A, B & C


10BASE-T : An approved proposal by the Institute of Electrical and Electronics Engineers 802.3 committee for a Draft Industry Standard enabling transport of 10-Mbps Ethernet local-area network traffic over unshielded twisted-pair wiring.

3-COM : Communication equipment manufacturer, among the three world leaders.

802.3 : The physical and medium access control standards for CSMA/CD (carrier sense multiple access with collision detection) local-area networks such as Ethernet.

80x8x : A family of Intel microprocessors used in IBM and IBM-compatible PCs and workstations.

A

Active matrix display (Affichage Matriciel actif) : Laptop display screen using TFT transistors to activate individually each LCD pixel. By controlling the light passage through each pixel, this display type offers a permanent, well contrasted and fast display, contrarily to other LCD displays. In fact the image is even better than with CRTs, because the image is permanent instead of being refreshed continuously.

ANSI : American National Standards Institute. In the United States, ANSI serves as a quasi-national standards organisation. It provides "area charters" for groups to write and develop standards in specific fields. These groups include the Institute of Electrical and Electronics Engineers (IEEE) and Electronic Industries Association (EIA).

APM : Automated Power Management. Series of techniques used to reduce the power consumption, especially on portable computers, in order to lengthen their autonomy.

API : Application Programming Interface. The formally defined programming language interface between a program provided by a vendor and its user. APIs, not products, are strategic. They are the important component of any software product. There are no "strategic" software products, only strategic interfaces. IBM's Systems Application Architecture, for example, is not a product grouping, but a collection of APIs.

Architecture : Structure of a part or the entire computer system. Combination of hardware and software linking systems across a network.

ASCII : American Standard Code for Information Interchange. A standard table of seven-bit designations for digital representation of upper-and lower-case Roman letters, numbers , and special control characters in teletype, computer, and word processor systems. ASCII is used for alphanumeric communication by everyone except IBM, whose own similar code is called EBCDIC. Since most computer systems use a full byte to send an ASCII character, many hardware and software companies have made their own non-standard and mutually incompatible extensions of the official ASCII 128 character set to 256-character set.

Asynchronous (Asynchrone): Characterised by not having a constant time interval between successive bits, characters or events. Transmission generally uses one start and one stop bit for character element synchronisation (often called start-stop transmission).

ATM : Asynchronous Transfer Mode. A wide-area network technology ; a transfer mode for switching and transmission that efficiently and flexibly organises information into cells. It is asynchronous in the sense that the recurrence of cells depends on the required or instantaneous bit rate. Thus, empty cells do not go unutilised when data is waiting. ATM's powerful flexibility lies in its ability to provide a high-capacity, low-latency switching fabric---for all types of information, including data, video, image and voice --- that is protocol , speed and distance independent. Of the plethora of benefits ATM will accrue to its users, probably the most significant is that it represents an enduring, architectural approach due to its inherent scalability. It scales well from small to large systems, from very low to very high transmission speeds (more than 100 Mbps), and from local-area, through metropolitan-area, to wide-area networking environments. This promising technology is not anticipated to be widely used until 1998.

AT&T : US telecom operator.

Authentication Service : A mechanism, analogous to the use of passwords on time-sharing systems, for the secure authentication of the identity of network by servers, and vice versa, without presuming the operating system integrity of either (e.g., Massachusetts Institute of Technology's Kerberos) .

AUI : Interface type between a computer and the LAN.

AUTOEXEC.BAT :

AUTOUSER.BAT : In a PMF system, set of commands accessible by the user in lieu of AUTOEXEC.BAT.

AZERTY : Same as QWERTY for a French-style keyboard.

B

Baud : Origin of the name : a mister BAUDOT invented many decades ago the telex system, and the associated data coding technique. It measures, for a signal, the speed of state changing. It can correspond to more than the number of bits transmitted per unit of time.

Backbone Network : A high-speed transmission facility, or an arrangement of such facilities, designed to interconnect lower-speed distribution channels or clusters of dispersed user devices.

Bandwidth (Bande Passante) : 1) The range of frequencies that can be passed through a channel. A channel carrying digital information has a data rate proportional to its bandwidth. 2) The signal-to-noise ratio of a modulate signal is tested within a range of frequencies on either side of the carrier frequency. This range is also called a bandwidth.

Base Memory : Refer to "Conventional Memory".

Basic Rate Interface : The Integrated Services Digital Network basic rate interface consists of two 64-Kbps data or voice channels, which are designated as B (bearer) channels. The interface also has a 16-Kbps signalling or packet-data channel designated as the D (delta) channel. The interface is, therefore, often referred to as 2B+D

Baud Rate : A measure of the speed at which computers send data from one device to another, typically 300, 1,200 or 2,400, with the higher numbers representing faster transmissions. One Baud may carry one or some bits of data per second.

Benchmark : A routine or program used to evaluate computer performance.

Binary Large Objects (BLOB) Support : The storage and retrieval of "binary large objects" bytes streams of data that may represent images, sound, or video. BLOBs have meaning to client application programs and need not be interpreted by the server.

BIOS : Basic Input Output System. In as DOS system, software residing in ROM which provides the basic functionality of the computer.

B-ISDN : Broadband Integrated Services Digital Network. A high-speed (greater than ISDN primary rate), asynchronous, time division multiplexed transmission facility, or an arrangement of such facilities, designed to provide a wide range of audio, video and date application in the same network.

Bit : Abbreviation for binary digit, the minimum unit of binary information. A bit can have only two states, on or off, which are commonly called one and zero.

BitMap Police : Character set generated using a method which handles each character as a pixel set. Contrarily, the vectorial polices handle the characters by representing their shape, thus being independent of the actual size.

Blob : Binary Large Object. A generic term used to describe the handing and storage of long strings of data by middleware. Typically associated with image and video. Refer to Binary Large Object Support.

BNC : Interface type between a computer and the LAN.

Boot : On a PC, operation consisting of initialising the system. This is done automatically at power-on, or on request, when pressing the Ctrl+Alt+Del keys. The previous state of the main storage is lost.

Boot sector : Instructions allowing the hard disk to load the DOS operating system. This record is one of the privileged targets for viruses, because it is executed at each computer power-on.

Bpi : Bits Per Inch. The number of bits recorded per linear inch of recording surface.

Bps : Bits Per Second. Basic unit of measure for serial date transmission capacity ; the number of binary digits transmitted over a communications channel in a second. On a classical dial-up line, this speed was 1,200 in the 70s, 4,800 in the 80s. It is now (1995) commonly 14,400 and 28,800 is arriving. With compression techniques (now common in modems and routers), this speed is multiplied by a factor 2 to 3, thus allowing a throughput approaching 10,000 characters per second (or more than 30 million characters per hour).

Bridge (Pont) : A relatively simple device that passes data from one local-area network (LAN) segment to another without changing it. The separate LAN segments that are bridged use the same protocol.

Broadcast (Emission) : The process of sending a signal or message from one station on a network to multiple stations on the network at the same time.

Bus :

  1. In data communications, a network topology in which stations are arranged along a linear medium (e.g., a length of cable).
  2. In computer architecture, a path over which information travels internally among various components of a system.

Button (Bouton) : In a graphical user interface, an icon symbolising a button is used to allow the user to select among options, or to confirm an action.

Byte (Octet) : A group of eight bits handled as a logical unit.

C

C : The programming language created by Dennis Ritchie of Bell Laboratories in 1972 when he and Ken Thompson worked on the UNIX operating system design. It was based on Thompson's B language. It has found widespread use on personal computers and is one of the languages in which expert system shells are implemented.

C++ : An extension to the C language . As a superset of C, it provides additional features for data abstraction and object-oriented programming.

C2 : Discretionary Controlled Access Protection . A class of computer system security defined by the US Department of Defence. With C2 systems, information is accessible only to specifically authorised users. C2 functionality (although not necessarily formal Department of Defence evaluation) is of significant value in commercial applications.

CA : Refer to Computer Associates.

CA90s : Computer Associates's integrated software architecture that attempts to bring order and form to existing CA technology. Its advantage include its lack of hardware bias and the fact that it is not standard-dependent. One of its main components is CA-UNICENTER, selected as System Administration software in France.

Cache memory (Memoire Cache) : Very fast memory (generally SRAM) used often as intermediate between the CPU and the central storage, thus accelerating the system throughput. For example, on a 100MHz CPU, one cycle is executed in 10 ns, that is much faster than the 70 ns RAM cycle.

CAD/CAM : Computer-Aided Design/Computer-Aided Manufacturing. Two highly specialised technical applications of a computer to improve the productivity of the engineer.

CASE : Computer-Aided Software Engineering. CASE is an umbrella term for a collection of tools and techniques which are said by their distributors to promise revolutionary gains in analyst and programmer productivity. The two prominent delivered technologies are application generators and PC-based workstations that provide graphics-oriented automation of the front end of the development process.

CCD : Charge Coupled Device. A semiconductor device capable of both photodetection and memory, which converts light to electronic impulses. One- and two-dimensional CCD arrays are used in scanners to perform the first stage in converting an image into digital data. They are particularly attractive because they can step the signals from each detector across the array in response to a clock signal, permitting each scan line to be read through a single electrical connection.

CCITT : Abbreviation of the French name for the International Telegraph and Telephone Consultative Committee.

CCITT Group III : The original standard for compression and decompression of facsimile.

CCITT Group IV : The optimised standard for black-and-white office documents. Neither Group III nor Group IV handles color. Both are required to reduce bandwidth and storage demand.

CD : Compact Disc. The trademarked name for the laser read digital audio disk, 12 centimetres in diameter, developed jointly by Philips and Sony.

CD-ROM : Compact Disc Read-Only Memory. A version of the standard compact disc intended to store general-purpose digital data; provides 556-Mbytes user capacity at 10-13 corrected bit error rate compared to 653 Mbytes at 10-9 for the standard CD.

Cell : A block of fixed length identified by a label at Layer 1 of the Open Systems Interconnection /International Standards Organisation (OSI/ISO) reference model. The fundamental building block of ATM (asynchronous transfer mode) and broadband ISDN (Integrated Services Digital Network).

CGA : Ancient screen resolution standard, characterised by a low resolution (320 x 200).

Chip (Puce) : Integrated electronic circuit, engraved on one silicon slice.

CISC : Complex Instruction Set Computer. A computer in which individual instructions may perform many operations and take many cycles to execute , in contrast with reduced instruction set computer. Examples include IBM System/370, Digital Equipment Corp. VAX, Motorola 68020 and Intel 80386.

Class (Classe) : Often confused with object, a class defines an entity in the application to be programmed by specifying its data structure and the procedures that can operate on the data. A specific instance of a class, created at run time, is an object

Clear To Send : Signal sent by a modem to a computer indicating that the modem is ready to accept data and to forward them to the telephone line.

Click : Action consisting of placing the mouse over an object and pressing the button without moving the mouse.

Client : A client is as system or program that requests the activity of one or more other systems or programs, called servers, to accomplish specific tasks. In a client/server environment, the workstation is usuallythe client.

Client/Server : A concept that functionally divides the execution of a unit of work between activities initiated by an end user or program (client) and resource responses (services) to the activity request. Client/server is an application of cooperative processing in which the end-user interaction with the computing environment is through a programmable workstation that executes some portion of the application (beyond terminal emulation).

Clock (Horloge) : Function allowing the computer to maintain date and time, and to calculate the elapsed time between two events.

CMOS : Complementary Metal-Oxide Semiconductor. Integrated-circuit technology noted for its low-power requirements and low-transmission time. Often used in processor and memory chips for portable computers.

COBOL language : A COBOL language compliant, at the high level of required modules, with the American National Standards Institute X3.23-1985 standard.

Codec : Codec/Decoder. Compression and decompression software and hardware used in video-teleconferencing applications.

COMMAND.COM : File mandatory for PC system initialisation. It determines the guide message display and the keyed in commands interpretation.

Compaq : PC systems manufacturer, world leader in 1994.

Compiler (Compilateur) : Computer program in charge of converting a source program (composed of sentences according to the computer language syntax) in an executable program (composed of machine-readable instructions).

Compression : In the specific context of digital image representation, refers to the process of compacting the data based on the presence of large white or black areas in common business documents, printed pages, and engineering drawings. The International Telegraph and Telephone Consultative Committee (CCITT) digital facsimile standards contain standard one- and two-dimensional compression/decompression algorithms. This technology is used to speed up transmission and to lower storage requirement.

Computer Associates : (CA)A major independent software vendor established in 1976. It had its initial public offering in December 1981. CA has assumed the role of receive of troubled software companies. In 1987, having already acquired 16 companies in five years, CA hit full stride. During the next two years, it purchased Uccel, Applied Data Research and Cullinet. They then purchased Legent in 1995. CA has been able to trim fat from the acquired companies and then pump the acquired products through its distribution channels.

COMx : Serial communication interface identification (COM1 or COM2 for example). It is an internal software address used for transmitting data between a PC/DOS computer and an external device.

CONFIG.SYS : In a DOS PC system, configuration file which contains system configuration commands. These commands are executed at system initialisation time.

Conventional memory (Memoire Conventionnelle) : In a PC DOS system, part of storage between 0 and 640 KB, in which most DOS native applications work. Synonymous of "Base Memory".

Cooperative Processing : The process by which a single application is partitioned between two or more hardware platforms. Each segment of the application can communicate with the others. Physical connectivity can occur via a direct channel connection, a local-area network node, a peer-to-peer communication link or a master/slave link. The application software can exist in a distributed processing environment, but this is not a requirement.

Coprocessor (Coprocesseur) : Complementary microprocessor in charge of handling specifically math operations, faster than the CPU.

CORBA : Common Object Request Broker Architecture . Interfaces defined by the Object Management Group in January 1992 that provide mechanisms by which objects transparently receive messages and make responses over a network.

CPU : Central Processing Unit. Core of a computer, unit in which are grouped the circuits in charge of managing the instructions interpretation and execution.

CRT : Cathode-Ray Tube. Basic technology used for TV sets and desktop displays. An electron beam produced at the bottom of the tube is directed toward the front of the tube where, when activated, it lights on the screen surface. This process is periodically repeated over all the screen, across each row.

CSMA/CD : Carrier Sense Multiple Access with Collision Detection. A local-area network access technique in which multiple stations connected to the same channel can sense transmission activity on that channel and defer the initiation of transmission while the channel is active. Sometimes called contention access.

Cylinder (Cylindre) : On a hard disk, vertical column of tracks accessible without moving the arm containing the reading heads.


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