that the argument of the "head" function was a list without specifying a type for the elements of the list. In Haskell we would write: head :: [a] -> a meaning head has type function from "list of a" to "a" where "a" is a type variable). This is known as parametric polymorphism. Polymorphic typing allows strong type checking as well as generic functions. ML in 1976 was the first language with polymorphic typing. See also generic type variable. (2014-01-05) 1 1 1 1 1 paraML An extension of Standard ML which supports coarse-grained parallelism. Peter Bailey, while at the Edinburgh Parallel Computing Centre at University of Edinburgh, has implemented of Murray Cole's original four skeletons in paraML. See also Skel-ML. 1 1 1 1 1 paranoid programming A programming style that tries to prepare for the worst external conditions, including incorrect input, resource limitations, hardware and software failure and even can't happen errors, to the fullest possible extent. While some believe in the motto "professional programming is paranoid programming", the expression usually has the connotation that the efforts are unnecessary or too costly ("Maybe this code is just paranoid programming, but I think it is necessary to avoid a possible overflow condition".) (2001-01-27) 1 1 1 1 1 ParaSoft Corp Distributors of the message passing system Express. (ftp://ftp.parasoft.com/). Telephone: +1 (818) 792-9941. E-mail: <support@parasoft.com>. (1994-10-19) 1 1 1 1 1 Parasol Parallel Systems Object Language. An object-oriented language which supports network and parallel computing. It has modules and exceptions. ["The Parasol Programming Language", R. Jervis <hjervis!rbj@uunet.uu.net>, Dr Dobbs J, Oct 1993, pp. 34-41]. (1995-01-26) 1 1 1 1 1 PARC XEROX PARC 1 1 1 1 1 ParcPlace Systems A company spun-off from Xerox PARC that developed the original version of VisualWorks. (2002-04-15) 1 1 1 1 1 parent The ancestor node in a tree that points to the current node (one of its child nodes). (2005-09-15) 1 1 1 1 1 parentheses See left parenthesis, right parenthesis. (1997-12-03) 1 1 1 1 1 parent message What a followup follows up. [Jargon File] (1997-12-03) 1 1 1 1 1 parent process The Unix process that created one or more other processes. Every process except process 0 is created when another process executes the fork system call. The process that invoked fork is the parent process, and the newly created process is the child process. Every process has one parent process, but can have many child processes. The kernel identifies each process by its process identifier (PID). Process 0 is a special process that is created when the system boots; after forking a child process (process 1), process 0 becomes the swapper process. Process 1, known as init, is the ancestor of every other process in the system and enjoys a special relationship with them. (1997-12-03) 1 1 1 1 1 Pari A system for symbolic mathematics, especially number theory. Version 1.37 for Unix, Macintosh, MS-DOS, Amiga. E-mail: <pari@alioth.greco-prog.fr>. (ftp://math.ucla.edu/pub/pari). (1995-04-12) 1 1 1 1 1 Paris PARallel Instruction Set. A low-level language for the Connection Machine. (1995-02-16) 1 1 1 1 1 parity An extra bit added to a byte or word to reveal errors in storage (in RAM or disk) or transmission. Even (odd) parity means that the parity bit is set so that there are an even (odd) number of one bits in the word, including the parity bit. A single parity bit can only reveal single bit errors since if an even number of bits are wrong then the parity bit will not change. Moreover, it is not possible to tell which bit is wrong, as it is with more sophisticated error detection and correction systems. See also longitudinal parity, checksum, cyclic redundancy check. (1996-03-01) 1 1 1 1 1 parity bit An extra bit added to a byte or word to reveal errors. See parity. (1996-03-01) 1 1 1 1 1 parity error An error discovered by the inclusion of a parity bit. (1996-03-01) 1 1 1 1 1 Parkinson's Law of Data Data expands to fill the space available for storage; buying more memory encourages the use of more memory-intensive techniques. It has been observed over the last 10 years that the memory usage of evolving systems tends to double roughly once every 18 months. Fortunately, memory density available for constant dollars also tends to double about once every 12 months (see Moore's Law); unfortunately, the laws of physics guarantee that the latter cannot continue indefinitely. [Jargon File] 1 1 1 1 1 Park-Miller A pseudorandom number generation algorithm which was discredited by Marsaglia and Steve Sullivanin in the July 1993 CACM. [CACM Oct 1988]. 1 1 1 1 1 Parlance A concurrent language. ["Parallel Processing Structures: Languages, Schedules, and Performance Results", P.F. Reynolds, PhD Thesis, UT Austin 1979]. (1994-12-12) 1 1 1 1 1 Parlog Clark & Gregory, Imperial College 1983. An AND-parallel Prolog, with guards and committed choice nondeterminism (don't care nondeterminism). Shallow backtracking only. Implementations: MacParlog and PC-Parlog from Parallel Logic Programming Ltd., Box 49 Twickenham TW2 5PH, UK. See also SPM. (ftp://ftp.inria.fr/lang/Parlog.tar.Z). E-mail: <parlog@doc.ic.ac.uk>. ["Parlog: A Parallel Logic Programming Language", K.L. Clark and S. Gregory, Imperial College, London, May 1983]. ("Parlog83", in which the ouput mechanism was assignment). ["Parallel Logic Programming in PARLOG, The Language and Its Implementation", S. Gregory, A-W 1987]. ("Parlog86", in which the output mechanism was unification, as in GHC). (See Strand). 1 1 1 1 1 Parlog++ An object-oriented extension to MacParlog. It combines object-oriented and parallel logic programming, giving the benefits of both paradigms within a single coherent development environment. Andrew Davison <ad@cs.mu.oz.au>, then Imperial College now U Melbourne. Object orientation plus parallel logic, built on top of MacParlog. Parlog++: A Parlog Object-Oriented Language, A. Davison, Parlog Group, Imperial College 1988. Sold by PLP Ltd. E-mail: <parlog@doc.ic.ac.uk>. 1 1 1 1 1 parm /parm/ Further-compressed form of param. This term is an IBMism, and written use is almost unknown outside IBM shops; spoken /parm/ is more widely distributed, but the synonym arg is favoured among hackers. Compare var. [Jargon File] 1 1 1 1 1 PARMACS The "Argonne macros" from Argonne National Laboratory. A package of macros written in m4 for portable parallel programming, using monitors on shared memory machines, and message passing on distributed memory machines. [E. Lusk et al, "Portable Programs for Parallel Processors", HRW 1987. p4]. (ftp://research.att.com/netlib/parmacs). 1 1 1 1 1 ParMod Parallel Programming with ParMod, S. Eichholz, Proc 1987 Intl Conf on Parallel Proc, pp.377-380. 1 1 1 1 1 PARS Programmable Airline Reservation System 1 1 1 1 1 parse parser 1 1 1 1 1 PARSEC An extensible language with PL/I-like syntax, derived from PROTEUS. ["PARSEC User's Manual", Bolt Beranek & Newman, Dec 1972]. (2009-06-26) 1 1 1 1 1 parser An algorithm or program to determine the syntactic structure of ("parse") a sentence or string of symbols in some language. A parser normally takes as input a sequence of tokens output by a lexical analyser. It may produce some kind of abstract syntax tree as output. A parser may be produced automatically from a grammar by a parser generators such as yacc. A parser is normally part of some larger program, like a compiler, which takes the output of the parser and attempts to extract meaning from it in some way, e.g. translating it into another language. (2009-06-26) 1 1 1 1 1 parser generator A program which takes a formal description of a grammar (e.g. in BNF) and outputs source code for a parser which will recognise valid strings obeying that grammar and perform associated actions. Unix's yacc is a well known example. 1 1 1 1 1 parsing parser 1 1 1 1 1 Parsley A Pascal extension for construction of parse trees, by Barber of Summit Software. It features Iterators. ["PARSLEY: A New Compiler-Compiler", in Software Development Tools, Techniques and Alternatives, Arlington VA, Jul 1983, pp.232-241]. (1995-02-22) 1 1 1 1 1 Partial Differential Equation LANguage (PDELAN) ["An Extension of Fortran Containing Finite Difference Operators", J. Gary et al, Soft Prac & Exp 2(4) (Oct 1972)]. 1 1 1 1 1 partial equivalence relation (PER) A relation R on a set S where R is symmetric (x R y => y R x) and transitive (x R y R z => x R z) and where there may exist elements in S for which the relation is not defined. A PER is an equivalence relation on the subset for which it is defined, i.e. it is also reflexive (x R x). 1 1 1 1 1 partial evaluation (Or "specialisation") An optimisation technique where the compiler evaluates some subexpressions at compile-time. For example, pow x 0 = 1 pow x n = if even n then pxn2 * pxn2 else x * pow x (n-1) where pxn2 = pow x (n/2) 1 1 1 1 1 partial function A function which is not defined for all arguments of its input type. E.g. f(x) = 1/x if x /= 0. The opposite of a total function. In denotational semantics, a partial function f : D -> C may be represented as a total function ft : D' -> lift(C) where D' is a superset of D and ft x = f x if x in D ft x = bottom 1 1 1 1 1 partial key A key which identifies a subset of a set of information items (e.g. database "records"), and which could narrow the subset to one item if other partial key(s) were combined with it. (1997-04-26) 1 1 1 1 1 partially ordered set A set with a partial ordering. 1 1 1 1 1 partial ordering A relation R is a partial ordering if it is a pre-order (i.e. it is reflexive (x R x) and transitive (x R y R z => x R z)) and it is also antisymmetric (x R y R x => x = y). The ordering is partial, rather than total, because there may exist elements x and y for which neither x R y nor y R x. In domain theory, if D is a set of values including the undefined value (bottom) then we can define a partial ordering relation <= on D by x <= y if x = bottom or x = y. The constructed set D x D contains the very undefined element, (bottom, bottom) and the not so undefined elements, (x, bottom) and (bottom, x). The partial ordering on D x D is then (x1,y1) <= (x2,y2) if x1 <= x2 and y1 <= y2. The partial ordering on D -> D is defined by 1 1 1 1 1 Partial Response Maximum Likelihood (PRML) A method for converting the weak analog signal from the head of a magnetic disk drive into a digital signal. PRML attempts to correctly interpret even small changes in the analog signal, whereas peak detection relies on fixed thresholds. Because PRML can correctly decode a weaker signal it allows higher density recording. For example, PRML would read the magnetic flux density pattern 70, 60, 55, 60, 70 as binary "101", and the same for 45, 40, 30, 40, 45. A peak detector would decode everything above, say, 50 as high, and below 50 as low, so the first pattern would read "111" and the second as "000". (1996-12-27) 1 1 1 1 1 partition 1. <storage> A logical section of a disk. Each partition normally has its own file system. Unix tends to treat partitions as though they were separate physical entities. 2. <mathematics> A division of a set into subsets so that each of its elements is in exactly one subset. (1996-12-09) 1 1 1 1 1 partitioned data set (PDS) A data set on an IBM mainframe that contains members, each of which acts like a separate data set. Partitioned data sets are more space-efficient than individual data sets, because they can put more than one data set on a track. They are also used to hold libraries, with one function per member. The syntax for a member is NAME.OF.PDS(MEMBER) although some systems (such as Phoenix) could use NAME.OF.PDS:MEMBER Original PDSes were of fixed size, and needed frequent compression to recover space after deleting or changing members. Newer PDS/E Extended PDSes do not have this problem. (2003-12-05) 1 1 1 1 1 PARTS Digitalk. Visual language for OS/2 2.0. 1 1 1 1 1 PARULEL The PARULEL Parallel Rule Language, S. Stolfo et al, Proc 1991 Intl Conf Parallel Proc, CRC Press 1991, pp.36-45. 1 1 1 1 1 PASC Perceptional Adaptive Subband Coding 1 1 1 1 1 Pascal (After the French mathematician Blaise Pascal (1623-1662)) A programming language designed by Niklaus Wirth around 1970. Pascal was designed for simplicity and for teaching programming, in reaction to the complexity of ALGOL 68. It emphasises structured programming constructs, data structures and strong typing. Innovations included enumeration types, subranges, sets, variant records, and the case statement. Pascal has been extremely influential in programming language design and has a great number of variants and descendants. ANSI/IEEE770X3.97-1993 is very similar to ISO Pascal but does not include conformant arrays. ISO 7185-1983(E). Level 0 and Level 1. Changes from Jensen & Wirth's Pascal include name equivalence; names must be bound before they are used; loop index must be local to the procedure; formal procedure parameters must include their arguments; conformant array schemas. 1 1 1 1 1 Pascal- Pascal subset used in Brinch Hansen on Pascal Compilers, P. Brinch Hansen, P-H 1985. [Jargon File] 1 1 1 1 1 Pascal-80 A successor of Platon. Developed at RC International for systems programming. Later it was renamed Real-Time Pascal. PASCAL80 Report, J. Staunstrup, RC Intl, Denmark Jan 1980. 1 1 1 1 1 Pascal+CSP Pascal+CSP, Merging Pascal and CSP in a Parallel Processing Oriented Language, J. Adamo, Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982, pp.542-547. 1 1 1 1 1 Pascal-F Pascal extended to include fixed-point arithmetic. E. Nelson, "Pascal-F: Programming Language for Real-Time Automotive Control, IEEE ElectroTechnol. Rev. (USA), 2:39, 1968." 1 1 1 1 1 Pascal-FC A Pascal derived from Pascal-S which provides several types of concurrency: semaphores, monitors, both occam/CSP-style and Ada-style rendezvous. ["The Teaching Language Pascal-FC", G.L. Davies et al, Computer J 33(2):147-154 (Apr 1990)]. (1994-11-02) 1 1 1 1 1 Pascal/L A SIMD parallel extension of Pascal. ["Implementation of an Array and Vector Processing Language", C. Fernstrom, Intl Conf Parallel Proc, IEEE, pp.113-127 (1982)]. (1994-11-02) 1 1 1 1 1 Pascal-Linda Ian Flockhart, U Edinburgh, 1991. Under development. 1 1 1 1 1 Pascal-m ["Pascal-m: A Language for Loosely Coupled Distributed Systems", S. Abramsky et al in Distributed Computing Systems, Y. Paker et al eds, Academic Press 1986, pp. 163-189]. (1994-11-02) 1 1 1 1 1 Pascal-P The variant of Pascal used by the UCSD p-system environment. Pascal-P has extended string and array operations, random-access files and separate compilation. It uses P-code intermediate code and is available from Pecan. (1994-11-02) 1 1 1 1 1 Pascal P4 compiler and interpreter Version ? 1 compiler, assembler/interpreter, documentation Urs Ammann, Kesav Nori, Christian Jacobi (ftp://ftp.cwi.nl/pascal/). A compiler for Pascal written in Pascal, producing an intermediate code, with an assembler and interpreter for the code. reference: Pascal Implementation, by Steven Pemberton and Martin Daniels, published by Ellis Horwood, Chichester, UK (an imprint of Prentice Hall), ISBN: 0-13-653-0311. Also available in Japanese. E-mail: <Steven.Pemberton@cwi.nl>. (1993-07-05) 1 1 1 1 1 Pascal Plus Pascal with extensions for object-oriented multiprogramming by Jim Welsh and D. Bustard of Queens University, Belfast, UK. Pascal Plus uses an "envelope" construct for both packages and classes. ["Pascal Plus - Another Language for Modular Multiprogramming", J. Welsh et al, Soft Prac & Exp 9:947 (1979)]. ["Sequential Program Structures", J. Welsh et al, P-H 1984, ISBN 0-13806828-3]. (1997-12-09) 1 1 1 1 1 Pascal/R Pascal with relational database constructs added. The first successful integrated database language. ["Pascal/R Report", J.W. Schmidt et al, U Hamburg, Fachbereich Informatik, Report 66, Jan 1980]. (1994-10-19) 1 1 1 1 1 Pascal-S Simplified Pascal. June, 1975. A strict subset of Pascal, omits scalar types, subranges, sets, files, pointers, packed structures, 'with' and 'goto. Source for a complete Pascal-S compiler is in "Pascal-S: A Subset and Its Implementation", N. Wirth in Pascal - The Language and Its Implementation, by D.W. Barron, Wiley 1979. (ftp://csseq.cs.tamu.edu/mcguire/pascal-s). 1 1 1 1 1 Pascal-SC ESPRIT DIAMOND Project. An extension of Pascal for numerical analysis, with controlled rounding, overloading, dynamic arrays and modules. "PASCAL-SC, A Computer Language for Scientific Computation", G. Bohlender et al, Academic Press 1987 1 1 1 1 1 pasos2 version: Alpha parts: Compiler, run-time library author: Willem Jan Withagen <wjw@eb.ele.tue.nl> how to get: (ftp://ftp.eb.ele.tue.nl/pub/src/pascal/pasos2*). A PASCAL/i386 compiler which generates code for OS/2 and DOS. It uses EMX as DOS extender and GNU/GAS, MASM or TASM as assembler. 12/17/93 1 1 1 1 1 Pasqual ["Pasqual: A Proposed Generalization of Pascal", R.D. Tennent, TR75-32, Queen's U, Canada, 1975]. 1 1 1 1 1 PASRO PAScal for RObots. ["PASRO - Pascal for Robots", C. Blume et al, Springer 1985]. (1999-07-19) 1 1 1 1 1 PASSIM A simulation language based on Pascal. ["PASSIM: A Discrete-Event Simulation Package for Pascal", D.H Uyeno et al, Simulation 35(6):183-190 (Dec 1980)]. 1 1 1 1 1 passive matrix display A type of liquid crystal display which relies on persistence to maintain the state of each display element (pixel) between refresh scans. The resolution of such displays is limited by the ratio between the time to set a pixel and the time it takes to fade. Contrast active matrix display. (1995-12-09) 1 1 1 1 1 passphrase A string of words and characters that you type in to authenticate yourself. Passphrases differ from passwords only in length. Passwords are usually short - six to ten characters. Passphrases are usually much longer - up to 100 characters or more. Modern passphrases were invented by Sigmund N. Porter in 1982. Their greater length makes passphrases more secure. Phil Zimmermann's popular encryption program PGP, for example, requires you to make up a passphrase that you then must enter whenever you sign or decrypt messages. (http://world.std.com/~reinhold/diceware.page.html). (1996-12-21) 1 1 1 1 1 passw0rd A common default password, often given out by system administrtors to new users, the hope being that they will change it immediately. (2011-11-22) 1 1 1 1 1 password An arbitrary string of characters chosen by a user or system administrator and used to authenticate the user when he attempts to log on, in order to prevent unauthorised access to his account. A favourite activity among unimaginative computer nerds and crackers is writing programs which attempt to discover passwords by using lists of commonly chosen passwords such as people's names (spelled forward or backward). It is recommended that to defeat such methods passwords use a mixture of upper and lower case letters or digits and avoid proper names and real words. If you have trouble remembering random strings of characters, make up an acronym like ihGr8trmP ("I have great trouble remembering my password"). (1994-10-27) 1 1 1 1 1 Password Authentication Protocol (PAP) An authentication scheme used by PPP servers to validate the identity of the originator of the connection. PAP applies a two-way handshaking procedure. After the link is established the originator sends an id-password pair to the server. If authentication succeeds the server sends back an acknowledgement; otherwise it either terminates the connection or gives the originator another chance. PAP is not a strong authentication method. Passwords are sent over the circuit "in the clear" and there is no protection against playback or repeated "trial and error" attacks. The originator is in total control of the frequency and timing of the attempts. Therefore, any server that can use a stronger authentication method, such as CHAP, will offer to negotiate that method prior to PAP. The use of PAP is appropriate, however, if a plaintext password must be available to simulate a login at a remote host. 1 1 1 1 1 paste copy and paste 1 1 1 1 1 pastie /pay'stee/ An adhesive label designed to be attached to a key on a keyboard to indicate some non-standard character which can be accessed through that key. Pasties are likely to be used in APL environments, where almost every key is associated with a special character. A pastie on the R key, for example, might remind the user that it is used to generate the rho character. The term properly refers to nipple-concealing devices formerly worn by strippers in concession to indecent-exposure laws; compare tits on a keyboard. [Jargon File] 1 1 1 1 1 PAT 1. <language> Personalized Array Translator. 2. <networking> Port Address Translation. (1998-05-09) 1 1 1 1 1 PATA 1. <storage> Parallel Advanced Technology Attachment. 2. Pooling Agreement for Technical Assistance. 1 1 1 1 1 patch 1. A temporary addition to a piece of code, usually as a quick-and-dirty remedy to an existing bug or misfeature. A patch may or may not work, and may or may not eventually be incorporated permanently into the program. Distinguished from a diff or mod by the fact that a patch is generated by more primitive means than the rest of the program; the classical examples are instructions modified by using the front panel switches, and changes made directly to the binary executable of a program originally written in an HLL. Compare one-line fix. 2. To insert a patch into a piece of code. 3. [in the Unix world] A diff. 4. A set of modifications to binaries to be applied by a patching program. IBM systems often receive updates to the operating system in the form of absolute hexadecimal patches. If you have modified your OS, you have to disassemble these back to the source code. The patches 1 1 1 1 1 patch pumpkin pumpkin 1 1 1 1 1 patch space An unused block of bits left in a binary so that it can later be modified by insertion of machine-language instructions there (typically, the patch space is modified to contain new code, and the superseded code is patched to contain a jump or call to the patch space). The widening use of HLLs has made this term rare; it is now primarily historical outside IBM shops. See patch, zap, hook. [Jargon File] 1 1 1 1 1 PATCHY A Fortran code management program written at CERN. 1 1 1 1 1 path 1. <file system> pathname. 2. <networking> A bang path or explicitly routed Internet address; a node-by-node specification of a link between two machines. 3. <operating system> The list of directories the kernel (under Unix) or the command interpreter (under MS-DOS) searches for executables. It is stored as part of the environment in both operating systems. Other, similar constructs abound under Unix; the C preprocessor, for example, uses such a search path to locate "#include" files. [Jargon File] (1996-11-21) 1 1 1 1 1 path coverage testing Testing a program by examining which lines of executable code are visited (as in code coverage testing) and also the ways of getting to each line of code and the subsequent sequence of execution. Path coverage testing is the most comprehensive type of testing that a test suite can provide. It can find more bugs, especially those that are caused by data coupling. However, path coverage is hard and usually only used for small and/or critical sections of code. (2005-01-25) 1 1 1 1 1 pathname (Or "path") The specification of a node (file or directory) in a hierarchical file system. The path is usually specified by listing the nodes top-down, separating the directories by the pathname separator ("/" in Unix, "\" in MS-DOS). A pathname may be an absolute pathname (starting from the root directory, "/") or a relative pathname (starting from the current working directory). The part of the pathname of a file after the last separator is called the basename. (1997-03-10) 1 1 1 1 1 pathname separator The character used to separate elements of a path or pathname. Under Unix and POSIX.1 compliant systems the pathname separator is the (forward) slash, in MS-DOS backslash serves the same purpose. For obvious reasons the no directory or file name can contain this character. (1996-11-21) 1 1 1 1 1 pathological 1. [scientific computation] Used of a data set that is grossly atypical of normal expected input, especially one that exposes a weakness or bug in whatever algorithm one is using. An algorithm that can be broken by pathological inputs may still be useful if such inputs are very unlikely to occur in practice. 2. When used of test input, implies that it was purposefully engineered as a worst case. The implication in both senses is that the data is spectacularly ill-conditioned or that someone had to explicitly set out to break the algorithm in order to come up with such a crazy example. 3. Also said of an unlikely collection of circumstances. "If the network is down and comes up halfway through the execution of that command by root, the system may just crash." "Yes, but that's a pathological case." Often used to dismiss the case from discussion, with the implication that the consequences are acceptable, since they will happen so 1 1 1 1 1 Path Pascal Parallel extension of Pascal. Processes have shared access to data objects. Constraints on their synchronisation are specified in a path expression. ["An Overview of Path Pascal's Design", R.H. Campbell, SIGPLAN Notices 15(9):13-24 (Sep 1980)]. 1 1 1 1 1 pathspec pathname 1 1 1 1 1 pattern matching 1. A function is defined to take arguments of a particular type, form or value. When applying the function to its actual arguments it is necessary to match the type, form or value of the actual arguments against the formal arguments in some definition. For example, the function length [] = 0 length (x:xs) = 1 + length xs uses pattern matching in its argument to distinguish a null list from a non-null one. There are well known algorithm for translating pattern matching into conditional expressions such as "if" or "case". E.g. the above function could be transformed to length l = case l of 1 1 1 1 1 pattern recognition A branch of artificial intelligence concerned with the classification or description of observations. Pattern recognition aims to classify data (patterns) based on either a priori knowledge or on statistical information extracted from the patterns. The patterns to be classified are usually groups of measurements or observations, defining points in an appropriate multidimensional space. A complete pattern recognition system consists of a sensor that gathers the observations to be classified or described; a feature extraction mechanism that computes numeric or symbolic information from the observations; and a classification or description scheme that does the actual job of classifying or describing observations, relying on the extracted features. The classification or description scheme is usually based on the availability of a set of patterns that have already been 1 1 1 1 1 PAW Physics Analysis Workbench. 1 1 1 1 1 PAW++ An extended version of PAW with a Motif human interface. 1 1 1 1 1 payware /pay'weir/ Commercial software. Opposite: shareware or freeware. [Jargon File] 1 1 1 1 1 PB Cache Pipeline Burst Cache 1 1 1 1 1 PBCAK PEBCAK 1 1 1 1 1 PBD Programmer Brain Damage 1 1 1 1 1 PBEM play by electronic mail 1 1 1 1 1 PBKAC PEBCAK 1 1 1 1 1 PBM play by mail. See play by electronic mail. 1 1 1 1 1 PBX Private Branch Exchange 1 1 1 1 1 PC 1. <computer> personal computer. 2. <computer> IBM PC. 3. <hardware> program counter. 4. <hardware> printed circuit. 5. <language> Parallel C. 1 1 1 1 1 pC++ Data parallel extension to C++. Classes and methods for managing distributed collections. E-mail: Dennis Gannon <gannon@cs.indiana.edu>. ["Distributed pC++: Basic Ideas for an Object Parallel Language", F. Bodin et al, Proc Supercomput 91, ACM SIGARCH, pp. 273-282]. (2001-02-22) 1 1 1 1 1 PC-1834 An IBM PC-like computer, using a K1810 WM 86 Intel 8086 clone from the formerly known Eastern bloc, introduced in 1988. (2004-03-24) 1 1 1 1 1 PC200 Sinclair PC200 1 1 1 1 1 PC-7150 An IBM PC-like computer, using a K1810 WM 86 Intel 8086 clone from the formerly known Eastern bloc, introduced in 1988. (2004-03-24) 1 1 1 1 1 PCA A dynamic analyser from DEC giving information on run-time performance and code use. (2004-03-24) 1 1 1 1 1 P-CAD A CAE system marketed by CADAM, an IBM company. (2004-03-24) 1 1 1 1 1 PC AT IBM PC AT 1 1 1 1 1 PCB 1. <hardware> Power Circuit Breaker. 2. <hardware> Power Control Box. 3. <hardware> Printed Circuit Board. 4. Process Control Block. 5. Product Configuration Baseline. 6. Program Control Block. 7. <networking> Protocol Control Block. (TCP). 1 1 1 1 1 PC Card Personal Computer Memory Card International Association 1 1 1 1 1 PCCTS Purdue Compiler-Construction Tool Set 1 1 1 1 1 PCF A simply typed, functional language. ["Fully Abstract Translations Between Functional Languages", J. Riecke, 18th POPL, pp. 245-254 (1991)]. ["LCF Considered as a Programming Language", Theor CS 5:223, 1977]. (1996-01-18) 1 1 1 1 1 PCI Peripheral Component Interconnect 1 1 1 1 1 PCI bus Peripheral Component Interconnect 1 1 1 1 1 PCI Configuration Utility (PCU) A piece of software for configuring a specific PCI hardware device. [What software? What hardware?] (1998-11-22) 1 1 1 1 1 PCI Mezzanine Card (PMC) A family of low profile mezzanine cards for VMEbus, Futurebus+, desktop computers and other computer systems with logical and electrical layers based on the Peripheral Component Interconnect (PCI) specification. PMC is defined in IEEE P1386.1 and follows the Common Mezzanine Card (CMC) mechanical specification. PCI2.0 defines a 4.2 inch by 12.3 inch board that plugs perpendicularly into a mother board. (1994-10-06) 1 1 1 1 1 PCI slot A connector on Peripheral Component Interconnect and the associated physical space occupied by the installed PCI card. (1997-12-07) 1 1 1 1 1 PC-ism /P-C-izm/ A piece of code or coding technique that takes advantage of the unprotected single-tasking environment in IBM PCs and the like, e.g. by busy-waiting on a hardware register, direct diddling of screen memory or using hard timing loops. Compare ill-behaved, vaxism, Unixism. [Jargon File] 1 1 1 1 1 PCjr IBM PCjr 1 1 1 1 1 PCL 1. Printer Control Language. A Document description language used by Hewlett-Packard Laserjet printers, a superset of HP-GL/2. [PCL 5 Printer Language Printer Technical Reference Manual, HP 33459-90903. Versions: PCL 3, PCL 5]. 2. Portable CommonLoops. 3. Peripheral Conversion Language. A Honeywell command language for file transfer between I/O devices on the CP-V and CP-6 operating systems. 4. ["PCL - A Process Oriented Job Control Language", V. Lesser et al, Proc 1st Intl Conf Distrib Comp Sys, IEEE 1979, pp.315-329]. 1 1 1 1 1 PCLIPS Parallel CLIPS - U Lowell. Concurrent independent CLIPS expert systems. They use 'rassert' (remote assert) to enter facts into each other's database. "PCLIPS: A Distributed Expert System Environment", R. Miller, CLIPS Users Group Conf, Aug 1990. E-mail: <pclips@dragon.ulowell.edu>(?). 1 1 1 1 1 PCM 1. <data> Pulse Code Modulation. 2. <company> Plug Compatible Manufacturer. (2003-06-24) 1 1 1 1 1 PCMCIA Personal Computer Memory Card International Association. (Or People Can't Memorise Computer Industry Acronyms). 1 1 1 1 1 PCMIA Personal Computer Manufacturer Interface Adaptor 1 1 1 1 1 PCN 1. Program Composition Notation. 2. <communications> Personal Communication Network. 1 1 1 1 1 PC-NFS Personal Computer Network File System 1 1 1 1 1 P-code The intermediate language produced by the Pascal-P compiler. P-code is the assembly language for a hypothetical stack machine, the P-machine, said to imitate the instruction set of the Burroughs 6700. The term was first used in the Wirth reference below. Byte articles on writing a Pascal Compiler in Northstar BASIC (ca Aug 1978) also used the term. P-code was initially the intermediate code generated by the P2 compiler from ETH Zurich. P-code was later used as the intermediate language in the UCSD Pascal System, and in its two main derivatives, Apple Pascal and the UCSD P-system. Variants: P2 P-code, P4 P-code, UCSD P-code, LASL P-code. [Algorithms + Data Structures = Programs, N. Wirth, P-H 1976]. ["A Comparison of PASCAL Intermediate Languages", P.A. Nelson, SIGPLAN Notices 14(8):208-213, Aug 1979]. (2004-11-08) 1 1 1 1 1 PC Pursuit A TELENET service which enabled people to dial up BBSes in other cities for less than normal long-distance rates. PC Pursuit died because TELENET were too mean to upgrade beyond 2400 bits per second. (1994-10-17) 1 1 1 1 1 PC-RT An incorrect name for the RT-PC. (1995-04-06) 1 1 1 1 1 PCS 1. Personal Communication Services. 2. PC-Scheme. 1 1 1 1 1 PC-Scheme Version 3.03 compiler, debugger, profiler, editor, libraries (ftp://altdorf.ai.mit.edu/archive/pc-scheme/). Written at Texas Instruments. Runs on MS-DOS 286/386 IBM PCs and compatibles. Includes an optimising compiler, an emacs-like editor, inspector, debugger, performance testing, foreign function interface, window system and an object-oriented subsystem. Also supports the dialect used in Hal Abelson and Gerald Sussman's SICP. Conformance: Revised^3 Report, also supports dialect used in SICP. restriction: official version is $95, contact <rww@ibuki.com> ports: MS-DOS See also PCS/Geneva. 1 1 1 1 1 PCS/Geneva A cleaned-up version of Texas Instrument's PC Scheme developed at the University of Geneva. The main extensions to PC Scheme are 486 support, BGI graphics, LIM-EMS pagination support, line editing and assembly code-level interfacing. Version 4.02PL1. E-mail: <schemege@uni2a.unige.ch>. (1994-01-11) 1 1 1 1 1 PC support (Or "PC analyst", end user support) A person who works with microcomputer applications including word processors, spreadsheets, presentation graphics, database management systems, electronic mail, and communications. He also evaluates, installs and supports PCs, Macintoshes, and associated peripherals. (2004-03-20) 1 1 1 1 1 PC-TALK III An MS-DOS communications program by Andrew Fluegelman. (1997-08-25) 1 1 1 1 1 PCTE Portable Common Tool Environment 1 1 1 1 1 PCTE+ A European NATO specification based on PCTE with security enhancements. 1 1 1 1 1 PC-TILES A visual programming language. (1997-08-25) 1 1 1 1 1 PCU PCI Configuration Utility 1 1 1 1 1 PC-ware Pejorative term for software full of PC-isms on a machine with a more capable operating system. 1 1 1 1 1 pcx A filename extension for images created with the IBM PC Paintbrush tool. [Format?] (1995-12-10) 1 1 1 1 1 PD public domain 1 1 1 1 1 PDA Personal Digital Assistant 1 1 1 1 1 PDC Primary Domain Controller 1 1 1 1 1 PDC Prolog Prolog Development Centre Prolog. A Prolog evolved from Turbo Prolog by the original authors. 1 1 1 1 1 PDEL Partial Differential Equation Language. A preprocessor for PL/I. ["PDEL - A Language for Partial Differential Equations", A.F. Cardenas, CACM 13(3):184-191 (Mar 1970)]. 1 1 1 1 1 PDELAN Partial Differential Equation LANguage 1 1 1 1 1 PDES Product Data Exchange using STEP 1 1 1 1 1 PDF Portable Document Format 1 1 1 1 1 PDFTeX A modification of TeX to produce PDF output instead of the canonical DVI. pdftexlib.tar.gz (ftp://ftp.tug.org/pub/tex/pdftexlib.tar.gz). Thanh's source of pdfTeX (ftp://ftp.muni.cz/pub/tex/local/cstug/thanh/pdftex/). User Manual (http://tug.cs.umb.edu/applications/pdftex/pdftex-s.pdf). FAQ (http://tug.cs.umb.edu/applications/pdftex/pdfTeX-FAQ-scr.pdf). (2000-12-21) 1 1 1 1 1 PDH Plesiochronous Digital Hierarchy 1 1 1 1 1 PDIL A language developed at Agence d'Informatique, France in the 1970s for description of communication protocols. It was part of the RHIN project. (1995-02-28) 1 1 1 1 1 pdksh Version 4.9 interpreter Simon J. Gerraty <sjg@zen.void.oz.au> comp.sources.misc volume 4 It is not intended to be the ultimate shell but rather a usable ksh work alike. conformance: Almost identical to ksh88, but missing arrays E-mail: Simon J Gerraty <sjg@melb.bull.oz.au> (zen.void.oz.au is down) ports: Sun, 386bsd, ? 10/11/93 1 1 1 1 1 PDL 1. Page Description Language. 2. Program Design Language. 3. Push Down List. 4. Dave Lebling, one of the co-authors of Zork. His network address on the ITS machines was at one time <pdl@dms>. 5. Propositional Dynamic Logic. [Jargon File] 1 1 1 1 1 PDL2 Process Design Language 2. 1 1 1 1 1 PDM 1. Product Development Management. 2. Product Data Management. (1997-02-11) 1 1 1 1 1 PDP Programmed Data Processor 1 1 1 1 1 PDP-10 Programmed Data Processor model 10. The series of mainframes from DEC that made time-sharing real. It looms large in hacker folklore because of its adoption in the mid-1970s by many university computing facilities and research labs, including the MIT AI Lab, Stanford, and CMU. Some aspects of the instruction set (most notably the bit-field instructions) are still considered unsurpassed. The PDP-10 was eventually eclipsed by the VAX machines (descendants of the PDP-11) when DEC recognised that the PDP-10 and VAX product lines were competing with each other and decided to concentrate its software development effort on the more profitable VAX. The machine was finally dropped from DEC's line in 1983, following the failure of the Jupiter Project at DEC to build a viable new model. (Some attempts by other companies to market clones came to nothing; see Foonly and Mars.) This event spelled the doom of ITS and the 1 1 1 1 1 PDP-11 Programmed Data Processor model 11. A series of minicomputers based on an instruction set designed by C. Gordon Bell at DEC in the early 1970s (late 60s?). The PDP-11 family, which came after, but was not derived from, the PDP-10, was the most successful computer of its time until it was itself succeeded by the VAX. Models included the 11/23 and 11/24 (based on the F11 chipset); 11/44, 11/04, 11/34, 11/05, 11/10, 11/15, 11/20, 11/35, 11/40, 11/45, 11/70, 11/60 (MSI and SSI); LSI-11/2 and LSI-11 (LSI-11 chipset). In addition there were the 11/8x (J11 chipset) and SBC-11/21 (T11 chip) and then there was compatibility mode in the early VAX processors. The B and C languages were both used initially to implement Unix on the PDP-11. The microprocessor design tradition owes a heavy debt to the PDP-11 instruction set. See also SEX. (1994-12-21) 1 1 1 1 1 PDP-20 The most famous computer that never was. PDP-10 computers running the TOPS-10 operating system were labelled DECsystem-10 as a way of differentiating them from the PDP-11. Later on, those systems running TOPS-20 were labelled "DECSYSTEM-20" (the block capitals being the result of a lawsuit brought against DEC by Singer, which once made a computer called "system-10"), but contrary to popular lore there was never a "PDP-20"; the only difference between a 10 and a 20 was the operating system and the colour of the paint. Most (but not all) machines sold to run TOPS-10 were painted "Basil Blue", whereas most TOPS-20 machines were painted "Chinese Red" (often mistakenly called orange). [Jargon File] (1994-12-21) 1 1 1 1 1 PDP-6 Programmed Data Processor model 6. A computer designed around 1960 with more or less exactly the same hardware architecture as the PDP-10. It already had multi-user time sharing and batch processing and multi-level priority interrupts (1996-12-21) 1 1 1 1 1 PDP-7 A minicomputer sold by DEC in 1964. It had a memory cycle time of 1.75 microseconds and add time of 4 microseconds. I/O included a keyboard, printer, paper-tape and dual transport DECtape drives (type 555). DEC provided an "advanced" Fortran II compiler, a Symbolic Assembler, Editor, DDT Debugging System, Maintenance routines and a library of arithmetic, utility and programming aids developed on the program-compatible PDP-4. [DEC sales brochure]. The PDP-7 was considered reliable enough (when properly programmed) to be used for control of nuclear reactors and such. Around 1970 Ken Thompson built the operating system that became Unix on a scavenged PDP-7 so he could play a descendant of the SPACEWAR game. (1995-03-10) 1 1 1 1 1 PDP Assembly Language (PAL) The assembly language for the PDP-8 and PDP-11. [Description?] (1995-01-26) 1 1 1 1 1 PDS 1. <hardware> Processor Direct Slot. 2. partitioned data set. 1 1 1 1 1 PDSA cycle Plan, Do, See, Approve (from Japan). 1 1 1 1 1 PDS/MaGen Problem Descriptor System. A system for generating matrices and reports for mathematical programming and operations research. ["PDS MaGen User Information Manual", Haverly Systems (Dec 1977)]. (1994-10-27) 1 1 1 1 1 PDU Protocol Data Unit 1 1 1 1 1 PE 1. <database> periodic group 2. <storage> Phase Encoded. 3. <architecture> processing element. (1995-10-30) 1 1 1 1 1 pe The country code for Peru. (1999-01-27) 1 1 1 1 1 PeaceNet One of the IGC networks. PeaceNet serves peace and social justice advocates around the world in such areas as human rights, disarmament, and international relations. A number of alternative news services provide a range of information about these and other topics from around the world. E-mail: <peacenet@igc.apc.org>. (ftp://igc.apc.org/). 1 1 1 1 1 peak envelope power (PEP) The maximum power output by a radio transmitter over one complete RF cycle at any modulation. (2008-02-11) 1 1 1 1 1 Peano Giuseppe Peano 1 1 1 1 1 Peano arithmetic Giuseppe Peano's system for representing natural numbers inductively (induction) using only two symbols, "0" (zero) and "S" (successor). This system could be expressed as a recursive data type with the following Haskell definition: data Peano = Zero | Succ Peano The number three, usually written "SSS0", would be Succ (Succ (Succ Zero)). Addition of Peano numbers can be expressed as a simple syntactic transformation: plus Zero n = n plus (Succ m) n = Succ (plus m n) (1995-03-28) 1 1 1 1 1 PEARL 1. <language, mathematics> A language for constructive mathematics developed by Constable at Cornell University in the 1980s. 2. <language, real-time> Process and Experiment Automation Real-Time Language. 3. <language, education> One of five pedagogical languages based on Markov algorithms, used in "Nonpareil, a Machine Level Machine Independent Language for the Study of Semantics", B. Higman, ULICS Intl Report No ICSI 170, U London (1968). Compare Brilliant, Diamond, Nonpareil, Ruby. 4. <language> A multilevel language developed by Brian Randell ca 1970 and mentioned in "Machine Oriented Higher Level Languages", W. van der Poel, N-H 1974. 5. <language, tool, history> An obsolete term for Larry Wall's PERL programming language, which never fell into common usage other than in typographical errors. The missing 'a' remains as an atrophied remnant in the expansion 1 1 1 1 1 Pebble A polymorphic language. ["A Kernel Language for Abstract Data Types and Modules", R.M. Burstall & B. Lampson, in Semantics of Data Types, LNCS 173, Springer 1984]. (1995-01-26) 1 1 1 1 1 Pebbleman DoD requirements that led to APSE. They were written in Jul 1978 and revised Jan 1979. (1995-01-26) 1 1 1 1 1 PEBCAK (Or "PEBKAC", "PBCAK", "PBKAC") Tech support shorthand for "Problem (Exists) between Chair and Keyboard". An alternative is "PICNIC" - "Problem In Chair, Not In Computer". An acronym commonly used by helpdesk technicians to indicate that a problem is due to the user rather than the system. See also UBD. (2012-08-26) 1 1 1 1 1 PEBKAC PEBCAK 1 1 1 1 1 PECOS A constraint-based language, built on the object-oriented module of Le-Lisp. ["Pecos Reference Manual", ILOG, 1990. ILOG, 12 av Raspail, BP 7, F94251 Gentilly, France]. (1995-01-26) 1 1 1 1 1 Pedagogic Algorithmic Language ["PAL - A Language for Teaching Programming Linguistics", A. Evans Jr, Proc ACM 23rd Natl Conf, Brandon/Systems Press (1968)]. (1995-01-26) 1 1 1 1 1 PEEK The command in most microcomputer BASICs for reading memory contents (a byte) at an absolute address. POKE is the corresponding command to write a value to an absolute address. This is often extended to mean the corresponding constructs in any High Level Language. Much hacking on small microcomputers without MMUs consists of "peek"ing around memory, more or less at random, to find the location where the system keeps interesting stuff. Long (and variably accurate) lists of such addresses for various computers circulate (see interrupt list). The results of pokes at these addresses may be highly useful, mildly amusing, useless but neat, or total lossage (see killer poke). Since a real operating system provides useful, higher-level services for the tasks commonly performed with peeks and pokes on micros, and real languages tend not to encourage low-level memory groveling, a question like "How do I do a peek in C?" 1 1 1 1 1 PEEL Used to implement version of Emacs on PRIME computers. 1 1 1 1 1 peephole optimisation A kind of low-level code optimisation that considers only a few adjacent machine code instructions at a time and looks for certain combinations which can be replaced with more efficient sequences. E.g. ADD R0, #1 ADD R0, #1 (add one to register R0) could be replaced by ADD R0, #2 as long as there were no jumps to the second instruction. (2008-11-17) 1 1 1 1 1 peephole optimization peephole optimisation 1 1 1 1 1 peer A unit of communications hardware or software that is on the same protocol layer of a network as another. A common way of viewing a communications link is as two protocol stacks, which are actually connected only at the very lowest (physical) layer, but can be regarded as being connected at each higher layer by virtue of the services provided by the lower layers. Peer-to-peer communication refers to these real or virtual connections between corresponding systems in each layer. To give a simple example, when two people talk to each other, the lowest layer is the physical layer which concerns the sound pressure waves travelling from mouth to ear (so mouths and ears are peers) the next layer might be the speech and hearing centres in the people's brains and the top layer their cerebellums or minds. Although, barring telepathy, nothing passes directly between the two minds, there is a peer-to-peer communication between them. 1 1 1 1 1 peer-to-peer 1. The kind of communication found in a system using layered protocols. Each software or hardware component can be considered to communicate only with its peer in the same layer via the connection provided by the lower layers. (1994-12-14) 2. A decentralised file sharing system like BitTorrent, Gnutella or Kazaa where computers that download data also store that data and serve it to other downloaders. This increases the total bandwidth available in proportion to the number of users and so reduces download time. It also improves resilience by providing multiple redundant sources for the same data. This contrasts with client-server where all clients download the data from a single server (or mirror), sharing its fixed bandwidth. Peer-to-peer networks are typically ad-hoc and rely on users sharing the content they have downloaded for the benefit of 1 1 1 1 1 peer-to-peer network peer-to-peer 1 1 1 1 1 Pegasus 1. <networking, product> A product to support Internet searches, electronic mail, and Usenet news. [Details? Addesss?] (1997-07-14) 2. <project> An open source project run by The Open Group which implements a Common Information Model (CIM) Object Manager. Pegasus Home (http://openpegasus.org/). (2003-06-07) 1 1 1 1 1 PEIPA Pilot European Image Processing Archive 1 1 1 1 1 PEM Privacy Enhanced Mail 1 1 1 1 1 PENCIL Pictorial ENCodIng Language. On-line system to display line structures. Sammet 1969, 675. 1 1 1 1 1 pencil and paper An archaic information storage and transmission device that works by depositing smears of graphite on bleached wood pulp. More recent developments in paper-based technology include improved "write-once" update devices which use tiny rolling heads similar to mouse balls to deposit coloured pigment. All these devices require an operator skilled at so-called handwriting technique. These technologies are ubiquitous outside hackerdom, but nearly forgotten inside it. Most hackers had terrible handwriting to begin with, and years of keyboarding tend to have encouraged it to degrade further. Perhaps for this reason, hackers deprecate pencil-and-paper technology and often resist using it in any but the most trivial contexts. [Jargon File] (1994-12-06) 1 1 1 1 1 penis war (Or "Dick Size War", "DSW") Any argument which has degenerated into quantitative boasting of the sort "My [program|bot|etc.] is [faster|meaner|etc.] than yours!". Generally as unconstructive (and with as little emphasis on empirical proof) as men debating who has the biggest penis. The term is often used on IRC, news:alt.sysadmin.recovery, and sometimes applied to IRC botwars, because of their equally pointless nature. (1999-07-14) 1 1 1 1 1 Pentium Intel's superscalar successor to the 486. It has two 32-bit 486-type integer pipelines with dependency checking. It can execute a maximum of two instructions per cycle. It does pipelined floating-point and performs branch prediction. It has 16 kilobytes of on-chip cache, a 64-bit memory interface, 8 32-bit general-purpose registers and 8 80-bit floating-point registers. It is built from 3.1 million transistors on a 262.4 mm^2 die with ~2.3 million transistors in the core logic. Its clock rate is 66MHz, heat dissipation is 16W, integer performance is 64.5 SPECint92, floating-point performance 56.9 SPECfp92. It is called "Pentium" because it is the fifth in the 80x86 line. It would have been called the 80586 had a US court not ruled that you can't trademark a number. The successors are the Pentium Pro and Pentium II. The following Pentium variants all belong to "x86 Family 6", as reported by "Microsoft Windows" when identifying the CPU: 1 1 1 1 1 Pentium 2 Pentium II 1 1 1 1 1 Pentium 3 Pentium III 1 1 1 1 1 Pentium II Intel Corporation's successor to the Pentium Pro. The Pentium II can execute all the instructions of all the earlier members of the Intel 80x86 processor family. There are four versions targetted at different user markets. The Celeron is the simplest and cheapest. The standard Pentium II is aimed at mainstream home and business users. The Pentium II Xeon is intended for higher performance business servers. There is also a mobile version of the Pentium II for use in portable computers. All versions of the Pentium II are packaged on a special daughterboard that plugs into a card-edge processor slot on the motherboard. The daughterboard is enclosed within a rectangular black box called a Single Edge Contact (SEC) cartridge. The budget Celeron may be sold as a card only without the box. Consumer line Pentium II's require a 242-pin slot called Slot 1. The Xeon uses a 330-pin slot called 1 1 1 1 1 Pentium III The microprocessor that was Intel Corporation's successor to the Pentium II, introduced in 1999 with a 500 MHz clock rate. The Pentim III is very similar to the Pentium II in architecture. Its external bus can be clocked at 100 or 133 MHz, it can have up to 512 KB of secondary cache, and it comes in various packages including SECC2 and FC-PGA. The Pentium III has a P6 Dynamic Execution microarchitecture, a multi-transaction system bus, and MMX, like the Pentium II. It adds Dual Independent Bus (DIB) Architecture, the Intel Processor Serial Number, Internet Streaming SIMD Extensions and 70 new instructions. Some versions also include an Advanced Transfer Cache and Advanced System Buffering. When Intel released a 1.13 GHz version of the Pentium III processor using a 0.18 micron fabrication process on 2000-07-31, it was the world's highest performance microprocessor for PCs. 1 1 1 1 1 Pentium II Xeon The successor to Intel Corporation's Pentium II processor. The Xeon has the same P6 core as existing Pentium Pro/Pentium II units, but it supports a 100 MHz system bus and offers as much as 2 MB of level 2 cache. (http://intel.com/PentiumII/xeon/home.htm). (1998-09-09) 1 1 1 1 1 Pentium Pro (Known as "P6" during development) Intel's successor to the Pentium processor, in development Jan 1995, generally available 1995-11-01. The P6 has an internal RISC architecture with a CISC-RISC translator, 3-way superscalar execution, and out-of order execution (or speculative execution, which Intel calls "Dynamic Execution"). It also features branch prediction and register renaming, and is superpipelined (14 stages). The P6 is made as a two-chip assembly: the first chip is the CPU and 16 kilobyte first-level cache (5.5 million transistors) and the other is a 256 (or 512) kilobyte second-level cache (15 million transistors). The first version has a clock rate of 133 Mhz and consumes about 20W of power. It is about twice as fast as the 100 MHz Pentium. The original 0.35 micron versions of the Pentium Pro released on 1995-11-01 run at 150 and 166 Mhz for desktop machines and up to 200 Mhz for servers. Heat disspation is about 20 1 1 1 1 1 peon A person with no special (root or wheel) privileges on a computer system. "I can't create an account on foovax for you; I'm only a peon there." [Jargon File] (2001-12-23) 1 1 1 1 1 PeopleSoft A company selling web-based ERP systems. Originally PeopleSoft supplied human resource management systems, they now provide financial data management, customer relationship management, supply chain management, workforce management, and data analytics systems. (http://peoplesoft.com/). (2003-06-01) 1 1 1 1 1 PEP peak envelope power 1 1 1 1 1 Pepper A variant of POP-11 by Chris Dollin <kers@hplb.hpl.hp.com>. (2002-05-26) 1 1 1 1 1 PEPsy Prolog extended with parallel modules within which explicit OR-parallelism can be used. ["PEPsy: A Prolog for Parallel Processing", M. Ratcliffe et al, ECRC TR CA-17, 1986]. 1 1 1 1 1 PER 1. <networking> Packed Encoding Rules. 2. <mathematics> partial equivalence relation. (1998-05-27) 1 1 1 1 1 percent % Common: ITU-T: percent sign; mod; grapes. INTERCAL: double-oh-seven. (1995-03-06) 1 1 1 1 1 Perceptional Adaptive Subband Coding (PASC) A version of MPEG-1 Layer 1 used for the Philips Digital Compact Cassette DCC. (2001-12-13) 1 1 1 1 1 perceptron 1. A single McCulloch-Pitts neuron. 2. A network of neurons in which the output(s) of some neurons are connected through weighted connections to the input(s) of other neurons. A multilayer perceptron is a specific instance of this. 1 1 1 1 1 percussive maintenance The fine art of whacking a device to get it working, possibly using a fine adjuster. (1999-01-15) 1 1 1 1 1 perf chad 1 1 1 1 1 perfect programmer syndrome Arrogance; the egotistical conviction that one is above normal human error. Most frequently found among programmers of some native ability but relatively little experience (especially new graduates; their perceptions may be distorted by a history of excellent performance at solving toy problems). "Of course my program is correct, there is no need to test it." "Yes, I can see there may be a problem here, but *I'll* never type rm -r /"" while in root mode.""" [Jargon File] 1 1 1 1 1 PERFORM A COBOL statement used for executing paragraphs. [What's a paragraph?] (1997-06-10) 1 1 1 1 1 period 1. <data> The time between repetitions of any cyclic event or phenomenon such as an electromagnetic wave or planetary orbit. Period is the reciprocal of frequency. 2. <character> American for full stop. (2010-07-25) 1 1 1 1 1 periodic group (PE) Groups of logically related fields which occur multiple times within a group. Periodic groups are a non-relational technique. An example of a PE would be for storing the history of a person's name changes, where name was kept in logically related fields such as surname, first name and middle name - with the person having changed their name more than once. [Clarification?] (1995-10-30) 1 1 1 1 1 peripheral (Or "peripheral device", "device") Any part of a computer other than the CPU or working memory, i.e. disks, keyboards, monitors, mice, printers, scanners, tape drives, microphones, speakers, cameras, to list just the less exotic ones. High speed working memory, such as RAM, ROM or, in the old days, core would not normally be referred to as peripherals. The more modern term "device" is also more general in that it is used for things such as a pseudo-tty, a RAM drive, or a network adaptor. Some argue that, since the advent of the personal computer, the motherboard, hard disk, keyboard, mouse, and monitor are all parts of the base system, and only use the term peripheral for optional additional components. (2002-09-03) 1 1 1 1 1 Peripheral Component Interconnect (PCI) A standard for connecting peripherals to a personal computer, designed by Intel and released around Autumn 1993. PCI is supported by most major manufacturers including Apple Computer. It is technically far superior to VESA's local bus. It runs at 20 - 33 MHz and carries 32 bits at a time over a 124-pin connector or 64 bits over a 188-pin connector. An address is sent in one cycle followed by one word of data (or several in burst mode). PCI is used in systems based on Pentium, Pentium Pro, AMD 5x86, AMD K5 and AMD K6 processors, in some DEC Alpha and PowerPC systems, and probably Cyrix 586 and Cyrix 686 systems. However, it is processor independent and so can work with other processor architectures as well. Technically, PCI is not a bus but a bridge or mezzanine. It includes buffers to decouple the CPU from relatively slow peripherals and allow them to operate asynchronously. (1997-12-07) 1 1 1 1 1 peripheral device peripheral 1 1 1 1 1 Peripheral Technology Group A national and international distributor of IBM PC-to-Unix and Internet connectivity products. They cater for resellers, dealers and VARs and are one of the top Seagate and Micropolis distributors in the US. (http://ptgs.com/). Address: Eden Prairie, MN, USA (a suburb of Minneapolis). Eden Prairie ("Silicon Prairie") is the home of Digi International, Ontrack, Open Systems, LaserMaster, Best Buy, and others. (1995-11-29) 1 1 1 1 1 Perl A high-level programming language, started by Larry Wall in 1987 and developed as an open source project. It has an eclectic heritage, deriving from the ubiquitous C programming language and to a lesser extent from sed, awk, various Unix shell languages, Lisp, and at least a dozen other tools and languages. Originally developed for Unix, it is now available for many platforms. Perl's elaborate support for regular expression matching and substitution has made it the language of choice for tasks involving string manipulation, whether for text or binary data. It is particularly popular for writing CGI scripts. The language's highly flexible syntax and concise regular expression operators, make densely written Perl code indecipherable to the uninitiated. The syntax is, however, really quite simple and powerful and, once the basics have been mastered, a joy to write. 1 1 1 1 1 Perl5 A commonly used but unofficial term for 5.* versions of Perl. (1999-12-04) 1 1 1 1 1 perl-byacc A modified version of byacc that generates a parser in Perl code, by Rick Ohnemus <rick@imd.sterling.com>. It has a "-p" switch so multiple parsers can be used in one program (C or Perl). Version 1.8.2 should work on most Unix systems. It also works with SAS/C 6.x on Amiga. (1993-01-24) 1 1 1 1 1 Perl profiler (pprof) A tool by Anthony Iano-Fletcher of Nottingham University, UK to profile, and collate data from, Perl scripts. Version: 1? Source posted on comp.lang.perl in mid-June 1993. (1993-06-17) 1 1 1 1 1 permanent link A URL that always points to the same piece of web content. Web pages that appear for a limited time at their main URL, such as web logs or news sites, often display an alternative, permanent link. Readers can quote, bookmark, or link to this URL in order to refer to a particular item, rather than the page displaying the latest item. For example, the URL http://news.bbc.co.uk/ points to the latest news from the BBC whereas http://news.bbc.co.uk/1/2614839.stm is a permanent link to a particular news story. (2003-12-27) 1 1 1 1 1 Permanent Virtual Circuit (PVC, or in ATM terminology, "Permanent Virtual Connection") A virtual circuit that is permanently established, saving the time associated with circuit establishment and tear-down. (1997-10-06) 1 1 1 1 1 Permanent Virtual Connection Permanent Virtual Circuit 1 1 1 1 1 permission (Or "file mode") The ability to access (read, write, execute, traverse, etc.) a file or directory. Depending on the operating system, each file may have different permissions for different kinds of access and different users or groups of users. chmod ("change mode") is the UNIX command to change permissions. (2000-12-07) 1 1 1 1 1 permutation 1. An ordering of a certain number of elements of a given set. For instance, the permutations of (1,2,3) are (1,2,3) (2,3,1) (3,1,2) (3,2,1) (1,3,2) (2,1,3). Permutations form one of the canonical examples of a "group" #NAME? that reverses the action of any given permutation. The number of permutations of r things taken from a set of n is n P r = n! / (n-r)! where "n P r" is usually written with n and r as subscripts and n! is the factorial of n. What the football pools call a "permutation" is not a permutation but a combination - the order does not matter. 2. A bijection for which the domain and range are the same set and so 1 1 1 1 1 perplexity The geometric mean of the number of words which may follow any given word for a certain lexicon and grammar. 1 1 1 1 1 persistence 1. <programming> A property of a programming language where created objects and variables continue to exist and retain their values between runs of the program. 2. <hardware> The length of time a phosphor dot on the screen of a cathode ray tube will remain illuminated after it has been energised by the electron beam. Long-persistence phosphors reduce flicker, but generate ghost-like images that linger on screen for a fraction of a second. (1994-11-09) 1 1 1 1 1 persistent persistence 1 1 1 1 1 Persistent Functional Language (PFL) A functional database language developed by Carol Small at Birkbeck College, London, UK and Alexandra Poulovassilis (now at King's College London). In PFL, functions are defined equationally and bulk data is stored using a special class of functions called selectors. PFL is a lazy language, supports higher-order functions, has a strong polymorphic type inference system, and allows new user-defined data types and values. All functions, types and values persist in a database. Functions can be written which update all aspects of the database: by adding data to selectors, by defining new equations, and by introducing new data types and values. PFL is "semi-referentially transparent", in the sense that whilst updates are referentially opaque and are executed destructively, all evaluation is referentially transparent. Similarly, type checking is "semi-static" in the sense that whilst updates are dynamically type checked at run time, 1 1 1 1 1 persistent memory non-volatile storage 1 1 1 1 1 Personal Communication Network (PCN) Any network supporting Personal Communication Service (PCS). Also, sometimes used to refer to the specific implementation (using the GSM-derivative DCS-1800) of initial PCS capabilities in the United Kingdom. (1996-08-23) 1 1 1 1 1 Personal Communication Services (PCS) Telecommunications services that bundle voice communications, numeric and text messaging, voice-mail and various other features into one device, service contract and bill. PCS are carried over cellular links, most often digital. (1996-08-01) 1 1 1 1 1 personal computer (PC) A general-purpose single-user microcomputer designed to be operated by one person at a time. This term and the concept has been successfully hijacked by IBM due to the huge market share of the IBM PC, despite its many obvious weaknesses when compared to other equally valid claimants to the term, e.g. the Acorn Archimedes, Amiga, Atari, Macintosh. (1994-11-02) 1 1 1 1 1 Personal Computer Memory Card International Association (PCMCIA, or "PC Card") An international trade association and the standards they have developed for devicies, such as modems and external hard disk drives, that can be plugged into notebook computers. A PCMCIA card is about the size of a credit card. For some unfathomable reason, around 1995(?) they decided to rename PCMCIA cards "PC Cards", perhaps to encourage sales to confused purchasers. (ftp://ftp.sidewinder.com/pub/Portables/PCMCIA). Address: PCMCIA Administration, 1030 East Duane Avenue, Suite G, Sunnyvale, CA 94086 USA. Telephone: +1 (408) 720 0107. Fax: +1 (408) 720 9416. BBS: +1 (408) 720 9388. (1996-10-16) 1 1 1 1 1 Personal Digital Assistant (PDA) A small hand-held computer typically providing calendar, contacts, and note-taking applications but may include other applications, for example a web browser and media player. Small keyboards and pen-based input systems are most commonly used for user input. The Apple Newton was a fairly early example. [First? Notable examples? Current Best?] (2002-09-03) 1 1 1 1 1 Personal Identification Number (PIN, "PIN number") A password, typically four digits entered through a telephone keypad or automatic teller machine. (1996-11-03) 1 1 1 1 1 Personalized Array Translator (PAT) A small subset of APL. E-mail: <oed@watsol.uwaterloo.ca>. [Sammet 1969, p. 252]. (1998-05-09) 1 1 1 1 1 person of no account (University of California at Santa Cruz) Used when referring to a person with no network address, frequently to forestall confusion. Most often as part of an introduction: "This is Bill, a person of no account, but he used to be bill@random.com". Compare return from the dead. [Jargon File] (1994-11-22) 1 1 1 1 1 perspective In computer games, the virtual position from which the human player views the playing area. There are three different perspectives: first person, second person, and third person. First person perspective: Viewing the world through the eyes of the primary character in three dimensions. e.g. Doom, Quake. Second person perspective: Viewing the game through a spectator's eyes, in two or three dimensions. Depending on the game, the main character is always in view. e.g. Super Mario Bros., Tomb Raider. Third person perspective: a point of view which is independent of where characters or playing units are. The gaming world is viewed much as a satellite would view a battlefield. E.g. Warcraft, Command & Conquer. (1997-06-19) 1 1 1 1 1 PERT Program Evaluation and Review Technique 1 1 1 1 1 pessimal /pes'im-l/ (Latin-based antonym for "optimal") Maximally bad. This is a pessimal situation. Also "pessimise" To make as bad as possible. These words are the obvious Latin-based antonyms for "optimal" and "optimise", but for some reason they do not appear in most English dictionaries, although pessimise is listed in the OED. [Jargon File] (1995-02-01) 1 1 1 1 1 pessimising compiler /pes'*-mi:z"ing k*m-pi:l"r/ (Antonym of "optimising compiler") A compiler that produces object code that is worse than the straightforward or obvious hand translation. The implication is that the compiler is actually trying to optimise the program, but through excessive cleverness is doing the opposite. A few pessimizing compilers have been written on purpose, however, as pranks or burlesques. (1995-02-01) 1 1 1 1 1 peta- prefix 1 1 1 1 1 petabyte (PB) A unit of data equal to one quadrillion bytes but see binary prefix for other definitions. A petabyte is 10^15 bytes or 1000^5 bytes or 1000 terabytes. As of 2013-11-05, the Internet Archive Wayback Machine contains almost two petabytes of data. A petabyte is the amount of data that would be required to store a 2000 by 1600 pixel image of every one of the 314 million people living in the USA in 2012. 1000 petabytes are one exabyte. See prefix. (2007-09-13) 1 1 1 1 1 petaflops 10^15 flops or 1000 teraflops. As with flops, the term ends in S in both the singular and plural as the S stands for seconds. The first computer to perform one petaflops was recorded in June 2008 (http://top500.org/list/2008/06/100). By June 2012 (http://top500.org/list/2012/06/100) there were 20. (2013-04-27) 1 1 1 1 1 petdingo An Estelle to C++ translator. (1997-01-24) 1 1 1 1 1 Peter Chen The developer of the Entity-Relationship model. (1995-02-07) 1 1 1 1 1 Petri net A directed, bipartite graph in which nodes are either "places" (represented by circles) or transitions (represented by rectangles), invented by Carl Adam Petri. A Petri net is marked by placing "tokens" on places. When all the places with arcs to a transition (its input places) have a token, the transition "fires", removing a token from each input place and adding a token to each place pointed to by the transition (its output places). Petri nets are used to model concurrent systems, particularly network protocols. Variants on the basic idea include the coloured Petri Net, Time Petri Net, Timed Petri Net, Stochastic Petri Net, and Predicate Transition Net. FAQ (http://daimi.aau.dk/PetriNets/faq/answers.htm). (1996-09-10) 1 1 1 1 1 PETSCII /pet'skee/ PET ASCII. The variation (many would say perversion) of the ASCII character set used by the Commodore Business Machines' PET series of personal computers and the later Commodore 64, Commodore 16, and Commodore 128 computers. The PETSCII set used left-arrow and up-arrow (as in old-style ASCII) instead of underscore and caret, placed the unshifted alphabet at positions 65--90, put the shifted alphabet at positions 193--218, and added graphic characters. [Jargon File] (1995-10-29) 1 1 1 1 1 PEX (PHIGS Extension to X) Extension to the X Window System providing 3d graphics support. 1 1 1 1 1 pf The country code for French Polynesia. (1999-01-27) 1 1 1 1 1 PFE 1. <text, editor> Programmer's File Editor. 2. <language> Portable Forth Environment. (2000-12-07) 1 1 1 1 1 PFL 1. <language> A concurrent extension of ML by Holmstrom and Matthews, using CCS. ["PFL: A Functional Language for Parallel Programming", S. Holmstrom in Proc Declarative Language Workshop, London 1983]. 2. <language, database> Persistent Functional Language. 1 1 1 1 1 pfm program file manager 1 1 1 1 1 pForth A portable (hence the "p") ANS-standard Forth implemented in ANSI C. Phil Burk (http://softsynth.com/philburk.html) initially began developing pForth in 1994 to support ASIC development at 3DO. (1998-06-30) 1 1 1 1 1 Pfortran Parallel Fortran 1 1 1 1 1 PFP Plastic Flat Package 1 1 1 1 1 pg The country code for Papua New Guinea. (1999-01-27) 1 1 1 1 1 PGA 1. <graphics, specification> Professional Graphics Adapter. 2. <hardware> Pin Grid Array. (1999-08-04) 1 1 1 1 1 PGA370 Socket 370 1 1 1 1 1 PGP Pretty Good Privacy 1 1 1 1 1 PH The tool for looking up people in Eudora on the Macintosh. Equivalent to Unix's finger service. (1995-03-31) 1 1 1 1 1 pH Parallel Haskell 1 1 1 1 1 ph The country code for the Philippines. (1999-01-27) 1 1 1 1 1 phacker A telephone system cracker. A phacker may attempt to gain unauthorised access to a phone system in order to make free or untraceable calls or he may disrupt, alter or illegally tap phone systems via computer. The disruptions may include causing a phone line to be engaged so no calls go in or out, redirecting outgoing or incoming calls, as well as listening to actual calls made. Phackers are frequently confidence tricksters or phone freaks (nuisance callers who can only relate to other people by phone). Phackers are sometimes employed by illegal enterprises to conduct business using untraceable calls, or to disrupt, or follow legal authorities' investigations. Phackers interventions may be lethal to the person being phacked. A phacker may be a phone company employee, or usually, ex-employee who specialises in illegal phone system disruption, alteration or tapping via physically altering 1 1 1 1 1 phage A program that modifies other programs or databases in unauthorised ways; especially one that propagates a virus or Trojan horse. See also worm, mockingbird. The analogy, of course, is with phage viruses in biology. [Jargon File] 1 1 1 1 1 phase 1. The offset of one's waking-sleeping schedule with respect to the standard 24-hour cycle; a useful concept among people who often work at night and/or according to no fixed schedule. It is not uncommon to change one's phase by as much as 6 hours per day on a regular basis. "What's your phase?" "I've been getting in about 8 P.M. lately, but I'm going to wrap around to the day schedule by Friday." A person who is roughly 12 hours out of phase is sometimes said to be in "night mode". (The term "day mode" is also (but less frequently) used, meaning you're working 9 to 5 (or, more likely, 10 to 6).) The act of altering one's cycle is called "changing phase"; phase shifting has also been recently reported from Caltech. 2. "change phase the hard way": To stay awake for a very long time in order to get into a different phase. 3. "change phase the easy way": To stay asleep, etc. However, some claim that either staying awake longer or sleeping longer is easy, and that it is *shortening* your day or night that is 1 1 1 1 1 phase alternating line (PAL) The video signal format used in the UK [where else?]. PAL uses Amplitude Modulation for the video information, and Frequency Modulation for the audio information. The phase of the colour subcarrier is reversed on alternate lines which (together with the use of a delay line) allows the receiver to cancel any phase errors introduced in the path between the studio and the end-user's receiver. Such phase errors are quite common and would cause the displayed colours to shift in hue. The US equivalent, NTSC, does not have this feature and thus requires a user control to correct for transmission phase errors, hence the mis-expansion "Never Twice the Same Colour". (2001-06-08) 1 1 1 1 1 Phase Encoded (PE) A recording method used for 1600 BPI magnetic tapes. Compare NRZI, GCR. (1996-02-03) 1 1 1 1 1 phase of the moon Used humorously as a random parameter on which something is said to depend. Sometimes implies unreliability of whatever is dependent, or that reliability seems to be dependent on conditions nobody has been able to determine. "This feature depends on having the channel open in mumble mode, having the foo switch set, and on the phase of the moon." See also heisenbug. True story: Once upon a time there was a bug that really did depend on the phase of the moon. There was a little subroutine that had traditionally been used in various programs at MIT to calculate an approximation to the moon's true phase. GLS incorporated this routine into a Lisp program that, when it wrote out a file, would print a timestamp line almost 80 characters long. Very occasionally the first line of the message would be too long and would overflow onto the next line, and when the file was later read back in the program would barf. The length of the first 1 1 1 1 1 phase-shift keying (PSK) A digital modulation scheme that conveys data by changing the phase of a carrier wave. The data can either determine the absolute phase relative to the unmodulated carrier or reference signal ("coherent phase-shift keying", CPSK) or the change in phase ("differential phase-shift keying", DPSK). The number of different phases used determines the amount of data that can be transmitted in each cycle. Each cycle can be considered to constitute one symbol, e.g. with two possible phases, each cycle carries one bit. The more phases that are used, the less tollerant to noise the transmissions becomes. Alternatives to PSK are amplitude-shift keying (ASK) and frequency-shift keying (FSK). (2010-01-26) 1 1 1 1 1 phase space The 2n-dimensional space consisting of the possible values of (x1, x1., x2, x2., ..., xn, xn.) for a system of n first-order ordinary differential equations (or more generally, Pfaffian forms). If n=1, the phase space is known as a phase plane. (http://mathworld.wolfram.com/PhaseSpace.html). (2008-05-02) 1 1 1 1 1 phase-wrapping (MIT) wrap around. [Jargon File] (1995-02-22) 1 1 1 1 1 PHIGS Programmers Hierarchical Interactive Graphics System 1 1 1 1 1 Philip R. Bagley A pioneer of computer document retrieval. See metadata. (2010-05-15) 1 1 1 1 1 Philips A Dutch multinational electronics company. It produces washing machines, consumer electronics, integrated circuits and light bulbs. Together with Sony they set the Compact Disc standard, especially Green Book CD-ROM. They are members of the Open Software Foundation. Philips Research Labs developed the POOL and SPL languages. Address: Philips Research Labs, Eindhoven, Netherlands. (1995-02-07) 1 1 1 1 1 Philips SCC68070 A microprocessor which is object code compatible with the Motorola 68000. It is not a performance improvement over the 68060; it's performance rather resembles that of the 68000. (1995-04-22) 1 1 1 1 1 philosophy See computer ethics, liar paradox, netiquette, proof. 1 1 1 1 1 phishing ("brand spoofing", "carding", after "fishing") /fishing/ Sending e-mail that claims to be from some well-known organisation, e.g. a bank, to trick the recipient into revealing information for use in identity theft. The user is told to visit a website where they are asked to enter information such as passwords, credit card details, social security or bank account numbers. The website usually looks like it belongs to the organisation in question and may silently redirect the user to the real website after collecting their data. For example, a scam started in 2003 claimed that the user's eBay account would be suspended unless he updated his credit card information on a given website. (2006-01-19) 1 1 1 1 1 PHOCUS An object-oriented Prolog-like language. ["PHOCUS: Production Rules, Horn Clauses, Objects and Contexts in a Unification Based System", D. Chan et al, Actes du Sem Prog et Logique, Tregastel (May 1987), pp. 77-108]. (1994-11-09) 1 1 1 1 1 Phoenix An operating system, built in BCPL on top of IBM MVT and later MVS by Cambridge University Computing Service from 1973 to 1995, which ran on the university central mainframe. All parts of the system were named after birds, including Eagle (the job scheduler, also the nearest pub), Pigeon (the mailer), GCAL (the text processor) and Wren (the command language), leading to Wren Libraries (a local pun). Phoenix was much used by chemists in daytime and by the rest of the university in the evenings, and was only abandoned in favour of Unix in 1995; it is one reason Cambridge made little contribution to Unix until then. Computing Service Phoenix closure memo (http://cam.ac.uk/cs/newsletter/1995/nl183/phoenix.html) (2003-12-05) 1 1 1 1 1 phone mail voice mail 1 1 1 1 1 Phonetastic A CTI product from Callware. Phonetastic employs if-then rules and customer records to tell those receiving calls who is calling (based on ANI and DNIS) and to determine how the call should be routed, e.g. to a certain sales representative or to the general sales department; receive high-priority treatment; receive a fax-back, etc. (1996-12-08) 1 1 1 1 1 Phong shading A model of how light is reflected from surfaces used extensively in three dimensional graphics to generate visually realistic images. [Details?] (1994-11-09) 1 1 1 1 1 phosphor fatigue screen saver 1 1 1 1 1 photo CD A standard for storing photographic images on CD-ROM, produced by Kodak. Kodak Photo CD page (http://kodak.com/digitalImaging/aboutPhotoCD/aboutPCD.shtml). (1995-12-12) 1 1 1 1 1 Photoshop An image manipulation program by Adobe Systems, Inc.. (http://adobe.com/Apps/Photoshop.html). [Summary?] (1995-07-05) 1 1 1 1 1 PHP PHP: Hypertext Preprocessor 1 1 1 1 1 PHP: Hypertext Preprocessor (PHP) An Open Source, server-side, cross-platform, scripting language used to create dynamic web pages. PHP can be embedded in HTML using special tags like: <?php echo '<p>Hello World</p>'; ?> This is stored in a file with a ".php" extension. The web server passes the file to the PHP interpreter which executes the code in the <?php ... ?> tags. The tagged code is then replaced with its output, typically ordinary HTML, in the response sent to the web browser. PHP is a recursive acronym. Latest version: 5.3.2 2010-03-04, as of 2010-03-20. PHP Home (http://php.net/). Cheat sheet (http://addedbytes.com/cheat-sheets/php-cheat-sheet/). (2010-03-20) 1 1 1 1 1 phreaking /freek'ing/ "phone phreak" 1. The art and science of cracking the telephone network so as, for example, to make free long-distance calls. 2. By extension, security-cracking in any other context (especially, but not exclusively, on communications networks). At one time phreaking was a semi-respectable activity among hackers; there was a gentleman's agreement that phreaking as an intellectual game and a form of exploration was OK, but serious theft of services was taboo. There was significant crossover between the hacker community and the hard-core phone phreaks who ran semi-underground networks of their own through such media as the legendary "TAP Newsletter". This ethos began to break down in the mid-1980s as wider dissemination of the techniques put them in the hands of less responsible phreaks. Around the same time, changes in the phone network made old-style technical ingenuity less effective as a way of hacking it, so phreaking came to depend 1 1 1 1 1 physical The opposite of logical in its jargon sense. Compare real, virtual, and transparent. It is said that what you can touch and see is real; what you can see but not touch is virtual; what you can touch but not see is transparent; and what you can neither touch nor see is probably imaginary. (2001-10-26) 1 1 1 1 1 physical address The address presented to a computer's main memory in a virtual memory system, in contrast to the virtual address which is the address generated by the CPU. A memory management unit translates virtual addresses into physical addresses. (1995-03-31) 1 1 1 1 1 physical addressing The low level addressing scheme used on Ethernet. The 48-bit destination Ethernet address in a packet is compared with the receiving node's Ethernet address. Compare IP address. (1994-12-23) 1 1 1 1 1 physical file A low-level view of the physical characteristics of a file, such as its location on a disk or its physical structure, for example, whether indexed or sequential. (2004-12-23) 1 1 1 1 1 physical layer Layer one, the lowest layer in the OSI seven layer model. The physical layer encompasses details such as electrical and mechanical connections to the network, transmission of binary data as changing voltage levels on wires or similar concepts on other connectors, and data rates. The physical layer is used by the data link layer. Example physical layer protocols are CSMA/CD, token ring and bus. (2004-06-29) 1 1 1 1 1 physical memory The memory hardware (normally RAM) installed in a computer. The term is only used in contrast to virtual memory. (1996-03-23) 1 1 1 1 1 physical memory address physical address 1 1 1 1 1 Physical Sequential (PS, QSAM, Queued Sequential Access Method) The simplest data set on an IBM mainframe. Sequential files can only be read or written from the beginning: they do not support random access. [Why "Queued"?] (2003-12-05) 1 1 1 1 1 Physical Transport Network (PTN) The actual hardware through which data transfer devices are connected. Virtual Circuits may be leased by the owner of the physical network to organisations which cannot afford the high costs of laying long distance cable. (2003-11-23) 1 1 1 1 1 Physics Analysis Workbench (PAW) A general purpose portable tool for analysis and presentation of physics data. (1994-11-28) 1 1 1 1 1 PI An interface between Prolog application programs and the X Window System that aims to be independent from the Prolog engine, provided that it has a Quintus foreign function interface (e.g. SICStus and YAP). PI is mostly written in Prolog and is divided in two libraries: Edipo - the lower level interface to the Xlib functions; and Ytoolkit #NAME? (ftp://ftp.ncc.up.pt/pub/prolog/ytoolkit.tar.Z). E-mail: Ze' Paulo Leal <zp@ncc.up.pt>. (1993-03-02) 1 1 1 1 1 pi 1. <character> The greek lower-case letter P. 2. <mathematics> The mathematical constant that is the circumference of a circle divided by its diameter. Pi is written as the greek character pi. Some have suggested that pi is the wrong choice and a better constant to describe the geometry of circles would have been 2*pi, for which they have proposed the name tau. Most practising mathematicians think this is silly. The xkcd comic strip proposed (http://xkcd.com/1292/) a compromise between pi and tau, namely 1.5*pi or "pau". (2013-12-09) 1 1 1 1 1 PIC 1. <hardware> programmable interrupt controller. 2. A graphics language by Brian Kernighan, for textually describing pictures with troff. [Featured in "More Programming Pearls", Jon Bentley]. ["PIC - A Language for Typesetting Graphics", B.W. Kernighan, Soft Prac & Exp 12(1):1-21 (Jan 1982)]. ["PIC - A Graphics Language for Typesetting, Revised User Manual", Bell Labs TR 116, Dec 1984]. (1994-10-28) 3. personal intelligent communicator. (2001-04-30) 1 1 1 1 1 pi-calculus A process algebra in which channel names can act both as transmission medium and as transmitted data. Its basic atomic actions are individual point to point communications which are nondeterministically selected and globally sequentialised. [Details? Examples?] (1995-03-20) 1 1 1 1 1 Pick BASIC Data/BASIC 1 1 1 1 1 PICL Language on Ncube or iPSC machines? 1 1 1 1 1 PICNIC PEBCAK 1 1 1 1 1 pico- prefix 1 1 1 1 1 picosecond 10^-12 seconds. (1997-04-26) 1 1 1 1 1 PICS Platform for Internet Content Selection 1 1 1 1 1 PICT An Apple graphics format. [Details?] (1997-06-06) 1 1 1 1 1 PicTeX A version of TeX for pictures. (ftp://june.cs.washington.edu/tex/PiCTeX.tar.Z). 1 1 1 1 1 pictogram (Or "pictograph") A symbol which is a picture that represents an object or concept, e.g. a picture of an envelope used to represent an e-mail message. Pictograms are common in everyday life, e.g. signs in public places or roads, whereas the term "icon" is specific to interfaces on computers or other electronic devices. Pictograms are the most common kind of ideogram (symbols representing concepts), the other kind are not pictures but are conventions. (2014-07-30) 1 1 1 1 1 pictograph pictogram 1 1 1 1 1 Pictorial Janus K. Kahn, Xerox. Visual extension of Janus. Requires Strand88 and a PostScript interpreter. 1 1 1 1 1 picture image 1 1 1 1 1 picture element (pixel) The smallest resolvable rectangular area of an image, either on a screen or stored in memory. Each pixel in a monochrome image has its own brightness, from 0 for black to the maximum value (e.g. 255 for an eight-bit pixel) for white. In a colour image, each pixel has its own brightness and colour, usually represented as a triple of red, green and blue intensities (see RGB). Compare voxel. (1998-05-08) 1 1 1 1 1 Picture Quality Scale (PQS) A system for rating image quality based upon features of images that affect their perception by the human eye, rather than the traditional signal-to-noise ratio which examines differences for every single pixel. [Details?] (1995-01-12) 1 1 1 1 1 PID process identifier 1 1 1 1 1 pidgen+ A language for the Apple II. (ftp://ftp.wustl.edu/system/apple2/Lang/pidgen/). [Published in Dr. Dobbs Journal?] (1994-11-29) 1 1 1 1 1 Pidgin A text chat application that work with many different chat systems at the same time. Systems it works with include AOL Instant Messenger, Yahoo! Messenger, Windows Live Messenger, IRC and Facebook. There are plug-ins to add even more systems, e.g. Skype and to add features. Pidgin was first released in 1998. The name "Pidgin" was applied in 2007. It is available for several operating systems. It is licensed under the GNU General Public License. The name "Pidgin" comes from the term for a simplified human language that evolves from two or more languages. Pidgin Home (http://pidgin.im/). (2012-04-15) 1 1 1 1 1 PIE A language from CMU similar to Actus. (1994-11-29) 1 1 1 1 1 pif Program Information File 1 1 1 1 1 piggybacking 1. A method for passing acknowledgement frames and data frames in the same direction along a line. 2. The practice of increasing memory capacity by soldering chips on top of other chips. The chip-enable or high address pins would be connected to the address bus by a flying lead. Many Ohio Superboards were expanded to a massive 8K of RAM in this way. (1994-11-29) 1 1 1 1 1 pig, run like a To run very slowly on given hardware, said of software. Distinct from hog. [Jargon File] (1994-11-29) 1 1 1 1 1 PIGUI Platform Independent Graphical User Interface 1 1 1 1 1 PIL Procedure Implementation Language. A subsystem of DOCUS. [Sammet 1969, p.678]. (1994-11-29) 1 1 1 1 1 PILE 1. Polytechnic's Instructional Language for Educators. Similar in use to an enhanced PILOT, but structurally more like Pascal with Awk-like associative arrays (optionally stored on disk). Distributed to about 50 sites by Initial Teaching Alphabet Foundation for Apple II and CP/M. ["A Universal Computer Aided Instruction System," Henry G. Dietz & Ronald J Juels, Proc Natl Educ Computing Conf '83, pp.279-282]. 2. <language, music> ["PILE _ A Language for Sound Synthesis", P. Berg, Computer Music Journal 3.1, 1979]. (1999-06-04) 1 1 1 1 1 PIL/I Variant of JOSS. Sammet 1969, p.217. 1 1 1 1 1 PILOT Programmed Inquiry Learning Or Teaching. CAI language, many versions. "Guide to 8080 PILOT", J. Starkweather, Dr Dobb's J (Apr 1977). 1 1 1 1 1 pilot error (Sun, from aviation) A user's misconfiguration or misuse of a piece of software, producing apparently bug-like results. E.g. "Joe Luser reported a bug in sendmail that causes it to generate bogus headers." "That's not a bug, that's pilot error. His "sendmail.cf" is hosed." Compare UBD. [Jargon File] (1994-12-05) 1 1 1 1 1 Pilot European Image Processing Archive (PEIPA) An archive devoted to image processing, computer vision, and computer graphics. It includes software, images, reference material, and miscellaneous goodies. The archive is funded by the British Machine Vision Association (BMVA) and the University of Essex and is closely associated with the Pixel mailing list and Technical Committee 5 (Benchmarking and Software) of the IAPR. (http://peipa.essex.ac.uk/). 1 1 1 1 1 PIM 1. Personal Information Manager. 2. Product Information Management. (1997-02-11) 1 1 1 1 1 PIN Personal Identification Number 1 1 1 1 1 PINBOL A decision table language for controlling pinball machines used at Atari. PINBOL included a multitasking executive and an interpreter that worked on data structures compiled from condition:action lists. (1996-11-03) 1 1 1 1 1 Pine Program for Internet News & Email. A tool for reading, sending, and managing electronic messages. It was designed specifically with novice computer users in mind, but can be tailored to accommodate the needs of "power users" as well. Pine uses Internet message protocols (e.g. RFC 822, SMTP, MIME, IMAP, NNTP) and runs under Unix and MS-DOS. The guiding principles for Pine's user-interface were: careful limitation of features, one-character mnemonic commands, always-present command menus, immediate user feedback, and high tolerance for user mistakes. It is intended that Pine can be learned by exploration rather than reading manuals. Feedback from the University of Washington community and a growing number of Internet sites has been encouraging. Pine's message composition editor, Pico, is also available as a separate stand-alone program. Pico is a very simple and easy-to-use text editor offering paragraph justification, 1 1 1 1 1 pin feed sprocket feed 1 1 1 1 1 ping (ping, originally contrived to match submariners' term for the sound of a returned sonar pulse) A program written in 1983 by Mike Muuss (who also wrote TTCP) used to test reachability of destinations by sending them one, or repeated, ICMP echo requests and waiting for replies. Since ping works at the IP level its server-side is often implemented entirely within the operating system kernel and is thus the lowest level test of whether a remote host is alive. Ping will often respond even when higher level, TCP-based services cannot. Sadly, Mike Muuss was killed in a road accident on 2000-11-20. The term is also used as a verb: "Ping host X to see if it is up." The Unix command "ping" can be used to do this and to measure round-trip delays. The funniest use of "ping" was described in January 1991 by Steve Hayman on the Usenet group comp.sys.next. He was 1 1 1 1 1 ping command ping 1 1 1 1 1 ping-flood To flood another user with ping requests. (1997-04-07) 1 1 1 1 1 pinging ping 1 1 1 1 1 ping-pong A phenomenon which can occur in a multi-processor system with private caches where two processors are alternately caching a shared location. Each time one writes to it, it invalidates the other's copy. (1995-12-29) 1 1 1 1 1 Pin Grid Array (PGA) A style of integrated circuit socket or pin-out with pins laid out on a square or rectangular grid with a separation of 0.1 inch in each direction. The pins near the centre of the array are often missing. PGA is often used on motherboards for processors, e.g. Socket 6 and Socket 8. PPGA is "plastic PGA" (as opposed to ceramic?). See also SPGA. (2000-03-09) 1 1 1 1 1 Pink-Shirt Book "The Peter Norton Programmer's Guide to the IBM PC". The original cover featured a picture of Peter Norton with a silly smirk on his face, wearing a pink shirt. Perhaps in recognition of this usage, the current edition has a different picture of Norton wearing a pink shirt. See also book titles. [Jargon File] (1995-03-28) 1 1 1 1 1 pin-out (Or "pinout") The allocation of logical functions or signals to the electrical connection points (pins) of an integrated circuit or other component or connector. (1996-04-04) 1 1 1 1 1 PIO mode programmed input/output mode 1 1 1 1 1 PIP Peripheral Interchange Program. A program on CP/M, RSX-11, RSTS/E, TOPS-10, and OS/8 (derived from a utility on the PDP-6) that was used for file copying (and in OS/8 and RT-11 for just about every other file operation you might want to do). It is said that when the program was written, during the development of the PDP-6 in 1963, it was called ATLATL ("Anything, Lord, to Anything, Lord"; this played on the Nahuatl word "atlatl" for a spear-thrower, with connotations of utility and primitivity that were no doubt quite intentional). See also BLT, dd, cat. [Jargon File] (1995-03-28) 1 1 1 1 1 pipe 1. <operating system> One of Unix's buffers which can be written to by one asynchronous process and read by another, with the kernel suspending and waking up the sender and receiver according to how full the pipe is. In later versions of Unix, rather than using an anonymous kernel-managed temporary file to implement a pipe, it can be named and is implemented as a local socket pair. 2. <character> "|" ASCII character 124. Used to represent a pipe between two processes in a shell command line. E.g. grep foo log | more which feeds the output of grep into the input of more without requiring a named temporary file and without waiting for the first process to finish. 3. <jargon, networking> A connection to a network. See also light pipe. (1996-09-24) 1 1 1 1 1 pipeline A sequence of functional units ("stages") which performs a task in several steps, like an assembly line in a factory. Each functional unit takes inputs and produces outputs which are stored in its output buffer. One stage's output buffer is the next stage's input buffer. This arrangement allows all the stages to work in parallel thus giving greater throughput than if each input had to pass through the whole pipeline before the next input could enter. The costs are greater latency and complexity due to the need to synchronise the stages in some way so that different inputs do not interfere. The pipeline will only work at full efficiency if it can be filled and emptied at the same rate that it can process. Pipelines may be synchronous or asynchronous. A synchronous pipeline has a master clock and each stage must complete its work within one cycle. The minimum clock period is thus determined by the slowest stage. An asynchronous pipeline 1 1 1 1 1 pipeline break (Or "pipeline stall") The delay caused on a processor using pipelines when a transfer of control is taken. Normally when a control-transfer instruction (a branch, conditional branch, call or trap) is taken, any following instructions which have been loaded into the processor's pipeline must be discarded or "flushed" and new instructions loaded from the branch destination. This introduces a delay before the processor can resume execution. Delayed control-transfer is a technique used to reduce this effect. (1996-10-13) 1 1 1 1 1 Pipeline Burst Cache (PB Cache) A synchronous cache built from pipelined SRAM. A cache in which reading or writing a new location takes multiple cycles but subsequent locations can be accessed in a single cycle. On Pentium systems in 1996, pipeline burst caches are frequently used as secondary caches. The first 8 bytes of data are transferred in 3 CPU cycles, and the next 3 8-byte pieces of data are transferred in one cycle each. (1996-10-13) 1 1 1 1 1 pipelined pipeline 1 1 1 1 1 Pipelined Burst Cache Pipeline Burst Cache 1 1 1 1 1 pipeline stall pipeline break 1 1 1 1 1 pipelining pipeline 1 1 1 1 1 PIPEX Ltd. UUNET PIPEX 1 1 1 1 1 piping pipe 1 1 1 1 1 piracy software piracy 1 1 1 1 1 pirate software pirate 1 1 1 1 1 PIRL Pattern Information Retrieval Language. A language for digraph manipulation, embeddable in Fortran or ALGOL, for IBM 7094. ["PIRL - Pattern Information Retrieval Language", S. Berkowitz, Naval Ship Res Dev Ctr, Wash DC]. (1994-11-29) 1 1 1 1 1 pistol [IBM] A tool that makes it all too easy for you to shoot yourself in the foot. "Unix "rm *" makes such a nice pistol!" [Jargon File] 1 1 1 1 1 PIT Language for IBM 650. (See IT). 1 1 1 1 1 PITA Pain in the arse/ass. 1 1 1 1 1 pixel picture element 1 1 1 1 1 pixels per inch (ppi) The unit used to measure resolution of a bitmap display or video input device. (2010-02-28) 1 1 1 1 1 pixmap (Contraction of "pixel map"). A 3 dimensional array of bits corresponding to a 2 dimensional array of pixels. It is used, for example, in the X Window System to describe a memory region where graphics can be drawn without affecting the screen. Typically this is used for the efficient handling of expose events, icon images or for animation. Compare bitmap. [Xlib Guide]. 1 1 1 1 1 pizza box [Sun] The largish thin box housing the electronics in (especially Sun) desktop workstations, so named because of its size and shape and the dimpled pattern that looks like air holes. Two megabyte single-platter removable disk packs used to be called pizzas, and the huge drive they were stuck into was referred to as a pizza oven. It's an index of progress that in the old days just the disk was pizza-sized, while now the entire computer is. [Jargon File] 1 1 1 1 1 PJPEG Progressive JPEG 1 1 1 1 1 pk The country code for Pakistan. (1999-01-27) 1 1 1 1 1 PKE public-key encryption 1 1 1 1 1 PKI Public Key Infrastructure 1 1 1 1 1 PKLITE An executable file compression utility for MS-DOS from PKWARE, Inc.. PKLITE compresses the body of the executable and adds a small, fast decompress routine in the header. In many cases it performs better than lzexe. With headpack the output is smaller and cannot be decompressed. (1999-01-07) 1 1 1 1 1 PKUNZIP A program to unpack archives created by PKZIP, written by PKWARE, Inc. and released as shareware. Versions exist for MS-DOS, Microsoft Windows and Open VMS. PKUNZIP is no longer distributed, its functions having been incorporated into PKZIP. (1999-01-07) 1 1 1 1 1 PKWARE, Inc. The company which produces the PKZIP and PKUNZIP compression tools and libraries for many platforms. (http://pkware.com/). E-mail: info@pkware.com. Telephone: +1 (414) 354 8699. Address: 9025 N. Deerwood Drive, Brown Deer, WI 53223-2480, USA. (1999-01-07) 1 1 1 1 1 PKZIP A file compression and archiver utility for MS-DOS and Microsoft Windows from PKWARE, Inc.. PKZIP uses a variation on the sliding window compression algorithm. It comes with pkunzip and pklite and is available as shareware from most FTP archives in a self-expanding MS-DOS executable. Current versions as of 1999-10-07: PKZIP 2.60 GUI for Microsoft Windows 3.1x, Windows 9x, Windows NT; PKZIP 2.50 Command Line for Windows 9x NT; PKZIP 2.04g for MS-DOS; PKZIP 2.51 for Unix, (Linux, SPARC Solaris, Digital, HP-UX, IBM AIX and SCO Unix); PKZIP 2.50 for OS/2; PKZIP for Open VMS/VAX. WINZIP is a version with a GUI for Microsoft Windows. A distribution in about 1995-06-22 claiming to be "PKZIP 3" was actually a Trojan horse which attempted to reformat the hard disk and delete all files on it. (http://pkware.com/catalog/pkzip_win.html). 1 1 1 1 1 pl The country code for Poland. (1999-01-27) 1 1 1 1 1 PL1 It's spelled "PL/I". (1996-12-13) 1 1 1 1 1 PL/1 It's spelled "PL/I". (1996-12-13) 1 1 1 1 1 PL-11 A high-level machine-oriented language for the PDP-11 developed by R.D. Russell of CERN in Nov 1971. It is similar to PL360 and is written in Fortran IV and cross-compiled on other machines. (1995-01-05) 1 1 1 1 1 PL360 Structured assembly language for the IBM 360 and IBM 370, with a few high-level constructs. Syntactically it resembles ALGOL 60. Its grammar is defined entirely by operator precedence. ["PL/360, A Programming Language for the 360 Computers", N. Wirth, J ACM 15(1):37-74 (Jan 1968)]. (1995-01-05) 1 1 1 1 1 PL516 An ALGOL-like assembly language for the DDP-516, similar to PL360. ["PL 516, An ALGOL-like Assembly Language for the DDP-516", B.A. Wichmann, Natl Phys Lab UK, Report CCU 9, 1970]. (1995-01-05) 1 1 1 1 1 PL-6 A PL/I-like system language for the Honeywell operating system, CP-6. (1995-01-05) 1 1 1 1 1 PL.8 A systems dialect of PL/I, developed originally for the IBM 801 RISC minicomputer, later used internally for IBM RT and R/6000 development. ["An Overview of the PL.8 Compiler", M. Auslander et al, Proc SIGPLAN '82 Symp on Compiler Writing]. (1995-01-05) 1 1 1 1 1 Pla A high-level music programming language, written in SAIL. Pla includes concurrency based on message passing. ["Pla: A Composer's Idea of a Language", B. Schottstaedt, Computer Music J 7(1):11-20, Winter 1983]. (1999-06-04) 1 1 1 1 1 PLACE Programming Language for Automatic Checkout Equipment. ["The Compiler for the Programming Language for Automatic Checkout Equipment (PLACE)", AFAPL TR-68-27, Battelle Inst, Columbus, May 1968]. 1 1 1 1 1 PLAGO A translator-interpreter for a PL/I subset. "PLAGO/360 User's Manual, Poly Inst Brooklyn. 1 1 1 1 1 plaid screen [XEROX PARC] A "special effect" that occurs when certain kinds of memory smashes overwrite the control blocks or image memory of a bit-mapped display. The term "salt and pepper" may refer to a different pattern of similar origin. Though the term as coined at PARC refers to the result of an error, some of the X demos induce plaid-screen effects deliberately as a display hack. [Jargon File] 1 1 1 1 1 PLAIN Programming LAnguage for INteraction. Pascal-like, with extensions for database, string handling, exceptions and pattern matching. "Revised Report on the Programming Language PLAIN", A. Wasserman, SIGPLAN Notices 6(5):59-80 (May 1981). 1 1 1 1 1 plain ASCII /playn-as'kee/ flat ASCII. [Jargon File] 1 1 1 1 1 Plain Old Documentation (pod, occasionally "POD") A simple markup language used to embed documentation, literate programming-style, in Perl programs. Pod readers and converters are part of the standard Perl distribution and the documentation provided with Perl is all in pod format. The Pod Specification (http://perl.com/CPAN-local/doc/manual/html/pod/perlpod.html). (1998-12-18) 1 1 1 1 1 Plain Old Telephone Service (POTS) The traditional voice service provided by phone companies, especially when opposed to data services. Note that the acronym POTS is sometimes expanded as "Plain Old Telephone System" in which sense it is synonymous to Public Switched Telephone Network but used somewhat derogatively. (1998-05-18) 1 1 1 1 1 Plain Old Telephone System Public Switched Telephone Network 1 1 1 1 1 plain TeX Donald Knuth's original set of user-level macros for interaction with his TeX formatter. Dedicated TeX fans still prefer these over the more user-friendly LaTeX macros used by the majority of the TeX community. (1997-11-20) 1 1 1 1 1 plaintext A message before encryption or after decryption, i.e. in its usual form which anyone can read, as opposed to its encrypted form ("ciphertext"). (1995-05-10) 1 1 1 1 1 PLAN Programming LANguage Nineteen hundred. The assembly language for ICL 1900 series computers. (1995-03-21) 1 1 1 1 1 Plan 9 (Named after the classically bad, exceptionally low-budget SF film "Plan 9 from Outer Space") An operating system developed at Bell Labs by many researchers previously intimately involved with Unix. Plan 9 is superficially Unix-like but features far finer control over the name-space (on a per-process basis) and is inherently distributed and scalable. Plan 9 is divided according to service functions. CPU servers concentrate computing power into large multiprocessors; file servers provide repositories for storage and terminals give each user of the system a dedicated computer with bitmap screen and mouse on which to run a window system. The sharing of computing and file storage services provides a sense of community for a group of programmers, amortises costs and centralises and hence simplifies management and administration. The pieces communicate by a single protocol, built above a 1 1 1 1 1 Planet ["An Experiment in Language Design for Distributed Systems", D. Crookes et al, Soft Prac & Exp 14(10):957-971 (Oct 1984)]. 1 1 1 1 1 plan file On Unix systems that support finger, the ".plan" file in a user's home directory is displayed when the user is fingered. This feature was originally intended to be used to keep potential fingerers apprised of one's location and near-future plans, but has been turned almost universally to humorous and self-expressive purposes (like a sig block). See also Hacking X for Y. A later innovation in plan files was the introduction of scrolling plan files which are one-dimensional animations made using only the printable ASCII character set, carriage return and line feed, avoiding terminal specific escape sequences, since the finger command will (for security reasons; see letterbomb) not pass the escape character. Scrolling .plan files have become art forms in miniature, and some sites have started competitions to find who can create the longest running, funniest, and most original animations. A compiler (ASP) is available on Usenet for producing them. 1 1 1 1 1 PLANIT Programming LANguage for Interaction and Teaching. CAI language. "PLANIT - A Flexible Language Designed for Computer-Human Interaction", S.L. Feingold, Proc FJCC 31, AFIPS (Fall 1967) Sammet 1969, p.706. 1 1 1 1 1 Plankalkül (Or "Plankalkuel" if you don't have umlauts). The first programming language, designed by Konrad Zuse, ca. 1945. Zuse wrote "Rechenplan allgemeiner Struktur" in 1944 which developed into Plankalkül. Plankalkül included arrays and records and used a style of assignment in which the new value appears on the right. Zuse wrote Plankalkül for his Z3 computer (finished before 1945) and implemented it on there as well. Much of his work may have been either lost or confiscated in the aftermath of World War II. ESR Plankalkül (http://tuxedo.org/~esr/retro/plankalkuel/). ["The Plankalkül of Konrad Zuse", F.L. Bauer et al, CACM 15(7):678-685, Jul 1972]. (2002-05-28) 1 1 1 1 1 PLANNER A language for writing theorem provers by Carl Hewitt <hewitt@ai.mit.edu> MIT 1967. Never fully implemented. CONNIVER was an outgrowth of PLANNER and microPLANNER a subset. PLASMA is a PLANNER-like system modelled on Actors. See also POPLER, QLISP, Scheme. ["PLANNER: A Language for Proving Theorems in Robots", Carl Hewitt, Proc IJCAI-69, Wash DC, May 1969]. 1 1 1 1 1 Planner-73 The original name for PLASMA. 1 1 1 1 1 PLANS Programming Language for Allocation and Network Scheduling. A PL/I preprocessor, used for developing scheduling algorithms. "A User's Guide to the Programming Language for Allocation and Network Scheduling, H.R. Ramsey et al, TR SAI-77-068-DEN," Science Applications Inc (Jun 1977). 1 1 1 1 1 plants ["The Algorithmic Beauty of Plants", Przemyslaw Prusinkiewicz, Aristid Lindenmayer. New York: Springer-Verlag, 1990. 3-54097297-8]. 1 1 1 1 1 PLASMA PLAnner-like System Modelled on Actors. Carl Hewitt, 1975. The first actor language. Originally called Planner-73, and implemented in MacLisp. Lisp-like syntax, but with several kinds of parentheses and brackets. ["A PLASMA Primer", B. Smith et al, AI Lab Working Paper 92, MIT Oct 1975]. ["Viewing Control Structures as Patterns of Passing Messages", C. Hewitt, AI Lab Memo 410, MIT 1976]. 1 1 1 1 1 Plastic Pin Grid Array (PPGA) The package used for certain Intel Celeron processors. PPGA processors fit into Socket 370 motherboard sockets. The Plastic Pin Grid Array packaging is similar to that used on Pentium processors. The silicon core is covered by a heat slug that faces down toward the motherboard. The Celeron 300A to the 533 use a PPGA package. The Celeron 566 onward use a FC-PGA package. Celeron processors are also available in Slot 1 SEPP packaging. (2000-08-26) 1 1 1 1 1 platform Specific computer hardware, as in the phrase platform-independent. It may also refer to a specific combination of hardware and operating system and/or compiler, as in "this program has been ported to several platforms". It is also used to refer to support software for a particular activity, as in "This program provides a platform for research into routing protocols". (1994-12-07) 1 1 1 1 1 Platform for Internet Content Selection (PICS) A standard for metadata associated with web content, originally designed to help parents and teachers control what children access on the Internet, but also used for code signing and privacy. The PICS platform is one on which other rating services and filtering software have been built. (http://w3.org/PICS). (2001-03-29) 1 1 1 1 1 Platform Independent Graphical User Interface (PIGUI) The PIGUI FAQ (ftp://rtfm.mit.edu/pub/usenet/news.answers/portable-GUI-software/). [Summary?] (1994-11-22) 1 1 1 1 1 platinum-iridium A standard, against which all others of the same category are measured. Usage: silly. The notion is that one of whatever it is has actually been cast in platinum-iridium alloy and placed in the vault beside the Standard Kilogram at the International Bureau of Weights and Measures near Paris, as the bar defining the standard metre once was. "This garbage collection algorithm has been tested against the platinum-iridium cons cell in Paris." Compare golden. [Jargon File] (1997-02-20) 1 1 1 1 1 Platon Distributed language based on asynchronous message passing. ["Message Passing Communication Versus Procedure Call Communication", J. Staunstrup, Soft Prac & Exp 12(3):223-234 (Mar 1982)]. ["Platon Reference Manual", S. Soerensen et al, RECAU, U Aarhus, Denmark]. 1 1 1 1 1 PLAY A language for real-time music synthesis. 1977 ["An Introduction to the Play Program", J. Chadabe ete al, Computer Music J 2,1 (1978)]. (1999-06-04) 1 1 1 1 1 play by electronic mail A kind of game where the players use electronic mail to communicate. This may be done via a human moderator or an automatic mailing list exploder on some central machine or it may be fully distributed with each player just addressing his mail to all other players. This is a natural extension of "play by mail" games conducted via snail mail. (http://fermi.clas.virginia.edu/~gl8f/pbm.html). Usenet newsgroup: news:rec.games.pbm. (1994-10-27) 1 1 1 1 1 Playground A visual language for children, developed for Apple's Vivarium Project. OOPSLA 89 or 90? 1 1 1 1 1 Play, Inc. The company which designed and markets Snappy Video Snapshot. (http://play.com). (1997-07-11) 1 1 1 1 1 playpen (IBM) A room where programmers work. Compare salt mines. [Jargon File] 1 1 1 1 1 Playstation The leading family of games consoles, from Sony Corporation consisting of the original Playstation (PS1) and the Playstation 2 (PS2). The basic Playstations consist of a small box containing the processor and a DVD reader, with video outputs to connect to a TV, sockets for two game controllers, and a socket for one or two memory cards. The PS2 also has USB sockets. The PS2 can run PS1 software because the PS2's I/O processor is the same as the PS1's CPU. (http://scea.sony.com/playstation/). FAQ (http://flex.net/users/cjayc/vgfa/system/sony_psx.txt). [Dates? Features?] (2003-07-29) 1 1 1 1 1 playte /playt/ 16 bits, by analogy with byte. Usage: rare and extremely silly. See also dynner, crumb. [Jargon File] (1997-12-03) 1 1 1 1 1 PLC Programmable Logic Controller 1 1 1 1 1 PL/C Programming Language/Cornell 1 1 1 1 1 PL Cornell Programming Language/Cornell 1 1 1 1 1 PLD Programmable Logic Device 1 1 1 1 1 plenum cable Cable that can be (legally) installed in the plenum (the space between a ceiling and the floor above it). Such cable is (usually) teflon-coated so that it will not give off toxic fumes when burned. In some parts of the world such cable is required by law. (1996-08-25) 1 1 1 1 1 pleonasm Redundancy of expression; tautology. (1995-03-25) 1 1 1 1 1 plesiochronous Nearly synchronised, a term describing a communication system where transmitted signals have the same nominal digital rate but are synchronised on different clocks. According to ITU-T standards, corresponding signals are plesiochronous if their significant instants occur at nominally the same rate, with any variation in rate being constrained within specified limits. [Pronunciation? /ples'ee-oh-kroh'nus/?] (1995-03-02) 1 1 1 1 1 Plesiochronous Digital Hierarchy (PDH) A transmission system for voice communication using plesiochronous synchronisation. PDH is the conventional multiplexing technology for network transmission systems. The transmitter adds dummy information bits to allow multiple channels to be bit interleaved. The receiver discards these bits once the signals have been demultiplexed. PDH combines multiple 2 Mb/s (E1) channels in Europe and 1.544 Mb/s (DS1) channels in the US and Japan. PDH is being replaced by SONET and other SDH (Synchronous Digital Hierarchy) schemes. (2003-09-30) 1 1 1 1 1 Pleuk grammar development system A shell for grammar development by Jo Calder <jcalder@cs.sfu.ca>, Kevin Humphreys <kwh@cogsci.ed.ac.uk>, Chris Brew <Chris.Brew@edinburgh.ac.uk>, and Mike Reape <mreape@cs.tcd.ie>. It handles various grammatical formalisms and requires SICStus Prolog version 2.1#6 or later. Latest version: 1.0, as of 1993-06-18. (ftp://ai.uga.edu/ai.natural.language/). E-mail: <pleuk@cogsci.ed.ac.uk>. (2000-07-22) 1 1 1 1 1 Plexus A modular web server written in Perl by Tony Sanders <sanders@earth.com>. Comes with interfaces to allow many other information services to be served via the Web. Version 3.0m 1994-07-22 (ftp://ftp.earth.com/plexus/). (1994-07-22) 1 1 1 1 1 PL/I Programming Language One. An attempt to combine the best features of Fortran, COBOL and ALGOL 60. Developed by George Radin of IBM in 1964. Originally named NPL and Fortran VI. The result is large but elegant. PL/I was one of the first languages to have a formal semantic definition, using the Vienna Definition Language. EPL, a dialect of PL/I, was used to write almost all of the Multics operating system. PL/I is still widely used internally at IBM. The PL/I standard is ANS X3.53-1976. PL/I has no reserved words. Types are fixed, float, complex, character strings with maximum length, bit strings, and label variables. Arrays have lower bounds and may be dynamic. It also has summation, multi-level structures, structure assignment, untyped pointers, side effects and aliasing. Control flow constructs include goto; do-end groups; do-to-by-while-end loops; external procedures; internal nested procedures and blocks; generic procedures 1 1 1 1 1 PL/I-FORMAC A variant of FORMAC. ["The PL/I-FORMAC Interpreter", J. Xenakis, Proc 2nd Symp Symbolic and Algebraic Manip, ACM, Mar 1971]. [Sammet 1969, p. 486]. [Details? Relatonship to PL/I?] (1994-10-25) 1 1 1 1 1 pling exclamation mark. [Does anyone call vertical bar ("|", broken or unbroken) pling?] (1998-09-20) 1 1 1 1 1 plingnet UUCPNET. See also pling. [Jargon File] 1 1 1 1 1 PLisp 1. PostScript Lisp? A Common Lisp translator and programming environment in PostScript by John Peterson <peterson-john@cs.yale.edu>. 2. Pattern LISP. 1990. A pattern-matching rewrite-rule language, optimised for describing syntax translation rules. (See LISP70). 1 1 1 1 1 PL/I SUBSET An early 70's version of PL/I for minicomputers. 1 1 1 1 1 PL/I Subset G ("General Purpose") The commercial PL/I subset, i.e. what was actually implemented by most vendors. ANS X3.74-1981. 1 1 1 1 1 PLITS Programming Language In The Sky. A computational model for concurrency with communication via asynchronous message-passing. ["High Level Programming for Distributed Computing", J.A. Feldman, CACM 22(6):353- 368 (Jun 1979)]. 1 1 1 1 1 PLL phase-locked loop 1 1 1 1 1 PL/M Programming Language/Microcomputers. MAA (later Digital Research) for Intel, 1972. A very low level language incorporating ideas from PL/I, ALGOL and XPL. Integrated macro processor. Originally the implementation language for CP/M. "PL/M-80 Programming Manual", Doc 98-268B, Intel 1976. A Guide to PL/M Programming for Microcomputer Applications, D. McCracken, A-W 1978. Versions: PL/M-80, PL/M-86, PL/M-286. 1 1 1 1 1 PLMK please let me know. (1999-09-27) 1 1 1 1 1 plokta /plok't*/ Press Lots Of Keys To Abort. To press random keys in an attempt to get some response from the system. One might plokta when the abort procedure for a program is not known, or when trying to figure out if the system is just sluggish or really hung. Plokta can also be used while trying to figure out any unknown key sequence for a particular operation. Someone going into "plokta mode" usually places both hands flat on the keyboard and mashes them down, hoping for some useful response. A slightly more directed form of plokta can often be seen in mail messages or Usenet articles from new users - the text might end with ^X^C q quit :q ^C 1 1 1 1 1 plonk (Usually written "*plonk*") The sound a newbie makes as he falls to the bottom of a kill file. In the first of a series of humourous books by Stephen Potter, One-Upmanship (published in 1952) a "plonk" - a pompous bit of misinformation said in a "plonking" tone - was a key feature of his advice on how to "creatively intimidate" someone by making them feel inferior and thereby gain the status of being "one-up" on them. Since these efforts are usually transparently pathetic, the term became widely applied to any idiotic statement. The term appeared on-line in the Usenet newsgroup news:talk.bizarre and, by 1994, was widespread on Usenet and mailing lists as a form of public ridicule. The term may have been influenced by British slang "plonker" for someone behaving stupidly. The expansion "Person with Little Or No Knowledge" may be a backronym. (2012-05-27) 1 1 1 1 1 plotter A device that uses one or more pens that can be raised, lowered and moved over the printing media to draw graphics or text. The heart of the plotter is the printer head assembly, consisting of a horizontal bar and, attached to it, the head assembly holding the pen in use. The pen can be positioned horizontally by moving the pen assembly along the bar. Vertical positioning is achieved by either moving the bar (stationary page plotter) or the paper (rolling page plotter). Combinations of horizontal and vertical movement are used to draw arbitrary lines and curves in a single action, in contrast to printers which usually scan horizontally across the page. Colour plots can be made by using more than one pen. Older plotters required a separate pen for each colour and the pens had to be changed by hand. Modern colour plotters usually use only four pens (cyan, magenta, yellow, and black, see CMYK) 1 1 1 1 1 PL/P Programming Language, Prime. Russ Barbour, PRIME Computer, late 70's. Subset of PL/I used internally for implementation of PRIMOS. (See SPL[4]). 1 1 1 1 1 PL/PROPHET PL/I-like language for the PROPHET system, used by pharmacologists. "The Implementation of the PROPHET System", P.A. Castleman et al, NCC 43, AFIPS (1974). 1 1 1 1 1 PL/S Programming Language/Systems 1 1 1 1 1 PL/Seq Programming Language for Sequences. A DSP language. "A General High Level Language for Signal Processors", J. Skytta & O. Hyvarinen, Digital Signal Processing 84, Proc Intl Conf, Fiorence, Italy, Sep 1984, pp.217-221. 1 1 1 1 1 PL/SQL Procedural Language/SQL 1 1 1 1 1 PLTL Propositional Linear Temporal Logic 1 1 1 1 1 plug and play 1. Hardware or software that, after being installed ("plugged in"), can immediately be used ("played with"), as opposed to hardware or software which requires configuration. See also turnkey, plug and pray. 2. A new recruit who needs no training. "The new guy, John, is great. He's totally plug-and-play." (1997-03-30) 1 1 1 1 1 plug and pray The Windows 95 equivalent of the Macintosh's plug and play, referring to difficulties encountered when setting up new hardware under Windows 95. (1997-10-11) 1 1 1 1 1 Plug Compatible Manufacturer (PCM) A manufacturer of equipment that some other manufacturer's system can identify and work with. The PCM's device replaces the original manufacturer's. Most PCMs competed with IBM. PCM devices normally offer a cost-performance benefit over the original device. For example, several PCM versions of the Direct-Access Storage Device IBM 3350 offered twice the storage and improved data access (dual port). Plug compatible devices include replacement CPUs, such as the Hitachi 7/90 series (which could be substituted for IBM 3090 series processors), I/O subsystems, and dumb terminals like the IBM 3270. [Used outside mainframe market?] (2003-06-24) 1 1 1 1 1 Pluggable Authentication Module (PAM) The new industry standard integrated login framework. PAM is used by system entry components, such as the Common Desktop Environment's dtlogin, to authenticate users logging into a Unix system. It provides pluggability for a variety of system-entry services. PAM's ability to stack authentication modules can be used to integrate login with different authentication mechanisms such as RSA, DCE and Kerberos, and thus unify login mechanisms. PAM can also integrate smart card authentication. White paper (http://gr.osf.org/book/psm-wppr.htm). [OSF-RFC 86.0 V. Samar, R. Schemers, "Unified Login with Pluggable Authentication Modules (PAM)", Oct 1995]. (1997-07-18) 1 1 1 1 1 plugh /ploogh/ A magic word from the ADVENT game. [Jargon File] (1996-04-01) 1 1 1 1 1 plug-in A file containing data used to alter, enhance, or extend the operation of a parent application program. One of the first uses of this term was in Silicon Beach's SuperPaint application (late 1980s?) for the Macintosh. It had a Plug-ins folder containing different tools and effects. The Netscape Navigator web browser supports plug-ins which display or interpret a particular file format or protocol such as Shockwave, RealAudio, Adobe Systems, Inc. PDF, Corel CMX (vector graphics). The file to be displayed is included in a web page using an EMBED HTML tag. Plug-ins, both commercially and indepently authored, can usually be downloaded for free and are stored locally. Plug-ins come in different versions specific to particular operating systems (Microsoft Windows 3.1, 3.2, and Macintosh are available). 1 1 1 1 1 PLUM A compiler for a substantial subset of PL/I for the Univac 1100, from the University of Maryland. ["PL/I Programming with PLUM", M.V. Zelkowitz, Paladin House, 1978]. (1995-02-23) 1 1 1 1 1 Plumber A system for obtaining information about memory leaks in Ada and C programs. (http://home.earthlink.net/~owenomalley/plumber.html). (17 Feb 1999) 1 1 1 1 1 plumbing (Unix) Term used for shell code, so called because of the prevalence of "pipelines" that feed the output of one program to the input of another. Under Unix, user utilities can often be implemented or at least prototyped by a suitable collection of pipelines and temporary file grinding encapsulated in a shell script. This is much less effort than writing C every time, and the capability is considered one of Unix's major winning features. A few other operating systems such as IBM's VM/CMS support similar facilities. The tee utility is specifically designed for plumbing. [Jargon File] (1995-02-23) 1 1 1 1 1 Plural EuLisp EuLisp with parallel extensions. "Collections and Garbage Collection", S.C. Merall et al, in Memory Management - IWMM92, Springer 1992, pp.473-489. 1 1 1 1 1 PLUS Late 60's. Machine-oriented systems language used internally by Univac. 1 1 1 1 1 plus "+", ASCII character 43, 0x2B. The mathematical symbol for the addition operator, also used with the same meaning in arithmetic expressions in nearly all programming languages. Common names: ITU-T: plus; add. Rare: cross; INTERCAL: intersection. In programming, the operator is sometimes overloaded to perform other tasks like concatenating strings. In the C language and its many imitators, the symbol is doubled, as in x++ or "++x" to give an increment operator that adds one to its operand ("x" in this case) and also returns x's previous or resulting value respectively. In a regular expression, "+" means match one or more instances of the previous pattern. Thus /b(an)+a/ would match any of "bana", "banana", "bananana", etc. (see banana problem). (2010-03-20) 1 1 1 1 1 PLUSS Proposition of a Language Useable for Structured Specifications 1 1 1 1 1 ply 1. Of a node in a tree, the number of branches between that node and the root. 2. Of a tree, the maximum ply of any of its nodes. (1998-12-29) 1 1 1 1 1 PM 1. preventive maintenance. 2. Presentation Manager 3. ["PM, A System for Polynomial Manipulations", G.E. Collins, CACM 9(8):578-589 (Aug 1966)]. [Jargon File] 1 1 1 1 1 pm The country code for St. Pierre and Miquelon. (1999-01-27) 1 1 1 1 1 pm2 A software emulator for parallel random access machine (PRAM) and a parallel Modula-2 compiler for the emulator. pm2 programming language is Modula-2/Pascal mixture having extensions for parallel execution in a PRAM. Parallelism is expressed by pardo-loop-structure. Additional features include private/shared variables, two synchronisation strategies, load balancing and parallel dynamic memory allocation. (ftp://cs.joensuu.fi/pub/Software/pram/). E-mail: Simo Juvaste <sjuva@cs.joensuu.fi>. (1997-06-04) 1 1 1 1 1 P-mail Physical mail, as opposed to e-mail. Synonymous with snail-mail. [Jargon File] 1 1 1 1 1 PMBX Private Manual Branch EXchange 1 1 1 1 1 PMC PCI Mezzanine Card 1 1 1 1 1 PML Parallel ML. ["Synchronous Operations as First-Class Values", J.H. Reppy <jhr@research.att.com>, Proc SIGPLAN 88 Conf Prog Lang Design and Impl, June 1988, pp. 250-259]. 1 1 1 1 1 PMP Portable Media Player 1 1 1 1 1 pn The country code for Pitcairn Island. (1999-01-27) 1 1 1 1 1 pnambic /p*-nam'bik/ (From the scene in the film, "The Wizard of Oz" in which the true nature of the wizard is first discovered: "Pay no attention to the man behind the curtain"). A term coined by Daniel Klein <dvk@lonewolf.com> for a stage of development of a process or function that, owing to incomplete implementation or to the complexity of the system, requires human interaction to simulate or replace some or all of its actions, inputs or outputs. The term may also be applied to a process or function whose apparent operations are wholly or partially falsified or one requiring prestidigitization. The ultimate pnambic product was "Dan Bricklin's Demo", a program which supported flashy user-interface design prototyping. There is a related maxim among hackers: "Any sufficiently advanced technology is indistinguishable from a rigged demo." See magic for illumination of this point. 1 1 1 1 1 PNG Portable Network Graphics 1 1 1 1 1 PNP 1. <electronics> A type of bipolar transistor consisting of a layer of N-doped semiconductor (the "base") between two P-doped layers (the "collector" and "emitter"). PNP transistors are commonly operated with the emitter at ground and the collector at a negative voltage. In the 1960s, the germanium PNP transistor was the cheapest and best for use at ordinary temperatures. The leakage current from collector to base in this type of device is larger than for the silicon transistor, and also varies more with temperature. The effect of these deficiencies can be lessened by proper biasing and feedback, which can make the circuit both serviceable and reliable. Neither germanium nor PNP transistors are as common today. The voltages used on a PNP transistor are inverted when compared with vacuum tubes. Further, the behaviour of vacuum tubes is usually described in terms of voltages whereas transistors are better described in terms of 1 1 1 1 1 PNU-Prolog A parallel extension of NU-Prolog, implemented as a preproccessor. (ftp://munnari.oz.au/pub/bebop.tar.Z). 1 1 1 1 1 POA Portable Object Adapter 1 1 1 1 1 PoB Prisoner of Bill 1 1 1 1 1 POC Point Of Contact 1 1 1 1 1 POCAL PETRA Operator's CommAnd Language. 1 1 1 1 1 pocket calculator A small battery-powered digital electronic device for performing simple arithmetic operations on data input on a keypad and outputting the result (usually a single number) to a simple LCD or other display. The most sophisticated programmable calculators are really pocket computers which are limited to handling numerical data only. (1996-12-23) 1 1 1 1 1 pocket computer palmtop 1 1 1 1 1 pod Not to be confused with P.O.D.. 1. <printer> (Allegedly from abbreviation POD for "Prince Of Darkness") A Diablo 630 (or, latterly, any letter-quality impact printer). From the DEC-10 PODTYPE program used to feed formatted text to it. 2. <text> Plain Old Documentation. [Jargon File] (1998-12-18) 1 1 1 1 1 P.O.D. Piece Of Data (as opposed to code). [Jargon File] (2000-04-08) 1 1 1 1 1 podcast Any series of audio files that can be downloaded from the Internet, often released on some regular schedule, e.g. daily or weekly. Podcasts are named after Apple Computer, Inc.'s iPod portable audio players, though most podcasts are in MP3 format and so can be played on virtually any modern audio player. (2009-12-16) 1 1 1 1 1 POE PowerOpen Environment 1 1 1 1 1 POFAC A subset of Fortran. [Mentioned in Machine Oriented Higher Level Languages, W. van der Poel, N-H 1974, p. 273]. ["POFAC Description", R. Haentjens, Report 19, Cenre d'Information, Ecole Royale Militaire, Brussels, 1973]. (1994-10-20) 1 1 1 1 1 POFOD Probability of Failure on Demand 1 1 1 1 1 POGO Early system on G-15. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 point 1. <unit, text> (Sometimes abbreviated "pt") The unit of length used in typography to specify text character height, rule width, and other small measurements. There are six slightly different definitions: Truchet point, Didot point, ATA point, TeX point, Postscript point, and IN point. In Europe, the most commonly used is Didot and in the US, the formerly standard ATA point has essentially been replaced by the PostScript point due to the demise of traditional typesetting systems and rise of desktop computer based systems running software such as QuarkXPress, Adobe InDesign and Adobe Pagemaker. There are 20 twips in a point and 12 points in a pica (known as a "Cicero" in the Didot system). Different point systems (http://vakcer.com/oberon/dtp/fonts/point.htm). (2004-12-23) 1 1 1 1 1 point-and-drool interface (Or "point-and-grunt interface") A parody of point-and-shoot interface, describing a windows, icons, and mouse-based (WIMP) graphical user interface. The implication, of course, is that such an interface is only suitable for idiots. See for the rest of us, WIMP, drool-proof paper. [Jargon File] (2000-08-08) 1 1 1 1 1 point-and-grunt interface point-and-drool interface 1 1 1 1 1 pointed domain In most formulations of domain theory, a domain is defined to have a bottom element and algebraic CPOs without bottoms are called "predomains". David Schmidt's domains do not have this requirement and he calls a domain with a bottom "pointed". (1999-07-07) 1 1 1 1 1 pointer 1. <programming> An address, from the point of view of a programming language. A pointer may be typed, with its type indicating the type of data to which it points. The terms "pointer" and "reference" are generally interchangeable although particular programming languages often differentiate these two in subtle ways. For example, Perl always calls them references, never pointers. Conversely, in C, "pointer" is used, although "a reference" is often used to denote the concept that a pointer implements. Anthony Hoare once said: Pointers are like jumps, leading wildly from one part of the data structure to another. Their introduction into high-level languages has been a step backward from which we may never recover. [C.A.R.Hoare "Hints on Programming Language Design", 1973, Prentice-Hall collection of essays and papers by Tony Hoare]. 2. <operating system> (Or "mouse pointer") An icon, usually 1 1 1 1 1 pointer swizzling swizzle 1 1 1 1 1 pointing device Any hardware component that allows a user to input spatial data to a computer. CAD systems and Graphical User Interfaces (GUI) allow the user to control and provide data to the computer using physical "gestures" - point, click, and drag - typically by moving a hand-held mouse across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on a graphical representation of a desktop on the screen by movements of the mouse pointer and other visual changes. While the most common pointing device by far is a mouse, other kinds include tracker ball, trackpad, lightpen, various kinds of digitising tablets which use a stylus, and even a special "data glove" that translates the user's movements to computer gestures. (1997-02-03) 1 1 1 1 1 pointing stick TrackPoint 1 1 1 1 1 Point Of Contact (POC) An individual associated with a particular Internet entity (IP network, domain, ASN). (1998-09-07) 1 1 1 1 1 point of presence (PoP) A site where there exists a collection of telecommunications equipment, usually modems, digital leased lines and multi-protocol routers. An Internet access provider may operate several PoPs distributed throughout their area of operation to increase the chance that their subscribers will be able to reach one with a local telephone call. The alternative is for them to use virtual PoPs (virtual points of presence) via some third party. (1994-12-13) 1 1 1 1 1 point of sale terminal (Or "POS") A computer, probably with a bar code reader, serving as a glorified cash register. (1997-11-23) 1 1 1 1 1 Point-to-Point Protocol (PPP) The protocol defined in RFC 1661, the Internet standard for transmitting network layer datagrams (e.g. IP packets) over serial point-to-point links. PPP has a number of advantages over SLIP; it is designed to operate both over asynchronous connections and bit-oriented synchronous systems, it can configure connections to a remote network dynamically, and test that the link is usable. PPP can be configured to encapsulate different network layer protocols (such as IP, IPX, or AppleTalk) by using the appropriate Network Control Protocol (NCP). RFC 1220 describes how PPP can be used with remote bridging. Usenet newsgroup: news:comp.protocols.ppp. A paper on PPP (ftp://ftp.uu.net/vendor/MorningStar/papers/sug91-cheapIP.ps.Z). (1994-12-13) 1 1 1 1 1 Point-to-Point Protocol over ATM (PPPoA) A network protocol for encapsulating PPP frames in ATM AAL5. It is used mainly with cable modem, DSL and ADSL services. PPPoA offers standard PPP features such as authentication, encryption, and compression. It is very slightly more efficient than PPPoE and, like PPPoE, supports VC-MUX and LLC encapsulation. PPPoA is specified in RFC 2364. (2007-06-15) 1 1 1 1 1 Point-to-Point Protocol over Ethernet (PPPoE) The protocol defined in RFC 2516 that allows one or more computers to connect to the Internet via a shared modem. The computers connect to the modem via a local area network such as Ethernet and the modem connects to an Internet Service Provider (ISP) via a serial connection such as PPP over ADSL. PPPoE provides each user with a connection that looks and behaves like a point-to-point dial-up connection even though they are actually sharing an Ethernet or wireless network. At the same time, the ISP only needs to provide a single Internet connection, with the same kind of accounting as for PPP. Also, the IP address is only assigned when the PPPoE connection is open, allowing the dynamic reuse of IP addresses via DHCP. PPPoE works by encapsulating PPP frames in Ethernet frames. (2006-09-20) 1 1 1 1 1 Point-to-Point Tunneling Protocol (PPTP) A tunneling protocol for connecting Windows NT clients and servers over Remote Access Services (RAS). PPTP can be used to create a Virtual Private Network between computers running NT. It is an extension of PPP sponsored by Microsoft. Microsoft Point to Point Encryption may be used with PPTP to provide an encrypted connection but PPTP itself does not use encryption. Compare: Layer Two Tunneling Protocol. [Origin? Standard? Document?] (1998-09-23) 1 1 1 1 1 Poisson distribution A probability distribution used to describe the occurrence of unlikely events in a large number of independent trials. Poisson distributions are often used in building simulated user loads. [Formula?] (2003-03-18) 1 1 1 1 1 POJO Plain Old Java Object [As opposed to?] 1 1 1 1 1 poke The BASIC command to write a value to an absolute address. See peek. [Jargon File] (1995-01-31) 1 1 1 1 1 Pokémon exception handling A humourous term for a try-catch exception handling construct with no constraint on which exceptions will be caught, for when you just "Gotta Catch 'Em All." (a slogan used in the Pokémon media empire). Pokémon is a trademark of the Pokémon Company of Japan. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-07-10) 1 1 1 1 1 Polka An object-oriented parallel logic programming language, built on top of Parlog. ["Polka: A Parlog Object-Oriented Language", Andrew Davison, TR, Parlog Group, Imperial College, London 1988]. (1995-01-31) 1 1 1 1 1 poll To check the status of an input line, sensor, or memory location to see if a particular external event has been registered. Contrast interrupt. [Jargon File] (1995-01-31) 1 1 1 1 1 polling poll 1 1 1 1 1 Poly 1. A polymorphic, block-structured language developed by D.C.J. Matthews at Cambridge in the early 1980s. ["An Overview of the Poly Programming Language", D.C.J. Matthews, in Data Types and Persistence, M.P. Atkinson et al eds, Springer 1988]. 2. A language developed at St Andrews University, Scotland. [Software Practice & Exp, Oct 1986]. 3. A polymorphic language used in the referenced book. ["Polymorphic Programming Languages", David M. Harland, Ellis Horwood 1984]. (2000-11-07) 1 1 1 1 1 polygon pusher (Or "rectangle slinger"). A chip designer who spends most of his or her time at the physical layout level (which requires drawing *lots* of multi-coloured polygons). [Jargon File] 1 1 1 1 1 POLYGOTH A distributed language integrating classes with a parallel block structure, including multiprocedures and fragments. ["Operational Semantics of a Distributed Object-Oriented Language and its Z Formal Specification", M. Benveniste <mbenveni@irisa.irisa.fr>, TR532, IRISA/INRIA-Rennes]. (1995-10-17) 1 1 1 1 1 polylithism A property of a data-object that can exist in many shapes and sizes, but not simultaneously; which distinguishes it from a union. It is often implemented as a set of classes (or structs) derived from a common base class (or with a common header, as in the case of structs), typically without any methods. It has been loosely described as polymorphic data. [Clarification?] (1996-01-07) 1 1 1 1 1 Poly/ML SML implemented in D.C.J. Matthews's Poly, for Motorola 68020 and SPARC by Abstract Hardware Ltd. (1999-11-23) 1 1 1 1 1 polymorphic polymorphism 1 1 1 1 1 polymorphic lambda-calculus (Or "second order typed lambda-calculus", System F, "Lambda-2"). An extension of typed lambda-calculus allowing functions which take types as parameters. E.g. the polymorphic function "twice" may be written: twice = /\ t . \ (f :: t -> t) . \ (x :: t) . f (f x) (where "/\" is an upper case Greek lambda and "(v :: T)" is usually written as v with subscript T). The parameter t will be bound to the type to which twice is applied, e.g.: twice Int takes and returns a function of type Int -> Int. (Actual type arguments are often written in square brackets [ ]). Function twice itself has a higher type: twice :: Delta t . (t -> t) -> (t -> t) 1 1 1 1 1 polymorphism The ability to leave parts of a type in a typed language unspecified. The term has three distinct uses: * Parametric polymorphism refers to the use of type variables in a strongly typed language. * Overloading, sometimes called ad-hoc polymorphism, means using the same syntax for different types. * object-orientated polymorphism allows a variable to refer to objects whose class is not known at compile time. (2014-01-05) 1 1 1 1 1 polynomial 1. <mathematics> An arithmetic expression composed by summing multiples of powers of some variable. P(x) = sum a_i x^i for i = 0 .. N The multipliers, a_i, are known as "coefficients" and N, the highest power of x with a non-zero coefficient, is known as the "degree" of the polynomial. If N=0 then P(x) is constant, if N=1, P(x) is linear in x. N=2 gives a "quadratic" and N=3, a "cubic". 2. <complexity> polynomial-time. 1 1 1 1 1 polynomial-time (P) The set or property of problems which can be solved by a known polynomial-time algorithm. (1995-04-10) 1 1 1 1 1 polynomial-time algorithm A known algorithm (or Turing Machine) that is guaranteed to terminate within a number of steps which is a polynomial function of the size of the problem. See also computational complexity, exponential time, nondeterministic polynomial-time (NP), NP-complete. (1995-04-13) 1 1 1 1 1 polyvinyl chloride (PVC) A common plastic used for insulating and jacketing many wire and cable products. (2001-03-26) 1 1 1 1 1 POM phase of the moon Usually used in the phrase "POM-dependent", which means flaky. (1995-04-10) 1 1 1 1 1 Ponder A non-strict polymorphic, functional language by Jon Fairbairn <jf@cl.cam.ac.uk>. Ponder's type system is unusual. It is more powerful than the Hindley-Milner type system used by ML and Miranda and extended by Haskell. Ponder adds extra recursive 'mu' types to those of Girard's System F, allowing more general recursion. Surprisingly, the type system and type inference algorithm are still not completely understood. ["Ponder and its Type System", J. Fairbairn, TR 31, Cambridge U Computer Lab, Nov 1982]. [J. Fairbairn, "Design and Implementation of a Simple Typed Language based on the Lambda-Calculus", Technical Report No. 75, Computer Laboratory, University of Cambridge, May 1985]. [J. Fairbairn, "A New Type-Checker for a Functional Language", Technical Report No. 53, Computer Laboratory, University of Cambridge, 1984]. 1 1 1 1 1 Pong A computer game invented in 1972 by Atari's Nolan Bushnell. The game is a minimalist rendering of table tennis. Each of the two players are represented as a white slab, controllable by a knob, which deflects a bouncing ball. The goal of the game is to "AVOID MISSING BALL FOR HIGH SCORE". Yahoo (http://yahoo.com/Recreation/Games/Video_Games/Classic_Arcade_Games/Titles/Pong/). (1997-11-23) 1 1 1 1 1 POOL Parallel Object-Oriented Language. A series of languages from Philips Research Labs. See POOL2, POOL-I, POOL-T. (1995-02-07) 1 1 1 1 1 POOL2 Parallel Object-Oriented Language 2. Philips Research Labs, 1987. Strongly typed, synchronous message passing, designed to run on DOOM (DOOM = Decentralised Object-Oriented Machine). ["POOL and DOOM: The Object- Oriented Approach", J.K. Annot, PAM den Haan, in Parallel Computers, Object-Oriented, Functional and Logic, P. Treleaven ed]. ["Issues in the Design of a Parallel Object-Oriented Language", P. America, Formal Aspects of Computing 1(4):366-411 (1989)]. (1995-02-07) 1 1 1 1 1 POOL-I One of the POOL languages. ["A Parallel Object-Oriented Language with Inheritance and Subtyping", P. America et al, SIGPLAN Notices 25(10):161-168 (OOPSLA/ECOOP '90) (Oct 1990)]. (1995-02-07) 1 1 1 1 1 Pooling Agreement for Technical Assistance (PATA) Written limitations on what types of technical information is shared when two companies (or departments) work together on a common project. Often because of security concerns rather than marketing concerns. (2010-02-20) 1 1 1 1 1 POOL-T Object-oriented, concurrent, synchronous. Predecessor of POOL2. ["Definition of the Programming Language POOL-T", Esprit Project 415, Doc. 0091, Philips Research Labs, Eindhoven, Netherlands, June 1985]. (1995-02-07) 1 1 1 1 1 POP 1. <language> A family of programming languages, POP-1, POP-2, POP-10, Pop-11, POP++, POP-9X, POPLOG. 2. Post Office Protocol. See also pop, PoP. [Jargon File] (1996-02-18) 1 1 1 1 1 PoP Point Of Presence 1 1 1 1 1 pop To remove something from the top of a stack. Opposite of push. (Not to be confused with Post Office Protocol or POP-1 the language). [Jargon File] (1996-02-18) 1 1 1 1 1 POP++ An object-oriented extension of POPLOG. Available from Integral Solutions. [Jargon File] 1 1 1 1 1 POP-1 Package for Online Programming. Edinburgh, 1966. First of the POP family of languages. Used reverse Polish notation. Implemented as a threaded interpreter. EPU-R-17, U Edinburgh (Jul 1966). "POP-1: An Online Language", R. Popplestone, Mach Intell 2, E. Dale et al eds, Oliver and Boyd, Edinburgh 1968. 1 1 1 1 1 POP-10 Descendant of POP-2, for the PDP-10 by Julian Davies, 1973. ["POP-10 User's Manual", D.J.M. Davies, CS R25, U West Ontario, 1976]. 1 1 1 1 1 Pop-11 A programming language created by Robin Popplestone in 1975, originally for the PDP-11. Pop-11 is stack-oriented, extensible, and efficient like FORTH. It is also functional, dynamically typed, interactive, with garbage collection like LISP, and the syntax is block structured like Pascal. ["Programming in POP-11", J. Laventhol <jcl@deshaw.com>, Blackwell 1987]. AlphaPop is an implementation for the Macintosh from Computable Functions Inc. PopTalk and POPLOG from the University of Sussex are available for VAX/VMS and most workstations. E-mail: Robin Popplestone <pop@cs.umass.edu> (2003-03-25) 1 1 1 1 1 POP-2 Robin POPplestone, Edinburgh, 1967. An innovative language incorporating many of Landin's ideas, including streams, closures, and functions as first-class citizens. ALGOL-like syntax. The first implementation was named Multi-POP, based on a REVPOL function written in POP-1, producing the reverse-polish form as output. "POP-2 Papers", R.M. Burstall et al, Oliver & Boyd 1968. "Programming in POP-2", R.M. Burstall et al, Edinburgh U Press 1971. "POP-2 User's Manual", R. Popplestone, Mach Intell 2, E. Dale et al eds, Oliver and Boyd, Edinburgh 1968. 1 1 1 1 1 POP3 Version 3 of the Post Office Protocol. POP3 is defined in RFC 1081, written in November 1988 by Marshall Rose, which is based on RFC 918 (since revised as RFC 937). POP3 allows a client computer to retrieve electronic mail from a POP3 server via a (temporary) TCP/IP or other[?] connection. It does not provide for sending mail, which is assumed to be done via SMTP or some other method. POP is useful for computers, e.g. mobile or home computers, without a permanent network connection which therefore require a "post office" (the POP server) to hold their mail until they can retrieve it. Although similar in form to the original POP proposed for the Internet community, POP3 is similar in spirit to the ideas investigated by the MZnet project at the University of California, Irvine, and is incompatible with earlier versions of POP. Substantial work was done on examining POP in a PC-based 1 1 1 1 1 POP-9X Proposed BSI standard for Pop-11. 1 1 1 1 1 POPART A grammar-driven programming environment generator. Uses Paddle. ["POPART: Producer of Paddles and Related Tools, System Builders' Manual", D.S. Wile TR RR-82-21, ISI, Marina del Rey, CA 1982]. (1994-11-30) 1 1 1 1 1 POPCORN AI system built on POP-2. "The POPCORN Reference Manual", S. Hardy, Essex U, Colchester, 1973. 1 1 1 1 1 pop-down menu pull-down menu 1 1 1 1 1 POPJ /pop'J/ [PDP-10 return-from-subroutine instruction]. To return from a digression. By verb doubling, "Popj, popj" means roughly "Now let's see, where were we?" See RTI. [Jargon File] 1 1 1 1 1 Poplar Morris, 1978. A blend of LISP with SNOBOL4 pattern matching and APL-like postfix syntax. Implicit iteration over lists, sorting primitive. "Experience with an Applicative String-Processing Language", J.H. Morris et al, 7th POPL, ACM 1980, pp.32-46. 1 1 1 1 1 POPLER A PLANNER-type language for the POP-2 environment. ["Popler 1.6 Reference Manual", D. Davies et al, U Edinburgh, TPU Report No 1 (May 1973)]. 1 1 1 1 1 POPLOG A multi-language programming environment, which includes the languages Pop-11, ML, Common Lisp and Prolog. It supports mixed-language programming and incremental compilation and includes a comprehensive X Window System interface. It is built on top of a two-stack virtual machine, PVM. POPLOG was developed at the University of Sussex, Brighton, UK. ["POPLOG's Two-Level Virtual Machine Support for Interactive Languages", R. Smith et al, in Research Directions in Cognitive Science, v.5 (1992)]. 1 1 1 1 1 POPLOG ML SML for the Poplog system from the University of Sussex, UK. 1 1 1 1 1 POP server Post Office Protocol 1 1 1 1 1 PopTalk A commercial object-oriented derivative of POP, from Cambridge Consultants, used in the expert system MUSE. (1995-02-27) 1 1 1 1 1 POR power-on reset 1 1 1 1 1 porn pornography 1 1 1 1 1 porno pornography 1 1 1 1 1 pornography Still and moving images, usually of women, in varying states of nudity, posing or performing erotic acts with men, women, animals, machines, or other props. Some say it degrades women, some say it corrupts young boys (who down-load it from the web or exchange it on floppy disks). Most of it is in the form of JPEG images. Many websites offer porn of all sorts, almost always for a subscription. It is said that these are a driving force in the evolution of new technology and techniques for the web. Advertisments for them certainly constitute a significant proportion of all spam. There are even pornographic computer games, an early example being Mac Playmate. Beware - many institutions, particularly universities, have strict rules against their computers and networks being used to transfer or store such things, and you might get corrupted. (2002-03-08) 1 1 1 1 1 port 1. <networking> A logical channel or channel endpoint in a communications system. The Transmission Control Protocol and User Datagram Protocol transport layer protocols used on Ethernet use port numbers to distinguish between (demultiplex) different logical channels on the same network interface on a computer. Each application program has a unique port number associated with it, defined in /etc/services or the Network Information Service "services" database. Some protocols, e.g. telnet and HTTP (which is actually a special form of telnet) have default ports specified as above but can use other ports as well. Some port numbers are defined in RFC 3232 (which replaces RFC 1700). Ports are now divided into: "Well Known" or Privileged, and "Ephemeral" or "Unprivileged" (comprising Registered, "Dynamic", "Private"). (2004-12-30) 1 1 1 1 1 portability The ease with which a piece of software (or file format) can be "ported", i.e. made to run on a new platform and/or compile with a new compiler. The most important factor is the language in which the software is written and the most portable language is almost certainly C (though see Vaxocentrism for counterexamples). This is true in the sense that C compilers are available for most systems and are often the first compiler provided for a new system. This has led several compiler writers to compile other languages to C code in order to benefit from its portability (as well as the quality of compilers available for it). The least portable type of language is obviously assembly code since it is specific to one particular (family of) processor(s). It may be possible to translate mechanically from one assembly code (or even machine code) into another but this is not really portability. At the other end of the 1 1 1 1 1 portable portability 1 1 1 1 1 Portable AIRTIME A wireless, digital communications system enabling user-to-user voice communication, quicknotes, and alphanumeric messaging. [Details?] (2000-12-07) 1 1 1 1 1 Portable Commodore 64 A version of the Commodore 64 modelled after the original Osborne portable PCs, with a flip-down keyboard that revealed a 5-inch colour monitor, and a built-in 1541 floppy disk drive. It is thought that few were made but that they did go on sale, at least in Canada. [Relationship to Commodore 65?] (1997-09-14) 1 1 1 1 1 Portable Common Loops (PCL) A language which started out as an implementation of CommonLoops and turned into a portable CLOS implementation. Version 1992-08-28. It runs under Lucid Common LISP 4.0.1 and CMU Common LISP 16e. (ftp://parcftp.xerox.com/pcl). (1992-09-02) [Was it developed by Richard Harris <rharris@ptolemy2.rdrc.rpi.edu>?] 1 1 1 1 1 Portable Common Tool Environment (PCTE) An ECMA standard framework for software tools developed in the Esprit programme. It is based on an entity-relationship Object Management System and defines the way in which tools access this. (2001-03-03) 1 1 1 1 1 portable computer (Commonly, "laptop") A portable personal computer you can carry with one hand. Some laptops run so hot that it would be quite uncomforable to actually use them on your lap for long. The term "notebook" is often used to describe these, though it also implies a low weight (less than 2kg). A luggable is one you could carry in one hand but is so heavy you wouldn't want to. One that can by easily operated while held in one hand is a "palmtop". The computer considered by most historians to be the first true portable computer was the Osborne 1 but see the link below for other contenders. History of laptop computers (http://inventors.about.com/library/inventors/bllaptop.htm). (2007-05-21) 1 1 1 1 1 Portable Document Format (PDF) The native file format for Adobe Systems' Acrobat. PDF is the file format for representing documents in a manner that is independent of the original application software, hardware, and operating system used to create those documents. A PDF file can describe documents containing any combination of text, graphics, and images in a device-independent and resolution independent format. These documents can be one page or thousands of pages, very simple or extremely complex with a rich use of fonts, graphics, colour, and images. (http://adobe.com/products/acrobat/adobepdf.html). ["The Portable Document Format Reference Manual", Adobe systems, Inc. Addison-Wesley Publ. Co., ISBN: 0-201-62628-4]. (2000-09-08) 1 1 1 1 1 Portable Forth Environment (PFE) A highly portable Forth development system based on the ANSI standard for Forth, by Dirk-Uwe Zoller of FHT, Mannheim, Germany. PFE aims to be correct, complete, usable, and simple but it isn't optimised for speed. It supports all dpANS word sets. It runs on Linux, RS/6000, and HP-UX. Tektronix adopted PFE in 1998 and added modules and multithreading. You can load additional C objects at run time to extend the Forth dictionary. It can be targeted at different embedded environments by changing the terminal driver and initilisation routines. Latest version: 0.30.27 preview, as of 2000-11-23. (http://pfe.sourceforge.net/). E-mail: Guido Draheim <guidod@gmx.de>. (2000-12-07) 1 1 1 1 1 Portable Network Graphics /ping/ (PNG) An extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. Indexed-colour, greyscale and truecolour images are supported, plus an optional alpha channel. Sample depths range from 1 to 16 bits. PNG is designed for on-line viewing applications, such as the World Wide Web, so it is fully streamable with a progressive display option. PNG is robust, providing both full file integrity checking and simple detection of common transmission errors. Also, PNG can store gamma correction and chromaticity data for improved colour matching on heterogeneous platforms. Filename extension: .png. RFC 2083. W3C PNG pages (http://w3.org/Graphics/PNG/). PNG home page 1 1 1 1 1 Portable Object Adapter (POA) Part of the CORBA architecture. [Details?] (2004-06-23) 1 1 1 1 1 Portable Operating System Interface (POSIX) A set of IEEE standards designed to provide application portability between Unix variants. IEEE 1003.1 defines a Unix-like operating system interface, IEEE 1003.2 defines the shell and utilities and IEEE 1003.4 defines real-time extensions. ["More UNIX For Dummies", ISBN: 1-56884-361-5] says it stands for "Portable Operating System Interface with an X thrown in to make it sound cooler." (1997-12-04) 1 1 1 1 1 Portable Pixmap (PPM) A colour image file format. A PPM file contains the following: a two character "magic number" - "P3", the width in pixels, the height in pixels, the maximum colour component value, HEIGHT rows of WIDTH pixels. The rows are ordered from top to bottom with the pixels in each row ordered from left to right. Each pixel is represented as three values for red, green, and blue. All parts are separated by whitespace and numbers are in decimal ASCIII representation. A zero pixel component means that colour is absent. Characters from a "#" to the next end-of-line are ignored and no line should be longer than 70 characters. Here is an example of a small pixmap in this format: P3 1 1 1 1 1 Portable Scheme Debugger (PSD) A package for source code debugging of R4RS-compliant Scheme under GNU Emacs by Kellom ?ki Pertti <pk@cs.tut.fi>. Version 1.1. Distributed under GNU GPL. It works with scm, Elk and Scheme->C. (ftp://ftp.cs.tut.fi/pub/src/languages/schemes/psd.tar.Z). (1992-10-08) 1 1 1 1 1 Portable Scheme Interpreter (PSI) A portable scheme interpreter by Ozan Yigit <oz@ursa.sis.yorku.ca>, David Keldsen and Pontus Hedman that includes a simple DAG compiler and a virtual machine. It can be used as an integrated extension interpreter in other systems and allows easy addition of new primitives. There are some unique debugging and tracing facilities. Acceptable performance results from a fairly straight-forward implementation. Continuations are fully and portably supported and perform well. PSI is based on the simple compilers and virtual machine in Kent Dbyvig's thesis. The pre-release version conforms to R4RS with a number of useful extensions. (1993-02-19) 1 1 1 1 1 Portable Standard Lisp (PSL) A dialect of Lisp from Utah University. PSL is available as a kit for 68000 and also runs on VAX. It compiles Lisp to C-code virtual machine language. ["The Portable Standard LISP Users Manual", TR-10, CS Dept, U Utah, Jan 1982]. ["A Portable Lisp System", M.L. Griss et al, Proc 1982 ACM Symp on Lisp and Functional Prog, Aug 1982]. (2000-09-25) 1 1 1 1 1 Portable Tool Interface (PTI) A standard such as PCTE, allowing interworking between different software tools via defined interfaces to the user and to the repository or object management system. (2000-09-25) 1 1 1 1 1 Port Address Translation (PAT) A function provided by some routers which allows hosts on a LAN to communicate with the rest of a network (such as the Internet) without revealing their own private IP address. All outbound packets have their IP address translated to the routers external IP address. Replies come back to the router which then translates them back into the private IP address of the original host for final delivery. Compare SOCKS. (1998-05-08) 1 1 1 1 1 PORTAL Process-Oriented Real-Time Algorithmic Language. ["PORTAL - A Pascal-based Real-Time Programming Language", R. Schild in Algorithmic Languages, J.W. deBakker et al eds, N-H 1981]. 1 1 1 1 1 portal A website that aims to be an entry point to the web, typically offering a search engine and/or links to useful pages, and possibly news or other services. These services are usually provided for free in the hope that users will make the site their default home page or at least visit it often. Popular examples are Yahoo and MSN. Most portals on the Internet exist to generate advertising income for their owners, others may be focused on a specific group of users and may be part of an intranet or extranet. Some may just concentrate on one particular subject, say technology or medicine, and are known as a vertical portals. (2001-07-07) 1 1 1 1 1 porting Translating software to run on a different computer and/or operating system. (1995-01-06) 1 1 1 1 1 Port Language ["Communicating Parallel Processes", J. Kerridge et al, Soft Prac & Exp 16(1):63-86 (Jan 1986)]. 1 1 1 1 1 portmapper A server that converts TCP/IP protocol port numbers into RPC program numbers. It must be running in order to make RPC calls. When an RPC server starts, it tells portmap the port number it is listening on and what RPC program numbers it serves. Before a client can call a given RPC program number, it must contacts portmap on the server machine to determine the port number to which RPC packets should be sent. (1996-12-09) 1 1 1 1 1 port number port 1 1 1 1 1 POS point of sale 1 1 1 1 1 POSE language A query language written in 1967. ["POSE: A Language for Posing Problems to Computers", S. Schlesinger et al, CACM 10:279-285, May 1967]. (1996-12-09) 1 1 1 1 1 poset partially ordered set 1 1 1 1 1 positional representation The conventional way of writing numbers as a string of digits in which each digit, D, has value D * R^I, where R is the radix or (number) base and I is the digit's position counting leftward from zero at the least significant (right-hand) end. Each digit can be zero to R-1. Each position has a weight or significance R times greater than the position to its right and the right-most place has a weight of one. Decimal numbers are radix ten, binary numbers are radix two, octal radix eight and hexadecimal radix 16. Positional representation makes arithmetic operations on large numbers much easier than, say, roman numerals. It is fundamental to the binary representation used by digital computers. (2006-11-10) 1 1 1 1 1 POSIX Portable Operating System Interface 1 1 1 1 1 POSIX Threads (Pthreads) A POSIX standard API that defines a set of C programming language types, functions and constants for creating and manipulating pre-emptive threads. The standard's full name is "POSIX.1c, Threads extensions (IEEE Std 1003.1c-1995)". Implementations are available on many Unix-like POSIX-conformant operating systems such as FreeBSD, NetBSD, OpenBSD, GNU/Linux, Mac OS X and Solaris as well as DR-DOS and Microsoft Windows. Pthreads was designed and implemented in the PART Project (POSIX / Ada-Runtime Project). (2012-04-18) 1 1 1 1 1 POST power-on self-test 1 1 1 1 1 post To send a message to a mailing list or newsgroup. Usually implies that the message is sent indiscriminately to multiple users, in contrast to "mail" which implies one or more deliberately selected individual recipients. You should only post a message if you think it will be of interest to a significant proportion of the readers of the group or list, otherwise you should use private electronic mail instead. See netiquette. [Jargon File] (1997-12-04) 1 1 1 1 1 postcardware Shareware that borders on freeware, in that the author requests only that satisfied users send a postcard of their home town or something. (This practice, silly as it might seem, serves to remind users that they are otherwise getting something for nothing, and may also be psychologically related to real estate "sales" in which $1 changes hands just to keep the transaction from being a gift.) [Jargon File] 1 1 1 1 1 posted write-through A cache with a posted write-through policy (e.g. Intel 80386) delays the write-back to main memory until the bus is not in use. 1 1 1 1 1 Postel, Jon Jon Postel 1 1 1 1 1 postfix notation (Or "Reverse Polish Notation", RPN) One of the possible orderings of functions and operands: in postfix notation the functions are preceded by all their operands. For example, what may normally be written as "1+2" becomes "1 2 +". Postfix notation is well suited for stack based architectures but modern compilers reduced this advantage considerably. The best-known language with postfix syntax is FORTH. Some Hewlett-Packard calculators use it, e.g. HP-25, HP-29C, HP-41C, HP-23SII. Compare: infix notation, prefix notation. (2003-06-23) 1 1 1 1 1 postfix syntax postfix notation 1 1 1 1 1 POSTGRES An active DBMS developed at the University of California at Berkeley by a team led by Michael Stonebraker (1986-1994). Postgres was later taken by Illustra and developed into a commercial product, which in turn was bought by Informix and integrated into their product, Universal Server. PostgreSQL is a further development of the original POSTGRES code as a free software alternative to commercial DBMS vendor offerings. [Details? Reference? Relationship to Ingres?] (1999-07-04) 1 1 1 1 1 PostgreSQL /'post-gres-kyu-el/ An enhancement of the POSTGRES database system. PostgreSQL is an advanced relational database management system with some object oriented approaches. PostgreSQL is developed and distributed as free software, and while retaining its freedom it remains technically and featurewise a worthy competitor to even the most advanced commercial alternatives. It was also one of the first databases to offer MVCC as opposed to row-level locking or table locking, thereby greatly improving multi-user performance. PostgreSQL implements an extended subset of ANSI SQL and runs on many platforms. It also has interfaces to many different programming languages and database protocols, like ODBC and JDBC. (http://postgresql.org/). (1999-09-18) 1 1 1 1 1 posting A message sent to a newsgroup or mailing list (may also be called "a post") or the act of sending it. Distinguished from a "letter" or ordinary electronic mail message by the fact that it is broadcast rather than point-to-point. It is not clear whether messages sent to a small mailing list are postings or e-mail; perhaps the best dividing line is that if you don't know the names of all the potential recipients, it is a posting. [Jargon File] 1 1 1 1 1 postmaster The electronic mail contact and maintenance person at a site connected to the Internet or UUCPNET. Often, but not always, the same as the admin. The Internet standard for electronic mail (RFC 822) requires each machine to have a postmaster address; usually it is aliased to this person. See also webmaster. 1 1 1 1 1 post office problem Given a set of points (in N dimensions), find another point which minimises the sum of the distances from that point to each of the others. (2007-03-07) 1 1 1 1 1 Post Office Protocol (POP) A protocol designed to allow single-user computers to retrieve electronic mail from a POP server via TCP/IP. The default port is 110. The POP server might be a computer with a permanent Internet connection whereas its clients might only connect to it occasionally, e.g. by modem. There are (in 1994) three versions: POP, POP2, and POP3. Later versions are NOT compatible with earlier ones. [Details?] (2007-03-07) 1 1 1 1 1 post-order traversal traversal 1 1 1 1 1 POSTQUEL POSTGRES QUERy Language. The language used by the POSTGRES database system. ["The Design of POSTGRES", M. Stonebraker et al, Proc ACM SIGMOD Conf, June 1986]. Version 4.0 (ftp://postgres.berkeley.edu/pub/postgresv4r0.tar.Z). 1 1 1 1 1 PostScript A page description language based on work originally done by John Gaffney at Evans and Sutherland in 1976, evolving through "JaM" ("John and Martin", Martin Newell) at XEROX PARC, and finally implemented in its current form by John Warnock et al. after he and Chuck Geschke founded Adobe Systems, Inc. in 1982. PostScript is an interpreted, stack-based language (like FORTH). It was used as a page description language by the Apple LaserWriter, and now many laser printers and on-screen graphics systems. Its primary application is to describe the appearance of text, graphical shapes, and sampled images on printed or displayed pages. A program in PostScript can communicate a document description from a composition system to a printing system in a device-independent way. PostScript is an unusually powerful printer language because it is a full programming language, rather than a series of 1 1 1 1 1 Postscript point The variant of the point used by Postscript, equal to 0.3527777778 mm, or 1/72 inch. (2002-03-11) 1 1 1 1 1 Post, Telephone and Telegraph administration (PTT) One of the many national bodies responsible for providing communications services in a particular country. Traditionally, PTTs had monopolies in their respective countries. This monopoly was first broken in the USA, with the UK joining somewhat later. Currently the markets are being deregulated in Europe as well as other parts of the world. Well-known PTTs include MCI, AT&T, and British Telecom. Compare: telco. (1998-05-18) 1 1 1 1 1 POSYBL Programming system for distributed applications. A Linda implementation for Unix networks by Ioannis Schoinas <sxoinas@csd.uch.gr>. (ftp://ariadne.csi.forth.gr/pub/POSYBL.TAR.Z). (1995-12-04) 1 1 1 1 1 potential difference voltage 1 1 1 1 1 POTS Plain Old Telephone Service 1 1 1 1 1 pound A British pound sign or Americal hash character. (2013-08-15) 1 1 1 1 1 pound on bang on 1 1 1 1 1 pound sign "£", ASCII character 163, 0xA3. A stylised capital L used to prefix amounts in British pounds sterling (GBP). Americans call the hash character ("#") "pound" but that is an antiquated reference to pounds weight (lb). (2013-08-15) 1 1 1 1 1 POWER Performance Optimization with Enhanced RISC. The IBM processor architecture on which PowerPC was based. 1 1 1 1 1 PowerBuilder A graphical user interface development tool from Powersoft for developing client-server database applications. It runs under MS-DOS(?) and Microsoft Windows. There are also versions for Microsoft Windows, Windows NT, Macintosh, and Unix. Applications can be built by creating windows, controls (such as listboxes and buttons), and menus within the PowerBuilder development environment. The language used to program PowerBuilder, PowerScript, is loosely based on BASIC. PowerBuilder supports programming on many database backends including Sybase and Oracle. It also has added support for ODBC database drivers. PowerBuilder also comes with a built-in database backend (WATCOM SQL 32-bit relational database). Product information (http://powersoft.com/mktg/prodinfo/prodintr.html). 1 1 1 1 1 power cycle (Or "cycle power", "cycle") To turn a machine's power off and on, with the intention of clearing some kind of hung or gronked state. Synonym 120 reset; see also Big Red Switch. Compare Vulcan nerve pinch, bounce and boot, and see the AI Koan about Tom Knight and the novice. [Jargon File] (2012-02-09) 1 1 1 1 1 powerdomain The powerdomain of a domain D is a domain containing some of the subsets of D. Due to the asymmetry condition in the definition of a partial order (and therefore of a domain) the powerdomain cannot contain all the subsets of D. This is because there may be different sets X and Y such that X <= Y and Y <= X which, by the asymmetry condition would have to be considered equal. There are at least three possible orderings of the subsets of a powerdomain: Egli-Milner: X <= Y iff for all x in X, exists y in Y: x <= y and for all y in Y, exists x in X: x <= y ("The other domain always contains a related element"). Hoare or Partial Correctness or Safety: 1 1 1 1 1 PowerFuL A language combining functional programming and logic programming, using "angelic Powerdomains". (1998-06-30) 1 1 1 1 1 power hit (Or "power glitch") A sudden increase (spike) or decrease (drop-out) in the mains electricity supply. These can cause crashes and even permanent damage to computers. Computers and other electronic equipment should really include some kind of over-voltage protection in its mains input to prevent such damamge. [Jargon File] 1 1 1 1 1 Power Mac Apple Computer's personal computer based on the PowerPC, introduced on 1994-03-14. The Power Mac G4 (Quicksilver 2002) was the first Power Mac to clock at 1 GHz. In mid-2003, the Power Mac G5 was released, the first Mac to be based on a 64-bit architecture. IBM manufactured the CPU for this new model. The clock speed was initially 1.6 GHz but a dual 2 GHz system was available in September. Existing 680x0 code (both applications and device drivers) run on Power Mac systems without modification via a Motorola 68LC040 emulator. The performance of these unmodified applications is equivalent to a fast 68040-based Macintosh, e.g. a fast Macintosh Quadra. The Power Mac runs Macintosh operating system from System 7.5 to Mac OS 8.5. Latest version, as of 2003-11-26: Power Mac G5. Power Mac Home (http://apple.com/powermac/). (2003-11-26) 1 1 1 1 1 Power Macintosh Power Mac 1 1 1 1 1 power-on reset POR) The processes that take place when a hardware device is turned on. This may include running power-on self-test or reloading software from non-volatile storage. The term implies that the device has some reasonably complex internal state that will be set back to a "normal" initial condition. This state may include the physical state of the device (e.g. a printer) as well as data in the memory of an embedded system. If a device has no reset button, and sometimes even if it does, turning it off and on again (power cycling) may be the only way to clear a fault. (2012-02-09) 1 1 1 1 1 power-on self-test (POST) A sequence of diagnostic tests that are run automatically by a device when the power is turned on. In a personal computer a typical POST sequence does the following: - checks that the system board is working - checks that the memory is working #NAME? recorded by the PC's configuration program to see if anything has been added or removed or broken #NAME? - checks that the diskette drive, hard disk drive, CD-ROM drive, and any other drives that may be installed are working. When POST is finished, typically it will beep, and then let your operating system start to boot. If POST finds an error, it may beep more than once (or possibly not at all if it is your PC speaker that is broken) and display a POST 1 1 1 1 1 PowerOpen The PowerOpen Association defines and promotes the PowerOpen Environment (POE). 1 1 1 1 1 PowerOpen Association An independent body established to promote, and test conformance with, the PowerOpen Environment (POE). (1994-11-08) 1 1 1 1 1 PowerOpen Environment (POE) A definition containing API and ABI specifications based on the PowerPC architecture. It is not an operating system. The presence of the ABI specification in the POE distinguishes it from other open systems (POSIX, XPG4, etc.) since it allows platform independent binary compatibility which is otherwise typically limited to particular hardware. The POE is an open standard, derived from AIX and conforming to industry open standards including POSIX, XPG4 and Motif. The POE specification will be publicly available to anyone wishing to produce either application programs or hardware platforms. The PowerOpen Association will provide the necessary conformance testing and POE branding. The POE is hardware bus independent. System implementations can range from laptop computers to supercomputers. It requires a multi-user, multitasking operating system. It 1 1 1 1 1 PowerPC (PPC) A RISC microprocessor designed to meet a standard which was jointly designed by Motorola, IBM, and Apple Computer (the PowerPC Alliance). The PowerPC standard specifies a common instruction set architecture (ISA), allowing anyone to design and fabricate PowerPC processors, which will run the same code. The PowerPC architecture is based on the IBM POWER architecture, used in IBM's RS/6000 workstations. Currently IBM and Motorola are working on PowerPC chips. The PowerPC standard specifies both 32-bit and 64-bit data paths. Early implementations were 32-bit (e.g. PowerPC 601); later higher-performance implementations were 64-bit (e.g. PowerPC 620). A PowerPC has 32 integer registers (32- or 64 bit) and 32 floating-point (IEEE standard 64 bit) floating-point registers. The POWER CPU chip and PowerPC have a (large) common core, but both have instructions that the other doesn't. The PowerPC 1 1 1 1 1 PowerPC 601 A 32-bit RISC processor with 2.8 million transistors (~1.2 million in the core logic) and 32 kilobytes of on-chip cache. Die size: 118.8 mm2. Heat dissipation at 66MHz: 9W. Performance at 66MHz: integer >60 SPECint92, floating-point >80 SPECfp92. Estimated manufacturing cost: $76. Maximum instructions per cycle: 3. 32 32-bit general-purpose registers. 32 64-bit floating-point registers. Successors: PowerPC 603, 604, 620. (2000-01-12) 1 1 1 1 1 PowerPC G3 A processor chip from Apple Computer, Inc.. Described by Apple as "the third generation in the development of advanced processor technology" the first PowerPC G3 products were launched in 1997. It is specifically optimised for the Macintosh Operating System and uses backside cache to improve performance. The PowerPC G3 has been used by Apple in notebook, desktop and server products. (http://apple.com/powermac/technologies/g3.html). (1998-10-03) 1 1 1 1 1 PowerPC Platform (PPCP, PReP - PowerPC Reference Platform, formerly CHRP - Common Hardware Reference Platform) An open system standard, designed by IBM, intended to ensure compatibility among PowerPC-based systems built by different companies. The PReP standard specifies the PCI bus, but will also support ISA, MicroChannel and PCMCIA. PReP-compliant systems will be able to run the Macintosh OS, OS/2, WorkplaceOS, AIX, Solaris, Taligent and Windows NT. IBM systems will (of course) be PReP-compliant. Apple's first PowerPC Macintoshes will not be compliant, but future ones may be. IBM info (http://fnctsrv0.chips.ibm.com/products/ppc/L3ppcp.html). (http://billboard.emedia.com.au/chipster/computers/CHRP/whatsCHRP.html). [Current OS statuses?] (1997-03-23) 1 1 1 1 1 PowerPC Reference Platform PowerPC Platform 1 1 1 1 1 Powerpoint A Microsoft application for creating presentations, speeches, slides, etc. (1996-08-26) 1 1 1 1 1 power save mode A feature of a component or subsystem designed to actively reduce its power consumption when not in use. Almost any electronic device might benefit from having a power save mode but the most common application is for portable computers which attempt to conserve battery life by incorporating power saving modes in the CPU, display, disks, printer, or other units. (1995-10-14) 1 1 1 1 1 powerset The powerset of a set S is the set of possible subsets of S, usually written PS. (1994-11-08) 1 1 1 1 1 Powersoft Corporation A leading vendor of client/server application development tools. In February 1994, Watcom became a wholly-owned subsidiary of Powersoft Corporation which merged with Sybase on 13 February 1995. In April 1995, the new company is the fastest growing top-ten software company and the seventh largest software company in the world. (http://powersoft.com/). Headquarters: Concord, Massachusetts, USA. (1995-12-27) 1 1 1 1 1 power supply power supply unit 1 1 1 1 1 power supply unit (PSU) An electronic module that converts high voltage (110 or 240 VAC) alternating current mains electricity into smoothed direct current at the various differnt voltages required by the motherboard; internal peripheral devices, cheifly storage devices: hard disks, CD or DVD, floppy disks and external connections such as USB. A PSU needs a high enough power output rating to supply all the devices connected to it and should output as little as possible electrical noise, both on the output wires and as electromagnetic radiation. See also uninterruptable power supply. (2007-09-20) 1 1 1 1 1 PP96 A parallel Pascal extension. [Details? Any relation to Parallel Pascal?] (1998-04-29) 1 1 1 1 1 PPC PowerPC 1 1 1 1 1 PPCP PowerPC Platform 1 1 1 1 1 PPD Parallel Presence Detect 1 1 1 1 1 PPGA Plastic Pin Grid Array 1 1 1 1 1 ppi pixels per inch 1 1 1 1 1 PPL Polymorphic Programming Language. An interactive, extensible language, based on APL, from Harvard University. ["Some Features of PPL - A Polymorphic Programming Language", T.A. Standish, SIGPLAN Notices 4(8) (Aug 1969)]. (1994-10-06) 1 1 1 1 1 PPLambda essentially the first-order predicate calculus superposed upon the simply-typed polymorphic lambda-calculus. PPLambda is the object language for LCF. ["Logic and Computation: Interactive Proof with Cambridge LCF", L. Paulson, Cambridge U Press, 1987]. (1995-05-01) 1 1 1 1 1 PPM Portable Pixmap 1 1 1 1 1 PPN Project-Programmer Number. A user-ID under TOPS-10 and its various mutant progeny at SAIL, BBN, CompuServe and elsewhere. Old-time hackers from the PDP-10 era sometimes use this to refer to user IDs on other systems as well. [Jargon File] (1994-11-18) 1 1 1 1 1 PPP Point-to-Point Protocol 1 1 1 1 1 PPPoA Point-to-Point Protocol over ATM 1 1 1 1 1 PPPoE Point-to-Point Protocol over Ethernet 1 1 1 1 1 P-Prolog A parallel logic language. ["P-Prolog: A Parallel Logic Language Based on Exclusive Relation", R. Yang et al, Third Intl Conf on Logic Prog, 1986, pp. 255-269]. (1994-11-18) 1 1 1 1 1 PPTP Point-to-Point Tunneling Protocol 1 1 1 1 1 PQS Picture Quality Scale 1 1 1 1 1 PR Packet Radio 1 1 1 1 1 pr The country code for Puerto Rico. (1999-01-27) 1 1 1 1 1 pr0n pron 1 1 1 1 1 PRA PRAgmatics. The language used by COPS for specification of code generators. ["Metalanguages of the Compiler Production System COPS", J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159]. (1994-11-18) 1 1 1 1 1 pragma (pragmatic information) A standardised form of comment which has meaning to the compiler or some other program. It may use a special syntax or a specific form within the normal comment syntax. A pragma usually conveys non-essential information, often intended to help the compiler to optimise the program or to generate formatted documentation. (2010-01-19) 1 1 1 1 1 PRAM 1. parallel random-access machine. 2. parameter RAM. 1 1 1 1 1 Praxis Critical Systems The company that supplies SPARK. (2001-07-12) 1 1 1 1 1 pre\box Phase 5's Amiga clone, announced on 1998-03-10. The pre\box will have a processor card with four PowerPC processors running in parallel. The processors will range from four 200 MHz PPC604e chips to four 300MHz PPC750 chips. It will have a Voodoo2 video graphics card, as well as a custom video chip working in concert, with 8 MB of video ram. It will run Amiga OS 3.1 (or higher if Gateway 2000 delivers the next upgrade before its release) and have Motorola 68000 CPU emulation in software. Other features include EIDE, Ultra Wide SCSI-II, PCI, Ethernet and DIMM sockets. Extra RAM, hard disks and CD-ROM will be available. The initial specification will probably be 32MB RAM, 32-speed CD and 4GB hard disk in an ATX minitower. Systems should start at about $2000 for four parallel 200 MHZ CPUs and be available at the end of 1998. Full press release (http://cucug.org/amiga/aminews/1998/980310-phase5.html). 1 1 1 1 1 PRE-CC PREttier Compiler-Compiler. An earlier version of PRECCX. (1995-01-24) 1 1 1 1 1 PRECCX (Pre-C-Compiler eXtended) An infinite-lookahead compiler-compiler by Peter Breuer <ptb@comlab.ox.ac.uk> for context dependent grammars. PRECCX generates ANSI C. Specification scripts are in very EBNF with inherited attributes and synthetic attributes allowed. Scripts can be compiled in separate modules and linked later. Meta-production rules are allowed. Grammars can be essentially LL(oo) with optimisations. A converter for yacc scripts is available. Versions 1.xx were known as "PRECC" and only had unbounded lookahead. The 2.xx series added the "X" for "extended" and featured higher order parameterisation (inherited attributes). Version 2.42 integrates inherited and synthesized attributes by using a "monadic" model for parsing. You can now synthsize attributes during the pass and inherit them in the remainder, e.g. 1 1 1 1 1 precedence operator precedence 1 1 1 1 1 precedence lossage /pre's*-dens los'*j/ A misunderstanding of operator precedence resulting in unintended grouping of arithmetic or logical operators when coding an expression. Used especially of mistakes in C code due to the nonintuitively low precedence of "&", "|", "^", "<<" and ">>". For example, the following C expression, intended to test the least significant bit of x, x & 1 == 0 is parsed as x & (1 == 0) which is always zero (false). Some lazy programmers ignore precedence and parenthesise everything. Lisp fans enjoy pointing out that this can't happen in *their* favourite language, which eschews precedence entirely, requiring one to use explicit parentheses 1 1 1 1 1 precharge The phase in the access cycle of DRAM during which the storage capacitors are charged to the appropriate value. (1997-02-23) 1 1 1 1 1 precision The number of decimal places to which a number is computed. Compare accuracy. (1998-04-19) 1 1 1 1 1 predecessor parent 1 1 1 1 1 predicate calculus predicate logic 1 1 1 1 1 predicate logic (Or "predicate calculus") An extension of propositional logic with separate symbols for predicates, subjects, and quantifiers. For example, where propositional logic might assign a single symbol P to the proposition "All men are mortal", predicate logic can define the predicate M(x) which asserts that the subject, x, is mortal and bind x with the universal quantifier ("For all"): All x . M(x) Higher-order predicate logic allows predicates to be the subjects of other predicates. (2002-05-21) 1 1 1 1 1 predict 1. <simulation> simulation, predictive analytics. 2. <architecture> branch prediction. 3. <audio, compression> predictive audio compression. 1 1 1 1 1 predomain A domain with no bottom element. (1995-05-04) 1 1 1 1 1 pre-emptive multitasking A type of multitasking where the scheduler can interrupt and suspend ("swap out") the currently running task in order to start or continue running ("swap in") another task. The tasks under pre-emptive multitasking can be written as though they were the only task and the scheduler decides when to swap them. The scheduler must ensure that when swapping tasks, sufficient state is saved and restored that tasks do not interfere. The length of time for which a process runs is known as its time slice and may depend on the task's priority or its use of resources such as memory and I/O. OS/2, Unix and the Amiga use pre-emptive multitasking. This contrasts with cooperative multitasking where each task must include calls to allow it to be descheduled periodically. (1995-03-20) 1 1 1 1 1 prefetch instruction prefetch 1 1 1 1 1 prefix 1. <unit> An SI prefix used to multiply the value of an SI (Système International) unit by some power of ten. 2. <programming, mathematics> In mathematics or programming, a prefix operator is one that is written before its operand. In a programming language using prefix notation, all operators are prefix operators. (2014-07-08) 1 1 1 1 1 prefix notation (Or "prefix syntax") One of the possible orderings of functions and operands: in prefix notation the function precedes all its operands. For example, what may normally be written as "1+2" becomes "(+ 1 2)". A few languages (e.g., lisp) have strictly prefix syntax, many more employ prefix notation in combination with infix notation. The opposite, postfix notation, is somewhat rarer. (2014-07-08) 1 1 1 1 1 prefix syntax prefix notation 1 1 1 1 1 pre-order 1. traversal. 2. A relation R is a pre-order if it is reflexive (x R x) and transitive (x R y R z => x R z). If it is also antisymmetric (x R y R x => x = y) then it is a partial ordering. (2001-10-01) 1 1 1 1 1 pre-order traversal traversal 1 1 1 1 1 PREP 1. (PReP) PowerPC Reference Platform. 2. (PREP) PRogrammed Electronics Patterns. Language for designing integrated circuits. ["Computer Assisted Mask Production", R.L. Rosenfeld, Proc IEEE 57(9) Sep 1969]. 1 1 1 1 1 prepaging (Or "working set model") A technique whereby the operating system in a paging virtual memory multitasking environment loads all pages of a process's working set into memory before the process is restarted. Under demand paging a process accesses its working set by page faults every time it is restarted. Under prepaging the system remembers the pages in each process's working set and loads them into physical memory before restarting the process. Prepaging reduces the page fault rate of reloaded processes and hence generally improves CPU efficiency. ["Modern Operating Systems", Andrew S. Tanenbaum, pub. Prentice Hall, Inc. 1992]. (1998-04-23) 1 1 1 1 1 prepend /pree'pend'/ (by analogy with "append") To prefix or add to the beginning. [Jargon File] (1998-04-23) 1 1 1 1 1 preprocessor A program that transforms input data in some way before it is read by the main program. In the case of a compiler, the input is source code. The main advantage of using a preprocessor is that it is possible to change the specification of the input data without changing the main program. The separation can also help to make the system's overall behaviour easier to understand. The disadvantage is that performance may be reduced by the extra input and output performed between the two programs. For example, the C preprocessor, cpp, handles textual macro substitution (it acts as a "macro preprocessor"), conditional compilation and inclusion of other files. A preprocessor may be used to transform a program into a simpler language, e.g. to transform C++ into C. (2007-04-05) 1 1 1 1 1 pre-sales support rep A person who supports sales by analysing customer requirements, proposing and demonstrating technical solutions, ensuring acceptable product installations, training users and providing initial technical support. (2004-03-20) 1 1 1 1 1 presence detect A means of identifying a memory chip to the memory controller logic. The original scheme, Parallel Presence Detect (PPD) used a separate pin for each bit of information. The limited number of pins available only gave the density and the speed of the chips. To pass more information, the Serial Presence Detect (SPD) scheme was introduced, storing the information in serial EEPROM with one pin to enable it and one for data. (2012-06-25) 1 1 1 1 1 presentation layer The second highest layer (layer 6) in the OSI seven layer model. Performs functions such as text compression, code or format conversion to try to smooth out differences between hosts. Allows incompatible processes in the application layer to communicate via the session layer. Documents: ITU Rec. X.226 (ISO 8823), ITU Rec. X.216 (ISO 8822). (1996-07-20) 1 1 1 1 1 Presentation Manager The elephantine graphical user interface to the OS/2 operating system. 1 1 1 1 1 prestidigitization /pres`t*-di"j*-ti:-zay"sh*n/ 1. A term coined by Daniel Klein <dvk@lonewolf.com> for the act of putting something into digital notation via sleight of hand. ["Open Channel", IEEE "Computer", November 1981]. 2. Data entry through legerdemain. [Jargon File] (1994-11-01) 1 1 1 1 1 PRESTO A parallel language for shared-memory multiprocessors, built on top of C++ by Bershad et al, U Washington 1987. PRESTO provides classes for threads and spinlocks as well as Mesa-style monitors and condition variables. (ftp://cs.washington.edu/pub/presto1.0.tar.Z). E-mail: <presto@cs.washington.edu>. ["PRESTO: A Kernel for Parallel Programming Environments", B.N. Bershad et al, U Wash CS TR, Jan 1987]. 1 1 1 1 1 Pretty Amazing New Stuff (PANS) What PSTN is evolving into. (1996-10-16) 1 1 1 1 1 Pretty Good Privacy (PGP) A high security RSA public-key encryption application for MS-DOS, Unix, VAX/VMS, and other computers. It was written by Philip R. Zimmermann <pkz@acm.org> of Phil's Pretty Good(tm) Software and later augmented by a cast of thousands, especially including Hal Finney, Branko Lankester, and Peter Gutmann. PGP was distributed as "guerrilla freeware". The authors don't mind if it is distributed widely, just don't ask Philip Zimmermann to send you a copy. PGP uses a public-key encryption algorithm claimed by US patent #4,405,829. The exclusive rights to this patent are held by a California company called Public Key Partners, and you may be infringing this patent if you use PGP in the USA. This is explained in the PGP User's Guide, Volume II. PGP allows people to exchange files or messages with privacy and authentication. Privacy and authentication are provided without managing the keys associated with conventional 1 1 1 1 1 pretty pictures (scientific computation) The next step up from numbers. Interesting graphical output from a program that may not have any sensible relationship to the system the program is intended to model, but good for showing to management. [Jargon File] (1995-02-15) 1 1 1 1 1 prettyprint /prit'ee-print/ (Or "pretty-print") To generate "pretty" human-readable output from a hairy internal representation; especially used for the process of grinding program code. [Jargon File] (1995-02-15) 1 1 1 1 1 pretzel key feature key 1 1 1 1 1 preventive maintenance (PM) To bring down a machine for inspection or test purposes. See provocative maintenance, scratch monkey. (1995-02-15) 1 1 1 1 1 PRI ISDN Primary Rate Interface. See also BRI (1994-12-08) 1 1 1 1 1 primary cache (L1 cache, level one cache) A small, fast cache memory inside or close to the CPU chip. For example, an Intel 80486 has an eight-kilobyte on-chip cache, and most Pentiums have a 16-KB on-chip level one cache that consists of an 8-KB instruction cache and an 8-KB data cache. The larger, slower secondary cache is normally connected to the CPU via its external bus. (1997-06-25) 1 1 1 1 1 Primary Domain Controller (PDC) Each Windows NT domain has a Primary Domain Controller and zero or more Backup Domain Controllers. The PDC holds the SAM database and authenticates access requests from workstations and servers in the domain. (2003-07-16) 1 1 1 1 1 primary key A unique identifier, often an integer, that labels a certain row in a table of a relational database. When this value occurs in other tables as a reference to a particular row in the first table it is called a "foreign key". Some RDBMSes can generate a new unique identifier each time a new row is inserted, others merely allow a column to be constrained to contain unique values. A table may have multiple candidate keys, from which the primary key is chosen. The primary key should be an arbitrary value, such as an autoincrementing integer. This avoids dependence on uniqueness, permanence and format of existing columns with real-world meaning (e.g. a person's name) or other external identifier (e.g. social security number). There should be enough possible primary key values to cater for the current and expected number of rows, bearing in mind that a wider column will generally be slower to process. 1 1 1 1 1 primary management domain (PRMD) The component of an X.400 electronic mail address that gives the organisation name, usually abbreviated to p= in written addresses. See also ADMD. (2003-05-15) 1 1 1 1 1 Primary Rate Interface (PRI) A type of ISDN connection. In North America and Japan, this consists of 24 channels, usually divided into 23 B channels and 1 D channel, and runs over the same physical interface as T1. Elsewhere the PRI has 31 user channels, usually divided into 30 B channels and 1 D channel and is based on the E1 interface. PRI is typically used for connections such as one between a PBX (private branch exchange, a telephone exchange operated by the customer of a telephone company) and a CO (central office, of the telephone company) or IXC (inter exchange carrier, a long distance telephone company). (1995-01-18) 1 1 1 1 1 primary storage main memory 1 1 1 1 1 Prime Computer (Or "Pr1ME") A minicomputer manufacturer. [Dates? Status? Products? Addresses?] (1996-09-28) 1 1 1 1 1 Primenet, Inc. Arizona's Internet provider. (1994-12-08) 1 1 1 1 1 prime number theorem The number of prime numbers less than x is about x/log(x). Here "is about" means that the ratio of the two things tends to 1 as x tends to infinity. This was first conjectured by Gauss in the early 19th century, and was proved (independently) by Hadamard and de la Vall'ee Poussin in 1896. Their proofs relied on complex analysis, but Erdös and Selberg later found an "elementary" proof. (1995-04-10) 1 1 1 1 1 prime time (From TV programming) Normal high-usage hours on a time-sharing system; the day shift. Avoidance of prime time was traditionally given as a major reason for night mode hacking. The rise of the personal workstation has rendered this term, along with time-sharing itself, almost obsolete. The hackish tendency to late-night hacking runs has changed not a bit. [Jargon File] (1995-01-18) 1 1 1 1 1 primitive A function, operator, or type which is built into a programming language (or operating system), either for speed of execution or because it would be impossible to write it in the language. Primitives typically include the arithmetic and logical operations (plus, minus, and, or, etc.) and are implemented by a small number of machine language instructions. (1995-05-01) 1 1 1 1 1 Princeton University Chartered in 1746 as the College of New Jersey, Princeton was British North America's fourth college. First located in Elizabeth, then in Newark, the College moved to Princeton in 1756. The College was housed in Nassau Hall, newly built on land donated by Nathaniel and Rebeckah FitzRandolph. Nassau Hall contained the entire College for nearly half a century. The College was officially renamed Princeton University in 1896; five years later in 1900 the Graduate School was established. Fully coeducational since 1969, Princeton now enrolls approximately 6,400 students (4,535 undergraduates and 1,866 graduate students). The ratio of full-time students to faculty members (in full-time equivalents) is eight to one. Today Princeton's main campus in Princeton Borough and Princeton Township consists of more than 5.5 million square feet of space in 160 buildings on 600 acres. The University's James Forrestal Campus in Plainsboro consists of one million 1 1 1 1 1 principal type The most general type of an expression. For example, the following are all valid types for the lambda abstraction (\ x . x): Int -> Int Bool -> Bool (a->b) -> (a->b) but any valid type will be an instance of the principal type: a -> a. An instance is derived by substituting the same type expression for all occurences of some type variable. The principal type of an expression can be computed from those of its subexpressions by Robinson's unification algorithm. (1994-12-16) 1 1 1 1 1 PRINT PRe-edited INTerpreter. An early mathematics language for the IBM 705. [Sammet 1969, p. 134]. (1995-05-01) 1 1 1 1 1 printed circuit board (PCB) A thin board to which electronic components are fixed by solder. Component leads and integrated circuit pins may pass through holes ("vias") in the board or they may be surface mounted, in which case no holes are required (though they may still be used to connect different layers). The simplest kind of PCB has components and wires on one side and interconnections (the printed circuit) on the other. PCBs may have components mounted on both sides and may have many internal layers, allowing more connections to fit in the same board area. Boards with internal conductor layers usually have "plated-through holes" to improve the electrical connection to the internal layers. The connections are metal strips (usually copper). The pattern of connections is often produced using photo-resist and acid etching. Boards, especially those for high frequency circuits such as modern microprocessors, usually have one or more "ground planes" and "power planes" which are large 1 1 1 1 1 printer A peripheral device for producing text and images on paper. There are many different types, broadly grouped into "impact printers" and "non-impact printers". Compare plotter. See also Braille printer, tree-killer. (1996-01-13) 1 1 1 1 1 Printer Access Protocol (PAP) A protocol used in Mac OS Appletalk to provide bi-directional communication between PostScript printers and the client computer. (1999-03-02) 1 1 1 1 1 printer port A connector found on many microcomputers intended for attaching a printer. This may be a general-purpose input/output parallel port or may be a special Centronics interface. Most printers can also be connected to a serial port but that is unlikely to be described as a "printer port". (1996-01-07) 1 1 1 1 1 printf The standard function in the C programming language library for printing formatted output. The first argument is a format string which may contain ordinary characters which are just printed and "conversion specifications" - sequences beginning with '%' such as %6d which describe how the other arguments should be printed, in this case as a six-character decimal integer padded on the right with spaces. Possible conversion specifications are d, i or u (decimal integer), o (octal), x, X or p (hexadecimal), f (floating-point), e or E (mantissa and exponent, e.g. 1.23E-22), g or G (f or e format as appropriate to the value printed), c (a single character), s (a string), % (i.e. %% - print a % character). d, i, f, e, g are signed, the rest are unsigned. The variant fprintf prints to a given output stream and sprintf stores what would be printed in a string variable. 1 1 1 1 1 PRINT I An early system on IBM 705. [CACM 2(5):16 (May 1959)]. 1 1 1 1 1 printing discussion [XEROX PARC] A protracted, low-level, time-consuming, generally pointless discussion of something only peripherally interesting to all. [Jargon File] 1 1 1 1 1 print server A server device that is set up on a network to route print requests and status information between computers and printers connected by a network. A typical print server routes print requests for multiple computers and printers on a network. For example, a networked workstation user submits a print command that includes a print file and information about the printer to be used, usually a nearby printer for convenience. The print server sends the print file to the requested printer. The printer spools the print file and provides job status. The print server relays the status of the printer back to the workstation and makes this status information available to other devices on the network. (1999-02-18) 1 1 1 1 1 Print Services Facility (PSF) IBM's system software which generates native IBM printer language, IPDS and, depending on the version, PostScript and LaserJet PCL. See also: Advanced Function Presentation. (1998-06-28) 1 1 1 1 1 priority inheritance A technique for avoiding priority inversion by temporarily raising the prioriry of all processes that want to access a shared resource to the highest priority level of any of them. Priority inversion occurs where a low priority process, L is holding a resource required by a high priority process, H, but L is not running because a medium priority process, M is running. Under priority inheritance, L temporarily inherits H's priority, allowing L to run and release the resource H is waiting for. For example, an ambulance (H) is stuck behind a lorry (L) waiting at a junction (the shared resource) for a gap in a line of cars (M) using the junction. Applying priority inheritance, the cars give way to the lorry as they would to the ambulance, thus allowing the lorry and then the ambulance to use the junction. (2005-02-11) 1 1 1 1 1 priority interrupt Any stimulus compelling enough to yank one right out of hack mode. Classically used to describe being dragged away by an SO for immediate sex, but may also refer to more mundane interruptions such as a fire alarm going off in the near vicinity. Also called an NMI (non-maskable interrupt), especially in PC-land. [Jargon File] (2005-02-13) 1 1 1 1 1 priority inversion The state of a concurrent system where a high priority task is waiting for a low priority task which is waiting for a medium priority task. The system may become unstable and crash under these circumstances. In an operating system that uses multiple tasks, each task (or context) may be given a priority. These priorities help the scheduler decide which task to run next. Consider tasks, L, M, and H, with priorities Low, Medium, and High. M is running and H is blocked waiting for some resource that is held by L. So long as any task with a priority higher than L is runable, it will prevent task L, and thus task H, from running. Priority inversion is generally considered either as a high-level design failure or an implementation issue to be taken into account depending on who is talking. Most operating systems have methods in place to prevent or take inversion into account. Priority inheritance is one method. 1 1 1 1 1 priority queue A data structure with three operations: insert a new item, return the highest priority item, and remove the highest priority item. The obvious way to represent priority queues is by maintaining a sorted list but this can make the insert operation very slow. Greater efficiency can be achieved by using heaps. (1996-03-12) 1 1 1 1 1 priority scheduling Processes scheduling in which the scheduler selects tasks to run based on their priority as opposed to, say, a simple round-robin. Priorities may be static or dynamic. Static priorities are assigned at the time of creation, while dynamic priorities are based on the processes' behaviour while in the system. For example, the scheduler may favour I/O-intensive tasks so that expensive requests can be issued as early as possible. A danger of priority scheduling is starvation, in which processes with lower priorities are not given the opportunity to run. In order to avoid starvation, in preemptive scheduling, the priority of a process is gradually reduced while it is running. Eventually, the priority of the running process will no longer be the highest, and the next process will start running. This method is called aging. 1 1 1 1 1 PRISM A distributed logic language. ["PRISM: A Parallel Inference System for Problem Solving", S. Kasif et al, Proc 1983 Logic Prog Workshop, pp. 123-152]. 1 1 1 1 1 Prisoner of Bill (PoB) A derisory term, in use generally among Unix users, for anyone who uses Microsoft products either because they don't know there is anything better (i.e. Unix) or because they would be incapable of working anything more complex (i.e. Unix). The interesting and widespread presumption among users of the term is that (at least at the time of writing, 1998) using anything other than Unix or a Microsoft OS (whether VMS, Macintosh, Amiga) is so eccentric a choice as to be at least somewhat praiseworthy. (1998-09-07) 1 1 1 1 1 privacy An attribute of a system's security that ensures that only intended or desired people or bodies can read a message or piece of stored data. Privacy is often enforced by some kind of access control or encryption. (2011-06-03) 1 1 1 1 1 Privacy Enhanced Mail messaging< (PEM) Internet electronic mail which provides confidentiality, authentication and message integrity using various encryption methods. See also Pretty Good Privacy. (2009-06-03) 1 1 1 1 1 private privacy 1 1 1 1 1 Private Automatic Branch eXchange (PABX) A telephone exchange operated within an organisation, used for switching calls between internal lines and between internal and PSTN lines. In contrast to a PMBX, a PABX can route calls without manual intervention, based entirely on the number dialed. Not all PABXs can route external calls to internal numbers automatically however. (1998-08-07) 1 1 1 1 1 Private Branch Exchange (PBX) A telephone exchange local to a particular organisation who use, rather than provide, telephone services. The earliest PBXs were manual (Private Manual Branch EXchange, PMBX) but are now more likely to be automatic (Private Automatic Branch eXchange). (1997-06-25) 1 1 1 1 1 private key A piece of data used in private-key cryptography and public-key cryptography. In the former the private key is known by both sender and recipient whereas in the latter it is known only to the sender. (2008-02-07) 1 1 1 1 1 private-key cryptography As opposed to public-key cryptography, a cryptographic method in which the same key is used to encrypt and decrypt the message. Private-key algorithms include the obsolescent Data Encryption Standard (DES), triple-DES (3DES), the Advanced Encryption Standard (AES), also known as Rijndael, Blowfish, Twofish RC2, RC4, RC5 and RC6. A problem with private-key cryptography is that the sender and the recipient of the message must agree on a common key via some alternative secure channel. Public-key cryptography gives an answer to this problem. (2008-02-07) 1 1 1 1 1 Private Manual Branch eXchange (PMBX) The original manual equivalent of a PABX; a PMBX involves company employed operators manually switching each call using a manual switchboard. (1998-08-07) 1 1 1 1 1 privileged instruction A machine code instruction that may only be executed when the processor is running in supervisor mode. Privileged instructions include operations such as I/O and memory management. (1995-02-15) 1 1 1 1 1 PRL Proof Refinement Logic. Versions: micro-PRL, lambda-PRL, nu-PRL. ["PRL: Proof Refinement Logic Programmer's Manual", CS Dept, Cornell, 1983]. (1995-01-24) 1 1 1 1 1 PRMD primary management domain 1 1 1 1 1 PRML Partial Response Maximum Likelihood 1 1 1 1 1 probabilistic Relating to, or governed by, probability. The behaviour of a probabilistic system cannot be predicted exactly but the probability of certain behaviours is known. Such systems may be simulated using pseudorandom numbers. Evolutionary computation uses probabilistic processes to generate new (potential) solutions to a problem. See also deterministic, non-probabilistic. (1995-09-22) 1 1 1 1 1 probabilistic automaton nondeterministic automaton 1 1 1 1 1 Probability of Failure on Demand (POFOD) The likelihood that some system will fail when a service request is made. (2010-09-26) 1 1 1 1 1 Probe An object-oriented logic language based on ObjVlisp. ["Proposition d'une Extension Objet Minimale pour Prolog", Actes du Sem Prog en Logique, Tregastel (May 1987), pp. 483-506]. 1 1 1 1 1 problem state IBM jargon for user mode, the opposite of "supervisor state". On IBM System 360, 370 and 390 mainframes privileged instructions may only be executed in "supervisor state". Application programs request the operating system to perform these operations by using the Supervisor Call (SVC) instruction. (1995-02-15) 1 1 1 1 1 Problem Statement Language/Problem Statement Analyser (PSL/PSA) A CASE system developed by D. Teichroew that allows computer-based development and analysis of a statement of requirements, and assistance during the design phase. (2010-01-26) 1 1 1 1 1 PROC The job control language used in the Pick operating system. ["Exploring the Pick Operating System", J.E. Sisk et al, Hayden 1986]. (1998-10-13) 1 1 1 1 1 procedural procedural language 1 1 1 1 1 procedural language Any programming language in which the programmer specifies an explicit sequences of steps to follow to produce a result (an algorithm). The term should not be confused with "imperative language" - a language that specifies explicit manipulation of state. An example (non-imperative) procedural language is LOGO, which specifies sequences of steps to perform but does not have an internal state. Other procedural languages include Basic, Pascal, C, and Modula-2. Both procedural and imperative languages are in contrast to declarative languages, in which the programmer specifies neither explicit steps nor explicit state manipulation. (2004-05-17) 1 1 1 1 1 Procedural Language/SQL (PL/SQL) Oracle Corporation's proprietary procedural language extension of industry-standard SQL. [Features? Reference? Any relation to PL/I?] (1999-09-14) 1 1 1 1 1 procedure subroutine 1 1 1 1 1 proceedings (Proc.) A printed collection of papers presented at a conference or meeting, e.g. "The Proceedings of the Fifth International Conference on Microelectronics for Neural Networks and Fuzzy Systems". Along with learned journals, conference proceedings are a major repository of peer-reviewed research results. (2008-07-16) 1 1 1 1 1 process 1. <operating system, software> The sequence of states of an executing program. A process consists of the program code (which may be shared with other processes which are executing the same program), private data, and the state of the processor, particularly the values in its registers. It may have other associated resources such as a process identifier, open files, CPU time limits, shared memory, child processes, and signal handlers. One process may, on some platforms, consist of many threads. A multitasking operating system can run multiple processes concurrently or in parallel, and allows a process to spawn "child" processes. (2001-06-16) 2. <business> The sequence of activities, people, and systems involved in carrying out some business or achieving some desired result. E.g. software development process, project management process, configuration management process. 1 1 1 1 1 Process and Experiment Automation Real-Time Language (PEARL) A real-time language for programming process control systems, widely used in Europe. Size and complexity exceeds Ada. Defined in DIN 66253 Teil 2. ["Programmiersprache PEARL", Beuth-Verlag, Nov 1980]. (2000-08-16) 1 1 1 1 1 process data data processing 1 1 1 1 1 Process Design Language 2 (PDL2) A language developed for the Texas Instruments ASC computer. ["Texas Instruments Process Design Methodology - Design Specification: Process Design Language", Volume I (Sep 1976)]. [Mentioned in "An Overview of Ada" J.G.P. Barnes, Soft Prac & Exp 10:851-887 (1980)]. (1995-08-13) 1 1 1 1 1 process ID process identifier 1 1 1 1 1 process identifier (PID) An integer used by the Unix kernel to uniquely identify a process. PIDs are returned by the fork system call and can be passed to wait() or kill() to perform actions on the given process. (1996-12-09) 1 1 1 1 1 processing Performing some predefined sequence of operations on an input to produce an output or change of internal state; activity specifically involving the computer's CPU. The term is often qualified: "data processing" treats digital data, "signal processing" treats analog data (possibly in digital form), "word processing" takes in typed human language input and produces digital documents, image processing transforms digital images. (2003-10-23) 1 1 1 1 1 processor central processing unit 1 1 1 1 1 Processor Direct Slot (PDS) Apple Computer's name for a local bus connection. Most Macintoshes have only one PDS connector. Different Apple computers have different PDS specifications. (1995-05-02) 1 1 1 1 1 processor farm A parallel processor where tasks are distributed, or "farmed out", by one "farmer" processor to several "worker" processors, and results are sent back to the farmer. This arrangement is suitable for applications which can be partitioned into many separate, independent tasks, the canonical examples being ray tracing and the Mandelbrot set. In order to be efficient, the extra time spent on communications must be small compared to the time spent processing each task. (2001-05-28) 1 1 1 1 1 Processor System Modeling Language (PSML) A language for simulating computer systems designs, implemented as a preprocessor to SIMSCRIPT. ["Processor System Modeling - A Language and Simulation System", F. Pfisterer, Proc Symp on Simulation of Computer Systems, Aug 1976]. (2009-05-11) 1 1 1 1 1 processor time The amount of time a process takes to run, given that it has exclusive and uninterrupted use of the CPU. Note that in a modern computer, this would be very unusual, and so the processor time calculation for most processes involves adding up all the small amounts of time the CPU actually spends on the process. Some systems break processor time down into user time and system time. Compare wall clock time. (1998-03-13) 1 1 1 1 1 process scheduling multitasking 1 1 1 1 1 process table A table containing all of the information that must be saved when the CPU switches from running one process to another in a multitasking system. The information in the process table allows the suspended process to be restarted at a later time as if it had never been stopped. Every process has an entry in the table. These entries are known as process control blocks and contain the following information: process state - information needed so that the process can be loaded into memory and run, such as the program counter, the stack pointer, and the values of registers. memory state - details of the memory allocation such as pointers to the various memory areas used by the program resource state - information regarding the status of files being used by the process such as user ID. Accounting and scheduling information. An example of a UNIX process table is shown below. 1 1 1 1 1 PROCOL A parallel object language with protocols, constraints and distributed delegation by J. Van Den Bos of Erasmus University, Rotterdam. ["PROCOL: A Parallel Object Language with Protocols", J. Van Den Bos et al, SIGPLAN Notices 24(10):95-102 (OOPSLA '89), Oct 1989]. (1998-03-23) 1 1 1 1 1 Procomm A terminal emulator program, originally from Datastorm Technologies, used for connection to BBSes etc. Procomm Plus for Windows incorporates automatic modem detection, a custom log-on script generator and sophisticated off-line message managers for CompuServe and MCI Mail. It also has a fax send and receive capability. Version 2.0 was chosen as the Editors Choice in PC Magazine 1995-03-14. Procomm Plus is now distributed by Symantec, Inc.. Procomm Home (http://symantec.com/procomm/). Version 2.4.3 1989-01-01 (http://ftp.bauru.unesp.br/comunicacao/procomm/PRCM243.NEW). Current Version: Procomm Plus 4.8, as of 2004-06-29. (2004-06-29) 1 1 1 1 1 Procrustean string A fixed-length string. If a string value is too long for the allocated space, it is truncated to fit; and if it is shorter, the empty space is padded, usually with space characters. This is an allusion to Procrustes, a legendary robber of ancient Attica. He bound his victims to a bed, and if they were shorter than the bed, he stretched their limbs until they would fit; if their limbs were longer, he lopped them off. (1997-09-12) 1 1 1 1 1 Prodigy A commercial on-line conferencing service, co-developed by IBM and Sears, Roebuck, Inc. Prodigy's main competitors are AOL and Compuserve. (1995-03-01) 1 1 1 1 1 ProDoc A set of tools for software documentation from SPC. (2006-10-12) 1 1 1 1 1 product An expression in mathematics or computer programming consisting of two other expressions multiplied together. In mathematics, multiplication is usually represented by juxtaposition, e.g. "x y", whereas in programming, "*" is used as an infix operator, e.g. "salary * tax_rate. In the most common type of product, each operand is a number (integer, real number, fraction or imaginary number) but the term extends naturally to cover more complex operations like multiplying a string by an integer (e.g., in Perl, "foo" x 2) or multiplying vectors and matrices or more than two operands. In type systems, a tuple is sometimes known as a "product type". (2006-10-12) 1 1 1 1 1 production system A production system consists of a collection of productions (rules), a working memory of facts and an algorithm, known as forward chaining, for producing new facts from old. A rule becomes eligible to "fire" when its conditions match some set of elements currently in working memory. A conflict resolution strategy determines which of several eligible rules (the conflict set) fires next. A condition is a list of symbols which represent constants, which must be matched exactly; variables which bind to the thing they match and "<> symbol" which matches a field not equal to symbol. Example production systems are OPS5, CLIPS, flex. (2005-06-17) 1 1 1 1 1 Professional Graphics Adapter (PGA) A computer video display standard produced by IBM for early CAD applications. It had a resolution of 640x400 pixels. (1997-04-25) 1 1 1 1 1 Professional Office System (PROFS) An office messaging system from IBM, used worldwide, mainly on IBM mainframes. (1996-03-23) 1 1 1 1 1 professional programming paranoid programming 1 1 1 1 1 professional services A department of a supplier providing consultancy and programming manpower for the supplier's products. (2004-03-09) 1 1 1 1 1 PROFILE Simple language for matching and scoring data. "User's Manual for the PROFILE System", Cambridge Computer Assoc (May 1974). [Jargon File] 1 1 1 1 1 profile 1. A control file for a program, especially a text file automatically read from each user's home directory and intended to be easily modified by the user in order to customise the program's behaviour. Used to avoid hard-coded choices (see also dot file, rc file). 2. A report on the amounts of time spent in each routine of a program, used to find and tune away the hot spots in it. This sense is often verbed. Some profiling modes report units other than time (such as call counts) and/or report at granularities other than per-routine, but the idea is similar. 1 1 1 1 1 PROFS Professional Office System 1 1 1 1 1 PROGENY 1961. Report generator for UNIVAX SS90. 1 1 1 1 1 proglet /prog'let/ [UK] A short extempore program written to meet an immediate, transient need. Often written in BASIC, rarely more than a dozen lines long and containing no subroutines. The largest amount of code that can be written off the top of one's head, that does not need any editing, and that runs correctly the first time (this amount varies significantly according to one's skill and the language one is using). Compare toy program, noddy, one-liner wars. [Jargon File] 1 1 1 1 1 program software 1 1 1 1 1 Program Composition Notation (PCN) A specification language for parallelism between C and Fortran modules. PCN provides a simple language for specifying concurrent algorithms, interfaces to Fortran and C, a portable toolkit that allows applications to be developed on a workstation or small parallel computer and run unchanged on supercomputers and integrated debugging and performance analysis tools. PCN was developed at Argonne National Laboratory and the California Institute of Technology. It has been used to develop a wide variety of applications, in areas such as climate modelling, fluid dynamics, computational biology, chemistry, and circuit simulation. Version 2.0 runs on networks of workstations: Sun-4, NeXT, RS/6000, SGI; multicomputers: iPSC/860, Touchstone DELTA; and shared memory multiprocessors: Symmetry/Dynix. (ftp://info.mcs.anl.gov/pub/pcn). 1 1 1 1 1 program counter (PC) A register in the central processing unit that contains the addresss of the next instruction to be executed. After each instruction is fetched, the PC is automatically incremented to point to the following instruction. It is not normally manipulated like an ordinary register but instead, special instructions are provided to alter the flow of control by writing a new value to the PC, e.g. JUMP, CALL, RTS. IBM call it the Instruction Address Register. (1995-03-21) 1 1 1 1 1 Program Design Language Any of a large class of formal and profoundly useless pseudo-languages in which management forces one to design programs. Too often, management expects PDL descriptions to be maintained in parallel with the code, imposing massive overhead of little or no benefit. See also flow chart. (1995-04-01) 1 1 1 1 1 Program Evaluation and Review Technique (PERT) A method used to size a software product and calculate the Standard Deviation (SD) for risk assessment. The PERT equation (beta distribution) estimates the Equivalent Delivered Source Instructions (EDSIs) and the SD based on the analyst's estimates of the lowest possible size, the most likely size, and the highest possible size of each computer program component (CPC). (1996-05-29) 1 1 1 1 1 Program Information File Under Windows, a file providing information on how a non-Windows application program should be run, including how much memory should be allocated to it and what graphics interface it requires. Filename extension: .pif (1997-10-11) 1 1 1 1 1 Programmable Airline Reservation System (PARS) An IBM proprietary large scale airline reservation application, executing under the control of IBM's ACP (and later its successor, TPF). In the early days of automated reservations systems in the 1960s and 1970s the combination of ACP and PARS provided unprecendented scale and performance from an on-line real-time system, and for a considerable period ranked among the largest networks and systems of the era. IPARS was the international version. (1999-01-18) 1 1 1 1 1 Programmable Array Logic (PAL) A family of fuse-programmable logic integrated circuits originally developed by MMI. Registered or combinatorial output functions are modelled in a sum of products form. Each output is a sum (logical or) of a fixed number of products (logical and) of the input signals. This structure is well suited for automatic generation of programming patterns by logic compilers. PAL devices are programmed by blowing the fuses permanently using overvoltage. Today, more complex devices based on the same original architecture are available (CPLD's for Complex PLD's) that incorporate the equivalent of several original PAL chips. PAL chips are, however, still popular due to their high speed. Generic Array Logic devices are reprogrammable and contain more logic gates. (1995-12-09) 1 1 1 1 1 Programmable Interrupt Controller PIC A special-purpose integrated circuit that functions as an overall manager in an interrupt driven system. It accepts requests from the peripheral equipment, determines which of the incoming requests is of the highest priority, ascertains whether the incoming request has a higher priority value than the level currently being serviced, and issues an interrupt to the CPU based on this determination. PICs typically have eight interrupt lines, and two PICs are often cascaded to provide 15 available interrupt lines. See also: Advanced Programmable Interrupt Controller. (2003-03-18) 1 1 1 1 1 Programmable Logic Controller (PLC) A device used to automate monitoring and control of industrial plant. Can be used stand-alone or in conjunction with a SCADA or other system. (1997-02-11) 1 1 1 1 1 Programmable Read-Only Memory (PROM) A kind of ROM which can be written using a PROM programmer. The contents of each bit is determined by a fuse or antifuse. The memory can be programmed once after manufacturing by "blowing" the fuses, which is an irreversible process. Blowing a fuse opens a connection while blowing an antifuse closes a connection (hence the name). Programming is done by applying high-voltage pulses which are not encountered during normal operation. (1995-04-22) 1 1 1 1 1 Programmed Data Processor (PDP) Early (1960's?) Digital Equipment Corporation family of minicomputers. The best known ranges were the PDP-10 and PDP-11. PAL was the assembly language. (1997-11-21) 1 1 1 1 1 PROgrammed Graph REwriting Systems (PROGRES) A very high level language based on graph grammars, developed by Andy Scheurr <andy@i3.informatik.rwth-aachen.de> and Albert Zuendorf <albert@i3.informatik.rwth-aachen.de> of RWTH, Aachen in 1991 PROGRES supports structurally object-oriented specification of attributed graph structures with multiple inheritance hierarchies and types of types (for parametric polymorphism). It also supports declarative/relational specification of derived attributes, node sets, binary relationships (directed edges) and Boolean constraints, rule-oriented/visual specification of parameterised graph rewrite rules with complex application conditions, nondeterministic and imperative programming of composite graph transformations (with built-in backtracking and cancelling arbitrary sequences of failing graph modifications). 1 1 1 1 1 programmer (Or "computer programmer", "developer") Someone who writes or debugs computer programs, for a living or for fun. Analyst/developer is a common equivalent job title, implying the added role of system analysis. The term may be qualified according to the type of software or programming language - application programmer, "system programmer", Perl programmer, etc. A contract programmer usually has a fixed-length contract, unlike a permanent employee. (2000-01-24) 1 1 1 1 1 Programmer Brain Damage (PBD) A classification of a bug which was obviously introduced by an incompetent or short-sighted programmer. Compare UBD. See also brain-damaged. (1996-10-13) 1 1 1 1 1 Programmer's Cheer "Shift to the left! Shift to the right! Pop up, push down! Byte! Byte! Byte!" [Origin?] [Jargon File] (1996-10-13) 1 1 1 1 1 Programmers Hierarchical Interactive Graphics System (PHIGS) An ANSI/ISO standard. Worked on by the ISO/IEC group JTC1/SC24. [More detail?] (1995-01-04) 1 1 1 1 1 PROgrammer's Microapplication Language (PROMAL) An interpreted C-like language from Systems Management Associates for MS-DOS, Commodore 64, and Apple II. [Computer Language, Mar 1986, pp. 128-134]. (1996-03-21) 1 1 1 1 1 Programmer's Switch A button on the front of some Apple Macintosh computers which, when pressed, causes a command line prompt to appear. This gives access to the built-in mini-debugger, which has commands to dump memory, return to the application that was broken out, and others. A more sophisticated debugger must be installed in order to inspect breakpoints, etc. (2000-11-01) 1 1 1 1 1 programming 1. The art of debugging a blank sheet of paper (or, in these days of on-line editing, the art of debugging an empty file). 2. A pastime similar to banging one's head against a wall, but with fewer opportunities for reward. 3. The most fun you can have with your clothes on (although clothes are not mandatory). [Jargon File] (2003-02-12) 1 1 1 1 1 programming fluid (Or "wirewater") Coffee, unleaded coffee (decaffeinated), Cola, or any caffeinacious stimulant. Many hackers consider these essential for those all-night hacking runs. (1996-05-01) 1 1 1 1 1 programming language A formal language in which computer programs are written. The definition of a particular language consists of both syntax (how the various symbols of the language may be combined) and semantics (the meaning of the language constructs). Languages are classified as low level if they are close to machine code and high level if each language statement corresponds to many machine code instructions (though this could also apply to a low level language with extensive use of macros, in which case it would be debatable whether it still counted as low level). A roughly parallel classification is the description as first generation language through to fifth generation language. The other major classification of languages distinguishes between imperative languages, procedural language and declarative languages. Programming languages in this dictionary (/contents/language.html). 1 1 1 1 1 Programming Language/Cornell (PL/C) A large subset of PL/I from Cornell University, aimed at novice programmers. ["Introduction to PL/1 and PL/C programming", Kochenburger, Ralph J., Santa Barbara, Hamilton, c1974]. ["User's Guide to PL/C", S. Worona et al, Cornell, June 1974]. ["PL/C - A High Performance Compiler" H.L. Morgan et al, Proc SJCC, AFIPS 38:503-510 (1971)]. (1999-05-26) 1 1 1 1 1 Programming Language/Systems (PL/S) An IBM machine-oriented language derived from PL/I, in the late 1960s, for the IBM 360 and IBM 370. PL/S permitted inline assembly language and control over register usage. Previous IBM 360 operating systems such as OS/MFT and OS/MVT had been written entirely in assembly language. The first IBM OS that had any significant portion written in PL/S was MVS, followed by OS/VS1, OS/VS2 and OS/SVS. PL/S was part of IBM's OCO (http://www.landley.net/history/mirror/ibm/oco.html) (object code only) effort, started in 1983. PL/S was used internally and never released to the public. It is documented in various IBM internal ZZ-? publications. Versions: PLS1, PLSII. ["PL/S, Programming Language/Systems", W.R. Brittenham, Proc GUIDE Intl, GUIDE 34, May 14, 1972, pp. 540-556]. (2012-01-20) 1 1 1 1 1 Program Temporary Fix (PTF) (Colloquially: Probably This Fixes) An IBM sanctioned patch, often implemented using ZAP or SUPERZAP. (1998-07-08) 1 1 1 1 1 program transformation The systematic development of efficient programs from high-level specifications by meaning-preserving program manipulations. Also known as optimisation. See fusion, loop combination, peephole optimisation, register allocation, tupling, unfold/fold. 1 1 1 1 1 Prograph A visual dataflow programming language and environment from the Technical University of Halifax. Prograph is an entirely graphical visual programming language, other than for the text of method names, and supports the program development process in a highly-interactive fashion. Operation icons are connected by data links through which information flows. It supports object orientation via class-based data abstraction with single inheritance. Prograph is available for the Macintosh, and soon for Windows and Unix, from TGS Systems. (1995-03-31) 1 1 1 1 1 PROGRES PROgrammed Graph REwriting Systems. 1 1 1 1 1 progressive coding (Or "interlacing") An aspect of a graphics storage format or transmission algorithm that treats bitmap image data non-sequentially in such a way that later data adds progressively greater resolution to an already full-size image. This contrasts with sequential coding. Progressive coding is useful when an image is being sent across a slow communications channel, such as the Internet, as the low-resolution image may be sufficient to allow the user to decide not to wait for the rest of the file to be received. In an interlaced GIF89 image, the pixels in a row are stored sequentially but the rows are stored in interlaced order, e.g. 0, 8, 4, 12, 2, 6, 8, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15. Each vertical scan adds rows in the middle of the gaps left by the previous one. PNG interlaces both horizontally and vertically using the 1 1 1 1 1 Progressive JPEG (PJPEG) An implementation of JPEG that supports progressive coding. [Standards documents?] (1998-02-10) 1 1 1 1 1 progressive/sequential coding The kind of image compression algorithm used in JBIG where an image coded using progressive coding can be decoded sequentially, and vice versa. (1995-03-01) 1 1 1 1 1 PROJECT Subsystem of ICES. Sammet 1969, p.616. 1 1 1 1 1 project assurance The process of specifying the support system: techniques, internal standards, measurements, tools, and training for a project; counselling the project team in the application of these elements and monitoring the adherence to the standards. 1 1 1 1 1 Project Athena A distributed system project for support of educational and research computing at MIT. Much of the software developed is now in wider use, especially the X Window System. (2000-02-24) 1 1 1 1 1 Project Guardian A project which grew out of the ARPA support for Multics and the sale of Multics systems to the US Air Force. The USAF wanted a system that could be used to handle more than one security classification of data at a time. They contracted with Honeywell and MITRE Corporation to figure out how to do this. Project Guardian led to the creation of the Access Isolation Mechanism, the forerunner of the B2 labeling and star property support in Multics. The DoD Orange Book was influenced by the experience in building secure systems gained in Project Guardian. (1997-01-29) 1 1 1 1 1 projection In domain theory, a function, f, which is (a) idempotent, i.e. f(f(x))=f(x) and (b) whose result is no more defined than its argument. E.g. F(x)=bottom or F(x)=x. In reduction systems, a function which returns some component of its argument. E.g. head, tail, \ (x,y) . x. In a graph reduction system the function can just return a pointer to part of its argument and does not need to build any new graph. (1997-01-29) 1 1 1 1 1 projective plane The space of equivalence classes of vectors under non-zero scalar multiplication. Elements are sets of the form kv: k != 0, k scalar, v != O, v a vector where O is the origin. v is a representative member of this equivalence class. The projective plane of a vector space is the collection of its 1-dimensional subspaces. The properties of the vector space induce a topology and notions of smoothness on the projective plane. A projective plane is in no meaningful sense a plane and would therefore be (but isn't) better described as a "projective space". (1996-09-28) 1 1 1 1 1 Project MAC A project suggested by J C R Licklider; its founding director was MIT Prof. Robert M Fano. MAC stood for Multiple Access Computers on the 5th floor of Tech Square, and Man and Computer on the 9th floor. The major efforts were Corbato's Multics development and Marvin Minsky's Artificial Intelligence Laboratory. In 1963 Project MAC hosted a summer study, which brought many well-known computer scientists to Cambridge to use CTSS and to discuss the future of computing. Funding for Project MAC was provided by the Information Processing Techniques Office of the Advanced Research Projects Agency (ARPA) of the US Department of Defense. See also Early PL/I, MacLisp, MACSYMA, MDL, Multipop-68, OCAL. (1997-01-29) 1 1 1 1 1 project management The process of planning, organising, staffing, directing and controlling the production of a system. Software tools are available to help with this, e.g. PERT chart editors. (1998-12-12) 1 1 1 1 1 project planning project management 1 1 1 1 1 Prolog Programming in Logic or (French) Programmation en Logique. The first of the huge family of logic programming languages. Prolog was invented by Alain Colmerauer and Phillipe Roussel at the University of Aix-Marseille in 1971. It was first implemented 1972 in ALGOL-W. It was designed originally for natural-language processing but has become one of the most widely used languages for artificial intelligence. It is based on LUSH (or SLD) resolution theorem proving and unification. The first versions had no user-defined functions and no control structure other than the built-in depth-first search with backtracking. Early collaboration between Marseille and Robert Kowalski at University of Edinburgh continued until about 1975. Early implementations included C-Prolog, ESLPDPRO, Frolic, LM-Prolog, Open Prolog, SB-Prolog, UPMAIL Tricia Prolog. In 1998, the most common Prologs in use are 1 1 1 1 1 Prolog++ (After C++) Prolog with object-oriented features added by Phil Vasey of Logic Programming Associates. Prolog++ is available for MS-DOS and the X Window System. It is distributed by AI International Ltd. in England and by Quintus. 1 1 1 1 1 Prolog-2 An implementation of Edinburgh Prolog by Nick Henfrey, ESL. ["An Advanced Logic Programming Language", Anthony Dodd]. 1 1 1 1 1 Prolog-D-Linda Embeds the Linda parallel paradigm into SISCtus Prolog. (ftp://ftp.cs.uwa.au/). E-mail: <geoff@cs.uwa.edu.au>. 1 1 1 1 1 Prolog-II Prolog with two new predicates: "dif" for coroutines and freeze for delayed evaluation. Available from ExperIntelligence, Santa Barbara CA. ["Prolog II Reference Manual and Theoretical Model", A. Colmerauer, Internal Report, GroupeIA, U Aix-Marseille (Oct 1982)]. 1 1 1 1 1 Prolog-III A. Colmerauer, U Aix-Marseille, ca 1984. Marseille Prolog, with unification replaced by constraint resolution. [deferred goals too?] (Not to be confused with Prolog 3, a commercial product?) Version 1.2 for MS-DOS. ["Opening the Prolog-III Universe", BYTE 12(9):177-182 (Aug 1987)]. ["An Introduction to Prolog III", A. Colmerauer, CACM 33(7):69-90 (1990)]. 1 1 1 1 1 Prolog-Linda 1. Prolog extended with Linda-style parallelism. Proc 4th Australian Conf on Artif Intell. (ftp://bison.cs.uwa.oz.au/). 2. Neil MacDonald, U Edinburgh 1989. Another Prolog extended with Linda, implemented on a Computing Surface. 1 1 1 1 1 Prolog/Mali (PM) Lambda-Prolog for the MALI-V06 abstract memory system, developed by Pascal Brisset at IRISA, France. There is a compiler which compiles to C, a linker, libraries, run-time system, and documentation. It runs under Unix. (ftp://ftp.irisa.fr/pm/). Mailing list: prolog-mali-request@irisa.fr. E-mail: <pm@irisa.fr>. (1992-07-06) 1 1 1 1 1 PROM Programmable Read-Only Memory 1 1 1 1 1 PROMAL PROgrammer's Microapplication Language 1 1 1 1 1 Prometheus A programmaing language geared for logic, mathematics, AI, and string, list and database processing. Prometheus runs on a variety of platforms from Macintosh to MS-DOS (http://aard.tracor.com/Jason/Prometheus/). (1996-03-04) 1 1 1 1 1 promiscuous mode Where a node on a network accepts all packets, regardless of their destination address. (1996-03-04) 1 1 1 1 1 PROM monitor a small program stored in PROM (or ROM), responsible for both loading the OS and providing some means to analyse OS crashes. It may also have some sort of user interface which can be used to examine and change the contents of memory, control the boot process (specifying arguments to the kernel, or changing where to look for the it), and so forth. The main difference between a PROM monitor and a bootstrap loader is that the PROM monitor regains control when the OS terminates. This may enable a wizard to find out what went wrong if the OS crashed, although it is usually of little help for the average sysadmin. (1996-12-03) 1 1 1 1 1 pron (Or "pr0n") B1FF-speak for pornography. Often seen on IRC in such desperate cries for help as "I WNAT PRON!!!!!" (1997-09-14) 1 1 1 1 1 Pronet ["The Design of a Programming Language Based on Connectivity Networks", R. LeBlanc et al, Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982, pp. 532-541]. (1997-09-14) 1 1 1 1 1 Pronunciation In this dictionary slashes (/../) bracket phonetic pronunciations of words not found in a standard English dictionary. The notation, and many of the pronunciations, were adapted from the Hacker's Jargon File. Syllables are separated by dash or followed single quote or back quote. Single quote means the preceding syllable is stressed (louder), back quote follows a syllable with intermediate stress (slightly louder), otherwise all syllables are equally stressed. Consonants are pronounced as in English but note: ch soft, as in "church" g hard, as in "got" 1 1 1 1 1 proof 1. <logic> A finite sequence of well-formed formulas, F1, F2, ... Fn, where each Fi either is an axiom, or follows by some rule of inference from some of the previous F's, and Fn is the statement being proved. See also proof theory. 2. A left-associative natural language parser by Craig R. Latta <latta@xcf.berkeley.edu>. Ported to Decstation 3100, Sun-4. (ftp://scam.berkeley.edu/pub/src/local/proof/). E-mail: <proof@xcf.berkeley.edu>. Mailing list: proof-requestf@xcf.berkeley.edu (Subject: add me). (1994-11-29) 1 1 1 1 1 PROOF/L A functional, object-oriented language with implicit parallelism. [J Parallel Dist Comp 12:202-212 (1991)]. [Forthcoming Technical Report from RADC]. (1994-10-31) 1 1 1 1 1 proof theory The branch of logic describing procedures for combining logical statements to show, by a series of truth-preserving transformations, that one statement is a consequence of some other statement or group of statements. (1994-10-31) 1 1 1 1 1 propeller head Used by hackers, this is synonym with computer geek. Non-hackers sometimes use it to describe all techies. Probably derives from SF fandom's tradition (originally invented by old-time fan Ray Faraday Nelson) of propeller beanies as fannish insignia (though nobody actually wears them except as a joke). [Jargon File] (1995-01-18) 1 1 1 1 1 propeller key feature key 1 1 1 1 1 proportionally spaced font proportional font 1 1 1 1 1 Proposal Writing Extension of Fortran for proposal writing. [Sammet 1969, p. 170]. (1995-01-18) 1 1 1 1 1 proposition A statement in propositional logic which may be either true or false. Each proposition is typically represented by a letter in a formula such as "p => q", meaning proposition p implies proposition q. (2006-03-14) 1 1 1 1 1 propositional calculus propositional logic 1 1 1 1 1 propositional logic (or "propositional calculus") A system of symbolic logic using symbols to stand for whole propositions and logical connectives. Propositional logic only considers whether a proposition is true or false. In contrast to predicate logic, it does not consider the internal structure of propositions. (2002-05-21) 1 1 1 1 1 Proposition of a Language Useable for Structured Specifications (PLUSS) An algebraic specification language, built on top of ASL. ["A First Introduction to PLUSS", M.C. Gaudel, TR, U Paris Sud, Orsay 1984]. (2006-03-14) 1 1 1 1 1 proprietary 1. In marketroid-speak, superior; implies a product imbued with exclusive magic by the unmatched brilliance of the company's own hardware or software designers. 2. In the language of hackers and users, inferior; implies a product not conforming to open-systems standards, and thus one that puts the customer at the mercy of a vendor who can inflate service and upgrade charges after the initial sale has locked the customer in. [Jargon File] 1 1 1 1 1 PROSE 1. PROblem Solution Engineering. Numerical problems including differentiation and integration. "Computing in Calculus", J. Thames, Research/Development 26(5) (May 1975). 2. A constraints-and-sequencing system similar to Kaleidoscope. "Reflexive Constraints for Dynamic Knowledge Bases", P. Berlandier et al in Proc First Intl CS Conf '88: AI: Theory and Appls, Dec 1988. 1 1 1 1 1 ProSet A derivative of SETL with Ada-like syntax developed at the University of Essen in 1990. Formerly known as SETL/E. ["SETL/E, A Prototyping System Based on Sets", E.E. Doberkat et al, in Tagungsband TOOL90, W. Zorn ed, pp. 109-118, U Karlsruhe, Nov 1990]. ["ProSet - A Language for Prototyping with Sets", E.-E. Doberkat et al, in Proc Third Intl Workshop on Rapid System Prototyping, N. Kanopoulos ed, IEEE Comp Soc Press, June 1992, pp. 235-248]. 1 1 1 1 1 PROSPER ["PROSPER: A Language for Specification by Prototyping", J. Leszczylowski, Comp Langs 14(3):165-180 (1989)]. 1 1 1 1 1 Prospero A tool for organising Internet resources. Prospero allows each user to organise the contents of remote file servers into his own virtual file system with his own hierarchical name space consisting of links to remote objects. Remote indexing services are made available by treating the results as a virtual directory. A "union link" allows the contents of the link's target directory to appear as part of the directory containing the link. Arbitrary filters can be associated with links to modify the representation of the target directory as desired. Prospero directories can be shared between users. The Prospero protocol is used for communication between clients and servers in the archie system. A prototype of Prospero has been available since December 1990. It interfaces with Sun NFS, the Andrew File System and FTP (with local caching) and Archie. Support for web and WAIS is planned (1992). E-mail: <info-prospero@isi.edu>. 1 1 1 1 1 ProTalk Quintus. An object-oriented Prolog. 1 1 1 1 1 protected mode An operating mode of Intel 80x86 processors. The opposite of real mode. The Intel 8088, Intel 8086, Intel 80188 and Intel 80186 had only real mode, processors beginning with the Intel 80286 feature a second mode called protected mode. In real mode, addresses are generated by adding an address offset to the value of a segment register shifted left four bits. As the segment register and address offset are 16 bits long this results in a 20-bit address. This is the origin of the one megabyte (2^20) limit in real mode. There are 4 segment registers on processors before the Intel 80386. The 80386 introduced two more segment registers. Which segment register is used depends on the instruction, on the addressing mode and of an optional instruction prefix which selects the segment register explicitly. In protected mode, the segment registers contain an index into a table of segment descriptors. Each segment descriptor 1 1 1 1 1 PROTEUS An extensible language, the core of PARSEC. ["The Design of a Minimal Expandable Computer Language", J.R. Bell, PhD Thesis, CS, Stanford University (Dec 1968)]. 1 1 1 1 1 protocal It's spelled "protocol". 1 1 1 1 1 protocol A set of formal rules describing how to transmit data, especially across a network. Low level protocols define the electrical and physical standards to be observed, bit- and byte-ordering and the transmission and error detection and correction of the bit stream. High level protocols deal with the data formatting, including the syntax of messages, the terminal to computer dialogue, character sets, sequencing of messages etc. Many protocols are defined by RFCs or by OSI. See also handshaking. [Jargon File] (1995-01-12) 1 1 1 1 1 protocol analyser Any device that captures and interprets the network traffic between two or more connected computer systems. The traffic can then be decoded so that it is possible to see what processes are occurring. By examining the flow of traffic, protocol analysers can be used to find out where problems (such as bottlenecks or the failure of a network device) are on a LAN. Advanced protocol analysers can also provide statistics on the traffic that can help to identify trends that may in future lead to further problems with the network. (2000-07-24) 1 1 1 1 1 protocol converter A device or program to translate between different protocols which serve similar functions (e.g. TCP and TP4). Some call this a "gateway", though others use that term for other kinds of internetworking device. (1996-03-07) 1 1 1 1 1 Protocol Data Unit (PDU) A packet of data passed across a network. The term implies a specific layer of the OSI seven layer model and a specific protocol. (1994-10-13) 1 1 1 1 1 protocol layer The software and/or hardware environment of two or more communications devices or computers in which a particular network protocol operates. A network connection may be thought of as a set of more or less independent protocols, each in a different layer or level. The lowest layer governs direct host-to-host communication between the hardware at different hosts; the highest consists of user application programs. Each layer uses the layer beneath it and provides a service for the layer above. Each networking component hardware or software on one host uses protocols appropriate to its layer to communicate with the corresponding component (its "peer") on another host. Such layered protocols are sometimes known as peer-to-peer protocols. The advantages of layered protocols is that the methods of passing information from one layer to another are specified clearly as part of the protocol suite, and changes within a 1 1 1 1 1 protocol stack A layered set of protocols which work together to provide a set of network functions. Each intermediate protocol layer uses the layer below it to provide a service to the layer above. The OSI seven layer model is an attempt to provide a standard framework within which to describe protocol stacks. (1997-12-07) 1 1 1 1 1 protoduction A prototype that ends up in a production environment. [chris-pebble, Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)] (2014-09-21) 1 1 1 1 1 PROTON 1. A home computer made by Acorn Computers under a contract won from the BBC in April 1981. [Details?] 2. Something to do with Microsoft SoftLib? (1994-11-28) 1 1 1 1 1 Protosynthex A query system for English text. [Sammet 1969, p. 669]. 1 1 1 1 1 prototype 1. <systems> An early version of a product, designed to demonstrate feasability and elicit feedback. A prototype usually has some subset of the functions, behaviour and appearance of the finished product. It is usually made using a method suitable for producing a one-off rather than mass production. 2. <programming> In prototype-based programming, an object that is intended to be cloned to create similar objects which may then be modified independently and/or cloned themselves. (2010-03-02) 1 1 1 1 1 Prototyper An interface builder for the Macintosh from Smethers Barnes. (1994-11-28) 1 1 1 1 1 prototyping The creation of a model and the simulation of all aspects of a product. CASE tools support different degrees of prototyping. Some offer the end-user the ability to review all aspects of the user interface and the structure of documentation and reports before code is generated. 1 1 1 1 1 provably difficult The set or property of problems for which it can be proven that no polynomial-time algorithm exists, only exponential-time algorithms. 1 1 1 1 1 provably unsolvable The set or property of problems for which no algorithm at all exists. E.g. the Halting Problem. See also provably difficult. 1 1 1 1 1 provider Internet Access Provider 1 1 1 1 1 provocative maintenance [Common ironic mutation of "preventive maintenance"] Actions performed upon a machine at regularly scheduled intervals to ensure that the system remains in a usable state. So called because it is all too often performed by a field servoid who doesn't know what he is doing; such "maintenance" often *induces* problems, or otherwise results in the machine's remaining in an *un*usable state for an indeterminate amount of time. See also scratch monkey. [Jargon File] 1 1 1 1 1 prowler (Unix) A daemon that is run periodically (typically once a week) to seek out and erase core files, truncate administrative logfiles, nuke "lost+found" directories, and otherwise clean up the cruft that tends to pile up in the corners of a file system. See also GFR, reaper, skulker. (1995-02-14) 1 1 1 1 1 proxy A process that accepts requests for some service and passes them on to the real server. A proxy may run on dedicated hardware or may be purely software. It may transform the request in some way or provide some additional layer of functionality such as caching or remote access. A proxy may be intended to increase security, e.g. a web proxy that allows multiple clients inside an organisation to access the Internet through a single secure, shared connection. (2007-09-03) 1 1 1 1 1 proxy ARP The technique in which one host, usually a router, answers Address Resolution Protocol (ARP) requests intended for another machine. By "faking" its identity, the router accepts responsibility for routing packets to the real destination. Proxy ARP allows a site to use a single IP address with two physical networks. Subnetting would normally be a better solution. (2007-09-03) 1 1 1 1 1 proxy gateway proxy server 1 1 1 1 1 Proxy Server (Capitalised) Microsoft's proxy server and proxy gateway, designed to provide extensible firewall and network security. Proxy Server is part of BackOffice. (1999-09-17) 1 1 1 1 1 proxy server A server process that intercepts requests from a client, passes them to an origin server and returns the response to the client while performing various other operations in the process. An HTTP proxy server is a common example. A proxy may be used for purposes of security, performance (caching) or anonymity. It may be purely software or may run on its own hardware, either a standard PC or server machine or a custom hardware appliance. A software proxy may be on the same computer as the client or the origin server, separate hardware may be anywhere on the network in between. The proxy may filter requests, rejecting some if the request or response matches certain conditions (e.g. an antivirus proxy). It may cache requests and responses to reduce load on the origin server or data volume on the network or to provide quicker response to the client for common requests. The proxy may modify the request or response, e.g. to convert between 1 1 1 1 1 PS 1. <language, text, graphics> PostScript. 2. <file format> Physical Sequential. 1 1 1 1 1 PS1 Sony Playstation 1 1 1 1 1 PS2 Sony Playstation 1 1 1 1 1 PS/2 IBM's second generation of personal computers. The PS/2 series introduced three advances over the PC series: 3.5" 1.44 megabyte microfloppy disks, VGA and 8514 graphics display standards, and the Micro Channel bus architecture. The 3.5" disks and VGA can be easily installed on other PCs and will become the standard for new compatible computers. The Micro Channel bus allows for multiprocessing and less aggravation, but cannot be retrofitted to older PCs. PS/2 models 25 and 30 are ISA, other models have Micro Channel and ESDI. (1995-11-27) 1 1 1 1 1 PS 440 The system implementation language for the Telefunken TR 440 computer, developed by K. Lagally in about 1974 (2003-07-29) 1 1 1 1 1 PSA Problem Statement Analizer. See PSL/PSA. 1 1 1 1 1 PS-ALGOL Persistent ALGOL. ca 1981, released 1985. A derivative of S-ALGOL. Database capability derived from the longevity of data. "The PS- Algol Reference Manual", TR PPR-12-85, CS Dept, U Glasgow 1985. IBM PC version available from CS Dept, U Strathclyde, Glasgow. 1 1 1 1 1 pSather A parallel extension of Sather for a clustered shared memory model. It features threads synchronised by monitor objects ("gates"); locality assertions and placement operators. There is an implementation for the CM-5. ["pSather Monitors: Design, Tutorial, Rationale and Implementation", J.A. Feldman et al, TR-91-031 and TR-93-028, ICSI, Berkeley, CA]. (1995-03-13) 1 1 1 1 1 PSD Portable Scheme Debugger. 1 1 1 1 1 PSDN Public Switched Data Network. 1 1 1 1 1 pseudo /soo'doh/ (Usenet) Pseudonym. 1. An electronic-mail or Usenet persona adopted by a human for amusement value or as a means of avoiding negative repercussions of one's net.behaviour; a "nom de Usenet", often associated with forged postings designed to conceal message origins. Perhaps the best-known and funniest hoax of this type is BIFF. 2. Notionally, a flamage-generating AI program simulating a Usenet user. Many flamers have been accused of actually being such entities, despite the fact that no AI program of the required sophistication yet exists. However, in 1989 there was a famous series of forged postings that used a phrase-frequency-based travesty generator to simulate the styles of several well-known flamers; it was based on large samples of their back postings (compare Dissociated Press). A significant number of people were fooled by the forgeries, and the debate over their authenticity was settled only when 1 1 1 1 1 pseudocode A notation resembling a programming language but not intended for actual compilation. It usually combines some of the structure of a programming language with an informal natural language description of the computations to be carried out. Some CASE systems produce it as a basis for later hand coding. (2011-01-29) 1 1 1 1 1 pseudoprime A backgammon prime (six consecutive occupied points) with one point missing. This term is an esoteric pun derived from a mathematical method that, rather than determining precisely whether a number is prime (has no divisors), uses a statistical technique to decide whether the number is probably prime. A number that passes this test is called a pseudoprime. The hacker backgammon usage stems from the idea that a pseudoprime is almost as good as a prime: it does the job of a prime until proven otherwise, and that probably won't happen. [Jargon File] 1 1 1 1 1 pseudorandom number One of a sequence of numbers generated by some algorithm so as to have an even distribution over some range of values and minimal correlation between successive values. Pseudorandom numbers are used in simulation and encryption. They are pseudorandom not random because the sequence eventually repeats exactly and is entirely determined by the initial conditions. One of the simplest algorithms is x[i+1] = (a * x[i] + c) mod m but this repeats after at most m numbers and successive numbers are closely related. Better algorithms generally use more previous numbers to calculate the next number. (http://random.mat.sbg.ac.at/). (2007-06-29) 1 1 1 1 1 PseudoScheme A translator from Scheme to Common Lisp by Jonathan Rees <jar@cs.cornell.edu>. Version 2.8. It conforms to all of R3RS except call/cc and requires Common Lisp. Runs on Lucid, Symbolics CL, VAX Lisp, Explorer CL. Mailing list: info-clscheme-request@mc.lcs.mit.edu. (1994-10-28) 1 1 1 1 1 pseudosuit /soo'doh-s[y]oot"/ A suit wannabee; a hacker who has decided that he wants to be in management or administration and begins wearing ties, sport coats, and (shudder!) suits voluntarily. It's his funeral. See also lobotomy. [Jargon File] 1 1 1 1 1 pseudo-tty Berkeley Unix networking device which appears to an application program as an ordinary terminal but which is in fact connected via the network to a process running on a different host or a windowing system. Pseudo-ttys have a slave half and a control half. The slave tty (/dev/ttyp*) is the device that user programs use and the control tty (/dev/ptyp*) is used by daemons to talk to the net. (1994-11-08) 1 1 1 1 1 PSF Print Services Facility 1 1 1 1 1 PSI Portable Scheme Interpreter 1 1 1 1 1 Psion The UK company that produced the Psion Organiser. They also wrote software for the Sinclair QL. Psion Home (http://psionteklogix.com/). (2009-05-27) 1 1 1 1 1 Psion Organiser A popular pocket computer from the UK Company Psion plc. The organiser uses a graphical user interface with windows, menus, icons and dialog boxes. There have been several versions so far: Series3a, Series3, HC, MC, OrgII. Usenet newsgroups: news:comp.sys.psion, news:comp.binaries.psion. (1995-03-03) 1 1 1 1 1 PSK 1. <communications> Phase-Shift Keying. 2. <cryptography, networking> Pre-Shared Key. 1 1 1 1 1 PSL 1. Portable Standard Lisp. 2. Problem Statement Language. 1 1 1 1 1 PSL/PSA Problem Statement Language/Problem Statement Analyser 1 1 1 1 1 PSML Processor System Modeling Language. 1 1 1 1 1 PSN Packet Switch Node 1 1 1 1 1 PSO Oracle Parallel Server 1 1 1 1 1 PSPP A GNU version of SPSS. [URL? Features?] (2010-03-21) 1 1 1 1 1 PSTN Public Switched Telephone Network 1 1 1 1 1 PSU power supply unit 1 1 1 1 1 psychedelicware /si:"k*-del"-ik-weir/ [UK] Synonym display hack. See also smoking clover. [Jargon File] 1 1 1 1 1 psyton /si:'ton/ (From TMRC) The elementary particle carrying the sinister force. The probability of a process losing is proportional to the number of psytons falling on it. Psytons are generated by observers, which is why demos are more likely to fail when lots of people are watching. This term appears to have been largely superseded by bogon; see also quantum bogodynamics. (1997-04-26) 1 1 1 1 1 pt 1. <text, unit> point. 2. <networking> The country code for Portugal. (1999-01-27) 1 1 1 1 1 P-TAC Parallel Three Address Code. Kid is a refinement of P-TAC, used as an intermediate language for Id. ["P-TAC: A Parallel Intermediate Language", Z. Ariola et al, Fourth Intl Conf Func Prog Langs and Comp Arch, ACM Sept 1989]. 1 1 1 1 1 ptc A Pascal to C translator. (ftp://uxc.sco.uiuc.edu/languages/ptc). 1 1 1 1 1 PTF Program Temporary Fix 1 1 1 1 1 Pthreads POSIX Threads 1 1 1 1 1 PTI Portable Tool Interface 1 1 1 1 1 PTN Physical Transport Network 1 1 1 1 1 Ptolemy A flexible foundation for the specification, simulation, and rapid prototyping of systems. It is an object-oriented framework within which diverse models of computation can co-exist and interact. For example, using Ptolemy a data-flow system can be easily connected to a hardware simulator which in turn may be connected to a discrete-event system. Because of this, Ptolemy can be used to model entire systems. In addition, Ptolemy now has code generation capabilities. From a flow graph description, Ptolemy can generate both C code and DSP assembly code for rapid prototyping. Note that code generation is not yet complete, and is included in the current release for demonstration purposes only. Version 0.4.1 includes a graphical algorithm layout, code generator and simulator. It requires C++, C and has been ported to Sun-4, MIPS/Ultrix; DSP56001, DSP96002. Ptolemy is an active research project. 1 1 1 1 1 PTT Post, Telephone and Telegraph administration 1 1 1 1 1 PUB 1. PUBlishing. A 1972 text-formatting language for TOPS-10, with syntax based on SAIL. Influenced TeX and Scribe. ["PUB: The Document Compiler", Larry Tesler, Stanford AI Proj Op Note, Sept 1972]. 2. /pub, the top-level, publicly accessible directory on most anonymous FTP archives. This is usually where the interesting files are. See pubic directory. 1 1 1 1 1 pubic directory [NYU] (also "pube directory" /pyoob' d*-rek't*-ree/) The "pub" (public) directory on a machine that allows FTP access. So called because it is the default location for SEX (software exchange). [Jargon File] 1 1 1 1 1 public domain (PD) The total absence of copyright protection. If something is "in the public domain" then anyone can copy it or use it in any way they wish. The author has none of the exclusive rights which apply to a copyright work. The phrase "public domain" is often used incorrectly to refer to freeware or shareware (software which is copyrighted but is distributed without (advance) payment). Public domain means no copyright -- no exclusive rights. In fact the phrase public domain has no legal status at all in the UK. See also archive site, careware, charityware, copyleft, crippleware, guiltware, postcardware and -ware. Compare payware. 1 1 1 1 1 public domain software public domain 1 1 1 1 1 public-key cryptography public-key encryption 1 1 1 1 1 Public-Key Cryptography Standards (PKCS) A set of standards for public-key cryptography, developed by RSA Data Security, Inc. in cooperation with an informal consortium, originally including Apple, Microsoft, DEC, Lotus, Sun and MIT. The PKCS have been cited by the OSI Implementers' Workshop (OIW) as a method for implementation of OSI standards. PKCS includes both algorithm-specific and algorithm-independent implementation standards. Many algorithms are supported, including RSA and Diffie-Hellman key exchange, however, only the latter two are specifically detailed. PKCS also defines an algorithm-independent syntax for digital signatures, digital envelopes, and extended digital certificates; this enables someone implementing any cryptographic algorithm whatsoever to conform to a standard syntax, and thus achieve interoperability. E-mail: pkcs@rsa.com. 1 1 1 1 1 public-key encryption (PKE, Or "public-key cryptography") An encryption scheme, introduced by Diffie and Hellman in 1976, where each person gets a pair of keys, called the public key and the private key. Each person's public key is published while the private key is kept secret. Messages are encrypted using the intended recipient's public key and can only be decrypted using his private key. This is often used in conjunction with a digital signature. The need for sender and receiver to share secret information (keys) via some secure channel is eliminated: all communications involve only public keys, and no private key is ever transmitted or shared. Public-key encryption can be used for authentication, confidentiality, integrity and non-repudiation. RSA encryption is an example of a public-key cryptosystem. alt.security FAQ (http://cis.ohio-state.edu/hypertext/faq/bngusenet/alt/security/top.html). 1 1 1 1 1 Public Key Infrastructure (PKI) A system of public key encryption using digital certificates from Certificate Authorities and other registration authorities that verify and authenticate the validity of each party involved in an electronic transaction. PKIs are currently evolving and there is no single PKI nor even a single agreed-upon standard for setting up a PKI. However, nearly everyone agrees that reliable PKIs are necessary before electronic commerce can become widespread. US DOD PKI (http://www-pki.itsi.disa.mil/). US NIST PKI (http://csrc.ncsl.nist.gov/pki/). IETF PKIX Working Group (http://imc.org/ietf-pkix/). (1999-11-30) 1 1 1 1 1 Public Switched Telephone Network (PSTN, T.70) The collection of interconnected systems operated by the various telephone companies and administrations (telcos and PTTs) around the world. Also known as the Plain Old Telephone System (POTS) in contrast to xDSL and ISDN (not to mention other forms of PANS). The PSTN started as human-operated analogue circuit switching systems (plugboards), progressed through electromechanical switches. By now this has almost completely been made digital, except for the final connection to the subscriber (the "last mile"): The signal coming out of the phone set is analogue. It is usually transmitted over a twisted pair cable still as an analogue signal. At the telco office this analogue signal is usually digitised, using 8000 samples per second and 8 bits per sample, yielding a 64 kb/s data stream (DS0). Several such data streams are usually combined into a fatter stream: in the US 24 channels are combined into a T1, in Europe 31 DS0 channels are combined 1 1 1 1 1 puff To decompress data that has been crunched by Huffman coding. At least one widely distributed Huffman decoder program was actually *named* "PUFF", but these days it is usually packaged with the encoder. Opposite: huff. [Jargon File] (1996-10-16) 1 1 1 1 1 PUFFT ["The Purdue University Fast Fortran Translator", Saul Rosen et al, CACM 8(11):661-666 (Nov 1965)]. (1995-01-05) 1 1 1 1 1 pull pull media 1 1 1 1 1 pull-down list (Or "drop-down list") A graphical user interface component that allows the user to choose one (or sometimes more than one) item from a list. The current choice is visible in a small rectangle and when the user clicks on it, a list of items is revealed below it. The user can then click on one of these to make it the current choice and the list disappears. In some cases, by holding down a modifier key such as Ctrl when clicking, the selection is added to (or removed from) the set of current choices rather than replacing it. (1999-09-25) 1 1 1 1 1 pull-down menu (Or "drop-down menu", "pop-down menu") A menu in a graphical user interface, whose title is normally visible but whose contents are revealed only when the user activates it, normally by pressing the mouse button while the pointer is over the title, whereupon the menu items appear below the title. The user may then select an item from the menu or click elsewhere, in either case the menu contents are hidden again. A menu item is selected either by dragging the mouse from the menu title to the item and releasing or by clicking the title and then the item. When a pull-down menu appears in the main area of a window, as opposed to the menu bar, it may have a small, downward-pointing triangle to the right. Compare: scrollable list. (1999-09-22) 1 1 1 1 1 pull media A model of media distribution were the bits of content have to be requested by the user, e.g. normal use of HTTP on the web. Opposite: "push media". (1997-04-10) 1 1 1 1 1 Pulse Code Modulation (PCM) A method by which an audio signal is represented as digital data. Virtually all digital audio systems use PCM, including, CD, DAT, F1 format, 1630 format, DASH, DCC, and MD. Many people get confused because "PCM" is also slang for Sony's F1 format which stores PCM digital audio on videotape. (1995-02-09) 1 1 1 1 1 pumpkin A humourous term for the token - the object (notional or real) that gives its possessor (the "pumpking" or the "pumpkineer") exclusive access to something, e.g. applying patches to a master copy of source (for which the pumpkin is called a "patch pumpkin"). Chip Salzenberg <chip@perl.com> wrote: David Croy once told me once that at a previous job, there was one tape drive and multiple systems that used it for backups. But instead of some high-tech exclusion software, they used a low-tech method to prevent multiple simultaneous backups: a stuffed pumpkin. No one was allowed to make backups unless they had the "backup pumpkin". (1999-02-23) 1 1 1 1 1 pumpkineer pumpkin 1 1 1 1 1 pumpking pumpkin 1 1 1 1 1 punch card punched card 1 1 1 1 1 punched card (Or "punch card") The signature medium of computing's Stone Age, now long obsolete outside of a few legacy systems. The punched card actually predates computers considerably, originating in 1801 as a control device for Jacquard looms. Charles Babbage used them as a data and program storage medium for his Analytical Engine: "To those who are acquainted with the principles of the Jacquard loom, and who are also familiar with analytical formulæ, a general idea of the means by which the Engine executes its operations may be obtained without much difficulty. In the Exhibition of 1862 there were many splendid examples of such looms. [...] These patterns are then sent to a peculiar artist, who, by means of a certain machine, punches holes in a set of pasteboard cards in such a manner that when those cards are placed in a Jacquard loom, it will then weave upon its produce the exact pattern designed by the artist. [...] The analogy of the Analytical Engine with this well-known process is nearly perfect. There are therefore two sets of cards, the first to direct the nature of the operations to be performed -- these are called operation cards: the other to direct the particular variables on which those cards are required to operate -- these latter are called variable cards. Now the symbol of each variable or constant, is placed at the top of a column capable of containing any required number of digits." -- from Chapter 8 of Charles Babbage's "Passages from the Life of a Philosopher", 1864. The version patented by Herman Hollerith and used with mechanical tabulating machines in the 1890 US Census was a piece of cardboard about 90 mm by 215 mm. There is a widespread myth that it was designed to fit in the currency trays used for that era's larger dollar bills, but recent investigations have falsified this. IBM (which originated as a tabulating-machine manufacturer) married the punched card to computers, encoding binary 1 1 1 1 1 punt (From the punch line of an old joke referring to American football: "Drop back 15 yards and punt!") 1. To give up, typically without any intention of retrying. "Let's punt the movie tonight." "I was going to hack all night to get this feature in, but I decided to punt" may mean that you've decided not to stay up all night, and may also mean you're not ever even going to put in the feature. 2. More specifically, to give up on figuring out what the Right Thing is and resort to an inefficient hack. 3. A design decision to defer solving a problem, typically because one cannot define what is desirable sufficiently well to frame an algorithmic solution. "No way to know what the right form to dump the graph in is - we'll punt that for now." 4. To hand a tricky implementation problem off to some other section of the design. "It's too hard to get the compiler to do that; let's punt to the run-time system." 1 1 1 1 1 Purdue Compiler-Construction Tool Set (PCCTS) A highly integrated lexical analser generator and parser generator by Terence J. Parr <parrt@acm.org>, Will E. Cohen and Henry G. Dietz <hankd@ecn.purdue.edu>, both of Purdue University. ANTLR (ANother Tool for Language Recognition) corresponds to YACC and DLG (DFA-based Lexical analyser Generator) functions like LEX. PCCTS has many additional features which make it easier to use for a wide range of translation problems. PCCTS grammars contain specifications for lexical and syntactic analysis with selective backtracking ("infinite lookahead"), semantic predicates, intermediate-form construction and error reporting. Rules may employ Extended BNF (EBNF) grammar constructs and may define parameters, return values, and have local variables. Languages described in PCCTS are recognised via LLk parsers constructed in pure, human-readable, C code. Selective backtracking is available to handle non-LL(k) constructs. 1 1 1 1 1 Purdue University (http://purdue.edu/). (1995-01-05) 1 1 1 1 1 pure functional language purely functional language 1 1 1 1 1 pure lambda-calculus Lambda-calculus with no constants, only functions expressed as lambda abstractions. (1994-10-27) 1 1 1 1 1 PureLink An incremental linker from Pure Software. 1 1 1 1 1 Pure Lisp A purely functional language derived from Lisp by excluding any feature which causes side-effects. 1 1 1 1 1 purely functional language A language that supports only functional programming and does not allow functions to have side-effects. Program execution consists of evaluation of an expression and all subexpressions are referentially transparent. (2003-03-25) 1 1 1 1 1 Purify A debugging tool from Pure Software. 1 1 1 1 1 Purple Book 1. <publication> The "System V Interface Definition". The covers of the first editions were an amazingly nauseating shade of off-lavender. 2. <publication> The Wizard Book. See also book titles. [Jargon File] 1 1 1 1 1 purple wire Wire installed by IBM Field Engineers to work around problems discovered during testing or debugging. These are called "purple wires" even when (as is frequently the case) they are yellow. Compare blue wire, yellow wire, and red wire. (1995-04-11) 1 1 1 1 1 Purveyor A web server for Windows NT and Windows 95 (when available). (http://process.com/). E-mail: <info@process.com>. (1995-04-11) 1 1 1 1 1 push 1. <programming> To put something onto a stack or pdl. Opposite: "pop". 2. <communications> push media. [Jargon File] (1997-04-10) 1 1 1 1 1 push-button A roughly fingertip-sized plastic cover attached to a spring-loaded, normally-open switch, which, when pressed, closes the switch. Typical examples are the keys on a computer or calculator keyboard and mouse buttons. (1997-07-07) 1 1 1 1 1 Push Down List (PDL) In ITS days, the preferred MITism for stack. See overflow pdl. (1995-12-21) 1 1 1 1 1 push media A model of media distribution where items of content are sent to the user (viewer, listener, etc.) in a sequence, and at a rate, determined by a server to which the user has connected. This contrasts with pull media where the user requests each item individually. Push media usually entail some notion of a "channel" which the user selects and which delivers a particular kind of content. Broadcast television is (for the most part) the prototypical example of push media: you turn on the TV set, select a channel and shows and commercials stream out until you turn the set off. By contrast, the web is (mostly) the prototypical example of pull media: each "page", each bit of content, comes to the user only if he requests it; put down the keyboard and the mouse, and everything stops. At the time of writing (April 1997), much effort is being put into blurring the line between push media and pull media. 1 1 1 1 1 P value The probability that the opposite of some hypothesis is true, based on some set of results; a way of expressing the significance of a statistical observation. The lower the P value, the more significant the result. For example, if the hypothesis was "This vaccine prevents flu" then the opposite hypothesis (the "null hypothesis") would be This vaccine has no effect on flu. If the occurence of flu was measured in a sample of people taking the vaccine then one might say that the hypothesis was confirmed with a p value of 5%. That would mean there was a 5% chance of obtaining the same results or better from a similar sample of the whole population even if the vaccine had no effect. (2015-02-23) 1 1 1 1 1 PVC 1. <networking> Permanent Virtual Circuit. 2. <hardware> polyvinyl chloride. (2001-03-26) 1 1 1 1 1 PVM Parallel Virtual Machine 1 1 1 1 1 PV-WAVE (Precision Visuals' Workstation Analysis and Visualization Environment) Interactive scientific visualisation software originally from Precision Visuals, Inc., but now owned by Visual Numerics, Inc. (VNI). (1999-07-18) 1 1 1 1 1 pw The country code for Palau. (1999-01-27) 1 1 1 1 1 PWM pulse width modulation 1 1 1 1 1 py The country code for Paraguay. (1999-01-27) 1 1 1 1 1 Pythagoras (Pythagoras of Samos, Ionia; about 569-475 BC) The Greek mathematician who founded a philosophical and religious school in Croton (now Crotone) in southern Italy. Pythagoras is most famous for Pythagoras's Theorem but other important postulates are attributed to him, e.g. the sum of the angles of a triangle is equal to two right angles. (2004-02-12) 1 1 1 1 1 Pythagoras's Theorem The theorem of geometry, named after Pythagoras, of Samos, Ionia, stating that, for a right-angled triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides. I.e. if the longest side has length A and the other sides have lengths B and C (in any units), A^2 = B^2 + C^2 (2004-02-12) 1 1 1 1 1 Pythagoras' Theorem It's Pythagoras's Theorem. (2007-06-07) 1 1 1 1 1 Pythagorean Theorem Pythagoras's Theorem 1 1 1 1 1 Python 1. <language> A simple, high-level interpreted language invented by Guido van Rossum <guido@cwi.nl> in 1991. Python combines ideas from ABC, C, Modula-3 and Icon. It bridges the gap between C and shell programming, making it suitable for rapid prototyping or as an extension language for C applications. It is object-oriented and supports packages, modules, classes, user-defined exceptions, a good C interface, dynamic loading of C modules and has no arbitrary restrictions. Python is available for many platforms, including Unix, Windows, DOS, OS/2, Macintosh and Amoeba. Latest version: 2.5, as of 2007-02-21. (http://python.org/). Usenet newsgroup: news:comp.lang.python. (2007-02-21) 2. <compiler> A compiler for CMU Common LISP. Python is more sophisticated than other Common Lisp compilers. It 1 1 1 1 1 Q A very high level language by Per Bothner based on lazy generalised sequences. Q has lexical scope, and some support for logic programming[?] and constraint programming. The language includes small subsets of Common Lisp and Scheme. Q was a test-bed for programming language ideas. Where APL uses arrays for looping, Q uses generalised sequences which may be infinite and may be stored or calculated on demand. It has macros, primitives to run programs, and an interactive command language. Q is implemented in C++, and comes with an interpreter, compiler framework, libraries, and documentation. It runs on Linux and SUN-4 and should work on any 32-bit Unix. Latest version: 1, as of 1993-06-07. Development stopped in 1994 (http://kelso.bothner.com/~per/software/#Q ). E-mail: Per Bothner <per@bothner.com>. 1 1 1 1 1 QA Quality Assurance 1 1 1 1 1 qa The country code for Qatar. (1999-01-27) 1 1 1 1 1 QA4 Question-answering language. A procedural calculus for intuitive reasoning. A LISP-based pattern-matching language for theorem proving. "QA4, A Language for Writing Problem-Solving Programs", J.F. Rulifson et al, Proc IFIP Congress 1968. 1 1 1 1 1 QAM 1. Quadrature Amplitude Modulation. 2. Quality Assurance Management. 1 1 1 1 1 Qbasic Quick basic. A version of BASIC from Microsoft, later known as MS-BASIC. (1995-03-16) 1 1 1 1 1 QBE Query By Example 1 1 1 1 1 QCA Quantum-dot Cellular Automata 1 1 1 1 1 QCIF Quarter CIF 1 1 1 1 1 qdjanus A Janus-to-Prolog compiler by Saumya Debray <debray@cs.arizona.edu>. It is meant to be used with Sicstus Prolog and is mostly compliant with "Programming in Janus" by Saraswat, Kahn, and Levy. Latest version: 1.3. (ftp://cs.arizona.edu/janus/qdjanus/). (1992-05-18) 1 1 1 1 1 QDOS The Sinclair QL's proprietary operating system. The origin of the name is uncertain (a weak pun on kudos, perhaps, as Unix was on Multics). There was another OS around from the birth of personal computers called Q.D.O.S. - Quick And Dirty Operating System. QDOS might also stand for QL Data/Disk/Drive/Device Operating System. QDOS did the usual OS sorts of things, as well as multitasking. It was unusual in several ways. It treated all devices (serial ports, mouse ports, screen, microdrive, disk drive, keyboard, etc.) uniformly, so you could print a text file direct to disk or save a binary to the screen for example. Also logical channels could be assigned to particular physical devices. Output directed to a channel would go to the appropriate in/output. This also meant you could have many windows on screen (the QL booted up from internal ROMs with 3 windows - command line, output and program listing) all 1 1 1 1 1 QEMM386 A combined expanded memory manager and extended memory manager for IBM PCs with an Intel 80386 or higher processor from Quarterdeck Office Systems. QEMM386 can also act as an UMB provider and an A20 handler. (1996-01-10) 1 1 1 1 1 QIC Quarter-Inch Cartridge 1 1 1 1 1 QL (Quantum Leap) Sir Clive Sinclair's first Motorola 68008-based personal computer, developed from around 1981 and released about 1983. The QL ran Sinclair's QDOS operating system which was the first multitasking OS on a home computer, though few programmers used this feature. It had a structured, extended BASIC and a suite of integrated application programs written by Psion. It featured innovative "microdrives" which were random-access tape drives. It was not a success. The microdrives were innovative but probably a mistake. Though reliable and quite quick, they sounded like they were going to jam and explode, releasing a shower of plastic shavings and tape into your face. The QL and QDOS only supported two graphics modes - ominously named high res and low res. High res had four (fixed) colours at a resolution of 512 by 256 pixels. Low res had 8 colours (black, blue, red, magenta, green, cyan, yellow, white) plus a 1 1 1 1 1 Qlambda A LISP by Richard Gabriel and John McCarthy. ["Queue-based Multi-processing Lisp", R. Gabriel & J. McCarthy, Proc 1984 Symp Lisp and Functional Prog, pp. 25-44]. (1999-10-12) 1 1 1 1 1 QLISP 1. SRI 1973. General problem solving, influenced by PLANNER. QA4 features merged with INTERLISP. ["QLISP - A Language for the Interactive Development of Complex Systems", E. Sacerdoti et al, NCC 45:349-356, AFIPS, 1976]. 2. A parallel LISP. ["Qlisp", R. Gabriel et al in Parallel Computation and Computers for AI, J. Kowalik ed, 1988, pp.63-89]. (1999-10-12) 1 1 1 1 1 QLOG A version of Prolog implemented in Lisp which allows Prolog programs to call Lisp and vice versa. ["QLOG - The Programming Environment for Prolog in LISP", H.J. Komorowski in Logic Prgramming, K.L. Clark et al eds, Academic Press 1982]. (1995-01-25) 1 1 1 1 1 QMQP Quick Mail Queueing Protocol 1 1 1 1 1 QMTP Quick Mail Transfer Protocol 1 1 1 1 1 QMW Queen Mary and Westfield College 1 1 1 1 1 Q'NIAL A portable incremental compiler for NIAL, written in C at Queen's University, Canada. There aree versions for Unix and MS-DOS, from NIAL Systems Ltd. ["The Q'NIAL Reference Manual", M.A. Jenkins, Queen's U Report, Dec 1983]. (1995-01-25) 1 1 1 1 1 QNX A realtime, network distributed, POSIX-certified, microkernel, multi-user, multitasking, ROMable, fault-tolerant, embeddable operating system that supports TCP/IP, NFS, FTP, the X Window System, Microsoft Windows as a guest process, Ethernet, Token Ring, Arcnet and Watcom ANSI C/C++. Support for Pentium, 486, 386, 286, 80x87. Developed and distributed by QNX Software Systems, Ltd. Latest version: 6.1, as of 2001-09-02. QNX Home (http://qnx.com/). OpenQNX: The QNX community portal (http://openqnx.com). Papers (ftp://ftp.cse.ucsc.edu/pub/qnx/qnx-paper.ps.Z). (128.114.134.19). Usenet newsgroup: news:comp.os.qnx. E-mail: <info@qnx.com>. (2003-07-27) 1 1 1 1 1 QoS Quality of service 1 1 1 1 1 QPE 1. A two-dimensional pictorial query language. ["Pictorial Information Systems", S.K. Chang et al eds, Springer 1980]. [Q-systems. A. Colmerauer, 1969]. 2. A rewrite system with one-way unification, used for English-French translation. It led to Prolog. ["The Birth of Prolog" A. Colmerauer et al, SIGPLAN Notices 28(3):37-52 March 1993]. (2003-12-25) 1 1 1 1 1 QSAM Physical Sequential 1 1 1 1 1 QT-OBJECTS A library by Michael Travers <mt@media.mit.edu> and others providing an interface between MCL and QuickTime. (1992-12-20) 1 1 1 1 1 QTRADER Analytical software for stock and commodity trading, released in July 1995 by Caribou CodeWorks. QTRADER allows dynamic automated analysis of current trends and features "Paper Trade" plotting, as well as "TradeSignal Bands" and "StudyMatrix" filter to screen potential trades. Projected ranges are handled with a "Tomorrow's Bar". QTRADER version 3.0 runs on IBM PC-compatibles, a Macintosh version is not available until late 1996. Demo copy (http://winternet.com/~jottis). (ftp://ftp.winternet.com/users/jottis). (1995-11-05) 1 1 1 1 1 quad The rectangle or box glyph used in the APL language for various arcane purposes mostly related to I/O. [Jargon File] (2007-05-31) 1 1 1 1 1 Quadralay Corporation The developers of GWHIS. (http://quadralay.com/). Telephone: +1 512-346-9199. Fax: +1 512-346-8990. (2000-08-12) 1 1 1 1 1 Quadrature Amplitude Modulation (QAM) A method for encoding digital data in an analog signal in which each combination of phase and amplitude represents one of sixteen four bit patterns. This is required for fax transmission at 9600 bits per second. (1995-02-02) 1 1 1 1 1 quadruple bucky Obsolete. 1. On an MIT space-cadet keyboard, use of all four of the shifting keys (control, meta, hyper, and super) while typing a character key. 2. On a Stanford or MIT keyboard in raw mode, use of four shift keys while typing a fifth character, where the four shift keys are the control and meta keys on *both* sides of the keyboard. This was very difficult to do! One accepted technique was to press the left-control and left-meta keys with your left hand, the right-control and right-meta keys with your right hand, and the fifth key with your nose. Quadruple-bucky combinations were very seldom used in practice, because when one invented a new command one usually assigned it to some character that was easier to type. If you want to imply that a program has ridiculously many commands or features, you can say something like: "Oh, the command that makes it spin the tapes while whistling Beethoven's Fifth Symphony is quadruple-bucky-cokebottle." See double bucky, 1 1 1 1 1 quadruplex A kind of telegraphy system developed by Thomas A. Edison in the 1870s combining diplex and duplex communications to support simultaneous transmission of two messages in each direction. (2000-04-02) 1 1 1 1 1 Quake A string-oriented language designed to support the construction of Modula-3 programs from modules, interfaces and libraries. Written by Stephen Harrison of DEC SRC, 1993. 1 1 1 1 1 Qualcomm A California-based technology company; their primary product is the OMNITRACS tractor-trailer-tracking system. They also develop the free and commercial versions of Eudora for Macintosh and IBM PC. (1995-10-05) 1 1 1 1 1 quality The totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs. Not to be mistaken for "degree of excellence" or fitness for use which meet only part of the definition. [ISO8402]. (1995-11-10) 1 1 1 1 1 quality assurance (QA) A planned and systematic pattern of all actions necessary to provide adequate confidence that the product optimally fulfils customers' expectations, i.e. that it is problem-free and well able to perform the task it was designed for. The QA of a commercial product usually involves alpha testing, where an early version of the product is tested at the developer's site, and is then improved accordingly. Then, an almost complete version of the product is made available for beta testing by (selected) real users. Faults identified during beta testing should be fixed before the product is released for full scale manufacturing and distribution. (2001-04-21) 1 1 1 1 1 quality control The assessment of product compliance with stated requirements. Quality control should be independent from production. (2001-05-20) 1 1 1 1 1 quality of service (QoS) The performance properties of a network service, possibly including throughput, transit delay, priority. Some protocols allow packets or streams to include QoS requirements. (1998-07-30) 1 1 1 1 1 Quality Systems & Software Ltd. The company which produced the DOORS requirements engineering tool. They also provide consultancy as Requirements Engineering Ltd. (http://qss.co.uk/). E-mail: Ian Alexander <iany@easynet.co.uk>, Amanda Haisman-Baker <100023.44@compuserve.com>. (1995-11-11) 1 1 1 1 1 quantifier An operator in predicate logic specifying for which values of a variable a formula is true. Universally quantified means "for all values" (written with an inverted A, LaTeX \forall) and existentially quantified means "there exists some value" (written with a reversed E, LaTeX \exists). To be unambiguous, the set to which the values of the variable belong should be specified, though this is often omitted when it is clear from the context (the "universe of discourse"). E.g. Forall x . P(x) <=> not (Exists x . not P(x)) meaning that any x (in some unspecified set) has property P which is equivalent to saying that there does not exist any x which does not have the property. If a variable is not quantified then it is a free variable. In logic programming this usually means that it is actually universally quantified. 1 1 1 1 1 Quantify A performance analysis tool from Pure Software. 1 1 1 1 1 quantum time slice 1 1 1 1 1 quantum bogodynamics /kwon'tm boh"goh-di:-nam"iks/ A theory that characterises the universe in terms of bogon sources (such as politicians, used-car salesmen, TV evangelists, and suits in general), bogon sinks (such as taxpayers and computers), and bogosity potential fields. Bogon absorption causes human beings to behave mindlessly and machines to fail (and may also cause both to emit secondary bogons); however, the precise mechanics of bogon-computron interaction are not yet understood. Quantum bogodynamics is most often invoked to explain the sharp increase in hardware and software failures in the presence of suits; the latter emit bogons, which the former absorb. [Jargon File] (1994-11-02) 1 1 1 1 1 quantum cell (Or "quantum dot cell") A structure comprising four quantum dots arranged in a square, with two diagonally opposed dots containing electron charges. One diagonal containing charges is arbitrarily defined as representing a value of '1', the other as '0'. In a five-dot cell, the fifth, central dot contains no charge. See also: quantum cell wire, quantum-dot cellular automata. (http://mitre.org/research/nanotech/quantum_dot_cell.html). ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley & Sons Ltd., Dec 1998]. [Implementations?] (2001-07-17) 1 1 1 1 1 quantum cell wire (Or "quantum wire", "binary wire") Quantum cells arranged in a line to carry signals. Adjacent cells with the same orientation are at a low energy state and a change of orientation at one end of a quantum wire propagates along the wire, transmitting a signal. However, unlike conventional wire, since only the orientation of charge pairs changes, no current flows. Circuits created using quantum cell wires are referred to as Quantum-dot Wireless Digital Circuits, see quantum dot, Quantum-dot Cellular Automata. (http://mitre.org/research/nanotech/quantum_dot_cell.html). ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley & Sons Ltd., Dec 1998] (2001-07-17) 1 1 1 1 1 quantum computer A type of computer which uses the ability of quantum systems, such as a collection of atoms, to be in many different states at once. In theory, such superpositions allow the computer to perform many different computations simultaneously. This capability is combined with interference among the states to produce answers to some problems, such as factoring integers, much more rapidly than is possible with conventional computers. In practice, such machines have not yet been built due to their extreme sensitivity to noise. Oxford University (http://eve.physics.ox.ac.uk/QChome.html), Stanford University (http://feynman.stanford.edu/qcomp/). A quantum search algorithm (ftp://parcftp.xerox.com/pub/dynamics/quantum.html) for constraint satisfaction problems exhibits the phase transition for NP-complete problems. (1997-02-11) 1 1 1 1 1 quantum computing quantum computer 1 1 1 1 1 quantum dot (Or "single-electron transistor") A location capable of containing a single electrical charge; i.e., a single electron of Coulomb charge. Physically, quantum dots are nanometer-size semiconductor structures in which the presence or absence of a quantum electron can be used to store information. See also: quantum cell, quantum cell wire, quantum-dot cellular automata. (http://www-mtl.mit.edu/MTL/bulletin/v6n2/Kumar.html). ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley & Sons Ltd., Dec 1998]. (2001-07-17) 1 1 1 1 1 Quantum-dot Cellular Automata (QCA) Quantum logic circuits created by orientating pairs of quantum cells so that their relative positions determine their affect on each other. This is functionally analogous but structurally different from how individual gates in integrated circuits are combined to create logical and memory circuitry. The advantages of quantum-dot cellular automata over conventional circuitry are extremely small size/high density, low power requirements, and potentially high processing speeds. Disadvantages (in 2000) are difficulty of fabrication and low yield. See also: quantum cell wire. (http://nd.edu/~qcahome/). (http://mitre.org/research/nanotech/quantum_dot_cell.html). ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley & Sons Ltd., Dec 1998]. (2001-07-17) 1 1 1 1 1 quarter crumb 1 1 1 1 1 Quarter CIF (QCIF), a video format standard used in videoconferencing, that transfers one fourth as much data as Common Intermediate Format (CIF). QCIF is defined in ITU H.261 as having 144 lines and 176 pixels per line, with half as many chrominance pixels in each direction. QCIF is suitable for videoconferencing systems that use telephone lines. The codec standard specifies that QCIF compatibility is mandatory, and CIF compatibility is optional. (1999-04-22) 1 1 1 1 1 Quarter Inch Cartridge /kwik/ (QIC) a type of magnetic tape and tape drive. Development standards for QIC make it possible for tapes written on one QIC drive to be read on another. QIC drives are made to work with different lengths of tape. The model number of the drive consists of QIC followed by a number which indicates the drives tape capacity in megabytes (MB). (1996-12-09) 1 1 1 1 1 Quay Financial Software CSK Software 1 1 1 1 1 QUEASY An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-25) 1 1 1 1 1 Queen Mary and Westfield College (QMW) One of the largest of the multi-faculty schools of the University of London. QMW has some 6000 students and over 600 teaching and research staff organised into seven faculties. QMW was one of the first colleges in the University of London to develop fully the course-unit, or modular, approach to degree programmes. Cross faculty courses are encouraged and the physical proximity of all the College buildings is a major factor in enabling students to adopt an interdisciplinary approach to their studies. (http://qmw.ac.uk/). (1995-01-25) 1 1 1 1 1 Queens Problem Eight Queens Puzzle 1 1 1 1 1 Queens Puzzle Eight Queens Puzzle 1 1 1 1 1 Queen's University A Canadian University. Source of GVL, NIAL, Pasqual, Q'NIAL and TXL. (ftp://ftp.qucis.queensu.ca/pub/). (1994-10-20) 1 1 1 1 1 QUEL The query language used by the database management system INGRES. (1995-01-31) 1 1 1 1 1 query 1. <database, information science> A user's (or agent's) request for information, generally as a formal request to a database or search engine. SQL is the most common database query language. 2. <character> question mark. (1997-04-09) 1 1 1 1 1 Query By Example (QBE) A user-friendly query language developed by Moshé Zloof of IBM in 1975. (http://informatik.uni-trier.de/~ley/db/indices/a-tree/z/Zloof:Mosh=eacute=_M=.html). [Moshé M. Zloof, "Query By Example", AFIPS NCC 1975: 431-438]. [Moshé M. Zloof, "Query-by-Example: A Data Base Language", IBM Systems Journal 16(4): 324-343, 1977]. ["QBE/OBE: A Language for Office and Business Automation", M.M. Zloof, Computer pp.13-22, May 1981]. (2001-03-25) 1 1 1 1 1 query expansion Adding search terms to a user's search. Query expansion is the process of a search engine adding search terms to a user's weighted search. The intent is to improve precision and/or recall. The additional terms may be taken from a thesaurus. For example a search for "car" may be expanded to: car cars auto autos automobile automobiles. The additional terms may also be taken from documents that the user has specified as being relevant; this is the basis for the "more like this" feature of some search engines. The extra terms can have positive or negative weights. (1999-08-27) 1 1 1 1 1 ques question mark 1 1 1 1 1 Quest 1. A language designed for its simple denotational semantics. The Denotational Semantics of Programming Languages, R. Tennent, CACM 19(8):437-453 (Aug 1976). 2. QUantifiers and SubTypes. Language with a sophisticated type system. Just as types classify values, "kinds" classify types and type operators. Explicit universal and existential quantification over types, type operators, and subtypes. Subtyping is defined inductively on all type constructions, including higher-order functions and abstract types. User-definable higher-order type operators. Typeful Programming, Luca Cardelli <luca@src.dec.com>, RR 45, DEC SRC 1989. Implemented in Modula-3. (ftp://gatekeeper.dec.com/pub/DEC/Quest/quest12A.tar.Z). 3. <tool, text> A multimedia authoring system. Quest has been available for MS-DOS for some time. Version 3.5 for Microsoft Windows was released around March 1995. It 1 1 1 1 1 question mark "?", ASCII character 63. Common names: query; ITU-T: question mark; ques. Rare: whatmark; INTERCAL: what; wildchar; huh; hook; buttonhook; hunchback. Question mark is used, along with colon for C's lazy triadic "if" operator (similar to the IIF function in Visual Basic). The expression x?y:z evaluates x, then if x is true it returns y else it returns z. In Unix shell file name patterns, question mark matches any single character. (2003-06-17) 1 1 1 1 1 queue A first-in first-out data structure used to sequence objects. Objects are added to the tail of the queue ("enqueued") and taken off the head ("dequeued"). For example, an operating system might use a queue to serialise concurrent demands for a resource such as a printer, processor or communications channel. Users might place files on a print queue and a background process or demon would take them off and print them. Another common use is to pass data between an interrupt handler and a user process. (2007-05-18) 1 1 1 1 1 Queued Sequential Access Method Physical Sequential 1 1 1 1 1 QUICK An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1995-05-11) 1 1 1 1 1 quick-and-dirty Describes a crock put together under time or user pressure. Used especially when you want to convey that you think the fast way might lead to trouble further down the road. "I can have a quick-and-dirty fix in place tonight, but I'll have to rewrite the whole module to solve the underlying design problem." See also kluge. [Jargon File] (1995-05-11) 1 1 1 1 1 QuickDraw Part of the software in the Apple Macintosh's ROM that performs graphics operations. (1995-05-11) 1 1 1 1 1 Quick Mail Queueing Protocol (QMQP) A protocol that provides a central e-mail queue for a cluster of hosts. QMOP is supposed to provide fast transfers of messages with many recipients as it can batch them up as a single transaction. It listens on port 628. (http://cr.yp.to/mail.html) (2007-05-25) 1 1 1 1 1 Quick Mail Transfer Protocol (QMTP) An SMTP replacement that works better over high latency links as it doesn't require as much interaction as SMTP. QMTP listens on port 209 and is used by qmail. (http://cr.yp.to/mail.html) (2007-05-25) 1 1 1 1 1 Quicksilver A dBASE-like compiler for MS-DOS from WordTech. (1995-05-11) 1 1 1 1 1 Quicksort A sorting algorithm with O(n log n) average time complexity. One element, x of the list to be sorted is chosen and the other elements are split into those elements less than x and those greater than or equal to x. These two lists are then sorted recursively using the same algorithm until there is only one element in each list, at which point the sublists are recursively recombined in order yielding the sorted list. This can be written in Haskell: qsort :: Ord a => [a] -> [a] qsort [] = [] qsort (x:xs) = qsort [ u | u<-xs, u<x ] ++ 1 1 1 1 1 QuickTime Apple Computer's software for playing audio and video. The QuickTime application is a free media player. QuickTime Pro is a paid-for version with editing ability. QuickTime's native format for audio and video is .mov but it can handle many others. (http://apple.com/quicktime/what-is) (2011-01-04) 1 1 1 1 1 quiesce To render quiescent, i.e. temporarily inactive or disabled. For example to quiesce a device (such as a digital modem). It is also a system command in MAX TNT software which is used to "Temporarily disable a modem or DS0 channel". Also used as an adjective, in the expression "quiesce time". (2000-03-05) 1 1 1 1 1 quiesce time The length of time taken to quiesce a system (to render it inactive), or the length of time between periods of inactivity. (2000-03-05) 1 1 1 1 1 QUIKSCRIPT Simulation language derived from SIMSCRIPT, based on 20-GATE. ["Quikscript - A Simpscript-like Language for the G-20", F.M. Tonge et al, CACM 8(6):350-354 (June 1965)]. 1 1 1 1 1 QUIKTRAN Fortran-like, interactive with debugging facilities. Sammet 1969, p.226. 1 1 1 1 1 QUIN Pyle 1965. Interactive language. Sammet 1969, p.691. 1 1 1 1 1 quine /kwi:n/ (After the logician Willard V. Quine, via Douglas Hofstadter) A program that generates a copy of its own source text as its complete output. Devising the shortest possible quine in some given programming language is a common hackish amusement. In most interpreted languages, any constant, e.g. 42, is a quine because it "evaluates to itself". In certain Lisp dialects (e.g. Emacs Lisp), the symbols "nil" and "t" are self-quoting, i.e. they are both a symbol and also the value of that symbol. In some dialects, the function-forming function symbol, "lambda" is self-quoting so that, when applied to some arguments, it returns itself applied to those arguments. Here is a quine in Lisp using this idea: ((lambda (x) (list x x)) (lambda (x) (list x x))) Compare this to the lambda expression: (\ x . x x) (\ x . x x) 1 1 1 1 1 Quintec-Objects Based on Quintec Prolog (not Quintus). British. 1 1 1 1 1 quintillion 10^30 in Europe (this is called a nonillion in the United States and Canada). 10^18 in the United States and Canada (this is called a trillion in Europe). [Collins dictionary]. 1 1 1 1 1 Quintus Prolog A version of Prolog developed by Quintus. Development of Quintus Prolog had transferred to the Swedish Institute of Computer Science by December 1998. (ftp://ftp.quintus.com/). Telephone: +1 (800) 542 1283. [More details? Features?] (1998-12-12) 1 1 1 1 1 quote chapter and verse [by analogy with the mainstream phrase] To cite a relevant excerpt from an appropriate bible. "I don't care if "rn" gets it wrong; "Followup-To: poster" is explicitly permitted by RFC 1036. I'll quote chapter and verse if you don't believe me." See also legalese, language lawyer, RTFS (sense 2). [Jargon File] 1 1 1 1 1 quotient The number obtained by dividing one number (the "numerator") by another (the "denominator"). If both numbers are rational then the result will also be rational. 1 1 1 1 1 Qu-Prolog An extension of Prolog which performs meta-level computations over object languages, such as predicate calculi and lambda-calculi, which have object-level variables, and quantifiers that create local scopes for those variables. Qu-Prolog is well suited as an implementation language for theorem provers and support notations typically found in texts on mathematics and logic. 1 1 1 1 1 Quty A functional plus logic language. "Quty: A Functional Language Based on Unification", M. Sato et al, in Conf. Fifth Gen. Computer Systems, ICOT 1984, pp.157-165. 1 1 1 1 1 qux /kwuhks/ A metasyntactic variable in the foo series; a mutation from quux. (2015-03-22) 1 1 1 1 1 QWERTY /kwer'tee/ (From the top left row of letter keys of most keyboards) Pertaining to a standard English-language typewriter keyboard (sometimes called the Sholes keyboard after its inventor), as opposed to Dvorak or foreign-language layouts (e.g. "keyboard AZERTY" in french-speaking countries) or a space-cadet keyboard or APL keyboard. The QWERTY layout is a fine example of a fossil. It is sometimes said that it was designed to slow down the typist, but this is wrong; it was designed to allow *faster* typing - under a constraint now long obsolete. In early typewriters, fast typing using nearby type-bars jammed the mechanism. So Sholes fiddled the layout to separate the letters of many common digraphs (he did a far from perfect job, though; "th", tr, "ed", and "er", for example, each use two nearby keys). Also, putting the letters of "typewriter" on one line allowed it to be typed with particular speed and accuracy for demos. 1 1 1 1 1 QX (Meaning "OK", from E.E. Smith SF books) A language for digital signal processing of digitised speech, by Richard Gillmann of SDC, Santa Monica. QX was part of SDC's speech recognition project. (1995-02-09) 1 1 1 1 1 R2000 MIPS R2000 1 1 1 1 1 R2RS A revision of RRS, itself revised in R3RS. ["The Revised Revised Report on the Algorithmic Language Scheme", Clinger, AI Memo 848, MIT Aug 1985]. (1995-02-09) 1 1 1 1 1 R3.99RS R4RS without the macros. 1 1 1 1 1 R3RS A revision of R2RS, revised in R4RS. ["The Revised^3 Report on the Algorithmic Language Scheme", J. Rees et al, SIGPLAN Notices 21(12):37-79 (Dec 1986)]. 1 1 1 1 1 R4RS A revision of R3RS, revised in R3.99RS. (ftp://altdorf.ai.mit.edu/). ["The Revised^4 Report on the Algorithmic Language Scheme", W. Clinger et al, MIT (Nov 1991)]. (1994-10-28) [Later revisions?] 1 1 1 1 1 rabbit job (Cambridge) A batch job that does little, if any, real work, but creates one or more copies of itself, breeding like rabbits. Compare wabbit, fork bomb. [Jargon File] (1994-11-09) 1 1 1 1 1 RACE Requirements Acquisition and Controlled Evolution. (1995-11-21) 1 1 1 1 1 race condition Anomalous behavior due to unexpected critical dependence on the relative timing of events. For example, if one process writes to a file while another is reading from the same location then the data read may be the old contents, the new contents or some mixture of the two depending on the relative timing of the read and write operations. A common remedy in this kind of race condition is file locking; a more cumbersome remedy is to reorganize the system such that a certain processes (running a daemon or the like) is the only process that has access to the file, and all other processes that need to access the data in that file do so only via interprocess communication with that one process. As an example of a more subtle kind of race condition, consider a distributed chat network like IRC, where a user is granted channel-operator privileges in any channel he starts. If two users on different servers, on different 1 1 1 1 1 RACF Resource Access Control Facility 1 1 1 1 1 RAD Rapid Application Development. 1 1 1 1 1 Raddle ["On the Design of Large Distributed Systems", I.R. Forman, Proc 1st IEEE Intl Conf Comp Langs, pp.25-27 (Oct 1986)]. (2008-07-30) 1 1 1 1 1 Radio-frequency identification (RFID) Small radio transponders or "tags" designed to be attached to items like products in a supermarket to allow the items to be identified and tracked by a remote system. Typically an RFID tag includes an integrated circuit that stores data and interfaces to the antenna, allowing the stored data to be retrieved by the remote system. (2008-07-30) 1 1 1 1 1 Radio Frequency Interference (RFI) Electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. The most important means of reducing RFI are: use of bypass or decoupling capacitors on each active device (connected across the power supply, as close to the device as possible), risetime control of high speed signals using series resistors and VCC filtering. Shielding is usually a last resort after other techniques have failed because of the added expense of RF gaskets and the like. The efficiency of the radiation is dependent on the height above the ground or power plane (at RF one is as good as the other) and the length of the conductor in relationship to the wavelength of the signal component (fundamental, harmonic or transient (overshoot, undershoot or ringing)). At lower 1 1 1 1 1 radio in the loop Wireless Local Loop 1 1 1 1 1 radiosity A method for rendering a view of a three-dimensional scene that provides realistic lighting effects, such as interobject reflections and color bleeding. Radiosity methods are computationally intense, due to the use of linear systems of equations and the spatial complexity of large scenes. Usenet newsgroup: news:comp.graphics. [Is radiosity more accurate than ray tracing? Does it take more computing power? How does compute time scale with scene complexity?] (2003-06-01) 1 1 1 1 1 RADIUS Remote Authentication Dial-In User Service 1 1 1 1 1 radix The ratio, R, between the weights of adjacent digits in positional representation of numbers. The right-most digit has weight one, the digit to its left has weight R, the next R^2, R^3, etc. The radix also determines the set of digits which is zero to R-1. E.g. decimal (radix ten) uses 0-9 and each digit is worth ten times as much as you move left along the number. (2006-11-10) 1 1 1 1 1 RAID Redundant Arrays of Independent Disks 1 1 1 1 1 RAIL Automatix. High-level language for industrial robots. (2006-11-10) 1 1 1 1 1 rainbow series Any of several series of technical manuals distinguished by cover colour. The original rainbow series was the NCSC security manuals (see Orange Book, crayola books); the term has also been commonly applied to the PostScript reference set (see Red Book, Green Book, Blue Book, White Book). Which books are meant by ""the" rainbow series" unqualified is thus dependent on one's local technical culture. [Jargon File] (1996-12-03) 1 1 1 1 1 rain dance 1. Any ceremonial action taken to correct a hardware problem, with the expectation that nothing will be accomplished. This especially applies to reseating printed circuit boards, reconnecting cables, etc. "I can't boot up the machine. We'll have to wait for Greg to do his rain dance." 2. Any arcane sequence of actions performed with computers or software in order to achieve some goal; the term is usually restricted to rituals that include both an incantation or two and physical activity or motion. Compare magic, voodoo programming, black art, cargo cult programming, wave a dead chicken. [Jargon File] (1995-02-09) 1 1 1 1 1 RAIS Redundant Array of Inexpensive Servers 1 1 1 1 1 RAISE Rigorous Approach to Industrial Software Engineering 1 1 1 1 1 RAISE Specification Language (RSL) (RAISE = Rigorous Approach to Industrial Software Engineering). A wide-spectrum specification and design language developed by ESPRIT Project 315 at CRI A/S, Denmark. Systems may be modular, concurrent and nondeterministic. Specifications may be applicative or imperative, explicit or implicit, abstract or concrete. ["The RAISE Specification Language", RAISE Language Group, P-H 1992, ISBN 0-13-752833-7]. (2007-10-02) 1 1 1 1 1 RAL 1. Rutherford Appleton Laboratory (UK). 2. An expert system. 1 1 1 1 1 RAM random-access memory 1 1 1 1 1 Rambus DRAM (RDRAM) A high bandwidth DRAM, designed by Rambus, Inc. of Mountain View, CA. RDRAM is used mainly for video accelerators, and also in the Ultra 64 from Nintendo. It offers sustained transfer rates of around 1000 Mbps, compared to 200 Mbps for ordinary DRAM. Although it cannot be used as a direct replacement for existing memory, it is likely that it will replace DRAM and SDRAM as the main memory system in personal computers as the bus speeds required by these machines increase. SDRAM can operate up to around 100MHz, but RDRAM has been demonstrated by the manufacturers running at 600MHz. The memory is also only 8 or 9 bits wide, so the bandwidth would increase enormously if it were used in parallel to give 32 or 64-bit memory. RDRAM Installation (http://www.cheapestrdram.com/rdram_install.php). (2007-06-13) 1 1 1 1 1 Rambus, Inc. The company which designed Rambus DRAM. (http://rambus.com/). Address: Mountain View, CA., USA. (1996-12-15) 1 1 1 1 1 RAMDAC Random Access Memory Digital-to-Analog Converter 1 1 1 1 1 RAM disk A memory-resident program which mimics a hard disk drive. It uses part of computer's RAM to store data which can be accessed as files. Unlike a real disk drive, this drive forgets all stored data when the computer is turned off. (1995-03-14) 1 1 1 1 1 RAM drive RAM disk 1 1 1 1 1 RAMIS II Rapid Access Management Information System. A database from On-Line Software International. (1994-11-14) 1 1 1 1 1 RAMTRON The company which holds the patents for FRAM and licenses the technology to other companies. The licensees are currently (Feb 1997) Hitachi, Rohm, Samsung, SGS-Thomson and Toshiba, none of who offer FRAM products of their own yet. (http://csn.net/ramtron/). (1997-02-19) 1 1 1 1 1 random 1. Unpredictable (closest to mathematical definition); weird. The system's been behaving pretty randomly. 2. Assorted; undistinguished. "Who was at the conference?" Just a bunch of random business types. 3. (pejorative) Frivolous; unproductive; undirected. "He's just a random loser." 4. Incoherent or inelegant; poorly chosen; not well organised. The program has a random set of misfeatures. "That's a random name for that function." "Well, all the names were chosen pretty randomly." 5. In no particular order, though deterministic. "The I/O channels are in a pool, and when a file is opened one is chosen randomly." 6. Arbitrary. "It generates a random name for the scratch file." 7. Gratuitously wrong, i.e. poorly done and for no good apparent reason. For example, a program that handles file 1 1 1 1 1 random-access memory (RAM) (Previously "direct-access memory"). A data storage device for which the order of access to different locations does not affect the speed of access. This is in contrast to, say, a magnetic disk, magnetic tape or a mercury delay line where it is very much quicker to access data sequentially because accessing a non-sequential location requires physical movement of the storage medium rather than just electronic switching. In the 1970s magnetic core memory was used and some old-timers still call RAM "core". The most common form of RAM in use today is semiconductor integrated circuits, which can be either static random-access memory (SRAM) or dynamic random-access memory (DRAM). The term "RAM" has gained the additional meaning of read-write. Most kinds of semiconductor read-only memory (ROM) are actually "random access" in the above sense but are never referred to as RAM. Furthermore, memory referred to as 1 1 1 1 1 Random Access Memory Digital-to-Analog Converter (RAMDAC) A combination of three fast DACs with a small SRAM used in graphics display adapters to store the colour palette and to generate the analog signals to drive a colour monitor. The logical colour number from the display memory is fed into the address inputs of the SRAM to select a palette entry to appear on the output of the SRAM. This entry is composed of three separate values corresponding to the three components (red, green, and blue) of the desired physical colour. Each component value is fed to a separate DAC, whose analog output goes to the monitor, and ultimately to one of its three electron guns (or equivalent in non-CRT displays). DAC word lengths range usually from 6 to 10 bits. The SRAM's wordlength is three times the DAC's word length. The SRAM acts as a colour lookup table. It usually has 256 entries (and thus an 8-bit address). If the DAC's word length is also 8 bits, we have a 256 x 24-bit SRAM which allows a selection 1 1 1 1 1 randomness 1. An inexplicable misfeature; gratuitous inelegance. 2. A hack or crock that depends on a complex combination of coincidences (or, possibly, the combination upon which the crock depends for its accidental failure to malfunction). "This hack can output characters 40--57 by putting the character in the four bit accumulator field of an XCT and then extracting six bits - the low 2 bits of the XCT opcode are the right thing. ""What randomness!""" 3. Of people, synonymous with "flakiness". The connotation is that the person so described is behaving weirdly, incompetently, or inappropriately for reasons which are (a) too tiresome to bother inquiring into, (b) are probably as inscrutable as quantum phenomena anyway, and (c) are likely to pass with time. "Maybe he has a real complaint, or maybe it's just randomness. See if he calls back." [Jargon File] 1 1 1 1 1 random number pseudorandom number 1 1 1 1 1 random testing A black-box testing approach in which software is tested by choosing an arbitrary subset of all possible input values. Random testing helps to avoid the problem of only testing what you know will work. (2001-04-30) 1 1 1 1 1 range 1. interval. 2. image. 1 1 1 1 1 ransomware A kind of malware that encrypts files on your computer and then demands that you send the malware operator money in order to have the files decrypted. CryptoLocker was the best known example of ransomware. (2015-01-22) 1 1 1 1 1 Rapid Application Development (RAD) A loose term for any software life-cycle designed to give faster development and better results and to take maximum advantage of recent advances in development software. RAD is associated with a wide range of approaches to software development: from hacking away in a GUI builder with little in the way of analysis and design to complete methodologies expanding on an information engineering framework. Some of the current RAD techniques are: CASE tools, iterative life-cycles, prototyping, workshops, SWAT teams, timebox development, and Re-use of applications, templates and code. RAD at BSO/Den Haag (http://riv.nl/origin/company/denhaag/RAD.HTM). ["Rapid Application Development", James Martin]. (1995-09-23) 1 1 1 1 1 RapidCAD A specially packaged Intel 486DX and a dummy floating point unit (FPU) designed as pin-compatible replacements for an Intel 80386 processor and 80387 FPU. Since the DX variant has a working on-chip FPU, a dummy FPU package is supplied to go in the 387 FPU socket. (1995-05-10) 1 1 1 1 1 Rapidly Extensible Language, English (REL English) A formal language based on English. ["Practical Natural Language Processing: The REL System as Prototype", Adv in Computers 13, Academic Press 1975]. (1997-04-09) 1 1 1 1 1 rapid prototyping The creation of a working model of a software module to demonstrate the feasibility and suitability of the function. The prototype is expected to be replaced or refined before inclusion in the final product. Rapid prototyping contrasts with a DIRFT approach which emphasises careful design and implementation to avoid the overheads of debugging and testing prototype code. Rapid prototyping is appropriate when the requirements are unclear or likely to change (which is most of the time). (2012-11-17) 1 1 1 1 1 Rapidwrite A method for translating set of abbreviations into the much more verbose COBOL code. [Sammet 1969, p. 338]. (1995-05-10) 1 1 1 1 1 RAPT ["An Interpreter for a Language for Describing Assemblies", R.J. Popplestone et al, Artif Intell 14:79-107 (1980)]. (1995-05-10) 1 1 1 1 1 RARE Réseaux Associés pour la Recherche Européenne 1 1 1 1 1 rare mode Unix CBREAK mode (character-by-character with keyboard interrupts enabled). Distinguished from raw mode and cooked mode; the phrase "a sort of half-cooked (rare?) mode" is used in the V7/BSD manuals to describe the mode. Usage: rare. [Jargon File] (1995-05-10) 1 1 1 1 1 RARP Reverse Address Resolution Protocol 1 1 1 1 1 RAS 1. <hardware, storage> Row Address Strobe. 2. <communications> Remote Access Services. 3. <systems> Reliability, Availability, Serviceability. (2000-08-13) 1 1 1 1 1 RASP ["RASP - A Language with Operations on Fuzzy Sets", D.D. Djakovic, Comp Langs 13(3):143-148 (1988)]. (1995-05-10) 1 1 1 1 1 raster The area of a video display that is covered by sweeping the electron beam of the display in a series of horizontal lines from top to bottom. The beam then returns to the top during the vertical flyback interval. See also CRT, frame buffer. (1995-03-22) 1 1 1 1 1 raster blaster (Cambridge) Specialised hardware for bitblt operations (a blitter). Allegedly inspired by Rasta Blasta, British slang for the sort of portable stereo Americans call a "boom box" or "ghetto blaster". [Jargon File] (1995-03-22) 1 1 1 1 1 raster burn 1. (Or terminal illness) Eyestrain brought on by too many hours of looking at low-resolution, poorly tuned, or glare-ridden monitors, especially graphics monitors. 2. The "burn-in" condition your CRT tends to get if you don't use a screen saver. [Jargon File] 1 1 1 1 1 raster font bitmap font 1 1 1 1 1 rastergram Single Image Random Dot Stereogram 1 1 1 1 1 raster graphics Computer graphics in which an image is composed of an array of pixels arranged in rows and columns. Opposite: vector graphics. (1995-03-22) 1 1 1 1 1 Raster Image Processor (RIP) A device (usually hardware but can be software) that takes a Page Description Language description of a page and converts it into a bitmap for printing. (2003-09-10) 1 1 1 1 1 rasterising A transformation that can be applied to an image to prepare it for printing. Rasterising reduces resolution by a factor of typically four to eight. It also reduces sensitivity to paper properties. Rasterising can be combined with dithering. [How does it work?] (2003-07-20) 1 1 1 1 1 rasterizing rasterising 1 1 1 1 1 raster subsystem The part of a graphics system concerned with an image after it has been transformed and scaled to screen coordinates. It includes scan conversion and display. (1995-03-22) 1 1 1 1 1 Ratatosk An SLR parser generator written in Gofer (a Haskell variant) by Torben AEgidius Mogensen <torbenm@diku.dk>. Ratatosk generates purely functional backtracking LR0 grammar parsers (also in Gofer). Even though the sematic value of a production is a function of the attributes of its right-hand side (and thus apparently purely synthesised), inherited attributes are easily simulated by using higher-order functions. (ftp://ftp.diku.dk/pub/diku/dists/Ratatosk.tar.Z). 1 1 1 1 1 rat belt A cable tie, especially the sawtoothed, self-locking plastic kind that you can remove only by cutting (as opposed to a random twist of wire or a twist tie or one of those humongous metal clip frobs). Small cable ties are "mouse belts". [Jargon File] 1 1 1 1 1 RatC Rationalized C 1 1 1 1 1 RATEL Raytheon Automatic Test Equipment Language. For analog and digital computer controlled test centres. "Automatic Testing via a Distributed Intelligence Processing System", S.J. Ring, IEEE AUTOTESTCON 77 (Nov 1977). 1 1 1 1 1 Rate monotonic scheduling A means of scheduling the time allocated to periodic hard-deadline real-time users of a resource. The users are assigned priorities such that a shorter fixed period between deadlines is associated with a higher priority. Rate monotonic scheduling provides a low-overhead, reasonably resource-efficient means of guaranteeing that all users will meet their deadlines provided that certain analytical equations are satisfied during the system design. It avoids the design complexity of time-line scheduling and the overhead of dynamic approaches such as earliest-deadline scheduling. [D. R. Wilcox, Naval Ocean Systems Center Technical Report 1310, August 1989, "Periodic Phase Adjustment Distributed Clock Synchronization in the Hard Realtime Environment", p. 9]. (1996-03-23) 1 1 1 1 1 RATFIV An enhancement to the RATFOR programming language, developed by Bill Wood while at the Institute for Cancer Research (Philadelphia PA, now the Fox Chase Cancer Center) in 1980-1981. RATFIV was released on several DECUS (Digital Equipment Corporation User's Group) tapes for VAX/VMS. Among its enhancements were: optional Fortan 77 output, an enhanced Format statement and enhanced macros. (2007-05-16) 1 1 1 1 1 RATFOR RATional Fortran 1 1 1 1 1 rational [Mathematics] a fractional number n/d, where n and d are integers, n is the numerator and d is the denominator. The set of all rational numbers is usually called Q. Computers do not usually deal with rational numbers but instead convert them to real numbers which are represented (approximately in some cases) as floating-point numbers. Compare irrational. 1 1 1 1 1 RATional Fortran (RATFOR) Brian Kernighan's Fortran preprocessor that allows programming with C-like control flow. RATFOR is mainly of historical significance. A translator from Ratfor to Fortran IV was posted to comp.sources.Unix volume 13. (ftp://ftp.wustl.edu/mirrors/Unix-c/languages/ratfor.tar-z). ["Ratfor - A Preprocessor for a Rational Fortran", B.W. Kernighan, Soft Prac & Exp 5:395-406, Oct 1975]. ["Software Tools", B.W. Kernighan & P.J. Plauger, A-W, 1976]. (2001-07-31) 1 1 1 1 1 Rationalized C (RatC, after "RATFOR") A version of Ron Cain's original Small-C compiler. ["A Book on C", R.E. Berry and B.A. Meekings, 1984, ISBN 0-333-36821-5]. [In what way was it "rationalized"?] (1999-06-28) 1 1 1 1 1 rave [WPI] 1. To persist in discussing a specific subject. 2. To speak authoritatively on a subject about which one knows very little. 3. To complain to a person who is not in a position to correct the difficulty. 4. To purposely annoy another person verbally. 5. To evangelise. See flame. 6. Also used to describe a less negative form of blather, such as friendly bullshitting. "Rave" differs slightly from flame in that "rave" implies that it is the persistence or obliviousness of the person speaking that is annoying, while flame implies somewhat more strongly that the tone or content is offensive as well. [Jargon File] 1 1 1 1 1 rave on! Sarcastic invitation to continue a rave, often by someone who wishes the raver would get a clue but realises this is unlikely. 1 1 1 1 1 ravioli code Object-oriented code consisting of a number of small and loosely-coupled software components. Presumably, the term is a compliment, contrasting the code with spaghetti code. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-10-28) 1 1 1 1 1 raw data data 1 1 1 1 1 raw mode A mode that allows a program to transfer bits directly to or from an I/O device without any processing, abstraction, or interpretation by the operating system. Systems that make this distinction for a disk file are generally regarded as broken. Compare rare mode, cooked mode. [Jargon File] (2002-04-14) 1 1 1 1 1 RAWOOP-SNAP An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (1996-05-29) 1 1 1 1 1 ray casting A simplified form of ray tracing. A ray is fired from each pixel in the view plane, and information is accumulated from all the voxels in the volume data it intersects. Each voxel is first given an associated colour and opacity. The ray is sampled at a fixed number of evenly spaced locations and the colour and opacity are trilinearly interpolated from the eight nearest voxels. These are then composed linearly back to front to give a single colour for the pixel. Ray casting was invented by John Carmack for the game Wolfenstein 3D. It is faster and lower quality than ray tracing, and is ideal for interactive applications. It parallelises well, although random access is needed to the voxels. (2004-01-06) 1 1 1 1 1 Rayleigh distribution A curve that yields a good approximation to the actual labour curves on software projects. [Details? Equation?] (1996-05-29) 1 1 1 1 1 Ray Tomlinson An engineer at Bolt Beranek and Newman who, in July 1972 while designing the first[?] electronic mail program, chose the commercial at symbol "@" to separate the user name from the computer name. (2004-08-22) 1 1 1 1 1 ray tracing A technique used in computer graphics to create realistic images by calculating the paths taken by rays of light entering the observer's eye at different angles. The paths are traced backward from the viewpoint, through a point (a pixel) in the image plane until they hit some object in the scene or go off to infinity. Objects are modelled as collections of abutting surfaces which may be rectangles, triangles, or more complicated shapes such as 3D splines. The optical properties of different surfaces (colour, reflectance, transmitance, refraction, texture) also affect how it will contribute to the colour and brightness of the ray. The position, colour, and brightness of light sources, including ambient lighting, is also taken into account. Ray tracing is an ideal application for parallel processing since there are many pixels, each of whose values is independent and can thus be calculated in parallel. Compare: radiosity. 1 1 1 1 1 R:BASE An MS-DOS 4GL from Microrim based on the minicomputer DBMS RIM. [Was Wayne Erickson the author?] (2004-09-01) 1 1 1 1 1 RBASIC Database language for Revelation, by Cosmos, Inc. Combines features of BASIC, Pascal and Fortran. 1 1 1 1 1 RBCSP Roper and Barter's CSP. ["A Communicating Sequential Process Language and Implementation", T. Roper & J. Barter, Soft Prac & Exp 11(11):1215-1234 (Nov 1981)]. 1 1 1 1 1 RBOC Regional Bell Operating Company 1 1 1 1 1 rc 1. <filename extension> run commands. 2. A shell from AT&T's Plan 9, by Tom Duff. rc offers much the same capabilities as a traditional Bourne shell, but with a much cleaner syntax. An open source reimplementation was made by Byron Rakitzis, and is now maintained by Tim Goodwin <tjg@star.le.ac.uk>. Latest version: 1.6, as of 2000-06-15. (http://star.le.ac.uk/~tjg/rc). (2000-06-17) 1 1 1 1 1 RC4 A cipher designed by RSA Data Security, Inc. which can accept keys of arbitrary length, and is essentially a pseudo random number generator with the output of the generator being XORed with the data stream to produce the encrypted data. For this reason, it is very important that the same RC4 key never be used to encrypt two different data streams. The encryption mechanism used to be a trade secret, until someone posted source code for an algorithm onto Usenet News, claiming it to be equivalent to RC4. The algorithm is very fast, its security is unknown, but breaking it does not seem trivial either. There is very strong evidence that the posted algorithm is indeed equivalent to RC4. The United States government routinely approves RC4 with 40-bit keys for export. Keys this small can be easily broken by governments, criminals, and amateurs. The exportable version of Netscape's Secure Socket Layer, which uses 1 1 1 1 1 RCA 1802 An extremely simple microprocessor fabricated in CMOS, running at 6.4 MHz at 10V (very fast for 1974). It could be suspended with the clock stopped. It was an 8-bit processor, with 16-bit addressing. Simplicity was the primary design goal, and in that sense it was one of the first RISC chips. It had sixteen 16-bit registers, which could be accessed as thirty-two 8-bit registers, and an accumulator D used for arithmetic and memory access - memory to D, then D to registers and vice versa, using one 16-bit register as an address. This led to one person describing the 1802 as having 32 bytes of RAM and 65535 I/O ports. A 4-bit control register P selected any one general register as the program counter, while control registers X and N selected registers for I/O Index and the operand for the current instruction. All instructions were 8 bits - a 4-bit op code (total of 16 operations) and 4-bit operand register stored in N. There was no real conditional branching, no subroutine support 1 1 1 1 1 RCA 1805 A later, enhanced version of the RCA 1802. It added several Forth language primitives. (1994-11-16) 1 1 1 1 1 RCC An extensible language. [More detail?] 1 1 1 1 1 rc file /R C fi:l/ [Unix: from the startup script "/etc/rc", but this is commonly believed to have been named after older scripts to run commands] Script file containing startup instructions for an application program (or an entire operating system), usually a text file containing commands of the sort that might have been invoked manually once the system was running but are to be executed automatically each time the system starts up. See also dot file, profile (sense 1). [Jargon File] 1 1 1 1 1 RCL Reduced Control Language. A simplified job control language for OS360, translated to IBM JCL. "Reduced Control Language for Non- Professional Users", K. Appel in Command Languages, C. Unger ed, N-H 1973. 1 1 1 1 1 rcp (Remote copy) The Unix utility for copying files over Ethernet. Rcp is similar to FTP but uses the hosts.equiv user authentication method. Unix manual page: rcp(1). (1997-01-12) 1 1 1 1 1 RCS Revision Control System 1 1 1 1 1 Rdb Oracle Rdb 1 1 1 1 1 rdb A roll-your-own database, created in the Unix toolkit philosophy. It appears to be written in the awk language, and is very compatible with awk. It uses awk's syntax and can be combined with awk commands. The definitive introduction is "Unix Relational Database Management: Application Development in the Unix Environment", by Rod Manis, Evan Schaeffer, and Robert Jorgensen, published by Prentice Hall. The book tells how to use rdb to create database/spreadsheets in the awk tradition, only easier. It's a good way to get into programming for novices. It's also a good way to learn DB theory and construction quite painlessly. 1 1 1 1 1 RDBA Remote Database Access 1 1 1 1 1 RDBMS relational database 1 1 1 1 1 RDF Resource Description Framework 1 1 1 1 1 RDI Receiver Data Interface 1 1 1 1 1 RDL Requirements and Development Language. ["RDL: A Language for Software Development", H.C. Heacox, SIGPLAN Notices 14(9):71-79 (Sep 1979)]. 1 1 1 1 1 RDOS Realtime Disk Operating System 1 1 1 1 1 RDP 1. Reliable Data Protocol. 2. Remote Desktop Protocol. (2004-09-14) 1 1 1 1 1 RDRAM Rambus DRAM 1 1 1 1 1 RDS Random Dot Stereogram 1 1 1 1 1 RE regular expression 1 1 1 1 1 re 1. <networking> The country code for Reunion. 2. <chat> /re-/ (From "rehi") Hello again. A greeting originating in, and most often heard on, Internet interactive conversation services. [Jargon File] (1999-02-08) 1 1 1 1 1 read-eval-print loop (REPL) A programming structure within LISP which repeatedly reads a form from the user, evaluates it, and displays the result. A read-eval-print loop forms the basis of the Top-Level shell that programmers of the LISP family of languages interact with. In many dialects of LISP a very simple REPL could be implemented as: (loop (print (eval (read)))). (2003-06-23) 1 1 1 1 1 README file A text file traditionally included in the top-level directory of a software distribution, containing pointers to documentation, credits, revision history, notes, etc. Originally found in Unix source distributions, the convention has spread to many other products. The file may be named README, READ.ME, ReadMe or readme.txt or some other variant. In the Macintosh and IBM PC worlds, software is not usually distributed in source form, and the README is more likely to contain user-oriented material like last-minute documentation changes, error workarounds, and restrictions. The README convention probably follows the famous scene in Lewis Carroll's "Alice's Adventures In Wonderland" in which Alice confronts magic munchies labeled "Eat Me" and "Drink Me". [Jargon File] (1995-02-28) 1 1 1 1 1 Read-Only Memory (ROM) A type of data storage device which is manufactured with fixed contents. In its most general sense, the term might be used for any storage system whose contents cannot be altered, such as a gramophone record or a printed book; however, the term is most often applied to semiconductor integrated circuit memories, of which there are several types, and CD-ROM. ROM is inherently non-volatile storage - it retains its contents even when the power is switched off, in contrast to RAM. ROM is often used to hold programs for embedded systems since these usually have a fixed purpose. ROM is also used for storage of the lowest level bootstrap software (firmware) in a computer. See also Programmable Read-Only Memory. (1995-05-09) 1 1 1 1 1 read-only user Describes a luser who uses computers almost exclusively for reading Usenet, bulletin boards, and/or electronic mail, rather than writing code or purveying useful information. See twink, terminal junkie, lurker. [Jargon File] (1995-02-28) 1 1 1 1 1 real 1. Not simulated. Often used as a specific antonym to virtual in any of its jargon senses. 2. <mathematics> real number. [Jargon File] (1997-03-12) 1 1 1 1 1 RealAudio A program from Real Media for playing audio over the Internet, and the lossy audio compression format it uses. The system is implemented as a client/server architecture. The RealAudio server incorporates an encoder which compresses sound into RealAudio files. The client side is a web browser plug-in or add-on (a recent version of Internet Explorer apparently has built-in support for RealAudio) which allows the stream of data sent from the server to be uncompressed and output using the normal sound facilities of the computer, such as a sound card. A 14.4 KBps or better modem is required, and a 28.8 KBps connection is recommended for music-quality sound. (http://realaudio.com/). (2001-12-13) 1 1 1 1 1 real estate May be used for any critical resource measured in units of area. Most frequently used of "chip real estate", the area available for logic on the surface of an integrated circuit (see also nanoacre). May also be used of floor space in a dinosaur pen, or even space on a crowded desktop (whether physical or electronic). [Jargon File] (1996-11-06) 1 1 1 1 1 real hack A crock. This is sometimes used affectionately; see hack. [Jargon File] 1 1 1 1 1 reality check The simplest kind of functional test of software or hardware; doing the equivalent of asking it what 2 + 2 is and seeing if it says four. The software equivalent of a smoke test. A reality check may include letting a real user try out prototype software. A sanity check is even more basic, the equivalent of checking that the above addition was implemented with an addition operator rather than subtraction. (2007-03-15) 1 1 1 1 1 realization A UML semantic relationship between a classifier that specifies a contract and another classifier that guarantees to carry it out. [Handout by Mr. David Gillibrand]. (2007-03-15) 1 1 1 1 1 Really Simple Syndication Rich Site Summary 1 1 1 1 1 real mode An operating mode of Intel 80x86 processors. The opposite of protected mode. (1995-03-29) 1 1 1 1 1 real number One of the infinitely divisible range of values between positive and negative infinity, used to represent continuous physical quantities such as distance, time and temperature. Between any two real numbers there are infinitely many more real numbers. The integers ("counting numbers") are real numbers with no fractional part and real numbers ("measuring numbers") are complex numbers with no imaginary part. Real numbers can be divided into rational numbers and irrational numbers. Real numbers are usually represented (approximately) by computers as floating point numbers. Strictly, real numbers are the equivalence classes of the Cauchy sequences of rationals under the equivalence relation "~", where a ~ b if and only if a-b is Cauchy with limit 0. The real numbers are the minimal topologically closed 1 1 1 1 1 real operating system The sort the speaker is used to. People from the BSDophilic academic community are likely to issue comments like "System V? Why don't you use a *real* operating system?", people from the commercial/industrial Unix sector are known to complain "BSD? Why don't you use a *real* operating system?", and people from IBM object "Unix? Why don't you use a *real* operating system?" See holy wars, religious issues, proprietary, Get a real computer!. [Jargon File] (1997-03-12) 1 1 1 1 1 Real Programmer (From the book "Real Men Don't Eat Quiche") A variety of hacker possessed of a flippant attitude toward complexity that is arrogant even when justified by experience. The archetypal "Real Programmer" likes to program on the bare metal and is very good at it, remembers the binary op codes for every machine he has ever programmed, thinks that high-level languages are sissy, and uses a debugger to edit his code because full-screen editors are for wimps. Real Programmers aren't satisfied with code that hasn't been bummed into a state of tenseness just short of rupture. Real Programmers never use comments or write documentation: "If it was hard to write", says the Real Programmer, "it should be hard to understand." Real Programmers can make machines do things that were never in their spec sheets; in fact, they are seldom really happy unless doing so. A Real Programmer's code can awe with its fiendish brilliance, even as its crockishness appals. 1 1 1 1 1 Real Programmers Don't Use Pascal Back in the good old days - the "Golden Era" of computers, it was easy to separate the men from the boys (sometimes called "Real Men" and "Quiche Eaters" in the literature). During this period, the Real Men were the ones that understood computer programming, and the Quiche Eaters were the ones that didn't. A real computer programmer said things like "DO 10 I=1,10" and "ABEND" (they actually talked in capital letters, you understand), and the rest of the world said things like "computers are too complicated for me" and "I can't relate to computers - they're so impersonal". (A previous work [1] points out that Real Men don't "relate" to anything, and aren't afraid of being impersonal.) But, as usual, times change. We are faced today with a world in which little old ladies can get computers in their microwave ovens, 12-year-old kids can blow Real Men out of the water playing Asteroids and Pac-Man, and anyone can buy and even understand their very own Personal Computer. The Real 1 1 1 1 1 Real Simple Syndication Illiterate form of Really Simple Syndication. (2013-08-15) 1 1 1 1 1 Real Soon Now (RSN) A phrase used ironically when you believe an event will take a long or unknown time to occur. The term originated in SF's fanzine community, popularised by Jerry Pournelle's column in BYTE. The phrase can be used, for example, when a manager asks how long it will take you to debug some software and you have no idea. I'll have it working Real Soon Now. [Jargon File] (2013-08-22) 1 1 1 1 1 real-time 1. Describes an application which requires a program to respond to stimuli within some small upper limit of response time (typically milli- or microseconds). Process control at a chemical plant is the classic example. Such applications often require special operating systems (because everything else must take a back seat to response time) and speed-tuned hardware. 2. In jargon, refers to doing something while people are watching or waiting. "I asked her how to find the calling procedure's program counter on the stack and she came up with an algorithm in real time." Used to describe a system that must guarantee a response to an external event within a given time. (1997-11-23) 1 1 1 1 1 Real-Time Common Design Language (RT-CDL) A real-time language for the design of reliable reactive systems. ["RT-CDL: A Real-Time Description Language and Its Semantics", L.Y. Lin et al, 11th World Computer Congress IFIP '89 pp.19-26 Sep 1989]. (2003-06-07) 1 1 1 1 1 Realtime Disk Operating System A Data General operating system developed in the 1970s or 1980s. When used in conjuction with a BASIC (e.g. Business Basic) it could support 16 concurrent users at the record locking level and two printers all on 128K memory. Reputedly IBM wanted to license this for the first IBM PC but DG turned them down so they went to Microsoft instead. How different the world could have been. [Before or after IBM wanted CP/M?] (1997-11-23) 1 1 1 1 1 Real-Time Euclid Real-time language, restriction to time-bounded constructs. ["Real-Time Euclid: A Language for Reliable Real-Time Systems", E. Kligerman et al, IEEE Trans Software Eng SE-12(9):941-1986-09-949]. 1 1 1 1 1 Real-Time Mentat An extension of C++. "Real-Time Mentat: A Data-Driven Object-Oriented System", A.S. Grimshaw et al, Proc IEEE Globecom, Nov 1989 pp.232-241. 1 1 1 1 1 Real-Time Object-Oriented Modeling (ROOM Methodology) (http://objectime.on.ca/ROOM.HTML). [Summary?] (1997-02-17) 1 1 1 1 1 Real-Time Operating System (RTOS) Any operating system where interrupts are guaranteed to be handled within a certain specified maximum time, thereby making it suitable for control of hardware in embedded systems and other time-critical applications. RTOS is not a specific product but a class of operating systems. [Other criteria?] (1998-02-27) 1 1 1 1 1 Real-Time Operating System Nucleus The Real-Time Operating System Nucleus 1 1 1 1 1 Real-Time Pascal A later name for Pascal-80 by RC International, Denmark. (1995-05-09) 1 1 1 1 1 Real Time Streaming Protocol (RTSP) An application layer protocol for controlling delivery of a stream of real-time multimedia content. RTSP allows users to start playing from a certain position. It does not actually deliver the data, but works alongside existing delivery channels such as UDP, TCP, or IP multicast. RTSP was developed by RealNetworks, Netscape Communications, and Columbia University, and is described in RFC 2326, April 1998. RTSP is an IETF proposed standard. FAQ (http://real.com/devzone/library/fireprot/rtsp/faq.html). (1999-08-26) 1 1 1 1 1 real-time structured analysis (RTSA) Any version of structured analysis capable of modelling real-time aspects of software. (1995-04-06) 1 1 1 1 1 Real-Time Transport Protocol (RTP) An Internet protocol for transmitting real-time data such as audio and video. RTP itself does not guarantee real-time delivery of data, but it does provide mechanisms for the sending and receiving applications to support streaming data. Typically, RTP runs on top of the UDP protocol, although the specification is general enough to support other transport protocols. RTP has received wide industry support. Netscape intends to base its LiveMedia technology on RTP, and Microsoft claims that its NetMeeting product supports RTP. (2003-07-06) 1 1 1 1 1 real user 1. A commercial user. One who is paying *real* money for his computer usage. 2. A non-hacker. Someone using the system for an explicit purpose (a research project, a course, etc.) other than pure exploration. See user. Hackers who are also students may also be real users. "I need this fixed so I can do a problem set. I'm not complaining out of randomness, but as a real user." See also luser. [Jargon File] 1 1 1 1 1 Real Video A lossy video compression format from Real Media. (2001-12-13) 1 1 1 1 1 Real World 1. Those institutions at which "programming" may be used in the same sentence as "Fortran", "COBOL", "RPG", "IBM", DBASE, etc. Places where programs do such commercially necessary but intellectually uninspiring things as generating payroll checks and invoices. 2. The location of non-programmers and activities not related to programming. 3. A bizarre dimension in which the standard dress is shirt and tie and in which a person's working hours are defined as 9 to 5 (see code grinder). 4. Anywhere outside a university. "Poor fellow, he's left MIT and gone into the Real World." Used pejoratively by those not in residence there. In conversation, talking of someone who has entered the Real World is not unlike speaking of a deceased person. It is also noteworthy that on the campus of Cambridge University in England, there is a gaily-painted lamp-post which bears the label "REALITY CHECKPOINT". It 1 1 1 1 1 reaper A prowler that GFRs files. A file removed in this way is said to have been "reaped". [Jargon File] 1 1 1 1 1 reassembly segmentation 1 1 1 1 1 reboot (From boot) A boot with the implication that the computer has not been down for long, or that the boot is a bounce intended to clear some state of wedgitude. See warm boot. (1995-11-27) 1 1 1 1 1 REC CONVERT 1 1 1 1 1 recent changes Recent changes to FOLDOC (/new.html). 1 1 1 1 1 recipe suspension 1 1 1 1 1 recipient One who receives; receiver. E.g. "No recipient of the e-mail message will know about the other addressees who were listed in the BCC header." (2000-03-22) 1 1 1 1 1 Recital dBASE-like language and DBMS from Recital Corporation. Versions include Vax VMS. 1 1 1 1 1 RECOL REtrieval COmmand Language. CACM 6(3):117-122 (Mar 1963). 1 1 1 1 1 Recommended Standard (RS) A series of EIA standards including EIA-232. (1995-03-28) 1 1 1 1 1 record An ordered set of fields, usually stored contiguously. The term is used with similar meaning in several different contexts. In a file, a "record" probably has some fixed length, in contrast to a "line" which may have any length and is terminated by some End Of Line sequence). A database record is also called a "row". In a spreadsheet it is always called a "row". Some programming languages use the term to mean a type composed of fields of several other types (C calls this a "struct"). In all these cases, a record represents an entity with certain field values. Fields may be of a fixed width (bits or characters) or they may be separated by a delimiter character, often comma (CSV) or HT (TSV). In a database the list of values of a given field from all records is called a column. (2002-03-22) 1 1 1 1 1 Record Management Services (RMS) Procedures in the VMS operating system that programs call to process files and records within files. RMS allows programs to issue GET and PUT requests at the record level (record I/O) as well as read and write blocks (block I/O). VMS RMS is an integral part of the system software; its procedures run in executive mode. (2003-11-11) 1 1 1 1 1 records record 1 1 1 1 1 Record Separator (RS) ASCII character 30. 1 1 1 1 1 rectangle slinger polygon pusher 1 1 1 1 1 recurrence relation An equation that defines each element of a sequence in terms of one or more earlier elements. E.g. The Fibonacci sequence, X[1] = 1 X[2] = 1 X[n] = X[n-1] + X[n-2] Some recurrence relations can be converted to "closed form" where X[n] is defined purely in terms of n, without reference to earlier elements. (2008-01-14) 1 1 1 1 1 recurse recursion 1 1 1 1 1 recursion When a function (or procedure) calls itself. Such a function is called "recursive". If the call is via one or more other functions then this group of functions are called "mutually recursive". If a function will always call itself, however it is called, then it will never terminate. Usually however, it first performs some test on its arguments to check for a "base case" #NAME? calling itself. The canonical example of a recursive function is factorial: factorial 0 = 1 factorial n = n * factorial (n-1) Functional programming languages rely heavily on recursion, using it where a procedural language would use iteration. 1 1 1 1 1 recursion theory The study of problems that, in principle, cannot be solved by either computers or humans. [Proper definition?] (1999-03-01) 1 1 1 1 1 recursive recursion 1 1 1 1 1 recursive acronym A hackish (and especially MIT) tradition is to choose acronyms and abbreviations that refer humorously to themselves or to other acronyms or abbreviations. The classic examples were two MIT editors called EINE ("EINE Is Not Emacs") and ZWEI ("ZWEI Was EINE Initially"). More recently, there is a Scheme compiler called LIAR (Liar Imitates Apply Recursively), and GNU stands for "GNU's Not Unix!" - and a company with the name CYGNUS, which expands to "Cygnus, Your GNU Support". See also mung. [Jargon File] (1995-04-28) 1 1 1 1 1 recursive definition See recursive definition. 1 1 1 1 1 recursive descent parser A "top-down" parser built from a set of mutually-recursive procedures or a non-recursive equivalent where each such procedure usually implements one of the productions of the grammar. Thus the structure of the resulting program closely mirrors that of the grammar it recognises. ["Recursive Programming Techniques", W.H. Burge, 1975, ISBN 0-201-14450-6]. (1995-04-28) 1 1 1 1 1 Recursive Functional Algorithmic Language (REFAL) A language developed by V.F. Turchin (later at CUNY?) in Moscow in about 1972. See also supercompilation. [V.F. Turchin, "An algorithm of generalisation in the supercompiler", Workshop on partial evaluation and mixed computations, Oct 1987, Denmark, Eds. D. Bjorner, A.P. Ershov, N.D. Jones]. [V. Turchin, "Supercompiler System Based on the Language Refal", V. Turchin, SIGPLAN Notices 14(2):46-54 (Feb 1979)]. (1998-06-29) 1 1 1 1 1 Recursive Macro Actuated Generator (RMAG) Robert A. Magnuson, NIH ca 1970. A stand-alone macroprocessor for IBM 360/370 under VS or OS. Many built-in features and a library of several hundred macros. Several large systems were written in RMAG to generate source code for languages such as IBM JCL, IBM assembly language, COBOL. There was also a system (SLANG: Structured LANGuage compiler) which would generate 370 assembly language from a pseudo-structured-programming language, based on Michael Kessler's structure programming macros developed at IBM. ["Project RMAG--RMAG22 User's Guide", R.A. Magnuson, NIH-DCRT-DMB-SSS-UG103, NIH, DHEW, Bethesda, MD 20205 (1977)]. (1995-11-23) 1 1 1 1 1 recursive type A data type which contains itself. The commonest example is the list type, in Haskell: data List a = Nil | Cons a (List a) which says a list of a's is either an empty list or a cons cell containing an 'a' (the "head" of the list) and another list (the "tail"). Recursion is not allowed in Miranda or Haskell synonym types, so the following Haskell types are illegal: type Bad = (Int, Bad) type Evil = Bool -> Evil whereas the seeminly equivalent algebraic data types are acceptable: data Good = Pair Int Good 1 1 1 1 1 Red (Or "REDL") A language proposed by Intermetrics to meet the Ironman requirements which led to Ada. ["On the RED Language Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices 13(10):27 (Oct 1978)]. ["RED Language Reference Manual", J. Nestor and M. van Deusen, Intermetrics 1979]. (1995-01-19) 1 1 1 1 1 Red Book 1. <publication> Informal name for one of the four standard references on PostScript. The other three official guides are known as the Blue Book, the Green Book, and the White Book. ["PostScript Language Reference Manual", Adobe Systems, Addison-Wesley, 1985 (ISBN 0-201-10174-2); second edition 1990 (ISBN 0-201-18127-4)]. 2. <publication> Informal name for one of the three standard references on Smalltalk. This book also has blue and green siblings. ["Smalltalk-80: The Interactive Programming Environment", Adele Goldberg, Addison-Wesley, 1984; (ISBN 0-201-11372-4)]. 3. <publication> Any of the 1984 standards issued by the ITU-T eighth plenary assembly. These include, among other things, the X.400 electronic mail specification, the Group 1 through 4 fax standards, ISDN, the R2 signalling system (Q.400 series recommendations), data communication via the 1 1 1 1 1 Red Brick Intelligent SQL (RISQL) A vendor-specific extension to SQL designed specifically for business managers. It augments SQL with a variety of operations appropriate to data analysis and decision support applications such as ranking, moving averages, comparisons, market share, this year vs. last year, etc. It was developed to simplify the creation of complex business queries. Home (http://redbrick.com/products/white/papers/risql/risql.html). (1998-10-15) 1 1 1 1 1 Redcode The ICWS standard language for Core War "battle programs". [Spec?] (1998-10-30) 1 1 1 1 1 redex Reducible Expression. An expression matching the left hand side of a reduction rule or definition. 1 1 1 1 1 Red Hat A distribution of Linux. (http://redhat.com/). (1996-12-21) 1 1 1 1 1 RediLisp R.M. Keller, U Utah. Dialect of Lisp used on the Rediflow machine, a derivative of FEL. 1 1 1 1 1 redirection 1. <operating system> input/output redirection. 2. <web> URL redirection. (1997-07-15) 1 1 1 1 1 redirector network redirector 1 1 1 1 1 RedNet Ltd. A systems integration company who also provide onLine, an Internet service aimed at both hobbyists and corporate end-users. The service offers dial-in with slip or PPP, POP3 electronic mail. (http://rednet.co.uk). E-mail: <info@rednet.co.uk> (with INFO in the body). Snail mail: RedNet Ltd., 6 Cliveden Office Village, Lancaser Road, High Wycombe, Bucks, HP12 3YZ, UK. Telephone: +44 (1494) 513 333. Fax: +44 (494) 443 374. (1994-11-08) 1 1 1 1 1 redocumentation The creation or revision of a semantically equivalent representation within the same relative abstraction level. The resulting forms of representation are usually considered alternate views intended for a human audience. 1 1 1 1 1 REDUCE A symbolic mathematics language with ALGOL-like syntax, written in Lisp by Anthony Hearn in 1963 Reduce 2 is a version based on Portable Standard LISP. (http://rrz.uni-koeln.de/REDUCE/). E-mail: <reduce@rand.org>. Server: reduce-netlib@rand.org. ["REDUCE, Software for Algebraic Computation", G. Rayna, Springer 1987]. (1994-10-31) 1 1 1 1 1 Reduced Instruction Set Computer (RISC) A processor whose design is based on the rapid execution of a sequence of simple instructions rather than on the provision of a large variety of complex instructions (as in a Complex Instruction Set Computer). Features which are generally found in RISC designs are uniform instruction encoding (e.g. the op-code is always in the same bit positions in each instruction which is always one word long), which allows faster decoding; a homogenous register set, allowing any register to be used in any context and simplifying compiler design; and simple addressing modes with more complex modes replaced by sequences of simple arithmetic instructions. Examples of (more or less) RISC processors are the Berkeley RISC, HP-PA, Clipper, i960, AMD 29000, MIPS R2000 and DEC Alpha. IBM's first RISC computer was the RT/PC (IBM 801), they now produce the RISC-based RISC System/6000 and SP/2 lines. 1 1 1 1 1 reduction (Or "contraction") The process of transforming an expression according to certain reduction rules. The most important forms are beta reduction (application of a lambda abstraction to one or more argument expressions) and delta reduction (application of a mathematical function to the required number of arguments). An evaluation strategy (or reduction strategy), determines which part of an expression (which redex) to reduce first. There are many such strategies. See graph reduction, string reduction, normal order reduction, applicative order reduction, parallel reduction, alpha conversion, beta conversion, delta conversion, eta conversion. (1995-02-21) 1 1 1 1 1 reduction strategy An algorithm for deciding which redex(es) to reduce next. Different strategies have different termination properties in the presence of recursive functions or values. See string reduction, normal order reduction, applicative order reduction, parallel reduction (1995-05-09) 1 1 1 1 1 redundancy 1. <architecture, parallel> The provision of multiple interchangeable components to perform a single function in order to provide resilience (to cope with failures and errors). Redundancy normally applies primarily to hardware. For example, a cluster may contain two or three computers doing the same job. They could all be active all the time thus giving extra performance through parallel processing and load balancing; one could be active and the others simply monitoring its activity so as to be ready to take over if it failed ("warm standby"); the "spares" could be kept turned off and only switched on when needed ("cold standby"). Another common form of hardware redundancy is disk mirroring. 2. <data, communications, storage> data redundancy. (1995-05-09) 1 1 1 1 1 Redundant Array of Independent Disks (RAID) A standard naming convention for various ways of using multiple disk drives to provide redundancy and distributed I/O. The original ("..Inexpensive..") term referred to the 3.5 and 5.25 inch disks used for the first RAID system but no longer applies. As solid state drives are becoming a practical repacement for magnetic disks, "RAID" is sometimes expanded as Redundant Array of Independent Drives. The following standard RAID specifications exist: RAID 0 Non-redundant striped array RAID 1 Mirrored arrays RAID 2 Parallel array with ECC RAID 3 Parallel array with parity 1 1 1 1 1 Redundant Array of Independent Drives Redundant Arrays of Independent Disks 1 1 1 1 1 Redundant Array of Inexpensive Disks Redundant Arrays of Independent Disks 1 1 1 1 1 Redundant Array of Inexpensive Servers (RAIS) The use of multiple servers to provide the same service in such a way that service will still be available if one or more of the servers fails. The term may or may not imply some kind of load balancing between the servers. See cluster. The term "RAIS" follows RAID, which describes schemes for resilient disk storage. (2007-02-28) 1 1 1 1 1 Redundant Arrays of Inexpensive Disks Redundant Arrays of Independent Disks 1 1 1 1 1 red wire (IBM) Patch wires installed by programmers who have no business mucking with the hardware. It is said that the only thing more dangerous than a hardware guy with a code patch is a softy with a soldering iron. Compare blue wire, yellow wire, purple wire. [Jargon File] (1994-12-23) 1 1 1 1 1 red zone An environment located between internal and external firewalls where software and hardware are deployed to enable access to extranet applications. Compare De-Militarised Zone. (1997-11-05) 1 1 1 1 1 re-engineering The examination and modification of a system to reconstitute it in a new form and the subsequent implementation of the new form. (http://erg.abdn.ac.uk/users/brant/sre). (1994-12-23) 1 1 1 1 1 re-entrant Used to describe code which can have multiple simultaneous, interleaved, or nested invocations which will not interfere with each other. This is important for parallel processing, recursive functions or subroutines, and interrupt handling. It is usually easy to arrange for multiple invocations (e.g. calls to a subroutine) to share one copy of the code and any read-only data but, for the code to be re-entrant, each invocation must use its own copy of any modifiable data (or synchronised access to shared data). This is most often achieved using a stack and allocating local variables in a new stack frame for each invocation. Alternatively, the caller may pass in a pointer to a block of memory which that invocation can use (usually for outputting the result) or the code may allocate some memory on a heap, especially if the data must survive after the routine returns. Re-entrant code is often found in system software, such as 1 1 1 1 1 refactoring Improving a computer program by reorganising its internal structure without altering its external behaviour. When software developers add new features to a program, the code degrades because the original program was not designed with the extra features in mind. This problem could be solved by either rewriting the existing code or working around the problems which arise when adding the new features. Redesigning a program is extra work, but not doing so would create a program which is more complicated than it needs to be. Refactoring is a collection of techniques which have been designed to provide an alternative to the two situations mentioned above. The techniques enable programmers to restructure code so that the design of a program is clearer. It also allows programmers to extract reusable components, streamline a program, and make additions to the program easier to 1 1 1 1 1 REFAL Recursive Functional Algorithmic Language 1 1 1 1 1 REF-ARF ["REF-ARF: A System for Solving Problems Stated as Procedures", R.E. Fikes, Artif Intell J 1(1), Spring 1970]. (1998-06-29) 1 1 1 1 1 reference pointer 1 1 1 1 1 reference counting A garbage collection technique where each memory cell contains a count of the number of other cells which point to it. If this count reaches zero the cell is freed and its pointers to other cells are followed to decrement their counts, and so on recursively. This technique cannot cope with circular data structures. Cells in such structures refer (indirectly) to themselves and so will never have a zero reference count. This means they would never be reclaimed, even when there are no references from outside the structure. (1995-02-22) 1 1 1 1 1 referential integrity A collection of properties which should be possessed by data in a relational database. For example, in a database of family members, if we enter A as a spouse of B, we should also enter B as a spouse of A. Similarly, if we remove one end of the relationship we should also remove the other. (1998-02-18) 1 1 1 1 1 referentially transparent referential transparency 1 1 1 1 1 referential transparency An expression E is referentially transparent if any subexpression and its value (the result of evaluating it) can be interchanged without changing the value of E. This is not the case if the value of an expression depends on global state which can change value. The most common example of changing global state is assignment to a global variable. For example, if y is a global variable in: f(x) return x+y; g(z) a = f(1); 1 1 1 1 1 referer A misspelling of "referrer" which somehow made it into the HTTP standard. A given web page's referer (sic) is the URL of whatever web page contains the link that the user followed to the current page. Most browsers pass this information as part of a request. (1998-10-19) 1 1 1 1 1 referrer referer 1 1 1 1 1 REFINE 1. "Research on Knowledge-Based Software Environments at Kestrel Institute", D.R. Smith et al, IEEE Trans Soft Eng, SE-11(11) (1985). E-mail: <maria@kestrel.edu>. 2. Cordell Green et al, Stanford U. Uses logic to specify and evolve programs. [same as 1?] Reasoning Systems, Inc. E-mail: <help@reasoning.com>. 1 1 1 1 1 Refined C (RC) An extension of C to directly specify data access rights so that flow analysis, and hence automatic parallelisation, is more effective. Research implementations only. "Refining A Conventional Language For Race-Free Specification Of Parallel Algorithms," H.G. Dietz et al, Proc 1984 Intl Conf Parallel Proc, pp.380-382. 1 1 1 1 1 Refined Fortran (RF) Similar to Refined C. Research implementations only. "Refined Fortran: Another Sequential Language for Parallel Programming, H.G. Dietz et al, Proc 1986 Intl Conf Parallel" Proc, pp.184-191. 1 1 1 1 1 reflexive A relation R is reflexive if, for all x, x R x. Equivalence relations, pre-orders, partial orders and total orders are all reflexive. (1999-01-28) 1 1 1 1 1 reflexive domain A domain satisfying a recursive domain equation. E.g. D = D -> D. 1 1 1 1 1 Reflexive transitive closure Two elements, x and y, are related by the reflexive transitive closure, R+, of a relation, R, if they are related by the transitive closure, R*, or they are the same element. 1 1 1 1 1 RefLisp A small Lisp interpreter written in C++ by Bill Birch of Bull, UK. RefLisp has a built-in web server, Wiki, LISP server pages, SQL Databases, XML parser, MD5 hashing, regular expressions, reference counting and mark-sweep garbage collection. RefLisp has shallow-binding and dynamic scope with optional support for lexical scope, Common Lisp compatibility and for indefinite extent Scheme programs. RefLisp is distributed under the GPL. Latest version: 5.0 Beta, as of 2005-01-19. RefLisp Home (http://sourceforge.net/projects/reflisp/). (2005-02-08) 1 1 1 1 1 refresh 1. <storage> DRAM refresh. 2. <hardware> screen refresh. (1998-10-19) 1 1 1 1 1 refreshable braille display braille display 1 1 1 1 1 refreshable display braille display 1 1 1 1 1 refresh rate (Or "vertical refresh rate", "vertical scan rate") The maximum number of frames that can be displayed on a monitor in a second, expressed in Hertz. The scan rate is controlled by the vertical sync signal generated by the video controller, ordering the monitor to position the electron gun at the upper left corner of the raster, ready to paint another frame. It is limited by the monitor's maximum horizontal scan rate and the resolution, since higher resolution means more scan lines. Increasing the refresh rate decreases flickering, reducing eye strain, but few people notice any change above 60-72 Hz. (1999-08-01) 1 1 1 1 1 refuctoring Taking a well-designed piece of code and, through a series of small, reversible changes, making it completely unmaintainable by anyone except yourself. The term is a humourous play on the term refactoring and was coined by Jason Gorman in a pub in 2002. Refuctoring techniques include: Using Pig Latin as a naming convention. Stating The Bleeding Obvious - writing comments that paraphrase the code (e.g., "declare an integer called I with an initial value of zero"). Module Gravity Well - adding all new code to the biggest module. Unique Modeling Language - inventing your own visual notation. Treasure Hunt - Writing code consisting mostly of references to other code and documents that reference other documents. Rainy Day Module - writing spare code just in case somebody needs it later. Waterfall 2006 presentation 1 1 1 1 1 refutable In lazy functional languages, a refutable pattern is one which may fail to match. An expression being matched against a refutable pattern is first evaluated to head normal form (which may fail to terminate) and then the top-level constructor of the result is compared with that of the pattern. If they are the same then any arguments are matched against the pattern's arguments otherwise the match fails. An irrefutable pattern is one which always matches. An attempt to evaluate any variable in the pattern forces the pattern to be matched as though it were refutable which may fail to match (resulting in an error) or fail to terminate. Patterns in Haskell are normally refutable but may be made irrefutable by prefixing them with a tilde (~). For example, (\ (x,y) -> 1) undefined ==> undefined 1 1 1 1 1 regex The GNU regular expression matching library. See also Rx. 1 1 1 1 1 regexp 1. regular expression. 2. Name of a well-known PD regexp-handling package in portable C, written by revered Usenetter Henry Spencer <henry@zoo.toronto.edu>. [Jargon File] 1 1 1 1 1 Regina A widely-used open source Rexx interpreter by Anders Christensen <anders@pvv.unit.no>, ported to many platforms including Unix, Windows 95, Windows NT, OS/2. Regina is currently maintained by Mark Hessling. Regina conforms almost completely to Rexx Language Level 4.00, with some Rexx SAA API extensions. It is distributed under the GNU General Public License. Latest version: 2.0+, as of 2001-03-30. Home http://lightlink.com/hessling/). Usenet newsgroup: news:comp.lang.rexx. (2001-03-30) 1 1 1 1 1 regional network mid-level network 1 1 1 1 1 register 1. One of a small number of high-speed memory locations in a computer's CPU. Registers differ from ordinary random-access memory in several respects: There are only a small number of registers (the "register set"), typically 32 in a modern processor though some, e.g. SPARC, have as many as 144. A register may be directly addressed with a few bits. In contrast, there are usually millions of words of main memory (RAM), requiring at least twenty bits to specify a memory location. Main memory locations are often specified indirectly, using an indirect addressing mode where the actual memory address is held in a register. Registers are fast; typically, two registers can be read and a third written -- all in a single cycle. Memory is slower; a single access can require several cycles. The limited size and high speed of the register set makes it one of the critical resources in most computer architectures. 1 1 1 1 1 register allocation The phase of a compiler that determines which values will be placed in registers. Register allocation may be combined with register assignment. This problem can be shown to be isomorphic to graph colouring by relating values to nodes in the graph and registers to colours. Values (nodes) which must be valid simultaneously are linked by edges and cannot be stored in the same register (coloured the same). See also register dancing and register spilling. [Preston Briggs, PhD thesis, Rice University, April 1992 "Register Allocation via Graph Coloring" (ftp://ftp.cs.rice.edu/public/preston/thesis.ps.gz)]. (2000-12-04) 1 1 1 1 1 register assignment The phase of a compiler that determines which register to use for each program value selected during register allocation. (2000-12-04) 1 1 1 1 1 register dancing Many older processor architectures suffer from a serious shortage of general-purpose registers. This is especially a problem for compiler-writers, because their generated code needs places to store temporaries for things like intermediate values in expression evaluation. Some designs with this problem, like the Intel 80x86, do have a handful of special-purpose registers that can be pressed into service, providing suitable care is taken to avoid unpleasant side effects on the state of the processor: while the special-purpose register is being used to hold an intermediate value, a delicate minuet is required in which the previous value of the register is saved and then restored just before the official function (and value) of the special-purpose register is again needed. [Jargon File] 1 1 1 1 1 registered port Any TCP or UDP port with a number in the range 1025 to 65535 (i.e. not a well-known port) that is registered with IANA. 1 1 1 1 1 register set All a processor's registers. The size and arrangement of a processor's register set is one of the crucial factors in its performance. 1 1 1 1 1 register spilling (By analogy with spilling the contents of an overfull container) When a compiler is performing the register allocation phase of generating machine code and there are more live variables than the machine has registers and it has to transfer or "spill" some variables from registers to memory. (2014-08-02) 1 1 1 1 1 Register Transfer Language (RTL) 1. A kind of hardware description language (HDL) used in describing the registers of a computer or digital electronic system, and the way in which data is transferred between them. 2. An intermediate code for a machine with an infinite number of registers, used for machine-independent optimisation. RTL was developed by Chris Fraser <cwf@research.att.com> and J. Davidson <jwd@virginia.edu> at the University of Arizona in the early 1980s. RTL is used by the GNU C compiler, gcc and by Davidson's VPCC (Very Portable C compiler). ["Quick Compilers Using Peephole Optimisation", Davidson et al, Soft. Prac. & Exp. 19(1):79-97 (Jan 1989)]. (1994-11-16) 1 1 1 1 1 registry Windows Registry 1 1 1 1 1 regression 1. <mathematics> A mathematical method where an empirical function is derived from a set of experimental data. 2. regression testing. (1995-03-14) 1 1 1 1 1 regression testing Part of the test phase of software development where, as new modules are integrated into the system and the added functionality is tested, previously tested functionality is re-tested to assure that no new module has corrupted the system. [Bennatan, E.M., "Software Project Management", 2nd edition, McGraw-Hill International, 1992]. (1995-12-04) 1 1 1 1 1 REG-SYMBOLIC An early system on the IBM 704. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-02) 1 1 1 1 1 REGTRAL Mentioned in Attribute Grammars, LNCS 323, p.108. Relational Language. Clark & Gregory. First parallel logic language to use the concept of committed choice. Forerunner of PARLOG. "A Relational Language for Parallel Programming", K.L. Clark et al, Proc ACM Conf on Functional Prog Langs and Comp Arch, pp.171-178, ACM 1981. 1 1 1 1 1 regular expression 1. <text, operating system> (regexp, RE) One of the wild card patterns used by Perl and other languages, following Unix utilities such as grep, sed, and awk and editors such as vi and Emacs. Regular expressions use conventions similar to but more elaborate than those described under glob. A regular expression is a sequence of characters with the following meanings (in Perl, other flavours vary): An ordinary character (not one of the special characters discussed below) matches that character. A backslash (\) followed by any special character matches the special character itself. The special characters are: . matches any character except newline; "RE*" (where RE is any regular expression and the "*" is called the "Kleene star") matches zero or more occurrences of RE. If there is any choice, the longest leftmost matching string is chosen. ^ at the beginning of an RE matches the start of a line and $ at the end of an RE matches the end of a line. 1 1 1 1 1 Regular Expression Converter CONVERT 1 1 1 1 1 regular graph A graph in which all nodes have the same degree. (1995-03-07) 1 1 1 1 1 rehi Hello again. (1995-02-28) 1 1 1 1 1 Reid, Brian Brian Reid 1 1 1 1 1 reify To regard (something abstract) as a material thing. (1995-03-07) 1 1 1 1 1 re-image To re-install a computer's operating system, and possibly other software, by writing a disk image to the hard disk, replacing the entire contents. Re-imaging is quicker, easier and more reliable than going through a complete install but it relies on having a disk image available. "Sometimes if your PC has a virus, the only cure is to re-image it." (2007-06-26) 1 1 1 1 1 reincarnation, cycle of cycle of reincarnation 1 1 1 1 1 reinvent the wheel To design or implement a tool equivalent to an existing one or part of one, with the implication that doing so is silly or a waste of time. This is often a valid criticism. On the other hand, automobiles don't use wooden rollers, and some kinds of wheel have to be reinvented many times before you get them right. On the third hand, people reinventing the wheel do tend to come up with the moral equivalent of a trapezoid with an offset axle. [Jargon File] (1997-04-12) 1 1 1 1 1 relation 1. <mathematics> A subset of the product of two sets, R : A x B. If (a, b) is an element of R then we write a R b, meaning a is related to b by R. A relation may be: reflexive (a R a), symmetric (a R b => b R a), transitive (a R b & b R c => a R c), antisymmetric (a R b & b R a => a = b) or total (a R b or b R a). See equivalence relation, partial ordering, pre-order, total ordering. 2. <database> A table in a relational database. (1995-02-28) 1 1 1 1 1 relational algebra A family of algebra with a well-founded semantics used for modelling the data stored in relational databases, and defining queries on it. The main operations of the relational algebra are the set operations (such as union, intersection, and cartesian product), selection (keeping only some lines of a table) and the projection (keeping only some columns). The relational data model describes how the data is structured. Codd's reduction algorithm can convert from relational calculus to relational algebra. (1997-02-17) 1 1 1 1 1 relational calculus An operational methodolgy, founded on predicate calculus, dealing with descripitive expressions that are equivalent to the operations of relational algebra. Codd's reduction algorithm can convert from relational calculus to relational algebra. Two forms of the relational calculus exist: the tuple calculus and the domain calculus. ["An Introduction To Database Systems" (6th ed), C. J. Date, Addison Wesley]. (1998-10-05) 1 1 1 1 1 relational database (RDBMS - relational database management system) A database based on the relational model developed by E.F. Codd. A relational database allows the definition of data structures, storage and retrieval operations and integrity constraints. In such a database the data and relations between them are organised in tables. A table is a collection of rows or records and each row in a table contains the same fields. Certain fields may be designated as keys, which means that searches for specific values of that field will use indexing to speed them up. Where fields in two different tables take values from the same set, a join operation can be performed to select related records in the two tables by matching values in those fields. Often, but not always, the fields will have the same name in both tables. For example, an "orders" table might contain (customer_id, product_code) pairs and a "products" table might contain (product_code, price) pairs so to calculate a given 1 1 1 1 1 relational database management system relational database 1 1 1 1 1 relational data model (Or "relational model") A data model introduced by E.F. Codd in 1970, particularly well suited for business data management. In this model, data are organised in tables. The set of names of the columns is called the schema of the table. Here is an example table with the schema (account number, amount) and 3 lines. account number amount -------------- --------- 12343243546456 +30000.00 23149875245824 +2345.33 18479827492874 -123.25 The data can be manipulated using a relational algebra. SQL is a standard language for talking to a database built on the relational model (a "relational database"). ["A relational model for large shared data banks" Communications of ACM 13:6, pp 377-387]. 1 1 1 1 1 relational DBMS relational database 1 1 1 1 1 relational language Any kind of programming language that specifies output in terms of some property and some arguments. For example, if Tom has two brothers, Dick and Harry, a relational language will respond to the query "Who is Tom's brother?" with either Dick or Harry. Notice that unlike functional languages, relational languages do not require a unique output for each predicate/argument pair. Prolog is the best known relational language. (2004-05-17) 1 1 1 1 1 relational model relational data model 1 1 1 1 1 RELATIVE Early system on IBM 650. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 relatively prime Having no common divisors (greater than 1). Two numbers are said to be relativey prime if there is no number greater than unity that divides both of them evenly. For example, 10 and 33 are relativly prime. 15 and 33 are not relatively prime, since 3 is a divisor of both. (1997-03-11) 1 1 1 1 1 relative pathname A path relative to the working directory. Its first character can be anything but the pathname separator. (1996-11-21) 1 1 1 1 1 Relative Record Data Set (RRDS) One of the access methods used by IBM's VSAM. [What is it?] (1999-01-12) 1 1 1 1 1 RELCODE Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 release (Or "released version", "baseline") A version of a piece of software which has been made public (as opposed to a version that is in development, or otherwise unreleased). A release is either a major release, a revision, or a bugfix. Pre-release versions may be called alpha test, or beta test versions. See change management. (1996-08-04) 1 1 1 1 1 released version release 1 1 1 1 1 REL English Rapidly Extensible Language, English 1 1 1 1 1 relevance A measure of how closely a given object (file, web page, database record, etc.) matches a user's search for information. The relevance algorithms used in most large web search engines today are based on fairly simple word-occurence measurement: if the word "daffodil" occurs on a given page, then that page is considered relevant to a query on the word daffodil; and its relevance is quantised as a factor of the number of times the word occurs in the page, on whether daffodil occurs in title of the page or in its META keywords, in the first N words of the page, in a heading, and so on; and similarly for words that a stemmer says are based on "daffodil". More elaborate (and resource-expensive) relevance algorithms may involve thesaurus (or synonym ring) lookup; e.g. it might rank a document about narcissuses (but which may not mention the word "daffodil" anywhere) as relevant to a query 1 1 1 1 1 reliability An attribute of any system that consistently produces the same results, preferably meeting or exceeding its specifications. The term may be qualified, e.g software reliability, reliable communication. Reliability is one component of RAS. (2000-08-13) 1 1 1 1 1 Reliability, Availability, Serviceability (RAS) Three key attributes of a computing system design. See reliability, availability, and serviceability. The term "RAS" is fairly common in the computing industry (particularly computers and storage) as computing becomes more fundamental. For example, a vehicle may depend on dozens of computers, and the consequences of the failure can be significant (e.g., an ambulance's engine won't start). (2000-08-13) 1 1 1 1 1 reliable communication Communication where messages are guaranteed to reach their destination complete and uncorrupted and in the order they were sent. This reliability can be built on top of an unreliable protocol by adding sequencing information and some kind of checksum or cyclic redundancy check to each message or packet. If the communication fails, the sender will be notified. Transmission Control Protocol is a reliable protocol used on Ethernet. (2004-09-14) 1 1 1 1 1 Reliable Data Protocol (RDP) A protocol designed to provide a reliable data transport service for packet-based applications such as remote loading and debugging. RDP is intended to be simple to implement but still be efficient in environments where there may be long transmission delays and loss or non-sequential delivery of message segments. RDP is defined in RFC 908. (2004-09-14) 1 1 1 1 1 religion of CHI /ki:/ [Case Western Reserve University] Yet another hackish parody religion (see also Church of the SubGenius, Discordianism). In the mid-70s, the canonical "Introduction to Programming" courses at CWRU were taught in ALGOL, and student exercises were punched on cards and run on a Univac 1108 system using a homebrew operating system named CHI. The religion had no doctrines and but one ritual: whenever the worshipper noted that a digital clock read 11:08, he or she would recite the phrase "It is 11:08; ABS, ALPHABETIC, ARCSIN, ARCCOS, ARCTAN." The last five words were the first five functions in the appropriate chapter of the ALGOL manual; note the special pronunciations /obz/ and /ark'sin/ rather than the more common /ahbz/ and /ark'si:n/. Using an alarm clock to warn of 11:08's arrival was considered harmful. [Jargon File] 1 1 1 1 1 religious issues Questions which seemingly cannot be raised without touching off holy wars, such as "What is the best operating system (or editor, language, architecture, shell, mail reader, news reader)?", "What about that Heinlein guy, eh?", "What should we add to the new Jargon File?" See holy wars; see also theology, bigot. This term is a prime example of ha ha only serious. People actually develop the most amazing and religiously intense attachments to their tools, even when the tools are intangible. The most constructive thing one can do when one stumbles into the crossfire is mumble Get a life! and leave - unless, of course, one's *own* unassailably rational and obviously correct choices are being slammed. (1996-08-16) 1 1 1 1 1 REM (From "remark") The keyword used in BASIC to introduce a comment (which continues to the end of the line). MS-DOS probably borrowed it from BASIC. Might be used in the form "REM out" meaning to comment out. (1998-04-27) 1 1 1 1 1 remailer anonymous remailer 1 1 1 1 1 Remote Access Services (RAS) A service provided by Windows NT which allows most of the services which would be available on a network to be accessed over a modem link. The service includes support for dialup and logon, and then presents the same network interface as the normal network drivers (albeit slightly slower!). It is not necessary to run Windows NT on the client - there are client versions for other Windows operating systems. [What services?] (1996-08-14) 1 1 1 1 1 Remote Database Access (RDBA) A standard permitting the exchange of information between different DBMS systems. (1998-09-23) 1 1 1 1 1 Remote Desktop Protocol (RDP) A Microsoft protocol that provides remote display and input for Windows. RDP's video driver renders display output by sending packets to the client which translates them into corresponding Microsoft Win32 graphics device interface API calls. Client mouse and keyboard events are redirected from the client to virtual keyboard and mouse drivers on the server. RDP 4.0 was introduced with Windows NT Server 4.0, Terminal Server Edition. Windows 2000 Terminal Services included RDP 5.0. The Terminal Services Advanced Client (TSAC), an RDP client based on an ActiveX control, also supports RDP 5.0. RDP 5.0 provides enhanced performance over low-speed connections. Windows XP uses RDP 5.1 and includes Remote Desktop Web Connection, which is an updated version of the TSAC. RDP extends the ITU T.120 protocols, allowing separate virtual channels for device communication and presentation 1 1 1 1 1 remote echo (Obsolete: "full-duplex") A mode of operation of communicating programs or devices in which the sending system does not display the characters the user enters, but only sends them to the remote system which then "echoes" them back to be displayed to the user. This lets the operator see not only typing errors, but also transmission errors. This is now the usual mode of most systems with remote users. Contrast: local echo. (2000-03-30) 1 1 1 1 1 Remote Job Entry (RJE) A system, widely used in the mid/late 1960s, for submitting jobs to mainframes like the IBM 360 under OS/MFT. Communication with the computer operator was via the keyboard and later via CRTs. (1999-03-26) 1 1 1 1 1 remote login A client-server program and protocol that provides an interactivel command line interface to a remote computer, using a protocol over a computer network, simulating a locally attached terminal. rlogin is the BSD Unix program and protocol for this, telnet is an earlier, more widely implemented protocol. (1999-03-26) 1 1 1 1 1 Remote Method Invocation (RMI) Part of the Java programming language library which enables a Java program running on one computer to access the objects and methods of another Java program running on a different computer. Home (http://java.sun.com/products/jdk/1.1/docs/guide/rmi/index.html). (1997-09-04) 1 1 1 1 1 remote monitoring (RMON) A network management protocol that allows network information to be gathered at a single computer. Whereas SNMP gathers network data from a single type of Management Information Base (MIB), RMON 1 defines nine additional MIBs that provide a much richer set of data about network usage. For RMON to work, network devices, such as hubs and switches, must be designed to support it. The newest version of RMON, RMON 2, provides data about traffic at the network layer in addition to the physical layer. This allows administrators to analyse traffic by protocol. (2003-09-15) 1 1 1 1 1 Remote Operations Service Element (ROSE) A sub-layer of protocol layer six (presentation layer) in the OSI seven layer model which provides SASE for remote operations. Documents: ITU Rec. X.229 (ISO 9072-2), ITU Rec. X.219 (ISO 9072-1). (1997-12-07) 1 1 1 1 1 Remote Procedure Call (RPC) A protocol which allows a program running on one host to cause code to be executed on another host without the programmer needing to explicitly code for this. RPC is an easy and popular paradigm for implementing the client-server model of distributed computing. An RPC is initiated by the caller (client) sending request message to a remote system (the server) to execute a certain procedure using arguments supplied. A result message is returned to the caller. There are many variations and subtleties in various implementations, resulting in a variety of different (incompatible) RPC protocols. Sun RPC is defined in RFC 1057 and ONC RPC in RFC 1831. (2003-06-04) 1 1 1 1 1 Remote Reference Layer (RRL) Part of Java's Remote Method Invocation protocol. RRL exists in both the RMI client and server. It is used by the stub or skeleton protocol layer and uses the transport layer. RRL is reponsible for transport-independent functioning of RMI, such as connection management or unicast/multicast object invocation. [Specification URL?] (1997-12-03) 1 1 1 1 1 Remote Spooling Communication Subsystem (RSCS) A networking protocol used primarily on Bitnet. [Details?] (1996-02-04) 1 1 1 1 1 Remote Write Protocol (RWP) A proposed Internet protocol for exchanging short messages between terminals. The RWP proposal is detailed in RFC 1756. (1996-09-08) 1 1 1 1 1 removable disk removable hard disk 1 1 1 1 1 removable hard disk A type of magnetic disk, or possibly magneto-optical disk which is not permanently attached to the disk drive (not a fixed disk) but which can be taken out and replaced, allowing many disks to be used in the same drive. The term "removable disk" would seem to be applicable to floppy disks but is generally reserved for hard disks in suitable cartridges such as those made by Syquest, Iomega and others. Removable disk packs were common on minicomputers such as the PDP-11 in use in the 1970s except that the drives were the size of washing machines and the disk packs as big as car wheels. Removable disks became popular on microcomputers in the 1990s as a cheap way of expanding disk space, transporting large amounts of data between computers and storing backups. Large, cheap fixed hard disks and USB memory sticks have made removable disks less attractive. 1 1 1 1 1 rendering The conversion of a high-level object-based description into a graphical image for display. For example, ray-tracing takes a mathematical model of a three-dimensional object or scene and converts it into a bitmap image. Another example is the process of converting HTML into an image for display to the user. (2001-02-06) 1 1 1 1 1 RenderMan Shading Language ["The RenderMan Companion", S. Upstill, A-W 1989, chaps 13-15]. 1 1 1 1 1 rendezvous 1. In Ada, the method of synchronising the activity of different tasks. 2. Query language, close to natural English. ["Seven Steps to Rendezvous with the Casual User", E. Codd in Data Base Management, J.W. Klimbie et al eds, N-H 1974, pp.179-199]. 1 1 1 1 1 REP A directive used in IBM object code card decks (and later PTF Tapes) to REPlace fragments of already assembled or compiled object code prior to link edit. Recompiling or reassembling the source code to produce a whole new object module was only possible if the source code was available, which it rarely was (if you had the object you were lucky!) It was also quicker to apply incremental changes with REP cards and they also circumvented the checksums and card sequence numbers present in the object code. (1998-07-16) 1 1 1 1 1 repeat repeat loop 1 1 1 1 1 repeater A network or communications device which propagates electrical signals from one cable to another, amplifying them to restore them to full strength in the process. Repeaters are used to counter the attenuation which occurs when signals travel long distances (e.g. across an ocean). A network repeater is less intelligent than a bridge, gateway or router since it works at the physical layer. (1998-07-16) 1 1 1 1 1 repeating group Any attribute that can have multiple values associated with a single instance of some entity. For example, a book might have multiple authors. Such a "-to-many" relationship might be represented in an unnormalised relational database as multiple author columns in the book table or a single author(s) column containing a string which was a list of authors. Converting this to "first normal form" is the first step in database normalisation. Each author of the book would appear in a separate row along with the book's primary key. Later nomalisation stages would move the book-author relationship into a separate table to avoid repeating other book attibutes (e.g. title, publisher) for each author. (2005-07-28) 1 1 1 1 1 repeat loop (Or "do loop") A loop construct found in many procedural languages which repeatedly executes some instructions while a condition is true. Repeat loops are found in Perl, Pascal, BASIC and C. The initial keyword may be "repeat" or "do" and the condition may be introduced with a "while" or "until" keyword. In constrast to a while loop, the "loop body" is executed once before the condition is tested. This is useful when the condition depends on the action of the loop body. In the following BASIC loop "Hello" is printed once despite the fact that the condition is false; i = 2 repeat print "Hello" i = i+1 until i>0 See also while loop and for loop. 1 1 1 1 1 repetitive strain disorder overuse strain injury 1 1 1 1 1 repetitive strain injury overuse strain injury 1 1 1 1 1 REPL 1. <language, LISP, programming> read-eval-print loop. 2. <language> Restricted EPL. (2003-06-23) 1 1 1 1 1 replacement algorithm The method used to determine which entry in an associative cache to flush to main memory when it is desired to cache a new block of data. The "least recently used" algorithm flushed the block which has not been accessed for the longest time. A random replacement algorithm picks any block with equal probability. 1 1 1 1 1 Replay Acorn Computers' full-motion video system written by Roger Wilson. Video and sound information are stored in compressed form. Compression is relatively slow but decompression is done in real-time with quality and frame-rate varying with the processing power available, the size of the picture and whether it appears in a window or uses the whole screen. (1994-11-09) 1 1 1 1 1 replication Creating and maintaining a duplicate copy of a database or file system on a different computer, typically a server. The term usually implies the intelligent copying of parts of the source database which have changed since the last replication with the destination. Replication may be one-way or two-way. Two-way replication is much more complicated because of the possibility that a replicated object may have been updated differently in the two locations in which case some method is needed to reconcile the different versions. For example, Lotus Notes can automatically distribute document databases across telecommunications networks. Notes supports a wide range of network protocols including X25 and Internet TCP/IP. Compare mirror. See also rdist. (1997-12-12) 1 1 1 1 1 replicator Any construct that acts to produce copies of itself; this could be a living organism, an idea (see meme), a program (see quine, worm, wabbit, fork bomb, and virus), a pattern in a cellular automaton (see life), or (speculatively) a robot or nanobot. It is even claimed by some that Unix and C are the symbiotic halves of an extremely successful replicator; see Unix conspiracy. [Jargon File] 1 1 1 1 1 reply followup 1 1 1 1 1 Repondez s'il vous plait Répondez s'il vous plait 1 1 1 1 1 Report Program Generator (RPG) An IBM programming language developed by Wilf Hey at IBM in 1965 for easy production of sophisticated large system reports. RPG is a 3GL similar to COBOL, but more concise and supposedly easier for non-programmers to use. It processes its input one line at a time and does not treat tables as conceptual entities. It was popular on System 34/36 minicomputers. Versions: RPG II, RPG III, RPG/400 for IBM AS/400. MS-DOS versions by California Software and Lattice. Unix version by Unibol. Cross-platform version by J & C Migrations runs on MS-DOS, Windows, AIX, HP-UX, and OS/390. See also CL, OCL. (2004-08-24) 1 1 1 1 1 repository 1. <database> See data dictionary. 2. <programming> The core of a CASE tool, typically a DBMS where all development documents are stored. (1999-04-27) 1 1 1 1 1 Representation Language Language (RLL) A frame language. ["A Representation Language Language", R. Greiner and D.B. Lenat, Proc AAAI-80, 1980]. (2003-06-02) 1 1 1 1 1 Request For Comments (RFC) One of a series, begun in 1969, of numbered Internet informational documents and standards widely followed by commercial software and freeware in the Internet and Unix communities. Few RFCs are standards but all Internet standards are recorded in RFCs. Perhaps the single most influential RFC has been RFC 822, the Internet electronic mail format standard. The RFCs are unusual in that they are floated by technical experts acting on their own initiative and reviewed by the Internet at large, rather than formally promulgated through an institution such as ANSI. For this reason, they remain known as RFCs even once adopted as standards. The RFC tradition of pragmatic, experience-driven, after-the-fact standard writing done by individuals or small working groups has important advantages over the more formal, committee-driven process typical of ANSI or ISO. Emblematic of some of these advantages is the existence of a 1 1 1 1 1 request for proposal (RFP) The publication by a prospective software purchaser of details of the required system in order to attract offers by software developers to supply it. Software development under contract starts with the selection of the software developer by the customer. A request for proposal (also called in Britain an "invitation to tender") is the beginning of the selection process. [Bennatan, E.M., "Software Project Management", 2nd edition, McGraw-Hill International, 1992]. (1995-12-04) 1 1 1 1 1 Request For Technology (RFT) The process established by the OSF to get proposals for new standards. (1994-11-30) 1 1 1 1 1 Required-COBOL A minimal subset of COBOL developed in 1961. It was later dropped entirely. [Sammet 1969, p. 339]. (1994-11-30) 1 1 1 1 1 requirements The first stage of software development which defines what the potential users want the system to do. In modern methods these requirements should be testable, and will usually be traceable in later development stages. A common feature of nearly all software is that the requirements change during its lifetime. See software life-cycle. (1995-11-11) 1 1 1 1 1 Requirements Acquisition and Controlled Evolution (RACE) A "back to basics" approach to requirements engineering. The method, is being pieced together through a series of intermediate research studies. In essence, the approach has been to establish requirements for RACE, identify individual techniques that meet those requirements, experiment with the combined use of the techniques, and finally assemble the method. In practice, RACE has been influenced significantly by Checkland and Wilson's Soft Systems Methodology (SSM) and this forms the core of the method. (1995-11-21) 1 1 1 1 1 requirements analysis The process of reviewing a business's processes to determine the business needs and functional requirements that a system must meet. (1996-08-01) 1 1 1 1 1 Requirements Engineering The task of capturing, structuring, and accurately representing the user's requirements so that they can be correctly embodied in systems which meet those requirements (i.e. are of good quality). DOORS is one product to help with this task. (1995-11-11) 1 1 1 1 1 Research Systems, Inc. (RSI) Distributors of Interactive Data Language (IDL). (ftp://gateway.rs.inc.com/pub/). E-mail: <info@rsinc.com>. (1994-10-07) 1 1 1 1 1 ResEdit A free resource editor for Win32 programs. ResEdit can create dialogs, icon, version information or other types of resources. Output files can be compiled by any Win32 compiler like MinGW and Microsoft Visual C++. Latest version: 1.3.5, as of 2007-03-24. (http://www.resedit.net/). (2007-03-24) 1 1 1 1 1 reserved memory The address range 640-1024 kilobytes on an IBM PC, reserved for BIOS, video cards, and add-on cards. Depending on the configuration some of the address space may be unused in which case it can be used by EMS or UMB. (1996-01-10) 1 1 1 1 1 resolution 1. <hardware> the maximum number of pixels that can be displayed on a monitor, expressed as (number of horizontal pixels) x (number of vertical pixels), i.e., 1024x768. The ratio of horizontal to vertical resolution is usually 4:3, the same as that of conventional television sets. 2. <logic> A mechanical method for proving statements of first order logic, introduced by J. A. Robinson in 1965. Resolution is applied to two clauses in a sentence. It eliminates, by unification, a literal that occurs positive in one and "negative" in the other to produce a new clause, the resolvent. For example, given the sentence: (man(X) => mortal(X)) AND man(socrates). The literal "man(X)" is "negative". The literal man(socrates) could be considered to be on the right hand side of the degenerate implication 1 1 1 1 1 resolver The TCP/IP protocol library software that formats requests to be sent to the Domain Name Server for hostname to IP address conversion. (1995-03-28) 1 1 1 1 1 Resource Access Control Facility (RACF) IBM's large system security product. It originally ran only under MVS but has since been ported to run under VM. (1995-02-07) 1 1 1 1 1 Resource Description Framework (RDF) A specification being developed in 2000 by the W3C as a foundation for processing metadata regarding resources on the Internet, including the web. Resource Description Framework data consists of resources (nodes), and property/value pairs describing the resource. A node is any object which can be pointed to by a URI, properties are attributes of the node, and values can be either atomic values for the attribute, or other nodes. For example, information about a particular web page (a node), might include the property "Author". The value for the Author property could be either a string giving the name of the author, or a link to a resource describing the author. Resource Description Framework only specifies a mechanism for encoding and transferring metadata. It does not specify what that metadata should, or can be. RDF does not, for example, define an "Author" attribute. Sets of properties are defined 1 1 1 1 1 resource fork Macintosh file system 1 1 1 1 1 Resource Reservation Protocol (RSVP) A protocol that supports quality of service. (http://zdnet.com/pcweek/stories/news/0,4153,389107,00.html). (2001-03-18) 1 1 1 1 1 Restricted EPL (REPL) The efficient subset of EPL used to write the core of Multics. (2003-06-23) 1 1 1 1 1 restriction A bug or design error that limits a program's capabilities, and which is sufficiently egregious that nobody can quite work up enough nerve to describe it as a feature. Often used (especially by marketroid types) to make it sound as though some crippling bogosity had been intended by the designers all along, or was forced upon them by arcane technical constraints of a nature no mere user could possibly comprehend (these claims are almost invariably false). Old-time hacker Joseph M. Newcomer advises that whenever choosing a quantifiable but arbitrary restriction, you should make it either a power of 2 or a power of 2 minus 1. If you impose a limit of 17 items in a list, everyone will know it is a random number - on the other hand, a limit of 15 or 16 suggests some deep reason (involving 0- or 1-based indexing in binary) and you will get less flamage for it. Limits which are round numbers in base 10 are always especially suspect. [Jargon File] 1 1 1 1 1 Restructured EXtended eXecutor (REXX, or "System Product Interpreter", originally known as "REX") A scripting language for IBM VM and MVS systems, developed by M. Cowlishaw at IBM ca. 1979, replacing EXEC2. Versions: PC-Rexx for MS-DOS, AREXX for the Amiga, the OS/2 implementation from IBM, WINREXX (Rexx for Windows, from Quercus systems) and Personal Rexx (Rexx for MS-DOS, from Quercus systems). See also Regina, freerexx, imc. REXXWARE is an implementation of REXX for Novell NetWare. Usenet newsgroup: news:comp.lang.rexx. ["The REXX Language: A Practical Approach to Programming", M.F. Cowlishaw, 1985]. (1992-05-13) 1 1 1 1 1 restructuring The transformation from one representation form to another at the same relative abstraction level, while preserving the subject system's external behaviour (functionality and semantics). 1 1 1 1 1 retcon /ret'kon/ retroactive continuity. The common situation in fiction where a new story "reveals" things about events in previous stories, usually leaving the facts the same (thus preserving continuity) while completely changing their interpretation. For example, revealing that a whole season of "Dallas" was a dream was a retcon. This term was once thought to have originated on the Usenet newsgroup news:rec.arts.comics but is now believed to have been used earlier in comic fandom. [Jargon File] (1994-12-08) 1 1 1 1 1 rete /Re'te/ (From Latin "net") A net or network; a plexus; particularly, a network of blood vessels or nerves, or a part resembling a network. [How is it used in AI? What is a "rete procedure "?] (2002-03-14) 1 1 1 1 1 RETI RTI 1 1 1 1 1 Retrieve A query language inspired JPLDIS which led to Vulcan and then to dBASE II, developed by Tymshare Corp in the 1960s. (1998-04-29) 1 1 1 1 1 retrocomputing /ret'-roh-k*m-pyoo'ting/ Refers to emulations of way-behind-the-state-of-the-art hardware or software, or implementations of never-was-state-of-the-art; especially if such implementations are elaborate practical jokes and/or parodies, written mostly for hack value, of more "serious" designs. Perhaps the most widely distributed retrocomputing utility was the "pnch(6)" or "bcd(6)" program on V7 and other early Unix versions, which would accept up to 80 characters of text argument and display the corresponding pattern in punched card code. Other well-known retrocomputing hacks have included the programming language INTERCAL, a JCL-emulating shell for Unix, the card-punch-emulating editor named 029, and various elaborate PDP-11 hardware emulators and RT-11 OS emulators written just to keep an old, sourceless Zork binary running. [Jargon File] 1 1 1 1 1 retronym A term invented to distinguish a subclass of things from new members of the superclass, where the distinction was previously not necessary, since the old subclass had been all there was of the superclass. For example, the retronyms "snail mail" and "paper mail" were coined by those for who "mail" was likely to mean electronic mail. While the English language in general has a few retronyms ("whole milk", "snow skiing", "acoustic guitar"), hacker jargon is necessarily (at points capriciously) rich in retronyms, e.g. plaintext, natural language, impact printer, eyeball search, biological virus. [More examples?] (2001-02-25) 1 1 1 1 1 return from interrupt (RTI) An instruction mnemonic on many computers including the 6502 and 6800. The variant "RETI" is found among former Zilog Z80 hackers (almost nobody programs these things in assembly code anymore). The Intel 80x86 equivalent is "IRET". (1994-10-31) 1 1 1 1 1 return from the dead To regain access to the net after a long absence. Compare person of no account. [Jargon File] (1999-01-14) 1 1 1 1 1 Return To Zero A class of encoding methods for physical circuits in which the carrier (current, voltage) returns to zero after each transmitted bit, i.e. the data is carried in pulse width or polarity, not in the level of the signal. Contrast NRZ. (1995-11-11) 1 1 1 1 1 reusability reuse 1 1 1 1 1 reuse Using code developed for one application program in another application. Traditionally achieved using program libraries. Object-oriented programming offers reusability of code via its techniques of inheritance and genericity. Class libraries with intelligent browsers and application generators are under development to help in this process. Polymorphic functional languages also support reusability while retaining the benefits of strong typing. See also DRAGOON, National Software Reuse Directory, RLF. 1 1 1 1 1 Reverse Address Resolution Protocol (RARP) A protocol defined in RFC 903 which provides the reverse function of ARP. RARP maps a hardware address (MAC address) to an IP address. It is used primarily by diskless nodes, when they first initialise, to find their IP address. See also BOOTP. (1994-12-08) 1 1 1 1 1 Reverse ARP Reverse Address Resolution Protocol 1 1 1 1 1 reverse engineering The process of analysing an existing system to identify its components and their interrelationships and create representations of the system in another form or at a higher level of abstraction. Reverse engineering is usually undertaken in order to redesign the system for better maintainability or to produce a copy of a system without access to the design from which it was originally produced. For example, one might take the executable code of a computer program, run it to study how it behaved with different inputs and then attempt to write a program which behaved identically (or better). An integrated circuit might also be reverse engineered by an unscrupulous company wishing to make unlicensed copies of a popular chip. (1995-10-06) 1 1 1 1 1 Reverse Polish Notation postfix notation 1 1 1 1 1 reverse polish syntax postfix notation 1 1 1 1 1 Revised ALGOL 60 ALGOL 60 Revised 1 1 1 1 1 revision A release of a piece of software which is not a major release or a bugfix, but only introduces small changes or new features. (1996-08-04) 1 1 1 1 1 Revision Control System (RCS) A version control system that automates the storing, retrieval, logging, identification, and merging of revisions. RCS is useful for text that is revised frequently, for example programs, documentation, graphics, papers, and form letters. Unix manual page: rcs(1). ["RCS -- A System for Version Control", Walter F. Tichy, Software--Practice & Experience 15, 7, July 1985, 637-654]. [Features? Availability? URL?] (1994-12-23) 1 1 1 1 1 Revolutionary Surrealist Vandal Party (RSVP) (http://impropaganda.com/kultcha.html#bullet21). (1996-12-01) 1 1 1 1 1 revolutions per minute (rpm, rarely: rotations per minute) A unit of angular velocity equal to 1/60 of a revolution per second. (2015-02-26) 1 1 1 1 1 REX The original name for Restructured EXtended eXecutor. 1 1 1 1 1 REXX Restructured EXtended eXecutor 1 1 1 1 1 REXXWARE An implementation of REXX for Novell NetWare produced by Simware, Inc. in January 1994. It is used by LAN managers to automate LAN administration chores on a Novell NetWare server. As a scripting language, REXXWARE is an NLM (NetWare Loadable Module) that runs on Novell NetWare servers. It includes more than 275 NetWare-specific functions, plus the standard REXX keywords, instructions, built-in functions, flow-control, tracing, and error trapping and recovery features. REXXWARE is certified by Novell for use with NetWare. E-mail: <rexxware@simware.com>. (1995-01-11) 1 1 1 1 1 RF radio frequency 1 1 1 1 1 RFC Request For Comments 1 1 1 1 1 RFC 1014 The RFC defining eXternal Data Representation. (rfc:1014). (1994-12-13) 1 1 1 1 1 RFC 1034 One of the RFCs defining the Domain Name System. (rfc:1034). (1997-12-15) 1 1 1 1 1 RFC 1035 One of the RFCs defining the Domain Name System. (rfc:1035). (1997-12-15) 1 1 1 1 1 RFC 1057 The RFC defining Sun RPC. (rfc:1057). (2003-06-04) 1 1 1 1 1 RFC 1058 The RFC defining Routing Information Protocol. Updated by RFC 1388. (rfc:1058). (1994-11-30) 1 1 1 1 1 RFC 1081 The RFC defining POP3, Post Office Protocol version 3. (rfc:1081). (1994-12-12) 1 1 1 1 1 RFC 1094 The RFC defining Sun Microsystems's Network File System (NFS). (rfc:1094). (1994-12-12) 1 1 1 1 1 RFC 1112 The RFC describing MBONE. (rfc:1112). (1994-11-11) 1 1 1 1 1 RFC 1119 The RFC defining Network Time Protocol. (rfc:1119). (1994-11-30) 1 1 1 1 1 RFC 1123 The RFC "Requirements for Internet Hosts Application and Support" which clarifies or changes the specification of protocols given in earlier RFCs. RFC 1123 defines the terms "MUST", "SHOULD", "MAY", unconditionally compliant, "conditionally compliant". Capitals are used to emphasise that the official definition of the word is being used. MUST or REQUIRED means an absolute requirement for conformance. SHOULD or RECOMMENDED means the item can be ignored under certain circumstances, although the full implications should be understood. MAY or OPTIONAL means the implementor can choose, usually depending on whether it is needed or not. Something "unconditionally compliant" meets all the MUST and SHOULD requirements, "conditionally compliant" meets all the MUST requirements and "not compliant" - does not meet some 1 1 1 1 1 RFC 1156 The RFC which established the MIB I Management Information Base standard. (rfc:1156). (1994-11-14) 1 1 1 1 1 RFC 1157 The RFC defining Simple Network Management Protocol. (rfc:1157). (1994-11-14) 1 1 1 1 1 RFC 1171 The RFC defining the Point-to-Point Protocol. (rfc:1171). (1994-12-13) 1 1 1 1 1 RFC 1208 The RFC defining many of the network-related terms in this dictionary. (rfc:1208). ["A Glossary of Networking Terms", Jacobsen, O., and D. Lynch, RFC 1208, Interop, Inc., March 1991.] (1996-08-06) 1 1 1 1 1 RFC 1213 The RFC which definied the MIB II Management Information Base. (rfc:1213). (1994-11-14) 1 1 1 1 1 RFC 1267 One of the RFCs describing Border Gateway Protocol. (rfc:1267). 1 1 1 1 1 RFC 1268 One of the RFCs describing Border Gateway Protocol. (rfc:1268). 1 1 1 1 1 RFC 1304 One of the RFCs describing SMDS Interface Protocol. (rfc:1304). (2000-09-02) 1 1 1 1 1 RFC 1321 The RFC defining the Message Digest 5 algorithm. (rfc:1321). (1996-08-04) 1 1 1 1 1 RFC 1334 The RFC defining Challenge-Handshake Authentication Protocol and Password Authentication Protocol. (rfc:1334). (1996-03-23) 1 1 1 1 1 RFC 1341 The June 1992 RFC defining Multipurpose Internet Mail Extensions (MIME). This RFC has been obsoleted by RFC 2045, RFC 2046, RFC 2047, RFC 2048, RFC 2049, and BCP0013. (rfc:1341). (1997-08-30) 1 1 1 1 1 RFC 1347 One of the RFCs describing the TUBA protocol. (rfc:1347). (1997-08-30) 1 1 1 1 1 RFC 1350 The RFC defining TFTP. (rfc:1350). (1997-08-30) 1 1 1 1 1 RFC 1388 An update to RFC 1058, the RFC defining Routing Information Protocol. (rfc:1388). (1994-11-30) 1 1 1 1 1 RFC 1436 The RFC defining the Internet Gopher protocol. (rfc:1436). (1995-11-16) 1 1 1 1 1 RFC 1441 The RFC introducing SNMP v2. (rfc:1441). (1997-11-23) 1 1 1 1 1 RFC 1442 The RFC defining SMI for SNMP v2. (rfc:1442). (1997-11-23) 1 1 1 1 1 RFC 1443 The RFC defining textual conventions for SNMP v2. (rfc:1443). (1997-11-23) 1 1 1 1 1 RFC 1444 The RFC defining conformance statements for SNMP v2. (rfc:1444). (1997-11-23) 1 1 1 1 1 RFC 1445 The RFC defining the administrative model for SNMP v2. (rfc:1445). (1997-11-23) 1 1 1 1 1 RFC 1446 The RFC defining security protocols for SNMP v2. (rfc:1446). (1997-11-23) 1 1 1 1 1 RFC 1447 The RFC defining Party MIB for SNMP v2. (rfc:1447). (1997-11-23) 1 1 1 1 1 RFC 1448 The RFC defining protocol operations for SNMP v2. (rfc:1448). (1997-11-23) 1 1 1 1 1 RFC 1449 The RFC defining transport mappings for SNMP v2. (rfc:1449). (1997-11-23) 1 1 1 1 1 RFC 1450 The RFC defining MIB for SNMP v2. (rfc:1450). (1997-11-23) 1 1 1 1 1 RFC 1451 The RFC defining Manager to Manger MIB. (rfc:1451). (1997-11-23) 1 1 1 1 1 RFC 1452 The RFC describing coexistance between SNMP v1 and SNMP v2. (rfc:1452). (1995-02-15) 1 1 1 1 1 RFC 1475 The RFC describing the TP/IX protocol. (rfc:1475). (1995-04-03) 1 1 1 1 1 RFC 1508 One of the RFCs defining GSS-API. (rfc:1508). (1996-05-19) 1 1 1 1 1 RFC 1509 One of the RFCs defining GSS-API. (rfc:1509). (1996-05-19) 1 1 1 1 1 RFC 1520 The RFC defining Classless Inter-Domain Routing. (rfc:1520). (1996-10-01) 1 1 1 1 1 RFC 1521 An RFC defining Multipurpose Internet Mail Extensions (MIME). This RFC has been obsoleted by RFC 2045, RFC 2046, RFC 2047, RFC 2048, RFC 2049, and BCP0013. (rfc:1521). (1997-11-23) 1 1 1 1 1 RFC 1526 One of the RFCs describing the TUBA protocol. (rfc:1526). (1997-11-23) 1 1 1 1 1 RFC 1531 The original RFC defining DHCP, obsoleted by RFC 2131. (rfc:1531). (1998-11-20) 1 1 1 1 1 RFC 1550 An RFC white paper on IPng. (rfc:1550). (1995-04-03) 1 1 1 1 1 RFC 1561 One of the RFCs describing the TUBA protocol. (rfc:1561). (1997-11-23) 1 1 1 1 1 RFC 1568 An RFC defining the Simple Network Paging Protocol (SNPP) which is designed to support Internet access to paging services such as those based on the Telocator Alphanumeric Protocol. See also RFC 1861. (rfc:1568). (1996-06-24) 1 1 1 1 1 RFC 1591 The RFC defining the Domain Name System. Written by J. Postel in March 1994. (2001-05-14) 1 1 1 1 1 RFC 1630 The RFC defining the Universal Resource Identifier. (rfc:1630). (1995-01-13) 1 1 1 1 1 RFC 1661 The RFC defining Point-to-Point Protocol. (rfc:1661). (1997-02-05) 1 1 1 1 1 RFC 1700 The original RFC defining "Assigned Numbers" such as standard "well-known" TCP and UDP port numbers, now superseded by RFC 3232. (rfc:1700). (2001-04-08) 1 1 1 1 1 RFC 1701 The RFC defining Generic Routing Encapsulation. See also RFC 1702. (rfc:1701). (1997-04-02) 1 1 1 1 1 RFC 1702 The RFC defining Generic Routing Encapsulation over IP. (rfc:1702). (1997-04-02) 1 1 1 1 1 RFC 1707 The RFC defining CATNIP. (rfc:1707). (1996-03-23) 1 1 1 1 1 RFC 1730 An old RFC defining IMAP, obsoleted by RFC 2060, RFC 2061 and others. (rfc:1730). (1996-03-11) 1 1 1 1 1 RFC 1756 The RFC describing Remote Write Protocol. (rfc:1756). (1996-09-08) 1 1 1 1 1 RFC 1760 The RFC describing the S/KEY One-Time Password system. (rfc:1760). (2000-01-31) 1 1 1 1 1 RFC 1777 The RFC defining Lightweight Directory Access Protocol. (rfc:1777). (1996-08-23) 1 1 1 1 1 RFC 1778 The RFC that defines the requirements that must be satisfied by encoding rules used to render X.500 Directory attribute syntaxes into a form suitable for use in LDAP. (rfc:1778). (2002-03-02) 1 1 1 1 1 RFC 1795 The RFC that defines Data Link Switching. (rfc:1795). (2008-01-11) 1 1 1 1 1 RFC 1823 The RFC defining the C language application program interface to the Lightweight Directory Access Protocol. (rfc:1823). (1996-11-28) 1 1 1 1 1 RFC 1825 The RFC describing security mechanisms for Internet Protocol version 4 and IP version 6 and the services that they provide. (rfc:1825). (1997-07-09) 1 1 1 1 1 RFC 1831 The RFC describing ONC RPC. (2003-06-04) 1 1 1 1 1 RFC 1861 The RFC defining Simple Network Paging Protocol. See also RFC 1568. (rfc:1861). (1997-04-25) 1 1 1 1 1 RFC 1938 The RFC describing a proposed standard for a One-Time Password system, obsoleted by RFC 2289. ["A One-Time Password System.", N. Haller & C. Metz]. (rfc:1938). (2000-03-05) 1 1 1 1 1 RFC 1951 The RFC describing deflate compression. (rfc:1951). (1997-06-21) 1 1 1 1 1 RFC 1959 The RFC defining a URL format for the Lightweight Directory Access Protocol. (rfc:1959). (1996-11-28) 1 1 1 1 1 RFC 1960 The RFC defining the human-readable format of search filters used with the Lightweight Directory Access Protocol. (rfc:1960). (2002-03-02) 1 1 1 1 1 RFC 2045 One of the RFCs defining MIME. (rfc:2045). (1999-10-29) 1 1 1 1 1 RFC 2046 One of the RFCs defining MIME. (rfc:2046). (1999-10-29) 1 1 1 1 1 RFC 2047 One of the RFCs defining MIME. (rfc:2047). (1999-10-29) 1 1 1 1 1 RFC 2048 The RFC explaining registration of MIME types. (rfc:2048). (1998-02-11) 1 1 1 1 1 RFC 2049 One of the RFCs defining MIME. (rfc:2049). (1999-10-29) 1 1 1 1 1 RFC 2060 One of the RFCs describing IMAP. (rfc:2060). (1999-03-14) 1 1 1 1 1 RFC 2061 One of the RFCs describing IMAP. (rfc:2061). (1999-03-14) 1 1 1 1 1 RFC 2068 The RFC defining HTTP version 1.1. (rfc:2068). (1997-05-03) 1 1 1 1 1 RFC 2093 The RFC specifying the Inverse Address Resolution Protocol. (rfc:2093). (2000-01-15) 1 1 1 1 1 RFC 2131 The RFC defining DHCP. Obsoletes RFC 1531. (rfc:2131). (1998-11-22) 1 1 1 1 1 RFC 2234 The RFC defining Augmented Backus-Naur Form. (rfc:2234). (1997-11-23) 1 1 1 1 1 RFC 2236 The RFC describing IGMP version 2. (rfc:2236). (1999-11-08) 1 1 1 1 1 RFC 2246 The RFC that defines TLS protocol Version 1.0. Written by T. Dierks and C. Allen in January 1999 (rfc:2246). (2003-10-25) 1 1 1 1 1 RFC 2279 The RFC defining UTF-8. (rfc:2279). (1998-07-29) 1 1 1 1 1 RFC 2281 The RFC describing CISCO Hot Standby Routing Protocol. (rfc:2281). (2005-01-26) 1 1 1 1 1 RFC 2298 The RFC proposing a standard One-Time Password system. (rfc:2298). (2000-03-05) 1 1 1 1 1 RFC 2326 The RFC defining RTSP. (rfc:2326). (1999-10-12) 1 1 1 1 1 RFC 2364 The RFC defining PPPoA. (rfc:2364). (2007-06-15) 1 1 1 1 1 RFC 2408 The RFC proposing ISAKMP. (rfc:2408). (2000-02-08) 1 1 1 1 1 RFC 2516 The RFC defining Point-to-Point Protocol over Ethernet (PPPoE). (rfc:2516). (2006-09-20) 1 1 1 1 1 RFC 2543 One of the RFCs describing Session Initiation Protocol. (rfc:2543). (2000-07-08) 1 1 1 1 1 RFC 2795 The RFC describing The Infinite Monkey Protocol Suite . (rfc:2795). 1 1 1 1 1 RFC 2821 The RFC describing SMTP. RFC 2821 supersedes RFC 821. (rfc:2821). (2007-06-01) 1 1 1 1 1 RFC 3232 The RFC describing TCP port numbers. RFC 3232 supersedes RFC 1700. (rfc:3232). See also IANA, STD 2. (2004-12-30) 1 1 1 1 1 RFC 4213 The RFC defining mechanisms for transitioning to IPv6, such as dual-stack versus tunnelling. (rfc:4213). (2013-11-12) 1 1 1 1 1 RFC 792 The RFC defining Internet Control Message Protocol. (rfc:792). (1996-08-23) 1 1 1 1 1 RFC 821 The original RFC defining SMTP. Updated by RFC 2821. (rfc:821). (2007-06-01) 1 1 1 1 1 RFC 822 The RFC defining the Internet standard format for electronic mail message headers. Also STD 11, evolved from RFC 733. (rfc:822). (1997-03-08) 1 1 1 1 1 RFC 826 The RFC defining the Address Resolution Protocol. (rfc:826). (1997-11-21) 1 1 1 1 1 RFC 854 The RFC defining the telnet protocol. ["Telnet Protocol specification", J. Postel, J.K. Reynolds, 1983-05-01]. (rfc:854). (2000-03-18) 1 1 1 1 1 RFC 903 The RFC defining Reverse Address Resolution Protocol. (rfc:903). (1994-12-08) 1 1 1 1 1 RFC 908 The July 1984 RFC defining Reliable Data Protocol (RDP). (rfc:908). (2004-09-14) 1 1 1 1 1 RFC 959 The RFC containing the official specification of File Transfer Protocol (FTP). (rfc:959). (1995-01-12) 1 1 1 1 1 RFCOMM (RS232 Serial Cable Emulation Profile) A Bluetooth transport protocol in the Core Protocol Stack based on the ETSI standard. RFCOMM Layer Tutorial (http://palowireless.com/infotooth/tutorial/rfcomm.asp). (2002-06-28) 1 1 1 1 1 RFE 1. Request For Enhancement (compare RFC). 2. (From "Radio Free Europe", Bellcore and Sun) Radio Free Ethernet. A system originated by Peter Langston for broadcasting audio among Sun SPARCstations over the Ethernet. [Jargon File] (1994-12-06) 1 1 1 1 1 RFI radio frequency interference 1 1 1 1 1 RFID Radio-frequency identification 1 1 1 1 1 RFP 1. <business> Request for Proposal. 2. <Debian> Request for Package. (2001-01-15) 1 1 1 1 1 RFT Request For Technology 1 1 1 1 1 RG58 A common, low-impedance (52 ohm), quarter-inch diameter coaxial cable with BNC connectors, used for 10base2 Ethernet wiring, sometimes called cheapernet in comparison with "full spec" RG8 cabling. A member of the "Radio Guide" series. (2002-06-17) 1 1 1 1 1 RG8 The original "full spec" cable used for 10base5 Ethernet networks. RG8 is stiff, large diameter coaxial cable with an impedance of 50 ohms, a member of the Radio Guide series. The outer sheath is usually yellow, to indicate double shielding, so it is often just called "yellow cable". 10base5 cable is designed to allow transceivers to be added while existing connections are live. This is achieved using a vampire tap. RG8 is sometimes called "thicknet" or "thick Ethernet" in contrast to RG58, a cheaper, thinner, more flexible alternative. (2014-09-06) 1 1 1 1 1 RGB Red, Green, Blue. The three colours of light which can be mixed to produce any other colour. Coloured images are often stored as a sequence of RGB triplets or as separate red, green and blue overlays though this is not the only possible representation (see CMYK and HSV). These colours correspond to the three "guns" in a colour cathode ray tube and to the colour receptors in the human eye. Often used as a synonym for colour, as in "RGB monitor" as opposed to monochrome (black and white). 1 1 1 1 1 Rhapsody Apple Computer, Inc.'s next-generation operating system for PowerPC processor-based systems capable of running Mac OS. Rhapsody includes four components: the Core OS, the Blue Box (the implementation of the Mac OS within Rhapsody), the Yellow Box, and the Advanced Mac Look and Feel. Rhapsody for Intel runs on Intel processors [which ones?]. It includes the Core OS, the Yellow Box, and the Advanced Mac Look and Feel, but lacks the Blue Box and therefore is unable to run Mac OS software. Rhapsody Developer Release is a developer-only release of Rhapsody, scheduled for release in late 1997. It will go to all members of the Macintosh Developer Program and the Apple Media Program worldwide who have signed nondisclosure agreements. Rhapsody Premier Release will be the second release of Rhapsody, scheduled for early 1998. It is meant for early 1 1 1 1 1 ribbon cable A type of flat multicore cable with cores positioned side-by-side, making it quick and relatively easy to clamp an Insulation Displacement Connector (IDC) across all cores. Ribbon cables typically have grey insulation with cores on a 0.050" pitch and a red stripe marking Pin 1. They are less resilient than screened, multicore cable and are usually used inside equipment where little movement or plugging and unplugging are expected. A common use is connecting a disk drive to the motherboard in a PC. (2007-07-21) 1 1 1 1 1 rib site (By analogy with backbone site) A host with an on-demand high-speed link to a backbone site that serves as a regional distribution point for lots of third-party traffic in electronic mail and Usenet news. Compare leaf site. [Jargon File] (1994-11-30) 1 1 1 1 1 rice box (From ham radio slang) Any Asian-made commodity computer, especially an 80x86-based machine built to IBM PC-compatible ISA or EISA-bus standards. [Jargon File] (1994-11-30) 1 1 1 1 1 Richard Gabriel (Dick, RPG) Dr. Richard P. Gabriel. A noted SAIL LISP hacker and volleyball fanatic. Consulting Professor of Computer Science at Stanford University. Richard Gabriel is a leader in the Lisp and OOP community, with years of contributions to standardisation. He founded the successful company, Lucid Technologies, Inc.. In 1996 he was Distinguished Computer Scientist at ParcPlace-Digitalk, Inc. (later renamed ObjectShare, Inc.). See also gabriel, Qlambda, QLISP, saga. (1999-10-12) 1 1 1 1 1 Richard Hamming Professor Richard Wesley Hamming (1915-02-11 - 1998-01-07). An American mathematician known for his work in information theory (notably error detection and correction), having invented the concepts of Hamming code, Hamming distance, and Hamming window. Richard Hamming received his B.S. from the University of Chicago in 1937, his M.A. from the University of Nebraska in 1939, and his Ph.D. in mathematics from the University of Illinois at Urbana-Champaign in 1942. In 1945 Hamming joined the Manhattan Project at Los Alamos. In 1946, after World War II, Hamming joined the Bell Telephone Laboratories where he worked with both Shannon and John Tukey. He worked there until 1976 when he accepted a chair of computer science at the Naval Postgraduate School at Monterey, California. Hamming's fundamental paper on error-detecting and error-correcting codes ("Hamming codes") appeared in 1950. 1 1 1 1 1 Richard Korf A Professor of computer science at the University of California, Los Angeles. Richard Korf received his B.S. from MIT in 1977, and his M.S. and Ph.D. in computer science from Carnegie-Mellon University in 1980 and 1983. From 1983 to 1985 he served as Herbert M. Singer Assistant Professor of Computer Science at Columbia University. Dr. Korf studies problem-solving, heuristic search and planning in artificial intelligence. He wrote "Learning to Solve Problems by Searching for Macro-Operators" (Pitman, 1985). He serves on the editorial boards of Artificial Intelligence, and the Journal of Applied Intelligence. Dr. Korf is the recipient of several awards and is a Fellow of the American Association for Artificial Intelligence. Richard Korf home page (http://www.cs.ucla.edu/~korf/). (2007-05-01) 1 1 1 1 1 Richard P. Feynman /fayn'mn/ 1918-1988. A US physicist, computer scientist and author who graduated from Massachusetts Institute of Technology and Princeton. Feynmane was a key figure in helping Oppenheimer and team develop atomic bomb. In 1950 he became a professor at Caltech and in 1965 became Nobel Prize Laureate in Physics for QED (quantum electrodynamics). He was a primary figure in solving the Challenger disaster O-ring problem. He rediscovered the former Soviet Socialist Republic of Tuva. The 2001 film "Infinity" about Feynman's early life featured Matthew Broderick and Patricia Arquette. In 2001, "QED", a play about Feynman's life featuring Alan Alda opened. (http://www.feynman.com/). (2008-01-14) 1 1 1 1 1 Richard P. Gabriel Richard Gabriel 1 1 1 1 1 Richard Stallman Richard M. Stallman. Founder of the GNU project. He resigned from the AI lab at MIT so he would be free to produce free software which he could then distribute on his own terms. He went on to establish the Free Software Foundation to support the production of free software and ensure its free distribution. E-mail: <rms@gnu.ai.mit.edu>. (1994-10-28) 1 1 1 1 1 rich object In artificial intelligence, an object which cannot be completely described or represented but about which assertions can be made. (1994-12-14) 1 1 1 1 1 Rich Site Summary (RSS, blog, feed) A family of standard web document types containing regularly updated, short articles or news items. RSS documents (generally called "RSS feeds", "news feeds" or just feeds) can be read with an RSS reader like BottomFeeder or Feedly. These are sometimes called "aggregators" because they combine multiple RSS feeds which the user can browse as a single list. The RSS reader tracks which articles the use has read, and is typically set to show only new articles, hence the idea of a feed or flow of new items. Most RSS feeds are based on RDF. RDF is a structured document format for describing textual resources such as news articles available on the web. RSS originally stood for "RDF Site Summary" as it was designed to provide short descriptions of (changes to) a website. Because it provides a standard way to deliver, or "syndicate", news or updates from one site to another, RSS is sometimes 1 1 1 1 1 Rich Text Format (RTF) An interchange format from Microsoft for exchange of documents between Word and other document preparation systems. (1994-12-08) 1 1 1 1 1 RIFF Microsoft's equivalent to the Amiga's IFF files format. RIFF is used for WAV and AVI files. (1995-04-21) 1 1 1 1 1 RIGAL A language for compiler writing. Data strucures are atoms, lists/trees. Control is based on pattern matching. ["Programming Language RIGAL as a Compiler Writing Tool", M.I. Augustson, Inst of Math and CS of Latvia U, 1987]. (1994-10-28) 1 1 1 1 1 Rigel A database language? Based on Pascal. Listed by M.P. Atkinson & J.W. Schmidt in a tutorial presented in Zurich, 1989. (1994-10-28) 1 1 1 1 1 right brace "". ASCII character 125. Common names: close brace; right brace; right squiggly; right squiggly bracket/brace; right curly bracket/brace; ITU-T: closing brace. Rare: unbrace; uncurly; rytit ("" = leftit); right squirrelly; INTERCAL: bracelet ("" = embrace). Paired with left brace (1995-03-30) 1 1 1 1 1 right bracket "]". ASCII character 93. Common names: right square bracket; ITU-T: closing bracket; unbracket. Rare: unsquare; INTERCAL: U turn back. Paired with left bracket. (1997-11-23) 1 1 1 1 1 right-click To click the right-most mouse button on a mouse with more than one button. This usually performs a different function from the left button, e.g. displaying a context-sensitive menu (Microsoft Windows), extending the selection (X). When used as a verb it is often written as two words with a space instead of a hyphen. (2006-07-09) 1 1 1 1 1 right join outer join 1 1 1 1 1 right outer join outer join 1 1 1 1 1 right parenthesis ")". ASCII character 41. Common names: right paren; right parenthesis; right; close; thesis ("(" = paren); close paren; close parenthesis; right parenthesis; right banana. Rare: already ("(" = so); rparen; ITU-T: closing parenthesis; close round bracket, right round bracket, INTERCAL: wane ("(" = wax); unparenthisey ("(" = parenthisey); right ear. Paired with left parenthesis. (1995-03-06) 1 1 1 1 1 Right Thing That which is *compellingly* the correct or appropriate thing to use, do, say, etc. Always capitalised, always emphasised in speech as though capitalised. Use of this term often implies that in fact reasonable people may disagree. "What's the Right Thing for Lisp to do when it sees "(mod a 0)"? Should it return "a", or give a divide-by-0 error?" Opposite: Wrong Thing. [Jargon File] (1994-10-28) 1 1 1 1 1 Rijndael Advanced Encryption Standard 1 1 1 1 1 ring network A network topology in which all nodes are connected to a single wire in a ring or point-to-point. There are no endpoints. This topology is used by token ring networks. Compare: bus network, star network. (2000-11-16) 1 1 1 1 1 ring topology ring network 1 1 1 1 1 Riordan's Internet Privacy Enhanced Mail (RIPEM) A (not yet complete, but useful) implementation of Privacy Enhanced Mail (PEM). RIPEM allows your electronic mail to have the four security facilities provided by PEM: disclosure protection (optional), originator authenticity, message integrity measures and non-repudiation of origin (always). RIPEM was written primarily by Mark Riordan <mrr@scss3.cl.msu.edu>. Most of the code is in the public domain, except for the RSA routines, which are a library called RSAREF licensed from RSA Data Security, Inc. The current (November 1993) version of RIPEM is 1.1a; the current version of the Macintosh port of RIPEM is 0.8b1. (1998-07-03) 1 1 1 1 1 RIP 1. <networking> Routing Information Protocol. 2. <application, printer> Raster Image Processor. (2003-09-10) 1 1 1 1 1 rip (From "rip off" - to steal) To copy audio or video, typically from a compact disc or DVD, to a file on a computer hard disk. A dedicated program to do this is called a "ripper" though it is often a function of player software. Ripping usually includes converting the data to a format that is more suitable for computer playback, e.g. MP3 digital audio or DivX video. The process is entirely digital so it is possible to make a perfect copy of the data. However the resulting files are large (a few megabytes for an audio track, a few gigabytes for a film) so the conversion often includes compression to reduce the file size at the cost of some loss of quality. While it may be legal to do this for personal use, distributing a ripped copyright work to others could result in prosecution. See also ripcording. 1 1 1 1 1 ripcording (From "ripping" and "recording") Encoding streaming digital audio from the Internet to an MP3 file or similar. Ripcording is commononly used to copy commercial music from a free stream instead of paying to download. (2006-01-27) 1 1 1 1 1 RIPE Réseaux IP Européens 1 1 1 1 1 RIPEM Riordan's Internet Privacy Enhanced Mail 1 1 1 1 1 ripper rip 1 1 1 1 1 RISC Reduced Instruction Set Computer 1 1 1 1 1 RISCiX /risk-icks/ (Or "RISC iX") BSD-based Unix developed by Acorn Computers Ltd. (Cambridge, UK) to run on 32-bit ARM RISC processors. RISCiX was launched circa 1989 for three production machines - the R140, R260, the discless R225; and other prototypes. (2003-09-24) 1 1 1 1 1 RISC OS (Reduced Instruction Set Computer Operating System) The operating system originally developed by Acorn Computers for their Archimedes family of personal computers. RISC OS replaced the Arthur operating system used on the first Archimedeses. It is written in ARM assembly code and distributed on ROM so it takes up no disk space and takes no time to load. It supports cooperative multitasking with memory management and includes a graphical user interface or "WIMP". It is written in a highly modular style and makes extensive use of vectors so it is easy to modify and extend by loading new modules in RAM. Many system calls (called "SWIs" - software interrupts) are available to application programmers and some of these are available as user comands via a built-in command-line interpreter. RISC OS also supported outline fonts when only bitmap fonts were available on most other 1 1 1 1 1 RiscPC The final addition to Acorn's Archimedes family of personal computers, released in April 1994. The RiscPC allowed a second processor, e.g. an Intel 486 or a second ARM, to share the bus, memory and peripherals with the main processor. It also had full 24-bit colour graphics support. The Risc PC 600 (the first to be launched) had the new ARM600 processor and RISC OS 3.5. The RiscPC 700 had an ARM710 processor and RISC OS 3.6, and the SA had the StrongARM processor and RISC OS 3.7. Castle Technology Ltd later introduced the IYONIX pc with the 32-bit X-Scale processor and USB sockets. USB and StrongArm can also be retrofitted to earlier RiscPCs. RiscPCs are among the most energy efficient home computers. Acorn Computer Museum (http://pages.zoom.co.uk/acorn.computer/riscpc.html). (2004-09-21) 1 1 1 1 1 RISC System/6000 (Or "RS/6000") IBM's current RISC-based Unix computer. The RS/6000, announced in 1990, replaced the RT-PC. It runs AIX 3.x and 4.x. Most models have an MCA bus. A wide range of models are available. (1995-04-06) 1 1 1 1 1 Risk Based Testing Testing based on identification of potential risks (or "candidate risks"), which should be analysed by the project stakeholder or which might appear during the project's development. (2006-09-07) 1 1 1 1 1 RISQL Red Brick Intelligent SQL 1 1 1 1 1 RITL Wireless Local Loop 1 1 1 1 1 RJ-11 An American-style telephone jack with six possible connections. A telephone normally uses two pairs of wires. Often found on the back of US-manufactured modems or for connection to a leased line. (1998-06-30) 1 1 1 1 1 RJ-45 A serial connector which looks very much like a standard telephone connector, except it houses eight wires instead of four. RJ-45s are typically found on computers either integrated into the mother board or on a NIC. Because they are so small they are often used on devices such as terminal servers that have many ports. Ethernet (10baseT) and Token Ring sometimes use four wires of an RJ-45 plug, 100baseVG uses all eight. 100BaseTX uses the same four wires of the RJ-45 connector as 10baseT but the wire must be category 5 instead of category 3. [Would the cable normally be shielded twisted pair or unshielded twisted pair?] (2004-05-22) 1 1 1 1 1 RJE Remote Job Entry 1 1 1 1 1 RKM Rom Kernel Manual 1 1 1 1 1 RL (MUD community) Real Life. Firiss laughs in RL means that Firiss's player is laughing. Opposite: VR. [Jargon File] (1995-05-09) 1 1 1 1 1 rl Kent Wittenburg <kentw@bellcore.com>. The RL files contain code for defining relational grammars and using them in a bottom-up parser to recognise and/or parse expressions in Relational Languages. The approach is a simplification of that described in Wittenburg, Weitzman, and Talley (1991), Unification-Based Grammars and Tabular Parsing for Graphical Languages, Journal of Visual Languages and Computing 2:347-370. This code is designed to support the definition and parsing of Relational Languages, which are characterised as sets of objects standing in user-defined relations. Correctness and completeness is independent of the order in which the input is given to the parser. Data to be parsed can be in many forms as long as an interface is supported for queries and predicates for the relations used in grammar productions. To date, this software has been used to parse recursive 1 1 1 1 1 RLaB A MATLAB-like matrix-oriented programming language/toolbox. RLaB focusses on creating a good experimental environment (or laboratory) in which to do matrix mathematics. Currently RLaB has numeric scalars and matrices (real and complex), and string scalars, and matrices. RLaB also contains a list variable type, which is a heterogeneous associative array. Version 0.95 includes an interpreter, libraries and documentation. E-mail: Ian Searle <ians@eskimo.com>. (ftp://evans.ee.adfa.oz.au). Requires GNUPLOT, lib[IF]77.a (from f2c). Ported to many platforms including Unix, OS/2, Amiga. (1993-10-27) 1 1 1 1 1 RLDRAM (Reduced Latency DRAM) A kind of dynamic random access memory. RLDRAM comes in "common IO" and "separate IO" configurations. It supports broadside addressing. It is typically used in networking gear and set-top boxes that require high bandwidth memory. [What is the latency, and how does it compare to ordinary DRAM?] (2007-03-20) 1 1 1 1 1 RLE run-length encoding 1 1 1 1 1 RLF Reuse Library Framework of the DoD. 1 1 1 1 1 RLL 1. <language> Representation Language Language. 2. <storage> Run Length Limited. (2003-07-24) 1 1 1 1 1 rlogin (Remote login) The 4.2BSD Unix utility to allow a user to log in on another host via a network. Rlogin communicates with a daemon on the remote host. Unix manual page: rlogin(1). See also telnet. (1997-01-12) 1 1 1 1 1 RMAG Recursive Macro Actuated Generator 1 1 1 1 1 RMAIL A MUA written in Emacs Lisp to run within Emacs. (1996-03-21) 1 1 1 1 1 RMI Remote Method Invocation 1 1 1 1 1 RM-ODP The ISO Reference Model for Open Distributed Environments. (http://pepper.open.ac.uk/~armsarms/sa.html). (1995-11-23) 1 1 1 1 1 RMON 1. <networking> remote monitoring. 2. Remote Monitor. (2003-09-15) 1 1 1 1 1 RMS 1. Record Management Services. 2. Richard Stallman. 1 1 1 1 1 RNF root normal form 1 1 1 1 1 ro The country code for Romania. (1999-01-27) 1 1 1 1 1 roach A Bell Labs term meaning destroy, especially of a data structure. Hardware gets toasted or fried, software gets roached. [Why?] [Jargon File] (1999-02-08) 1 1 1 1 1 ROADS Subsystem of ICES. Sammet 1969, p.616. 1 1 1 1 1 Robert T. Morris The creator of the "Internet Worm" that wreaked havoc on many Internet systems for a day or two. Morris, the son of an NSA spook, did some jail time for releasing the worm. (1995-01-12) 1 1 1 1 1 ROBEX ROBot EXapt. Aachen Tech College. Based on EXAPT. Version: ROBEX-M for micros. 1 1 1 1 1 RoboHELP A Microsoft Windows Help authoring tool from Blue Sky Software. Used with Microsoft Word to create Help files for inclusion in a Windows application or for stand alone use. (1997-01-19) 1 1 1 1 1 robot 1. <robotics> A mechanical device for performing a task which might otherwise be done by a human, e.g. spraying paint on cars. See also cybernetics. 2. <chat> An IRC or MUD user who is actually a program. On IRC, typically the robot provides some useful service. Examples are NickServ, which tries to prevent random users from adopting nicks already claimed by others, and MsgServ, which allows one to send asynchronous messages to be delivered when the recipient signs on. Also common are annoybots, such as KissServ, which perform no useful function except to send cute messages to other people. Service robots are less common on MUDs; but some others, such as the "Julia" robot active in 1990--91, have been remarkably impressive Turing test experiments, able to pass as human for as long as ten or fifteen minutes of conversation. 1 1 1 1 1 robot exclusion standard standard for robot exclusion 1 1 1 1 1 robots.txt standard for robot exclusion 1 1 1 1 1 robust Said of a system that has demonstrated an ability to recover gracefully from the whole range of exceptional inputs and situations in a given environment. One step below bulletproof. Carries the additional connotation of elegance in addition to just careful attention to detail. Compare smart, opposite: brittle. [Jargon File] 1 1 1 1 1 Rockwell Protocol Interface (RPI) A cost-cutting feature of some modems allowing data compression and error correction (e.g. ITU-T V.42bis, V.42) to be provided in software instead of hardware. Usually an RPI modem comes with RPI-aware software (e.g. the low-end RPI models of Supra come with the COMit which supports RPI, providing MNP 2,4,5,7, V.42 and V.42bis). RPI is not supported by many commercial packages nor by current releases of popular shareware communication programs (Telix v3.22 and Telemate v4.12). ProComm Plus for Windows 2.0 will support RPI. Currently Rockwell produce two classes of RPI chip set. The original is capable of 2400 bit/s data, 9600 bit/s class 1-only fax. The newer one is capable of 14400 bit/s data/fax. Currently there are no RPI chipset from Rockwell supporting speeds higher than 14400 bit/s. (1994-07-01) 1 1 1 1 1 Rocky Mountain Basic The BASIC language used by Hewlett Packard on their 680x0-based computers. Rocky Mountain Basic is good for interfaces to IEEE 488 controls and contains many mathematical and matrix functions. It has about 600 commands. Typical applications include automatic test stations. (1996-04-28) 1 1 1 1 1 rococo Baroque in the extreme. Used to imply that a program has become so encrusted with the software equivalent of gold leaf and curlicues that they have completely swamped the underlying design. Called after the later and more extreme forms of Baroque architecture and decoration prevalent during the mid-1700s in Europe. Alan Perlis said: "Every program eventually becomes rococo, and then rubble." Compare critical mass. [Jargon File] (1996-04-06) 1 1 1 1 1 ROCOF Rate of Occurrence of Failures 1 1 1 1 1 roff A text formatting language associated with Unix. See groff, nroff, troff. [Was roff the original? Platform(s)?] (1998-11-14) 1 1 1 1 1 ROFL ROTFL 1 1 1 1 1 ROFLMAO ROTFLMAO 1 1 1 1 1 rogue [Unix] A Dungeons-and-Dragons-like game using character graphics, written under BSD Unix and subsequently ported to other Unix systems. The original BSD "curses(3)" screen-handling package was hacked together by Ken Arnold to support "rogue(6)" and has since become one of Unix's most important and heavily used application libraries. Nethack, Omega, Larn, and an entire subgenre of computer dungeon games all took off from the inspiration provided by "rogue(6)". See also nethack. [Jargon File] 1 1 1 1 1 rollback Reverting data in a database to an earlier state, usually in response to an error or aborted operation. In a transaction based database system, transactions are considered atomic. If an error occurs while performing a transaction, the database is automatically rolled back to the state at the previous commit. Rollback may also be performed by an explicit rollback transaction. (2000-01-15) 1 1 1 1 1 ROM Read-Only Memory 1 1 1 1 1 ROM BIOS Basic Input/Output System 1 1 1 1 1 ROME An experimental object-oriented language. ["The Point of View Notion for Multiple Inheritance", B. Carre et al, SIGPLAN Notices 25(10):312-321 (OOPSLA/ECOOP '90) (Oct 1990)]. (1994-11-30) 1 1 1 1 1 Rom Kernel Manual (RKM) A series of books or files for developers for the Amiga computer, containing information about the operating system kernel stored in ROM. (1996-04-06) 1 1 1 1 1 room channel 1 1 1 1 1 ROOM Methodology Real-Time Object-Oriented Modeling 1 1 1 1 1 room-temperature IQ (IBM) 80 or below. Used in describing the expected intelligence range of the luser. "Well, but how's this interface going to play with the room-temperature IQ crowd?" This is a much more insulting phrase in countries that use Celsius thermometers. See drool-proof paper. [Jargon File] (1996-04-06) 1 1 1 1 1 root 1. <operating system> The Unix superuser account (with user name "root" and user ID 0) that overrides file permissions. The term avatar is also used. By extension, the privileged system-maintenance login on any operating system. See root mode, go root, wheel. [Jargon File] (1994-10-27) 2. <operating system> root directory. (1996-11-21) 3. <data> root node. (1998-11-14) 1 1 1 1 1 root bridge A bridge which continuously transmits network topology information to other bridges, using the spanning tree protocol, in order to notify all other bridges on the network when topology changes are required. This means that a network is able to reconfigure itself whenever a network link (e.g. another bridge) fails, so an alternative path can be found. The presence of a root bridge also prevents loops (network loop) from forming in the network. The root bridge is where the paths that frames take through the network they are assigned. It should be located centrally on the network to provide the shortest path to other links on the network. Unlike other bridges, the root bridge always forwards frames out over all of its ports. Every network should only have one root bridge. It should have the lowest bridge ID number. (2000-11-26) 1 1 1 1 1 root directory The topmost node of a hierarchical file system. (1996-11-21) 1 1 1 1 1 root mode Synonym with wizard mode or "wheel mode". Like these, it is often generalised to describe privileged states in systems other than operating systems. [Jargon File] 1 1 1 1 1 root node In a tree, a node with no parents, but which typically has daughters. (1998-11-14) 1 1 1 1 1 Root Normal Form (RNF) Head Normal Form in graph rewriting. 1 1 1 1 1 root version The initial value of an object in a change management system. 1 1 1 1 1 ROSE Remote Operations Service Element 1 1 1 1 1 Rosette A concurrent object-oriented language from MCC. [Details?] (1997-11-26) 1 1 1 1 1 Roskind grammars Yacc-based parsers for C and C++ by Jim Roskind. It does not use the %prec and %assoc YACC features so conflicts are never hidden. The C grammar has only one shift-reduce conflict, the C++ grammar has a few more. With byacc it can produce graphical parse trees automatically. The C grammar conforms to ANSI C and the C++ grammar supports cfront 2.0 constructs. Latest version: cpp5 (cf2.0). (ftp://ftp.infoseek.com/pub/c++grammar/). (2003-10-09) 1 1 1 1 1 rot13 /rot ther'teen/ [Usenet: from "rotate alphabet 13 places"], v. The simple Caesar-cypher encryption that replaces each English letter with the one 13 places forward or back along the alphabet, so that "The butler did it!" becomes "Gur ohgyre qvq vg!" Most Usenet news reading and posting programs include a rot13 feature. It is used to enclose the text in a sealed wrapper that the reader must choose to open - e.g. for posting things that might offend some readers, or spoilers. A major advantage of rot13 over rot(N) for other N is that it is self-inverse, so the same code can be used for encoding and decoding. [Jargon File] 1 1 1 1 1 rotary debugger (Commodore) Essential equipment for those late-night or early-morning debugging sessions. Mainly used as sustenance for the hacker. Comes in many decorator colours, such as Sausage, Pepperoni, and Garbage. (1995-01-11) 1 1 1 1 1 rotational latency The time for the start of the required sector on a disk to appear underneath the read/write head. The worst case is where it has just passed the head when the request is received. For a disk drive with N heads per surface, rotating at R revolutions per minute, the average rotational latency will be L = 30/NR seconds. Rotational latency is one component of access time. (2009-11-06) 1 1 1 1 1 rotations per minute revolutions per minute 1 1 1 1 1 ROTFL (Or "ROFL") Rolling on the floor laughing (or rolls...). Used in chat, MUD, news. See also ROTFLMAO, ROTFLOL. (1996-02-22) 1 1 1 1 1 ROTFLMAO Rolling on the floor laughing my ass (arse) off. An extreme form of ROTFL. (2000-11-12) 1 1 1 1 1 ROTFLMAOASTC Rolling on the floor laughing my ass (or arse) off and scaring the cat. The superlative form of ROTFL. (2004-04-06) 1 1 1 1 1 ROTFLOL Rolling on the floor laughing out loud. See ROTFL. (1997-03-06) 1 1 1 1 1 round-robin A scheduling algorithm in which processes are activated in a fixed cyclic order. Those which cannot proceed because they are waiting for some event (e.g. termination of a child process or an input/output operation) simply return control to the scheduler. The virtue of round-robin scheduling is its simplicity - only the processes themselves need to know what they are waiting for or how to tell if it has happened. However, if a process goes back to sleep just before the event for which it is waiting occurs then the event will not get handled until all the other processes have been activated. Compare priority scheduling. (1996-02-10) 1 1 1 1 1 round tape Industry-standard 1/2-inch magnetic tape (7- or 9-track) on traditional circular reels. See macrotape, opposite: square tape. [Jargon File] (1996-02-03) 1 1 1 1 1 round-trip time (RTT) A measure of the current delay on a network, found by timing a packet bounced off some remote host. This can be done with ping -s. (1994-11-30) 1 1 1 1 1 route /root/ The sequence of hosts, routers, bridges, gateways, and other devices that network traffic takes, or could take, from its source to its destination. As a verb, to determine the link down which to send a packet, that will minimise its total journey time according to some routeing algorithm. You can find the route from your computer to another using the program traceroute on Unix or tracert on Microsoft Windows. (2001-05-26) 1 1 1 1 1 routed /root dee/ Route Daemon. A program which runs under 4.2BSD Unix systems and derivatives to propagate routes among machines on a local area network, using the Routing Information Protocol. See also gated. (2002-07-31) 1 1 1 1 1 route flapping flapping router 1 1 1 1 1 routeing (US "routing") /roo'ting/ The process, performed by a router, of selecting the correct interface and next hop for a packet being forwarded. This is the British and international standard spelling. See also Exterior Gateway Protocol, Interior Gateway Protocol. (2001-05-28) 1 1 1 1 1 routeing domain (US "routing") A set of routers that exchange routeing information within an administrative domain. (1994-12-14) 1 1 1 1 1 router /roo't*/ A device which forwards packets between networks. The forwarding decision is based on network layer information and routing tables, often constructed by routing protocols. Unix manual page: route(8). See also bridge, gateway, Exterior Gateway Protocol, Interior Gateway Protocol, flapping router. (1999-08-24) 1 1 1 1 1 routine subroutine 1 1 1 1 1 routing /row'ting/ Using a kind of rotating cutting tool called a router, pronounced /row't*/. In the USA a router, pronounced /row't*/, is also a network device that performs routing. In the UK, the network device is pronounced /roo't*/ and what it does is spelled "routeing". (2002-07-31) 1 1 1 1 1 Routing Information Protocol 1. <networking> (RIP) A distance vector, as opposed to link state, routing protocol. RIP is an Internet standard Interior Gateway Protocol defined in STD 34, RFC 1058 and updated by RFC 1388. See also Open Shortest Path First. 2. <networking> (RIP) A companion protocol to IPX for exchange of routing information in a Novell network. RIP has been partly superseded by NLSP. It is not related to the Internet protocol of the same name. (1997-03-04) 1 1 1 1 1 routing policy Rules implemented on a router or other network device to select routes from peers, customers, and upstream providers; select and modify routes you send to peers, customers and upstream providers and identify routes within your own Autonomous System. (http://www.nanog.org/mtg-0202/ppt/golding/sld005.htm). (2008-12-12) 1 1 1 1 1 Routing Table Maintenance Protocol (RTMP) A protocol used by AppleTalk to ensure that all routers on the network have consistent routing information. (1997-05-11) 1 1 1 1 1 row record 1 1 1 1 1 Row Address Strobe (RAS) An input to a dynamic random-access memory (DRAM) to indicate that the row address lines are valid. (2004-02-15) 1 1 1 1 1 row-level locking A technique used in database management systems, where a row is locked for writing to prevent other users from accessing data being while it is being updated. Other techniques are table locking and MVCC. (1999-06-18) 1 1 1 1 1 Royal Veterinary and Agricultural University Address: Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark. (1994-12-12) 1 1 1 1 1 RPC Remote Procedure Call 1 1 1 1 1 RPG 1. <games> Role-Playing Game. 2. <tool> Report Program Generator. 3. <person> Richard Gabriel. (1999-10-12) 1 1 1 1 1 RPG-II Report Program Generator 1 1 1 1 1 RPI Rockwell Protocol Interface 1 1 1 1 1 RPL Reverse Polish LISP. Language used by HP-28 and HP-48 calculators. 1 1 1 1 1 RPL-1 Data reduction language. Proc SJCC 30:571-575, AFIPS (Spring 1967). 1 1 1 1 1 RPM A Unix package-management system that helps installation of software packages; similar to an install program. [More details? Reference? Expansion?] (1996-03-07) 1 1 1 1 1 rpm revolutions per minute 1 1 1 1 1 RPN postfix notation 1 1 1 1 1 Répondez s'il vous plait (RSVP) French for "please reply", commonly found (abbreviated) on invitations. (1996-12-02) 1 1 1 1 1 RPT Unify. Report Writer Language. 1 1 1 1 1 RRL Remote Reference Layer 1 1 1 1 1 RRS An early definition of Scheme. Revised in R2RS. ["The Revised Report on Scheme", G.L. Steele et al, AI Memo 452, MIT, Jan 1978]. (1994-10-28) [Was the original "Report on Scheme" published?] 1 1 1 1 1 RS 1. <character> Record Separator 2. <standard> Recommended Standard, a series of EIA standards including EIA-232. 1 1 1 1 1 RS-232 EIA-232 1 1 1 1 1 RS-232C Renamed EIA-232C (2004-08-02) 1 1 1 1 1 RS-232D The EIA equivalent of ITU-T standard V.28. [Difference from EIA-232/EIA-232C?] (1995-03-02) 1 1 1 1 1 RS-422 EIA-422 1 1 1 1 1 RS-423 EIA-423 1 1 1 1 1 RS-449 EIA-449 1 1 1 1 1 RS-485 EIA-485 1 1 1 1 1 RS6000 RISC System/6000 1 1 1 1 1 RS/6000 RISC System/6000 1 1 1 1 1 RS6K RISC System/6000 1 1 1 1 1 RSA (The initials of the authors) 1. RSA Data Security, Inc. 2. Their cryptography systems, especially RSA encryption. The RSA algorithm was first described in the paper: [R. Rivest, A. Shamir, L. Adleman, "A Method for Obtaining Digital Signatures and Public-key Cryptosystems". CACM 21,2; 1978] (1995-03-21) 1 1 1 1 1 RSA Data Security, Inc. (After Rivest, Shamir, Adleman - see RSA) A recognised world leader in cryptography, with millions of copies of its software encryption and authentication installed and in use worldwide. RSA's technologies are the global de facto standard for public key cryptography and digital signatures, and are part of existing and proposed standards for the Internet, ITU-T, ISO, ANSI, PKCS, IEEE and business and financial networks around the world. (http://rsa.com/). (1994-12-08) 1 1 1 1 1 RSA encryption A public-key cryptosystem for both encryption and authentication, invented in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman. Its name comes from their initials. The RSA algorithm works as follows. Take two large prime numbers, p and q, and find their product n = pq; n is called the modulus. Choose a number, e, less than n and relatively prime to (p-1)(q-1), and find its reciprocal mod (p-1)(q-1), and call this d. Thus ed = 1 mod (p-1)(q-1); e and d are called the public and private exponents, respectively. The public key is the pair (n, e); the private key is d. The factors p and q must be kept secret, or destroyed. It is difficult (presumably) to obtain the private key d from the public key (n, e). If one could factor n into p and q, however, then one could obtain the private key d. Thus the entire security of RSA depends on the difficulty of factoring; an easy method for factoring products of large prime numbers 1 1 1 1 1 RSCS Remote Spooling Communication Subsystem. (1996-02-04) 1 1 1 1 1 Réseaux Associés pour la Recherche Européenne (RARE) An association of national and international European networks and users. See also CCIRN. (1994-11-30) 1 1 1 1 1 Réseaux IP Européens (RIPE) A collaboration between European networks which use the TCP/IP protocol suite to provide Internet services. (1994-11-30) 1 1 1 1 1 RS flip-flop SR flip-flop 1 1 1 1 1 rsh Remote shell. A Berkeley Unix networking command to execute a given command on a remote host, passing it input and receiving its output. Rsh communicates with a daemon on the remote host. It is sometimes called remsh to avoid confusion with the restricted shell, also called "rsh". Unix manual page: rsh(1). (1994-12-08) 1 1 1 1 1 RSI 1. <medical> overuse strain injury. 2. <company> Research Systems, Inc.. (1999-01-08) 1 1 1 1 1 RSL RAISE Specification Language 1 1 1 1 1 RSN Real Soon Now 1 1 1 1 1 RSS Rich Site Summary 1 1 1 1 1 RSS feed Rich Site Summary 1 1 1 1 1 rstat netstat 1 1 1 1 1 RSTS/E A multi-user, general purpose timesharing operating system produced by Mentec, Inc. and licensed bu Digital Equipment Corporation. RSTS/E can be used for interactive timesharing, batch processing, indirect command file processing, program development using a variety of languages and tools, and a wide variety of special purpose applications. Up to 127 concurrent terminal users in both local and remote locations through multi-terminal services can interact with application tasks. Without multi-terminal services, 63 users are the maximum. Tasks can share computational, storage, and input/output services provided by the RSTS/E system. Full description (http://pyrfect.ico.olivetti.com/SPD/13-01-37.txt). (1996-06-04) 1 1 1 1 1 RSVP 1. <chat> Répondez s'il vous plait. 2. <protocol> Resource Reservation Protocol. 3. <body> Revolutionary Surrealist Vandal Party. (2001-03-18) 1 1 1 1 1 RT-11 A real time operating system for the DEC PDP-11 computers, used in the early 1980s and still in 2005 found occasionally in old embedded systems. (2005-01-26) 1 1 1 1 1 RTBM (Unix) Read The Bloody Manual. Commonwealth Hackish variant of RTFM. RTBM is often the entire text of the first reply to a question from a newbie; the *second* would escalate to "RTFM". [Jargon File] (1994-12-08) 1 1 1 1 1 RTC++ A real-time extension of C++. ["Object-Oriented Real-Time Language Design: Constructs for Timing Constraints", Y. Ishikawa et al, SIGPLAN Notices 25(10):289-298 (OOPSLA/ECOOP '90) (Oct 1990)]. (1994-12-08) 1 1 1 1 1 RT-CDL Real-Time Common Design Language 1 1 1 1 1 RTEE Real Time Engineering Environment: a set of CASE tools produced by Westmount Technology B.V. 1 1 1 1 1 RTF Rich Text Format 1 1 1 1 1 RTFAQ (Usenet, primarily written, by analogy with RTFM) Read the FAQ! An exhortation that the person addressed ought to read the newsgroup's FAQ list before posting questions. [Jargon File] (1994-12-08) 1 1 1 1 1 RTFB (By analogy with RTFM) Read The Fucking Binary. Used when neither documentation nor source for the problem at hand exists, and the only thing to do is use some debugger or monitor and directly analyse the assembler or even the machine code. RTFB is the least pejorative of the RTF? forms, the anger is directed at the absence of both source *and* adequate documentation rather than at the person asking a question. [Jargon File] (1995-08-20) 1 1 1 1 1 RTFM /R T F M/ Read The Fucking Manual (always abbreviated, sometimes bowdlerised to "Fine" or "Friendly") An (unhelpful) guru's traditional response when someone asks a question in a newsgroup or mailing list which he could have easily answered for himself had he bothered to RTFM. The term may also be used to indicate that you couldn't find the answer in the manual. E.g. "How do I interface Unix to my toaster? And yes, I did RTFM but the FM didn't help and I can't RTFS." Other derived forms include RTFAQ, RTFB, RTM, RYFM and, more recently, STFW. Compare: UTSL. [Earliest use?] [Jargon File] (2003-06-07) 1 1 1 1 1 RTFS 1. Read The Fucking Source. Variant form of RTFM, used when the problem at hand is not necessarily obvious and not answerable from the manuals - or the manuals are not yet written and maybe never will be. For even trickier situations, see RTFB. Unlike RTFM, the anger inherent in RTFS is not usually directed at the person asking the question, but rather at the people who failed to provide adequate documentation. 2. Read The Fucking Standard; this oath can only be used when the problem area (e.g. a language or operating system interface) has actually been codified in a ratified standards document. The existence of these standards documents (and the technically inappropriate but politically mandated compromises that they inevitably contain, and the impenetrable legalese in which they are invariably written, and the unbelievably tedious bureaucratic process by which they are produced) can be unnerving to hackers, who are used to a certain amount of 1 1 1 1 1 RTI Return from interrupt 1 1 1 1 1 RTL 1. <hardware> Resistor-Transistor Logic. 2. <language> Register Transfer Language. 1 1 1 1 1 RTL/1 Real Time Language. A real-time language written by J.G.P. Barnes of ICI in 1971. It was the predecessor of RTL/2. ["Real Time Languages for Process Control", J.G.P. Barnes, Computer J 15(1):15-17, Feb 1972]. (1994-11-09) 1 1 1 1 1 RTL/2 Real Time Language. A small real-time language based on ALGOL 68, with separate compilation designed by J.G.P. Barnes of ICI in 1972 as a successor to RTL/1. A program is composed of separately compilable modules called bricks which may be datablocks, procedures or stack. A stack is a storage area for use as a workspace by a task. The language is block-structured and weakly typed. Simple types are byte, int, frac and real. There are no Booleans. Compound types may be formed from arrays, records and refs (pointers). There are no user-defined types. Control statements are if-then-elseif-else-end, for-to-by-do-rep, block-endblock, switch, goto, and label variables. ["RTL/2: Design and Philosophy", J.G.P. Barnes, Hayden & Son, 1976]. 1 1 1 1 1 RTM 1. [Usenet] Read The Manual. Politer variant of RTFM. 2. Robert T. Morris Jr. The perpetrator of the great Internet worm of 1988 (see Great Worm); villain to many, naive hacker gone wrong to a few. Morris claimed that the worm that brought the Internet to its knees was a benign experiment that got out of control as the result of a coding error. After the storm of negative publicity that followed this blunder, Morris's user name on ITS was hacked from RTM to RTFM. [Jargon File] (1995-03-31) 1 1 1 1 1 RTMP Routing Table Maintenance Protocol 1 1 1 1 1 RTOS Real-Time Operating System 1 1 1 1 1 RTP Real-Time Transport Protocol 1 1 1 1 1 RT-PC RISC Technology Personal Computer. (Commonly, but incorrectly, known as the "PC-RT", later changed to just "RT") IBM's first RISC-based Unix computer. The RT-PC was the predecessor to IBM's RS/6000. It ran AIX 1.x and 2.x and had a PC-AT bus and IBM's ROMP microprocessor. It was withdrawn from the marketing around 1989 or 1990. (1995-04-06) 1 1 1 1 1 RTS 1. <operating system> run-time system. 2. <programming> return from subroutine. (1999-07-26) 1 1 1 1 1 RTSA real-time structured analysis 1 1 1 1 1 RTSP Real Time Streaming Protocol 1 1 1 1 1 RTT Round-Trip Time 1 1 1 1 1 RTTI Run Time Type Information 1 1 1 1 1 RTTY radio teletypewriter 1 1 1 1 1 ru The country code for the Russian Federation. (1999-01-27) 1 1 1 1 1 rubi furigana 1 1 1 1 1 Ruby 1. A relational language designed by Jones and M. Sheeran in 1986 for describing and designing circuits (a hardware description language). Ruby programs denote binary relations and programs are built-up inductively from primitive relations using a pre-defined set of relational operators. Ruby programs also have a geometric interpretation as networks of primitive relations connected by wires, which is important when layout is considered in circuit design. Ruby has been continually developed since 1986, and has been used to design many different kinds of circuits, including systolic arrays, butterfly networks and arithmetic circuits. (ftp://ftp.cs.chalmers.se/pub/misc/ruby/). E-mail: <graham@cs.chalmers.se>. ["Ruby - A Language of Relations and Higher-Order Functions", 1 1 1 1 1 rude [WPI] 1. Badly written or functionally poor, e.g. a program that is very difficult to use because of gratuitously poor design decisions. Opposite: cuspy. 2. Anything that manipulates a shared resource without regard for its other users in such a way as to cause a (non-fatal) problem. Examples: programs that change tty modes without resetting them on exit, or windowing programs that keep forcing themselves to the top of the window stack. Compare all-elbows. [Jargon File] (1994-10-27) 1 1 1 1 1 RUFL Rhodes University Functional Language. A Miranda-like functional language from Rhodes University, Grahamstown, South Africa with a SPARC code generator. (1994-10-27) 1 1 1 1 1 run execution 1 1 1 1 1 RUNCIBLE Early system for mathematics on IBM 650. See also FORTRUNCIBLE, IT. [Listed in CACM 2(5):16 (May 1959)]. (1994-10-27) 1 1 1 1 1 run commands The expansion of the file name suffix, "rc", common to many Unix configuration files, e.g. .newsrc, .cshrc, .twmrc, elmrc, etc. Always abbreviated to /R C/ when spoken. Note, "rc" is not a typical filename extension as it doesn't start with a dot. The suffix "rc" derives from a script-creation utility in CTSS called "runcom". Unix FAQ (http://cis.ohio-state.edu/hypertext/faq/usenet/unix-faq/faq/top.html). (2014-11-19) 1 1 1 1 1 runes 1. Anything that requires heavy wizardry or black art to parse: core dumps, JCL commands, APL or code in a language you haven't a clue how to read. Not quite as bad as line noise, but close. Compare casting the runes, Great Runes. 2. Special display characters (for example, the high-half graphics on an IBM PC). [Jargon File] 1 1 1 1 1 runic Obscure, consisting of runes. VMS fans sometimes refer to Unix as "RUnix". Unix fans return the compliment by expanding VMS to "Very Messy Syntax" or "Vachement Mauvais Systeme" (French; literally "Cowlike Bad System", idiomatically "Bitchy Bad System"). (1996-09-17) 1 1 1 1 1 run-length encoding A kind of compression algorithm which replaces sequences ("runs") of consecutive repeated characters (or other units of data) with a single character and the length of the run. This can either be applied to all input characters, including runs of length one, or a special character can be used to introduce a run-length encoded group. The longer and more frequent the runs are, the greater the compression that will be achieved. This technique is particularly useful for encoding black and white images where the data units would be single bit pixels. (1994-10-27) 1 1 1 1 1 Run Length Limited (RLL) The most popular scheme for encoding data on magnetic disks. RLL packs up to 50% more data on a disk than MFM. IBM invented RLL encoding and used it in mainframe disk drives. During the late 1980s, PC hard disks began using RLL. Today, virtually every drive on the market uses some form of RLL. Groups of bits are mapped to specific patterns of flux. The density of flux transitions is limited by the spatial resolution of the disk and frequency response of the head and electronics. However, transitions must be close enough to allow reliable clock recovery. RLL implementations vary according to the minimum and maximum allowed numbers of transition cells between transitions. For example, the most common variant today, RLL 1,7, can have a transition in every other cell and must have at least one transition every seven cells. The exact mapping from bits to transitions is 1 1 1 1 1 run time 1. The elapsed time to perform a computation on a particular computer. 2. The amount of time a processor actually spent on a particular process and not on other processes or overhead (see time-sharing). 3. The period of time during which a program is being executed, as opposed to compile-time or load time. The term should be hyphenated when used as an adjective. 4. run-time support. (2001-09-14) 1 1 1 1 1 run-time environment A collection of subroutines and environment variables that provide commonly used functions and data for a program while it is running. Compare run-time support. (1995-03-22) 1 1 1 1 1 run-time error An error in the execution of a program which occurs at run time, as opposed to a compile-time error. A good programming language should, among other things, aim to replace run-time errors by compile-time errors. Language features such as strong typing help. A good program should attempt to avoid run-time errors by, for example, checking that their input data is sensible. Where this is not possible, the program should attempt to detect the error and handle it gracefully rather than just exiting via the language or operating system's default handler. Here again, a good language will make this easy to do (or at least possible). See also abort, core dump, GPF. (1997-01-13) 1 1 1 1 1 run-time library A file containing routines which are linked with a program at run time rather than at compile-time. The advantage of such dynamic linking is that only one copy of the library needs to be stored, rather than a copy being included with each executable that refers to it. This can greatly reduce the disk space occupied by programs. Furthermore, it means that all programs immediately benefit from changes (e.g. bug fixes) to the single copy of the library without requiring recompilation. Since the library code is normally classified as read-only to the memory management system, it is possible for a single copy of the library to be loaded into memory and shared by all active programs, thus reducing RAM and virtual memory requirements and program load time. (1997-07-16) 1 1 1 1 1 run-time support run-time system 1 1 1 1 1 run-time system (RTS, run-time support, run-time) Library code and processes which support software written in a particular language running on a particular platform. The RTS typically deals with details of the interface between the program and the operating system such as system calls, program start-up and termination, and memory management. (1999-07-26) 1 1 1 1 1 Run-Time Type Information (RTTI) Facilities included in C++ compilers to allow the type of an object to be determined at run time. This facility, found in good C++ compilers and some other high level languages, adds type information to memory resident objects (i.e. type name or unique type-id). This allows the run-time system to determine if an object is of a specific type, for example, to ensure that a cast of an object is valid. (1996-04-15) 1 1 1 1 1 ruptime Unix Berkeley networking command to report the status of all hosts on the net. See also rwho. See ruptime(1N). 1 1 1 1 1 RUSH 1. <language> An interactive dialect of PL/I, related to CPS, dated about 1966. The name is the abbreviation of Remote Use of Shared Hardware. ["Introduction to RUSH", Allen-Babcock Computing 1969. Sammet 1969, p.309.] 2. <language> A high-level language that closely resembles Tcl but aimed to provide substantially faster execution. See An Introduction to the Rush Language (ftp://ginsberg.cs.berkeley.edu/pub/papers/asah/rush-tcl94.ps.gz). by Adam Sah, Jon Blow, and Brian Dennis (1994). (1996-12-17) 1 1 1 1 1 Russell (After Bertrand Russell) A compact, polymorphically typed functional language by A. Demers & J. Donahue with bignums and continuations. Types are themselves first-class values and may be passed as arguments. (ftp://parcftp.xerox.com/pub/russell/russell.tar.Z). ["An Informal Description of Russell", H. Boehm et al, Cornell CS TR 80-430, 1980]. ["Understanding Russell: A First Attempt", J.G. Hook in LNCS 173, Springer]. (1995-03-27) 1 1 1 1 1 Russell, Bertrand Bertrand Russell 1 1 1 1 1 Russell's Attic An imaginary room containing countably many pairs of shoes (i.e. a pair for each natural number), and countably many pairs of socks. How many shoes are there? Answer: countably many (map the left shoes to even numbers and the right shoes to odd numbers, say). How many socks are there? Also countably many, we want to say, but we can't prove it without the Axiom of Choice, because in each pair, the socks are indistinguishable (there's no such thing as a left sock). Although for any single pair it is easy to select one, we cannot specify a general method for doing this. (1995-03-29) 1 1 1 1 1 Russell's Paradox A paradox (logical contradiction) in set theory discovered by Bertrand Russell. If R is the set of all sets which don't contain themselves, does R contain itself? If it does then it doesn't and vice versa. The paradox stems from the acceptance of the following axiom: If P(x) is a property then x : P is a set. This is the Axiom of Comprehension (actually an axiom schema). By applying it in the case where P is the property "x is not an element of x", we generate the paradox, i.e. something clearly false. Thus any theory built on this axiom must be inconsistent. In lambda-calculus Russell's Paradox can be formulated by representing each set by its characteristic function - the property which is true for members and false for non-members. The set R becomes a function r which is the negation of its 1 1 1 1 1 rusty iron Synonym tired iron. It has been claimed that this is the inevitable fate of water MIPS. [Jargon File] (1995-03-25) 1 1 1 1 1 rusty memory Mass-storage that uses iron-oxide-based magnetic media (especially magnetic tape and the pre-Winchester removable disk packs used in washing machines). Compare donuts. [Jargon File] (1997-07-20) 1 1 1 1 1 RUTH D.A. Harrison at Newcastle University. Real-time language based on LispKit. Uses timestamps and real-time clocks. ["RUTH: A Functional Language for Real-Time Programming", D. Harrison in PARLE: Parallel Architectures and Languages Europe, LNCS 259, Springer 1987, pp.297-314]. 1 1 1 1 1 rw The country code for Rwanda. (1999-01-27) 1 1 1 1 1 rwho The Berkeley Unix networking command to report who is logged in on all hosts on the local network segment. Unix manual page: rwho(1). (1996-09-08) 1 1 1 1 1 RWP Remote Write Protocol 1 1 1 1 1 Rx A pattern matcher compatible with GNU regex, but generally faster. Version 0.05, released 1994-05-18, contained substantial changes from the version last distributed with GNU sed. These changes provide low-level support for searching across arbitrarily fragmented strings and suspendable searches. 1 1 1 1 1 RYFM 1. "Read Your Fucking Manual". Uncommon variant of RTFM. 2. "Read Your Fucking Mail". A gentle reminder to someone to check their corresponence and, who knows, maybe even respond. (2012-10-27) 1 1 1 1 1 S A statistical analysis language from AT&T. ["S: An Interactive Environment for Data Analysis and Graphics", Richard A. Becker, Wadsworth 1984]. (1997-01-21) 1 1 1 1 1 s/// s/foo/bar/ is an idiom which means "I didn't mean to type 'foo', I meant to type 'bar'". Its use in talk systems, especially irc, comes from the use of s/// as a substitution operator in Perl, sed and ed. In these languages and tools, s/foo/bar/ would replace any substring matching the regular expression "foo" with the string "bar". (1997-03-16) 1 1 1 1 1 S3 1. <language> An ALGOL 68-like system language for the ICL 2900 computer. 2. <graphics, hardware> A video chipset. 3. <graphics> An X Window System screen server. (2003-02-28) 1 1 1 1 1 SA Structured Analysis 1 1 1 1 1 sa The country code for Saudi Arabia. (1999-01-27) 1 1 1 1 1 SA-110 The first member of the StrongARM family resulting from the architecture license agreement between Digital Equipment Corporation and Advanced RISC Machines Ltd. (ARM), developer of the ARM 32-bit RISC architecture. The SA-110 combines ARM's low-power architecture with Digital's processor design and CMOS process expertise, and is targetted at embedded consumer electronics products. (1996-02-06) 1 1 1 1 1 SAA Systems Application Architecture 1 1 1 1 1 Saber-C Renamed to CodeCenter. 1 1 1 1 1 Saber-C++ Renamed to ObjectCenter. 1 1 1 1 1 SAC 1. An early system on the Datatron 200 series. [Listed in CACM 2(5):16 (May 1959)]. (1995-04-12) 2. Service Access Controller. (2002-12-30) 1 1 1 1 1 SAC-1 An early symbolic mathematics system, written in Fortran by G.E. Collins. [Proc 2nd Symp Symb Alg Manip pp.144-152 (1971)]. (1995-04-12) 1 1 1 1 1 SAC2 A symbolic mathematics system which compiles to Fortran or Common Lisp. E-mail: <jma@poly.polytechnique.fr>. (1995-04-12) 1 1 1 1 1 sacadm (Service Access Controller Administration) A Unix (Solaris?) command for administering both ttymon and listen. It can be used to add and remove, start and stop, and enable and disable port monitors. (2002-12-30) 1 1 1 1 1 sacred Reserved for exclusive use by something. The term might mean only writable by whatever it is sacred to. For example, "Register 7 is sacred to the interrupt handler" would mean that if any other code changed the contents of register 7, dire consequences would ensue. [Jargon File] (2002-12-30) 1 1 1 1 1 SAD Systems Analysis Definition 1 1 1 1 1 SAD SAM Query language by Lindsay. Sammet 1969, p.669. 1 1 1 1 1 SADT Structured Analysis and Design Technique 1 1 1 1 1 SAFARI ON-line text editing system by MITRE Corporation. Sammet 1969, p.685. 1 1 1 1 1 safe A safe program analysis is one which will not reach invalid conclusions about the behaviour of the program. This may involve making safe approximations to properties of parts of the program. A safe approximation is one which gives less information. For example, strictness analysis aims to answer the question will this function evaluate its argument?. The two possible results are "definitely" and "don't know". A safe approximation for "definitely" is "don't know". The two possible results correspond to the two sets: "the set of all functions which evaluate their argument" and "all functions". A set can be safely approximated by another which contains it. 1 1 1 1 1 safe mode An alternative way to start Microsoft Windows such that only a minimal set of software components (drivers and background processes) are loaded, making it easier to diagnose problems. Safe mode loads a standard low resolution video driver and does not support connection to the Internet. Windows will sometimes restart in safe mode automatically following a crash. All Windows versions except Windows 3.1 can be started in safe mode, usually by holding the Ctrl or F8 key while the computer is restarting. To start Windows NT in safe mode you need to edit C:\boot.ini. Once the problem is fixed you need to restart Windows normally to load all the installed components. (2004-12-31) 1 1 1 1 1 safety See safe, safety-critical system. 1 1 1 1 1 safety-critical system A computer, electronic or electromechanical system whose failure may cause injury or death to human beings. E.g. an aircraft or nuclear power station control system. Common tools used in the design of safety-critical systems are redundancy and formal methods. See also aeroplane rule. 1 1 1 1 1 saga (WPI) A cuspy but bogus raving story about N random broken people. Here is a classic example of the saga form, as told by Guy Steele (GLS): Jon L. White (login name JONL) and I (GLS) were office mates at MIT for many years. One April, we both flew from Boston to California for a week on research business, to consult face-to-face with some people at Stanford, particularly our mutual friend Richard Gabriel (RPG). RPG picked us up at the San Francisco airport and drove us back to Palo Alto (going logical south on route 101, parallel to El Camino Bignum). Palo Alto is adjacent to Stanford University and about 40 miles south of San Francisco. We ate at The Good Earth, a "health food" restaurant, very popular, the sort whose milkshakes all contain honey and protein powder. JONL ordered such a shake - the waitress claimed the flavour of the day was "lalaberry". I still have 1 1 1 1 1 sagan /say'gn/ (From Carl Sagan's TV series "Cosmos") Billions and billions. A large quantity of anything. There's a sagan different ways to tweak Emacs. "The US Government spends sagans on bombs and welfare - hard to say which is more destructive." [Jargon File] (1999-10-12) 1 1 1 1 1 SAGE 1. <body, job> Systems Administrators Guild. 2. <project> Semi-Automatic Ground Environment. (2001-01-27) 1 1 1 1 1 SAIC (http://saic.com). (1996-03-21) 1 1 1 1 1 SAID Security Association ID 1 1 1 1 1 SAIL 1. <body, education> Stanford Artificial Intelligence Laboratory. 2. <language> Stanford Artificial Intelligence Language. 3. <language> An early system on the Larc computer. [Listed in CACM 2(5):16, May 1959]. [Jargon File] (2001-06-22) 1 1 1 1 1 SAINT 1. <language> Symbolic Automatic INTegrator. 2. <networking, security, tool> Security Administrator's Integrated Network Tool. 1 1 1 1 1 Saint Andrews Static Language St Andrews Static Language 1 1 1 1 1 SAL 1. Simple Actor Language. 2. SPARK Annotation Language. 1 1 1 1 1 SALEM ["SALEM - A Programming System for the Simulation of Systems Described by Partial Differential Equations", S.M. Morris et al, Proc SJCC 33(1), 1968]. (1994-12-08) 1 1 1 1 1 Sales Automation Sales Force Automation 1 1 1 1 1 salescritter /sayls'kri"tr/ Pejorative hackerism for a computer salesperson. Hackers tell the following joke: Q. What's the difference between a used-car dealer and a computer salesman? A. The used-car dealer knows he's lying. [Some versions add: ...and probably knows how to drive.] This reflects the widespread hacker belief that salescritters are self-selected for stupidity (after all, if they had brains and the inclination to use them, they'd be in programming). The terms "salesthing" and "salesdroid" are also common. Compare marketroid, suit. [Jargon File] (1994-12-08) 1 1 1 1 1 Sales Force Automation (Sales Automation, SFA, SFFA, Sales & Field Force Automation) Software to support sales reps. The software gives sales representitives access to contacts, appointments and e-mail. It is likely to be integrated with Customer Relationship Management systems and Opportunity Management Systems. (1999-08-20) 1 1 1 1 1 S-ALGOL Orthogonal data structures on ALGOL 60. "S-Algol Language Reference Manual", R. Morrison, TR CS/79/1 U St Andrews, 1979. An Introduction to Programming with S-Algol, A.J. Cole & R. Morrison, Cambridge U Press 1982. 1 1 1 1 1 SALT 1. Symbolic Assembly Language Trainer. Assembly-like language implemented in BASIC by Kevin Stock, now at Encore in France. 2. Sam And Lincoln Threaded language. A threaded extensible variant of BASIC. "SALT", S.D. Fenster et al, BYTE (Jun 1985) p.147. [Jargon File] 1 1 1 1 1 salt A tiny bit of near-random data inserted where too much regularity would be undesirable; a data frob (sense 1). For example, the Unix crypt(3) manual page mentions that "the salt string is used to perturb the DES algorithm in one of 4096 different ways." 1 1 1 1 1 salt mines Dense quarters housing large numbers of programmers working long hours on grungy projects, with some hope of seeing the end of the tunnel in N years. Noted for their absence of sunshine. Compare playpen, sandbox. [Jargon File] 1 1 1 1 1 salt substrate [MIT] Collective noun used to refer to potato chips, pretzels, saltines, or any other form of snack food designed primarily as a carrier for sodium chloride. From the technical term chip substrate, used to refer to the silicon on the top of which the active parts of integrated circuits are deposited. 1 1 1 1 1 SAM System Account Manager 1 1 1 1 1 sam A multi-file screen editor with structural regular expressions. Sam runs under the X Window System. (2000-07-16) 1 1 1 1 1 SAM76 A macro language by Claude Kagan descended from TRAC. There is a version for CP/M. [Dr Dobbs J ca 1977]. 1 1 1 1 1 Samba A free suite of programs which implement the Server Message Block (SMB) protocol. Originally developed for Unix by Andrew Tridgell at the Australian National University, the Samba server allows files and printers on the host operating system to be shared with clients such as Windows for Workgroups, DOS, OS/2, Windows NT and others. For example, instead of using telnet to log in to a Unix machine to edit a file there, a Windows 95 user might connect a drive in the Windows Explorer to a Samba server on the Unix machine and edit the file in a Windows editor. A Unix client called smbclient, built from the same source code, allows ftp-like access to SMB resources. Samba is available for many Unix variants, OS/2, and VMS. Porting to Novell Netware is in progress (August 1996). smblib is a portable generic library for making SMB calls for implementing client/server functions from within any 1 1 1 1 1 SAME 1. Standard ANSI Module language with Extensions. 2. <architecture> Stripe And Mirror Everything. 1 1 1 1 1 same-day service An ironic term used to describe long response time, particularly with respect to MS-DOS system calls (which ought to require only a tiny fraction of a second to execute). Such response time is a major incentive for programmers to write programs that are not well-behaved. See also PC-ism. [Jargon File] (1996-12-17) 1 1 1 1 1 SAMeDL SQL Ada Module Description Language. Used to interface Ada application programs to SQL-based DBMSs. E-mail: Marc Graham <marc@sei.cmu.edu>. (ftp://ajpo.sei.cmu.edu/public/atip/samedl/). ["Rationale for SQL Ada Module Description Language SAMeDL", SEI-92-TR-016]. 1 1 1 1 1 samizdat (Russian, literally "self publishing") The process of disseminating documentation via underground channels. Originally referred to photocopy duplication and distribution of banned books in the former Soviet Union; now refers by obvious extension to any less-than-official promulgation of textual material, especially rare, obsolete, or never-formally-published computer documentation. Samizdat is obviously much easier when one has access to high-bandwidth networks and high-quality laser printers. Strictly, "samizdat" only applies to distribution of needed documents that are otherwise unavailable, and not to duplication of material that is available for sale under copyright. See Lions Book for a historical example. See also: hacker ethic. [Jargon File] (2000-03-23) 1 1 1 1 1 SAML An XML framework for communicating user authentication, entitlement, and attribute information, developed by the Security Services Technical Committee of OASIS. SAML supports federation, allowing business entities to make assertions regarding the identity, attributes and entitlements of a subject (an entity that is often a human user) to other entities, such as a partner company or another enterprise application. (2011-05-12) 1 1 1 1 1 Sammet, Jean E. Jean E. Sammet 1 1 1 1 1 sample The result of measuring the amplitude of an analog signal at a specified time. In digital signal processing a sample is a signed or unsigned number and the number of samples per second is called the sample rate. (2001-06-06) 1 1 1 1 1 sample rate The number of times an analog signal is measured (sampled) per second. The unit of sample rate is "samples per second". This is often expressed in kiloHertz (kHz). For example, "CD quality" sound has a sample rate of 44 kHz. Compare data rate. See Nyquist frequency. [Is it correct to use Hertz for things other than the frequency of a sine wave?] (2001-06-06) 1 1 1 1 1 sampling The process of taking a sample of a signal at evenly spaced intervals of time. This is the first step in Digital Signal Processing. (2001-06-06) 1 1 1 1 1 sampling frequency sample rate 1 1 1 1 1 samurai A hacker who hires out for legal cracking jobs, snooping for factions in corporate political fights, lawyers pursuing privacy-rights and First Amendment cases, and other parties with legitimate reasons to need an electronic locksmith. In 1991, mainstream media reported the existence of a loose-knit culture of samurai that meets electronically on BBS systems, mostly bright teenagers with personal micros; they have modelled themselves explicitly on the historical samurai of Japan and on the "net cowboys" of William Gibson's cyberpunk novels. Those interviewed claim to adhere to a rigid ethic of loyalty to their employers and to disdain the vandalism and theft practiced by criminal crackers as beneath them and contrary to the hacker ethic; some quote Miyamoto Musashi's Book of Five Rings, a classic of historical samurai doctrine, in support of these principles. See also Stupids, social engineering, cracker, hacker ethic, and dark-side hacker. 1 1 1 1 1 SAN Storage Area Network 1 1 1 1 1 sandbender [IBM] A person involved with silicon lithography and the physical design of integrated circuits. Compare ironmonger, polygon pusher. 1 1 1 1 1 sandbox (UK: "sandpit") 1. <operating system> A protected, limited environment where applications (e.g. Java programs downloaded from the Internet) are allowed to "play" without risking damage to the rest of the system. 2. <jargon> A term for the R&D department at many software and computer companies (where hackers in commercial environments are likely to be found). The term is half-derisive, but reflects the truth that research is a form of creative play. Compare playpen. 3. <operating system> link farm. [Jargon File] (2001-02-08) 1 1 1 1 1 Sandman The DoD requirements that led to APSE. 1 1 1 1 1 San Francisco IBM's Java component framework application template. The San Francisco Project, started in 1998(?), aims to create a generic set of java building blocks to provide the core functions of general business processes such as sales order processing, general ledger, inventory management and product distribution. The project aims to use component based design allowing easy vendor customisation and Java code generation allowing applications to be built and run across multiple platforms. It also aims to be compatible with third party development tools. (http://ibm.com/Java/Sanfrancisco/). (1998-08-16) 1 1 1 1 1 sanity check 1. Checking code (or anything else, e.g. a Usenet posting) for completely stupid mistakes. Implies that the check is to make sure the author was sane when it was written; e.g. if a piece of scientific software relied on a particular formula and was giving unexpected results, one might first look at the nesting of parentheses or the coding of the formula, as a "sanity check", before looking at the more complex I/O or data structure manipulation routines, much less the algorithm itself. Compare reality check. 2. A run-time test, either validating input or ensuring that the program hasn't screwed up internally (producing an inconsistent value or state). [Jargon File] (1998-08-29) 1 1 1 1 1 Santa Cruz Operation (SCO) A supplier of Unix systems for Intel microprocessors. They supply Xenix and Open Desktop. Founded in 1979, SCO became a public company in May, 1993 and trades on the Nasdaq National Market System under the symbol SCOC. SCO maintains its world headquarters in Santa Cruz, California, USA; a European headquarters in Watford, England; a Government Systems Group in Reston, Virginia; and offices in Asia, Australia, Canada, Latin America, and throughout Europe and the United States. In February 1993, SCO acquired IXI Limited of Cambridge, England, the leading supplier of Unix System windowing software. (http://websco.sco.com/). (1994-10-28) [Addresses?] 1 1 1 1 1 SAP 1. <company> SAP AG (Systems, Applications and Products in Data Processing). 2. <protocol> Service Advertising Protocol. 3. <networking> Service Access Point. 4. <language> Symbolic Assembler Program. (1999-05-26) 1 1 1 1 1 SAP AG (Systeme, Anwendungen, Produkte in der Datenverarbeitung - German for "Systems, Applications and Products in Data Processing") A company from Germany that sells the leading suite of client-server business software. The US branch is called SAP America. (http://sap.com/). [Details?] (1998-07-28) 1 1 1 1 1 SAPI 1. <programming> Speech Application Programming Interface. 2. <programming> Scheduling Application Programming Interface. 3. <networking> Service Access Point Identifier. (1996-10-03) 1 1 1 1 1 SAR segmentation and reassembly 1 1 1 1 1 SAS 1. <language> Statistical Analysis System. 2. <tool> SAS System. (1998-11-06) 1 1 1 1 1 SASD Structured Analysis, Structured Design 1 1 1 1 1 SASE Specific Application Service Element. Opposite: CASE. 1 1 1 1 1 SASI Small Computer System Interface 1 1 1 1 1 SASL 1. <language> St Andrews Static Language. 2. <networking> Simple Authentication and Security Layer. 1 1 1 1 1 SASL+LV Unifies logic and functional programming. A more complete version of FGL+LV, in SASL syntax. "Combinator Evaluations of Functional Programs with Logical Variables", G. Bage et al, TR UUCS-87-027, U Utah, Oct 1987. 1 1 1 1 1 SASL-YACC A version of Yacc written in SASL by Simon Peyton-Jones. 1 1 1 1 1 SAS System (SAS) Integrated software to access, manage, analyze, and present data. The SAS System can be used to perform data entry, retrieval and management; report writing and graphics design; statistical and mathematical analysis; business forecasting and decision support; operations research; project management and applications development. (1998-11-06) 1 1 1 1 1 SATA Serial Advanced Technology Attachment 1 1 1 1 1 SATAN Security Administrator's Integrated Network Tool 1 1 1 1 1 Sather /Say-ther/ (Named after the Sather Tower at UCB, as opposed to the Eiffel Tower). An interactive object-oriented language designed by Steve M. Omohundro at ICSI in 1991. Sather has simple syntax, similar to Eiffel, but it is non-proprietary and faster. Sather 0.2 was nearly a subset of Eiffel 2.0, but Sather 1.0 adds many distinctive features: parameterised classes, multiple inheritance, statically-checked strong typing, garbage collection. The compiler generates C as an intermediate language. There are versions for most workstations. Sather attempts to retain much of Eiffel's theoretical cleanliness and simplicity while achieving the efficiency of C++. The compiler generates efficient and portable C code which is easily integrated with existing code. A variety of development tools including a debugger and browser based on gdb and a GNU Emacs development 1 1 1 1 1 Sather-K Karlsruhe Sather. A sublanguage of Sather used for introductory courses in object-oriented design and typesafe programming. E-mail: <trapp@karlsruhe.gmd.de>. (1994-11-11) 1 1 1 1 1 satisfiability problem A problem used as an example in complexity theory. It can be stated thus: Given a Boolean expression E, decide if there is some assignment to the variables in E such that E is true. A Boolean expression is composed of Boolean variables, (logical) negation (NOT), (logical) conjunction (AND) and parentheses for grouping. The satisfiability problem was the first problem to be proved to be NP-complete (by Cook). ["Introduction to Automata Theory, Languages, and Computation" by Hopcroft and Ullman, pub. Addison-Wesley]. (1994-11-11) 1 1 1 1 1 saturation 1. <graphics> In colour theory, the "colourfulness" of a stimulus relative to its brightness, the amount of the dominant wavelength relative to other wavelengths in the colour, one of the three coordinates in the hue, saturation, value (HSV) and hue, saturation, brightness (HSB) colour models. White, black and grey contain equal amounts of red, green and blue light and are completely unsaturated. A pure colour with very little gray in it is highly saturated. The amount of saturation does not affect the hue of a colour and is unrelated to the value (total amount of light in a colour). There are several competing mathematical definitions of saturation. (http://www.ncsu.edu/scivis/lessons/colormodels/color_models2.html#saturation). (http://www.pomona.edu/academics/courserelated/classprojects/visual-lit/saturation/saturation.html). 2. The state of any system that is operating at its maximum capacity, e.g. a network connection that is carry a continuous 1 1 1 1 1 Saturday-night special (From police slang for a cheap handgun) A quick-and-dirty program or feature kluged together during off hours, under a deadline, and in response to pressure from a salescritter. Such hacks are dangerously unreliable, but all too often sneak into a production release after insufficient review. [Jargon File] (1994-11-11) 1 1 1 1 1 sausage code Code which, once you know the details of how it's made, you'll never want to use again. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-11-22) 1 1 1 1 1 SAVE An assembler for the Burroughs 220 written by Melvin Conway. The name "SAVE" didn't stand for anything; it was just that you lost fewer card decks and listings because they all had SAVE written on them. [Jargon File] (1995-01-16) 1 1 1 1 1 save To copy data to a more permanent form of storage. The term is commonly used for when some kind of document editing application program writes the current document from RAM to a file on hard disk at the request of the user. The implication is that the user might later load the file back into the editor again to view it, print it, or continue editing it. Saving a document makes it safe from the effects of power failure. The "document" might actually be anything, e.g. a word processor document, the current state of a game, a piece of music, a website, or a memory image of some program being executed (though the term "dump" would probably be more common here). Data can be saved to any kind of (writable) storage: hard disk, floppy disk, CD-R; either locally or via a network. A program might save its data without any explicit user 1 1 1 1 1 save as A variant of save that saves the current document in an alternative format. (2005-02-15) 1 1 1 1 1 say A human may "say" things to a computer by typing them on a terminal. "To list a directory verbosely, say "ls -l"." Tends to imply a newline-terminated command (a "sentence"). A computer may "say" things to you, even if it doesn't have a speech synthesiser, by displaying them on a terminal in response to your commands. This usage often confuses mundanes. [Jargon File] 1 1 1 1 1 sb The country code for the Solomon Islands. (1999-01-27) 1 1 1 1 1 SB AWE32 A standard SB16 MultiCD sound card with the EMU8000 "Advanced WavEffect" music synthesizer integrated circuit. The card includes all the standard SB16 features as well as the Advanced Signal Processor and multiple interfaces supporting Creative, Mitsumi and Sony CD-ROM drives. The EMU8000 comes integrated with 1MB of General MIDI samples and 512kB of DRAM for additional sample downloading. It can address up to 28 MB of external DRAM. The SB AWE32 supports General MIDI, Roland GS, and Sound Canvas MT-32 emulation. (1996-12-16) 1 1 1 1 1 SBCS (IBM) single-byte character set. A character set that uses 8 bits to represent a character. (1995-03-21) 1 1 1 1 1 SBD Smart Battery Data 1 1 1 1 1 SBE Microsoft Office Small Business Edition 1 1 1 1 1 SBM Solution Based Modelling 1 1 1 1 1 SB-Prolog Stony Brook Prolog. A public domain Prolog interpreter for Unix. Version 3.1. Distributed under the GNU General Public License. (ftp://sbcs.sunysb.edu/pub/sbprolog/). Amiga version 2.3.2 (ftp://ftp.cso.uiuc.edu/amiga/fish/f1/ff140) and (ftp://ftp.cso.uiuc.edu/amiga/fish/f1/ff141). E-mail: <warren@sbcs.sunysb.edu>. (1995-01-16) 1 1 1 1 1 SBR Spectral Band Replication 1 1 1 1 1 SBus The hardware interface for add-in boards in later Sun-3 (and Sun-4?) workstations. [Reference?] (2001-09-07) 1 1 1 1 1 SC Subcommittee (of ISO, JTC?). 1 1 1 1 1 sc The country code for the Seychelles. (1999-01-27) 1 1 1 1 1 SCA Single Connection Attach 1 1 1 1 1 SCADA Supervisory Control and Data Acquisition 1 1 1 1 1 scag To destroy the data on a disk, either by corrupting the file system or by causing media damage. Compare scrog, roach. [Jargon File] (1995-01-16) 1 1 1 1 1 scalability How well a solution to some problem will work when the size of the problem increases. For example, a central server of some kind with ten clients may perform adequately but with a thousand clients it might fail to meet response time requirements. In this case, the average response time probably scales linearly with the number of clients, we say it has a complexity of O(N) ("order N") but there are problems with other complexities. E.g. if we want N nodes in a network to be able to communicate with each other, we could connect each one to a central exchange, requiring O(N) wires or we could provide a direct connection between each pair, requiring O(N^2) wires (the exact number or formula is not usually so important as the highest power of N involved). (1995-03-29) 1 1 1 1 1 Scalable Coherent Interface (SCI) The ANSI/IEEE 1596-1992 standard that defines a point-to-point interface and a set of packet protocols. The SCI protocols use packets with a 16-byte header and 16, 64, or 256 data bytes. Each packet is protected by a 16-bit CRC code. The standard defines 1 Gbit/second serial fiber-optic links and 1 Gbyte/second parallel copper links. SCI has two unidirectional links that operate concurrently. The SCI protocols support shared memory by encapsulating bus requests and responses into SCI request and response packets. Packet-based handshake protocols guarantee reliable data delivery. A set of cache coherence protocols are defined to maintain cache coherence in a shared memory system. Message passing is supported by a compatible subset of the SCI protocols. This protocol subset does not invoke SCI cache coherency protocols. 1 1 1 1 1 Scalable Processor ARChitecture (SPARC) An instruction set architecture designed by Sun Microsystems for their own use in 1985. Sun was a maker of 680x0-based Unix workstations. Research versions of RISC processors had promised a major step forward in speed but existing manufacturers were slow to introduce a RISC type processor, so Sun went ahead and developed its own, based on the University of California at Berkley's RISC I and RISC II 1980-2. In keeping with their open philosophy, they licenced it to other companies, rather than manufacture it themselves. The evolution and standardisation of SPARC is now directed by the non-profit consortium SPARC International, Inc. SPARC was not the first RISC processor. The AMD 29000 came before it, as did the MIPS R2000 (based on Stanford's design) and Hewlett-Packard Precision Architecture CPU, among others. The SPARC design was radical at the time, even omitting multiple cycle multiply and divide instructions (like 1 1 1 1 1 Scalable Sampling Rate (SSR) See, e.g., MPEG-4 AAC SSR. (2001-12-08) 1 1 1 1 1 Scalable Vector Graphics A W3C standard for vector graphics, based on XML. (http://w3.org/Graphics/SVG/). (2001-02-06) 1 1 1 1 1 scalar 1. <mathematics> A single number, as opposed to a vector or matrix of numbers. Thus, for example, "scalar multiplication" refers to the operation of multiplying one number (one scalar) by another and is used to contrast this with "matrix multiplication" etc. 2. <architecture> In a parallel processor or vector processor, the "scalar processor" handles all the sequential operations - those which cannot be parallelised or vectorised. See also superscalar. 3. <programming> Any data type that stores a single value (e.g. a number or Boolean), as opposed to an aggregate data type that has many elements. A string is regarded as a scalar in some languages (e.g. Perl) and a vector of characters in others (e.g. C). (2002-06-12) 1 1 1 1 1 SCALLOP A medium-level language for CDC computers, used to bootstrap the first Pascal compiler. (1994-11-01) 1 1 1 1 1 SCAN 1. ["A Parallel Implementation of the SCAN Language", N.G. Bourbakis, Comp Langs 14(4):239-254 (1989)]. 2. A real-time language from DEC. [Are these the same language?] (1994-11-01) 1 1 1 1 1 scan 1. (computer peripheral) See scanner. 2. (circuit design) See scan design. 3. (functional programming) See scanl, scanr. 4. <storage, algorithm> An algorithm for scheduling multiple accesses to a disk. A number of requests are ordered according to the data's position on the storage device. This reduces the disk arm movement to one "scan" or sweep across the whole disk in the worst case. The serivce time can be estimated from the disk's track-to-track seek time, maximum seek time (one scan), and maximum rotational latency. Scan-EDF is a variation on this. (1995-11-15) 1 1 1 1 1 scan design (Or "Scan-In, Scan-Out") A electronic circuit design technique which aims to increase the controllability and observability of a digital logic circuit by incorporating special "scan registers" into the circuit so that they form a scan path. Some of the more common types of scan design include the multiplexed register designs and level-sensitive scan design (LSSD) used extensively by IBM. Boundary scan can be used alone or in combination with either of the above techniques. ["Digital Systems Testing and Testable Design" by Abramovici, Breuer, and Friedman, ISBN 0-7167-8179-4]. ["Design of Testable Logic Circuits" by R.G. Bennetts, (Brunel/Southhampton Universities), ISBN 0-201-14403-4]. (1995-02-23) 1 1 1 1 1 SCANDISK An MS-DOS command to check for faults on a disk and provide a graphical representation the results. Scandisk was introduced with MS-DOS version 6 to replace CHKDSK. [What kinds of disk? What faults?] (1997-07-16) 1 1 1 1 1 Scan-EDF A variation of the Scan disk aceess algorithm for use in a real-time environment where, in general, requests are served according to Earliest Deadline First. If two requests share the same deadline, they may be reorganised according to Scan. A typical example is a video server that retrieves video data from a hard disk. The playback of a video impose tight real-time constraints but if the server retrieves data once every second for each video channel, Scan-EDF can be applied, reducing the seek overhead. (1995-11-15) 1 1 1 1 1 scanf The C library routine that reads data from the standard input stream stdin into the locations given by each entry in its argument list. The first argument is a format string which controls interpretation of the input and each subsequent argument points to a variable with a type that corresponds to a type specifier in the format-string. Unix manual page: scanf(3). (1995-02-23) 1 1 1 1 1 Scan-In, Scan-Out scan design 1 1 1 1 1 scan line A horizontal line of pixels generated by a single horizontal sweep of the beam from a monitor's electron gun. The number of scanlines that make up a frame is the vertical resolution. (1996-02-09) 1 1 1 1 1 scanner 1. An input device that takes in an optical image and digitises it into an electronic image represented as binary data. This can be used to create a computerised version of a photo or illustration. A scanner may be linked to optical character recognition software allowing printed documents to be converted to electronic text without having to type them in at a keyboard. 2. lexical analyser. (1995-02-14) 1 1 1 1 1 scanno /skan'oh/ An error in a document caused by a scanner glitch, analogous to a typo or thinko. [Jargon File] (1995-02-14) 1 1 1 1 1 scan path (circuit design) A technique used to increase the controllability and observability of a logic circuit by incorporating "scan registers" into the circuit. Normally these act like flip-flops but they can be switched into a test mode where they all become one long shift register. This allows data to be clocked serially through all the scan registers and out of an output pin at the same time as new data is clocked in from an input pin. Using this technique, the state of certain points in the circuit can be examined and modified at any time by suspending normal operation and switching to test mode. If the scan path is placed adjacent to the circuit's input and output pins then this is known as "boundary scan". (1995-02-14) 1 1 1 1 1 scan register A digital logic circuit which can act either as a flip-flop or as a serial shift register and which is used to form a scan path for testing. The most common design is a multiplexed flip-flop: ___ ____ normal in --| \ | | |mux |------|D Q|---- normal/scan scan in ----|___/ | | output | |flip| 1 1 1 1 1 scar tissue code Old code that is commented out but still included in the current release. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-01-04) 1 1 1 1 1 SCC strongly connected component 1 1 1 1 1 SCCS Source Code Control System: a popular source code management system found on Unix since early versions. Unix manual page: sccs(1). (2011-12-16) 1 1 1 1 1 SCEPTRE Designing and analysing circuits. ["SCEPTRE: A Computer Program for Circuit and Systems Analysis", J.C. Bowers et al, P-H 1971]. 1 1 1 1 1 Schachter's Hypothesis The observation that "Given two unrelated technical terms, an Internet search engine will retrieve only résumés". This was first formulated by Joshua Eli Schachter (http://burri.to/~joshua/) in about 1998, while poring over the uniformly irrelevant pages that resulted from a search he'd run on "+Perl +MAPI" in Altavista. (2002-02-04) 1 1 1 1 1 scheduler scheduling 1 1 1 1 1 scheduling The arrangement of a number of related operations in time. There are several kinds of scheduling related to computers: instruction scheduling - sequencing the instructions executed by the CPU multitasking ("process scheduling") - sharing a CPU between several processes application software to help organise your daily meetings etc. task scheduling - algorithms to solve the general problem of satisfying time and resource constraints between a number of tasks. Compare planning. (1998-04-25) 1 1 1 1 1 Scheduling API Scheduling Application Programming Interface 1 1 1 1 1 Scheduling Application Programming Interface (SAPI, Scheduling API) An API aimed at software which aids humans in arranging their (business) activities. Microsoft has defined a SAPI for its Schedule+ application. (1995-01-11) 1 1 1 1 1 Schelog (Previously "slog"?) A Prolog to Chez Scheme macro translator by <dorai@cs.rice.edu>. Schelog relies on continuations. (http://cs.rice.edu/CS/PLT/packages/schelog). (2000-11-20) 1 1 1 1 1 schema 1. <database> database schema. 2. <logic> axiom schema. 3. <data> XML schema. 1 1 1 1 1 Schema Definition Set (SDS) Something in Portable Common Tool Environment. [What?] (2001-03-03) 1 1 1 1 1 Schema Representation language (SRL) ["SRL/2 Users Manual", J.M. Wright et al, Robotics Inst, CMU, 1984]. 1 1 1 1 1 schematic capture The process of entering the logical design of an electronic circuit into a CAE system by creating a schematic representation of components and interconnections. 1 1 1 1 1 schematic type variable generic type variable 1 1 1 1 1 Schematik A NeXT front-end to MIT Scheme for the NeXT by Chris Kane and Max Hailperin <max@nic.gac.edu>. Schematik provides syntax-knowledgeable text editing, graphics windows and a user-interface to an underlying MIT Scheme process. It comes with MIT Scheme 7.1.3 ready to install on the NeXT and requires NEXTSTEP. Version: 1.1.5.2. USA FTP (ftp://ftp.gac.edu/pub/next/scheme/). Germany (ftp://ftp.informatik.uni-muenchen.de/pub/next/ProgLang). E-mail: <schematik@gac.edu>. (1993-03-11) 1 1 1 1 1 Scheme (Originally "Schemer", by analogy with Planner and Conniver). A small, uniform Lisp dialect with clean semantics, developed initially by Guy Steele and Gerald Sussman in 1975. Scheme uses applicative order reduction and lexical scope. It treats both functions and continuations as first-class objects. One of the most used implementations is DrScheme, others include Bigloo, Elk, Liar, Orbit, Scheme86 (Indiana U), SCM, MacScheme (Semantic Microsystems), PC Scheme (TI), MIT Scheme, and T. See also Kamin's interpreters, PSD, PseudoScheme, Schematik, Scheme Repository, STk, syntax-case, Tiny Clos, Paradigms of AI Programming. There have been a series of revisions of the report defining Scheme, known as RRS (Revised Report on Scheme), R2RS (Revised Revised Report ..), R3RS, R3.99RS, R4RS. Scheme resources (http://schemers.org/). 1 1 1 1 1 Scheme84 Scheme from Indiana University. It requires Franz Lisp on a VAX under VMS or BSD. E-mail: Nancy Garrett <nlg@indiana.edu>. Send a tape with return postage to Scheme84 Distribution, Nancy Garrett, c/o Dan Friedman, Department of Computer Science, Indiana University, Bloomington, Indiana. Telephone: +1 (812) 335 9770. 1 1 1 1 1 Scheme88 (ftp://nexus.yorku.ca/pub/scheme/). [Description?] 1 1 1 1 1 Scheme->C Scheme-to-C 1 1 1 1 1 Scheme Library (SLIB) A portable Scheme library providing compatibiliy and utility functions for all standard Scheme implementations. Version 2c5 supports Bigloo, Chez, ELK, GAMBIT, MacScheme, MITScheme, PocketScheme, RScheme, Scheme->C, Scheme48, SCM, SCSH, T3.1, UMB-Scheme, and VSCM. (http://swissnet.ai.mit.edu/~jaffer/SLIB.html). (1999-06-07) 1 1 1 1 1 Scheme-Linda A Scheme interface to Linda written by Ulf Dahlen of University of Edinburgh in 1990. It runs on the Computing Surface and the Symmetry. ["Scheme-Linda", U. Dahlen et al, EPCC-TN-90-01 Edinburgh 1990]. (1994-12-15) 1 1 1 1 1 Scheme Object System (SOS) Chris Hanson? (ftp://altdorf.ai.mit.edu/archive/cph/sos.tar.gz). [Description?] 1 1 1 1 1 Scheme Repository A collection of free Scheme programs. (ftp://nexus.yorku.ca/pub/scheme/). 1 1 1 1 1 Scheme-to-C A Scheme compiler written in C that emits C and is embeddable in C. Scheme-to-C was written by Joel Bartlett of Digital Western Research Laboratory. Version 15mar93 translates a superset of Revised**4 Scheme to C that is then compiled by the native C compiler for the target machine. This design results in a portable system that allows either stand-alone Scheme programs or programs written in both compiled and interpreted Scheme and other languages. It supports "expansion passing style" macros, foreign function calls, records, and interfaces to Xlib (Ezd and Scix). Scheme-to-C runs on VAX, ULTRIX, DECstation, Alpha AXP OSF/1, Windows 3.1, Apple Macintosh 7.1, HP 9000/300, HP 9000/700, Sony News, SGI Iris and Harris Nighthawk, and other Unix-like 88000 systems. The earlier 01nov91 version runs on Amiga, SunOS, NeXT, and Apollo systems. 1 1 1 1 1 Schlaer-Mellor An object-oriented analysis (OOA), design and modelling method that addresses the integration of structural and behavioural properties. It also allows an animation of the design. I-OOA is a tool that supports the Schlaer Mellor Design Method. (1995-01-31) 1 1 1 1 1 Schoonschip (From the Dutch for "beautiful ship" or clean ship) A program for symbolic mathematics, especially High Energy Physics, written by M. Veltman of CERN in 1964. Schoonschip only does algebra, no derivatives. It was implemented originally in CDC 6600 and CDC 7600 assembly language and currently in 680x0 assembly language. Latest versions run on Amiga, Atari ST, Sun-3 and NeXT. It was once maintained by David Williams at the University of Michigan Physics Department. (ftp://archive.umich.edu/physics/schip). (2000-11-14) 1 1 1 1 1 schrödinbug /shroh'din-buhg/ (MIT, from the Schrödinger's Cat thought-experiment in quantum physics) A design or implementation bug that doesn't manifest until someone reading the source code or using the program in an unusual way notices that it never should have worked, at which point it stops working until fixed. Though (like bit rot) this sounds impossible, it happens; some programs have harboured schrödinbugs for years. Compare heisenbug, Bohr bug, mandelbug. [Jargon File] (1995-02-28) 1 1 1 1 1 SCI 1. Scalable Coherent Interface. 2. UART. (1998-02-14) 1 1 1 1 1 Science and Engineering Research Council (SERC) Formerly the largest of the five research councils funded by the British Government through the Office of Science and Technology. SERC funded higher education research in science and engineering, including computing and was responsible for the Rutherford Appleton Laboratory, near Oxford; the Daresbury Laboratory, near Warrington; the Royal Greenwich Observatory at Cambridge and the Royal Observatory, Edinburgh. In April 1994 SERC was split into the Engineering and Physical Sciences Research Council and the Particle Physics and Astronomy Research Council. SERC's remote sensing efforts have been transferred to the Natural Environment RC and its biotechnology efforts merged with the Agriculture and Food RC to make the new Biotechnology and Biological Sciences RC. The two major SERC laboratories - Rutherford Appleton Laboratory and Daresbury Laboratory are now independent. (http://unixfe.rl.ac.uk/serc/serc.html). 1 1 1 1 1 Scientific Data Systems (SDS) The company that produced the SDS 940 (later renamed XDS 940). Around 1968 Xerox bought out SDS and renamed the SDS machines to XDS. [What else?] (2001-03-03) 1 1 1 1 1 SCL 1. System Control Language. 2. Symbolic Communication Language. Designed primarily for the manipulation of symbolic formulas. Featured pattern matching (which was partly the inspiration for SNOBOL), string operations in buffers, and automatic storage management. "A Language for Symbolic Communication", C.Y. Lee et al, Tech Mem 62-3344-4, Bell Labs, Sept 1962. 1 1 1 1 1 SCM 1. <business> Supply Chain Management. (2003-10-09) 2. <language> A Scheme interpreter in C by Aubrey Jaffer and others. SCM conforms to R4RS and IEEE P1178 and includes a conformance test. It is distributed under GPL. Version 5d0 runs under Amiga, Atari-ST, MacOS, MS-DOS, OS/2, NOS/VE, Unicos, VMS, Unix, and similar systems. x-scm provides an X Window System interface for SCM programs. (http://swissnet.ai.mit.edu/~jaffer/SCM.html). (1999-06-07) 1 1 1 1 1 SC/MP (Nicknamed "Scamp") A typical 8-bit microprocessor from National Semiconductor released in April 1976. It was intended for control applications (a simple BASIC in a 2.5K ROM was added to one version). It featured 16 bit addressing, with 12 address lines and 4 lines borrowed from the data bus (it was common to borrow lines from the data bus for addressing). Internally, it included three index registers (P1 to P3) and two 8-bit general-purpose registers. It had a PC, but no stack pointer or subroutine instructions (though they could be emulated with index registers). During interrupts, the PC was saved in P3. It was meant for embedded control, and these features were omitted for cost reasons. It was also bit serial internally to keep it cheap. The unique feature was the ability to completely share a system bus with other processors. Most processors of the time assumed they were the only ones accessing memory or I/O 1 1 1 1 1 SCO Santa Cruz Operation 1 1 1 1 1 Scode The internal representation used by the Liar compiler for MIT Scheme. (1994-11-01) 1 1 1 1 1 SCOOP Structured Concurrent Object-Oriented Prolog. ["SCOOP, Structured Concurrent Object-Oriented Prolog", J. Vaucher et al, in ECOOP '88, S. Gjessing et al eds, LNCS 322, Springer 1988, pp.191-211]. 1 1 1 1 1 SCOOPS Scheme Object-Oriented Programming System. Developed at Texas Instruments in 1986. It supports multiple inheritance and class variables. (ftp://altdorf.ai.mit.edu/archive/scheme-library/unsupported/CScheme). (1994-11-01) 1 1 1 1 1 SCOPE Software Evaluation and Certification Programme Europe. An ESPRIT project. (1995-04-12) 1 1 1 1 1 scope The scope of an identifier is the region of a program source within which it represents a certain thing. This usually extends from the place where it is declared to the end of the smallest enclosing block (begin/end or procedure/function body). An inner block may contain a redeclaration of the same identifier in which case the scope of the outer declaration does not include (is "shadowed" or occluded by) the scope of the inner. See also activation record, dynamic scope, lexical scope. (1994-11-01) 1 1 1 1 1 Scorpion Twenty tools that can be used to construct specialised programming environments. The Scorpion Project was started by Prof. Richard Snodgrass <rts@cs.arizona.edu> as an outgrowth of the SoftLab Project (which produced the IDL Toolkit) that he started when he was at the University of North Carolina. The Scorpion Project is directed by him at the University of Arizona and by Karen Shannon at the University of North Carolina at Chapel Hill. Version 6.0 runs on Sun-3, Sun-4, VAX, Decstation, Iris, Sequent, HP9000. See also Candle. (ftp://cs.arizona.edu/scorpion/). Mailing list: info-scorpion-request@cs.arizona.edu. E-mail: <scorpion-project@cs.arizona.edu>. (1993-11-04) 1 1 1 1 1 Scott-closed A set S, a subset of D, is Scott-closed if (1) If Y is a subset of S and Y is directed then lub Y is in S and (2) If y <= s in S then y is in S. I.e. a Scott-closed set contains the lubs of its directed subsets and anything less than any element. (2) says that S is downward closed (or left closed). ("<=" is written in LaTeX as \sqsubseteq). (1995-02-03) 1 1 1 1 1 Scott domain An algebraic, boundedly complete, complete partial order. Often simply called a domain. (1994-11-01) 1 1 1 1 1 SCPI Standard Commands for Programmable Instruments 1 1 1 1 1 SCPI Consortium A body established to promote Standard Commands for Programmable Instruments. Address: 8380 Hercules Drive, Suite P3, La Mesa, CA 91942, USA. SCPI in Europe (http://ourworld.compuserve.com/homepages/acea/scpi_uk.htm). Address: ACEA, P.O. Box 134, 7640 AC Wierden The Netherlands. Telephone: +31 546 577 994. E-mail: <ACEA@compuserve.com>. (1999-01-05) 1 1 1 1 1 scram switch (From the nuclear power industry) An emergency power-off switch (see Big Red Switch), especially one positioned to be easily hit by evacuating personnel. In general, this is *not* something you frob lightly; these often initiate expensive events (such as Halon dumps) and are installed in a dinosaur pen for use in case of electrical fire or in case some luckless field servoid should put 120 volts across himself while Easter egging. SCRAM stands for Safety Control Rod Ax Man. In the early days of nuclear power, boron moderator rods were raised and lowered on ropes. In the event of a runaway chain reaction, a man with an axe would chop the rope and drop the rods into the nuclear pile to stop the reaction. See also molly-guard, TMRC. [Jargon File] (2003-05-17) 1 1 1 1 1 SCRAP Something written at CSIR, Pretoria, South Africa in the late 1970s. It ran on Interdata and Perkin-Elmer computers and was in use until the late 1980s. [But what was it?] (1994-12-15) 1 1 1 1 1 scratch 1. (From "scratchpad") Describes a data structure or recording medium attached to a machine for testing or temporary-use purposes; one that can be scribbled on without loss. Usually in the combining forms "scratch memory", "scratch register", "scratch disk", "scratch tape", "scratch volume". See also scratch monkey. 2. (primarily IBM) To delete (as in a file). [Jargon File] (1994-12-15) 1 1 1 1 1 scratch disk 1. <storage> See scratch. 2. <operating system> Unallocated space on Windows 95's primary hard disk partition, used for virtual memory. Shortage of space on this partition can result in the error scratch disk full. (2000-03-07) 1 1 1 1 1 scratch monkey As in "Before testing or reconfiguring, always mount a scratch monkey", a proverb used to advise caution when dealing with irreplaceable data or devices. Used to refer to any scratch volume hooked to a computer during any risky operation as a replacement for some precious resource or data that might otherwise get trashed. This term preserves the memory of Mabel, the Swimming Wonder Monkey, star of a biological research program at the University of Toronto. Mabel was not (so the legend goes) your ordinary monkey; the university had spent years teaching her how to swim, breathing through a regulator, in order to study the effects of different gas mixtures on her physiology. Mabel suffered an untimely demise one day when a DEC engineer troubleshooting a crash on the program's VAX inadvertently interfered with some custom hardware that was wired to Mabel. It is reported that, after calming down an understandably irate customer sufficiently to ascertain the facts of the 1 1 1 1 1 Scratchpad I A general-purpose language originally for interactive symbolic mathematics by Richard Jenks, Barry Trager, Stephen M. Watt and Robert S. Sutor of IBM Research, ca 1971. It features abstract parametrised data types, multiple inheritance and polymorphism. There were implementations for VM/CMS and AIX. ["Scratchpad User's Manual", RA 70, IBM (June 1975)]. (1994-12-15) 1 1 1 1 1 Scratchpad II See Scratchpad I, AXIOM. ["Scratchpad II Programming Language Manual", R.D. Jenks et al, IBM, 1985]. [Scratchpad II Newsletter: Computer Algebra Group, TJWRC, Box 218, Yorktown Hts, NY 10598]. 1 1 1 1 1 scream and die Synonym cough and die, but connotes that an error message was printed or displayed before the program crashed. [Jargon File] 1 1 1 1 1 Screamer An extension of Common Lisp providing nondeterministic backtracking and constraint programming. (ftp://ftp.ai.mit.edu/pub/screamer.tar.Z). [Isn't all backtracking nondeterministic by definition?] 1 1 1 1 1 screaming tty [Unix] A terminal line which spews an infinite number of random characters at the operating system. This can happen if the terminal is either disconnected or connected to a powered-off terminal but still enabled for login; misconfiguration, misimplementation, or simple bad luck can start such a terminal screaming. A screaming tty or two can seriously degrade the performance of a vanilla Unix system; the arriving "characters" are treated as userid/password pairs and tested as such. The Unix password encryption algorithm is designed to be computationally intensive in order to foil brute-force crack attacks, so although none of the logins succeeds; the overhead of rejecting them all can be substantial. [Jargon File] 1 1 1 1 1 screen 1. <hardware> A generic term for a display device that shows text and/or images on a roughly flat rectangular surface. The most common type is usually refered to as a "monitor" and is based on a cathode-ray tube, though flat panel displays have, since around 2000, become increasingly competitive in price and performance. (2005-07-28) 2. A screen multiplexer utility which lets you run multiple interactive terminal sessions (and curses programs) through a single terminal connection (on one virtual console, one terminal, through one modem link, telnet session or xterm). Screen can detach processes from one terminal and attach them to another. "Auto-detach" lets you continue working after being disconnected and reconnected. It supports keyboard driven cut and paste from any text and/or curses application (like Lynx) to any other (like xemacs). 1 1 1 1 1 screen blanker screen saver 1 1 1 1 1 screen dump (Or "screen shot") An image, often stored in a file, of what was displayed on a computer's screen at some time. Sending someone a screen dump can be very useful for remote support and diagnosis because it may show important details that the user didn't realise were significant, e.g. which web browser they were using. (2009-01-05) 1 1 1 1 1 Screen Peace A screen saver for Microsoft Windows by Anthony Andersen. Released as charityware. It can load extension modules with filename extension ".SPX". Some modules (ftp://src.doc.ic.ac.uk/computing/systems/ibmpc/windows3/desktop/spx2.zip). (1997-11-23) 1 1 1 1 1 screen popping The use of CTI to make customer data appear on a call centre terminal at the same time as the customer call is transferred. (2003-12-04) 1 1 1 1 1 screen reader A text-to-speech system, intended for use by blind or low-vision users, that speaks the text content of a computer display. (1998-10-19) 1 1 1 1 1 screen refresh refresh rate 1 1 1 1 1 screen saver A program which displays either a completely black image or a constantly changing image on a computer monitor to prevent a stationary image from "burning" into the phosphor of the screen. Screen savers usually start automatically after the computer has had no user input for a preset time. Some screen savers come with many different modules, each giving a different effect. Approximately pre-1990, many cathode ray tubes, in TVs, computer monitors or elsewhere, were prone to "burn-in"; that is, if the same pattern (e.g., the WordPerfect status line; the Pong score readout; or a TV channel-number display) were shown at the same position on the screen for very long periods of time, the phosphor on the screen would fatigue and that part of the screen would seem greyed out, even when the CRT was off. Eventually CRTs were developed which were resistant to burn-in (and which sometimes went into sleep mode after a period of 1 1 1 1 1 screen scraper A piece of software used to automate interaction between two computer systems through the terminal interface (designed for human use) of one of those systems. Typically, the screen scraper interacts with terminal emulation software to generate input to and process output from the "host" system through terminal screens. Screen scrapers are advantageous when modifications to the host system are undesireable, when it is desireable to make use of the existing business and data integrity logic on the host, and when no other (peer-to-peer) interface method is available. Some products employ screen scraping combined with additional functionality which provides a DBMS-like or other specialised interface to the host. The host system is often called a "legacy system" because it usually the older of the systems involved and based on older technology. (1995-04-19) 1 1 1 1 1 screen server Do you mean "screen saver"? (2004-08-21) 1 1 1 1 1 screen sharing Audiographic Teleconferencing 1 1 1 1 1 Screenwrite A columnar format third generation programming language similar in layout to assembler and used for transaction processing, solely on the Honeywell Bull TPS6 database/transaction management system on their Level 6 DPS6 minicomputers running under the GCOS6 operating system. In the UK it was mainly used by local authorities and the Ministry of Defense. Being proprietary technology, its popularity waned with the introduction of open systems standards, relational databases and fourth generation languages but it is believed that some systems made it through Y2K. [Dates?] (2003-05-15) 1 1 1 1 1 screw (MIT) A failure, usually in software. Especially used for user-visible misbehaviour caused by a bug or misfeature. This use has become quite widespread outside MIT. [Jargon File] (1994-12-01) 1 1 1 1 1 screwage /skroo'*j/ Like lossage but connotes that the failure is due to a designed-in misfeature rather than a simple inadequacy or a mere bug. [Jargon File] (1994-12-01) 1 1 1 1 1 scribble To modify a data structure in a random and unintentionally destructive way. "Bletch! Somebody's disk-compactor program went berserk and scribbled on the i-node table." "It was working fine until one of the allocation routines scribbled on low core." Synonymous with trash; compare mung, which conveys a bit more intention, and mangle, which is more violent and final. [Jargon File] 1 1 1 1 1 Scribe A text-formatting language by Brian Reid. (1994-12-01) 1 1 1 1 1 SCRIPT 1. An early system on the IBM 702. [Listed in CACM 2(5):16 (May 1959)]. 2. A real-time language. ["A Communication Abstraction Mechanism and its Verification", N. Francez et al, Sci Comp Prog 6(1):35-88 (1986)]. (1994-12-01) 1 1 1 1 1 script A program written in a scripting language, but see Ousterhout's dichotomy. (1999-02-22) 1 1 1 1 1 Scriptics John Ousterhout's company that is the home of Tcl development and the TclPro tool suite. (http://scriptics.com/). (1998-11-27) 1 1 1 1 1 scripting language (Or "glue language") A loose term for any language that is weakly typed or untyped and has little or no provision for complex data structures. A program in a scripting language (a "script") is often interpreted (but see Ousterhout's dichotomy). Scripts typically interact either with other programs (often as glue) or with a set of functions provided by the interpreter, as with the file system functions provided in a UNIX shell and with Tcl's GUI functions. Prototypical scripting languages are AppleScript, C Shell, MS-DOS batch files and Tcl. (2001-03-06) 1 1 1 1 1 scrog /skrog/ [Bell Labs] To damage, trash, or corrupt a data structure. "The list header got scrogged." Also reported as skrog, and ascribed to the comic strip "The Wizard of Id". Compare scag; possibly the two are related. Equivalent to scribble or mangle. [Jargon File] 1 1 1 1 1 SCROLL String and Character Recording Oriented Logogrammatic Language. ["SCROLL - A Pattern Recording Language", M. Sargent, Proc SJCC 36 (1970)]. (1994-12-01) 1 1 1 1 1 scroll (From a scroll of paper) To change the portion of a document displayed in a window or on a VDU screen. In a graphical user interface, scrolling is usually controlled by the user via scroll bars, whereas on a VDU the text scrolls up automatically as lines of data are output at the bottom of the screen. (2001-04-27) 1 1 1 1 1 scrollable list A list of information in a graphical user interface with a scroll bar, often used to present a list of choices. (1999-10-03) 1 1 1 1 1 scroll bar A widget found in graphical user interfaces and used to show and control ("scroll") which portion of a document is currently visible in a window. A window may have a horizontal or, most often, vertical scroll bar or both. A vertical scroll bar is a narrow strip drawn up the side of the window containing a "bubble" whose position in the scroll bar represents the position of the visible part within the whole document. By dragging the bubble with the mouse the user can scroll the view over the entire document. Arrow buttons are usually provided at the end(s) of the scroll bar to allow the window to be scrolled by a small amount, e.g. one line of text, in either direction by clicking them with the mouse. Some programs provide a second pair of buttons for scrolling a page at a time or some other unit. Clicking on the scroll bar outside the bubble will either, depending on the particular WIMP, move the bubble to that point or move it some amount (typically a screenful) in that direction. 1 1 1 1 1 scrolling To flood a chat room or Internet game with text or macros in an attempt to annoy the occupants. This can often cause the chat room to be "uninhabitable" due to the noise created by the scroller. Compare spam. (2001-03-27) 1 1 1 1 1 scrool /skrool/ [The pioneering Roundtable chat system in Houston ca. 1984; probably originated as a typo for "scroll"] The log of old messages, available for later perusal or to help one get back in synch with the conversation. It was originally called the "scrool monster", because an early version of the roundtable software had a bug where it would dump all 8K of scrool on a user's terminal. [Jargon File] 1 1 1 1 1 scrozzle /skroz'l/ Used when a self-modifying code segment runs incorrectly and corrupts the running program or vital data. (1994-11-24) 1 1 1 1 1 scruffies neats vs. scruffies 1 1 1 1 1 SCSI Small Computer System Interface 1 1 1 1 1 SCSI-1 The original SCSI, as opposed to SCSI-2 or SCSI-3. (1995-04-20) 1 1 1 1 1 SCSI-2 A version of the SCSI command specification. SCSI-2 shares the original SCSI's asynchronous and synchronous modes and adds a "Fast SCSI" mode (<10MB/s) and "Wide SCSI" (16 bit, <20MB/s or rarely 32 bit). Another major enhancement was the definition of command sets for different device classes. SCSI-1 was rather minimalistic in this respect which led to various incompatibilities especially for devices other than hard-disks. SCSI-2 addresses that problem. allowing scanners, hard disk drives, CD-ROM drives, tapes and many other devices to be connected. Normal SCSI-2 equipment (not wide or differential) can be connected to a SCSI-1 bus and vice versa. (1995-04-19) 1 1 1 1 1 SCSI-3 An ongoing standardisation effort to extend the capabilities of SCSI-2. SCSI-3's goals are more devices on a bus (up to 32); faster data transfer; greater distances between devices (longer cables); more device classes and command sets; structured documentation; and a structured protocol model. In SCSI-2, data transmission is parallel (8, 16 or 32 bit wide). This gets increasingly difficult with higher data rates and longer cables because of varying signal delays on different wires. Furthermore, wiring cost and drive power increases with wider data words and higher speed. This has triggered the move to serial interfacing in SCSI-3. By embedding clock information into a serial data stream signal delay problems are eliminated. Driving a single signal also consumes less driving power and reduces connector cost and size. To allow for backward compatibility and for added flexibility 1 1 1 1 1 SCSI adaptor (Or "host adaptor") A device that communicates between a computer and its SCSI peripherals. The SCSI adaptor is usually assigned SCSI ID 7. It is often a separate card that is connected to the computer's bus (e.g. PCI, ISA, PCMCIA) though increasinly, SCSI adaptors are built in to the motherboard. Apart from being cheaper, busses like PCI are too slow to keep up with the newer SCSI standards like Ultra SCSI and Ultra-Wide SCSI. There are several varieties of SCSI (and their connectors) and an adaptor will not support them all. The performance of SCSI devices is limited by the speed of the SCSI adaptor and its connection to the computer. An adaptor that plugs into a parallel port is unlikely to be as fast as one incorporated into a motherboard. Fast adaptors use DMA or bus mastering. Some SCSI adaptors include a BIOS to allow PCs to boot from a SCSI hard disk, if their own BIOS supports it. 1 1 1 1 1 SCSI controller SCSI adaptor 1 1 1 1 1 SCSI ID The unique address of a SCSI device. SCSI IDs range from 0 to 7 for 8-bit SCSI systems, 0 to 15 for 16-bit and 0 to 31 for 32-bit systems. The SCSI adaptor is usually assigned ID 7. A device's SCSI ID is often set by switches on the device. (1999-09-01) 1 1 1 1 1 SCSI initiator A device that begins a SCSI transaction by issuing a command to another device (the SCSI target), giving it a task to perform. Typically a SCSI host adapter is the initiator but targets may also become initiators. (1999-02-10) 1 1 1 1 1 SCSI interface SCSI adaptor 1 1 1 1 1 SCSI reconnect The ability of a SCSI initiator to initiate new transactions before earlier ones have completed. A target or initiator can disconnect from the bus when it experiences a delay in completing a task so that another device can use the bus. It can reconnect later and complete the task. (1999-02-16) 1 1 1 1 1 SCSI target A SCSI device that executes a command from a SCSI initiator to perform some task. Typically the target is a SCSI peripheral device but the host adapter can also be a target. (1999-02-10) 1 1 1 1 1 ScumOS /skuhm'os/ or /skuhm'O-S/ An Unflattering hackerism for SunOS, the Unix variant once supported on Sun Microsystems's Unix workstations. Despite what this term might suggest, Sun was founded by hackers and still enjoys excellent relations with hackerdom; usage is more often in exasperation than outright loathing. See also sun-stools. Compare AIDX, Macintrash, Nominal Semidestructor, Open DeathTrap, HP-SUX. [Jargon File] (1995-04-19) 1 1 1 1 1 scuzzy The usual pronunciation of SCSI. 1 1 1 1 1 SD Structured Design 1 1 1 1 1 sd The country code for the Sudan. (1999-01-27) 1 1 1 1 1 SDDI Sony Digital Data Interface 1 1 1 1 1 SDE Software Development Environment: equivalent to SEE. 1 1 1 1 1 SDF Syntax Definition Formalism. A language for lexical and syntactic specification. ["The Syntax Definition Formalism SDF - Reference Manual", J. Heering et al, Centre for Math & CS, Amsterdam]. ["Algebraic Specification", J.A. Bergstra et al eds, ACM Press 1989, Chap 6. To appear]. (1994-10-27) 1 1 1 1 1 SDH Synchronous Digital Hierarchy 1 1 1 1 1 SDI 1. <library> Selective Dissemination of Information. 2. <programming> Single Document Interface. (1999-03-30) 1 1 1 1 1 SDK Software Developers Kit (or "Software Development Kit"). 1 1 1 1 1 SDL Specification and Design Language. Defined by the ITU-T (recommendation Z100) to provide a tool for unambiguous specification and description of the behaviour of telecommunications systems. The area of application also includes process control and real-time applications. SDL provides a Graphic Representation (SDL/GR) and a textual Phrase Representation (SDL/PR), which are equivalent representations of the same semantics. A system is specified as a set of interconnected abstract machines which are extensions of the Finite State Machine (FSM). 1. System Software Development Language. System software for the B1700. "System Software Development Language Reference Manual", 1081346, Burroughs Corp (Dec 1974). 2. Specification and Description Language. ITU-T. Specification language with both graphical and character-based syntaxes for defining interacting extended finite state machines. Used to specify discrete interactive systems such 1 1 1 1 1 SDL 92 SDL[2] with object-orientation. 1 1 1 1 1 SDLC 1. <communications> Synchronous Data Link Control. 2. <programming> Systems Development Life Cycle. (2000-12-24) 1 1 1 1 1 SDM Schematic Data Model 1 1 1 1 1 SDMS A query language. 1 1 1 1 1 SDP Service Discovery Protocol 1 1 1 1 1 SDRAM Synchronous Dynamic Random Access Memory 1 1 1 1 1 SDRC The company behind VGX. (http://sdrc.com/). [More details?] (1998-02-06) 1 1 1 1 1 SDR-RAM Single Data Rate Random Access Memory 1 1 1 1 1 SDR-SDRAM Single Data Rate Random Access Memory 1 1 1 1 1 SDS 1. <company> Scientific Data Systems. 2. <tool> Schema Definition Set. (2001-03-03) 1 1 1 1 1 SDS 92 A 12-bit computer from Scientific Data Systems which preceded the Xerox Data Systems Model 940. (2001-03-03) 1 1 1 1 1 SDS 940 Xerox Data Systems Model 940 1 1 1 1 1 SDSL Single-line Digital Subscriber Line 1 1 1 1 1 SE 1. <software> software engineering. 2. IBM Systems Engineer. (1998-07-08) 1 1 1 1 1 se The country code for Sweden. (1999-01-27) 1 1 1 1 1 SEA Self Extracting Archive 1 1 1 1 1 Seagate Technology A major manufacturer of hard disk drives, founded in 1979 as "Shugart Technology" by Alan F. Shugart and Finis Conner. That name is on the original patents for the 5.25" hard disk drive. They changed the name to Seagate Technology soon after to avoid confusion, and also to avoid friction with Xerox, which had since purchased Alan's earlier company, Shugart Associates. (http://seagate.com/). Technical information at Impediment (http://impediment.com/seagate/). Address: 920 Disc Drive, Scotts Valley, CA 95066, USA. Fax: +1 (408) 438 3320. (2000-02-09) 1 1 1 1 1 SEAL Semantics-directed Environment Adaptation Language. (ftp://ftp.cwi.nl/pub/gipe/0092b.ps.Z). 1 1 1 1 1 search 1. <web> web search. 2. <computability> search problem. 3. <theory> search algorithm. 1 1 1 1 1 search algorithm Any algorithm for identifying a solution to a problem (a search problem) out of a space of potential solutions by considering several potential solutions until one is found that meets certain criteria. See A* search, beam search, best-first search, breadth-first search, depth-first search. (2007-11-03) 1 1 1 1 1 search-and-destroy mode Hackerism for a noninteractive search-and-replace facility in an editor, so called because an incautiously chosen match pattern can cause infinite damage. [Jargon File] 1 1 1 1 1 search engine A remotely accessible program that lets you do keyword searches for information on the Internet. There are several types of search engine; the search may cover titles of documents, URLs, headers, or the full text. A list of search engines (http://cuiwww.unige.ch/meta-index.html#MISC), Centre Universitaire d'Informatique at the University of Geneva (1995-11-28) 1 1 1 1 1 search problem A computational problem that requires identifying a solution from some, possibly infinite, solution space (set of possible solutions). E.g. "What is the millionth prime number?". This contrasts with a decision problem which merely asks whether a given answer is a solution or not. (1999-02-15) 1 1 1 1 1 search term An element of a search or query. A search term is the basic building block of a boolean search or a weighted search. In a search engine a search term is typically a word, phrase, or pattern match expression. For example: cosmonaut or "space travel" or astronaut* In a database a term is typically the comparison of a column with a constant or with another column. For example: last_name like 'Smith%' (1999-08-27) 1 1 1 1 1 Search The Fucking Web (Always abbreviated STFW) A response implying that an inquirer could have easily found an answer to his question using Google or some other web search engine. It is now often quicker and more productive to search the World-Wide Web than to RTFM. JFGI, GIYF and lmgtfy.com convey the same message. (2014-05-23) 1 1 1 1 1 SEC Single Edge Contact Cartridge 1 1 1 1 1 SECC Single Edge Contact Cartridge 1 1 1 1 1 SECD machine Stack Environment Control Dump machine 1 1 1 1 1 secondary cache (Or "second level cache", "level two cache", "L2 cache") A larger, slower cache between the primary cache and main memory. Whereas the primary cache is often on the same integrated circuit as the central processing unit (CPU), a secondary cache is usually external. (1997-06-25) 1 1 1 1 1 secondary damage When a fatal error occurs (especially a segfault) the immediate cause may be that a pointer has been trashed due to a previous fandango on core. However, this fandango may have been due to an *earlier* fandango, so no amount of analysis will reveal (directly) how the damage occurred. "The data structure was clobbered, but it was secondary damage." By extension, the corruption resulting from N cascaded fandangoes on core is "Nth-level damage". There is at least one case on record in which 17 hours of grovelling with adb actually dug up the underlying bug behind an instance of seventh-level damage! The hacker who accomplished this near-superhuman feat was presented with an award by his fellows. [Jargon File] 1 1 1 1 1 secondary key A candidate key which is not selected as a primary key. (1997-04-26) 1 1 1 1 1 secondary storage Any non-volatile storage medium that is not directly accessible to the processor. Memory directly accessible to the processor includes main memory, cache and the CPU registers. Secondary storage includes hard drives, magnetic tape, CD-ROM, DVD drives, floppy disks, punch cards and paper tape. Secondary storage devices are usually accessed via some kind of controller. This contains registers that can be directly accessed by the CPU like main memory ("memory mapped"). Reading and writing these registers can cause the device to perform actions like reading a block of data off a disk or rewinding a tape. See also DMA. Programs and data stored in secondary storage must first be loaded into main memory before the processor can use them. (1997-11-05) 1 1 1 1 1 second generation 1. <language> second generation language. 2. <architecture> second generation computer. 1 1 1 1 1 second generation computer A computer built from transistors, designed between the mid-1950s and mid-1960s. Ferrite core memory and magnetic drums replaced cathode ray tubes and delay-line storage for main memory. Index registers and floating point arithmetic hardware became widespread. Machine-independent high level programming languages such as ALGOL, COBOL and Fortran were introduced to simplify programming. I/O processors were introduced to supervise input-output operations independently of the CPU thus freeing the CPU from time-consuming housekeeping functions. The CPU would send the I/O processor an initial instruction to start operating and the I/O processor would then continue independently of the CPU. When completed, or in the event of an error, the I/O processor sent an interrupt to the CPU. Batch processing became feasible with the improvement in I/O and storage technology in that a batch of jobs could be 1 1 1 1 1 second generation language assembly language See also first generation language, third generation language. 1 1 1 1 1 second level cache secondary cache 1 1 1 1 1 second normal form database normalisation 1 1 1 1 1 Second-Order Lambda-calculus (SOL) A typed lambda-calculus. ["Abstract Types have Existential Type", J. Mitchell et al, 12th POPL, ACM 1985, pp. 37-51]. (1995-07-29) 1 1 1 1 1 second-system effect (Sometimes, more euphoniously, "second-system syndrome") When one is designing the successor to a relatively small, elegant, and successful system, there is a tendency to become grandiose in one's success and design an elephantine feature-laden monstrosity. The term was first used by Fred Brooks in his classic "The Mythical Man-Month. It described the jump from a set of nice, simple operating systems on the IBM 70xx series to OS/360 on the 360 series. A similar effect can also happen in an evolving system; see Brooks's Law, creeping elegance, creeping featurism. See also Multics, OS/2, X, software bloat. [Jargon File] 1 1 1 1 1 sector interleave (Or sector map) The mapping from logical to physical sector numbers on a magnetic disk designed to optimise sequential reads and writes. Data is usually transferred to and from the disk in blocks or sectors where one sector lies within a continuous range of rotational angle of the disk. If logical sectors are assigned sequentially to physical sectors (0,1,2,...) then by the time one sector has been read and processed (e.g. writen to main memory) the start of the next logical sector will have passed the read/write head and will not be accessible until the disk's rotation brings it back under the head. Staggering the physical sectors (e.g. 0,3,6,1,4,7,2,5,8) aims to allow just enough time deal with one sector before the next is accessible. This obviously depends on the relative speed of the rotation of the disk, sector size, sectors per track and the speed of transfer of sectors to main memory. 1 1 1 1 1 sector interleaving sector interleave 1 1 1 1 1 sector map sector interleave 1 1 1 1 1 sector mapping In this scheme the memory and cache are divided into blocks of 2^m bytes (the cache line size). A sector consists of 2^n consecutive blocks. When a block is cached, it is read into the correct position in any sector of the cache, given by discarding the bottom m address bits and taking the next n as the block number within the sector. That whole sector is then tagged with the remaining upper address bits and the other blocks in the sector are marked as invalid. This scheme takes advantage of locality of reference to consecutive blocks and needs fewer tags thus reducing the cost of associative access to the tags. 1 1 1 1 1 Secure File Transfer Protocol SSH File Transfer Protocol 1 1 1 1 1 Secure Hash Algorithm algorithm, cryptography (SHA) A one-way hash function developped by NIST and defined in standard FIPS 180. SHA-1 is a revision published in 1994; it is also described in ANSI standard X9.30 (part 2). (2003-04-12) 1 1 1 1 1 Secure Multipurpose Internet Mail Extensions (S-MIME) A specification for secure electronic mail. S-MIME was designed to add security to e-mail messages in MIME format. The security services offered are authentication (using digital signatures) and privacy (using encryption). (http://rsa.com/rsa/S-MIME/). (1997-05-10) 1 1 1 1 1 Secure Shell (ssh) A Unix shell program for logging into, and executing commands on, a remote computer. ssh is intended to replace rlogin and rsh, and provide secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over the secure channel. (http://cs.hut.fi/ssh/). (1997-01-07) 1 1 1 1 1 Secure Sockets Layer (SSL) A protocol designed by Netscape Communications Corporation to provide secure communications over the Internet using asymmetric key encryption. SSL is layered beneath application protocols such as HTTP, SMTP, Telnet, FTP, Gopher and NNTP and is layered above the connection protocol TCP/IP. It is used by the HTTPS access method. (2007-05-25) 1 1 1 1 1 security Protection against unauthorized access to, or alteration of, information and system resources including CPUs, storage devices and programs. Security includes: * confidentiality - preventing unauthorized access; integrity - preventing or detecting unauthorized modification of information. * authentication - determining whether a user is who they claim to be. * access control - ensuring that users can access the resources, and only the resources, that they are authorised to. * nonrepudiation - proof that a message came from a certain source. * availability - ensuring that a system is operational and accessible to authorised users despite hardware or software failures or attack. 1 1 1 1 1 Security Administrator's Integrated Network Tool (SAINT, originally "Security Administrator Tool for Analyzing Networks", SATAN) A tool written by Dan Farmer and Wietse Venema which remotely probes systems via the network and stores its findings in a database. The results can be viewed with an web browser. SAINT requires Perl 5.000 or better. In its simplest mode, SAINT gathers as much information about remote hosts and networks as possible by examining such network services as finger, NFS, NIS, FTP, TFTP, rexd, and other services. The information gathered includes the presence of various network information services as well as potential security flaws - usually in the form of incorrectly setup or configured network services, well-known bugs in system or network utilities, or poor or ignorant policy decisions. It can then either report on this data or use a simple rule-based system to investigate any potential security problems. Users can then examine, query, and analyze 1 1 1 1 1 Security Association The relationship between two or more entities (typically, a computer, but could be a user on a computer, or software component) which describes how the entities will use security services, such as encryption, to communicate. See RFC 1825. (1997-07-09) 1 1 1 1 1 Security Association ID (SAID) A 32-bit field added to packet headers for encryption and authentication in the proposed Internet Protocol Version 6. (1997-07-09) 1 1 1 1 1 security through obscurity Or "security by obscurity". A term applied by hackers to most operating system vendors' favourite way of coping with security holes - namely, ignoring them, documenting neither any known holes nor the underlying security algorithms, trusting that nobody will find out about them and that people who do find out about them won't exploit them. This never works for long and occasionally sets the world up for debacles like the RTM worm of 1988 (see Great Worm), but once the brief moments of panic created by such events subside most vendors are all too willing to turn over and go back to sleep. After all, actually fixing the bugs would siphon off the resources needed to implement the next user-interface frill on marketing's wish list - and besides, if they started fixing security bugs customers might begin to *expect* it and imagine that their warranties of merchantability gave them some sort of rights. Historical note: There are conflicting stories about the 1 1 1 1 1 security vulnerability vulnerability 1 1 1 1 1 SED smoke-emitting diode 1 1 1 1 1 Sed Stream editor. The Unix stream editor. It has a powerful but cryptic command language and is based on regular expressions. There is a GNU version called GNU Sed. [Jargon File] (1994-11-03) 1 1 1 1 1 SEE 1. Simultaneous Engineering Environment. 2. Software Engineering Environment. (1999-04-26) 1 1 1 1 1 seed BitTorrent 1 1 1 1 1 seek 1. <storage> To move the head of a disk drive radially, i.e., to move from one track to another. 2. <storage> To wind the tape to a given location. 3. <programming> To move the pointer that marks the next byte to be read from or written to a file. (1997-07-15) 1 1 1 1 1 seeking seek 1 1 1 1 1 seek time The time it takes for a disk drive to move its head(s) from one track to another. The seek time depends on the power of the servo, the mass of the heads, the number of tracks traversed and the time taken to position the heads over the target track accurately enough to start data transfer. See also: average seek time, minimum seek time, maximum seek time. (1997-07-15) 1 1 1 1 1 SEESAW An early system on the IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-15) 1 1 1 1 1 see u see me CU-SeeMe 1 1 1 1 1 SEGA manufacturer of video game hardware and software. Usenet newsgroup: news:rec.games.video.sega. (1995-03-01) 1 1 1 1 1 Sega Genesis/MegaDrive A games console made by SEGA. The Genesis used a Zilog Z80 for its sound generator. This made the Genesis compatible with Sega Master System games through a device called a "Power Base Converter" which basically shut down the Genesis/MegaDrive's 68000 CPU and made the Z80 the CPU. (2008-07-28) 1 1 1 1 1 segfault segmentation fault 1 1 1 1 1 seggie /seg'ee/ British shorthand for a Unix segmentation fault. [Jargon File] (1994-12-15) 1 1 1 1 1 segment /seg'ment/ 1. <architecture> A collection of pages in a memory management system. 2. <programming> A separately relocatable section of an executable program. Unix executables have a text segment (executable machine instructions), a data segment (initialised data) and a bss segment (uninitialised data). 3. <networking> network segment. 4. To experience a segmentation fault. Confusingly, the stress is often put on the first syllable, like the noun "segment", rather than the second like mainstream verb "segment". This is because it is actually a noun shorthand that has been verbed. 5. A block of memory in a segmented address space. [Jargon File] (2004-02-27) 1 1 1 1 1 segmentation (Or "segmentation and reassembly", SAR) Breaking an arbitrary size packet into smaller pieces at the transmitter. This may be necessary because of restrictions in the communications channel or to reduce latency. The pieces are joined back together in the right order at the receiver ("reassembly"). Segmentation may be performed by a router when routing a packet to a network with a smaller maximum packet size. The term "segmentation" is used in ATM, in TCP/IP, it is called "fragmentation" an is performed at the IP layer before the "fragments" are passed to the transport layer. See for example ATM forum UNI 4.0 specification. [Better reasons?] (1999-06-14) 1 1 1 1 1 segmentation and reassembly segmentation 1 1 1 1 1 segmentation fault An error in which a running Unix program attempts to access memory not allocated to it and terminates with a segmentation violation error and usually a core dump. [Jargon File] (1994-12-15) 1 1 1 1 1 segmented address space An addressing scheme where all memory references are formed by adding an offset to a base address held in a segment register. The effect is to segment memory into blocks, which may overlap either partially or completely, depending on the contents of the segment registers but normally they would be distinct to give access to the maximum total range of addresses. In this case the scheme does provide some degree of memory protection within a single process since, for example, a data reference cannot affect an area of memory containing code. However, compilers must either generate slower code or code with artificial limits on the size of data structures. The best known implementation is that used on the Intel 8086 and later Intel microprocessors, where a 16-bit offset is added to a 16-bit base address held in one of four segment base registers. Each instruction has a default segment (code (CS), data (DS), stack (SS), ? (ES)) which determines which 1 1 1 1 1 segv /seg'vee/ segmentation violation. segmentation fault (1994-12-15) 1 1 1 1 1 SEI Software Engineering Institute. (Carnegie Mellon University). 1 1 1 1 1 Seiko RC-4000 A wristwatch with an EIA-232 interface. A clip fitted round the watch and made electrical contact. This clip had a socket for a stereo style jack lead the other end of which was a 25-way D-type connector. The lead allowed you to enter phone numbers etc. into the watch without having to play with tiny buttons. It also meant if the battery on your watch ran out you could restore the data without having to type it all in again. It was around the era of the 8-bit home computers like the Spectrum, BBC Microcomputer, Apple II, C64 - the 1980s. (1995-01-30) 1 1 1 1 1 SEL 1. Self-Extensible Language. 2. Subset-Equational Language. 1 1 1 1 1 Selective Dissemination of Information (SDI) (From Library Science) SDI is a current awareness system which alerts you to the latest publications in your specified field(s) of interest. A user registers at such a system with keywords representing his or her fields of interest, called a search profile. When new publications matching the search profile appear, the system informs the user of them instantly, periodically or upon request. Some systems may also be able to inform the user if changes in already notified publications occur. Health Science Library SDI (http://www-hsl.mcmaster.ca/sdi.html). FIZ Karlsruhe Scientific Service Institution (http://fiz-karlsruhe.de/mc-sdi.html). (1997-03-10) 1 1 1 1 1 selector 1. In Smalltalk or Objective C, the syntax of a message which selects a particular method in the target object. 2. An operation that returns the state of an object but does not alter that state. Selector functions or methods often have names which begin with "get" and corresponding modifier methods or procedures whose names begin with "set". (1998-01-12) 1 1 1 1 1 Self A small, dynamically typed object-oriented language, based purely on prototypes and delegation. Self was developed by the Self Group at Sun Microsystems Laboratories, Inc. and Stanford University. It is an experimental exploratory programming language. Release 2.0 introduces full source-level debugging of optimised code, adaptive optimisation to shorten compile pauses, lightweight threads within Self, support for dynamically linking foreign functions, changing programs within Self and the ability to run the experimental Self graphical browser under OpenWindows. Designed for expressive power and malleability, Self combines a pure, prototype-based object model with uniform access to state and behaviour. Unlike other languages, Self allows objects to inherit state and to change their patterns of inheritance dynamically. Self's customising compiler can generate very efficient code compared to other dynamically-typed 1 1 1 1 1 Self-Extensible Language ["SEL - A Self-Extensible Programming Language", G. Molnar, Computer J 14(3):238-242 (Aug 1971)]. (1994-12-15) 1 1 1 1 1 Self Extracting Archive (SEA) An archive format used on the Apple Macintosh. Double-clicking a file of this type should extract its contents. (1995-05-02) 1 1 1 1 1 self-reference See self-reference. [Jargon File] 1 1 1 1 1 selvage chad 1 1 1 1 1 SEM The semantic specification language for COPS. ["Metalanguages of the Compiler Production System COPS", J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159]. 1 1 1 1 1 semantic gap The difference between the complex operations performed by high-level language constructs and the simple ones provided by computer instruction sets. It was in an attempt to try to close this gap that computer architects designed increasingly complex instruction set computers. (1994-10-10) 1 1 1 1 1 semantic network A graph consisting of nodes that represent physical or conceptual objects and arcs that describe the relationship between the nodes, resulting in something like a data flow diagram. Semantic nets are an effective way to represent data as they incorporate the inheritance mechanism that prevents duplication of data. That is, the meaning of a concept comes from its relationship to other concepts and the information is stored by interconnecting nodes with labelled arcs. (1999-01-07) 1 1 1 1 1 semantics The meaning of a string in some language, as opposed to syntax which describes how symbols may be combined independent of their meaning. The semantics of a programming language is a function from programs to answers. A program is a closed term and, in practical languages, an answer is a member of the syntactic category of values. The two main kinds are denotational semantics and operational semantics. (1995-06-21) 1 1 1 1 1 semaphore The classic method for restricting access to shared resources (e.g. storage) in a multi-processing environment. They were invented by Dijkstra and first used in T.H.E operating system. A semaphore is a protected variable (or abstract data type) which can only be accessed using the following operations: P(s) Semaphore s; while (s == 0) ; /* wait until s>0 */ 1 1 1 1 1 semi /se'mee/ or /se'mi:/ A spoken abbreviation for semicolon. Commands to grind are prefixed by semi semi star means that the prefix is ";;*", not 1/4 of a star. [Jargon File] (1995-01-31) 1 1 1 1 1 Semi-Automatic Ground Environment (SAGE) The computer system of the old US Norad air defence system. SAGE was ground-breaking in many ways, such as being one of the first very large software projects and the first real-time system. MIT Lincoln Laboratory developed SAGE and MITRE Corporation was responsible for system engineering and implementation oversight. (http://togger.com/), (http://jps.net/ethelen/sage.html), (http://eskimo.com/%7Ewow-ray/sage28.html). [Confirm? Dates? Connection with MIT Research Laboratory for Electronics?] (1999-12-16) 1 1 1 1 1 semicolon ; Common: ITU-T: semicolon; semi. Rare: weenie; INTERCAL: hybrid, pit-thwong. 1 1 1 1 1 semiconductor A material, typically crystaline, which allows current to flow under certain circumstances. Common semiconductors are silicon, germanium, gallium arsenide. Semiconductors are used to make diodes, transistors and other basic "solid state" electronic components. As crystals of these materials are grown, they are "doped" with traces of other elements called donors or acceptors to make regions which are n- or p-type respectively for the electron model or p- or n-type under the hole model. Where n and p type regions adjoin, a junction is formed which will pass current in one direction (from p to n) but not the other, giving a diode. One model of semiconductor behaviour describes the doping elements as having either free electrons or holes dangling at the points in the crystal lattice where the doping elements replace one of the atoms of the foundation material. When external electrons are applied to n-type material (which 1 1 1 1 1 Semidetached Mode A term used by COCOMO to describe a project development somewhere between organic and embedded. The team members have a mixture of experienced and inexperienced personnel. The software to be developed has some characteristics of both organic and embedded modes. Semidetached software can be as large as 300K DSIs. (1996-05-29) 1 1 1 1 1 SENDIT Systems Engineering for Network Debugging, Integration and Test. A two-year European Commission funded project to produce software tools for distributed applications running on networks of microcontrollers. (1994-07-21) 1 1 1 1 1 sendmail The BSD Unix Message Transfer Agent supporting mail transport via TCP/IP using SMTP. Sendmail is normally invoked in the background via a Mail User Agent such as the mail command. Sendmail was written by Eric Allman at the University of California at Berkeley during the late 1970s. He now has his own company, Sendmail Inc. Sendmail was one of the first programs to route messages between networks and today is still the dominant e-mail transfer software. It thrived despite the awkward ARPAnet transition between NCP to TCP protocols in the early 1980s and the adoption of the new SMTP Simple Mail Transport Protocol, all of which made the business of mail routing a complex challenge of backward and forward compatibility for several years. There are now over one million copies of Sendmail installed, representing over 75% of all Internet mail servers. 1 1 1 1 1 sendmail.cf sendmail's configuration file, which it reads once when starting up, usually found in the /etc directory. Only real Unix Gurus can understand, let alone modify, this file since it consists moslty of header rewrite rules written as M4 macros, as well as various other one- or two-character commands. (1996-12-09) 1 1 1 1 1 Sendmail Inc. The company, announced in November 1997 and launched in March 1998, created by Eric Allman, the original author of Sendmail. Allman is Chief Technology Officer, Greg Olson is President and CEO. Sendmail Inc. will sell commercial upgrades, service and support to Internet Service Providers and corporations running critical e-mail applications, while still continuing freeware development. Sun Microsystems founders Bill Joy and Andy Bechtolscheim are among the investors in the company, along with Tim O'Reilly of publishers O'Reilly & Associates and John Funk of e-mail company InfoBeat Inc.. Allman said that he devoted the fist six months of the life of Sendmail Inc. to finalising the freeware release. A commercial version was due in summer 1998, at around $1000 per server. The company is expected to reach $40m annual sales within three years. Funding is in the region of $1.25m. 1 1 1 1 1 Seneca Oberon-V 1 1 1 1 1 senior bit [IBM] Synonym meta bit. [Jargon File] 1 1 1 1 1 sense A meaning of a word. (2007-05-03) 1 1 1 1 1 sensor An electronic device used to measure a physical quantity such as temperature, pressure or loudness and convert it into an electronic signal of some kind (e.g a voltage). Sensors are normally components of some larger electronic system such as a computer control and/or measurement system. Analog sensors most often produce a voltage proportional to the measured quantity. The signal must be converted to digital form with a ADC before the CPU can process it. Digital sensors most often use serial communication such as EIA-232 to return information directly to the controller or computer through a serial port. (1997-04-15) 1 1 1 1 1 sentence A collection of clauses. See also definite sentence. (2003-12-04) 1 1 1 1 1 SE-ODP Support Environment for Open Distributed Processing. An ECMA standard. 1 1 1 1 1 SEP 1. Someone Else's Problem. 2. <tool> A SASD tool from IDE. (1995-10-12) 1 1 1 1 1 separate compilation A feature of most modern programming languages that allows each program module to be compiled on its own to produce an object file which the linker can later combine with other object files and libraries to produce the final executable. Separate compilation avoids processing all the source code every time the program is built, thus saving development time. The object files are designed to require minimal processing at link time. They can also be collected together into libraries and distributed commercially without giving away source code (though they can be disassembled). Examples of the output of separate compilation are C object files (extension ".o") and Java ".class" files. (2005-02-19) 1 1 1 1 1 SEPIA Standard ECRC Prolog Integrating Applications. Prolog with many extensions including attributed variables ("metaterms") and declarative coroutining. "SEPIA", Micha Meier <micha@ecrc.de> et al, TR-LP-36 ECRC, March 1988. Version 3.1 available for Suns and VAX. (See ECRC-Prolog). E-mail: <sepia-request@ecrc.de>. 1 1 1 1 1 SEPP Single Edge Processor Package 1 1 1 1 1 Seque Seque: A Programming Language for Manipulating Sequences, R.E. Griswold et al, Comp Langs 13(1):13-22 (1988). 1 1 1 1 1 Sequel 1. Precursor to SQL. ["System R: Relational Approach to Database Management", IBM Res Lab, San Jose, reprinted in Readings in Database Systems]. 2. U Leeds. Theorem prover specification language. Pattern matching notation similar to Prolog. Compiled into Lisp. [Proc ICJAI 13]. (ftp://agora.leeds.ac.uk/scs/logic/). 1 1 1 1 1 sequence A collection of related things in a specific order. In mathematics, numbers are represented as sequences of digits e.g. bits, decimal digits, hexadecimal digits, etc. There are also sequences of numbers where each number is related to previous numbers, e.g. the Fibonacci sequence. In computing the sequence of instructions that a computer follows when executing a program is called control flow; a sequence of characters is also known as a "(character) string" (e.g. an escape sequence); a sequence of images forms a video; a sound recording is an example of a sequence of samples of an analogue signal. In probability theory, a sequence of events can be described by a Markov chain. (2015-09-01) 1 1 1 1 1 Sequenced Packet Exchange (SPX) A transport layer protocol built on top of IPX. SPX is used in Novell NetWare systems for communications in client/server application programs, e.g. BTRIEVE (ISAM manager). SPX is not used for connections to the file server itself; this uses NCP. It has been extended as SPX-II. SPX/IPX perform equivalent functions to TCP/IP. (http://developer.novell.com/research/appnotes/1995/december/03/04.htm). [Better reference?] (1999-05-27) 1 1 1 1 1 sequencer Any system for recording and/or playback of music via a programmable memory which stores music not as audio data, but as some representation of notes. The most common modern usage of "sequencer" is to refer to systems (whether in software, or as a feature of devices like synthesizers or drum machines) that deal with MIDI data. (1999-06-04) 1 1 1 1 1 Sequent A computer manufacturer. Quarterly sales $109M, profits $7M (Aug 1994). Sequent computers was acquired by IBM in 1999. [History?] (2003-10-21) 1 1 1 1 1 sequential coding The usual bitmap image data storage format or transmission algorithm where the resoluton is constant and later data adds only more area. This contrasts with progressive coding. (2000-09-12) 1 1 1 1 1 sequential file matching A programming technique that matches records in one sequential file with records in another sequential file. The records are accessed in the physical order in which they are stored. (1994-11-02) 1 1 1 1 1 Sequential Parlog Machine (SPM) The virtual machine (and its machine code) for the Parlog logic programming language. (ftp://nuri.inria.fr/lang/Parlog.tar.Z). ["Parallel Logic Programming in PARLOG", Steve Gregory, Addison-Wesely, UK, 1987]. 1 1 1 1 1 sequential processing (Or "serial processing") Running a single task to completion on a single processor, in contrast to parallel processing or multitasking. (1995-04-23) 1 1 1 1 1 SERC Science and Engineering Research Council 1 1 1 1 1 SERCOS serial real-time communications system [What is it?] ["More choices link motors and drives to controls", by L. Langnau. Power Transmission Design, vol. 37, no. 7, pp. 33-36]. (1996-01-23) 1 1 1 1 1 serial 1. <communications> serial communications 2. <architecture> serial processor. 1 1 1 1 1 Serial Advanced Technology Attachment (SATA, Serial ATA) A computer bus technology primarily designed for transfer of data to and from a hard disk. SATA is the successor to Advanced Technology Attachment (ATA), which was given the retronym Parallel ATA (PATA) to distinguish it from Serial ATA. Serial ATA is designed to be scalable. The original SATA/150 or "SATA 1" can transfer up to 150 MBps and "SATA 3.0 Gbit/s" has a maximum data rate of 300 MBps. Both SATA and PATA drives have built-in low level control electronics but the term IDE is usually restricted to parallel ATA drives. (http://www.serialata.org/). (2007-02-23) 1 1 1 1 1 Serial ATA Serial Advanced Technology Attachment 1 1 1 1 1 serial communications Communication via a single channel that delivers one bit of data at a time, in contrast to parallel communications where multiple serial channels are combined, either physically (e.g. multiple cores in a cable) or by multiplexing. 1 1 1 1 1 Serial Communications Interface UART 1 1 1 1 1 Serial Interface Adaptor (SIA) The Ethernet driver chip used on a Filtabyte Ethernet card. 1 1 1 1 1 serial IO chip UART 1 1 1 1 1 serialise To represent an arbitrarily complex data structure in a location-independent way so that it can be communicated or stored elsewhere. For example, an object representing a time, with attributes for year, month, timezone, etc., could be serialised as the string "2002-02-24T14:33:52-0800", or an XML element "<dateobj year='2002' month='02' day='24' hour='14' minute='33' second='52' timezone='-0800' />", or as a binary string. As well as providing an external data representation (e.g. representing an integer as a string of ASCII digits) and marshalling components into a single block of data, a serialisation algorithm needs to follow pointers to include objects referred to by the initial object. This is further complicated by the possible presence of cycles in the object graph. It should be possible to store the serialised representation 1 1 1 1 1 serialize serialise 1 1 1 1 1 serial line Wires which connect two serial ports carrying serial data consisting of sequential bits represented by one of two voltages. A common electrical specification for the signals on a serial line is RS-423. (ftp://ftp.acorn.co.uk/pub/documents/appnotes/231-245/234.ps). (1995-02-02) 1 1 1 1 1 Serial Line Internet Protocol (SLIP) Software allowing the Internet Protocol (IP), normally used on Ethernet, to be used over a serial line, e.g. an EIA-232 serial port connected to a modem. It is defined in RFC 1055. SLIP modifies a standard Internet datagram by appending a special SLIP END character to it, which allows datagrams to be distinguished as separate. SLIP requires a port configuration of 8 data bits, no parity, and EIA or hardware flow control. SLIP does not provide error detection, being reliant on other high-layer protocols for this. Over a particularly error-prone dial-up link therefore, SLIP on its own would not be satisfactory. A SLIP connection needs to have its IP address configuration set each time before it is established whereas Point-to-Point Protocol (PPP) can determine it automatically once it has started. See also SLiRP. 1 1 1 1 1 Serial Line IP (SLIP) Serial Line Internet Protocol. 1 1 1 1 1 Serial Peripheral Interface (SPI) A serial interface in which a master device supplies clock pulses to exchanges data serially with a slave over two data wires (Master-Slave and Slave-Master). This term probably originated with Motorola in about 1979 with their first all-in-one microcontroller. (2003-07-13) 1 1 1 1 1 serial port (Or "com port") A connector on a computer to which you can attach a serial line connected to peripherals which communicate using a serial (bit-stream) protocol. The most common type of serial port is a 25-pin D-type connector carrying EIA-232 signals. Smaller connectors (e.g. 9-pin D-type) carrying a subset of EIA-232 are often used on personal computers. The serial port is usually connected to an integrated circuit called a UART which handles the conversion between serial and parallel data. In the days before bit-mapped displays, and today on multi-user systems, the serial port was used to connect one or more terminals (teletypewriters or VDUs), printers, modems and other serial peripherals. Two computers connected together via their serial ports, possibly via modems, can communicate using a protocol such as UUCP or CU or SLIP. (1995-01-12) 1 1 1 1 1 Serial Presence Detect presence detect 1 1 1 1 1 serial processing sequential processing 1 1 1 1 1 serial processor A computer whose central processing unit performs a single machine-level operation at a time. This term would be used mostly in contrast to a parallel processor. (2008-03-14) 1 1 1 1 1 Serial Storage Architecture (SSA) IBM's proposed ANSI standard for a standard high-speed interface to disk clusters and arrays. SSA allows full-duplex packet multiplexed serial data transfers at rates of 20Mb/sec in each direction. According to John Taylor, programme manager at IBM's Storage Division at Havant, SSA will be used in arrays of discs working with high-end computers ranging from mainframes down to LAN servers. Taylor said that SSA differs from the IEEE proposed P1394 serial interface specification in its ability to offer simultaneous multiplexed transfers from more than one disk or array. IBM also supports the P1394 standard which will be used primarily by desktop PCs for multimedia applications. SSA has received backing from a number of companies including connector makers Molex, ITT Cannon and AMP, disk drive makers Conner and Western Digital and RAID array suppliers like Dynatech and NCR. IBM expects to see the first SSA products 1 1 1 1 1 serve To be a server, to provide a service. E.g., "The shttpd serves requested documents to clients over a secure link." (1997-09-11) 1 1 1 1 1 servelet Java servlet 1 1 1 1 1 server 1. A program which provides some service to other (client) programs. The connection between client and server is normally by means of message passing, often over a network, and uses some protocol to encode the client's requests and the server's responses. The server may run continuously (as a daemon), waiting for requests to arrive or it may be invoked by some higher level daemon which controls a number of specific servers (inetd on Unix). There are many servers associated with the Internet, such as those for HTTP, Network File System, Network Information Service (NIS), Domain Name System (DNS), FTP, news, finger, Network Time Protocol. On Unix, a long list can be found in /etc/services or in the NIS database "services". See client-server. 2. A computer which provides some service for other computers connected to it via a network. The most common example is a file server which has a local disk and services requests 1 1 1 1 1 serverlet Java Servlet 1 1 1 1 1 Server Message Block (SMB) A client/server protocol that provides file and printer sharing between computers. In addition SMB can share serial ports and communications abstractions such as named pipes and mail slots. SMB is similar to remote procedure call (RPC) specialised for file system access. SMB was developed by Intel, Microsoft, and IBM in the early 1980s. It has also had input from Xerox and 3Com. It is the native method of file and print sharing for Microsoft operating systems; where it is called Microsoft Networking. Windows for Workgroups, Windows 95, and Windows NT all include SMB clients and servers. SMB is also used by OS/2, Lan Manager and Banyan Vines. There are SMB servers and clients for Unix, for example Samba and smbclient. SMB is a presentation layer protocol structured as a large set of commands (Server Message Blocks). There are commands to support file sharing, printer sharing, user 1 1 1 1 1 server-parsed HTML (SPML, SHTML) A kind of HTML file containing server-specific, non-standard commands which are interpreted by the HTTP server and replaced by standard HTML or text before the data is returned to the client. Different servers use different command syntax and support different sets of commands. The most common example is a server-side include command which simply expands to the contents of some given file and allows bits of HTML or text to be shared between pages for ease of updating. Other commands insert the value of an environment variable or the output of a shell command. These allow pages to be different each time they are served without requiring a CGI script. Some servers distinguish SPML from HTML with a different filename extension, others use the execute bit of the file's permissions. (1996-09-29) 1 1 1 1 1 server room The room where all the server computers are housed. The workstations at which people sit and program are usually located elsewhere. Compare: sun lounge, dinosaur pen, play pen, salt mines, disk farm. (1998-07-06) 1 1 1 1 1 servers server 1 1 1 1 1 server-side Processing or content generation that is done on the web server or other server, as opposed to on the client computer where the web browser is running. An example is server-side include where one file is inserted in another before it is served, rather than, say, having the browser request the files separately and combine them using an iframe. A very common kind of server-side processing is the inclusion of data from a database in a web page. There are many software environments and technologies designed for server-side processing, e.g. CGI, ISAPI, WebObjects and ASP. The greatest advantage of server-side processing is that it is independent of the many different client software environments that exist on the Internet, chiefly different web browsers and operating systems. The disadvantage is that the user must wait for a response from the server which is a much slower form of interaction than is possible with client-side 1 1 1 1 1 server-side include (SSI) The facility provided by most web servers, e.g. NCSA httpd, to replace special tags in an HTML file with the contents of another file before the file is sent out by the server, i.e. an HTML macro. NCSA httpd tutorial (http://hoohoo.ncsa.uiuc.edu/docs/tutorials/includes.html). (1996-09-08) 1 1 1 1 1 service Work performed (or offered) by a server. This may mean simply serving simple requests for data to be sent or stored (as with file servers, gopher or http servers, e-mail servers, finger servers, SQL servers, etc.); or it may be more complex work, such as that of irc servers, print servers, X Windows servers, or process servers. E.g. "Access to the finger service is restricted to the local subnet, for security reasons". (1997-09-11) 1 1 1 1 1 serviceability The ease with which corrective maintenance or preventative maintenance can be performed on a system (e.g. by a hardware service technician). Higher serviceability improves availability and reduces service cost. Serviceability is one component of RAS. (2000-08-13) 1 1 1 1 1 Service Access Point (SAP) The OSI term for the component of a network address which identifies the individual application on a host which is sending or receiving a packet. TCP/IP's equivalent term is "port". Different SAPs distinguish between different services or applications on a host, e.g. electronic mail, FTP, HTTP. (1996-12-23) 1 1 1 1 1 Service Advertising Protocol (SAP) A Novell NetWare protocol. SAP follows the spirit of the Xerox Clearinghouse protocol, it permits file, print, and gateway servers to advertise their services and addresses. (1996-01-13) 1 1 1 1 1 Service Discovery Protocol (SDP) A Bluetooth protocol in the Core Protocol Stack that allows devices to connect to other services. Bluetooth SDP (http://bluetooth.org/assigned-numbers/sdp.htm). (2002-06-28) 1 1 1 1 1 service-oriented architecture (SOA) Systems built from loosely-coupled software modules deployed as services, typically communicating via a network. This allows different modules to be implemented and deployed in different ways, e.g. owned by different organisations, developed by different teams, written in different programming languages, running on different hardware and operating systems. The key to making it work is interoperability and standards so that modules can exchange data. SOAs often support service discovery, allowing a service to be changed without having to explicitly reconnect all its clients. Many different frameworks have been developed for SOA, including SOAP, REST, RPC, DCOM, CORBA, web services and WCF. (2009-01-23) 1 1 1 1 1 service provider An organisation that provides a service by telephone, such as an 0800 (toll free) number. The service provider buys the services of a telecom supplier (e.g. BT) but advertises the service and deals with the calls itself. Increasingly, service providers are now also managing their advanced call-routing. (1996-08-27) 1 1 1 1 1 Service Set Identifier (SSID) A 32-character unique identifier that distinguishes one wireless network from another. All devices attempting to connect to a specific network use the same SSID, which appears in the header of packets. Because an SSID can be intercepted, it does not supply any security to the network. (2009-01-23) 1 1 1 1 1 servlet Java servlet 1 1 1 1 1 session 1. A lasting connection between a user (or user agent) and a peer, typically a server, usually involving the exchange of many packets between the user's computer and the server. A session is typically implemented as a layer in a network protocol (e.g. telnet, FTP). In the case of protocols where there is no concept of a session layer (e.g. UDP) or where sessions at the session layer are generally very short-lived (e.g. HTTP), virtual sessions are implemented by having each exchange between the user and the remote host include some form of cookie which stores state (e.g. a unique session ID, information about the user's preferences or authorisation level, etc.). See also login. 2. A lasting connection using the session layer of a networking protocol. (1997-08-03) 1 1 1 1 1 Session Initiation Protocol (SIP) A very simple text-based application-layer control protocol. It creates, modifies, and terminates sessions with one or more participants. Such sessions include Internet telephony and multimedia conferences. It is described in RFC 2543. (2000-05-31) 1 1 1 1 1 session layer The third highest protocol layer (layer 5) in the OSI seven layer model. The session layer uses the transport layer to establish a connection between processes on different hosts. It handles security and creation of the session. It is used by the presentation layer. Documents: ITU Rec. X.225 (ISO 8327), ITU Rec. X.215 (ISO 8326). [Examples?] (1997-12-07) 1 1 1 1 1 SES/workbench An iconic simulation and design tool, linked to some of the major CASE systems now available or in development. (1996-03-28) 1 1 1 1 1 SET 1. <security> Secure Electronic Transaction. 2. <electronics> Single Electron Tunneling. 3. <standard> Standard d'Echange et de Transfert. (1999-03-26) 1 1 1 1 1 set A collection of objects, known as the elements of the set, specified in such a way that we can tell in principle whether or not a given object belongs to it. E.g. the set of all prime numbers, the set of zeros of the cosine function. For each set there is a predicate (or property) which is true for (possessed by) exactly those objects which are elements of the set. The predicate may be defined by the set or vice versa. Order and repetition of elements within the set are irrelevant so, for example, 1, 2, 3 = 3, 2, 1 = 1, 3, 1, 2, 2. Some common set of numbers are given the following names: N = the natural numbers 0, 1, 2, ... Z = the integers ..., -2, -1, 0, 1, 2, ... Q = the rational numbers p/q where p, q are in Z and q /= 0. R = the real numbers C = the complex numbers. The empty set is the set with no elements. The intersection 1 1 1 1 1 set abstraction list comprehension 1 1 1 1 1 set associative cache A compromise between a direct mapped cache and a fully associative cache where each address is mapped to a certain set of cache locations. The address space is divided into blocks of 2^m bytes (the cache line size), discarding the bottom m address bits. An "n-way set associative" cache with S sets has n cache locations in each set. Block b is mapped to set "b mod S" and may be stored in any of the n locations in that set with its upper address bits as a tag. To determine whether block b is in the cache, set b mod S is searched associatively for the tag. A direct mapped cache could be described as "one-way set associative", i.e. one location in each set whereas a fully associative cache is N-way associative (where N is the total number of blocks in the cache). Performance studies have shown that it is generally more effective to increase the number of entries rather than associativity and that 2- to 16-way set associative caches perform almost as well as fully 1 1 1 1 1 set complement The complement of set A in set U is all elements of U which are not elements of A. (1995-01-24) 1 1 1 1 1 set comprehension list comprehension 1 1 1 1 1 Setext A markup scheme intended for documents that are both human- and computer-readable. 1 1 1 1 1 SETL SET Language. A very high level language based on sets, designed by Jack Schwartz at the Courant Institute in the early 1970s. It was possibly the first use of list comprehension notation. Data types include sets (unordered collections), tuples (ordered collections) and maps (collections of ordered pairs). Expressions may include quantifiers ('for each' and 'exists'). The first Ada translator was written in SETL. See also ISETL, ProSet, SETL2. ["Programming With Sets - An Introduction to SETL", Jacob T. Schwartz et al, Springer 1986]. 1 1 1 1 1 SETL2 SETL with more conventional Ada-like syntax, lexical scope, full block structure, first-class functions and a package and library system. Ported to OS/2, MS-DOS (3.1 up), Extended MS-DOS (80286 and higher processors with extended memory), Macintosh (with the MPW environment), Sun-3 (SunOS 4), Sun-4 (SunOS 4), IBM RS/6000 (AIX 3.1), DEC RISC product line (Ultrix 4.0), DEC Vaxen (Mt. Xinu Unix or VMS). (ftp://cs.nyu.edu/pub/languages/setl2). Please e-mail Kirk Snyder <snyder@spunky.cs.nyu.edu> if you take a copy. ["The SETL2 Programming Language", W. Kirk Snyder, Courant Inst TR 490, Jan 1990]. 1 1 1 1 1 SETL/E ProSet 1 1 1 1 1 Set Priority Level (SPL) The way traditional Unix kernels implement mutual exclusion by running code at high interrupt priority levels and thus blocking lower level interrupts. (1994-11-23) 1 1 1 1 1 SETS Set Equation Transformation System. Symbolic manipulation of Boolean equations. "Efficient Ordering of Set Expressions for Symbolic Expansion", R.G. Worrell et al, J ACM 20(3):482-488 (Jul 1973). 1 1 1 1 1 set theory A mathematical formalisation of the theory of sets (aggregates or collections) of objects ("elements" or members). Many mathematicians use set theory as the basis for all other mathematics. Mathematicians began to realise toward the end of the 19th century that just doing "the obvious thing" with sets led to embarrassing paradoxes, the most famous being Russell's Paradox. As a result, they acknowledged the need for a suitable axiomatisation for talking about sets. Numerous such axiomatisations exist; the most popular among ordinary mathematicians is Zermelo Fränkel set theory. The beginnings of set theory (http://www-groups.dcs.st-and.ac.uk/~history/HistoryTopics.html). (1995-05-10) 1 1 1 1 1 set-top box (STB) Any electronic device designed to produce output on a conventional televesion set (on top of which it nominally sits) and connected to some other communications channels such as telephone, ISDN, optical fibre or cable. The STB usually runs software to allow the user to interact with the programmes shown on the television in some way. Online Media are one STB manufacturer. (1997-05-16) 1 1 1 1 1 SEUS R. Weyrauch et al. Language allowing functions to return multiple values. Implemented but never published. Mentioned in "Evolution of Lisp", G.L. Steele et al, SIGPLAN Notices 28(3):231-270 (March 1993). 1 1 1 1 1 seven layer model Open Systems Interconnect 1 1 1 1 1 Seven-Segment Display (SSD) A kind of display element consisting of seven independently controllable lines arranged as a rectangular figure eight. A seven-segment display is the simplest device that can display any of the digits zero to nine (and some other characters) by lighting different combinations of lines. They are often seen in electronic calculators or measuring equipment. (2013-04-27) 1 1 1 1 1 SEX /seks/ [Sun Users' Group & elsewhere] 1. Software EXchange. A technique invented by the blue-green algae hundreds of millions of years ago to speed up their evolution, which had been terribly slow up until then. Today, SEX parties are popular among hackers and others (of course, these are no longer limited to exchanges of genetic software). In general, SEX parties are a Good Thing, but unprotected SEX can propagate a virus. See also pubic directory. 2. The mnemonic often used for Sign EXtend, a machine instruction found in the PDP-11 and many other architectures. The RCA 1802 chip used in the early Elf and SuperElf personal computers had a "SEt X register" SEX instruction, but this seems to have had little folkloric impact. DEC's engineers nearly got a PDP-11 assembler that used the "SEX" mnemonic out the door at one time, but (for once) marketing wasn't asleep and forced a change. That wasn't the 1 1 1 1 1 sexadecimal hexadecimal 1 1 1 1 1 sex changer gender mender 1 1 1 1 1 SEXI SNOBOL 1 1 1 1 1 Seymour Cray The founder of Cray Research and designer of several of their supercomputers. Cray has been a charismatic yet somewhat reclusive figure. He began Cray Research in Minnesota in 1972. In 1988, Cray moved his Cray-3 project to Colorado Springs. The next year, Cray Research spun it off to create Cray Computer. In 1989, Cray left Cray Research and started Cray Computer Corporation in Colorado Springs. His quest to build a faster computer using new-generation materials failed in 1995, and his bankruptcy cost half a billion dollars and more than 400 jobs. The company was unable to raise $20 million needed to finish the Cray-4 and filed for bankruptcy in March 1995. In the summer of 1996, Cray started a Colorado Springs-based company called SRC Computers, Inc. "We think we'll build computers, but who knows what kind or how," Cray said at the time. "We'll talk it over and see if we can come up with a 1 1 1 1 1 SFA Sales Force Automation 1 1 1 1 1 SFBI Shared Frame Buffer Interconnect (Intel) 1 1 1 1 1 SFD-ALGOL System Function Description-ALGOL. Extension of ALGOL for synchronous systems. Sammet 1969, p.625. 1 1 1 1 1 SFFA Sales Force Automation 1 1 1 1 1 SFL System Function Language. Assembly language for the ICL2900. SFL Language Definition Manual, TR 6413, Intl Computers Ltd. 1 1 1 1 1 SFLV Unifies logic and functional programming. SASL+LV with unification moved from actual/formal parameter matching to equational clauses. "Static Analysis of Functional Programs with Logical Variables", G. Lindstrom in Programming Languages Implementation and Logic Programming, P. Deransart et al eds, LNCS 348, Springer 1988. 1 1 1 1 1 sFTP Secure File Transfer Protocol 1 1 1 1 1 sg The country code for Singapore. (1999-01-27) 1 1 1 1 1 SGCP Simple Gateway Control Protocol 1 1 1 1 1 SGI Silicon Graphics, Inc. 1 1 1 1 1 SGML Standard Generalized Markup Language 1 1 1 1 1 sgmls Sgmls is an SGML parser derived from the ARCSGML parser materials which were written by Charles Goldfarb. It outputs a simple, easily parsed, line oriented, ASCII representation of an SGML document's Element Structure Information Set (see pp 588-593 of "The SGML Handbook"). It is intended to be used as the front end for structure-controlled SGML application programs. Version 1.1 for Unix and MS-DOS by James J. Clark <jjc@jclark.com> and Charles Goldfarb. (ftp://ftp.uu.net/pub/text-processing/sgml/sgmls-1.0.tar.Z), (ftp://ftp.jclark.com/sgmls/sgmls-1.1.tar.Z). E-mail: James Clark <jjc@jclark.com>. (1993-02-22) 1 1 1 1 1 SGML Tagger A tool to assist with adding SGML to a piece of text. The Tagger only lets the user insert a mark-up tag which is correct in that particular context. (http://www1.oup.co.uk/cite/oup/E-P/Humanities/The_SGML_Tagger/). (1997-03-18) 1 1 1 1 1 SGRAM Synchronous Graphics Random Access Memory 1 1 1 1 1 sh 1. <operating system> Bourne shell. 2. <networking> The country code for St. Helena. (1999-01-27) 1 1 1 1 1 SHA Secure Hash Algorithm 1 1 1 1 1 SHACO An early system on the IBM 701. [Listed in CACM 2(5):1959-05-16]. (1995-10-25) 1 1 1 1 1 SHADOW A syntax-directed compiler written by Barnett and Futrelle in 1962. It was the predecessor to SNOBOL(?) [Sammet 1969, p. 448, 605]. (1995-01-16) 1 1 1 1 1 shadowing aliasing 1 1 1 1 1 shadow ram A memory area in PC-AT compatibles used to store frequently accessed ROM code to speed up operation. (1995-01-16) 1 1 1 1 1 shallow binding A method of storing variable bindings where the current value of a variable can be found at a known location rather than by searching an environment or association list. When a new binding is made, the old value is copied into the environment. 1 1 1 1 1 shambolic link /sham-bol'ik link/ A Unix symbolic link, particularly when it confuses you, points to nothing at all, or results in your ending up in some completely unexpected part of the file system. [Jargon File] 1 1 1 1 1 Shape_VC A code management system which offers version control functionality similar to systems like RCS or SCCS with some extensions and a more Unix-like command interface. (1994-11-04) 1 1 1 1 1 ShapeTools A code management system for Unix from The Technical University of Berlin. (1995-05-11) 1 1 1 1 1 shar ("Shell archive", after ar and tar) Any of the many Unix programs that creates a flattened representation of one or more files, with the unique property that it can be unflattened (the original files extracted) merely by feeding it through a standard Unix shell. The output of shar, known as a "shar file" or "sharchive", can be distributed to anyone running Unix, and no special unpacking software is required. Sharchives are intriguing in that they are typically created by shell scripts; the script that produces sharchives is thus a script which produces self-unpacking scripts, which may themselves contain scripts. The disadvantage of sharchives are that they are an ideal venue for Trojan horse attacks and that, for recipients not running Unix, no simple un-sharchiving program is possible; sharchives can and do make use of arbitrarily-powerful shell features and other Unix commands. 1 1 1 1 1 sharchive shar 1 1 1 1 1 sharding A form of data partitioning in which a large database table is split over multiple servers in order to balance load (load balancing). Some property of the data is used to select which server should handle a given row, e.g. the primary id modulo the number of servers. Sharding should be a last resort in database performance optimisation because of the difficulty of changing the allocation of data to servers, e.g. if the number of servers changes or the distribution is found to be uneven. Sharding Your Database, Ovid, perl.org (http://blogs.perl.org/users/ovid/2010/05/sharding-your-database.html). (2010-05-16) 1 1 1 1 1 Share and enjoy! 1. Commonly found at the end of software release announcements and README files, this phrase indicates allegiance to the hacker ethic of free information sharing (see hacker ethic). 2. The motto of the Sirius Cybernetics Corporation (the ultimate gaggle of incompetent suits) in Douglas Adams's Hitch Hiker's Guide to the Galaxy. The irony of using this as a cultural recognition signal appeals to freeware hackers. [Jargon File] 1 1 1 1 1 shared memory 1. Memory in a parallel computer, usually RAM, which can be accessed by more than one processor, usually via a shared bus or network. It usually takes longer for a processor to access shared memory than to access its own private memory because of contention for the processor-to-memory connections and because of other overheads associated with ensuring synchronised access. Computers using shared memory usually have some kind of local cache on each processor to reduce the number of accesses to shared memory. This requires a cache consistency protocol to ensure that one processor's cached copy of a shared memory location is invalidated when another processor writes to that location. The alternative to shared memory is message passing where all memory is private to some particular processor and processors communicate by sending messages down special links. This is usually slower than shared memory but it 1 1 1 1 1 Shared Time Repair of Big Electronic Systems (STROBES) A language for computer testing. [Sammet 1969, p. 699]. (1995-02-06) 1 1 1 1 1 shareware /sheir'weir/ Software that, like freeware, can be usually obtained (downloaded) and redistributed for free, but most often is under copyright and does legally require a payment in the EULA, at least beyond the evaluation period or for commercial applications. This payment, as well as fulfilling the user's legal obligations, may buy additional support, documentation, or functionality. Generally, source code for shareware programs is not available. Shareware is sometimes also nagware and/or crippleware, which muddles the term and is frowned upon in the community. See also careware, charityware, guiltware, postcardware, and -ware; compare payware. [Jargon File] (2002-01-30) 1 1 1 1 1 shar file shar 1 1 1 1 1 sharp hash. 1 1 1 1 1 Sharp APL (Or "Dictionary APL") ["A Dictionary of the APL Language", K. Iverson, Pub 0402, Sharp Assocs, Toronto, 1985]. (ftp://watserv1.waterloo.edu/languages/apl/sharp.apl). (1997-09-02) 1 1 1 1 1 S-HDSL Single-pair High Speed Digital Subscriber Line 1 1 1 1 1 shebang (Or "shebang line", "bang path") /sh*-bang'/ (From "sharp" and "bang") The magic cookie #! used in Unix to mark the start of a script, e.g. a shell script or Perl script. Under Unix, if the first two bytes of an executable file are "#!", the kernel treats the file as a script rather than a machine code program. The word following the "!" (i.e., everything up to the first whitespace) is used as the pathname of the interpreter. For example, if the first line of an executable is #!/usr/local/bin/perl the script will be treated as a Perl script and passed as an argument to /usr/local/bin/perl to be interpreted. Some variants of Unix also allow one or more parameters to be passed to the interpreter, for example, you can write #!/usr/bin/perl -w and the script will be started as if you typed 1 1 1 1 1 SHEEP A package for symbolic mathematics, especially tensor analysis and General Relativity, developed by Inge Frick in Stockholm in the late 1970s to early 1980s. SHEEP was implemented in DEC-10 assembly language, then in several LISPs. The current version runs on Sun-3 and is based on Portable Standard LISP. ["Sheep, a Computer Algebra System for General Relativity", J.E.F. Skea et al in Proc First Brazilian School on Comp Alg, W. Roque et al eds, Oxford U Press 1993, v2]. (http://riaca.win.tue.nl/archive/can/SystemsOverview/Special/Tensoranalysis/SHEEP/index.html). (2002-12-28) 1 1 1 1 1 shelf A public library of classes for the Eiffel language. 1 1 1 1 1 shelfware /shelfweir/ Software which is never used and so ends up on the shelf. Shelfware may be purchased on a whim by an individual, or in accordance with corporate policy, but not actually required for any particular use. Alternatively, it may be software that has been developed (unlike vaporware), but is never released as a product -- a common occurrence at DEC. [Jargon File] (1997-07-20) 1 1 1 1 1 SHELL An early system on the Datatron 200 series. [Listed in CACM 2(5):16 (May 1959)]. [Jargon File] (1995-05-11) 1 1 1 1 1 shell 1. <operating system> (Originally from Multics, widely propagated via Unix) The command interpreter used to pass commands to an operating system; so called because it is the part of the operating system that interfaces with the outside world. The commonest Unix shells are the c shell (csh) and the Bourne shell (sh). 2. (Or "wrapper") Any interface program that mediates access to a special resource or server for convenience, efficiency, or security reasons; for this meaning, the usage is usually "a shell around" whatever. [Jargon File] (1995-05-11) 1 1 1 1 1 shell out [Unix] To spawn an interactive subshell from within a program (e.g. a mailer or editor). "Bang foo runs foo in a subshell, while bang alone shells out." [Jargon File] (1995-05-11) 1 1 1 1 1 shell script A program written to be interpreted by the shell of an operating system, especially Unix. Compare: script, glue language. (1999-02-22) 1 1 1 1 1 shell variable One of the variables accessible to a Unix shell process, including environment variables (e.g. $HOME), command line arguments (e.g. $1) and local variables (e.g. $input_file). Other operating systems have similar variables. (1999-01-26) 1 1 1 1 1 shielded twisted pair (STP) A kind of cable used for most Ethernet cabling, especially fast ethernet connections such as 100 Mbps. Compare: unshielded twisted pair. (1999-11-15) 1 1 1 1 1 SHIFT Scalable Heterogeneous Integrated Facility Testbed. A parallel processing project at CERN. 1 1 1 1 1 Shift In (SI, Control-O, ASCII 15) The character used on some ancient teletypes to start using an alternative character set. (1996-06-24) 1 1 1 1 1 shift left logical logical shift 1 1 1 1 1 Shift Out (SO, Control-N, ASCII 14) The character which was used to "shift out" of an alternate character set on some ancient teletypes, reversing the effect of the Shift In (SI, ASCII 15) character. (1996-06-24) 1 1 1 1 1 shift right logical logical shift 1 1 1 1 1 shim A small piece of data inserted in order to achieve a desired memory alignment or other addressing property. For example, the PDP-11 Unix linker, in split I&D (instructions and data) mode, inserts a two-byte shim at location 0 in data space so that no data object will have an address of 0 (and be confused with the C null pointer). See also loose bytes. [Jargon File] (1994-12-21) 1 1 1 1 1 shitogram /shit'oh-gram/ A *really* nasty piece of e-mail. Compare nastygram, flame. [Jargon File] (1994-12-21) 1 1 1 1 1 Shockwave A program from Macromedia for viewing files created with Macromedia Director. Shockwave is freely available as a plug-in for the Netscape Navigator web browser. Shocked pages that incorporate documents created in Director can usually only be enjoyed by users with an ISDN or faster connection. (http://macromedia.com/shockwave/). [Filetypes? More detail?] (1998-07-07) 1 1 1 1 1 shockwave The propagation of failure, shutdown, meltdown, net overload, or a virus from one network node to another, resulting in a wave of inactivity across the net. (1997-05-16) 1 1 1 1 1 Shockwave Flash Flash 1 1 1 1 1 shopbot A kind of bot that searches the World-Wide Web to find the best price for a product you're looking for. [Examples?] (1999-06-19) 1 1 1 1 1 short card A half-length IBM PC expansion card or adaptor that will fit in one of the two short slots located toward the right rear of a standard chassis (tucked behind the floppy disk drives). See also: tall card. [What bus?] [Jargon File] (1998-07-08) 1 1 1 1 1 Short Code (SHORTCODE) A pseudocode interpreter for mathematics problems, designed by John Mauchly in 1949 to execute on Eckert and Mauchly's BINAC and later on UNIVAC I and II. Short Code was possibly the first attempt at a high level language. [Sammet 1969, p. 129]. (1996-11-01) 1 1 1 1 1 shortcut Microsoft Corporation's term for a symbolic link, stored as a file with extension ".lnk". Shortcuts first appeared in 1996 in the Windows 95 operating system. Windows shortcuts can link to any file or directory ("folder"), including those on remote computers, using UNC paths. Each shortcut can also have its own icon. A shortcut that links to an executable file can pass arguments and specify the directory in which the command should run. Unlike a Unix symbolic link, a shortcut does not always behave exactly like the target file or directory. Compare pif. (2001-12-18) 1 1 1 1 1 Shorten A form of lossless audio compression. [Details?] (2001-12-17) 1 1 1 1 1 shortest job first A scheduling algorithm used in multitasking operating systems that favours processes with the shortest estimated running time. (1998-04-25) 1 1 1 1 1 Short Message Service (SMS) A message service offered by the GSM digital cellular telephone system. Using SMS, a short alphanumeric message (160 alphanumeric characters) can be sent to a mobile phone to be displayed there, much like in an alphanumeric pager system. The message is buffered by the GSM network until the phone becomes active. (1996-02-18) 1 1 1 1 1 shotgun debugging The software equivalent of Easter egging; the making of relatively undirected changes to software in the hope that a bug will be perturbed out of existence. This almost never works, and usually introduces more bugs. [Jargon File] 1 1 1 1 1 shoulder surfing Secretly watching someone perform some supposedly secure action; looking over their shoulder. The canonical example is watching what keys someone presses when they enter a password. Other examples include using binoculars to watch someone across the street enter their PIN in a cash machine or simply reading sensitive information off somebody's screen without them realising. (2013-11-06) 1 1 1 1 1 shovelware /shuh'v*l-weir"/ Extra software dumped onto a CD-ROM or tape to fill up the remaining space on the medium after the software distribution it's intended to carry, but not integrated with the distribution. 1 1 1 1 1 Show-And-Tell A visual dataflow language designed for use by elementary school children. ["A Visual Language for Keyboardless Programming", T. Kimura et al, TR WUCS-86-6, CS Dept Washington U, Mar 1986]. ["Show and Tell: A Visual Language", T.D. Kimura et al in Visual Programming Environments: Paradigms and Systems, E.P. Glinert ed, IEEE Comp Sci Press, 1990, pp. 397-404]. (1995-01-31) 1 1 1 1 1 showstopper A hardware or (especially) software bug that makes an implementation effectively unusable; one that absolutely has to be fixed before development can go on. Opposite in connotation from its original theatrical use, which refers to something stunningly *good*. [Jargon File] (1995-01-31) 1 1 1 1 1 shriek exclamation mark 1 1 1 1 1 shrug report A bug report with no error message or reproduction steps and only a vague description of the problem. Usually contains the phrase "doesn't work." [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)] (2012-02-04) 1 1 1 1 1 sht server-parsed HTML 1 1 1 1 1 SHTF shit hit the fan 1 1 1 1 1 shtml server-parsed HTML 1 1 1 1 1 Shub-Internet /shuhb in't*r-net/ (MUD, from H. P. Lovecraft's evil fictional deity "Shub-Niggurath", the Black Goat with a Thousand Young) The harsh personification of the Internet, Beast of a Thousand Processes, Eater of Characters, Avatar of Line Noise, and Imp of Call Waiting; the hideous multi-tendriled entity formed of all the manifold connections of the net. A sect of MUDders worships Shub-Internet, sacrificing objects and praying for good connections. To no avail - its purpose is malign and evil, and is the cause of all network slowdown. Often heard as in "Freela casts a tac nuke at Shub-Internet for slowing her down." (A forged response often follows along the lines of: "Shub-Internet gulps down the tac nuke and burps happily.") Also cursed by users of FTP and telnet when the system slows down. The dread name of Shub-Internet is seldom spoken aloud, as it is said that repeating it three times will cause the being to wake, deep within its lair beneath the Pentagon. 1 1 1 1 1 SHUG Scottish Hypermedia Users' Group 1 1 1 1 1 Shugart, Alan F. Alan F. Shugart 1 1 1 1 1 Shugart Associates The disk drive company, founded by Alan F. Shugart, which developed SCSI. Alan left Shugart Associates in 1974 [did he quit or was he fired?]. Shugart Associates was bought, and eventually shut down by Xerox. (2000-02-09) 1 1 1 1 1 Shugart Technology Seagate Technology 1 1 1 1 1 SI 1. <unit> Système International. 2. <character> Shift In. 1 1 1 1 1 si The country code for Slovenia. (1999-01-27) 1 1 1 1 1 SIA Serial Interface Adaptor 1 1 1 1 1 SIBO SIxteen Bit Organisers 1 1 1 1 1 SICL Standard Instrument Control Library 1 1 1 1 1 SICS Swedish Institute for Computer Science 1 1 1 1 1 SICStus Prolog A Prolog from the SICS (Swedish Inst of Comp Sci). E-mail: <sicstus-request@sics.se>. Mailing list: sicstus-users@sics.se. (1995-01-05) 1 1 1 1 1 sidecar 1. Synonym slap on the side. Especially used of add-ons for the late and unlamented IBM PCjr. 2. The IBM PC compatibility box that could be bolted onto the side of an Amiga. Designed and produced by Commodore, it broke all of the company's own design rules. If it worked with any other peripherals, it was by magic. [Jargon File] 1 1 1 1 1 side-effect A language construct that modifies the state of the system. The most common side-effects are assignment, input and output. A language without side-effects is purely-functional - execution consists of the evaluation of an expression and all subexpressions are referentially transparent. (1995-02-16) 1 1 1 1 1 Siemens A German semiconductor and electronics manufacturer. (http://siemens.de/). [Summary?] (1995-07-26) 1 1 1 1 1 Siemens Nixdorf Informationssteme, AG (SNI) A separate company within Siemens, the largest IT company in Europe. SNI sells the BS2000 operating system, a wide variety of databases, servers and other products. (1997-06-13) 1 1 1 1 1 Sierra (Or "Sierra On-Line") A computer game developer founded in the early 1980s by Ken and Roberta Willams in the small mountain town of Oakhurst California. Sierra was named after the local mountian range, 15 miles from the famous Yosemite National Park. In 1997 Sierra was purchased by CUC and its main office is now in Seattle, WA, USA. Products include Kings Quest, Space Quest, Police Quest, Quest for Glory, Robin Hood, Phantasmagoria, Leisure Suit Larry, Eco Quest and many more. (http://sierra.com /). (1997-11-23) 1 1 1 1 1 SIFT SHARE Internal Fortran Translator. Translation utility designed for converting Fortran II to Fortran IV. The word sift was often used as a verb to describe converting code from one language to another. Sammet 1969, p.153. 1 1 1 1 1 SIG Special Interest Group 1 1 1 1 1 Sig Signal Processing, Analysis, and Display program. An environment with an associated programming language by Jan Carter of Argonne National Lab. Telephone +1 (312) 972 7250 [Jargon File] 1 1 1 1 1 sig signature 1 1 1 1 1 sig block /sig blok/ [Unix; often written ".sig" there]. See signature. [Jargon File] 1 1 1 1 1 SIGBUS bus error 1 1 1 1 1 SIGhyper Special Interest Group on Hypertext and Multimedia of the SGML Users' Group. 1 1 1 1 1 SIGLA SIGma LAnguage. A language for industrial robots from Olivetti. ["SIGLA: The Olivetti Sigma Robot Programming Language", M. Salmon, Proc 8th Intl Symp on Industrial Robots, 1978, pp. 358-363]. 1 1 1 1 1 SIGMA A scientific visual programming environment from NASA. (http://fi-www.arc.nasa.gov/fia/projects/sigma/). 1 1 1 1 1 SIGNAL A synchronous language by Le Guernic et al of INRIA. ["SIGNAL - A Data Flow-Oriented Language for Signal Processing," P. le Guernic, IEEE Trans Acoustics Speech & Signal Proc, ASSP-34(2):362-1986-04-374]. (1996-12-10) 1 1 1 1 1 signal A predefined message sent between two Unix processes or from the kernel to a process. Signals communicate the occurrence of unexpected external events such as the forced termination of a process by the user. Each signal has a unique number associated with it and each process has a signal handler set for each signal. Signals can be sent using the kill system call. (1996-12-10) 1 1 1 1 1 signalling rate The number of times per second the amplitude, frequency or phase of the signal transmitted down a communications channel changes each second. The signalling rate is measured in baud. (1998-02-14) 1 1 1 1 1 Signalling System 7 (SS7) A protocol suite used for communication with, and control of, telephone central office switches and their attached processors. (1995-03-01) 1 1 1 1 1 signal-to-noise ratio 1. <communications> (SNR, "s/n ratio", "s:n ratio") "Signal" refers to useful information conveyed by some communications medium, and "noise" to anything else on that medium. The ratio of these is usually expressed logarithmically, in decibels. 2. <networking> The term is often applied to Usenet newsgroups though figures are never given. Here it is quite common to have more noise (inappropriate postings which contribute nothing) than signal (relevant, useful or interesting postings). The signal gets lost in the noise when it becomes too much effort to try to find interesting articles among all the crud. Posting "noise" is probably the worst breach of netiquette and is a waste of bandwidth. [Jargon File] (1996-01-29) 1 1 1 1 1 signature 1. A set of function symbols with arities. 2. <messaging> (Or sig) A few lines of information about the sender of an electronic mail message or news posting. Most Unix mail and news software will automagically append a signature from a file called .signature in the user's home directory to outgoing mail and news. A signature should give your real name and your e-mail address since, though these appear in the headers of your messages, they may be munged by intervening software. It is currently (1994) hip to include the URL of your home page on the web in your sig. The composition of one's sig can be quite an art form, including an ASCII logo or one's choice of witty sayings (see sig quote, fool file). However, large sigs are a waste of bandwidth, and it has been observed that the size of one's sig block is usually inversely proportional to one's prestige on the net. 1 1 1 1 1 sig quote /sig kwoht/ A maxim, quote, proverb, joke, or slogan embedded in one's sig block (as used in Usenet news) and intended to convey something of one's philosophical stance, pet peeves, or sense of humour. "Calm down, it's only ones and zeroes." [Jargon File] (1994-11-04) 1 1 1 1 1 sig virus A parasitic meme embedded in a sig block. There was a meme plague or fad for these on Usenet in late 1991. Most were equivalents of "I am a .sig virus. Please reproduce me in your .sig block.". Of course, the .sig virus's memetic hook is the giggle value of going along with the gag; this, however, was a self-limiting phenomenon as more and more people picked up on the idea. There were creative variants on it; some people stuck "sig virus antibody" texts in their sigs, and there was at least one instance of a sig virus eater. [Jargon File] 1 1 1 1 1 SIL 1. "SIL - A Simulation Language", N. Houbak, LNCS 426, Springer 1990. 2. SNOBOL Implementation Language. Intermediate language forming a virtual machine for the implementation of portable interpreters. ["The Design of Transportable Interpreters", F. Druseikis, SNOBOL4 Project Document S4D49, U Arizona (Feb 1975)]. Version 3.11. (ftp://cs.arizona.edu/snobol4/). E-mail: <snobol4@arizona.edu>. (1986-07-29) 1 1 1 1 1 Silage Synchronous DSP specification language. ["Silage Reference Manual, Draft 1.0", D.R. Genin & P.N. Hilfinger, Silvar-Lisco, Leuven 1989]. 1 1 1 1 1 silicon 1. <electronics> The material used as the base (or substrate) for most integrated circuits. 2. <jargon> Hardware, especially integrated circuits or microprocessor-based computer systems (compare iron). Contrast: software. See also sandbender. [Jargon File] (1996-05-28) 1 1 1 1 1 silicon chip integrated circuit 1 1 1 1 1 Silicon Graphics, Inc. (SGI) Manufacturer of workstations and software for graphics and image processing. SGI was founded by Dr. James H. Clark, who left some time before May 1994 to head Mosaic Communications Corporation. Quarterly sales $433M, profits $44M (Aug 1994). (http://sgi.com/). (1994-09-26) 1 1 1 1 1 Siliwood (Or "Hollywired") The coming convergence of film, interactive TV and computers. (1999-01-15) 1 1 1 1 1 silly walk [Monty Python's Flying Circus] 1. A ridiculous procedure required to accomplish a task. Like grovel, but more random and humorous. "I had to silly-walk through half the /usr directories to find the maps file." 2. Synonym fandango on core. [Jargon File] 1 1 1 1 1 silo The FIFO input-character buffer in an EIA-232 serial line card. So called from DEC terminology used on DH and DZ line cards for the VAX and PDP-11, presumably because it was a storage space for fungible stuff that went in at the top and came out at the bottom. 1 1 1 1 1 Silver Book Jensen and Wirth's infamous "Pascal User Manual and Report", so called because of the silver cover of the widely distributed Springer-Verlag second edition of 1978 (ISBN 0-387-90144-2). See also book titles, Pascal. [Jargon File] (1996-12-03) 1 1 1 1 1 silver bullet magic bullet 1 1 1 1 1 SIM Subscriber Identity Module 1 1 1 1 1 SIMAN SIMulation ANalysis 1 1 1 1 1 SimCity Maxis Software's simulation game which lets you design and build your own city, which must be administered well if it is to thrive. Land must be zoned, transportation systems built, and police and fire protection provided. Once you've zoned some land, and provided electrical power, the simulation takes over, and simcitizens move in. If you perform your mayoral duties poorly, however, they will move out again. If you don't provide enough police, crime will rise and sims will vote with their feet. Try to save money on fire protection, and your city may burn to the ground. There is no predefined way to win the game, building the largest city you can is just one possible strategy. SimCity runs on Archimedes, Amiga, Atari ST, IBM PC and Macintosh. There was also a NeWS version for Sun SPARC workstations running OpenWindows. SimCity 2000 is an upgrade of SimCity. (1995-06-11) 1 1 1 1 1 SimCity 2000 An upgraded version of the game/simulation SimCity by Maxis Software. In the new version you can raise, lower and level terrain; build roads and railways at 45-degree angles; name things in your city by planting "signs"; build raised highways, subways, and train and bus stations, schools, colleges, hospitals, electricity, water, recreational marinas and zoos. There are three levels of zoom, and the view may be rotated to look at your city from any of the four directions. A query feature which will tell you the zoning, land value, etc. of any square. You get newspapers, advice from council members, graphs, and charts. (1995-02-08) 1 1 1 1 1 SIMD Single Instruction/Multiple Data 1 1 1 1 1 Similix An autoprojector (self-applicable partial evaluator) for a higher order subset of the strict functional language Scheme. Similix handles programs with user defined primitive abstract data type operators which may process global variables (such as input/output operators). Version 5.0. Anders Bondorf <anders@diku.dk> conformance: extension of large subset of R4RS Scheme. requires: Scheme ports: Scm, Chez Scheme portability: high E-mail: Anders Bondorf <anders@diku.dk> (ftp://ftp.diku.dk/pub/diku/dists/Similix.tar.Z). (1993-05-18) 1 1 1 1 1 SIML/I Simulation language, descendant of ASPOL. ["The Simulation Language SIML/I", M.H. MacDougall, Proc NCC 1979, pp. 39-44]. 1 1 1 1 1 SIMM Single in-line memory module 1 1 1 1 1 Simone A simulation language by A. Hoare et al. based on Pascal. ["Quasiparallel Programming", W.H. Kaubisch et al, Soft Prac & Exp 6:341-356 1976]. [C.A.R. Hoare?] (1996-01-18) 1 1 1 1 1 Simonyi, Charles Charles Simonyi 1 1 1 1 1 SIMPAC Early simulation language with fixed time steps. Simpac User's Manual, R.P. Bennett et al, TM-602/000/000, Sys Devel Corp, Apr 1962. 1 1 1 1 1 SIMPAS Event scheduling language, implemented as Pascal preprocessor. SIMPAS - A Simulation Language Based on Pascal, R.M. Bryant in Proc 1980 Winter Sim Conf, T.I Oren et al eds, pp.559-572. 1 1 1 1 1 SIMPL Simulation language, descendant of OPS-4, compiled into PL/I on Multics. The SIMPL Primer, M.W. Jones et al, Oct 1971. 1 1 1 1 1 SIMPLE 1. Early system on Datatron 200 series. Listed in CACM 2(5):16 (May 1959). 2. Simulation of Industrial Management Problems with Lots of Equations. R.K. Bennett, 1958. Predecessor to DYNAMO, for IBM 704. 1 1 1 1 1 Simple Actor Language (SAL) A minimal actor language, used for teaching in: ["Actors, A Model of Concurrent Computation in Distributed Systems", G. Agha, MIT Press 1986]. (1994-12-08) 1 1 1 1 1 Simple Authentication and Security Layer (SASL) (http://asg2.web.cmu.edu/sasl/). [Summary?] (2001-08-24) 1 1 1 1 1 Simple Gateway Control Protocol (SGCP) An IETF work in progress, superseded by MGCP. (1999-04-26) 1 1 1 1 1 Simple Mail Transfer Protocol (SMTP) A protocol defined in STD 10, RFC 821, used to transfer electronic mail between computers, usually over Ethernet. It is a server to server protocol, so other protocols are used to access the messages. The SMTP dialog usually happens in the background under the control of the message transfer agent, e.g. sendmail but it is possible to interact with an SMTP server using telnet to connect to the normal SMTP port, 25. E.g. telnet mhs-relay.ac.uk 25 You should normally start by identifying the local host: HELO wombat.doc.ic.ac.uk You can then issue commands to verify an address or expand an alias: VRFY fred@doc.ic.ac.uk 1 1 1 1 1 simple multicast protocol A proposed mulitcast protocol that would ease the requirements for IP Multicast, such as no longer mandating that routers be able to calculate the source of a multicast stream. This has not been adopted by the IETF. (http://infoworld.com/cgi-bin/displayStory.pl?981125.whmulti.htm). [Reference?] (2001-07-02) 1 1 1 1 1 Simple Network Management Protocol (SNMP) The Internet standard protocol, defined in STD 15, RFC 1157, developed to manage nodes on an IP network. SNMP is not limited to TCP/IP. It can be used to manage and monitor all sorts of equipment including computers, routers, wiring hubs, toasters and jukeboxes. See also Management Information Base, Simple Network Management Protocol version 2. (1995-02-15) 1 1 1 1 1 Simple Network Management Protocol version 2 (SNMP v2) A revision of Simple Network Management Protocol (not just a new MIB) which includes improvements in the areas of performance, security, confidentiality, and manager-to-manager communications. The major components of SNMPv2 are defined in the following RFCs: RFC 1089 - SNMP over Ethernet RFC 1140 - IAB Official Protocol Standards RFC 1155 - Structure and Identification of Management Information for TCP/IP based internets RFC 1156 (H) - Management Information Base Network Management of TCP/IP based internets RFC 1157 - A Simple Network Management Protocol RFC 1158 - Management Information Base Network 1 1 1 1 1 Simple Network Paging Protocol (SNPP) A standard for sending one- and two-way wireless messages to pagers. In its simplest form, SNPP provides a simple way to make a link between the Internet and a Telocator Alphanumeric input Protocol (TAP) paging terminal. SNPP is defined in RFC 1861. (1997-04-25) 1 1 1 1 1 Simple Object Access Protocol (SOAP) A minimal set of conventions for invoking code using XML over HTTP. DevelopMentor, Microsoft Corporation, and UserLand Software submitted SOAP to the IETF as an internal draft in December 1999. Latest version: SOAP 1.1 defined by World Wide Web Consortium. (http://w3.org/TR/SOAP/). (2000-01-08) 1 1 1 1 1 simplex 1. <communications> Used to describe a communications channel that can only ever carry a signal in one direction, like a one-way street. Television is an example of (broadcast) simplex communication. Opposite: duplex. 2. <algorithm> The simplex method. (2001-07-21) 1 1 1 1 1 simplex method An algorithm for solving the classical linear programming problem; developed by George B. Dantzig in 1947. The simplex method is an iterative procedure, solving a system of linear equations in each of its steps, and stopping when either the optimum is reached, or the solution proves infeasible. The basic method remained pretty much the same over the years, though there were many refinements targeted at improving performance (eg. using sparse matrix techniques), numerical accuracy and stability, as well as solving special classes of problems, such as mixed-integer programming. (2003-07-09) 1 1 1 1 1 simplex printer A term applied by Western Union Telegraph Company to teletypewriters that are not part of a multiplex system. They usually provided for alternate transmission in both directions. If working simplex or half-duplex, what was keyed in at the keyboard would be typed out at the printing portion. If working full-duplex, sending would be blind as the printing portion was being used only for reception. (2000-04-02) 1 1 1 1 1 SIMPL/I A simulation language implemented as a PL/I preprocessor. ["SIMPL/I (Simulation Language Based on PL/I). Program Reference Manual", IBM SH19- 5060-0 (June 1972)]. (1994-12-07) 1 1 1 1 1 Simplified Multicast Routing Protocol (SMRP) A transport-layer protocol to route multimedia data streams over AppleTalk networks. SMRP supports Apple's QuickTime Conferencing (QTC). Documentation (http://cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/smrp.htm). (2001-07-02) 1 1 1 1 1 SIMPL-T The base language for a family of languages and compilers. ["SIMPL-T, A Structured Programming Language", V.R. Basili, Paladin House 1976]. (1994-12-07) 1 1 1 1 1 SIMSCRIPT A free-form, English-like general-purpose simulation language produced by Harry Markowitz et al of Rand Corp in 1963. It was implemented as a Fortran preprocessor on IBM 7090 and was designed for large discrete simulations. It influenced Simula. Later versions included SIMSCRIPT I.5 and SIMSCRIPT II.5. 1 1 1 1 1 SIMSCRIPT I.5 A version of SIMSCRIPT developed at CACI in 1965. It produced assembly language. 1 1 1 1 1 SIMSCRIPT II.5 Another version of SIMSCRIPT from CACI. ["SIMSCRIPT: A Simulation Programming Language", P.J. Kiviat et al, CACI, 1973]. 1 1 1 1 1 simship simultaneous shipment 1 1 1 1 1 SIMULA SIMUlation LAnguage. See Lund Simula, SIMULA 67, SIMULA I. See also Association for SIMULA Users, C++SIM, FLEX, MODSIM, SIMSCRIPT. A simula-to-C compiler project is underway. E-mail: Harald Thingelstad <harald.thingelstad@basalmed.uio.no>. Usenet newsgroup: news:bit.listserv.simula. (1995-03-29) 1 1 1 1 1 SIMULA 67 A version of SIMULA I? Association for SIMULA Users Simula a.s., Postboks 4403 - Torshov, N-0402 Oslo 4, Norway, versions for almost every computer. E-mail: Henry Islo <hio@helios.sunet.se>. (ftp:/lund.se:/mac/misc/simula/), (ftp://ftp.fenk.wau.nl/pub/simula/compilers), (ftp://ftp.ifi.uio.no/cim/). ["Object-Oriented Programming with SIMULA", Bjorn Kirkerud, A-W 1989]. ["Data Processing - Programming Languages - SIMULA", Swedish Standard SS 63 61 14 (1987), available through ANSI]. [Difference from SIMULA I?] (1995-03-29) 1 1 1 1 1 SIMULA I SIMUlation LAnguage. An extension to ALGOL 60 for the Univac 1107 designed in 1962 by Kristen Nygaard and Ole-Johan Dahl and implemented in 1964. SIMULA I was designed for discrete simulation. It introduced the record class, leading the way to data abstraction and object-oriented programming languages like Smalltalk. It also featured coroutines. SIMULA's philosophy was the result of addressing the problems of describing complex systems for the purpose of simulating them. This philosophy proved to be applicable for describing complex systems generally (not just for simulation) and so SIMULA is a general-purpose object-oriented application programming language which also has very good discrete event simulation capability. Virtually all OOP products are derived in some manner from SIMULA. For a description of the evolution of SIMULA and therefore the fundamental concepts of OOP, see Dahl and Nygaard in ["History 1 1 1 1 1 simulate simulation 1 1 1 1 1 simulated annealing A technique which can be applied to any minimisation or learning process based on successive update steps (either random or deterministic) where the update step length is proportional to an arbitrarily set parameter which can play the role of a temperature. Then, in analogy with the annealing of metals, the temperature is made high in the early stages of the process for faster minimisation or learning, then is reduced for greater stability. 1 1 1 1 1 Simulating Digital Systems Fortran-like language for describing computer logic design. Sammet 1969, p.622. 1 1 1 1 1 simulation Attempting to predict aspects of the behaviour of some system by creating an approximate (mathematical) model of it. This can be done by physical modelling, by writing a special-purpose computer program or using a more general simulation package, probably still aimed at a particular kind of simulation (e.g. structural engineering, fluid flow). Typical examples are aircraft flight simlators or electronic circuit simulators. A great many simulation languages exist, e.g. Simula. See also emulation, Markov chain. (1995-02-23) 1 1 1 1 1 SIMulation ANalysis (SIMAN) A simulation language, especially for manufacturing systems, developed by C. Dennis Pegden in 1983. ["Introduction to Simulation using SIMAN", C.D. Pegden et al, McGraw-Hill 1990]. (1999-01-13) 1 1 1 1 1 Simulation Language for Alternative Modeling (SLAM) A simulation language descended from GASP. Implemented as a Fortran preprocessor. 1 1 1 1 1 Simulation Oriented Language (SOL) An ALGOL extension for discrete simulation by Donald Knuth and McNeley. ["SOL - A Symbolic Language for General Purpose System Simulation", D.E. Knuth et al, IEEE Trans Elec Comp, EC-13(4):401-408 (Aug 1964)]. [Sammet 1969, p. 656]. (1995-07-26) 1 1 1 1 1 Simultaneous Engineering Environment (SEE) A CAE framework from DAZIX. (1994-11-03) 1 1 1 1 1 Simultaneous Peripheral Operation On-Line (SPOOL) Accessing peripheral devices with the help of an off-line tape drive. The term was derived by IBM for use with the IBM 360 operating systems. In the early days of computing (early 1960s), before multitasking was invented, computers (e.g. IBM 704) could run only one job at a time. As peripheral devices such as printers or card readers were much slower than the CPU, devoting the computer (the only computer in many cases) to controlling such devices was impractical. To free the CPU for useful work, the output was sent to a magnetic tape drive, which was much faster than a printer and much cheaper than a computer. After the job was finished the tape was removed from the tape drive attached to the computer and mounted on a tape drive connected to a printer (such as the IBM 1403). The printer could then print the data without holding up the computer. Similarly, instead of 1 1 1 1 1 simultaneous shipment (simship) The release of international, localised versions of software at the same time, or within a short period of time of the original release. Major software publishers can release as many as 30 different localised versions within a month or two of the original version. These products may have thousands of pages of documentation. (1999-06-09) 1 1 1 1 1 Simware, Inc. The producers of REXXWARE. E-mail: <rexxware@simware.com>. Address: Ottawa, Canada. (1995-01-11) 1 1 1 1 1 SINA ["An Implementation of the Object-Oriented Concurrent Programming Language SINA", A. Tripathi et al, Soft Prac & Exp 19(3):235-256 (1989)]. 1 1 1 1 1 since time T equals minus infinity A long time ago; for as long as anyone can remember; at the time that some particular frob was first designed. Usually the word "time" is omitted. See also time T; contrast epoch. [Jargon File] 1 1 1 1 1 Sinclair, Clive Clive Sinclair 1 1 1 1 1 Sinclair PC200 (http://nonowt.demon.co.uk/magfold/articfol/the_miss.htm). [Summary?] 7/28/98 1 1 1 1 1 Sinclair Radionics Sinclair Research 1 1 1 1 1 Sinclair Research A British microelectronics developer and manufacturer. Evolving from Sinclair Radionics in 1979, Sinclair Research was owned by Sir Clive Sinclair. Sinclair Radionics produced electronic components and devices (such as calculators and pocket radios and televisions), but Sinclair Research began by producing some of the first 8-bit home microcomputers. Sinclair produced five microcomputers from 1980 to 1987, all based on the Zilog Z80 microprocessor (except for the QL, which used the Motorola 68008 - a variant on the 68000). The 1K kit-build ZX80, introduced in 1980, was followed by the 1K ZX81 (expandable to 16K) in 1981, the 16K (expandable to 48K) ZX Spectrum in 1982 (then superseded by two distinct 48K models and a 128K model in 1986) and the QL (Quantum Leap) in 1984. A portable laptop computer, the Z88, was released in 1987 under the Cambridge Computers banner. 1 1 1 1 1 sine wave A waveform of a single constant frequency and amplitude that continues for all time. Compare wavelet. (1994-11-09) 1 1 1 1 1 single assignment A property of variables in a functional language. If a variable is only assigned a value once then an instance of that variable is thereafter semantically equivalent to the value. SISAL is an example of a language with this property. See also zero assignment. (2003-12-22) 1 1 1 1 1 single assignment language Any programming language with the single assignment property. (2007-03-21) 1 1 1 1 1 single-attached Connected to only one of the two rings of an FDDI network. This is the kind of connection normally used for a host computer, as opposed to routers and concentrators which are normally "dual-attached". (1994-12-13) 1 1 1 1 1 Single Connection Attach (SCA, "Single Connector Attachment") A non-standard type of SCSI connector, used mostly by OEMs, which carries both power and data on one 80-pin connector. SCA SCSI drives tend to be cheaper but use with standard SCSI cables requires an adaptor and external termination. (http://pcmech.com/show/harddrive/152/). (2003-06-21) 1 1 1 1 1 Single Connector Attachment Single Connection Attach 1 1 1 1 1 Single Data Rate Random Access Memory (SDR-RAM, SDR-SDRAM, Single Data Rate Synchronous Dynamic Random Access Memory) RAM or SDRAM that transfers data on only one clock transition (0-1 or 1-0), in contrast to DDR-RAM. (2001-05-24) 1 1 1 1 1 Single Data Rate Synchronous Dynamic Random Access Memory Single Data Rate Random Access Memory 1 1 1 1 1 Single Document Interface (SDI) A limitation applying to an application program that only shows a single windows giving a view of one document at a time. The opposite is Multiple Document Interface (MDI). (1999-03-30) 1 1 1 1 1 single-duplex (From telegraphy) A full-duplex link with one telegrapher at each end, transmitting alternately in each direction. (2000-03-30) 1 1 1 1 1 Single Edge Contact (SEC) The type of cartridge in which a Pentium II is packaged. [Other uses?] (1999-02-15) 1 1 1 1 1 Single Edge Contact Cartridge (SEC, SECC) The cased daughterboard housing Intel's Pentium II, Pentium III, and Xeon microprocessors. A SECC fits into a Slot 1 or Slot 2 connector. [SECC 2?] (1999-08-05) 1 1 1 1 1 Single Edge Processor Package (SEPP) The caseless daughterboard containing Intel's Celeron processor. A SEPP fits into a Slot 1 connector. (1999-08-04) 1 1 1 1 1 single-electron transistor quantum dot 1 1 1 1 1 Single Electron Tunneling (SET) A New electrical standard for capacitance. SET devices can be used to construct circuits which process information by manipulating individual electrons. SET devices are small, dissipate little power, and can detect exquisitely small quantities of charge. The small size and low power dissipation of SET circuits makes them potentially useful for the Information Technology industry. (1999-01-06) 1 1 1 1 1 Single Electron Tunneling Technology A neural network hardware concept based on single electron tunneling. Single electron tunneling transistors have some properties which make them attractive for neural networks, among which their small size, low power consumption and potentially high speed. Simulations have been performed on some small circuits of SET transistors that exhibit functional properties similar to those required for neural networks. (http://computer.org/conferen/proceed/mn96/ABSTRACT.HTM#125). [Proceedings of the Fifth International Conference on Microelectronics for Neural Networks and Fuzzy Systems (MicroNeuro '96). Martijn J. Goossens, Chris J.M. Verhoeven, and Arthur H.M. van Roermund]. (1999-01-06) 1 1 1 1 1 single ended An electrical connection where one wire carries the signal and another wire or shield is connected to electrical ground. This is in contrast to a differential connection where the second wire carries an inverted signal. 1 1 1 1 1 Single Image Random Dot Stereogram (SIRDS, originally "autostereogram") A stereogram composed of (coloured) dots which when viewed correctly appears three-dimensional. SIRDs were invented by Dr. Christoper Tyler, Associate Director of the Smith-Kettlewell Eye Research Institute in San Francisco (1999). FAQ (http://cs.waikato.ac.nz/~singlis/sirds.html). Nice pictures (http://eleves.ens.fr:8080/home/massimin/index.ang.html). Picture Gallery (http://h2.ph.man.ac.uk/gareth/sirds.html). Vern Hart's SIRDS Gallery (http://vern.com/). SGI Gallery (http://sgi.com/free/gallery.html). (1996-11-06) 1 1 1 1 1 single inheritance In object-oriented programming, the restriction that a class can have only one superclass in the class hierarchy. The opposite is multiple inheritance. (2014-09-06) 1 1 1 1 1 Single In-line Memory Module (SIMM) A small circuit board or substrate, typically about 10cm x 2cm, with RAM integrated circuits or die on one or both sides and a single row of pins along one long edge. Several SIMMs are mounted with their substrates at right-angles to the main circuit board (the motherboard). This configuration allows greater packing density than direct mounting of, e.g. DIL (dual in-line) RAM packages on the motherboard. In 1993 one SIMM typically held one or four megabytes, by early 1997 one could hold 8, 16, or 32 MB. (1997-01-05) 1 1 1 1 1 Single Inline Pin Package (SIPP) An integrated circuit package with a single line of pins. Compare Dual Inline Package, Single In-line Memory Module. (1995-03-01) 1 1 1 1 1 Single Instruction Multiple Data Single Instruction/Multiple Data 1 1 1 1 1 Single Instruction/Multiple Data (SIMD) (Or "data parallel") The classification under Flynn's taxonomy for a parallel processor where many processing elements (functional units) perform the same operations on different data. There is often a central controller which broadcasts the instruction stream to all the processing elements. Contrast Multiple Instruction/Multiple Data. (1994-11-04) 1 1 1 1 1 Single-line Digital Subscriber Line (SDSL, or Single-pair High Speed Digital Subscriber Line, S-HDSL) A form of Digital Subscriber Line similar to HDSL but providing T1 or E1 connections over a single twisted-pair copper line. (1998-05-18) 1 1 1 1 1 single-page web application A web site that behaves more like an application program in that, instead of clicking a link causing the web browser to load a whole new web page, changes of state are performed by JavaScript running in the web browser fetching new content or data from the web server and using it to update (parts of) the existing page. This is often done via a protocol like AJAX. This way of working allows the browser to maintain the user's session state more easily and minimise the amount of data that needs to be downloaded and rendered thus largely eliminating the delay incurred when moving from page to page in a traditional web site. Gmail is a well-known example of a single-page web application. (2014-11-27) 1 1 1 1 1 Single-pair High Speed Digital Subscriber Line Single-line Digital Subscriber Line 1 1 1 1 1 single program/multiple data (SPMD) A kind of parallel processing where the same program is run on multiple processors. Every instance of the program knows which part of the computation it should perform and the results of the computation are combined somehow. (2002-04-21) 1 1 1 1 1 single quote "'" ASCII character 39. Common names include single quote; quote; ITU-T: apostrophe. Rare: prime; glitch; tick; irk; pop; INTERCAL: spark; ITU-T: closing single quotation mark; ITU-T: acute accent. Single quote is used in C and derived languages to introduce a single character literal value which is represented internally by its ASCII code. In the Unix shells and Perl single quote is used to delimit strings in which variable substitution is not performed (in contrast to double-quote-delimited strings). Single quote is often used in text for both open and close single quotation mark and apostrophe. Typesetters use two different symbols - open has a tail going up, close and apostrophe have tails hanging down (like a raised comma). Some people use back quote (`) for open single quotation mark. (1998-04-04) 1 1 1 1 1 single sign-on (SSO) Any user authentication system permiting users to access multiple data sources through a single point of entry. Part of an integrated access management framework. (2003-12-31) 1 1 1 1 1 single sourcing Using a single original document set to generate dead tree and on-line documentation, and usually also on-line help. In practice, it most often refers to a FrameMaker file set with conditional text which, when the conditions are set appropriately, allows you to create variants of the original document (e.g., for a product that runs on different Unix platforms) as well as for different media -- typically task-oriented on-line help to be accessed under Microsoft Windows or from a web browser, linear printed document, and HTML delivered via the WWW and/or CD-ROM. 1 1 1 1 1 single static assignment (Also known as SSA form) A special form of code where each variable has only one single definition in the program code. "Static" comes from the fact that the definition site may be in a loop, thus dynamically executed several times. SSA form is used for program optimization or static analysis and optimisation. (2003-04-12) 1 1 1 1 1 singleton variable A variable which is only referred to once in a piece of code, probably because of a programming mistake. To be useful, a variable must be set and read from, in that order. If it is only referred to once then it cannot be both set and read. There are various exceptions. C-like assignment operators, e.g. "x += y", read and set x and return its new value (they are abbreviations for "x = x+y", etc). A function argument may be passed only for the sake of uniformity or to support future enhancements. A good compiler or a syntax checker like lint should report singleton variables but also allow specific instances to be marked as deliberate by the programmer. (1997-12-20) 1 1 1 1 1 Single Virtual Storage OS/VS2 1 1 1 1 1 siod (Scheme In One Defun or Scheme In One Day) A small Scheme implementation in C by George Carrette <gjc@world.std.com>, <gjc@mitech.com>. SIOD is arranged as a set of subroutines that can be called from any main program for the purpose of introducing an interpreted extension language. It compiles to 20 kbytes of executable (VAX/VMS). Lisp calls C and C calls Lisp transparently. SIOD supports symbols, strings, arrays, hash coding, file i/o (binary, text, seek), data save/restore in binary and text, interface to commercial databases such Oracle and Digital RDB. Version 3.0 runs on VAX/VMS,Unix, Sun-3, Sun-4, Amiga, Macintosh, MIPS, Cray, ALPHA/VMS, Windows NT and OS/2. It can be compiled by most ANSI C compilers and C++ compilers, e.g. gcc -Wall. (ftp://world.std.com/pub/gjc/), 1 1 1 1 1 SIP 1. <protocol> Session Initiation Protocol. 2. <text, standard> Supplementary Ideographic Plane. (2003-12-26) 1 1 1 1 1 SIPB Student Information Processing Board, MIT. (http://mit.edu:8001/afs/athena.mit.edu/user/r/e/rei/WWW/GAME/sipbroom.html). 1 1 1 1 1 SIPLAN SIte PLANning computer language. Interactive language for space planning. "Formal Languages for Site Planning", C.I. Yessios in Spatial Synthesis for Computer-Aided Design, C. Eastman ed, Applied Science Publ 1976. 1 1 1 1 1 SIPP Single Inline Pin Package 1 1 1 1 1 SI prefix The standard metric prefixes used in the Système International d'Unités (SI) conventions for scientific measurement. Here are the SI magnifying prefixes, along with the corresponding binary interpretations in common use: prefix abr decimal binary yocto- 1000^-8 zepto- 1000^-7 atto- 1000^-6 femto- f 1000^-5 pico- p 1000^-4 nano- n 1000^-3 micro- * 1000^-2 * Abbreviation: Greek mu milli- m 1000^-1 kilo- k 1000^1 1024^1 = 2^10 = 1,024 mega- 1 1 1 1 1 Siprol Signal Processing Language. A DSP language. ["SIPROL: A High Level Language for Digital Signal Processing", H. Gethoffer, Proc ICASSP-80, 1980, pp.1056-1059]. 1 1 1 1 1 SIR 1. <language> An early system on the IBM 650. [Listed in CACM 2(5):16, May 1959]. 2. <standard> Serial Infrared. An infrared standard from IrDA, part of IrDA Data. SIR supports asynchronous communications at 9600 bps - 115.2 Kbps, at a distance of up to 1 metre. [Reference?] (1999-10-14) 1 1 1 1 1 SIRDS Single Image Random Dot Stereogram 1 1 1 1 1 Siri An object-oriented constraint language using a single abstraction mechanism developed by Bruce Horn of CMU in 1991. Siri is a conceptual blend of BETA and Bertrand. It is similar to Kaleidoscope. ["Constraint Patterns as a Basis for Object-Oriented Constraint Programming", B. Horn, OOPSLA '92 (Sept 1992)]. (1994-11-04) 1 1 1 1 1 SIRTS Single Image Random Text Stereogram. (Or ASCII stereogram). 1 1 1 1 1 SISAL (Streams and Iteration in a Single Assignment Language) A general-purpose single assignment functional programming language with strict semantics, automatic parallelisation and efficient arrays. Outputs a dataflow graph in IF1 (Intermediary Form 1). Derived from VAL, adds recursion and finite streams. Pascal-like syntax. Designed to be a common high-level language for numerical programs on a variety of multiprocessors. Implementations exist for Cray X-MP, Cray Y-MP, Cray-2, Sequent, Encore Alliant, dataflow architectures, transputers and systolic arrays. Defined in 1983 by James McGraw et al, Manchester University, Lawrence Livermore National Laboratory, Colorado State University and DEC. Revised in 1985. First compiled implementation in 1986. Performance superior to C and competitive with Fortran, combined with efficient and automatic parallelisation. 1 1 1 1 1 sit Stuffit 1 1 1 1 1 SITBOL A SNOBOL4 interpreter for the PDP-10. ["SITBOL Version 3.0", J.F. Gimpel, TRS4D30b, Bell Labs, 1973]. (1997-09-14) 1 1 1 1 1 site map A web page listing the other main pages on a website to help users find pages they want and see what areas are available. FOLDOC doesn't really have a site map but it does have a contents page (/contents.html). (2009-03-07) 1 1 1 1 1 sitename hostname 1 1 1 1 1 SIxteen Bit Organisers (SIBO) Psion's family of PDAs running EPOC, including the MC200, MC400, Series 3 (1991-1998), Series 3a, Series 3c, Series 3mx, Siena, Workabout and Workabout mx. (2009-05-26) 1 1 1 1 1 sj The country code for Svalbard and Jan Mayen Islands. (1999-01-27) 1 1 1 1 1 sk The country code for Slovakia. (1999-01-27) 1 1 1 1 1 Skel-ML A parallel variant of ML using skeletons being developed (April 1994) as part of Tore Bratvold's PhD in the Department of Computing and Electronic Engineering, Heriot-Watt University, Edinburgh, UK. Programs are written in a subset of Standard ML, and parallelism is extracted from the use of certain higher-order functions. The SkelML compiler uses profiling information together with skeleton performance models to distinguish useful from non-useful parallelism. An important feature is the ability to perform transformations between skeletons to improve performance. Skeletons currently supported are map, filter, fold, pipe (implicitly extracted from function application) and various combinations of these. See also paraML. E-mail: Tore A Bratvold <tore@cee.hw.ac.uk>. 1 1 1 1 1 Sketchpad A program that allowed users to draw on a screen with a light pen. It supported constraints (e.g. drawing a constrained ellipse produced a circle). It also had some computer aided design features (e.g. computing loads on beams). Sketchpad was the subject of Ivan E. Sutherland's 1963 MIT PhD thesis, which opened the field of computer graphics. It was the progenitor of computer drawing packages like MacDraw or Adobe Illustrator. There is a film of Sketchpad in action. It solved constraints using value inference and introduced the "ring" list structure. ["Sketchpad: A Man-Machine Graphical Communication System", I.e. Sutherland, MIT Lincoln Lab, TR 296 (Jan 1963)]. [Sammet 1969, p. 678]. (1995-02-14) 1 1 1 1 1 S/Key One-Time Password 1 1 1 1 1 Skill A somewhat peculiar blend between Franz-Lisp and C, with a large set of various CAD primitives. It is owned by Cadence Design Systems and has been used in their CAD frameworks since 1985. It's an extension language to the CAD framework (in the same way that Emacs-Lisp extends GNU Emacs), enabling you to automate virtually everything that you can do manually in for example the graphic editor. Skill accepts C-syntax, fun(a b), as well as Lisp syntax, (fun a b), but most users (including Cadence themselves) use the C-style. [Jonas Jarnestrom <etxjojm@eua.ericsson.se>]. (1995-02-14) 1 1 1 1 1 Skim A Scheme implementation with packages and other enhancements, by Alain Deutsch et al, France. (2000-11-02) 1 1 1 1 1 SkipJack An encryption algorithm created by the NSA (National Security Agency) which encrypts 64-bit blocks of data with an 80-bit key. It is used in the Clipper chip, a VLSI device with an ARM processor core, which is intended to perform cryptographic operations while allowing the security agencies listen in. There are (apparently) two agencies, both of whom have to agree that there is a valid reason to decode a message. Don't laugh, they are serious. [Algorithm?] (1995-12-07) 1 1 1 1 1 SKOL Fortran pre-processor for COS (Cray Operating System). 1 1 1 1 1 skolemisation A means of removing quantifiers from first order logic formulas. [Details?] 1 1 1 1 1 S-K reduction machine An abstract machine defined by Professor David Turner to evaluate combinator expressions represented as binary graphs. Named after the two basic combinators, S and K. 1 1 1 1 1 skrog scrog 1 1 1 1 1 SKsh Steve Koren/Korn shell. A Unix ksh-like shell which runs under AmigaDos by Steve Koren <koren@hpfcogv.fc.hp.com>. SKsh provides a Unix-like environment but supports many AmigaDos features such as resident commands and ARexx. Scripts can be written to run under either ksh or SKsh and many of the useful Unix commands such as xargs, grep and find are provided. Latest version: 2.1. (ftp://hubcap.clemson.edu/pub/amiga/incom*/utils/SKsh021.lzh). (1992-12-16) 1 1 1 1 1 SKU stock-keeping unit 1 1 1 1 1 skulker prowler 1 1 1 1 1 SL Features of some Intel processors, including the Pentium, for reducing power consumption. These features operate at two levels: the microprocessor and the system. The processor can enter a low power state during non-processor intensive tasks (such as word processing), or a very low-power state when the computer is not in use ("sleep" mode). At the system level, system management mode can slow down, suspend, or completely shut down various system components to save energy. (1995-05-06) 1 1 1 1 1 sl The country code for Sierra Leone. (1999-01-27) 1 1 1 1 1 SL5 String and list processing language with expression-oriented syntax. Coroutines. ["An Overview of SL5", Ralph E. Griswold, SIGPLAN Notices 12(4):40-50 (Apr 1977)]. 1 1 1 1 1 slack 1. <operating system> Internal fragmentation. Space allocated to a disk file but not actually used to store useful information. 2. <jargon> In the theology of the Church of the SubGenius, a mystical substance or quality that is the prerequisite of all human happiness. Since Unix files are stored compactly, except for the unavoidable wastage in the last block or fragment, it might be said that "Unix has no slack". See ha ha only serious. [Jargon File] (1995-03-01) 1 1 1 1 1 slackware A distribution of the Linux operating system by Patrick Volkerding <volkerdi@mhd1.moorhead.msus.edu>, <volkerdi@ftp.cdrom.com>. cdrom.com (ftp://ftp.cdrom.com/pub/linux/). FAQ (ftp://sunsite.unc.edu/pub/Linux/distributions/slackware/SLAKWARE.FAQ). Sunsite Linux archives (http://sunsite.unc.edu/pub/Linux/distributions/slackware/). Sunsite mirrors (http://sunsite.unc.edu/pub/Linux/MIRRORS.html). (1995-03-01) 1 1 1 1 1 SLAM 1. <language> Simulation Language for Alternative Modeling. 2. A continuous simulation language. ["SLAM - A New Continuous Simulation Language", N.A. Wallington et al, in SCS Simulation Council Proc Series: Toward Real-Time Simulation (Languages, Models and Systems), R.E. Crosbie et al eds, 6(1):85-89 (Dec 1976)]. (1995-03-03) 1 1 1 1 1 SLANG 1. R.A. Sibley. CACM 4(1):75-84 (Jan 1961). 2. Set LANGuage. Jastrzebowski, ca 1990. C extension with set-theoretic data types and garbage collection. "The SLANG Programming Language Reference Manual, Version 3.3", W. Jastrzebowski <wojtek@loml.math.yale.edu>, 1990. 3. Structured LANGuage. Michael Kessler, IBM. A language based on structured programming macros for IBM 370 assembly language. "Project RMAG: SLANG (Structured Language) Compiler", R.A. Magnuson, NIH-DCRT-DMB-SSS-UG105, NIH, DHEW, Bethesda, MD 20205 (1980). 4. "SLANG: A Problem Solving Language for Continuous-Model Simulation and Optimisation", J.M. Thames, Proc 24th ACM Natl Conf 1969. 1 1 1 1 1 S-Lang A small but highly functional embedded interpreter. S-Lang was a stack-based postfix language resembling Forth and BC/DC with limited support for infix notation. Now it has a C-like infix syntax. Arrays, stings, integers, floating-point and autoloading are all suported. The editor JED embeds S-lang. S-Lang is available under the GNU Library General Public License. It runs on MS-DOS, Unix, and VMS. Latest version: 0.94, as of 1993-06-12. (ftp://amy.tch.harvard.edu/). E-mail: John E. Davis <davis@tch.harvard.edu>. (2000-10-30) 1 1 1 1 1 slap on the side (Also called a sidecar, or abbreviated "SOTS"). A type of external expansion hardware marketed by computer manufacturers (e.g. Commodore for the Amiga 500/1000 series and IBM for the hideous failure called IBM PCjr). Various SOTS boxes provided necessities such as memory, hard drive controllers, and conventional expansion slots. [Jargon File] 1 1 1 1 1 slash oblique stroke 1 1 1 1 1 slashdot effect An effect where a document on a WWW server is linked to from another, popular, site, with the resultant traffic overloading the server so that a connection cannot be made to it. This is especially likely if the server is running Microsoft IIS. The term was coined by readers of the Unix advocacy web site slashdot.org (http://slashdot.org/). (1998-10-24) 1 1 1 1 1 slave tty (/dev/ttyp*) The half of a pseudo-tty which programs (e.g. getty) read from and write to as though it was an ordinary serial line. 1 1 1 1 1 SLD resolution (Selected, Linear, Definite) Linear resolution with a selection function for definite sentences. A definite sentence has exactly one positive literal in each clause and this literal is selected to be resolved upon, i.e. replaced in the goal clause by the conjunction of negative literals which form the body of the clause. [Why is SLD resolution important?] (2003-12-04) 1 1 1 1 1 sleep 1. <operating system> (Or "block") When a process on a multitasking system asks the scheduler to deactivate it until some given external event (e.g. an interrupt or a specified time delay) occurs. The alternative is to poll or "busy wait" for the event but this uses processing power. Also used in the phrase "sleep on" (or "block on") some external event, meaning to wait for it. E.g. the Unix command of the same name which pauses the current process for a given number of seconds. 2. <hardware> To go into partial deactivation to save power. [Jargon File] (2000-09-25) 1 1 1 1 1 SLIB Scheme Library 1 1 1 1 1 Slide A now-retired Jakarta project to develop a repository for content management. Slide is no longer in development. It featured WebDAV, DeltaV WebDAV versioning, different databases and file system storage, transactions and locking, flexible permissions per file and more. Slide home (http://jakarta.apache.org/slide/). (2008-06-04) 1 1 1 1 1 sliding-window A method of flow control in which a receiver gives a transmitter permission to transmit data until a window is full. When the window is full, the transmitter must stop transmitting until the receiver advertises a larger window. TCP, other transport protocols, and several link-layer protocols use this method of flow control. (2002-12-02) 1 1 1 1 1 SLIM A VLSI language for translating DFA's into circuits. J.L. Hennessy, "SLIM: A Simulation and Implementation Language for VLSI Microcode", Lambda, Apr 1981, pp.20-28. [Jargon File] 1 1 1 1 1 slim A small, derivative change (e.g. to code). (2003-05-13) 1 1 1 1 1 Slingshot CSK Software's real time financial server for the Internet. Slingshot allows the delivery of real time market data across the Internet and private intranets quickly, cheaply and securely. The first beta-test version was released free to the Internet on 6 August 1996. Slingshot allows any financial institution, regardless of size, to publish their rates and associated information to a global audience using standard Internet protocols and software. The real-time data can be seamlessly integrated into any standard web application and thus combined with static text, database queries and even audio and video objects, to create services. The Slingshot protocol enables the delivery of other forms of real time data over the Internet, thus making Slingshot useful in industries as varied as manufacturing, betting, telemetry, weather, transport and medicine. Version 2's improved protocol minimises the required 1 1 1 1 1 SLIP 1. Serial Line Internet Protocol. 2. Symmetric LIst Processsor. Early 1960's list processing subroutine package for Fortran by J. Weizenbaum. Later also embedded in MAD and ALGOL. ["Symmetric List Processor", J. Weizenbaum CACM 6:524-544(1963). Sammet 1969, p.387]. 1 1 1 1 1 SlipKnot A graphical web browser specifically designed for Microsoft Windows users who have Unix shell accounts with their service providers. Its primary feature is that it does not require SLIP or PPP or TCP/IP services. SlipKnot is distributed as restricted shareware. Version: 1.0. SlipKnot home (http://micromind.com/slipknot.htm). E-mail: <slipknot@micromind.com>. (2003-03-25) 1 1 1 1 1 SLIPS An Interpreter for SLIPS - An Applicative Language Based on Lambda-Calculus, V. Gehot et al, Comp Langs 11(1):1-14 (1986). 1 1 1 1 1 SLiRP A SLIP emulator by Danny Gasparovski, faster than TIA. Version: 0.95H 12 Sep 95. (http://webcom.com/~llarrow/slirp.html). (1995-09-15) 1 1 1 1 1 SLLIC An intermediate language developed at HP. An infinite-register version of the Precision Architecture instruction set? (1995-05-28) 1 1 1 1 1 slog Schelog 1 1 1 1 1 Sloop Parallel Programming in a Virtual Object Space, S. Lucco, SIGPLAN Notices 22(12):26-34 (OOPSLA '87) (Dec 1987). 1 1 1 1 1 slop 1. A one-sided fudge factor, that is, an allowance for error but in only one of two directions. For example, if you need a piece of wire 10 feet long and have to guess when you cut it, you make very sure to cut it too long, by a large amount if necessary, rather than too short by even a little bit, because you can always cut off the slop but you can't paste it back on again. When discrete quantities are involved, slop is often introduced to avoid the possibility of being on the losing side of a fencepost error. 2. The percentage of "extra" code generated by a compiler over the size of equivalent assembly code produced by hand-hacking; i.e. the space (or maybe time) you lose because you didn't do it yourself. This number is often used as a measure of the quality of a compiler; slop below 5% is very good, and 10% is usually acceptable. Modern compilers, especially on RISCs, may actually have *negative* slop; that is, they may generate better code than humans. This is one of 1 1 1 1 1 slopsucker /slop'suhk-r/ A lowest-priority task that only runs when the computer would otherwise be idle. Also called a "hungry puppy" or "bottom feeder" (after the fishermen's and naturalists' term for finny creatures who subsist on the primordial ooze). One common variety of slopsucker hunts for large prime numbers. Compare background. [Jargon File] (2003-09-29) 1 1 1 1 1 slosh backslash 1 1 1 1 1 Slot 1 The physical and electrical specification for the connector used by some of Intel's microprocessor cards, currently (August 1999) the SEPP Celeron and the SECC Pentium II. Slot 1 is a departure from the square ZIF PGA/SPGA sockets used by Pentium and earlier processors, the processor being mounted on a card, with a 242-lead edge-connector. The Slot 1 specification allows for higher bus rates than Socket 7. Slot 1 motherboards use the GTL+ bus protocol. See also Slot 2, Slot A. [bus rates?] (1999-08-04) 1 1 1 1 1 Slot 2 A physical and electrical specification for the 330-lead edge-connector used by some of Intel's microprocessor cards, currently (August 1999) the SECC Pentium III/Xeon. Slot 2 is intended for use in high end multi-processor workstations and servers. See also Slot A, Slot 1. [Multi processor support?] (1999-08-04) 1 1 1 1 1 Slot A The physical and electrical specification for the edge-connector used by AMD's Athlon processor. The connector allows for a higher bus rate than Socket 7 or Super 7. Slot A motherboards use Compaq's EV6 bus protocol. Slot A is mechanically compatible but electrically incompatible with Intel's Slot 1. (1999-08-05) 1 1 1 1 1 slurp To read a large data file entirely into core before working on it. This may be contrasted with the strategy of reading a small piece at a time, processing it, and then reading the next piece. "This program slurps in a 1K-by-1K matrix and does an FFT." See also sponge. [Jargon File] 1 1 1 1 1 sm The country code for San Marino. (1999-01-27) 1 1 1 1 1 smail snail-mail 1 1 1 1 1 SMALGOL SMall ALGOL. A subset of ALGOL 60. ["SMALGOL-61", G.A. Bachelor et al CACM 4(11):499-502 (Nov 1961)]. [Sammet 1969]. (1995-01-31) 1 1 1 1 1 SMALL 1. Functional, lazy, untyped. ["SMALL - A Small Interactive Functional System", L. Augustsson, TR 28, U Goteborg and Chalmers U, 1986]. 2. A toy language used to illustrate denotational semantics. ["The Denotational Description of Programming Languages", M.J.C. Gordon, Springer 1979]. 1 1 1 1 1 Small Business Edition Microsoft Office Small Business Edition 1 1 1 1 1 Small-C A subset of C. The original compiler, written in C by Ron Cain, appeared in Dr. Dobb's Journal. James E. Hendrix improved and extended the original compiler and published "The Small-C Handbook". Both these compilers produced 8080 assembly code. A Small-C compiler based on RatC produced 6502 assembly code for the BBC Microcomputer. It was written in Small-C and bootstrapped using Zorland C on an Amstrad PC1512 under MS-DOS 3.2, then transferred onto a BBC Micro using Kermit. The compiler can be used to cross-compile 6502 code from an MS-DOS host, or as a resident Small-C compiler on a BBC Micro. It runs on 68000, 6809, VAX, 8080, BBC Micro and Zilog Z80. Posted to comp.sources.unix volume 5. (ftp://apple.com/ArchiveVol1/Unix_lang). ["Small-C"?, Ron Cain, Dr. Dobb's Journal, May 1980, Dec 1982?] 1 1 1 1 1 Small Computer System Interface (SCSI) /skuh'zee/, /sek'si/ The most popular processor-independent standard, via a parallel bus, for system-level interfacing between a computer and intelligent devices including hard disks, floppy disks, CD-ROM, printers, scanners, and many more. SCSI can connect multiple devices to a single SCSI adaptor (or "host adaptor") on the computer's bus. SCSI transfers bits in parallel and can operate in either asynchronous or synchronous modes. The synchronous transfer rate is up to 5MB/s. There must be at least one target and one initiator on the SCSI bus. SCSI connections normally use "single ended" drivers as opposed to differential drivers. Single ended SCSI can suport up to six metres of cable. Differential ended SCSI can support up to 25 metres of cable. SCSI was developed by Shugart Associates, which later became Seagate. SCSI was originally called SASI for "Shugart 1 1 1 1 1 small-office/home-office (SoHo) A term describing the market for certain computer goods. (1995-01-11) 1 1 1 1 1 Small Outline DIMM (SO-DIMM) A smaller kind of DIMM with 72 pins (supporting 32-bit transfers) or 144 pins (64-bit transfers). Regular DIMMs have 168 pins and support 64-bit transfers. Being roughly half the size of the regular DIMM, SO-DIMMs are often used in notebook computers. Kingston Memory Guide (http://kingston.com/tools/umg/newumg05a.asp). (2001-02-16) 1 1 1 1 1 Smalltalk The pioneering object-oriented programming system developed in 1972 by the Software Concepts Group, led by Alan Kay, at Xerox PARC between 1971 and 1983. It includes a language, a programming environment, and an extensive object library. Smalltalk took the concepts of class and message from Simula-67 and made them all-pervasive. Innovations included the bitmap display, windowing system, and use of a mouse. The syntax is very simple. The fundamental construction is to send a message to an object: object message or with extra parameters object message: param1 secondArg: param2 .. nthArg: paramN where "secondArg:" etc. are considered to be part of the message name. 1 1 1 1 1 Smalltalk-80 The classic standard Smalltalk dialect, described in Adele's book, cited below, commonly known as "The Blue Book". ["Smalltalk-80: The Language and Its Implementation", Adele Goldberg et al, A-W 1983]. [BYTE 6(8), Aug 1981]. (ftp://st.cs.uiuc.edu/pub/ISA), (ftp://st.cs.uiuc.edu/pub/Smalltalk/MANCHESTER), (ftp://gnu.org/pub/gnu). Mail server: goodies-lib@r5.cs.man.ac.uk. (2004-12-14) 1 1 1 1 1 Smalltalk/V The first widely available version of Smalltalk, developed by Digitalk in 1986 for IBM PC and Macintosh. (1995-02-14) 1 1 1 1 1 SmallVDM ["SmallVDM: An Environment for Formal Specification and Prototyping in Smalltalk", in Object Oriented Specification Case Studies, K. Lano et al eds, P-H 1993]. (1996-04-20) 1 1 1 1 1 SMALLWORLD A trademark of Smallworldwide Plc. (http://smallworld.co.uk/). (1999-08-26) 1 1 1 1 1 SmallWorld An object-oriented language. ["SW 2 - An Object-based Programming Environment", M.R. Laff et al, IBM TJWRC, 1985]. (1996-04-20) 1 1 1 1 1 Smarandache logic neutrosophic logic 1 1 1 1 1 SMART For MS-DOS? [Jargon File] 1 1 1 1 1 smart 1. <programming> Said of a program that does the Right Thing in a wide variety of complicated circumstances. There is a difference between calling a program smart and calling it intelligent; in particular, there do not exist any intelligent programs (yet - see AI-complete). Compare robust (smart programs can be brittle). 2. <hardware> Incorporating some kind of digital electronics. (1995-03-28) 1 1 1 1 1 Smart Battery Data (SBD) A method to monitor a rechargeable battery pack, initiated by Duracell and Intel. An special IC in the battery pack monitors the battery and reports information to the SMBus. This information might include: type, model number, manufacturer, characteristics, discharge rate, predicted remaining capacity, almost-discharged alarm so that the PC can shut down gracefully; temperature and voltage to provide safe fast-charging. Smart Battery System Implementers Forum (http://sbs-forum.org/). (1999-08-08) 1 1 1 1 1 smart card Any plastic card (like a credit card) with an embedded integrated circuit for storing information. Smart cards are being incorporated into soldier's dog-tags and used to store hospital patients' medical records. This way they are always instantly accessible. Other uses are as a form of token in banking systems. You could store electronic money on the card or less valuable tokens such as those given away by petrol companies which you collect to exchange for free gifts at a later date. The idea being that one smart card is easier to carry around than a multitude of paper tokens. news:alt.technology.smartcards (1995-01-06) 1 1 1 1 1 Smartdrive A Microsoft MS DOS disk cache program to speed up disk access. For most users, a 1MB cache is sufficient. Devoting more memory to the cache offers diminishing returns, since the additional cache hits become fewer (and the extra memory could be better used to reduce swapping). Typing SMARTDRV /S at a DOS prompt shows the cache size, a hit-and-miss report, and information about which drives are being cached. The hit-and-miss statistics are crucial for gauging the effectiveness of SmartDrive settings. A score in the high 80s shows that SmartDrive is well configured. Run SMARTDRV /S several times during a Windows session and note the-hit-and-miss figures each time. If your percentage usually falls below 80 percent, you should consider increasing the cache size. You can edit the SMARTDRV line in your AUTOEXEC.BAT file to increase both the InitCacheSize and the WinCacheSize parameters. 1 1 1 1 1 SMARTdrv Smartdrive 1 1 1 1 1 smart terminal intelligent terminal 1 1 1 1 1 smash case case sensitivity 1 1 1 1 1 smash sum coalesced sum 1 1 1 1 1 smash the stack In C programming, to corrupt the execution stack by writing past the end of a local array or other data structure. Code that smashes the stack can cause a return from the routine to jump to a random address, resulting in insidious data-dependent bugs. Variants include "trash" the stack, scribble the stack, mangle the stack. See spam; see also aliasing bug, fandango on core, memory leak, memory smash, precedence lossage, overrun screw. [Jargon File] (1995-03-16) 1 1 1 1 1 SMB 1. <protocol> Server Message Block. 2. <hardware, protocol> System Management Bus. (1999-08-08) 1 1 1 1 1 smbclient Samba 1 1 1 1 1 smblib Samba 1 1 1 1 1 SMBus System Management Bus 1 1 1 1 1 SMCC Sun Microsystems Computer Corporation. 1 1 1 1 1 SMDS Switched Multimegabit Data Service 1 1 1 1 1 SMG Screen Management Guidelines. A VMS package of run-time library routines providing windows on DEC VT100 terminals. 1 1 1 1 1 SMI Structure of Management Information 1 1 1 1 1 SMIL 1. <language> The machine language for a Swedish computer. (ftp://ftp.wustl.edu/mirrors/info-mac/lang/smil-emulator.hqx). 2. <hypertext, language, multimedia, text, web> Synchronized Multimedia Integration Language. (2000-04-21) 1 1 1 1 1 smiley emoticon 1 1 1 1 1 smilies emoticon 1 1 1 1 1 S-MIME Secure Multipurpose Internet Mail Extensions 1 1 1 1 1 SML 1. Standard ML. 2. Small Machine Language. Barnes, ICI 1969. Real-time language, an ALGOL variant, and the predecessor of RTL. "SML User's Guide", J.G.P. Barnes, ICI, TR JGPB/69/35 (1969). 1 1 1 1 1 SML# An extension of SML/NJ with polymorphic field selection and nondestructive field update. "A Compilation Method for ML-style Polymorphic Record Calculi", A. Ohori, POPL 1992. (ftp://ftp.cis.upenn.edu/pub/sml#/). 1 1 1 1 1 sml2c A Standard ML to C compiler. sml2c is a batch compiler and compiles only module-level declarations, i.e. signatures, structures and functors. It provides the same pervasive environment for the compilation of these programs as SML/NJ. As a result, module-level programs that run on SML/NJ can be compiled by sml2c without any changes. Based on SML/NJ version 0.67 and shares front end and most of its run-time system, but does not support SML/NJ style debugging and profiling. School of Computer Science, Carnegie Mellon University (ftp://dravido.soar.cs.cmu.edu/usr/nemo/sml2c/sml2c.tar.Z). Linux (ftp://ftp.dcs.glasgow.ac.uk/pub/linux/smlnj-0.82-linux.tar.Z). conformance: superset + first-class continuations, 1 1 1 1 1 SML/NJ Standard ML of New Jersey 1 1 1 1 1 SMM System Management Mode 1 1 1 1 1 SMNP Do you mean "SNMP"? If not, please tell me. 1 1 1 1 1 smoke 1. To crash or blow up, usually spectacularly. "The new version smoked, just like the last one." Used for both hardware (where it often describes an actual physical event), and software (where it's merely colourful). 2. [Automotive slang] To be conspicuously fast. "That processor really smokes." Compare magic smoke. [Jargon File] 1 1 1 1 1 smoke and mirrors Marketing deceptions. The term is mainstream in this general sense. Among hackers it's strongly associated with bogus demos and crocked benchmarks (see also MIPS, machoflops). "They claim their new box cranks 50 MIPS for under $5000, but didn't specify the instruction mix - sounds like smoke and mirrors to me." The phrase has been said to derive from carnie slang for magic acts and "freak show" displays that depend on "trompe l"oeil' effects, but also calls to mind the fierce Aztec god Tezcatlipoca (lit. "Smoking Mirror") for whom the hearts of huge numbers of human sacrificial victims were regularly cut out. Upon hearing about a rigged demo or yet another round of fantasy-based marketing promises, hackers often feel analogously disheartened. 1 1 1 1 1 smoke-emitting diode (From "light-emitting diode") An incorrectly connected diode, probably a light-emitting diode, in the process of losing its magic smoke and becoming a friode. See also LER. (1996-04-28) 1 1 1 1 1 smoke test 1. A rudimentary form of testing applied to electronic equipment following repair or reconfiguration, in which power is applied and the tester checks for sparks, smoke, or other dramatic signs of fundamental failure. See magic smoke. 2. By extension, the first run of a piece of software after construction or a critical change. See and compare reality check. There is an interesting semi-parallel to this term among typographers and printers: When new typefaces are being punch-cut by hand, a "smoke test" (hold the letter in candle smoke, then press it onto paper) is used to check out new dies. [Jargon File] 1 1 1 1 1 smoking clover [ITS] A display hack originally due to Bill Gosper. Many convergent lines are drawn on a colour monitor in AOS mode (so that every pixel struck has its colour incremented). The lines all have one endpoint in the middle of the screen; the other endpoints are spaced one pixel apart around the perimeter of a large square. The colour map is then repeatedly rotated. This results in a striking, rainbow-hued, shimmering four-leaf clover. Gosper joked about keeping it hidden from the FDA (the US's Food and Drug Administration) lest its hallucinogenic properties cause it to be banned. 1 1 1 1 1 SMoLCS Specification metalanguage used for a formal definition of Ada. "An Introduction to the SMoLCS Methodology", E. Astesiano, U Genova 1986. 1 1 1 1 1 SMOP /S-M-O-P/ [Simple (or Small) Matter of Programming] 1. A piece of code, not yet written, whose anticipated length is significantly greater than its complexity. Used to refer to a program that could obviously be written, but is not worth the trouble. Also used ironically to imply that a difficult problem can be easily solved because a program can be written to do it; the irony is that it is very clear that writing such a program will be a great deal of work. "It's easy to enhance a Fortran compiler to compile COBOL as well; it's just an SMOP." 2. Often used ironically by the intended victim when a suggestion for a program is made which seems easy to the suggester, but is obviously (to the victim) a lot of work. [Jargon File] 1 1 1 1 1 SMP 1. Symbol Manipulation Program. 2. <computer, parallel> symmetric multiprocessing. (1995-03-19) 1 1 1 1 1 SMPS switch mode power supply 1 1 1 1 1 SMPT Do you mean SMTP? (2003-11-24) 1 1 1 1 1 SMRP Simplified Multicast Routing Protocol 1 1 1 1 1 SMS 1. <messaging> Short Message Service. 2. <storage> Storage Management Services. 3. <operating system> System Management Server. (1999-05-02) 1 1 1 1 1 SMT Station Management 1 1 1 1 1 SMTP Simple Mail Transfer Protocol 1 1 1 1 1 smug report A bug report submitted by a user who thinks he knows more about the system's design than he really does, filled with irrelevant technical details and (incorrect) suggestions about the cause and solution of the problem. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2011-11-30) 1 1 1 1 1 smurf /smerf/ (From the news:soc.motss Usenet newsgroup, after some obnoxiously gooey cartoon characters) A newsgroup regular with a habitual style that is irreverent, silly, and cute. Like many other hackish terms for people, this one may be praise or insult depending on who uses it. In general, being referred to as a smurf is probably not going to make your day unless you've previously adopted the label yourself in a spirit of irony. Compare old fart. [Jargon File] (1995-10-25) 1 1 1 1 1 sn The country code for Senegal. (1999-01-27) 1 1 1 1 1 SNA Systems Network Architecture 1 1 1 1 1 snacc (Sample Neufeld ASN.1 to C/C++ Compiler) A program by Mike Sample <msample@opentext.com> which compiles 1990 ASN.1 data structures (including some macros) into C, C++ or type tables. The generated C/C++ includes a .h file with the equivalent data struct and a .c/.C file for the BER encode and decode, print and free routines. snacc includes the compiler, run-time BER libraries, and utility programs. snacc is compiled under GNU General Public License. It requires yacc or bison, lex or flex, and cc (ANSI or non-ANSI). ITU TS X.208/ISO 8824. Latest version: 1.1, as of 1993-07-12. Home (http://fokus.gmd.de/ovma/freeware/snacc/entry.html). E-mail: <snacc-bugs@cs.ubc.ca>. [Michael Sample and Gerald Neufeld, "Implementing Efficient Encoders and Decoders for Network Data Representations", IEEE 1 1 1 1 1 snaf chad 1 1 1 1 1 SNAFU principle /sna'foo prin'si-pl/ [WWII Army acronym for "Situation Normal: All Fucked Up"] "True communication is possible only between equals, because inferiors are more consistently rewarded for telling their superiors pleasant lies than for telling the truth." - a central tenet of Discordianism, often invoked by hackers to explain why authoritarian hierarchies screw up so reliably and systematically. The effect of the SNAFU principle is a progressive disconnection of decision-makers from reality. This lightly adapted version of a fable dating back to the early 1960s illustrates the phenomenon perfectly: In the beginning was the plan, and then the specification; And the plan was without form, and the specification was void. And darkness was on the faces of the implementors thereof; And they spake unto their leader, 1 1 1 1 1 snag bug 1 1 1 1 1 snail mail (Or "snailmail", "smail" from "US Mail" via USnail; "paper mail"). Bits of dead tree sent via the postal service as opposed to electronic mail. One's postal address is, correspondingly, a "snail (mail) address". There have even been parody USnail posters and stamps made. The variant "paper-net" is a hackish way of referring to the postal service, comparing it to a very slow, low-reliability network. Sig blocks sometimes include a "Paper-Net:" header just before the sender's postal address; common variants of this are "Papernet" and "P-Net". Note that the standard netiquette guidelines discourage this practice as a waste of bandwidth, since netters are quite unlikely to casually use postal addresses and if they really wanted your snail mail address they could always ask for it by e-mail. Compare voice-net, sneakernet, P-mail. (1995-01-31) 1 1 1 1 1 SNAP 1. An early (IBM 360?) interpreted text-processing language for beginners, close to basic English. ["Computer Programming in English", M.P. Barnett, Harcourt Brace 1969]. 2. ["Some Proposals for SNAP, A Language with Formal Macro Facilities", R.B. Napper, Computer J 10(3):231-243, 1967]. [Same as 1?] (2006-05-27) 1 1 1 1 1 snap 1. <programming> To remove indirection, e.g. by replacing a pointer to a pointer with a pointer to the final target (see chase pointers). The underlying metaphor may be a rubber band stretched through a number of points; if you release it from the intermediate points, it snaps to a straight line from first to last. Often a trampoline performs an error check once and then snaps the pointer that invoked it so subsequent calls will bypass the trampoline (and its one-shot error check). In this context one also speaks of "snapping links". For example, in a Lisp implementation, a function interface trampoline might check to make sure that the caller is passing the correct number of arguments; if it is, and if the caller and the callee are both compiled, then snapping the link allows that particular path to use a direct procedure-call instruction with no further overhead. [Jargon File] 1 1 1 1 1 snap dump A memory dump, often partial, requested by a program to display its current status for debugging. Program execution often continues normally following a snap dump, as opposed to a crash dump. [Short for "snapshot"?] (2006-05-27) 1 1 1 1 1 Snappy Snappy Video Snapshot 1 1 1 1 1 Snappy Video Snapshot (registered trademark) A frame grabber for the IBM PC designed and marketed by Play, Inc.. (1997-07-11) 1 1 1 1 1 snarf /snarf/ 1. To grab, especially to grab a large document or file for the purpose of using it with or without the author's permission. See also BLT. 2. (Unix) To fetch a file or set of files across a network. See also blast. 3. To acquire, with little concern for legal forms or politesse (but not quite by stealing). "They were giving away samples, so I snarfed a bunch of them." 4. Synonym for slurp. "This program starts by snarfing the entire database into core." 5. (GEnie) To spray food or programming fluids due to laughing at the wrong moment. This sense appears to be widespread among mundane teenagers - ESR. 6. This term was mainstream in the late 1960s, meaning "to eat piggishly". It may still have this connotation in context. 7. A creature on the Thundercats, fond of eating, usually 1 1 1 1 1 snarf & barf /snarf'n-barf`/ Under a WIMP environment, the act of grabbing a region of text and then stuffing the contents of that region into another region (or the same one) to avoid retyping a command line. In the late 1960s, this was a mainstream expression for an "eat now, regret it later" cheap restaurant expedition. [Jargon File] (1994-11-04) 1 1 1 1 1 snarf down To snarf, with the connotation of absorbing, processing, or understanding. "I'll snarf down the latest version of the nethack user's guide - it's been a while since I last played." [Jargon File] (1994-11-04) 1 1 1 1 1 snark [Lewis Carroll, via the Michigan Terminal System] 1. A system failure. When a user's process bombed, the operator would get the message "Help, Help, Snark in MTS!" 2. More generally, any kind of unexplained or threatening event on a computer (especially if it might be a boojum). Often used to refer to an event or a log file entry that might indicate an attempted security violation. See snivitz. 3. UUCP name of snark.thyrsus.com, home site of the Hacker Jargon File versions 2.*.*. [Jargon File] 1 1 1 1 1 sneakernet /snee'ker-net/ Term used (generally with ironic intent) for transfer of electronic information by physically carrying tape, disks, or other media from one machine to another. "Never underestimate the bandwidth of a station wagon filled with magtape, or a 747 filled with CD-ROMs." Also called tennis-net, armpit-net, floppy-net, shoe-net, walk-net, foot-net. (2003-07-02) 1 1 1 1 1 sneck The sound made by deboursification, according to Sam Spade anti-spam software. (1999-09-15) 1 1 1 1 1 snert A derogatory term commonly used on the Internet ECHO BBS, echonyc.com, meaning to "make overtures of a sexual nature". It implies terminal cluelessness. (1995-03-01) 1 1 1 1 1 SNI Siemens Nixdorf Informationssteme, AG 1 1 1 1 1 Sniff A C++/C programming environment providing browsing, cross-referencing, design visualisation, documentation and editing support. Developed by UBS Switzerland and marketed by takeFive Salzburg. [Jargon File] 1 1 1 1 1 sniff poll 1 1 1 1 1 sniffer packet sniffer 1 1 1 1 1 snivitz /sniv'itz/ A hiccup in hardware or software; a small, transient problem of unknown origin (less serious than a snark). Compare glitch. [Jargon File] (1995-03-28) 1 1 1 1 1 SNMP Simple Network Management Protocol 1 1 1 1 1 SNMP agent A software process that responds to queries using the Simple Network Management Protocol to provide status and statistics about a network node. (1995-11-11) 1 1 1 1 1 SNMPv2 Simple Network Management Protocol version 2 1 1 1 1 1 SNOBOL String Oriented Symbolic Language 1 1 1 1 1 SNOBOL2 A SNOBOL variant which existed only briefly. It featured built-in functions, but not programmer-defined ones. ["SNOBOL2", D.J. Farber, R.E. Griswold and I.P. Polonsky, TR Bell Labs, Apr 1964]. 1 1 1 1 1 SNOBOL3 SNOBOL with user-defined functions. Written in 1965. The SNOBOL 6.3 compiler for the PDP-6 and PDP-10 was written in SNOBOL. ["The SNOBOL3 Programming Language", D.J. Farber et al, Bell Sys Tech J 45(6):895-944 (Jul 1966)]. (1994-11-04) 1 1 1 1 1 SNOBOL4 A quite distinct descendant of SNOBOL, developed by Griswold et al in 1967. SNOBOL4 is declarative with dynamic scope. Patterns are first-class data objects that can be constructed by concatenation and alternation. Success and failure are used for flow control. Delayed (unevaluated) expressions can be used to implement recursion. It has a table data type. Strings generated at run time can be treated as programs and executed. See also vanilla. SNOBOL 4 (http://snobol4.org/). (ftp://apple.com/ArchiveVol1/Unix_lang). A FOLDOC parser in SNOBOL4 (http://www.topcat.hypermart.net/foldoc.html)! ["The SNOBOL4 Programming Language", Ralph E. Griswold et al, P-H 1971]. (2011-01-05) 1 1 1 1 1 SNOOPS Craske, 1988. An extension of SCOOPS with meta-objects that can redirect messages to other objects. "SNOOPS: An Object-Oriented language Enhancement Supporting Dynamic Program Reeconfiguration", N. Craske, SIGPLAN Notices 26(10): 53-62 (Oct 1991). 1 1 1 1 1 SNPP Simple Network Paging Protocol 1 1 1 1 1 SNR signal-to-noise ratio 1 1 1 1 1 S/N ratio signal-to-noise ratio 1 1 1 1 1 SNR bandwidth product The integral of the SNR over frequency. The SNR bandwidth product is an important limit in the capacity of a communication channel. (2003-07-20) 1 1 1 1 1 SO 1. <character> Shift Out 2. Significant Other, almost invariably written abbreviated and pronounced /S-O/ by hackers. Used to refer to one's primary relationship, especially a live-in to whom one is not married. [Jargon File] 1 1 1 1 1 so The country code for Somalia. (1999-01-27) 1 1 1 1 1 SO 2 An early system on IBM 701. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-04) 1 1 1 1 1 SOA 1. <architecture> service-oriented architecture. 2. <networking> start of authority. 1 1 1 1 1 SOAP 1. <protocol> Simple Object Access Protocol. 2. <language> Symbolic Optimal Assembly Program. (2001-03-23) 1 1 1 1 1 SOAR 1. State, Operator And Result. A general problem-solving production system architecture, intended as a model of human intelligence. Developed by A. Newell in the early 1980s. SOAR was originally implemented in Lisp and OPS5 and is currently implemented in Common Lisp. Version: Soar6. E-mail: <soar@cs.cmu.edu>. ["The SOAR Papers", P.S. Rosenbloom et al eds, MIT Press 1993]. (1994-11-04) 2. Smalltalk On A RISC. A RISC microprocessor designed by David Patterson's at Berekeley. (1994-11-04) 1 1 1 1 1 social engineering A term used among crackers and samurai for cracking techniques that rely on weaknesses in wetware rather than software; the aim is to trick people into revealing passwords or other information that compromises a target system's security. Classic scams include phoning up a mark who has the required information and posing as a field service tech or a fellow employee with an urgent access problem. See also the tiger team story in the patch entry. [Jargon File] (2006-11-22) 1 1 1 1 1 social network Any website designed to allow multiple users to publish content themselves. The information may be on any subject and may be for consumption by (potential) friends, mates, employers, employees, etc. The sites typically allow users to create a "profile" describing themselves and to exchange public or private messages and list other users or groups they are connected to in some way. There may be editorial content or the site may be entirely user-driven. Content may include text, images (e.g. (http://flickr.com/)), video (e.g. (http://youtube.com/)) or any other media. Social networks on the the web are a natural extension of mailing lists and buletin boards. They are related to wikis like (http://wikipedia.org/) but typically do not allow users to modify content once it has been submitted, though usually you can publish comments on others' submissions. 1 1 1 1 1 social networking social network 1 1 1 1 1 social science number (IBM) A statistic that is content-free, or nearly so. A measure derived via methods of questionable validity from data of a dubious and vague nature. Predictively, having a social science number in hand is seldom much better than nothing, and can be considerably worse. Management loves them. See also numbers, math-out, pretty pictures. (1994-11-04) 1 1 1 1 1 socket The Berkeley Unix mechansim for creating a virtual connection between processes. Sockets interface Unix's standard I/O with its network communication facilities. They can be of two types, stream (bi-directional) or datagram (fixed length destination-addressed messages). The socket library function socket() creates a communications end-point or socket and returns a file descriptor with which to access that socket. The socket has associated with it a socket address, consisting of a port number and the local host's network address. Unix manual page: socket(2). (1995-01-31) 1 1 1 1 1 Socket 1 x86 processor socket 1 1 1 1 1 Socket 2 x86 processor socket 1 1 1 1 1 Socket 3 x86 processor socket 1 1 1 1 1 Socket 370 (PGA370) A physical and electrical specification for a motherboard processor socket. Socket 370 uses a square SPGA ZIF socket with 370 pins, arranged 37x37 (sometimes described as 19x19). Intel originally designed Socket 370 for PPGA Celeron processors. Newer Socket 370 motherboards additionally support FC-PGA Celeron and Pentium III processors. The difference between the two versions is electrical; some pins are used differently and voltage requirements have been changed from Intel's VRM 8.2 to VRM 8.4. In addition, Celeron processors require a 66 MHz front side bus (FSB), and Pentium III processors require a 100/133 MHz FSB. Some older Socket 370 motherboards support VRM 8.4 and variable bus speeds, so adapters are available that convert the socket pinout to allow FC-PGA processors to work. VIA's Cyrix III processor was designed to work with Socket 370 motherboards. 1 1 1 1 1 Socket 4 x86 processor socket 1 1 1 1 1 Socket 5 x86 processor socket 1 1 1 1 1 Socket 6 x86 processor socket 1 1 1 1 1 Socket 7 A physical and electrical specification for the x86 processor socket matching the pins on Pentium microprocessors manufactured by Intel, and compatibles made by Cyrix, AMD and others. Any CPU chip conforming to this specification can be plugged into any conforming motherboard. Supported processors include: 2.5V - 3.5V Pentiums 75-233 MHz, AMD K5 through K6, Cyrix 6x86 (and MX) P120 - P233. Socket 7 uses a SPGA socket, either a 296 pin LIF or a 321 pin ZIF arranged as 37x37 or 19x19 (depending on who you speak to!). See also Super 7. Intel's Pentium II processor uses Slot 1 mounting. [Pin-out?] (1999-08-29) 1 1 1 1 1 Socket 8 A physical and electrical specification for the x86 processor socket matching the pins on a Pentium Pro microprocessor. Socket 8 uses a dual pattern PGA/SPGA LIF/ZIF socket with 387 pins, arranged 24x26. (1999-08-04) 1 1 1 1 1 SOCKS A security package that allows a host behind a firewall to use finger, FTP, telnet, Gopher, and Mosaic to access resources outside the firewall while maintaining the security requirements. [The Security FAQ, Usenet newsgroups news:comp.security.misc, news:comp.security.unix, news:alt.security]. (1995-01-31) 1 1 1 1 1 SOCRATIC An early interactive learning system (not a language(?)) developed at Bolt, Beranek & Newman. [Sammet 1969, p. 702]. (1994-11-04) 1 1 1 1 1 SODA Symbolic Optimum DEUCE Assembly Program 1 1 1 1 1 SODAS [D.L. Parnas & J.A. Darringer. Proc FJCC 31:449-474, AFIPS (Fall 1967)]. (1994-11-04) 1 1 1 1 1 SO-DIMM Small Outline DIMM 1 1 1 1 1 Sod's Law Murphy's Law. [Or is it "Sodd"?] (1995-12-29) 1 1 1 1 1 SOE Standard Operating Environment 1 1 1 1 1 SoftBench An IPSE from Hewlett-Packard. 1 1 1 1 1 soft boot A boot which resets only part of the system. For example, "If you're running the mess-dos emulator, control-alt-insert will cause a soft boot of the emulator, while leaving the rest of the system running". Contrast hard boot. [Jargon File] (1995-11-27) 1 1 1 1 1 softcopy /soft'kop-ee/ (by analogy with "hardcopy") A machine-readable ("machinable") form of corresponding hardcopy. [Jargon File] (1994-11-04) 1 1 1 1 1 Softlab A software engineering company strong in the UK and Germany. [Details?] 1 1 1 1 1 soft link symbolic link 1 1 1 1 1 SoftModem The integration of modem controller and data pump algorithms into a single RAM-based DSP hardware architecture. These integrated algorithms are stored on the computer's hard disk, from which they are downloaded into the DSP board's random-access memory (RAM). This downloading, or booting process of the PC-installed software algorithms occurs as part of the computer's power-up initialisation process in less than 100 milliseconds, making it transparent to the user. [Digicom Modem FAQ version 2.03]. 1 1 1 1 1 SoftVelocity Inc. The distributors of the Clarion family of application development systems. SoftVelocity, Inc. (http://softvelocity.com). (2003-10-15) 1 1 1 1 1 software (Or "computer program", "program", "code") The instructions executed by a computer, as opposed to the physical device on which they run (the "hardware"). The term was coined by the eminent statistician, John Tukey. Programs stored on non-volatile storage built from integrated circuits (e.g. ROM or PROM) are usually called firmware. Software can be split into two main types - system software and application software or application programs. System software is any software required to support the production or execution of application programs but which is not specific to any particular application. Examples of system software would include the operating system, compilers, editors and sorting programs. Examples of application programs would include an accounts package or a CAD program. Other broad classes of application software include real-time software, business 1 1 1 1 1 Software AG A German software engineering company that started with the ADABAS database. Natural is their 4GL development environment, EntireX is their DCOM for Unix and IBM. BOLERO, is an object-oriented development environment and application server specially made for Electronic Business applications. (http://softwareag.com/). Mailing-list: <sag-l@uafsysb.uark.edu>. (1999-03-06) 1 1 1 1 1 software audit A regular investigation of the software installed on all computers in an organisation to ensure that it is authorised or licensed. Software audits minimise the risk of prosecution for software theft, minimise the risk of viruses through uncontrolled software copying, and ensure technical support is available to all users. The Business Software Alliance Guide To Software Management (http://bsa.org/bsa). (1996-05-19) 1 1 1 1 1 Software BackPlane A CASE framework from Atherton. (1996-05-19) 1 1 1 1 1 software bloat The result of adding new features to a program or system to the point where the benefit of the new features is outweighed by the extra resources consumed (RAM, disk space or performance) and complexity of use. Software bloat is an instance of Parkinson's Law: resource requirements expand to consume the resources available. Causes of software bloat include second-system effect and creeping featuritis. Commonly cited examples include Unix's "ls(1)" command, the X Window System, BSD, Missed'em-five, OS/2 and any Microsoft product. [Jargon File] (1995-10-16) 1 1 1 1 1 Software bus A support environment for heterogeneous distributed processing, such as the ANSA Testbench. 1 1 1 1 1 software copyright Copyright on a piece of software. Software raises interesting questions in relation to copyright, such as what constitutes a "performance" of a piece of software and which aspects of software are restricted. (2008-05-22) 1 1 1 1 1 Software Description Database Archie's database of names and short descriptions of many of the software packages, documents (like RFCs and educational material), and data files that are available via the Internet. (1995-11-12) 1 1 1 1 1 Software Developers Kit (SDK, or "Software Development Kit") Software provided by a software vendor to allow their products to be used with those of other software vendors. (1995-03-01) 1 1 1 1 1 software development life cycle software life cycle 1 1 1 1 1 software enabling (Or "enabling") Modification of the design or implementation of software to allow internationalisation to take place. In particular, enabling may refer to the modification of software to support double-byte character sets, hence Unicode enabling and "double-byte enabling". (1999-06-28) 1 1 1 1 1 software engineering (SE) A systematic approach to the analysis, design, implementation and maintenance of software. It often involves the use of CASE tools. There are various models of the software life-cycle, and many methodologies for the different phases. (1994-11-03) 1 1 1 1 1 Software Engineering Environment (SEE) A set of management and technical tools to support software development, usually integrated in a coherent framework; equivalent to an IPSE. (1994-11-03) 1 1 1 1 1 software handshaking The transmission of extra data on a channel in order to control the device sending data in the other direction on that channel. For an EIA-232 connection, this means sending Control-S and Control-Q characters to stop and start transmission. Since software handshaking requires the transmission and processing of extra data it can be less efficient than hardware handshaking. (1996-10-16) 1 1 1 1 1 software interrupt An interrupt caused by a specific machine language operation code (e.g. the Motorola 68000's TRAP, the IBM System/390's SVC or the ARM's SWI) rather than by a hardware event. As with a hardware interrupt, this causes the processor to store the current state, store identifying information about the particular interrupt, and pass control to a first level interrupt handler. A trap is similar except that it is caused by an unexpected software condition or error (e.g. divide by zero, undefined instruction) rather than a deliberate instruction. (1995-02-14) 1 1 1 1 1 Software in the Public Interest, Inc. (SPI) A non-profit corporation which helps organisations develop and distribute open hardware and open software. SPI's goals are: * to create, form and establish an organization to formulate and provide software systems for use by the general public without charge; * to teach and train individuals regarding the use and application of such systems; * to hold classes, seminars and workshops concerning the proper use and application of computers and computer systems; * to endeavor to monitor and improve the quality of currently existing publicly available software; * to support, encourage and promote the creation and development of software available to the general public; * to provide information and education regarding the proper use of the Internet; * to organize, hold and conduct meetings, discussions and 1 1 1 1 1 software laser An optical laser works by bouncing photons back and forth between two mirrors, one totally reflective and one partially reflective. If the lasing material (usually a crystal) has the right properties, photons scattering off the atoms in the crystal will excite cascades of more photons, all in lockstep. Eventually the beam will escape through the partially reflective mirror. One kind of sorcerer's apprentice mode involving bounce messages can produce closely analogous results, with a cascade of messages escaping to flood nearby systems. By mid-1993 there had been at least two publicised incidents of this kind. [Jargon File] 1 1 1 1 1 software law Software may, under various circumstances and in various countries, be restricted by patent or copyright or both. Most commercial software is sold under some kind of software license. A patent normally covers the design of something with a function such as a machine or process. Copyright restricts the right to make and distribute copies of something written or recorded, such as a song or a book of recipies. Software has both these aspects - it embodies functional design in the algorithms and data structures it uses and it could also be considered as a recording which can be copied and "performed" (run). Look and feel lawsuits attempt to monopolize well-known command languages; some have succeeded. Copyrights on command languages enforce gratuitous incompatibility, close opportunities for competition, and stifle incremental improvements. 1 1 1 1 1 software life-cycle The phases a software product goes through between when it is conceived and when it is no longer available for use. The software life-cycle typically includes the following: requirements analysis, design, construction, testing (validation), installation, operation, maintenance, and retirement. The development process tends to run iteratively through these phases rather than linearly; several models (spiral, waterfall etc.) have been proposed to describe this process. Other processes associated with a software product are: quality assurance, marketing, sales and support. (1996-12-27) 1 1 1 1 1 Software Method Software Methodology 1 1 1 1 1 Software Methodology The study of how to navigate through each phase of the software process model (determining data, control, or uses hierarchies, partitioning functions, and allocating requirements) and how to represent phase products (structure charts, stimulus-response threads, and state transition diagrams). (1996-05-29) 1 1 1 1 1 software metric A measure of software quality which indicates the complexity, understandability, testability, description and intricacy of code. (1994-11-16) 1 1 1 1 1 software patent A patent intended to prevent others from using some programming technique. There have been several infamous patents for software techniques which most experienced programmers would consider fundamental or trivial, such as the idea of using exclusive-or to plot a cursor on a bitmap display. The spread of software patents could stifle innovation and make programming much harder because programmers would have to worry about patents when designing or choosing algorithms. There are over ten thousand software patents in the US, and several thousand more are issued each year. Each one may be owned by, or could be bought by, a grasping company whose lawyers carefully plan to attack people at their most vulnerable moments. Of course, they couch the threat as a reasonable offer to save you miserable years in court. Divide and conquer is the watchword: pursue one group at a time, while advising the rest of us to relax because we are in 1 1 1 1 1 software piracy Making or distributing unauthorised copies of software, either for kudos or for profit. See software theft. (2010-02-03) 1 1 1 1 1 software pirate Someone engaged in software piracy. (2010-02-03) 1 1 1 1 1 Software Practice and Experience (SPE) A journal about software. (http://columbus.cs.nott.ac.uk/compsci/spe/). [Publisher? UK?] (1997-12-12) 1 1 1 1 1 Software Productivity Centre (SPC) A non-profit organisation based in Vancouver, BC, Canada with the mandate to assist software developers to improve their software engineering process. (1998-10-13) 1 1 1 1 1 Software Publishing Certificate (SPC) A public key certification standard (PKCS) #7 signed data object containing X.509 certificates. SPCs are used for digital signatures as applicable to computer software. (2007-05-16) 1 1 1 1 1 Software Publishing Corporation (SPC) The company that produces Harvard Graphics. (http://spco.com/). (1998-10-13) 1 1 1 1 1 software reliability See also formal methods, safety-critical system. (ftp://ftp.sei.cmu.edu/pub/depend-sw). Mailing list: depend-sw@sei.cmu.edu. [Summary?] 1 1 1 1 1 software rot The tendency of software that has not been used in a while to fail; such failure may be semi-humorously ascribed to bit rot. More commonly, "software rot" strikes when a program's assumptions become out of date. If the design was insufficiently robust, this may cause it to fail in mysterious ways. For example, owing to shortsightedness in the design of some COBOL programs, many would have succumbed to software rot when their 2-digit year counters wrapped around at the beginning of the year 2000. A related incident made the news in 1990, when a gentleman born in 1889 applied for a driver's licence renewal in Raleigh, North Carolina. The system refused to issue the card, probably because with 2-digit years the ages 101 and 1 cannot be distinguished. Historical note: Software rot in an even funnier sense than the mythical one was a real problem on early research computers (e.g. the R1; see grind crank). If a program 1 1 1 1 1 software theft Unauthorised duplication and/or use of computer software. This usually means unauthorised copying, either by individuals for use by themselves or their friends or by companies who then sell the illegal copies to users. Many kinds of software protection have been invented to try to reduce software theft but, with sufficient effort, it is always possible to bypass or "crack" the protection, and software protection is often annoying for legitimate users. Software theft in 1994 was estimated to have cost $15 billion in worldwide lost revenues to software publishers. It is an offence in the UK under the Copyright, Designs and Patents Act 1988, which states that "The owner of the copyright has the exclusive right to copy the work." It is estimated that European software houses alone lose $6 billion per year through the unlawful copying and distribution of software, with much of this loss being through business users rather than "basement hackers". One Italian pirating 1 1 1 1 1 Software through Pictures (StP) A set of CASE tools distributed by Aonix (http://aonix.com/). (1999-05-21) 1 1 1 1 1 software tool A program that aids in the development of other programs. It may assist the programmer in the design, code, compile, link, edit, or debug phases. (1996-05-28) 1 1 1 1 1 Software Verification Research Centre (SVRC) A Special Research Centre of the Australian Research Council. Its mission is to create improved methods and tools, of industrial significance, for developing verified software. Two of the SVRC's core projects are the Cogito methodology and the Ergo proof tool. (1995-11-14) 1 1 1 1 1 Software Writer's Language (SWL) /swil/ An industrial strength dialect of Pascal that allowed multiple source code files, originally developed at Control Data Corporation (CDC) prior to 1973. Development continued at the Integrated Systems Laboratory. SWL was adopted by NCR as its corporate operating system and compiler implementation language (1978-1982+). The NCR SWL dialect was renamed NCRL (NCR Language) in 1981 and continued development [until ?]. (2003-12-31) 1 1 1 1 1 softwarily /soft-weir'i-lee/ In a way pertaining to software. "The system is softwarily unreliable." The adjective "softwary" is *not* used. See hardwarily. [Jargon File] 1 1 1 1 1 softy (IBM) Hardware hackers' term for a software expert who is largely ignorant of the mysteries of hardware. (1995-01-11) 1 1 1 1 1 SOH Start Of Header 1 1 1 1 1 SOHIO An early system on the IBM 705. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-11) 1 1 1 1 1 SoHo small-office/home-office. 1 1 1 1 1 SOIF Summary Object Interchange Format 1 1 1 1 1 SOJ Small Outline J 1 1 1 1 1 SOL 1. <language> Simulation Oriented Language. 2. Second-Order lambda-calculus. 3. Semantic Operating Language. Language for manipulating semantic networks for building cognitive models, particularly for natural language understanding. "Explorations in Cognition", D.A. Norman et al, W.H. Freeman 1974. 4. Shit Outta Luck. 1 1 1 1 1 Solaris Sun Microsystems, Inc.'s version of the Unix operating system. As well as the core operating system, Solaris inludes networking software, the Java Virtual Machine, the CDE/Desktop that includes an X11-based windowing environment and graphical user interface. Sun claim that Solaris is not just an operating system but an operating environment. Solaris 1.x was a retroactive (marketing?) name for SunOS 4.1.x (where x>=1). Solaris 2.x (which is the first version most people call Solaris) includes SunOS5.x, which is an SVR4-derived Unix, OpenWindows 3.x, and tooltalk. Version 2.7 ("Solaris 7") was around in 1999-03-02. Version 2.8 was released in June 2000. Latest version: 9, as of 2002-07-15. (http://sun.com/solaris/). (2002-07-15) 1 1 1 1 1 solid state (Often hyphenated when used as an adjective) A term describing any device that uses semiconductor components rather than electron tubes or relays. Semiconductors are "solid" in that they contain no gas ("vacuum" tubes contain a small amount as the vacuum is not perfect) or moving parts (like relays), but probably more important is the connotation of reliability and durability that made possible things like portable radios. (2007-09-21) 1 1 1 1 1 Solid State Disk (SSD) <storage> Any kind of solid-state storage device that appears to the system as a disk drive. SSDs are more expensive that the same capacity of magnetic disk but have much shorter access time. (2013-04-27) 1 1 1 1 1 solid-state storage device Any memory component with no moving parts, typically built around some kind of semiconductor integrated circuit. An example is bubble memory. See also: RAM disk. (2001-12-31) 1 1 1 1 1 SOLO [SOL (Semantic Operating Language) + LOGO]. A variant of LOGO with primitives for dealing with semantic networks and pattern matching rather than lists. ["A User-Friendly Software Environment for the Novice Programmer", M. Eisenstadt <marc@open.ac.uk>, CACM 27(12):1056-1064 (1983)]. 1 1 1 1 1 solution A marketroid term for something he wants to sell you without bothering you with the often dizzying distinctions between hardware, software, services, applications, file formats, companies, brand names and operating systems. Flash is a perfect image-streaming solution. "What is it?" "Um... about a thousand dollars." See also: technology. (1998-07-07) 1 1 1 1 1 Solution Based Modelling (SBM) A software development process described in the book Developing Object-Oriented Software for the Macintosh written by Neal Goldstein and Jeff Alger, published by Addison Wesley in 1992. 1 1 1 1 1 Solve Parallel object-oriented language. "Message Pattern Specifications: A New Technique for Handling Errors in Parallel Object- Oriented Systems", J.A. Purchase et al, SIGPLAN Notices 25(10):116-125 (OOPSLA/ECOOP '90) (Oct 1990). 1 1 1 1 1 SOM System Object Model. An implementation of CORBA by IBM. 1 1 1 1 1 Somar DumpAcl A utilty which provides a concise report of Windows NT file system permissions, to help find holes in system security. (1995-04-10) 1 1 1 1 1 Somar Software The distributors of Somar DumpAcl and other utilities for Windows NT. (http://somar.com/). Address: Washington, DC, USA. (1995-04-10) 1 1 1 1 1 some random X Used to indicate a member of class X, with the implication that Xs are interchangeable. "I think some random cracker tripped over the guest timeout last night." See also J. Random. [Jargon File] (1995-03-03) 1 1 1 1 1 Sonata The code name for the major Mac OS release due in mid-1999. (http://devworld.apple.com/mkt/informed/appledirections/mar97/roadmap.html). (1997-10-15) 1 1 1 1 1 SONET Synchronous Optical NETwork 1 1 1 1 1 Sony Playstation Playstation 1 1 1 1 1 SORCERER A simple tree parser generator by Terence Parr <parrt@s1.arc.umn.edu>. SORCERER is suitable for translation problems lying between those solved by code generator generators and by full source-to-source translator generators. SORCERER generates simple, flexible, top-down, tree parsers that, in contrast to code generators, may execute actions at any point during a tree walk. SORCERER accepts extended BNF notation, allows predicates to direct the tree walk with semantic and syntactic context information, and does not rely on any particular intermediate form, parser generator, or other pre-existing application. SORCERER is included in the Purdue Compiler-Construction Tool Set. Version: 1.00B (ftp://marvin.ecn.purdue.edu/pub/pccts/sorcerer/). E-mail: <parrt@acm.org> ("e-mail sor.tar.Z.uu" in subject). 1 1 1 1 1 sorcerer's apprentice mode (From Johann Wolfgang von Goethe's "Der Zauberlehrling", via the Walt Disney film "Fantasia") A bug in a protocol where, under some circumstances, the receipt of a message causes multiple messages to be sent, each of which, when received, triggers the same bug. Used especially of such behaviour caused by bounce message loops in electronic mail software. Compare broadcast storm, network meltdown, software laser, ARMM. Der Zauberlehrling (http://unix-ag.uni-kl.de/~conrad/lyrics/zauber.html). [Jargon File] (1999-10-08) 1 1 1 1 1 sort 1. <application, algorithm> To arrange a collection of items in some specified order. The items - records in a file or data structures in memory - consist of one or more fields or members. One of these fields is designated as the "sort key" which means the records will be ordered according to the value of that field. Sometimes a sequence of key fields is specified such that if all earlier keys are equal then the later keys will be compared. Within each field some ordering is imposed, e.g. ascending or descending numerical, lexical ordering, or date. Sorting is the subject of a great deal of study since it is a common operation which can consume a lot of computer time. There are many well-known sorting algorithms with different time and space behaviour and programming complexity. Examples are quicksort, insertion sort, bubble sort, heap sort, and tree sort. These employ many different data structures to store sorted data, such as arrays, 1 1 1 1 1 sorting sort 1 1 1 1 1 SOS 1. Scheme Object System. 2. An infamously losing text editor. Once, back in the 1960s, when a text editor was needed for the PDP-6, a hacker crufted together a quick-and-dirty "stopgap editor" to be used until a better one was written. Unfortunately, the old one was never really discarded when new ones (in particular, TECO) came along. SOS is a descendant ("Son of Stopgap") of that editor, and many PDP-10 users gained the dubious pleasure of its acquaintance. Since then other programs similar in style to SOS have been written, notably the early font editor BILOS /bye'lohs/, the Brother-In-Law Of Stopgap (the alternate expansion "Bastard Issue, Loins of Stopgap" has been proposed). 3. The PDP-10 instruction to decrease a value. Oppose AOS. [Jargon File] 1 1 1 1 1 sound 1. audio. 2. <logic> An inference system A is sound with respect to another system B if A can only reach conclusions which are true in B. A type inference system is considered sound with respect to a semantics if the type inferred for an expression is the same as the type inferred for the meaning of that expression under the semantics. The dual to soundness is completeness. (1995-03-01) 1 1 1 1 1 Sound Blaster The best known family of sound cards for the IBM PC from Creative Labs. [Features? Models? Reference?] (1998-04-28) 1 1 1 1 1 sound card A plug-in optional circuit card for an IBM PC. It provides high-quality stereo sound output under program control. A multimedia PC usually includes a sound card. One of the best known is the Sound Blaster. [Other kinds?] (1995-03-01) 1 1 1 1 1 soundex An algorithm for encoding a word so that similar sounding words encode the same. The first letter is copied unchanged then subsequent letters are encoded as follows: bfpv -> "1" cgjkqsxz -> "2" dt -> "3" l -> "4" 1 1 1 1 1 soundness The quality of being sound (2). 1 1 1 1 1 source source code 1 1 1 1 1 source code (Or "source", or rarely "source language") The form in which a computer program (software) is written by the programmer. Source code is written in some formal programming language which can be compiled automatically into object code or machine code or executed by an interpreter. Source code might be stored in a source code management system. If you have the source code for a program rather than just its compiled, executable form, then you can, with the right tools, modify it to fix bugs or add new features. This is the basis of the open source philosophy - empowering people to improve the software they use for the benefit of themselves and others. The Jargon File would have us believe that an old-time hacker might refer to source code informally as "English", with the implication that to him his favourite programming language is at least as readable as English. (2014-06-27) 1 1 1 1 1 source code control source code management 1 1 1 1 1 source code escrow An arrangement where some source code is held in escrow by a third party as long as it is supported by the vendors, but should they cease to support it, it becomes the property of the purchasers so that they can arrange for its continued maintenance. (1999-12-14) 1 1 1 1 1 source code management The use of software systems to help program developers keep track of version history of source code modules as well as releases, parallel versions (code branches), etc. The free CVS was an early example, mostly replaced by Subversion and git. Perforce is a powerful commercial product. SCCS was once popular on Unix and VSS is Microsoft's offering. (2011-12-16) 1 1 1 1 1 source language source code 1 1 1 1 1 source-level debugger A debugger that shows the programmer the line or expression in the source code that resulted in a particular machine code instruction of a running program loaded in memory. This helps the programmer to analyse a program's behaviour in the high-level terms like source-level flow control constructs, procedure calls, named variables, etc instead of machine instructions and memory locations. Source-level debugging also makes it possible to step through execution a line at a time and set source-level breakpoints. In order to support source-level debugging, the program must be compiled with this option enabled so that extra information is included in the executable code to identify the corresponding positions in the source code. A symbolic debugger is one level lower - it displays symbols (procedure and variable names) stored in the executable but not individual source code lines. 1 1 1 1 1 source of all good bits A person from whom (or a place from which) useful information may be obtained. If you need to know about a program, a guru might be the source of all good bits. The title is often applied to a particularly competent secretary. [Jargon File] (2001-01-27) 1 1 1 1 1 source package A collection (usually an archive file) containing all the files necessary to build and modify a piece of software. A Debian source package includes the original source archive (.orig.tar.gz), Debianisation diffs (-<debian-version>.diff.gz) and a Debian source control file (-<debian-version>.dsc). (2000-05-31) 1 1 1 1 1 source route An electronic mail address which specifies the route the message should take as a sequence of hostnames. It is called a source route because the route is determined at the source of the message rather than at each stage as is now more common. The most common kind of source route is a UUCP style bang path, "foo!bar!baz!fred'. The RFC 822 syntax, @foo:@bar:fred@baz, is seldom seen because most systems which understand RFC 822 also perform automatic routing based on the destination hostname. A third, intermediate, form is sometimes seen: "fred%baz%bar@foo.com". 1 1 1 1 1 source routing source route 1 1 1 1 1 southbridge The integrated circuit in a core logic chip set that controls the IDE bus, USB, plug-n-play support, the PCI-ISA bridge, keyboard/mouse controller, power management, and various other features. One brand provides sound card functions. Other functions are provided by the northbridge chip. (http://maximumpc.com/terminator/terminator_s.html). (2000-01-15) 1 1 1 1 1 SP Simplicity and Power. A Prolog-like language. ["Simplicity and Power - Simplifying Ideas in Computing", J.G. Wolff, Computer J 33(6):518-534 (Dec 1990)]. (1994-12-01) 1 1 1 1 1 SP2 SP/2 [Which is correct?] 1 1 1 1 1 SP/2 Scalable POWERparallel 2. A line of RISC-based processors from IBM using symmetric multi-processing. SP/2 replaced SP/1. The SP2 is a classical MPP design, based on a Shared Nothing architecture. The SP2 is an example of the Distributed Memory Processor (DMP) parallel model, with individual nodes interconnected over a LAN, or a High-Performance Switch (HPS). SP2 systems can have from 2 to 512 nodes. Each node is a RISC system/6000 running IBM's AIX operating system. The SP2 supports applications in both technical and commercial environments. In terms of commercial applications, the SP2 is typically being used in support of, MIS/DSS including data mining, business applications e.g. SAP, Alternative Mainframe/Mainframe Offload, LAN Server Consolidation. (1995-03-07) 1 1 1 1 1 space The space character, ASCII 32. See octal forty. (2007-01-29) 1 1 1 1 1 space bar (Or "space key") The extra-wide key at the near edge of every keyboard that is used to enter a space character. In some Graphical User Interfaces, the space bar can be used to select the current item where the context does not allow text entry, e.g. when the input focus is on a push button or tick box. (2007-01-29) 1 1 1 1 1 space-cadet keyboard A now-legendary device used on MIT Lisp machines, which inspired several still-current jargon terms and influenced the design of Emacs. It was equipped with no fewer than *seven* shift keys: four keys for bucky bits ("control", "meta", hyper, and "super") and three like regular shift keys, called "shift", "top", and "front". Many keys had three symbols on them: a letter and a symbol on the top, and a Greek letter on the front. For example, the "L" key had an "L" and a two-way arrow on the top, and the Greek letter lambda on the front. By pressing this key with the right hand while playing an appropriate "chord" with the left hand on the shift keys, you could get the following results: L lowercase l shift-L uppercase L 1 1 1 1 1 space complexity The way in which the amount of storage space required by an algorithm varies with the size of the problem it is solving. Space complexity is normally expressed as an order of magnitude, e.g. O(N^2) means that if the size of the problem (N) doubles then four times as much working storage will be needed. See also computational complexity, time complexity. (1996-05-08) 1 1 1 1 1 space key space bar 1 1 1 1 1 space leak A data structure which grows bigger, or lives longer, than might be expected. Such unexpected memory use can cause a program to require more garbage collections or to run out of heap. Space leaks in functional programs usually result from excessive laziness. For example, the Haskell function sum [] = 0 sum (x:xs) = x + sum xs when applied to a list will build a chain of closures for the additions and only when it reaches the end of the list will it perform the additions and free the storage. Another example is the function mean l = sum l / length l The sum function forces the entire list l to be evaluated and built in the heap. None of it can be garbage collected until 1 1 1 1 1 SPACEWAR A space-combat simulation game for the PDP-1 written in 1960-61 by Steve Russell, an employee at MIT. SPACEWAR was inspired by E. E. "Doc" Smith's "Lensman" books, in which two spaceships duel around a central sun, shooting torpedoes at each other and jumping through hyperspace. MIT were wondering what to do with a new vector video display so Steve wrote the world's first video game. Steve now lives in California and still writes software for HC12 emulators. SPACEWAR aficionados formed the core of the early hacker culture at MIT. Nine years later, a descendant of the game motivated Ken Thompson to build, in his spare time on a scavenged PDP-7, the operating system that became Unix. Less than nine years after that, SPACEWAR was commercialised as one of the first video games; descendants are still feeping in video arcades everywhere. ["SPACEWAR" or "Space Travel"?] [Jargon File] 1 1 1 1 1 SPADE Specification Processing And Dependency Extraction. Specification language. G.S. Boddy, ICL Mainframes Div, FLAG/UD/3DR.003 1 1 1 1 1 spaghetti code A pejorative term for code with a complex and tangled control structure, especially one using many GOTOs, exceptions, or other "unstructured" branching constructs. The synonym "kangaroo code" has been reported, doubtless because such code has so many jumps in it. Object-oriented programming may also feature spaghetti inheritance or spaghetti with meatballs code. [Jargon File] (2013-07-31) 1 1 1 1 1 spaghetti inheritance A term used by users of object-oriented languages with inheritance, such as Smalltalk for a convoluted class-subclass graph, often resulting from carelessly deriving subclasses from other classes just for the sake of reusing their code. Coined to discourage such practice, through guilt-by-association with spaghetti code. [Jargon File] (2013-07-31) 1 1 1 1 1 spaghetti with meatballs code Object-oriented code that depends on messy procedural spaghetti code. May also feature spaghetti inheritance. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-07-31) 1 1 1 1 1 spam 1. <messaging> (From Hormel's Spiced Ham, via the Monty Python Spam song) To post irrelevant or inappropriate messages to one or more Usenet newsgroups, mailing lists, or other messaging system in deliberate or accidental violation of netiquette. It is possible to spam a newsgroup with one well- (or ill-) planned message, e.g. asking "What do you think of abortion?" on soc.women. This can be done by cross-posting, e.g. any message which is crossposted to alt.rush-limbaugh and alt.politics.homosexuality will almost inevitably spam both groups. (Compare troll and flame bait). Posting a message to a significant proportion of all newsgroups is a sure way to spam Usenet and become an object of almost universal hatred. Canter and Siegel spammed the net with their Green card post. If you see an article which you think is a deliberate spam, DO NOT post a follow-up - doing so will only contribute to the 1 1 1 1 1 spamdex (Presumably from "spam", "index") word spamming. "Spamdexing has come a long way from the halcyon days of the summer of 1995. Back then, all one needed to do was add the word 'sex' a thousand times at the end of a Web page to attract attention from the likes of Lycos. The search-engine operators caught on fast -- Andrew Leonard, Hotwired 1996" (http://packet.com/packet/leonard/96/32/index3a.html). (1997-04-09) 1 1 1 1 1 spamming spam 1 1 1 1 1 spanning tree algorithm An IEEE 802.1 standard providing distributed routing over multiple LANs connected by bridges. (2010-09-26) 1 1 1 1 1 SPAR Early system on Datatron 200 series. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 SPARC 1. <processor> Scalable Processor ARChitecture. 2. <database> ANSI/SPARC Architecture. (1999-02-27) 1 1 1 1 1 SPARC International, Inc. An organisation established to promote the Scalable Processor ARChitecture (SPARC). Their main service is conformance testing. They also produce the "SPARC flash" newsletter and publish lists of SPARC compliant machines tested by SPARC International to be binary compatible with other compliant machines. (http://sparc.com/). SPARC(R) is a registered trademark of SPARC International, Inc. in the United States and other countries. (1995-01-04) 1 1 1 1 1 SPARCStation A family of workstations from Sun Microsystems based on the SPARC architecture. Models include the SPARCStation 1, 1+, SLC, SPARCStation ELC, IPX, SPARCStation 5, SPARCStation 10 and SPARCStation 20. (1994-11-23) 1 1 1 1 1 SPARCstation 10 A SPARCStation with a 4-way associative data cache and a five-way associative instruction cache. The 10/31, 10/41 and 10/51 also have a secondary cache not present on earlier SPARCStations. (1994-12-02) 1 1 1 1 1 SPARCstation 20 A SPARCStation based on the HyperSPARC processor. The 20 is compatible with the earlier SPARCstation 10. It has a clock rate of 100MHz and delivers a SPECfp92 of 127.6. The SPARCstation 20 Model 71 and 712MP uses the 75MHz SuperSPARC processors that give a 35% and 14% boost to SPECint92 and SPECfp92 respectively compared to the 61/612MP. (1994-12-02) 1 1 1 1 1 SPARCsystem 4 A computer built with the MicroSPARC ii 70MHz CPU as used in the SPARC 5 Model 70. The SPARCsystem 4 is basically a cheaper, cut-down SPARC 5. It has an 8-bit pixel accelerator instead of the SBus Turbo GX card. Memory expansion is limited to 160 MB. Availability was planned for March/April 1995. (1995-02-07) 1 1 1 1 1 SPARC Xterminal 1 Sun's lowest cost networked Unix desktop, it is board-upgradeable to a SPARC 4. It comes with a choice of frame buffers: 8-bit colour, Turbo GX, or Turbo GX plus. This product was expected to replace the SPARCclassic X. UK availability was planned for March 1995. (1995-02-08) 1 1 1 1 1 SPARK An annotated subset of Ada supported by tools supplied by Praxis Critical Systems (originally by PVL). (http://sparkada.com). (2001-07-12) 1 1 1 1 1 SPARK Annotation Language (SAL) ICL, Ltd. Used in the verification of SPARK programs against Z specifications. (1994-12-08) 1 1 1 1 1 SPARKS Fortran superset, used in Fundamentals of Data Structures, E. Horowitz & S. Sahni, Computer Science Press 1976 (2007-03-21) 1 1 1 1 1 sparse A sparse matrix (or vector, or array) is one in which most of the elements are zero. If storage space is more important than access speed, it may be preferable to store a sparse matrix as a list of (index, value) pairs or use some kind of hash scheme or associative memory. (1995-01-16) 1 1 1 1 1 Spatial Technologies Distributors of the ACIS solid modelling engine. [More info?] (1999-06-29) 1 1 1 1 1 spawn To create a child process in a multitasking operating system. E.g. Unix's fork system call or one of the spawn() library routines provided by most MS-DOS, Novell NetWare and OS/2 C compilers - spawnl(), spawnle(), etc. (1995-03-28) 1 1 1 1 1 SPC 1. <business> Statistical Process Control. Something to do with quality management. [What is it?] 2. <body> Software Productivity Centre. 3. <company> Software Publishing Corporation. 4. <security> Software Publishing Certificate. 1 1 1 1 1 SPD Serial Presence Detect 1 1 1 1 1 SPDL Standard Page Description Language A draft within the ODA standard. (1995-03-28) 1 1 1 1 1 SPE Software Practice and Experience 1 1 1 1 1 Speakeasy Simple array-oriented language with numerical integration and differentiation, graphical output, aimed at statistical analysis. ["Speakeasy", S. Cohen, SIGPLAN Notices 9(4), (Apr 1974)]. ["Speakeasy-3 Reference Manual", S. Cohen et al. 1976]. 1 1 1 1 1 speaker 1. <audio, hardware> loudspeaker. 2. The person who is (assumed to be) talking. (1996-12-01) 1 1 1 1 1 SPEC Standard Performance Evaluation Corporation. A non-profit corporation registered in California formed to "establish, maintain and endorse a standardized set of relevant benchmarks that can be applied to the newest generation of high-performance computers (from SPEC's" bylaws). The founders believe that the user community will benefit greatly from an objective series of applications-oriented tests, which can serve as common reference points and be considered during the evaluation process. SPEC develops suites of benchmarks intended to measure computer performance. These are available to the public for a fee covering development and administration costs. The current (14 Nov 94) SPEC benchmark suites are: CINT92 (CPU intensive integer benchmarks); CFP92 (CPU intensive floating-point benchmarks); SDM (UNIX Software Development Workloads); SFS (System level file server (NFS) workload). Results (ftp://ftp.cdf.toronto.edu/pub/spectable). SPEC also publishes a quarterly report of SPEC news and 1 1 1 1 1 Spec A specification language. It expresses black box interface specifications for large distributed systems with real-time constraints. It incorporates conceptual models, inheritance and the event model. It is a descendant of MSG.84. ["An Introduction to the Specification Language Spec", V. Berzins et al, IEEE Software 7(2):74-84 (Mar 1990)]. 1 1 1 1 1 spec specification 1 1 1 1 1 SPECbase_fp92 A variant of SPECfp92 that reports "baseline" results, using stricter run rules. (1994-11-14) 1 1 1 1 1 SPECbase_int92 A variant of SPECint92 that reports "baseline" results, using stricter run rules. (1994-11-14) 1 1 1 1 1 SPECbaserate A variant of SPECrate that reports "baseline" results, using stricter run rules. See SPECrate_base_fp92, SPECrate_base_int92. (1994-11-14) 1 1 1 1 1 SPEC CFP92 A benchmark suite from SPEC containing 14 programs performing floating-point computations. 12 are written in Fortran and two in C. They can be used to estimate the performance of CPU, memory system, and compiler code generation. The individual programs are Circuit Design, Simulation (2x), Quantum Chemistry (3x), Electromagnetism, Geometric Translation, Optics, Robotics, Medical Simulation, Quantum Physics, Astrophysics, NASA Kernels. The benchmark suite can be used either for speed measurement, resulting in SPEC ratios, or for throughput measurement, resulting in SPEC rates (1994-11-15) 1 1 1 1 1 SPEC CINT92 A benchmark suite from SPEC, which contains six benchmarks in C performing integer computations. They can be used to estimate the performance of CPU, memory system, and compiler code generation. The individual programs are Logic Design (2x), Interpreter, Data Compression, Spreadsheet. The approximate size of the suite is 85500 lines of source code without comments. The benchmark suite can be used either for speed measurement, resulting in SPEC ratios, or for throughput measurement, resulting in SPEC rates (1994-11-15) 1 1 1 1 1 SPECfp92 A benchmark result derived from the results of a set of CPU intensive floating-point benchmarks from SPEC (the geometric mean of the 14 SPEC ratios of CFP92). SPECfp92 can be used to estimate a machine's single-tasking performance on floating-point code. Results (ftp://ftp.nosc.mil/pub/aburto/specfp92.tbl). (1994-11-14) 1 1 1 1 1 SPECIAL A specification language, developed at SRI around 1976, used to specify the abstract machines in Hierarchical Design Methodology (HDM). ["SPECIAL - A Specification and Assertion Language", L. Robinson et al, TR CSL-46, SRI, Jan 1977]. (2012-07-08) 1 1 1 1 1 special-case To write unique code to handle input to or situations arising in a program that are somehow distinguished from normal processing. This would be used for processing of mode switches or interrupt characters in an interactive interface (as opposed, say, to text entry or normal commands), or for processing of hidden flags in the input of a batch program or filter. [Jargon File] 1 1 1 1 1 Special Interest Group (SIG) One of several technical areas, sponsored by the Association for Computing Machinery. Well-known SIGs include SIGPLAN (the Special Interest Group on Programming Languages), SIGARCH (the Special Interest Group for Computer Architecture) and SIGGRAPH (the Special Interest Group for Computer Graphics). (1994-10-27) 1 1 1 1 1 specialisation A reduction in generality, usually for the sake of increased efficiency. If a piece of code is specialised for certain values of certain variables (usually function arguments), this is known as "partial evaluation". In a language with overloading (e.g. Haskell), an overloaded function might be specialised to a non-overloaded instance at compile-time if the types of its arguments are known. 1 1 1 1 1 specification (spec) A document describing how some system should work. (2001-02-06) 1 1 1 1 1 specific markup In computerised document preparation, a method of adding formatting commands to the text to control layout, such as new line, new page, centre text etc. Compare generic markup. (2001-02-06) 1 1 1 1 1 SPECint92 A benchmark result derived from the results of a set of integer benchmarks from SPEC (geometric mean of the 6 SPEC ratios of CINT92) which can be used to estimate a machine's single-tasking performance on integer code. SPECint92 obsoletes SPECint89. Results (ftp://ftp.nosc.mil/pub/aburto/specin92.tbl). See also SPECbase_int92. (1994-11-14) 1 1 1 1 1 SPECmark The average of a set of floating-point and integer SPEC benchmark results. While the old average SPECmark89 has been popular with the industry and the press, SPEC has intentionally *not* defined an average "SPECmark92" over all CPU benchmarks of the 1992 suites (CINT92 and CFP92), for the following reasons: With 6 integer (CINT92) and 14 floating-point (CFP92) benchmarks, the average would be biased too much toward floating-point. Customers' workloads are different, some integer-only, some floating-point intensive, some mixed. Current processors have developed their strengths in a more diverse way (some more emphasizing integer performance, some more floating-point performance) than in 1989. Some SPECmark results are available here (ftp://ftp.cdf.toronto.edu/pub/spectable). See also SPECint92, SPECfp92, SPECrate_int92, SPECrate_fp92. 1 1 1 1 1 SPECmark89 An old SPECmark benchmark result derived from a set of floating-point and integer benchmarks. It is the geometric mean of ten SPEC ratios of the outdated 1989 SPEC benchmark suite. The use of SPECmark89 is strongly discouraged, having been superseded by CINT92 and CFP92. (1994-11-29) 1 1 1 1 1 SPECOL ["SPECOL - A Computer Enquiry Language for the Non-Programmer", B.T. Smith, Computer J 11:121 (1968)]. 1 1 1 1 1 SPEC rate Results of the throughput measurement using SPEC benchmark suites CINT92 and CFP92. With the throughput measurement method, several copies of a given benchmark are executed. The method is particularly suitable for multiprocessor systems. The results, called SPEC rate, express how many jobs of a particular type (characterised by the individual benchmark) can be executed in a given time (The SPEC reference time happens to be a week, the execution times are normalized with respect to a VAX 11/780). The SPEC rates therefore characterise the capacity of a system for compute-intensive jobs of similar characteristics. See also SPEC ratio. (1994-11-14) 1 1 1 1 1 SPECrate_base_fp92 A variant of SPECrate_fp92 that reports baseline results, using stricter run rules. (1994-11-15) 1 1 1 1 1 SPECrate_fp92 A benchmark result derived from the results of a set of floating-point benchmarks (the geometric mean of 14 SPEC rates from CFP92) run multiple times simultaneously, which can be used to estimate a machine's overall multi-tasking throughput for floating-point code. It is typically used on multiprocessor machines. SPECrate_fp92 obsoletes SPECfpThruput89. (1994-11-14) 1 1 1 1 1 SPECrate_int92 The integer SPECrate derived from the results of a set of integer benchmarks (the geometric mean of six SPEC rates from CINT92) run multiple times simultaneously, and can be used to estimate a machine's overall multi-tasking throughput for integer code. It is typically used on multiprocessor machines. SPECrate_int92 obsoletes SPECintThruput89. See also SPECbaserate. (1994-11-14) 1 1 1 1 1 SPEC ratio Results for each individual benchmark of the SPEC benchmark suites, for example CINT92 and CFP92, expressed as the ratio of the wall clock time to execute one single copy of the benchmark, compared to a fixed "SPEC reference time", which was chosen early-on as the execution time on a VAX 11/780. See also SPEC rate. (1994-11-14) 1 1 1 1 1 Spectral Band Replication (SBR) Guessing the nontransmitted higher frequency range of a compressed audio file by some helper bits (transmiited with the stream) and the transmitted base band. SBR allows a restoration (not reconstruction) of the upper frequency range without lots of bits. It was developed by Coding Technology (http://codingtechnology.com/), and is useful for medium and high quality coding at low and medium data rates. It is used by Digital Radio Mondiale and MP3 Pro. (2004-12-10) 1 1 1 1 1 Spectrum ZX Spectrum 1 1 1 1 1 speculative evaluation A technique used in parallel processing where some evaluation may be started before it is known whether it is needed (Eager evaluation). This may result in some wasted processing and may introduce unnecessary non-terminating processes but it can reduce the overall run time by making some needed results available earlier than they would be otherwise. Opposite: conservative evaluation. (1995-05-05) 1 1 1 1 1 speculative execution A technique allows a superscalar processor to keep its functional units as busy as possible by executing instructions before it is known that they will be needed. The Intel P6 uses speculative execution. Compare branch prediction, speculative evaluation. (1995-05-05) 1 1 1 1 1 Speech Application Programming Interface (SAPI) Microsoft's standard API for speech synthesis and speech recognition in Windows 95. The idea is to let developers try out and use various low-level speech software from any number of verndors, while retaining the same API. Mike Rozak is the lead of the SAPI project at Microsoft. Numerous major speech vendors have announced SAPI-support plans. SRAPI, the competing speech recognition API by Lotus/WordPerfect, is fast becoming obsolete. (1996-03-04) 1 1 1 1 1 speech recognition (Or voice recognition) The identification of spoken words by a machine. The spoken words are digitised (turned into sequence of numbers) and matched against coded dictionaries in order to identify the words. Most systems must be "trained," requiring samples of all the actual words that will be spoken by the user of the system. The sample words are digitised, stored in the computer and used to match against future words. More sophisticated systems require voice samples, but not of every word. The system uses the voice samples in conjunction with dictionaries of larger vocabularies to match the incoming words. Yet other systems aim to be "speaker-independent", i.e. they will recognise words in their vocabulary from any speaker without training. Another variation is the degree with which systems can cope with connected speech. People tend to run words together, e.g. "next week" becomes "neksweek" (the "t" is dropped). For 1 1 1 1 1 Speech Recognition Application Program Interface (SRAPI) Novell, Inc.'s high level API for speech recognition which will be rolled out with WordPerfect 7.0 and Perfect Office 7.0. SRAPI is in competition with SAPI from Microsoft, a high level API which currently addresses command and control (but not yet dictation). [Byte; March 1996; page 30; "Battle of the Dictaion APIs"]. (1996-03-12) 1 1 1 1 1 speech synthesis The generation of an sound waveform of human speech from a textual or phonetic description. See also speech recognition. There are demonstrations which say a number (http://cs.yale.edu/cgi-bin/saynumber.au) or say a phrase (http://wwwtios.cs.utwente.nl/say/form/). 1 1 1 1 1 SPEED Early system on LGP-30. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 Speedcoding A pseudocode interpreter for mathematics on IBM 701 and IBM 650 written by John Backus in 1953. [Sammet 1969, p. 130]. (2000-03-27) 1 1 1 1 1 Speedcoding 3 [Listed in CACM 2(5):16, May 1959]. (2000-03-27) 1 1 1 1 1 SPEEDEX Early system on IBM 701. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 speedometer A pattern of lights displayed on a linear set of LEDs (today) or nixie tubes (yesterday, on ancient mainframes). The pattern is shifted left every N times the operating system goes through its main loop. A swiftly moving pattern indicates that the system is mostly idle; the speedometer slows down as the system becomes overloaded. The speedometer on Sun Microsystems hardware bounces back and forth like the eyes on one of the Cylons from the wretched "Battlestar Galactica" TV series. Historical note: One computer, the GE 600 (later Honeywell 6000) actually had an *analog* speedometer on the front panel, calibrated in instructions executed per second. [Jargon File] 1 1 1 1 1 spell incantation 1 1 1 1 1 spelling flame A Usenet posting ostentatiously correcting a previous article's spelling, possibly as a way of casting scorn on the point the article was trying to make, instead of actually responding to that point (compare dictionary flame). Of course, people who are more than usually slovenly spellers are prone to think *any* correction is a spelling flame. It's an amusing comment on human nature that spelling flames themselves often contain spelling errors. [Jargon File] (1994-11-22) 1 1 1 1 1 Sperry Corporation The company which merged with the Burroughs Corporation to form Unisys Corporation. Divisions included Sperry Univac, Sperry Flight Systems, and others. Some of these were sold off after the merger. (1995-03-27) 1 1 1 1 1 Sperry Univac One of the divisions of Sperry Corporation at the time that company merged with the Burroughs Corporation to form Unisys Corporation. [Connection with the Univac computer?] (1994-11-22) 1 1 1 1 1 SPG System Program Generator. A compiler-writing language. ["A System Program Generator", D. Morris et al, Computer J 13(3) (1970)]. 1 1 1 1 1 SPGA Staggered Pin Grid Array 1 1 1 1 1 SPI 1. <company> Software in the Public Interest, Inc.. 2. <hardware> Serial Peripheral Interface. (2003-07-13) 1 1 1 1 1 Spice Lisp A flavour of Lisp, the sources of which (in Lisp) are available from CMU. (1998-03-14) 1 1 1 1 1 SPID Service Provider ID 1 1 1 1 1 spider (Or "robot", "crawler") A program that automatically explores the web by retrieving a document and recursively retrieving some or all the documents that are referenced in it. This is in contrast with a normal web browser operated by a human that doesn't automatically follow links other than inline images and URL redirection. The algorithm used to pick which references to follow strongly depends on the program's purpose. Index-building spiders usually retrieve a significant proportion of the references. The other extreme is spiders that try to validate the references in a set of documents; these usually do not retrieve any of the links apart from redirections. The standard for robot exclusion is designed to avoid some problems with spiders. Early examples were Lycos and WebCrawler. Home (http://info.webcrawler.com/mak/projects/robots/robots.html). 1 1 1 1 1 Spiderweb A program for creating versions of Knuth's WEB self-documenting programs ("literate programming"). (ftp://princeton.edu/). (1999-08-26) 1 1 1 1 1 spiffy /spi'fee/ 1. Said of programs having a pretty, clever, or exceptionally well-designed interface. "Have you seen the spiffy X version of empire yet?" This was common mainstream slang during the 1940s. 2. Said sarcastically of a program that is perceived to have little more than a flashy interface going for it. Which meaning should be drawn depends delicately on tone of voice and context. [Jargon File] 1 1 1 1 1 spike To defeat a selection mechanism by introducing a (sometimes temporary) device that forces a specific result. The word is used in several industries; telephone engineers refer to spiking a relay by inserting a pin to hold the relay in either the closed or open state, and railroaders refer to spiking a track switch so that it cannot be moved. In programming environments it normally refers to a temporary change, usually for testing purposes (as opposed to a permanent change, which would be called hard-coded). (1999-10-18) 1 1 1 1 1 spill register spilling 1 1 1 1 1 spim (From spam and IM) Unsolicited commercial messages sent via an instant messaging system, instant messenger spam. (2008-01-21) 1 1 1 1 1 spin Equivalent to buzz. More common among C and Unix programmers. [Jargon File] (2008-01-21) 1 1 1 1 1 spin control A type of input control available on most graphical user interfaces, consisting of a text box or list control with associated up and down buttons. The user can either type in the text box or select an item from the list by clicking on it directly, or they can repeatedly select the next or previous value by clicking the up or down button. (2008-09-26) 1 1 1 1 1 spinner spin control 1 1 1 1 1 spiral model A software life-cycle model which supposes incremental development, using the waterfall model for each step, with the aim of managing risk. In the spiral model, developers define and implement features in order of decreasing priority. [Barry Boehm, "A Spiral Model of Software Development and Enhancement", ACM SIGSOFT Software Engineering Notes, August 1986]. [Barry Boehm "A Spiral Model of Software Development and Enhancement" IEEE Computer, vol.21, #5, May 1988, pp 61-72]. [Better explanation?] (1997-11-23) 1 1 1 1 1 SPIT Language for IBM 650. (See IT). 1 1 1 1 1 SPITBOL SPeedy ImplemenTation of snoBOL. "Macro SPITBOL - A SNOBOL4 Compiler", R.B.K. Dewar et al, Soft Prac & Exp 7:95-113, 1971. Current versions: SPITBOL-68000, Sparc SPITBOL from Catspaw Inc, (719)539-3884. 1 1 1 1 1 spiware Misspelling of spyware. (2008-10-07) 1 1 1 1 1 SP/k (Subset PL/I, k=1..8) A series of PL/I subsets, simplified for student use. ["SP/k: A System for Teaching Computer Programming", R.C. Holt et al, CACM 20(5):301-309, May 1977]. (1997-12-27) 1 1 1 1 1 SPL 1. Synchronous Programming Language. A DSP language. Introduction to the SPL Compiler, Computalker Consultants, 1986 2. Space Programming Language. Realtime language used by the US Air Force for aerospace software. Aka SPL/J6. Similar to JOVIAL. "Space Programming Language Development", SAMSO TP 70-325, System Development Corp (Sep 1970). (See CLASP). 3. System Programming Language. HP, 1977. An ALGOL-like language for the HP3000 computer allowing inline assembly code. MPE, the OS for the HP3000 was written in SPL. Pub.No.30000-90024, HP. See also SPLash!. 4. Systems Programming Language. PRIME Computer, 80's. A variant of PL/I used on PRIME computers. PL/I subset G, less I/O plus a few extensions. SPL User's Reference Guide, Prime. (See PL/P.) 5. Systems Programming Language. A PL/I subset/extension for the P1000. 1 1 1 1 1 SPL/1 SPL/I 1 1 1 1 1 SPLash! 1. Software Research Northwest, 1987. Compiler for SPL[3]. 2. Systems Programming LAnguage for Software Hackers. Mentioned in TeX for the Impatient, Paul W. Abrahams, A-W 1990 1 1 1 1 1 splash screen An initial screen displayed by interactive software, usually containing a logo, version information, author credits and/or a copyright notice. The term originated among Macintosh users and spread, the synonym banner was once also used. [Jargon File] (1998-04-28) 1 1 1 1 1 splat 1. Name used in many places (DEC, IBM, and others) for the asterisk ("*") character (ASCII 0101010). This may derive from the "squashed-bug" appearance of the asterisk on many early line printers. 2. Name used by some MIT people for the "#" character (ASCII 35). 3. (Rochester Institute of Technology) The feature key on a Mac (same as alt). 4. An obsolete name used by some people for the Stanford/ITS extended ASCII circle-x character. This character is also called "blobby" and "frob", among other names; it is sometimes used by mathematicians as a notation for "tensor product". 5. An obsolete name for the semi-mythical Stanford extended ASCII circle-plus character. See also ASCII. [Jargon File] 1 1 1 1 1 SPL/I Signal Processing Language One. (Or "SPL/1") A language designed by Intermetrics for acoustic signal processing. It has graphics and multiprocessing features. ["SPL/I Language Reference Manual", M.S. Kosinski, Intermetrics Report 172-1 (July 1976)]. (1995-01-19) 1 1 1 1 1 SPLINTER A PL/I interpreter with debugging features. [Sammet 1969, p.600]. (1995-01-19) 1 1 1 1 1 split chunker 1 1 1 1 1 Split-C Parallel extension of C for distributed memory multiprocessors. Aims to provide efficient low-level access to the underlying machine. CM5 (ftp://ftp.cs.berkeley.edu/ucb/CASTLE/Split-C). Mail-list: split-c@boing.cs.berkeley.edu. 1 1 1 1 1 splot A graph plotting package from Stanford University which produces encapsulated PostScript. splot is more flexible than gnuplot in producing histograms, and you can set font and symbol sizes individually. (1997-09-26) 1 1 1 1 1 SPLX Specification Language for Parallel cross-product of processes and sequential modules. ["Parallel Module Specification on SPLX", C.F. Nourani, SIGPLAN Notices 27(1):114-115, Jan 1992]. (1997-09-26) 1 1 1 1 1 SPM Sequential Parlog Machine 1 1 1 1 1 SPMD single processor/multiple data 1 1 1 1 1 SPML server-parsed HTML 1 1 1 1 1 spod (Great Britain) A lower form of life found on chat systems and MUDs. The spod has few friends in RL and uses chat instead, finding communication easier and preferable over the net. He has all the negative traits of the computer geek without having any interest in computers per se. Lacking any knowledge of, or interest in, how networks work, and considering his access a God-given right, he is a major irritant to sysadmins, clogging up lines in order to reach new MUDs, following passed-on instructions on how to sneak his way onto Internet ("Wow! It's in America!") and complaining when he is not allowed to use busy routes. A true spod will start any conversation with "Are you male or female?" (and follow it up with "Got any good numbers/IDs/passwords?") and will not talk to someone physically present in the same terminal room until they log onto the same computer that he is using and enter chat. Compare newbie, tourist, weenie, twink, terminal 1 1 1 1 1 spoiler 1. A remark which reveals important plot elements from books or movies, thus denying the reader (of the article) the proper suspense when reading the book or watching the movie. 2. Any remark which telegraphs the solution of a problem or puzzle, thus denying the reader the pleasure of working out the correct answer (see also interesting). Either sense readily forms compounds like "total spoiler", "quasi-spoiler" and even "pseudo-spoiler". By convention, Usenet news articles which are spoilers in either sense should contain the word "spoiler" in the Subject: line, or guarantee via various tricks that the answer appears only after several screens-full of warning, or conceal the sensitive information via rot13, or some combination of these techniques. [Jargon File] (1995-01-18) 1 1 1 1 1 sponge A kind of Unix filter that reads its entire input before writing any output, e.g. sort. Unlike most filters, a sponge can safely overwrite the input file with the output data. On a file system with file versioning (like ITS or VMS) the distinction is less significant because output would be written to a new version of the input file anyway. See also slurp. [Jargon File] (2014-06-21) 1 1 1 1 1 spoo Variant of spooge, sense 1. [Jargon File] 1 1 1 1 1 spoof spoofing 1 1 1 1 1 spoofing A technique used to reduce network overhead, especially in wide area networks (WAN). Some network protocols send frequent packets for management purposes. These can be routing updates or keep-alive messages. In a WAN this can introduce significant overhead, due to the typically smaller bandwidth of WAN connections. Spoofing reduces the required bandwidth by having devices, such as bridges or routers, answer for the remote devices. This fools (spoofs) the LAN device into thinking the remote LAN is still connected, even though it's not. The spoofing saves the WAN bandwidth, because no packet is ever sent out on the WAN. LAN protocols today do not yet accommodate spoofing easily. ["Network Spoofing" by Jeffrey Fritz, BYTE, December 1994, pages 221 - 224]. (1995-01-13) 1 1 1 1 1 spooge /spooj/ Inexplicable or arcane code, or random and probably incorrect output from a computer program. [Jargon File] (1995-01-12) 1 1 1 1 1 SPOOL Acronym for Simultaneous Peripheral Operation On-Line; but see also spool. [Jargon File] (1996-05-20) 1 1 1 1 1 Spool An object-oriented logic programming language. ["An Experience with a Prolog Based Language", K. Fukunaga et al, SIGPLAN Notices 21(11):224-231 (Nov 1986) (OOPSLA '86)]. [Jargon File] (1995-03-25) 1 1 1 1 1 spool To send files to some device or program (a spooler or demon) that puts them in a queue for later processing of some kind. Without qualification, the spooler is the "print spooler" controlling output of jobs to a printer; but the term has been used in connection with other peripherals (especially plotters and graphics devices) and occasionally even for input devices. The term "SPOOL" has been attributed to IBM as an acronym for Simultaneous Peripheral Operation On-Line but it's widely thought to have been contrived for effect. [No connection with "spool of magnetic tape"?] [Jargon File] (1996-05-20) 1 1 1 1 1 spooler Software or hardware to which data is spooled and which processes that data (e.g. prints it) in the background. (1995-03-25) 1 1 1 1 1 spool file Any file to which data is spooled to await the next stage of processing. Especially used in circumstances where spooling the data copes with a mismatch between speeds in two devices or pieces of software. For example, when you send mail under Unix, it's typically copied to a spool file to await a transport demon's attentions. [Jargon File] 1 1 1 1 1 SpoolView A printing system for Unix. SpoolView can control several printers connected to a TCP/IP network. Different printers can be loaded with different paper and forms. After submitting a print request, the user can change the printer, form, number of copies or priority. Administrators can register new printers, change paper forms on printers, cancel requests, suspend printers. Light Infocon S.A. (http://light.com.br/). (1998-12-21) 1 1 1 1 1 spray A Unix command that sends packets to a host and reports performance statistics. The number of packets, delay between packets and packet length can all be specified. The spray command uses the Remote Procedure Call (RPC) protocol to send a one-way stream of packets to the sprayd daemon on the given host. With the "-i" option, spray uses the Internet Control Message Protocol (ICMP) instead of RPC. Normally these will be echoed automatically, creating a return stream. Unix manual page: spray(1M). (2007-03-12) 1 1 1 1 1 spreadsheet (Or rarely "worksheet") A type of application program which manipulates numerical and string data in rows and columns of cells. The value in a cell can be calculated from a formula which can involve other cells. A value is recalculated automatically whenever a value on which it depends changes. Different cells may be displayed with different formats. Some spreadsheet support three-dimensional matrices and cyclic references which lead to iterative calculation. An essential feature of a spreadsheet is the copy function (often using drag-and-drop). A rectangular area may be copied to another which is a multiple of its size. References between cells may be either absolute or relative in either their horizontal or vertical index. All copies of an absolute reference will refer to the same row, column or cell whereas a relative reference refers to a cell with a given offset from the current cell. 1 1 1 1 1 spread spectrum communications (Or "spread spectrum") A technique by which a signal to be transmitted is modulated onto a pseudorandom, noise-like, wideband carrier signal, producing a transmission with a much larger bandwidth than that of the data modulation. Reception is accomplished by cross correlation of the received wide band signal with a synchronously generated replica of the carrier. Spread-spectrum communications offers many important benefits: Low probability of detection, interception or determination of the transmitter's location. To an observer who does not possess information about the carrier, the transmission is indistinguishable from other sources of noise. High immunity against interference and jamming (intentional interference). The presence of (narrowband) interference signals only decreases the channel's signal-to noise ratio and therefore its error rate, which can be dealt with by 1 1 1 1 1 SPRING String PRocessING language 1 1 1 1 1 SPRINT List processing language involving stack operations. "SPRINT - A Direct Approach to List Processing Languages", C.A. Kapps, Proc SJCC 30 (1967). Sammet 1969, p 462. 1 1 1 1 1 Sprintnet A public packet-switched network using the ITU-T X.25 protocols, that provides dial-up access to services like Delphi, Portal, GEnie and Compuserve. (1994-10-17) 1 1 1 1 1 Sprite An operating system from Berkeley supporting multiprocessing and distributed files. [Details? References?] (1994-10-17) 1 1 1 1 1 sprite A small bitmap image, often used in animated games but also sometimes used as a synonym for icon. (1997-06-29) 1 1 1 1 1 sprocket feed (Or "tractor feed", "pin feed") A method some printers use to move paper by rotating wheels with pins or studs (tractors) that engage holes along the sides of the (usually fanfold) paper. A sprocket feed printer does not slip unless the paper jams, but cannot feed standard typing paper or work with a sheet feeder like friction feed. Some paper for sprocket feed printers has the edge strips with the holes in detachable from the rest of the paper. These strips are known as chad (and other names). (1997-06-29) 1 1 1 1 1 SPS Symbolic Programming System. Assembly language for IBM 1620. 1 1 1 1 1 SPSS Statistical Package for the Social Sciences 1 1 1 1 1 SPSS, Inc. A company selling a variety of software under the general description of "Statistical Product and Service Solutions". The company was founded to distribute and support the Statistical Package for the Social Sciences, but now supplies software or four broad markets: data mining, survey/market research, quality improvement, and scientific research. (http://spss.com/). (1999-07-20) 1 1 1 1 1 SPUR An early system on the IBM 650. [Listed in CACM 2(5):16 (May 1959)]. (1994-12-01) 1 1 1 1 1 SPX 1. <networking> Sequenced Packet Exchange. 2. <application> A graphics program for the Atari microcomputer. (ftp://src.doc.ic.ac.uk/computing/systems/atari/umich/Graphics/spx_v18.lzh). 3. Simplex. (1997-03-04) 1 1 1 1 1 spx The filename extension for Screen Peace eXtension files. (1995-03-14) 1 1 1 1 1 spyware (Or "adware") Any type of software that transmits information without the user's knowledge. Information is sent via the Internet to a server somewhere, normally as a hidden side effect of using a program. Gathering this information may benefit the user indirectly, e.g. by helping to improve the software he is using. It may be collected for advertising purposes or, worst of all, to steal security information such as passwords to online accounts or credit card details. Spyware may be installed along with other software or as the result of a virus infection. There are many tools available to locate and remove various forms of spyware from a computer. Some HTTP cookies could be considered as spyware as their use is generally not made explicit to users. It is however possible to disallow them, either totally or individually, and some are actually useful, e.g. recording the fact that a user has logged in. 1 1 1 1 1 SQE Signal Quality Error IEEE 802.3, Ethernet. Equivalent to D/I/X "Collision Presence Test". (1995-04-14) 1 1 1 1 1 SQL /S Q L/ An industry-standard language for creating, updating and, querying relational database management systems. SQL was developed by IBM in the 1970s for use in System R. It is the de facto standard as well as being an ISO and ANSI standard. It is often embedded in general purpose programming languages. The first SQL standard, in 1986, provided basic language constructs for defining and manipulating tables of data; a revision in 1989 added language extensions for referential integrity and generalised integrity constraints. Another revision in 1992 provided facilities for schema manipulation and data administration, as well as substantial enhancements for data definition and data manipulation. Development is currently underway to enhance SQL into a computationally complete language for the definition and management of persistent, complex objects. This includes: 1 1 1 1 1 SQL2 An extended version of the SQL standard. (1995-03-20) 1 1 1 1 1 SQL3 A draft standard for another extension of SQL. The latest SQL3 Working Draft addresses the requirement for objects and "object identifiers" in SQL and also specifies supporting features such as encapsulation, subtypes, inheritance, and polymorphism. In the USA, SQL3 is being processed as both an ANSI Domestic ("D") project and as an ISO project. It is expected to be complete in 1998. November 1992 paper (ftp://speckle.ncsl.nist.gov/isowg3/dbl/BASEdocs/sql3overview.txt). Working draft (ftp://gatekeeper.dec.com/pub/standards/sql/). [ISO/IEC SQL Revision. ISO-ANSI Working Draft Database Language SQL (SQL3), Jim Melton - Editor, document ISO/IEC JTC1/SC21 N6931, ANSI, July 1992]. [Current Status?] (2002-04-21) 1 1 1 1 1 SQL Access Group The origanisaton which defined Call-Level Interface, on which ODBC is based. It is now part of X/Open. [Address, details?] (1995-11-05) 1 1 1 1 1 SQL/DS A database package from IBM including a relational DBMS. 1 1 1 1 1 SQL Module Language A language used to interface other languages (Ada, C, COBOL) to SQL-based DBMSes. It is an ANSI standard. Version: Ada/SAME by Informix. (1994-11-23) 1 1 1 1 1 SQL Server (Note capitalised) 1. Sybase Adaptive Server Enterprise. 2. Microsoft SQL Server. (2003-07-02) 1 1 1 1 1 SQL server (Note not capitalised) Any database management system (DBMS) that can respond to queries from clients formatted in the SQL language. Two popular examples are Microsoft SQL Server and Sybase SQL Server. (1997-12-07) 1 1 1 1 1 SQLWindows A package used to graphically develop MS-Windows client-server applications. Sold by Gupta Corporation. (http://wji.com/gupta/w1000030.html). Demos FTP (ftp://wji.com/gupta/sqlw.demodisk/). (1995-07-05) 1 1 1 1 1 SQR A fourth generation language for the creation of reports from databases. SQR is interpreted to dynamically generate SQL queries and format the results. Originally a Sybase product, it was then sold to MITI, who subsequently changed their name to SQRIBE. SQR Server supports native database access for all major DBMSs and the use of platform independent Java code. (1998-09-19) 1 1 1 1 1 SQRIBE The company formerly known as MITI which bought SQR from Sybase. (http://sqribe.com/). (1998-09-24) 1 1 1 1 1 Square A query language, a precursor to SQL. ["Specifying Queries as Relational Expressions: The SQUARE Data Sublanguage", R.E. Boyce et al, CACM 18(11):621-628 (Nov 1975)]. (1995-05-02) 1 1 1 1 1 square-headed boyfriend square-headed girlfriend 1 1 1 1 1 square-headed girlfriend A computer. (1999-01-15) 1 1 1 1 1 square tape Mainframe magnetic tape cartridges for use with IBM 3480 or compatible tape drives; or QIC tapes used on workstations and microcomputers. The term comes from the square (actually rectangular) shape of the cartridges; contrast round tape. [Jargon File] 1 1 1 1 1 Squeak 1. <graphics> ["Squeak: A Language for Communicating with Mice", L. Cardelli et al, Comp Graphics 19(3):199-204, July 1985]. See Newsqueak. 2. A Smalltalk implementation and a media authoring tool by members of the original Xerox PARC team which created Smalltalk (Alan Kay, Dan Ingalls, et al). Squeak is an open-source implementation, with a highly portable virtual machine implemented in a subset of Smalltalk (translated into C and compiled by a C compiler of the target platform). Squeak Home (http://squeak.org/). SqueakCentral (http://squeakland.org/). (2002-11-03) 1 1 1 1 1 Squiggol Bird-Meertens Formalism 1 1 1 1 1 squirt the bird To transmit a signal up to a satellite. "Crew and talent are ready, what time do we squirt the bird?" (1997-04-29) 1 1 1 1 1 SR Synchronizing Resources. A language for concurrent programming. Resources encapsulate processes and variables they share. Each Resource can be separately compiled. "Operations" provide the primary mechanism for process interaction. SR provides a novel integration of the mechanisms for invoking and servicing operations. Consequently, it supports local and remote procedure call, rendezvous, message passing, dynamic process creation, multicast, semaphores and shared memory. Version 2.2 has been ported to Sun-3, Sun-4, Decstation, SGI Iris, HP PA, HP 9000/300, NeXT, Sequent Symmetry, DG AViiON, RS/6000, Multimax, Apollo and others. (ftp://cs.arizona.edu/sr/sr.tar.Z). E-mail: <sr-project@cs.arizona.edu>. Mailing list: info-sr-request@cs.arizona.edu. 1 1 1 1 1 sr The country code for Suriname. (1999-01-27) 1 1 1 1 1 SRAM static random-access memory 1 1 1 1 1 SRAPI Speech Recognition Application Program Interface 1 1 1 1 1 SRC Modula-3 Version 2.11 compiler(->C), run-time, library, documentation The goal of Modula-3 is to be as simple and safe as it can be while meeting the needs of modern systems programmers. Instead of exploring new features, we studied the features of the Modula family of languages that have proven themselves in practice and tried to simplify them into a harmonious language. We found that most of the successful features were aimed at one of two main goals: greater robustness, and a simpler, 1 1 1 1 1 SRDL Small algebraic specification language, allows distfix operators. ["A Constructive Method for Abstract Algebraic Software Specification", H. Klaeren, Theor Computer Sci 30, pp.134-204, 1984]. 1 1 1 1 1 SR flip-flop (Or "RS flip-flop") A "set/reset" flip-flop in which activating the "S" input will switch it to one stable state and activating the "R" input will switch it to the other state. The outputs of a basic SR flip-flop change whenever its R or S inputs change appropriately. A clocked SR flip-flop has an extra clock input which enables or disables the other two inputs. When they are disabled the outputs remain constant. If we connect two clocked SR flip-flops so that the Q and /Q outputs of the first, "master" flip-flop drive the S and R inputs of the second, "slave" flip-flop, and we drive the slave's clock input with an inverted version of the master's clock, then we have an edge-triggered RS flip-flop. The external R and S inputs of this device are latched on one edge (transition) of the clock (e.g. the falling edge) and the outputs will only change on the next opposite (rising) edge. If both R and S inputs are active (when enabled), a race 1 1 1 1 1 SRI SRI International 1 1 1 1 1 SRI International One of the world's largest contract research firms. Founded in 1946 in conjuction with Stanford University as the Stanford Research Institute, they later became fully independent and were incorporated as a non-profit organisation under U.S. and California laws. SRI does research and development in many areas, independently and for hire. They produce and sell reports on the independent research. (http://sri.com/). Address: Menlo Park, California, USA; Cambridge, UK. (2003-04-12) 1 1 1 1 1 SRL 1. Bharat Jayaraman. ["Towards a Broader Basis for Logic Programming", B. Jayaraman, TR CS Dept, SUNY Buffalo, 1990]. 2. Schema Representation language. 3. Structured Robot Language. C. Blume & W. Jacob, U Karlsruhe. (1995-01-26) 1 1 1 1 1 SRP A data link layer protocol. 1 1 1 1 1 SS7 Signalling System 7 1 1 1 1 1 SSA Single Static Assignment Serial Storage Architecture 1 1 1 1 1 SSADM A software engineering method and toolset required by some UK government agencies. 1 1 1 1 1 SSBA Suite Synthetique des Benchmarks de l'AFUU 1 1 1 1 1 SSD 1. Solid State Disk 2. Seven-Segment Display 1 1 1 1 1 SSE Streaming SIMD Extensions 1 1 1 1 1 SSE-2 Intel Corporation's extention of their SSE floating point SIMD instructions to handle 64-bit floating point numbers. SSE-2 was introduced with the Pentium 4. (2001-12-23) 1 1 1 1 1 ssh 1. Steve's Shell. 2. Secure Shell. (1997-01-07) 1 1 1 1 1 SSH File Transfer Protocol (SFTP) A version of File Transfer Protocol (FTP) using an encrypted network connection provided by Secure Shell (SSH), usually SSH 2. The SFTP protocol allows for a range of operations on remote files, making it more like a remote file system protocol. SFTP clients can resume interrupted transfers, get directory listings and remove remote files. SFTP has largely replaced Secure Copy (SCP). IETF spec (http://ietf.org/internet-drafts/draft-ietf-secsh-filexfer-13.txt). (2006-09-28) 1 1 1 1 1 SSI 1. <electronics> small scale integration. 2. <computer> A kind of PDP-11(?). [What kind?] 3. <web> server-side include. (1996-09-08) 1 1 1 1 1 SSID Service Set Identifier 1 1 1 1 1 SSII Societe de Service en Ingenierie Informatique 1 1 1 1 1 SSL 1. <language> Synthesizer Specification Language. 2. <language> Syntax/Semantic Language (S/SL). 3. <networking, web> Secure Sockets Layer. (1996-09-08) 1 1 1 1 1 S/SL Syntax/Semantic Language 1 1 1 1 1 SSLeay A free implementation of Netscape's Secure Socket Layer protocol, coded from scratch, using only the publically available documentation of the various protocols, by Eric Young in Australia. SSLeay supports the DES, RSA, RC4, and IDEA encryption algorithms. [Home?] (2000-12-07) 1 1 1 1 1 SSMA some such meaningless acronym. (1998-10-30) 1 1 1 1 1 SSO single sign-on 1 1 1 1 1 SSR Scalable Sampling Rate 1 1 1 1 1 st The country code for Sao Tome and Principe. (1999-01-27) 1 1 1 1 1 ST-506 The first full-height 5.25 inch hard disk drive for personal computers, introduced in 1980 by Shugart Technology (now Seagate Technology). The ST-506 stored up to 5 megabtyes after formatting using MFM encoding. It transferred data at 625 kilobytes per second. The ST-506 (like the ST-412) was interfaced to a computer via a disk controller. The interface was a faster version of the Shugart Associates SA1000 interface, which was in turn based upon the floppy disk drive interface. Two cables connected the controller to the disk. The 34-pin control cable controlled mechanical motion and data was read or written serially using two pins of the 20-pin data cable. Other companies copied the interface, creating a universal de facto standard that was further strengthened by its revision to support Seagate's 10 MB ST-412 drive that was adopted for the IBM PC XT. Around 1990, SCSI and ATA superseded ST-506. These 1 1 1 1 1 STAB A descendent of BCPL. (1996-08-25) 1 1 1 1 1 STAB-11 ["The Translation and Interpretation of STAB-11", A.J.T. Colin et al, Soft Prac & Exp 5(2):123-138, Apr 1975]. (1996-08-25) 1 1 1 1 1 STAC 1. <language> Storage Allocation and Coding Program. 2. <company> The company responsible for Stacker and stac compression. (http://stac.com/). (1998-06-08) 1 1 1 1 1 stac compression A data compression technique from STAC, used with modems. Stac compression is capable of compressing data by a factor of about four. [Details?] (1998-06-08) 1 1 1 1 1 stack (See below for synonyms) A data structure for storing items which are to be accessed in last-in first-out order. The operations on a stack are to create a new stack, to "push" a new item onto the top of a stack and to "pop" the top item off. Error conditions are raised by attempts to pop an empty stack or to push an item onto a stack which has no room for further items (because of its implementation). Most processors include support for stacks in their instruction set architectures. Perhaps the most common use of stacks is to store subroutine arguments and return addresses. This is usually supported at the machine code level either directly by "jump to subroutine" and "return from subroutine" instructions or by auto-increment and auto-decrement addressing modes, or both. These allow a contiguous area of memory to be set aside for use as a stack and use either a special-purpose register or a general 1 1 1 1 1 Stack Environment Control Dump machine (SECD machine) The first abstract machine for reducing lambda-calculus expressions, invented by P. J. Landin. The machine has four registers holding pointers to linked lists operated as push-down stacks which hold the information required for the evaluation of an expression. The registers point to (1) Stack which holds the arguments of partially evaluated expressions and results of completely evaluated ones, (2) Environment where the current expression being evaluated is stored, (3) Control which holds the machine instructions that manipulate the contents of the four registers that represent the expression being evaluated, (4) Dump on which the state of the machine is temporarily saved during the evaluation of expressions. See also Lispkit. 1 1 1 1 1 stack frame activation record 1 1 1 1 1 stacking order The relationship between windows that (partially) obscure each other. A window manager will include commands to alter the stacking order by bringing a chosen window to the front (top) or back (bottom) of the stack. (1995-03-21) 1 1 1 1 1 stack loader (Or "autoloader") A magnetic tape drive that can automatically fetch tapes from a stack and load them. Compare jukebox. [Sequential or random access?] (1996-12-12) 1 1 1 1 1 stack overflow An error condition which results from attempting to push more items onto a stack than space has been allocated for. Often, this will simply overwrite the adjacent memory locations causing hard-to-trace bugs. Stack overflow can result, for example, from an insufficient number of stack frames to handle hardware interrupts. (1995-03-21) 1 1 1 1 1 stack pointer (SP) A register or variable pointing to the top of a stack. (2004-11-08) 1 1 1 1 1 stack puke Some processor architectures are said to "puke their guts onto the stack" to save their internal state during exception processing. The Motorola 68020, for example, regurgitates up to 92 bytes on a bus fault. On a pipelined machine, this can take a while. [Jargon File] (1994-11-01) 1 1 1 1 1 stack traceback (The results of) determining the sequence of nested procedure calls a program has made up to a certain point in its execution. A traceback may also show values of procedure arguments and local variables stored on the stack. (1995-03-21) 1 1 1 1 1 STAGE2 A macro language. ["The Mobile Programming System: STAGE2", W.M. Waite, CACM 13:415 (1970)]. (1994-10-27) 1 1 1 1 1 Staggered Pin Grid Array (SPGA) A style of integrated circuit socket or pin-out with a staggered grid of pins around the edge of the socket, positioned as several squares, one inside the other. SPGA is commonly used on motherboards for processors, e.g. Socket 5, Socket 7 and Socket 8. See also PGA. [Better description?] (1999-08-04) 1 1 1 1 1 staircase jaggies 1 1 1 1 1 staircasing jaggies 1 1 1 1 1 stale pointer bug (Or "aliasing bug") A class of subtle programming errors that can arise in code that does dynamic allocation, especially via malloc or equivalent. If several pointers address (are "aliases for") a given hunk of storage, it may happen that the storage is freed or reallocated (and thus moved) through one alias and then referenced through another, which may lead to subtle (and possibly intermittent) lossage depending on the state and the allocation history of the malloc arena. This bug can be avoided by never creating aliases for allocated memory, or by use of a higher-level language, such as Lisp, which employs a garbage collector. The term "aliasing bug" is nowadays associated with C programming, it was already in use in a very similar sense in the ALGOL 60 and Fortran communities in the 1960s. See also smash the stack, fandango on core, memory leak, memory smash, spam. 1 1 1 1 1 Stallman, Richard M. Richard Stallman 1 1 1 1 1 stand-alone Capable of operating without other programs, libraries, computers, hardware, networks, etc. Exactly what is absent is presumed to be obvious from context. "We only run Windows on stand-alone PCs because it's too dangerous to run it on networked ones." (1998-02-11) 1 1 1 1 1 standard Standards are necessary for interworking, portability, and reusability. They may be de facto standards for various communities, or officially recognised national or international standards. Andrew Tanenbaum, in his Computer Networks book, once said, "The nice thing about standards is that there are so many of them to choose from, a reference to the fact that competing" standards become a source of confusion, division, obsolescence, and duplication of effort instead of an enhancement to the usefulness of products. Some bodies concerned in one way or another with computing standards are IAB (RFC and STD), ISO, ANSI, DoD, ECMA, IEEE, IETF, OSF, W3C. (1999-07-06) 1 1 1 1 1 Standard Commands for Programmable Instruments (SCPI) A standard complementing IEEE 488, developed by Hewlett-Packard and promoted by the SCPI Consortium. (1994-11-01) 1 1 1 1 1 Standard d'Echange et de Transfert (SET) A French standard for exchange of CAD data. (1998-03-07) 1 1 1 1 1 standard deviation (SD) A measure of the range of values in a set of numbers. Standard deviation is a statistic used as a measure of the dispersion or variation in a distribution, equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean. The standard deviation of a random variable or list of numbers (the lowercase greek sigma) is the square of the variance. The standard deviation of the list x1, x2, x3...xn is given by the formula: sigma = sqrt(((x1-(avg(x)))^2 + (x1-(avg(x)))^2 + ... + (xn(avg(x)))^2)/n) The formula is used when all of the values in the population are known. If the values x1...xn are a random sample chosen from the population, then the sample Standard Deviation is calculated with same formula, except that (n-1) is used as the denominator. [dictionary.com (http://dictionary.com/)]. 1 1 1 1 1 standard for robot exclusion A proposal to try to prevent the havoc wreaked by many of the early web robots when they retrieved documents too rapidly or retrieved documents that had side effects (such as voting). The proposed standard for robot exclusion offers a solution to these problems in the form of a file called "robots.txt" placed in the document root of the website. W3C standard (http://w3.org/TR/html4/appendix/notes.html#h-B.4.1.1). (2006-10-17) 1 1 1 1 1 Standard for the exchange of product model data (STEP) A draft ISO standard for the exchange of CAD data. See also PDES. (1995-02-22) 1 1 1 1 1 Standard Generalised Markup Language ISO spell it "Standard Generalized Markup Language". (1996-12-13) 1 1 1 1 1 Standard Generalized Markup Language (SGML) A generic markup language for representing documents. SGML is an International Standard that describes the relationship between a document's content and its structure. SGML allows document-based information to be shared and re-used across applications and computer platforms in an open, vendor-neutral format. SGML is sometimes compared to SQL, in that it enables companies to structure information in documents in an open fashion, so that it can be accessed or re-used by any SGML-aware application across multiple platforms. SGML is defined in "ISO 8879:1986 Information processing -- Text and office systems -- Standard Generalized Markup Language (SGML)", an ISO standard produced by JTC 1/SC 18 and amended by "Amendment 1:1988". Unlike other common document file formats that represent both content and presentation, SGML represents a document's content data and structure (interrelationships among the data). 1 1 1 1 1 standard input/output The predefined input/output channels which every Unix process is initialised with. Standard input is by default from the terminal, and standard output and standard error are to the terminal. Each of these channels (controlled via a file descriptor 0, 1, or 2 - stdin, stdout, stderr) can be redirected to a file, another device or a pipe connecting its process to another process. The process is normally unaware of such I/O redirection, thus simplifying prototyping of combinations of commands. The C programming language library includes routines to perform basic operations on standard I/O. Examples are printf, allowing text to be sent to standard output, and scanf, allowing the program to read from standard input. (1996-06-07) 1 1 1 1 1 Standard Instrument Control Library (SICL) A platform-independent API for software to control and test electronic instruments conforming to IEEE 488. (1995-01-05) 1 1 1 1 1 standard interpretation standard semantics 1 1 1 1 1 standard I/O standard input/output 1 1 1 1 1 Standard Lisp A subset of Lisp 1.5 developed by A. Hearn primarily for implementing REDUCE. It was replaced by Portable Sandard LISP. ["Standard LISP Report", J. Marti et al, SIGPLAN Notices 14(10):48-58 (Oct 1979)]. (1994-11-04) 1 1 1 1 1 Standard ML (SML) Originally an attempt by Robin Milner <rm@lfcs.edinburgh.ac.uk> ca. 1984 to unify the dialects of ML, SML has evolved into a robust general-purpose language. Later versions have been maintained by D. B. MacQueen, Lal George <george@research.att.com>, and J. H. Reppy <jhr@research.att.com> at AT&T, and A. W. Appel <appel@princeton.edu>. SML is functional, with imperative programming features. It is environment based and strict. It adds to ML the call-by-pattern of Hope, recursive data types, reference types, typed exceptions, and modules. (The core language excludes the modules). Standard ML is polymorphically typed and its module system supports flexible yet secure large-scale programming. Standard ML of New Jersey is an optimising native-code compiler for Standard ML that is written in Standard ML. It runs on a wide range of architectures. The distribution also 1 1 1 1 1 Standard ML of New Jersey (SML/NJ) An implementation of SML by Andrew Appel at Princeton <Appel@princeton.edu> and Dave MacQueen at AT&T. Version 0.93. ["Standard ML of New Jersey", A. Appel et al, "Proc Third Intl Symp on Prog Lang Impl and Logic Programming", LNCS Springer 1991]. Versions for Unix, Mac. (ftp://cs.yale.edu/pub/ml), (ftp://research.att.com/dist/ml). Mailing list: sml@cs.cmu.edu. 1 1 1 1 1 Standard Operating Environment (SOE) A specification of the architecture, operating systems, application set and configuration of computers within an organisation. (2007-06-11) 1 1 1 1 1 standard semantics The standard interpretation of a term in some language yields the term's standard denotational semantics, i.e. its "meaning". This is usually given by a semantic function which maps a term in the abstract syntax to a point in some domain. The domain is the interpretation of the term's type. The semantic function also takes an environment - a function which maps the free variables of the term to their meaning. We say that a domain point "denotes", or "is the denotation of", a term. A non-standard semantics results from some other interpretation, e.g. an abstract interpretation. 1 1 1 1 1 Standard Widget Toolkit (SWT) The Eclipse Foundation's framework for developing graphical user interfaces in Java. SWT is written in explicitly standard Java but uses the Java Native Interface to talk to a platform-native GUI library. SWT is the third major attempt to give Java a decent GUI framework, following AWT and Swing. Of the three, SWT is the most consistent with the native GUIs but its programming model is hard to port to non-Windows platforms. Wikipedia (http://en.wikipedia.org/wiki/SWT). (2004-12-21) 1 1 1 1 1 St Andrews Static Language (SASL) A functional programming language designed by Professor David Turner in 1976 whilst at St. Andrews University. SASL is a derivative of ISWIM with infinite data structures. It is fully lazy but weakly typed. It was designed for teaching functional programming, with very simple syntax. Example syntax: def fac n = n = 0 -> 1 ; n x fac(n-1) A version of the expert system EMYCIN has been written in SASL. SASL was originally known as "St Andrews Standard Language". Not to be confused with SISAL. (ftp://a.cs.uiuc.edu/uiuc/kamin.distr/distr/sasl.p). See also Kamin's interpreters. 1 1 1 1 1 Stanford Artificial Intelligence Laboratory (SAIL) /sayl/, not /S-A-I-L/ An important site in the early development of LISP; with the MIT AI Lab, BBN, CMU, XEROX PARC, and the Unix community, one of the major wellsprings of technical innovation and hacker-culture traditions (see the WAITS entry for details). The SAIL machines were shut down in late May 1990, scant weeks after the MIT AI Lab's ITS cluster was officially decommissioned. [Jargon File] (2001-06-22) 1 1 1 1 1 Stanford Artificial Intelligence Language (SAIL) Dan Swinehart & Bob Sproull, Stanford AI Project, 1970. A large ALGOL 60-like language for the DEC-10 and DEC-20. Its main feature is a symbolic data system based upon an associative store (originally called LEAP). Items may be stored as unordered sets or as associations (triples). Processes, events and interrupts, contexts, backtracking and record garbage collection. Block- structured macros. "Recent Developments in SAIL - An ALGOL-based Language for Artificial Intelligence", J. Feldman et al, Proc FJCC 41(2), AFIPS (Fall 1972). (See MAINSAIL). The Stanford Artificial Intelligence Language used at SAIL (the place). It was an ALGOL 60 derivative with a coroutining facility and some new data types intended for building search trees and association lists. A number of interesting software systems were coded in SAIL, including early versions of FTP and TeX and a document formatting system called PUB. 1 1 1 1 1 Stanford Research Institute Former name of SRI International. 1 1 1 1 1 Stanford University A University in the city of Palo Alto, California, noted for work in computing, especially artificial intelligence. See SAIL. (2003-02-28) 1 1 1 1 1 STAPLE A programming language written at Manchester (University?) and used at ICL in the early 1970s for writing the test suites. STAPLE was based on Algol 68 and had a very advanced optimising compiler. (2003-02-28) 1 1 1 1 1 Staple St Andrews Applicative Persistent Language. Language combining functional programming with persistent storage, developed at St. Andrews University in Scotland. Tony Davie, <ad@cs.st-andrews.ac.uk>. (2007-03-22) 1 1 1 1 1 STAR 0 Early system on Datatron 200 series. Listed in CACM 2(5):16 (May 1959). 1 1 1 1 1 StarBurst An active DBMS from IBM Almaden Research Center. 1 1 1 1 1 StarLISP *LISP 1 1 1 1 1 StarMOD *MOD 1 1 1 1 1 star network A network topology where every node has a direct connection (only) to the central node, which might be a hub, switch, or server. (1999-10-29) 1 1 1 1 1 Starset Portable storage/retrieval language for distributed databases. Starset programming Language, M.M. Gilula et al, Nauka, Moscow 1991, ISBN 5-02-006831-4. 1 1 1 1 1 STARSYS Convergent Technologies Operating System 1 1 1 1 1 start bit A bit which signals the start of transmission of a character on a serial line. For an RS-423 signal, the line is normally at logical zero which there is no data and the start bit is a logical one. The zero-one transition tells the receiver when to start sampling the signal to extract the data bits. [Is this upside-down?] (1995-02-02) 1 1 1 1 1 start of authority (SOA) A type of resource record used by the Domain Name System (DNS) to give metadata about a set of domain name data (the contents of a "zone file"). An SOA record has the following parameters: Serial: the zone serial number - a version number for the zone file. Refresh: the number of seconds between update requests from secondary and slave name servers. Retry: the number of seconds the secondary or slave will wait before retrying when an attempt fails. Expire: (time to live - TTL) the number of seconds a master or slave will wait before considering cached data out-of-date. Minimum: previously used to determine the minimum TTL, this offers negative caching. (2007-05-11) 1 1 1 1 1 Start Of Header (SOH) mnemonic for ASCII 1. [What header?] (1996-05-31) 1 1 1 1 1 Start Of Text (STX) Mnemonic for ASCII 2. (1996-05-31) 1 1 1 1 1 start tag tag 1 1 1 1 1 state How something is; its configuration, attributes, condition, or information content. The state of a system is usually temporary (i.e. it changes with time) and volatile (i.e. it will be lost or reset to some initial state if the system is switched off). A state may be considered to be a point in some space of all possible states. A simple example is a light, which is either on or off. A complex example is the electrical activation in a human brain while solving a problem. In computing and related fields, states, as in the light example, are often modelled as being discrete (rather than continuous) and the transition from one state to another is considered to be instantaneous. Another (related) property of a system is the number of possible states it may exhibit. This may be finite or infinite. A common model for a system with a finite number of discrete state is a finite state machine. 1 1 1 1 1 state diagram state transition diagram 1 1 1 1 1 stateless A stateless server is one which treats each request as an independent transaction, unrelated to any previous request. This simplifies the server design because it does not need to allocate storage to deal with conversations in progress or worry about freeing it if a client dies in mid-transaction. A disadvantage is that it may be necessary to include more information in each request and this extra information will need to be interpreted by the server each time. An example of a stateless server is a web server. These take in requests (URLs) which completely specify the required document and do not require any context or memory of previous requests. Contrast this with a traditional FTP server which conducts an interactive session with the user. A request to the server for a file can assume that the user has been authenticated and that the current directory and transfer mode have been set. 1 1 1 1 1 state machine finite state machine 1 1 1 1 1 statement A single instruction in a computer program written in a procedural language. Typical examples are an assignment statement, an if statement (conditional), a loop statement ("while", "for", "repeat", "until", etc.), a procedure call, a procedure exit, function return statement, switch statement or goto statement. In many languages, one or more simple statements can be executed sequentially as a compound statement, e.g. bracketed between "begin" and "end" or "" and "" which can then appear in place of a simple statement in an "if" or loop. Each statement in a high-level language will typically be translated into several machine code instructions by a compiler or, alternatively, executed by an interpreter. (2009-10-23) 1 1 1 1 1 state transition diagram A diagram consisting of circles to represent states and directed line segments to represent transitions between the states. One or more actions (outputs) may be associated with each transition. The diagram represents a finite state machine. 1 1 1 1 1 State University of New York (SUNY) The public university system of New York State, USA, with campuses throughout the state. (1995-03-01) 1 1 1 1 1 static static typing, static variable. <storage> static random-access memory. <web> static content. <theory, programming> static analysis. 1 1 1 1 1 statically typed static typing 1 1 1 1 1 static analysis A family of techniques of program analysis where the program is not actually executed (as opposed to dynamic analysis), but is analyzed by tools to produce useful information. Static analysis techniques range from the most mundane (statistics on the density of comments, for instance) to the more complex, semantics-based techniques. Qualities sought in static analysis techniques are soundness and completeness. (2003-04-12) 1 1 1 1 1 static database management system (static DBMS) A database consisting of information-based relationships, one that is rigorously structured to facilitate retrieval and update in terms of inherent relationships. This creates a static environment wherein the locations of the related records are already known. Typical static DBMS are either hierarchical (IMS, System 2000) or a CODACYL (network or plex) DBMS (such as TOTAL, IDMS, IDS, DMS-2). These environments facilitate rapid, high volume processing of data. The opposite is a dynamic database management system. (1998-10-07) 1 1 1 1 1 static DBMS static database management system 1 1 1 1 1 static link (Or "access link" or "environment link") A pointer from an activation record to the activation record for the textually enclosing scope. A static link is only required in a statically (lexically) scoped language. The number of static links to follow may be determined statically (at compile time). It is simply the difference in lexical nesting depth between the declaration and the reference. See also display. (1995-03-07) 1 1 1 1 1 static method In object-oriented programming, a function packaged along with a given class; not really a method at all. For example, a String class might include a static method, concatenate(), which returns its arguments joined into one string. It might be called like this: print String.concatenate("FOL", "DOC"); which would print "FOLDOC". The same result might be achieved with a real object method, append(), which returns its argument string appended to the object it is invoked on, e.g.: String s = "FOL"; print s.append("DOC"); While the syntax looks similar, the two are completely different. The static method is just a function called String.concatenate which can be resolved to the address of some code at compile time (or load time if the String class is dynamically loaded). When invoking an object method, the class of 1 1 1 1 1 static nested scope Where the scope of an identifier is fixed at compile-time to be the smallest block (begin/end, function, or procedure body) containing the identifier's declaration. This means that an identifier declared in some block is only accessible within that block and from procedures declared within it. This term is used in the Python community. Compare lexical scope. (2002-02-18) 1 1 1 1 1 static nested scoping static nested scope 1 1 1 1 1 static RAM static random-access memory 1 1 1 1 1 static random-access memory (SRAM) Random-access memory in which each bit of storage is a bistable flip-flop, commonly consisting of cross-coupled inverters. It is called "static" because it will retain a value as long as power is supplied, unlike dynamic random-access memory (DRAM) which must be regularly refreshed. It is however, still volatile, i.e. it will lose its contents when the power is switched off, in contrast to ROM. SRAM is usually faster than DRAM but since each bit requires several transistors (about six) you can get less bits of SRAM in the same area. It usually costs more per bit than DRAM and so is used for the most speed-critical parts of a computer (e.g. cache memory) or other circuit. (1995-04-22) 1 1 1 1 1 static scope lexical scope 1 1 1 1 1 static typing Enforcement of type rules at compile time rather than at run time. Static typing catches more errors at compile time than dynamic typing. Ada, C, C++, Haskell, Java, and ML are examples of statically typed languages. Statically typed languages may have strong typing or weak typing. (2004-07-20) 1 1 1 1 1 static variable A kind of local variable in certain programming languages that retains its value even when program execution moves outside its scope. This contrasts with an ordinary, automatic variable, which is reinitialised (possibly to an undefined value) every time the block is entered. Static variables have a fixed location in the data section of the program's address space whereas automatic variables are typically allocated on the stack. (2009-12-14) 1 1 1 1 1 Station Management (SMT) Station Management One of the 4 key FDDI component layers. SMT is an overlay function that handles the management of the FDDI ring. It handles neighbor identification, fault detection and reconfiguration, insertion and de-insertion from the ring, and traffic statistics monitoring. (1997-05-11) 1 1 1 1 1 Statistical Analysis System (SAS) A statistical and matrix handling language with PL/I-like syntax. ["A User's Guide to SAS", A.J. Barr, SAS Inst 1976]. (1994-12-12) 1 1 1 1 1 Statistical Package for the Social Sciences (SPSS) The flagship program of SPSS, Inc., written in the late 1960s. ["SPSS X User's Guide", SPSS, Inc. 1986]. [Details?] (1999-07-20) 1 1 1 1 1 statistical time division multiplexing (STDM, StatMUX) A system developed to overcome some inefficiencies of standard time division multiplexing, where time slices are still allocated to channels, even if they have no information to transmit. STDM uses a variable time slot length and by allowing channels to vie for any free slot space. It employs a buffer memory which temporarily stores the data during periods of peak traffic. This scheme allows STDM to waste no high-speed line time with inactive channels. STDM requires each transmission to carry identification information (i.e. a channel identifier). To reduce the cost of this overhead, a number of characters for each channel are grouped together for transmission. ["Data Communications, Computer Networks and Open Systems", Halsall & Fred, Addison Wesley, p160-161, 1995]. ["Digital, Analog, and Data Communication", Sinnema & McGovern, Prentice Hall, p245, 1986]. 1 1 1 1 1 statistics The practice, study or result of the application of mathematical functions to collections of data in order to summarise or extrapolate that data. The subject of statistics can be divided into descriptive statistics - describing data, and analytical statistics - drawing conclusions from data. (1997-07-16) 1 1 1 1 1 StatMUX statistical time division multiplexing 1 1 1 1 1 STB set-top box 1 1 1 1 1 STD 1. state transition diagram. 2. Internet standard. A subseries of Request For Comments (RFC) that specify Internet standards. The official list of Internet standards is STD 1. See also For Your Information. rfc.net (http://rfc.net/). (1994-11-30) 1 1 1 1 1 STD 1 The Internet Architecture Board official list of Internet standards. [Postel, J., "IAB Official Protocol Standards", STD 1, RFC 1360, Internet Architecture Board, September 1992]. (1995-02-07) 1 1 1 1 1 STD 13 One of the STDs defining the Domain Name System. (1997-12-15) 1 1 1 1 1 STD 15 The STD defining Simple Network Management Protocol. (1994-11-14) 1 1 1 1 1 STD 2 The document listing the current Internet Assigned Numbers. [Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1340, USC/Information Sciences Institute, July 1992]. (2001-04-08) 1 1 1 1 1 STD 9 The STD defining File Transfer Protocol (FTP). (1995-02-07) 1 1 1 1 1 stderr standard input/output 1 1 1 1 1 stdin standard input/output 1 1 1 1 1 stdio standard input/output 1 1 1 1 1 stdio.h standard input/output header file. (1996-01-28) 1 1 1 1 1 STDM statistical time division multiplexing 1 1 1 1 1 stdout standard input/output 1 1 1 1 1 STDWIN A windowing interface from CWI with windows, menus, modal dialogs, mouse and keyboard input, scroll bars, drawing primitives, etc that is portable between platforms. STDWIN is available for Macintosh and the X Window System. 1 1 1 1 1 steam-powered Old-fashioned or underpowered; archaic. This term does not have a strong negative loading and may even be used semi-affectionately for something that clanks and wheezes a lot but hangs in there doing the job. [Jargon File] 1 1 1 1 1 Steelman DoD, June 1978. Fifth and last of the series of DoD requirements that led to Ada. "Steelman Requirements for High Order Programming Languages", US Dept of Defense, June 1978. SIGPLAN Notices 13(12) (Dec 1978). (See Strawman, Woodenman, Tinman, Ironman). 1 1 1 1 1 steganography Hiding a secret message within a larger one in such a way that others can not discern the presence or contents of the hidden message. For example, a message might be hidden within an image by changing the least significant bits to be the message bits. [Chaffing and Winnowing: Confidentiality without Encryption, Ronald L. Rivest, MIT Lab for Computer Science, 1998-03-22 (http://theory.lcs.mit.edu/~rivest/chaffing.txt)]. (1998-07-13) 1 1 1 1 1 stemmer A program or algorithm which determines the morphological root of a given inflected (or, sometimes, derived) word form -- generally a written word form. A stemmer for English, for example, should identify the string "cats" (and possibly "catlike", "catty" etc.) as based on the root "cat", and "stemmer", "stemming", "stemmed" as based on "stem". English stemmers are fairly trivial (with only occasional problems, such as "dries" being the third-person singular present form of the verb "dry", "axes" being the plural of ax as well as "axis"); but stemmers become harder to design as the morphology, orthography, and character encoding of the target language becomes more complex. For example, an Italian stemmer is more complex than an English one (because of more possible verb inflections), a Russian one is more complex (more possible noun declensions), a Hebrew one is even 1 1 1 1 1 stemming stemmer 1 1 1 1 1 STENSOR L. Hornfeldt, Stockholm, mid-80's. Symbolic math, especially General Relativity. Implemented on top of SHEEP and MACSYMA. 1 1 1 1 1 STEP Standard for the exchange of product model data 1 1 1 1 1 Stephen Cole Kleene Stephen Kleene 1 1 1 1 1 Stephen Jobs Stephen P. Jobs (born 24 February 1955). The co-founder and ex-president of Apple Computer, leader of the team that produced the Macintosh. In 1979, when he was president of Apple, Steven Jobs saw a demonstration of Smalltalk at Xerox's Palo Alto Research Center. He and other Apple employees were "very impressed with the unique and revolutionary user-friendly design". The first Macintosh was released in January 1984. Jobs described it as insanely great. Jobs was ousted from Apple in 1985 and founded Next, Inc.. In December 1996 he was re-employed by Apple when they bought NeXT. See also lithium lick, Mathematica. (1997-03-18) 1 1 1 1 1 Stephen Kleene Professor Stephen Cole Kleene (1909-01-05 - 1994-01-26) /steev'n (kohl) klay'nee/ An American mathematician whose work at the University of Wisconsin-Madison helped lay the foundations for modern computer science. Kleene was best known for founding the branch of mathematical logic known as recursion theory and for inventing regular expressions. The Kleene star and Ascending Kleene Chain are named after him. Kleene was born in Hartford, Conneticut, USA. He received his Bachelor of Arts degree from Amherst College in 1930. From 1930 to 1935, he was a graduate student and research assistant at Princeton University where he received his doctorate in mathematics in 1934. In 1935, he joined UW-Madison mathematics department as an instructor. He became an assistant professor in 1937. From 1939 to 1940, he was a visiting scholar at Princeton's Institute for Advanced Study where he laid the foundation 1 1 1 1 1 stepper motor An electric motor that rotates in small, fixed increments and is used, among other things, to control the radial position (seeking) of the heads on a disk drive. (2006-12-24) 1 1 1 1 1 Stepstone Corp A company founded by Brad Cox, responsible for Objective C. Telephone: +1 (203) 426-1875. (1996-08-04) 1 1 1 1 1 stepwise refinement top-down design 1 1 1 1 1 stereogram A two-dimensional image which, when viewed correctly appears three-dimensional. E.g. SIRDS or SIRTS. (ftp://katz.anu.edu.au/pub/stereograms). (1994-11-03) 1 1 1 1 1 Sterling Software, Inc. A software company which was bought out by Computer Associates International, Inc. Acquisition (http://ca.com/acq/sterling/). (2002-04-20) 1 1 1 1 1 Steve Jobs Stephen Jobs 1 1 1 1 1 Steve's Shell (ssh) A Unix shell with many csh- and ksh-like features, by Steve Baker <ice@judy.indstate.edu> and Thomas Moore. Version 1.7 has been ported to Sequent, Sun, NeXT, Ultrix, BSDI and is available from comp.sources.unix volume 26. (1993-04-15) 1 1 1 1 1 Steve Wozniak Co-founder of Apple Computer with Steve Jobs on 01 April 1976 and the inventor of the Apple II personal computer. (1998-04-05) 1 1 1 1 1 STFT Short Term Fourier Transform 1 1 1 1 1 STFU Shut the fuck up. (2008-03-04) 1 1 1 1 1 STFW Search The Fucking Web 1 1 1 1 1 Sticks&Stones A functional, polymorphic hardware description language loosely based on ML by Lucca Cardelli. ["An Algebraic Approach to Hardware Description and Verification", L. Cardelli, Thesis, Edinburgh U, 1982]. ["Sticks&Stones II: A Functional Language VLSI Layout Generation Tool", Andrew Butterfield <butrfeld@cs.tcd.ie>, Thesis, Trinity College, 1990]. (2008-03-04) 1 1 1 1 1 sticky analysis A kind of program analysis that uses information from all the call sites of a function or procedure. (1999-06-15) 1 1 1 1 1 sticky bit The bit in the mode of a Unix file which, if set for an executable, tells the kernel to keep the code loaded in swap space even after it has finished executing on the assumption that it is likely to be used again soon. This performance optimisation was included in some early (and recent?) versions of Unix to save reloading frequently used programs such as the shell or vi from disk. If the sticky bit is set on a directory, an unprivileged user may not delete or rename files of other users in that directory even if he has write access to the directory. The Unix "ls" command displays a set sticky bit as a "t" in the permissions of a file or directory. (1997-02-26) 1 1 1 1 1 sticky content web pages that refer only or mostly to pages on the same website. This is important to some commercial sites who want users to keep accessing pages from their site because they receive advertising income from each hit. It does however somewhat miss the point of the web which is to link useful information across the whole Internet. (1999-06-15) 1 1 1 1 1 stiffy (University of Lowell, Massachusetts) A 3.5-inch microfloppy, so called because their jackets are more rigid than those of the 5.25-inch and the (obsolete) 8-inch floppy disk. Elsewhere this might be called a firmy. [Jargon File] (1994-11-03) 1 1 1 1 1 STIL STatistical Interpretive Language. ["STIL User's Manual", C.F. Donaghey et al, Indust Eng Dept, U Houston (Aug 1969)]. 1 1 1 1 1 STING A parallel dialect of Scheme intended to serve as a high-level operating system for symbolic programming languages. First-class threads and processors and customisable scheduling policies. E-mail: <suresh@research.nj.dec.com>. ["A Customizable Substrate for Concurrent Languages", S. Jagannathan et al, ACM SIGPLAN Notices, 1992]. (1994-11-03) 1 1 1 1 1 STk A Scheme interpreter blended with Ousterhout's Tk package by Erick Gallesio <eg@unice.fr>. STk expresses all of Tk as Scheme objects. STk includes a slow CLOS/Dylan-like object-oriented extension. STk almost conforms to R4RS and runs on SunOS 4.1.x and Ultrix/MIPS. Latest version: 4.0.1, as of 2000-09-24. (ftp://kaolin.unice.fr/pub/STk-1.00.tar.gz). (ftp://ftp.cs.indiana.edu/pub/scheme-repository/imp/STk-2.1.tar.Z). (2000-12-16) 1 1 1 1 1 STMP Did you mean SMTP? 1 1 1 1 1 stochastic probabilistic 1 1 1 1 1 stock-keeping unit (SKU) /skyoo/ (rarely seen expanded) A common term for a unique numeric identifier, typically in a database. Originally this was used only for products, but has spread in usage. Compare with UID for sense development. (1998-09-27) 1 1 1 1 1 STOIC STring Oriented Interactive Compiler 1 1 1 1 1 stomp on To inadvertently overwrite something important, usually automatically. "All the work I did this weekend got stomped on last night by the nightly server script." Compare scribble, mangle, trash, scrog, roach. [Jargon File] 1 1 1 1 1 STONE A Structured and Open Environment: a project supported by the German Ministry of Research and Technology (BMFT) to design, implement and distribute a SEE for research and teaching. 1 1 1 1 1 Stone Age In computer folklore, an ill-defined period from ENIAC (ca. 1943) to the mid-1950s; the great age of electromechanical dinosaurs. Sometimes used for the entire period up to 1960-61 (see Iron Age); however, it is more descriptive to characterise the latter period in terms of a Bronze Age era of transistor-logic, pre-ferrite core memory machines with drum or CRT mass storage (as opposed to just mercury delay lines and/or relays). More generally, the term is used pejoratively for ancient hardware or software, even by survivors from the Stone Age. [Jargon File] (2003-09-27) 1 1 1 1 1 stone knives and bearskins (From the Star Trek Classic episode "The City on the Edge of Forever") A term traditionally used to describe (and deprecate) computing environments that are grotesquely primitive in light of what is known about good ways to design things. As in "Don't get too used to the facilities here. Once you leave SAIL it's stone knives and bearskins as far as the eye can see". Compare steam-powered. [Jargon File] (1995-01-24) 1 1 1 1 1 Stoneman The requirements, written by the HOLWG of the US DoD in Feb 1980, that led to APSE. ["Requirements for Ada Programming Support Environments: STONEMAN", US Dept of Defense, Feb 1980]. (1995-01-24) 1 1 1 1 1 stop bit In serial communications, where each bit of the message is transmitted in sequence, stop bits are extra "1" bits which follow the data and any parity bit. They mark the end of a unit of transmission (normally a byte or character). For example, characters on an EIA-232 serial line may have one or two stop bits added. Some UARTs even allow for 1.5 stop bits but one is probably the most commonly used. A serial connection may be described as, for example, "8N1" which means eight data bits, no parity and one stop bit. (1995-01-24) 1 1 1 1 1 stoppage /sto'p*j/ Extreme lossage that renders something (usually something vital) completely unusable. "The recent system stoppage was caused by a fried transformer." [Jargon File] (1995-01-24) 1 1 1 1 1 storage (Or "memory") A device into which data can be entered, in which it can be held, and from which it can be retrieved at a later time. The distinguishing characteristics of a device are its capacity (the number of bytes it can hold), its access speed, whether it is volatile (loses data when the power is turned off), removeable and/or writeable. Common examples are DRAM, hard disk, CD-ROM, Flash memory. (2009-02-23) 1 1 1 1 1 Storage Allocation and Coding Program (STAC) A symbolic macro-assembler for the English Electric DEUCE. ["DEUCE STAC Programming Manual", DEUCE News No. 38, Report K/AA y 1 DEUCE Library Service, Data Processing and COntrol Systems DIvision, English Electric Company, Kidsgrove, June]. (1998-06-08) 1 1 1 1 1 Storage Area Network (SAN) A high-speed subnetwork of shared storage devices. A storage device is a machine that contains nothing but a disk or disks for storing data. A SAN's architecture works in a way that makes all storage devices available to all servers on a LAN or WAN. As more storage devices are added to a SAN, they too will be accessible from any server in the larger network. The server merely acts as a pathway between the end user and the stored data. Because stored data does not reside directly on any of a network's servers, server power is used for business applications, and network capacity is released to the end user. 1 1 1 1 1 Storage Management Services (SMS) Software that enables network administrators to route backup data from various devices on a network to another device such as a server or a magnetic tape backup unit. This is done either to make use of a high-capacity storage system such as a tape juke-box or for disaster protection. (1996-02-18) 1 1 1 1 1 storage media Devices on which data is stored, as opposed to the device ("drive") used to read and write data from and to the media. The term typically applies to removeable storage such as magnetic tape or flash memory, rather than fixed devices like a hard disk. (2009-02-23) 1 1 1 1 1 store In some varieties of Commonwealth hackish, the preferred synonym for core. Thus, "bringing a program into store" means that a program is being swapped in from backing store to main store. [Jargon File] (2006-12-06) 1 1 1 1 1 store and forward (Or "message switching") A kind of message passing system where a complete message is received before any of it is passed on to the next node. This means that each message is using at most one interprocessor link at any time but intermediate nodes will require more storage buffers than under the alternative, wormhole routing. E-mail transmission is an example of store and forward message passing. (1995-02-16) 1 1 1 1 1 stored procedure A subroutine stored in a database and executed by the database management system. The subroutine may be written in the same language in which the database is queried and may be precompiled to improve performance. Typically a stored procedure encapsulates some business process. Performing this on the database server avoids the network overhead of transferring input data to the client for processing. This would be particularly significant if processing lots of data and returning a small result set like a total or maximum. Stored procedures also provide consistent implementation of the business logic to clients written in different languages and running in different environments. Some financial systems allow databases access through stored procedures alone, this restricts actions on the data to a small number of auditable queries. Sybase SQL Server (Adaptive Server Enterprise) was the first commercially successful RDBMS to support stored procedures. 1 1 1 1 1 storm broadcast storm 1 1 1 1 1 Story of Mel The story of Mel 1 1 1 1 1 STP shielded twisted pair 1 1 1 1 1 StP Software through Pictures 1 1 1 1 1 STP4 A statistical language. 1 1 1 1 1 Strachey, Christopher Christopher Strachey 1 1 1 1 1 Strand 1. AND-parallel logic programming language. Essentially flat Parlog83 with sequential-and and sequential-or eliminated. ["Strand: New Concepts on Parallel Programming", Ian Foster et al, P-H 1990]. Strand88 is a commercial implementation. 2. A query language, implemented on top of INGRES (an RDBMS). ["Modelling Summary Data", R. Johnson, Proc ACM SIGMOD Conf 1981]. 1 1 1 1 1 Strand88 A commercial implementation of Strand from Strand Software Technologies Ltd., UK and Strand Software, Beaverton, OR, USA. E-mail: <strand88@sstl.uucp>. 1 1 1 1 1 Stratus One of the leading manufacturers of fault-tolerant computer systems. While virtually all of Stratus' core hardware and software is sold into the financial services, telecommunications, travel and transportation, and gaming these markets, a broad range of middleware and applications are developed and marketed by Stratus, its subsidiaries, and third party partners. Yearly sales $609M, profits $43.5M (1996). (http://stratus,com). (1997-04-24) 1 1 1 1 1 Strawman The first of the series of DoD requirements that led to Ada (Woodenman, Tinman, Ironman, Steelman). Strawman was produced by the HOLWG in Apr 1975. (1995-01-30) 1 1 1 1 1 STREAM ["STREAM: A Scheme Language for Formally Describing Digital Circuits", C.D. Kloos in PARLE: Parallel Architectures and Languages Europe, LNCS 259, Springer 1987]. (1995-01-30) 1 1 1 1 1 stream 1. <communications> An abstraction referring to any flow of data from a source (or sender, producer) to a single sink (or receiver, consumer). A stream usually flows through a channel of some kind, as opposed to packets which may be addressed and routed independently, possibly to multiple recipients. Streams usually require some mechanism for establishing a channel or a "connection" between the sender and receiver. 2. <programming> In the C language's buffered input/ouput library functions, a stream is associated with a file or device which has been opened using fopen. Characters may be read from (written to) a stream without knowing their actual source (destination) and buffering is provided transparently by the library routines. 3. <operating system> Confusingly, Sun have called their modular device driver mechanism "STREAMS". 4. <operating system> In IBM's AIX operating system, a stream is a full-duplex processing and data transfer path 1 1 1 1 1 streaming Playing sound or video in real time as it is downloaded over the Internet as opposed to storing it in a local file first. A plug-in to a web browser such as Netscape Navigator decompresses and plays the data as it is transferred to your computer over the web. Streaming audio or video avoids the delay entailed in downloading an entire file and then playing it with a helper application. Streaming requires a fast connection and a computer powerful enough to execute the decompression algorithm in real time. (1996-11-06) 1 1 1 1 1 Streaming SIMD Extensions (SSE) Intel Corporation's floating point SIMD extention of their Pentium microprocessor architecture. SSE was formerly know as KNI (Katmai New Instructions). It was introduced with the Pentium III. Intel Pentium III (http://developer.intel.com/design/pentiumiii/prodbref/). ipoem (http://ipoem.com/technology/Docs/pentium4.html). (2003-07-13) 1 1 1 1 1 stream-oriented connection-oriented 1 1 1 1 1 STREAMS A collection of system calls, kernel resources, and kernel utility routines that can create, use, and dismantle a stream. A "stream head" provides the interface between the stream and the user processes. Its principal function is to process STREAMS-related user system calls. A "stream module" processes data that travel bewteen the stream head and driver. The "stream end" provides the services of an external input/output device or an internal software driver. The internal software driver is commonly called a pseudo-device driver. The STREAMS concept has been formalised in Unix System V. For example, SVR4 implements sockets and pipes using STREAMS, resulting in pipe(2) openning bidirectional pipes. [IBM AIX 3.2 Communication Programming Concepts, SC23-2206-03]. (1999-06-29) 1 1 1 1 1 strength reduction An optimisation where a function of some systematically changing variable is calculated more efficiently by using previous values of the function. In a procedural language this would apply to an expression involving a loop variable and in a declarative language it would apply to the argument of a recursive function. E.g. f x = ... (2**x) ... (f (x+1)) ... ==> f x = f' x (2**x) where f ' x z = ... z ... (f' (x+1) 2*z) ... 1 1 1 1 1 STRESS STRuctual Engineering Systems Solver. A system for structural analysis problems in Civil Engineering. STRESS was superseded by STRUDL. ["STRESS: A User's Manual", S.J. Fenves et al, MIT Press 1964]. [Sammet 1969, p. 612]. (1995-01-31) 1 1 1 1 1 stress testing Testing aimed at investigating the behaviour of a software or hardware equipment in out of ordinary operating conditions. (1998-03-27) 1 1 1 1 1 strict A function f is strict in an argument if f bottom = bottom (See bottom). In other words, the result depends on the argument so evaluation of an application of the function cannot terminate until evaluation of the argument has terminated. If the result is only bottom when the argument is bottom then the function is also bottom-unique. See also strict evaluation, hyperstrict. (1995-01-25) 1 1 1 1 1 strict evaluation Call-by-value evaluation order is sometimes called "strict evaluation" because, in a sequential system, it makes functions behave as though they were strict, in the sense that evaluation of a function application cannot terminate before evaluation of the argument. Similarly, languages are called strict if they use call-by-value argument passing. Compare eager evaluation, lazy evaluation. (1994-12-21) 1 1 1 1 1 strided /str:'d*d/ (scientific computing) Said of a sequence of memory reads and writes to addresses, each of which is separated from the last by a constant interval called "the stride length", or just "the stride". These can be a worst-case access pattern for cache schemes when the stride length is a multiple of the cache line size. Strided references are often generated by loops through an array, and (if the data is large enough that access-time is significant) it can be worthwhile to tune for better locality by inverting double loops or by partially unrolling the outer loop of a loop nest. [Jargon File] (1994-12-21) 1 1 1 1 1 string (Or "character string") A sequence of characters. Most programming languages consider characters and strings (e.g. "124:shabooya:\n", "hello world") to be distinct from numbers, which are typically stored in fixed-length binary or floating-point representation. A bit string is a sequence of bits. (2015-11-29) 1 1 1 1 1 String EXpression Interpreter String Oriented Symbolic Language 1 1 1 1 1 stringly typed A humourous play on "strongly typed", coined by Mark Simpson, for an implementation that uses strings instead of more appropriate types, thus preventing compile-time type checking. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2012-06-25) 1 1 1 1 1 STring Oriented Interactive Compiler (STOIC) A language from the Smithsonian Astrophysical Observatory. STOIC is similar to FORTH for strings and includes many VAX-specific items. (1998-09-27) 1 1 1 1 1 String Oriented Symbolic Language (SNOBOL) A string processing language for text and formula manipulation, developed by David J. Farber, Ralph E. Griswold and Ivan P. Polonsky at Bell Labs in 1962. SNOBOL had only simple control structures but provided a rich string-matching formalism of power comparable to regular expressions but implemented differently. People used it for simple natural language processing analysis tasks well into the 1980s. Since then, Perl has come into favour for such tasks. SNOBOL was originally called "SEXI" - String EXpression Interpreter. In spite of the suggestive name, SNOBOL is not related to COBOL. Farber said the name SNOBOL was largely contrived at the time the original JACM article was published when one of the implementors said something like, "This program doesn't have a snowball's chance in hell of ...". The expansion to "String Oriented Symbolic Language" was contrived later. 1 1 1 1 1 String PRocessING language (SPRING) ["From SPRING to SUMMER: Design, Definition and Implementation of Programming Languages for String Manipulation and Pattern Matching", Paul Klint, Math Centre, Amsterdam 1982]. (1996-02-06) 1 1 1 1 1 string reduction A reduction system where an expression is represented as a string of function names, constants and parentheses. It is reduced by replacing parts of the string representing subterms by their value. It is harder to represent sharing of subexpressions in string reduction than in graph reduction. (1995-02-06) 1 1 1 1 1 stripe data striping 1 1 1 1 1 stripe set data striping 1 1 1 1 1 striping data striping 1 1 1 1 1 STROBES Shared Time Repair of Big Electronic Systems 1 1 1 1 1 stroke The oblique stroke character, "/", ASCII 47. See ASCII for other synonyms. [Jargon File] 1 1 1 1 1 StrongARM A collaborative project between Digital Equipment Corporation and Advanced RISC Machines Ltd. (ARM) announced on 1995-02-06 licensing the ARM RISC architecture to Digital Semiconductor for the development of high-performance, low power microprocessors. The StrongARM family of 32-bit RISC products developed under the agreement are faster versions of the existing ARM processors with a somewhat different instruction set. They are targetted at applications such as next-generation personal digital assistants with improved user interfaces and communications; interactive television and set-top products; video games and multimedia edutainment systems with realistic imaging, motion and sound; and digital imaging, including low cost digital image capture and photo-quality scanning and printing. The StrongARM family has limited software compatibility with the ARM6, ARM7 and ARM8 families due to its separate 1 1 1 1 1 strongly connected component (SCC) A subset, S, of the nodes of a directed graph such that any node in S is reachable from any other node in S and S is not a subset of any larger such set. SCCs are equivalence classes under the transitive closure of the "directly connected to" relation. (1995-02-06) 1 1 1 1 1 strongly typed strong typing 1 1 1 1 1 strong typing Strict enforcement of type rules with no exceptions. Incorrect type usage can be detected either at run time or at compile time. Strong typing catches more type errors than weak typing, resulting in fewer hard errors. In a strongly typed language, conversion between types requires the use of explicit conversion functions ("casts") as opposed to implicit type coercion. Typing strength is a continuum; ML is more strongly typed than Java, which is more strongly typed than C. Strong or weak typing is independent of the choice between static typing and dynamic typing. Among strongly typed languages, Ada, Java, Haskell and ML are statically typed, whereas Python and Ruby are dynamically typed. (2004-07-20) 1 1 1 1 1 Stroustrup, Bjarne Bjarne Stroustrup 1 1 1 1 1 struct A data type in C and C++ corresponding to a record in Ada or Pascal or a tuple in functional programming. A struct has one or more members, each of which may have different types. It is used to group associated data together. (1995-02-14) 1 1 1 1 1 structural recursion The process of transforming an expression by expressing its structure as a syntax tree and applying a certain transformation rule to each kind of node, starting from the top. Rules for non-leaf nodes will normally return a result which depends on applying the rules recursively to its sub-nodes. Examples include syntax analysis, code generation, abstract interpretation and program transformation. (1995-01-11) 1 1 1 1 1 structured analysis One of a number of requirements analysis methods used in software engineering. 1 1 1 1 1 Structured Analysis and Design Technique (SADT) A function modeling method for analysing and communicating the functional perspective of a system. SADT was commissioned by The United States Air Force. IDEF0 was derived from SADT. (2007-01-08) 1 1 1 1 1 structured design (SD) One of a number of systematic top-down design techniques used in software engineering, usually after structured analysis. (1995-04-28) 1 1 1 1 1 structure diagram A pictorial representation of the composition, grouping and relationship of data items. (1998-06-11) 1 1 1 1 1 structured language block-structured 1 1 1 1 1 structured programming Any software development technique that includes structured design and results in the development of a program consisting of blocks of code whose internal details are independent. Structured programming is usually done in a block-structured language. (2004-09-29) 1 1 1 1 1 Structured Query Language SQL 1 1 1 1 1 Structure of Management Information (SMI) The rules used to define the objects that can be accessed via a network management protocol. This protocol is defined in STD 16, RFC 1155. See also Management Information Base. (1994-11-14) 1 1 1 1 1 strudel Common (spoken) name for the commercial at sign, @, ASCII 64. [Jargon File] (1995-03-13) 1 1 1 1 1 STRUDL STRUctured Design Language. Dynamic and finite-element analysis, steel and concrete structures. Subsystem of ICES. ["ICES STRUDL-II Engineering User's Manual", R68-91, CE Dept MIT (Nov 1968) Sammet 1969, p.613]. 1 1 1 1 1 STSC APL Implementation of APL by Scientific Time-Sharing Corporation 1 1 1 1 1 stub 1. <programming> A dummy procedure used when linking a program with a run-time library. The stub routine need not contain any code and is only present to prevent "undefined label" errors at link time. 2. <programming, networking> A local procedure in a remote procedure call. The client calls the stub to perform some task and need not necessarily be aware that RPC is involved. The stub transmits parameters over the network to the server and returns the results to the caller. (1995-11-09) 1 1 1 1 1 stub network A network which only carries packets to and from local hosts. Even if it has paths to more than one other network, it does not carry traffic for other networks. See also backbone, transit network. 1 1 1 1 1 stubroutine /stuhb'roo-teen/ [contraction of "stub subroutine"] Tiny, often vacuous placeholder for a subroutine that is to be written or fleshed out later. [Jargon File] 1 1 1 1 1 STUDENT D.G. Bobrow 1964. Early query system. Sammet 1969, p.664. 1 1 1 1 1 Student PL/I A translator-interpreter for a PL/I subset derived from SPL. ["Student PL/I Compiler", R.A. Vowels, RMIT, Melbourne, 1971]. (1996-01-19) 1 1 1 1 1 studly Impressive; powerful. Said of code and designs which exhibit both complexity and a virtuoso flair. Has connotations similar to hairy but is more positive in tone. Often in the emphatic "most studly" or as noun-form "studliness". "Smail 3.0's configuration parser is most studly." [Jargon File] 1 1 1 1 1 studlycaps /stuhd'lee-kaps/ A hackish form of silliness similar to BiCapitalisation for trademarks, but applied randomly and to arbitrary text rather than to trademarks. ThE oRigiN and SigNificaNce of thIs pRacTicE iS oBscuRe. (1995-03-01) 1 1 1 1 1 Stuffit (filename extension: .sit) A file archiving and compression utility, developed by Aladdin Systems, Inc.. Stuffit was originally developed for the Macintosh and is still the Mac standard tool for compression and archiving (compressing multiple files into one). Stuffit is now also available for Microsoft Windows and Linux. Compared to the standard Windows tool, WinZip, it is faster and gives better compression. Stuffit archives can be extracted with Stuffit Expander. Stuffit Home (http://stuffit.com/). (2003-09-20) 1 1 1 1 1 Stupids Term used by samurai for the suits who employ them. Succinctly expresses an attitude at least as common, though usually better disguised, among other subcultures of hackers. There may be intended reference here to an SF story originally published in 1952 but much anthologised since, Mark Clifton's Star, Bright. In it, a super-genius child classifies humans into a very few "Brights" like herself, a huge majority of Stupids, and a minority of "Tweens", the merely ordinary geniuses. [Jargon File] 1 1 1 1 1 stupid-sort Synonym bogo-sort. 1 1 1 1 1 Sturgeon's Law Ninety percent of everything is crap. Derived from a quote by science fiction author Theodore Sturgeon, who once said, "Sure, 90% of science fiction is crud. That's because 90% of everything is crud. Oddly, when Sturgeon's Law is cited, the" final word is almost invariably changed to "crap". Compare Ninety-Ninety Rule. Though this maxim originated in SF fandom, most hackers recognise it and are all too aware of its truth. [Jargon File] 1 1 1 1 1 STX Start Of Text 1 1 1 1 1 style The visual presentation or formatting of web content, chiefly either HTML content with style controlled by Cascading Style Sheets (CSS) or XML content controlled by XSL. Style is distinguished from meaning, which is encoded with semantic markup. The latter deals with logical divisions of content such as headings, lists and paragraphs. (2008-02-25) 1 1 1 1 1 su (substitute user) The Unix command which allows you to become another user after entering their password. su is most often used without arguments in which case it defaults to user root. Some versions of Unix only allows this command to be used by members of the wheel group. Unix manual page: su(1). (1996-09-08) 1 1 1 1 1 SUB Substitute 1 1 1 1 1 subband encoding An audio compression technique where the sound is split into frequency bands and then parts of the signal which the ear cannot detect are removed, e.g. a quiet sound masked by a loud one. The remaining signal is encoded using variable bit-rates with more bits per sample being used in the mid frequency range. Subband encoding is used in MPEG-1. (1994-11-02) 1 1 1 1 1 subclass class hierarchy 1 1 1 1 1 subject In subject-oriented programming, a subject is a collection of classes or class fragments whose class hierarchy models its domain in its own, subjective way. A subject may be a complete application in itself, or it may be an incomplete fragment that must be composed with other subjects to produce a complete application. Subject composition combines class hierarchies to produce new subjects that incorporate functionality from existing subjects. (1999-08-31) 1 1 1 1 1 subject index An information resource that contains references to other resources, categorised by subject, usually in a hierarchy. Yahoo is the most popular Internet subject index. Like most other subject indices (http://yahoo.com/Computers_and_Internet/Internet/World_Wide_Web/Searching_the_Web/Web_Directories/), Yahoo is arranged ontologically. Subject indices are not to be confused with search engines, which are based not on subject, but instead on relevance, although (1) this difference is often (possibly rightly) hidden from the unsophisticated user, and (2) future integration of knowledge representation into relevance ranking algorithms will make this a hazy distinction. (1997-04-09) 1 1 1 1 1 subject-oriented programming Program composition that supports building object-oriented systems as compositions of subjects, extending systems by composing them with new subjects, and integrating systems by composing them with one another (perhaps with glue or adapter subjects). The flexibility of subject composition introduces novel opportunities for developing and modularising object-oriented programs. Subject-oriented programming-in-the-large involves dividing a system into subjects and writing rules to compose them correctly. It complements object-oriented programming, solving a number of problems that arise when OOP is used to develop large systems or suites of interoperating or integrated applications. IBM subject-oriented programming (http://research.ibm.com/sop/). (1999-08-31) 1 1 1 1 1 sublanguage One of the languages associated with a DBMS, for example a data-definition language or query language. (1999-10-18) 1 1 1 1 1 subnet A portion of a network, which may be a physically independent network segment, which shares a network address with other portions of the network and is distinguished by a subnet number. A subnet is to a network what a network is to an internet. 1 1 1 1 1 subnet address The subnet portion of an IP address. In a subnetted network, the host portion of an IP address is split into a subnet portion and a host portion using an address mask (the subnet mask). 1 1 1 1 1 subnet mask address mask 1 1 1 1 1 subnet number subnet address 1 1 1 1 1 subroutine (Or "procedure") A sequence of instructions for performing a particular task. Most programming languages, including most machine languages, allow the programmer to define subroutines. This allows the subroutine code to be called from multiple places, even from within itself (in which case it is called recursive). The programming language implementation takes care of returning control to (just after) the calling location, usually with the support of call and return instructions at machine language level. Most languages also allow arguments to be passed to the subroutine, and one, or occasionally more, return values to be passed back. A function is often very similar to a subroutine, the main difference being that it is called chiefly for its return value, rather than for any side effects. (1996-10-01) 1 1 1 1 1 subscribe To request to receive messages posted to a mailing list or newsgroup. In contrast to the mundane use of the word this is often free of charge. (1997-03-27) 1 1 1 1 1 Subscriber Identity Module (SIM or "SIM card") A component, usually in the form of a miniature smart-card, that is theoretically tamper-proof and is used to associate a mobile subscriber with a mobile network subscription. The SIM holds the subscriber's unique MSISDN along with secret information such as a private encryption key and encryption and digital signature algorithms. Most SIMs also contain non-volatile storage for network and device management, contact lists, text messages sent and received, logos and in some cases even small Java programs. (2007-01-06) 1 1 1 1 1 subscribing subscribe 1 1 1 1 1 Subset-Equational Language (SEL) A declarative language for set processing by Bharat Jayaraman with subset and equational program clauses; pattern matching over sets (it supports efficient iteration over sets); annotations to say which functions distribute over union in which arguments (for point-wise/incremental computation over sets); defining transitive closures through circular constraints (implemented by mixed top-down/memoisation and bottom-up strategy); meta-programming and simple higher-order programming; modest user-interface including tracing. The SEL compiler, written in Quintus Prolog, generates WAM-like code, extended to deal with set-matching, memoisation, and the novel control structure of the language. The run-time system is written in C. (ftp://ftp.cs.buffalo.edu/users/bharat/SEL2). E-mail: Bharat Jayaraman <bharat@cs.buffalo.edu>. ["Towards a Broader Basis for Logic Programming", 1 1 1 1 1 Substitute (SUB) ASCII character 26. [Why?] (1996-06-28) 1 1 1 1 1 substrate The body or base layer of an integrated circuit, onto which other layers are deposited to form the circuit. The substrate is usually Silicon, though Sapphire is used for certain applications, particularly military, where radiation resistance is important. The substrate is originally part of the wafer from which the die is cut. It is used as the electrical ground for the circuit. (1996-04-07) 1 1 1 1 1 subtype If S is a subtype of T then an expression of type S may be used anywhere that one of type T can and an implicit type conversion will be applied to convert it to type T. In object oriented programming, this means that objects of type S must accept every message that one of type T would. (1997-07-28) 1 1 1 1 1 subtyping subtype 1 1 1 1 1 SuccessoR A language for distributed computing derived from SR. ["SuccessoR: Refinements to SR", R.A. Olsson et al, TR 84-3, U Arizona 1984]. (1994-12-15) 1 1 1 1 1 successor daughter 1 1 1 1 1 sucking mud (Or "pumping mud") (Applied Data Research) Crashed or wedged. Usually said of a machine that provides some service to a network, such as a file server. This Dallas regionalism derives from the East Texas oilfield lament, "Shut 'er down, Ma, she's a-suckin' mud". Often used as a query. "We are going to reconfigure the network, are you ready to suck mud?" [Jargon File] (1994-12-15) 1 1 1 1 1 Sue The system language used to write an operating system for the IBM 360. It is a cross between Pascal and XPL. It allows type checked separate compilation of internal procedures using a program library. ["The System Language for Project Sue", B.L. Clark e al, SIGPLAN Notices 6(9):79-88 (Oct 1971)]. (1994-12-01) 1 1 1 1 1 sufficiently small suitably small 1 1 1 1 1 SUGAR A simple lazy functional language designed at Westfield College, University of London, UK and used in Principles of Functional Programming, Hugh Glaser et al, P-H 1984. (1994-12-01) 1 1 1 1 1 suicideware A program which entirely stops functioning after a predefined date. Used to ensure that beta versions don't remain in circulation indefinitely or in demo versions to ensure that they can only be used to try out the program. (1997-05-26) 1 1 1 1 1 SUIF Stanford University Intermediate Format. A register-oriented intermediate language. (1994-12-01) 1 1 1 1 1 suit 1. Ugly and uncomfortable "business clothing" often worn by non-hackers. Invariably worn with a "tie", a strangulation device that partially cuts off the blood supply to the brain. It is thought that this explains much about the behaviour of suit-wearers. 2. A person who habitually wears suits, as distinct from a techie or hacker. See loser, burble, management, Stupids, SNAFU principle, and brain-damaged. [Jargon File] (1998-07-01) 1 1 1 1 1 suitably small (From mathematical jargon) An expression used ironically to characterise unquantifiable behaviour that differs from expected or required behaviour. For example, suppose a newly created program came up with a correct full-screen display, and one publicly exclaimed: "It works!" Then, if the program dumped core on the first mouse click, one might add: "Well, for suitably small values of `works'." Compare the characterisation of pi under for values of. [Jargon File] (1997-09-21) 1 1 1 1 1 Suite Synthetique des Benchmarks de l'AFUU (SSBA, AFUU Synthetic Benchmark Suite) A public domain benchmark suite produced by the AFUU. Version: 2.3 (1995-07-14). (1996-06-11) 1 1 1 1 1 sum 1. <theory> In domain theory, the sum A + B of two domains contains all elements of both domains, modified to indicate which part of the union they come from, plus a new bottom element. There are two constructor functions associated with the sum: inA : A -> A+B inB : B -> A+B inA(a) = (0,a) inB(b) = (1,b) and a disassembly operation: case d of isA(x) -> E1; isB(x) -> E2 This can be generalised to arbitrary numbers of domains. See also smash sum, disjoint union. 2. <tool> A Unix utility to calculate a 16-bit checksum of the data in a file. It also displays the size of the file, 1 1 1 1 1 Summary Object Interchange Format (SOIF) The attribute-value pair record format which Harvest Brokers use to exchange Harvest content summaries. SOIF provides a means of bracketing collections of summary objects, allowing Harvest Brokers to retrieve SOIF content summaries for many objects in a single, efficient compressed stream. Harvest Brokers provide support for querying SOIF data using structured attribute-value queries and many other types of queries. (http://ust.hk/Harvest/brokers/soifhelp.html). (1996-09-16) 1 1 1 1 1 SUMMER String manipulation and pattern matching language by Klint & Sint at CWI in the late 1970s. It was recently used as the input and implementation language for the Dataflow Compiler Project at CWI. ["An Overview of the SUMMER Programming Language", Paul Klint, 7th POPL, ACM 1980, pp. 47-55]. 1 1 1 1 1 SUMMER SESSION An early system on MIT's Whirlwind. [Listed in CACM 2(5):16 (May 1959)]. (1995-01-19) 1 1 1 1 1 sum of products 1. <mathematics, logic> Any mathematical expression in which an addition operator is applied to two or more subexpressions each of which is an application of a multiplication operator. The most common case would be scalar addition and multiplication, e.g. ab + cd but the term is used for other kinds of operators with similar properties, such as AND and OR in Boolean algebra, e.g. (a AND b) OR (c AND d) 2. <types> algebraic data type. (2008-02-04) 1 1 1 1 1 sum of products type algebraic data type 1 1 1 1 1 Sun Sun Microsystems 1 1 1 1 1 Sun-2 Workstation A Unix workstation produced by Sun Microsystems, Inc., based on the Motorola 68000. Followed by the Sun-3 Workstation. [Details? Dates?] (2001-03-11) 1 1 1 1 1 Sun-3 Workstation A Unix workstation produced by Sun Microsystems, Inc. in the 1980s, based on the Motorola 68020. Successor to the Sun-2 Workstation, followed by the Sun-4 Workstation. The Sun-3 had a custom MMU. A couple of mutant models used an entirely different architecture. [Details? Dates?] (2001-03-11) 1 1 1 1 1 Sun-4 Workstation A Unix workstation produced by Sun Microsystems, Inc. in the late 1980s[?], based on SPARC processors. The Sun-4 followed the Sun-3 Workstation. Later SPARC-based workstations were called "SPARCstations". [Details? Dates? Was "Sun-4" a SPARCstation?] (2001-03-11) 1 1 1 1 1 sun lounge (Great Britain) The room where all the Sun workstations live. The humour in this term comes from the fact that it's also in mainstream use to describe a solarium, and all those Sun workstations clustered together give off an amazing amount of heat. [Jargon File] (1995-01-19) 1 1 1 1 1 Sun Microsystems, Inc. One of the first, and now biggest, US computer manufacturers. They also manufacture in Europe. The Sun-2 and 3 series of workstations and servers were based on the Motorola 680x0 family of microprocessors and the Sun-4 series on the SPARC. Sun also produce their own version of Unix, originally called SunOS and now Solaris. Their Network File System has become the de facto standard for sharing files between Unix systems. Sun own MySQL AB. Sun was bought by Oracle Corporation on 2009-04-20. Quarterly sales $1403M, profits $78M (Aug 1994). (http://sun.com/). Sun World Online (http://sun.com/sunworldonline/). Address: 2550 Garcia Ave., Mt. View, CA 94043 -1100 USA. (1995-10-14) 1 1 1 1 1 SunOS Sun Microsystems' version of Unix for Sun workstations. SunOS is similar to BSD Unix with some SVR4 features and OpenWindows 3.0. After version 4, SunOS was integrated into Sun's Solaris operating environment. (1999-03-26) 1 1 1 1 1 sunspots 1. Notional cause of an odd error. "Why did the program suddenly turn the screen blue?" "Sunspots, I guess." 2. Also the cause of bit rot - from the myth that sunspots will increase cosmic rays, which can flip single bits in memory. See also phase of the moon. [Jargon File] 1 1 1 1 1 sun-stools Unflattering hackerism for SunTools, a pre-X windowing environment notorious in its day for size, slowness, and misfeatures. X, however, is larger and slower; see second-system effect. 1 1 1 1 1 SunView A windowing system from Sun Microsystems, superseded by NeWS. 1 1 1 1 1 SUNY State University of New York 1 1 1 1 1 SUPER The successor to LOGLISP, based on LNF. ["New Generation Knowledge Processing: Final Report on the SUPER System", J Alan Robinson et al, CASE Center TR 8707, Syracuse U, 1987]. (1994-11-24) 1 1 1 1 1 Super 7 An upgrade to Socket 7 to support AGP and a 100 MHz system bus,, supported by non-Intel processor and motherboard manufacturers such as AMD and Cyrix. Due to faster access to L2 cache and memory, Super 7 gives a 10% performance boost over Socket 7 motherboards for the same processor. Super 7 motherboards should support all Socket 7 processors. (1999-08-04) 1 1 1 1 1 Superbrain A personal computer released in 1980 by Intertec. The Superbrain had two Z80A microprocessors running at 4 MHz, one for the main processing and the other for peripheral activities. It had an integrated keyboard and display. It was sold with the CP/M operating system, Microsoft Basic, an 8080 assembler and Microsoft Cobol 74. The base model, the "Superbrain 10", had no drives, only a network connection. Other models added one or two 5" floppy disc units. The "Jr" had 170K drives (single-sided), the "QD" had 340 KB drives (double-sided) and the "SD" had 780k. Intertec did not sell or support a hard drive or an S-100 bus for these machines. The network version of the SuperBrain was called CompuStar. The network was a large gray parallel cable. CompuStar had three file servers that accepted up to 255 machines. These were the DSS-10 with a 10MB 8" Winchester drive; the "CDC" with 96MB consisting of 80MB fixed and a 16MB removable platter; and the 1 1 1 1 1 SuperBrain II The 1982 successor to the Superbrain with a faster and enhanced disk operating system and improved video and graphics. (http://www.old-computers.com/museum/computer.asp?st=1&c=204). (2013-12-30) 1 1 1 1 1 superclass class hierarchy 1 1 1 1 1 supercombinators Combinators with coarser granularity than those proposed by David Turner. A functional program is translated to a set of functions without free variables. The members of the set are selected to be optimal for that program. Supercombinators were proposed by John Hughes at University of Edinburgh. 1 1 1 1 1 supercompilation A function program transformation technique invented by Turchin. A program is evaluated symbolically in order to observe the possible history of computation states called configurations. Based on this Turchin's REFAL compiler would try to construct a better program. 1 1 1 1 1 supercomputer A broad term for one of the fastest computers currently available. Such computers are typically used for number crunching including scientific simulations, (animated) graphics, analysis of geological data (e.g. in petrochemical prospecting), structural analysis, computational fluid dynamics, physics, chemistry, electronic design, nuclear energy research and meteorology. Perhaps the best known supercomputer manufacturer is Cray Research. A less serious definition, reported from about 1990 at The University Of New South Wales states that a supercomputer is any computer that can outperform IBM's current fastest, thus making it impossible for IBM to ever produce a supercomputer. (1996-12-13) 1 1 1 1 1 SuperDrive Apple Computer, Inc.'s name for a combined DVD-ROM, DVD-RW, CD-RW drive that appeared in the iMac in 2002. (2009-05-05) 1 1 1 1 1 superhighway information superhighway 1 1 1 1 1 SuperJanet An initiative started in 1989, under the Computer Board, with the aim of developing of a national broadband network to support UK higher education and research. The preparatory work culminated in 1992 with the award of a contract worth 18M pounds to British Telecom to provide networking services over a four year period that extends to March 1997. The BT contract will provide a national network with two components: a high speed, configurable bandwidth network serving up to 16 sites, initially using PDH to be replaced with SDH, and a high speed switched data service (SMDS) serving 50 or more sites. The primary role of the PDH/SDH component will be to support the development and deployment of an ATM network. These components will be complemented by several high performance Metropolitan Area Networks each serving several closely located sites. The aim is to provide, within the first year of the project, a pervasive network capable of supporting a large and diverse user community. 1 1 1 1 1 SUPERMAC A general-purpose macro language, embeddable in existing languages as a run-time library. ["SUPERMAC - A Macro Facility That can be Added to Existing Compilers", P.J. Brown, Soft Prac & Exp 10(6):431-434]. (1994-12-15) 1 1 1 1 1 super minicomputer Any minicomputer distinguished by having intelligent peripherals or multiple processors. The DEC PDP-8 was a minicomputer, the PDP-11 could be a minicomputer or a super minicomputer depending upon the sub-model. (2004-08-25) 1 1 1 1 1 SuperPaint A pioneering graphics program and framebuffer computer system developed by Richard Shoup at Xerox PARC. Design started in 1972 and the system produced its first stable image in April 1973. SuperPaint was one of the first computers used for creative work, video editing and animation, all which would become major sections within the entertainment industry and major components of industrial design. SuperPaint had a graphical user interface and could capture images from video input or combine them with digital data. SuperPaint was the first program with features such as changing hue, saturation and value, a colour palette, custom polygons and lines, virtual paintbrushes and pencils, auto-filling of images and anti-aliasing. Richard Shoup's website (http://www.rgshoup.com/prof/SuperPaint/). (2008-11-27) 1 1 1 1 1 Super Pascal A Pascal variant used in the reference below. Super Pascal adds non-numeric labels, a return statement and expressions as names of types. ["Data Structures and Algorithms", A. Aho, Hopcroft & Ullman, A-W 1983] (2004-08-25) 1 1 1 1 1 superpipelined 1. Traditional pipelined architectures have a single pipeline stage for each of: instruction fetch, instruction decode, memory read, ALU operation and memory write. A superpipelined processor has a pipeline where each of these logical steps may be subdivided into multiple pipeline stages. 2. Marketese for pipelined. 1 1 1 1 1 superprogrammer A prolific programmer; one who can code exceedingly well and quickly. Not all hackers are superprogrammers, but many are. Productivity can vary from one programmer to another by three orders of magnitude. For example, one programmer might be able to write an average of three lines of working code in one day, while another, with the proper tools, might be able to write 3,000. This range is astonishing; it is matched in very few other areas of human endeavour. The term "superprogrammer" is more commonly used within such places as IBM than in the hacker community. It tends to stress naive measures of productivity and to underweight creativity, ingenuity, and getting the job *done* - and to sidestep the question of whether the 3,000 lines of code do more or less useful work than three lines that do the Right Thing. Hackers tend to prefer the terms hacker and wizard. [Jargon File] 1 1 1 1 1 superscalar A superscalar architecture is a uniprocessor that can execute two or more scalar operations in parallel. Some definitions include superpipelined and VLIW architectures; others do not. Superscalar architectures (apart from superpipelined architectures) require multiple functional units, which may or may not be identical to each other. In some superscalar processors the order of instruction execution is determined statically (purely at compile-time), in others it is determined dynamically (partly at run time). 1 1 1 1 1 super source quench A special packet designed to shut up an Internet host. The Internet Protocol (IP) has a control message called Source Quench that asks a host to transmit more slowly on a particular connection to avoid congestion. It also has a Redirect control message intended to instruct a host to send certain packets to a different local router. A "super source quench" is actually a redirect control packet, forged to look like it came from a local router, that instructs a host to send all packets to its own local loopback address. This will effectively tie many Internet hosts up in knots. Compare godzillagram, breath-of-life packet. [Jargon File] 1 1 1 1 1 SuperTalk Silicon Beach Software. A superset of HyperTalk used in SuperCard. 1 1 1 1 1 superuser [Unix] Synonym root, avatar. This usage has spread to non-Unix environments; the superuser is any account with all wheel bits on. A more specific term than wheel. [Jargon File] 1 1 1 1 1 Super VGA Super Video Graphics Array 1 1 1 1 1 Super Video Graphics Adapter Super Video Graphics Array 1 1 1 1 1 Super Video Graphics Adaptor Super Video Graphics Array 1 1 1 1 1 Super Video Graphics Array (SVGA) A video display standard created by VESA for IBM PC compatible personal computers. The resolution is 800 x 600 4-bit pixels. Each pixel can therefore be one of 16 colours. See Video Graphics Array. [Is there a palette? Standard document? Adapter, Adaptor, or Array?] (1995-01-12) 1 1 1 1 1 supervisor mode (Or "supervisor state") An execution mode on some processors which enables execution of all instructions, including privileged instructions. It may also give access to different a address space, to memory management hardware and to other peripherals. This is the mode in which the operating system usually runs. Opposite: user mode. (1995-02-15) 1 1 1 1 1 Supervisory Control and Data Acquisition (SCADA) Systems are used in industry to monitor and control plant status and provide logging facilities. SCADA systems are highly configurable, and usually interface to the plant via PLCs. (1997-02-11) 1 1 1 1 1 SuperZap An IBM utility program used to quickly patch operating system or application program executable code in preference to editing the source code and recompiling. The SuperZAP program was a quick hack written by one IBM Engineer, possibly from IBM UK, in the late 1960s to directly fix executable files. He needed to fix a bug but it would have taken hours to rebuild the vast OS/360 executables. The S/360 architecture has an instruction ZAP (Zero and Add Packed) for packed decmial arithmetic, that sets the byte at a given address to a given value. Superzap used this to write data given as a string of hex digits to a given location in an executable file in a matter of seconds. Soon the IBM development labs were releasing all Programming Temporary Fixes (PTFs) to OS/360 in this form. OS/360 included a version called IMASPZAP or AMASPZAP which persisted through MVS, MVS/SP, MVS/XA, OS/390 and probably still remains in z/OS, the distant descendent of OS/360. 1 1 1 1 1 Supplementary Ideographic Plane (SIP) The third plane (plane 2) defined in Unicode/ISO 10646, designed to hold all the ideographs descended from Chinese writing (mainly found in Vietnamese, Korean, Japanese and Chinese) that aren't found in the Basic Multilingual Plane. The BMP was supposed to hold all ideographs in modern use; unfortunately, many Chinese dialects (like Cantonese and Hong Kong Chinese) were overlooked; to write these, characters from the SIP are necessary. This is one reason even non-academic software must support characters outside the BMP. Unicode home (http://unicode.org). (2002-06-19) 1 1 1 1 1 support After-sale handholding; something many software vendors promise but few deliver. To hackers, most support people are useless - because by the time a hacker calls support he or she will usually know the software and the relevant manuals better than the support people. A hacker's idea of support is an electronic exchange with the software's designer. [Jargon File] (1995-02-15) 1 1 1 1 1 supremum least upper bound 1 1 1 1 1 Sure ["Towards a Broader Basis for Logic Programming", Bharat Jayaraman, TR CS Dept, SUNY Buffalo, 1990]. (1995-01-05) 1 1 1 1 1 surfing ("Internet surfing") Used by analogy to describe the ease with which an expert user can use the waves of information flowing around the Internet to get where he wants. The term became popular in the early 1990s as access to the Internet became more widespread and tools such as web browsers made its use simpler and more pleasant. (1995-01-05) 1 1 1 1 1 SURGE Sorter, Updater, Report Generator, Etc. IBM 704, 1959. Sammet 1969, p.8. 1 1 1 1 1 surjection A function f : A -> B is surjective or onto or a surjection if f A = B. I.e. f can return any value in B. This means that its image is its codomain. Only surjections have right inverses, f' : B -> A where f (f' x) = x since if f were not a surjection there would be elements of B for which f' was not defined. See also bijection, injection. (1995-05-27) 1 1 1 1 1 surjective surjection 1 1 1 1 1 surrogate key A unique primary key generated by the RDBMS that is not derived from any data in the database and whose only significance is to act as the primary key. A surrogate key is frequently a sequential number (e.g. a Sybase "identity column") but doesn't have to be. Having the key independent of all other columns insulates the database relationships from changes in data values or database design and guarantees uniqueness. Some database designers use surrogate keys religiously regardless of the suitability of other candidate keys. However, if a good key already exists, the addition of a surrogate key will merely slow down access, particularly if it is indexed. Compare: intelligent key. (1999-12-07) 1 1 1 1 1 suspension In lazy evaluation, a suspension (or in Henderson's terminology, a "recipe") is a closure with a flag indicating whether the expression has been evaluated or not. When the expression is evaluated the first time, this flag is set. Subsequent requests for the value of the expression will not attempt to re-evaluate it. (1995-02-06) 1 1 1 1 1 Suzie COBOL /soo'zee koh'bol/ 1. (IBM, probably from Frank Zappa's "Suzy Creamcheese") A coder straight out of training school who knows everything except the value of comments in plain English. Also (fashionable among personkind wishing to avoid accusations of sexism) "Sammy Cobol" or (in some non-IBM circles) "Cobol Charlie". 2. (proposed) Meta-name for any code grinder, analogous to J. Random Hacker. [Jargon File] (1995-02-06) 1 1 1 1 1 sv The country code for El Salvador. (1999-01-27) 1 1 1 1 1 SVC 1. <operating system> Supervisor Call. 2. <networking> switched virtual connection. (2001-10-25) 1 1 1 1 1 SVG Scalable Vector Graphics 1 1 1 1 1 SVGA Super Video Graphics Array (not Adapter). (1995-11-16) 1 1 1 1 1 SVGA monitor A monitor capable of displaying the output of an SVGA card. (1997-02-25) 1 1 1 1 1 SVID System V Interface Definition 1 1 1 1 1 S-Video A video format offering a higher quality signal than composite video, but a lower quality than component video. This mid-level format divides the signal into two channels - luminance and chrominance. [Used where and for what?] (1998-06-25) 1 1 1 1 1 SVR4 AT&T/USL Unix System V Release 4. (1995-03-28) 1 1 1 1 1 SVRC Software Verification Research Centre. (1995-11-14) 1 1 1 1 1 SVS OS/VS2 1 1 1 1 1 swab /swob/ The PDP-11 swap byte instruction mnemonic, as immortalised in the dd option "conv=swab". 1. To solve the NUXI problem by swapping bytes in a file. 2. The program in V7 Unix used to perform this action, or anything functionally equivalent to it. See also big-endian, little-endian, middle-endian, bytesexual. [Jargon File] 1 1 1 1 1 SWAG Scientific (or Silly) Wild Ass Guess. A term used by technical teams when establishing high level sizings for large projects. (2000-08-09) 1 1 1 1 1 swap To move a program from fast-access memory to a slow-access memory ("swap out"), or vice versa ("swap in"). The term often refers specifically to the use of a hard disk (or a swap file) as virtual memory or "swap space". When a program is to be executed, possibly as determined by a scheduler, it is swapped into core for processing; when it can no longer continue executing for some reason, or the scheduler decides its time slice has expired, it is swapped out again. This contrasts with "paging" systems in which only parts of a program's memory is transfered. [Jargon File] (1996-11-22) 1 1 1 1 1 swap file A file used by a program or, more often, an operating system as swap space. A swap file is usually allocated as a long contiguous section of a hard disk to reduce access time. The disk space used for a swap file can not be used for other things. Under Microsoft Windows, swap files are recommended not to exceed three times the available RAM and are usually 150 percent of the RAM size. (1996-11-15) 1 1 1 1 1 swapped in swap 1 1 1 1 1 swapped out swap 1 1 1 1 1 swapping swap 1 1 1 1 1 swap space An area of disk (e.g. a swap file) used to store the state of a process that has been swapped out. Under a virtual memory system, it is the amount of swap space rather than the amount of physical memory which determines the maximum size of a single process and the maximum total size of all active processes. [Jargon File] (1994-11-03) 1 1 1 1 1 Sweden Country code: se. 1 1 1 1 1 SweetLambda Sugared lambda-calculus(?). 1 1 1 1 1 swf /S W F/ The filename extension for Adobe Shockwave Flash animated vector graphics files, common on the web. A rarely used alternative expansion is "Small Web Format". (2007-09-07) 1 1 1 1 1 Swing Java's graphical user interface (GUI) package that provides a large collection of widgets (buttons, labels, lists etc.) that behave similarly on different platforms. Swing features "pluggable look & feel", allowing the program to look like a Windows, Motif or Macintosh) application. It is implemented using the Model-View-Controller (MVC) architecture and makes extensive use of nested "containers" to control the handling of events such as keystrokes. (http://java.sun.com/j2se/1.3/docs/api/javax/swing/package-summary.html). (2007-05-30) 1 1 1 1 1 SWI-Prolog A Prolog by Jan Wielemaker <jan@swi.psy.uva.nl> like a superset of Edinburgh Prolog. Version 1.7.2. Docking Station is distributed under General Public License. It runs on Sun-4, Sun-3, Linux, DEC MIPS (incomplete), RS/6000, PS2/AIX, Atari ST, Gould PN, NeXT, VAX, HP-UX (problems), MS-DOS, and OS/2. (ftp://swi.psy.uva.nl/pub/SWI-Prolog). OS/2 (ftp://mpii02999.ag2.mpi-sb.mpg.de/pub/toolw/SWI/). Mailing list: prolog-request@swi.psy.uva.nl. (2000-03-23) 1 1 1 1 1 Swiss Army Code Code for an application that is suffering from feature creep. Swiss Army Code does many things, but does none of them well. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2014-06-06) 1 1 1 1 1 switch 1. <programming> switch statement. 2. <software> command line option. 3. <networking> packet switch, circuit switch. (1999-01-14) 1 1 1 1 1 Switched Multimegabit Data Service (SMDS) An emerging high-speed datagram-based public data network service developed by Bellcore and expected to be widely used by telephone companies as the basis for their data networks. See also Metropolitan Area Network. (1997-01-31) 1 1 1 1 1 switched virtual circuit virtual circuit 1 1 1 1 1 switched virtual connection (SVC) A virtual connection in an ATM network set up on demand by the signalling control point. Contrast with permanent virtual connection. (2001-06-29) 1 1 1 1 1 switching Establishing the correct path through a network for a single packet of data (packet switching) or a persistent end-to-end connection (circuit switching). (2007-08-16) 1 1 1 1 1 switching hub A circuit switching hub. (1999-01-01) 1 1 1 1 1 switch statement (Or case statement, multi-way branch) A construct found in most high-level languages for selecting one of several possible blocks of code or branch destinations depending on the value of an expression. An example in C is switch (foo(x, y)) case 1: printf("Hello\n"); /* fall through */ case 2: printf("Goodbye\n"); break; case 3: printf("Fish\n"); break; default: fprintf(stderr, "Odd foo value\n"); exit(1); 1 1 1 1 1 swizzle To convert external names, array indices, or references within a data structure into address pointers when the data structure is brought into main memory from external storage (also called pointer swizzling); this may be done for speed in chasing references or to simplify code (e.g. by turning lots of name lookups into pointer dereferences). The converse operation is sometimes termed "unswizzling". See also snap. [Jargon File] 1 1 1 1 1 SWL Software Writer's Language 1 1 1 1 1 SWT Standard Widget Toolkit 1 1 1 1 1 swung dash A character similar to tilde but appearing in the same vertical position as a dash, i.e. half way up rather than at the top like tilde. ASCII does not include a swung dash so tilde is used instead. It is commonly used for "approximates" or "is approximately equal to". (1997-06-28) 1 1 1 1 1 sy The country code for Syria. (1999-01-27) 1 1 1 1 1 Sybase, Inc. A software vendor focused on database management software. Yearly sales: $903.9 million (1997). Address: 6475 Christie Ave., Emeryville, California, USA. (http://sybase.com). (1998-05-18) 1 1 1 1 1 Sybase SQL Server Adaptive Server Enterprise 1 1 1 1 1 SYDEL A system language, fully typed, with inline assembly code, by Jan Garwick, ca 1974. 1 1 1 1 1 SYGMA A symbolic generator and macro assembler by A.P. Ershov et al of Novosibirsk. For the BESM-6, M-220 and Minsk-22. ["SYGMA, A Symbolic Generator and Macroassembler", A.P. Ershov et al, in Symbol Manipulation Languages and Techniques, D.G. Bobrow ed, N-H 1968, pp.226- 246]. 1 1 1 1 1 SYLK Symbolic Link 1 1 1 1 1 syllogism /sil'oh-jiz`*m/ <logic> Deductive reasoning in which a conclusion is derived from two premises. The conclusion necessarily follows from the premises so that, if these are true, the conclusion must be true, and the syllogism amounts to demonstration. To put it another way, the premises imply the conclusion. For example, every virtue is laudable; kindness is a virtue; therefore kindness is laudable. Strangely, a syllogism can still be true if the premises are false. Compare inference rule. [Relationship between premises?] (2009-10-28) 1 1 1 1 1 Sylvan [Distributed language?] 1 1 1 1 1 Symantec Software manufacturer of utility and development applications for Windows and Macintosh platforms. Products include ACT!, Norton Utilities, Norton AntiVirus, Symantec AntiVirus for Macintosh, Symantec Cafe. (http://symantec.com/). (1997-03-10) 1 1 1 1 1 SYMBAL SYMbolic ALgebra. A symbolic mathematics language with ALGOL-like syntax by Max Engeli, late 60's. Implemented for CDC 6600. ["User's Manual for the Formula Manipulation Language SYMBAL", M. Engeli, TRM-8.00, Comp Ctr UT Austin, June 1968]. 1 1 1 1 1 SymbMath A small symbolic mathematics package for MS-DOS which can learn new facts. Latest version: 2.1.1. (Home (http://symbmath.com/). (2001-03-26) 1 1 1 1 1 SYMBOLANG Lapidus & Goldstein, 1965. Symbol manipulating Fortran subroutine package for IBM 7094, later CDC 6600. ["Some Experiments in Algebraic Manipulation", CACM 8:501-508 1965]. (1995-03-16) 1 1 1 1 1 Symbolic Assembler Program (SAP) The assembly language for the IBM 704, defined in the late 1950s. (1994-12-12) 1 1 1 1 1 SYMBOLIC ASSEMBLY An early system on the IBM 705. [Listed in CACM 2(5):16, May 1959]. (1996-01-15) 1 1 1 1 1 Symbolic Automatic INTegrator (SAINT) A symbolic mathematics program written in Lisp by J. Slagle at MIT in 1961. [Sammet 1969, p. 410]. (1994-12-08) 1 1 1 1 1 symbolic inference The derivation of new facts from known facts and inference rules. This is one of the fundamental operations of artificial intelligence and logic programming languages like Prolog. Inference is a basic part of human reasoning. For example given that all men are mortal and that Socrates is a man, it is a trivial step to infer that Socrates is mortal. We might express these symbolically: man(X) => mortal(X). man(socrates). ("if X is a man then X is mortal" and "Socrates is a man"). Here, "man", "mortal" and "socrates" are just arbitrary symbols which the computer manipulates without reference to or knowledge of their external meaning. A forward chaining system (a production system) could use these to infer the 1 1 1 1 1 Symbolic Link (SYLK) A Microsoft file format for spreadsheets, (not to be confused with symbolic link). SYLK format existed in one form or another in as early as 1987, and was part of Excel v1.0. It is is an outgrowth of VisiCalc DIF file format. SYLK format is ascii text and represents information about both formula, value, and some formatting information, which makes it something like an RTF for spreadsheets. It is used as a general tabular data exchange format. (http://netghost.narod.ru/gff/graphics/summary/micsylk.htm). [Reference?] (2004-04-08) 1 1 1 1 1 symbolic link (Or "symlink", "soft link" (by contrast with hard link), "shortcut", "alias") A special type of Unix file which refers to another file by its pathname. A symbolic link is created with the "ln" (link) command: ln -s OLDNAME NEWNAME Where OLDNAME is the target of the link (usually a pathname) and NEWNAME is the pathname of the link itself. Most operations (open, read, write) on the symbolic link automatically dereference it and operate on its target (OLDNAME). Some operations (e.g. removing) work on the link itself (NEWNAME). In contrast with hard links, there are no restrictions on where a symbolic link can point, it can refer to a file on another file system, to itself or to a file which does not even exist (e.g. when the target of the symlink is removed). Such problems will only be detected when the link is accessed. 1 1 1 1 1 symbolic logic The discipline that treats formal logic by means of a formalised artificial language or symbolic calculus, whose purpose is to avoid the ambiguities and logical inadequacies of natural language. (1995-12-24) 1 1 1 1 1 Symbolic Mathematical Laboratory An on-line system under CTSS for symbolic mathematics. It used a display screen and a light pen. [Sammet 1969, p.514]. (1995-04-16) 1 1 1 1 1 symbolic mathematics (Or "symbolic math") The use of computers to manipulate mathematical equations and expressions in symbolic form, as opposed to manipulating the numerical quantities represented by those symbols. Such a system might be used for symbolic integration or differentiation, substitution of one expression into another, simplification of an expression, change of subject etc. One of the best known symbolic mathematics software packages is Mathematica. Others include ALAM, ALGY, AMP, Ashmedai, AXIOM*, CAMAL, CAYLEY, CCalc, CLAM, CoCoA(?), ESP, FLAP, FORM, FORMAL, Formula ALGOL, GAP, JACAL, LiE, Macaulay, MACSYMA, Magic Paper, MAO, Maple, Mathcad, MATHLAB, MuMath, Nother, ORTHOCARTAN, Pari, REDUCE, SAC-1, SAC2, SAINT, Schoonschip, Scratchpad I, SHEEP, STENSOR, SYMBAL, SymbMath, Symbolic Mathematical Laboratory, TRIGMAN, UBASIC. 1 1 1 1 1 Symbolic Optimal Assembly Program (SOAP) The IBM 650's assembly language. Optimal refers to rearranging instructions on slowly rotating drum memory. Versions: SOAP I, SOAP II, CASE SOAP III. [Listed in CACM 2(5):16, May 1959]. (1994-11-04) 1 1 1 1 1 Symbolic Optimum DEUCE Assembly Program (SODA) The symbolic assembler for a one-level storage virtual machine for the English ELectric DEUCE. ["SODA Manual of Operation", R. C. Brigham and C. G. Bell, School of Elec Eng, U New S Wales, Sydney, NSW, 1958]. (1994-11-04) 1 1 1 1 1 Symbolics, Inc. The company which produced the Lisp Machine. The Symbolics Museum (http://SMBX.org/). [Summary?] (2003-11-24) 1 1 1 1 1 Symbol Manipulation Program (SMP) Steven Wolfram's earlier symbol manipulation program, before he turned to Mathematica. ["SMP Handbook", C. Cole, S. Wolfram et al, Caltech 1981]. (1995-01-29) 1 1 1 1 1 symlink symbolic link 1 1 1 1 1 symmetric 1. A relation R is symmetric if, for all x and y, x R y => y R x If it is also antisymmetric (x R y & y R x => x == y) then x R y => x == y, i.e. no two different elements are related. 2. In linear algebra, a member of the tensor product of a vector space with itself one or more times, is symmetric if it is a fixed point of all of the linear isomorphisms of the tensor product generated by permutations of the ordering of the copies of the vector space as factors. It is said to be antisymmetric precisely if the action of any of these linear maps, on the given tensor, is equivalent to multiplication by the sign of the permutation in question. (1996-09-22) 1 1 1 1 1 symmetric key cryptography A cryptography system in which both parties have the same encryption key, as in secret key cryptography. Opposite: public-key cryptography. (1998-06-09) 1 1 1 1 1 Symmetric LISP A parallel Lisp in which environments are first-class objects. It is implemented in Common LISP. ["Parallelism, Persistence and Meta-Cleanliness in the Symmetric Lisp Processor", D. Gelernter et al, SIGPLAN Notices 22(7):274-282 (July 1987)]. ["A Programming Language Supporting First-Class Parallel Environments", S. Jagannathan, MIT-LCS/TR 434, 1989]. E-mail: Suresh Jagannathan <suresh@research.nj.nec.com>. (1995-03-16) 1 1 1 1 1 symmetric multiprocessing (SMP) Two or more similar processors connected via a high-bandwidth link and managed by one operating system, where each processor has equal access to I/O devices. This is in contrast to the "compute server" kind of parallel processor where a front-end processor handles all I/O to disks, terminals and local area network etc. The processors are treated more or less equally, with application programs able to run on any or perhaps all processors in the system, interchangeably, at the operating system's discretion. Simple MP usually involves assigning each processor to a fixed task (such as managing the file system), reserving the single main CPU for general tasks. OS/2 currently supports so-called HMP (Hybrid Multiprocessing), which provides some elements of symmetric multiprocessing, using add-on IBM software called MP/2. OS/2 SMP was planned for release in late 1993. (1995-03-19) 1 1 1 1 1 symmetric multiprocessor symmetric multiprocessing 1 1 1 1 1 Symphony Lotus Development's successor to their Lotus 1-2-3 spreadsheet. Unlike 1-2-3, Symphony allowed a limited form of multitasking. The user could switch manually between it and MS-DOS and separate graph and spreadsheet windows could be opened simultaneously and would be updated automatically when cells were changed. In addition, a small word processor could be opened in a third window. These all could be printed out on the same report. Symphony could read and write Lotus 1-2-3 files and had interactive graphical output and a word processor, thus making it effectively a report generator. Unlike 1-2-3, Symphony was not a great commercial success. (1995-03-28) 1 1 1 1 1 SYMPL SYsteMs Programming Language. CDC's derivative of Jovial. SYMPL is a non-re-entrant block structured language with extensive bit manipulation facilities, which is linkable with Fortran. Major parts of CDC systems during the 1970s were written in SYMPL. (1995-02-14) 1 1 1 1 1 SYN 1. <character> Synchronous idle. 2. <language> A syntactic specification language for COPS. ["Metalanguages of the Compiler Production System COPS", J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159]. 3. [TCP/IP SYN request?] (1996-04-17) 1 1 1 1 1 sync /sink/ (Or "synch") 1. To synchronise, to bring into synchronisation. 2. <file system> To force ("flush") all pending buffered disk writes to the disk. 3. More generally, to force a number of competing processes or agents to a state that would be "safe" if the system were to crash, i.e. to checkpoint in the database sense. [Jargon File] (1994-11-11) 1 1 1 1 1 Synchronized Multimedia Integration Language (SMIL) A language based on Extensible Markup Language (XML), that enables people without programming or scripting backgrounds to author multimedia presentations in a simple text editor. SMIL is suitable for use on the web. For example, a developer can write SMIL to display an image after an audio track ends. SMIL uses two main tags: parallel and sequential. It refers to media objects by URLs, allowing them to be shared between presentations and stored on different servers for load balancing. The language can also associate different media objects with different bandwidths. SMIL 1.0 became an official recommendation of the World Wide Web Consortium W3C in June 1998. W3C (http://w3c.org/audiovideo/). (2000-04-21) 1 1 1 1 1 synchronous 1. Two or more processes that depend upon the occurrences of specific events such as common timing signals. 2. Occurring at the same time or at the same rate or with a regular or predictable time relationship or sequence. Opposite: asynchronous. (1996-04-11) 1 1 1 1 1 Synchronous Data Link Control (SDLC) An IBM protocol. A discipline conforming to subsets of the ADCCP of ANSI and the HDLC of the International Organization for Standardization. SDLC manages synchronous, code-transparent, bit-serial communication which can be duplex or half-duplex; switched or non-switched; point-to-point, multipoint, or loop. Compare Binary Synchronous Communication. (1995-03-22) 1 1 1 1 1 Synchronous Digital Hierarchy (SDH) An international digital telecommunications network hierarchy which standardises transmission around the bit rate of 51.84 megabits per second, which is also called STS-1. Multiples of this bit rate comprise higher bit rate streams. Thus STS-3 is 3 times STS-1, STS-12 is 12 times STS-1, and so on. STS-3 is the lowest bit rate expected to carry ATM traffic, and is also referred to as STM-1 (Synchronous Transport Module-Level 1). The SDH specifies how payload data is framed and transported synchronously across optical fibre transmission links without requiring all the links and nodes to have the same synchronized clock for data transmission and recovery (i.e. both the clock frequency and phase are allowed to have variations, or be plesiochronous). SDH offers several advantages over the current multiplexing technology, which is known as Plesiochronous Digital Hierarchy. Where PDH lacks built-in facilities for automatic 1 1 1 1 1 Synchronous DRAM Synchronous Dynamic Random Access Memory 1 1 1 1 1 Synchronous Dynamic Random Access Memory (SDRAM, Synchronous DRAM) A form of DRAM which adds a separate clock signal to the control signals. SDRAM chips can contain more complex state machines, allowing them to support "burst" access modes that clock out a series of successive bits (similar to the nibble mode DRAM). (2007-05-08) 1 1 1 1 1 Synchronous Graphics RAM Synchronous Graphics Random Access Memory 1 1 1 1 1 Synchronous Graphics Random Access Memory (SGRAM, Synchronous Graphics RAM) A type of Synchronous DRAM optimised for use in graphics hardware. Extra features can include burst operation, block write and write per bit. SGRAMs are designed to provide the very high throughput needed for graphics-intensive operations such as 3d rendering and full-motion video. (1996-11-28) 1 1 1 1 1 Synchronous idle (SYN) The mnemonic for ASCII character 22. [Why?] (1996-06-28) 1 1 1 1 1 synchronous key encryption Data encryption using two interlocking keys where enything encoded using one key may be decoded using the other key. This means if someone makes one of the two keys publicly available (as in public-key encryption) and keeps the other private, then anyone may send them a message or data that only they can decode, giving privacy, and furthermore, the sender may also encrypt that same message additionally with their own private key, making it impossible to read without decoding first with *their* __public__ key by the receiver, this gives authenticity. It is a very powerful system. One cannot determine one key from the other, nor can they crack the encryption by computing all combinations, because, depending on the size of the keys (sometimes as large as 1024 bytes, though having grown from smaller versions in popular implementations of the software which does this), the amount of computing power required to crack the code is unavailable, even supercomputers would take 1 1 1 1 1 Synchronous Optical NETwork (SONET) A broadband networking standard based on point-to-point optical fibre networks. SONET will provide a high-bandwidth "pipe" to support ATM-based services. The SONET standard will establish a digital hierarchical network with a consistent worldwide transport scheme. SONET has been designed to take advantage of fibre, in contrast to the plain old telephone system which was designed for copper wires. SONET carries circuit-switched data in frames at speeds in multiples of 51.84 megabits per second (Mbps) up to 48 * 51.84 Mbps = 2.488 gigabits per second. Since SONET uses multiple channels to transmit data, each SONET frame can be considered to be a two-dimensional table of bytes that is 9 rows high and 90 columns deep. For every OC-n level, SONET can transmit n number of frames at a given time. Groups of frames are called superframes. 1 1 1 1 1 syncronous It's spelled "synchronous". (1996-12-13) 1 1 1 1 1 synflood To flood another machine with bogus TCP/IP SYN requests. (1997-04-07) 1 1 1 1 1 synonym ring A list of words with related meanings used to broaden the scope of a word search. As well as returning documents which contain a sought-for word a search using a synonym ring might also return documents which contain words in the same synonym ring as a sought-for word. Synonym rings are produced manually and are usually specific to a certain field, e.g. legal knowhow. (1997-04-09) 1 1 1 1 1 syntactic salt The opposite of syntactic sugar, a feature designed to make it harder to write bad code. Specifically, syntactic salt is a hoop the programmer must jump through just to prove that he knows what's going on, rather than to express a program action. Some programmers consider required type declarations to be syntactic salt. A requirement to write "end if", "end while", "end do", etc. to terminate the last block controlled by a control construct (as opposed to just "end") would definitely be syntactic salt. Syntactic salt is like the real thing in that it tends to raise hackers' blood pressures in an unhealthy way. Compare candygrammar. [Jargon File] 1 1 1 1 1 syntactic sugar Term coined by Peter Landin for additions to the syntax of a language which do not affect its expressiveness but make it sweeter for humans to use. Syntactic sugar gives the programmer an alternative way of coding that is more succinct or more like some familiar notation. It does not affect the expressiveness of the formalism (compare chrome). Syntactic sugar can be easily translated ("desugared") to produce a program in some simpler "core" syntax. E.g. C's a[i] notation is syntactic sugar for "*(a + i)". In a (curried) functional language, all operators are really functions and the use of infix notation "x+y" is syntactic sugar for function application "(+) x y". Alan Perlis once quipped, "Syntactic sugar causes cancer of the semicolon." The variants "syntactic saccharin" and "syntactic syrup" are also recorded. These denote something even more gratuitous, in that they serve no purpose at all. Compare candygrammar, 1 1 1 1 1 syntax The structure of valid strings in a given language, as described by a grammar. For example, the syntax of a binary number could be expressed as binary_number = bit [ binary_number ] bit = "0" | "1" meaning that a binary number is a bit optionally followed by a binary number and a bit is a literal zero or one digit. The meaning of the language is given by its semantics. See also abstract syntax, concrete syntax. (1994-10-31) 1 1 1 1 1 Syntax-Case A macro system for Scheme by R. Kent Dybvig <dyb@cs.indiana.edu>. It is superior to the low-level system described in the Revised^4 Report (R4RS). Pattern variables are ordinary identifiers with essentially the same status as lexical variable names and macro keywords. The syntax is modified to recognise and handle references to pattern variables. Version 2.1 works with Chez Scheme and the Macintosh port runs under MacGambit 2.0 (ftp://iuvax.cs.indiana.edu/pub/scheme/syntax-case.tar.Z). Macintosh (ftp://maya.dei.unipd.it/pub/mac/gambit/). ["Syntactic Abstraction in Scheme", Robert Hieb, R. Kent Dybvig and Carl Bruggeman IUCS TR #355, 6/92 (revised 7/3/92)]. ["Writing Hygienic Macros in Scheme with Syntax-Case", R. Kent Dybvig, IUCS TR #356, 6/92 (revised 7/3/92)]. (1992-07-06) 1 1 1 1 1 syntax directed translation A technique where the structure of a language processor (e.g. a compiler) is based on the structure of the language's abstract syntax. There might be one procedure in the translator corresponding to each category in the abstract syntax. That procedure is responsible for processing constructs of that category. Each procedure would call others corresponding to the construct's subconstituents and then combine their results to give the overall result for that construct. 1 1 1 1 1 Syntax/Semantic Language (S/SL) A high level specification language for recursive descent parsers developed by J.R. Cordy <cordy@cs.queensu.ca> and R.C. Holt <holt@uwaterloo.ca> at the University of Toronto in 1980. S/SL is a small language that supports cheap recursion and defines input, output, and error token names (& values), semantic mechanisms (class interfaces whose methods are really escapes to routines in a host programming language but allow good abstraction in the pseudo-code) and a pseudo-code program that defines the syntax of the input language by the token stream the program accepts. Alternation, control flow and one-symbol look-ahead constructs are part of the language. The S/SL processor compiles this pseudo-code into a table (byte-codes) that is interpreted by the S/SL table-walker (interpreter). The pseudo-code language processes the input language in recursive descent LL1 style but extensions allow it to process any LRk language relatively easily. S/SL is 1 1 1 1 1 syntax tree A tree representing the abstract syntax of some tokens in a language. (1998-11-12) 1 1 1 1 1 synthesis The process of deriving (efficient) programs from (clear) specifications. See also program transformation. (1996-08-23) 1 1 1 1 1 Synthesizer Specification Language (SSL) A specification language based on term algebra and attribute grammars. SSL is used by the Synthesizer Generator, a generator for language-based editors such as the Cornell Program Synthesizer. ["Generating Language Based Environments", T. Reps, MIT Press 1984]. (1994-12-16) 1 1 1 1 1 sypware spyware 1 1 1 1 1 SyQuest Technology, Inc. An early entrant into the removable hard disk market for personal computers. For may years SyQuest held the market, particularly as a method of transferring large desktop publisher documents to printers. SyQuest aim their products to give personal computer users "endless" hard drive space for data-intensive applications like desktop publishing, Internet information management, pre-press, multimedia, audio, video, digital photography, fast backup, data exchange, archiving, confidential data security and easy portability for the road. At the top of their current (Mar 1997) range are two drives, The SyJet 1.5 GB a 3.5 inch, double platter removable drive and the EZFlyer 230 MB also on 3.5 inch media. A cartridge holding over 4.7GB is promised before the end of 1997 In recent years they have not fared as well in the market, whilst Iomega has cornered the Small Office/Home Office 1 1 1 1 1 sysadmin system administrator 1 1 1 1 1 sysape /sys'ayp/ A rather derogatory term for a computer operator; a play on sysop common at sites that use the banana hierarchy of problem complexity (see one-banana problem). [Jargon File] 1 1 1 1 1 Sysdeco Mimer AB Part of the international software group Sysdeco Group AS. They developed the MIMER RDBMS. (http://mimer.se/). Address: Uppsala, Sweden. (1995-11-11) 1 1 1 1 1 sys-frog /sis'frog/ (the PLATO system) A playful variant of sysprog. [Jargon File] (1994-11-04) 1 1 1 1 1 SYSKEY A utility that encrpyts the hashed password information in a SAM database using a 128-bit encryption key. SYSKEY was an optional feature added in Windows NT 4.0 SP3. It was meant to protect against offline password cracking attacks so that the SAM database would still be secure even if someone had a copy of it. However, in December 1999, a security team from BindView (http://bindview.com/) found a security hole in SYSKEY which indicates that a certain form of cryptoanalytic attack is possible offline. A brute-force attack then appeared to be possible. Microsoft later collaborated with BindView to issue a fix (dubbed the 'Syskey Bug') which appears to have been settled and SYSKEY pronounced secure enough to resist brute-force attack. According to Todd Sabin of the BindView team RAZOR, the pre-RC3 versions of Windows 2000 were also affected. 1 1 1 1 1 SYSLISP System language used in the implementation of Portable Standard Lisp. Mentioned in "The Evolution of Lisp", G.L. Steele et al, SIGPLAN Notices 28(3):231-270 (Mar 1993). 1 1 1 1 1 sysop system operator 1 1 1 1 1 Sysplex An IBM term for communicating MVS systems. See also "Parallel Sysplex". (1996-11-23) 1 1 1 1 1 sysprog Systems programmer 1 1 1 1 1 system 1. The supervisor program or operating system on a computer. 2. The entire computer system, including input/output devices, the supervisor program or operating system and possibly other software. 3. Any large program. 4. Any method or algorithm. [Jargon File] 1 1 1 1 1 System/360 The generic name for the CPUs and architecture released by IBM on 1964-04-07. The 360 was marketed as a general purpose computer with 'all round' functionality - hence 360 (degrees). Models ranged from the 360/20 to the 360/65 and later the 360/95, with typical memory configurations from 16K to 1024K. Elements of the architecture, such as the basic instruction set are still in use on IBM mainframes today. Operating System/360 (OS/360) was developed for System/360. Other associated operating systems included DOS, OS/MFT and OS/MVT. The 360 architecture was based on an 8-bit byte, 16 general purpose registers, 24-bit addressing, and a PSW (Program Status Word) including a location counter. Gene Amdahl, then an IBM employee, is generally acknowledged as the 360's chief architect. He later went on to found Amdahl Corporaton, a manufacture of PCM mainframe 1 1 1 1 1 System/370 (S/370) An IBM mainframe computer introduced in 1970 as a successor to the IBM 360. Enhancements included the ability to support virtual memory and improved main storage. Two models were available initially: 165 and 155, with cycle times of 80 and 115 nanoseconds. Press Release (http://www-1.ibm.com/ibm/history/exhibits/mainframe/mainframe_PR370.html). (2004-06-06) 1 1 1 1 1 System 5 System V 1 1 1 1 1 System 7.5 A version of Mac OS, the latest release as of Oct 1996 was 7.5.5. Superseded by Mac OS 7.6 around March 1997 Mac OS home (http://macos.apple.com/). [Dates? Features?] (1997-03-23) 1 1 1 1 1 System Account Manager (SAM) A password database stored as a registry file in Windows NT and Windows 2000. The System Account Manager (SAM) database stores users' passwords in a hashed format. Since a hash function is one-way, this provides some measure of security for the storage of the passwords. In an attempt to enhance the security of the SAM database against offline cracking, Microsoft introduced the SYSKEY utility in Windows NT 4.0. (2000-07-19) 1 1 1 1 1 system administration Activities performed by a system administrator (or admin, "sysadmin", "site admin") such as monitoring security configuration, managing allocation of user names and passwords, monitoring disk space and other resource use, performing backups, and setting up new hardware and software. system administrators often also help users, though in a large organisation this may be a separate job. Compare postmaster, sysop, system management, systems programmer. [Other tasks?] (1999-05-02) 1 1 1 1 1 system administrator system administration 1 1 1 1 1 system analysis systems analysis 1 1 1 1 1 system analyst systems analysis 1 1 1 1 1 system board motherboard 1 1 1 1 1 system call The mechanism used by an application program to request service from the operating system. System calls often use a special machine code instruction which causes the processor to change mode (e.g. to supervisor mode or "protected mode"). This allows the OS to perform restricted actions such as accessing hardware devices or the memory management unit. (1995-03-01) 1 1 1 1 1 system catalog The data dictionary of a DBMS. The system catalogue stores metadata including the schemas of the databases. It is a mini-database, and is usually stored using the DBMS itself in special tables called system tables. It maybe referred to as being "on line", as it is active, and can be queried by users like any other table. (1999-04-27) 1 1 1 1 1 System Control Language (SCL) The command language for the VME/B operating system on the ICL2900. SCL was block structured and supported strings, lists of strings ("superstrings"), integer, Boolean, and array types. You could trigger a block whenever a condition on a variable value occured. It supported macros and default arguments. Commands were treated like procedure calls. ["VME/B SCL Syntax", Intl Computers Ltd. 1980]. (2003-01-08) 1 1 1 1 1 Systeme International Système International d'Unités 1 1 1 1 1 System F polymorphic lambda-calculus 1 1 1 1 1 System International Système International d'Unités 1 1 1 1 1 system management Activities performed by a system manager, aiming to minimise the use of excessive, redundant resources to address the overlapping requirements of performance balancing, network management, reducing outages, system maintenance costs, diagnosis and repair, and migration to new hardware and software system versions. Compare: system administration. (1995-11-10) 1 1 1 1 1 System Management Bus (SMBus, SMB) A simple two-wire bus used for communication with low-bandwidth devices on a motherboard, especially power related chips such as a laptop's rechargeable battery subsystem (see Smart Battery Data). Other devices might include temperature sensors and lid switches. A device can provide manufacturer information, indicate its model/part number, save its state for a suspend event, report different types of errors, accept control parameters, and return status. The SMB is generally not user configurable or accessible. The bus carries clock, data, and instructions and is based on Philip's I2C serial bus protocol. Support for SMBus devices is provided on Windows 2000. Windows 98 does not support such devices. The PIIX4 chipset provides SMBus functionality. Vendors using SMBus would be required to pay royalties. SMBus website 1 1 1 1 1 System Management Mode (SMM) A reduced power consumption state provided by some Intel microprocessors. When a CPU enters SMM it saves its current state in a special area of static RAM called SMRAM (System Management RAM) and then runs a program, also stored in SMRAM, the SMM handler. SMM is implemented in all Intel "SL" suffixed CPUs. In June 1993, Intel announced it was discontinuing its SL range and instead making all its current processors SL enhanced. See also Auto Idle. (1994-11-09) 1 1 1 1 1 System Management Server (SMS) Software used by Microsoft Windows NT system administrators to manage personal computers on any size network. SMS can distribute software to desktops from one central location, detect every machine on the network, track software and hardware configurations, send key information back to a central database, and perform other tasks. Home (http://microsoft.com/ntserver/management/exec/overview/sms.asp). (1999-03-24) 1 1 1 1 1 system manager system management 1 1 1 1 1 system mangler A humorous synonym for "system manager", possibly from the fact that one major IBM operating system had a root account called SYSMANGR. The term refers specifically to a systems programmer in charge of administration, software maintenance, and updates at some site. Unlike admin, this term emphasises the technical end of the skills involved. [Jargon File] (1995-11-10) 1 1 1 1 1 system operator (Always abbreviated to "sysop") /sis'op/ A term used in the BBS world for the operator of a bulletin-board system (who is usually also the owner). A common neophyte mistake on FidoNet is to address a message to "sysop" in an international echo, thus sending it to hundreds of sysops around the world. Contrast: system administrator. (1999-10-20) 1 1 1 1 1 System Product Interpreter Restructured EXtended eXecutor 1 1 1 1 1 system programming language Ousterhout's dichotomy 1 1 1 1 1 System R A database system built as a research project at IBM San Jose Research (now IBM Almaden Research Center) in the 1970s. System R introduced the SQL language and also demonstrated that a relational system database could provide good transaction processing performance. (http://mcjones.org/System_R/). (1998-09-29) 1 1 1 1 1 Systems Administrators Guild (SAGE) A special technical group of the USENIX Association. (http://usenix.org/sage). [Details?] (2001-01-27) 1 1 1 1 1 systems analysis Study of the design, specification, feasibility, cost, and implementation of a computer system for business. What a systems analyst does. (1997-04-25) 1 1 1 1 1 Systems Analysis Definition (SAD) The analysis of the role of a proposed system and the identification of the requirements that it should meet. SAD is the starting point for system design. The term is most commonly used in the context of commercial programming, where software developers are often classed as either systems analysts or programmers. The systems analysts are responsible for identifying requirements (i.e. systems analysis) and producing a design. The programmers are then responsible for implementing it. (1996-03-07) 1 1 1 1 1 systems analyst systems analysis 1 1 1 1 1 Systems Application Architecture (SAA) IBM's family of standard interfaces which enable software to be written independently of hardware and operating system. (1997-04-25) 1 1 1 1 1 Systems Development Life Cycle (SDLC, or "Software...") Any logical process used by a systems analyst to develop or redesign an information system. SDLC includes requirements, design, development, integration, testing, validation, training, user ownership, operations, analysis and maintenance. An SDLC should result in a system that meets or exceeds customer expectations, within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, is cheap to maintain and cost-effective to enhance. (http://www.sdlc.ws/what-is-sdlc/). US DOJ SDLC (http://www.justice.gov/jmd/irm/lifecycle/table.htm). (2013-11-12) 1 1 1 1 1 systems jock jock 1 1 1 1 1 Systems Network Architecture (SNA) IBM's proprietary high level networking protocol standard, used by IBM and IBM compatible mainframes. Also referred to as "Blue Glue", SNA is a bletcherous protocol once widely favoured at commercial shops. The official IBM definition is "that which binds blue boxes together." It may be relevant that Blue Glue is also a 3M product commonly used to hold down carpets in dinosaur pens. [Jargon File] (1994-11-23) 1 1 1 1 1 system software Any software required to support the production or execution of application programs but which is not specific to any particular application. System software typically includes an operating system to control the execution of other programs; user environment software such as a command-line interpreter, window system, desktop; development tools for building other programs such as assemblers, compilers, linkers, libraries, interpreters, cross-reference generators, version control, make; debugging, profiling and monitoring tools; utility programs, e.g. for sorting, printing, and editting. Different people would classify some or all of the above as part of the operating system while others might say the operating system was just the kernel. Some might say system software includes utility programs like sort. (2007-02-02) 1 1 1 1 1 systems operator system operator 1 1 1 1 1 systems programmer (sysprog) A generic job title that covers a variety of specialist roles such as writing low-level code that talks to directly to the operating system on a server. Typical skills required are experience of specific operating systems, networking (TCP/IP, ATM, Ethernet, DNS), electronic mail (POP, IMAP, SMTP), web servers, RDBMS, operating system and network security, and hardware (SCSI, hard disks, and backup devices). Contrast: system administration. (1999-09-14) 1 1 1 1 1 systems programming systems programmer 1 1 1 1 1 system testing (Or "application testing") A type of testing to confirm that all code modules work as specified, and that the system as a whole performs adequately on the platform on which it will be deployed. System testing should be performed by testers who are trained to plan, execute, and report on application and system code. They should be aware of scenarios that might not occur to the end user, like testing for null, negative, and format inconsistent values. A tester should be able to repeat the steps that caused an error. (2003-09-24) 1 1 1 1 1 system unit The main body of a computer, consisting of a plastic or metal enclosure, the motherboard, and (typically) internal disk drives, a power supply, cooling fans, and whatever circuit boards plugged into the mother board, such as a video card. The system unit is occasionally referred to as the CPU, though this really means central processing unit. (2000-08-10) 1 1 1 1 1 System V 1. The other major versions of the Unix operating system apart from BSD. Developed by AT&T. Later versions of Unix such as SunOS combined the best features of System V and BSD Unix. (1994-10-31) [Differences?] 2. A supplier of Unix open systems for Intel x86 processors. They supply products from SCO and Solaris and offer general support for Unix, TCP/IP, and Internet. They serve and create third-party WWW pages and provide on-line support for commercial and non-commercial applications. (http://systemv.com/). See also System V Interface Definition. (1994-12-12) 1 1 1 1 1 System V Interface Definition (SVID) A standard allowing source code portability between different platforms running Unix System V. (1995-03-28) 1 1 1 1 1 Système International Système International d'Unités 1 1 1 1 1 Système International d'Unités (SI - International System of Units) The standard set of units of measurement set by the 11th General Conference on Weights and Measures in 1960. There are seven base units: the metre (length), the kilogram (mass), the second (time), the ampere (electrical current), the kelvin (temperature), the mole (number of atoms) and the candela (luminous intensity). These are defined either in terms of physical properties such as the speed of light or, in the case of mass, by a "prototype" lump of platinum-iridium kept at BIPM. Derived units like meters per second (speed) are formed by combining base units. SI also specifies a list of prefixes (multipliers like "k" for 1000). SI Home (http://www.bipm.org/en/si/). (2014-07-08) 1 1 1 1 1 systolic array (By analogy with the regular pumping of blood by the heart) An arrangement of processors in an array (often rectangular) where data flows synchronously across the array between neighbours, usually with different data flowing in different directions. H. T. Kung and Charles Leiserson publish the first paper describing systolic arrays in 1978 [reference?]. Each processor at each step takes in data from one or more neighbours (e.g. North and West), processes it and, in the next step, outputs results in the opposite direction (South and East). An example of a systolic algorithm might be matrix multiplication. One matrix is fed in a row at a time from the top of the array and is passed down the array, the other matrix is fed in a column at a time from the left hand side of the array and passes from left to right. Dummy values are then passed in until each processor has seen one whole row and 1 1 1 1 1 SysVile Missed'em-five 1 1 1 1 1 sz The country code for Swaziland. (1999-01-27) 1 1 1 1 1 T 1. True. A Lisp compiler by Johnathan A. Rees in 1982 at Yale University. T has static scope and is a near-superset of Scheme. Unix source is available. T is written in itself and compiles to efficient native code. Used as the basis for the Yale Haskell system. Maintained by David Kranz <kranz@masala.lcs.mit.edu>. Latest version: 3.1. (ftp://ftp.ai.mit.edu/pub/systems/t3.1). A multiprocessing version of T is available (ftp://masala.lcs.mit.edu/pub/mult). Runs on Decstation, SPARC, Sun-3, Vax under Unix, Encore, HP, Apollo, Macintosh under A/UX. E-mail: <t3-bugs@cs.yale.edu> (bugs). E-mail: <t-project@cs.yale.edu>. (1991-11-26) ["The T Manual", Johnathan A. Rees <jar@zurich.ai.mit.edu> et al, Yale U, 1984]. 1 1 1 1 1 T1 An AT&T term for a digital carrier facility used to transmit a DS1 formatted digital signal at 1.544 megabits per second. T1 transmission uses a bipolar Return To Zero alternate mark inversion line coding scheme to keep the DC carrier component from saturating the line. Although some consider T1 signaling obsolete, much equipment operates at the "T1 rate" and such signals are either combined for transmission via faster circuits, or demultiplexed into 64 kilobit per second circuits for distribution to individual subscribers. T1 signals can be transported on unshielded twisted pair telephone lines. The transmitted signal consists of pips of a few hundred nanoseconds width, each inverted with respect to the one preceding. At the sending end the signal is 1 volt, and as received, greater than 0.01 volts. This requires repeaters about every 6000 feet. 1 1 1 1 1 T1 line T1 1 1 1 1 1 T1 rate T1 1 1 1 1 1 T3 A digital carrier facility used to transmit a DS3 formatted digital signal at 44.736 megabits per second. See also Integrated Services Digital Network. (1994-11-23) 1 1 1 1 1 T3 line T3 1 1 1 1 1 TA Terminal Adaptor 1 1 1 1 1 TAA Track Average Amplitude 1 1 1 1 1 TAB HT 1 1 1 1 1 table A collection of records in a relational database. (1997-06-04) 1 1 1 1 1 table locking A technique used in database management systems, where an entire table is locked while data in it is being updated. Other techniques are row-level locking and MVCC. (1999-06-18) 1 1 1 1 1 tablespace A logical unit of storage used by an Oracle database. A tablespace is made up of one or more operating system files. Each table, index or other object that requires storage is located in a tablespace. The database administrator typically assigns a default and a temporary tablespace to each user and grants a quota on each so they can create tables and indexes. (2006-08-24) 1 1 1 1 1 TABLET A query language. ["Human Factor Comparison of a Procedural and a Non-procedural Query Language", C. Welty et al, ACM Trans Database Sys 6(4):626-649 (Dec 1981)]. (1994-11-23) 1 1 1 1 1 TABLOG A programming language based on first order predicate logic with equality that combines relational programming and functional programming. It has functional notation and unification as its binding mechanism. TABLOG supports a more general subset of standard first order logic than Prolog. It employs the Manna-Waldinger 'deductive-tableau' proof system as an interpreter instead of resolution. (1997-06-19) 1 1 1 1 1 tab-separated values (TSV) A file format used as a portable representation of a database. Each line represents one entry or record; and in every line, each field is separated from the next by a tab character (HT). Compare CSV. (2001-03-16) 1 1 1 1 1 TABSOL A language extension for GECOM written in the form of truth tables which was compiled into code for the tests and actions described. TABSOL was developed by T.F. Kavanaugh, and was in use around 1964-5. (1996-09-15) [Proc FJCC 18:117-136, AFIPS (Fall 1960)]. (1996-09-16) 1 1 1 1 1 Tabulating Machine Company The company founded in 1896 by Herman Hollerith to exploit his invention of the punched card. It became part of IBM in 1924. (1996-01-02) 1 1 1 1 1 TAC 1. Translator Assembler-Compiler. For Philco 2000. 2. Terminal Access Controller. 1 1 1 1 1 TACL Tandem Advanced Command Language. Tandem, about 1987. The shell language used in Tandem computers. 1 1 1 1 1 TACPOL A PL/I-like language used by the US Army for command and control. (2001-01-31) 1 1 1 1 1 Tactile User Interface (TUI) Hardware and software to provide access to computer-based graphical[?] information using touch, often intended for blind people. See also haptics. (2003-10-17) 1 1 1 1 1 tag An SGML, HTML, or XML token representing the beginning (start tag: "<p ...>") or end (end tag: "</p>") of an element. In normal SGML syntax (and always in XML), a tag starts with a "<" and ends with an >. In HTML jargon, the term "tag" is often used for an element. (2001-01-31) 1 1 1 1 1 Tagged Image File Format (TIFF) A file format used for still-image bitmaps, stored in tagged fields. Application programs can use the tags to accept or ignore fields, depending on their capabilities. While TIFF was designed to be extensible, it lacked a core of useful functionality, so that most useful functions (e.g. lossless 24-bit colour) requires nonstandard, often redundant, extensions. The incompatibility of extensions has led some to expand "TIFF" as "Thousands of Incompatible File Formats". Compare GIF, PNG, JPEG. (1997-10-11) 1 1 1 1 1 tagged queueing A method allowing a device or controller to process commands received from a device driver out of order. It requires that the device driver attaches a tag to each command which the controller or device can later use to identify the response to the command. Tagged queueing can speed up processing considerably if a controller serves devices of very different speeds, such as an SCSI controller serving a mix of CD-ROMs and high-speed disks. In such cases if a request to fetch data from the CD-ROM is shortly followed by a request to read from the disk, the controller doesn't have to wait for the CD-ROM to fetch the data, it can instead instruct the disk to fetch the data and return the value to the device driver, while the CD-ROM is probably still seeking. (1997-07-04) 1 1 1 1 1 tagged types Ada's type mechanism in which types can be extended via single inheritance. (2000-02-21) 1 1 1 1 1 tag name generic identifier 1 1 1 1 1 tail call optimisation last call optimisation 1 1 1 1 1 tail call optimization last call optimisation 1 1 1 1 1 tail circuit A circuit which connects the serial lines of two modems together. [Why do that?] (1996-10-16) 1 1 1 1 1 tail recursion When the last thing a function (or procedure) does is to call itself. Such a function is called tail recursive. A function may make several recursive calls but a call is only tail-recursive if the caller returns immediately after it. E.g. f n = if n < 2 then 1 else f (f (n-2) + 1) In this example both calls to f are recursive but only the outer one is tail recursive. Tail recursion is a useful property because it enables tail recursion optimisation. If you aren't sick of them already, see recursion and tail recursion. [Jargon File] (2006-04-16) 1 1 1 1 1 tail recursion modulo cons A generalisation of tail recursion introduced by D.H.D. Warren. It applies when the last thing a function does is to apply a constructor functions (e.g. cons) to an application of a non-primitive function. This is transformed into a tail call to the function which is also passed a pointer to where its result should be written. E.g. f [] = [] f (x:xs) = 1 : f xs is transformed into (pseudo C/Haskell): f [] = [] f l = f' l allocate_cons f' [] p = *p = nil; 1 1 1 1 1 tail recursion optimisation (TRO) Discarding the calling environment (call stack frame) when the last thing a function or procedure does is to call itself. This is important when a procedure calls itself recursively many times since, without tail recursion optimisation, the environments of earlier invocations would fill up the memory only to be discarded when (if) the last call terminated. Tail recursion optimisation is a special case of last call optimisation but it allows the further optimisation that some arguments may be passed in situ, possibly in registers. It allows recursive functions to be compiled into iterative loops. See also conversion to iteration, tail recursion modulo cons. (2006-04-16) 1 1 1 1 1 tail-strict A tail-strict function evaluates every cons cell in its (list) argument. It will therefore fail to terminate if its argument is an infinite list or if any tail of its argument fails to terminate. The archetypal tail-strict function is length. See also Head-strict, Hyper-strict. 1 1 1 1 1 TAL Transaction Application Language 1 1 1 1 1 TALE Typed Applicative Language Experiment. M. van Leeuwen. Lazy, purely applicative, polymorphic. Based on typed second order lambda-calculus. "Functional Programming and the Language TALE", H.P. Barendregt et al, in Current Trends in Concurrency, LNCS 224, Springer 1986, pp.122-207. 1 1 1 1 1 Taligent A company founded jointly by Apple and IBM in March 1992. HP announced in January, 1994 that it would buy a 15% stake in Taligent. They are working on an "object-oriented operating system", due to be finished sometime in 1995. However, various independent pieces of Taligent will likely appear to be used with other operating systems, e.g. IBM's WorkplaceOS. Pink is an older name for Taligent, dating back to work that Apple did before the formation of Taligent. 1 1 1 1 1 talk A Unix program and protocol supporting conversation between two or more users who may be logged into the same computer or different computers on a network. Variants include ntalk, ytalk, and ports or emulators of these programs for other platforms. Unix has the talk program and protocol and its variants xtalk and ytalk for the X Window System; VMS has phone; Windows for Workgroups has chat. ITS also has a talk system. These split the screen into separate areas for each user. Unix's write command can also be used, though it does not attempt to separate input and output on the screen. Users of such systems are said to be in talk mode which has many conventional abbreviations and idioms. Most of these survived into chat jargon, but many fell out of common use with the migration of user prattle from talk-like systems to 1 1 1 1 1 talk bomb flash 1 1 1 1 1 talker system talk 1 1 1 1 1 talk mode Using a talk system. E.g., "B1FF had me in talk mode for hours last night. I had to bring his box down just to get him to shut up." The (1980s?) term now is as dated as talk itself which has been largely replaced by chat. [Jargon File] (1998-01-19) 1 1 1 1 1 TALL TAC List Language. ["TALL - A List Processor for the Philco 2000", J. Feldman, CACM 5(9):484-485 (Sep 1962)]. (1995-03-01) 1 1 1 1 1 tall card An expansion card for the IBM PC AT. These can be larger than IBM PC or IBM PC XT cards because the AT case is bigger. When IBM introduced the PS/2 model 30 (its last gasp at supporting the ISA) they made the case lower and many industry-standard tall cards wouldn't fit. This was felt to be a reincarnation of the connector conspiracy, done with less style. See also short card. [Jargon File] (1995-03-01) 1 1 1 1 1 Tandem Application Language Transaction Application Language 1 1 1 1 1 Tandem Computers A US computer manufacturer. Quarterly sales $544M, profits $49M (Aug 1994). (1994-09-26) 1 1 1 1 1 Tandy A US company, the parent company of Radio Shack, makers of the TRS-80 and other early personal computers. (1995-02-28) 1 1 1 1 1 Tanenbaum, Andrew Andrew Tanenbaum 1 1 1 1 1 Tangible User Interface An attempt to give physical form to digital information, making bits directly manipulable and perceptible by people. Tangible Interfaces will make bits accessible through augmented physical surfaces (e.g. walls, desktops, ceilings, windows), graspable objects (e.g. building blocks, models, instruments) and ambient media (e.g. light, sound, airflow, water-flow, kinetic sculpture) within physical environments. MIT Tangible Media Group (http://tangible.media.mit.edu/). (2003-10-17) 1 1 1 1 1 tanked 1. <jargon> Same as down, used primarily by Unix hackers. See also hosed. 2. Popularised as a synonym for "drunk" by Steve Dallas in the late lamented "Bloom County" comic strip. [Jargon File] (1995-02-28) 1 1 1 1 1 TANSTAAFL /tan'stah-fl/ (From Robert Heinlein's classic "The Moon is a Harsh Mistress") "There Ain't No Such Thing As A Free Lunch". Often invoked when someone is balking at the prospect of using an unpleasantly heavyweight technique, or at the poor quality of some piece of free software, or at the signal-to-noise ratio of unmoderated Usenet newsgroups. "What? Don't tell me I have to implement a database back end to get my address book program to work! ""Well, TANSTAAFL you" know." This phrase owes some of its popularity to the high concentration of science-fiction fans and political libertarians in hackerdom. [Jargon File] (1995-02-28) 1 1 1 1 1 TAO 1. A Lisp dialect with concurrency, object-orientation and logic. ["Concurrent Programming in TAO - Practice and Experience", I. Takeuchi in Parallel Lisp: Languages and Systems, T. Ito et al eds, LNCS 441, Springer 1989, pp. 271-299]. (2006-02-06) 2. A programming language for APE/Quadrics parallel computers, largely modelled on FORTRAN and evolved from the even more primitive APESE language. TAO is particularly hard to work with, due to the lack of systematics, poor documentation and a primitive compiler. [Reference? Dates?] (2006-02-06) 1 1 1 1 1 TAOS Technology for Autonomous Operation Survivability 1 1 1 1 1 TAP Telocator Alphanumeric Protocol 1 1 1 1 1 tap hit 1 1 1 1 1 tape 1. magnetic tape. 2. paper tape. (1996-05-25) 1 1 1 1 1 tape archive tar 1 1 1 1 1 tape drive magnetic tape drive 1 1 1 1 1 tape head The electromagnetic component in a magnetic tape drive which reads and writes magnetic tape as it passes over it. Tape heads need to be cleaned periodically to remove the oxide particles which accumulate on them and can lead to errors. (1997-03-12) 1 1 1 1 1 Tape Operating System (TOS) An IBM operating system for System 360, used in the early days around 1965 to support the IBM 360 model 30 et al. TOS was a predecessor to IBM's Disk Operating System. TOS died out really early as disks such as the 2311 and 2314 became common with the IBM 360 whereas thet had been a real luxury on the IBM 7090. [Relationship to BOS?] (1999-01-20) 1 1 1 1 1 TAPI Telephony Application Programming Interface 1 1 1 1 1 tar ("Tape ARchive", following ar) Unix's general purpose archive utility and the file format it uses. Tar was originally intended for use with magnetic tape but, though it has several command line options related to tape, it is now used more often for packaging files together on other media, e.g. for distribution via the Internet. The resulting archive, a "tar file" (humourously, "tarball") is often compressed, using gzip or some other form of compression (see tar and feather). There is a GNU version of tar called gnutar with several improvements over the standard versions. Filename extension: .tar MIME type: unregistered, but commonly application/x-tar Unix manual page: tar(1). Compare shar, zip. (1998-05-02) 1 1 1 1 1 tar and feather (A sick contrivance from the Unix tar command and the Ku Klux Klan torture method) To create a transportable archive from a group of files by first sticking them together with tar (the Tape ARchiver) and then compressing the result. The latter action is dubbed "feathering" (purely for contrived effect) by analogy to what you do with an aeroplane propeller to decrease wind resistance, or with an oar to reduce water resistance; smaller files, after all, slip through comm links more easily. [Jargon File] (1997-05-26) 1 1 1 1 1 tarball tar 1 1 1 1 1 targa A graphics data format for bitmap images. It uses 24 bits per pixel and is a common output format for ray tracing programs. (1995-01-05) 1 1 1 1 1 Targa Graphics Adaptor (TGA) The Truevision Targa Graphics Adaptor file format. The TGA format is a common bitmap file format for storage of 24-bit images. It supports colourmaps, alpha channels, compression and comments. Filename extension: .tga. More information is available from Truevision (http://truevision.com/) and The Graphics File Format Page (http://dcs.ed.ac.uk/~mxr/gfx/). [What does it have to do with graphics adaptors?] (1997-08-07) 1 1 1 1 1 target SCSI target 1 1 1 1 1 Target-Machine Description Language (TMDL) The machine-description language used in the Graham-Glanville code generator. ["Table-Driven Code Generation", S.L. Graham, IEEE Computer 13(8):25-34 (Aug 1980)]. (1995-02-21) 1 1 1 1 1 TARTAN A simple language proposed to meet the Ironman requirements. ["TARTAN - Language Design for the Ironman Requirements: Reference Manual", Mary Shaw et al, SIGPLAN Notices 13(9):36-58 (Sep 1978)]. (1995-01-05) 1 1 1 1 1 taskbar The part of the Microsoft Windows graphical user interface (GUI) typically occupying a fixed strip along the bottom of the screen, showing a rectangular icon for each running application. The taskbar also contains the Start menu at its left-hand end and the notification area at the right-hand end. Other toolbars can be added such as the Quick Launch toolbar. Clicking an application's taskbar icon makes its windows visible in front of other windows and gives one of them the input focus, or if it is already in front, minimises it. Right-clicking an icon gives a window manager menu, possibly customised by the application. Right-clicking the taskbar itself performs global window manager actions such as minimising all windows and also allows you to set taskbar properties. The taskbar can be locked in position or resized or dragged to the top, left or right of the screen. (2007-06-13) 1 1 1 1 1 Task Control Block An MVS control block used to communicate information about tasks within an address space that are connected to an MVS subsystem such as MQSeries for MVS/ESA or CICS. FAQ (http://www-4.ibm.com/software/ts/mqseries/library/manuals/csqfao/CSQFAO22.HTM). (2000-12-30) 1 1 1 1 1 task scheduling The assignment of start and end times to a set of tasks, subject to certain constraints. Constraints are typically either time constraints (the payload must be installed before the payload bay doors are closed) or resource constraints (this task requires a small crane and a crane operator). In the case where the tasks are programs to run concurrently on a computer, this is also known as multitasking. (1998-04-25) 1 1 1 1 1 TASM Turbo Assembler. MS-DOS assembler from Borland. 1 1 1 1 1 TASS Template ASSembly language. Intermediate language produced by the Manchester SISAL compiler. 1 1 1 1 1 taste 1. (primarily MIT) The quality of a program that tends to be inversely proportional to the number of features, hacks, and kluges it contains. Taste refers to sound judgment on the part of the creator. See also elegant, flavour. 2. Alternative spelling of "tayste". [Jargon File] 1 1 1 1 1 tatar A Turkic language spoken by about five million Tatars in Russia, Ukraine, Turkey and elsewhere; the official language of the Republic of Tatarstan (Russian Federation). language codes: tt, tat. (2006-12-11) 1 1 1 1 1 tau The mathematical constant that is the circumference of a circle divided by its radius, equal to twice pi. Some have suggested that pi is the wrong choice of constant to describe the geometry of circles etc. and tau = 2*pi would have been better. Most practising mathematicians think this is silly. The xkcd comic strip facetiously proposed (http://xkcd.com/1292/) a compromise of 1.5*pi or "pau". The Pi Manifesto (http://www.thepimanifesto.com/). (2013-12-10) 1 1 1 1 1 tautological probability A notion introduced by Florentin Smarandache whereby the probability of some event is more than one. Tautological probability is used for universally true propositions, i.e. those which do not depend on time, space, subjectivity, etc. [Florentin Smarandache, "A Unifying Field in Logics. / Neutrosophy: Neutrosophic Probability, Set, and Logic", American Research Press, Rehoboth 1999]. (2001-04-06) 1 1 1 1 1 tautological set A notion introduced by Florentin Smarandache: An element x(T, I, F) belongs more than sure to the set M; here T, I, F are real subsets representing the truth, indeterminacy, and falsity percentages respectively, and sup(T)>100. tautological set are used for universally true propositions where no parameter such as time, space, or subjectivity influences the truth value. [Florentin Smarandache, "A Unifying Field in Logics. / Neutrosophy: Neutrosophic Probability, Set, and Logic", American Research Press, Rehoboth, 1999 (http://gallup.unm.edu/~smarandache/neut-ad.htm)] (1999-11-24) 1 1 1 1 1 tautology A proposition which is always true. Compare: paradox. The Linguistic Smarandache Tautologies, (http://gallup.unm.edu/~smarandache/tautolog.txt). (1999-07-28) 1 1 1 1 1 TAWK Tiny AWK 1 1 1 1 1 Taxis ["A Language Facility for Designing Database-Intensive Applications", J. Mylopoulos et al, ACM Trans Database Sys 5(2):185-207 (June 1980)]. 1 1 1 1 1 tayste crumb 1 1 1 1 1 taz tgz 1 1 1 1 1 TB terabyte 1 1 1 1 1 TBF Mean Time Between Failures 1 1 1 1 1 TBIL Tiny Basic Interpreter Language 1 1 1 1 1 TBK Tool Builder Kit 1 1 1 1 1 Tbl 1. A language by M.E. Lesk for formatting tables, implemented as a preprocessor to nroff. (1994-11-01) 2. Table Building Language. A simple language by Robert Freiburghouse of MIT which combines user-defined actions into an abstract machine. It can be used to build table-driven predictive parsers and code generators in the MULTICS Fortran compiler and several PL/I compilers, including VAX-11 PL/I. ["Engineering A Compiler: VAX-11 Code Generation and Optimisation", P. Anklam et al, Digital Press 1977]. (1994-11-01) 1 1 1 1 1 tc The country code for the Turks and Caicos Islands. (1999-01-27) 1 1 1 1 1 T-carrier system A series of wideband digital data transmission formats originally developed by the Bell System and used in North America and Japan. The basic unit of the T-carrier system is the DS0, which has a transmission rate of 64 Kbps, and is commonly used for one voice circuit. Originally the 1.544 megabit per second T1 format carried 24 pulse-code modulated, time-division multiplexed speech signals each encoded in 64 kilobit per second streams, leaving 8 kilobits per second of framing information which facilitates the synchronisation and demultiplexing at the receiver. T2 and T3 circuits channels carry multiple T1 channels multiplexed, resulting in transmission rates of up to 44.736 Mbps. The T-carrier system uses in-band signaling, resulting in lower transmission rates than the E-carrier system. It uses a restored polar signal with 303-type data stations. 1 1 1 1 1 TCB 1. <jargon> Trouble Came Back. 2. <security> (Orange Book) Trusted Computing Base. 3. <operating system> Task Control Block. [Jargon File] (1998-07-02) 1 1 1 1 1 TCGS Twente Compiler Generator System 1 1 1 1 1 TC/IX The LynxOS kernel ported to the MIPS R3000 RISC processor by CDC. 1 1 1 1 1 Tcl Tool Command Language 1 1 1 1 1 Tcl Consortium A non-profit agency dedicated to promoting Tcl. (http://tclconsortium.org/). (1998-11-27) 1 1 1 1 1 tcl-debug A debugger for Tcl by Don Libes <libes@cme.nist.gov> that can be easily embedded in other applications. It is included with many other Tcl libraries. (ftp://ftp.cme.nist.gov/pub/expect/tcl-debug.tar.Z). (1994-10-31) 1 1 1 1 1 Tcl-DP Tcl-DP extends Tcl's "send" by removing the restriction that you can only send to other clients of the same X11 server. Version 3.0 library by Larry Rowe. (ftp://toe.cs.berkeley.edu/pub/multimedia/Tcl-DP). 1 1 1 1 1 tclhttpd An embeddable Tcl-based web server. [Details?] (1998-11-27) 1 1 1 1 1 TclX Extended Tcl 1 1 1 1 1 TCM Trellis Code Modulation 1 1 1 1 1 TCO Total Cost of Ownership 1 1 1 1 1 Tcode Intermediate language used by the Spineless Tagless G-machine (an abstract machine based on graph reduction) designed as a target for compilation of non-strict functional languages. The Spineless tagless G- machine, S. Peyton Jones et al, Fourth Intl Conf Func Prog Langs and Comp Arch pp.184-201, ACM Sept 1989. 1 1 1 1 1 TCOL CMU. Tree-based intermediate representation produced by the PQCC compiler generator. "An Overview of the Production Quality Compiler- Compiler Projects", B.W. Leverett et al, IEEE Computer 13(8): 38-49 (Aug 1980). (See LG). 1 1 1 1 1 TCOL.Ada CMU, 1980. An intermediate representation for Ada, was merged with AIDA to form Diana. "TCOL.Ada: Revised Report on an Intermediate Representation for the DOD Standard Programming Language", J.M. Newcomer et al, CMU-CS-79-128 (June 1979). 1 1 1 1 1 TCP Transmission Control Protocol 1 1 1 1 1 TCPIP Normally written "TCP/IP". 1 1 1 1 1 TCP/IP Transmission Control Protocol over Internet Protocol. The de facto standard Ethernet protocols incorporated into 4.2BSD Unix. TCP/IP was developed by DARPA for internetworking and encompasses both network layer and transport layer protocols. While TCP and IP specify two protocols at specific protocol layers, TCP/IP is often used to refer to the entire DoD protocol suite based upon these, including telnet, FTP, UDP and RDP. See also ICMP, SMTP, SNMP. (1995-03-17) 1 1 1 1 1 tcsh A Unix shell by Christos Zoulas <christos@ee.cornell.edu>, based on csh. tcsh adds WYSIWYG command line editing, command name completion, input history and various other features. Version 6.04 runs under many versions of Unix and under OpenVMS. tcsh has been largely replaced by bash. (ftp://ftp.spc.edu/). (2014-09-14) 1 1 1 1 1 Tcsim Time Complex Simulator 1 1 1 1 1 TCVN 5773 A 1993 Vietnamese character standard that includes Han characters. (2001-01-02) 1 1 1 1 1 TCVN 6056 A 1995 Vietnamese character standard that includes Han characters. (2001-01-02) 1 1 1 1 1 td The country code for Chad. (1999-01-27) 1 1 1 1 1 TDD 1. <testing> test-driven development. 2. <communications> Telecommunications Device for the Deaf. 1 1 1 1 1 TDEL thick film dielectric electroluminescence 1 1 1 1 1 TDF An intermediate language, a close relative of ANDF. A TDF program is an ASCII stream describing an abstract syntax tree. TDF became part of TenDRA in abut 2001. ["TDF Specification", Defence Research Agency/Electronics Division, Great Malvern, England, +44 684 895314]. (2003-05-13) 1 1 1 1 1 TDFL Dataflow language. "TDFL: A Task-Level Dataflow Language", P. Suhler et al, J Parallel Dist Comp 9(2):103-115 (Jun 1990). 1 1 1 1 1 TDI Transport Driver Interface 1 1 1 1 1 TDM 1. Technical Data Management 2. Time Division Multiplexing 1 1 1 1 1 TDMA time division multiple access 1 1 1 1 1 TDR time domain reflectometer 1 1 1 1 1 Teamwork A SASD tool from Sterling Software, formerly CADRE Technologies, which supports the Shlaer/Mellor Object-Oriented method and the Yourdon-DeMarco, Hatley-Pirbhai, Constantine and Buhr notations. Teamwork was abandoned when Computer Associates acquired Sterling Software in March 2000. (2002-05-29) 1 1 1 1 1 Technical/Office Protocol (TOP) An applications layer network application and protocol stack for office automation developed by Boeing following the OSI model. This protocol is very similar to MAP except at the lowest levels, where it uses Ethernet (IEEE 802.3) rather than Token Bus (IEEE 802.4). 1 1 1 1 1 Technion Israel Institute of Technology. (http://technion.ac.il/). (ftp://ftp.technion.ac.il/). Address: Haifa, Israel. (1995-05-09) 1 1 1 1 1 technology Marketroid jargon for "software", "hardware", protocol or something else too technical to name. The most flagrant abuse of this word has to be "Windows NT" (New Technology) - Microsoft's attempt to make the incorporation of some ancient concepts into their OS sound like real progress. The irony, and even the meaning, of this seems to be utterly lost on Microsoft whose Windows 2000 start-up screen proclaims "Based on NT Technology", (meaning yet another version of NT, including some Windows 95 features at last). See also: solution. (2001-06-28) 1 1 1 1 1 Technology Enabled Relationship Manager Customer Relationship Management 1 1 1 1 1 Technology of Object-Oriented Languages and Systems (TOOLS) One of the oldest object-oriented conferences, with 18 published proceedings volumes. TOOLS is organised by Interactive Software Engineering. (1995-12-29) 1 1 1 1 1 TechRef /tek'ref/ [MS-DOS] The original "IBM PC Technical Reference Manual", including the BIOS listing and complete schematics for the PC. The only PC documentation in the issue package that's considered serious by real hackers. [Jargon File] 1 1 1 1 1 TECO /tee'koh/ (Originally an acronym for "[paper] Tape Editor and COrrector"; later, "Text Editor and COrrector"]) A text editor developed at MIT and modified by just about everybody. With all the dialects included, TECO may have been the most prolific editor in use before Emacs, to which it was directly ancestral. The first Emacs editor was written in TECO. It was noted for its powerful programming-language-like features and its unspeakably hairy syntax (see write-only language). TECO programs are said to resemble line noise. Every string of characters is a valid TECO program (though probably not a useful one); one common game used to be predict what the TECO commands corresponding to human names did. As an example of TECO's obscurity, here is a TECO program that takes a list of names such as: Loser, J. Random 1 1 1 1 1 tee A Unix command which copies its standard input to its standard output (like cat) but also to a file given as its argument. tee is thus useful in pipelines of Unix commands (see plumbing) where it allows you to create a duplicate copy of the data stream. E.g. egrep Unix Dictionary | tee /dev/tty | wc -l searches for lines containing the string "Unix" in the file Dictionary, prints them to the terminal (/dev/tty) and counts them. Unix manual page: tee(1). [Jargon File] (1996-01-22) 1 1 1 1 1 TEI 1. <communications> Terminal Endpoint Identifier. 2. <text, project> Text Encoding Initiative. (1997-03-11) 1 1 1 1 1 telco (from telephone company) A company providing phone services to end users. The company may or may not provide other phone services such operating long-distance/international backbones but the name telco usually emphasises its operation as a local service provider. Compare: PTT. (1998-05-18) 1 1 1 1 1 TELCOMP A variant of JOSS. [Sammet 1969, p.217]. (1997-04-07) 1 1 1 1 1 Telecommunication Display Device Telecommunications Device for the Deaf 1 1 1 1 1 Telecommunications Device for the Deaf (TDD) A terminal device used widely by deaf people for text communication over telephone lines. The acronym TDD is sometimes expanded as "Telecommunication Display Device" but is generally considered to be derived from Telecommunications Device for the Deaf. The deaf themselves do not usually use the term "TDD", but prefer simply "TTY" #NAME? the other meanings of "TTY" is generally not problematic. The acronym "TTD" is also common [Teletype for the deaf?]. The standard most used by TDDs is reportedly a survivor of Baudot code. It uses asynchronous transmission of 1400 Hz and 1600 Hz tones at 45.5 or 50 baud, with one start bit, 5 data bits and 1.5 stop bits. This is generally incompatible with standard modems. A typical TDD is a device about the size of a small laptop computer (resembling, in fact, a circa 1983 Radio Shack Model 100 computer) with a QWERTY keyboard, and small 1 1 1 1 1 Telecommunications Industry Association (TIA) An association that sets standards for communications cabling. Cables that TIA set standards for include: EIA/TIA-568A and EIA/TIA-568B category three, four and five cable. (http://tiaonline.org/). [Details?] (2000-04-24) 1 1 1 1 1 telecommuting The practice of working at home and communicating with your fellow workers through the phone, typically with a computer and modem. Telecommuting saves the employee getting to and from work and saves the employer from supplying support services such as heating and cleaning, but it can also deprive the worker of social contact and support. (1995-01-05) 1 1 1 1 1 teledildonics /tel"*-dil-do"-niks/ Sex in a computer simulated virtual reality, especially computer-mediated sexual interaction between the VR presences of two humans. This practice is not yet possible except in the rather limited form of erotic conversation on MUDs and the like. The term, however, is widely recognised in the VR community as a ha ha only serious projection of things to come. "When we can sustain a multi-sensory surround good enough for teledildonics, *then* we'll know we're getting somewhere." [Jargon File] (1995-02-06) 1 1 1 1 1 telegraphy A historical term for communication, either wired or wireless, using Morse code. The term is used in contrast with telephony meaning voice transmission. Telegraphy is sometimes (somewhat incorrectly) referred to as continuous wave or CW transmission. (2009-11-24) 1 1 1 1 1 telematics The combination of telecommunications and computing. Data communications between systems and devices. (1995-02-07) 1 1 1 1 1 TelEnet The old name for Sprintnet. TELENET used to provide a service called PC Pursuit. Not to be confused with telnet the program and protocol. (1994-10-17) 1 1 1 1 1 TELEPAC The Swiss PTT X.25 network. (1995-11-09) 1 1 1 1 1 Telephone Application Program Interface (TAPI) Officially it's Telephony Application Programming Interface. (1995-11-27) 1 1 1 1 1 telephony Communication, often two-way, of spoken information, by means of electrical signals carried by wires or radio waves. The term was used to indicate transmission of the voice, as opposed to telegraphy (done in Morse code and usually called "continuous wave" or CW transmission), radio teletypewriter (RTTY) transmission (also called FSK for Frequency Shift Keying, the modulation scheme used by such machines), and later, facimile. (1995-03-14) 1 1 1 1 1 Telephony Application Programming Interface (TAPI, or "Telephone Application Program Interface") A Windows 95 Application Program Interface enabling hardware independent access to telephone based communication. TAPI covers a rather wide area of services from initialising the equipment (e.g. a modem) and placing a call to voice mail or control of a remote computer. [Telephone or Telephony?] (1995-12-05) 1 1 1 1 1 Telephony User Interface (TUI) Either a software interface to telephony (e.g. a phone-capable PC) or a DTMF-based interface to software (e.g. voicemail). (2003-10-21) 1 1 1 1 1 Telerat /tel'*-rat/ Unflattering hackerism for Teleray, a line of extremely losing terminals. [Jargon File] (1995-01-19) 1 1 1 1 1 Telescope User Interface (TUI) A remote control interface for a telescope. (2003-10-21) 1 1 1 1 1 Telescript A communications-oriented programming language using "active software agents", released by General Magic in 1994. What PostScript did for cross-platform, device-independent documents, Telescript aims to do for cross-platform, network-independent messaging. Telescript protects programmers from many of the complexities of network protocols. (1995-01-16) 1 1 1 1 1 Teletype (tty) A trademark for a hard-copy teletypewriter produced by Teletype Corporation. (2000-04-02) 1 1 1 1 1 teletype teletypewriter 1 1 1 1 1 Teletype Corporation The company which made Teletype teletypewriters. Address: Skokie, Illinois, USA. (2000-04-03) 1 1 1 1 1 teletypewriter (Nearly always abbreviated to "teletype" or tty) An obsolete kind of terminal, with a noisy mechanical printer for output, a very limited character set, and poor print quality. See also bit-paired keyboard. (2000-04-02) 1 1 1 1 1 TeleUSE An interface builder for Motif. 1 1 1 1 1 television A dedicated push media device for receiving streaming video and audio, either by terrestrial radio broadcast, satellite or cable. (1997-11-23) 1 1 1 1 1 Television Interface Adaptor (TIA) The graphics chip in the Atari 2600, also used as a sound chip for some arcade game. (1999-12-06) 1 1 1 1 1 TELNET /tel'net/ 1. The Internet standard protocol for remote login. Runs on top of TCP/IP. Defined in STD 8, RFC 854 and extended with options by many other RFCs. Unix BSD networking software includes a program, telnet, which uses the protocol and acts as a terminal emulator for the remote login session. Sometimes abbreviated to TN. TOPS-10 had a similar program called IMPCOM. 2. The US nationwide network into which one dials to access CompuServe. It was created by John Goltz, one of the founders and system guru of CompuServe. He later worked for Tymshare, one of CompuServe's big competitors. [Jargon File] (2004-09-14) 1 1 1 1 1 Telocator Alphanumeric Protocol (TAP, or "IXO", "PET") A protocol for submitting requests to a pager service. IXO/TAP is an ASCII-based, half-duplex protocol that allows the submission of a numeric or alphanumeric message. Examples, protocol description, clarifications (ftp://mirror.lcs.mit.edu/telecom-archives/technical). See also RFC 1568. (1996-04-07) 1 1 1 1 1 Telon CA-Telon 1 1 1 1 1 TELOS 1. The LeLisp Version 16 Object System. Also used in EuLisp. The object-oriented core of EuLisp. Incorporates ideas from CLOS, ObjVLisp and OakLisp. Total merging of types with classes and message-passing with normal function application. 2. A Pascal-based AI language. ["Design Rationale for TELOS, a Pascal-based AI Language", Travis et al, SIGPLAN Notices 12(8) (Aug 1977)]. 1 1 1 1 1 TELSIM Busch, ca 1966. Digital simulation. [Sammet 1969, p. 627]. 1 1 1 1 1 template A document that contains parameters, identified by some special syntax, that are replaced by actual arguments by the template processing system. For example: Dear <guest>, <host> would like to invite you to a party at <location> on <date> at <time>. Where the words in angle brackets are the parameters to be replaced by the name of an actual guest, etc. More sophisticated systems allow repetition, where a section is repeated in a single output document using a list of inputs; conditional sections or (nested) inclusion of other templates. See also class template. (2007-10-14) 1 1 1 1 1 template code Pseudocode generated by an automated CASE system and requiring further hand-coding before compilation. (2008-10-22) 1 1 1 1 1 template wizard Software to guide the creation of some kind of template. Examples include Excel's Template Wizard add-in for creating databases to receive form data. Most web authoring tools include facilities for inserting text into template page designs. (2008-10-22) 1 1 1 1 1 TEMPLOG Extension of Prolog to handle a clausal subset of first-order temporal logic with discrete time. Proposed by M. Abadi and Z. Manna of Stanford University. ["Temporal Logic in Programming", M. Abadi et al, INtl Symp Logic Prog pp.4-16 (1987)]. 1 1 1 1 1 TEMPO A programming language with simple syntax and semantics designed for teaching semantic and pragmatic aspects of programming languages. ["TEMPO: A Unified Treatment of Binding Time and Parameter Passing Concepts in Programming Languages", N.D. Jones et al, LNCS 66, Springer 1978]. 1 1 1 1 1 Tempo The original code name for Mac OS version 8 (1997-10-15) 1 1 1 1 1 temporal database A database that can store and retrieve temporal data, that is, data which depends on time in some way. [More details? Examples?] (1996-05-25) 1 1 1 1 1 temporal logic An extension of predicate calculus which includes notation for arguing about *when* statements are true. Time is discrete and extends indefinitely into the future. Three prefix operators, represented by a circle, square and diamond mean "is true at the next time instant", "is true from now on" and "is eventually true". x U y means x is true until y is true. x P y means x precedes y. There are two types of formula: "state formulae" about things true at one point in time, and "path formulae" about things true for a sequence of steps. An example of a path formula is x U y, and example of a state formula is "next x" or a simple atomic formula such at "waiting". true until in this context means that a state formula holds at every point in time up to a point when another formula holds. "x U y" is the "strong until" and implies that there is a time when y is true. "x W y" is the "weak until" in which it is not necessary that y holds eventually. 1 1 1 1 1 Tempura Language based on temporal logic. "Executing Temporal Logic Programs", B. Moszkowski, Camb U Press 1986. 1 1 1 1 1 Ten15 A universal intermediate language, a predecessor to TDF. Ten15 Home (http://mca-ltd.com/martin/Ten15). ["Ten15: An Overview", P. Core et al, Royal Signals Radar Establishment TR 3977, Sept 1986]. [Polymorphic?] (2003-05-13) 1 1 1 1 1 tendinitis overuse strain injury 1 1 1 1 1 TenDRA TenDRA home (http://tendra.org/). [Summary?] (2003-05-13) 1 1 1 1 1 ten-finger interface The interface between two networks that cannot be directly connected for security reasons; refers to the practice of placing two terminals side by side and having an operator read from one and type into the other. [Jargon File] 1 1 1 1 1 tennis elbow overuse strain injury 1 1 1 1 1 tense Of programs, very clever and efficient. A tense piece of code often got that way because it was highly bummed, but sometimes it was just based on a great idea. A comment in a clever routine by Mike Kazar, once a grad-student hacker at CMU: "This routine is so tense it will bring tears to your eyes." A tense programmer is one who produces tense code. [Jargon File] 1 1 1 1 1 tensor product A function of two vector spaces, U and V, which returns the space of linear maps from V's dual to U. Tensor product has natural symmetry in interchange of U and V and it produces an associative "multiplication" on vector spaces. Wrinting * for tensor product, we can map UxV to U*V via: (u,v) maps to that linear map which takes any w in V's dual to u times w's action on v. We call this linear map u*v. One can then show that u * v + u * x = u * (v+x) u * v + t * v = (u+t) * v and hu * v = h(u * v) = u * hv ie, the mapping respects linearity: whence any bilinear 1 1 1 1 1 tenured graduate student One who has been in graduate school for 10 years (the usual maximum is 5 or 6): a "ten-yeared" student (get it?). Actually, this term may be used of any grad student beginning in his seventh year. Students don't really get tenure, of course, the way professors do, but a tenth-year graduate student has probably been around the university longer than any untenured professor. [Jargon File] (1996-09-27) 1 1 1 1 1 tera- prefix 1 1 1 1 1 terabyte (TB) A unit of data equal to one trillion bytes. A terabyte is 10^12 bytes or 1000^4 bytes or 1000 gigabytes. A terabyte is roughly the amount of data in 117 DVDs (at 8.5 gigabytes each). 1000 terabytes are one petabyte. (Note the spelling - one 'r'). See prefix. (2013-11-03) 1 1 1 1 1 teraflop 10^12 flops. Intel beat Hitachi to the record of 1.06 teraflops, on 04 Dec 1996, unofficially in Beverton, Oregon, using 7264 Pentium Pro chips. (1997-07-21) 1 1 1 1 1 teraflop club /te'r*-flop kluhb/ (From tera- and flops) A mythical association of people who consume outrageous amounts of computer time in order to produce a few simple pictures of glass balls with intricate ray-tracing techniques. Caltech professor James Kajiya is said to have been the founder. [Jargon File] (1997-07-21) 1 1 1 1 1 TERM 1. <networking> A program by Michael O'Reilly <michael@iinet.com.au> for people running Unix who have Internet access via a dial-up connection, and who don't have access to SLIP, or PPP, or simply prefer a more lightweight protocol. TERM does end-to-end error-correction, compression and mulplexing across serial links. This means you can upload and download files as the same time you're reading your news, and can run X clients on the other side of your modem link, all without needing SLIP or PPP. Latest version: 1.15. (ftp://tartarus.uwa.edu.au/pub/oreillym/term/term115.tar.gz). 2. <business> Technology Enabled Relationship Management. (1999-10-04) 1 1 1 1 1 TERMAC An interactive matrix language. ["Users Guide to TERMAC", J.S. Miller et al, MIT Dec 1968]. (1994-11-04) 1 1 1 1 1 termcap (terminal capabilities) A Unix database listing different types of terminal (or terminal emulation) and the character strings to send to make the terminal perform certain functions such as move the cursor up one line or clear the screen. Programs written using termcap can work on any terminal in the database which supports the necessary functions. Typical programs are text editors or file viewers like more. The termcap routines look for an environment variable "TERM" to determine which terminal the user is using. terminfo is a later version of termcap. (1998-10-30) 1 1 1 1 1 terminak /ter'mi-nak`/ [Caltech, ca. 1979] Any malfunctioning computer terminal. A common failure mode of Lear-Siegler ADM 3a terminals caused the "L" key to produce the "K" code instead; complaints about this tended to look like "Terminak #3 has a bad keyboard. Pkease fix." See AIDX, Nominal Semidestructor, Open DeathTrap, ScumOS, sun-stools, Telerat, HP-SUX. [Jargon File] (1995-04-14) 1 1 1 1 1 terminal 1. <hardware> An electronic or electromechanical device for entering data into a computer or a communications system and displaying data received. Early terminals were called teletypes, later ones VDUs. Typically a terminal communicates with the computer via a serial line. 2. <electronics> The end of a line where signals are either transmitted or received, or a point along the length of a line where the signals are made available to apparatus. 3. <electronics> Apparatus to send and/or receive signals on a line. (1995-10-02) 1 1 1 1 1 Terminal Access Controller (TAC) A device which connects terminals to the Internet, usually using dial-up modem connections and the TACACS protocol. (1997-11-27) 1 1 1 1 1 terminal adapter Terminal Adaptor 1 1 1 1 1 Terminal Adaptor (TA) Equipment used to adapt Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) channels to existing terminal equipment standards such as EIA-232 and V.35. A Terminal Adaptor is typically packaged like a modem, either as a stand-alone unit or as an interface card that plugs into a computer or other communications equipment (such as a router or PBX). A Terminal Adaptor does not interoperate with a modem; it replaces it. [ISDN FAQ]. (1994-10-03) 1 1 1 1 1 terminal brain death The extreme form of terminal illness. What someone who has obviously been hacking continuously for far too long is said to be suffering from. [Jargon File] 1 1 1 1 1 terminal emulation What a terminal emulator does. 1 1 1 1 1 terminal emulator A program that allows a computer to act like a (particular brand of) terminal, e.g. a vt-100. The computer thus appears as a terminal to the host computer and accepts the same escape sequences for functions such as cursor positioning and clearing the screen. xterm is a terminal emulator for the X Window System. (1995-02-16) 1 1 1 1 1 terminal illness raster burn 1 1 1 1 1 terminal junkie (UK) A wannabee or early larval stage hacker who spends most of his or her time wandering the directory tree and writing noddy programs just to get a fix of computer time. Variants include "terminal jockey", "console junkie", and console jockey. The term "console jockey" seems to imply more expertise than the other three (possibly because of the exalted status of the console relative to an ordinary terminal). See also twink, read-only user. [Jargon File] (1995-02-16) 1 1 1 1 1 terminal node leaf 1 1 1 1 1 Terminal Oriented Real Time Operating System (TORTOS) An operating system developed from MVT at Health Sciences Computing, UCLA by Dr. Patrica Britt from the late 1960s to the mid 1970s. Dr. Britt was a senior scientist at IBM, who become the Assistant Director of HSCF. TORTOS pre-dated TSO and provided batch, real-time and time sharing on an IBM 360/91. (2004-07-02) 1 1 1 1 1 Terminal Oriented Social Science (TOSS) The Cambridge Project Project MAC was an ARPA-funded political science computing project. They worked on topics like survey analysis and simulation, led by Ithiel de Sola Pool, J.C.R. Licklider and Douwe B. Yntema. Yntema had done a system on the MIT Lincoln Labs TX-2 called the Lincoln Reckoner, and in the summer of 1969 led a Cambridge Project team in the construction of an experiment called TOSS. TOSS was like Logo, with matrix operators. A major feature was multiple levels of undo, back to the level of the login session. This feature was cheap on the Lincoln Reckoner, but absurdly expensive on Multics. (1997-01-29) 1 1 1 1 1 Terminal Productivity eXecutive (TPX) A multiple session manager used to access mainframe applications. It was written by Morgan Stanley, acquired by Duquesne Systems and is now owned by Computer Associates. TPX allows you to work in multiple mainframe applications concurrently; lock and unlock your TPX screen; place your applications on hold; logon to TPX from a different terminal without losing your place; customize your TPX menu and send a screen image to another TPX user. TPX runs on MVS and VM. On VM, like VTAM, it uses the MVS-like facilities of GCS. It has a complete scripting facility and lets you see other user's sessions. The client-server version allows each managed session to open in its own window. Richard Kuebbing has built a complete e-mail system into it. Unicenter CA-TPX (http://www3.ca.com/Solutions/Product.asp?ID=1531). (2005-09-29) 1 1 1 1 1 terminal server A device which connects many terminals (serial lines) to a local area network through one network connection. A terminal server can also connect many network users to its asynchronous ports for dial-out capabilities and printer access. (1995-02-16) 1 1 1 1 1 Terminal User Interface Textual User Interface 1 1 1 1 1 Terminate and Stay Resident (TSR) A type of DOS utility which, once loaded, stays in memory and can be reactivated by pressing a certain combination of keys. 1 1 1 1 1 termination analysis A program analysis which attempts to determine whether evaluation of a given expression will definitely terminate. Evaluation of a constant is bound to terminate, as is evaluation of a non-recursive function applied to arguments which are either not evaluated or which can themselves be proved to terminate. A recursive function can be shown to terminate if it can be shown that the arguments of the recursive calls are bound to reach some value at which the recursion will cease. Termination analysis can never guarantee to give the correct answer because this would be equivalent to solving the halting problem so the answer it gives is either "definitely terminates" or "don't know". (1994-10-20) 1 1 1 1 1 terminator A resistor connected to a signal wire in a bus or network for the purpose of impedance matching to prevent reflections. For example, a 50 ohm resistor connected across the end of an Ethernet cable. SCSI chains and some LocalTalk wiring schemes also require terminators. (1995-05-17) 1 1 1 1 1 term rewriting system (TRS) A collection of rewrite rules used to transform terms (expressions, strings in some formal language) into equivalent terms. See reduction. (1994-11-04) 1 1 1 1 1 Terms Of Service (TOS) The rules laid down by an on-line service provider such as AOL that members must obey or risk being TOS-sed (disconnected). (1999-04-02) 1 1 1 1 1 ternary A description of an operator taking three arguments. The only common example is C's ?: operator which is used in the form "CONDITION ? EXP1 : EXP2" and returns EXP1 if CONDITION is true else EXP2. Haskell has a similar "if CONDITION then EXP1 else EXP2" operator. See also unary, binary. (1998-07-29) 1 1 1 1 1 terpri /ter'pree/ TERminate PRInt line. [LISP 1.5 and later, MacLISP] To output a newline. Still used in Common LISP. On some early operating systems and hardware, no characters would be printed until a complete line was formed, so this operation terminated the line and emitted the output. [Jargon File] (1996-06-24) 1 1 1 1 1 terrabyte It's spelled "terabyte". (1997-01-23) 1 1 1 1 1 Terse Language for decryption of hardware logic. ["Hardware Logic Simulation by Compilation", C. Hansen, 25th ACM/IEEE Design Automation Conf, 1988]. 1 1 1 1 1 test The process of exercising a product to identify differences between expected and actual behaviour. Typically testing is bottom-up: unit testing and integration testing by developers, system testing by testers, and user acceptance testing by users. Test coverage attempts to assess how complete a test has been. 2. The second stage in a generate and test search algorithm. [Jargon File] (2003-09-24) 1 1 1 1 1 test coverage A measure of the proportion of a program exercised by a test suite, usually expressed as a percentage. This will typically involve collecting information about which parts of a program are actually executed when running the test suite in order to identify which branches of conditional statements which have been taken. The most basic level of test coverage is code coverage testing and the most methodical is path coverage testing. Some intermediate levels of test coverage exist, but are rarely used. The standard Unix tool for measuring test coverage is tcov, which annotates C or Fortran source with the results of a test coverage analysis. GCT is a GNU equivalent. (2001-05-20) 1 1 1 1 1 test-driven development (TDD) An iterative software development process where each iteration consists of the developer writing an automated test case for an unimplemented improvement or function, then producing code to pass that test and finally refactoring the code to acceptable standards. Kent Beck, who is credited with having developed or rediscovered the technique, stated in 2003 that TDD encourages simple designs and inspires confidence. TDD is related to the humourous definition of programming as the process of debugging an empty file. (2012-05-01) 1 1 1 1 1 testing test 1 1 1 1 1 TET Test Environment Toolkit project coordinated by X/Open. 1 1 1 1 1 TeX /tekh/ An extremely powerful macro-based text formatter written by Donald Knuth, very popular in academia, especially in the computer-science community (it is good enough to have displaced Unix troff, the other favoured formatter, even at many Unix installations). The first version of TeX was written in the programming language SAIL, to run on a PDP-10 under Stanford's WAITS operating system. Knuth began TeX because he had become annoyed at the declining quality of the typesetting in volumes I-III of his monumental Art of Computer Programming (see Knuth, also bible). In a manifestation of the typical hackish urge to solve the problem at hand once and for all, he began to design his own typesetting language. He thought he would finish it on his sabbatical in 1978; he was wrong by only about 8 years. The language was finally frozen around 1985, but volume IV of "The Art of Computer Programming" has yet to appear as of mid-1997. 1 1 1 1 1 TeX-78 The original version of TeX. (1997-11-20) 1 1 1 1 1 TeX-82 The version of TeX described in The TeXbook, Donald Knuth, A-W 1984. (1997-11-20) 1 1 1 1 1 Texas Instruments (TI) A US electronics company. A TI engineer, Jack Kilby invented the integrated circuit in 1958. Three TI employees left the company in 1982 to start Compaq. The COOL and OATH C++ class libraries were developed at TI, as were PDL2 and the ASC computer, PC-Scheme and Texas Instruments Pascal. (ftp://ti.com/). (1994-09-26) 1 1 1 1 1 Texinfo A GNU documentation system that uses a single source file to produce both on-line information and printed output. You can read the on-line information, known as an "Info file", with an Info documentation-reading program. By convention, Texinfo source file names end with a ".texi" or ".texinfo" extension. You can write and format Texinfo files into Info files within GNU Emacs, and read them using the Emacs Info reader. If you do not have Emacs, you can format Texinfo files into Info files using "makeinfo" and read them using "info". TeX is used to typeset Texinfo files for printing. Texinfo is available from your nearest GNU archive site. Latest version: 3.1, as of 1993-03-23. (1994-10-05) 1 1 1 1 1 TeX point The variant of the point used by TeX, equal to 0.3514598035 mm, or 1/72.27 inch. [Why yet another variant?] (2002-03-11) 1 1 1 1 1 text 1. Executable code, especially a "pure code" portion shared between multiple instances of a program running in a multitasking operating system. Compare English. 2. Textual material in the mainstream sense; data in ordinary ASCII or EBCDIC representation (see flat ASCII). "Those are text files; you can review them using the editor." These two contradictory senses confuse hackers too. [Jargon File] (1995-03-16) 1 1 1 1 1 text-based Working under a non-window-based operating system (e.g. MS-DOS) as opposed to a graphical user interface (e.g. Microsoft Windows). An MS-DOS text-based program uses a screen with a fixed array of 80x25 or 80x40 characters. Examples are WordPerfect before version 5.1 and Microsoft Word. (1995-03-16) 1 1 1 1 1 text editor A utility program for creating and modifying text files. This differs from a word processor in that the word processors often embed special control codes or escape sequences in the file to control formatting. (1996-11-15) 1 1 1 1 1 Text Encoding Initiative (TEI) A project working to establish a standard for interchanging electronic text for scholarly research. The TEI has adopted SGML and implemented the TEI standard as an SGML Document Type Definition. The TEI was incorporated as a not-for-profit consortium in December 2000, with host sites in Bergen, Oxford, Virginia, and Providence RI, USA. (http://tei-c.org/). See also Corpus Processing. [Any connection with Computational Linguistics or Natural Language Processing?] (2001-03-23) 1 1 1 1 1 text file A file containing no "invisible" control characters, only printable letters, numbers and symbols, usually from the ASCII character set. A text file can be produced with a text editor and can usually be imported into any word processor though it will probably appear unformatted. Compare binary file, flat file, rich text file. (1996-11-15) 1 1 1 1 1 Text Processing Utility (TPU) A DEC language for creation of text-processing interfaces, used to implement DEC's Extensible VAX Editor (EVE). (2000-05-08) 1 1 1 1 1 Text Reckoning And Compiling (TRAC) An interactive macro generator language for string manipulation by Calvin N. Mooers and Peter Deutsch of Sun Microsystems. TAC derived ideas from Macro SAP. There are versions for PDP-1, PDP-8, PDP-10 and PDP-11. See also MINT, SAM76. E-mail: Preston Briggs <preston@rice.edu>. ["TRAC: A Procedure- Describing Language for the Reactive Typewriter", Calvin N. Mooers, CACM 9(3):215-219 (Mar 1966). Rockford Research Inst, 1972]. [Sammet 1969, pp.448-454]. ["Macro Processors", A.J. Cole, Cambridge U Press]. (1994-12-21) 1 1 1 1 1 text segment code segment 1 1 1 1 1 Text To Speech (TTS) Automatic conversion of text streams to voice. [Details?] (1997-05-11) 1 1 1 1 1 Textual User Interface (TUI) Either a text-based version of a GUI, or a full-screen version of a CLI. (2003-10-21) 1 1 1 1 1 texture A measure of the variation of the intensity of a surface, quantifying properties such as smoothness, coarseness and regularity. It's often used as a region descriptor in image analysis and computer vision. The three principal approaches used to describe texture are statistical, structural and spectral. Statistical techniques characterise texture by the statistical properties of the grey levels of the points comprising a surface. Typically, these properties are computed from the grey level histogram or grey level cooccurrence matrix of the surface. Structural techniques characterise texture as being composed of simple primitives called "texels" (texture elements), that are regularly arranged on a surface according to some rules. These rules are formally defined by grammars of various types. Spectral techiques are based on properties of the Fourier spectrum and describe global periodicity of the grey levels of 1 1 1 1 1 tf The country code for French southern territories. (1999-01-27) 1 1 1 1 1 TFDL ["TFDL : A Task-level Dataflow Language", P.A. Suhler et al, J Parallel and Distrib Comput 9:103-115 (1990)]. (1995-05-11) 1 1 1 1 1 TFT Thin Film transistor 1 1 1 1 1 TFTP Trivial File Transfer Protocol 1 1 1 1 1 tg The country code for Togo. (1999-01-27) 1 1 1 1 1 TGA Targa Graphics Adaptor 1 1 1 1 1 T-gen A general-purpose object-oriented tool for the automatic generation of string-to-object translators. It was written in Smalltalk by Justin Graver <graver@comm.mot.com> and runs in the Smalltalk programming environment. T-gen supports the generation of both top-down parsers (LL parsers) and bottom-up parsers (LR parsers), which will automatically generate derivation trees, abstract syntax trees or arbitrary Smalltalk objects. The simple specification syntax and graphical user interface are intended to enhance the learning, comprehension and usefulness of T-gen. Latest version: 2.1. Runs on Smalltalk-80, ParcPlace Objectworks/Smalltalk 4.0 or 4.1. (ftp://st.cs.uiuc.edu/pub/st80_r41/T-gen2.1/). (1992-10-18) 1 1 1 1 1 TGS-II Translator Generator System. Contained TRANDIR. [Sammet 1969, p. 640]. 1 1 1 1 1 TGS Systems Suppliers of Prograph. Telephone: +1 (902) 429 5642. (1995-03-31) 1 1 1 1 1 tgz (Or less often "taz", Tar GNU zip) A filename extension for a file or directory which has been archived with tar and then compressed with gzip. The full form ".tar.gz" is also common on proper file systems not limited to 8.3 file names. (1996-11-03) 1 1 1 1 1 th The country code for Thailand. (1999-01-27) 1 1 1 1 1 thanks in advance (Usually "TIA") A conventional Usenet net.politeness ending a posted request for information or assistance. Sometimes written "advTHANKSance" or aTdHvAaNnKcSe. [Jargon File] (1999-02-09) 1 1 1 1 1 That's not a bug, that's a feature! The canonical first parry in a debate about a purported bug. The complainant, if unconvinced, is likely to retort that the bug is then at best a misfeature. See also feature. [Jargon File] (1995-02-02) 1 1 1 1 1 T.H.E The operating system in which semaphores were first used. [Details?] (1999-10-12) 1 1 1 1 1 The Cuckoo's Egg A great book (and subsequent BBC TV series) telling the true story of Clifford Stoll, an astronomy professor at UCB's Lawrence Berkeley Lab. A 75-cent accounting error alerted him to the presence of an unauthorised user (a cracker) on his system. The cracker, code named "Hunter", was breaking into US computer systems and stealing sensitive military and security information. Hunter was part of a spy ring paid in cash and cocaine, and reporting to the KGB. ["The Cuckoo's Egg", Clifford Stoll, London: Bodley Head, 1990, ISBN 0-370-31433-6, ISBN 0-671-72688-9]. [FTP?] (1994-11-15) 1 1 1 1 1 The Dojo Toolkit A modular, open source JavaScript library. Dojo is designed for easy development of JavaScript- or AJAX based applications and websites. It is supported by the Dojo Foundation, which is sponsored by IBM, AOL, Sun and others. The name is from the Japanese term meaning "place of the way", used for a formal place of training. (2008-07-23) 1 1 1 1 1 The Force A data parallel language by Harry Jordan <harry@boulder.colorado.edu> which extends Fortran for shared memory multiprocessors. It features parallel case statements and critical sections. ["The Force", H. Jordan, in "The Characteristics of Parallel Algorithms", L. Jamieson et al eds, MIT Press 1987, pp. 395-436]. (1994-12-14) 1 1 1 1 1 The Internet Account An Internet provider in Sydney, Australia who provides SLIP, PPP and CLI accounts for the same rates. <riscman@geko.com.au> handles Acorn software. (http://geko.com.au/). (ftp://ftp.geko.com.au/pub/). E-mail: <accounts@geko.com.au>. Telephone: +61 (2) 968 4333. Fax: +61 (2) 968 4334. Address: PO BOX 473, Crows Nest, NSE 2065, Australia. (1995-02-02) 1 1 1 1 1 The MathWorks, Inc. The company marketing MATLAB. (http://mathworks.com/). E-mail: <info@mathworks.com>. Address: 3 Apple Hill Drive, Natick, Massachusetts 01760-2098 USA. Telephone: +1 (508) 647-7000. Fax: +1 (508) 647-7101. (2005-08-13) 1 1 1 1 1 The Metadata Company A company founded by Jack E. Myers, originally known as Metadata Information Partners. Myers trademarked the word Metadata (unhyphenated with initial capital, as opposed to the general term metadata) to represent implementations of his MetaModel and to designate his company. Myers claims that a data and publication search in the summer of 1969 failed to discover any use either of the word metadata or "meta data". (http://metadata.com/). E-mail: <metadata@metadata.com>. Address: 444 West Ocean Blvd, Suite 1600, Long Beach CA 90802, USA. (2010-05-15) 1 1 1 1 1 The Microsoft Network (MSN) Microsoft's ISP and online content service, launched in October 1996. Not to be confused with Microsoft Networking. MSN was originally based on custom software and protocols, however Microsoft saw the error of their ways and adopted Internet standards. MSN now provides standard WWW and email facilities, albeit with Microsoft's Internet Explorer web-browser and the Outlook Express email software. The service also provides "Community Services" including newsgroups, forums, and chat. (http://msn.com/). (1998-08-11) 1 1 1 1 1 The Mythical Man-Month Fred Brooks's excellent 1975 book on software engineering. See also Brooks's Law. ["The Mythical Man-Month: Essays on Software Engineering", Fred Brooks, Addison-Wesley, 1975, ISBN 0-201-00650-2]. (1996-06-20) 1 1 1 1 1 The Network network, the 1 1 1 1 1 THEO A frame language. ["Theo: A Framework for Self-Improving Systems", Mitchell et al, in Architectures for Intelligence, K. VanLehn ed, Erlbaum, 1989]. (1994-12-14) 1 1 1 1 1 theology 1. Ironically or humorously used to refer to religious issues. 2. Technical fine points of an abstruse nature, especially those where the resolution is of theoretical interest but is relatively marginal with respect to actual use of a design or system. Used especially around software issues with a heavy AI or language-design component, such as the smart-data vs. smart-programs dispute in AI. [Jargon File] 1 1 1 1 1 The Open Group (Formerly "X/Open") A vendor- and technology-neutral consortium of buyers and suppliers of information systems that aims to ease integration by testing and certifying products against open standards. The Open Group Home (http://opengroup.org). (2006-07-13) 1 1 1 1 1 theory The consensus, idea, plan, story, or set of rules that is currently being used to inform a behaviour. This usage is a generalisation and (deliberate) abuse of the technical meaning. "What's the theory on fixing this TECO loss?" What's the theory on dinner tonight? ("Chinatown, I guess.") "What's the current theory on letting lusers on during the day?" "The theory behind this change is to fix the following well-known screw...." (1994-12-14) 1 1 1 1 1 theory change The study of methods used to incorporate new information into a knowledge base when the new information may conflict with existing information. Belief revision is one area of theory change. [Others?] (1995-03-20) 1 1 1 1 1 The Real-Time Operating System Nucleus (TRON) A project to develop an operating system and man-machine interface that can work with other operating systems to provide an environment for many small distributed computers to cooperate in real time. TRON is headed by Dr. Ken Sakamura of the University of Tokyo and supported by most of the major Japanese computer makers and NTT. (http://atip.org/public/atip.reports.91/tron.html). (2003-05-23) 1 1 1 1 1 There's More Than One Way To Do It (TMTOWTDI) One of the design principles of Perl. The Perl man page ends with a note: The Perl motto is "There's more than one way to do it." Divining how many more is left as an exercise to the reader. (2001-03-15) 1 1 1 1 1 Theseus A language based on Euclid, never implemented. ["Theseus - A Programming Language for Relational Databases", J.E. Shopiro, ACM Trans Database Sys 4(4):493-517, Mar 1979]. (1994-12-14) 1 1 1 1 1 The story of Mel The story of Mel, a Real Programmer 1 1 1 1 1 The story of Mel, a Real Programmer A 1983 article by Ed Nather about hacker Mel Kaye. The full text follows. A recent article devoted to the macho side of programming made the bald and unvarnished statement, "Real Programmers write in FORTRAN". Maybe they do now, in this decadent era of Lite beer, hand calculators and "user-friendly" software but back in the Good Old Days, when the term "software" sounded funny and Real Computers were made out of drums and vacuum tubes, Real Programmers wrote in machine code - not Fortran, not RATFOR, not even assembly language - Machine Code, raw, unadorned, inscrutable hexadecimal numbers, directly. Lest a whole new generation of programmers grow up in ignorance of this glorious past, I feel duty-bound to describe, as best I can through the generation gap, how a Real Programmer wrote code. I'll call him Mel, because that was his name. 1 1 1 1 1 The World Of Cryton (TWOC) A BBS for the Acorn Archimedes. Telephone: +44 (1749) 670 030 (24hrs, most speeds). (1994-11-08) 1 1 1 1 1 the X that can be Y is not the true X Yet another instance of hackerdom's peculiar attraction to mystical references - a common humorous way of making exclusive statements about a class of things. The template is from the "Tao te Ching": "The Tao which can be spoken of is not the true Tao." The implication is often that the X is a mystery accessible only to the enlightened. See the trampoline entry for an example, and compare has the X nature. [Jargon File] 1 1 1 1 1 thicket Multiple files output from some operation. The term has been heard in use at Microsoft to describe the set of files output when Microsoft Word does "Save As a Web Page" or "Save as HTML". The process can result in a main XML or HTML file, a graphic file for each image in the original, a CSS file, etc. This can be an issue as XML can be used as the default format in Office 2000, and document management systems can't yet cope with the relationship between the files in a thicket when checking in and out. (2001-09-01) 1 1 1 1 1 thick Ethernet cable RG8 1 1 1 1 1 thick film dielectric electroluminescence (TDEL) A phenomenon used in some flat panel displays. (2007-06-04) 1 1 1 1 1 thicknet 10base5 1 1 1 1 1 thin client A simple client program or hardware device which relies on most of the function of the system being in the server. Gopher clients, for example, are very thin; they are stateless and are not required to know how to interpret and display objects much more complex than menus and plain text. Gopher servers, on the other hand, can search databases and provide gateways to other services. By the mid-1990s, the model of decentralised computing where each user has his own full-featured and independent microcomputer, seemed to have displaced a centralised model in which multiple users use thin clients (e.g. dumb terminals) to work on a shared minicomputer or mainframe server. Networked personal computers typically operate as fat clients, often providing everything except some file storage and printing locally. By 1996, reintroduction of thin clients is being proposed, 1 1 1 1 1 thin Ethernet cable RG58 1 1 1 1 1 ThingLab A simulation system written in Smalltalk-80. It solves constraints using value inference. Version: ThingLab II. ["The Programming Language Aspects of ThingLab, A Constraint-Oriented Simulation Laboratory", A. Borning, ACM TOPLAS 3(4):353-387 (Oct 1981)]. 1 1 1 1 1 Think C An extension of ANSI C for the Macintosh by Symantec Corporation. It supports object-oriented programming techniques similar to C++. 1 1 1 1 1 Thinking Machines Corporation The company that introduced the Connection Machine parallel computer ca 1984. Four of the world's ten most powerful supercomputers are Connection Machines. Thinking Machines is the leader in scalable computing, with software and applications running on parallel systems ranging from 16 to 1024 processors. In developing the Connection Machine system, Thinking Machines also did pioneering work in parallel software. The 1993 technical applications market for massively parallel systems was approximately $310 million, of which Thinking Machines Corporation held a 29 percent share. Thinking Machines planned to become a software provider by 1996, by which time the parallel computing market was expected to have grown to $2 billion. Thinking Machines Corporation has 200 employees and offices worldwide. Address: 245 First Street, Cambridge, MA 02142-1264, USA. 1 1 1 1 1 thinko /thing'koh/ (Or "braino", by analogy with "typo") A momentary, correctable glitch in mental processing, especially one involving recall of information learned by rote; a bubble in the stream of consciousness. See also brain fart. Compare mouso. [Jargon File] (1996-04-20) 1 1 1 1 1 thinnet cheapernet 1 1 1 1 1 third generation computer A computer built with small-scale integration integrated circuits, designed after the mid-1960s. Third generation computers use semiconductor memories in addition to, and later instead of, ferrite core memory. The two main types of semiconductor memory are Read-Only Memory (ROM) and read-and-write memories called random-access memory (RAM). A technique called microprogramming became widespread and simplified the design of the CPUs and increased their flexibility. This also made possible the development of operating systems as software rather than as hard-wiring. A variety of techniques for improving processing efficiency were invented, such as pipelining, (parallel operation of functional units processing a single instruction), and multiprocessing (concurrent execution of multiple programs). As the execution of a program requires that program to be in memory, the concurrent running of several programs requires 1 1 1 1 1 third generation language (3GL, "high level language") A language designed to be easier for a human to understand, including things like named variables. A fragment might be let c = c + 2 * d Fortran, ALGOL and COBOL are early examples of this sort of language. Most "modern" languages (BASIC, C, C++) are third generation. Most 3GLs support structured programming. See also second generation language, fourth generation language. (1996-05-30) 1 1 1 1 1 third normal form database normalisation 1 1 1 1 1 This can't happen can't happen 1 1 1 1 1 this dictionary Free On-line Dictionary of Computing 1 1 1 1 1 This time, for sure! Ritual affirmation frequently uttered during protracted debugging sessions involving numerous small obstacles (e.g. attempts to bring up a UUCP connection). For the proper effect, this must be uttered in a fruity imitation of Bullwinkle J. Moose. Also heard: "Hey, Rocky! Watch me pull a rabbit out of my hat!" The canonical response is, of course, "But that trick *never* works!" See hacker humour. [Jargon File] (1995-09-27) 1 1 1 1 1 thn thumbnail 1 1 1 1 1 Thomas A language compatible with the language Dylan(TM). Thomas is NOT Dylan(TM). The first public release of a translator to Scheme by Matt Birkholz, Jim Miller, and Ron Weiss, written at Digital Equipment Corporation's Cambridge Research Laboratory runs (slowly) on MIT's CScheme, DEC's Scheme->C, Marc Feeley's Gambi, Macintosh, PC, Vax, MIPS, Alpha, 680x0. (ftp://gatekeeper.pa.dec.com/pub/DEC/Thomas). Mailing list: <info-thomas@crl.dec.com>. ["Dylan(TM) an object-oriented dynamic language", Apple Computer, Eastern Research and Technology, April 1992]. (1992-09-11) 1 1 1 1 1 thrash To move wildly or violently, without accomplishing anything useful. Paging or swapping systems that are overloaded waste most of their time moving data into and out of core (rather than performing useful computation) and are therefore said to thrash. Thrashing can also occur in a cache due to cache conflict or in a multiprocessor (see ping-pong). Someone who keeps changing his mind (especially about what to work on next) is said to be thrashing. A person frantically trying to execute too many tasks at once (and not spending enough time on any single task) may also be described as thrashing. Compare multitask. [Jargon File] 1 1 1 1 1 thrashing thrash 1 1 1 1 1 thread 1. See multithreading. 2. See threaded code. 3. topic thread. [Jargon File] 1 1 1 1 1 threaded thread 1 1 1 1 1 threaded code A technique for implementing virtual machine interpreters, introduced by J.R. Bell in 1973, where each op-code in the virtual machine instruction set is the address of some (lower level) code to perform the required operation. This kind of virtual machine can be implemented efficiently in machine code on most processors by simply performing an indirect jump to the address which is the next instruction. Many Forth implementations use threaded code and nowadays some use the term "threading" for almost any technique used to implement Forth's virtual machine. (http://complang.tuwien.ac.at/forth/threaded-code.html). ["James R. Bell", "Threaded Code", CACM, 1973, 16, 6, pp 370-372]. ["An Architectural Trail to Threaded Code Systems", Kogge, P. M., IEEE Computer, March 1982]. (1998-09-02) 1 1 1 1 1 threading thread 1 1 1 1 1 Thread Language Zero (TL0) The instruction set of the TAM (Threaded Abstract Machine), used to implement Id. ["Fine-grain Parallelism with Minimal Hardware Support", David Culler et al, SIGPLAN Notices 26(4):164-175, ASPLOS-IV Proc, Apr 1991]. (1995-03-13) 1 1 1 1 1 thread-safe A description of code which is either re-entrant or protected from multiple simultaneous execution by some form of mutual exclusion. (1997-01-30) 1 1 1 1 1 three-finger salute Vulcan nerve pinch 1 1 1 1 1 three-letter acronym (TLA) The canonical, self-describing acronym for the name of a species with which computing terminology is infested. Examples include MCA, FTP, SNA, CPU, MMU, DMU, FPU, TLA. This dictionary contains many TLAs. Sometimes used by extension for any confusing acronym. People who like this looser usage argue that not all TLAs have three letters, just as not all four-letter words have four letters. One also hears of "ETLA" (Extended Three-Letter Acronym) being used to describe four-letter acronyms. The term "SFLA" (Stupid Four-Letter Acronym) has also been reported. See also YABA. The self-effacing phrase "TDM TLA" (Too Damn Many...) is used to bemoan the plethora of TLAs in use. In 1989, a random of the journalistic persuasion asked hacker Paul Boutin "What do you think will be the biggest problem in computing in the 90s?" Paul's straight-faced response: "There are only 17,000 1 1 1 1 1 three-tier A client-server architecture in which the user interface, functional process logic ("business rules") and data storage and access are developed and maintained as independent modules, most often on separate platforms. Apart from the usual advantages of modular software with well defined interfaces, the three-tier architecture is intended to allow any of the three tiers to be upgraded or replaced independently as requirements or technology change. For example, an upgrade of desktop operating system from Microsoft Windows to Unix would only affect the user interface code. Typically, the user interface runs on a desktop PC or workstation and uses a standard graphical user interface, functional process logic may consist of one or more separate modules running on a workstation or application server, and an RDBMS on a database server or mainframe contains the data storage logic. The middle tier may be multi-tiered 1 1 1 1 1 throughput 1. The rate at which a processor can work expressed in instructions per second or jobs per hour or some other unit of performance. 2. <communications> data transfer rate. (2001-05-22) 1 1 1 1 1 thud 1. Yet another metasyntactic variable (see foo). It is reported that at CMU from the mid-1970s the canonical series of these was "foo", "bar", "thud", "blat". 2. Rare term for the hash character, "#" (ASCII 35). See ASCII for other synonyms. [Jargon File] 1 1 1 1 1 Thumb An extension to the Advanced RISC Machine architecture, announced on 06 March 1995 by Advanced RISC Machines Ltd. By identifying the critical subset of the ARM instruction set and encoding it into 16 bits, ARM has succeeded in reducing typical program size by 30-40% from ARM's already excellent code density. Since this Thumb instruction set uses less memory for program storage, cost is further reduced. All Thumb-aware processor cores combine the capability to execute both the 32-bit ARM and the 16-bit Thumb instruction sets. Careful design of the Thumb instructions allow them to be decompressed into full ARM instructions transparently during normal instruction decoding without any performance penalty. This differs from other 32-bit processors, like the Intel 486SX, with a 16-bit data bus, which require two 16-bit memory accesses to execute every 32-bit instruction and so halve performance. 1 1 1 1 1 thumb The slider or "bubble" on a window system scrollbar. So called because moving it allows you to browse through the contents of a text window in a way analogous to thumbing through a book. [Jargon File] (1995-03-14) 1 1 1 1 1 thumbnail (From "thumbnail sketch") A file format used by Graphics Workshop for Microsoft Windows. Filename extension: ".thn". [What's in the files?] (1996-05-28) 1 1 1 1 1 Thunderbird A complete free, open-source e-mail client from the Mozilla Foundation and therefore a true code descendent of the e-mail code in Netscape Navigator. The first non-beta release was in late 2004. The Firefox web browser is from the same source. Thunderbird Home (http://mozilla.org/products/thunderbird). (2005-01-26) 1 1 1 1 1 thunk /thuhnk/ 1. "A piece of coding which provides an address", according to P. Z. Ingerman, who invented thunks in 1961 as a way of binding actual parameters to their formal definitions in ALGOL 60 procedure calls. If a procedure is called with an expression in the place of a formal parameter, the compiler generates a thunk which computes the expression and leaves the address of the result in some standard location. 2. The term was later generalised to mean an expression, frozen together with its environment (variable values), for later evaluation if and when needed (similar to a closure). The process of unfreezing these thunks is called "forcing". 3. A stubroutine, in an overlay programming environment, that loads and jumps to the correct overlay. Compare trampoline. There are a couple of onomatopoeic myths circulating about the 1 1 1 1 1 TIA 1. <chat> Thanks in advance. 2. <body> Telecommunications Industry Association. 3. <software> The Internet Adapter. 4. <graphics, hardware> Television Interface Adaptor. (1999-12-06) 1 1 1 1 1 tick 1. A jiffy (sense 1). 2. In simulations, the discrete unit of time that passes between iterations of the simulation mechanism. In AI applications, this amount of time is often left unspecified, since the only constraint of interest is the ordering of events. This sort of AI simulation is often pejoratively referred to as "tick-tick-tick" simulation, especially when the issue of simultaneity of events with long, independent chains of causes is handwaved. 3. In the FORTH language, a single quote character. [Jargon File] 1 1 1 1 1 TickIT A software industry quality assessment scheme. 1 1 1 1 1 Tickle A text editor, file translator and TCL interpreter for the Macintosh. Version 5.0v1. The text editor breaks the 32K limit (like MPW). The file translation utilities support drag and drop handling via tcl scripts of BinHex, MacBinary, Apple Computer Single/Double, StuffIt (with engine), Unix compress, Unix tar and UUencode files as well as text translation. Tickle implements tcl 7.0 with tclX extensions and Macintosh equivalents of Unix's ls, pwd, cd commands. It provides Macintosh access to Resource Manager, Communications Toolbox, OSA Components (and AppleScript), Editions (publish and subscribe) and Apple Events (including AEBuild and AEPrint). OSA Script support allows programming of any OSA scripting component within Tickle interpreter windows. It provides the OSAtcl and OSAJ 1 1 1 1 1 tickle a bug To cause a normally hidden bug to manifest itself through some known series of inputs or operations. "You can tickle the bug in the Paradise VGA card's highlight handling by trying to set bright yellow reverse video." [Jargon File] 1 1 1 1 1 tick-list features (Acorn Computers) Features in software or hardware that customers insist on but never use (calculators in desktop TSRs and that sort of thing). The American equivalent would be checklist features, but this jargon sense of the phrase has not been reported. (1995-01-06) 1 1 1 1 1 TIFF Tagged Image File Format 1 1 1 1 1 tiger team (US military jargon) 1. Originally, a team whose purpose is to penetrate security, and thus test security measures. These people are paid professionals who do hacker-type tricks, e.g. leave cardboard signs saying "bomb" in critical defence installations, hand-lettered notes saying "Your codebooks have been stolen" (they usually haven't been) inside safes, etc. After a successful penetration, some high-ranking security type shows up the next morning for a "security review" and finds the sign, note, etc. and all hell breaks loose. Serious successes of tiger teams sometimes lead to early retirement for base commanders and security officers (see the patch entry for an example). 2. Recently, and more generally, any official inspection team or special firefighting group called in to look at a problem. A subset of tiger teams are professional crackers, testing the security of military computer installations by attempting 1 1 1 1 1 tight loop A loop of code that executes without releasing any resources to other programs or the operating system. Consider the following pointless BASIC loop that counts upward indefinitely 10 i = i + 1 20 GOTO 10 Run on a single-user system such as MS-DOS this will not cause any problems. Run on a cooperative multitasking operating system such as Windows 3, the system would appear to freeze. A pre-emptive multitasking operating system such as UNIX or Windows NT would "steal" cycles away from the program and continue to run other programs. See also busy-wait and multitasking. (1999-05-06) 1 1 1 1 1 tilde "~" ASCII character 126. Common names are: ITU-T: tilde; squiggle; twiddle; not. Rare: approx; wiggle; swung dash; enyay; INTERCAL: sqiggle (sic). Used as C's prefix bitwise negation operator; and in Unix csh, GNU Emacs, and elsewhere, to stand for the current user's home directory, or, when prefixed to a login name, for the given user's home directory. The "swung dash" or "approximation" sign is not quite the same as tilde in typeset material but the ASCII tilde serves for both (compare angle brackets). [Has anyone else heard this called "tidal" (as in wave)?] (1996-10-18) 1 1 1 1 1 TILE Forth A Forth interpreter in C for Unix by Mikael Patel <mip@sectra.se>. TILE Forth comes with many Forth libraries. It conforms to the Forth83 standard and is distributed under GPL. Latest version: 2.1, as of 1991-11-13. Availalbe via FTP from a GNU archive site. (1991-11-13) 1 1 1 1 1 Tim Berners-Lee The man who invented the web while working at the Center for European Particle Research (CERN). Now Director of the web Consortium. Tim Berners-Lee graduated from the Queen's College at Oxford University, England, 1976. Whilst there he built his first computer with a soldering iron, TTL gates, an M6800 processor and an old television. He then went on to work for Plessey Telecommunications, and D.G. Nash Ltd (where he wrote software for intelligent printers and a multi-tasking operating system), before joining CERN, where he designed a program called 'Enquire', which was never published, but formed the conceptual basis for today's web. In 1984, he took up a fellowship at CERN, and in 1989, he wrote the first web server, "httpd", and the first client, "WorldWideWeb" a hypertext browser/editor which ran under NEXTSTEP. The program "WorldWideWeb" was 1 1 1 1 1 time bomb A subspecies of logic bomb that is triggered by reaching some preset time, either once or periodically. There are numerous legends about time bombs set up by programmers in their employers' machines, to go off if the programmer is fired or laid off and is not present to perform the appropriate suppressing action periodically. Interestingly, the only such incident for which we have been pointed to documentary evidence took place in the Soviet Union in 1986! A disgruntled programmer at the Volga Automobile Plant (where the Fiat clones called Ladas were manufactured) planted a time bomb which, a week after he'd left on vacation, stopped the entire main assembly line for a day. The case attracted lots of attention in the Soviet Union because it was the first cracking case to make it to court there. The perpetrator got 3 years in jail. [Jargon File] (2001-09-15) 1 1 1 1 1 time complexity The way in which the number of steps required by an algorithm varies with the size of the problem it is solving. Time complexity is normally expressed as an order of magnitude, e.g. O(N^2) means that if the size of the problem (N) doubles then the algorithm will take four times as many steps to complete. See also computational complexity, space complexity. (1996-05-08) 1 1 1 1 1 Time Complex Simulator (Tcsim) Complex arithmetic version of Tsim. Contact: ZOLA Technologies. (1996-01-18) 1 1 1 1 1 time division multiple access time division multiplexing 1 1 1 1 1 time division multiplexing (TDM) A type of multiplexing where two or more channels of information are transmitted over the same link by allocating a different time interval ("slot" or slice) for the transmission of each channel. I.e. the channels take turns to use the link. Some kind of periodic synchronising signal or distinguishing identifier is usually required so that the receiver can tell which channel is which. TDM becomes inefficient when traffic is intermittent because the time slot is still allocated even when the channel has no data to transmit. Statistical time division multiplexing was developed to overcome this problem. Compare wavelength division multiplexing, frequency division multiplexing, code division multiplexing. (2001-06-27) 1 1 1 1 1 Time Domain Reflectometer (TDR) An electronic device for detecting and locating short- or open-circuits in an Ethernet cable. TDRs can also measure how the characteristic impedance of a line varies along its length. (1995-12-28) 1 1 1 1 1 timeout A period of time after which an error condition is raised if some event has not occured. A common example is sending a message. If the receiver does not acknowledge the message within some preset timeout period, a transmission error is assumed to have occured. (1995-11-09) 1 1 1 1 1 time quantum time slice 1 1 1 1 1 time-sharing (Or "timesharing") An operating system feature allowing several users to run several tasks concurrently on one processor, or in parallel on many processors, usually providing each user with his own terminal for input and output. time-sharing is multi-user multitasking. (2009-11-23) 1 1 1 1 1 Time Sharing Option (TSO) System software from IBM that provides time-sharing on an IBM mainframe running in an MVS environment. (2003-08-15) 1 1 1 1 1 time shifting A technique used to work around problems due to the Year 2000 and the "millennium bug". Time shifting involves translating date fields in a database back by a fixed number of years to avoid year 2000 problems with the database management system. Typically dates are shifted back 28 years so that the occurrence of leap years and days of the week match with the actual year. (2003-08-15) 1 1 1 1 1 Time Simulator (Tsim) A stack-based simulation language. Contact: ZOLA Technologies. (1999-10-04) 1 1 1 1 1 time sink (By analogy with "heat sink" or "current sink") A project that consumes unbounded amounts of time. [Jargon File] (1995-02-07) 1 1 1 1 1 time slice (Or "time quantum", "quantum") The period of time for which a process is allowed to run uninterrupted in a pre-emptive multitasking operating system. The scheduler is run once every time slice to choose the next process to run. If the time slice is too short then the scheduler will consume too much processing time but if it is too long then processes may not be able to respond to external events quickly enough. (1998-11-06) 1 1 1 1 1 times-or-divided-by (By analogy with "plus-or-minus") A term occasionally used when describing the uncertainty factor associated with a estimate, for either humorous or brutally honest effect. For example, a software project usually has a scheduling uncertainty factor of at least two. [Jargon File] (2009-05-29) 1 1 1 1 1 time T /ti:m T/ An unspecified but usually well-understood time, often used in conjunction with a later time T+1. "We'll meet on campus at time T or at Louie's at time T+1" means, in the context of going out for dinner: "We can meet on campus and go to Louie's, or we can meet at Louie's itself a bit later." (Louie's was a Chinese restaurant in Palo Alto that was a favourite with hackers.) Had the number 30 been used instead of the number 1, it would have implied that the travel time from campus to Louie's is 30 minutes; whatever time T is (and that hasn't been decided on yet), you can meet half an hour later at Louie's than you could on campus and end up eating at the same time. See also since time T equals minus infinity. [Jargon File] (1994-12-12) 1 1 1 1 1 Time to Live (TTL) A field in the Internet Protocol header which indicates how many more hops this packet should be allowed to make before being discarded or returned. (1994-12-12) 1 1 1 1 1 time zone One of approximately 24 longitudinal divisions of the globe, nominally 15 degrees wide, in which clocks show the same time. Some zones follow the boundaries of states or territories, others differ from neighbouring zones by more or less than one hour. Computers can be programmed to take into account the time zone each user is working in, which is not necessarily the same as the zone the computer is in. See also TZ. (1997-07-20) 1 1 1 1 1 TINC There Is No Cabal 1 1 1 1 1 Tinman The third of the series of DoD requirements that led to Ada. Written by HOLWG, DoD, Jan 1976. See Strawman, Woodenman, Ironman, Steelman. (1976-01-01) 1 1 1 1 1 tinman+ Macro language for Apple II? Published in DDJ? 1 1 1 1 1 TINT Interpreted version of JOVIAL. [Sammet 1969, p. 528]. 1 1 1 1 1 tint hue 1 1 1 1 1 Tiny 1. A language which provides concurrency through message-passing to named message queues. 2. A tool written by Michael Wolfe <mwolfe@cse.ogi.edu> at Oregon Graduate Institute of Science & Technology for examining array data dependence algorithms and program transformations for scientific computations. Extended Tiny was used to implement the Omega test. Michael Wolfe has also made extensions to his version of tiny. (1994-12-12) 1 1 1 1 1 Tiny BASIC A dialect of BASIC developed by Dr. Wang [Wong?] in the late 1970s. Tiny BASIC was 2K bytes in size and was loaded from paper tape. It ran on almost any Intel 8080 or Zilog Z80 microprocessor for which the user could provide the necessary I/O driver software. Tiny BASIC was distributed as [the first ever?] freeware. The program listing contained the following phrases "All Wrongs reserved" and "CopyLeft", he obviously wasn't interested in money. See also Tiny Basic Interpreter Language. [More info?] (1997-09-12) 1 1 1 1 1 Tiny Basic Interpreter Language (TBIL) The inner interpreter of Tom Pittman's set of Tiny Basics in Dr Dobb's Journal. (1997-09-12) 1 1 1 1 1 Tiny Clos A core part of Common Lisp Object System (CLOS) ported to Scheme and rebuilt using a MOP (Metaobject Protocol). This should be interesting to those who want to use MOPs without using a full Common Lisp or Dylan. The first release works with MIT Scheme 11.74. (ftp://parcftp.xerox.com/pub/mops/). E-mail: Gregor Kiczales <gregor@parc.xerox.com>. Mailing list: mops (administered by <gregor@parc.xerox.com>). (1992-12-14) 1 1 1 1 1 TIP 1. Texas Instruments Pascal. 2. A Unix program for interactive communication via serial lines. Unix manual page: tip(1). 1 1 1 1 1 TIPL 1. Teach IPL. An interpretive IPL teaching system. [Sammet 1969, p. 393]. 2. A dialect of IGL. 1 1 1 1 1 tip of the ice-cube [IBM] The visible part of something small and insignificant. Used as an ironic comment in situations where "tip of the iceberg" might be appropriate if the subject were at all important. [Jargon File] 1 1 1 1 1 tired iron [IBM] Hardware that is perfectly functional but far enough behind the state of the art to have been superseded by new products, presumably with sufficient improvement in bang-per-buck that the old stuff is starting to look a bit like a dinosaur. 1 1 1 1 1 tits on a keyboard Small bumps on certain keycaps to help touch-typists find the home keys (ASDF and JKL;) without looking. They are found on the "F" and "J" of a QWERTY and the "5" of a numeric keypad. The Macintosh, perverse as usual, has, or had, them on the "D" and "K" keys. This term is based on the vernacular American expression "as useful as tits on a boar" (or boar-hog, bull, bullfrog, or many other variants), meaning "not useful". [Jargon File] (1998-02-25) 1 1 1 1 1 tj The country code for Tajikistan. (1999-01-27) 1 1 1 1 1 Tk A GUI library, generally used with TCL by John Ousterhout, but also available from within C or Perl. Tk is available for X Window System, Microsoft Windows and Macintosh. Tk looks very similar to Motif. Version 3.5. (ftp://ftp.cs.berkeley.edu/ucb/tcl/). (1995-11-09) 1 1 1 1 1 tk The country code for Tokelau. (1999-01-27) 1 1 1 1 1 TK-90X A Brazilian clone, manufactured by Micro Digital, of the British Sinclair Research ZX Spectrum 8-bit microcomputer. It differed from the standard Spectrum by adding an Interface 2-compatible joystick interface, and extra BASIC commands to aid programming and graphics-editing. Because of these differences, it was slightly incompatible with the standard Spectrum. A later model, the TK-95, which boasted an improved keyboard (similar to the Commodore 64's) and a more compatible ROM, was little more than a Timex TC2048 (another Spectrum clone) in disguise. comp.sys.sinclair FAQ (http://kendalls.demon.co.uk/cssfaq/). ["comp.sys.sinclair FAQ", D Burke M Fayzullin P Kendall et al, pub. Philip Kendall 1998] (1998-11-09) 1 1 1 1 1 TK-95 TK-90X 1 1 1 1 1 T. Kohonen A researcher at the University of Helsinki who has been studying neural networks for many years with the idea of modelling as closely as possible the behaviour of biological systems. His name is commonly associated with a particular kind of neural network in which there are only two kinds of neurons (see McCulloch-Pitts), input and others. All the input neurons are connected to all others and the others are connected only to their other nearest neighbors. The training algorithm is a relatively simple one based on the geometric layout of the neurons, and makes use of simulated annealing. (1994-10-19) 1 1 1 1 1 TK!Solver Software Arts 1983. Numerical constraint-oriented language. The TK!Solver Book, M. Konopasek et al, McGraw-Hill 1984. 1 1 1 1 1 TL0 Thread Language Zero 1 1 1 1 1 TL1 Transaction Language 1. A subset of ITU-T's MML from Bellcore, with simpler syntax. TL1 is similar to USL. It is used in communications between telephone operating systems and remote network test equipment. [OTGR, TR-TSY-000439, section 12, Bellcore]. (1994-12-14) 1 1 1 1 1 TLA three-letter acronym 1 1 1 1 1 TLAs As of 2014-08-14, this dictionary included 1285 three-letter acronyms, which is 7% of the 26^3 = 17576 possible. Here's a grep command to find them: egrep '^[A-Z][A-Z][A-Z]$' Dictionary or a GNU Emacs command: (occur "^[A-Z][A-Z][A-Z]$") Here they are: AAC, AAL, AAP, ABC, ABI, ABM, ABP, ABR, ACA, ACE, ACF, ACK, ACL, ACM, ACP, ACT, ADC, ADL, ADM, ADO, ADR, ADS, ADT, AED, AEP, AES, AFJ, AFK, AFP, AFS, AGL, AGP, AIA, AID, AIR, AIT, AIX, AKC, AKL, ALC, ALF, ALM, ALP, ALU, AMD, AMI, AML, AMO, AMP, AMS, AND, ANI, ANL, ANR, ANS, ANU, AOL, AOP, AOS, APA, APC, APE, API, APL, APM, APT, AQL, ARC, ARL, ARM, ARP, ARQ, 1 1 1 1 1 TLB Translation Look-aside Buffer 1 1 1 1 1 TLD top-level domain 1 1 1 1 1 TLI Transport Layer Interface 1 1 1 1 1 TL/I An intermediate language for Turing Machines. ["Examples of Formal Semantics", D. Knuth in Symp on Semantics of Algorithmic Languages, E. Engeler ed, LNM 188, Springer 1971, pp. 212-235]. (1994-12-02) 1 1 1 1 1 T Lisp T 1 1 1 1 1 TLS Transport Layer Security protocol 1 1 1 1 1 TM 1. Turing Machine. 2. A formal database specification language. [Jargon File] 1 1 1 1 1 tm The country code for Turkmenistan. Heavily used for vanity domains because it looks like the abbreviation for "trademark". (1999-01-27) 1 1 1 1 1 TMDL Target-Machine Description Language 1 1 1 1 1 TMG TransMoGrifier. An early language for writing recursive descent compilers. It was macroed from the IBM 1604 to the IBM 709 to the IBM 7094 to the GE-635, where it was used by McIlroy and Morris to write the EPL compiler for Multics. ["TMG - A Syntax-Directed Compiler", R.M. McClure, Proc ACM 20th Natl Conf (1965)]. [Sammet 1969, p.636]. (1994-12-02) 1 1 1 1 1 TMRC /tmerk'/ The Tech Model Railroad Club at MIT, one of the wellsprings of hacker culture. The 1959 "Dictionary of the TMRC Language" compiled by Peter Samson included several terms that became basics of the hackish vocabulary (see especially foo, mung, and frob). By 1962, TMRC's legendary layout was already a marvel of complexity (and has grown in the thirty years since; all the features described here are still present). The control system alone featured about 1200 relays. There were scram switches located at numerous places around the room that could be thwacked if something undesirable was about to occur, such as a train going full-bore at an obstruction. Another feature of the system was a digital clock on the dispatch board, which was itself something of a wonder in those bygone days before cheap LEDS and seven-segment displays. When someone hit a scram switch the clock stopped and the display was replaced with the word "FOO"; at TMRC the scram switches 1 1 1 1 1 TMRCie /tmerk'ee/, (MIT) A denizen of TMRC. 1 1 1 1 1 TMS 9900 One of the first true 16-bit microprocessors, released by Texas Instruments in June 1976 (the first are probably National Semiconductor IMP-16 or AMD-2901 bit slice processors in 16-bit configuration). It was designed as a single chip version of the TI 990 minicomputer series, much like the Intersil 6100 was a single chip PDP-8, and the Fairchild 9440 and Data General mN601 were both one chip versions of Data General's Nova. Unlike the IMS 6100, however, the TMS 9900 had a mature, well thought out design. It had a 15-bit address space and two internal 16 bit registers. One unique feature was that all user registers were actually kept in memory - this included stack pointers and the program counter. A single workspace register pointed to the 16 register set in RAM, so when a subroutine was entered or an interrupt was processed, only the single workspace register had to be changed - unlike some 1 1 1 1 1 tn The country code for Tunisia. (1999-01-27) 1 1 1 1 1 tn3270 A program, similar to telnet, used to connect to remote IBM mainframe hosts, many of which do not understand telnet. The program emulates a 3270-type terminal. For many tn3270 versions, the "clear screen" function is activated by typing Control-Z. When logged on to an IBM host and "HOLDING" or "MORE..." appears at the lower right corner of the screen, the "clear screen" function must be entered to display the next screen. tn3270 emulations usually include function key definitions. (1994-11-03) 1 1 1 1 1 TNC A threaded version of a BNC. (1996-12-21) 1 1 1 1 1 TNSTAAFL TANSTAAFL 1 1 1 1 1 TNX Thanks. Also "TNX 1.0E6" or "TNXE6" - thanks a million. (1996-05-19) 1 1 1 1 1 TNXE6 Thanks a million. "E" is used in many programming languages to separate the mantissa and exponent of a floating-point constant so a number ending in "E6" means "times ten to the power six", i.e. times a million. 1 1 1 1 1 to The country code for Tonga. Heavily used for vanity domains because it looks like the English word "to". (1999-01-27) 1 1 1 1 1 to a first approximation 1. When one is doing certain numerical computations, an approximate solution may be computed by any of several heuristic methods, then refined to a final value. By using the starting point of a first approximation of the answer, one can write an algorithm that converges more quickly to the correct result. 2. In jargon, a preface to any comment that indicates that the comment is only approximately true. The remark "To a first approximation, I feel good" might indicate that deeper questioning would reveal that not all is perfect (e.g. a nagging cough still remains after an illness). [Jargon File] 1 1 1 1 1 toast 1. Any completely inoperable system or component, especially one that has just crashed and burned: "Uh, oh ... I think the serial board is toast." 2. To cause a system to crash accidentally, especially in a manner that requires manual rebooting. "Rick just toasted the firewall machine again." Compare fried. (1995-05-01) 1 1 1 1 1 toaster 1. The archetypal really stupid application for an embedded microprocessor controller; often used in comments that imply that a scheme is inappropriate technology (but see elevator controller). "DWIM for an assembler? That'd be as silly as running Unix on your toaster!" 2. A very, very dumb computer. "You could run this program on any dumb toaster." See bitty box, Get a real computer!, toy, beige toaster. 3. A Macintosh, especially the Classic Mac. Some hold that this is implied by sense 2. 4. A peripheral device. "I bought my box without toasters, but since then I've added two boards and a second disk drive". This is not usually to be taken literally but, to show off the expansion capabilities of the Risc PC, Acorn Computers Ltd. built a seven-slice machine (which they called "the rocket-ship") and installed every imaginable peripheral. In a 1 1 1 1 1 toasternet 1. A low cost, low tech, publicly accessible local community network. This is probably an extension of the term "toaster" used to mean a small, cheap, slow computer. community networks (gopher://gopher.well.sf.ca.us/00/Community/communets/about.nets). 2. The title of some informal notes on IP addressing, ("Toasternet Part I and II"), circulated on the IETF mailing list during November 1991 and March 1992. Subsequent work was published in June 1993 in RFC 1475 and RFC 1476 and the "CATNIP" Internet-Draft by Robert L. Ullmann (1995-05-01) 1 1 1 1 1 to a zeroth approximation (From "to a first approximation") A *really* sloppy approximation; a wild guess. Compare social science number. [Jargon File] (1994-12-12) 1 1 1 1 1 toggle To change a bit from whatever state it is in to the other state; to change from 1 to 0 or from 0 to 1. This comes from toggle switches, such as standard light switches, though the word "toggle" actually refers to the mechanism that keeps the switch in the position to which it is flipped rather than to the fact that the switch has two positions. There are four things you can do to a bit: set it (force it to be 1), clear (or zero) it, leave it alone, or toggle it. [Jargon File] (1994-12-12) 1 1 1 1 1 TOK Referred to in Ursula K. LeGuin's "Always Coming Home." Seems to be similar to the original BASIC. (1994-12-12) 1 1 1 1 1 token 1. <grammar> A basic, grammatically indivisible unit of a language such as a keyword, operator or identifier. Compare: lexeme. 2. <convention> (Or "pumpkin") An abstact concept passed between cooperating agents to ensure synchronised access to a shared resource. Such a token is never duplicated or destroyed (unless the resource is) and whoever has the token has exclusive access to the resource it controls. See for example token ring. If several programmers are working on a program, one programmer will "have the token" at any time, meaning that only he can change the program whereas others can only read it. If someone else wants to modify it he must first obtain the token. (1999-02-23) 1 1 1 1 1 token bus (IEEE 802.4) A networking protocol which mediates access to a bus topology network as though it were a token ring. This eliminates the collisions found in carrier sense collision detect protocols. Nodes can be configured to pass the token in any order, not necessarily related to their physical ordering on the bus. The token is sent from one node to its successor in the logical ring by broadcast on the bus and is ignored by the other nodes. (1996-12-13) 1 1 1 1 1 token ring A computer local area network arbitration scheme in which conflicts in the transmission of messages are avoided by the granting of "tokens" which give permission to send. A station keeps the token while transmitting a message, if it has a message to transmit, and then passes it on to the next station. Often, "Token Ring" is used to refer to the IEEE 802.5 token ring standard, which is the most common type of token ring. Usenet newsgroup: news:comp.dcom.lans.token-ring. 1 1 1 1 1 TomeRaider A cross-platform reference and e-book reader program and file format. TomeRaider files are highly compressed and cross-referenced. The reader displays the text and can follow the hypertext links embedded in the text. TomeRaider Home (http://www.tomeraider.com/). (2008-02-15) 1 1 1 1 1 Tom Knight A noted hacker at MIT. (http://ai.mit.edu/people/tk/tk.html). (1996-12-12) 1 1 1 1 1 tone brightness 1 1 1 1 1 Tony Hoare Anthony Hoare 1 1 1 1 1 tool 1. <tool> A program used primarily to create, manipulate, modify, or analyse other programs, such as a compiler or an editor or a cross-referencing program. Opposite: app, operating system. 2. A Unix application program with a simple, "transparent" (typically text-stream) interface designed specifically to be used in programmed combination with other tools (see filter, plumbing). 3. <jargon> (MIT: general to students there) To work; to study (connotes tedium). The TMRC Dictionary defined this as "to set one's brain to the grindstone". See hack. 4. <jargon, person> (MIT) A student who studies too much and hacks too little. MIT's student humour magazine rejoices in the name "Tool and Die". [Jargon File] (1996-12-12) 1 1 1 1 1 toolbar A common graphical user interface component, consisting of a permanently visible row of button icons that, when clicked with the mouse, cause the program to perform some action such as printing the current document or changing the mode of operation. The toolbar buttons often invoke functions accessible via menus but they are easier to use since they are permanently visible. A typical use would be in a paint program where the toolbar allows the users to select one of the various painting "tools" - brush, pencil, bucket etc. Some application programs under some operating systems may allow the user to customise the functions accessible via toolbars; in others, the choice is fixed by the programmer. (2003-10-24) 1 1 1 1 1 toolbook A Microsoft Windows utility to make easy-to-use applications with a graphical user interface. E.g. a guided tour of some software. (1995-03-14) 1 1 1 1 1 Toolbuilder Tool Builder Kit 1 1 1 1 1 Tool Builder Kit (TBK) A product from IPSYS which allows users to develop CASE tools appropriate to any software engineering methodology. (1996-05-08) 1 1 1 1 1 Tool Command Language /tik*l/ (Tcl) An interpreted string processing language for issuing commands to interactive programs, developed by John Ousterhout at UCB. Each application program can extend tcl with its own set of commands. Tcl is like a text-oriented Lisp, but lets you write algebraic expressions for simplicity and to avoid scaring people away. Though originally designed to be a "scripting language" rather than for serious programming, Tcl has been used successfully for programs with hundreds of thousands of lines. It has a peculiar but simple syntax. It may be used as an embedded interpreter in application programs. It has exceptions and packages (called libraries), name-spaces for procedures and variables, and provide/require. It supports dynamic loading of object code. It is eight-bit clean. It has only three variable types: strings, lists and associative arrays but no structures. 1 1 1 1 1 TOOLS Technology of Object-Oriented Languages and Systems 1 1 1 1 1 toolsmith The software equivalent of a tool-and-die specialist; one who specialises in making the tools with which other programmers create applications. Many hackers consider this more fun than applications per se; to understand why, see uninteresting. Jon Bentley, in the "Bumper-Sticker Computer Science" chapter of his book "More Programming Pearls", quotes Dick Sites from DEC as saying "I'd rather write programs to write programs than write programs". [Jargon File] 1 1 1 1 1 TOP Technical/Office Protocol 1 1 1 1 1 top-down design (Or "stepwise refinement"). The software design technique which aims to describe functionality at a very high level, then partition it repeatedly into more detailed levels one level at a time until the detail is sufficient to allow coding. This approach to software design probably originated at IBM, and grew out of structured programming practices. (1996-08-04) 1 1 1 1 1 Top-Down Model A method for estimating the overall cost and effort of the proposed software project from global properties of the project. The total cost and schedule is partitioned into components for planning purposes. (1996-05-29) 1 1 1 1 1 topic drift Term used on GEnie, Usenet and other electronic fora to describe the tendency of a thread to drift away from the original subject of discussion (and thus, from the Subject header of the originating message). Often used in gentle reminders that the discussion has strayed off any useful track. "I think we started with a question about Niven's last book, but we've ended up discussing the sexual habits of the common marmoset. Now *that's* topic drift!" [Jargon File] (1996-05-29) 1 1 1 1 1 topic group forum 1 1 1 1 1 topic map A collection of "topics", their relationships, and information sources. A topic map captures the subjects of which information sources speak, and the relationships between them, in a way that is implementation independent. A topic is a symbol within the computer that represents something in the world such as the play Hamlet, the playwright William Shakespeare, or the "authorship" relationship. Topics can have names. They can also have occurrences, that is, information resources that are considered to be relevant in some way to their subject. Topics can play roles in relationships. Thus, topics have three kinds of characteristics: names, sources, and roles played in relationships. The assignment of such characteristics is considered to be valid within a certain scope, or context. Topic maps can be merged. Merging can take place at the discretion of the user or application (at runtime), or may be 1 1 1 1 1 topic thread (From Usenet, GEnie, CompuServe) A more or less continuous chain of postings on a single subject, sent to a forum such as a Usenet newsgroup. To "follow a thread" is to read a series of postings sharing a common subject. On Usenet these are connected by "Reference" headers. The better newsreaders can present news in thread order automatically. (2008-02-06) 1 1 1 1 1 top-level domain The last and most significant component of an Internet fully qualified domain name, the part after the last ".". For example, host wombat.doc.ic.ac.uk is in top-level domain "uk" (for United Kingdom). Every other country has its own top-level domain, including .us for the U.S.A. Within the .us domain, there are subdomains for the fifty states, each generally with a name identical to the state's postal abbreviation. These are rarely used however. Within the .uk domain, there is a .ac.uk subdomain for academic sites and a .co.uk domain for commercial ones. Other top-level domains may be divided up in similar ways. In the US and some other countries, the following top-level domains are used much more widely than the country code: .com - commercial bodies 1 1 1 1 1 topology 1. <mathematics> The branch of mathematics dealing with continuous transformations. 2. <networking> Which hosts are directly connected to which other hosts in a network. Network layer processes need to consider the current network topology to be able to route packets to their final destination reliably and efficiently. (2001-03-29) 1 1 1 1 1 TOPS-10 /tops-ten/ DEC's proprietary OS for the fabled PDP-10 machines, long a favourite of hackers but now effectively extinct. A fountain of hacker folklore. See also ITS, TOPS-20, TWENEX, VMS, operating system. TOPS-10 was sometimes called BOTS-10 (from "bottoms-ten") as a comment on the inappropriateness of describing it as the top of anything. [Jargon File] 1 1 1 1 1 TOPS-20 TWENEX 1 1 1 1 1 Tornado The software development environment previously distributed with VxWorks. (1996-11-29) 1 1 1 1 1 Toronto Euclid The standard dialect of Euclid, as compared to Ottawa Euclid. (1996-11-29) 1 1 1 1 1 torrent BitTorrent 1 1 1 1 1 TORTOS Terminal Oriented Real Time Operating System 1 1 1 1 1 TOS /toss/ 1. IBM's Tape Operating System. 2. The operating system of the Atari ST range of computers. This range included the 512ST, 1040ST and the F, FM and E variations (e.g.1040STE). Later, 32-bit machines (TT, Falcon030 and MegaSTE) were developed using a new version of TOS, called MultiTOS which was based on MinT. TOS went through several revisions starting initially as a derivative of CP/M, but developing into a remarkably complete and flexible operating system. Features include: a flat memory model, MS-DOS-compatible disk format and support for MIDI and SCSI (in later versions). TOS was designed to run Atari's version of the GEM GUI. There is some argument as to what TOS stands for, the main candidates being "Tramiel Operating System" (named after Atari's head at the time) or simply "The Operating System". 3. <networking> Terms Of Service. 1 1 1 1 1 Toshiba Corporation A Japanese technology manufacturer with 364 subsidiaries worldwide. Toshiba makes and sells electronics for home, office, industry and health care including information and communication systems, electronic components, heavy electrical apparatus, consumer products and medical diagnostic imaging equipment. In FY 2003-4, Toshiba employed 161,286 people. Toshiba Home (http://toshiba.co.jp/). (2005-01-19) 1 1 1 1 1 TOSS Terminal Oriented Social Science 1 1 1 1 1 total function A function which is defined for all arguments of the appropriate type. The opposite is a partial function. (1997-01-10) 1 1 1 1 1 totally ordered Having a total ordering. (1997-01-10) 1 1 1 1 1 totally ordered set A set with a total ordering. 1 1 1 1 1 total ordering A relation R on a set A which is a partial ordering; i.e. it is reflexive (xRx), transitive (xRyRz => xRz) and antisymmetric (xRyRx => x=y) and for any two elements x and y in A, either x R y or y R x. See also equivalence relation, well-ordered. (1995-02-16) 1 1 1 1 1 toto /toh-toh'/ The default scratch file name among French-speaking programmers; the French equivalent of foo. toto may be followed by the phonetic mutations "titi", "tata", and "tutu". [Jargon File] (1995-04-18) 1 1 1 1 1 touchpad (Or "trackpad") A stationary pointing device used mainly on laptop computers. Touchpads provide a small, flat surface that you slide your finger over using the same movements as you would a mouse. They were originally developed to provide a more natural and intuitive connection for the computer user than the mouse. Touchpads use a principle called coupling capacitance, and requires a conductive pointer such as a finger. They contain a two-layer grid of electrodes which are connected to an integrated circuit (IC) mounted under the pad. The upper layer contains vertical electrode strips while the lower layer is composed of horizontal electrode strips. Capacitance from each of the horizontal electrodes to each of the vertical electrodes is measured by the IC. A finger near the intersection of two electrodes modifies the capacitance between them, since a finger has very different dielectric properties than air. The position of the finger is precisely 1 1 1 1 1 touch screen An input device that allows user to interact with computer by touching the display screen. Often this uses beams of infrared light that are projected across the screen surface. Interrupting the beams generates an electronic signal identifying the location of the screen. Software interprets the signal and performs the required operation. (1995-04-13) 1 1 1 1 1 tourist A guest on the system, especially one who generally logs in over a network from a remote location for comm mode, electronic mail, games and other trivial purposes. A tourist is one step below a luser. Hackers often spell this turist, perhaps by some sort of tenuous analogy with luser (this also expresses the ITS culture's penchant for six-letterisms). Compare twink, read-only user. [Jargon File] (1995-03-10) 1 1 1 1 1 tourist information Information in an on-line display that is not immediately useful, but contributes to a viewer's gestalt of what's going on with the software or hardware behind it. Whether a given piece of info falls in this category depends partly on what the user is looking for at any given time. The "bytes free" information at the bottom of an MS-DOS "dir" display is tourist information; so (most of the time) is the TIME information in a Unix "ps(1)" display. [Jargon File] 1 1 1 1 1 Towers of Hanoi A classic computer science problem, invented by Edouard Lucas in 1883, often used as an example of recursion. "In the great temple at Benares, says he, beneath the dome which marks the centre of the world, rests a brass plate in which are fixed three diamond needles, each a cubit high and as thick as the body of a bee. On one of these needles, at the creation, God placed sixty-four discs of pure gold, the largest disc resting on the brass plate, and the others getting smaller and smaller up to the top one. This is the Tower of Bramah. Day and night unceasingly the priests transfer the discs from one diamond needle to another according to the fixed and immutable laws of Bramah, which require that the priest on duty must not move more than one disc at a time and that he must place this disc on a needle so that there is no smaller disc below it. When the sixty-four discs shall have been thus transferred from the needle on which at the creation God placed them to one of the other needles, tower, temple, and Brahmins alike will crumble into dust, and with a thunderclap the world will vanish." The recursive solution is: Solve for n-1 discs recursively, then move the remaining largest disc to the free needle. Note that there is also a non-recursive solution: On odd-numbered moves, move the smallest sized disk clockwise. On even-numbered moves, make the single other move which is possible. ["Mathematical Recreations and Essays", W W R Ball, p. 304] The rec.puzzles Archive (http://rec-puzzles.org/sol.pl/induction/hanoi). (2003-07-13) 1 1 1 1 1 Tower Technology Corporation A company, established in 1992 by the merger of two OOT companies, with the intention of supplying high performance Eiffel compilation systems. Tower provides development tools, reusable class libraries, and services supporting large scale system development. (http://cm.cf.ac.uk/Tower/). E-mail: <tower@twr.com> (orders and inquiries), <outlook@twr.com> (The Eiffel Outlook Journal). Telephone: +1 (512) 452 9455 (8:30 to 5:30 CST business days). Fax: +1 (512) 452 1721. Sales +1 (800) 285-5124 (Free, USA and Canada only). Address: Tower Technology, 1501 W. Koenig Lane, Austin, TX 78756, USA. (1994-12-12) 1 1 1 1 1 toy A computer system; always used with qualifiers. 1. "nice toy": One that supports the speaker's hacking style adequately. 2. "just a toy": A machine that yields insufficient computrons for the speaker's preferred uses. This is not condemnatory, as is bitty box; toys can at least be fun. It is also strongly conditioned by one's expectations; Cray XMP users sometimes consider the Cray-1 a "toy", and certainly all RISC boxes and mainframes are toys by their standards. See also Get a real computer!. [Jargon File] 1 1 1 1 1 Toy/Ada A compiler for a subset of Ada, written in SML/NJ by Amit Bhatiani at Rose-Hulman University. (ftp://master.cs.rose-hulman.edu/pub/). (1992-04-08) 1 1 1 1 1 toy language A language useful for instructional purposes or as a proof-of-concept for some aspect of computer-science theory, but inadequate for general-purpose programming. Bad Things can result when a toy language is promoted as a general purpose solution for programming (see bondage-and-discipline language); the classic example is Pascal. Several moderately well-known formalisms for conceptual tasks such as programming Turing Machines also qualify as toy languages in a less negative sense. See also MFTL. [Jargon File] (1995-05-09) 1 1 1 1 1 Toyohashi University Parallel Lisp Environment (TUPLE) A parallel Lisp based on KCL. ["Memory Management and Garbage Collection of an Extended Common Lisp System for Massively Parallel SIMD Architecture", Taiichi Yuasa, in Memory Management, IWMM92, Springer 1992, 490-507]. (1994-11-08) 1 1 1 1 1 toy problem [AI] A deliberately oversimplified case of a challenging problem used to investigate, prototype, or test algorithms for a real problem. Sometimes used pejoratively. See also gedanken, toy program. [Jargon File] 1 1 1 1 1 toy program 1. A trivial program that can be readily comprehended. 2. A program for which the effort of initial coding dominates the costs through its life cycle. See also noddy. (1996-05-19) 1 1 1 1 1 tp The country code for East Timor. (1999-01-27) 1 1 1 1 1 TPA Transient Program Area 1 1 1 1 1 TPF Transaction Processing Facility 1 1 1 1 1 TP/IX An Internet protocol, described in RFC 1475, which changes TCP and UDP headers to give a 64-bit IP address, a 32-bit port number, and a 64 bit sequence number. (1995-04-03) 1 1 1 1 1 TPL 1. Table Producing Language. "The Bureau of Labor Statistics Table Producing Language (TPL)", R.C. Mendelssohn, Proc ACM Annual Conf (1974). 2. Fleming Nielson. A concurrent functional language. 3. Terminal Programming Language. Texas Inst, late 70's. Used on the TI-990/1 Small Business Computer and the TI-771 Intelligent Terminal. 1 1 1 1 1 TPO twisted pair only 1 1 1 1 1 TPS Tree Pruning System. "An Adaptive Tree Pruning System: A Language for Programming Heuristic Tree Searches", E.W. Kozdrowicki, Proc ACM 23rd Natl Conf 1968. 1 1 1 1 1 tptc A Turbo Pascal to Turbo C translator. Comes with full source. (ftp://wuarchive.wustl.edu/mirrors/msdos/turbopas/tptc17*.zip). 1 1 1 1 1 TPU Text Processing Utility 1 1 1 1 1 TPX Terminal Productivity eXecutive 1 1 1 1 1 tr The country code for Turkey. (1999-01-27) 1 1 1 1 1 TRAC Text Reckoning And Compiling 1 1 1 1 1 traceroute A TCP/IP utility, originally Unix, which allows the user to determine the route packets are taking to a particular host. Traceroute works by increasing the time to live value of packets and seeing how far they get, until they reach the given destination; thus, a lengthening trail of hosts passed through is built up. (2007-02-02) 1 1 1 1 1 trace scheduling A method of controlling and coordinating the operation of multiple hardware elements of a Very Long Instruction Word processor. It was developed by Josh Fisher at the now-defunct Multiflow Computer Corporation [Details?] (1995-03-01) 1 1 1 1 1 track The part of a disk which passes under one read/write head while the head is stationary. The number of tracks on a disk surface therefore corresponds to the number of different radial positions of the head(s). The collection of all tracks on all surfaces at a given radial position is known a cylinder and each track is divided into sectors. (1997-07-15) 1 1 1 1 1 track ball tracker ball 1 1 1 1 1 tracker ball A pointing device consisting of a ball housed in a socket containing sensors to detect rotation of the ball about two axes - like an upside-down mouse. The user rolls the ball with his thumb or the palm of his hand to move a cursor. Tracker balls are common on CAD workstations for ease of use and on modern portable computers, where there may be no desk space on which to use a mouse. Some clip onto the side of the keyboard and have integral buttons which have the same function as mouse buttons. (1996-08-04) 1 1 1 1 1 tracking The horizontal spacing between characters in a line of text. Tracking is set when a font is designed but can often be altered in order to change the appearance of the text or for special effects. It applies to both proportional fonts and monospaced fonts. Tracking should not be confused with kerning which deals with the spacing between certain pairs of characters in a proportional font. See also leading. (2013-12-05) 1 1 1 1 1 tracking cookie An HTTP cookie used to identify a user of a website in order to log which pages they visit. The site owner can use this information to optimise the site, e.g. for marketing purposes. (2013-12-05) 1 1 1 1 1 tracking file tracking cookie 1 1 1 1 1 trackpad touchpad 1 1 1 1 1 TrackPoint (Or "pointing stick", "nipple") A small knob found in the middle of some keyboards that works like a very short isometric joystick. Pressing it toward or away from you or from side to side moves the pointer on the screen. Ted Selker brought the concept of an in-keyboard pointing device to IBM in September 1987. TrackPoint was introduced in 1992 on the IBM ThinkPad and later on some desktops. It takes up virtually no extra room on the box or the work area and also requires minimal movement of the hands from the keyboard. Many imitations of highly variable quality appeared. Pointing sticks have also been used in many other notebook brands, including TI, HP, Compac, Dell, Toshiba (e.g. Portege 4000's "AccuPoint II"), and AST (e.g. Ascentia 910N). TrackPoint and "Trackpoint" are IBM trademarks. (http://research.ibm.com/mathsci/cmc/trackpoint.htm). 1 1 1 1 1 tractor feed sprocket feed 1 1 1 1 1 TrafoLa A functional programming language designed in the PROSPECTRA ESPRIT project to support declarative specification of program transformations. It provides higher-order pattern matching on expression trees with backtracking. [Heckmann88]. (1996-06-07) 1 1 1 1 1 Trafola-H A specification language for program transformations. Functional, statically typed, polymorphic, with extended constructs for pattern-matching. "Trafola-H Reference Manual", R. Heckmann et al, U Saarlandes, Saarbrucken 1991. 1 1 1 1 1 trampoline An incredibly hairy technique, found in some HLL and program-overlay implementations (e.g. on the Macintosh), that involves on-the-fly generation of small executable (and, likely as not, self-modifying) code objects to do indirection between code sections. These pieces of live data are called trampolines. Trampolines are notoriously difficult to understand in action; in fact, it is said by those who use this term that the trampoline that doesn't bend your brain is not the true trampoline. See also snap. [Jargon File] (2003-03-26) 1 1 1 1 1 TRANDIR TRANslation DIRector. A language for syntax-directed compiling. Sammet 1969, p.640. 1 1 1 1 1 TRANQUIL 1966. ALGOL-like language with sets and other extensions, for the Illiac IV. "TRANQUIL: A Language for an Array Processing Computer", N.E. Abel et al, Proc SJCC 34 (1969). 1 1 1 1 1 TRANS TRAffic Network Simulation Language. "A Model for Traffic Simulation and a Simulation Language for the General Transportation Problem", Proc FJCC 37 (1970). 1 1 1 1 1 transaction A unit of interaction with a DBMS or similar system. It must be treated in a coherent and reliable way independent of other transactions. See atomic. 1 1 1 1 1 Transaction Application Language (TAL) Not "Tandem Application Language". A block-structured, procedural language optimised for use on Tandem hardware. TAL is a cross between C and Pascal and is the primary system programming language on Tandem computers. Tandem has no assembler and originally had no C or Pascal. [Was TAL derived from HP's System Programming Language?] (2001-07-09) 1 1 1 1 1 Transaction Processing Facility (TPF) A real-time mainframe operating system released by IBM around 1976. TPF is particularly suited to organisations dealing in very high I/O message switching and large global networks. Current users include British Airways (reservations), VISA International (authorisations), Holiday Inn, and Quantas. TPF was traditionally a 370/Assembler environment although the latest, release 4.1, contains C. Formerly known as ACP (Airline Control Program), it was renamed "TPF" to suggests its greater scope. It is common for TPF sites to use IBM's MVS and VM operating systems for off-line processing. (1996-08-27) 1 1 1 1 1 transceiver Transmitter-receiver, any device that performs both functions. For example, on an Ethernet network, a transceiver is the hardware that connects a host interface (e.g. an Ethernet controller) to a local area network. Ethernet transceivers contain electronics that apply signals to the cable and sense other host's signals and collisions. See also CSMA/CD. (2008-08-04) 1 1 1 1 1 TRANSCODE An early system on the Ferut computer. [Listed in CACM 2(5):16, May 1959]. (2008-08-04) 1 1 1 1 1 transducer 1. A device for converting sound, temperature, pressure, light or other signals to or from an electronic signal. 2. Finite State Machine. (1995-02-15) 1 1 1 1 1 transfer 1. <data> data transfer. 2. <programming> transfer of control. 3. <messaging> The movement of electronic mail between servers by a Message Transfer Agent. 1 1 1 1 1 transfer none introspection annotation 1 1 1 1 1 transfer of control To cause execution of a program to continue from a different address instead of proceding sequentially to the next instruction. This may happen as a result of a jump instruction or some kind of interrupt. This term is more common when discussing machine code, the high-level language equivalent is a goto statement. (2009-06-09) 1 1 1 1 1 transfer rate data transfer rate 1 1 1 1 1 transfer syntax The actual representation of data as it is transmitted over a network (as opposed to abstract syntax). (1998-05-19) 1 1 1 1 1 transfinite induction Induction over some (typically large) ordinal. (1995-03-30) 1 1 1 1 1 transformation program transformation 1 1 1 1 1 transient 1. <electronics> A sudden, brief increase in current or voltage in a circuit that can damage sensitive components and instruments. (2003-06-12) 2. <software> A software object with a short and limited lifetime which is not saved for later reuse. (1998-04-19) 1 1 1 1 1 Transient Program Area (TPA) The region of memory CP/M set aside for user programs. (2001-11-01) 1 1 1 1 1 transistor A three terminal semiconductor amplifying device, the fundamental component of most active electronic circuits, including digital electronics. The transistor was invented on 1947-12-23 at Bell Labs. There are two kinds, the bipolar transistor (also called the junction transistor), and the field effect transistor (FET). Transistors and other components are interconnected to make complex integrated circuits such as logic gates, microprocessors and memory. (1995-10-05) 1 1 1 1 1 Transistor-Transistor Logic (TTL) A common semiconductor technology for building discrete digital logic integrated circuits. It originated from Texas Instruments in 1965. There have been several series of TTL logic: 7400: 10 ns propagation time, 10 mW/gate power consumption, obsolete; 74L00: Low power: higher resistances, less dissipation (1 mW), longer propagation time (30 ns); 74H00: High power: lower resistances, more dissipation: less sensitivity for noise; 74S00: Schottky-clamped: faster switching (3 ns, 19 mW) by 1 1 1 1 1 TRANSIT A subsystem of ICES. [Sammet 1969, p.616]. (2003-07-12) 1 1 1 1 1 transition ad interstitial 1 1 1 1 1 transitive A relation R is transitive if x R y & y R z => x R z. Equivalence relations, pre-, partial and total orders are all transitive. 1 1 1 1 1 transitive closure The transitive closure R* of a relation R is defined by x R y => x R* y x R y and y R* z => x R* z I.e. elements are related by R* if they are related by R directly or through some sequence of intermediate related elements. E.g. in graph theory, if R is the relation on nodes "has an edge leading to" then the transitive closure of R is the relation "has a path of zero or more edges to". See also Reflexive transitive closure. 1 1 1 1 1 transit network A network which passes traffic between other networks in addition to carrying traffic for its own hosts. It must have paths to at least two other networks. See also backbone, stub. (1995-01-30) 1 1 1 1 1 Translation Look-aside Buffer (TLB) A table used in a virtual memory system, that lists the physical address page number associated with each virtual address page number. A TLB is used in conjunction with a cache whose tags are based on virtual addresses. The virtual address is presented simultaneously to the TLB and to the cache so that cache access and the virtual-to-physical address translation can proceed in parallel (the translation is done "on the side"). If the requested address is not cached then the physical address is used to locate the data in main memory. The alternative would be to place the translation table between the cache and main memory so that it will only be activated once there was a cache miss. (1995-01-30) 1 1 1 1 1 Transmission Control Protocol (TCP) The most common transport layer protocol used on Ethernet and the Internet. It was developed by DARPA. TCP is the connection-oriented protocol built on top of Internet Protocol (IP) and is nearly always seen in the combination TCP/IP (TCP over IP). It adds reliable communication and flow-control and provides full-duplex, process-to-process connections. TCP is defined in STD 7 and RFC 793. User Datagram Protocol is the other, connectionless, protocol that runs on top of IP. (2001-06-14) 1 1 1 1 1 transparent 1. <jargon> Not visible, hidden; said of a system which functions in a manner not evident to the user. For example, the Domain Name System transparently resolves a fully qualified domain name into an IP address without the user being aware of it. Compare this to what Donald Norman (http://atg.apple.com/Norman/) calls "invisibility", which he illustrates from the user's point of view: "You use computers when you use many modern automobiles, microwave ovens, games, CD players and calculators. You don't notice the computer because you think of yourself as doing the task, not as using the computer. [""The Design of Everyday" Things", New York, Doubleday, 1989, p. 185]. 2. <theory> Fully defined, known, predictable; said of a sub-system in which matters generally subject to volition or stochastic state change have been chosen, measured, or determined by the environment. Thus for transparent systems, output is a known function of the inputs, and users can both predict the behaviour and depend upon it. (1996-06-04) 1 1 1 1 1 transparent audio coding A lossy audio compression algorithm is transparent if the original and decoded signal are indistinguishable to the human ear. The bit rate depends on the codec and the audio material. Some codecs (e.g. AAC, MP3) are optimized for transparent coding at a low data rate, others (e.g. VQF, MP3Pro, AAC+SBR, WMA) for distinguisable but pleasant reproduction at lower bit rates. Typical data rates in kbps for different codecs are: MP1 288-320 MP2 224-256 MP3 160-224 MPEG-2 AAC 128-160 MPEG-4 AAC 112-144 MPEGplus 160-200 (2001-12-23) 1 1 1 1 1 Transport Driver Interface (TDI) Developed by SUN, IBM, and Microsoft (and others?), the TDI is a software interface between the protocols and application programing interface layers of the Windows NT network model. (1997-11-05) 1 1 1 1 1 transport layer (Or "host-host layer") The middle layer in the OSI seven layer model. The transport layer determines how to use the network layer to provide a virtual error-free, point to point connection so that host A can send messages to host B and they will arrive un-corrupted and in the correct order. It establishes and dissolves connections between hosts. It is used by the session layer. An example transport layer protocol is Transmission Control Protocol (TCP). OSI documents: ITU Rec. X.214 (ISO 8072), ITU Rec. X.224 (ISO 8073). (1997-12-07) 1 1 1 1 1 Transport Layer Interface (TLI, or "Transport Level Interface") A protocol-independent interface for accessing network facilities, modelled after the ISO transport layer (level 4), that first appeared in Unix SVR3. TLI is defined by SVID as transport mechanism for networking interfaces, in preference to sockets, which are biased toward IP and friends. A disavantage is that a process cannot use read/write directly, but has to use backends using stdin and stdout to communicate with the network connection. TLI is implemented in SVR4 using the STREAMS interface. It adds no new system calls, just a library, libnsl_s.a. The major functions are t_open, t_bind, t_connect, t_listen, t_accept, t_snd, t_rcv, read, write. According to the Solaris t_open man page, XTI (X/OPEN Transport Interface) evolved from TLI, and supports the TLI API for compatibility, with some variations on semantics. (1999-06-10) 1 1 1 1 1 Transport Layer Security protocol (TLS) A protocol designed to allow client/server applications to communicate over the Internet without eavesdropping, tampering, or message forgery. TLS is defined in RFC 2246. (2003-10-03) 1 1 1 1 1 Transport Level Interface Transport Layer Interface 1 1 1 1 1 Transport Service Access Point (TSAP) Part of the OSI IP Presentation Addressing schema. A TSAP identifes the service access point between the session layer and the transport layer. (1999-08-01) 1 1 1 1 1 transputer (Note lower case) A family of microprocessors from Inmos with interprocessor links, programmable in occam. [More details?] (1994-11-18) 1 1 1 1 1 TRANS-USE An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 1 1 1 1 1 trap 1. A program interrupt, usually an interrupt caused by some exceptional situation in the user program. In most cases, the OS performs some action, then returns control to the program. 2. To cause a trap. "These instructions trap to the monitor." Also used transitively to indicate the cause of the trap. The monitor traps all input/output instructions. This term is associated with assembler programming ("interrupt" or "exception" is more common among HLL programmers) and appears to be fading into history among programmers as the role of assembler continues to shrink. However, it is still important to computer architects and systems hackers (see system, sense 1), who use it to distinguish deterministically repeatable exceptions from timing-dependent ones (such as I/O interrupts). [Jargon File] 1 1 1 1 1 trap door Or "trapdoor" 1. back door. 2. trap-door function 1 1 1 1 1 trap-door function A special class of one-way function, which is reversible if you know a certain secret associated with the function. (http://rsasecurity.com/rsalabs/faq/2-3-2.html). (http://ieor.berkeley.edu/~jshu/knapsack/Review/OverviewPK.html). (2003-05-22) 1 1 1 1 1 trash To destroy, e.g. the contents of a data structure. The most common of the family of near-synonyms including mung, mangle, and scribble. [Jargon File] (1994-11-03) 1 1 1 1 1 Trash-80 Derogatory name for Tandy's TRS-80. (1994-11-03) 1 1 1 1 1 traveling salesman problem US spelling of travelling salesman problem. (1996-12-13) 1 1 1 1 1 travelling salesman travelling salesman problem 1 1 1 1 1 travelling salesman problem (TSP or "shortest path", US: traveling) Given a set of towns and the distances between them, determine the shortest path starting from a given town, passing through all the other towns and returning to the first town. This is a famous problem with a variety of solutions of varying complexity and efficiency. The simplest solution (the brute force approach) generates all possible routes and takes the shortest. This becomes impractical as the number of towns, N, increases since the number of possible routes is !(N-1). A more intelligent algorithm (similar to iterative deepening) considers the shortest path to each town which can be reached in one hop, then two hops, and so on until all towns have been visited. At each stage the algorithm maintains a "frontier" of reachable towns along with the shortest route to each. It then expands this frontier by one hop each time. 1 1 1 1 1 traversal Processing nodes in a graph one at a time, usually in some specified order. Traversal of a tree is recursively defined to mean visiting the root node and traversing its children. Visiting a node usually involves transforming it in some way or collecting data from it. In "pre-order traversal", a node is visited __before__ its children. In "post-order" traversal, a node is visited __after__ its children. The more rarely used "in-order" traversal is generally applicable only to binary trees, and is where you visit first a node's left child, then the node itself, and then its right child. For the binary tree: T / \ I S / \ D E 1 1 1 1 1 traverse traversal 1 1 1 1 1 trawl To sift through large volumes of data (e.g. Usenet postings, FTP archives, or the Jargon File) looking for something of interest. [Jargon File] 1 1 1 1 1 tree A directed acyclic graph; i.e. a graph wherein there is only one route between any pair of nodes, and there is a notion of "toward top of the tree" (i.e. the root node), and its opposite direction, toward the leaves. A tree with n nodes has n-1 edges. Although maybe not part of the widest definition of a tree, a common constraint is that no node can have more than one parent. Moreover, for some applications, it is necessary to consider a node's daughter nodes to be an ordered list, instead of merely a set. As a data structure in computer programs, trees are used in everything from B-trees in databases and file systems, to game trees in game theory, to syntax trees in a human or computer languages. (1998-11-12) 1 1 1 1 1 tree-killer (Sun) 1. A printer. 2. A person who wastes paper. This epithet should be interpreted in a broad sense; "wasting paper" includes the production of spiffy but content-free documents. Thus, most suits are tree-killers. This term may derive from J.R.R. Tolkien's "Lord of the Rings" (http://sf.www.lysator.liu.se/sf_archive/sf-texts/SF_resource_guide/sfrgft.htm). in which Treebeard the Ent uses it to refer to the orcs' master, Saruman of Isengard. Saruman represents, among other things, technology at its most misguided. See also: dead tree. [Jargon File] (1999-11-03) 1 1 1 1 1 TREET E.C. Haines, 1964. An experimental variant of LISP1.5, implemented on the STRETCH computer. Basic structure was a trinary tree. ["The TREET Time-Sharing System", H.A. Bayard et al, Proc 2nd Symp Symb and Alg Manip, ACM (Mar 1971)]. [Sammet 1969, pp.457-461]. 1 1 1 1 1 TREETRAN A Fortran IV subroutine package for tree manipulation. 1 1 1 1 1 Tree Transformation Language (TXL) A hybrid functional language and rule-based language developed by J.R. Cordy <cordy@cs.queensu.ca> et al of Queen's University, Canada in 1988. TXL is suitable for performing source to source analysis and transformation and for rapid prototyping of new languages and language processors. It uses structural transformation based on term rewriting. TXL has been particularly successful in software engineering tasks such as design recovery, refactoring, and reengineering. Most recently it has been applied to artificial intelligence tasks such as recognition of hand-written mathematics, and to transformation of structured documents in XML. TXL takes as input an arbitrary context-free grammar in extended BNF-like notation, and a set of show-by-example transformation rules to be applied to inputs parsed using the grammar. TXL supports the notion of agile parsing, the 1 1 1 1 1 treeware /tree'weir/ Printouts, books, documentation, and other information media made from pulped dead trees by a tree-killer. [Jargon File] (1999-01-15) 1 1 1 1 1 Trellis 1. An object-oriented language from the University of Karlsruhe(?) with static type-checking and encapsulation. 2. An object-oriented application development system from DEC, based on the Trellis language. (Formerly named Owl). E-mail: Jerry Smith <smith@pipe.enet.dec.com> ["Persistent and Shared Objects in trellis/owl", P. O'Brien et al, Proc 1986 IEEE Workshop on Object-Oriented Database Systems, IEEE, NY 1986]. 1 1 1 1 1 Trellis Code Modulation (TCM) A modulation technique with hardware error detection and correction. [Details?] (1995-02-22) 1 1 1 1 1 Trident A video card manufacturer. [More info?] (1997-07-16) 1 1 1 1 1 trigger An action causing the automatic invocation of a procedure, for instance to preserve referential integrity. A triggers goes into effect when a user attempts to modify data with an insert, delete, or update command. A trigger can instruct the system to take any number of actions when a specified change is attempted. By preventing incorrect, unauthorized, or inconsistent changes to data, triggers help maintain the integrity of the database. [Sybase SQL Server Release 10.0 Transact-SQL User's Guide]. (1995-02-22) 1 1 1 1 1 trigger finger overuse strain injury 1 1 1 1 1 TRIGMAN A system for symbolic mathematics, especially celestial mechanics. (1994-12-14) 1 1 1 1 1 trillion In Britain, France, and Germany, 10^18 or a million cubed. In the USA and Canada, 10^12. [Elsewhere?] (1996-10-03) 1 1 1 1 1 Trilogy A strongly typed logic programming language with numerical constraint-solving over the natural numbers, developed by Paul Voda <voda@voda.ii.fmph.uniba.sk> at UBC in 1988. Trilogy is syntactically a blend of Prolog, Lisp, and Pascal. It contains three types of clauses: predicates (backtracking but no assignable variables), procedures (if-then-else but no backtracking; assignable variables), and subroutines (like procedures, but with input and system calls; callable only from top level or from other subroutines). Development of Trilogy I stopped in 1991. Trilogy II, developed by Paul Voda 1988-92, was a declarative general purpose programming language, used for teaching and to write CL. (http://fmph.uniba.sk/~voda). ["The Constraint Language Trilogy: Semantics and Computations", P. Voda, Complete Logic Systems, 741 Blueridge 1 1 1 1 1 triple DES A product cipher which, like DES, operates on 64-bit data blocks. There are several forms, each of which uses the DES cipher 3 times. Some forms use two 56-bit keys, some use three. The DES "modes of operation" may also be used with triple-DES. (1995-05-11) 1 1 1 1 1 tri state A feature of some digital electronic devices which allows a connector (pin) to either act as a normal output, driving a signal onto a line, or to be "tri stated" - set to a high-impedance ("high Z") condition. This allows other outputs to drive signals onto the line. Often the same connector also functions as an input when its output circuitry is tri stated. Tri-state outputs are typically used for the connection of several digital circuits to a shared bus onto which any one of them may output data for the others to input. (1996-07-26) 1 1 1 1 1 trit /trit/ (By analogy with "bit") One base-3 digit; the amount of information conveyed by a selection among one of three equally likely outcomes. Trits arise, for example, in the context of a flag that should actually be able to assume *three* values - such as yes, no, or unknown. Trits are sometimes jokingly called "3-state bits". A trit may be semi-seriously referred to as "a bit and a half", although it is linearly equivalent to 1.5849625 bits (that is, log2(3) bits). [Jargon File] (1995-05-11) 1 1 1 1 1 Triton Intel's Pentium core logic chip set. In addition to the traditional features, this chip set supports: EDO DRAM to increase the bandwidth of the DRAM interface; "pipelined burst SRAM" for a cheaper, faster second level cache; "bus master IDE" control logic to reduce processor load; a plug and play port for easy implementation of functions such as audio. The Triton I chipset (official name 82430FX) consists of 4 chips: one 82437FX TSC (Triton Sysetm Controller), two 82438FX TDP (Triton Data Path), and one 82371FB PIIX (PCI IDE Xcellerator). It supports PB Cache, EDO DRAM, and a maximum PCI and memory burst data transfer rate of 100 megabytes per second. There are also Moble Triton (82430MX), Triton II (82430HX), and the Triton VX (82430VX) chip sets. Introduction (http://asus.com.tw/Products/TB/triton-intro.html). 1 1 1 1 1 Triton II (Official name 82430HX) A version of Intel's Triton processor chip set with all the features of the Triton I plus support for ECC, parity RAM, two-way SMP, USB, and Concurrent PCI to improve speed. It consists of one 82439HX TXC and one 82371SB PIIX3. (1996-04-03) 1 1 1 1 1 Triton VX (Official name 82430VX) A version of Intel's Triton processor chip set with all the features of the Triton I plus support for SDRAM, USB, and a UMA option. Triton VX consists of one 82437VX TVC, two 82438VX TVP, and one 82371SB PIIX3. (1996-04-03) 1 1 1 1 1 Trivial File Transfer Protocol (TFTP) A simple file transfer protocol used for down-loading boot code to diskless workstations. TFTP is defined in RFC 1350. [Details? Other uses? Relationship to FTP?] (1997-08-30) 1 1 1 1 1 TRO tail recursion optimisation 1 1 1 1 1 troff /T'rof/ or /trof/ The grey eminence of Unix text processing; a formatting and phototypesetting program, written originally in PDP-11 assembly code and then in barely-structured early C by the late Joseph Ossanna, modelled after the earlier ROFF which was in turn modelled after Multics' RUNOFF by Jerome Saltzer (*that* name came from the expression "to run off a copy"). A companion program, nroff, formats output for terminals and line printers. In 1979, Brian Kernighan modified troff so that it could drive phototypesetters other than the Graphic Systems CAT. His paper describing that work ("A Typesetter-independent troff", AT&T CSTR #97) explains troff's durability. After discussing the program's "obvious deficiencies - a rebarbative input syntax, mysterious and undocumented properties in some areas, and a voracious appetite for computer resources" and noting the ugliness and extreme hairiness of the code and internals, 1 1 1 1 1 troglodyte (Commodore) 1. A hacker who never leaves his cubicle. The term "Gnoll" (from Dungeons & Dragons) is also reported. 2. A curmudgeon attached to an obsolescent computing environment. The combination "ITS troglodyte" was flung around some during the Usenet and e-mail wringle-wrangle attending the 2.x.x revision of the Jargon File; at least one of the people it was intended to describe adopted it with pride. [Jargon File] (1995-01-11) 1 1 1 1 1 troglodyte mode (Rice University) Programming with the lights turned off, sunglasses on, and the terminal inverted (black on white) because you've been up for so many days straight that your eyes hurt (see raster burn). Loud music blaring from a stereo stacked in the corner is optional but recommended. See larval stage, hack mode. [Jargon File] (1995-03-21) 1 1 1 1 1 trojan Trojan horse 1 1 1 1 1 Trojan horse (Or just "trojan") A term coined by MIT-hacker-turned-NSA-spook Dan Edwards for a malicious, security-breaking program that is disguised as something benign, such as a directory lister, archiver, game or (in one notorious 1990 case on the Mac) a program to find and destroy viruses! A Trojan horse is similar to a back door. See also RFC 1135, worm, phage, mockingbird. [Jargon File] (2008-06-19) 1 1 1 1 1 TROLL An array language for continuous simulation, econometric modelling or statistical analysis. ["TROLL Reference Manual", D0062, Info Proc Services, MIT (1973-76)]. 1 1 1 1 1 troll An electronic mail message, Usenet posting or other (electronic) communication which is intentionally incorrect, but not overtly controversial (compare flame bait), or the act of sending such a message. Trolling aims to elicit an emotional reaction from those with a hair-trigger on the reply key. A really subtle troll makes some people lose their minds. (1994-10-17) 1 1 1 1 1 TRON 1. <project> The Real-Time Operating System Nucleus. 2. <language, programming, testing, tool> (TRace ON) A command used when debugging programs written in early line-numbered BASIC that contained GOTO and GOSUB statements. When the TRON command had been executed, the program ran with a window open indicating the line number being executed at that instant. The TROFF (an abbreviation for "TRace OFF") command turned the tracing off. (2003-02-02) 1 1 1 1 1 tron (NRL, CMU, probably from the film "Tron") To become inaccessible except via electronic mail or talk especially when one is normally available via telephone or in person. Compare spod. [Jargon File] (1994-11-03) 1 1 1 1 1 Trouble Came Back (TCB) An IBM term for an intermittent or difficult-to-reproduce problem that has failed to respond to neglect or shotgun debugging. Compare heisenbug. (1998-07-02) 1 1 1 1 1 TRS term rewriting system 1 1 1 1 1 TRS-80 A series of personal computers sold by Tandy Radio Shack. The '80' refers to the use of Zilog Z-80 processor (NOT Intel 80x8x). There were 7.5 computers in the TRS-80 line: Models I, II, III, 4, 100, 102, 200. The Model 4P was a portable version of the Model 4 with no tape drive -- only 2 1/2-height single sided disk drives. Later models that Radio Shack produced were not TRS-80 machines -- they were based on the Intel 80x8x architecture. These included Tandy 1000, Tandy 2000, Tandy 3000, and others. The 1000 had a proprietary Color card. The 2000 was a powerful machine for its time, but was based on the Intel 80186, so when IBM didn't build a computer based on this chip, it failed. It was used to design a boat for the America's Cup. The TRS-80 GUI, DeskMate, was proprietary, but no more than Windoze at the time. 1 1 1 1 1 Truchet point An obsolete variant of the point, equal to 0.188 mm. (2002-03-11) 1 1 1 1 1 True BASIC A compiled BASIC, by John Kemeny and Thomas E. Kurtz, requiring no line numbers. (1996-03-24) 1 1 1 1 1 true colour A system where the red, green, and blue components of a colour are stored in display memory, as opposed to storing logical colours and using a colour palette to convert them to red, green, blue components. The advantage of true colour over a palette is that it does not restrict the range of colours which can be displayed on screen simultaneously. For example, if eight bits are used to store each component of each pixel then a total of 2^24 (about 17 million) different colours can be displayed at once which would require a (very expensive) palette with 3 * 2^24 bytes (about 50 megabytes) of memory. The disadvantage of true colour is that image transformations which would normally be done by changing the palette must be done to every pixel of the image which can be much slower. Compare high colour. (1996-03-24) 1 1 1 1 1 true hacker (By analogy with "trufan" from SF fandom) One who exemplifies the primary values of hacker culture, especially competence and helpfulness to other hackers. A high compliment. "He spent 6 hours helping me bring up UUCP and netnews on my FOOBAR 4000 last week - manifestly the act of a true-hacker". Compare demigod, opposite: munchkin. [Jargon File] (1996-01-07) 1 1 1 1 1 TRUENAME An undocumented DOS command to find the UNC name of a file or directory on a network drive. (2003-10-21) 1 1 1 1 1 TrueType An outline font standard first developed by Apple Computer, and later embraced by Microsoft, as a competitor to Adobe Systems, Inc.'s PostScript which is still more popular. (1995-03-16) 1 1 1 1 1 Trumpet A news reader for Microsoft Windows, using the WinSock library. There is also an MS-DOS version. Trumpet is shareware from Australia. (ftp://ftp.utas.edu.au/pc/trumpet). (ftp://ftp.demon.co.uk/pub/ibmpc/winsock/stacks/trumpwsk/). news:alt.winsock.trumpet. [Author?] (1995-01-12) 1 1 1 1 1 TRUSIX TRUSted Unix operating system 1 1 1 1 1 truth table A table listing all possible combinations of inputs and the corresponding output of a Boolean function such as AND, OR, NOT, IMPLIES, XOR, NAND, NOR. Truth tables can be used as a means of representing a function or as an aid in designing a circuit to implement it. (1998-07-30) 1 1 1 1 1 TS Typed Smalltalk. A Smalltalk by Ralph Johnson <johnson@speedy.cs.uiuc.edu> of the University of Illinois. ["TS: An Optimising Compiler for Smalltalk", R.E. Johnson et al, SIGPLAN Notices 23(11) (Nov 1988)]. (1995-01-12) 1 1 1 1 1 TSAP Transport Service Access Point 1 1 1 1 1 TSEE Technical and Engineering Environment: part of the RTEE toolset. 1 1 1 1 1 TSIA Title Says It All. Something to put in the body of a electronic mail message or bulletin board posting when no body is really necessary because the title or subject header contains the whole message. (2000-02-10) 1 1 1 1 1 Tsim Time Simulator 1 1 1 1 1 TSL-1 Task Sequencing Language. Language for specifying sequences of tasking events in Ada programs. ["Task Sequencing Language for Specifying Distributed Ada Systems", D.C. Luckham et al in PARLE: Parallel Architectures and Langs Europe, LNCS 259, Springer 1987, pp.444-463]. 1 1 1 1 1 TSO Time Sharing Option 1 1 1 1 1 TSP travelling salesman problem 1 1 1 1 1 TSR Terminate and Stay Resident 1 1 1 1 1 TSV tab-separated values 1 1 1 1 1 tt The country code for Trinidad and Tobago. (1999-01-27) 1 1 1 1 1 TTD Telecommunications Device for the Deaf 1 1 1 1 1 TTFN ta-ta for now - goodbye for now. Used in the UK, USA and probably elsewhere. (1998-07-02) 1 1 1 1 1 TTL 1. transistor-transistor logic. 2. Time to Live. 1 1 1 1 1 TTS Text To Speech 1 1 1 1 1 tty /tit'ee/ (ITS pronunciation, but some Unix people say it this way as well; this pronunciation is not considered to have sexual undertones), /T T Y/ 1. teletypewriter. 2. (Especially Unix) Any terminal at all; sometimes used to refer to the particular terminal controlling a given job (it is also the name of a Unix command which outputs the name of the current controlling terminal). 3. (Unix) Any serial port, whether or not the device connected to it is a terminal; so called because under Unix such devices have names of the form tty*. Ambiguity between senses 2 and 3 is common but seldom bothersome. 4. A TDD. [Jargon File] (1995-11-23) 1 1 1 1 1 TTYL talk to you later. (1998-01-18) 1 1 1 1 1 TUB Technische Universita't Berlin. (Berlin technical university). 1 1 1 1 1 TUBA An Internet protocol, described in RFC 1347, RFC 1526 and RFC 1561, and based on the OSI Connectionless Network Protocol (CNLP). TUBA is one of the proposals for Internet Protocol Version 6. (1995-04-03) 1 1 1 1 1 tube 1. <hardware> A CRT terminal. Never used in the mainstream sense of TV; real hackers don't watch TV, except for Loony Toons, Rocky & Bullwinkle, Trek Classic, the Simpsons, and the occasional cheesy old swashbuckler movie. 2. <electronics> electron tube. 3. <jargon> (IBM) To send a copy of something to someone else's terminal. "Tube me that note." [Jargon File] (1996-02-05) 1 1 1 1 1 tube time Time spent at a terminal or console. More inclusive than hacking time; commonly used in discussions of what parts of one's environment one uses most heavily. "I find I'm spending too much of my tube time reading mail since I started this revision." [Jargon File] 1 1 1 1 1 Tuckals An old statistical package still in use on some VM computers. (1995-11-28) 1 1 1 1 1 TUI 1. Textual User Interface. 2. Terminal User Interface. Alternative name for Textual User Interface. 3. <communications> Telephony User Interface. 4. Tangible User Interface. 5. Tactile User Interface. 6. Telescope User Interface. (2003-10-17) 1 1 1 1 1 Tukey, John John Tukey 1 1 1 1 1 Tuki An intermediate code for functional languages. "Another Implementation Technique for Applicative Languages", H. Glaser et al, ESOP86, LNCS 213, Springer 1986. 1 1 1 1 1 tunafish In hackish lore, refers to the mutated punchline of an age-old joke to be found at the bottom of the manual pages of "tunefs(8)" in the original 4.2BSD distribution. The joke was removed in later releases once commercial sites started using 4.2. Tunefs relates to the tuning of file-system parameters for optimum performance, and at the bottom of a few pages of wizardly inscriptions was a "BUGS" section consisting of the line "You can tune a file system, but you can't tunafish". Variants of this can be seen in other BSD versions, though it has been excised from some versions by humourless management droids. The [nt]roff source for SunOS 4.1.1 contains a comment apparently designed to prevent this: "Take this out and a Unix Demon will dog your steps from now until the "time_t's wrap around." [Jargon File] (1997-01-12) 1 1 1 1 1 tune (From musical, possibly via automotive, usage) To optimise a program or system for a particular environment, especially by adjusting numerical parameters designed as hooks for tuning, e.g. by changing "#define" lines in C. One may "tune for time" (fastest execution), "tune for space" (least memory use), or "tune for configuration" (most efficient use of hardware). See bum, hot spot, hand-hacking. [Jargon File] (1999-06-05) 1 1 1 1 1 tunneling spelling US spelling of tunnelling. 1 1 1 1 1 tunnelling (US: "tunneling") A networking technique used to carry data encoded in one protocol, A, over a channel using another protocol, B. Protocol A is said to be "encapsulated" in protocol B and treats B as though it were a data link layer. Tunnelling is used to get data between administrative domains which use a protocol that is not supported by the internet connecting those domains. A historical example would be transmitting written text via Morse code - instead of having someone carry the text on paper, it is converted to (or encapsulated as) Morse code at one end and converted back to written text at the other. A more recent example would be tunnelling IPv6 over an IPv4 network that does not support IPv6 natively. Tunnelling techniques such as 6to4 or 6rd are used to encapsulate IPv6 in the absence of native dual-stack support. (2013-10-07) 1 1 1 1 1 Tunny Emulator A special-purpose computer designed at Bletchley Park (UK) based upon the reverse engineering of the Lorenz Cypher. The Lorenz Cypher was used by the German army to encrypt high command orders for transmission via teleprinter (the Enigma was a field-use cypher). Once the key to a message was discovered (by the computer Colossus) the Tunny machine would be set to decrypt the message. The process took about four days from intercept to printout. The original Tunny machine was built about 1943 and scrapped after the war. In 2011 a working model was re-built at Bletchley Park where it is on display. (2012-03-25) 1 1 1 1 1 TUPLE Toyohashi University Parallel Lisp Environment 1 1 1 1 1 tuple In functional languages, a data object containing two or more components. Also known as a product type or pair, triple, quad, etc. Tuples of different sizes have different types, in contrast to lists where the type is independent of the length. The components of a tuple may be of different types whereas all elements of a list have the same type. Examples of tuples (in Haskell notation) are: (1,2), ("Tuple",True), (w,(x,y),z). The degenerate tuple type with zero components, written (), is known as the unit type since it has only one possible value which is also written (). The implementation of tuples in a language may be either lifted or not. If tuples are lifted then (bottom, bottom) /= bottom (where bottom represents non-termination) and the evaluation of a tuple may fail to terminate. E.g. in Haskell: f (x, y) = 1 --> f bottom = bottom 1 1 1 1 1 tuple calculus A form of relational calculus in which a variable's only permitted values are tuples of a given relation. Codd's unimplemented language ALPHA and the subsequent QUEL are examples of the tuple calculus. (1998-10-05) 1 1 1 1 1 Tuple Space Smalltalk ["Using Tuple Space Communication in Distributed Object-Oriented Languages", S. Matsuoka et al, SIGPLAN Notices 23(11):276-284 (Nov 1988)]. (1994-11-08) 1 1 1 1 1 tupling A program transformation where several results are returned from a single traversal of a data structure. E.g. mean l = sum l / length l ==> mean l = s/n where (s,n) = sumLen l sumLen [] = (0,0) 1 1 1 1 1 Turbo C Borland's C compiler for IBM PCs. Turbo C, version 1.0, was introduced by Borland in 1987. It offered the first integrated edit-compile-run development environment for C on IBM PCs. It ran in 384KB of memory. It allowed inline assembly, supported all memory models, and offered optimisations for speed, size, constant folding, and jump elimination. Version 1.5 shipped on five 360 KB diskettes of uncompressed files, and came with sample C programs, including a stripped down spreadsheet called mcalc. Turbo C 2.0 has a debugger, a fast assembler, and an extensive graphics library. Turbo C has been largely supplanted by Turbo C++, introduced circa September, 1990 for both MS-DOS and Microsoft Windows. ["Compiling the facts on C", Richard Hale Shaw, PC Magazine, September 13, 1988, pages 115-183]. 1 1 1 1 1 Turbo C++ Borland's first C/C++ integerated development environment, including a compler, a linker, a high-level debugger, a code editor and other tools. Turbo C++ conformed to AT&T's C++ 2.0 language specification. The development environment and command line tools originally ran under MS-DOS. A 1992 version ran on Windows 3.1. Version 1 came in two forms: Turbo C++ and Turbo C++ Professional. The latter included Turbo Assembler, Turbo Debugger and Turbo Profile. It superceded the C-only Turbo C and was itself superceded by C++ Builder. (http://community.borland.com/article/0,1410,21751,00.html) (2008-01-21) 1 1 1 1 1 Turbo Debugger A source-level debugger designed for use with Borland and other compilers. (http://borland.com/). (1999-04-23) 1 1 1 1 1 turbo nerd computer geek 1 1 1 1 1 Turbo Pascal Borland International's Pascal. Perhaps the first integrated development environment for MS-DOS. Versions 1.0-3.0: standard Pascal with a few extensions Versions 4.0 (1987) and 5.0: separate compilation. Version 5.5: object-oriented. Version 6.0: Turbo Vision OOP library. (http://borland.com/Product/ProdInfo.html). tptc translates Turbo Pascal to Turbo C. (1995-05-01) 1 1 1 1 1 Turbo Prolog A strongly typed Prolog-like logic programming language. 1986. It has user-defined domains. Programs are arranged in sections: DOMAINS, CLAUSES, PREDICATES, DATABASE and GOAL. It is currently known as PDC Prolog and is distributed by Prolog Development Center, Atlanta +1 404 873 1366. E-mail: <pdc@mcimail.com>. 1 1 1 1 1 Turing 1. Alan Turing. 2. R.C. Holt <holt@csri.toronto.edu> & J.R. Cordy <cordy@cs.queensu.ca>, U Toronto, 1982. Descendant of Concurrent Euclid, an airtight super-Pascal. Used mainly for teaching programming at both high school and university level. Available from Holt Software Assocs, Toronto. Versions for Sun, MS-DOS, Mac, etc. E-mail: <distrib@turing.toronto.edu>. ["Turing Language Report", R.C. Holt & J.R. Cordy, Report CSRI-153, CSRI, U Toronto, Dec 1983]. ["The Turing Programming Language", R.C. Holt & J.R. Cordy, CACM 31(12) (Dec 1988)]. 1 1 1 1 1 Turing Machine A hypothetical machine defined in 1935-6 by Alan Turing and used for computability theory proofs. It consists of an infinitely long "tape" with symbols (chosen from some finite set) written at regular intervals. A pointer marks the current position and the machine is in one of a finite set of "internal states". At each step the machine reads the symbol at the current position on the tape. For each combination of current state and symbol read, a program specifies the new state and either a symbol to write to the tape or a direction to move the pointer (left or right) or to halt. In an alternative scheme, the machine writes a symbol to the tape *and* moves at each step. This can be encoded as a write state followed by a move state for the write-or-move machine. If the write-and-move machine is also given a distance to move then it can emulate an write-or-move program by using states with a distance of zero. A further variation is whether 1 1 1 1 1 Turingol A high-level language for programming Turing Machines by Donald Knuth. It was the subject of the first construction of a nontrivial attribute grammar. ["Semantics of Context-Free Languages", D. Knuth, Math Sys Thy 2:127-145 (1975)]. (1995-10-08) 1 1 1 1 1 Turing Plus Systems programming language, a concurrent descendant of Turing. ["The Turing Plus Report", R.C. Holt & J.R. Cordy, CSRI, U Toronto, Feb 1987]. Available from Holt Software Assocs, Toronto <distrib@hsa.on.ca>. 1 1 1 1 1 Turing tar-pit A place where anything is possible but nothing of interest is practical. Alan M. Turing helped lay the foundations of computer science by showing that all machines and languages capable of expressing a certain very primitive set of operations are logically equivalent in the kinds of computations they can carry out, and in principle have capabilities that differ only in speed from those of the most powerful and elegantly designed computers. However, no machine or language exactly matching Turing's primitive set has ever been built (other than possibly as a classroom exercise), because it would be horribly slow and far too painful to use. A "Turing tar-pit" is any computer language or other tool that shares this property. That is, it's theoretically universal but in practice, the harder you struggle to get any real work done, the deeper its inadequacies suck you in. Compare bondage-and-discipline language. 1 1 1 1 1 Turing test A criterion proposed by Alan Turing in 1950 for deciding whether a computer is intelligent. Turing called it "the Imitation Game" and offered it as a replacement for the question, "Can machines think?" A human holds a written conversation on any topic with an unseen correspondent (nowadays it might be by electronic mail or chat). If the human believes he is talking to another human when he is really talking to a computer then the computer has passed the Turing test and is deemed to be intelligent. Turing predicted that within 50 years (by the year 2000) technological progress would produce computing machines with a capacity of 10**9 bits, and that with such machinery, a computer program would be able to fool the average questioner for 5 minutes about 70% of the time. The Loebner Prize is a competition to find a computer 1 1 1 1 1 turist /too'rist/ Variant spelling of tourist. Possibly influenced by luser and "Turing". [Jargon File] 1 1 1 1 1 TURN An SMTP command with which a client asks the server to open an SMTP connection to the client, thus reversing their roles. Superseded by ETRN. (1997-11-21) 1 1 1 1 1 turn-key A term which describes a complete system (hardware and software) which can be used for a specific application without requiring further programming or software installation. The user can just "turn the key" (switch it on) and use it. Compare end-to-end solution. (2006-03-30) 1 1 1 1 1 turtle graphics The line drawings produced by programs in LOGO. (2003-05-04) 1 1 1 1 1 TUTOR A Scripting language on PLATO systems from CDC. ["The TUTOR Language", Bruce Sherwood, Control Data, 1977]. 1 1 1 1 1 Tuxedo Cross-platform distributed transaction monitor middleware marketed by BEA systems. Tuxedo supports the production of scalable client-server applications and the coordination of transactions spanning heterogeneous databases, operating systems, and hardware. BEA Home (http://beasys.com/). [Connection with Novell, Inc.?] (2003-01-08) 1 1 1 1 1 TV television 1 1 1 1 1 tv The country code for Tuvalu. Heavily used for vanity domains by TV stations. (1999-01-27) 1 1 1 1 1 tw The country code for Taiwan. (1999-01-27) 1 1 1 1 1 TWAIN An image capture API for Microsoft Windows and Apple Macintosh operating systems that enables the user to control a scanner or digital camera from image processing software. TWAIN was first released on 1992-02-29 and is currently ratified at version 2.0 as of 2005-11-28. It is maintained by the TWAIN Working Group. Kevin Bier, chairman-emeritus of the TWAIN Working Group and the one of the original co-author/editors of TWAIN 1.0, chose the name TWAIN after reading letters by Mark Twain. It was unofficially considered to mean "toolkit without an important name." The word "twain" is an archaic form meaning "two". It appears in Kipling's "The Ballad of East and West" - "...and never the twain shall meet...", reflecting the difficulty, at the time, of connecting scanners and personal computers. It was up-cased to TWAIN to make it more distinctive. This led 1 1 1 1 1 tweak 1. To change slightly, usually in reference to a value. Also used synonymously with twiddle. If a program is almost correct, rather than figure out the precise problem you might just keep tweaking it until it works. See frobnicate and fudge factor; also see shotgun debugging. 2. To tune or bum a program; preferred usage in the UK. [Jargon File] 1 1 1 1 1 tweening An interpolation technique where an animation program generates extra frames between the key frames that the user has created. This gives smoother animation without the user having to draw every frame. A scene is described by a mathematical model - a set of two- or three-dimensional objects whose positions in are given by sets of coordinates. Tweening uses mathematical formulae to generate these coordinates at a sequence of discrete times. The simplest system would move each point at a constant rate in a straight line between its initial and final positions, though other kinds of path are possible. The coordinates at each time step are used to generate (or "render") a two-dimensional image of the scene which forms one "frame" of the animation. Tweening is similar to morphing except that morphing is usually performed by interpolating between corresponding points marked by the user on two images, rather than between 1 1 1 1 1 tweeter woofer 1 1 1 1 1 TWENEX /twe'neks/ The TOPS-20 operating system by DEC - the second proprietary OS for the PDP-10 - preferred by most PDP-10 hackers over TOPS-10 (that is, by those who were not ITS or WAITS partisans). TOPS-20 began in 1969 as Bolt, Beranek & Newman's TENEX operating system using special paging hardware. By the early 1970s, almost all of the systems on the ARPANET ran TENEX. DEC purchased the rights to TENEX from BBN and began work to make it their own. The first in-house code name for the operating system was VIROS (VIRtual memory Operating System); when customers started asking questions, the name was changed to SNARK so DEC could truthfully deny that there was any project called VIROS. When the name SNARK became known, the name was briefly reversed to become KRANS; this was quickly abandoned when someone objected that "krans" meant "funeral wreath" in Swedish (though some Swedish speakers have since said it means simply "wreath"; this part of the story may be apocryphal). 1 1 1 1 1 Twente Compiler Generator System (TCGS) A compiler generator developed at the University of Twente, The Netherlands. (1998-04-27) 1 1 1 1 1 Twentel A functional language. ["The TWENTEL System (Version 1).", H. Kroeze, CS Dept TR, U Twente, 1986]. 1 1 1 1 1 twiddle 1. <character> The tilde character. 2. <jargon> (To make) a small or insignificant change. E.g. twiddling a program often fixes one bug and generates several new ones (see also shotgun debugging). Bits are often twiddled. Twiddling a switch or knob implies much less sense of purpose than toggling or tweaking it; see frobnicate. Bit twiddling connotes aimlessness, and at best doesn't specify what you're doing to the bit; to toggle a bit has a more specific meaning. [Jargon File] (1995-01-31) 1 1 1 1 1 TWIG Tree-Walking Instruction Generator. A code generator language. ML-Twig is an SML/NJ variant. ["Twig Language Manual", S.W.K. Tijang, CS TR 120, Bell Labs, 1986]. (1995-01-31) 1 1 1 1 1 twilight zone [IRC] Notionally, the area of cyberspace where IRC operators live. An op is said to have a "connection to the twilight zone". [Jargon File] 1 1 1 1 1 twink /twink/ [UCSC] Equivalent to read-only user. Also reported on the Usenet group soc.motss; may derive from gay slang for a cute young thing with nothing upstairs (compare mainstream chick). 1 1 1 1 1 twinning Keeping a mirror of a magnetic tape. (1997-07-18) 1 1 1 1 1 Twin Vector Quantization (VQF) Part of the MPEG-4 standard dealing with time domain weighted interleaved vector quantization. [Why "VQF"?] (2001-12-17) 1 1 1 1 1 twip (TWentIeth of a Point) 1/20 of a Postscript point, or 1/1440th of an inch. There are thus 1440 twips to an inch or about 567 twips to a centimeter. Twips are used in Microsoft formats and products, notably Rich Text Format, Visual BASIC, Visual C++, and printer drivers; and in IBM AFP products. Twips were devised in the olden days to describe the sizes of characters produced by dot matrix printers that were constrained to multiples of either 12 or 10 dots per inch. [Is it definitely relative to a __Postscript__ point, as opposed to one of the other definitions of point?] (2002-03-11) 1 1 1 1 1 twirling baton The overstrike sequence -/|\-/|\- which produces an animated twirling baton. If you output it with a single backspace between characters, the baton spins in place. If you output the sequence BS SP between characters, the baton spins from left to right. If you output BS SP BS BS between characters, the batton spins from right to left. The twirling baton was a popular component of animated signature files on the pioneering PLATO educational time-sharing system. The "archie" Internet service is perhaps the best-known baton program today; it uses the twirling baton as an idler indicating that the program is working on a query. [Jargon File] (1995-02-23) 1 1 1 1 1 twisted pair A type of cable in which pairs of conductors are twisted together to randomise possible cross-talk from nearby wiring. Inadequate twisting is detectable using modern cable testing instruments. (1995-02-23) 1 1 1 1 1 twisted pair only (TPO) A network connection to an Ethernet PCMCIA card using twisted pair cable. [Other options?] (1997-05-12) 1 1 1 1 1 Twitter A free Internet service for posting short messages, known as "tweets", via a central server, which are then sent to all users who have chosen to follow you or to a specific user. A variety of client programs are available in addition to the website. Launched in about 2008. Twitter home (http://twitter.com/). (2009-06-10) 1 1 1 1 1 twm Tab Window Manager. A window manager for the X Window System. Twm provides titlebars, shaped windows, several forms of icon management, user-defined macro functions, click-to-type and pointer-driven keyboard focus, and user-specified key and pointer button bindings. It can be extensively configured by a startup file. Twm was written by Tom LaStrange, Solbourne Computer; Jim Fulton, MIT X Consortium; Steve Pitschke, Stardent Computer; Keith Packard, MIT X Consortium; Dave Sternlicht, MIT X Consortium; Dave Payne, Apple Computer. An extended version, vtwm, provides a virtual desktop. [Why "Tab"?] (1995-02-14) 1 1 1 1 1 two-binary, one-quaternary (2B1Q) A physical layer encoding used for Integrated Services Digital Network basic rate interface. 2B1Q represents two bits (2B - a "dibit") using one of four signal levels (1Q - a "quadratude"). The first bit of the dibit is indicated by polarity: positive indicates a binary 1 and negative indicates a 0. The second half of the dibit is indicated by voltage magnitude: 1 Volt indicates a binary 1 and 3 Volts indicates binary 0. (2003-01-10) 1 1 1 1 1 twonkie /twon'kee/ The software equivalent of a Twinkie (a variety of sugar-loaded junk food, or (in gay slang) the male equivalent of "chick"); a useless "feature" added to look sexy and placate a marketroid. Compare Saturday-night special. The term may also be related to "The Twonky", title menace of a classic SF short story by Lewis Padgett (Henry Kuttner and C. L. Moore), first published in the September 1942 Astounding Science Fiction and subsequently much anthologised. [Jargon File] (1994-10-20) 1 1 1 1 1 two-phase commit A technique for maintaining integrity in distributed databases. Where a system uses two or more database, a transaction among the distibuted database should be atomic ("all or nothing"). This is done by handling the transaction in two phases. First the databases prepare the transaction, confirm that it is possible to process it, and lock the relevant record. Once all the required databases confirm that the transaction is viable, the system instructs them all to commit it - i.e. to make it permanent. If it is not possible to process it, the system will instruct the databases to rollback (undo) the transaction. (2000-02-28) 1 1 1 1 1 twos complement A system used in some computers to represent negative numbers in binary. Each bit of the number is inverted (zeros are replaced with ones and vice versa), as for ones complement, but then one (000...0001) is added (ignoring overflow). This avoids the two representations for zero found in ones complement by using all ones to represent -1. ... 000...00011 = +3 000...00010 = +2 000...00001 = +1 000...00000 = 0 1 1 1 1 1 two-to-the-N An amount much larger than N but smaller than infinity. I have 2-to-the-N things to do before I can go out for lunch means you probably won't show up. Numbers of the form two-to-the-N are very important in computing because they represent the value of bit N of a binary number (counting from 0) and the number of things you can count with an N bit number. [Jargon File] (1994-12-06) 1 1 1 1 1 two-valued logic (Commonly known as "Boolean algebra") A mathematical system concerning the two truth values, TRUE and FALSE and the functions AND, OR, NOT. Two-valued logic is one of the cornerstones of logic and is also fundamental in the design of digital electronics and programming languages. The term "Boolean" is used here with its common meaning - two-valued, though strictly Boolean algebra is more general than this. Boolean functions are usually represented by truth tables where "0" represents "false" and "1" represents "true". E.g.: A | B | A AND B --+---+-------- 0 | 0 | 0 1 1 1 1 1 TX-0 The first transistorised computer, the direct ancestor of the PDP-1 built at MIT's Lincoln Lab in 1957. (1994-12-06) 1 1 1 1 1 TXL Tree Transformation Language 1 1 1 1 1 TYMCOM-X Tymshare's operating system which ran for many years on Tymshare's PDP-10s. It was a descendent of TOPS-10 but had many of the important features of TOPS-20 such as real paging and controllable/spawnable processes. TYMCOM-X, one of the best kept secrets in the PDP-10 folklore, was written by Bill Weiher, Vance Socci <vsocci@vcctech.com>, Allen Ginzburg, Karen Kolling, Art Atkinson, Gary Morgenthaler (founder of the company that produced IDRIS), Todd Corenson and Murray Bowles. Some copies still run today. Most TYMNET development was done under TYMCOM-X and Tymshare sold a TYMCOM-X system to TRW to use in their credit reporting network, which was based on a purchased copy of TYMNET circa 1979. [E-mail from Vance Socci 1994-05-20]. (1995-11-09) 1 1 1 1 1 TYMNET A United States-wide commercial computer network, created by Tymshare, Inc. some time before 1970, and used for remote login and file transfer. The network public went live in November 1971. In its original implementation, it consisted of fairly simple circuit-oriented nodes, whose circuits were created by central network supervisors writing into the appropriate nodes' "permuter tables". The supervisors also performed login validations as well as circuit management. Circuits were character oriented and the network was oriented toward interactive character-by-character full-duplex communications circuits. The network had more than one supervisor running, but only one was active, the others being put to sleep with "sleeping pill" messages. If the active supervisor went down, all the others would wake up and battle for control of the network. After the battle, the supervisor with the highest pre-set priority 1 1 1 1 1 Tymshare, Inc. The US company that created the TYMNET network. (1999-03-17) 1 1 1 1 1 type (Or "data type") A set of values from which a variable, constant, function, or other expression may take its value. A type is a classification of data that tells the compiler or interpreter how the programmer intends to use it. For example, the process and result of adding two variables differs greatly according to whether they are integers, floating point numbers, or strings. Types supported by most programming languages include integers (usually limited to some range so they will fit in one word of storage), Booleans, floating point numbers, and characters. Strings are also common, and are represented as lists of characters in some languages. If s and t are types, then so is s -> t, the type of functions from s to t; that is, give them a term of type s, functions of type s -> t will return a term of type t. Some types are primitive - built-in to the language, with no visible internal structure - e.g. Boolean; others are 1 1 1 1 1 type-ahead The facility where the user can type more characters before the system has fully responded to those already typed. Type-ahead is common on most current systems. It allows the user to type without worrying that the computer may miss input because it is temporarily busy, e.g. reformating a page, checking spelling, or simply suffering from network latency. There is usually some limit to the amount of input the system can buffer, beyond which it __will__ lose input. [Equivalent term for speech recognition?] (2003-06-15) 1 1 1 1 1 type-ahead search incremental search 1 1 1 1 1 type assignment A mapping of the free variables of some expression E to types. This is used in type inference to deduce the type of E and its subexpressions. (2002-02-22) 1 1 1 1 1 type class A set of types for which certain operations or methods are defined. E.g. the class Number might have methods for addition and subtraction. Classes are a feature of object oriented languages and of the functional programming language Haskell. See also inheritance. 1 1 1 1 1 typed lambda-calculus (TLC) A variety of lambda-calculus in which every term is labelled with a type. A function application (A B) is only synctactically valid if A has type s --> t, where the type of B is s (or an instance or s in a polymorphic language) and t is any type. If the types allowed for terms are restricted, e.g. to Hindley-Milner types then no term may be applied to itself, thus avoiding one kind of non-terminating evaluation. Most functional programming languages, e.g. Haskell, ML, are closely based on variants of the typed lambda-calculus. (1995-03-25) 1 1 1 1 1 TypedProlog A strongly typed logic programming language. (1995-03-25) 1 1 1 1 1 typeface The style or design of a font. Other independent parameters are size, boldness (thickness of lines), and obliqueness (a sheer transformation applied to the characters, not to be confused with a specifically designed italic font). (1996-08-02) 1 1 1 1 1 type inference An algorithm for ascribing types to expressions in some language, based on the types of the constants of the language and a set of type inference rules such as f :: A -> B, x :: A #NAME? f x :: B This rule, called "App" for application, says that if expression f has type A -> B and expression x has type A then we can deduce that expression (f x) has type B. The expressions above the line are the premises and below, the conclusion. An alternative notation often used is: G |- x : A 1 1 1 1 1 type scheme A typing of an expression which may include type variables. E.g. \ x . x :: a -> a where a is a generic type variable which may be instantiated to any type. (1994-10-31) 1 1 1 1 1 typo typographical error 1 1 1 1 1 typographical error (typo) An error while inputting text via keyboard, made despite the fact that the user knows exactly what to type in. This usually results from the operator's inexperience at keyboarding, rushing, not paying attention, or carelessness. Compare: mouso, thinko. (1996-04-20) 1 1 1 1 1 TYPOL A specialised logic programming language. ["TYPOL: A Formalism to Implement Natural Semantics", T. Despeyroux, RR 94, INRIA, 1988]. (1994-10-31) 1 1 1 1 1 typo squatter A domain squatter who registers a domain name that is a common typographical error for a popular website so that people will visit their site accidentally, e.g. (http://goggle.com/) for (http://google.com/). (2007-07-13) 1 1 1 1 1 tyt Take your time. (2004-02-15) 1 1 1 1 1 TZ The Unix environment variable containing the current time zone identifier, e.g. "GMT", EST. In early versions of Unix this variable simply contained the standard identifier for the zone, an offset in hours from GMT and an identifier to use during daylight saving time (e.g. "GMT0BST"). In later systems it stores the name of a file containing the details of a particular zone such as the dates when DST is in force. Unix manual page: ctime(3V). (1997-07-20) 1 1 1 1 1 tz The country code for Tanzania. (1999-01-27) 1 1 1 1 1 ua The country code for the Ukraine. (1999-01-27) 1 1 1 1 1 UAN User Action Notation. A notation from VPI for representation of activity in a graphical user interface. [H. Hartson et al, ACM Trans on Info Sys, July 1990]. (1994-10-31) 1 1 1 1 1 UART Universal Asynchronous Receiver/Transmitter 1 1 1 1 1 UAT User Acceptance Testing 1 1 1 1 1 UAW Misspelling of "IAW"? 1 1 1 1 1 UBASIC Yuji Kida <kida@rkmath.rikkyo.ac.jp>. An extension of BASIC for symbolic mathematics and number theory. UBASIC supports bignums, fractions, complex numbers, polynomials and integer factorisation. It runs under MS-DOS and is written in assembly language. Latest version: 8. (ftp://ftp.simtel.com/math/utk/software/msdos/number.theory/ubasic/). [Review, W.D. Neumann, Notices of AMS 36 (May/June 1989)] ["A math-oriented high-precision BASIC", Notices of the A.M.S, 38 (Mar 1991)]. (1992-07-06) 1 1 1 1 1 UBD User Brain Damage 1 1 1 1 1 ubiquitous computing Computers everywhere. Making many computers available throughout the physical environment, while making them effectively invisible to the user. Ubiquitous computing is held by some to be the Third Wave of computing. The First Wave was many people per computer, the Second Wave was one person per computer. The Third Wave will be many computers per person. Three key technical issues are: power consumption, user interface, and wireless connectivity. The idea of ubiquitous computing as invisible computation was first articulated by Mark Weiser in 1988 at the Computer Science Lab at Xerox PARC. (http://ubiq.com/hypertext/weiser/weiser.html). (1994-12-23) 1 1 1 1 1 uC++ Micro-C++. A extension of C++, by Peter A Ruhr <pabuhr@plg.uwaterloo.ca> of the University of Waterloo, with light-weight concurrency coroutines and mutual exclusion. Version 3.7 for Unix uses GCC 2.3.3 and requires dmake 3.0+ and the setitimer and sigcontext library calls. It runs on Sequent, Sun-4, Sun-3, Ultrix, SGI, RS/6000, HP-PA. (ftp://plg.uwaterloo.ca/pub/uSystem/u++-3.7.tar.Z). [Software--Practice and Experience, 22(2):137-172, February 1992]. (1993-06-10) 1 1 1 1 1 UCB University of California at Berkeley 1 1 1 1 1 UCHO (Polish for "ear") A program by Stanislaw Raczynski for analysing wav audio files to determine which musical notes are sounding at each instant. UCHO can output the results as a MIDI file. UCHO home (http://www.stanr.com/ucho/ucho.htm). (2008-03-17) 1 1 1 1 1 U-Code Universal Pascal Code. Intermediate language, a generalisation of P-code for easier optimisation. Developed originally for the Los Alamos Cray-1 and the Lawrence Livermore S-1. A refined version currently used by MIPS compilers is descended from one at Stanford U. "Machine Independent Pascal Code Optimisation", D.R. Perkins et al, SIGPLAN Notices 14(8): 201-201 (1979). "A Transporter's Guide to the Stanford U-Code Compiler System", P. Nye et al, TR CSL Stanford U, June 1983. (See HPcode). 1 1 1 1 1 UCP Universal Computer Protocol 1 1 1 1 1 UCS Universal Character Set 1 1 1 1 1 UCSD Pascal Pascal-P 1 1 1 1 1 UCS transformation format (UTF) A set of standard character encodings in accordance with ISO 10646. One of a set of standard character encodings, the most widely used of which are UTF-8, UTF-16, and UTF-32. The code tables in ISO 10646 and in the Unicode standard are identical, although the Unicode standard includes additional material. UTF-8 is the most widely used encoding, at least on Unix systems. Since it does not include any bytes like '\0' or '/' which have a special meaning in filenames and other C library function parameters, and 7-bit ASCII characters have the same encoding under both ASCII and UTF-8, the required changes to existing software are minimised. Other UTFs: UTF-1 and UTF-7 are not widely used. UTF-8 and Unicode FAQ for Unix/Linux (http://cl.cam.ac.uk/~mgk25/unicode.html#ucs). (2002-01-15) 1 1 1 1 1 UCX Universal Communications X 1 1 1 1 1 udb Universal Debugger 1 1 1 1 1 UDDI Universal Description, Discovery, and Integration 1 1 1 1 1 UDF Universal Disk Format 1 1 1 1 1 UDMA ATA-4 1 1 1 1 1 UDP User Datagram Protocol 1 1 1 1 1 uemacs MicroEmacs. ("u" looks a bit like the Greek letter micro). 1 1 1 1 1 UFO (United Functions and Objects) A hybrid functional and object-oriented language designed by John Seargant at Manchester University for general-purpose parallel computation. To a first approximation, UFO is a strict, higher-order functional language with an object-oriented type system, and strong support for numeric computation in the form of SISAL-style arrays and loops. Parallelism is implicit, and applies at various different levels of granularity, thereby facilitating implementations on a wide range of parallel architectures. It is planned to run it on a 64 processor KSR machine. (1996-08-22) 1 1 1 1 1 UFO bug A bug reported over and over again by users who believe it is real even after they have been shown that it doesn't exist. [Dodgy Coder (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)]. (2013-02-07) 1 1 1 1 1 ug The country code for Uganda. (1999-01-27) 1 1 1 1 1 UGLIAC An early system on the Datatron 200 series. [Listed in CACM 2(5):16 (May 1959)]. (2013-02-07) 1 1 1 1 1 UHELP A linear programming system. ["UHELP User's Manual", D. Singh, Indus Eng Dept, U Houston (Oct 1969)]. 1 1 1 1 1 UI 1. user interface. 2. Unix International. 1 1 1 1 1 uid 1. user identifier. 2. unique identifier - of any sort, possibly following sense 1. Compare with SKU for sense-development. (1998-09-27) 1 1 1 1 1 UIDL Unique ID Listing 1 1 1 1 1 UIL User Interface Language 1 1 1 1 1 UIMS User Interface Management System: a system supporting the development and execution of user interfaces, usually on top of windowing systems. 1 1 1 1 1 UIMX An interface builder for Motif from Visual Edge. 1 1 1 1 1 UIS A VMS graphics programming interface package for VAXstations. (1998-10-25) 1 1 1 1 1 uk The country code for United Kingdom. (1999-01-27) 1 1 1 1 1 UKC University of Kent at Canterbury 1 1 1 1 1 UKERNA United Kingdom Education and Research Networking Association 1 1 1 1 1 UKUUG Ltd. The UK's Unix and Open Systems User Group is a non-profit organisation and technical forum for the advocacy of open systems, particularly Unix and Unix-like operating systems, the promotion of free and open source software, and the advancement of open programming standards and networking protocols. UKUUG aims to cater for all those working in, or interested in open systems and open standards. It has been known as UKUUG since 1977, but produced its first magazine - UK Universities UNIX Newsletter - in December 1976. UKUUG used to stand for "United Kingdom Unix Users Group" but is now just "UKUUG Ltd." UKUUG Home (http://ukuug.org/). (2006-08-23) 1 1 1 1 1 ULCC University of London Computing Centre 1 1 1 1 1 Ulm's Modula-2 System A Modula-2 compiler, library and tools by Andreas Borchert <borchert@mathematik.uni-ulm.de>. The compiler is derived from the ETHZ compiler for the Lilith system. Version 2.2.1 conforms to PIM3. It requires gas version 1.36 (to be found in the same directory). Commercial use requires a licence. It runs on Sun-3, Nixdorf Targon/31, Concurrent 3200 Series. (ftp://titania.mathematik.uni-ulm.de/pub/soft/modula/ulm/sun3/modula-2.2.1.tar.Z). (1992-03-02) 1 1 1 1 1 ULP 1. <language> A small structured language for use on microprocessors. ["User's Guide to the ULP Language for the PDP-11", CS TR 536, U Maryland, May 1977]. 2. <protocol> Upper Layer Protocol. (1999-02-17) 1 1 1 1 1 Ultra64 A Nintendo games machine, unveiled in May 1995 [Details?] (1995-05-10) 1 1 1 1 1 Ultra-ATA ATA-4 1 1 1 1 1 Ultra DMA ATA-4 1 1 1 1 1 Ultra-SCSI An extension of SCSI-2 proposed by a group of manufacturers which doubles the transfer speed of Fast-SCSI to give 20MByte/s on an 8-bit connection and 40MByte/s on a 16-bit connection. (1995-04-19) 1 1 1 1 1 Ultrix A version of Unix based on the Berkeley version, designed and implemented by DEC to run on their VAX and DECstation processors. (1994-10-26) 1 1 1 1 1 um The country code for United States minor outlying islands. (1999-01-27) 1 1 1 1 1 UMB 1. Upper Memory Block. 2. A university(?). (1996-01-10) 1 1 1 1 1 UMB Scheme A Scheme system including an editor and debugger by William Campbell <bill@cs.umb.edu>. Conforms to the R4RS. (ftp://nexus.yorku.ca/pub/scheme/). (1994-10-28) 1 1 1 1 1 UMDL University of Michigan Digital Library Project 1 1 1 1 1 UML Unified Modeling Language 1 1 1 1 1 uML Micro ML 1 1 1 1 1 UMTS Universal Mobile Telecommunications System 1 1 1 1 1 unary 1. <programming> (or "monadic") A description of a function or operator which takes one argument, e.g. the unary minus operator which negates its argument. The term is part of the same sequence as nullary and binary. 2. <data, humour> Base one. A number base with only one digit, namely zero, and which can therefore only be used to express the number zero. Attempting to add one to zero results in an infinite sequence of carries. Numbers in unary notation can be represented particularly efficiently however since each digit requires no storage. (2001-02-25) 1 1 1 1 1 UNC Universal Naming Convention 1 1 1 1 1 UNCL Universal Naming Code Locater 1 1 1 1 1 UNCOL UNiversal Computer Oriented Language. A universal intermediate language, discussed but never implemented. ["A First Version of UNCOL", T.B. Steel, Proc JCC 19:371-378 (Winter 1961)]. [Sammet 1969, p.708]. 1 1 1 1 1 uncompression compression 1 1 1 1 1 uncountable countable 1 1 1 1 1 uncurry uncurrying 1 1 1 1 1 uncurrying Transforming a curried function of the form f x y z = ... to one of the form f (x, y, z) = ... , i.e. all arguments are passed as one tuple. (1998-07-02) 1 1 1 1 1 undefined The value of a variable that has not been set or a function that does not return anything. In some programming languages, e.g. Perl, JavaScript, undefined is a named constant that can be used to explicitly set a variable or return undefined or can be passed as an actual argument. Other languages, e.g. Java, call it "null", but note that the null in relational database programming is subtly different. Many languages provide a built-in function to test whether an expression is undefined, e.g. Perl's defined() function. Attempting to operate on an undefined value, e.g. add it to a number or append it to a string, may either raise an error or result in the undefined value being converted (cast) to some appropriate value, e.g. false, zero or empty string, according to the type of expression. This definition is an example of a paradox. (2012-12-02) 1 1 1 1 1 undefined external reference [Unix] A message from Unix's linker, ld. Used in speech to flag loose ends or dangling references in an argument or discussion. [Jargon File] 1 1 1 1 1 underflow (or "floating point underflow", "floating underflow", after "overflow") A condition that can occur when the result of a floating-point operation would be smaller in magnitude (closer to zero, either positive or negative) than the smallest quantity representable. Underflow is actually (negative) overflow of the exponent of the floating point quantity. For example, an eight-bit twos complement exponent can represent multipliers of 2^-128 to 2^127. A result less than 2^-128 would cause underflow. Depending on the processor, the programming language and the run-time system, underflow may set a status bit, raise an exception or generate a hardware interrupt or some combination of these effects. Alternatively, it may just be ignored and zero substituted for the unrepresentable value, though this might lead to a later divide by zero error which cannot be so easily ignored. (2006-11-09) 1 1 1 1 1 Undernet An Internet Relay Chat network dating from the 1990s, when it broke away from the main (still larger) IRC network, EFNet. (http://undernet.org/). The History of the Undernet (http://www2.undernet.org:8080/~cs93jtl/unet_history.txt). (1995-11-09) 1 1 1 1 1 underscore _, ASCII 95. Common names: ITU-T: underline; underscore; underbar; under. Rare: score; backarrow; skid; INTERCAL: flatworm. See also left arrow. (1995-03-06) 1 1 1 1 1 under the hood [hot-rodder talk] 1. The underlying implementation of a product (hardware, software, or idea). Implies that the implementation is not intuitively obvious from the appearance, but the speaker is about to enable the listener to grok it. Let's now look under the hood to see how .... 2. Can also imply that the implementation is much simpler than the appearance would indicate: "Under the hood, we are just fork/execing the shell." 3. Inside a chassis, as in "Under the hood, this baby has a 40MHz 68030!" [Jargon File] 1 1 1 1 1 undocumented feature feature 1 1 1 1 1 U-NET Limited A dial-up Internet access provider based in Warrington, UK. Speeds 4800 - 28.8kbps. The currently support Microsoft Windows and RISC OS users. For 12 pounds to join and 12 pounds per month or 100 pounds per year you get a full SLIP account with a pernament IP address and POP3 electronic mail account. Membership includes a disk with Mosaic, Eudora, Trumpet2, Newsreader, FTP and Telnet and full Internet access. Users can choose their own user name and hostname. Allows some extra services such as more than one POP3 account per access account. User name is significant so that a company can have accounts with the same hostname (i.e. their company name) but the mail going to diffent machines. Mail in users POP3 account is accessible from anywhere not just via the dial-up connection. On your next business trip you can still check your e-mail (provided you can get onto the Internet). (http://u-net.com/). 1 1 1 1 1 unfold inline 1 1 1 1 1 unfold/fold A program transformation where a recursive call to a function is unfolded to an instance of the function's body and then later an instance of the function's body is replaced by a call. E.g. sumdouble l = sum (double l) double l = case l of [] -> [] x:xs -> 2*x + double xs ==> (unfold double) sumdouble l = sum (case l of 1 1 1 1 1 UNI 1. <standard, body> Ente Nazionale Italiano di Unificazione. 2. <networking> User Network Interface. (1999-02-01) 1 1 1 1 1 unicast Sending packets to a single destination, used in contrast to broadcast or multicast. The term is generally only used when talking about low level communications, typically at the network layer, e.g. Internet Protocol. (2008-06-23) 1 1 1 1 1 Unicode 1. <character> A 16-bit character set standard, designed and maintained by the non-profit consortium Unicode Inc. Originally Unicode was designed to be universal, unique, and uniform, i.e., the code was to cover all major modern written languages (universal), each character was to have exactly one encoding (unique), and each character was to be represented by a fixed width in bits (uniform). Parallel to the development of Unicode an ISO/IEC standard was being worked on that put a large emphasis on being compatible with existing character codes such as ASCII or ISO Latin 1. To avoid having two competing 16-bit standards, in 1992 the two teams compromised to define a common character code standard, known both as Unicode and BMP. Since the merger the character codes are the same but the two standards are not identical. The ISO/IEC standard covers only coding while Unicode includes additional specifications that 1 1 1 1 1 UniCOMAL COMmon Algorithmic Language 1 1 1 1 1 Unicorny A feature that's so early in the planning stages that it might as well be imaginary. [Dodgy Coder(http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)].1 (2013-06-17) 1 1 1 1 1 unicos A Unix variant for Cray computers. [More details?] (1994-12-06) 1 1 1 1 1 Uniface 1. <database, programming, product> A 4GL development environment and system integration tool marketed by Compuware. Uniface is database independent, with interfaces to more than 14 database management systems and file retrieval systems including DB2, IMS, SQL Server, Oracle, RDB, Sybase. It is currently supported on MS Windows (98, ME, NT, 2000, XP, 2003), various Unix flavours, Linux, OpenVMS, IBM iSeries (AS/400), IBM zSeries (MVS) and various web servers. Uniface can integrate with SAP, COM, Java, BEA Tuxedo, CICS, and various CORBA implementations. Uniface user group Germany (http://c-b-g.org/). Profesional Uniface Users Universe (http://puuu.org/). Free tutorials (http://march-hare.com.au/). 2. <text> Synonym of bitmap font. (1999-01-05) 1 1 1 1 1 unification The generalisation of pattern matching that is the logic programming equivalent of instantiation in logic. When two terms are to be unified, they are compared. If they are both constants then the result of unification is success if they are equal else failure. If one is a variable then it is bound to the other, which may be any term (which satisfies an "occurs check"), and the unification succeeds. If both terms are structures then each pair of sub-terms is unified recursively and the unification succeeds if all the sub-terms unify. The result of unification is either failure or success with a set of variable bindings, known as a "unifier". There may be many such unifiers for any pair of terms but there will be at most one "most general unifier", other unifiers simply add extra bindings for sub-terms which are variables in the original terms. (1995-12-14) 1 1 1 1 1 Unified Han Han character 1 1 1 1 1 Unified Modeling Language (UML) A non-proprietary, third generation modelling language. The Unified Modeling Language is an open method used to specify, visualise, construct and document the artifacts of an object-oriented software-intensive system under development. The UML represents a compilation of "best engineering practices" which have proven successful in modelling large, complex systems. UML succeeds the concepts of Booch, OMT and OOSE by fusing them into a single, common and widely usable modelling language. UML aims to be a standard modelling language which can model concurrent and distributed systems. UML is not an industry standard, but is taking shape under the auspices of the Object Management Group (OMG). OMG has called for information on object-oriented methodologies, that might create a rigorous software modelling language. Many industry leaders have responded in earnest to help create the standard. 1 1 1 1 1 unifier The unifier of a set of expressions is a set of substitutions of terms for variables such that the expressions are all equal. See also most general unifier, unification. (1994-12-06) 1 1 1 1 1 UNIFORM An intermediate language developed for reverse engineering both COBOL and Fortran. ["The REDO Compendium", H. van Zuylen ed, Wiley 1993]. (1994-12-06) 1 1 1 1 1 Uniform Naming Convention Universal Naming Convention 1 1 1 1 1 Uniform Resource Citation (URC) A set of attribute/value pairs describing an object. Some of the values may be URIs of various kinds. Others may include, for example, athorship, publisher, datatype, date, copyright status and shoe size. A URC is not normally considered as a string, but a set of fields and values with some defined free formatting. (1995-03-24) 1 1 1 1 1 Uniform Resource Locater Uniform Resource Locator 1 1 1 1 1 Uniform Resource Locator (URL, previously "Universal") A standard way of specifying the location of an object, typically a web page, on the Internet. Other types of object are described below. URLs are the form of address used on the World-Wide Web. They are used in HTML documents to specify the target of a hypertext link which is often another HTML document (possibly stored on another computer). Here are some example URLs: http://w3.org/default.html http://acme.co.uk:8080/images/map.gif http://foldoc.org/?Uniform+Resource+Locator http://w3.org/default.html#Introduction ftp://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip ftp://spy:secret@ftp.acme.com/pub/topsecret/weapon.tgz mailto:fred@doc.ic.ac.uk news:alt.hypertext telnet://dra.com 1 1 1 1 1 Uniform Resource Name (URN, previously Uniform/Universal Resource Number) 1. Any URI which is not a URL. 2. A particular scheme which is currently (1991-4) under development by the IETF, which should provide for the resolution using Internet protocols of names which have a greater persistence than that currently associated with Internet host names or organisations (as used in URLs). Uniform Resource Names will be URI schemes that improve on URLs in reliability over time, including authenticity, replication, and high availability. When defined, a URN in sense 1 will be an example of a URN in sense 2. (http://w3.org/pub/WWW/Addressing/Addressing.html). (2006-04-18) 1 1 1 1 1 Uniform Resource Number Former name for Uniform Resource Name. 1 1 1 1 1 Unify A relational database produced by Unify Corporation. (1995-03-15) 1 1 1 1 1 unify To perform unification. (1995-03-15) 1 1 1 1 1 Unify Corporation Developers of the Unify relational database. At one time, before Sybase, they were a competitor of Oracle, et al. (http://unify.com/). (ftp://ftp.unify.com/). (1995-03-15) 1 1 1 1 1 Unihan Han character 1 1 1 1 1 uninstaller A utility program to remove another application program from a computer's disks. Most commonly found on IBM PCs, as applications tend to leave files in various places on the hard disc, so special software is required to tidy up after them. Ken Spreitzer <ken@maximized.com> claims to have written the original PC program called "UnInstaller", first licensed to MicroHelp and now (Feb 1998) sold by CyberMedia. Compare with installer. (1998-02-09) 1 1 1 1 1 uninteresting 1. Said of a problem that, although nontrivial, can be solved simply by throwing sufficient resources at it. 2. Also said of problems for which a solution would neither advance the state of the art nor be fun to design and code. Hackers regard uninteresting problems as intolerable wastes of time, to be solved (if at all) by lesser mortals. *Real* hackers (see toolsmith) generalise uninteresting problems enough to make them interesting and solve them - thus solving the original problem as a special case (and, it must be admitted, occasionally turning a molehill into a mountain, or a mountain into a tectonic plate). See WOMBAT, SMOP. Compare toy problem. Oppose interesting. [Jargon File] (1995-03-10) 1 1 1 1 1 Uninterruptible Power Supply (UPS) A battery powered power supply unit that is guaranteed to provide power to a computer in the event of interruptions in the incoming mains electrical power. Different rating UPSs will provide power for different lengths of time. Modern UPSs connect to the computer's serial port and provide information such as battery time remaining, allowing the computer to shut down gracefully before complete loss of power. (1996-12-11) 1 1 1 1 1 union 1. <theory> An operation on two sets which returns the set of all elements that are a member of either or both of the sets; normally written as an infix upper-case U symbol. The operator generalises to zero or more sets by taking the union of the current partial result (initially the empty set) with the next argument set, in any order. For example, (a, b, c) U (c, d, e) = (a, b, c, d, e) 2. <programming> A type whose values may be of one of a number of other types, the current type depending on conditions that are only known at run-time. A variable of union type must be allocated sufficient storage space to hold the largest component type. Some unions include extra information to say which type of value the union currently has (a "tagged union"), others rely on the program to keep track of this independently. A union contrasts with a structure or record which stores values of all component types at once. 3. <database> An SQL operator that concatenates two result 1 1 1 1 1 Unipalm Group plc A company floated in March 1994. (http://unipalm.co.uk/index.html). (1996-12-11) 1 1 1 1 1 Unipress Software, Inc. A developer and distributor of Unix software. They produce PC-UNIX connectivity software, development tools and applications and provide technical support and maintenance, porting services, training and consulting. (http://unipress.com/). (1996-12-11) 1 1 1 1 1 uniprocessor (From "uni" - one) A computer with a single central processing unit, in contrast to a parallel processor. Most personal computers are currently (March 1997) uniprocessors. Some more expensive computers, typically servers, have multiple processors to provide increased throughput. See also symmetric multiprocessor and massively parallel processor. (1997-03-23) 1 1 1 1 1 UNIQUE A portable job control language. ["The UNIQUE Command Language - Portable Job Control", I.A. Newman, Proc DATAFAIR 73, 1973, pp. 353-357]. (1994-11-22) 1 1 1 1 1 Unique ID Listing (UIDL) A system used by POP3 electronic mail servers to uniquely identify a mail message. Normally, a message is identified by its position in the list of messages but this will change when an earlier message is deleted. The UIDL is a fixed string of characters which is unique to the message. The UIDL of a message never changes and will never be reused, even when the message has been deleted from the user's mailbox. RFC 1725 (http://ds0.internic.net/rfc/rfc1725.txt). (1997-04-16) 1 1 1 1 1 unique key A key which identifies only one body of information out of several. (1997-04-26) 1 1 1 1 1 unique sales point (USP) A feature that the salesman hopes will convince you to buy his product instead of another. (1999-10-21) 1 1 1 1 1 Unir Tech The company with the exclusive license from Bell Labs to distribute C+@. Unir is owned and operated by well-known anti-IETF ranter, Jim Fleming. Telephone: +1 (800) 222-8647. (2002-05-19) 1 1 1 1 1 UNISAP An early system on UNIVAC I or II. [Listed in CACM 2(5):16 (May 1959)]. (1994-11-22) 1 1 1 1 1 Unisys Corporation The company formed in 1984-5 when Burroughs Corporation merged with Sperry Corporation. This was when the phrase "dinosaurs mating" was coined. Unisys is one of the largest providers of information services, technology, and software in the world. They employ about 49,000 people and do business in some 100 countries. In 1994 about 80 percent of revenue was derived from commercial information systems and services, with the remainder coming from electronic systems and services for the defense market. The defense business was sold to Loral in early 1995. Slightly more than half of Unisys's revenue is from business in the United States. They specialise in providing business-critical solutions, based on open information networks, for organisations that operate in transaction-intensive environments. These organisations include financial services companies, airlines, telecommunications companies, government agencies, and other 1 1 1 1 1 United Kingdom Education and Research Networking Association (UKERNA or JANET (UK)) The trading name for JNT Association. (2016-04-12) 1 1 1 1 1 United Kingdom Unix Users Group UKUUG Ltd. 1 1 1 1 1 United Technologies Research Cente (UTRC) http://utrcwww.utc.com/. (1994-11-29) 1 1 1 1 1 Unit Separator (US) ASCII character 31. (1996-06-29) 1 1 1 1 1 unit testing The type of testing where a developer (usually the one who wrote the code) proves that a code module (the "unit") meets its requirements. (2003-09-24) 1 1 1 1 1 UNITY A high-level parallel language. A translator into MPL is available by (ftp://sanfrancisco.ira.uka.de/pub/maspar/maspar_unity.tar.Z). See also MasPar Unity. ["Parallel Program Design", K.M. Chandry and Misra, A-W 1988]. (1994-11-29) 1 1 1 1 1 Univac A brand of computer. There is a historical placard in the United States Census Bureau that has the following, "The Bureau of the Census dedicated the world's first electronic general purpose data processing computer, UNIVAC I, on June 14, 1951. Eckert-Mauchly Computer Corporation". The Eckert-Mauchly Computer Corporation designed and built Univac. Over the years, rights to the Univac name changed hands several times. Circa 1987, Sperry Univac merged with the Burroughs Corporation to form Unisys Corporation. (1994-11-22) 1 1 1 1 1 Universal algebra The model theory of first-order equational logic. (1997-02-25) 1 1 1 1 1 Universal Asynchronous Receiver/Transmitter (UART) An integrated circuit used for serial communications, containing a transmitter (parallel-to-serial converter) and a receiver (serial-to-parallel converter), each clocked separately. The parallel side of a UART is usually connected to the bus of a computer. When the computer writes a byte to the UART's transmit data register (TDR), the UART will start to transmit it on the serial line. The UART's status register contains a flag bit which the computer can read to see if the UART is ready to transmit another byte. Another status register bit says whether the UART has received a byte from the serial line, in which case the computer should read it from the receive data register (RDR). If another byte is received before the previous one is read, the UART will signal an overrun error via another status bit. The UART may be set up to interrupt the computer when data is received or when ready to transmit more data. 1 1 1 1 1 Universal Character Set (UCS, ISO/IEC 10646) A 1993 ISO and IEC standard character set, also known as "Universal Multiple-Octet Coded Character Set". UCS comes in a 16-bit variant called UCS-2 and a 32-bit variant called UCS-4, which is composed of 16-bit UCS-2 planes. So far only one 16-bit plane has been defined, which is known as the Basic Multilingual Plane. The implementation of UCS is still in its infancy, though some moves, such as the Java language defining a character to be 16 bits, are suggestive. [Relationship with Unicode?] (1997-07-04) 1 1 1 1 1 Universal Communications X (UCX) A software implementation of the ubiquitous TCP/IP suite of communications protocols for Digital Equipment Corporation's OpenVMS operating system. Users of the UCX product can connect to heterogeneous networks to access and download files, send electronic mail, run and develop applications, and monitor activity. "Software Product Description, DIGITAL TCP/IP Services for OpenVMS, Version 4.2", (http://digital.com/info/QAW009/QAW009HM.HTM). (2000-12-15) 1 1 1 1 1 Universal Computer Protocol An earlier form of External Machine Interface (EMI). (2007-09-10) 1 1 1 1 1 Universal Debugger (udb) KSR's interactive source level debugger for serial and parallel programs written in KSR, Fortran, KSR C and KSR1 assembly language. Udb is a source level debugger for testing and debugging serial and parallel programs; it is compatible with GDB and dbx. The user can direct udb either by typing commands or graphically through an X-based window interface; the latter provides simultaneous display of source code, I/O and instructions. For parallel programs, operations can be carried out per-thread. Home (http://tc.cornell.edu/Parallel.Tools/tools/udb.html). (1995-05-07) 1 1 1 1 1 Universal Description, Discovery, and Integration (UDDI) The service discovery protocol for Web Services through which companies can find one another to conduct business. This standard was unveiled by Ariba, IBM, Microsoft, and 33 other companies in September 2000. (2002-06-28) 1 1 1 1 1 Universal Disk Format (UDF) A CD-ROM file system standard that is required for DVD ROMs. UDF is the OSTA's replacement for the ISO 9660 file system used on CD-ROMs, but will be mostly used on DVD. DVD multimedia disks use UDF to contain MPEG audio and video streams. To read DVDs you need a DVD drive, the kernel driver for the drive, MPEG video support, and a UDF driver. DVDs containing both UDF filesystems and ISO 9660 filesystems can be read without UDF support. UDF can also be used by CD-R and CD-RW recorders in packet writing mode. (1999-09-01) 1 1 1 1 1 Universal Naming Convention (UNC) The type of file system path used in Microsoft Windows networking to completely specify a directory on a file server. The basic format is: \\servername\sharename where "servername" is the hostname or IP address of a network file server, and "sharename" is the name of a shared directory on the server. This is related to the conventional MS-DOS "C:\windows" style of directory name. E.g. \\server1\dave might be set up to point to C:\users\homedirs\dave on a server called "server1". It is possible to execute a program using this convention 1 1 1 1 1 universal quantifier quantifier 1 1 1 1 1 Universal Resource Identifier (URI, originally "UDI" in some WWW documents) The generic set of all names and addresses which are short strings which refer to objects (typically on the Internet). The most common kinds of URI are URLs and relative URLs. URIs are defined in RFC 1630. W3 specification (http://w3.org/hypertext/WWW/Addressing/URL/URI_Overview.html). (1997-07-16) 1 1 1 1 1 Universal Resource Locator Uniform Resource Locator 1 1 1 1 1 Universal Serial Bus (USB) An external peripheral interface standard for communication between a computer and external peripherals over an inexpensive cable using biserial transmission. USB is intended to replace existing serial ports, parallel ports, keyboard, and monitor connectors and be used with keyboards, mice, monitors, printers, and possibly some low-speed scanners and removable hard drives. For faster devices existing IDE, SCSI, or emerging FC-AL or FireWire interfaces can be used. USB works at 12 Mbps with specific consideration for low cost peripherals. It supports up to 127 devices and both isochronous and asynchronous data transfers. Cables can be up to five metres long and it includes built-in power distribution for low power devices. It supports daisy chaining through a tiered star multidrop topology. A USB cable has a rectangular "Type A" plug at the computer end and 1 1 1 1 1 universal thunk A software mechanism allowing a Windows 3.1 application to call a 32-bit dynamically linked library (DLL) under Win32s. The Windows 3.1 application which wants to call an entry in a 32-bit DLL instead calls a corresponding entry in a 16-bit DLL. The programmer must also include code to detect whether the 32-bit DLL is loaded. A 32-bit EXE loads the 32-bit DLL. See also Generic Thunk, Flat Thunk. ["Calling a Win32 DLL from a Windows 3.1 Application", Win32 SDK Knowledge Base, Article ID Q97785]. [Better explanation?] (1997-10-11) 1 1 1 1 1 Universal Time (UT) The mean solar time along the prime meridian (0 longitude) that runs through the Greenwich Observatory outside of London, UK, where the current system originated. UT is tied to the rotation of the Earth in respect to the fictitious "mean Sun". Greenwich Mean Time (GMT) was measured from Greenwich mean midday until 1925 when the reference point was changed from noon to midnight and the name changed to "Universal Time". There are three separate definitions, UT0, UT1, and UT2, depending on which corrections have been applied to the Earth's motion. Coordinated Universal Time is kept within 0.9 seconds of UT1, by addition of leap seconds to International Atomic Time. (2001-08-02) 1 1 1 1 1 Universal Time Coordinated An incorrect term for Coordinated Universal Time. (2001-08-01) 1 1 1 1 1 universe of discourse In ontology, the set of all entities that can be represented in some declarative language or other formal system. Each entity is represented by a name and may have some human-readable description of its meaning. Formal axioms constrain the interpretation and well-formed use of these names. (2005-07-29) 1 1 1 1 1 University of Arizona The University was founded in 1885 as a Land Grant institution with a three-fold mission of teaching, research and public service. Today, the University is one of the top 20 research universities in the nation, with a student enrollment of more than 35,000, a faculty and staff of 12,500, and a 345-acre campus. (http://arizona.edu/). Address: Tucson, Arizona, USA. 1 1 1 1 1 University of California at Berkeley (UCB) See also Berzerkley, BSD. (http://berkeley.edu/). Note to British and Commonwealth readers: that's /berk'lee/, not /bark'lee/ as in British Received Pronunciation. (1994-11-29) 1 1 1 1 1 University of Durham A busy research and teaching community in the historic cathedral city of Durham, UK (population 61000). Its work covers key branches of science and technology and traditional areas of scholarship. Durham graduates are in great demand among employers and the University helps to attract investment into the region. It provides training, short courses, and expertise for industry. Through its cultural events, conferences, tourist business and as a major employer, the University contributes in a wide social and economic sense to the community. Founded in 1832, the University developed in Durham and Newcastle until 1963 when the independent University of Newcastle upon Tyne came into being. Durham is a collegiate body, with 14 Colleges or Societies which are a social and domestic focus for students. In 1992, the Universities of Durham and Teesside launched University College, Stockton-on-Tees, which has 190 students in the first year. 1 1 1 1 1 University of East London (UEL) A UK University with six academic Faculties: Design and The Built Environment, East London Business School, Institute Of Health and Rehabilitation, Faculty Of Science, Social Sciences and Technology. (http://uel.ac.uk/). (1994-11-29) 1 1 1 1 1 University of Edinburgh A university in the centre of Scotland's capital. The University of Edinburgh has been promoting and setting standards in education for over 400 years. Granted its Royal Charter in 1582 by James VI, the son of Mary Queen of Scots, the University was founded the following year by the Town Council of Edinburgh, making it the first post-Reformation university in Scotland, and the first civic university to be established in the British Isles. Known in its early years as King James College, or the Tounis (Town's) College, the University soon established itself internationally, and by the 18th century Edinburgh was a leading centre of the European Enlightenment and one of the continent's principal universities. The University's close relationship with the city in which it is based, coupled with a forward-looking, international perspective, has kept Edinburgh at the forefront of new research and teaching developments whilst enabling it to retain a uniquely Scottish 1 1 1 1 1 University of Hawaii A University spread over 10 campuses on 4 islands throughout the state. (http://hawaii.edu/uhinfo.html). See also Aloha, Aloha Net. (1995-12-10) 1 1 1 1 1 University of Iceland The Home of Fjolnir. (http://rhi.hi.is/). (1995-03-17) 1 1 1 1 1 University of London Computing Centre (ULCC) One of the UK's national high performance computing centres. It provides networking services and large-scale computing facilities which are used by researchers from all over the UK. ULCC was founded in 1968 to provide a service for education and research. It has been at the forefront of advanced research computing since its foundation, initially providing large-scale CDC-based facilities, then from 1982 to 1991 a national Cray vector supercomputing service. Its high performance computing facilities are now centred on a 6 processor, 4 Gbyte Convex C3860 supercomputer (Neptune) with a Convex C3200 front-end (Pluto). ULCC is the main site for national and international network connections in the UK. They run the Network Operations and Service Centre for the JANET Internet Protocol Service (JIPS), the largest of the JANET NOCs and various international links and relays on behalf of UKERNA. 1 1 1 1 1 University of Michigan A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. 70% of the University's students graduated in the top 10% of their high school class. 90% rank in the top 20% of their high school class. 60% of the students receive financial aid. The main Ann Arbor Campus lies in the Huron River valley, 40 miles west of Detroit. The campus boasts 2700 acres with 200 buildings, six million volumes in 23 libraries, nine museums, seven hospitals, hundreds of laboratories and institutes, and over 18000 microcomputers. (http://umich.edu/). (1995-02-23) 1 1 1 1 1 University of Michigan Digital Library Project (UMDL) The University of Michigan's part of the Digital Library Initiative. 1 1 1 1 1 University of Minnesota The home of Gopher. (http://umn.edu/). Address: Minneapolis, Minnesota, USA. (1995-01-30) 1 1 1 1 1 University of Nijmegen Katholieke University of Nijmegen (KUN), Nijmegen, the Netherlands. KUN's Computing Science Institute (http://cs.kun.nl/csi). is known for the Clean, Comma, Communicating Functional Processes, and GLASS projects. (http://kun.nl/). (1995-11-07) 1 1 1 1 1 University of Pennsylvania The home of ENIAC and Machiavelli. (http://upenn.edu/). Address: Philadelphia, PA, USA. [More info?] (1995-02-21) 1 1 1 1 1 University of Tasmania (ftp://ftp.utas.edu.au/). (1995-01-25) 1 1 1 1 1 University of Twente A university in the east of The Netherlands for technical and social sciences. It was founded in 1961, making it one of the youngest universities in The Netherlands. It has 7000 students studying Applied Educational Science; Applied Mathematics; Applied Physics; Chemical Technology; Computer Science; Electrical Engineering; Mechanical Engineering; Philosophy of science, Technology and Society; Educational Technology. (http://nic.utwente.nl/uthomuk.htm). (1995-04-16) 1 1 1 1 1 Unix /yoo'niks/ (Or "UNIX", in the authors' words, "A weak pun on Multics") Plural "Unices". An interactive time-sharing operating system invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7. Dennis Ritchie, the inventor of C, is considered a co-author of the system. The turning point in Unix's history came when it was reimplemented almost entirely in C during 1972 - 1974, making it the first source-portable OS. Unix subsequently underwent mutations and expansions at the hands of many different people, resulting in a uniquely flexible and developer-friendly environment. By 1991, Unix had become the most widely used multi-user general-purpose operating system in the world. Many people consider this the most important victory yet of hackerdom over industry opposition (but see Unix weenie and Unix 1 1 1 1 1 Unix box box 1 1 1 1 1 Unix brain damage Something that has to be done to break a network program (typically a mailer) on a non-Unix system so that it will interoperate with Unix systems. The hack may qualify as "Unix brain damage" if the program conforms to published standards and the Unix program in question does not. Unix brain damage happens because it is much easier for other (minority) systems to change their ways to match non-conforming behaviour than it is to change all the hundreds of thousands of Unix systems out there. An example of Unix brain damage is a kluge in a mail server to recognise bare line feed (the Unix newline) as an equivalent form to the Internet standard newline, which is a carriage return followed by a line feed. Such things can make even a hardened jock weep. [Jargon File] 1 1 1 1 1 Unix conspiracy [ITS] According to a conspiracy theory long popular among ITS and TOPS-20 fans, Unix's growth is the result of a plot, hatched during the 1970s at Bell Labs, whose intent was to hobble AT&T's competitors by making them dependent upon a system whose future evolution was to be under AT&T's control. This would be accomplished by disseminating an operating system that is apparently inexpensive and easily portable, but also relatively unreliable and insecure (so as to require continuing upgrades from AT&T). This theory was lent a substantial impetus in 1984 by the paper referenced in the back door entry. In this view, Unix was designed to be one of the first computer viruses (see virus) - but a virus spread to computers indirectly by people and market forces, rather than directly through disks and networks. Adherents of this "Unix virus" theory like to cite the fact that the well-known quotation "Unix is snake oil" was uttered by DEC president 1 1 1 1 1 Unix International (UI) A consortium including Sun, AT&T and others formed to promote an open environment based on Unix System V, including the Open Look windowing system. 1 1 1 1 1 Unixism A piece of code or a coding technique that depends on the protected multitasking environment with relatively low process-spawn overhead that exists on virtual-memory Unix systems. Common Unixisms include: gratuitous use of "fork"; the assumption that certain undocumented but well-known features of Unix libraries such as "stdio" are supported elsewhere; reliance on obscure side-effects of system calls (use of sleep with a 0 argument to tell the scheduler that you're willing to give up your time-slice, for example); the assumption that freshly allocated memory is zeroed; and the assumption that fragmentation problems won't arise from never freeing memory. Compare vaxocentrism. See also New Jersey. [Jargon File] (1995-02-27) 1 1 1 1 1 Unix man page Unix manual page 1 1 1 1 1 Unix manual page (Or "man page") A part of Unix's extensive on-line documentation. To read a manual page from the Unix command line, type: man [-s<section>] <page> e.g. "man ftp" (the section number can usually be omitted). Pages are traditionally referred to using the notation page(section), e.g. ftp(1). Under SunOS (which is fairly typical), Section 1 covers commands, 2 system calls, 3 C library routines, 4 devices and networks, 5 file formats, 6 games and demos, 7 miscellaneous, 8 system administration. Each section has an introduction which can be obtained with, e.g., "man 2 intro". Manual pages are stored as nroff source files. Formatted versions are also usually cached. Man pages for most versions of Unix are available on-line in HTML. Unix manual page: man(1). 1 1 1 1 1 Unix System V System V 1 1 1 1 1 Unix to Unix Copy (uucp) A Unix utility program and protocol that allows one Unix system to send files to another via a serial line which may be a cable going directly from one machine's serial port to another's or may involve a modem at each end of a telephone line. Software is also available to allow uucp to work over Ethernet though there are better alternatives in this case, e.g. FTP or rcp for file transfer, SMTP for electronic mail or NNTP for news. The term is now also used to describe the large international network which uses UUCP to pass Usenet news and electronic mail, also known as "UUCPNET". Unix manual page: uucp(1). See also cu, uuencode. (1997-01-12) 1 1 1 1 1 UnixWare Novell's implementation of Unix System 5 heavily based on Release 4.2 but with enhancements and new bundled products. In 1993 Novell acquired Unix Systems Laboratories from AT&T along with the Unix trademark. UnixWare was the result of Novell's efforts to make Unix interoperable with Novell NetWare. In 1995 Novell sold UnixWare and the rights to the Unix operating system to SCO at a time when UnixWare was gainnig popularity. It was later the first 64-bit operating system on the Intel platform, and, in 1999, is the world's fastest-growing commercial operating system. [Any connection with X/Open? URL?] (1999-11-10) 1 1 1 1 1 Unix weenie (ITS) 1. A derogatory play on "Unix wizard", common among hackers who use Unix by necessity but would prefer alternatives. The implication is that although the person in question may consider mastery of Unix arcana to be a wizardly skill, the only real skill involved is the ability to tolerate (and the bad taste to wallow in) the incoherence and needless complexity that is alleged to infest many Unix programs. "This shell script tries to parse its arguments in 69 bletcherous ways. It must have been written by a real Unix weenie." 2. A derogatory term for anyone who engages in uncritical praise of Unix. Often appearing in the context "stupid Unix weenie". See Weenix, Unix conspiracy, weenie. [Jargon File] (1995-02-27) 1 1 1 1 1 Unix wizard Someone with a deep understanding of Unix. See wizard. (1995-05-11) 1 1 1 1 1 Unlicense A template for dedicating software to the public domain. It combines a copyright waiver like that of the SQLite project with the no-warranty statement from the MIT/X11 license. (http://unlicense.org/). (2014-07-31) 1 1 1 1 1 unnormalised normalisation 1 1 1 1 1 unproto A translator from ANSI C to K&R C by Wietse Venema <wietse@wzv.win.tue.nl>. (ftp://ftp.win.tue.nl/pub/Unix/unproto4.shar.Z). 1 1 1 1 1 unshar A Unix utility that removes e-mail and news header lines from its input, and feeds the remainder (which is presumed to be a shar file) to /bin/sh to unpack it. unshar is designed for unpacking archives directly from the news or mail systems simply by piping a message into it. 1 1 1 1 1 unshielded twisted pair (UTP) Normal telephone wire (in the USA). It may be used for computer to computer communications, e.g. using a version of Ethernet or localtalk. It is much cheaper than standard "full-spec" Ethernet cable. It comes in five catagories: cat. wires transmission 1 two voice no data (telephone cable) 2 four data up to 4 Mbps 3 four data up to 10 Mbps 4 four 1 1 1 1 1 unswizzle The opposite of swizzle. [Jargon File] (1995-02-15) 1 1 1 1 1 until while loop 1 1 1 1 1 untyped A variable which can hold values of any type or a programming language in which some or all variables are like this. An example would be VBScript, or Visual Basic's variant type. (2003-12-22) 1 1 1 1 1 unwind-protect (MIT) A Lisp operator which evaluates an expression and then, even if that expression causes a non-local exit, evaluates zero or more other expressions. This can be used to ensure that essential "clean-up" operations are performed even in the presence of errors. [Jargon File] (1994-11-03) 1 1 1 1 1 unwind the stack During the execution of a procedural language, one is said to "unwind the stack" from a called procedure up to a caller when one discards the stack frame and any number of frames above it, popping back up to the level of the given caller. In C this is done with "longjmp"/"setjmp", in Lisp with "throw/catch". See also smash the stack. [Jargon File] 1 1 1 1 1 UN*X Used to refer to the Unix operating system (a trademark of AT&T) in writing, but avoiding the need for the ugly (TM) typography. Also used to refer to any or all varieties of Unixoid operating systems. Ironically, lawyers now say that the requirement for the TM-postfix has no legal force, but the asterisk usage is entrenched anyhow. It has been suggested that there may be a psychological connection to practice in certain religions (especially Judaism) in which the name of the deity is never written out in full, e.g. "YHWH" or "G--d" is used. See also glob. (1998-04-17) 1 1 1 1 1 unzip 1. <tool, compression> To extract files from an archive created with PKWare's PKZIP archiver. 2. <tool, compression> A program to list, test, or extract files from a ZIP archive, commonly found on MS-DOS systems. zip, creates ZIP archives; both programs are compatible with archives created by PKWARE's PKZIP and PKUNZIP for MS-DOS. (1995-03-06) 1 1 1 1 1 up Working, in order. E.g. "The down escalator is up." Opposite: down. [Jargon File] (1995-03-06) 1 1 1 1 1 uparrow The graphic which the 1963 version of ASCII had in place of the caret character, ASCII 94. (1995-03-06) 1 1 1 1 1 UPenn University of Pennsylvania 1 1 1 1 1 upgradability (Or "upgradeability") How easily upgrades to a system can be produced and applied. E.g. "Buying a PC with more PCI slots gives you increased upgradeability." (1999-10-11) 1 1 1 1 1 upgrade 1. A new or better version of some hardware or software. Often used in marketroid-speak to mean "bug fix". 2. The act of developing or installing a new version. (1995-03-14) 1 1 1 1 1 upgradeability upgradability 1 1 1 1 1 upload /uhp'lohd/ To transfer programs or data over a digital communications link from a smaller or peripheral "client" system to a larger or central "host" one. Opposite: download. [Jargon File] (1994-10-27) 1 1 1 1 1 UPMAIL Tricia Prolog (ftp://ftp.csd.uu.se/pub/Tricia/README). E-mail: <tricia-request@csd.uu.se>. [Description?] (1994-10-27) 1 1 1 1 1 upper bound An upper bound of two elements x and y under some relation <= is an element z such that x <= z and y <= z. ("<=" is written in LaTeX as \sqsubseteq). See also least upper bound. (1995-02-15) 1 1 1 1 1 Upper Layer Protocol 1. (ULP, or upper-layer protocol) Any protocol residing in OSI layers five or above. The Internet protocol suite includes many upper layer protocols representing a wide variety of applications e.g. FTP, NFS, RPC, and SMTP. These and other network applications use the services of TCP/IP and other lower layer protocols to provide users with basic network services. 2. A protocol higher in the OSI reference model than the current reference point. Upper Layer Protocol is often used to refer to the next-highest protocol in a particular protocol stack. (1999-02-17) 1 1 1 1 1 upper memory block (UMB) Up to 64 kilobytes of the expanded memory page frame above the first 64 kilobytes. The UMB can be used to store TSR programs or device drivers thereby freeing parts of the precious conventional memory. The UMB is provided by special memory manager programs; many EMMs can provide UMB as well. (1996-01-10) 1 1 1 1 1 Upper Side-Band modulation (USB) A kind of modulation applied to a sinusoidal carrier. [Details?] (1997-07-16) 1 1 1 1 1 Upright Database Technology AB The Swedish company that developed the Mimer SQL database. (2002-06-03) 1 1 1 1 1 UPS 1. uninterruptible power supply. 2. A source level C debugger that runs under X11 or SunView by Mark Russell <mtr@ukc.ac.uk>. Ups includes a C interpreter which allows you to add fragments of code simply by editing them into the source window. Version 2.1. Ported to Sun, DECstation, VAX Ultrix, HLH Clipper. (ftp://export.lcs.mit.edu/contrib/). Mailing list: ups-users-request@ukc.ac.uk. Unofficial enhancements by Rod Armstrong <rod@sj.ate.slb.com> (ftp://sj.ate.slb.com/misc/Unix/ups/contrib/rob). (1991-05-20) 1 1 1 1 1 upstream Fewer network hops away from a backbone or hub. For example, a small ISP that connects to the Internet through a larger ISP that has their own connection to the backbone is downstream from the larger ISP, and the larger ISP is upstream from the smaller ISP. (1999-08-05) 1 1 1 1 1 upthread Earlier in the discussion (see thread), i.e. "above". See also followup. [Jargon File] 1 1 1 1 1 upward closure closure 1 1 1 1 1 Uranus Hideyuki Nakashima <nakashim@el.go.jp>, 1993. A logic-based knowledge representation language. An extension of Prolog written in Common Lisp, with Lisp-like syntax. Extends Prolog with a multiple world mechanism, plus term descriptions to provide functional programming. (ftp://etlport.etl.go.jp/pub/uranus/ftp). 1 1 1 1 1 urban legend A story, which may have started with a grain of truth, that has been embroidered and retold until it has passed into the realm of myth. It is an interesting phenomenon that these stories get spread so far, so fast and so often. Urban legends never die, they just end up on the Internet! Some legends that periodically make their rounds include "The Infamous Modem Tax", "Craig Shergold/Brain Tumor/Get Well Cards", and "The $250 Cookie Recipe". (1996-05-08) 1 1 1 1 1 URC Uniform Resource Citation (previously Universal). 1 1 1 1 1 urchin munchkin 1 1 1 1 1 URI Universal Resource Identifier 1 1 1 1 1 URL Uniform Resource Locator 1 1 1 1 1 URL forwarding URL redirection 1 1 1 1 1 URL redirection (Or "URL forwarding") When a web server tells the client browser to obtain a certain requested page from a different location. This is controlled by directives in the server's configuration files or a "Location: header output by a CGI script. The web server stores all its documents in a directory tree rooted at some configured directory, known as its "document root". Normally the URI part of the URL (the part after the hostname) is used as a relative path from the document root to the desired file or directory. A redirect directive allows the server administrator to specify exceptions to this general mapping from URL to file name by telling the browser try this URL instead. The new URL may be on the same server or a different one and may itself be subject to redirection. The user is normally unaware of this process except that it may introduce extra delay while the browser sends the new request and the browser will usually display the new URL 1 1 1 1 1 URN Uniform Resource Name 1 1 1 1 1 URouLette (After URL and roulette, the gambling game) A World-Wide Web service which selects other web pages at random. (http://kuhttp.cc.ukans.edu/cwis/organizations/kucia/uroulette/uroulette.html). (1994-11-24) 1 1 1 1 1 US Unit Separator 1 1 1 1 1 us The country code for the United States. Usually used only by schools, libraries, and some state and local governments. Other US sites, and many international ones, use the non-national top-level domains .com, .edu etc. (1999-01-27) 1 1 1 1 1 usability The effectiveness, efficiency, and satisfaction with which users can achieve tasks in a particular environment of a product. High usability means a system is: easy to learn and remember; efficient, visually pleasing and fun to use; and quick to recover from errors. (http://orrnet.com/). (1999-04-01) 1 1 1 1 1 USAModSim United States Army ModSim compiler. Version 1.0 runs on SPARC/SunOS, Silicon Graphics, MS-DOS. (ftp://max.cecer.army.mil/ftp/isle). E-mail: Charles Herring <herring@lincoln.cecer.army.mil>. (1993-12-29) 1 1 1 1 1 usa.net Internet Express 1 1 1 1 1 US-ASCII The 7-bit version of ASCII, which preceded (and is the basis for) 8-bit versions such as Latin-1, MacASCII and later, even larger coded character sets such as Unicode. US-ASCII is defined in Standard ANSI X3.4-1986, "US-ASCII. Coded Character Set - 7-Bit American Standard Code for Information Interchange." (1998-10-18) 1 1 1 1 1 USB 1. <architecture> Universal Serial Bus. 2. <communications> Upper Side-Band modulation. (1997-07-16) 1 1 1 1 1 USB 2.0 Universal Serial Bus 1 1 1 1 1 USB Adapter Card Support A set of software extensions that provide support for USB adapter cards installed in the PCI bus or Cardbus slots in Macintosh computers that do not have built-in USB ports. (2001-11-28) 1 1 1 1 1 USB drive A hard disk drive connected via Universal Serial Bus (USB). May also refer to some kind of memory stick connected via USB. (2008-05-21) 1 1 1 1 1 USE An early system on the IBM 1130. [Listed in CACM 2(5):16, May 1959]. (2004-09-14) 1 1 1 1 1 Usenet /yoos'net/ or /yooz'net/ (Or "Usenet news", from Users' Network) A distributed bulletin board system and the people who post and read articles thereon. Originally implemented in 1979 - 1980 by Steve Bellovin, Jim Ellis, Tom Truscott, and Steve Daniel at Duke University, and supported mainly by Unix machines, it swiftly grew to become international in scope and, before the advent of the web, probably the largest decentralised information utility in existence. Usenet encompasses government agencies, universities, high schools, businesses of all sizes, and home computers of all descriptions. In the beginning, not all Usenet hosts were on the Internet. As of early 1993, it hosted over 1200 newsgroups ("groups" for short) and an average of 40 megabytes (the equivalent of several thousand paper pages) of new technical articles, news, discussion, chatter, and flamage every day. By November 1999, the number of groups 1 1 1 1 1 Usenet news Usenet 1 1 1 1 1 Usenetter A (regular) user of Usenet. (1996-09-08) 1 1 1 1 1 USENIX Since 1975, the USENIX Association has provided a forum for the communication of the results of innovation and research in Unix and modern open systems. It is well known for its technical conferences, tutorial programs, and the wide variety of publications it has sponsored over the years. USENIX is the original not-for-profit membership organisation for individuals and institutions interested in Unix and Unix-like systems, by extension, X, object-oriented technology, and other advanced tools and technologies, and the broad interconnected and interoperable computing environment. USENIX's activities include an annual technical conference; frequent specific-topic conferences and symposia; a highly regarded tutorial program covering a wide range of topics, introductory through advanced; numerous publications, including a book series, in cooperation with The MIT Press, on advanced computing systems, proceedings from USENIX 1 1 1 1 1 user 1. <person> Someone doing "real work" with the computer, using it as a means rather than an end. Someone who pays to use a computer. A programmer who will believe anything you tell him. One who asks silly questions without thinking for two seconds or looking in the documentation. Someone who uses a program, however skillfully, without getting into the internals of the program. One who reports bugs instead of just fixing them. See also luser, real user. Users are looked down on by hackers to some extent because they don't understand the full ramifications of the system in all its glory. The term is relative: a skilled hacker may be a user with respect to some program he himself does not hack. A LISP hacker might be one who maintains LISP or one who uses LISP (but with the skill of a hacker). A LISP user is one who uses LISP, whether skillfully or not. Thus there is some overlap between the two terms; the subtle distinctions must be resolved by context. 1 1 1 1 1 user acceptance testing The type of testing where monitored users determine whether a system meets all their requirements, and will support the business for which it was designed. (2003-09-24) 1 1 1 1 1 user base The number of users of some product or standard. This term typically arises in discussions of backward compatibility or lock-in. (1998-01-15) 1 1 1 1 1 User Brain Damage (UBD) A description (usually abbreviated) used to close a trouble report obviously due to utter cluelessness on the user's part. Compare pilot error; opposite: PBD; see also brain-damaged, PEBCAK. (1998-08-27) 1 1 1 1 1 User Datagram Protocol (UDP) Internet standard network layer, transport layer and session layer protocols which provide simple but unreliable datagram services. UDP is defined in STD 6, RFC 768. It adds a checksum and additional process-to-process addressing information [to what?]. UDP is a connectionless protocol which, like TCP, is layered on top of IP. UDP neither guarantees delivery nor does it require a connection. As a result it is lightweight and efficient, but all error processing and retransmission must be taken care of by the application program. Unix manual page: udp(4). [Postel, Jon, User Datagram Protocol, RFC 768, Network Information Center, SRI International, Menlo Park, Calif., August 1980]. (1998-02-11) 1 1 1 1 1 user experience (UX) 1 1 1 1 1 user-friendly Programmer-hostile. Generally used by hackers in a critical tone, to describe systems that hold the user's hand so obsessively that they make it painful for the more experienced and knowledgeable to get any work done. See menuitis, drool-proof paper, Macintrash, user-obsequious. [Jargon File] 1 1 1 1 1 user id user identifier 1 1 1 1 1 user identifier 1. (Or "uid", "user id") A number or name which is unique to a particular user of a computer or group of computers which share user information. The operating system uses the uid to represent the user in its data structures, e.g. the owner of a file or process, the person attempting to access a system resource etc. A user database, e.g. Unix's /etc/passwd file or NIS, maps the uid to other information about that user such as their user name, password, home directory and real name. 2. user name. (1997-03-01) 1 1 1 1 1 user interface (UI) The aspects of a computer system or program which can be seen (or heard or otherwise perceived) by the human user, and the commands and mechanisms the user uses to control its operation and input data. A graphical user interface emphasises the use of pictures for output and a pointing device such as a mouse for input and control whereas a command line interface requires the user to type textual commands and input at a keyboard and produces a single stream of text as output. A user interface contrasts with, but is typically built on top of, an Application Program Interface (API). See also user interface copyright. (1995-02-20) 1 1 1 1 1 user interface copyright There have been several attempts, mostly by big US software companies, to enforce patents and copyright on user interfaces. Such legal action aims to restrict the use of certain command languages or graphical user interfaces to products from one software supplier. This is undesirable because it either forces users to buy software from the company whose interface they have learned or to learn more than one interface. An analogy is often drawn with the user interface of a car - the arrangement of pedals and steering wheel etc. If each car manufacturer was forced to use a different interface this would be very bad for car users. Following a non-jury trial, which began in early January 1987, a federal judge ruled on 1990-06-28 that keyboard commands and on-screen images produced by Lotus Development Corporation's popular 1-2-3 spreadsheet are protected by copyright. Paperback Software International and subcontractor Stephenson Software Ltd. who lost the case, argued that the 1 1 1 1 1 User Interface Language (UIL) A language for specifying widget hierarchies etc. in OSF/Motif and DECwindows. (1997-03-01) 1 1 1 1 1 user name (Or "logon") A unique name for each user of computer services which can be accessed by several persons. Users need to identify themselves for accounting, security, logging, and resource management. Usually a person must also enter a password in order to access a service. Once the user has logged on the operating system will often use a (short) user identifier, e.g. an integer, to refer to them rather than their user name. User names can usually be any short string of alphanumeric characters. Common choices are first name, initials, or some combination of first name, last name, initials and an arbitrary number. User names are often assigned by system administrators according to some local policy, or they may be chosen by the users themselves. User names are often also used as mailbox names in electronic mail addresses. 1 1 1 1 1 User Network Interface (UNI) An interface point between ATM end users and a private ATM switch, or between a private ATM switch and the public carrier ATM network. The physical and protocol specifications for UNIs are defined by the ATM Forum's UNI documents, which allow for various types of physical interfaces. See also: NNI (1999-01-23) 1 1 1 1 1 user-obsequious Emphatic form of user-friendly. Connotes a system so verbose, inflexible, and determinedly simple-minded that it is nearly unusable. "Design a system any fool can use and only a fool will want to use it." See WIMP, Macintrash. See also user-unctuous. [Jargon File] (1999-06-27) 1 1 1 1 1 user-unctuous (By analogy with user-friendly and user-obsequious) User-interfaces that attempt to soothe (or, some would say, stupify) users instead of cooperating with them. Common "features" of user-unctuous systems include: icons of happy faces; mellow colors; melodic sound effects or even mood music; help tips appearing unbidden and at unhelpful moments; and a cloying tone either in system messages ("Oops! I couldn't seem to find my old preferences file! I do think I'll have to make a new one! Please press OK to continue!") or in labelling of system components (such as the main hard drive being labelled "Your Hard Drive" -- or, with infantile pronoun-reversal, "My Hard Drive"). (1999-06-27) 1 1 1 1 1 Use the Source Luke (UTSL) (A pun on Obi-Wan Kenobi's "Use the Force, Luke!" in "Star Wars") A more polite version of RTFS. This is a common way of suggesting that someone would be better off reading the source code that supports whatever feature is causing confusion, rather than making yet another futile pass through the manuals, or broadcasting questions on Usenet that haven't attracted wizards to answer them. Once upon a time in Elder Days, everyone running Unix had source. After 1978, AT&T's policy tightened up, so this objurgation was in theory appropriately directed only at associates of some outfit with a Unix source licence. In practice, bootlegs of Unix source code (made precisely for reference purposes) were so ubiquitous that one could utter it at almost anyone on the network without concern. Nowadays, free Unix clones are becoming common enough that almost anyone can read source legally. The most widely distributed is probably Linux. FreeBSD, NetBSD, 1 1 1 1 1 USG Unix operating system /U-S-G yoo'niks/ Refers to AT&T Unix commercial versions after Version 7, especially System III and System V releases 1, 2, and 3. So called because during most of the lifespan of those versions AT&T's support crew was called the "Unix Support Group". Compare BSD. [Jargon File] (1997-02-20) 1 1 1 1 1 usim A Motorola 6809 emulator and assembler. (2014-06-24) 1 1 1 1 1 USL 1. Query language, close to natural English. 2. User System Language. Bellcore, "Operations Technology Generic Requirements: User System Interface", TR-825. 3. Unix System Laboratories: the software subsidiary of AT&T, responsible for Unix System V and related software. 1 1 1 1 1 USP unique sales point 1 1 1 1 1 USR U.S. Robotics, Inc. 1 1 1 1 1 usr User. The "/usr" directory hierarchy on Unix systems. Once upon a time, in the early days of Unix, this area actually held users' home directories and files. Since these tend to expand much faster than system files, /usr would be mounted on the biggest disk on the system. The root directory, "/" in contrast, contains only what is needed to boot the kernel, after which /usr and other disks could be mounted as part of the multi-user start-up process. /usr has been used as the "everything else" area, with many system files such as compiler libraries (/usr/include, /usr/lib), utilty programs (/usr/bin, /usr/ucb), games (/usr/games), local additions (/usr/local), manuals (/usr/man), temporary files and queues for various daemons (/usr/spool). These optional extras have grown in size as Unix has evolved and disks have dropped in price. Under later versions of SunOS, the user files have fled /usr altogether for a new "/home" partition and temporary files have moved 1 1 1 1 1 US Robotics U.S. Robotics, Inc. 1 1 1 1 1 U.S. Robotics, Inc. A US modem manufacturer. (http://usr.com/). (ftp://ftp.usr.com/). Finger: usr.com. E-mail: <support@usr.com>, <salesinfo@usr.com> (USA and Canada), <eurosupport@usr.com>, <eurosales@usr.com> (Europe), <intlsales@usr.com> (other). (1995-03-14) 1 1 1 1 1 USSA Object-oriented state language by B. Burshteyn, Pyramid, 1992. Documentation (ftp://primost.cs.wisc.edu/pub/ussa.ps.Z). 1 1 1 1 1 UTC Coordinated Universal Time 1 1 1 1 1 UTF UCS transformation format 1 1 1 1 1 UTF-8 (UCS transformation format 8) An ASCII-compatible multibyte Unicode and UCS encoding, used by Java and Plan 9. The Unicode character set occupies a 16-bit code space. The most obvious Unicode encoding (known as UCS-2) consists of a sequence of 16-bit words. Such strings can contain bytes like '\0' or '/' which have a special meaning in filenames and other C library function parameters. In addition, the majority of Unix tools expects ASCII files and can't read 16-bit words as characters without major modifications. For these reasons, UCS-2 is not a suitable external encoding of Unicode in filenames, text files, environment variables, etc. The ISO 10646 Universal Character Set (UCS), a superset of Unicode, occupies a 31-bit code space and the obvious UCS-4 encoding for it (a sequence of 32-bit words) has the same problems. The UTF-8 encoding of Unicode and UCS avoids the problems of 1 1 1 1 1 utility utility software 1 1 1 1 1 utility-coder A language for data manipulation and report generation. ["User's Manual for utility-coder", Cambridge Computer Association, Jul 1977]. (1997-12-09) 1 1 1 1 1 utility program utility software 1 1 1 1 1 utility software (Or utility program, tool) Any software that performs some specific task that is secondary to the main purpose of using the computer (the latter would be called application programs) but is not essential to the operation of the computer (system software). Many utilities could be considered as part of the system software, which can in turn be considered part of the operating system. The following are some broad categories of utility software, specific types and examples. * Disks disk formatter: FDISK, format defragmenter disk checker: fsck disk cleaner system profiler backup 1 1 1 1 1 UTOPIST A specification language for attribute grammars developed by E. Tyugu of the Academy of Science Estonia, Tallinn in 1983. ["Synthesis of a Semantic Processor from an Attribute Grammar", Prog and Comp Soft, 9(1):29-39, Jan 1983]. (2007-02-02) 1 1 1 1 1 UTP unshielded twisted pair 1 1 1 1 1 UTRC United Technologies Research Cente 1 1 1 1 1 UTSL Use the Source Luke 1 1 1 1 1 uucp Unix to Unix Copy 1 1 1 1 1 UUCPNET The international store and forward network consisting of all the world's connected Unix machines (and others running some clone of the UUCP software). Any machine reachable only via a bang path is on UUCPNET. See network address. [Jargon File] 1 1 1 1 1 uudecode A Unix program to convert the ASCII output of uuencode back to binary. See uuencode for details. 1 1 1 1 1 uuencode (Unix-to-Unix encode) A Unix program for encoding binary data as ASCII. Uuencode was originally used with uucp to transfer binary files over serial lines which did not preserve the top bit of characters, but is now used for sending binary files by e-mail and posting to Usenet newsgroups etc. The program uudecode reverses the effect of uuencode, recreating the original binary file exactly. Uuencoded data starts with a line of the form begin <mode> <file> where <mode> is the files read/write/execute permissions as three octal digits and <file> is the name to be used when recreating the binary data. Uuencode repeatedly takes in a group of three bytes, adding trailing zeros if there are less than three bytes left. These 24 bits are split into four groups of six which are treated as 1 1 1 1 1 UUNET PIPEX An Internet provider, part of the Unipalm Group. PIPEX launched their Internet service in March 1992, and by November 1993 provided Internet service to 150 customer sites in the UK. Each site is either a complete commercial company or a branch of one, or a public-sector organisation. They provide a commercial internetworking service, with 24-hour support, and a resilient backbone with multiple international links. PIPEX provides for individual users through their PIPEX Dial service, and has a number of re-sellers connected to its backbone, including CityScape, Direct Connection and the IBM PC User Group, who also offer such services. (http://pipex.net). E-mail: <support@pipex.net>. Address (Head office): Cambridge ? Address: King St. London EC2V(?) (1996-10-13) 1 1 1 1 1 UUPC UUCP for MS-DOS, Microsoft Windows, and OS/2. E-mail: <server@netmail.com> with subject SEND INDEX. 1 1 1 1 1 UX user experience 1 1 1 1 1 uy The country code for Uruguay. (1999-01-27) 1 1 1 1 1 uz The country code for Uzbekistan. (1999-01-27) 1 1 1 1 1 V Upper case V, ASCII character 86, known in INTERCAL as book. 1. A testbed for distributed system research. 2. Wide-spectrum language used in the knowledge-based environment CHI. "Research on Knowledge-Based Software Environments at Kestrel Inst", D.R. Smith et al, IEEE Trans Soft Eng SE-11(11):1278-1295 (1985). 1 1 1 1 1 V.10 An ITU-T recommendation on electrical characteristics for unbalanced double-current interchange circuits operating at data signalling rates nominally up to 100 kbps. This recommendation is also included but not published in ITU-T X series under alias number X.26. The circuit defined in this standard is used in other serial line standards such as EIA-232 and EIA-423, that implement single ended communication. (2002-10-05) 1 1 1 1 1 V.11 An ITU-T recommendation on electrical characteristics for balanced double-current interchange circuits operating at data signalling rates up to 10 Mbps. V.11 is also included but not published in the as ITU-T X.27. V.11 is used in other serial line standards such as EIA-422 and EIA-485, that implement differential line communication. (2003-04-06) 1 1 1 1 1 V.17 An ITU-T modem protocol for 14400 bps half duplex communications with fall back to 12000 bps, 9600 bps and 7200 bps. (2004-07-26) 1 1 1 1 1 V.21 An ITU-T modem protocol for 300 bps two-wire full-duplex communications using Frequency Shift Keying modulation. All modern modems support both V.21 and the close variant, Bell 103. (1996-07-22) 1 1 1 1 1 V.22 An ITU-T modem protocol which allowed data rates of 1200 bps. V.22bis doubled this. (2004-07-26) 1 1 1 1 1 V.22bis V.22 twice. An ITU-T modem protocol which allowed a data rate of 2400 bits per second, twice that of V.22. 1 1 1 1 1 V.23 An ITU-T modem protocol which allowed half-duplex (unidirectional) data transmission at 1200 bits per second with a 75 bps back channel and fall back to 600/75 bps. This was the main standard used for British Telecom's Prestel service. (2004-07-26) 1 1 1 1 1 V.24 The ITU-T standard defining interchange circuits between DTE and DCE. V.24 is the ITU-T equivalent of EIA standard EIA-232C, though V.24 only specifies the meaning of the signals, not the connector or the voltages used. V.24 recommends 12 modem carrier frequencies that will not interfere with Dual Tone Multi-Frequency or other telephone control tones. These are: GROUP A = 920 Hz, 1000 Hz, 1080 Hz, 1160 Hz GROUP B = 1320 Hz, 1400 Hz, 1480 Hz, 1560 Hz Group C = 1720 Hz, 1800 Hz, 1880 Hz, 1960 Hz (2004-08-02) 1 1 1 1 1 V.25 A standard allowing an auto-answer modem to determine the correct modulation standard to use. (2001-04-06) 1 1 1 1 1 V.25 bis A cryptic command language for modems. (2004-08-02) 1 1 1 1 1 V.27 ter An ITU-T modem protocol which allowed 4800 bps communications with fall back to 2400 bps. V27.ter was used by Fax machines. (2004-07-26) 1 1 1 1 1 V.28 An ITU-T physical interface standard for serial data communications equipment, formally titled "Electrical Characteristics for Unbalanced Double-Current Interchange Circuits". The combination of V.28 and V.24 is equivalent to the EIA's RS-232 and uses the same 25-pin connectors. (2001-04-06) 1 1 1 1 1 V.29 An ITU-T modem protocol which allows 9600 bps half duplex or four wire communications with fall back to 7200 bps and 4800 bps. V.29 is used by fax machines. (2004-07-30) 1 1 1 1 1 V.32 An ITU-T standard protocol for modems transmitting at 9600 bits per second with fall back to 4800 bps. V.32bis extended this to 14400 bps. V32 and V.32bis acheive bidirectional data transmission not by having different sets of tones at each end but by subtracting what is sent from what is received. (2004-07-30) 1 1 1 1 1 V.32bis V.32 twice. An extension of the ITU-T V.32 modem protocol allowing 14400 bits per second with fall back to 12000bps, 9600bps, 7200bps and 4800 bps. The modem should select the appropriate speed according to the current line conditions. See also V.32ter. (1994-12-15) 1 1 1 1 1 V.32ter An extension of the ITU-T V.32bis modem protocol. While waiting for V.34, many modem manufacturers decided to extend V.32bis to 19.2 kbps. This was known as V.32ter which some marketroids rechristened V.32 terbo which is not only misspelled but misses the fact that V.32ter means the third revision of V.32. (1994-12-15) 1 1 1 1 1 V.34 An ITU-T standard modem serial line protocol using symbol rates of 2400, 2743, 2800, 3000, >3200 and 3429 and up to 28800 bits per second. The official V.34 draft recommendation was titled: Modem operating at data signalling rates of up to 28 800 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits. During the lengthy process of approval by ITU-T, many manufacturers released 28.8 kbps modems described as "V.FAST". The V.34 recommendation was ratified by ITU-T on 20 September 1994. Rockwell and US Robotics both have seats on the ITU-T, and have both released chip set/BIOS combinations that they feel will meet V.34. V.34 modems will also support V.FC if the manufacturer currently supports V.FC (e.g. Rockwell). Some (all?) V.34 modems will also support line probing. ITU document 1 1 1 1 1 V.35 The ITU-T standard for data transmission at 48 kilobits per second over 60 - 108 KHz group band circuits. It contains the 34-pin V.34 connector specifications normally implemented on a modular RJ-45 connector. (1995-03-02) 1 1 1 1 1 V.42 An ITU-T standard protocol for error correction between modems, which includes MNP up to level 4 and asynchronous to synchronous conversion. (2004-08-02) 1 1 1 1 1 V.42bis An extension of the ITU-T V.42 standard modem protocol to included compression using a Lempel-Ziv related technique, which detects frequently occurring character strings and replaces them with tokens. This is similar to the Unix compress utility. Typical compression for text is 50% or better; with nearly 20% gain from synchronous conversion this gives reduces transmission time by almost 60%. [Details? On-line spec?] (2004-08-02) 1 1 1 1 1 V.90 An ITU-T standard modem serial line protocol allowing download speeds of up to 56 kbps with upload speeds of 33.6 kbps. V.90 modems are designed for connections that are digital at one end and have only one digital-to-analogue conversion. As of 1998-02-06 the V.90 standard, formerly called V.pcm, has been given final approval by ITU-T. On 1998-10-27 the ITU-T announced that approval of the V.90 standard was completed. Interoperability testing is complete or in progress for several modem manufacturers. The V.90 standard reconciles two competing standards, X2 and K56flex. The ITU-T has initiated the approval process for a new all-digital version of the protocol, to be known as V.91. ITU Press Release 98-04 (http://itu.int/newsroom/press/releases/1998/98-04.html). and NP-3 (http://itu.int/newsroom/press/releases/1998/NP-3.html). 1 1 1 1 1 V.91 An all-digital version of the V.90 protocol, undergoing ITU-T approval. (1999-01-13) 1 1 1 1 1 va The country code for the Vatican. (1999-01-27) 1 1 1 1 1 vacuum tube electron tube 1 1 1 1 1 vadding /vad'ing/ (From VAD, a permutation of ADV, i.e. ADVENT, used to avoid a particular admin's continual search-and-destroy sweeps for the game) A leisure-time activity of certain hackers involving the covert exploration of the "secret" parts of large buildings - basements, roofs, freight elevators, maintenance crawlways, steam tunnels, and the like. A few go so far as to learn locksmithing in order to synthesise vadding keys. The verb is "to vad" (compare phreaking; see also hack, sense 9). This term dates from the late 1970s, before which such activity was simply called hacking; the older usage is still prevalent at MIT. Vadding (pronounced /vay'ding/) was also popular CMU, at least as early as 1986. People who did it every night were called the "vaders," possibly after "elevator," which was one of the things they played with, or "invader," or "Darth Vader". This game was usually played along with no-holds-barred hide-and-seek. CMU grad students were the 1 1 1 1 1 VAL 1. Value-oriented Algorithmic Language. J.B. Dennis, MIT 1979. Single assignment language, designed for MIT dataflow machine. Based on CLU, has iteration and error handling, lacking in recursion and I/O. "A Value- Oriented Algorithmic Language", W.B. Ackermann et al, MIT LCS TR-218, June 1979. The VAL Language: Description and Analysis, J.R. McGraw, TOPLAS 4(1):44-82 (Jan 1982). 2. <language, robotics> Variable Assembly Language. Unimation. Language for industrial robots. Version: VAL II - "VAL II: A New Robot Control System for Automatic Manufacturing, B.E. Shimano et al, Proc IEEE Intl Conf on" Robotics 1984, pp.278-292. 3. VHDL Annotation Language. Stanford. (ftp://wilbur.stanford.edu/pub/valbin-sun3-4.0-0.1.3.tar.Z). Source in Ada available from Larry M. Augustin <lma@sierra.stanford.edu>. 1 1 1 1 1 Valencia Simple Tasker (VSTa) A small microkernel based Unix-like operating system, taking ideas from QNX and Plan 9, available under GPL. (http://chat.net/~jeske/VSTa/). (1999-03-03) 1 1 1 1 1 valency degree 1 1 1 1 1 Valid A dataflow language. ["A List-Processing-Oriented Data Flow Machine Architecture", Makoto Amamiya et al, AFIPS NCC, June 1982, pp. 143-151]. (1995-02-14) 1 1 1 1 1 validation The stage in the software life-cycle at the end of the development process where software is evaluated to ensure that it complies with the requirements. (1995-02-14) 1 1 1 1 1 value brightness 1 1 1 1 1 Value Added Network (VAN) A privately owned network that provides a specific service, such as legal research or access to a specialised database, for a fee. A Value Added Network usually offers some service or information that is not readily available on public networks. A Value Added Network's customers typically purchase leased lines that connect them to the network or they use a dial-up number, given by the network owner, to gain access to the network. (1998-11-10) 1 1 1 1 1 value added reseller (VAR, or "value added retailer") A company which sells something (e.g. computers) made by another company (an OEM) with extra components added (e.g. specialist software). (1995-02-14) 1 1 1 1 1 value added retailer value added reseller 1 1 1 1 1 valve UK term for a vacuum tube. (1996-01-10) 1 1 1 1 1 vampire tap A device to connect a network node to an RG8 thick ethernet cable without affecting other connected nodes. A vampire tap has an interface box with a "V" shaped groove along one side. A sharp needle protrudes from the center of the groove. The cable is clamped into the groove by a grooved plate held in position by two thumb screws. With sufficient practise, tightening the screws forces the needle through the cable jacket and into contact with the cable's center wire while other spikes bite into the outer conductor. The interface box has a 15 pin connector to connect to the network node. The vampire tap is often built into the transceiver, with a more flexible multi-wire "drop cable" to connect the transceiver to the node. (2004-08-25) 1 1 1 1 1 VAN Value Added Network 1 1 1 1 1 vanilla 1. (Default flavour of ice cream in the US) Ordinary flavour, standard. When used of food, very often does not mean that the food is flavoured with vanilla extract! For example, "vanilla wonton soup" means ordinary wonton soup, as opposed to hot-and-sour wonton soup. Applied to hardware and software, as in "Vanilla Version 7 Unix can't run on a vanilla PDP 11/34." Also used to orthogonalise chip nomenclature; for instance, a 74V00 means what TI calls a 7400, as distinct from a 74LS00, etc. This word differs from canonical in that the latter means "default", whereas vanilla simply means "ordinary". For example, when hackers go to a chinese restaurant, hot-and-sour wonton soup is the canonical wonton soup to get (because that is what most of them usually order) even though it isn't the vanilla wonton soup. [Jargon File] (1994-11-04) 1 1 1 1 1 vanity domain A domain you register for the sole purpose of having your own domain so you can have an easily remembered URL and e-mail address. The domain is usually served (often vhosted) off someone else's machines. This is as opposed to a domain you register because you have machines of your own which are already on the Internet and which you want to make addressable via something other than dot addresses. Whereas vanity domains were almost unheard-of in 1980s, since the invention and popularisation of the Web in the mid-1990s and the desire for URLs which consist only of memorable domain names (e.g., "http://pbs.org") for everything from movies to car wax, vanity domains have come to be the rule instead of the exception. (1997-09-11) 1 1 1 1 1 vannevar /van'*-var/ A bogus technological prediction or a foredoomed engineering concept, especially one that fails by implicitly assuming that technologies develop linearly, incrementally, and in isolation from one another when in fact the learning curve tends to be highly nonlinear, revolutions are common, and competition is the rule. The prototype was Vannevar Bush's prediction of "electronic brains" the size of the Empire State Building with a Niagara-Falls-equivalent cooling system for their tubes and relays, a prediction made at a time when the semiconductor effect had already been demonstrated. Other famous vannevars have included magnetic-bubble memory, LISP machines, videotex, and a paper from the late 1970s that computed a purported ultimate limit on areal density for integrated circuits that was in fact less than the routine densities of 5 years later. [Jargon File] (2000-02-29) 1 1 1 1 1 Vannevar Bush Dr. Vannevar Bush, 1890-1974. The man who invented hypertext, which he called memex, in the 1930s. Bush did his undergraduate work at Tufts College, where he later taught. His masters thesis (1913) included the invention of the Profile Tracer, used in surveying work to measure distances over uneven ground. In 1919, he joined MIT's Department of Electrical Engineering, where he stayed for twenty-five years. In 1932, he was appointed vice-president and dean. At this time, Bush worked on optical and photocomposition devices, as well as a machine for rapid selection from banks of microfilm. Further positions followed: president of the Carnegie Institute in Washington, DC (1939); chair of National Advisory Committee for Aeronautics (1939); director of Office of Scientific Research and Development. This last role was as presidential science advisor, which made him personally responsible for the 6,000 scientists involved in the war 1 1 1 1 1 vaporware /vay'pr-weir/ (UK "vapourware") Products announced far in advance of any release (which may or may not actually take place). The term came from Atari users and was later applied by Infoworld to Microsoft's continuous lying about Microsoft Windows. See also brochureware. [Jargon File] (2004-11-16) 1 1 1 1 1 vapourware UK spelling of "vaporware". (2004-11-16) 1 1 1 1 1 VAR Value Added Reseller (or retailer). 1 1 1 1 1 var variable 1 1 1 1 1 varchar A database data type for storing variable-length strings of ASCII data. The amount of storage space used depends on the length of the strings, in contrast to the ordinary "char" type. The maximum length of string must still be specified, e.g. varchar(256). (2009-02-25) 1 1 1 1 1 variable (Sometimes "var" /veir/ or /var/) A named memory location in which a program can store intermediate results and from which it can read it them. Each programming language has different rules about how variables can be named, typed, and used. Typically, a value is "assigned" to a variable in an assignment statement. The value is obtained by evaluating an expression and then stored in the variable. For example, the assignment x = y + 1 means "add one to y and store the result in x". This may look like a mathematical equation but the mathematical equality is only true in the program until the value of x or y changes. Furthermore, statements like x = x + 1 are common. This means "add one to x", which only makes sense 1 1 1 1 1 Variational Graphics eXtended (VGX) Software developed by SDRC for use in 3D CAD solid modelling. (1998-02-06) 1 1 1 1 1 VAX /vaks/ (Virtual Address eXtension) The most successful minicomputer design in industry history, possibly excepting its immediate ancestor, the PDP-11. Between its release in 1978 and its eclipse by killer micros after about 1986, the VAX was probably the hacker's favourite machine, especially after the 1982 release of 4.2BSD Unix. Especially noted for its large, assembly code-programmer-friendly instruction set - an asset that became a liability after the RISC revolution. VAX is also a British brand of carpet cleaner (http://vax.co.uk/) whose advertising slogan, "Nothing sucks like a VAX!" became a battle-cry of RISC partisans. It is even sometimes claimed that DEC actually entered a licencing deal that allowed them to market VAX computers in the UK in return for not challenging the carpet cleaner trademark in the US. The slogan originated in the late 1960s as "Nothing sucks like 1 1 1 1 1 VAX DOCUMENT A document preparation system from DEC. 1 1 1 1 1 VAXectomy /vak-sek't*-mee/ (By analogy with "vasectomy") Removal of a VAX. DEC's Microvaxen, especially, are much slower than newer RISC-based workstations such as the SPARC. Thus, if one knows one has a replacement coming, VAX removal can be cause for celebration. [Jargon File] (1995-02-20) 1 1 1 1 1 VAXen /vak'sn/ (From "oxen", perhaps influenced by "vixen") The plural canonically used among hackers for the DEC VAX computers. "Our installation has four PDP-10s and twenty vaxen." See boxen. [Jargon File] (1995-02-20) 1 1 1 1 1 vaxherd /vaks'herd/ ["oxherd"] An operator who tends one or more VAXen. [Jargon File] 1 1 1 1 1 vaxism /vak'sizm/ A piece of code that exhibits vaxocentrism in critical areas. Compare PC-ism, Unixism. 1 1 1 1 1 VAX MIPS (Or VAX Unit of Performance, VUP) The processing power normally attributed to a Digital Equipment Corporation VAX 11/780. Future VAX systems were rated according to this scale (e.g. VAX 8350's being 2.7 VUPs per CPU). A MicroVAX II is normally associated with 0.9 VUPs and at a later time the MicroVUP was coined to rate VAX workstations. The use of the VUP by Digital Equipment Corporation has been replaced with more standard benchmarks (SPECint and SPECfp) in the DEC Alpha processor systems. (1996-08-22) 1 1 1 1 1 vaxocentrism /vak"soh-sen"trizm/ [analogy with "ethnocentrism"] A notional disease said to afflict C programmers who persist in coding according to certain assumptions that are valid (especially under Unix) on VAXen but false elsewhere. Among these are: 1. The assumption that dereferencing a null pointer is safe because it is all bits 0, and location 0 is readable and 0. Problem: this may instead cause an illegal-address trap on non-VAXen, and even on VAXen under OSes other than BSD Unix. Usually this is an implicit assumption of sloppy code (forgetting to check the pointer before using it), rather than deliberate exploitation of a misfeature. 2. The assumption that characters are signed. 3. The assumption that a pointer to any one type can freely be cast into a pointer to any other type. A stronger form of this is the assumption that all pointers are the same size and format, which means you don't have to worry about getting the casts or types correct in calls. Problem: this fails on 1 1 1 1 1 VAXset A set of software development tools from DEC, including a language-sensitive editor, compilers etc. 1 1 1 1 1 VAXstation A family of workstations from DEC based on their VAX computer architecture. (1995-02-03) 1 1 1 1 1 VAX/VMS VMS 1 1 1 1 1 VB Visual BASIC 1 1 1 1 1 VBA Visual Basic for Applications 1 1 1 1 1 vbell visible bell 1 1 1 1 1 VBScript Visual BASIC Script 1 1 1 1 1 vbx The filename extension for Visual Basic Extension. (1995-02-03) 1 1 1 1 1 vc The country code for Saint Vincent and the Grenadines. (1999-01-27) 1 1 1 1 1 VCC filtering A technique for reducing the amount of Radio Frequency Interference spread via power supply connections. VCC is a common name for the non-ground power supply line in circuits based on bipolar transistors. When part of a circuit generates lots of radio-frequency noise, that portion of the power plane can be isolated from the rest of the circuit and power delivered to it via a low pass filter, usually a PI filter, as shown in the diagram below. source ________inductor_________ load | | capacitor capacitor 1 1 1 1 1 VCD Video Compact Disc 1 1 1 1 1 VCID Virtual Circuit Identifier 1 1 1 1 1 VCL Visual Component Library 1 1 1 1 1 VCODE 1. The intermediate language used in the compilation of NESL. ["Implementation of a Portable Nested Data-Parallel Language", Guy Blelloch et al, in Fourth ACM SIGPLAN Symposium on Princ and Practice of Parallel Programming, ACM, 1993]. 2. The intermediate language used in the compilation of C+@. (1995-01-12) 1 1 1 1 1 VCPI Virtual Control Program Interface 1 1 1 1 1 VCR Video Cassette Recorder 1 1 1 1 1 vdiff /vee'dif/ Visual diff. The operation of finding differences between two files by eyeball search. The term "optical diff" has also been reported, and is sometimes more specifically used for the act of superimposing two nearly identical printouts on one another and holding them up to a light to spot differences. Though this method is poor for detecting omissions in the "rear" file, it can also be used with printouts of graphics, a claim few if any diff programs can make. See diff. [Jargon File] 1 1 1 1 1 VDL Vienna Definition Language 1 1 1 1 1 VDM 1. Vienna Definition Method 2. Virtual Device Metafile. 1 1 1 1 1 VDM++ Object-oriented extension of VDM-SL. ["Object-Oriented Specification in VDM++", in Object Oriented Specification Case Studies, K. Lano et al eds, P-H 1993]. 1 1 1 1 1 VDM-SL Vienna Development Method Specification Language 1 1 1 1 1 VDSL Very high bit-rate Digital Subscriber Line 1 1 1 1 1 VDT video display terminal 1 1 1 1 1 VDU Visual Display Unit 1 1 1 1 1 vdx virtual network bios driver 1 1 1 1 1 ve The country code for Venezuela. (1999-01-27) 1 1 1 1 1 vector 1. <mathematics> A member of a vector space. 2. <graphics> A line or movement defined by its end points, or by the current position and one other point. See vector graphics. 3. <operating system> A memory location containing the address of some code, often some kind of exception handler or other operating system service. By changing the vector to point to a different piece of code it is possible to modify the behaviour of the operating system. Compare hook. 4. <programming> A one-dimensional array. (1996-09-30) 1 1 1 1 1 Vector C A variant of C from CMU(?), similar to ACTUS. (1996-09-30) 1 1 1 1 1 vector font outline font 1 1 1 1 1 vector graphics (Sometimes called "object-oriented" graphics, though it's nothing to do with object-oriented programming). The representation of separate shapes such as lines, polygons and text, and groups of such objects, as opposed to bitmaps. The advantage of vector graphics ("drawing") programs over bitmap ("paint") editors is that multiple overlapping elements can be manipulated independently without using differenet layers for each one. It is also easier to render an object at different sizes and to transform it in other ways without worrying about image resolution and pixels. (2001-02-06) 1 1 1 1 1 vector processor array processor 1 1 1 1 1 vector space An additive group on which some (scalar) field has an associative multiplicative action which distributes over the addition of the vector space and respects the addition of the (scalar) field: for vectors u, v and scalars h, k; h(u+v) = hu + hv; (h+k)u = hu + ku; (hk)u = h(ku). [Simple example?] (1996-09-30) 1 1 1 1 1 VECTRAN Fortran with array extensions. ["The VECTRAN Language: An Experimental Language for Vector/Matrix Array Processing", Report G320- 3334, IBM, Aug 1975]. (1996-01-19) 1 1 1 1 1 VEE HP VEE 1 1 1 1 1 veeblefeetzer veeblefetzer 1 1 1 1 1 veeblefester /vee'b*l-fes"tr/ (From "Born Loser" comix via Commodore; probably originally from "Mad" Magazine's Veeblefeetzer parodies ca. 1960) Any obnoxious person engaged in the (alleged) professions of marketing or management. Antonym of hacker. Compare suit, marketroid. See also veeblefetzer. [veeblefeetzer or veeblefetzer?] [Jargon File] (1996-03-31) 1 1 1 1 1 veeblefetzer /vee'b*l-fetz'*/ (Or "veeblefeetzer"?) A purposely nonsensical sounding word applied to any sort of obscure or complicated object, e.g. a piece of computer code, model railroad equipment, auto parts, etc. The more immediate origin of the word is "Mad" Magazine. In the late 1950s and early 1960s it used the word along the same lines, especially in its send-ups of big business. "North American Veeblefetzer" was the subject of satires of an annual reports, an in-house newsletter, and more. A Veeblefetzer, in their case, was a robot-like device that did something or other. The more distant source was probably a 19th century yiddish word, possibly with limited usage. In German, "Fetzer" is any contraption, while "Veeble" is a likely corruption of "Webel" #NAME? with very complicated, wildly active and very loud pieces of machinery. 1 1 1 1 1 VEL LISP70 1 1 1 1 1 Vendor Independent Messaging (VIM) An electronic mail API promoted by an industry group headed by Lotus Development. VIM is a competitor to Microsoft's MAPI. [Features?] (1995-03-28) 1 1 1 1 1 ventilator card lace card 1 1 1 1 1 Ventura Publisher Corel VENTURA 1 1 1 1 1 Venus flytrap firewall machine 1 1 1 1 1 verbage /ver'b*j/ Speech or writing with an excess of words or of obscure words. Although identical in meaning, and almost in spelling, to the common word verbiage, Patrick Flatley believes he was the first to coin the word "verbage", as a portmanteau of "verbal" and garbage, in the article cited below (itself a prime example of verbiage). [Fordham University student newspaper, "The Observer", 1982-10-06, p6]. (2011-12-21) 1 1 1 1 1 verbiage documentation, especially documentation that is verbose and/or obscure as in the common meaning of the term. [Jargon File] (2011-12-21) 1 1 1 1 1 Verdi (named after the Italian composer Giuseppe Verdi (1813-1901)) Provable systems language. Descendant of Ottawa Euclid. 1 1 1 1 1 verification The process of determining whether or not the products of a given phase in the life-cycle fulfil a set of established requirements. 1 1 1 1 1 Verilog A Hardware Description Language for electronic design and gate level simulation by Cadence Design Systems. xnf2ver is an XNF to Verilog translator. ["The Verilog Hardware Description Language", Donald E. Thomas & Philip Moorby, Kluwer, 1991]. (1999-04-16) 1 1 1 1 1 Verilog SA A French real-time software engineering company. (1999-04-16) 1 1 1 1 1 Veronica Very Easy Rodent-Oriented Net-wide Index to Computerized Archives. Veronica offers a keyword search of most gopher menu titles in the entire gopher web. As archie is to FTP archives, Veronica is to Gopherspace. A Veronica search produces a menu of Gopher items, each of which is a direct pointer to a Gopher data source. Because Veronica is accessed through a Gopher Client, it is easy to use, and gives access to all types of data supported by the Gopher protocol. To try Veronica, select it from the "Other Gophers" menu on Minnesota's gopher server, or point your gopher at: Name=veronica (search menu items in most of GopherSpace) Type=1 Port=70 Path=1/veronica Host=gopher.scs.unr.edu (gopher://gopher.scs.unr.edu/1/veronica). 1 1 1 1 1 Versa Module Europa (VME) A flexible open-ended bus system which makes use of the Eurocard standard. VME was introduced in 1981 by Motorola, Philips, Thompson, and Mostek. It was intended to be a flexible environment supporting a variety of computing intensive tasks, and has become a rather popular protocol in the computer industry. It is defined by the IEEE standard 1014-1987. (1997-03-10) 1 1 1 1 1 version One of a sequence of copies of a program, each incorporating new modifications. Each version is usually identified by a number, commonly of the form X.Y where X is the major version number and Y is the release number. Typically an increment in X (with Y reset to zero) signifies a substantial increase in the function of the program or a partial or total re-implementation, whereas Y increases each time the progam is changed in any way and re-released. Version numbers are useful so that the user can know if the program has changed (bugs have been fixed or new functions added) since he obtained his copy and the programmer can tell if a bug report relates to the current version. It is thus always important to state the version when reporting bugs. Statements about compatibility between different software components should always say which versions they apply to. See change management. (1997-12-07) 1 1 1 1 1 Version 7 (V7) The unsupported release of Unix ancestral to all current commercial versions. Brian Kernighan announced the release of V7 in summer 1979, at the Unix User's Group meeting in Toronto. Before the release of the POSIX/SVID standards, V7's features were often treated as a Unix portability baseline. Some old-timers impatient with commercialisation and kernel bloat still maintain that V7 was the Last True Unix. See BSD, USG Unix, System V. [Jargon File] (1996-05-22) 1 1 1 1 1 vertical application An application program supporting one specific industry process, e.g. for e-commerce purchasing applications, the entire distribution process including order entry, shipping, and customer service. Compare horizontal application. (2000-03-28) 1 1 1 1 1 vertical bar The character "|", ASCII code 124. Common names: bar; or; or-bar; v-bar; pipe; vertical bar. Rare: ITU-T: vertical line; gozinta; thru; pipesinta; INTERCAL: spike. Pipe, "gozinta", "thru" and "pipesinta" refer to the use of | in Unix shells to create a pipe. Some keyboards show both a solid vertical bar (code 124) and a broken vertical bar (code 166). [Does anyone call either kind of vertical bar "pling"? Other codes?] (1998-09-20) 1 1 1 1 1 vertical encoding An instruction set where a field (a bit or group of bits) of the instruction word is decoded (either by hard-wired logic or microcode) to generate signals to control the functional units, as opposed to horizontal encoding where the instruction word bits are used as the control signals directly. With vertical encoding, which combinations of signals and operations are possible is dictated by the decoding logic; the instruction field can only select one of these preprogrammed combinations. This has the advantage that many control signals can be generated based on only a few instruction word bits and only valid combinations of control signals can be generated, e.g. only one source driving a bus at once. An instruction set may use a mixture of horizontal and vertical encoding within each instruction. (1995-04-23) 1 1 1 1 1 vertical loop combination fusion 1 1 1 1 1 vertical microcode Microcode using vertical encoding. (1995-04-23) 1 1 1 1 1 Vertical Redundancy Check (VRC) An error checking method performed on one 8-bit ASCII character, where the 8th bit is used as the parity bit. The resulting parity bit is constructed by XORing the word. The result is a "1" if there is an odd number of 1s, and a "0" if there is an even number of 1s in the word. This method is unreliable because if an odd number of bits are distorted, the check will not detect the error. The Longitudinal Redundancy Check is an improvement. (2001-04-28) 1 1 1 1 1 vertical refresh rate Synonym for refresh rate. (1996-02-09) 1 1 1 1 1 vertical scan rate Synonym for refresh rate. (1996-02-09) 1 1 1 1 1 Very Efficient Speculative Parallel Architecture (VESPA, Portuguese for "wasp") An Edinburgh University project using speculative multithreading to improve single-application and multiprogramming performance, and to increase fault tolerance and reliability. The project aims to develop a compilation environment to generate efficient speculative parallel code, including speculative parallelisation and speculative helper threads. Other research involves the development of optimized thread-level speculative architectures and novel uses of speculative multithreading, such as fault-tolerance. VESPA Home (http://homepages.inf.ed.ac.uk/mc/Projects/VESPA/vespa.html). (2008-04-04) 1 1 1 1 1 Very high bit-rate Digital Subscriber Line (VDSL) A form of Digital Subscriber Line similar to ADSL but providing higher speeds at reduced lengths. (1998-05-18) 1 1 1 1 1 Very Large Database (VLDB) A database that can use a Very Large Memory model to keep as much data as possible in physical memory. (Oracle http://oracle.com/platforms/dec/collateral/vlmwp_3.html). (1998-07-07) 1 1 1 1 1 Very Large Memory (VLM) A processor and operating system that can use more than 4GB of RAM, which is the limit for systems using 32-bit addresses. VLM architectures allow application programs and Very Large Databases with more than 4GB of data to be placed entirely in physical memory, with large performance enhancements. Some recent processors like the DEC Alpha can process 64 bits of data at a time and use addresses wider than 32 bits. Digital Unix (http://unix.digital.com/unix/64bit/). (Solaris http://sun.com/solaris/64bit.html). (SGI http://sgi.com/Technology/standard/faq.html). (Unix 98 http://UNIX-systems.org/version2/whatsnew/login_64bit.html). [How wide are the address busses?] (1998-07-07) 1 1 1 1 1 Very Large Scale Integration (VLSI) A term describing semiconductor integrated circuits composed of hundreds of thousands of logic elements or memory cells. (1995-01-11) 1 1 1 1 1 Very Long Instruction Word (VLIW) Used to describe a machine code instruction set implemented using horizontal microcode. A horizontally encoded instruction word which encodes four or more operations might be considered "very long". VLIW architectures are sometimes classified as a type of static superscalar architecture. They are static in the sense that which units operate in parallel is determined by the instruction rather than by dynamic scheduling at run time. Producing code for VLIW machines is difficult; trace scheduling is a helpful compiler technique. The most famous VLIW machine was built by (the late) Multiflow Computer, Inc. (1994-11-11) 1 1 1 1 1 Very Small Aperture Terminal (VSAT) A kind of ground station used to contact a communications satellite such as INMARSAT. (1995-03-28) 1 1 1 1 1 VESA Video Electronics Standards Association 1 1 1 1 1 VESA Local Bus (VL, VLB) A local bus defined by the Video Electronics Standards Association, mostly used in personal computers based on the Intel 486. See also PCI. (1995-03-31) 1 1 1 1 1 VESPA Very Efficient Speculative Parallel Architecture 1 1 1 1 1 V.FAST V.34 1 1 1 1 1 VFAT A standard developed by Microsoft to enable long file names on standard FAT partitions. VFAT suffers from all the drawbacks of FAT and adds more problems but moving to it is very easy. (1996-12-23) 1 1 1 1 1 V.FC A serial line protocol supported by some modems. Uses symbol rates of 2400, 2800, 3000, >3200 and 3429 and up to 28800 baud. V.34 modems will also support V.FC if the manufacturer currently supports V.FC. The first V.FC modems were shipped in November 1993 and there have been many thousands sold. There will probably be in excess of a million V.FC modems installed by the end of 1994. V.FC was intended to take some of the techniques being proposed for V.34 and put them into a real modem that people could use. This also gave a lot of people the opportunity to try out 28.8 kilobit per second operation for the first time. There was never any intention from Hayes or Rockwell (who worked together for two years on V.FC) that V.FC would be compatible with V.34 - even if they had wanted it, others would have made sure it didn't happen! In fact, they made the start-up deliberately different from V.34 so that it would be 1 1 1 1 1 vg The country code for the British Virgin Islands. (1999-01-27) 1 1 1 1 1 VGA Video Graphics Array (not "Adapter"). (1995-11-16) 1 1 1 1 1 VGQF A query language. 1 1 1 1 1 vgrep /vee'grep/ (Or "optical grep") Visual grep. Finding patterns in a file by eye rather than digitally. Compare vdiff. [Jargon File] (1998-02-06) 1 1 1 1 1 VGX Variational Graphics eXtended 1 1 1 1 1 VHDL Very High Speed Integrated Circuit (VHSIC) Hardware Description Language. A large high-level VLSI design language with Ada-like syntax. The DoD standard for hardware description, now standardised as IEEE 1076. ["VHSIC Hardware Description Language", M.R. Shahdad et al, IEEE Computer 18(2):94-103 (Feb 1985)]. 1 1 1 1 1 VHE Virtual Home Environment 1 1 1 1 1 VHLL Very-High-Level Language. A bondage-and-discipline language that the speaker happens to like; Prolog and Backus's FP are often called VHLLs. (1994-12-07) 1 1 1 1 1 vhost virtual host 1 1 1 1 1 VHS 1. Very High Speed. 2. storage Video Home System. JVC's video cassette format. 3. Virtual Host Storage. 1 1 1 1 1 vi 1. <tool> Visual Interface. 2. <networking> The country code for the U. S. Virgin Islands. [Jargon File] (1999-01-27) 1 1 1 1 1 VIC-20 A home computer made by Commodore with a 6502 CPU, similar in style to the Commodore 64 and Commodore C16. The VIC-20 was released before the C64, and after the Commodore PET(?). It was intended to be more of a low-end home computer than the PET. The VIC-20 had connectors for game cartridges and a tape drive (compatible with a C64). It came with five kilobytes of RAM, but 1.5 KB were used by the system for various things, like the video display (which had an unusual 22x20 char/line screen layout), and other dynamic aspects of the operating system (such as it was). The RAM was expandable with a plug-in cartridge which used the same expansion port as games. Port expander boxes were available to allow more than one cartridge to be connected at a time. RAM cartridges were available in several sizes: 3K, 8K, 16K and 32K. The internal memory map was re-organised with the addition of each size cartridge, leading to the situation that 1 1 1 1 1 victim cache An extension to a direct mapped cache that adds a small, secondary, fully associative cache to store cache blocks that have been ejected from the main cache due to a capacity or conflict miss. These ejected blocks are likely to be needed again so storing them in the secondary cache should increase performance. Victim caches with as few as five places have been found to reduce conflict misses, especially for small, direct-mapped data caches. E.g. a four-place victim cache removed 20% to 95% (depending on program) of such misses in a 4-KB cache. (http://www.scism.sbu.ac.uk/ccsv/josephmb/CS-L2-MT/week12.html). (2007-02-23) 1 1 1 1 1 video Moving images presented as a sequence of static images (called "frames") representing snapshots of the scene, taken at regularly spaced time intervals, e.g. 50 frames per second. Apart from the frame rate, other important properties of a video are the resolution and colour depth of the individual images. Digital video data is typically stored and transmitted in a format like MPEG or H.264 that includes synchoronised sound. Unlike broadcast television, digital video on a computer or network uses compression. Compression is even more important for video that for static images due to the large amount of data involved in even a short video. Furthermore, compression allows video to be transmitted via a channel whose bandwidth is less than the raw data rate implied by the resolution and frame rate. This allows the recipient to start displaying the video before the transmission is complete, a 1 1 1 1 1 video adapter graphics adaptor 1 1 1 1 1 video card graphics adaptor 1 1 1 1 1 Video Compact Disc (VCD) A storage format used for film distribution. [Details? Relationship to audio CD?] (2004-02-15) 1 1 1 1 1 video compression Compression of sequences of images. Video compression algorithms use the fact that there are usually only small changes from one "frame" to the next so they only need to encode the starting frame and a sequence of differences between frames. This is known as "inter-frame coding" or "3D coding". MPEG is a committee producing standards in this area and also the name of their standard algorithm. H.261 is another standard. See also Integrated Information Technology, 3DO, full-motion video, Online Media. 1 1 1 1 1 video conference An instance of video conferencing. 1 1 1 1 1 video conferencing A discussion between two or more groups of people who are in different places but can see and hear each other using electronic communications. Pictures and sound are carried by the telecommunication network and such conferences can take place across the world. To overcome the bandwidth and latency limitations of current networks (especially the PSTN), some form of video compression is often used. (1995-05-01) 1 1 1 1 1 video dial tone A means by which telephone companies can deliver "television" programs on a common carrier basis and, by law, provide equal access to all. [What does this mean?] (1996-12-01) 1 1 1 1 1 video display standard display standard 1 1 1 1 1 video display terminal visual display unit 1 1 1 1 1 Video Electronics Standards Association (VESA) An industry standards organisation created in 1989 or 1990 mostly(?) concerned with IBM compatible personal computers. The first standard it created was the 800 x 600 pixel Super VGA (SVGA) display and its software interface. It also defined the VESA Local Bus (VLB). See also PCI. (http://vesa.org/). (1995-11-16) 1 1 1 1 1 Video Graphics Adapter Video Graphics Array 1 1 1 1 1 Video Graphics Adaptor Video Graphics Array 1 1 1 1 1 Video Graphics Array (VGA) A display standard for IBM PCs, with 640 x 480 pixels in 16 colours and a 4:3 aspect ratio. There is also a text mode with 720 x 400 pixels. IBM technical references define the *product name* of their original VGA display board as "Video Graphics Array", in contrast to the preceding boards, the "Color Graphics Adapter" (CGA) and "Enhanced Graphics Adapter" (EGA). See also Super Video Graphics Adapter. (1995-01-12) 1 1 1 1 1 video memory The memory in a computer's graphics adaptor, used to store the image displayed on a bitmap display. Often this is built using VRAM chips. There is normally a simple correspondence between groups of bits in video memory and the dots or "pixels" on the screen, such that writing to a given group of bits will alter the appearance of a single dot. If each pixel corresponds to eight bits then it can have any of 256 colours (or shades of grey on a monochrome display). The video display electronics is responsible for reading the data from video memory and converting it into the necessary signals to drive the display. Often this includes a colour palette which converts pixel values into RGB triplets. (1996-11-01) 1 1 1 1 1 Video on Demand (VoD) A planned system using video compression to supply programs to viewers when requested, via ISDN or cable. (1994-11-02) 1 1 1 1 1 video RAM video random-access memory 1 1 1 1 1 video random-access memory (VRAM) Fast memory designed for storing the image to be displayed on a computer's monitor. VRAM may be built from special memory integrated circuits designed to be accessed sequentially. VRAM must be fast enough to supply data to the display electronics at the speed at which the screen is scanned. Thus for example, for a resolution of 1280x1024 eight-bit pixels at a refresh rate of 70 Hz, the video memory would need to supply 1280x1024x70 = 90 Mbyte/s or one byte every 11 ns. The VRAM may be dual ported in order to allow the display electronics and the CPU to access it at the same time. In an IBM PC the VRAM is located on the display interface card and 0.5 - 2 MB is typical. A VRAM Song (http://fweep.com/vram.html)! (2001-02-14) 1 1 1 1 1 video terminal visual display unit 1 1 1 1 1 videotex An obsolete electronic service offering people the privilege of paying to read the weather on their television screens instead of having somebody read it to them for free while they brush their teeth. The idea bombed everywhere it wasn't government-subsidised, because by the time videotex was practical the installed base of personal computers could hook up to time-sharing services and do the things for which videotex might have been worthwhile better and cheaper. Videotex planners badly overestimated both the appeal of getting information from a computer and the cost of local intelligence at the user's end. Like the gorilla arm effect, this has been a cautionary tale to hackers ever since. See also vannevar. [Jargon File] 1 1 1 1 1 Vienna Definition Language (VDL) IBM Vienna Labs. A language for formal, algebraic definition via operational semantics. Used to specify the semantics of PL/I. See also VDM. ["The Vienna Definition Language", P. Wegner, ACM Comp Surveys 4(1):5-63 (Mar 1972)]. 1 1 1 1 1 Vienna Definition Method Vienna Development Method 1 1 1 1 1 Vienna Development Method (VDM) A program development method based on formal specification using the Vienna Development Method Specification Language (VDM-SL). [Details?] [Is there such a thing as "Vienna Definition Method"?] (2000-11-02) 1 1 1 1 1 Vienna Development Method Specification Language (VDM-SL, Meta-IV) A model-oriented specification language, upon which the Vienna Development Method is based. An ISO draft was released in April 1993. Version: BSI/VDM. (ftp://gateway.dec.com/pub/vdmsl_standard). ["The Vienna Development Method: The Meta-Language", D. Bjorner et al eds, LNCS 61, Springer 1978]. ["The VDM-SL Reference Guide", J. Dawes, Pitman 1991]. ["Systematic Software Development Using VDM", C.B. Jones, P-H 1989]. (2000-11-02) 1 1 1 1 1 Vienna Fortran A data-parallel extension of Fortran 77 for distributed memory multiprocessors by Hans Zima <zima@sophie.par.univie.ac.at>, Vienna University. ["Programming In Vienna Fortran", B. Chapman et al, Scientific Programming 1(1):31-50 (Aug 1992)]. 1 1 1 1 1 Vietnamese An Asian language that, like other CJKV languages, requires 16-bit character encodings but, unlike them, does not use Han characters. While normal Vietnamese has not used Han characters since the 18th century, the standards TCVN 5773 and TCVN 6056 contain Han characters and may be used by computers and academics. (2001-01-01) 1 1 1 1 1 viewer A program to allow a file to be read (or played) but not changed. Viewers are often freely distributable, even when the editor application is not. This allows you to create files with the editor and make the viewer available to other users to view your files, e.g. on a website. Examples include the Word and Adobe Acrobat viewers. (1997-08-29) 1 1 1 1 1 ViewPoints A framework for distributed and concurrent software engineering which provides an alternative approach to traditional centralised software development environments. Decentralised process models are used to drive consistency checking and conflict resolution. The process models use pattern matching on local development histories to determine the particular state of the development process, and employ rules to trigger situation-dependent assistance to the user. Communication between such process models facilitates the decentralised management of explicitly defined consistency constraints. [Ulf Leonhardt] (1995-03-27) 1 1 1 1 1 Views A Smalltalk extension for computer algebra. "An Object Oriented Approach to Algebra System Design", K. Abdali et al, in Symp Symb Alg Manip, ACM 1986, pp.24-30. 1 1 1 1 1 VIF VHDL Interface Format. Intermediate language used by the Vantage VHDL compiler. "A VHDL Compiler Based on Attribute Grammar Methodology", R. Farrow et al, SIGPLAN NOtices 24(7):120-130 (Jul 1989). 1 1 1 1 1 Vi Improved (VIM) (Previously "vi iMitation"), An improved version of vi, available for many platforms. VIM allows multiscreen editing, more flexible insert/command mode handling, better C indentation and much more. (http://vim.org/). (1999-06-15) 1 1 1 1 1 VIM 1. <messaging> Vendor Independent Messaging. 2. <text, tool> Vi Improved. (1999-06-15) 1 1 1 1 1 Vincennes LISP (VLISP) A dialect of Lisp resulting from development, starting in 1971, of Lisp interpreters and compilers at the University of Paris VIII - Vincennes. VLISP interpreters and compilers were designed to run on small computers. Documentation (http://www.artinfo-musinfo.org/en/issues/vlisp/). History of Lisp (http://www.softwarepreservation.org/projects/LISP/index.html#VLISP_). [Relationship to VLISP by Greussay at Paris VI?] (2008-03-16) 1 1 1 1 1 vines A family of local area networking products from Banyan. (1995-03-01) 1 1 1 1 1 Vine Technology A company which provides professional consulting services in the areas of networking, real-time systems, graphic arts, and web server advertisement space. (http://vine.com/). E-mail: <webmaster@vine.com>. (1995-03-03) 1 1 1 1 1 Vint Cerf (Vinton G. Cerf) The co-inventor with Bob Kahn of the Internet and its base protocol, TCP/IP. Like Jon Postel, he was crucial in the development of many higher-level protocols, and has written several dozen RFCs since the late 1960s. Vinton Cerf is senior vice president of Internet Architecture and Technology for MCI WorldCom. His team of architects and engineers design advanced Internet frameworks for delivering a combination of data, information, voice and video services for business and consumer use. In December 1997, President Clinton presented the U.S. National Medal of Technology to Cerf and his partner, Robert E. Kahn, for founding and developing the Internet. Prior to rejoining MCI in 1994, Cerf was vice president of the Corporation for National Research Initiatives (CNRI). As vice president of MCI Digital Information Services from 1982-1986, he led the engineering of MCI Mail, the first commercial 1 1 1 1 1 Vinton Cerf Vint Cerf 1 1 1 1 1 Viola An experimental hypercard-like interpreted hypertext system by Pei Y. Wei of Berkeley. (1994-11-30) 1 1 1 1 1 virgin Unused; pristine; in a known initial state. "Let's bring up a virgin system and see if it crashes again." (Especially useful after contracting a virus through SEX.) Also, by extension, buffers and the like within a program that have not yet been used. [Jargon File] (1994-11-30) 1 1 1 1 1 virgule Rare, and ambiguous: slash or comma. Virgule (or rather, Latin "virgula", meaning "little rod" or, vividly enough, "little penis") was the name of a punctuation character shaped like a small slash and used in the Latin writing system much like a modern comma -- hence the ambiguity of this term in modern English. Compare French "virgule" and Italian "virgola", meaning comma (not "slash"); Italian "doppia virgola" and virgoletta, both meaning "double quote". (1997-04-08) 1 1 1 1 1 Viron ["Five Paradigm Shifts in Programming Language Design and Their Realisation in Viron, a Dataflow Programming Environment", V. Pratt, 10th POPL, ACM 1983, pp. 1-9]. (1994-11-30) 1 1 1 1 1 virtual (Via the technical term virtual memory, probably from the term "virtual image" in optics) 1. Common alternative to logical; often used to refer to the artificial objects (like addressable virtual memory larger than physical memory) created by a computer system to help the system control access to shared resources. 2. Simulated; performing the functions of something that isn't really there. An imaginative child's doll may be a virtual playmate. Opposite of real or physical. [Jargon File] (1994-11-30) 1 1 1 1 1 virtual 86 mode (Or "virtual mode" or "virtual 8086 mode") An operating mode provided by the Intel 80386 and later processors to allow real mode programs to run under operating systems which use protected mode. In this sub-mode of protected mode, an operating environment is created which mimics the address calculation in real mode. In virtual 86 mode the segment MMU is practically turned off and the segment registers exhibit the same behaviour as in real mode. The paged MMU, however, still operates. This means that the one megabyte address space of real mode can be remapped in four kilobyte pages to anywhere in the 32 bit physical address space. Each page can be protected separately from read or write accesses. Virtual mode is handled on a per-task-basis, so each exception (from protection violations or interrupts) switches the processor back into protected mode. It is therefore possible to have multiple tasks in virtual mode 1 1 1 1 1 virtual address 1. <architecture> A memory location accessed by an application program in a system with virtual memory such that intervening hardware and/or software maps the virtual address to real (physical) memory. During the course of execution of an application, the same virtual address may be mapped to many different physical addresses as data and programs are paged out and paged in to other locations. 2. In IBM's VM operating system, Virtual Device Location. (2001-01-02) 1 1 1 1 1 virtual cache A cache which uses virtual address, i.e. it is between the processor and the memory management unit. A virtual cache cannot recognise external access to physical address, e.g. from DMA. The whole cache must be flushed when swapping between tasks which share same virtual address space. (1994-11-30) 1 1 1 1 1 virtual circuit A connection-oriented network service which is implemented on top of a network which may be either connection-oriented or connectionless (packet switching). The term "switched virtual circuit" was coined needlessly to distinguish an ordinary virtual circuit from a permanent virtual circuit. (One of the perpetrators of this confusion appears to be ["Networking Essentials", 1996, Microsoft Press, ISBN 1-55615-806-8], a book aimed at people preparing for the MCSE exam on LANs and WANs). Not to be confused with switched virtual connection. (2001-10-26) 1 1 1 1 1 Virtual Circuit Identifier (VCID) An identifier used for the routing of a virtual circuit. An ATM switch may route according to a Virtual Circuit Identifier, a Virtual Path Identifier, or a combination. (2001-05-16) 1 1 1 1 1 virtual connection 1. (VC) A connection or a path through an ATM network. The word "virtual" indicates that the connection is logical rather than physical. Nothing to do with a virtual circuit on a packet switching network. [Fred Halsall, "Data Communications, Computer Networks and Open Systems", 1996, Addison Wesley]. 2. A communications link that appears to be a direct connection between sender and receiver, although physically the link can be routed through a more circuitous path, running over virtual circuits instead of a private network built primarily with dedicated lines. A virtual connection can provide full-time connection among many sites, including those configured for SNA/SDLC protocol. A virtual connection can handle any transmission protocol and is supported worldwide. It can provide high throughput and low delay for LAN and Internet 1 1 1 1 1 Virtual Control Program Interface (VCPI) An alternative, and incompatible method for doing the same thing as DOS Protected Mode Interface (DPMI). (1995-01-12) 1 1 1 1 1 Virtual Device Driver (VxD) A device driver under Windows 3.x/Windows 95 running as part of the kernel and thus having access to the memory of the kernel and all running processes as well as raw access to the hardware. VxD's usually have the filename extension .386 under Windows 3.x and .vxd under Windows 95. VxD's written for Windows 3.x can be used under Windows 95 but not vice versa. (1997-02-27) 1 1 1 1 1 Virtual Device Location (Or "Virtual Address") The address of a device (e.g. disk, printer, terminal) belonging to a "guest" operating system. Such an address is mapped to a physical device. VM may remap several virtual disks to different parts of a single physical disk. (1995-02-22) 1 1 1 1 1 virtual disk RAM disk 1 1 1 1 1 Virtual Home Environment (VHE) A tool for using NFS on HP UX. (1994-12-07) 1 1 1 1 1 virtual host Most computers on the Internet have a single IP address; however, often via special kernel patches, a given computer can be made to respond to several IP addresses and provide different services (typically different Web services) on each. Each of these different IP addresess (which generally each have their own hostname) act as if they were distinct hosts on distinct machines, even though they are actually all one host. Hence, they are virtual hosts. A common use is when an Internet Service Provider "hosts" web or other services for several of their customers on one computer but giving the appearence that they are separate servers. (1997-09-11) 1 1 1 1 1 Virtual LAN Software defined groups of host on a local area network (LAN) that communicate as if they were on the same wire, even though they are physically on different LAN segments throughout a site. To define a virtual LAN, the network administrator uses a virtual LAN management utility to establish membersip rules that determine which hostss are in a specific virtual LAN. Many models may exist but two seem to dominate: (1) Vitual Segment (or Port-Group) Virtual LAN. These are switched at the data link layer (OSI layer 2). Virtual segments turn an arbitrary number of physical segments into a single virtual segment that funtions as a self-contained traffic domain. (2) Virtual Subnet Virtual LAN: These are switched at the Network Layer (OSI layer 3). Subnet-oriented virtual LANs are based on subnet addresses used by IP, IPX, and other network layer protocols to normally identify physical 1 1 1 1 1 Virtual Loadable Module (VLM) Novell's term for software modules that can be dynamically loaded to extend the functionality of the VLM NetWare Requester for MS-DOS that became standard beginning with Novell NetWare 4. (1995-01-11) 1 1 1 1 1 Virtual Local Area Network (VLAN) A logical grouping of two or more nodes which are not necessarily on the same physical network segment but which share the same IP network number. This is often associated with switched Ethernet. IEEE 802.1Q is a VLAN standard. [Confirm? Better description? Reference?] (2002-08-30) 1 1 1 1 1 Virtual Machine (VM) An IBM pseudo-operating system hypervisor running on IBM 370, ESA and IBM 390 architecture computers. VM comprises CP (Control Program) and CMS (Conversational Monitor System) providing Hypervisor and personal computing environments respectively. VM became most used in the early 1980s as a Hypervisor for multiple DOS/VS and DOS/VSE systems and as IBM's internal operating system of choice. It declined rapidly following widespread adoption of the IBM PC and hardware partitioning in microcode on IBM mainframes after the IBM 3090. VM has been known as VM/SP (System Product, the successor to CP/67), VM/XA, and currently as VM/ESA (Enterprise Systems Architecture). VM/ESA is still in used in 1999, featuring a web interface, Java, and DB2. It is still a major IBM operating system. (http://vmdev.gpl.ibm.com/). 1 1 1 1 1 virtual machine 1. An abstract machine for which an interpreter exists. Virtual machines are often used in the implementation of portable executors for high-level languages. The HLL is compiled into code for the virtual machine (an intermediate language) which is then executed by an interpreter written in assembly language or some other portable language like C. Examples are Core War, Java Virtual Machine, OCODE, OS/2, POPLOG, Portable Scheme Interpreter, Portable Standard Lisp, Parallel Virtual Machine, Sequential Parlog Machine, SNOBOL Implementation Language, SODA, Smalltalk. 2. A software emulation of a physical computing environment. The term gave rise to the name of IBM's VM operating system whose task is to provide one or more simultaneous execution environments in which operating systems or other programs may execute as though they were running "on the bare 1 1 1 1 1 Virtual Machine/Conversational Monitor System (VM/CMS) An IBM time-sharing and personal computing environment executing under Virtual Machine (VM) in a virtual machine environment. VM/CMS is designed to support large numbers of interactive users. It relies on numerous APIs into the Control Program (CP) to provide very efficient single-user processing VM/CMS was only adopted some time after the original design of Virtual Machine as a more efficient personal computing environment than MVS/TSO. (1999-01-19) 1 1 1 1 1 Virtual Machine Environment (VME) ICL's mainframe operating system. (1995-06-28) 1 1 1 1 1 Virtual Machine/ESA Virtual Machine 1 1 1 1 1 Virtual Machine/System Product Virtual Machine 1 1 1 1 1 Virtual Machine/XA Virtual Machine 1 1 1 1 1 virtual memory A system allowing a computer program to behave as though the computer's memory was larger than the actual physical RAM. The excess is stored on hard disk and copied to RAM as required. Virtual memory is usually much larger than physical memory, making it possible to run programs for which the total code plus data size is greater than the amount of RAM available. This is known as "demand paged virtual memory". A page is copied from disk to RAM ("paged in") when an attempt is made to access it and it is not already present. This paging is performed automatically by collaboration between the CPU, the memory management unit (MMU), and the operating system kernel. The program is unaware of virtual memory, it just sees a large address space, only part of which corresponds to physical memory at any instant. The virtual address space is divided into pages. Each virtual address output by the CPU is split into a 1 1 1 1 1 Virtual Memory System (VMS) DEC's proprietary operating system originally produced for its VAX minicomputer. VMS V1 was released in August 1978. VMS was renamed "OpenVMS" around version 5.5. The first version of VMS on DEC Alpha was known as OpenVMS for AXP V1.0, and the correct way to refer to the operating system now is OpenVMS for VAX or OpenVMS for Alpha. The renaming also signified the fact that the X/Open consortium had certified OpenVMS as having a high support for POSIX standards. VMS is one of the most secure operating systems on the market (making it popular in financial institutions). It currently (October 1997) has the best clustering capability (both number and distance) and is very scalable with binaries portable from small desktop workstations up to huge mainframes. Many Unix fans generously concede that VMS would probably be the hacker's favourite commercial OS if Unix didn't exist; 1 1 1 1 1 virtual path The location of a file or directory on a particular server, as seen by a remote client accessing it via web (or similar distributed document service). A virtual path provides access to files outside the default directory and subdirectories. It appears in the form .../~name/... where "~name" is replaced with actual path configured by the administrator. An access control list can be associated with a virtual path. (1995-04-13) 1 1 1 1 1 virtual point of presence (virtual PoP) A point, via which users can connect to an Internet access provider, which is not operated by the provider. The user is charged by the telephone company for the call to the virtual point of presence which relays his call via some third party circuit to the Internet provider's central location. This is in contrast to a physical point of presence (PoP) which is operated by the Internet provider themselves. The advantage of a virtual PoP is that the provider can keep all their modems in one location, thus improving availability and maintenance, but users do not have to pay long-distance call charges to that point. (1994-12-13) 1 1 1 1 1 virtual PoP virtual point of presence 1 1 1 1 1 Virtual Private Network (VPN) The use of encryption in the lower protocol layers to provide a secure connection through an otherwise insecure network, typically the Internet. VPNs are generally cheaper than real private networks using private lines but rely on having the same encryption system at both ends. The encryption may be performed by firewall software or possibly by routers. Link-level (layer 2 and 3) encryption provides extra protection by encrypting all of each datagram except the link-level information. This prevents a listener from obtaining information about network structure. While link-level encryption prevents traffic analysis (a form of attack), it must encrypt/decrypt on every hop and every path. Protocol-level encryption (layer 3 and 4) encryption encrypts protocol data but leaves protocol and link headers clear. While protocol-level encryption requires you to 1 1 1 1 1 virtual reality (VR) 1. <application> Computer simulations that use 3D graphics and devices such as the data glove to allow the user to interact with the simulation. 2. <games> A form of network interaction incorporating aspects of role-playing games, interactive theater, improvisational comedy, and "true confessions" magazines. In a virtual reality forum (such as Usenet's news:alt.callahans newsgroup or the MUD experiments on Internet and elsewhere), interaction between the participants is written like a shared novel complete with scenery, "foreground characters" that may be personae utterly unlike the people who write them, and common "background characters" manipulable by all parties. The one iron law is that you may not write irreversible changes to a character without the consent of the person who "owns" it, otherwise, anything goes. See bamf, cyberspace. 1 1 1 1 1 Virtual Reality Modeling Language (VRML) A draft specification for the design and implementation of a platform-independent language for virtual reality scene description. VRML 1.0 was released on 1995-05-26. (http://vrml.org/). Wired (http://vrml.wired.com/). Hypermail Archive (http://vrml.wired.com/arch/). Mailing list: <majordomo@wired.com> (message body: "subscribe www-vrml your-email-address"). (1995-07-20) 1 1 1 1 1 Virtual Sequential Access Method Virtual Storage Access Method 1 1 1 1 1 virtual server A configuration of a web server that appears to clients as an independent server but which is actually running on a computer that is shared by any number of other virtual servers. Each virtual server can be configured as an independent website, with its own hostname, content, and security settings. DNS maps the hostnames of all virtual servers on one physical server to its IP address. The web server software then uses the "Host" header in the HTTP request to determine which virtual server the request was for, and then processes the request using that virtual server's configuration. Virtual servers allow Internet Service Providers to share one computer between multiple websites while allowing the owner of each website to use and administer the server as though they had complete control. (2003-06-23) 1 1 1 1 1 virtual shredder The jargon equivalent of the bit bucket at shops using IBM's VM/CMS operating system. VM/CMS officially supports a whole bestiary of virtual card readers, virtual printers, and other phantom devices; these are used to supply some of the same capabilities Unix gets from pipes and I/O redirection. [Jargon File] (1995-01-30) 1 1 1 1 1 Virtual Software Factory (VSF) A product from Systematica which allows users to develop CASE tools appropriate to any software engineering methodology. (1997-06-09) 1 1 1 1 1 Virtual Storage Access Method (VSAM) An IBM disk file storage scheme first used in S/370 and virtual storage. VSAM comprises three access methods: Keyed Sequenced Data Set (KSDS), Relative Record Data Set (RRDS), and Entry Sequenced Data Set (ESDS). Both IMS/DB and DB2 are implemented on top of VSAM and use its underlying data structures. ["Storage" or "Sequential"?] (2002-07-26) 1 1 1 1 1 Virtual Storage Extended (VSE, formerly DOS/VSE) is a multitasking, IBM 370-architected operating system similar to Multiple Virtual Storage (MVS). VSE run jobs in partitions rather than address spaces, and uses POWER for input/output rather than JES, but is largely similar to MVS. Subsequent VSE/ESA releases gave VSE the XA-370 channel architecture, 31-bit virtual and real storage support, and data spaces. VSE is the IBM operating system on one-third of installed IBM 4381s and a significant proportion of IBM 9370s as well. It offers transaction processing and batch processing capabilities well beyond Virtual Machine's current capabilities, and has a close affinity with MVS. (1997-06-09) 1 1 1 1 1 Virtual Telecommunications Access Method (VTAM) A data communications access method compatible with IBM's Systems Network Architecture. [More detail?] (1995-01-30) 1 1 1 1 1 virus (By analogy with biological viruses, via science fiction) A program or piece of code, a type of malware, written by a cracker, that "infects" one or more other programs by embedding a copy of itself in them, so that they become Trojan horses. When these programs are executed, the embedded virus is executed too, thus propagating the infection. This normally happens invisibly to the user. A virus has an "engine" - code that enables it to propagate and optionally a "payload" - what it does apart from propagating. It needs a "host" - the particular hardware and software environment on which it can run and a "trigger" - the event that starts it running. Unlike a worm, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends (see SEX). The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently 1 1 1 1 1 viruses virus 1 1 1 1 1 visible bell (Or "visual bell") A program option (whether in a terminal program, termcap setting, or as a stand-alone program) which outputs the bell character code as a visual signal (e.g., a flashing status bar or menu bar). Generally intended for deaf or hearing-disabled users who couldn't hear the normal auditory beep; also widely used by users who simply don't want their machines feeping at them or disturbing other users. [Implementations?] (1997-04-07) 1 1 1 1 1 VisiCalc /vi'zi-calk/ The first spreadsheet program, conceived in 1978 by Dan Bricklin, while he was an MBA student at Harvard Business School. Inspired by a demonstration given by Douglas Engelbart of a point-and-click user interface, Bricklin set out to design an application that would combine the intuitiveness of pencil and paper calculations with the power of a programmable pocket calculator. Bricklin's design was based on the (paper) financial spreadsheet, a kind of document already used in business planning. (Some of Bricklin's notes for VisiCalc were scribbled on the back of a spreadsheet pad.) VisiCalc was probably not the first application to use a spreadsheet model, but it did have a number of original features, all of which continue to be fundamental to spreadsheet software. These include point-and-type editing, range replication and formulas that update automatically with changes to other cells. VisiCalc is widely credited with creating the sudden demand for 1 1 1 1 1 visionary 1. One who hacks vision, in the sense of an Artificial Intelligence researcher working on the problem of getting computers to "see" things using TV cameras. (There isn't any problem in sending information from a TV camera to a computer. The problem is, how can the computer be programmed to make use of the camera information? See SMOP, AI-complete.) 2. [IBM] One who reads the outside literature. At IBM, apparently, such a penchant is viewed with awe and wonder. [Jargon File] 1 1 1 1 1 visit To process a node while traversing a graph. (2001-09-30) 1 1 1 1 1 Visual BASIC (VB) A popular event-driven visual programming system from Microsoft Corporation for Microsoft Windows. VB is good for developing Windows interfaces, it invokes fragments of BASIC code when the user performs certain operations on graphical objects on-screen. It is widely used for in-house application program development and for prototyping. It can also be used to create ActiveX and COM components. Version 1 was released in 1991 [by Microsoft?]. Latest version: 6, as of 1999-11-26. (http://msdn.microsoft.com/vbasic/). History (http://iessoft.com/scripts/vbhistry.asp). Strollo Software (http://op.net/~jstrollo/vblinks.html). Books (http://wrox.com/Consumer/Default.asp?Category=Visual+Basic). (1999-11-26) 1 1 1 1 1 Visual Basic for Applications (VBA) Microsoft's common language for manipulating components of its Microsoft Office suite. It is used as the macro language for these applications and is the primary means of customising and extending them. A VBA program operates on objects representing the application and the entities it manipulates, e.g. a spreadsheet or a range of cells in Microsoft Excel. [Relationship to Visual BASIC? URL?] (1999-09-12) 1 1 1 1 1 Visual BASIC Script (VBScript) Microsoft's scripting language which is an extension of their Visual Basic language. VBScript can be used with Microsoft Office applications and others. It can also be embedded in web pages but can only be understood by Internet Explorer. Visual Basic is a BASIC variant with object-oriented features. Objects include applications, windows and selections. [Relationship with ASP? VBA?] (1998-07-05) 1 1 1 1 1 visual bell visible bell 1 1 1 1 1 Visual C++ A C and C++ programming environment sold by Microsoft Corporation. Usenet newsgroup: news:comp.lang.c++. [Differences? Features?] (1994-12-21) 1 1 1 1 1 Visual Component Library VCL A application framework library for Microsoft Windows and Borland Software Corp.'s Delphi and C++Builder rapid application development software. VCL was originally designed for Delphi but is now also used for C++Builder. This replaces OWL Object Windows Library as Borland's Windows C++ framework of choice. VCL encapsulates the C-based Win32 API into a much easier to use, object-oriented form. Like its direct rival, Microsoft Foundation Class Library (MFC), VCL includes classes to create Windows programs. The VCL component class can be inherited to create new VCL components, which are the building blocks of Delphi and C++Builder applications. VCL components are somewhat in competition with ActiveX controls, though a VCL wrapper can be created to make an ActiveX control seem like a VCL component. Home 1 1 1 1 1 Visual dBASE A Rapid Application Development suite with a compiler and intranet tools to enable developers to publish data on the web. Originally a Borland product, the first version released by dBase, Inc. was Visual dBase 5.7. (2003-11-24) 1 1 1 1 1 Visual Display Unit (VDU, or "video terminal", "video display terminal", VDT, "display terminal") A device incorporating a cathode ray tube (CRT) display, a keyboard and a serial port. A VDU usually also includes its own display electronics which store the received data and convert it into electrical waveforms to drive the CRT. VDUs fall into two categories: dumb terminals and intelligent terminals (sometimes called "programmable terminals"). Early VDUs could only display characters in a single preset font, and these were confined to being layed out in a rectangular grid, reproducing the functionality of the paper-based teletypes they were designed to replace. Later models added graphics facilities but were still driven via serial communications, typically with several VDUs attached to a single multi-user computer. This contrasts with the much faster single bitmap displays integrated into most 1 1 1 1 1 Visual FoxPro A Microsoft database derived from Fox Software's FoxPRO. Latest version: 5.0, as of 2000-06-21. (http://msdn.microsoft.com/vfoxpro/). [Features? Dates?] (2000-08-06) 1 1 1 1 1 Visual Interface (vi) /V-I/, /vi:/, *never* /siks/ A screen editor crufted together by Bill Joy for an early BSD release. vi became the de facto standard Unix editor and a nearly undisputed hacker favourite outside of MIT until the rise of Emacs after about 1984. It tends to frustrate new users no end, as it will neither take commands while expecting input text nor vice versa, and the default setup provides no indication of which mode the editor is in (one correspondent accordingly reports that he has often heard the editor's name pronounced /vi:l/). Nevertheless it is still widely used (about half the respondents in a 1991 Usenet poll preferred it), and even some Emacs fans resort to it as a mail editor and for small editing jobs (mainly because it starts up faster than the bulkier versions of Emacs). See holy wars. (1995-10-03) 1 1 1 1 1 visualisation Making a visible presentation of numerical data, particularly a graphical one. This might include anything from a simple X-Y graph of one dependent variable against one independent variable to a virtual reality which allows you to fly around the data. Gnuplot is the Free Software Foundation's utility for producing various kinds of graphs. Usenet newsgroup: news:comp.graphics. The Computer Graphics Resource Listing contains pointers to several visualisation tools. comp.graphics FAQ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.graphics/). Electronic Visualization Laboratory, University of Illinois at Chicago (http://ncsa.uiuc.edu/EVL/docs/Welcome.html). (2002-02-21) 1 1 1 1 1 visual language visual programming language 1 1 1 1 1 visual programming 1. Writing programs in a language which manipulates visual information or supports visual interaction. 2. Writing programs in a visual programming language. 3. Writing programs in a visual programming environment. 1 1 1 1 1 visual programming environment Software which allows the use of visual expressions (such as graphics, drawings, animation or icons) in the process of programming. These visual expressions may be used as graphical interfaces for textual programming languages. They may be used to form the syntax of new visual programming languages leading to new paradigms such as programming by demonstration or they may be used in graphical presentations of the behaviour or structure of a program. (1995-02-23) 1 1 1 1 1 visual programming language (VPL) Any programming language that allows the user to specify a program in a two-(or more)-dimensionsional way. Conventional textual languages are not considered two-dimensional since the compiler or interpreter processes them as one-dimensional streams of characters. A VPL allows programming with visual expressions - spatial arrangements of textual and graphical symbols. VPLs may be further classified, according to the type and extent of visual expression used, into icon-based languages, form-based languages and diagram languages. Visual programming environments provide graphical or iconic elements which can be manipulated by the user in an interactive way according to some specific spatial grammar for program construction. A visually transformed language is a non-visual language with a superimposed visual representation. Naturally visual languages have an inherent visual expression for which there 1 1 1 1 1 VisualWorks A modern commercial implementation of the Smalltalk programming language. VisualWorks descends directly from the original Smalltalk-80 by Xerox PARC and was originally developed (for some time under the name Objectworks\Smalltalk) by ParcPlace Systems. VisualWorks relies on dynamic translation as its virtual machine technology. VisualWorks Wiki (http://wiki.cs.uiuc.edu/VisualWorks). (2003-05-15) 1 1 1 1 1 VITAL A semantics language using FSL, developed by Mondshein in 1967 [Sammet 1969, p. 641]. (1995-02-23) 1 1 1 1 1 VIVID A numerical constraint-oriented language. ["VIVID: The Kernel of a Knowledge Representation Environment Based on the Constraints Paradigm of Computation", J. Maleki, Proc 20th Annual Hawaii Intl Conf on System Sciences (Jan 1987) pp.591-597]. (1995-02-23) 1 1 1 1 1 viz A visual language for specification and programming. ["viz: A Visual Language Based on Functions", C.M. Holt, 1990 IEEE Workshop on Visual Langs, Oct 1990, pp.221-226]. (1995-02-23) 1 1 1 1 1 VLAN Virtual Local Area Network 1 1 1 1 1 VLB VESA local bus 1 1 1 1 1 VLDB Very Large DataBase [How large?] (1996-12-21) 1 1 1 1 1 Vlisp 1. A Lisp dialect developed by Patrick Greussay <pg@litp.ibp.fr> in about 1973 with a fast interpreter and a portable virtual machine. Vlisp introduced the chronology, a dynamic environment for implementing interrupts. It led to Le_Lisp. See also ObjVlisp. ["Contribution a la Definition Interpretive et a l'Implementation des Lambda-Langages", P. Greussay, These d'Etat, U Paris VI, Nov 1977]. [Relationship to Vincennes LISP?] 2. Vincennes LISP. (2008-03-16) 1 1 1 1 1 VLIW Very Long Instruction Word 1 1 1 1 1 VLM 1. <architecture> Very Large Memory. 2. <networking> Virtual Loadable Module. (1998-02-24) 1 1 1 1 1 VLSI Very Large Scale Integration 1 1 1 1 1 VLSM Variable Length Subnet Masks 1 1 1 1 1 VM Virtual Machine 1 1 1 1 1 VM/CMS Virtual Machine/Conversational Monitor System 1 1 1 1 1 VME 1. <hardware> Versa Module Europa. See VMEbus. 2. <operating system> Virtual Machine Environment. 1 1 1 1 1 VMEbus A widely accepted backplane interconnection bus system developed by a consortium of companies led by Motorola, now standardised as IEEE 1014. (1995-06-01) 1 1 1 1 1 VME Microsystems International Corporation (VMIC) Address: Huntsville, AL, USA. Telephone: +1 800 322 3616. (1995-06-01) 1 1 1 1 1 VM/ESA Virtual Machine 1 1 1 1 1 VML VODAK Model Language. Language for an extensible object-oriented database. ["Object-Oriented Modeling for Hypermedia Systems Using the Object-Oriented VODAK Model Language (VML)" Wolfgang Klas et al, in Object-Oriented Database Management Systems, NATO ASI Series, Springer 1993]. E-mail: <aberer@darmstadt.gmd.de>. 1 1 1 1 1 VMS Virtual Memory System 1 1 1 1 1 VM/SP Virtual Machine 1 1 1 1 1 VM/XA Virtual Machine 1 1 1 1 1 vn The country code for Vietnam. (1999-01-27) 1 1 1 1 1 vocoder Hardware or software which implements a compression algorithm particular to voice. For example Qualcomm uses a vocoding algorithm to compresses voice data in digital communication systems such as wireless CDMA and Eudora voice attach. (1998-04-29) 1 1 1 1 1 vocoding vocoder 1 1 1 1 1 VoD video on demand 1 1 1 1 1 voice mail Any system for sending, storing and retrieving audio messages, like a telephone answering machine. A voice mailbox is typically associated with a telephone number or extension. When the number is called and the line is busy or not answered, the caller hears a message left by the owner and is given instructions for leaving a message or other available options, such as paging the individual or being transferred to an operator. The owner of a mailbox can change the outgoing message or listen to incoming messages after entering a PIN. Members of a voice mail system can generally forward or broadcast messages to other members' boxes. The experience of two people trying to reach other by telephone but always reaching each other's voice mail is referred to as "(tele)phone tag". (1996-11-03) 1 1 1 1 1 voice-net Hackish way of referring to the plain old telephone system, comparing it to a digital network. Usenet sig blocks sometimes include the sender's telephone number next to a Voice: or "Voice-Net:" header; variants of this are Voicenet and "V-Net". Compare paper-net, snail-mail. [Jargon File] (1995-02-16) 1 1 1 1 1 Voice over IP (VoIP) Any technology providing voice telephony services over IP, including CODECs, streaming protocols and session control. The major advantage of VoIP is lower cost, by avoiding dedicated voice circuits. Currently VoIP is being deployed on internal corporate networks, and, via the Internet, for low cost (and low quality) international calls. It is also used for telephony applications such as voice and fax mail. The ITU standard is H.323, which is a whole suite of protocols, while the IETF has developed the much simpler SIP to solve the session control problem and MGCP/Megaco to solve the gateway problem. (2003-11-30) 1 1 1 1 1 voice recognition speech recognition 1 1 1 1 1 VoIP Voice over IP 1 1 1 1 1 volatile 1. <programming> volatile variable. 2. <storage> See non-volatile storage. (1997-06-05) 1 1 1 1 1 volatile memory non-volatile storage 1 1 1 1 1 volatile storage non-volatile storage 1 1 1 1 1 volatile variable A variable in a computer program which can be modified by processes other than the program. For example, a variable that stores the value of a timer chip (either because it is located at the address of the hardware device or because it is updated on interrupts) needs to be volatile to be useful. A static variable, on the other hand, maintains its value until the program changes it or it is no longer needed. In addition, volatile variables can be held in the stack whereas static variables are usually stored in a program's data segment. (1995-05-17) 1 1 1 1 1 voltage (Or "potential difference", "electro-motive force" (EMF)) A quantity measured as a signed difference between two points in an electrical circuit which, when divided by the resistance in Ohms between those points, gives the current flowing between those points in Amperes, according to Ohm's Law. Voltage is expressed as a signed number of Volts (V). The voltage gradient in Volts per metre is proportional to the force on a charge. Voltages are often given relative to "earth" or "ground" which is taken to be at zero Volts. A circuit's earth may or may not be electrically connected to the actual earth. The voltage between two points is also given by the charge present between those points in Coulombs divided by the capacitance in Farads. The capacitance in turn depends on the dielectric constant of the insulators present. Yet another law gives the voltage across a piece of circuit as its inductance in Henries multiplied by the rate of change 1 1 1 1 1 Volume Table Of Contents (VTOC) /V-tock/ A special file on a disk, which contains a list of all the ordinary files on the disk and their addresses. Also called a directory. The term is used mostly with large mainframe disk drives. Storage administrators will often refer to the VTOC to obtain information on the number of files stored on a disk. (1997-04-15) 1 1 1 1 1 von Neumann architecture A computer architecture conceived by mathematician John von Neumann, which forms the core of nearly every computer system in use today (regardless of size). In contrast to a Turing machine, a von Neumann machine has a random-access memory (RAM) which means that each successive operation can read or write any memory location, independent of the location accessed by the previous operation. A von Neumann machine also has a central processing unit (CPU) with one or more registers that hold data that are being operated on. The CPU has a set of built-in operations (its instruction set) that is far richer than with the Turing machine, e.g. adding two binary integers, or branching to another part of a program if the binary integer in some register is equal to zero (conditional branch). The CPU can interpret the contents of memory either as instructions or as data according to the fetch-execute 1 1 1 1 1 von Neumann integer A finite von Neumann ordinal. The von Neumann integer N is a finite set with N elements which are the von Neumann integers 0 to N-1. Thus 0 = = 1 = 0 = 2 = 0, 1 = , 3 = 0, 1, 2 = , , , 1 1 1 1 1 von Neumann, John John von Neumann 1 1 1 1 1 von Neumann machine von Neumann architecture 1 1 1 1 1 von Neumann ordinal An implementation of ordinals in set theory (e.g. Zermelo Fränkel set theory or ZFC). The von Neumann ordinal alpha is the well-ordered set containing just the ordinals "shorter" than alpha. Reasonable set theories (like ZF) include Mostowski's Collapsing Theorem: any well-ordered set is isomorphic to a von Neumann ordinal. In really screwy theories (e.g. NFU -- New Foundations with Urelemente) this theorem is false. The finite von Neumann ordinals are the von Neumann integers. (1995-03-30) 1 1 1 1 1 voodoo programming (From George Bush's "voodoo economics") The use by guess or cookbook of an obscure or hairy system, feature, or algorithm that one does not truly understand. The implication is that the technique may not work, and if it doesn't, one will never know why. Almost synonymous with black magic, except that black magic typically isn't documented and *nobody* understands it. Compare magic, deep magic, heavy wizardry, rain dance, cargo cult programming, wave a dead chicken. [Jargon File] (1995-03-10) 1 1 1 1 1 Voronoi diagram (Or "Voronoi tessellation", "Voronoi decomposition", "Dirichlet tessellation", After Georgy Feodosevich Voronoy) For a set S of points in a Euclidean space, the partition Vor(S) of the plane into the voronoi polygons associated with the members of S, where each polygon is defined by the set of points nearer to some given point in S than to any other point in S. The Voronoi diagram is the dual of the Delaunay triangulation of S. (2008-04-18) 1 1 1 1 1 Voronoi polygon For a member s of a set S of points in a Euclidean space, the locus of points in the plane that are closer to s than to any other member of S. (1997-08-03) 1 1 1 1 1 VOS An operating system used in Stratus computers. See also FTX. [Details?] (1998-07-06) 1 1 1 1 1 Voters Telecommunications Watch (VTW) A non-profit organisation based in New York, founded by Shabbir J. Safdar to protect the rights of Internet users. The VTW has actively opposed regulation of encryption and restrictions on Internet free speech. VTW created the animated "Free Speech" fireworks icon that has been displayed on many web pages since June 12, 1996, the day that a three-judge panel in Philadelphia ruled the CDA unconstitutional. (http://vtw.org). (1996-11-03) 1 1 1 1 1 voxel (By analogy with "pixel") Volume element. The smallest distinguishable box-shaped part of a three-dimensional space. A particular voxel will be identified by the x, y and z coordinates of one of its eight corners, or perhaps its centre. The term is used in three dimensional modelling. (1995-03-10) 1 1 1 1 1 V.pcm V.90 1 1 1 1 1 VPL 1. visual programming language. ["VPL: An Active, Declarative Visual Programming System, D. Lau-Kee et al, 1991 IEEE Workshop on Vis Langs, Oct 1991, pp. 40-46]. 2. A dataflow language for interactive image processing. 1 1 1 1 1 VPN Virtual Private Network 1 1 1 1 1 VP-Planner A spreadsheet from Paperback Software. It has a graph menu within the spreadsheet program (with CGA graphics). The graphs are updated every time the graph screen is activated. (1995-03-28) 1 1 1 1 1 VQF Twin Vector Quantization 1 1 1 1 1 VR virtual reality 1 1 1 1 1 VRAM video random-access memory 1 1 1 1 1 VRC Vertical Redundancy Check 1 1 1 1 1 Vrije Universiteit, Amsterdam The "Free University of Amsterdam", founded in 1880 by Abraham Kuyper (who later became Prime Minister of The Netherlands). Originally only open to Reformed Christians, it is now open to all. Andrew Tanenbaum is a professor there. Not to be confused with the much older Universiteit van Amsterdam. (http://vu.nl/). (2005-11-05) 1 1 1 1 1 VRML Virtual Reality Modeling Language 1 1 1 1 1 VRTX Virtual Real-Time Executive. A real-time operating system from ReadySystems for the Motorola 68000 family of microprocessors. MPV is a multi-processing extension. (1994-11-08) 1 1 1 1 1 VSAM Virtual Storage Access Method 1 1 1 1 1 VSAT Very Small Aperture Terminal 1 1 1 1 1 VSCM A highly portable implementation of Scheme, written in ANSI C and Scheme. VSCM features exception and interrupt handling, executable portable memory images, coroutines and continuations with multiple arguments. Portability is achieved by exclusive use of legal ANSI C features. Version II Nov9 by Matthias Blume <blume@cs.princeton.edu> included run-time support and a bytecode compiler. It conforms to R4RS and IEEE P1178 and runs on Unix and Macintosh. VSCM is no longer actively developed - the author recommends StandardML. (http://cs.princeton.edu/~blume/vscm/). (2001-01-02) 1 1 1 1 1 VSE Virtual Storage Extended 1 1 1 1 1 V series A set of standards published by the CCITT for "Data Communication over the Telephone Network". The following standards describe the important modulation techniques: V.17, V.21, V.22, V.22 bis, V.23, V.27 ter, V.29, V.32, V.32 bis. Other V standards include V.24, V.25 bis, V.42, V.42 bis. (2004-07-20) 1 1 1 1 1 VSF Virtual Software Factory 1 1 1 1 1 VSP Very Simple Prolog+. 1 1 1 1 1 VSTa Valencia Simple Tasker. 1 1 1 1 1 VSX Verification Suite for X/open. 1 1 1 1 1 VT Vertical Tab, the mnemonic for ASCII 11. (1996-06-24) 1 1 1 1 1 vt100 DEC's definitive CRT video terminal of the early/mid 1980s. Its control codes and escape sequences still form the basis of the xterm set and of the ANSI or IBM PC standards. VT100 compatibility is still provided by most terminal emulators. [On-line documentation?] (1995-03-28) 1 1 1 1 1 vt220 A DEC video terminal, the successor to the VT100 series. [On-line documentation?] (1995-03-28) 1 1 1 1 1 VTAM Virtual Telecommunications Access Method 1 1 1 1 1 VTC video teleconferencing 1 1 1 1 1 VTOC Volume Table Of Contents 1 1 1 1 1 VTS A suite of test programs for Motif from OSF. 1 1 1 1 1 VTW Voters Telecommunications Watch 1 1 1 1 1 vu The country code for Vanuatu. (1999-01-27) 1 1 1 1 1 VUE Visual User Environment: a desktop manager for Unix from Hewlett-Packard. 1 1 1 1 1 VUIT Visual User Interface Tool: a WYSIWYG editor from DEC for building human interfaces to applications using OSF/Motif. It provides an interactive interface to UIL and the Motif toolkit. 1 1 1 1 1 VULCAN 1. <database> A version of JPLDIS ported to CP/M by Wayne Ratliff around 1980. VULCAN evolved into dBASE II. 2. <database> The dBASE-like interpreter and compiler sold by RSPI with their Emerald Bay product. [Same as 1?] 3. <language> An early string manipulation language. ["VULCAN - A String Handling Language with Dynamic Storage Control", E.P. Storm et al, Proc FJCC 37, AFIPS, Fall 1970]. 4. <language> A concurrent object-oriented logic programming language implemented as a preprocessor for FCP by Kahn et al at Xerox PARC. ["Vulcan: Logical Concurrent Objects", K. Kahn et al in Research Directions in Object- Oriented Programming, A.B. Shriver et al eds, MIT Press 1987]. (2004-09-01) 1 1 1 1 1 Vulcan death grip A variant of Vulcan nerve pinch derived from a Star Trek classic epsisode where a non-existant "Vulcan death grip" was used to fool Romulans that Spock had killed Kirk. (1996-10-27) 1 1 1 1 1 Vulcan nerve pinch (Or "three-finger salute", Vulcan death grip; from the old "Star Trek" TV series via Commodore Amiga hackers) The keyboard combination that forces a soft boot or jump to ROM monitor (on machines that support such a feature). On an Amiga this is done with Ctrl/Right Amiga/Left Amiga; on IBM PCs and many microcomputers it is Ctrl/Alt/Del; on Suns, L1-A; on some Macintoshes, it is <Cmd>-<Power switch>! Silicon Graphics users are obviously the most dextrous however, as these machines use the five-finger combination: Left Shift/Left Ctrl/Left Alt/Keypad Divide/F12. Compare quadruple bucky. [Jargon File] (2000-04-04) 1 1 1 1 1 vulnerability A bug or feature of a system that exposes it to possible attack, a flaw in the system's security. A common example of a vulnerability due to a bug is buffer overrun, where carefully constructed input can allow an attacker to insert arbitrary code into a running program and have it executed. The most serious vulnerabilities are those in network software, especially if they exploit traffic that is allowed through the firewall like HTTP, for example exploiting a bug in a web browser. The Open Source Vulnerability Database lists many vulnerabilities. (2007-12-02) 1 1 1 1 1 vulture capitalist A pejorative hackerism for "venture capitalist", deriving from the common practice of pushing contracts that deprive inventors of control over their own innovations and most of the money they ought to have made from them. [Jargon File] (1995-04-14) 1 1 1 1 1 VUP VAX MIPS 1 1 1 1 1 VxD Virtual Device Driver 1 1 1 1 1 VXI VMEbus Extension for Instrumentation 1 1 1 1 1 VxWorks A real-time multitasking operating system from Wind River Systems. Originally it used the VRTX kernel but this has been replaced by Wind River's own Wind kernel 2.4. Before version 5.3 VxWorks included a software development environment but this is now called "Tornado". Latest version: 5.3, as of 1996-11-28. (1996-11-29) 1 1 1 1 1 W2K Windows 2000 1 1 1 1 1 W3 A web browser for Emacs by William M. Perry <wmperry@indiana.edu>. (1994-12-16) 1 1 1 1 1 W3C World Wide Web Consortium 1 1 1 1 1 W3 Consortium World Wide Web Consortium 1 1 1 1 1 WA-12 Workflow Analysis in 12 different organisations. A project from the Department of Computer Science from the University of Twente, Enschede, The Netherlands. The final report of this project is available to the public (ISBN 90-365-0683-2). 1 1 1 1 1 wabbit /wab'it/ [almost certainly from Elmer Fudd's immortal line You wascawwy wabbit!] 1. A legendary early hack reported on a System/360 at RPI and elsewhere around 1978; this may have descended (if only by inspiration) from hack called RABBITS reported from 1969 on a Burroughs 55000 at the University of Washington Computer Center. The program would make two copies of itself every time it was run, eventually crashing the system. 2. By extension, any hack that includes infinite self-replication but is not a virus or worm. See fork bomb and rabbit job, see also cookie monster. [Jargon File] 1 1 1 1 1 Wabi Windows Application Binary Interface 1 1 1 1 1 WabiServer An addition to Wabi which allows the Microsoft Windows application to run on a server, e.g. a powerful Intel-based computer, with users accessing it from their desktop which can be a cheap computer such as an X terminal. (1997-01-08) 1 1 1 1 1 wacco A BNF-based LL(?) parser generator. Posted to comp.sources.misc. 1 1 1 1 1 Wafe (From Widget Athena front end) A package by Gustaf Neumann <Gustaf.Neumann@uni-essen.de> implementing a symbolic interface to the Athena widgets and OSF/Motif. A typical Wafe application consists of two parts: a front-end (Wafe) and an application program which runs as a separate process. The distribution contains sample application programs in Perl, GAWK, Prolog, TCL, C, and Ada talking to the same Wafe binary. The current Wafe version is 1.0.15. It supports Athena as distributed with X releases 4-6 and Motif versions 1.1, 1.2, and 2.0 but new distribution are only tested against X releases 5 and 6, and Motif versions 1.2.4 and 2.0. HOME (http://wu-wien.ac.at/wafe), (ftp://ftp.wu-wien.ac.at/pub/src/X11/wafe/). Mailing list: listserv@wu-wien.ac.at ("subscribe Wafe <Your Name>"). (1996-07-09) 1 1 1 1 1 WAFL WArwick Functional Language. Warwick U, England. LISP-like. 1 1 1 1 1 WAIS Wide Area Information Servers 1 1 1 1 1 WAITS /wayts/ The mutant cousin of TOPS-10 used on a handful of systems at SAIL up to 1990. There was never an "official" expansion of WAITS (the name itself having been arrived at by a rather sideways process), but it was frequently glossed as West-coast Alternative to ITS. Though WAITS was less visible than ITS, there was frequent exchange of people and ideas between the two communities, and innovations pioneered at WAITS exerted enormous indirect influence. The early screen modes of Emacs, for example, were directly inspired by WAITS's "E" editor - one of a family of editors that were the first to do "real-time editing", in which the editing commands were invisible and where one typed text at the point of insertion/overwriting. The modern style of multi-region windowing is said to have originated there, and WAITS alumni at XEROX PARC and elsewhere played major roles in the developments that led to the XEROX Star, the Macintosh, and the Sun workstations. Bucky bits were also invented there 1 1 1 1 1 wait state A delay of one or more clock cycles added to a processor's instruction execution time to allow it to communicate with slow external devices. The number and duration of wait states may be pre-configured or they may be controlled dynamically via certain control lines. (1996-10-16) 1 1 1 1 1 waldo /wol'doh/ [Robert A. Heinlein's story "Waldo"] 1. A mechanical agent, such as a gripper arm, controlled by a human limb. When these were developed for the nuclear industry in the mid-1940s they were named after the invention described by Heinlein in the story, which he wrote in 1942. Now known by the more generic term "telefactoring", this technology is of intense interest to NASA for tasks like space station maintenance. 2. At Harvard (particularly by Tom Cheatham and students), this is used instead of foobar as a metasyntactic variable and general nonsense word. [Jargon File] (2015-03-22) 1 1 1 1 1 walk To Traverse a data structure, especially an array or linked-list in core. See also codewalker, silly walk, clobber. (2001-04-12) 1 1 1 1 1 walking drives An occasional failure mode of magnetic-disk drives back in the days when they were huge, clunky washing machines. Those old dinosaur parts carried terrific angular momentum; the combination of a misaligned spindle or worn bearings and stick-slip interactions with the floor could cause them to "walk" across a room, lurching alternate corners forward a couple of millimeters at a time. There is a legend about a drive that walked over to the only door to the computer room and jammed it shut; the staff had to cut a hole in the wall in order to get at it! Walking could also be induced by certain patterns of drive access (a fast seek across the whole width of the disk, followed by a slow seek in the other direction). Some bands of old-time hackers figured out how to induce disk-accessing patterns that would do this to particular drive models and held disk-drive races. [Jargon File] (2009-05-14) 1 1 1 1 1 walk off the end of To attempt to process past the start or end of an array, list or medium after stepping through it. Often the result of an off-by-one error. Compare clobber, roach, smash the stack. (2009-05-14) 1 1 1 1 1 wall Unix's "write all" command which sends a message to everyone currently logged in. [Jargon File] (2009-05-14) 1 1 1 1 1 wall clock time The elapsed time between when a process starts to run and when it is finished. This is usually longer than the processor time consumed by the process because the CPU is doing other things besides running the process such as running other user and operating system processes or waiting for disk or network I/O. (1998-03-13) 1 1 1 1 1 wall follower A person or algorithm that compensates for lack of sophistication or native stupidity by efficiently following some simple procedure shown to have been effective in the past. Used of an algorithm, this is not necessarily pejorative; it recalls "Harvey Wallbanger", the winning robot in an early AI contest (named, of course, after the cocktail). Harvey successfully solved mazes by keeping a "finger" on one wall and running till it came out the other end. This was inelegant, but it was mathematically guaranteed to work on simply-connected mazes - and, in fact, Harvey outperformed more sophisticated robots that tried to "learn" each maze by building an internal representation of it. Used of humans, the term *is* pejorative and implies an uncreative, bureaucratic, by-the-book mentality. See also code grinder. [Jargon File] (2003-02-03) 1 1 1 1 1 wallpaper 1. A file containing a listing (e.g. assembly listing) or a transcript, especially a file containing a transcript of all or part of a login session. (The idea was that the paper for such listings was essentially good only for wallpaper, as evidenced at Stanford, where it was used to cover windows). The term is now rare, especially since other systems have developed other terms for it (e.g. PHOTO on TWENEX). However, the Unix world doesn't have an equivalent term, so perhaps wallpaper will take hold there. The term probably originated on ITS, where the commands to begin and end transcript files were ":WALBEG" and ":WALEND", with default file "WALL PAPER" (the space was a path delimiter). 2. The background pattern used on graphical workstations under the Microsoft Windows graphical user interface to MS-DOS. (1994-12-22) 1 1 1 1 1 wall plate A small rectangular panel, usually made of plastic, fixed to the wall, on which sockets and switches are mounted. These connect to wiring hidden in the wall. Common examples would be electrical mains and telephone sockets. (2009-03-19) 1 1 1 1 1 wall time (Or "wall clock time") 1. "Real world" time (what the clock on the wall shows), as opposed to the system clock's idea of time. 2. The real running time of a program, as opposed to the number of ticks required to execute it (on a time-sharing system these always differ, as no one program gets all the ticks, and on multiprocessor systems with good thread support one may get more processor time than real time). [Jargon File] 1 1 1 1 1 WAM Intermediate language for compiled Prolog, used by the Warren Abstract Machine. "An Abstract Prolog Instruction Set", D.H.D. Warren, TR 309, SRI 1983. 1 1 1 1 1 WAN Wide Area Network 1 1 1 1 1 Wang Laboratories Computer manufacturer, known for their office automation products and the Wang PC. Quarterly sales $208M, profits $3M (Aug 1994). (2008-05-28) 1 1 1 1 1 wango /wang'goh/ Random bit-level grovelling going on in a system during some unspecified operation. Often used in combination with mumble. For example: "You start with the ".o" file, run it through this postprocessor that does mumble-wango - and it comes out a snazzy object-oriented executable." [Jargon File] 1 1 1 1 1 Wang PC Personal computers made by Wang Laboratories. Wang's PCs had an operating system (based on MS-DOS) which was not compatible with the IBM PC. The Wang floppy disk format was compatible with the IBM PC. However, running an IBM "exe" program would generally crash a Wang PC unless a special Industry-Standard emulator program was running on the Wang. This program required the addition of a special card to the Wang PC. It enabled the Wang PC to run most, but not all, software written for the IBM PC. Most Wang software made use of two special keys: CANCEL and EXECUTE. These keys were used to carry out commands, make menu selections, and so on. The Wang OS was menu-driven. (2008-05-28) 1 1 1 1 1 wank /wangk/ [Columbia University: probably by mutation from Commonwealth slang "wank", to masturbate] Used much as hack is elsewhere, as a noun denoting a clever technique or person or the result of such cleverness. May describe (negatively) the act of hacking for hacking's sake ("Quit wanking, let's go get supper!") or (more positively) a wizard. "wanky" describes something particularly clever (a person, program, or algorithm). Conversations can also get wanky when there are too many wanks involved. This excess wankiness is signalled by an overload of the "wankometer" (compare bogometer). When the wankometer overloads, the conversation's subject must be changed, or all non-wanks will leave. Compare neep-neeping (under neep-neep). Usage: US only. In Britain and the Commonwealth this word is *extremely* rude and is best avoided unless one intends to give offense. 1 1 1 1 1 wannabee /won'*-bee/ (Or, more plausibly, spelled "wannabe") [Madonna fans who dress, talk, and act like their idol; probably originally from biker slang] A would-be hacker. The connotations of this term differ sharply depending on the age and exposure of the subject. Used of a person who is in or might be entering larval stage, it is semi-approving; such wannabees can be annoying but most hackers remember that they, too, were once such creatures. When used of any professional programmer, CS academic, writer, or suit, it is derogatory, implying that said person is trying to cuddle up to the hacker mystique but doesn't, fundamentally, have a prayer of understanding what it is all about. Overuse of hacker terms is often an indication of the wannabee nature. Compare newbie. Historical note: The wannabee phenomenon has a slightly different flavour now (1993) than it did ten or fifteen years ago. When the people who are now hackerdom's tribal elders 1 1 1 1 1 want list wish list 1 1 1 1 1 WAP Wireless Application Protocol 1 1 1 1 1 WAP Forum The official body developing Wireless Application Protocol. (http://wapforum.org/). (2000-02-10) 1 1 1 1 1 warchalk A system of runes and annotations chalked on walls or other surfaces to indicate to interested parties the presence of a wireless network node in the vicinity. Warchalking was inspired by "hobo language" - the signs used by American itinerants during the Depression years to indicate where they might find a meal. (http://blackbeltjones.com/warchalking/). (2002-06-26) 1 1 1 1 1 Ward Christensen The inventor of XMODEM and of the BBS. Ward did physics in college and programmed mainframes for IBM. Ward and friend Randy Suess set up their BBS on first on 1978-02-16 in Chicago. It ran on an S-100 computer with 64k RAM and two single-sided 8" 250kB diskettes. Freeware Hall of Fame (http://freewarehof.org/ward.html). (2005-09-20) 1 1 1 1 1 Ward Cunnigham The creator of the first wiki. (2004-07-11) 1 1 1 1 1 wardialer Almost certainly a shortened version of "WarGames dialer", from the film WarGames. 1. carrier scanner 2. A program which attempts to break a password of known length by iterating thru all possible combinations of characters that could make up that password. This approach is not feasable for cracking most passwords these days. However, as late as the mid-1980s, some long-distance companies required only very short numeric access codes (e.g. five digits) to verify the identity of their customers. Wardialers were created which would, running unattended, call up long-distance providers' local connect numbers and iteratively try possible access codes. Codes which worked were logged for later illicit use. These wardialers had a high success rate because of the small range of possibilities to iterate through, e.g. 10000 for a five digit access code, compared to hundreds of trillions of 1 1 1 1 1 wardriving (From wardialer in the "carrier scanner" sense of that word) To drive around with a laptop with a wireless card, and an antenna, looking for accessible wireless networks. (2003-06-24) 1 1 1 1 1 warez /weirz/ A term software pirates use to describe cracked games or applications made available to the Internet, at no cost, usually via FTP or telnet. Often the pirate will make use of a site with lax security. (1994-11-29) 1 1 1 1 1 WarGames (Not "War Games") A 1983 film about a schoolboy cracker using a wardialer to try to break into a games company's computer and accidentally connecting to a backdoor into "Whopper", a ficticious C3 computer at Norad (USAF). He then procedes to unwittingly initiate global thermonuclear warfare. Playing naughts and crosses finally teaches Whopper that the only way to win the game is never to play. IMDb (http://us.imdb.com/Title?WarGames+%281983%29). (1999-03-08) 1 1 1 1 1 warlording The act of excoriating a bloated, ugly or derivative sig block. Common grounds for warlording include the presence of a signature rendered in a BUAF, over-used or cliched sig quotes, ugly ASCII art, or simply excessive size. The original "Warlord" was a BIFF-like newbie c. 1991 who featured in his sig a particularly large and obnoxious ASCII graphic resembling the sword of Conan the Barbarian in the 1981 John Milius movie; the group name alt.fan.warlord was sarcasm, and the characteristic mode of warlording is devastatingly sarcastic praise. Usenet newsgroup: news:alt.fan.warlord. [Jargon File] (1994-11-29) 1 1 1 1 1 warm boot A boot from power on, where the CPU and peripherals are already powered up (warm). A warm boot might be performed after a software crash or a hardware reset. Contrast cold boot. See also reboot. [Jargon File] (1998-04-28) 1 1 1 1 1 Warm Silence Software A small company run by(?) Robin Watts, producing software for the Acorn Archimedes. (http://comlab.ox.ac.uk/oucl/users/robin.watts/). (1994-11-01) 1 1 1 1 1 Warp OS/2 1 1 1 1 1 wart A small, crocky feature that sticks out of an otherwise clean design. Something conspicuous for localised ugliness, especially a special-case exception to a general rule. For example, in some versions of "csh(1)", single quotes literalise every character inside them except "!". In ANSI C, the "?" syntax used for obtaining ASCII characters in a foreign environment is a wart. See also miswart. [Jargon File] 1 1 1 1 1 washing machine An old-style 14-inch hard disk in a floor-standing cabinet. So called because of the size of the cabinet and the top-loading access to the media packs - and, of course, they were always set on "spin cycle". The thick channel cables connecting these were called "bit hoses". The washing-machine idiom transcends language barriers; it is even used in Russian hacker jargon. See also walking drives. (1995-02-15) 1 1 1 1 1 Wasserman A.I. Wasserman (Tony), president of IDE. (1995-02-15) 1 1 1 1 1 WATBOL WATerloo COBOL. A COBOL for IBM MVS. (1995-02-15) 1 1 1 1 1 Watcom C/C++ A compiler and development tools for multi-platform, 16 and 32-bit applications. Watcom C/C++ 10.0 has an integrated development environment (IDE) and development tools. It includes the SOMobjects Toolkit to enable access to IBM's System Object Model (SOM) and Distributed System Object Model (DSOM). It supports 16 bit MS DOS, Microsoft Windows 3.x, OS/2 1.x, and 32 bit platforms including extended DOS, OS/2 2.x, Windows NT, Win32s, 32-bit Windows 3.x, Novell NLM and AutoCAD ADS/ADI. (1995-04-18) 1 1 1 1 1 Watcom International A provider of application development tools and IBM PC-based SQL database servers. Founded in 1974, Watcom initially focused on scientific and engineering markets establishing itself as a supplier of programming and information tools worldwide, serving customers in 60 countries with highly regarded products such as WATFOR-77 for mainframes, minicomputers and PCs. Since the introduction of Watcom C in 1988, the company has emerged as an industry leader in optimising compilers for 16 and 32-bit Intel-based IBM PCs. Moving into the client/server market in 1992, Watcom introduced Watcom SQL, including SQL database servers for multi-user networks and single-user stand-alone applications. The product has since been incorporated into Powersoft's PowerBuilder development environment and the Powersoft Enterprise Series. In June, 1993, Watcom launched VX*REXX, an integrated visual development environment for 1 1 1 1 1 Watcom SQL A family of databases from Watcom International, based on scalable technology and a SQL database engine. Version 4.0 adds stored procedures and triggers. It is designed for environments ranging from large departmental networks with a diverse range of PC client systems, to peer-to-peer workgroups, to stand-alone PCs. It is available in stand-alone versions for Microsoft Windows, Windows NT, OS/2 and MS DOS; and multi-user network server versions for Microsoft Windows, Windows NT, OS/2, NetWare NLM and MS DOS. (1995-04-18) 1 1 1 1 1 Watcom VX*REXX A visual development environment for creating OS/2 applications with graphical user interfaces. It includes a project management facility, visual designer and an interactive source level debugger. Version 2.1 introduced the VX*REXX Client/Server Edition for client/server GUI application development on OS/2 by incorporating database objects. Using IBM's DRDA support on OS/2, users can access DB2 for MVS, DB2/400 for AS/400, and DB2/VSE and VM (SQL/DS) for VM and VSE. Also supported are Watcom SQL and ODBC-enabled databases. Since the VX*REXX visual development environment is based on IBM's object-oriented SOM technology, VX*REXX applications are open and extensible through the addition of new SOM objects. (1995-04-18) 1 1 1 1 1 Waterfall Model A software life-cycle or product life-cycle model, described by W. W. Royce in 1970, in which development is supposed to proceed linearly through the phases of requirements analysis, design, implementation, testing (validation), integration and maintenance. The Waterfall Model is considered old-fashioned or simplistic by proponents of object-oriented design which often uses the spiral model instead. Earlier phases are sometimes called "upstream" and later ones downstream. Compare: iterative model. [W. W. Royce, "Managing the Development of Large Software Systems", Proceedings of IEEE WESCON, August 1970]. (1997-11-23) 1 1 1 1 1 water MIPS Large, water-cooled computers of either today's ECL-supercomputer flavour or yesterday's traditional mainframe type. See MIPS [Jargon File] (1995-03-25) 1 1 1 1 1 WATFIV WATerloo Fortran IV. U Waterloo, Canada. Student-friendly variant of Fortran IV. 1 1 1 1 1 WATFOR WATerloo FORtran. U Waterloo, Canada. Student-friendly variant of Fortran. "WATFOR - The University of Waterloo Fortran IV Compiler", P.W. Shantz et al, CACM 10(1):41-44 (Jan 1967). 1 1 1 1 1 wav (waveform) /wav/, /dot wav/ A sound format developed by Microsoft and used extensively in Microsoft Windows. Conversion tools are available to allow most other operating systems to play .wav files. .wav files are also used as the sound source in wavetable synthesis, e.g. in E-mu's SoundFont. In addition, .wav files are also supported by some MIDI sequencers as add-on audio. That is, pre-recorded .wav files are played back by control commands written in the sequence script. Specification (http://qzx.com/pc-gpe/wav.txt). (1997-10-11) 1 1 1 1 1 WAVE A robotics language. ["WAVE: A Model-Based Language for Manipulator Control", R.P. Paul, Ind Robot 4(1):10-17, 1979]. (1996-09-08) 1 1 1 1 1 wave a dead chicken To perform a ritual in the direction of crashed software or hardware that one believes to be futile but is nevertheless necessary so that others are satisfied that an appropriate degree of effort has been expended. "I'll wave a dead chicken over the source code, but I really think we've run into an OS bug". Compare voodoo programming, rain dance. [Jargon File] (1996-09-08) 1 1 1 1 1 wave division multiplexing A common misnomer for wavelength division multiplexing. (2002-07-16) 1 1 1 1 1 Waveform Generation Language (WGL) A data description language for test program description. [Reference? What kind of test programs?] (2001-05-20) 1 1 1 1 1 wavelength division multiplexing (WDM) Multiplexing several Optical Carrier n signals on a single optical fibre by using different wavelengths (colours) of laser light to carry different signals. The device that joins the signals together is known as a multiplexor, and the one that splits them apart is a demultiplexor. With the right type of fibre you can have a device that does both and that ought to be called a "mudem" but isn't. The first WDM systems combined two signals and appeared around 1985. Modern systems can handle up to 128 signals and can expand a basic 9.6 Gbps fibre system to a capacity of over 1000 Gbps. WDM systems are popular with telecommunications companies because they allow them to expand the capacity of their fibre networks without digging up the road again. All they have to do is to upgrade the (de)multiplexors at each end. However 1 1 1 1 1 wavelet A waveform that is bounded in both frequency and duration. Wavelet tranforms provide an alternative to more traditional Fourier transforms used for analysing waveforms, e.g. sound. The Fourier transform converts a signal into a continuous series of sine waves, each of which is of constant frequency and amplitude and of infinite duration. In contrast, most real-world signals (such as music or images) have a finite duration and abrupt changes in frequency. Wavelet transforms convert a signal into a series of wavelets. In theory, signals processed by the wavelet transform can be stored more efficiently than ones processed by Fourier transform. Wavelets can also be constructed with rough edges, to better approximate real-world signals. For example, the United States Federal Bureau of Investigation found that Fourier transforms proved inefficient for approximating the whorls of fingerprints but a wavelet 1 1 1 1 1 wavetable A type of sound generator often built in a sound card. A wavetable contains digitised samples of real instrument sounds or effect (FX) sounds. A wavetable chip often also contains a drum kit sound to faciliate rhythm accompaniment. A recorded wavetable sound may be edited and enhanced by various effects (reverb, chorus) and layered with other waveforms before writing it to ROM or RAM. The latter type serves as user sound memory. A wavetable generator is typically controlled by MIDI input. When a MIDI note-on signal is detected, the output part of a wavetable generator generates a sound with definitive pitch, typically a musical note. Wavetable sounds are used in games and music. The more realistic wavetable sounds have all but replaced the earlier synthetic FM (frequency modulation) sound generation in sound cards but to ensure compatibility with older games etc., an FM 1 1 1 1 1 wavetable synthesis wavetable 1 1 1 1 1 WaZOO Warp-zillion Opus-to-Opus. Fidonet's session layer protocol. Although it mentions Opus (a specific BBS from the 1980s), WaZOO is the session protocol used for the Fidonet network. Because WaZOO is much more efficient than other mechanisms (e.g., FTP), it is sometimes used for automated or batch communications in other parts of the Internet. (ftp://ftp.psg.com/pub/fidonet/stds/fts-0006.txt). (1995-11-16) 1 1 1 1 1 wb Welcome Back. 1 1 1 1 1 WBEM Web-Based Enterprise Management 1 1 1 1 1 WBMP wireless bitmap 1 1 1 1 1 WBS Work Breakdown Structure 1 1 1 1 1 WCDMA Wideband Code Division Multiple Access 1 1 1 1 1 WCL A Common Lisp implementation in a shared library by Wade Hennessey <wade@leland.Stanford.edu>. WCL is not a complete Common Lisp, but it does have the full development environment including dynamic file loading and debugging. A modified version of GDB provides mixed-language debugging. Version 2.14 includes a shared library, run-time support and source debugger. It requires GNU GCC 2.1 (not 2.2.2) and runs on SPARC under SunOS. (ftp://sunrise.stanford.edu/pub/wcl/). Mailing list: <wcl-request@sunrise.stanford.edu>. E-mail: <wcl@sunrise.stanford.edu>. [Proceedings of the 1992 Lisp and Functional Programming Conference]. (1992-10-28) 1 1 1 1 1 WD Western Digital 1 1 1 1 1 WDASM (Probably "Windows disassembler") An interactive Intel 486 disassembler for Windows 3.1 written by Eric Grass at the University of Missouri, St. Louis. WDASM supports multiple disassembly formats. (ftp://ftp.simtel.com/cica/win3/util/wdasm15.zip). (1993-06-01) 1 1 1 1 1 WDM wavelength division multiplexing 1 1 1 1 1 WE A hypertext authoring system developed at the University of North Carolina. (1994-11-07) 1 1 1 1 1 Weak Head Normal Form (WHNF) A lambda expression is in weak head normal form (WHNF) if it is a head normal form (HNF) or any lambda abstraction. I.e. the top level is not a redex. The term was coined by Simon Peyton Jones to make explicit the difference between head normal form (HNF) and what graph reduction systems produce in practice. A lambda abstraction with a reducible body, e.g. \ x . ((\ y . y+x) 2) is in WHNF but not HNF. To reduce this expression to HNF would require reduction of the lambda body: (\ y . y+x) 2 --> 2+x Reduction to WHNF avoids the name capture problem with its need for alpha conversion of an inner lambda abstraction and so is preferred in practical graph reduction systems. The same principle is often used in strict languages such as 1 1 1 1 1 weakly typed weak typing 1 1 1 1 1 weak typing Strict enforcement of type rules but with well-defined exceptions or an explicit type-violation mechanism. Weak typing is "friendlier" to the programmer than strong typing, but catches fewer errors at compile time. C and C++ are weakly typed, as they automatically coerce many types e.g. ints and floats. E.g. int a = 5; float b = a; They also allow ignore typedefs for the purposes of type comparison; for example the following is allowed, which would probably be disallowed in a strongly typed language: typedef int Date; /* Type to represent a date */ Date a = 12345; int b = a; /* What does the coder intend? */ C++ is stricter than C in its handling of enumerated types: enum animal CAT=0,DOG=2,ANT=3; 1 1 1 1 1 weasel (Cambridge) A naive user, one who deliberately or accidentally does things that are stupid or ill-advised. Roughly synonymous with loser. [Jargon File] (1995-03-21) 1 1 1 1 1 web 1. <hypertext> World-Wide Web. 2. <language> Donald Knuth's literate programming language, WEB (WEB - language). 1 1 1 1 1 Web 2.0 A loosely defined term for web applications that go beyond displaying individual pages of static content and allow users to interact with the site and each other by adding or updating the content. Examples include social-networking sites like Facebook and other web-based communities, hosted services like Google Docs, web applications like GMail, video-sharing sites (Youtube), wikis (Wikipedia), web logs, mashups and folksonomies. While Web 2.0 applications often use advanced web features like AJAX to improve the speed of interaction, the term is more about the type of applications than the technology used. The term was coined by Darcy DiNucci in 1999, though she was discussing designing websites for new hardware platforms. (2009-11-18) 1 1 1 1 1 web2c A utility by Karl Berry <karl@claude.cs.umb.edu> to translate WEB to C. Latest version: 5-851d. FTP UCI (ftp://ics.uci.edu/TeX/web2c.tar.Z). FTP Gernamy (ftp://ftp.th-darmstadt.de/pub/tex/src/web2c/web2c.tar.Z). (1996-05-10) 1 1 1 1 1 web address Uniform Resource Locator 1 1 1 1 1 web authoring Creating web content, e.g. HTML pages, images, JavaScript or Flash, for use on the World-Wide Web. Web authoring typically does not include generating the actual text or "copy" of web pages but is cheifly concerned with its presentation. (2009-02-06) 1 1 1 1 1 Web-Based Enterprise Management (WBEM) A DMTF management standard using the Common Information Model to represent systems, applications, networks, devices and other managed components; developed to unify the management of distributed computing environments. WBEM Home (http://dmtf.org/standards/wbem/)) (2005-02-19) 1 1 1 1 1 web browser A browser for the web. (1996-03-23) 1 1 1 1 1 webcam (web camera) Any video camera whose output is available for viewing via the Internet or an intranet. Typically a webcam would be a slow-scan CCD video camera connected to a video capture card in a computer. Images from the camera are captured periodically and made available on a web page. In 1999 there are hundreds of webcams in operation around the world showing everything from bedrooms to traffic. [List?] (1999-01-11) 1 1 1 1 1 webcasting (From "web" and broadcast, sometimes just called "push") Multicasting on the Internet. Webcasting implies real-time streaming transmission of encoded video (or audio) under the control of the server to multiple recipients who all receive the same content at the same time. This is in contrast to normal web browsing which is controlled from the browser by individual users and may take arbitrarily long to deliver a complete document. Pointcast and Marimba were early pioneers. International Webcasting Association (http://webcasters.org/). (2003-07-08) 1 1 1 1 1 WebCGM A Web-oriented version of the Computer Graphic Metafile file format. (1999-02-16) 1 1 1 1 1 WebCOMAL COMmon Algorithmic Language 1 1 1 1 1 web cramming Any kind of fraudulent charges made to the telephone account of the victim, typically a small business or non-profit group, e.g. while claiming to provide web design or hosting for little or no charge. ["Computer Forensics and Cyber Crime": Marjie T. Britz]. (2007-03-16) 1 1 1 1 1 WebCrawler A free web search engine developed by Brian Pinkerton at the University of Washington and now moved to America Online, Inc. WebCrawler collects URLs by searching the Internet and allows users to perform keyword searches through a web browser. (http://webcrawler.com/). (1995-11-28) 1 1 1 1 1 webhead A compulsive or frequent user of, or contributor to, the web. (1994-07-21) 1 1 1 1 1 web host A company that supplies web hosting. (2008-04-15) 1 1 1 1 1 web hosting Running web servers for other businesses or individuals, usually as a commercial venture. Basic web hosting would allow customers to upload own web site content - HTML pages, images, video - typically via FTP, to a shared web server which other people can access via the Internet. A web hosting (http://webhostingsearch.com/) businesses may provide any or all of the functions required by a website including: networking, HTTP server software, content storage, content management, running customer or off-the-shelf CGI programs, ASP scripts or other server extentions, load balancing, streaming content, domain name registration, DNS serving, electronic mail storage and forwarding, database, shell account, content design and creation, search engine optimisation, web log analysis and web applications such as on-line shopping with financial transaction processing. 1 1 1 1 1 WEB - language Donald Knuth's self-documenting literate programming, with algorithms and documentation intermixed in one file. They can be separated using Weave and Tangle. Versions exist for Pascal and C. Spiderweb can be used to create versions for other languages. FunnelWeb is a production-quality literate-programming tool. (ftp://princeton.edu/), (ftp://labrea.stanford.edu/). ["Literate Programming", D.E. Knuth, Computer J 27(2):97-111, May 1984]. (1996-05-10) 1 1 1 1 1 weblint (After lint) A syntax checker and style checker for HTML. Weblint is a Perl script which does for HTML pages what the traditional lint picks does for C programs. Version: 1.020 (1997-12-07). (http://cre.canon.co.uk/~neilb/weblint/). (1997-12-07) 1 1 1 1 1 web log blog 1 1 1 1 1 web mail An electronic mail user agent that is accessible on the web (via HTTP). HoTMail was one of the first (bought by Microsoft), Google's GMail is another popular example. (2007-02-13) 1 1 1 1 1 webmaster (Sometimes "webmistress") The alias or role of the person(s) responsible for the development and maintenance of one or more web servers and/or some or all of the web pages at a website. The term does not imply any particular level of skill or mastery (see "webmonkey"). The webmaster's e-mail address often appears on the home page of the site. Failing that, you could try sending e-mail to postmaster (from which the term is probably derived) or root at that host, possibly after removing an initial www.. (1999-04-01) 1 1 1 1 1 webmistress webmaster 1 1 1 1 1 webmonkey a largely unskilled Web worker - one with a passable understanding of HTML but little else. It is often supposed that, in the New Media food chain, there is nothing lower than a webmonkey. Alas, there is: people who barely have the skills to use FrontPage; these people are called "typists". The B1FF of webmonkeys is personified as Bobo the Webmonkey. Compare actor/singer/waiter/webmaster. And compare sysape, one-banana problem, scratch monkey, monkey up, and Infinite-Monkey Theorem for other simian allusions. (1998-04-04) 1 1 1 1 1 WebObjects Apple Computer, Inc.'s application server framework for developing dynamic web applications. WebObjects applications accept HTTP requests either directly (usually on a specific port) or via an adaptor that sits between them and the web server. Adaptors are either CGI programs or web server plug-ins (NSAPI or ISAPI). The server processes special tags in HTML pages to produce dynamic but standard HTML. Tools are provided to easily set and get object properties and invoke methods from these tags. Applications can maintain state over multiple HTTP request-response transactions (which are intrinsically stateless). Applications can also use Apple's Enterprise Object Framework object relational mapping libraries for object persistence and database access. WebObjects was originally based on Objective C and a simple scripting language but now is more likely to be used with Java. Versions are available for OS X, Windows and 1 1 1 1 1 web page A block of data available on the World-Wide Web, identified by a URL. In the simplest, most common case, a web page is a file written in HTML, stored on the server. It may refer to images which appear as part of the page when it is displayed by a web browser. It is also possible for the server to generate pages dynamically in response to a request, e.g. using a CGI script. A web page can be in any format that the browser or a helper application can display. The format is transmitted as part of the headers of the response as a MIME type, e.g. "text/html", "image/gif". An HTML web page will typically refer to other web pages and Internet resources by including hypertext links. A website often has a home page (usually just the hostname, e.g. http://foldoc.org/). It may also have individual home pages for each user with an account at the site. 1 1 1 1 1 web proxy HTTP proxy server 1 1 1 1 1 Web Request Broker (WRB) Part of Oracle Corporation's WebServer suite of programs. It is a high-performance, multi-threaded HTTP server which allows clients' requests to be directly translated into Oracle 7 database scripts, and automatically translates the results of the query back into HTML for delivery to the client browser. Oracle WebServer (http://oracle.com/products/websystem/webserver/html/ws2_info.html). (1997-03-14) 1 1 1 1 1 web server HTTP server 1 1 1 1 1 Web Service Definition Language (WSDL) An XML format for describing network services as a set of endpoints operating on messages containing either "document oriented" or "procedure oriented" information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). WSDL is typically used with SOAP over HTTP but it is extensible to allow description of endpoints and their messages independent of what message formats or network protocols. [Reference?] (2004-06-21) 1 1 1 1 1 Web Services A family of standards promoted by the W3C for working with other business, developers and programs through open protocols, languages and APIs, including XML, Simple Object Access Protocol, WSDL and UDDI. W3C Web Services (http://w3.org/2002/ws). (2004-06-23) 1 1 1 1 1 Web Services Business Process Execution Language (WSBPEL, BPEL4WS) An OASIS technical committee considering ways to enable users to describe business processes as web services and define how they can be connected to accomplish specific tasks. (http://oasis-open.org/committees/tc_home.php?wg_abbrev=wsbpel). (2006-08-15) 1 1 1 1 1 website (Or "web site") Any computer on the Internet running a web server process. A particular website is usually identified by the hostname part of a URL. Multiple hostnames may actually map to the same computer in which case they are known as virtual servers. (2005-07-12) 1 1 1 1 1 web smith A person who creates web pages. Not necessarily the same as a webmaster. (1997-02-05) 1 1 1 1 1 Webster 1. Webster's Dictionary. 2. A web browser for the Acorn Archimedes. The HTML files may reside locally or be retrieved using a "fetcher". An HTTP fetcher for use with KA9Q is supplied. Version: 0.05. HENSA Gopher (gopher://micros.hensa.ac.uk:70/11/micros/arch/riscos/c/c164). Demon FTP (ftp://ftp.demon.co.uk/pub/archimedes/developers/). (1995-02-21) 1 1 1 1 1 Webster's Dictionary Hypertext interface (http://c.gp.cs.cmu.edu:5103/prog/webster). (1996-04-10) 1 1 1 1 1 wedged 1. To be stuck, incapable of proceeding without help. This is different from having crashed. If the system has crashed, it has become totally non-functioning. If the system is wedged, it is trying to do something but cannot make progress; it may be capable of doing a few things, but not be fully operational. For example, a process may become wedged if it deadlocks with another (but not all instances of wedging are deadlocks). See also gronk, locked up, hosed. 2. Often refers to humans suffering misconceptions. "He's totally wedged - he's convinced that he can levitate through meditation." 3. [Unix] Specifically used to describe the state of a TTY left in a losing state by abort of a screen-oriented program or one that has messed with the line discipline in some obscure way. There is some dispute over the origin of this term. It is usually thought to derive from a common description of recto-cranial inversion; however, it may actually have 1 1 1 1 1 wedgie (Fairchild) A bug. Probably related to wedged. 1 1 1 1 1 wedgitude /wedj'i-t[y]ood/ The quality or state of being wedged. [Jargon File] 1 1 1 1 1 Weeble /wee'b*l/ An egg-shaped plastic toy person with a weight in the bottom so that, if tipped over, they would right themselves and stand up again. They were popular in the UK during the 1970s and were famous for the slogan "Weebles wobble but they don't fall down", unlike some computers (pretty tenuous link with computing). (1994-11-29) 1 1 1 1 1 weeds 1. Refers to development projects or algorithms that have no possible relevance or practical application. Comes from "off in the weeds". Used in phrases like "lexical analysis for microcode is serious weeds." 2. At CDC/ETA before its demise, the phrase "go off in the weeds" was equivalent to IBM's branch to Fishkill and mainstream hackerdom's jump off into never-never land. [Jargon File] 1 1 1 1 1 weenie 1. [on BBSes] Any of a species of luser resembling a less amusing version of BIFF that infests many BBSes. The typical weenie is a teenage boy with poor social skills travelling under a grandiose handle derived from fantasy or heavy-metal rock lyrics. Among sysops, "the weenie problem" refers to the marginally literate and profanity-laden flamage weenies tend to spew all over a newly-discovered BBS. Compare spod, computer geek, terminal junkie. 2. Among hackers, when used with a qualifier (for example, as in Unix weenie, VMS weenie, IBM weenie) this can be either an insult or a term of praise, depending on context, tone of voice, and whether or not it is applied by a person who considers him or herself to be the same sort of weenie. It implies that the weenie has put a major investment of time, effort and concentration into the area indicated; whether this is good or bad depends on the hearer's judgment of how the 1 1 1 1 1 Weenix /wee'niks/ An ITS fan's derogatory term for Unix, derived from Unix weenie. According to one noted ex-ITSer, it is "the operating system preferred by Unix Weenies: typified by poor modularity, poor reliability, hard file deletion, no file version numbers, case sensitivity everywhere, and users who believe that these are all advantages. Some ITS fans" behave as though they believe Unix stole a future that rightfully belonged to them. [Jargon File] (1995-01-18) 1 1 1 1 1 weighted search A search based on frequencies of the search terms in the documents being searched. Weighted search is often used by search engines. It produces a numerical score for each possible document. A document's score depends on the frequency of each search term in that document compared with the overall frequency of that term in the entire corpus of documents. A common approach is called tf.idf which stands for term frequency * inverse document frequency. Term frequency means "the more often a term occurs in a document, the more important it is in describing that document." http://ciir.cs.umass.edu/cmpsci646/ir4/tsld034.htm Inverse document frequency means the more documents a term appears in, the less important the term is. A simple weighted search is just a list of search terms, for example: car automobile Weighted search is often contrasted with boolean search. 1 1 1 1 1 well-behaved 1. [primarily MS-DOS] Said of software conforming to system interface guidelines and standards. Well-behaved software uses the operating system to do chores such as keyboard input, allocating memory and drawing graphics. Oppose ill-behaved. 2. Software that does its job quietly and without counterintuitive effects. Especially said of software having an interface spec sufficiently simple and well-defined that it can be used as a tool by other software. See cat. [Jargon File] 1 1 1 1 1 well-connected Said of a computer installation, asserts that it has reliable electronic mail links with the network and/or that it relays a large fraction of available Usenet newsgroups. Well-known can be almost synonymous, but also implies that the site's name is familiar to many (due perhaps to an archive service or active Usenet users). 1 1 1 1 1 well-known port A TCP or UDP port with a number in the range 0-1023 (originally 0-255). The well-known port numbers are assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users. (2002-10-06) 1 1 1 1 1 well-ordered set A set with a total ordering and no infinite descending chains. A total ordering "<=" satisfies x <= x x <= y <= z => x <= z x <= y <= x => x = y for all x, y: x <= y or y <= x In addition, if a set W is well-ordered then all non-empty subsets A of W have a least element, i.e. there exists x in A such that for all y in A, x <= y. Ordinals are isomorphism classes of well-ordered sets, just as integers are isomorphism classes of finite sets. (1995-04-19) 1 1 1 1 1 WEP Wireless Encryption Protocol 1 1 1 1 1 Wesley Clark One of the designers of the Laboratory Instrument Computer at MIT who subsequently had a quiet hand in many seminal computing events, such as the development of the Internet, the first really good description of the metastability problem in computer logic. (http://pretext.com/mar98/features/story1.htm). (1999-03-29) 1 1 1 1 1 Western Digital Corporation A company founded in 1970 as a specialised semiconductor manufacturer, which today manufactures and sells microcomputer products including small form factor hard disk drives for personal computers, integrated circuits and circuit boards for graphics, storage, communications, battery management, and logic functions. (http://wdc.com/). (1995-04-12) 1 1 1 1 1 Westmount A Dutch software engineering vendor of RTEE and other products. (1998-04-27) 1 1 1 1 1 wetware /wet'weir/ (Probably from the novels of Rudy Rucker, or maybe Stanislav Lem) The human nervous system, as opposed to electronic computer hardware or software. "Wetware has 7 plus or minus 2 temporary registers." Also, human beings (programmers, operators, administrators) attached to a computer system, as opposed to the system's hardware or software. See liveware, meatware. [True origin? Dates?] [Jargon File] (1996-08-19) 1 1 1 1 1 wf The country code for the Wallis and Futuna Islands. (1999-01-27) 1 1 1 1 1 WFL Work Flow Language. Burroughs, ca 1973. A job control language for the B6700/B7700 under MCP. WFL was a compiled block-structured language similar to ALGOL 60, with subroutines and nested begin-end's. ["Work Flow Management User's Guide", Burroughs Manual 5000714, 1973]. ["Burroughs B6700/B7700 Work Flow Language", R.M. Cowan in Command Languages, C. Unger ed, N-H 1975]. (1996-01-18) 1 1 1 1 1 WfMC Workflow Management Coalition 1 1 1 1 1 WFW Windows for Workgroups 1 1 1 1 1 WFWG Windows for Workgroups 1 1 1 1 1 WG Working Group 1 1 1 1 1 WGL Waveform Generation Language 1 1 1 1 1 whack According to arch-hacker James Gosling, to "...modify a program with no idea whatsoever how it works." (See whacker.) It is actually possible to do this in nontrivial circumstances if the change is small and well-defined and you are very good at glarking things from context. As a trivial example, it is relatively easy to change all "stderr" writes to "stdout" writes in a piece of C filter code which remains otherwise mysterious. [Jargon File] 1 1 1 1 1 whacker [University of Maryland: from hacker] 1. A person, similar to a hacker, who enjoys exploring the details of programmable systems and how to stretch their capabilities. Whereas a hacker tends to produce great hacks, a whacker only ends up whacking the system or program in question. Whackers are often quite egotistical and eager to claim wizard status, regardless of the views of their peers. 2. A person who is good at programming quickly, though rather poorly and ineptly. 1 1 1 1 1 whales like kicking dead whales down the beach 1 1 1 1 1 whalesong The peculiar clicking and whooshing sounds made by a PEP modem such as the Telebit Trailblazer as it tries to synchronise with another PEP modem for their special high-speed mode. This sound isn't anything like the normal two-tone handshake between conventional modems and is instantly recognizable to anyone who has heard it more than once. It sounds, in fact, very much like whale songs. This noise is also called "the moose call" or "moose tones". 1 1 1 1 1 whatis 1. A Unix command which searches for a given string in the headings of all man pages. 2. A command which searches the archie Software Description Database for a given string, with case being ignored. (1995-11-12) 1 1 1 1 1 What's a spline? [XEROX PARC] This phrase expands to: "You have just used a term that I've heard for a year and a half, and I feel I should know, but don't. My curiosity has finally overcome my guilt." The PARC lexicon adds "Moral: don't hesitate to ask questions, even if they seem obvious." [Jargon File] 1 1 1 1 1 What You Get Is What You Never Thought You Had (WYGIWYNTYH) A jibe at WYSIWYG systems that fail in their stated aim by rendering documents differently on screen and on paper. (1999-06-15) 1 1 1 1 1 What You See Is All You Get (WYSIAYG) /wiz'ee-ayg/ Describes a user interface under which "What You See Is *All* You Get"; an unhappy variant of WYSIWYG. Visual, "point-and-drool interfaces" are easy to learn but often lack depth; they often frustrate advanced users who would be better served by a command-style interface. When this happens, the frustrated user has a WYSIAYG problem. This term is most often used of editors, word processors, and document formatting programs. WYSIWYG "desktop publishing" programs, for example, are a clear win for creating small documents with lots of fonts and graphics in them, especially things like newsletters and presentation slides. When typesetting book-length manuscripts, on the other hand, scale changes the nature of the task; one quickly runs into WYSIAYG limitations, and the increased power and flexibility of a command-driven formatter like TeX or Unix's troff becomes not just desirable but a necessity. 1 1 1 1 1 What You See Is What You Get (WYSIWYG) /wiz'ee-wig/ Describes a user interface for a document preparation system under which changes are represented by displaying a more-or-less accurate image of the way the document will finally appear, e.g. when printed. This is in contrast to one that uses more-or-less obscure commands that do not result in immediate visual feedback. True WYSIWYG in environments supporting multiple fonts or graphics is rarely-attained; there are variants of this term to express real-world manifestations including WYSIAWYG (What You See Is *Almost* What You Get) and WYSIMOLWYG (What You See Is More or Less What You Get). All these can be mildly derogatory, as they are often used to refer to dumbed-down user-friendly interfaces targeted at non-programmers; a hacker has no fear of obscure commands (compare WYSIAYG). On the other hand, Emacs was one of the very first WYSIWYG editors, replacing (actually, at first overlaying) the extremely obscure, command-based TECO. 1 1 1 1 1 wheel [slang "big wheel" for a powerful person] A person who has an active wheel bit. "We need to find a wheel to unwedge the hung tape drives." (See wedged). [Jargon File] 1 1 1 1 1 wheel bit A privilege bit that allows the possessor to perform some restricted operation on a time-sharing system, such as read or write any file on the system regardless of protections, change or look at any address in the running monitor, crash or reload the system, and kill or create jobs and user accounts. The term was invented on the TENEX operating system, and carried over to TOPS-20, XEROX-IFS, and others. The state of being in a privileged logon is sometimes called "wheel mode". This term entered the Unix culture from TWENEX in the mid-1980s and has been gaining popularity there (especially at university sites). See also root. 1 1 1 1 1 wheel wars [Stanford University] A period in larval stage during which student hackers hassle each other by attempting to log each other out of the system, delete each other's files, and otherwise wreak havoc, usually at the expense of the lesser users. [Jargon File] 1 1 1 1 1 When It's Done A manufacturer's non-answer to questions about product availability. This answer allows the manufacturer to pretend to communicate with their customers without setting themselves any deadlines or revealing how behind schedule the product really is. It also sounds slightly better than "We don't know". (1999-08-22) 1 1 1 1 1 Whetstone The first major synthetic benchmark program, intended to be representative for numerical (floating-point intensive) programming. It is based on statistics gathered by Brian Wichmann at the National Physical Laboratory in England, using an Algol 60 compiler which translated Algol into instructions for the imaginary Whetstone machine. The compilation system was named after the small town of Whetstone outside the City of Leicester, England, where it was designed. The later dhrystone benchmark was a pun on Whetstone. Source code: C (ftp://netlib.att.com/netlib/benchmark/whetstonec.Z), single precision Fortran (ftp://netlib.att.com:/netlib/benchmark/whetstones.Z), double precision Fortran (ftp://netlib.att.com:/netlib/benchmark/whetstoned.Z). ["A Synthetic Benchmark", H.J. Curnow and B.A. Wichmann, The Computer Journal, 19,1 (1976), pp. 43-49]. 1 1 1 1 1 Which Stands For Nothing (WSFN) A beginner's language with emphasis on graphics produced by Atari in 1983 for Atari home computers. There is also Advanced WSFN. (1996-06-12) 1 1 1 1 1 while while loop 1 1 1 1 1 while loop The loop construct, found in nearly all procedural languages, that executes one or more instructions (the "loop body") repeatedly so long as some condition evaluates to true. In contrast to a repeat loop, the loop body will not be executed at all if the condition is false on entry to the while. For example, in C, a while loop is written while (<expr>) <statement>; where <expr> is any expression and <statement> is any statement, including a compound statement within braces ... A for loop, e.g. in the C language, extends the while loop syntax to collect pre-loop initialisation and loop-end logic into the beginning of the statement. Perl provides the "until" loop that loops until the loop condition is true. 1 1 1 1 1 Whirlwind An early computer from the MIT Research Laboratory for Electronics. Whirlwind used electrostatic memory and ran Laning and Zierler (1953); and ALGEBRAIC, COMPREHENSIVE and SUMMER SESSION (all 1959). [Details, reference?] (2002-06-03) 1 1 1 1 1 White Book 1. <language, publication> K&R. 2. <language, publication, file format> The fourth book in Adobe Systems, Inc.'s PostScript series, describing the previously-secret format of Type 1 fonts. The other three official guides are known as the Blue Book, the Green Book, and the Red Book. ["Adobe Type 1 Font Format, version 1.1", Addison-Wesley, 1990 (ISBN 0-201-57044-0)]. 3. <hardware, standard> White book CD-ROM. [Jargon File] (1996-12-03) 1 1 1 1 1 White book CD-ROM A more open CD-ROM standard than Green Book CD-ROM. All films mastered on CD-ROM after March 1994 use White Book. Like Green Book, it is ISO 9660 compliant, uses mode 2 form 2 addressing and can only be played on a CD-ROM drive which is XA (Extended Architecture) compatible. White book CDs are labelled "Video CD". (1994-11-02) 1 1 1 1 1 white box testing (Or "clear", "glass", "open") Software testing approaches that examine the program structure and derive test data from the program logic. Structural testing is sometimes referred to as clear-box testing since white boxes are considered opaque and do not really permit visibility into the code. (1996-05-10) 1 1 1 1 1 White pages A directory service for locating individuals by name (by analogy with the telephone directory). The Internet supports several databases that contain basic information about users, such as electronic mail addresses, telephone numbers and postal addresses. These databases can be searched to get information about particular individuals. See Knowbot, Netfind, whois, X.500, finger. 1 1 1 1 1 white paper A short treatise whose purpose is to educate industry customers. See, e.g., Architecture Neutral Distribution Format. (1997-10-24) 1 1 1 1 1 white point A set of three colour coordinates that define the colour white in image processing applications. (2008-03-10) 1 1 1 1 1 Whitesmiths style An obsolete and deprecated source code indent style popularised by the examples that came with Whitesmiths C, an early commercial C compiler. Basic indent per level is eight spaces, occasionally four. if (cond) <body> (2014-09-24) 1 1 1 1 1 whitespace (From the colour it produces on white paper) Any contiguous sequence of spaces, tabs, carriage returns, and/or line feeds. Whitespace might also possibly include form feed characters. The term is common on Unix. See also non-printing character. (1996-09-04) 1 1 1 1 1 white trash A pejorative term for Intel-based microcomputers, used by NeXT users at UK law firm Linklaters & Paines to contrast these machines with their black NeXT boxes. (1996-09-04) 1 1 1 1 1 WHNF weak head normal form 1 1 1 1 1 whois An Internet directory service for looking up names of people on a remote server. Many servers respond to TCP queries on port 43, in a manner roughly analogous to the DDN NIC whois service described in RFC 954. Other sites provide this directory service via the finger protocol or accept queries by electronic mail for directory information. On Unix the client command is whois -h server_name person_name You can also type "telnet server_name 43" and then type the person's name on a separate line. For a list of whois servers, FTP/Gopher: sipb.mit.edu. Or whois -h sipb.mit.edu whois-servers As the above command demonstrates, whois can find information about things other than users, e.g. domains, networks and hosts. 1 1 1 1 1 whole number integer 1 1 1 1 1 Whopper WarGames 1 1 1 1 1 WHQL Windows Hardware Quality Labs 1 1 1 1 1 WIBNI (Bell Labs) Wouldn't It Be Nice If. What most requirements documents and specifications consist entirely of. Compare IWBNI. [Jargon File] (1994-11-24) 1 1 1 1 1 WIC WAN Interface Card 1 1 1 1 1 Wide Area Information Servers (WAIS) A distributed information retrieval system. WAIS is supported by Apple Computer, Thinking Machines and Dow Jones. Clients are able to retrieve documents using keywords. The search returns a list of documents, ranked according to the frequency of occurrence of the keyword(s) used in the search. The client can retrieve text or multimedia documents stored on the server. WAIS offers simple natural language input, indexed searching for fast retrieval, and a "relevance feedback" mechanism which allows the results of initial searches to influence future searches. It uses the ANSI Z39.50 service. Public domain implementations are available. Other information retrieval systems include archie, Gopher, Prospero, and web. Usenet newsgroup: news:comp.infosystems.wais. Telnet (telnet://sunsite.unc.edu). 1 1 1 1 1 Wide Area Network (WAN) A network, usually constructed with serial lines, extending over distances greater than one kilometre. Compare local area network, metropolitan area network. (1994-11-24) 1 1 1 1 1 Wide Area Telecommunications Service (WATS) A special service provided by an inter-exchange carrier that allows a customer to use a specific trunk to make calls to specific geographic zones or to receive calls at a specified number at a discounted price. (2006-05-01) 1 1 1 1 1 Wideband ATM An enhanced form of ATM networking that transfers digital data over local area networks, originally at 0.96 Gbps, now (Aug 1996) at 1.0 Gbps. (1996-08-23) 1 1 1 1 1 Wide SCSI A variant on the SCSI-2 interface. It uses a 16-bit bus - double the width of the original SCSI-1 - and therefore cannot be connected to a SCSI-1 bus. It supports transfer rates up to 20 MB/s, like Fast SCSI. There is also a SCSI-2 definition of Wide-SCSI with a 32 bit data bus. This allows up to 40 megabytes per second but is very rarely used because it requires a large number of wires (118 wires on two connectors). Thus Wide SCSI usually means 16 bit-wide SCSI. (1995-04-21) 1 1 1 1 1 widget 1. <jargon> A placeholder term used to stand for a real object in didactic examples (especially database tutorials). Legend has it that the original widgets were holders for buggy whips. "But suppose the parts list for a widget has 52 entries..." 2. In a graphical user interface, a combination of a graphic symbol and some program code to perform a specific function. E.g. a scroll-bar or button. [possibly evoking "window gadget"] Windowing systems usually provide widget libraries containing commonly used widgets drawn in a certain style and with consistent behaviour. In Microsoft Windows GUI programming, these are generally known as "controls". [Jargon File] 1 1 1 1 1 wi-fi Either of two different incompatible radio-based LAN protocols, namely 802.11b (which speaks DSSS at 2.4GHz) and 802.11a (which speaks OFDM at 5GHz). The term was invented by the marketing departments of wi-fi equipment manufacturers. It is, notionally, short for wireless fidelity, on the analogy of hi-fi for "high fidelity" audio. (2003-09-02) 1 1 1 1 1 Wi-Fi Protected Access (WPA) A security scheme for wireless networks, developed by the networking industry in response to the shortcomings of Wired Equivalent Privacy (WEP). WPA uses Temporal Key Integrity Protocol (TKIP) encryption and provides built-in authentication, giving security comparable to VPN tunneling with WEP, with the benefit of easier administration and use. WPA-PSK is a simplified form of WPA. (2007-05-11) 1 1 1 1 1 Wi-Fi Protected Access Pre-Shared Key (WPA-PSK) A simplified but still powerful form of WPA, most suitable for home wireless networking. As with WEP, you set a static key or pass phrase, but WPA-PSK uses TKIP to automatically change the keys periodically, making it much more difficult to break the encryption. (2007-05-11) 1 1 1 1 1 wiggles [scientific computation] In solving partial differential equations by finite difference and similar methods, wiggles are sawtooth (up-down-up-down) oscillations at the shortest wavelength representable on the grid. If an algorithm is unstable, this is often the most unstable waveform, so it grows to dominate the solution. Alternatively, stable (though inaccurate) wiggles can be generated near a discontinuity by a Gibbs phenomenon. 1 1 1 1 1 wiki Any collaborative website that users can easily modify via the web, often without restriction. A wiki allows anyone, using a web browser, to create, edit or delete content that has been placed on the site, including the work of other authors. Text is entered using some simple mark-up language which is then rendered as HTML. A feature common to many of the different implementations is that any word in mixed case LikeThis (a "wikiword") is rendered as a link to a page of that name, which may or may not exist. Wikis work surprisingly well. The most famous example, Wikipedia (referred to as "wiki" by some), is one of the most visited sites on the web. Contributors tend to be more numerous and more persistent than vandals, and old versions of pages are always available. Like many simple concepts, open editing has profound effects on usage. Allowing everyday users to create and edit any page encourages democratic use of the web and promotes content composition by nontechnical users. 1 1 1 1 1 WiLAN wireless local area network 1 1 1 1 1 Wild_LIFE Logic, Inheritance, Functions and Equations parts: interpreter, manual, tests, libraries, examples Paradise Project, DEC Paris Research Laboratory. (ftp://gatekeeper.dec.com/pub/plan/Life.tar.Z) - Wild_LIFE interpreter from Paradise project at DEC's Paris Research Lab LIFE is an experimental programming language with a powerful facility for structured type inheritance. It reconciles styles from functional programming, logic programming, and object-oriented programming. LIFE implements a constraint logic programming language with equality (unification) and entailment (matching) constraints over order-sorted feature terms. The Wild_LIFE interpreter has a comfortable user interface with incremental query extension ability. It contains an extensive set of built-in operations as well as an X Windows interface. A semantic superset of LOGIN and LeFun. Syntax is similar to prolog. 1 1 1 1 1 wild card (From card games in which certain cards, often the joker, can act as any other card) A special character or character sequence which matches any character in a string comparison, like ellipsis ("...") in ordinary written text. In Unix filenames '?' matches any single character and '*' matches any zero or more characters. In regular expressions, '.' matches any one character and "[...]" matches any one of the enclosed characters. See also Backus-Naur Form. (1997-07-16) 1 1 1 1 1 Wilf Hey The person who originally developed Report Program Generator and coined the phrase GIGO (garbage in: garbage out). In 2004, after more than forty years in computing, he was writing for PC Plus magazine in the UK and doing Wilf's programmers workshop amongst other things. He died on 2007-01-01 after a long illness. (2007-01-06) 1 1 1 1 1 William Gibson Author of cyberpunk novels such as Neuromancer (1984), Count Zero (1986), Mona Lisa Overdrive, and Virtual Light (1993). Neuromancer, a novel about a computer hacker/criminal cowboy of the future helping to free an artificial intelligence from its programmed bounds, won the Hugo and Nebula science fiction awards and is credited as the seminal cyberpunk novel and the origin of the term "cyberspace". Gibson does not have a technical background and supposedly purchased his first computer in 1992. (1996-06-11) 1 1 1 1 1 William Hamilton A mathematician who posed Hamilton's problem. Biography (http://gregory.dcs.st-and.ac.uk/~history/ShortBiogs/H.html#Hamilton). [Summary?] (1995-11-02) 1 1 1 1 1 William Joy (Bill Joy) Author of the C shell and vi, he was also one of the people at the University of California at Berkeley responsible for the Berkeley Software Distribution of Unix. He also wrote a book on Unix. He was a co-founder of Sun Microsystems, Inc., where he is still (1997) Vice-President of Research. Among his many projects for Sun have been helping to design the Network File System and the SPARC architechture. Biography (http://sun.com/aboutsun/media/ceo/mgt_joy.html). See also dinosaur. [Book ref? E-mail?] (2000-10-30) 1 1 1 1 1 WIMP Windows, Icons, Menus and Pointers (or maybe Windows, Icons, Mouse, Pull-down menus). The style of graphical user interface invented at Xerox PARC, popularised by the Apple Macintosh and now available in other varieties such as the X Window System, OSF/Motif, NeWS, RISC OS and Microsoft Windows. See menuitis, user-obsequious, window system. (2007-09-12) 1 1 1 1 1 WIMP environment WIMP 1 1 1 1 1 win (Said of people, computers, algorithms, programs) (To be) a success at a given task. E.g. "WYSIWYG is a clear win for small documents". winnitude is the quality that something which wins has. winning is often (ab)used as an adjective. Synonyms: cuspy, elegant. Antonym: lose. Compare lossy, lossless. [Jargon File] (1996-09-08) 1 1 1 1 1 Win2K Windows 2000 1 1 1 1 1 Win32 An application programming interface that is common to all Microsoft's 32-bit Windows operating systems. These currently include: Windows 95, Windows 98, Windows NT and Windows CE. [Relationship with Win32s?] (1997-12-20) 1 1 1 1 1 Win32s A free extension for Microsoft Windows, released by Microsoft. Win32s is a software layer on top of Windows which allows 32-bit applications (e.g. Mosaic) to run on Windows. Both stand-alone Windows and Windows for Workgroups run as 16 bit, and both can use Win32s to run 32-bit applications. (1996-07-08) 1 1 1 1 1 Win 95 Windows 95 1 1 1 1 1 Win 98 Windows 98 1 1 1 1 1 winchester An informal generic term for floating head magnetic disk drives in which the read-write head planes over the disk surface on an air cushion. The name arose because the original 1973 engineering prototype for what later became the IBM 3340 featured two 30-megabyte volumes; 30--30 became "Winchester" when somebody noticed the similarity to the common term for a famous Winchester rifle (in the latter, the first 30 referred to caliber and the second to the grain weight of the charge). [Jargon File] (1994-12-06) 1 1 1 1 1 windowing window system 1 1 1 1 1 windowing system window system 1 1 1 1 1 window manager A part of a window system which arranges windows on a screen. It is responsible for moving and resizing windows, and other such functions common to all applications. Examples from the X Window System are twm, gwm, olwm. (1994-12-06) 1 1 1 1 1 Window RAM Window Random Access Memory 1 1 1 1 1 Window Random Access Memory (WRAM, Window RAM) A kind of RAM which is faster than VRAM. WRAM is used in the Matrox MGA Millennium video display card and almost certainly elsewhere. [More details?] (1996-06-05) 1 1 1 1 1 Windows See Microsoft Windows, Windows NT. (1997-11-23) 1 1 1 1 1 Windows 1 The first incarnation of Microsoft Windows, released in 1985. It took a total of 55 programmer-years to develop, and only allowed tiled windows. (1996-07-08) 1 1 1 1 1 Windows 2 The second version of Microsoft Windows, released in 1987. Windows 2 had considerably more features than Windows 1, such as overlapping windows and icons. When Windows/386 was released, Windows 2 was renamed Windows/286. 1 1 1 1 1 Windows 2000 (Win2k, W2k, NT5, Windows NT 5.0) An operating system developed by Microsoft Corporation for PCs and servers, as the successor to Windows NT 4.0. Early beta versions were referred to as "Windows NT 5.0". Windows 2000 was officially released on 2000-02-17. Windows 2000 is most commonly used on Intel x86 and Pentium processors, with a DEC Alpha version rumoured. Unlike Windows NT 4.0, Windows 2000 is not available for PowerPC or MIPS. Windows 2000's user interface is very similar to Windows 95 or Windows NT 4.0 with integrated Internet Explorer, or to Windows 98. It is available in four flavours: - Professional: the client version, meant for desktop workstations, successor to Windows NT Workstation. - Server: "entry-level" server, designed for small deployments, and departmental file, print, or intranet 1 1 1 1 1 Windows/286 Windows 2 1 1 1 1 1 Windows 2K Windows 2000 1 1 1 1 1 Windows 3.0 A complete rework of Microsoft Windows with many new facilities such as the ability to address memory beyond 640k. It was released in 1990, and vigorous development of applications by third parties helped Microsoft sell over 10 million copies. (1996-07-08) 1 1 1 1 1 Windows 3.1 A version of Microsoft Windows with many improvements over Windows 3.0, including True Type Fonts, Object Linking and Embedding (OLE) and Mouse Trails for use with LCD Devices. It also saw the loss of Real Mode, which meant it would no longer run on Intel 8086 processors (did anyone ever do this anyway?). Sometimes described as "stand-alone Windows", in contrast to Windows for Workgroups 3.1. Windows 3.11 is a free bug-fix update. 3.1's successors are Windows 95 and Windows NT. (1996-07-08) 1 1 1 1 1 Windows 3.11 A free minor bug-fix for Windows 3.1. (1996-07-08) 1 1 1 1 1 Windows/386 A version of Microsoft Windows released in late 1987. Windows/386 was basically the same as its predecessor, Windows/286 (as Windows 2 was renamed), but with the capability to run multiple MS-DOS applications simultaneously in extended memory. (1996-07-08) 1 1 1 1 1 Windows 4GL (INGRES/Windows 4GL) A graphical tool running on top of a workstation's native windowing system, to help developers to build user interfaces to INGRES applications. (1996-07-09) 1 1 1 1 1 Windows 94 A facetious name for Windows 95, so called because it was originally meant to ship in 1994. (1998-09-07) 1 1 1 1 1 Windows 95 (Win95) Microsoft's successor to their Windows 3.11 operating system for IBM PCs. It was known as "Chicago" during development. Its release was originally scheduled for late 1994 but eventually happened on 11 Jul 1995, followed by Service Release 1 on 1995-12-31 and OSR2 (OEM Service Release 2) on 1996-08-24. In contrast to earlier versions, Windows 95 is a complete operating system rather than a graphical user interface running on top of MS-DOS. It provides 32-bit application support, pre-emptive multitasking, threading and built-in networking (TCP/IP, IPX, SLIP, PPP, and Windows Sockets). It includes MS-DOS 7.0, but takes over completely after booting. The graphical user interface, while similar to previous Windows versions, is significantly improved. Windows 95 has also been described as "32-bit extensions and a graphical shell for a 16-bit patch to an 8-bit operating 1 1 1 1 1 Windows 98 Microsoft's 1998 update to Windows 95 that adds: * Hardware support for Universal Serial Bus (USB). * Internet Connection Sharing (IGC) - multiple PCs share a single connection to the Internet. * Microsoft WebTV for Windows - watch TV on your PC. * Support for new graphic, sound, and multimedia formats. * Internet Explorer release 5. * Windows 98 Service Pack - year 2000 updates. Windows 98 was followed logically by Windows ME but chronologically by Windows 2000 Professional Edition. (http://microsoft.com/windows98). (2002-01-19) 1 1 1 1 1 Windows 9X A shorthand meaning Windows 95 or Windows 98. (2004-03-28) 1 1 1 1 1 Windows Application Binary Interface (WABI) A software package from Sun Microsystems to allow certain Microsoft Windows applications under the X Window System. Wabi 2.2 runs under Solaris on SPARC, Intel, and PowerPC. Wabi works by providing translated versions of the three core Windows libraries, user.dll, kernel.dll, and gdi.dll which redirect Windows calls to Solaris equivalents. For code other than core library calls Wabi either executes the instructions directly on the hardware, if it is Intel, or emulates them, either one instruction at a time or by translating a block of instructions and caching the result (e.g. for a loop). WabiServer allows the Windows application and X display to be on different computers. Overview (http://sun.com/solaris/products/wabi/). (1997-01-08) 1 1 1 1 1 Windows CE /C E/ A version of the Microsoft Windows operating system that is being used in a variety of embedded products, from handheld PCs to specialised industrial controllers and consumer electronic devices. Programming for Windows CE is similar to programming for other Win32 platforms. Windows CE was developed to be a customisable operating system for embedded applications. Its kernel borrows much from other Microsoft 32-bit operating systems, while eliminating (or replacing) those operating system features that are not needed for typical Windows CE-based applications. For example, as on Windows NT, all applications running on Windows CE run in a fully preemptive multitasking environment, in fully protected memory spaces. The Win32 (API) for Windows CE is smaller than the Win32 API for the other 32-bit Windows operating systems. It includes approximately half the interface methods of the Windows NT 1 1 1 1 1 Windows for Workgroups (WFW, WFWG) A version of Windows 3.1 which works with a network. Although stand-alone 3.1 can be networked, the installation and configuration is much improved with Windows for Workgroups (3.1). Windows for Workgroups 3.11 was a significant upgrade to WFW 3.1, adding 32-bit file access, fax capability and higher performance. (1996-07-08) 1 1 1 1 1 Windows Hardware Quality Labs (WHQL) A Microsoft body that produces and supports the Microsoft Hardware Compatibility Test kit for current Microsoft operating systems. Products are tested with the kit to ensure that they meet Microsoft standards for compatibility with Windows and to qualify to use the Designed for Microsoft Windows logos. (http://microsoft.com/hwdq/hwtest/). (2002-11-13) 1 1 1 1 1 window shopping A term used among users of WIMP environments like the X Window System or the Macintosh at the US Geological Survey for extended experimentation with new window colours, fonts, and icon shapes. This activity can take up hours of what might otherwise have been productive working time. "I spent the afternoon window shopping until I found the coolest shade of green for my active window borders --- now they perfectly match my medium slate blue background." Serious window shoppers will spend their days with bitmap editors, creating new and different icons and background patterns for all to see. Also: "window dressing", the act of applying new fonts, colours, etc. See fritterware, compare macdink. [Jargon File] (1996-07-08) 1 1 1 1 1 Windows Internet Naming Service (WINS) Software which resolves NetBIOS names to IP addresses. [Details?] (1998-02-14) 1 1 1 1 1 Windows Management Interface (WMI) Microsoft's implementation of Web-Based Enterprise Management, a DMTF initiative to establish standards for accessing and sharing system management information over an enterprise network. (2005-02-15) 1 1 1 1 1 Windows ME Windows Millennium Edition 1 1 1 1 1 Windows Messaging Microsoft's Internet electronic mail application, formerly called Microsoft Exchange. (1998-07-05) 1 1 1 1 1 windows messaging An inter-process communication facility usually provided by vendors of graphical user interfaces for concurrent operating systems, such as Microsoft, The X Consortium and Apple. The system software translates hardware interrupts from various input devices into messages according to the current input context (e.g. the active window of the frontmost application). Each message is a short piece of information. A message's format depends on its type, which is usually encoded in its first field. The message is sent to the client application using some communication protocol (e.g. shared memory, internal socket, network socket). The client application dispatches the message and performs any actions required. The messages can also be sent by client applications. This provides convenient and flexible inter-process communication. (1998-07-06) 1 1 1 1 1 Windows Millennium Edition (Windows ME) An update of Microsoft Windows 98, released in 2000. ME included updates of packaged software and new software such as Windows Media Player 7, Windows Movie Maker. It also has an updated user interface with new colours and icons, but few major changes. Windows ME was followed by Windows XP. (2003-05-13) 1 1 1 1 1 Windows NT (Windows New Technology, NT) Microsoft's 32-bit operating system developed from what was originally intended to be OS/2 3.0 before Microsoft and IBM ceased joint development of OS/2. NT was designed for high end workstations (Windows NT 3.1), servers (Windows NT 3.1 Advanced Server), and corporate networks (NT 4.0 Enterprise Server). The first release was Windows NT 3.1. Unlike Windows 3.1, which was a graphical environment that ran on top of MS-DOS, Windows NT is a complete operating system. To the user it looks like Windows 3.1, but it has true multi-threading, built in networking, security, and memory protection. It is based on a microkernel, with 32-bit addressing for up to 4Gb of RAM, virtualised hardware access to fully protect applications, installable file systems, such as FAT, HPFS and NTFS, built-in networking, multi-processor support, and C2 security. 1 1 1 1 1 Windows NT 3.1 Microsoft's first version of Windows NT, released in September 1993, price UKP 395, after having been in beta-test for as long as anyone could remember. The person responsible for VMS on the DEC VAX [who?] was also responsible for Windows NT. Incrementing each letter in VMS yields WNT. (http://win2000mag.com/Articles/Index.cfm?ArticleID=4494). (2000-08-12) 1 1 1 1 1 Windows NT 3.5 A much improved version of Microsoft's Windows NT 3.1. NT is now (July 1996) supplied as "Windows NT 3.5 Workstation" and "Windows NT 3.5 Server". It has better OLE support, higher performance and requires less memory. (1996-07-08) 1 1 1 1 1 Windows NT 4 A version of Microsoft's Windows NT operating system, originally code named "Cairo". It was supposed to ship in the first half of 1995. Details are scarce, but it is intended to provide an object-oriented version of Windows. (1996-07-09) 1 1 1 1 1 Windows NT 5 Windows 2000 1 1 1 1 1 Windows NT Network Model The network model used by Windows NT. The model has the following layers: User Applications (e.g. Excel) APIs File System Drivers TDI Protocols NDIS v4 NDIS Wrapper NDIS Card Driver Network Adapter Card Compare OSI seven layer model. (1997-11-05) 1 1 1 1 1 Windows Open Service Architecture (WOSA) One of the mainstays of Microsoft Windows: the ethos of abstraction of core services. For each extension, Windows Open Services Architecture defines an API and an SPI, as well as a universal interface (usually placed in a single DLL) that both comply to. These then transparently let the operating system speak to device drivers, database managers, and other low level entities. These extensions include, among others, ODBC (called the crowning jewel of WOSA), TAPI, WOSA/XFS, SAPI and MAPI, and their supporting services, as well as the abstraction of access to printers, modems, and networking services, which run identically over TCP/IP, IPX/SPX, and NetBEUI. (2000-08-16) 1 1 1 1 1 Windows Registry The database used by Microsoft Windows 95 and later to store all sorts of configuration information such as which program should be used to open a .doc file, DLL registration information, application-specific settings and much more. The Registry is stored in .dat files, one in the user's profile containing their per-user settings and one in the Windows directory containing settings that are global to all users. These are loaded into memory at login. The loaded data appears as a tree with five main branches: HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS, HKEY_CURRENT_CONFIG. HKEY_CLASSES_ROOT defines file types and actions, HKEY_CURRENT_USER is an alias for one of the sub-trees of HKEY_USERS and contains user settings that override the global defaults in HKEY_LOCAL_MACHINE. The branches of the tree are called "keys" and are identified by paths like 1 1 1 1 1 Windows sockets (Winsock) A specification for Microsoft Windows network software, describing how applications can access network services, especially TCP/IP. Winsock is intended to provide a single API to which application developers should program and to which multiple network software vendors should conform. For any particular version of Microsoft Windows, it defines a binary interface (ABI) such that an application written to the Windows Sockets API can work with a conformant protocol implementation from any network software vendor. Winsock was conceived at Fall Interop '91 during a Birds of a Feather session. Windows Sockets is supported by Microsoft Windows, Windows for Workgroups, Win32s, Windows 95 and Windows NT. It will support protocols other than TCP/IP. Under Windows NT, Microsoft will provide Windows Sockets support over TCP/IP and IPX/SPX. DEC will be implementing 1 1 1 1 1 Windows XP The version of the Microsoft Windows operating system that, when it was released on 2001-10-25, finally merged the Windows 95 - Windows ME strain with the Windows NT - Windows 2000 one. XP comes in two main versions: Windows XP Professional Edition and a simplified subset for home users, Windows XP Home Edition. Windows XP home page (http://microsoft.com/windowsxp/). (2009-08-12) 1 1 1 1 1 Windows XP Pro Windows XP Professional Edition 1 1 1 1 1 Windows XP Professional Edition ("Windows XP Pro", "XP Pro") The version of Microsoft's Windows XP operating system intended for businesses and advanced users. The alternative, Windows XP Home Edition, is a subset of Pro without Remote Desktop, Multi-processor support, Automated System Recovery, Dynamic Disk Support, Fax, Internet Information Services, Encrypting File System, File-level access control, Active Directory, Group Policy, IntelliMirror, Roaming profiles and other features. Pro-Home Comparison (http://www.winsupersite.com/showcase/windowsxp_home_pro.asp). (2009-08-12) 1 1 1 1 1 window system Software which allows a computer's display to be divided into rectangular areas which act like a separate input/output devices under the control of different application programs. This gives the user the ability to see the output of several processes at once and to choose which one will receive input by selecting its window, usually by pointing at it with a mouse. Examples are the X Window System, proprietary systems on the Macintosh and NeXT, NeWS on Suns, RISC OS on the Archimedes and Microsoft Windows. See also WIMP. (2015-03-07) 1 1 1 1 1 Windoze Microsloth Windows 1 1 1 1 1 Wind River Systems A company founded in 1981, now a world leader in embedded systems, providing real-time operating systems and development tools. Wind River's development tools enable customers to standardise designs across projects and quickly develop feature-rich products. Wind River Systems employs over 500 people worldwide (1998). Service and support is provided through its U.S. headquarters and overseas operations in the U.K., France, Germany, Scandinavia and Japan. (http://wrs.com/). Address: Alameda, California, USA. (1998-11-06) 1 1 1 1 1 winged comments Comments set on the same line as code, as opposed to boxed comments. In C, for example: d = sqrt(x*x + y*y); /* distance from origin */ Generally these refer only to the action(s) taken on that line. [Jargon File] (1997-07-21) 1 1 1 1 1 winkey winkey face. See emoticon. [Jargon File] (1996-09-08) 1 1 1 1 1 WinMaker Pro RoboDemo 1 1 1 1 1 WINS Windows Internet Naming Service 1 1 1 1 1 Winsock Windows sockets 1 1 1 1 1 WinSoft Products Ltd The company which produces EMBLA Pro. (http://ftech.co.uk/~winsoft). E-mail: WinSoft Products Ltd <info@winsoft.ftech.co.uk> (1996-03-11) 1 1 1 1 1 wintel A term describing any computer platform consisting of some version of Microsoft Windows running on an Intel 80x86 processor or compatible. Despite the dominance of the wintel platform, in its many forms, from MS-DOS on an Intel 8088 to Windows 2000 on a Pentium II Xeon, there are many "non-wintel" platforms in use. These include Acorn, Amiga, Apple, ARM, Atari, A\Box, Be, Network Computer, OS/2, PowerPC, Psion, Linux and all other Unix systems. Convergence International (http://convergence.org/). (1999-09-15) 1 1 1 1 1 WINZIP A Microsoft Windows archiving and compression program, distributed by Nico Mak Computing, Inc. WINZIP has a graphical user interface front end and is compatible with PKZIP. WINZIP can be obtained as shareware, on evaluation, or as a licenced copy. It is much easier to use then PKZIP for DOS, and includes a helpful, help file. (http://winzip.com/). (2000-02-27) 1 1 1 1 1 wired hard-wired 1 1 1 1 1 wirehead /wi:r'hed/ (Probably from SF slang for an electrical brain-stimulation addict) 1. A hardware hacker, especially one who concentrates on communications hardware. 2. An expert in local-area networks. A wirehead can be a network software wizard too, but will always have the ability to deal with network hardware, down to the smallest component. Wireheads are known for their ability to lash up an Ethernet terminator from spare resistors, for example. [Jargon File] (1995-02-28) 1 1 1 1 1 wireless A term describing a computer network where there is no physical connection (either copper cable or fibre optics) between sender and receiver, but instead they are connected by radio. Applications for wireless networks include multi-party teleconferencing, distributed work sessions, personal digital assistants, and electronic newspapers. They include the transmission of voice, video, images, and data, each traffic type with possibly differing bandwidth and quality-of-service requirements. The wireless network components of a complete source-destination path requires consideration of mobility, hand-off, and varying transmission and bandwidth conditions. The wired/wireless network combination provides a severe bandwidth mismatch, as well as vastly different error conditions. The processing capability of fixed vs. mobile terminals may be expected to differ significantly. This then leads to such issues to be 1 1 1 1 1 Wireless Application Protocol (WAP) An open international standard for applications that use wireless communication, e.g. Internet access from a mobile phone. The official body developing WAP is the WAP Forum. (http://wapforum.org/). Technical data (http://wapforum.org/what/technical.htm). [More detailed summary?] (2000-02-10) 1 1 1 1 1 wireless bitmap (WBMP) A bitmap for display on a WAP mobile phone. Currently (2001) the only type of WBMP file defined is a simple black-and-white image file with one bit per pixel and no compression. [WAP Forum (http://wapforum.org/), "WAP-190-WAE-Spec" or "Wireless Application Protocol, Wireless Application Environment Specification]." (2001-05-23) 1 1 1 1 1 wireless hotspot A public place where you can connect to a wireless local area network, usually by paying. (2009-05-28) 1 1 1 1 1 wireless local area network (WLAN /W-lan/, or "LAWN" /lorn/, sometimes WiLAN /wi-lan/) A communication system that transmits and receives data using modulated electromagnetic waves, implemented as an extension to, or as an alternative for, a wired LAN. WLANs are typically found within a small client node-dense locale (e.g. a campus or office building), or anywhere a traditional network cannot be deployed for logistical reasons. Benefits include user mobility in the coverage area, speed and simplicity of physical setup, and scalability. Being a military spin-off, WLANs also provide security features such as encryption, frequency hopping, and firewalls. Some of these are intrinsic to the protocol, making WLANs at least as secure as wired networks, and usually more so. The drawbacks are high initial cost (mostly hardware), limited range, possibility of mutual interference, amd the need to security-enable clients. 1 1 1 1 1 Wireless Local Loop (WLL, radio in the loop, RITL, fixed-radio access, FRA) Connecting subscribers to the public switched telephone network (PSTN) using radio signals instead of copper wires. The wireless link may be all or part of the connection between the subscriber and the switch. WLL includes cordless access systems, proprietary fixed radio access and fixed cellular systems. (2008-03-15) 1 1 1 1 1 Wireless Transport Layer Security (WTLS) The WAP standard related to security. WTLS is based upon its TCP/IP counterpart, Secure Sockets Layer. [Reference?] (2003-06-17) 1 1 1 1 1 wirewater programming fluid. This melds the mainstream slang adjective "wired" (stimulated, up, hyperactive) with firewater; however, it refers to caffeinacious rather than alcoholic beverages. [Jargon File] (1995-02-27) 1 1 1 1 1 WISCII A version of ASCII used by Wang on their personal computers and mini computers in the 1980s. WISCII was used on the Wang PC, APC, OIS, Alliance and VS. The 7-bit characters were the same as ASCII, but the extended 8-bit characters were Wang-specific. (2008-05-28) 1 1 1 1 1 wish list A list of desired features or bug fixes that probably won't get done for a long time, usually because the person responsible for the code is too busy or can't think of a clean way to do it. "OK, I'll add automatic filename completion to the wish list for the new interface." Compare tick-list features. [Does anybody call this a "want list"?] [Jargon File] (1998-04-28) 1 1 1 1 1 Wisp ["An Experiment with a Self-Compiling Compiler for a Simple List-Processing Language", M.V. Wilkes, Ann Rev Automatic Programming 4:1-48. (1964)]. 1 1 1 1 1 within delta of delta 1 1 1 1 1 within epsilon of epsilon 1 1 1 1 1 wizard 1. A person who knows how a complex piece of software or hardware works (that is, who groks it); especially someone who can find and fix bugs quickly in an emergency. Someone is a hacker if he or she has general hacking ability, but is a wizard with respect to something only if he or she has specific detailed knowledge of that thing. A good hacker could become a wizard for something given the time to study it. 2. A person who is permitted to do things forbidden to ordinary people; one who has wheel privileges on a system. 3. A Unix expert, especially a Unix systems programmer. This usage is well enough established that "Unix Wizard" is a recognised job title at some corporations and to most headhunters. See guru, lord high fixer. See also deep magic, heavy wizardry, incantation, magic, mutter, rain dance, voodoo programming, wave a dead chicken. 1 1 1 1 1 Wizard Book Hal Abelson, Gerald Sussman and Julie Sussman's "Structure and Interpretation of Computer Programs" (MIT Press, 1984; ISBN 0-262-01077-1), an excellent computer science text used in introductory courses at MIT. So called because of the wizard on the jacket. One of the bibles of the LISP/Scheme world. Also, less commonly, known as the Purple Book. [Jargon File] (1995-01-10) 1 1 1 1 1 wizardly Pertaining to wizards. A wizardly feature is one that only a wizard could understand or use properly. [Jargon File] 1 1 1 1 1 wizard mode [rogue] A special access mode of a program or system, usually password protected, that permits some users godlike privileges. Generally not used for operating systems themselves ("root mode" or "wheel mode" would be used instead). This term is often used with respect to games that have editable state. 1 1 1 1 1 WizDOM Software for distributed Unix system management from TIVOLI Systems of Austin, Texas, USA. (1995-02-10) 1 1 1 1 1 wk1 (worksheet) The filename extension used by early versions of the Lotus 1-2-3 spreadsheet program including release 2.01 (1987). All files created by the user are given this extension. (1995-11-28) 1 1 1 1 1 WLAN wireless local area network 1 1 1 1 1 WLL Wireless Local Loop 1 1 1 1 1 WMA Windows Media Audio 1 1 1 1 1 wmf The filename extension for a Windows Metafile. (1995-04-25) 1 1 1 1 1 WMI Windows Management Interface 1 1 1 1 1 WML Wireless Markup Language 1 1 1 1 1 WMV Windows Media Video 1 1 1 1 1 WNPP Work Needed and Prospective Packages 1 1 1 1 1 WO WebObjects 1 1 1 1 1 Wolfram Research, Inc. The company founded by Stephen Wolfram in August 1987 to develop Mathematica which was released in June 1988 for the Macintosh and is now available on over 20 platforms. The company has offices in the United Kingdom and Tokyo, Japan. (http://wri.com/). E-mail: <info@wri.com>. (1995-02-10) 1 1 1 1 1 WOM write-only memory 1 1 1 1 1 woman A replacement for the Unix man documentation browsing command. Version 1.157 of woman runs under/on 386BSD, OSF, Apollo Domain/OS, BSD, HP-UX, IBM RS-6000, Irix, Linux, Solaris, Sony NEWS, SunOS, Ultrix, Unicos. Posted to comp.sources.reviewed Volume 3, Issue 50 on 05 Jul 1993 by Arne Henrik Juul <arnej@pvv.unit.no>, archive-name woman-1.157. FTP USC, USA (ftp://usc.edu/archive/usenet/sources/comp.sources.reviewed/volume3/woman-1.157/). FTP Imperial, UK (ftp://src.doc.ic.ac.uk/usenet/comp.sources.reviewed/volume3/woman-1.157/). (1995-03-21) 1 1 1 1 1 WOMBAT Waste Of Money, Brains, And Time. Problems which are both profoundly uninteresting in themselves and unlikely to benefit anyone interesting even if solved. Often used in fanciful constructions such as wrestling with a wombat. See also crawling horror, SMOP. [Jargon File] (1995-03-10) 1 1 1 1 1 wombat 1. <programming> A metasyntactic variable in Commonwealth Hackish. 2. <computer> wombat.doc.ic.ac.uk. [Jargon File] (1995-03-10) 1 1 1 1 1 wombat.doc.ic.ac.uk (Named after the Australian marsupial, vombatus ursinus). The Internet host from which this dictionary was originally served. IP address 146.169.22.42. Formerly a SPARCstation ELC. Kindly provided by the Computing Department, Imperial College, London. Replaced by foldoc.doc.ic.ac.uk (a Linux box) in June 1999. Alias foldoc.org added 2000-07-18, courtesy of Karl O. Pinc. (2000-10-09) 1 1 1 1 1 Woodenman HOLWG, DoD, 1975. Second of the series of DoD requirements that led to Ada. "Woodenman Set of Criteria and Needed Characteristics for a Common DoD High Order Programming Language", David A. Fisher, Inst for Def Anal Working Paper, Aug 1975. (See Strawman, Tinman, Ironman, Steelman). 1 1 1 1 1 woofer (University of Waterloo) Some varieties of wide paper for printers have a perforation 8.5 inches from the left margin that allows the 3.5 inch excess on the right-hand side to be torn off when the print format is 80 columns or less wide. If done with sufficient aplomb this makes a sound like the "woof" of a dog. If the large part is the "woofer" then the small part must obviously be the "tweeter", following the names for the large and small cones in a hi-fi loudspeaker. These terms have been in use at Waterloo since 1972, but are unknown elsewhere. Compare chad. [Jargon File] (1997-03-21) 1 1 1 1 1 WOOL Window Object Oriented Language. A small Common Lisp-like extension language. It claims to be the fastest interpreted language in C with run-time types. Colas Nahaboo <colas@sophia.inria.fr>. Version 1 is used as the kernel language of the GWM window manager. Version 2 has an object system. (ftp://export.lcs.mit.edu/contrib/gwm). 1 1 1 1 1 Worcester Polytechnic Institute (WPI) A well-regarded, small engineering college. Address: Worcester, MA, USA. (1995-03-01) 1 1 1 1 1 Word Microsoft Word 1 1 1 1 1 word A fundamental unit of storage in a computer. The size of a word in a particular computer architecture is one of its chief distinguishing characteristics. The size of a word is usually the same as the width of the computer's data bus so it is possible to read or write a word in a single operation. An instruction is usually one or more words long and a word can be used to hold a whole number of characters. These days, this nearly always means a whole number of bytes (eight bits), most often 32 or 64 bits. In the past when six bit character sets were used, a word might be a multiple of six bits, e.g. 24 bits (four characters) in the ICL 1900 series. (1994-11-11) 1 1 1 1 1 Word for Windows The version of Microsoft Word which runs under Microsoft Windows. Version 6.0. (1995-04-14) 1 1 1 1 1 WordNet A large lexical database of English, developed under the direction of George A. Miller. Nouns, verbs, adjectives and adverbs are grouped into sets of cognitive synonyms ("synsets"), each expressing a distinct concept. Synsets are interlinked by means of conceptual-semantic and lexical relations. The resulting network of words and concepts can be navigated with the browser. WordNet is freely available for download. WordNet's structure makes it a useful tool for computational linguistics and natural language processing. WordNet home (http://wordnet.princeton.edu/). (2007-04-20) 1 1 1 1 1 WordPerfect 1. <text, tool, product> A word processor for a wide range of computers. The first version was sold in 1980 for Data General machines, and by the end of 1993 versions were on sale for MS-DOS, Microsoft Windows and Macintosh computers. WordPerfect 6.0 for Unix was scheduled for introduction in May 1994. Versions: WordPerfect 6.1 for Windows, WordPerfect 3.1 for Macintosh/Power Macintosh, WordPerfect 6.0 for UNIX, WordPerfect 6.0 for DOS, WordPerfect 7.0 for Windows 95. [Distinguishing features?] (http://corel.com/products/wordperfect/). 2. WordPerfect Corporation. (1995-07-05) 1 1 1 1 1 WordPerfect Corporation The original developers of the WordPerfect word processor and a variety of other applications for personal computers. WordPerfect was founded in Provo, Utah, USA in 1979 by Alan Ashton and Bruce Bastion as "Satellite Software International". The company name was changed to Wordperfect Corporation in 1986. The company was bought by Novell, Inc. in 1994, who then sold it to Corel Corporation in 1996. (1997-03-12) 1 1 1 1 1 word processing word processor 1 1 1 1 1 word processor A program used to create and print (chiefly textual) documents that might otherwise be prepared on a typewriter. The key advantage of word processor is its ability to make changes easily, such as correcting spelling, changing margins, or adding, deleting, and relocating entire blocks of text. Once created, the document can be printed quickly and accurately and saved for later modifications. Today most popular word processors, such as Microsoft Word, offer a much greater range of facilities than the first such programs. Compare text editor. (1995-04-14) 1 1 1 1 1 word size The number of bits that a CPU can process at one time. Processors with many different word sizes have existed though powers of two (8, 16, 32, 64) have predominated for many years. A processor's word size is often equal to the width of its external data bus though sometimes the bus is made narrower than the CPU (often half as many bits) to economise on packaging and circuit board costs. (1995-04-23) 1 1 1 1 1 word spamming Repeating a word many times in a web page, in a (usually futile) attempt to increase its relevance ranking in a search engine's index (to "spam" the index). "Repeating a word over and over in a Web page (known as word spamming) has no effect on the [page's] ranking [in the index]. -- Altavista FAQ" (http://altavista.digital.com/cgi-bin/query?pg=tmpl&v=faq.html). See also spamdex. (1997-04-09) 1 1 1 1 1 WordTech Manufacturers of Quicksilver. Address: Orinda, CA, USA. (1995-05-11) 1 1 1 1 1 word wrap A feature of word processors and most text editors where a word which would extend past the right hand margin is moved to the following line. This is more sophisticated than character wrap which only moves to the next line for the first character past the right margin and thus will break some words in the middle. The program may actually insert a new line in the text at the point where it is wrapped or it may only display it as though it contained a new line at that point. (1996-07-24) 1 1 1 1 1 workaround A temporary kluge used to bypass, mask or otherwise avoid a bug or misfeature in some system. Customers often find themselves living with workarounds for long periods of time rather than getting a bug fix. [Jargon File] (1998-06-25) 1 1 1 1 1 Work Breakdown Structure (WBS) A division of a project into tasks and subtasks. The tasks are numbered to indicate their relationship to each other. WBSs are indespensible for project planning, particularly when estimating time and resource requirements. Some industries use established work breakdown structure systems for billing and reporting purposes. (2001-05-09) 1 1 1 1 1 workflow 1. <operating system> The scheduling of independent jobs on a computer. See also time-sharing, WFL. 2. <job> The set of relationships between all the activities in a project, from start to finish. Activities are related by different types of trigger relation. Activities may be triggered by external events or by other activities. 3. The movement of documents around an organisation for purposes including sign-off, evaluation, performing activities in a process and co-writing. [Stef Joosten et.al. "An empirical study about the practice of workflow management", WA-12 report, 1994]. (1995-03-27) 1 1 1 1 1 Workflow Management Coalition (WfMc) A non-profit, international organisation of workflow vendors, users, and analysts committed to establishing standards for workflow terminology, interoperability, and connectivity. WfMC was founded in 1993 and now (1999) has over 130 members. (http://aiim.org/wfmc). (1999-08-01) 1 1 1 1 1 workgroup Computer Supported Cooperative Work 1 1 1 1 1 working as designed (IBM) Conforming to a wrong or inappropriate specification; useful, but misdesigned. Frequently used as a sardonic comment on a program's utility or as a bogus reason for not accepting a criticism or suggestion. At IBM, this sense is used in official documents! See BAD. [Jargon File] (1995-04-04) 1 1 1 1 1 working memory The parts of main memory (RAM) currently in use. In a production system, working memory contains the facts, both initial and generated. (2005-06-17) 1 1 1 1 1 working set The set of all pages (in a paging virtual memory system) used by a process during some time interval. As a result of locality of reference, the working set frequently consists of a relatively small fraction of a process's total virtual memory pages. While a process's entire working set is in physical memory the process will run without page faults. If the working set is too large for available physical memory, the process causes frequent page faults. In a multitasking environment, information about which pages are in each process's working set allows the memory management system to improve CPU efficiency by prepaging (also called the working set model). ["Modern Operating Systems", Andrew S. Tanenbaum, pub. Prentice Hall, Inc. 1992]. (1997-04-09) 1 1 1 1 1 working set model prepaging 1 1 1 1 1 Work Needed and Prospective Packages (WNPP) A document, maintained on the Debian web site here (http://debian.org/devel/wnpp/), providing a current list of packages which are either orphaned (withdrawn from distribution), maintained but its developer would like to find a new person, currently being worked on to include in the distribution, or good ideas with no one working on them. WNPP is also a pseudo package on the Debian Bug Tracking System. Developers update the WNPP document by filing, modifying or closing bugs agains the psuedo package. (2000-09-06) 1 1 1 1 1 work path In Adobe Photoshop, a temporary path that appears in the Paths palette and defines the outline of a shape. (2009-03-02) 1 1 1 1 1 worksheet spreadsheet 1 1 1 1 1 workstation A general-purpose computer designed to be used by one person at a time and which offers higher performance than normally found in a personal computer, especially with respect to graphics, processing power and the ability to carry out several tasks at the same time. (1995-05-04) 1 1 1 1 1 World Time Coordinated Universal Time 1 1 1 1 1 World-Wide Wait A pejorative expansion of WWW reflecting on the slowness of some network connections and sites. (1997-03-30) 1 1 1 1 1 World Wide Web World-Wide Web. A web that's world-wide. (2015-05-09) 1 1 1 1 1 World-Wide Web (WWW, W3, The Web) An Internet client-server hypertext distributed information retrieval system. Basically, the web consists of documents or web pages in HTML format (a kind of hypertext), each of which has a unique URL or "web address". Links in a page are URLs of other pages which may be part of the same website or a page on another site on a different web server anywhere on the Internet. As well as HTML pages, a URL may refer to an image, some code (JavaScript or Java), CSS, a video stream or other kind of object. The vast majority of URLs start with "http://", indicating that the page needs to be fetched using the HTTP protocol. Other possibile "schemes" are HTTPS, which encrypts the request and the resulting page or FTP, the original protocol for transferring files over the Internet. RTSP is a streaming protocol that allow a continuous feed of audio or video from the server to the browser. Gopher was a 1 1 1 1 1 World Wide Web Consortium (W3C) The main standards body for the web. W3C works with the global community to establish international standards for client and server protocols that enable on-line commerce and communications on the Internet. It also produces reference software. W3C was created by the Massachusetts Institute of Technology (MIT) on 25 October 1994. Netscape Communications Corporation was a founding member. The Consortium is run by MIT LCS and INRIA, in collaboration with CERN where the web originated. W3C is funded by industrial members but its products are freely available to all. The director is Tim Berners-Lee who invented the web at the Center for European Particle Research (CERN). (http://w3.org/). (1996-11-03) 1 1 1 1 1 World Wide Web Worm (WWWW) One of the first automatic indexing tools for the web, being developed in September 1994 by Oliver McBryan <mcbryan@cs.colorado.edu> at the University of Colorado. The worm created a database of 300,000 multimedia objects which can be obtained or searched for keywords via the web. (http://cs.colorado.edu/home/mcbryan/WWWW.html). (1996-05-19) 1 1 1 1 1 WORM Write-Once Read-Many 1 1 1 1 1 worm (From "Tapeworm" in John Brunner's novel "The Shockwave Rider", via XEROX PARC) A program that propagates itself over a network, reproducing itself as it goes. Compare virus. Nowadays the term has negative connotations, as it is assumed that only crackers write worms. Perhaps the best-known example was the Great Worm. Compare Trojan horse. [Jargon File] (1996-09-17) 1 1 1 1 1 wormhole back door 1 1 1 1 1 wormhole routing A property of a message passing system in which each part of a message is transmitted independently and one part can be forwarded to the next node before the whole message has been received. All parts of a single message follow the same route. The independent parts are normally small, e.g. one 32-bit word. This reduces the latency and the storage requirements on each node when compared with message switching where a node receives the whole message before it starts to forward it to the next node. It is more complex than message switching because each node must keep track of the messages currently flowing through it. With cut-through switching, wormhole routing is applied to packets in a packet switching system so that forwarding of a packet starts as soon as its destination is known, before the whole packet had arrived. (2003-05-15) 1 1 1 1 1 WOSA Windows Open Services Architecture 1 1 1 1 1 WOSA Extensions for Financial Systems Extensions for Financial Services 1 1 1 1 1 WOSA/XFS Extensions for Financial Services 1 1 1 1 1 wound around the axle infinite loop 1 1 1 1 1 WPA Wi-Fi Protected Access 1 1 1 1 1 WPA Pre-Shared Key Wi-Fi Protected Access Pre-Shared Key 1 1 1 1 1 WPA-PSK Wi-Fi Protected Access Pre-Shared Key 1 1 1 1 1 WPG Workstation Products Group 1 1 1 1 1 WPI Worcester Polytechnic Institute 1 1 1 1 1 WPL+ Word-oriented language internal to PRODOS Applewriter 2.1. Available on GEnie. 1 1 1 1 1 WPOP WonderPop. Robert Rae <rhr@aiai.ed.ac.uk>, Edinburgh 1976. An implementation of POP for the PDP-10 that used cages for different data types. Introduced processes, properties, and some typed identifiers. 1 1 1 1 1 wps (Obsolete) Words per second (mostly used for Telex and TWX transmission). (1997-01-07) 1 1 1 1 1 WRAM Window Random Access Memory 1 1 1 1 1 wrap around (Or "wraparound", "wrap") The action of a counter that starts again at zero or at "minus infinity" (see infinity) after its maximum value has been reached, and continues incrementing, either because it is programmed to do so or because of an overflow (as when a car's odometer starts again at 0). [Jargon File] 1 1 1 1 1 wrapper Code which is combined with another piece of code to determine how that code is executed. The wrapper acts as an interface between its caller and the wrapped code. This may be done for compatibility, e.g. if the wrapped code is in a different programming language or uses different calling conventions, or for security, e.g. to prevent the calling program from executing certain functions. The implication is that the wrapped code can only be accessed via the wrapper. (1998-12-15) 1 1 1 1 1 wrats nest (From "wrap" and "rats nest") A wire-wrapping defect where all of the wire piles up around the bottom of the post instead of wrapping smoothly around it. It looks like a little bird nest. (1997-03-18) 1 1 1 1 1 wrb Web Request Broker 1 1 1 1 1 write 1. <chat> Unix's simple talk command and protocol. write has been largely superseded by talk and then irc. An enhancement, RWP, has been proposed. 2. <tool> A simple text editor for Windows. (1998-04-28) 1 1 1 1 1 WRITEACOURSE A CAI language for IBM 360. ["WRITEACOURSE: An Educational Programming Language", E. Hunt et al, Proc FJCC 33(2) 1968]. (1998-04-28) 1 1 1 1 1 write-back A cache architecture in which data is only written to main memory when it is forced out of the cache. Opposite of write-through. See also no-write allocation. (1996-06-12) 1 1 1 1 1 write buffer buffered write-through 1 1 1 1 1 Write-Once Read-Many (WORM) Any type of storage medium to which data can be written to only a single time, but can be read from any number of times. Typically this is an optical disk whose surface is permanently etched using a laser in order to record information. WORM media have a significantly longer shelf life than magnetic media and thus are used when data must be preserved for a long time. (1996-04-01) 1 1 1 1 1 write-only code [a play on "read-only memory"] Code so arcane, complex, or ill-structured that it cannot be modified or even comprehended by anyone but its author, and possibly not even by him/her. A Bad Thing. [Jargon File] 1 1 1 1 1 write-only language A language with syntax (or semantics) sufficiently dense and bizarre that any routine of significant size is automatically write-only code. A sobriquet applied occasionally to C and often to APL, though INTERCAL and TECO certainly deserve it more. 1 1 1 1 1 write-only memory 1. <jargon, humour> (WOM) The obvious antonym to "read-only memory" (ROM). Out of frustration with the long and seemingly useless chain of approvals required of component specifications, during which no actual checking seemed to occur, an engineer at Signetics once created a specification for a write-only memory and included it with a bunch of other specifications to be approved. This inclusion came to the attention of Signetics management only when regular customers started calling and asking for pricing information. Signetics published a corrected edition of the data book and requested the return of the "erroneous" ones. Later, around 1974, Signetics bought a double-page spread in "Electronics" magazine's April issue and used the spec as an April Fools' Day joke. Instead of the more conventional characteristic curves, the 25120 "fully encoded, 9046 x N, Random Access, write-only-memory" data sheet included diagrams of "bit 1 1 1 1 1 write protect A feature of certain removable media storage devices that tells the system whether or not it should allow the data on the media to be modified. Write protecting an item of media prevents accidental overwriting of valuable data. For example, the write protect tab on a 3.5-inch floppy disks is a small sliding plastic square that can either cover or expose a hole near the edge of the disk cover. The drive wil only allow the disk to be written to if the hole is closed. (2007-03-24) 1 1 1 1 1 write-through (Or "write-thru") A cache architecture in which data is written to main memory at the same time as it is cached. Opposite of write-back. See also buffered write-through, posted write-through, no-write allocation. (1996-06-12) 1 1 1 1 1 write-thru write-through 1 1 1 1 1 writing system The set of glyphs used for representing a given human language in written form, generally along with their conventions for use. (1998-10-19) 1 1 1 1 1 Wrong Thing A design, action, or decision that is clearly incorrect or inappropriate. Often capitalised; always emphasised in speech as if capitalised. The opposite of the Right Thing; more generally, anything that is not the Right Thing. In cases where "the good is the enemy of the best", the merely good - although good - is nevertheless the Wrong Thing. "In C, the default is for module-level declarations to be visible everywhere, rather than just within the module. This is clearly the Wrong Thing." [Jargon File] 1 1 1 1 1 WRT with regard to, with respect to. 1 1 1 1 1 ws The country code for Samoa. (1999-01-27) 1 1 1 1 1 WSBPEL Web Services Business Process Execution Language 1 1 1 1 1 WSDL Web Service Definition Language 1 1 1 1 1 WSFN Which Stands For Nothing 1 1 1 1 1 WSL Waterloo Systems Language. A C-like systems programming language. ["Waterloo Systems Language: Tutorial and Language Reference", F.D. Boswell, WATFAC Publications Ltd., Waterloo, Canada. ISBN 0-919884-00-8]. 1 1 1 1 1 WTF who/what/why the fuck? The universal interrogative particle. Also WTH. 1 1 1 1 1 WTFPL Do What the Fuck You Want to Public License 1 1 1 1 1 WTH who/what/why the hell? Also WTF. 1 1 1 1 1 WTLS Wireless Transport Layer Security 1 1 1 1 1 Wumpus Hunt the Wumpus 1 1 1 1 1 WWW world-wide web 1 1 1 1 1 WWW browser A browser for use on the web. (1996-10-28) 1 1 1 1 1 WWWW web Worm 1 1 1 1 1 WYGIWYNTYH What You Get Is What You Never Thought You Had 1 1 1 1 1 WYSIAYG What You See Is All You Get 1 1 1 1 1 WYSIWYG What You See Is What You Get 1 1 1 1 1 WYSWYG What You See Is What You Get 1 1 1 1 1 X 1. <convention> Used in various speech and writing contexts (also in lowercase) in roughly its algebraic sense of "unknown within a set defined by context" (compare N). Thus, the abbreviation 680x0 stands for 68000, 68010, 68020, 68030 or 68040, and 80x86 stands for Intel 80186, Intel 80286, Intel 80386 or Intel 80486. A Unix hacker might write these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86 respectively; see glob. 2. <graphics> An alternative name for the X Window System. 3. <storage> A suffix for the speed of a CD-ROM drive relative to standard music CDs (1x). 32x is common in September 1999. [Jargon File] (1999-09-15) 1 1 1 1 1 X-1 An early system on the UNIVAC I or II. [Listed in CACM 2(5):16 (May 1959)]. (1995-05-10) 1 1 1 1 1 X11R4 Version 11 release 4 of the X protocol. See X Window System. 1 1 1 1 1 X11R5 Version 11 release 5 of the X protocol. Released in June 1994. See X Window System. 1 1 1 1 1 X11R6 Version 11 release 6 of the X Window System. [Release date?] (1995-01-20) 1 1 1 1 1 X.12 The American equivalent of UN/EDIFACT and various other national and industry EDI messaging protocols. The first Y2K ready version of X.12 is version 4010. [What's "UN"? Details? Differences from EDIFACT?] (1999-09-10) 1 1 1 1 1 X2 A proprietary modem standard developed by US Robotics for 56 kbps communications. Not taken up as widely as K56flex and will shortly be superseded by the official V.90 standard. (1998-09-08) 1 1 1 1 1 X.208 Abstract Syntax Notation 1 1 1 1 1 1 X.209 Basic Encoding Rules 1 1 1 1 1 X.21 A digital signaling interface recommended by ITU-T that includes specifications for DTE/DCE physical interface elements, alignment of call control characters and error checking, elements of the call control phase for circuit switched services, data transfer at up to 2 Mbps, and test loops. 64 kbps is the most commonly used transfer rate. (2000-02-28) 1 1 1 1 1 X.214 transport layer 1 1 1 1 1 X.215 session layer 1 1 1 1 1 X.216 presentation layer 1 1 1 1 1 X.217 Association Control Service Element 1 1 1 1 1 X.219 Remote Operations Service Element 1 1 1 1 1 X.224 transport layer 1 1 1 1 1 X.225 session layer 1 1 1 1 1 X.226 presentation layer 1 1 1 1 1 X.227 Association Control Service Element 1 1 1 1 1 X.229 Remote Operations Service Element 1 1 1 1 1 X.25 An ITU-T standard protocol suite for the DTE-DCE interface in a packet-switched network, approved by ISO. X.25 defines standard physical layer, data link layer and network layers (layers 1 through 3). It was developed to describe how data passes into and out of public data communications networks. X.25 networks are in use throughout the world. Document: ISO 8208. Several other ITU-T recommendations are relevant to packet switching: X.3, X.28, X.29, X.75. (1996-08-10) 1 1 1 1 1 X.28 The ITU-T standard specifying how to control a PAD from character-mode DTE, approved by ISO. (1995-01-31) 1 1 1 1 1 X.29 The ITU-T standard, approved by ISO, specifying procedures for the exchange of control information and user data between a PAD and a remote packet-mode DTE. Character-mode DTEs are often referred to as X.29 terminals. (1995-01-31) 1 1 1 1 1 X.3 The ITU-T standard, approved by ISO, which specifies the basic functions and user-selectable capabilities of a PAD. (1995-01-31) 1 1 1 1 1 X3J16 The C++ standard technical committee. 1 1 1 1 1 X3T10 The ATA standards body. (1996-10-16) 1 1 1 1 1 X.400 The set of ITU-T communications standards covering electronic mail services provided by data networks. X.400 was widely used in Europe and Canada. X.400 addresses tend to be much longer than RFC 822 ones. They consist of a set of bindings for country (c), administrative domain (a), primary management domain (p), surname (s), given name (g). For example, the X.400 address, c=gb;a=attmail;p=Universal Export;s=Bond;g=James; might be equivalent to RFC 822 James.Bond@UniversalExport.co.uk [Reference?] (2003-06-24) 1 1 1 1 1 X.409 Part of the X.400 electronic mail specification which included the original definition of Abstract Syntax Notation 1. [What was it about?] (1998-08-06) 1 1 1 1 1 X.500 The set of ITU-T standards covering electronic directory services such as white pages, Knowbot, whois. Compare: LDAP. (1994-12-06) 1 1 1 1 1 X.680 [Is it Coordinated Universal Time or Abstract Syntax Notation 1?] (1999-12-09) 1 1 1 1 1 X.75 The ITU-T standard specifying the protocols for communication between two PSDNs. (1995-01-31) 1 1 1 1 1 x86 Intel 80x86 1 1 1 1 1 x86 processor socket One of the series of standard sockets into which you can plug various x86 microprocessors. These vary in the number of pins, package, voltages, bus speeds, and supported processors. Motherboards often have clock multipliers so that the processor runs at a multiple of the bus speed. Socket 1, 169 pin LIF/ZIF PGA (17x17), 5v, 16-33 MHz 486 SX, 486 DX, 486 DX2, DX4 Overdrive. Socket 1 was the first standard Intel 486 socket. Socket 2, 238 pin LIF/ZIF PGA (19x19), 5v, 25-50 MHz 486 SX, 486 DX, 486 DX2, 486 DX4, DX4 & Pentium Overdrive. Updated Socket 1, added support for Pentium Overdrive processors. Socket 3, 237 pin LIF/ZIF PGA (19x19), 3.3/5v, 25-50 MHz 486 SX, 486 DX, 486 DX2, 486 DX4, DX4 & Pentium Overdrive. Supports 5V & 3.3V processors, considered the latest 486 socket. Socket 4, 273 pin LIF/ZIF PGA (21x21), 5v, 60/66 MHz Pentium 1 1 1 1 1 XA Extended Architecture A specification for drives which can play CD-ROMs in Green book CD-ROM format. (1994-12-06) 1 1 1 1 1 Xaw The Athena Widget Set. A set of widgets distributed with the X Window System. (1994-11-02) 1 1 1 1 1 Xbase Generic term for the dBASE family of database languages. Coined in response to threatened litigation over use of the copyrighted trademark "dBASE." 1 1 1 1 1 xbeeb A BBC Microcomputer emulator for Unix and X11 by James Fidell <jfid@mfltd.co.uk>. Posted to alt.sources. (ftp://ftp.pipex.net/incoming/xbeeb). (1994-08-18) 1 1 1 1 1 xbm X bit map. The filename extension for files containing bitmaps for use in the X Window System. These are actually include files which can be #include'd into C program source to define images as initialised data. (1995-03-14) 1 1 1 1 1 XC A declarative extension of C++. ["XC - A Language for Embedded Rule Based Systems", E. Nuutila et al, SIGPLAN Notices 22(9):23-32 (Sep 1987)]. 1 1 1 1 1 X client An application process in the X Window System. It gains access to windowing services via the Xlib library. These are translated by the system into X protocol messages to an X server. 1 1 1 1 1 X Consortium A vendor consortium supporting development, evolution and maintenance of the X Window System. The X Consortium is an independent, not-for-profit company. It was formed in 1993 as the successor to the MIT X Consortium, a research group of the MIT Laboratory for Computer Science. (ftp://ftp.x.org). (http://x.org/). [Members?] 1 1 1 1 1 Xcoral A multiwindow mouse-based text editor, for the X Window System with a built-in browser to navigate through C functions and C++ classes hierarchies. Xcoral provides variables width fonts, menus, scrollbars, buttons, search, regions, kill-buffers and 3D look. Commands are accessible from menus or standard key bindings. Xcoral is a direct Xlib client and runs on colour or monochrome X displays. Version 1.72 (ftp://ftp.inria.fr/X/contrib/clients/xcoral*). (1993-03-14) 1 1 1 1 1 xdbx An X Window System front end for dbx developed by Po Cheung at MCC. Latest version: 2.1, as of 1992-02-22. Posted to comp.sources.x volumes 11, 12, 13, 14, 16. (2000-07-12) 1 1 1 1 1 X-Designer A user interface builder for Motif from Imperial Software Technology. (http://ist.co.uk/xd/). (1995-10-26) 1 1 1 1 1 X.desktop A desktop manager for Unix from IXI. 1 1 1 1 1 XDL An object-oriented extension to ITU-T's SDL. ["XDL: An Object-Oriented Extension to SDL", S.J. Ochuodho et al]. (1995-10-12) 1 1 1 1 1 XDR eXternal Data Representation 1 1 1 1 1 XDS 530 Xerox Data Systems Model 530 1 1 1 1 1 XDS 940 Xerox Data Systems Model 940 1 1 1 1 1 xDSL Digital Subscriber Line 1 1 1 1 1 Xemacs (Originally "Lucid Emacs") A text editor for the X Window System, based on GNU Emacs version 19, produced by a collaboration of Lucid, Inc., SunPro (a division of Sun Microsystems, Inc.), and the University of Illinois. Lucid chose to build part of Energize, their C/C++ development environment on top of GNU Emacs. Though their product is commercial, the work on GNU Emacs is free software, and is useful without having to purchase the product. They needed a version of Emacs with mouse-sensitive regions, multiple fonts, the ability to mark sections of a buffer as read-only, the ability to detect which parts of a buffer has been modified, and many other features. The existing version of Epoch was not sufficient; it did not allow arbitrary pixmaps and icons in buffers, "undo" did not restore changes to regions, regions did not overlap and merge their attributes. Lucid spent some time in 1990 working on Epoch but later decided that their efforts would be better 1 1 1 1 1 XENIX A commercial version of Unix for microprocessor-based computers, released by Microsoft in 1980. In 1992, SCO became Microsoft's co-development partner and the alternate source for the product. (1999-12-07) 1 1 1 1 1 Xeon Pentium II Xeon 1 1 1 1 1 xerox XEROX Corporation 1 1 1 1 1 XEROX Corporation A US company, founded in 1906, specialising in document related technology and services including photocopiers, printers and office software. Xerox's acquisition of Affiliated Computer Services added business process and document management to their product range. In 2013 they have 140,000 employees. Their research centre, XEROX PARC, prototyped several revolutionary advances in computing, which the company failed to exploit, including the WIMP desktop metaphor and XEROX Network Services. (http://xerox.com/). (2013-04-30) 1 1 1 1 1 Xerox Data Systems Model 530 (XDS 530) A computer from the Scientific Data Systems range, announced sometime after 1968 when Xerox bought out SDS. The XDS 530 was probably under development at SDS before the buy-out but only announced afterwards. (2004-06-17) 1 1 1 1 1 Xerox Data Systems Model 940 (SDS 940, XDS 940) A time-sharing system, announced in February 1966, developed by Scientific Data Systems with help from The University of California at Berkeley and Tymshare. SDS 940 was backward compatible with SDS's previous systems (except the 12-bit SDS 92). It had monitor and user modes, dynamic program relocation, automatic memory fragmentation, and system protection. After 1968 Xerox bought out SDS and renamed the SDS machines Xerox Data Systems (XDS). Xerox then produced the XDS 530. (2004-06-17) 1 1 1 1 1 XEROX Network Services (XNS) [Is this the same as/a misnomer for Xerox Network System?] (2003-10-05) 1 1 1 1 1 Xerox Network System (XNS) A proprietary network architecture developed by the Xerox Office Systems Division of Xerox corporation at Xerox PARC in the late 1970s/early 1980s to run on LAN (Ethernet) and WAN networks. The XNS protocol stack provided routing and packet delivery. Implementations exist for 4.3BSD derived systems and the Xerox Star computers. Novell based much of the lower layers of their protocol suite IPX/SPX on XNS. The main components are: Internet datagram protocol (IDP), Routing information protocol (RIP), Packet Exchange protocol (PEP), and Sequences packet protocol (SPP). XNS has strong parellels to TCP/IP in that the network layer, IDP, is roughly equivalent to IP. RIP has the same functions (and obviously name) as the routing information protocol, RIP. SPP, a connectionless transport layer protocol, is similar to UDP. PEP is also in the transport layer but is connection-oriented and similar to TCP. 1 1 1 1 1 XEROX PARC /zee'roks park'/ Xerox Corporation's Palo Alto Research Center. For more than a decade, from the early 1970s into the mid-1980s, PARC yielded an astonishing volume of ground-breaking hardware and software innovations. The modern mice, windows, and icons (WIMP) style of software interface was invented there. So was the laser printer and the local-area network; Smalltalk; and PARC's series of D machines anticipated the powerful personal computers of the 1980s by a decade. Sadly, the prophets at PARC were without honour in their own company, so much so that it became a standard joke to describe PARC as a place that specialised in developing brilliant ideas for everyone else. The stunning shortsightedness and obtusity of XEROX's top-level suits has been well described in the reference below. ["Fumbling The Future: How XEROX Invented, Then Ignored, the 1 1 1 1 1 Xerox Star Xerox 8010 1 1 1 1 1 XFree86 Project, Inc. A non-profit organisation that produces XFree86, a freely redistributable implementation of the X Window System that runs on Unix and Unix-like operating systems and OS/2. The XFree86 Project has traditionally focused on Intel x86 based platforms (hence the "86"), but the current release supports other platforms. (http://xfree86.org/). (1999-04-02) 1 1 1 1 1 XFS Extensions for Financial Services 1 1 1 1 1 Xfun A polymorphic functional language which is a cross between SML and Russell, developed by S. Dalmas <dalmas@sophia.inria.fr> of INRIA in 1991, and intended for computer algebra. ["A Polymorphic Functional language Applied to Symbolic Computation", S. Dalmas, Proc Intl Symp Symb Alg Comp, Berkeley 1992]. (1995-02-03) 1 1 1 1 1 XGA eXtended Graphics Array 1 1 1 1 1 XGA-2 eXtended Graphics Array 1 1 1 1 1 XHTML Extensible HyperText Markup Language 1 1 1 1 1 Xi A VLSI design language. ["The Circuit Design Language Xi", S.I. Feldman, unpublished memo, Bell Labs, 1982]. [Mentioned in Computational Aspects of VLSI, J.D. Ullman, CS Press 1984]. (1995-02-03) 1 1 1 1 1 XIE X Image Extension 1 1 1 1 1 Xilinx, Inc. The electronics company who invented the FPGA. Xilinx was founded in San Jose, California, in 1984, and invented the field-programmable gate array. They claim to command more than half of the world market for these devices today. More recent innovations include complex programmable logic devices. (http://xilinx.com/). Address: 2100 Logic Drive, San Jose, CA 95124, USA. (1998-09-25) 1 1 1 1 1 Xilinx Netlist Format (XNF) A Hardware Description Language for electronic circuit design, developed by Xilinx, Inc.. Xilinx-developed tools use XNF and handle the details of the FPGA architecture. Converters are available for a number of widely-used HDLs - for example Verilog (xnf2ver) - so that designers can use familiar tools to develop Logic Cell Array designs. In addition, XNF can be converted to the input language of different logic simulators. Specification (ftp://ftp.xilinx.com/pub/documentation/xactstep6/xnfspec.pdf). (1999-03-31) 1 1 1 1 1 X Image Extension (XIE) Extensions to the X protocol to handle images. (1995-02-03) 1 1 1 1 1 Xlib X library: program interface to the X Window System. 1 1 1 1 1 xlisp eXperimental LISP 1 1 1 1 1 xls Excel spreadsheet. (1995-10-17) 1 1 1 1 1 XML Extensible Markup Language 1 1 1 1 1 XML schema XML data that describes the relationship between elements and attributes in some other class of XML data. A schema may or may not include data type representations. XML schemas are a more advanced alternative to DTDs. (http://vbxml.com/conference/wrox/2000_vegas/text/kurt_schema.asp) (2006-08-23) 1 1 1 1 1 XML Template Pages (XTP) JSP transformed by XSL stylesheets. An XTP page is basically a JSP page which specifies an XSL stylesheet. The XSL specifies how selected tags in the XTP page should be rewritten. All other tags are passed through unchanged and so treated as standard JSP. JSP programmers can use XTP used as an easy introduction to XSL, incrementally applying styles to their pages. Caucho (http://caucho.com/resin/ref/xtp.xtp). (2003-07-13) 1 1 1 1 1 XML User-Interface Language (XUL) An XML-based language created for the Mozilla browser for development of cross-platform user interfaces. XUL supports input controls such as textboxes and checkboxes, toolbars, menus, dialogs, trees, keyboard shortcuts, and more. XULPlanet (http://xulplanet.com/). (2003-06-14) 1 1 1 1 1 XMM Extended Memory Manager 1 1 1 1 1 XMODEM Ward Christensen's file transfer protocol, probably the most widely available protocol used for file transfer over serial lines (e.g. between modems). XMODEM uses 128-byte packets with error detection, allowing the receiver to request retransmission of a corrupted packet. XModem is fairly slow but reliable. Several variations have been proposed with increasing packet sizes (e.g. XMODEM-1K) and different error detection (CRC instead of checksum) to take advantage of faster modems. Sending and receiving programs can negotiate to establish the best protocol they both support. John Mahr wrote the original XMODEM CRC error correction code. This implementation was backward compatible with Christensen's original checksum code. It improved the error detection from 98% to 99.97% and improved the reliability of transmitting binary files. Standard XMODEM specifies a one-second timeout during the 1 1 1 1 1 XMODEM-1K A version of XMODEM using 1 kilobyte packets. 1 1 1 1 1 xmosaic Mosaic for the X Window System. 1 1 1 1 1 XMS Extended Memory Specification. (1996-01-10) 1 1 1 1 1 XNF Xilinx Netlist Format 1 1 1 1 1 xnf2ver An XNF to Verilog translator by Martin J. Colley <martin@essex.ac.uk>. This program was written by a postgraduate student as part of his M.Sc course. It was designed to form part a larger system operating with the Cadence Edge 2.1 framework. This should be born in mind when considering the construction and/or operation of the program. (ftp://punisher.caltech.edu/pub/dank/xnf2ver.tar.Z). 1 1 1 1 1 XNS Xerox Network System or Xerox Network Services. [Which?] 1 1 1 1 1 XOFF control-S 1 1 1 1 1 XON control-Q 1 1 1 1 1 XON/XOFF software handshaking 1 1 1 1 1 Xopen X/Open 1 1 1 1 1 X/Open An international consortium of vendors who defined the X/Open Common Applications Environment to provide applications portability. They also produced the X/open Portability Guide (XPG). (1994-12-01) 1 1 1 1 1 X/open Portability Guide (XPG) A document which defines the interfaces of the X/Open Common Applications Environment. Version: XPG3. (1994-12-01) 1 1 1 1 1 X/Open System Interface (XSI) Part of the X/Open Common Applications Environment. (1994-11-03) 1 1 1 1 1 xor exclusive or 1 1 1 1 1 XP Windows XP 1 1 1 1 1 XPC eXplicitly Parallel C. A dialect of Parallel C which is efficiently compilable to both SIMD and MIMD architectures. Only research implementations exist. ["Toward Semantic Self-Consistency in Explicitly Parallel Languages," M.J. Phillip & H.G. Dietz, Proc 4th Intl Conf on Supercomputing, Santa Clara, CA, May 1989, v.1, pp.398-407]. (1994-12-01) 1 1 1 1 1 XperCASE A structure diagram editor for developing, re-engineering, maintaining and documenting programs, developed by Siemens AG, Austria. It runs under Microsoft Windows. (ftp://src.doc.ic.ac.uk/computing/systems/ibmpc/simtel/windows3/xperspx1.zip). E-Mail: <100141.2120@compuserve.com>. (1994-12-01) 1 1 1 1 1 XPG X/open Portability Guide 1 1 1 1 1 XPG3 Version 3 of the X/open Portability Guide. 1 1 1 1 1 XPL A small dialect of PL/I used for compiler writing from Stanford, 1967-69. XPL has one-dimensional arrays. I/O is achieved with character pseudo-variable INPUT and OUTPUT, e.g. OUTPUT = 'This is a line'; It has inline machine code. "Programmers are given all the rope they ask for. Novices tend to hang themselves fairly frequently." XPL has been implemented on IBM 360, Univac 1100, ICL System 4, CDC 6000 and Cyber series, XDS Sigma-5 and Sigma-7 and DEC PDP-10. An optimising XPL compiler (version 1) by Robin Vowels <robin_vowels@rmit.edu.au> is a standard implementation of XPL and is based on McKeeman, Horning, and Wortman's improved XCOM (which employs hashed symbol table generation). It includes the extra built-in function COREHALFWORD. The following areas have been optimised: procedures calls when 1 1 1 1 1 xpm X11 Pixmap. A pixmap image file format for the X Window System. (1995-04-28) 1 1 1 1 1 XPOP An extensible macro assembly language with user-redefinable grammar, for use with FAP. ["XPOP: A Meta-language Without Metaphysics", M.I. Halpern, Proc FJCC 25:57-68, AFIPS (Fall 1964)]. (1995-04-28) 1 1 1 1 1 XP Pro Windows XP Professional Edition 1 1 1 1 1 Xpress Transport Protocol (XTP) A transport layer protocol for high-speed networks promoted by the XTP Forum. XTP provides protocol options for error control, flow control, and rate control. Instead of separate protocols for each type of communication, XTP controls packet exchange patterns to produce different models, e.g. reliable datagrams, transactions, unreliable streams, and reliable multicast connections. XTP Home (http://ca.sandia.gov/xtp/). Contrast with Transmission Control Protocol. XTP does not employ congestion avoidance algorithms. (2003-03-22) 1 1 1 1 1 X protocol A standard protocol used by clients (applications) and servers in the X Window System for exchanging requests for window operations. (1995-04-28) 1 1 1 1 1 xref /X'ref/ 1. cross-reference. 2. A cross-reference generator tool by Jim Leinweber. (1985?) [Jargon File] 1 1 1 1 1 XRemote A serial line protocol for the X Window System. 1 1 1 1 1 XRN A newsreader program for Usenet news running under the X Window System. 1 1 1 1 1 XSB XSB extends the standard functionality of Prolog (being a descendant of PSB- and SB-Prolog) to include implementations of OLDT (tabling) and HiLog terms. OLDT resolution is extremely useful for recursive query computation, allowing programs to terminate correctly in many cases where Prolog does not. HiLog supports a type of higher-order programming in which predicate symbols can be variable or structured. This allows unification to be performed on the predicate symbols themselves in addition to the arguments of the predicates. Of course, Tabling and HiLog can be used together. Version 1.2 ports: Sun, Solaris, NeXT, Linux, 386 BSD, IRIX, HP-UX portability: Generally to 32-bit machines. interpreter, preprocessor(HiLog), documentation XSB research group / SUNY at Stony Brook 1 1 1 1 1 XScheme Scheme in C with object-oriented extensions by David Betz. Version 0.28 runs on IBM PC, Macintosh, Atari and Amiga. (ftp://labrea.stanford.edu/comp.sources.amiga/volume90). (ftp://nexus.yorku.ca/pub/scheme/). Usenet newsgroup: news:comp.lang.lisp.x. (1992-02-02) 1 1 1 1 1 x-scm An accessory for the scm Scheme interpreter, by Larry Campbell, that provides an environment for building Motif and OpenLook application programs. There is some support as well for raw Xlib applications, but not enough yet to be useful. Posted to alt.sources. (1992-08-10) 1 1 1 1 1 XSD XML Schema Definition 1 1 1 1 1 X server A process, in an X Window System which controls a bitmap display device and usually also a keyboard and mouse or other pointing device. The X server performs operations on request from client applications, which may be on the same computer or a different computer connected via a network. Note that typical client-server architectures do input-output on the client and processing on the server whereas in X the terms are reversed as the X server is serving IO rather than processing resources to the application. If the two computers are not both Unix machines (e.g. one is a Windows machine running VNC) or if a more secure connection is required (e.g. tunneling with ssh), the clients may talk to a proxy X server that forwards the requests to another machine where the real IO takes place. (2006-08-29) 1 1 1 1 1 XSI X/Open System Interface 1 1 1 1 1 XSL Extensible Stylesheet Language 1 1 1 1 1 XSLT Extensible Stylesheet Language Transformations 1 1 1 1 1 XT IBM PC XT 1 1 1 1 1 Xt The intrinsics of the X Window System Toolkit. [What does that mean?] 1 1 1 1 1 XT bus architecture (After the IBM PC XT) An eight-bit ISA bus architecture used by Intel 8086 and Intel 8088 systems in the IBM PC and IBM PC XT in the 1980s. It predates the 16-bit ISA architecture used on the Intel 80286 based machines. The XT bus has four DMA channels, of which three are brought out to the expansion slots. Of these three, two are normally allocated to machine functions: DMA channel Expansion Standard function 0 No dynamic RAM refresh 1 Yes add-on cards 2 1 1 1 1 1 xterm A terminal emulator program for the X Window System. A user can have many different invocations of xterm running at once on the same display, each of which provides independent input and output for the process running in it (normally a shell). (1996-08-23) 1 1 1 1 1 X terminal An intelligent terminal which operates as an X server directly connected to Ethernet. Not to be confused with the program xterm which is an X client. (1996-08-23) 1 1 1 1 1 XTI X/open Transport Interface 1 1 1 1 1 XTP Xpress Transport Protocol XML template pages 1 1 1 1 1 XTP Forum A consortium of for- and non-profit companies and research organisations promoting Xpress Transport Protocol. XTP Forum Home (http://ca.sandia.gov/xtp/forum.html). (2003-03-22) 1 1 1 1 1 XTRAN Fortran-like, interactive language. 1 1 1 1 1 XUI X User Interface: program interface to the X Window System supported by DEC. 1 1 1 1 1 XUL XML User-Interface Language 1 1 1 1 1 Xv++ A library of classes from Interface Engineering, Stevenage, providing a C++ Application Programmer's Interface to the XView toolkit. 1 1 1 1 1 XVGA eXtended Video Graphics Array 1 1 1 1 1 XView A toolkit from Sun, derived from SunView, providing an Open Look user interface for X applications. 1 1 1 1 1 XVT eXtensible Virtual Toolkit: a product allowing applications to be developed independent of GUI. 1 1 1 1 1 X-Windows A common misnomer for the X Window System. (1997-06-10) 1 1 1 1 1 X Window System A specification for device-independent windowing operations on bitmap display devices, developed initially by MIT's Project Athena and now a de facto standard supported by the X Consortium. X was named after an earlier window system called "W". It is a window system called "X", not a system called "X Windows". X uses a client-server protocol, the X protocol. The server is the computer or X terminal with the screen, keyboard, mouse and server program and the clients are application programs. Clients may run on the same computer as the server or on a different computer, communicating over Ethernet via TCP/IP protocols. This is confusing because X clients often run on what people usually think of as their server (e.g. a file server) but in X, it is the screen and keyboard etc. which is being "served out" to the applications. X is used on many Unix systems. It has also been described as over-sized, over-featured, over-engineered and incredibly 1 1 1 1 1 XWIP X Window Interface for Prolog. A package for Prologs following the Quintus foreign function interface (e.g. SICStus Prolog). XWIP provides a (low-level) Xlib-style interface to X. The current version was developed and tested on SICStus 0.7 and MIT X11 R5 under SunOS 4.1.1. It should be adaptable to many other Unix configurations. Version 0.6. (ftp://export.lcs.mit.edu/contrib/xwip-0.6.tar.Z). E-mail: <xwip@cs.ucla.edu>. (1993-02-25) 1 1 1 1 1 xxgdb An X11 front end for gdb by Pierre Willard <pierre@la.tce.com>. Version 1.06. Posted to comp.sources.x volumes 11, 12, 13, 14, & 16. (1992-02-22) 1 1 1 1 1 XXX /X-X-X/ A marker that attention is needed. Commonly used in program comments to indicate areas that are kluged or need to be. Some hackers liken "XXX" to the notional heavy-porn movie rating. Compare FIXME. [Jargon File] 1 1 1 1 1 Xy-pic A package for typesetting graphs and diagrams using TeX. It is structured as several modules, each defining a custom notation for a particular kind of graphical object or structure. Example objects are arrows, curves, and frames. These can be organised in matrix, directed graph, path, polygon, knot, and 2-cell structure. Xy-pic works with LaTeX, AMS-LaTeX, AMS-TeX, and plain TeX, and has been used to typeset complicated diagrams from many application areas including category theory, automata theory, algebra, neural networks and database theory. (http://ens-lyon.fr/~krisrose/Xy-pic.html). (1997-11-20) 1 1 1 1 1 xyzzy The canonical "magic word" from the ADVENT adventure game, in which the idea is to explore an underground cave with many rooms and to collect the treasures you find there. If you type "xyzzy" at the appropriate time, you can move instantly between two otherwise distant points. If, therefore, you encounter some bit of magic, you might remark on this quite succinctly by saying simply "Xyzzy!" "Ordinarily you can't look at someone else's screen if he has protected it, but if you type quadruple-bucky-clear the system will let you do it anyway. ""Xyzzy!"" Xyzzy has actually been" implemented as an undocumented no-op command on several OSes; in Data General's AOS/VS, for example, it would typically respond "Nothing happens", just as ADVENT did if the magic was invoked at the wrong spot or before a player had performed the action that enabled the word. In more recent 32 bit versions, by the way, AOS/VS responds "Twice as much happens". See also plugh. [Jargon File] 1 1 1 1 1 Y 1. General purpose language syntactically like RATFOR, semantically like C. Lacks structures and pointers. Used as a source language for Jack W. Davidson and Christopher W. Fraser's peephole optimiser which inspired GCC RTL and other optimisation ideas. (ftp://ftp.cs.princeton.edu/pub/y+po.tar.Z). It is a copy of the original distribution from the University of Arizona during the early 80's, totally unsupported. ["The Y Programming Language", D.R. Hanson, SIGPLAN Notices 16(2):59-68 (Feb 1981)]. [Jack W. Davidson and Christopher W. Fraser, "The Design and Application of a Retargetable Peephole Optimiser", TOPLAS, Apr. 1980]. [Jack W. Davidson, "Simplifying Code Through Peephole Optimisation" Technical Report TR81-19, The University of Arizona, Tucson, AZ, 1981]. [Jack W. Davidson and Christopher W. Fraser, "Register 1 1 1 1 1 Y2K Year 2000 1 1 1 1 1 YA- Yet Another 1 1 1 1 1 Yaa Yet Another Assembler - Macro assembler for GCOS 8 and Mark III on Bull DPS-8 machines. Available from Bull as part of U Waterloo Tools package (maintained by <pjf@thinkage.on.ca>). 1 1 1 1 1 YABA /ya'b*/ [Cambridge] Yet Another Bloody Acronym. Whenever some program is being named, someone invariably suggests that it be given a name that is acronymic. The response from those with a trace of originality is to remark ironically that the proposed name would then be "YABA-compatible". Also used in response to questions like "What is WYSIWYG?" See also YA-, TLA. [Jargon File] 1 1 1 1 1 yacc Yet Another Compiler Compiler 1 1 1 1 1 YADE Yet Another DSSSL Engine 1 1 1 1 1 YAFIYGI /yaf'ee-y*-gee/ You asked for it, you got it. The command-oriented ed/vi/nroff/TeX style of word processing or other user interfaces which are not WYSIWYG. What you actually asked for is often not immediately apparent. This precise sense of "You asked for it, you got it" seems to have first appeared in Ed Post's classic parody "Real Programmers don't use Pascal"; the acronym is a more recent (as of 1993) invention. [Jargon File] (1995-03-13) 1 1 1 1 1 YAGNI You aren't gonna need it 1 1 1 1 1 Yahoo Yet Another Hierarchical Officious/Obstreperous/Odiferous/Organized Oracle. (Or a member of a race of brutes in Swift's Gulliver's Travels who have the form and all the vices of man, or an uncouth or rowdy person). Probably the biggest hierarchical index of the World-Wide Web. Originally at Stanford University, Yahoo moved to its own site in April 1995. It allows you to move up and down the heirarchy, to search it and to suggest additions. It also features "What's New", "What's Popular", "What's Cool" and a random link. (http://yahoo.com/). (1995-04-05) 1 1 1 1 1 Yale Haskell A fully integrated Haskell programming environment. It provides tightly coupled interactive editing, incremental compilation and dynamic execution of Haskell programs. Two major modes of compilation, correspond to Lisp's traditional "interpreted" and "compiled" modes. Compiled and interpreted modules may be freely mixed in any combination. Yale Haskell is run using either a command-line interface or as an inferior process running under the Emacs editor. Using the Emacs interface, simple two-keystroke commands evaluate expressions, run dialogues, compile modules, turn specific compiler diagnostics on and off and enable and disable various optimisers. Commands may be queued up arbitrarily, thus allowing, for example, a compilation to be running in the background as the editing of a source file continues in Emacs in the foreground. A "scratch pad" may be automatically created for any module. 1 1 1 1 1 Yamaha A Japanese company best known for consumer electronics and motorbikes. They make music synthesizers, CD-Rom Writers and HiFi sound equipment. (http://yamaha.com/). (1997-04-29) 1 1 1 1 1 YAML YAML Ain't Markup Language 1 1 1 1 1 YAML Ain't Markup Language (YAML) A data serialisation language designed to be readable and writable by humans and to work well with modern programming languages. YAML uses printable Unicode characters to represent both structure and data. The structural syntax is simple and terse. For example, indentation is used for structure, colons separate pairs, and dashes are used for list items. YAML can represent mappings (hashes or dictionaries), sequences (arrays or lists), scalars (strings or numbers), or any combination of the above. It has a simple typing system and reference syntax. Its structures will be particularly familiar to programmers using Perl, Python, PHP, Ruby, or Javascript, but YAML can be used with any programming language. YAML is, in some respects, a simpler alternative to XML, though it does not share the constraints imposed by XML's SGML legacy and has somewhat different aims. 1 1 1 1 1 yank (From the colloquial meaning "to pull suddenly") To insert a copy of some saved text at the current position in a document being edited. The term is used in the Unix text editors GNU Emacs and vi but "paste" is more common elsewhere. [Used elsewhere?] (1998-07-01) 1 1 1 1 1 YAPS Yet Another Production System? College Park Software. A commercial production system rule language, simpler than OPS5. YAPS allows knowledge bases to be attached to instances of CLOS objects. E-mail: Liz Allen <liz@grian.cps.altadena.cs.us>. 1 1 1 1 1 YASOS Yet Another Scheme Object System 1 1 1 1 1 YAUN /yawn/ Yet Another Unix Nerd. Reported from the San Diego Computer Society (predominantly a microcomputer users' group) as a good-natured punning insult aimed at Unix zealots. [Jargon File] (1994-11-11) 1 1 1 1 1 Yay Yet Another Yacc 1 1 1 1 1 ye The country code for Yemen. (1999-01-27) 1 1 1 1 1 Year 2000 (Y2K, or "millennium bug") A common name for all the difficulties the turn of the century, or dates in general, bring to computer users. Back in the 1970s and 1980s, the turn of the century looked so remote and memory/disk was so expensive that most programs stored only the last two digits of the year. These produce surprising results when dealing with dates after 1999. They may believe that 1 January 2000 is before 31 December 1999 (00<99), they may miscalculate the day of week, etc. Some programs used the year 99 as a special marker; there are rumours that some car insurance policies were cancelled because a year of 99 was used to mark deleted records. Complete testing of date-dependent code is virtually impossible, especially where the system under test relies on other systems such as customers' or suppliers' computers. Despite this, the predicted "millennium meltdown" never occurred. Various fixes and work-arounds were successfully 1 1 1 1 1 Yellow A language from SRI proposed to meet the Ironman requirements which led to Ada. ["On the YELLOW Language Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices 13(10):22-26, Oct 1978]. (1994-11-09) 1 1 1 1 1 Yellow Book 1. <publication> Yellow Book, Jargon. 2. Yellow Book CD-ROM. [Jargon File] (1996-12-03) 1 1 1 1 1 Yellow Book CD-ROM A CD-ROM format which is ISO 9660 compliant and uses mode 1 addressing. Discs of this type can be played on most drives and would be appropriate for most multimedia applications which have been developed for personal computers. (1994-11-02) 1 1 1 1 1 Yellow Book, Jargon The print version of the Jargon File, titled The New Hacker's Dictionary. It includes essentially all the material the File, plus a Foreword by Guy L. Steele, Jr. and a Preface by Eric S. Raymond. Most importantly, the book version is nicely typeset and includes almost all of the infamous Crunchly cartoons by the Great Quux, each attached to an appropriate entry. The first, second, and third editions correspond to versions 2.9.6, 3.0.0, and 4.0.0 of the File, respectively. ["The New Hacker's Dictionary", 3rd edition, MIT Press, 1996 (ISBN 0-262-68092-0)]. (1996-12-03) 1 1 1 1 1 Yellow Box Apple Computer, Inc.'s new development platform for building desktop, server, and web applications. Yellow Box is a rich object-oriented environment that is tightly integrated with Java and allows you to deploy applications across five platforms: Rhapsody, Rhapsody for Intel, Windows 95, Windows NT, and Mac OS. All Yellow Box-based products are an evolution of OpenStep - an operating system-independent, object-oriented application platform from NeXT. Integrating the cross-platform robustness of OpenStep with Apple's market-leading digital media and graphics technologies will differentiate the Yellow Box from other development platforms. Yellow Box for Windows is the run-time software (implemented as dynamically linked libraries) that allows Yellow Box applications to run under Windows 95 and Windows NT. Applications that use it will feature a full 1 1 1 1 1 Yellow Pages Network Information Service 1 1 1 1 1 yellow wire (IBM) Repair wires used when connectors (especially ribbon connectors) got broken due to some schlemiel pinching them, or to reconnect cut traces after the field engineer mistakenly cut one. Compare blue wire, purple wire, red wire. [Jargon File] 1 1 1 1 1 Yerk (After Yerkes Observatory) An object-oriented language based on a Forth Kernel with some major modifications. It was originally known as Neon, developed and sold as a product by Kriya Systems from 1985 to 1989. Several people at The University of Chicago have maintained Yerk since its demise as a product. Because of possible trademark conflict they named it Yerk, which is not an acronym for anything, but rather stands for Yerkes Observatory, part of the Department of Astronomy and Astrophysics at U of C. Version 3.62. (ftp://oddjob.uchicago.edu/pub/Yerk/). E-mail: Bob Lowenstein <rfl@oddjob.uchicago.edu>. (1994-11-23) 1 1 1 1 1 Yet Another (YA-, after Unix's yacc - Yet Another Compiler-Compiler) A humorous allusion often used in titles to acknowledge that the topic is not original, though the content is. As in "Yet Another AI Group" or "Yet Another Simulated Annealing Algorithm". If used of others' work, it describes something of which there are already far too many. In hackish acronyms the "YA" prefix almost invariably expands to Yet Another, e.g. YABA, YAUN. [Jargon File] (1996-11-26) 1 1 1 1 1 Yet Another Compiler Compiler (yacc) The LALR parser generator found on most Unix systems. Also, the language used to describe the syntax of another language to yacc (the program). Implementations: ayacc, YAY, perln-byacc, SASL-Yacc - "Yacc in SASL - An Exercise in Functional Programming", Simon Peyton-Jones, Software Prac & Exp 15:807-820 (1985). Mentions also a BCPL implementation. Yacc++ - 1990. An object-oriented rewrite of yacc, supports regular expressions, produces an LR1 grammar parser. ["YACC Meets C++", S.C. Johnson, USENIX Spring '88 Conf]. Chris Clark, Compiler Resources Inc, +1 (508) 435-5016. MLYACC - Implementation and output in SML/NJ. (ftp:research.att.com/dist/ml/75.tools.tar.Z). A version, by David Poole at Montana University has been retargeted to Turbo Pascal. (ftp://iecc.com/pub/file/lyprg.zip). See also Bison, yet another, Yet Another Yacc. 1 1 1 1 1 Yet Another Scheme Object System (YASOS) A system for object-oriented programming in Scheme. E-mail: Ken Dickey <kend@newton.apple.com> (2010-02-28) 1 1 1 1 1 Yet Another Yacc (Yay) An extension of Yacc with LALR2 parsing. Yay is available from Bull as part of the University of Waterloo Tools package maintained by <pjf@thinkage.on.ca>. (1994-11-09) 1 1 1 1 1 YGMTPO (Usenet) "You Greatly Misunderstood The Purpose Of". (1998-03-03) 1 1 1 1 1 YLISP A variant of Xlisp from Hewlett-Packard for the HP-95LX palmtop. (ftp://hpcsos.col.hp.com/mirrors/.scsi5/hp95lx/languages). (1994-11-23) 1 1 1 1 1 YMMV Your mileage may vary 1 1 1 1 1 YMODEM A file transfer protocol used between modems. YMODEM was developed by Chuck Forsberg as the successor to XMODEM and was itself succeeded by ZMODEM. XMODEM used 128-byte packets, YMODEM can also use 1 kilobyte packets. Whereas YMODEM is a batch protocol, YMODEM-G is a non-stop version. File sizes are included in the YMODEM header when sending both binary and text files. Thus files transferred via YMODEM should preserve their exact length. File modification times may also be present in the YMODEM header. YModem can fall back to smaller packets when necessary but there is no backward compatibility with XModem's error detection. [Chuck Forsberg, "XMODEM/YMODEM Protocol Reference"]. (1995-02-02) 1 1 1 1 1 YMODEM-G A non-stop "streaming" version of YMODEM designed for error-free connections with proper flow control; the transmitting program sends packets to the receiver as fast as it can without waiting for acknowledgements. Any errors cause the entire file transfer to abort. 1 1 1 1 1 yocto- prefix 1 1 1 1 1 Yoda condition The programming practise of using if (constant == variable) e.g. if (4 == foo) instead of the more natural if (variable == constant) It is named after the Star Wars character Yoda who says things like "Strong is Vader". It may have been invented as a way to prevent coding errors like if (count = 5) (accidentally using a single "=" (assignment) instead of a double "==" (comparison)). The above is syntactically valid whereas the Yoda equivalent would give a compile-time error. (2012-06-25) 1 1 1 1 1 YOL Computers A company in London, UK that sells computer and network systems, established in 2001. (http://yolc.com/). (2008-01-28) 1 1 1 1 1 yotta- prefix 1 1 1 1 1 yottabyte (YB) A unit of data equal to 10^24 bytes but see binary prefix for other definitions. A yottabyte is 1000^8 bytes or 1000 zettabytes. It is estimated that the web contains about one yottabyte of data (2013). 1000 yottabytes has been called one brontobyte. See prefix. (2013-11-04) 1 1 1 1 1 You are not expected to understand this [Unix] The canonical comment describing something magic or too complicated to bother explaining properly. From an infamous comment in the context-switching code of the V6 Unix kernel. [Jargon File] 1 1 1 1 1 You aren't gonna need it (YAGNI) A motto of extreme programming expressing the principle that functionality should not be implemented until it is needed. The traditional waterfall model makes it difficult to add features after the specification has been signed off, tempting the specifier to add features that may never be used but which take time to program, debug, test and document. (2014-03-27) 1 1 1 1 1 Yourdon 1. <programming> The Yourdon methodology. 2. <person> Edward Yourdon. 3. <company> Yourdon, Inc.. (1995-04-07) 1 1 1 1 1 Yourdon/Constantine (Or "Constantine/Yourdon") A structured design methodology involving structure charts, developed by Larry Constantine. (1995-04-07) 1 1 1 1 1 Yourdon/Demarco (Or "DeMarco/Yourdon") A structured analysis methodology involving data flow diagrams, etc. developed by Edward Yourdon and Tom DeMarco. (1995-04-07) 1 1 1 1 1 Yourdon, Inc. The company founded in 1974 by Edward Yourdon to provide educational, publishing, and consulting services in state-of-the-art software engineering technology. Over the next 12 years, the company grew to a staff of over 150 people, with offices throughout North America and Europe. As CEO of the company, Yourdon oversaw an operation that trained over 250,000 people around the world; the company was sold in 1986 and eventually became part of CGI, the French software company that is now part of IBM. The publishing division, Yourdon Press (now part of Prentice Hall), has produced over 150 technical computer books on a wide range of software engineering topics; many of these "classics" are used as standard university computer science textbooks. (1995-04-16) 1 1 1 1 1 Yourdon methodology The software engineering methodology developed by Edward Yourdon and colleagues in the 1970s and 1980s. "Yourdon methodology" is a generic term for all of the following methodologies: Yourdon/Demarco, Yourdon/Constantine, Coad/Yourdon. (1995-04-07) 1 1 1 1 1 Your mileage may vary (YMMV) The disclaimer American car manufacturers attached to EPA mileage ratings. A humourous way of saying that the thing under discussion will not necessarily give you the same results as the author. Often used to convey the hardware dependence of Unix freeware distributions. [Jargon File] (2012-02-16) 1 1 1 1 1 youtube.com YouTube, Inc. 1 1 1 1 1 YouTube, Inc. An on-line video file sharing web site, founded on 2005-02-14 by Chad Hurley, Steve Chen, and Jawed Karim. Anyone can upload video clips to the site and these can then be viewed by others. In 2007, many such sites exist but YouTube is the best known. YouTube is funded by Sequoia Capital. In November 2006, YouTube was bought by Google Inc.. YouTube has partnership deals with content providers such as CBS, BBC, Universal Music Group, Sony Music Group, Warner Music Group, NBA, The Sundance Channel and many more. YouTube Home (http://youtube.com/). (2007-09-28) 1 1 1 1 1 Yow! /yow/ (From "Zippy the Pinhead" comics) A favoured hacker expression of humorous surprise or emphasis. "Yow! Check out what happens when you twiddle the foo option on this display hack!" Compare gurfle. [Jargon File] (1995-03-07) 1 1 1 1 1 yoyo mode The state in which a computer is said to be when it rapidly alternates several times between being up and being down. Interestingly (and perhaps not by coincidence), many hardware vendors give out free yoyos at Usenix exhibits. Sun Microsystems gave out logoised yoyos at SIGPLAN '88. Tourists staying at one of Atlanta's most respectable hotels were subsequently treated to the sight of 200 of the country's top computer scientists testing yo-yo algorithms in the lobby. [Is it "yoyo" or "yo-yo"?] [Jargon File] (1995-03-07) 1 1 1 1 1 YP Yellow Pages. The original name for Sun's Network Information Service. (1995-03-07) 1 1 1 1 1 YSM Yourdon Structured Method 1 1 1 1 1 yt The country code for Mayotte. (1999-01-27) 1 1 1 1 1 YTalk Version: V3.0 Patch Level 1. <networking, tool> A multi-user chat program by Britt Yenne <yenne@austin.eds.com>. YTalk works almost exactly like the standard Unix talk program and even communicates with the same talk daemon(s), but YTalk supports multiple connections. Multiple user names may be given as command-line arguments, in the form "name#tty@host" where the optional "#tty" specifies a particular tty. YTalk is able to communicate with both existing versions of Unix talk daemons. Once connected, typing escape gives access to a menu of commands to add or delete users, trace to a file, or set options. If run under the X Window System, YTalk will use separate X windows for each user in the conversaton, otherwise it will split the terminal screen between them. E-mail: <ytalk@austin.eds.com>. 1 1 1 1 1 yu The country code for the former Yugoslavia. (1999-01-27) 1 1 1 1 1 Yu-Shiang Whole Fish /yoo-shyang hohl fish/ An obsolete name for the Greek character gamma (extended SAIL ASCII code 9, Unicode glyph 0x0263) which with a loop in its tail looks like a little fish swimming down the page. The term is actually the name of a Chinese dish in which a fish is cooked whole (not parsed) and covered with Yu-Shiang (or Yu-Hsiang) sauce. Used primarily by people on the MIT LISP Machine, which could display this character on the screen. Tends to elicit incredulity from people who hear about it second-hand. [Jargon File] (1995-01-31) 1 1 1 1 1 Z /zed/ <language, specification> 1. (After Zermelo-Fränkel set theory) A specification language developed by the Programming Research Group at Oxford University around 1980. Z is used for describing and modelling computing systems. It is based on axiomatic set theory and first order predicate logic. Z is written using many non-ASCII symbols. It was used in the IBM CICS project. See also Z++. ["Understanding Z", J.M. Spivey, Cambridge U Press 1988]. 2. <language, simulation> A stack-based, complex arithmetic simulation language from ZOLA Technologies. (1995-08-11) 1 1 1 1 1 Z++ An object-oriented extension of Z. ["Z++, an Object-Oriented Extension to Z", Lano, Z User Workshop, Oxford 1990, Springer Workshops in Computing, 1991, pp.151-172]. (1995-04-22) 1 1 1 1 1 Z-1013 A Z80 clone home computer running at 1 MHz. The Z-1013 computer was introduced in 1986 in East Germany. The computer contained a tape for storing and loading programs and had an unusual keyboard. (2004-03-24) 1 1 1 1 1 Z180 An 8-bit microprocessor, code compatible with the Zilog Z80 and based on a design from Hitachi which is in turn based on the Zilog Z80. [Manufacturer?] (1995-04-22) 1 1 1 1 1 Z3 The third computer designed and built by Konrad Zuse and the first digital computer to successfully run real programs. The computer was ready in 1941, five years before ENIAC. Zuse began his work on program-driven calculating machines in 1935. His two predessors of the Z3, the Z1 and Z2, were unsuccessful mechanical calculating machines. The Z3 was delivered to the Deutsche Versuchsanstalt für Luftfahrt (German Experimental Department of Aeronautics) in Berlin and was used for deciphering coded messages. A 1960 reconstruction of the Z3 is in the Deutsche Museum in Munich. The Z3 used about 2600 relays of the kind used in telecommunications. Zuse wrote and implemented the language Plankalkül on the Z3. Programs were punched into cinefilm. Zuse built some more computers after World War II, including the Z3's successor, the Z4, which was set up at ETH Zurich, Switzerland. 1 1 1 1 1 Z39.50 ANSI Z39.50 1 1 1 1 1 Z8 Zilog Z8 1 1 1 1 1 Z80 Zilog Z80 1 1 1 1 1 Z8000 Zilog Z8000 1 1 1 1 1 za The country code for South Africa. (1999-01-27) 1 1 1 1 1 ZAP 1. <language> A language for expressing program transformations. ["A System for Assisting Program Transformation", M.S. Feather, ACM TOPLAS 4(1):1-20, Jan 1982]. 2. Zero and Add Packed. (2001-03-25) 1 1 1 1 1 zap 1. To modify, usually to correct; especially used when the action is performed with a debugger or binary patching tool. Also implies surgical precision. "Zap the debug level to 6 and run it again." In the IBM mainframe world, binary patches are applied to programs or to the operating system with a program called superzap, whose file name is "IMASPZAP" (possibly contrived from I M A SuPerZAP). See also Zero and Add Packed. 2. To fry a chip with static electricity. "Uh oh - I think that lightning strike may have zapped the disk controller." (1998-07-08) 1 1 1 1 1 ZAPP Zero Assignment Parallel Processor. A virtual tree machine architecture in which a process tree is dynamically mapped onto a fixed, strongly connected network of processors communicating by message passing. The basic operation of each node is to apply a divide and conquer function which takes four arguments: (1) a function 'primitive' which takes a problem description (PD) and returns true if it can be solved without division, (2) a function 'solve' which takes a primitive PD and returns its solution, (3) a function 'divide' which takes a PD and returns a list of PDs of smaller problems and (4) a function 'combine' which returns the solution to a problem by combining a list of solutions of subproblems. Each node has a copy of the code and one is given the initial problem description. Task distribution is by process stealing in which a process constructs a descriptor for each subtask and idle (lightly loaded) processors can steal a descriptor from a physically connected neighbour. 1 1 1 1 1 Z-buffer An array used to store the maximum Z coordinate of any feature plotted at a given (X, Y) location on the screen, used for hidden line removal in a 2D rendering of a 3D scene. The Z axis is perpendicular to the screen with values increasing toward the viewer so that any point whose Z coordinate is less than the corresponding Z-buffer value will be hidden behind some feature which has already been plotted. (1997-07-18) 1 1 1 1 1 ZEBRA A data management package in the CERN Program Library. 1 1 1 1 1 Zed 1978. Software Portability Group, U Waterloo. Eh, with types added. Similar to C. Implementation language for the Thoth realtime operating system. Added a few simple types for greater efficiency on byte-addressed machines. String constants in case statements. Enforces the naming convention: MANIFESTS, Externals and locals. "Porting the Zed Compiler", G.B. Bonkowski et al, SIGPLAN Notices 14(8):92-97 (Aug 1979). 1 1 1 1 1 Zen [Kehoe, B., "Zen and the Art of the Internet", February 1992.] [Jargon File] 1 1 1 1 1 zen To figure out something by meditation or by a sudden flash of enlightenment. Originally applied to bugs, but occasionally applied to problems of life in general. "How'd you figure out the buffer allocation problem?" "Oh, I zenned it." Contrast grok, which connotes a time-extended version of zenning a system. Compare hack mode. See also guru. (1996-09-17) 1 1 1 1 1 ZENO U Rochester 1978. Euclid with asynchronous message-passing. Preliminary ZENO Language Description, J.E. Ball et al, SIGPLAN Notices 14(9):17-34 (Sep 1979). 1 1 1 1 1 zepto prefix 1 1 1 1 1 Zermelo Fränkel set theory A set theory with the axioms of Zermelo set theory (Extensionality, Union, Pair-set, Foundation, Restriction, Infinity, Power-set) plus the Replacement axiom schema: If F(x,y) is a formula such that for any x, there is a unique y making F true, and X is a set, then F x : x in X is a set. In other words, if you do something to each element of a set, the result is a set. An important but controversial axiom which is NOT part of ZF theory is the Axiom of Choice. (1995-04-10) 1 1 1 1 1 Zermelo set theory A set theory with the following set of axioms: Extensionality: two sets are equal if and only if they have the same elements. Union: If U is a set, so is the union of all its elements. Pair-set: If a and b are sets, so is a, b. Foundation: Every set contains a set disjoint from itself. Comprehension (or Restriction): If P is a formula with one free variable and X a set then x: x is in X and P(x). is a set. Infinity: There exists an infinite set. Power-set: If X is a set, so is its power set. Zermelo set theory avoids Russell's paradox by excluding 1 1 1 1 1 ZERO An object oriented extension of Z. ["Object Orientation in Z", S. Stepney et al eds, Springer 1992]. [Jargon File] (1995-03-30) 1 1 1 1 1 zero 1. <character> 0, ASCI character 48. Numeric zero, as opposed to the letter "O" (the 15th letter of the English alphabet). In their unmodified forms they look a lot alike, and various kluges invented to make them visually distinct have compounded the confusion. If your zero is centre-dotted and letter-O is not, or if letter-O looks almost rectangular but zero looks more like an American football stood on end (or the reverse), you're probably looking at a modern character display (though the dotted zero seems to have originated as an option on IBM 3270 controllers). If your zero is slashed but letter-O is not, you're probably looking at an old-style ASCII graphic set descended from the default typewheel on the venerable ASR-33 Teletype (Scandinavians, for whom slashed-O is a letter, curse this arrangement). If letter-O has a slash across it and the zero does not, your display is tuned for a very old convention used at IBM and a 1 1 1 1 1 Zero and Add Packed (ZAP) An IBM 360/370 assembly language instruction used when performing packed arithmatic to initialise an accumulator. (2001-03-25) 1 1 1 1 1 zero assignment A property of a programming language in which there are no variables but only functions. See also single assignment. (2003-12-22) 1 1 1 1 1 zero-content content-free 1 1 1 1 1 Zero Insertion Force (ZIF) A kind of socket for integrated circuits. A ZIF socket can be opened and closed by means of a lever or screw. When open, there the chip may be placed in the socket without any pressure at all, the socket is then closed, causing its contacts to grip the pins of the chip. Such sockets are used where chips must be inserted and removed frequently, such as in test equipment. They are more expensive and usually take up more space than conventional IC sockets. (1994-12-05) 1 1 1 1 1 zeroth First. Since zero is the lowest value of an unsigned integer, which is one of the most fundamental types in programming and hardware design, it is often natural to count from zero rather than one, especially when the integer is actually an index or offset, as used when addressing hardware and arrays. Hackers, computer scientists and pure mathematicians often like to call the first chapter of a publication "Chapter 0", especially if it is of an introductory nature (one of the classic instances was in the First Edition of K&R). Zero-based numbering tends to reduce fencepost errors, though it cannot eliminate them entirely. Logically, the next item after the zeroth should be the oneth but this is never used. [Dijkstra, "Why Numbering Should Start at Zero" (http://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html)]. 1 1 1 1 1 ZEST An object-oriented extension of Z. ["Object Orientation in Z", S. Stepney et al eds, Springer 1992]. 1 1 1 1 1 ZetaLisp The Maclisp dialect used on the LISP Machine. The many extensions to Maclisp include vectors, closures, flavors, stack groups, locatives, and invisible pointers. Currently supported by Lisp Machines, Inc. and Symbolics. ["LISP Machine Manual", D. Weinreb and D. Moon, MIT AI Lab, 1981]. (1997-03-18) 1 1 1 1 1 zetta- prefix 1 1 1 1 1 zettabyte (ZB) A unit of data equal to 10^21 bytes but see binary prefix for other definitions. A zetabyte is 1000^7 bytes or 1000 exabytes. 1000 zettabytes are one yottabyte. See prefix. (2013-11-04) 1 1 1 1 1 Zeus Berkeley Yacc 1 1 1 1 1 ZFC Zermelo Fränkel set theory plus the Axiom of Choice. A favourite axiomatisation of set theory. (1995-03-29) 1 1 1 1 1 ZF expression (After Zermelo Fränkel set theory). David Turner's name for list comprehension. (1995-03-27) 1 1 1 1 1 ZIF Zero Insertion Force 1 1 1 1 1 zigamorph /zig'*-morf/ 1. Hex FF (11111111) when used as a delimiter or fence character. Usage: primarily at IBM shops. 2. [proposed] The Unicode non-character +UFFFF (1111111111111111), a character code which is not assigned to any character, and so is usable as end-of-string. [Jargon File] 1 1 1 1 1 ZIL Zork Implementation Language. Language used by Infocom's Interactive Fiction adventure games. Interpreted by the zmachine, for Unix and Amiga. (ftp://plains.nodak.edu/Minix/st.contrib.Infocom.tar.Z). 1 1 1 1 1 Zilog The microprocessor manufacturer who produced the Zilog Z80 in July 1976 (as used by Sinclair in the ZX-80, ZX-81 and ZX Spectrum computers) and later the Zilog Z8000. Zilog was founded in 1974 and became a wholly owned subsidiary of Exxon Corp. by 1980. The company's management and employees purchased Zilog back from Exxon in 1989. Zilog became a publicly-held company in February, 1991. In March of 1998, Zilog was privatised, as a result of the merger and recapitalisation transaction by Texas Pacific Group (TPG). Zilog now produce a range of 8-bit microcontrollers, 8-, 16- and 32-bit microprocessors, and digital signal processors, covering the home entertainment, communications, and embedded systems markets. (http://zilog.com/). Address: 910 East Hamilton Avenue, Suite 110, Campbell, CA 95008, USA. 1 1 1 1 1 Zilog Z280 An enhanced version of the Zilog Z80 with a 16 bit architecture, introduced in July, 1987. It added an MMU to expand addressing to 16Mb, features for multitasking, a 256 byte cache, and a huge number of new op codes (giving a total of over 2000!). Its internal clock runs at 2 or 4 times the external clock (e.g. a 16MHz CPU with a 4MHz bus). (1994-10-31) 1 1 1 1 1 Zilog Z8 A family of microcontrollers from Zilog with on-chip RAM and ROM. The Z8 is not related to the Zilog Z80, it uses a totally different architecture and instruction set. Competitors include the Motorola 6805/68HC05 family or the Intel 8051-family (or i51-family or MCS51-family - there is no standard family name). (1995-04-22) 1 1 1 1 1 Zilog Z80 An 8-bit microprocessor. It was released in July 1976 with a 2.5 MHz clock rate. The Z80 was a much improved Intel 8080 (as was the Intel 8085). It also used 8-bit data and 16-bit addressing, and could execute all of the 8080 op codes as well as 80 new ones, instructions that included 1, 4, 8 and 16-bit operations and even block move and block I/O instructions. The register set was doubled, with two banks of registers (including A and F) that could be switched between. This allowed fast operating system or interrupt context switches. It features 3 types of interrupt mode. The Z80 also added two index registers (IX and IY) and relocatable vectored interrupts (via the 8-bit IV register). Like many processors (including the 8085), the Z80 featured many undocumented op codes. Chip area near the edge was used for added instructions, but fabrication made the failure of these high. Instructions that often failed were just not 1 1 1 1 1 Zilog Z8000 A microprocessor from Zilog introduced not long after the Intel 8086, but with superior features. It was basically a 16-bit processor, but could address up to 23 bits in some versions by using segment registers (to supply the upper 7 bits). There was also an unsegmented version, but both could be extended further with an additional MMU that used 64 segment registers. Internally, the Z8000 had sixteen 16-bit registers, but register size and use were exceedingly flexible. The Z-8000 registers could be used as sixteen 8-bit registers (only the first half were used like this), sixteen 16-bit registers, eight 32-bit registers, or four 64-bit registers, and included 32-bit multiply and divide. They were all general purpose registers - the stack pointer was typically register 15, with register 14 holding the stack segment (both accessed as one 32-bit register for painless address calculations). The Z8000 featured two modes, one for the operating system 1 1 1 1 1 Zilog Z80000 A later version of the Zilog Z8000, expanded to 32 bits internally and with a 6-stage pipeline. (1997-12-16) 1 1 1 1 1 Zilog Z80A A version of the Zilog Z80 microprocessor with a 4 MHz clock rate. (1995-04-24) 1 1 1 1 1 zip 1. <tool, compression, file format> To create a compressed archive (a "zip file") from one or more files using PKWare's PKZIP or a compatible archiver. Its use is spreading from MS-DOS now that portable implementations of the algorithm have been written. zip is also the name of a Unix archiving utility compatible with PKZIP. unzip is the corresponding de-archiver. See also gzip, tar and feather. (1996-08-26) 2. <storage> Zip Drive. [Jargon File] 3. <functional programming> zip function. 1 1 1 1 1 Zipcode A parallel language at Lawrence Livermore(?). (1996-08-26) 1 1 1 1 1 Zip disc Zip drive 1 1 1 1 1 Zip disk Zip drive 1 1 1 1 1 Zip Drive A disk drive from Iomega Corporation which takes removable hard disks storig 100 to 750 megabytes. Both internal and external drives are manufactured, making the drive suitable for backup, mass storage or for moving files between computers. Software is included to help with file organisation. The internal SCSI model offers up to 60 MB / minute transfer rate. The Zip drive was awarded Byte's Readers' Hardware Choice Award 1996 (http://byte.com/art/9607/sec11/art1.htm). It was superceded by the Jaz drive which takes one gigbyte disks. (2008-01-21) 1 1 1 1 1 zip file zip 1 1 1 1 1 zip function A function that takes two lists and returns a list of pairs. The idea can easily be extended to take N lists and return a list of N-tuples. (2008-03-29) 1 1 1 1 1 zipped zip 1 1 1 1 1 zipped file zip 1 1 1 1 1 zipperhead An IBM term for a person with a closed mind. [Jargon File] (1994-11-30) 1 1 1 1 1 zm The country code for Zambia. (1999-01-27) 1 1 1 1 1 ZMODEM A file transfer protocol with error checking and crash recovery. Developed by Chuck Forsberg. Its transfer rate is similar to YMODEM-g. Like YMODEM-g, ZMODEM does not wait for positive acknowledgement after each block is sent, but rather sends blocks in rapid succession. If a ZMODEM transfer is cancelled or interrupted for any reason, the transfer can be resurrected later and the previously transferred information need not be resent. FTP Oakland (ftp://oak.oakland.edu/pub/simtelnet/msdos/zmodem/), FTP PDX (ftp://ftp.cs.pdx.edu/pub/zmodem/). Telephone: +1 900 737 7836. (1996-07-02) 1 1 1 1 1 ZOG A high-performance hypertext system developed at Carnegie-Mellon University. (1994-11-30) 1 1 1 1 1 ZOLA Technologies Producers of the Z simulation language. (1994-11-30) 1 1 1 1 1 zombie 1. <operating system> zombie process. 2. <chat> A ghost. [Jargon File] (1997-10-08) 1 1 1 1 1 zombie process (Or "defunct process") A Unix process that has terminated (either because it has been killed by a signal or because it has called exit()) and whose parent process has not yet received notification of its termination by executing (some form of) the wait() system call. A zombie process exists solely as a process table entry and consumes no other resources. This entry is retained to hold the child's exit status until the parent process wants to retrieve it. The parent can also be notified asynchronously via a signal of the child's termination. Zombie processes can be seen in "ps" listings occasionally (with a status "Z" in some versions). Compare orphan process. (1997-10-08) 1 1 1 1 1 zone A logical group of network devices on AppleTalk. (1994-11-30) 1 1 1 1 1 Zoo Berkeley Yacc 1 1 1 1 1 zoo A data compression program and format by Rahul Dhesi. Zoo is reported to use the same Lempel Ziv algorithm as LHA. It is available for many platforms and source is available. .zoo archives are handled by many other PC archiving programs. Version 2.10 was released in 1989. Search the web for zoo210 to obtain an executable. Description (http://sources.isc.org/archiver/zoo2.txt). (2000-07-05) 1 1 1 1 1 zoom To show a smaller area of an image at a higher magnification ("zoom in") or a larger area at a lower magnification ("zoom out"), as though using a zoom lense on a camera. Unlike in an optical system, zooming in on a computer image does not necessarily increase the amount of detail displayed since this is limited by what is actually stored in the image. Similarly, you cannot zoom out beyond the full size of the image. (1997-10-24) 1 1 1 1 1 Zoomer A PDA from Casio, based on the GEOS microkernel operating system. (http://biostat.washington.edu/zoomer.html). (http://eit.com/mailinglists/zoomer/resources.html). Usenet newsgroup: news:comp.sys.pen, news:comp.sys.handhelds, news:comp.sys.palmtops. (1995-01-23) 1 1 1 1 1 ZOPL A block structured, untyped low-level language used on computers manufactured by Geac. [Dates? Reference? Stands for?] (2002-02-24) 1 1 1 1 1 zorch /zorch/ 1. [TMRC] To attack with an inverse heat sink. 2. [TMRC] To travel with velocity approaching lightspeed. 3. [MIT] To propel something very quickly. "The new comm software is very fast; it really zorches files through the network." 4. [MIT] Influence. Brownie points. Good karma. The intangible and fuzzy currency in which favours are measured. "I'd rather not ask him for that just yet; I think I've used up my quota of zorch with him for the week." 5. [MIT] Energy, drive, or ability. "I think I'll punt that change for now; I've been up for 30 hours and I've run out of zorch." 6. [MIT] To flunk an exam or course. 7. Computing power. [Jargon File] (1997-07-09) 1 1 1 1 1 Zork /zork/ The second of the great early experiments in computer fantasy gaming; see ADVENT. Zork was originally written on MIT-DM during the late 1970s, later distributed with BSD Unix as a patched, sourceless RT-11 Fortran binary (see retrocomputing) and commercialised as "The Zork Trilogy" by Infocom. The Fortran source was later rewritten for portability and released to Usenet under the name Dungeon. Both Fortran "Dungeon" and translated C versions are available from many FTP archives. [Jargon File] (1998-09-21) 1 1 1 1 1 zorkmid /zork'mid/ The canonical unit of currency in hacker-written games. This originated in Zork but has spread to nethack and is referred to in several other games. [Jargon File] (1998-09-21) 1 1 1 1 1 z/OS An operating system from IBM. According to IBM, it is a secure, scalable, high-performance enterprise operating system on which to build and deploy Internet and Java-enabled applications, providing a comprehensive and diverse application execution environment. (http://ibm.com/servers/eserver/zseries/zos/). (2008-01-22) 1 1 1 1 1 zr The old country code for Zaire. cd is now used instead, since Zaire changed its name to the Democratic Republic of the Congo. (1999-01-27) 1 1 1 1 1 zsh Z shell 1 1 1 1 1 Z shell (zsh) 1. sh with list processing and database enhancements. Version 2.1.o (before 1995-10-30). (ftp://cs.ucsd.edu/pub/zsh/zsh2.1.0.tar.Z). 2. A Unix command interpreter shell by Paul Falstad <pf@ttisms.com> some time before 1993-03-23. It is similar to, but not completely compatible with, ksh, with many additions to please csh users and some tcsh features. zsh supports editing of multi-line commands in a single buffer; variable editing; a command buffer stack; recursive globbing; manipulation of arrays; and spelling correction. zsh uses GNU autoconf so should compile and run on any modern version of UNIX, and many not-so-modern. Latest version: 4.0.6, as of 2002-10-02. zsh home (http://zsh.org/). (1995-10-31) 1 1 1 1 1 ZUG A low-level Awk(?) from Geac. (1995-01-23) 1 1 1 1 1 Zulu time Coordinated Universal Time 1 1 1 1 1 ZUSE An LL(1) parser generator by Arthur Pyster of the University of California at Santa Barbara. ZUSE requires Pascal. (1986-09-23) 1 1 1 1 1 Zuse (After Konrad Zuse) A descendant of Ada, Modula-2, Mesa and Oberon-1, described by Christian Collberg <collberg@dna.lth.se> in his PhD thesis 1991. Zuse supports several levels of information hiding. The Zuse type system includes fully hidden types (similar to Modula-2 opaque types but without any implementation restriction), semi-open pointer types (same as Modula-2 opaque types), extensible record types (similar to Oberon-1 public projection types but without the compiler hint), enumeration types, extensible enumeration types, and extensible subrange types. A type can also be protected by specifying the operations that particular modules may perform (similar to C++ friend classes and Ada private types). Zuse also includes hidden and extensible constants and hidden inline procedures. In order to support the higher levels of information hiding the implementation employs partial intermediate code linking. 1 1 1 1 1 Zuse, Konrad Konrad Zuse 1 1 1 1 1 zw The country code for Zimbabwe. (1999-01-27) 1 1 1 1 1 ZX-80 Sinclair's cheap personal computer with built-in BASIC, launched at the end of January 1980 at a computer fair in Wembley, UK. The processor was an NEC 780-C running at 3.25 MHz. It had 1KB of RAM, externally expandable to 16KB, and 4KB of ROM. It had RF video output to a TV, displaying 24 lines by 32 characters of monochrome text. An audio cassette recorder was used to save programs. The ZX-80 was sold in kit form for £79.95 or ready-built for £99.95. It was used by many UK hobbyists as a means of learning the basics of computing. Some remember the 1KB ZX-80 for the claim in its advertising that you could control a nuclear power station with it. The ZX-80 was succeeded by the ZX-81. (http://home.t-online.de/home/p.liebert/zx80_eng.htm). Planet Sinclair (http://nvg.ntnu.no/sinclair/). The Sinclair Story (http://sincuser.f9.co.uk/046/sstory.htm). 1 1 1 1 1 ZX-81 An even more successful version of the Sinclair ZX-80, featuring a large uncommitted logic array instead of much discrete logic, an improved BASIC, and rather more expandability (it could take 16kb RAM packs). It was launched around 1981 and was eventually replaced by the Spectrum. (1995-11-04) 1 1 1 1 1 zxnrbl /sner'b*l/ Incorrect data introduced by transmission errors; any corrupted or uninterpretable data. The word originated in a 1978 advertisement for a Mockingboard, which "makes frogs croak, princesses shriek, and martians zxnrbl." "It's not misspelled on the original page. The Internet must have zxnrbled it on the way to you." (1997-03-16) 1 1 1 1 1 ZX Spectrum Sinclair's first personal computer with a colour display. The Spectrum used the Zilog Z80 processor like its predecessors the ZX-80 and ZX-81. It was originally available in 16k and 48k versions using cassette tape and later grew to 128k and sprouted floppy disks. It had a wider and more solid case and a marginally better "dead flesh" keyboard. Unlike the earlier models, it didn't require the presence of a cold carton of milk to prevent it overheating. It was possibly the most popular home computer in the UK for many years. The TK-90X was a clone. (1995-11-04) 1 1 1 1 1 Zynet Ltd. A UK Internet service provider offering full Internet Protocol connection by any reasonable means for any number of computers from individual dial-ups to leased line connections to entire networks. Zynet is a sister company of Minerva Software and thus claim a better than average understanding of the needs and idiosyncracies of Acorn systems and will be offering special services for education. (http://zynet.co.uk/). E-mail: <zynet@zynet.co.uk>. Telephone: +44 (1392) 426 160. Fax: +44 (1392) 421 762. Address: Minerva House, Baring Crescent, Exeter EX1 1TL, UK. (1995-01-31) 1 1 1 1 1 ZyXEL A modem manufacturer. (ftp://ftp.zyxel.com/pub/other/zyxel). E-mail: <tech@zyxel.com>, <sales@zyxel.com>. Telephone: +1 800-255-4101 (Sales), +1 714-693-0808 (tech), +1 714-693-0762 (BBS), +1 714-693-8811 (fax). Address: 4920 E. La Palma, Anaheim, CA 92807, USA. (1994-10-31) 1 1 1 1 1 IDF Intermediate Distribution Frame. 1 1 1 1 1 log ["log: A Logic Programming Language with Finite Sets", A Dovier et al, Proc 8th Intl Conf Logic Prog, June 1991, pp.111-124]. 1 1 1 1 1 searchTerms The placeholder or variable used in the <Url> element of an OpenSearchDescription XML file to show where the user's actual search terms should go. For example, this dictionary's Open Search description (published in file (/search.xml)) includes the following element: <Url type="text/html" template="http://foldoc.org/searchTerms" /> meaning that to search for, say, "foo", you should go to http://foldoc.org/foo. You may have reached this page because you were trying to use some system based on Open Search and failed to supply any search term to substitute into the URL. Open Search reference (http://www.opensearch.org/Specifications/OpenSearch/1.1#The_.22Url.22_element). (2014-08-22) 1 1 1 1 1