Glossary for Geospatial Science

ASCII:� American Standard Code for Information Interchange (pronounced �askee�).� The 7-bit (128 characters) used as a computer�s alphabet.� The Latin alphabet character set encoded into digital values between 0 and 127 includes lowercase and uppercase letters, the numerals 0�9, English punctuation marks, special symbols (such as @#$%^&*) and non-displaying characters often used as printer control codes.� The eighth bit, giving values from 128 to 255, is used in a nonstandard fashion and is not part of the standard ASCII code.� PCs normally have the �extended� character set in their system font for digital values from 128 to 255.� The characters used for values from 128 to 255 for TNTmips display screen fonts are unpredictable but can be displayed in the font style window.� Some fonts have no characters in this range while others have characters for some or all of these values.� ASCII is a proper subset of Latin-1, Unicode, and ISO 10646, which are the 1-byte, 2-byte, and 4-byte standards for international character encoding.

The term �ASCII file� is often used to mean a text-only file.� Documents in most word processors are not text-only files, since they include header information and formatting characters.� However most word processors have an export or print-to-file utility that will convert a document into a text-only ASCII format.