(
American
Standard
Code for
Information
Interchange) Pronounced "
ask-ee," ASCII is the built-in binary code for representing characters in all computers except IBM mainframes, which use EBCDIC coding. ASCII was originally developed for communications and uses seven bits per character, providing 128 combinations that include upper and lower case alphabetic letters, the numeric digits and special symbols such as the $ and %. The first 32 characters are format codes (tab, return, etc.) as well as control codes for communications and printers (see below). See
ASCII file,
ASCII ribbon campaign,
EBCDIC and
Unicode.
ASCII vs. Hex
In technical editors used by developers, there is a choice between entering data in ASCII or hexadecimal ("hex"). ASCII is all characters, but hex is limited (0 to 9 and A to F). See
hex chart and
hex editor.
A Byte Holds ASCII and Then Some
The common storage unit in a computer is an 8-bit byte that holds 256 character combinations (0-255). However, ASCII uses only the first 128 (0-127), and the rest (128-255) are foreign language and math symbols.