[W/K] :: American Standard Code for Information Interchange

  American Standard Code for Information Interchange
       n : (computer science) a code for information exchange between
           computers made by different companies; a string of 7
           binary digits represents each character; used in most
           microcomputers [syn: ASCII]

  American Standard Code for Information Interchange
       
          The basis of character sets used in almost all present-day
          computers.  US-ASCII uses only the lower seven bits
          ({character points 0 to 127) to convey some control codes,
          space, numbers, most basic punctuation, and unaccented letters
          a-z and A-Z.  More modern coded character sets (e.g.,
          Latin-1, Unicode) define extensions to ASCII for values
          above 127 for conveying special Latin characters (like
          accented characters, or German ess-tsett), characters from
          non-Latin writing systems (e.g., Cyrillic, or Han
          characters), and such desirable glyphs as distinct open-
          and close-quotation marks.  ASCII replaced earlier systems
          such as EBCDIC and Baudot, which used fewer bytes, but
          were each broken in their own way.
       
          Computers are much pickier about spelling than humans; thus,
          hackers need to be very precise when talking about characters,
          and have developed a considerable amount of verbal shorthand
          for them.  Every character has one or more names - some
          formal, some concise, some silly.
       
          Individual characters are listed in this dictionary with
          alternative names from revision 2.3 of the Usenet ASCII
          pronunciation guide in rough order of popularity, including
          their official ITU-T names and the particularly silly names
          introduced by INTERCAL.
       
          See V ampersand, asterisk, back quote, backslash,
          caret, colon, comma, commercial at, control-C,
          dollar, dot, double quote, equals, exclamation mark,
          greater than, hash, left bracket, left parenthesis,
          less than, minus, parentheses, oblique stroke,
          percent, plus, question mark, right brace, right
          brace, right bracket, right parenthesis, semicolon,
          single quote, space, tilde, underscore, vertical
          bar, zero.
       
          Some other common usages cause odd overlaps.  The "#", "$",
          ">", and "&" characters, for example, are all pronounced "hex"
          in different communities because various assemblers use them
          as a prefix tag for hexadecimal constants (in particular,
          "#" in many assembler-programming cultures, "$" in the 6502
          world, ">" at Texas Instruments, and "&" on the BBC Micro,
          Acorn Archimedes, Sinclair, and some Zilog Z80
          machines).  See also splat.
       
          The inability of US-ASCII to correctly represent nearly any
          language other than English became an obvious and intolerable
          misfeature as computer use outside the US and UK became the
          rule rather than the exception (see software rot).  And so
          national extensions to US-ASCII were developed, such as
          Latin-1.
       
          Hardware and software from the US still tends to embody the
          assumption that US-ASCII is the universal character set and
          that words of text consist entirely of byte values 65-90 and
          97-122 (A-Z and a-z); this is a major irritant to people who
          want to use a character set suited to their own languages.
          Perversely, though, efforts to solve this problem by
          proliferating sets of national characters produced an
          evolutionary pressure (especially in protocol design, e.g.,
          the URL standard) to stick to US-ASCII as a subset common
          to all those in use, and therefore to stick to English as the
          language encodable with the common subset of all the ASCII
          dialects.  This basic problem with having a multiplicity of
          national character sets ended up being a prime justification
          for Unicode, which was designed, ostensibly, to be the *one*
          ASCII extension anyone will need.
       
          A system is described as "{eight-bit clean" if it doesn't
          mangle text with byte values above 127, as some older systems
          did.
       
          See also ASCII character table, Yu-Shiang Whole Fish.
       
          (1995-03-06)