extendedASCII

Extended ASCII is a character encoding standard that expands upon the original 7-bit ASCII (American Standard Code for Information Interchange) to include additional symbols, characters, and control codes. While standard ASCII uses 7 bits to represent 128 characters (0-127), extended ASCII uses 8 bits, allowing for 256 characters (0-255). This broader range enables the representation of characters beyond the basic Latin alphabet, including accented letters, graphic symbols, and special characters used in various languages and applications.

The extended ASCII set is not universally standardized; different systems and publishers adopted various versions, leading to multiple character sets under the umbrella of extended ASCII. Notable variants include IBM's Code Page 437 (used in MS-DOS), ISO-8859-1 (Latin-1), and Windows-1252, among others. These variants differ mainly in the characters assigned to the range 128–255, tailored to specific languages or functional needs.

Extended ASCII became widely utilized during the 1980s and 1990s for text encoding in computer systems, programming, and data transmission before the adoption of Unicode, which aims to encompass all writing systems uniformly across different platforms. The diversity of extended ASCII variants contributed to compatibility challenges, making it necessary to specify which version was being used in a given context.

Today, extended ASCII is largely obsolete within modern systems, replaced by Unicode and its UTF-8 encoding, which provide comprehensive and consistent representations of characters across languages and symbols. Nonetheless, understanding extended ASCII remains relevant for historical and compatibility reasons in legacy computing environments and data formats.