A

alphanumeric
Consisting of numbers and letters.

American National Standards Institute (ANSI)
ANSI promotes standards for the American computer industry and coordinates American involvement in the International Standards Organization.

analog
Just as pairs of things are said to be analogs if they exhibit similar features and behavior, an analog device uses convenient physical quantities or properties to represent other physical quantities; for example, a variation in the electric current in a wire can represent an audible sound and this can be translated back into sound by a speaker unit (say in the part of a telephone handset placed on the ear). Likewise, an electric voltage or the position of a point on a dial might represent the speed of a motor or the temperature of a furnace. This contrasts with digital devices, which use numbers (or digits) to represent physical quantities.

anti-virus software
Software that detects and removes viruses from a system.

aperture grill pitch
Sony's version of dot pitch, using horizontal and vertical lines closely spaced. The horizontal lines isolate pixels and the vertical lines separate pixels.

application
A computer program designed to help people perform a certain type of work. Depending on the work for which it was designed, an application can manipulate text, numbers, graphics, or a combination of these elements. Some application packages offer considerable computing power by focusing on a single task, such as word processing; others, called integrated software, offer somewhat less power but include several applications, such as a word processor, a spreadsheet, and a database program.

architecture
A general term referring to the arrangement or design of all or part of a computer system.

Artificial Intelligence (AI)
A set of principles and associated methods that tries to mimic natural (living world) intelligence. Two extremely different approaches have yielded useful results: Rule-Based AI (as used in Expert Systems) and Neural Nets.

ASCII
Pronounced "askee"; acronym for American Standard Code for Information Interchange. A coding scheme that assigns numeric values to letters, numbers, punctuation marks, and certain other characters. By standardizing the values used for these characters, ASCII enables computers and computer programs to exchange information.

ASCII character
A 1-byte character from the ASCII character set, which includes alphabetic and numeric characters, punctuation, symbols and graphic characters.

asynchronous operation
Generally, an operation that proceeds independently of any timing mechanism, such as a clock. In communications, for example, two modems communicating asynchronously rely upon each sending the other start and stop signals in order to pace the exchange of information.

AT command
A set of characters beginning with AT that makes up a command line for the modem. AT commands can be up to 64 characters in length.

attribute
Literally, a characteristic. In databases, the name or structure of a field is considered to be an attribute of a record. For example, the files LASTNAME, FIRSTNAME, and PHONE would be attributes of each record in a PHONELIST database. In screen displays, attributes control the background color and foreground color of the character, underlining, and blinking.

AUTOEXEC.BAT
A special-purpose batch file (set of commands) that is automatically carried out by the MS-DOS operating system whenever the computer is started or restarted. The file contains basic startup commands that help configure (tailor) the system to install devices and to the user's preferences.

autosizing
True autosizing occurs when a monitor can maintain a constant image size across different video modes. Two common ways of achieving autosizing are mode sensing, pre-programmed factory settings and user defined modes.