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There are currently 500 names in this directory
-endian
A suffix indicating the ordering of bytes in a multi-byte number, as in big-endian, little-endian, or middle-endian.

.A3L
MacroMedia Authorware Windows Library (filename extension).

.arts
An ending of an address for a cultural site on the Internet. Example: http://www.renaissance.arts.

.cnt
Means: contents. It is a Windows file holding "table of contents" information.

.CRT
Certificate (filename extension).

.FLR
Folder (file name extension).

.gid
Global Index File. It is created by Windows once a help file is used for the first time. It serves as an index reference for the help system thereafter.

.idx
The extension used for an IDX (index file). Index files are not intended to be a readable file, but are used in conjunction with MBX (multi-index) files.

.info
An ending of an address for an Internet site that offers information services. Example: http://www.travelers.info.

.net
A top-level Internet domain name, short for .network.

.NET
Microsoft's framework for Web services and component software, introduced in 2000 and pronounced "dot-net."

.newsrc
(news run commands) A file that specifies the configuration for the UNIX rn newsreader.

.pac
1. Atari STAD bitmap image 2.Proxy AutoConfig. 3.SBStudio II package or song

.PDF
The file extension for a Portable Document Format file. Portable Document Format was designed by Adobe Systems, Inc. In order to view a .pdf file the user will need Adobe Acrobat Reader, a freeware product available for download via the Web.

.ptm
Polynomial texture map file format.

.PWL
Password List. Extension used by Microsoft for a database file which holds cached password information.

.rec
An ending of an address for an Internet site that is recreational. Example: http://www.games.rec.

.SWF
ShockWave Flash. A file format (pronounced 'swiff') designed to deliver graphics and animation over the Internet.

.swf
shockwave file extension

.swf
shockwave file extension

.twmrc
Tab Window Manager run commands; configuration file (filename extension).

(c)
An ASCII version of the circled c used as a copyright symbol. Unfortunately, (c) is not legally valid. The c must be circled completely, or the word (copyright) must be spelled out in full.

@loha
An add-on electronic mail program that makes it possible to include animation and sound with email messages.

'Snooze
Fidonews, the weekly online newsletter of FidoNet.


A clown emoticon

~
ASCII character 126: ~ tilde. Used in some cases to represent a user's home directory. World Wide Web home pages often use the tilde in this form: www.some.com/~jones.

100Base-T
A high-speed local area network, also called Fast Ethernet. 100BaseT transmits at 100 megabits per second.

101-key keyboard
A standard computer keyboard with 101 keys including the alphanumeric keys, the number pad, F keys, and arrow keys.

104-key keyboard
A keyboard with 104 keys designed to accommodate the Windows 95 operating system.

10Base-2
An Ethernet standard in which a thin coaxial cable is used to connect network nodes. The cable is attached by means of BNC T-connectors to the network cards.

10Base-T
A version of Ethernet in which stations are attached by twisted pair cable, the traditional cables used for telephone lines. 10BaseT uses a star formation, and transmits at 10 megabits per second.

15-bit color
15-bit color makes it possible to display up to 32,768 colors. Digital video requires at least 15-bit color.

16-bit color
A monitor with 16-bit color can display 65,536 colors. This kind of monitor can produce high-quality images for desktop publishing and multimedia.

16-bit computer
A computer whose central processing unit can process 16 bits of information at a time.

16-bit operating system
An operating system that can process 16 bits of data at once.

16-bit sound card
A sound card that takes 16-bit samples of a sound wave, measuring the wave on a scale of 65,536 increments. The 16-bit sound cards produce high-fidelity sound and music for multimedia.

2.5G
Second-and-a-half generation wireless service. Most carriers will move to this wireless service before making the drastic upgrade to 3G. 2.5G changes wireless service to a packet-switched service that will dramatically increase transmission speeds.

24-bit color
A monitor with 24-bit color can display 16.8 million colors. This kind of monitor can be used to display high-quality photography and video for professional design work and digital photo retouching.

24/7
Twenty-four hours a day, seven days a week. A term commonly used to describe the concept of Internet time and how it has affected services; i.e., is your help desk 24/7? Could be substituted for "always on."

286
Nickname for the 80286. The Intel microprocessor used with the IBM PC AT. Its register size is 16 bits, its bus size is 16 bits, and its clock speed is 8 MHz.

2G
Second generation wireless service. Also known as Personal Communications Services (PCS), 2G arrived in 1990 and is the current wireless service available in North America. It is based on circuit-switched technology where each call requires its own cell channel, which makes transmission of data quite slow. 2G services include Code Division Multiple Access(CDMA), Time Division Multiple Access (TDMA), and GSM (Global System for Mobile Communication (GSM). GSM is used in Europe and Personal Digital Communications (PDC) is used in Japan.

32 bit
See 32-bit computer, 32-bit color, 32-bit operating system, 32-bit addressing.

32-bit addressing
If a computer has 32-bit addressing, it means that each address in memory can have 32 numbers. Since each number could be a 1 or a 0, that means that 2^32 (four billion) addresses are available. The computer could theoretically address up to 4 gigabytes of memory; however, many computers with 32-bit addressing have far less than 4 gigabytes of memory.

32-bit color
A monitor with 24-bit color can display 16.8 million colors; 32-bit color does not add more colors, but gives the display additional masking and channeling abilities.

32-bit computer
A computer whose central processing unit can process 32 bits of information at a time.

32-bit operating system
An operating system that can process 32 bits of data at once. For example, Windows 95 and OS/2 Warp are 32-bit operating systems.

32-bit Windows
Windows 95, Windows 98, Windows CE and Windows NT, which are 32-bit operating systems.

386
Nickname for the 80386. A 32-bit microprocessor from Intel with a clock speed of 33 MHz. The 80386 is used in PCs.

3D sound
Three-dimensional sound. Sound that seems to come from various directions, creating the effect of a three-dimensional space. 3D sound is used in virtual reality; this effect can be obtained with stereo headphones.

3DFX
A manufacturer of add-on 3D cards for more powerful 3D graphics.

3G
Third generation wireless service. The next generation of wireless services, 3G will bring wireless transmission speeds up to 2Mbps, which allow for high-quality wireless audio and video. For up-to-date information on the move to 3G wireless service visit www.fcc.gov/3G/

3GL
Third-generation language. A language like PASCAL or FORTRAN, which is at a higher level than assembly language, and easier to understand.

3W or W3
World Wide Web. A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.

4-bit color
A monitor with 4-bit color can display 16 colors. Four-bit color is okay for office use, but not good for displaying graphics.

4004
The first microprocessor, released in 1971 by Intel, with a 4-bit register size and bus size, and a clock speed of 1 MHz.

486
Nickname for the 80486. A 32-bit microprocessor from Intel with a built-in coprocessor and a clock speed of 33 MHz.

4GL
Fourth-generation language. A language more advanced than third-generation languages, and closer to regular speech.

4QD
An electronic motor controller used for remote control of robots.

500 number
A telephone number assigned to an individual, rather than a location. A person with a 500 number can get calls, faxes, or data at any location.

56k line
A transmission channel that can transmit data at 56,000 bps.

586
Pentium. The Intel high-performance microprocessor introduced in 1993, also called P5 or 80586. It is about twice as fast as the 486.

6502
An 8-bit microprocessor from MOS Technology, with a clock speed of 1 MHz. It was used in the Apple II.

6502A
An 8-bit microprocessor from MOS Technology, with a clock speed of 2 MHz, used in the Commodore VIC-20.

68000
A microprocessor from Motorola with a 32-bit register size, a 16-bit bus, and a clock speed of 8 MHz, used in the original Macintosh computer.

68020
A microprocessor from Motorola with a32-bit register size and a 32-bit bus, with a clock speed of 16 MHz, used in the Macintosh LC series.

68030
A 32-bit microprocessor from Motorola with a clock speed of 40 MHz, used in the Macintosh IIfx.

68040
A 32-bit microprocessor from Motorola with a clock speed of 40 MHz and a coprocessor.

68060
A 32-bit microprocessor from Motorola with a clock speed of 66 MHz.

680x0
A series of microprocessors developed by Motorola, used in Macintosh computers. See 68000, 68020, 68030, 68040, 68060.

686
The Pentium Pro. Successor to the Pentium microprocessor; also called P6 or 80686. The 686 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.

6DOF
Six Degrees of Freedom. A virtual reality term used to describe movement in three-dimensional space.

8-bit color
A monitor with 8-bit color can display 256 colors, which is fine for business and home use, but not good enough for producing high-quality graphics. For multimedia applications, 256 colors is the minimum needed.

8-bit computer
A computer whose central processing unit can process 8 bits of information at a time.

8-bit sound card
A sound card that takes 8-bit samples of a sound wave, measuring the wave on a scale of 256 increments. These older sound cards have been mostly superseded by 16-bit sound cards, which have higher quality sound.

802.x
The set of IEEE standards for defining LAN protocols.

80286
The Intel microprocessor used with the IBM PC AT. Its register size is 16 bits, its bus size is 16 bits, and its clock speed is 8 MHz.

80386
A 32-bit microprocessor from Intel with a clock speed of 33 MHz. The 80386 is used in PCs.

80386SX
A less expensive version of the Intel 80386, with a 16-bit bus.

80486
A 32-bit microprocessor from Intel with a built-in coprocessor and a clock speed of 33 MHz.

80486SX
A less expensive version of the 80486 Intel microprocessor, with no coprocessor.

8051
An 8-bit microprocessor/microcontroller from Intel, with a clock speed of 1-12 MHz.

80586
Pentium. The Intel high-performance microprocessor introduced in 1993, also called P5 or 586. It is about twice as fast as the 486.

80686
The Pentium Pro. Successor to the Pentium microprocessor; also called P6 or 686. The 80686 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.

8080
An 8-bit microprocessor from Intel, with a clock speed of 2 MHz. It was the first general-purpose microprocessor.

8086
An Intel microprocessor with a register size of 16 bits and a bus size of 16 bits, with a clock speed of 8 MHz.

8088
The Intel microprocessor used for the original IBM PC. It had a register size of 16 bits, a bus size of 8 bits, and a clock speed of 4.77 MHz.

88000
A series of 32-bit RISC microprocessors from Motorola, beginning with the 88100. These chips have been used in computers made by Data General and Encore.

98lite
A shareware program developed by Shane Brooks which can be used to separate Windows 98 from Internet Explorer for people who want to install only Windows 98.

A
1. Ampere; a charge of one coulomb passing a point in one second. 2. Abbreviation for Angstrom; one 10-billionth of a meter. (The Angstrom abbreviation is actually the Norwegian capital A for the Norwegian letter aa. It has a diacritical mark, a circle, attached to the tip of the A. We could not create it here.) See also ampere and angstrom entries.

A Programming Language
(APL). A high-level mathematical programming language developed by Kenneth Iverson in the 1960s. It can be run on many different kinds of computers, and is still used for some applications. APL uses its own special characters to represent operations.

A-B box
A box that enables two or more computers to take turns using a peripheral device such as a printer or scanner. The user turns a switch on the box choosing A, B, etc. to change from one computer to another.

A:
The A: drive, the first drive in a computer or on a network. It can be a diskette or hard disk drive.

A/D converter
Analog-to-digital converter. A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.

A/UX
A version of UNIX developed by Apple Computer for the Macintosh.

AA
Auto Answer. Some modems can be set up to accept telephone calls and automatically establish a connection; this ability is called auto answer. When the AA light on the modem goes on, the modem is set to auto answer.

AAT
Average Access Time. The average amount of time it takes for a storage peripheral to transfer data to the CPU.

abend
ABnormal END. From an error message on the IBM 360. Also called a crash or bomb, it is the result of erroneous software logic or hardware failure.

ABI
Application Binary Interface. A specification for the application programming interface (API) and machine language for a hardware platform. The PowerOpen Environment and Windows Sockets are examples of ABIs.

ABIOS
Advanced Basic Input/Output System. A BIOS that is compatible with the latest software and peripherals.

ABIST
Automatic Built-In Self-Test. An automatic self-test performed by an IBM computer to make sure its various components are functioning properly.

abort
To cancel a command or stop a transmission.

Abort, Retry, Ignore, Fail?
A DOS error message that is displayed when the computer has trouble reading a disk or file.

ABR
(Automatic Baud Rate detection). The process in which a receiving device examines the first character of an incoming message to determines its speed, code level, and stop bits. Having this automatic function makes it possible to receive data from different transmitting devices operating at different speeds without having to establish data rates in advance.

abscissa
The x coordinate on an x,y graph (y is the ordinate).

absolute address
A specific location in the memory of a computer or peripheral device, which is not defined by reference to any other address. It is sometimes derived by taking a base address and adding to it a relative address.

absolute cell reference
In a spreadsheet, a reference to one specific cell, rather than a relative reference which would indicate the placement of a cell in reference to the current cell (for example, four rows above in the same column). Since cell references in a spreadsheet are relative references by default, an absolute cell reference must be indicated; this is done by different codes in different programs, but often by adding a dollar sign: $A42, $B$12.

absolute path
A designation of the location of a file which is given in relation to the root directory; it includes the root directory and the descending series of subdirectories leading to the end file.

absolute pathname
A pathname that is defined in relation to the root directory.

absolute reference
In a spreadsheet, a reference to one specific cell, rather than a relative reference which would indicate the placement of a cell in reference to the current cell (for example, four rows above in the same column). Since cell references in a spreadsheet are relative references by default, an absolute reference must be indicated; this is done by different codes in different programs, but often by adding a dollar sign: $A42, $B$12.

absolute vector
A vector whose end points are indicated as absolute coordinates.

Abstract Syntax Notation One
(ASN.1). The ISO language for describing abstract syntax.

Abstract Windows Toolkit
(AWT). A Java application programming interface that allows programmers to develop Java applications having windows, scroll bars, and other components of a graphical user interface, which are usable on a variety of platforms such as Windows, Macintosh, and UNIX. The AWT instructions are translated for the host operating system by Java Virtual Machine (VM).

AC
Alternating Current. Alternating current differs from direct current (DC) in that its direction is reversed 60 times per second (50 times per second in some countries). The electricity in ordinary home or office outlets is AC.

Accelerated Graphics Port
Accelerated Graphics Port. A bus specification from Intel that gives graphics cards faster access to main memory than the PCI bus, thus greatly speeding up graphics display and texture rendering, especially virtual reality and 3D rendering and display. AGP allows efficient use of frame buffer memory, thereby helping 2D graphics performance as well. The coherent memory management design allows scattered data in system memory to be read in rapid bursts. The PCI graphics accelerator bus has a data transfer rate of up to 133 MBps. Because it is directly on the motherboard's chipset and has a direct pipeline connection to the computer's main memory, AGP is much faster. AGP is available in two speeds: 1X transfers data at a rate of 264 MBps; 2X transfers data at 528 MBps. The AGP 4X, coming in 1999, will double the bandwidth peak again to 1 GBps.

accelerator
A key combination which substitutes for a mouse command, and makes certain operations faster.

accelerator board
A printed circuit board added to the computer that replaces the central processing unit with a faster one.

accelerator card
A special printed circuit board, usually plugged into one of the computer's expansion slots, that makes the computer work faster. For example, a graphics accelerator card speeds up the time it takes to display images on the computer screen.

acceptable use policy
(AUP). A policy which limits the way a network may be used; for instance, some networks are restricted to noncommercial use.

acceptance test
A formal test conducted by the end user of a system, to determine if the system works according to specifications and should be accepted.

access
To make use of a computer resource.

access code
The password which the user must type in to get access into a computer system.

access concentrator
see remote access concentrator.

access control
The mechanisms for permitting or limiting entry to a computer network. Access control manages user access by requiring authentication of the user's identity or membership in a predefined group; it is typically used by system administrators for controlling access to servers, directories or other network resources.

access control protocol
The authentication technology used to verify a user's identity and grant access to a computer or network.

access denied
A message that sometimes appears when requesting a file. When access is denied it may mean the file is already in use, or that access is restricted to specific users.

access line
The telephone line which connects a customer site to the telephone company's central office.

access method
Also termed access mechanism, access method is the manner in which an application reads from or writes to a resource for programming purposes. Access method is the software routine responsible for storing, retrieving, transmitting and receiving data; it is also able to detect errant transfers of data and correct them if possible. Tapes invariably use the sequential access method; disks either use indexed access method, indexed sequential access method or direct access method; communications access methods exchange data from a host computer to remote terminals.

access privileges
The extent to which a user may operate a system resource on a network or a file server. In many cases, permission to access a server, view its contents and modify or create files is limited by the network's system administrator in order to maintain security.

access provider
Service provider; an organization or company that provides access to a network.

access rights
see access privileges

access time
The amount of time it takes for a storage peripheral to transfer data to the CPU, measured from the instant the request is made until the instant the data is received.

accessory
A peripheral device that may perform a useful function but is not necessary for the operation of the computer. Examples are printers, scanners, and modems.

ACCU
Association of C and C++ Users. A worldwide association of people who are interested in C, C++, and related programming languages.

ACDI
Asynchronous Communications Device Interface. A software device that permits asynchronous transmission, a way of transmitting data in which one character is sent at a time, and there may be uneven amounts of time between characters. A start bit and a stop bit notify the receiving computer when the transmission begins and ends. In synchronous transmission, strings of multiple characters are transmitted; this method is faster, but more expensive.

ACK
Abbreviation for ACKnowledge. A modem receiving a data packet sends a signal back to the modem that sent it. If the data is complete and correct, it sends an ACK (acknowledgement) signal, which also indicates the next data packet should be sent. If the modem didn't get all the data, it sends back a NAK, or negative acknowledgement signal.

ACM
Association for Computing Machinery, 1515 Broadway, New York, NY 10036, 212/869-7440. Since 1947, the Association for Computing Machinery has been advancing information technology throughout the world. ACM offers chapters and activities, special interest groups, conferences and events, journals, magazines and films. ACM has SIGs in programming languages, software engineering, graphics, computer-human interaction, and more. Publications include Computing Reviews and the ACM Guide to Computing Literature, available online, and cover such topics as object technology, participatory design, internetworking, software project management, hypermedia, and wireless computing. ACM also recognizes important contributors in the field of computing.

Acorn Archimedes
A series of personal computers from Acorn Computers, Cambridge, UK; the first personal computers to use RISC architecture.

Acorn Computers Ltd.
A UK computer manufacturer, designer of the Advanced

acoustic coupler
A hardware device designed to convert electrical signals to sound, and sound to electrical signals in order to connect a modem to a telephone line via a handset. For current modems that have a direct electrical connection, acoustic couplers are not needed.

ACPI
Advanced Configuration and Power Interface. A power management specification that replaces APM in Windows machines. Developed by Intel, Microsoft, and Toshiba, ACPI gives the operating system the ability to control the amount of power given to each peripheral device, and to turn off devices when not in use.

Acrobat
Document exchange software from Adobe Systems, Inc. Acrobat provides a platform-independent means of creating, viewing, and printing documents. Acrobat can convert a DOS, Windows, UNIX or Macintosh document into a Portable Document Format (PDF) which can be displayed on any computer with an Acrobat reader. The Acrobat reader can be downloaded free from the Internet.

acronym
A word formed from some of the letters (usually the initials) of a phrase, such as RAM (Random-Access Memory). Computer terminology is rich in acronyms.

ACS
Advanced Communications Services.

ACSE
Association Control Service Element. OSI technology used to establish connections between applications.

action statement
An executable command that causes the computer to perform an action.

active cell
The cell in a spreadsheet in which numbers or formulas can be entered. The active cell shows a thick border, and its name is at the top of the screen; also called the current cell.

active component
A device that adds intelligence to a signal or data that passes through it, as opposed to passively permitting its passage without affecting the data in any manner.

Active Desktop
Microsoft's integration of Windows desktop for Windows 95/98 and Windows NT with Microsoft's Internet Explorer Web browser (4.0 and later) where users can access local and remote information from a single location.

Active Directory
The component of Microsoft's Active Platform that acts as an advanced directory service for distributed computing environments. The Active Directory presents applications with a single, simplified set of interfaces so that users can locate and utilize directory resources from a variety of networks while bypassing differences among proprietary services.

active hub
A central device to which other devices connect, and which not only forwards signals, but also amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance. An active hub is also called a repeater. See also passive hub, intelligent hub.

active matrix display
LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.

Active Matrix Liquid Crystal Display
(AMLCD). LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.

Active Server Page
(ASP). A specification for a Web page that is dynamically created by the Web server and contains both HTML and scripting code. With ASP, programs can be run on a Web server in a similar way to CGI scripts, but ASP uses uses the ActiveX scripting engine to support either VBScript or JScript. When a user requests data from an Active Server Page, the ActiveX server engine reads through the file, sends the HTML back to the browser and executes the script. Active Server Pages were first available on the Microsoft Internet Information Server (IIS) 3.0. They have the .ASP filename extension.

active star
Variant of active hub. An active star is the central connecting device that retransmits and regenerates all signals.

active window
In a graphical user interface, the window in current use, which appears in front of any other open windows on the screen.

active-matrix
A liquid crystal display (LCD) technology used to produce high-quality flat panel color displays, often used in laptop and notebook computers. Active matrix displays use one thin film transistor (TFT) per cell, producing brighter and sharper diplays viewable from wider angles than those produced by passive matrix displays.

ActiveMovie
A Microsoft video application programming interface providing online and desktop multimedia tools.

ActiveX
ActiveX is a model for writing programs so that other programs and the operating system can call them. ActiveX technology is used with Microsoft Internet Explorer to make interactive Web pages that look and behave like computer programs, rather than static pages. With ActiveX, users can ask or answer questions, use push buttons, and interact in other ways with the Web page. ActiveX controls are often written using Visual Basic.

ActiveX automation
A set of technologies developed by Microsoft in the 1990s and built on Microsoft's Component Object Model (COM), ActiveX exposes internal functions of a software application as COM objects so that certain tasks can be "automated" that are normally selected from menus.

ACTOR
An object-oriented programming language for Microsoft Windows written by Charles Duff of The Whitewater Group Inc., Evanston, IL. It has a Pascal/C-like syntax.

AD
Administrative Domain. Defined in RFC 1136. On the Internet, a group of networks, hosts, and routers operated by the same organization.

ad click
A user’s click on an ad banner. Some ads are paid by the number of user clicks they receive.

ad click rate
The percentage of ad views that result in a user clicking on the ad.

ad view
The downloading of a WWW ad banner which is presumably seen by the user. The number of ad views corresponds to the number of ad impressions in other media. If the same ad appears on more than one page at once, the full number of ad views may not be counted because of browser caching. Also, there is no reliable way to know whether the ad was fully downloaded and seen by the user.

Ada
A high-level, Pascal-based programming language designed in 1979 for the U.S. Department of Defense. Ada was named after Augusta Ada Byron, Countess of Lovelace. It was designed to enable computers to control automatic equipment, but is also used for other applications.

ADABAS
A relational database system from Software AG, used for IBM mainframes, UNIX, VAX, and OS/2.

ADAPSO
Now the ITAA (Information Technology Association of America, Arlington, VA, www.itaa.org), the former Association of Data Processing Service Organizations was formed in the 1960s.

adapter
A part that connects two devices or systems, physically or electrically, and enables them to work together. It can be a plug that allows two wires to be connected, for example, or a printed circuit board that modifies the computer so it can work with certain hardware or software.

Adaptiv Workforce
An application from Adaptiv Software which helps employers manage information about employees, shifts, and pay schedules, and build labor forecasts.

adaptive bridge
A network bridge programmed to remember destination addresses so that subsequent data will be routed more efficiently

adaptive compression
A technique where the compression algorithm used in the compression of data is chosen based on the characteristics of the data. Adaptive compression chooses the algorithm that offers optimal compression and the fastest transmission speed.

adaptive differential pulse code modulat
(ADPCM). A technique of translating analog sound into digital format that takes less computer memory than the regular pulse code modulation used by audio CDs. It is used on the Sony minidisk, and for CD-ROMs which have images and other data as well as sound. ADPCM takes rapid samples of sound and translates them into binary code, but instead of coding an absolute measurement at every sample point, it codes the difference between samples. ADPCM is used for long-distance telephone lines and outer-space communications because it eliminates errors in transmission.

Adaptive equalization
Adaptive equalization enables two modems to adjust the speed and modulation method of data transfer automatically based on the quality of the phone connection, increasing speed in optimal conditions and slowing down in high-risk situations.

Adaptive routing
The feature in a network software that allows the network to choose the best available path for data transfer.

adaptive suspension vehicle
(ASV). An advanced walking robot that is 16 feet long, 10 feet high, and weighs 6,000 pounds. The ASV has six legs and can sprint at eight miles per hour and step over a four-foot wall.

ADB
The Apple Desktop Bus is a serial communications pathway built in to all pre-G4 Apple Macintosh computers (except the iMac and the iBook) that permits communication between low-speed input devices like the keyboard, mouse, trackball and graphics tablet and the computer. The ADB can connect up to 16 input devices simultaneously.

ADC
Analog-to-Digital-Converter. A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.

ADCCP
Advanced Data Communications Control Procedure. A communications protocol used by the American National Standards Institute.

ADDMD
Administrative Directory Management Domain. A directory management domain that uses the X.500protocol, run by a Postal, Telegraph, and Telephone authority.

address
1. The identifying location of a device or an area of storage; for example, a memory register, disk sector, or network node. 2. To identify with an address.

address bus
Connections between the central processing unit (CPU) and memory which transmit the address from which the CPU will read, or to which the CPU will write. (The data is transmitted via the data bus.) The amount of memory the CPU can address is determined by the number of bits in the address bus.

address mask
A pattern of characters, 32 bits long, used to select some of the bits from an

address resolution
Translation of an Internet address into its physical address (MAC or Ethernet address), which is the actual number of the machine. This address is usually found using Address Resolution Protocol.

Address Resolution Protocol
(ARP). The Internet protocol which maps IP (Internet Protocol) addresses to physical addresses on local area networks so that packets can be transmitted. It is defined in RFC 826. An ARP request is broadcast onto the network for a particular IP address, and the node with that address replies with its physical address.

address space
1. The address space of a computer or processor is the range of addresses it can access, including physical memory and virtual memory. 2. The address space of a program or process is the range of memory it uses while running, including physical memory, virtual memory, or both.

ADLC
Asynchronous Data Link Control. See asynchronous transmission.

ADMD
Administration Management Domain or Administrative Management Domain. A public email message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.

admin
System administrator. The person in charge of a multiuser computer system, also called sys admin. The system administrator designs the system and manages its use.

Administration Management Domain
(ADMD). A public e-mail message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.

Administrative Directory Management Doma
(ADDMD). A directory management domain that uses the X.500 protocol, run by a PTT (Postal, Telegraph, and Telephone) authority.

administrative domain
(AD). Defined in RFC 1136. On the Internet, a group of networks, hosts, and routers operated by the same organization.

Administrative Management Domain
(ADMD). A public e-mail message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.

administrator
An administrator performs the service of maintaining a network resource, including registering users and user passwords.

Adobe Acrobat
Document exchange software from Adobe Systems, Inc. Acrobat provides a platform-independent means of creating, viewing, and printing documents. Acrobat can convert a DOS, Windows, UNIX or Macintosh document into a Portable Document Format (PDF) which can be displayed on any computer with an Acrobat reader. The Acrobat reader can be downloaded free from the Internet.

Adobe Illustrator
A draw program for Macintosh and Windows. It is especially useful for technical drawing.

Adobe Systems, Inc.
The creators of PostScript fonts, Adobe Acrobat, PDFs, Adobe PhotoShop, and Adobe Type Manager; a pioneering company in desktop publishing software. Adobe's Web site is at www.adobe.com.

Adobe Type Align
A program from Adobe Systems that can be used to align type with selected shapes for special effects; for example, making text curve around a semicircle.

Adobe Type Manager
(ATM). A font utility for Macintosh and Windows that enables a computer to print PostScript fonts and show PostScript screen fonts.

ADP
Automatic Data Processing. The processing of information by means of a computer.

ADPCM
Adaptive Differential Pulse Code Modulation. A technique of translating analog sound into digital format that takes less computer memory than the regular pulse code modulation used by audio CDs. It is used on the Sony minidisk, and for CD-ROMs which have images and other data as well as sound. ADPCM takes rapid samples of sound and translates them into binary code, but instead of coding an absolute measurement at every sample point, it codes the difference between samples. ADPCM is used for long-distance telephone lines and outer-space communications because it eliminates errors in transmission. Also called Adaptive Digital Pulse Code Modulation.

ADSL
Asymmetric Digital Subscriber Line, or Asymmetric Digital Subscriber Loop. A digital subscriber line (DSL) technology in which the transmission of data from server to client is much faster than the transmission from client to server. Whereas with HDSL (High-Speed Digital Subscriber Line), transmission is 784 kilobits per second in both directions, with ADSL, the rate from client to server is 640 kilobits per second and from server to client can be up to 6 megabits per second. This kind of connection is useful with applications such as interactive TV and Video on Demand, because the data the server sends is much more than the data sent by the client. ADSL uses bandwidth that is not used by voice; therefore voice and data can be transmitted at the same time.

Advanced Configuration and Power Interfa
(ACPI). A power management specification that replaces APM in Windows machines. Developed by Intel, Microsoft, and Toshiba, ACPI gives the operating system the ability to control the amount of power given to each peripheral device, and to turn off devices when not in use.

Advanced Interactive eXecutive
(AIX). IBM's version of UNIX.

Advanced Memory Management Architecture
(AMMA) Strategies for providing sufficient memory to all the processes in a computer system, performed by the memory management unit (MMU).

Advanced Micro Devices, Inc.
(AMD). A U.S. manufacturer of integrated circuits, microprocessors, memory, and other computer products.

Advanced Mobile Phone Service
(AMPS). A standard for analog cellular phone service used in the United States and other countries.

Advanced Peer-to-Peer Networking
(APPN). IBM data communications support that routes data between APPC systems to enable users anywhere on the network to have direct communication with each other.

Advanced Power Management
(APM) A feature from Intel and Microsoft for battery-powered computers, which powers-down or the display when the computer has been inactive for a certain length of time in order to conserve power. Monitors with this energy-saving capability are called "green monitors".

Advanced Program-to-Program Communicatio
(APPC). An IBM communications protocol that allows shared processing of programs on a network.

Advanced Research Projects Agency
(ARPA) An agency of the U.S. Department of Defense that developed technology for the military. ARPANET, which was one of its projects, grew into the Internet.

Advanced Research Projects Agency Networ
(ARPANET). A wide area network developed in the 1960s by the Advanced Research Projects Agency of the U.S. Department of Defense, that linked government sites, academic research sites, and industrial sites around the world. Later, the military communications part split off and was named MILNET. ARPANET was the testing ground and original backbone of the Internet.

Advanced RISC Machine
(ARM). One of a number of 32-bit RISC microprocessors for computing, games, multimedia, and many other uses. They are energy-efficient and economical.

Advanced SCSI Programming Interface
(ASPI). An interface from Adaptec that allows application programs to access SCSI hardware.

Advanced Technology Attachment
(ATA). The specification for IDE interface.

Advanced Technology Attachment Packet In
(ATAPI). An interface used to connect CD-ROMs, tape drives, and optical disks with the computer.

Advanced WavEffects
1. (AWE). A series of sound cards from Creative Labs that includes the Sound Blaster AWE 32, the Sound Blaster AWE64, and the AWE64 Gold. The AWE64 can play in 64 voices at the same time using Wave-Table synthesis, and has Plug and Play installation. 2. The engine used with the AWE sound cards.

Advent
(Adventure). One of the first text-based adventure games, which was a model for many games to follow. The name Adventure was shortened to Advent because the computer only allowed 6-letter file names.

Adventure
(Same as Advent). One of the first text-based adventure games, which was a model for many games to follow. The name Adventure was shortened to Advent because the computer only allowed 6-letter file names.

AFC
Automatic Frequency Control.

AFE
Apple File Exchange. In a Macintosh operating system, the AFE utility program allows the Mac to read and record data files from a floppy disk formatted for use on a PC.

AFP
AppleTalk Filing Protocol. An AppleTalk client/server protocol.

After Dark
A screen saver program for from Berkeley Systems, Inc., that allows users to create custom animations. There are versions for Macintosh and PC. Two of the best-known After Dark screen savers are the flying toasters and flying toilet seats.

AFUU
Association Francaise des Utilisateurs d'Unix. The French Association of Unix Users.

AFY2KDB
Air Force Year 2000 Database. A centralized database on Year 2000 matters maintained at Scott Air Force Base by INET.

agent
A software program that performs a service, such as alerting the user of something that needs to be done on a certain day; or monitoring incoming data and giving an alert when a message has arrived; or searching for information on electronic networks. An intelligent agent is enabled make decisions about information it finds.

aggregation
A computer security violation which is accomplished by collecting nonprivileged data and using it to extrapolate privileged data.

AGP
Accelerated Graphics Port. A bus specification from Intel that gives graphics cards faster access to

AI
Artificial Intelligence. Intelligence that mimics human intelligence, when exhibited by devices and applications such as robots or computers with voice recognition and language processing ability. This human-like intelligence implies the ability to learn or adapt through experience.

AIC
AIXwindows Interface Composer (IBM).

AIFF
(Audio Interchange File Format) A format developed by Apple Computer for storing high-quality sampled audio and musical instrument information. It can be played on PC and Mac, and is used by some professional audio software packages.

AIM
AOL Instant Messenger. The instant messaging program of America Online.

Aimnet
An Internet access provider in Cupertino, CA, U.S.A.

Air Force Year 2000 Database
(AFY2KDB). A centralized database on Year 2000 matters maintained at Scott Air Force Base by INET.

AIX
Advanced Interactive eXecutive. IBM's version of UNIX.

AL
Assembly Language. The language in between machine language and high-level programming languages.

Al-Khawarizmi
Muhammad ibn Musa Al-Khawarizmi (ca. 780 - ca. 850), a Persian mathematician who introduced Arabic numerals and decimal calculation to the west. The word "algorithm" is derived from his name.

Aladdin Systems
The developers of Stuffit, the file compression utility for Macintosh.

alarm filtering
The ability of a network management system to precisely identify the device that has failed.

Aldus
Creator of the PageMaker page layout program for Macintosh, a milestone in desktop publishing; now part of Adobe Systems.

Aldus Pagemaker
The first desktop publishing program, originally designed for Macintosh, now also available for PC.

Aldus Persuasion
A desktop presentation program for Mac from Adobe Systems, Inc.

alert
A signal from the computer that something requires the user's attention. It may be an error message or warning, and is often indicated with an alert box, a sound, or flashing words or images.

alert box
A box that pops up on the computer screen, often with a beep or other sound, to give a warning or error message. The user must hit the return key or click to acknowledge the message before continuing.

Alexa
A free Web browser enhancement linked to a database of over 400 million Web page archives. When Web surfers attempt to load a page that no longer exists they can simply choose the Alexa button on their toolbar and Alexa will attempt to retrieve the page from their archives.

algebra
A system of mathematics or logic in which abstract entities are represented in symbolic form and used in operations similar to arithmetic.

algebraic expression
An expression which uses symbols to represent numbers or abstract concepts for use in operations similar to arithmetic.

ALGOL
ALGOrithmic Language. A high-level compiler language for scientific computations. Two versions were developed: ALGOL 60, developed by an international committee in 1960; and ALGOL-68, a more complicated version released in 1968. ALGOL was the inspiration for Pascal.

algorithm
A detailed, ordered set of instructions for solving a problem. Named after Al-Khawarizmi, an Iranian mathematician. This term is used in computer programming to refer to instructions given to the computer.

ALGOrithmic Language
(ALGOL). A high-level compiler language for scientific computations. Two versions were developed: ALGOL 60, developed by an international committee in 1960; and ALGOL-68, a more complicated version released in 1968. ALGOL was the inspiration for Pascal.

alias
1. An abbreviation for an e-mail address that, when keyed in, sends the message to the complete address. 2. An alternate label for identifying an object, such as a file or data field. 3. A false signal created in the digitization of an analog audio sample.

aliasing
In computer graphics, the stairstepped appearance of diagonal or curved lines. Aliasing also refers to false frequencies in digitized sound.

alignment
Where text or other graphic elements are placed on the page in relation to other elements or the margins. For example, right-aligned text lines up with the right margin.

all-stations address
An address (such as 11111111) which will send a message to all stations on a network.

ALM
Assembly Language for Multics (Multiplexed Information and Computing Service). An early (1969) timesharing operating system, developed by MIT, GE, and Bell Laboratories, and introducing many new operating system features.

ALOHA
A transmission system developed at the University of Hawaii using time division multiple access (TDMA) technology. It has been used for satellite and terrestrial radio links. A packet is broadcast when ready, and if a collision occurs it is retransmitted. A variation called Slotted ALOHA sends packets at specific time slots to reduce the number of collisions.

Aloha Net
One of the first computer networks in the U.S.A., at the University of Hawaii, Manoa. It was initiated in the early 1970s, and used key punch cards and sent commercial telephone lines.

Alpha
A family of 64-bit RISC-based microprocessors from Digital, used with the Alpha AXP and other computer systems.

Alpha Processor
This is a RISC processor that was created by the Digital Equipment Corporation for their line of workstations and servers. These processors are the only microprocessors that run Windows NT outside of the traditional x86 microprocessors.

alpha testing
Testing new software in the factory by either the manufacturer's staff or outsiders. The next stage is beta testing, which is done by actual users in the kind of environment in which the software will be used.

alphanumeric
Using alphabetic letters, numbers, and special characters.

alphanumeric display
A display, usually a LCD, that shows alphabet characters and numbers.

alt
Top-level newsgroup category for a newsgroup with alternative discussions. Some of the topics are practical, some humorous, some bizarre. This category of newsgroup was created to avoid the bureaucratic process of forming a certified newsgroup.

alt key
The Alt key on a computer keyboard gives alternate meanings to other keys, thus expanding the keyboard's capability. The Alt key is held down like a Shift key, and another key is pressed.

Altair
An early microcomputer for hobbyists, sometimes called the world's first microcomputer.

AltaVista
A World Wide Web site hosted by Digital with a very fast Web and Usenet search engine, and one of the largest Web indexes. AltaVista can be found on the web at www.altavista.com.

alternate routing
Using another transmission channel when the regular channel is busy.

alternating current
(AC). An electric current that reverses its direction at regular intervals. See direct current.

ALU
1. Arithmetic & Logic Unit. The part of a computer's central processing unit which performs arithmetic operations on integers, and Boolean operations. Floating-point operations are handled by a separate floating-point unit. 2. (Association of Lisp Users). An international user group for the Lisp programming language.

AM
Amplitude Modulation. Blending a signal into a carrier wave by varying the amplitude of the carrier; also a broadcasting system that uses this kind of modulation.

AMD
1. Active Matrix Display. LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display. 2. Advanced Micro Devices, Inc., A U.S. manufacturer of integrated circuits, microprocessors, memory, and other computer products.

Amdahl Corporation
A Sunnyvale, California computer company founded by Gene Amdahl. Amdahl Corporation products include IBM-compatible mainframes, UNIX servers, applications development software, and other products and services.

Amdahl, Gene
Founder of Amdahl Corporation, later involved with Trilogy, and Andor Corporation.

America Online
(AOL). One of the largest providers of online services. AOL >www.aol.com

American National Standards Institute
(ANSI). An organization that develops standards for many things, only some having to do with computers, such as properties of diskettes, programming languages, etc. ANSI is the U.S. member of the

American Standard Code for Information I
(ASCII). A code in which each alphanumeric character is represented as a number from 0 to 127, translated into a 7-bit binary code for the computer. ASCII is used by most microcomputers and printers, and because of this, text-only files can be transferred easily between different kinds of computers. ASCII code also includes characters to indicate backspace, carriage return, etc., but does not include accents and special letters not used in English. Extended ASCII has additional characters (128-255).

American Telephone and Telegraph, Inc.
(AT&T). One of the largest corporations and telecommunications carriers in the United States. AT&T has been incorporated since 1885, and has provided telephone service throughout the United States and in other countries. AT&T was parent company of the Bell System of telephone companies, a monopoly which was dissolved in 1984 by a Federal court order. AT&T continues to be a competitive long distance telephone carrier. AT&T has been credited with breakthroughs in technology, including the UNIX operating system and the C and C++ programming languages. At&T can be found online at www.att.com.

Ami Pro
A word processing program developed by Samna Corporation for DOS and Windows. It was later bought by Lotus, and has been replaced by Word Pro.

Amiga
A group of home computers developed by Commodore Business Machines. Amigas have a graphical user interface and are used for games, video processing, multimedia, office applications, and desktop publishing. The German company Escom AG bought Commodore in April 1995.

Amiga-DOS
Amiga Disk Operating System. See Amiga and Disk Operating System.

AML
Astronomical Markup Language. A standardized format for exchange of metadata related to astronomy. This language will enhance the ability of astronomers to retrieve scientific data, and make it possible for humans and intelligent agents to use the same information. Humans can view AML documents by means of a Java AML browser; intelligent agents can use an Extensible Markup Language (XML) parser.

AMLCD
Active Matrix Liquid Crystal Display. LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.

AMMA
Advanced Memory Management Architecture. Strategies for providing sufficient memory to all the processes in a computer system, performed by the memory management unit.

Ampere
The basic unit of electric current in a circuit. A charge of one coulomb passing a point in one second.

ampersand
ASCII character 38: & "and". Sometimes called pretzel.

amplitude
The maximum value of a quantity that varies periodically, such as an alternating current or wave.

amplitude modulation
(AM). Blending a signal into a carrier wave by varying the amplitude of the carrier; also a broadcasting system that uses this kind of modulation.

AMPS
1. Analog Mobile Phone System. Non-digital cellular mobile phones. 2. Advanced Mobile Phone Service (Motorola).

analog
Representing data in continuously variable physical quantities, in contrast to the digital representation of data in discrete units (the binary digits 1 and 0). Analog systems handle information which is represented by continuous change and flow, such as voltage or current. Analog devices have dials and sliding mechanisms. Digital information, in contrast, is either on or off. An analog is a representation of a pattern by a similar pattern; for example, an analog clock represents the sun circling around the earth. An analog device converts a pattern such as light, temperature, or sound into an analogous pattern. An example is a video recorder, which converts light and sound patterns into electrical signals with the same patterns. An analog signal such as a sound wave is converted to digital by sampling at regular intervals; the more frequent the samples and the more data recorded, the more closely the digital representation resembles the analog signal. Converting analog signals into digital makes it possible to preserve the data indefinitely and make many copies without deterioration of quality.

analog channel
A voice or video communication channel which carries a signal with varying frequencies. Compare digital channel.

analog computer
A computer that uses analog methods to process data. An analog computer operates with numbers represented by directly measurable quantities (such as temperature changes or voltages) which vary continuously, whereas a digital computer works with signals which are either on or off (binary 0 or 1). All ordinary computers are digital; analog computers are employed for special uses, such as robotics, where an experimental design can be tested in real time.

analog-to-digital converter
(ADC). A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.

Analytical Engine
A computing machine conceived in 1830 by Charles Babbage. He received inspiration from his work on the "Difference Engine." The Analytical Engine was never completed, though Babbage worked on it until his death in 1871. It was intended to compute decisions based on prior computations and loops founded on Jacquard's punched cards. Babbage is often credited as being "the father of computers" for his work on the Analytical Engine.

Anarchie
A shareware application from Stairways Software which provides fast FTP (file transfer protocol) and Web connections.

AND
One of three logical operations of Boolean logic. The AND operation is true when the combining of two bits (0,1) or two Boolean values (false or true) is such that both inputs are true. See also Boolean algebra, Boolean operators, OR and NOT.

AND gate
A Boolean logic gate used in computer arithmetic. The AND gate has an output of 1 only if all of its inputs are 1. See also Boolean algebra, Boolean operations, and AND.

ANDF
Architecture Neutral Distributed Format. An intermediate language created by The Open Group to use in developing

angle brackets
The Keyboard symbols . Angle brackets are commonly used to enclose HTML tags and other codes.

angstrom
One 10-billionth of a meter. See also A.

ANI
Automatic Number Identification. A service that identifies the telephone number of each incoming telephone call.

animated graphic
An animated image produced by means of a series of computer graphic images; for example, a moving cartoon or diagram. Animated graphics add interest to a presentation, and use much less disk space than video images.

anisochronous transmission
A way of transmitting data in which there is always a whole number of unit intervals between any two significant instants in the same block or character, but not between significant instants in different blocks or characters. See isochronous transmission.

anisotropic
Not isotropic; having properties that vary depending on the direction of measurement. An example would be a transmission speed that is faster in one direction than another.

ANN
Artificial Neural Network. A network of many simple processors that imitates a biological neural network. Neural networks have some ability to "learn" from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting.

annoybot
An Internet Relay Chat (IRC) bot whose sole function is to send silly or annoying messages.

Anonymizer
A service offered by Infonex, Inc. that allows user to surf the Web anonymously. www.anonymizer.com.

anonymous FTP
A way of getting files from FTP sites on the Internet that have files available for public download. To transfer files using anonymous FTP, you must log in as "guest" or "anonymous" and enter your e-mail address as the password. Many of these sites are provided by universities and government agencies. The publicly available files are usually in a directory called "pub", which is isolated from the files used by other users on the system and will not accept uploads from anonymous users.

anonymous login
A login using "anonymous" for the user name and any text for the password.

ANSI
American National Standards Institute. An organization that develops standards for many things, only some having to do with computers, such as properties of diskettes, programming languages, etc. ANSI is the U.S. member of the International Standards Organization (ISO) and the International Electrotechnical Commission (IEC). ANSI standards are voluntary. ASCII is an ANSI character set.

ANSI character set
The ANSI (American National Standards Institute) extended character set used with

ANSI terminal
A display terminal which follows ANSI (American National Standards Institute) standard terminal language commands.

anthrobotics
The study and development of of human-like robots.

anti-aliasing
Smoothing the jaggies in a bitmapped image. When diagonal or curved lines are put in bitmapped form, these shapes must be made with square pixels; any lines that are not vertical or horizontal have a stair-stepped appearance. Anti-aliasing changes the pixels along the edges of the line into varying shades of gray or in-between color, in order to make the edge appear smoother. In a black-on-white image, for example, the shade of gray used is determined by how much of the in-between pixel overlaps the black area and how much overlaps the white area.

antiglare screen
A screen that is attached to the front of a computer monitor to reduce glare, thus easing strain on the user's eyes. Contrast with antiglare treatment.

antiglare treatment
A treatment of the glass of a monitor which reduces reflected glare by absorbing or diffusing light. Some methods which have been used are a silica-based coating, optical lenses, and mechanical etching. Many users prefer an antiglare screen attached to the front of the computer instead of antiglare treatment.

antivirus program
A program that detects and removes computer viruses.

antivirus software
A program that will detect and remove computer viruses.

Anyware Software, Inc.
A Los Angeles, California company that develops computer security and antivirus products for DOS and Windows.

AOCE
Apple Open Collaboration Environment. Macintosh System 7 extensions that make it possible to share e-mail, directory, and other services in a multiplatform environment.

AOE
Application Operating Environment (AT&T).

AOL
Acronym for America Online >www.aol.com

AOL Instant Messenger
(AIM). The instant messaging program of America Online.

aol.com
The Internet domain address for America Online.

AOW
Asia and Oceania Workshop. One of three regional OSI Implementors Workshops. See OIW and EWOS.

APA
1. Adaptive Packet Assembly 2. Application Portability Architecture. DEC portable applications software.

Apache
The Apache Project is a collaborative software development effort aimed at creating a robust, commercial-grade, featureful, and freely-available source code implementation of an HTTP (Web) server. The project is jointly managed by a group of volunteers located around the world, using the Internet and the Web to communicate, plan, and develop the server and its related documentation. These volunteers are known as the Apache Group. In addition, hundreds of users have contributed ideas, code, and documentation to the project.

APCUG
Association of Personal Computer User Groups. A nonprofit organization dedicated to encouraging communication among different user groups, and between user groups and vendors.

API
Application Program Interface. An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.

APL
A Programming Language. A programming language for notating mathematical algorithms, developed by Ken Iverson at Harvard University.

APM
Advanced Power Management. A feature from Intel and Microsoft for battery-powered computers, which powers-down or the display when the computer has been inactive for a certain length of time in order to conserve power. Monitors with this energy-saving capability are called "green monitors".

Apollo Computer, Inc.
A maker of high-performance workstations, and a pioneer in workstation networking. It became a division of HP in 1989.

apostrophe
ASCII character 39: ' . Also called single quote.

app
Abbreviation for application program.

APPC
Advanced Program to Program Communications. An IBM communications protocol that allows shared processing of programs on a network.

Apple Computer, Inc.
One of the largest personal computer manufacturers, located in Cupertino, California. The company was founded by Steve Jobs and Steve Wozniak, in a garage. The Apple II, released in 1977, became very popular for educational use. VisiCalc, the first computer spreadsheet, was designed for the Apple II. Another computer in the Apple line was the Lisa, introduced in 1983. In 1984, Apple released the first Macintosh computers. The graphical user interface and mouse of the Macintosh revolutionized personal computing, and Macintosh quickly became popular for desktop publishing. In the 1990s, Apple Computer, IBM, and Motorola began working together to develop compatible products, and in 1994, the PowerMac came out. Based on the PowerPC microprocessor, it can run both Macintosh, DOS, and Windows applications. Other Apple products are the PowerBook laptops and the Newton personal digital assistant. Apple can be found on the Web at

Apple Desktop Bus
(ADB). Port on the Macintosh for a keyboard, a mouse, and other peripherals.

Apple II
An 8-bit microcomputer introduced by Apple Computer in 1977 that became very popular for school and home use. The first personal computer spreadsheet, VisiCalc, was developed for the Apple II. Invented by Steve Wozniak, the Apple II originally had a 6502 processor and 4K RAM.

Apple II+
An improved Apple II introduced in 1979, with 48K of RAM and a screen resolution of 280x192x6.

Apple IIc
A portable Apple II released in 1984, the same year the Macintosh made its first appearance. See also Apple.

Apple IIe
An enhanced version of Apple II released in 1983, with 128K RAM.

Apple IIGS
An Apple II with enhanced graphics and sound, released in 1986. It had a 16-bit 65C816 CPU and 320x200x256 screen resolution.

Apple III
An Apple microcomputer introduced in 1980 for business use. It never became as popular as the Apple II.

Apple Mac
Apple Macintosh. A family of 32-bit personal computers introduced by Apple in 1984; the first widely used computers with a graphical user interface, a mouse, and windows. Rather than typing in commands, users open software and copy or delete files by clicking on icons on the screen that look like file folders, a trash can, and other things one would find in a real office. Macs quickly became popular because of their user-friendly interface. In 1994, PowerMacs, which use a PowerPC CPU, became available. The Macintosh Operating System is now called MacOS. Apple is located at http://www.apple.com.

Apple Macintosh
A family of 32-bit personal computers introduced by Apple in 1984; the first widely used computers with a graphical user interface, a mouse, and windows. Rather than typing in commands, users open software and copy or delete files by clicking on icons on the screen that look like file folders, a trash can, and other things one would find in a real office. Macs quickly became popular because of their user-friendly interface. In 1994, PowerMacs, which use a PowerPC CPU, became available. The Macintosh Operating System is now called MacOS.

Apple Newton
A personal digital assistant (PDA) made by Apple Computer.

Apple Open Collaboration Environment
(AOCE). Macintosh System 7 extensions that make it possible to share e-mail, directory, and other services in a multiplatform environment.

AppleScript
An object-oriented shell language and command-line interface for Macintosh, beginning with System 7 Pro.

AppleShare
File server software developed by Apple Computer, Inc. for Mac OS users that allows filesharing between Macintosh computers on the same network.

AppleSoft BASIC
A version of BASIC for Apple computers, originally installed with all Apple II models.

applet
A little application. An applet can be a utility or other simple program. On the World Wide Web, there are many applets written in Java language which are attached to HTML documents.

AppleTalk
A local area network protocol developed by Apple Computer for communication between Apple Computer products and other computers. There are implementations for LocalTalk, EtherTalk, and Token Ring networks. A PC can connect to an AppleTalk network using an adapter card; UNIX and 6025">VAX computers can also be set up to use AppleTalk.

AppleTalk Filing Protocol
(AFP). An AppleTalk client/server protocol.

application
A program that helps the user accomplish a specific task; for example, a word processing program, a spreadsheet program, or an FTP client. Application programs should be distinguished from system programs, which control the computer and run those application programs, and utilities, which are small assistance programs.

application binary interface
(ABI). A specification for the application programming interface (API) and machine language for a hardware platform. The PowerOpen Environment and Windows sockets are examples of ABIs.

Application Configuration Access Protoco
(ACAP) Formerly known as Internet Message Support Protocol (IMSP), ACAP is an e-mail protocol that allows access to related email servers such as mailboxes, addresses and bulletin boards. ACAP was initiated by the Internet Engineering Task Force (IETF), a standard-setting organization for the Internet. It was designed to complement Internet Message Access Protocol, a protocol for retrieving messages and searching for keywords within messages while they are still on the server.

application layer
Layer 7 of the Open Systems Interconnection (OSI) networking model, which defines standards for interaction at the user or application program level; for example, formatting electronic mail messages, reading and writing files, and file transfer. It is the highest layer of the protocol stack.

application program
A program that helps the user accomplish a specific task; for example, a word processing program, a spreadsheet program, or an FTP client. Application programs should be distinguished from system programs, which control the computer and run the application programs, and utilities, which are small assistance programs.

application program interface
Variant of Application Programming Interface (API). An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.

application programming interface
(API). An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.

application server
Software operating among browser-based computers, back-end databases, and business applications. Server applications assist in translating HTML commands so that databases can interpret them.

application sharing
A conferencing capability that allows two or more users work on the same application, at the same time.

application software
The programs that help the user accomplish tasks; for example, word processing programs, spreadsheet programs, or FTP clients. Application software is distinguished from the system software, which controls the computer and runs the application programs; and utilities, which are small assistance programs.

application suite
A set of individual, yet complimentary, applications presented to consumers as a comprehensive package. Microsoft Office and Windows Me are examples of application suites.

Application System/400
(AS/400). A family of IBM minicomputers designed primarily for business applications.

application viewing
A conferencing capability that lets two or more users view the same application at the same time, where only the user with the machine containing the application can edit the document. Contrast with application sharing.

application-specific integrated circuit.
(ASIC). A customized microchip which is designed for a specific application.

APPN
Advanced Peer to Peer Networking. IBM data communications support that routes data between Advanced Peer-to-Peer Communication (APPC) systems to enable users anywhere on the network to have direct communication with each other.

Aptiva
A family of home PCs from IBM, with home office software, Internet software, and multimedia features such as full-motion video, 3-D graphics, and surround-sound.

ARAG
AntiReflection AntiGlare. There are add-on screens for monitors that eliminate screen glare and protect the user’s eyes.

ARCA
Advanced RISC Computing Architecture. RISC--Reduced Instruction Set Computing--is a microprocessor design which is intended to make operations run faster by processing a few simple instructions rather than many complex ones. CISC--complex instruction set computing--processors do more of the processing of complex operations within the CPU than RISC processors, which require certain operations to be performed by the software before the data gets to the CPU. The operating system must be set up for RISC, and the applications used must be compiled specifically for RISC architecture, otherwise the RISC processor must emulate a CISC processor, and the benefits of RISC are lost. Examples of computers with RISC architecture are the IBM RISC Sytem/6000, the PowerPC, and the PowerMac.

Archie
(ARCHIvE). An Internet utility used for locating files that are accessible by anonymous FTP.

Archimedes
A series of personal computers from Acorn Computers, Cambridge, UK; the first personal computers to use RISC architecture.

architecture
The design of a computer, software, or network.

Architecture Neutral Distributed Format
(ANDF). An intermediate language created by The Open Group to use in developing UNIX software.

archival backup
1. A routine that makes it possible to back up only the files that have changed since the last backup, instead of backing up every file. Archival backup saves time and storage space. 2. A backup that will be stored for a long time.

archival finding aids
Metadata tools such as indexes, guides, and inventories; these tools are often used by libraries, museums, and other institutions.

archive
1. To transfer files off the computer into long-term storage. Archived files are often compressed to save space. 2. A file that has been archived. 3. A group of files which must be extracted and decompressed in order to use them; software to be installed sometimes comes in this format. 4. A file stored on a computer network, which can be retrieved by FTP or other means.

archive site
A computer where stored files are available for download via the Internet. Archive sites may be accessed by anonymous FTP, Gopher, World Wide Web, or other services.

ARCMac
A Macintosh utility for decompressing files that have the .arc extension. Usually these are from older operating systems.

ARCNET
(Attached Resource Computer Network). A local area network (LAN) introduced in 1968 by Datapoint Corporation. It can connect up to 255 nodes in a star topology, using twisted pair or coaxial cable. ARCNET is a data link protocol and uses the token passing access method.

ARDIS
Originally the Advanced National Radio Data Service www.ardis.com, ARDIS started out as a joint venture between Motorola and IBM to provide wireless data transmission in the 800 MHz FM Band. The first wireless data network in the U.S., ARDIS was acquired by Motient in 1998, the first and largest two-way wireless data network with satellite communication in the U.S.

area code
A three digit telephone number prefix which indicates a specific calling area.

arg
Argument. A value that is passed to a program, subroutine, procedure, or function by the calling program; one of the independent variables that determine the output.

argument
A value that is passed to a program, subroutine, procedure, or function by the calling program; one of the independent variables that determine the output.

Argus Clearinghouse
See The Argus Clearinghouse.

ARIN
American Registry for Internet Numbers www.arin.net. A non-profit organization founded in 1997, ARIN handles the registration and dispensation of Internet Protocal addresses in North and South America. Its European and Asian counterparts are Researux IP Europeens (RIPE) and Asian Pacific Network Information Center (APNIC).

arithmetic logic unit
(ALU). The part of a computer's central processing unit which performs arithmetic operations on integers, and Boolean operations. Floating-point operations are handled by a separate floating-point unit.

ARM
Advanced RISC Machine. One of a number of 32-bit RISC microprocessors for computing, games, multimedia, and many other uses. They are energy-efficient and economical.

ARP
Address Resolution Protocol. A method for finding a host's Ethernet address from its Internet address. An ARP request is sent to the network, naming the IP address; then the machine with that IP address returns its physical address so it can receive the transmission.

ARPA
Advanced Research Projects Agency. An agency of the U.S. Department of Defense that developed technology for the military. ARPANET, which was one of its projects, grew into the Internet.

ARPANET
Advanced Research Projects Agency Network. A Wide Area Network (WAN) developed in the 1960s by the Advanced Research Projects Agency of the U.S. Department of Defense, that linked government sites, academic research sites, and industrial sites around the world. Later, the military communications part split off and was named MILNET. ARPANET was the testing ground and original backbone of the Internet.

ARQ
Automatic Repeat Request. A modem status signal indicated by a light on the modem; in cases of transmissions errors, the ARQ is a request to the sender to retransmit.

array
An ordered arrangement of data elements in one or more dimensions: a list, a table, or a multidimensional arrangement of items. A vector is a one-dimensional array; a matrix is a two-dimensional array. Multidimensional arrays are used to store tables of data, especially in scientific simulation and mathematical processing. Data items in an array are distinguished by subscripts.

arrow keys
The keys on the keyboard that have arrows on them: up arrow, right arrow, left arrow, down arrow. They are used to move the cursor in the indicated directions, and have other uses in combination with other keys.

article
1. A news, magazine, or e-zine story. 2. A contribution to a Usenet discussion group, which can be sent by e-mail.

artificial intelligence
(AI). Intelligence that mimics human intelligence, when exhibited by devices and applications such as robots or computers with voice recognition and language processing ability. This human-like intelligence implies the ability to learn or adapt through experience.

artificial life
The study of synthetic systems to see in what way they behave like natural living systems. Artificla computer-generated systems are used to model the behavior of biological systems, including possible long-range outcomes of environmental changes. Some fields this study has been applied to are evolution, robotics, and engineering.

artificial neural network
(ANN). A network of many simple processors that imitates a biological neural network. Neural networks have some ability to "learn" from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting.

artificial reality
Same as virtual reality. A computer simulation of reality, using 3D graphics and sound effects, with user interfaces such as special goggles and gloves, to create a lifelike environment for entertainment, experimentation, and training.

Artisoft, Inc.
Providers of the LANtastic networking products.

ARTS
Asynchronous Remote Takeover Server.

ARTT
Asynchronous Remote Takeover Terminal.

AS/400
Application System/400. A family of IBM minicomputers designed primarily for business applications.

AS3AP
ANSI SQL Standard Scalable And Portable.

AS400
See AS/400.

ascender
The part of a lowercase character that rises above the main body of the character. Lowercase d, b, and h have ascenders; u, m, and n do not.

ASCII
American Standard Code for Information Interchange. A code in which each alphanumeric character is represented as a number from 0 to 127, translated into a 7-bit binary code for the computer. ASCII is used by most microcomputers and printers, and because of this, text-only files can be transferred easily between different kinds of computers. ASCII code also includes characters to indicate backspace, carriage return, etc., but does not include accents and special letters not used in English. Extended ASCII has additional characters (128-255).

ASCII art
The drawing of pictures and designs on a computer, using only ASCII characters. ASCII art appears a lot in text-based media, where other graphic images cannot be shown. Many e-mail signatures include an ASCII art image.

ASCII characters
American Standard Code for Information Interchange characters. ASCII is a 7-bit binary code for 128 characters, which include alphanumeric characters, punctuation marks, and control codes such as the end of line character. ASCII is the built-in character set in most minicomputers and all personal computers. Together with the original 128 characters, 128 more characters can be added for an extended set of 256 characters. The second 128 characters are usually foreign language accents, math or graphics symbols, and other special symbols, but are not the same on all computers; DOS and Windows have different standard sets, and the Macintosh allows users to define the second 128 characters. Other character sets include extended ASCII, ANSI, EBCDIC, and Unicode.

ASCII file
American Standard Code for Information Interchange file. A file whose data is in ASCII characters. An ASCII file does not include formatting such as bold, italic, centered text, etc. Each byte in the file is one ASCII character, represented as a number; for example, capital H is ASCII 72. Some ASCII files contain program source code, scripts, or macros written as text. ASCII files are useful in transferring text between files of different formats that can't be imported into each other. An ASCII file can be created with a text editor; some word processing programs, such as XyWrite and Microsoft Word, can also create ASCII files.

ASCII protocol
A communications protocol that transmits only ASCII characters and uses ASCII control codes. It is the simplest communications protocol and demands little, if any, error checking.

Ashton-Tate
The original developer of dBASE. In 1991 Borland International, Inc. took over Ashton-Tate.

ASIC
Application-Specific Integrated Circuit. A customized microchip which is designed for a specific application.

askSam
A PC text management system from askSam Systems, Perry, Florida.

ASL
Age, Sex, Location. This term is used to ask someone his or her age, gender, and place of residence. Most often it is the first thing someone will ask when you enter a chat room.

ASM
Association for Systems Management. An international organization which holds conferences for specialists in information systems management.

ASMO
Formerly MO7 (Magneto-Optic7) technology, Advanced Storage Magneto Optical is a rewritable optical disk technology that holds 7GB on a 12 cm disk.

ASMP
ASymetric MultiProcessing.

ASN.1
Abstract Syntax Notation One. The OSI language for describing abstract syntax.

ASP
1. Application Service Provider. A third-party software distribution and/or management service. Generally provides software via a wide area network from a centralized data center. Allows companies to oursource and more efficiently upgrade software. 2. Active Server Page. A specification for a Web page that is dynamically created by the Web server and contains both HTML and scripting code. With ASP, programs can be run on a Web server in a similar way to CGI scripts, but ASP uses uses the ActiveX scripting engine to support either VBScript or JScript. When a user requests data from an Active Server Page, the ActiveX server engine reads through the file, sends the HTML back to the browser and executes the script. Active Server Pages were first available on the Microsoft Internet Information Server (IIS) 3.0. They have the .ASP filename extension. 3. Association of Shareware Professionals. A trade association for shareware authors. Members submit shareware, which is tested and checked for viruses, then distributed on CDs.

aspect ratio
The ratio of width to height of an image on a television, motion picture, or computer screen.

ASPI
Advanced SCSI Programming Interface. An interface from

ASR
Automatic Speech Recognition.

assembler
A program that converts assembly language into machine language.

assembly code
Assembly language. The language in between machine language and high-level programming languages. Each statement in assembly code statement is translated into one machine code instruction.

assembly language
(AL). The language in between machine language and high-level programming languages. Each assembly language statement corresponds to one machine language instruction.

Association Control Service Element
(ACSE). OSI technology used to establish connections between applications.

Association for Computing Machinery
ACM, 1515 Broadway, New York, NY 10036, 212-869-7440. http://info.acm.org/ Since 1947, the Association for Computing Machinery has been advancing information technology throughout the world. ACM offers chapters and activities, special interest groups, conferences and events, journals, magazines and films. ACM has Special Interest Groups (SIGs) in programming languages, software engineering, graphics, computer-human interaction, and more. Publications include Computing Reviews and the ACM Guide to Computing Literature, available online, and cover such topics as object technology, participatory design, internetworking, software project management, hypermedia, and wireless computing. ACM also recognizes important contributors in the field of computing.

Association for Systems Management
(ASM). An international organization which holds conferences for specialists in information systems management.

Association Francaise des Utilisateurs d
(AFUU). The French Association of Unix Users.

Association of C and C++ Users
(ACCU) A worldwide association of people who are interested in C, C++, and related programming languages.

Association of Lisp Users
(ALU). An international user group for the Lisp programming language.

Association of Personal Computer User Gr
(APCUG). A nonprofit organization dedicated to encouraging communication among different user groups, and between user groups and vendors.

Association of Shareware Professionals
(ASP). A trade association for shareware authors. Members submit shareware, which is tested and checked for viruses, then distributed on CDs. See also ASP.

AST Research, Inc.
A manufacturer of PCs and add-in memory boards in Irvine, California.

asterisk
ASCII character 42: * . Also called star. Often used for footnotes. Sometimes used to *surround* words that the writer wants to emphasize in online communication, to substitute for italics.

Astronomical Markup Language
(AML). A standardized format for exchange of metadata related to astronomy. This language will enhance the ability of astronomers to retrieve scientific data, and make it possible for humans and intelligent agents to use the same information. Humans can view AML documents by means of a Java AML browser; intelligent agents can use an Extensible Markup Language (XML) parser.

ASV
Adaptive Suspension Vehicle. An advanced walking robot that is 16 feet long, 10 feet high, and weighs 6,000 pounds. The ASV has six legs and can sprint at eight miles per hour and step over a four-foot wall.

asymmetric cipher
Same as public-key cryptography. A form of cryptography in which each user has a public key and a private key. Messages are sent encrypted with the receiver's public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.

Asymmetric Digital Subscriber Line
(ADSL). A digital subscriber line (DSL) technology in which the transmission of data from server to client is much faster than the transmission from client to server. Whereas with HDSL (High-Speed Digital Subscriber Line), transmission is 784 kilobytes per second in both directions, with ADSL, the rate from client to server is 640 kilobytes per second and from server to client can be up to 6 megabits per second (Mbps). This kind of connection is useful with applications such as interactive TV and Video on Demand, because the data the server sends is much more than the data sent by the client. ADSL uses bandwidth that is not used by voice; therefore voice and data can be transmitted at the same time.

Asymmetric Digital Subscriber Loop
Variant of Asymmetric Digital Subscriber Line (ADSL).

ASYNC
Asynchronous. Not synchronized by a common timing signal. In asynchronous communication, each character can be transmitted at any time and is distinguished by a start bit and stop bit; in synchronous communication the start and stop bits are not needed as there is a regular time interval between transmissions. With asynchronous terminals, a transmission can be initiated at either end.

asynchronous
(ASYNC) Not synchronized by a common timing signal. In asynchronous communication, each character can be transmitted at any time and is distinguished by a start bit and stop bit; in synchronous communication the start and stop bits are not needed as there is a regular time interval between transmissions. With asynchronous terminals, a transmission can be initiated at either end.

asynchronous transfer mode
(ATM). A type of fast packet switching that uses a fixed size packet called a cell. This technique makes it possible to transmit data at great speed, and can make voice, multimedia, full-motion video, and video conferencing available to all users. It also makes dynamic allocation of bandwidth possible; telephone and cable TV companies can charge individual customers based on the amount of bandwidth they use.

asynchronous transmission
A way of transmitting data in which one character is sent at a time, and there may be uneven amounts of time between characters. A start bit and a stop bit notify the receiving computer when the transmission begins and ends. In synchronous transmission, strings of multiple characters are transmitted; this method is faster, but more expensive.

AT
Advanced Technology. An IBM PC introduced in 1984 that was the most advanced PC at that time, with an Intel 80286 processor, 16-bit bus, and 1.2MB floppy drive.

AT command set
The commands used for Hayes and Hayes-compatible modems, which begin with the letters AT.

AT keyboard
Advanced Technology keyboard. The keyboard that originally came with the IBM PC/AT computers, which had 84 keys including the alphanumeric keys, the number pad, F keys, and arrow keys.

AT motherboard
Advanced Technology motherboard. The motherboard that originally came with the IBM PC/AT computers, or one following the same design.

at sign (@)
The at sign distinguishes the domain name from the recipient in an Internet e-mail address (i.e. for the address james@computeruser.com, james is the recipient and computeruser.com is the domain).

AT&T
American Telephone and Telegraph, Inc. One of the largest corporations and telecommunications carriers in the United States. AT&T has been incorporated since 1885, and has provided telephone service throughout the United States and in other countries. AT&T was parent company of the Bell System of telephone companies, a monopoly which was dissolved in 1984 by a Federal court order. AT&T continues to be a competitive long distance telephone carrier. AT&T has been credited with breakthroughs in technology, including the UNIX operating system and the C and C++ programming languages. At&T can be found online at www.att.com.

ATA
Advanced Technology Attachment. The specification for IDE interface.

ATAPI
Advanced Technology Attachment Packet Interface. An interface used to connect CD-ROMs, tape drives, and optical disks with the computer.

Atari
A family of 16-bit and 32-bit microcomputers from Atari Computer, Sunnyvale, California, which became popular for games and for their MIDI interface. Some of the models are the Atari 520ST, 1040ST, Mega ST, STe, STacy, Mega STe, TT, and the Falcon. The Atari 2600, 5500 and 7800 were also popular.

ATDT
ATtention Dial Tone. One of the AT commands used with Hayes modems.

ATM
1. Asynchronous Transfer Mode, a network technology that enables the transmission of data, voice, audio, video, and frame relay traffic in real time. 2. Automatic Teller Machine, a bank terminal that lets customers deposit, withdraw cash, and perform other transactions electronically. 3. Adobe Type Manager, a software program that manages PostScript fonts on a system. 4. At The Moment (chat).

ATM Forum
Formed in 1991, this organization, which includes more than 750 companies, as well as research groups and government agencies, was founded in order to promote ATM technology, and set and accelerate standards.

ATM NIC
Asynchronous Transfer Mode (ATM) Network Interface Card (NIC). ATM NIC transmits or receives ATM commands and requests.

atomic
Indivisible. This word is used in computing to describe an operation which must be carried to completion or not performed at all.

attached processor
A processor that does not have Input/Output capability, and is attached to a processor that handles input and output.

Attached Resource Computer Network
(ARCNET). A local area network (LAN) introduced in 1968 by Datapoint Corporation. It can connect up to 255 nodes in a star topology, using twisted pair or coaxial cables. ARCNET is a data link protocol and uses the token passing access method.

attachment
1. A file linked to an e-mail message. Many mail programs use MIME encoding to attach files. 2. A device attached to a computer, along with any adapters used to attach it.

attack
An attempt to violate computer security.

atto-
The SI prefix meaning 10^-18.

ATX
An open specification from Intel for a motherboard that is a further evolution of the Baby AT, giving more space for expansion slots and Input/Output. The motherboard is rotated 90 degrees in its chassis. The ATX supports multimedia and USB (Universal Serial Bus). In this design, the power supply blows air over the processor chip instead of pulling air through the chassis.

audio
Relating to the range of frequencies within human hearing, generally between 15Hz and 20,000 Hz cycles per second.

audio adapter
An add-on adapter card that improves a computer's sound quality, and adds other sound capabilities, sometimes including MIDI. An audio adapter makes it possible to use speakers, a stereo, and a microphone to record and play sound.

Audio Interchange File Format
(AIFF). A format developed by Apple Computer for storing high-quality sampled audio and musical instrument information. It can be played on PC and Mac, and is used by some professional audio software packages.

audio streaming
Playing audio immediately as it is downloaded from the Internet, rather than storing it in a file on the receiving computer first. Streaming is accomplished by way of Web browser plug-ins, which decompress and play the file in real time; a fast computer and fast connection are necessary.

Audio Video Interleaved
(AVI). A Microsoft multimedia file format, similar to MPEG and QuickTime, used by Video for Windows. In AVI, audio and video elements are interleaved (stored in alternate segments) in the file.

audioconferencing
Teleconferencing using sound for communication between participants.

audiographic teleconferencing
A form of teleconferencing in which a voice connection and an electronic whiteboard are used to communicate ideas between participants.

AUG
Amiga User Group.

AUI
Acronym for Attachment Unit Interface, a device that contains a 15-bit pin, or socket, and is used to connect a Network Interface Card (NIC) with a standard Ethernet cable.

AUP
Acceptable Use Policy. A policy which limits the way a network may be used; for instance, some networks are restricted to noncommercial use.

AUSCERT
The Australian Computer Emergency Response Team.

authentication
Verification of identity as a security measure. Passwords and digital signatures are forms of authentication.

authoring
Creating a document; especially used for World Wide Web documents.

authoring language
A high-level application which helps non-programmers to create tutorials and courseware.

authoring program
A program that helps in the creation of interactive courseware.

authoring system
A collection of tools which can be used by non-programmers to create interactive applications.

authorization code
A set of characters or password giving a user access to a remote or local computer network.

Authorware Professional
A multimedia authoring tool from Macromedia, which can be used with Windows and Macintosh.

auto answer
(AA). Some modems can be set up to accept telephone calls and automatically establish a connection; this ability is called auto answer.

auto dial
The ability of some modems to dial the telephone number of another computer and make a connection.

autobaud
Automatic baud rate detection.

AutoCAD
A CAD program for mechanical engineering from Autodesk, Inc., which can be run on PC, Macintosh, UNIX, and VAX.

AUTOCODER
An early compiler for the Manchester Mark I computer.

AUTODIN
Abbreviation for AUTOmatic DIgital Network, the U.S. Defense Communication System's global communications network.

AUTOEXEC.BAT
(Automatically Executing Batch File). A DOS batch file that is executed automatically when the computer is started, after CONFIG.SYS is run. AUTOEXEC.BAT sets up the DOS prompt, tells the system which directories to search for programs to run, loads the mouse driver, configures the serial ports, and initializes RAM-resident programs and utilities. AUTOEXEC.BAT can be custom configured by the user, and may be used to configure network connections, or to load a particular application program on startup. New software packages often make automatic changes to AUTOEXEC.BAT upon installation. Windows 95 will use AUTOEXEC.BAT if it is present, but does not usually need it.

autoflow
A function of some programs that allows text to wrap around graphic images and spread from one page to the next, to fill the space as needed.

AutoLISP
A version of LISP used in AutoCAD.

automata
(Plural of automaton). Machines, robots, or systems which follow a preset sequence of instructions automatically.

automata theory
The study and invention of automata.

automatic baud rate detection
(ABR). The process in which a receiving device examines the first character of an incoming message to determines its speed, code level, and stop bits. Having this automatic function makes it possible to receive data from different transmitting devices operating at different speeds without having to establish data rates in advance.

automatic number identification
(ANI). A service that identifies the telephone number of each incoming telephone call.

automatic repeat request.
(ARQ). A modem status signal indicated by a light on the modem; in cases of transmissions errors, the ARQ is a request to the sender to retransmit.

Automatic Teller Machine
(ATM). An automated banking terminal where customers can deposit and withdraw cash by means of a magnetic ATM card. See also ATM.

automation
The automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that replace human control.

automaton
A machine, robot, or abstract device which performs tasks by following automatically a predetermined sequence of instructions. Some automata mimic human behavior.

Autonomic Computing
A term coined by IBM to describe their vision about the future direction of computing. Analogizing it to the autonomic functions that take place in a human's central nervous system, autonomic computing would be comprised of networks that are "self managing, self diagnostic, and transparent to the user." IBM sees it as a paradigm shift in thought, as computers would be defined less by computational speed, and more by the ability to access information.


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