Code page 949 (IBM): Difference between revisions

Revision as of 19:59, 15 October 2021

Revision as of 20:05, 15 October 2021

Line 27:

== History ==

A version of Code page 951 (a DBCS-PC, i.e. double-byte non-[[Extended Unix Code|EUC]] non-[[EBCDIC]], code), the double-byte component for IBM-949, is defined in the September 1992 revision of IBM Corporate Specification C-H 3-3220-125, along with Code page 834 (a DBCS-Host, i.e. double-byte EBCDIC, code), which is the double byte component of [[Code page 933]].<ref name="ch3320125-1992">{{cite web |url=ftp://public.dhe.ibm.com/as400/products/clientaccess/win32/files/globalization/Korean_base1992.pdf |title=IBM Korean Graphic Character Set: DBCS-Host and DBCS-PC |institution=[[IBM]] |orig-year=1992 |year=2001 |id=C-H 3-3220-125 1992-09}}</ref> TheThis Octoberversion 1989of editionCode hadpage instead949/951 definedconsidered Codethe pageentire 926lead asbyte itsrange DBCS0x8F–A0 to be a user-PCdefined coderegion, whichand encodedincluded theonly samestandard charactersWansung asassignments IBMand user-834defined inareas, athus layoutnot differingincluding fromsome bothcharacters IBM-951which andCode IBM-page 933/834, included.<ref name="ch3320125-1992"/> andSome waslater combinedversions, withsuch [[Codeas pagethat 1040]]implemented (8-bitby [[KSInternational XComponents 1001#1974|N-bytefor Hangul CodeUnicode]]; compare(ICU) howshrink [[Shiftthe JIS]]user-defined extendsregion 8-bitto [[JISinclude Xthese 0201]])characters toas form IBM-944extensions.<ref>{{cite web |archive-urlname=https:"ucm"//web.archive.org/web/20141201233858/http://www-01.ibm.com/software/globalization/ccsid/ccsid944.html |archive-date=2014-12-01 |url=http://www-01.ibm.com/software/globalization/ccsid/ccsid944.html |title=Coded character set identifiers: CCSID 944 |work=IBM Globalization |publisher=[[IBM]] |url-status=dead}}</ref>

{{anchor|926|944}}The earlier October 1989 revision of C-H 3-3220-125 had instead defined Code page 926 as its DBCS-PC code, which encoded the same characters as IBM-834 in a layout differing from both IBM-951 and IBM-834,<ref name="ch3320125-1992"/> and was combined with [[Code page 1040]] (8-bit [[KS X 1001#1974|N-byte Hangul Code]]; compare how [[Shift JIS]] extends 8-bit [[JIS X 0201]]) to form IBM-944.<ref name="ccsid944">{{cite web |archive-url=https://web.archive.org/web/20141201233858/http://www-01.ibm.com/software/globalization/ccsid/ccsid944.html |archive-date=2014-12-01 |url=http://www-01.ibm.com/software/globalization/ccsid/ccsid944.html |title=Coded character set identifiers: CCSID 944 |work=IBM Globalization |publisher=[[IBM]] |url-status=dead}}</ref> Code page 944/926 are now [[deprecated]]: the 1992 revision designates code page 926 as "restricted" ("limited to the particular environment for which [it is] registered") and does not give its chart or mappings from the other code pages,<ref name="ch3320125-1992"/> and CCSID 944 is categorised as "coexistence and migration"<ref name="ccsid944"/> (contrast "interoperable" for CCSID 949).<ref name="ccsid949"/> ICU includes [[Unicode]] mappings for IBM-949<ref name="icu"/><ref name="ucm"/> and IBM-933, but not for IBM-944.

This September 1992 version of Code page 949/951 considered the entire lead byte range 0x8F–A0 to be a user-defined region, and included only standard Wansung assignments and user-defined areas, thus not including some characters which Code page 933/834 included.<ref name="ch3320125-1992"/> Later versions<ref name="ucm"/> shrink the user-defined region to include these characters as extensions.

== Single byte codes ==