Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!ames!lll-winken!uunet!ccicpg!cci632!sjfc!deh0654 From: deh0654@sjfc.UUCP (Dennis E. Hamilton) Newsgroups: comp.std.internat Subject: Re: 7-bit ASCII vs. 8-bit ASCII Message-ID: <518@sjfc.UUCP> Date: 28 Apr 89 00:49:31 GMT References: <2568@ndsuvax.UUCP> <5153@hubcap.clemson.edu> <1468@auspex.auspex.com> <26644@ism780c.isc.com> Reply-To: deh0654@sjfc.UUCP (Dennis E. Hamilton) Distribution: usa Organization: Saint John Fisher College, Rochester, NY Lines: 40 In article <26644@ism780c.isc.com> greger@ism780b.UUCP (Greger Leijonhufvud) writes: >In article halldors@paul.rutgers.edu (Magnus M Halldorsson) writes: >>The ISO 8859 character sets specify sets for specific languages. Now >>what if one wants to use a combination of those? Is there any standard >>for storing, representing, and switching between various (ISO) >>character sets? What if one wants to allow for Japanese or Chinese as >>well? >[discussion of EUC and other Unix-flavored proposals] >There are also other encoding schemes, by Sun, Xerox and other >companies. > >There is, however, no standard as yet. Unfortunately. But, from V.4, >you should be able to mix Icelandic with Bulgarian, and get your >Greek quotations OK, too. There has been an ISO scheme for mixing code sets for some time now. ISO 2022-1973 specified basically unlimited code-extension techniques, and you can use either 7-bit or 8--bit ASCII to carry it in. (The 7-bit scheme has a shifting scheme for getting to the other codes that would normally have bit 8 set). Although it can be a little painful, there are alphabet registration systems that allow international identification of the code used in the code stream itself. You can use the code identification procedure to switch the 7/8-bit "window" over those codes you want to use at any particular time. When the special 8-bit character codes that are talked about here become approved, there will presumably also be internationally approved "announcement sequences" for shifting in and out of them. This works for communication better than for internal processing, of course. For what you want to see *internally* in a particular computer system, I suppose POSIX and other standards will have to make provision (and the C Language will become interesting, too). But for interchange purposes via 7/8-bit data streams, all of the machinery has been defined for some time, including the procedure for international registration of special code tables. -- Dennis E. Hamilton {uucp: ... !rochester!cci632!sjfc!deh0654} Robert Anson Heinlein, 1907-1988 May the First Muster always answer to your names.