Article View: comp.std.internat
Article #67Re: ASCII for national characters
From: Donn Terry
Date: Wed, 22 Nov 1989 18:43
Date: Wed, 22 Nov 1989 18:43
47 lines
2434 bytes
2434 bytes
There are actually a bunch of candidate character sets.
ISO646: 7-bit, kinda like ASCII, one country at a time. Each country that
uses it has it's own national variant in the "changable" characters.
ISO8859: 8-bit, using 2 96 (or 95, depending on what you do with DEL) planes.
Suitable for English plus choose 1 of Western Europe
Eastern (Latin) Europe
Cyrllic
Arabic
(Others; all "small" phonetic
alphabets)
I don't remember if Eastern Europe includes Turkish or whether it's
another case.
ISO2022: Lays on top of 646 or 8859 (or others) and defines language shifts.
Blows away any presumption that length of string in characters ==
length in bytes == space used in displaying text.
Various Asian national standards for the "Han" ("Chinese") character set
plus national character sets for Japan and Korea. No unification of
these sets.
ISO10646: 32-bit everything code. Treats the various Han character sets
as distinct character sets for each national usage, but unifies the
Latin characters into a single set. Variable length coding possible
to reduce space. Can degenerate to (something close to) 8859.
UNICODE: this isn't a standard but is proposed. Unifies the Han
character sets in the same way as the Latin ones (but with
obviously a much bigger payback because of the size). Fixed
length 16 bits. This fixes the length in characters vs. length
in bytes issue. (The issue of length in display space is
inherently harder because characters do vary in width in natural
usage in many phonetic alphabets, as well as in the ideographic
ones. See Arabic and Hindi where the constant-width usage is
considered "pretty awful", albeit readable. (Even in English,
good typesetting is not constant width.))
CCITT T2xx (I don't have the exact number). Another player that I just
recently found out about and don't know anything about in detail.
This is "teletext", I'm told.
There are certainly more.
Donn Terry
HP Ft. Collins
Technical Details
Message-ID:
<9300002@hpfcdc.HP.COM>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!apple!sun-barr!decwrl!ucbvax!hplabs!hpfcso!hpfcdc!donnReferences:
<472@enea.se>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!apple!sun-barr!decwrl!ucbvax!hplabs!hpfcso!hpfcdc!donn From: donn@hpfcdc.HP.COM (Donn Terry) Newsgroups: comp.std.internat Subject: Re: ASCII for national characters Message-ID: <9300002@hpfcdc.HP.COM> Date: 22 Nov 89 18:43:42 GMT References: <472@enea.se> Organization: HP Ft. Collins, Co. Lines: 47