Hardware code page: Difference between revisions

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==Code page assignments==
In North American [[IBM-compatible PC]]s, the hardware code page of the display adapter is typically [[code page 437]].<ref name="Elliott_2005_MDAElliott_2020_MDA"/> However, various portable machines<ref name="HP_1985_PP"/><ref name="HP_1986_PP"/><ref name="HP_1991_95LXUG"/> as well as (Eastern) European, Arabic, Middle Eastern and Asian PCs used a number of other code pages as their hardware code page,<ref name="Paul_2001_CPSwitchFD"/> including [[code page 100]] ("Hebrew"),<ref name="Paul_2002-09-05"/> [[code page 151|151]] ("Nafitha Arabic"),<ref name="Paul_2002-12-04"/> [[code page 667|667]] ("[[Mazovia encoding|Mazovia]]"),<ref name="Paul_2001_CPSwitchFD"/><ref name="Fujitsu_1994_DL6400_DL6600"/> [[code page 737|737]] ("Greek"), [[code page 850|850]] ("Multilingual"),<ref name="HP_1991_95LXUG"/><ref group="nb" name="NB_OmniGo_300"/> encodings like "[[HP Roman-8|Roman-8]]",<ref name="HP_1985_PP"/><ref name="HP_1986_PP"/> "[[Kamenický encoding|Kamenický]]",<ref name="Paul_2001_CPSwitchFD"/><ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1992_Flyer"/> "[[KOI-8]]", "[[MIK code page|MIK]]",<ref name="Fujitsu_1994_DL6400_DL6600"/> and others. Most display adapters support a single 8-bit hardware code page only.<ref name="Paul_2001_CPSwitchFD"/> The [[bitmap]]s were often stored in an [[EPROM]]<ref name="RBIL_61_INT15h_AX67C3h"/><ref name="Brown_2000_RBIL"/><ref name="Elliott_2005_MDAElliott_2020_MDA"/> in a [[DIP socket]].<ref name="Elliott_2005_MDAElliott_2020_MDA"/> At most, the hardware code page to be activated was user-selectable via [[jumper (computing)|jumper]]s,<ref name="Derfler_1985"/> configuration [[EEPROM]]s<ref name="HP_1985_PP"/><ref name="HP_1986_PP"/> or [[CMOS setup]].<ref name="HP_1996_200LXUG"/> However, some of the display adapters designed for Eastern European, Arabic and Hebrew PCs supported multiple software-''switchable'' hardware code pages, also named '''font pages''',<ref name="Paul_2001_CPSwitchFD"/> selectable via I/O ports<ref name="Elliott_2005_MDAElliott_2020_MDA"/> or additional BIOS functions.<ref name="RBIL_61_INT15h_AX67C3h"/><ref name="Brown_2000_RBIL"/>
 
In contrast to this, printers frequently support several user-switchable character sets, often including various variants of the 7-bit [[ISO/IEC 646]] character sets such as [[code page 367]] ("[[ISO/IEC 646-US]] / [[ASCII]]"<ref name="Paul_2001_CPSwitchFD"/>), sometimes also a couple of 8-bit code pages like [[code page 437]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1990_P90"/><ref name="Epson_1991_GQ"/> [[code page 850|850]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1990_P90"/><ref name="Epson_1991_GQ"/> [[code page 851|851]],<ref name="Fujitsu_1994_DL6400_DL6600"/> [[code page 852|852]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1993_EPROMs"/> [[code page 853|853]],<ref name="Epson_1992_EPL-4300"/> [[code page 855|855]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1993_EPROMs"/> [[code page 857|857]],<ref name="Epson_1992_EPL-4300"/> [[code page 860|860]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1990_P90"/><ref name="Epson_1991_GQ"/> [[code page 861|861]],<ref name="Epson_1991_GQ"/> [[code page 863|863]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1990_P90"/><ref name="Epson_1991_GQ"/> [[code page 865|865]],<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1990_P90"/><ref name="Epson_1991_GQ"/> and [[code page 866|866]].<ref name="Fujitsu_1994_DL6400_DL6600"/><ref name="NEC_1993_EPROMs"/><ref name="FreeBSD_2016_1"/><ref name="FreeBSD_2016_2"/> Printers for the Eastern European or Middle Eastern markets sometimes support other locale-specific hardware code pages to choose from. They can be selected via [[DIP switch]]es or configuration menus on the printer, or via specific [[escape sequence]]s.<ref name="Paul_2001_CPSwitchFD"/><ref group="nb" name="Escape_sequence_Epson_NEC"/>
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<ref name="Caldera_1998_USER-9">{{cite book |title=Caldera DR-DOS 7.02 User Guide |chapter=Chapter 9: Configuring the System |publisher=[[Caldera, Inc.]] |date=1998 |orig-date=1993, 1997 |chapter-url=http://www.drdos.net/documentation/usergeng/09ugch9.htm#807 |url-status=dead |archive-url=https://web.archive.org/web/20160607164317/http://www.drdos.net/documentation/usergeng/09ugch9.htm#807 |archive-date=2016-06-07}}</ref>
<ref name="Caldera_1998_USER-17">{{cite book |title=Caldera DR-DOS 7.02 User Guide |chapter=Chapter 17: Setting Up Code Page Switching |publisher=[[Caldera, Inc.]] |date=1998 |orig-date=1993, 1997 |chapter-url=http://www.drdos.net/documentation/usergeng/17ugch17.htm |url-status=dead |archive-url=https://web.archive.org/web/20160609203350/http://www.drdos.net/documentation/usergeng/17ugch17.htm |archive-date=2016-06-09}}</ref>
<ref name="Paul_1997_NWDOSTIP">{{cite book |title=NWDOS-TIPs &mdash; Tips & Tricks rund um Novell DOS 7, mit Blick auf undokumentierte Details, Bugs und Workarounds |workid=MPDOSTIP |author-first=Matthias R. |author-last=Paul |date=1997-07-30 |edition=3 |version=Release 157 |language=de |url=http://www.antonis.de/dos/dos-tuts/mpdostip/html/nwdostip.htm |access-date=2012-01-11 |url-status=live |archive-url=https://web.archive.org/web/20160522014302/http://www.antonis.de/dos/dos-tuts/mpdostip/html/nwdostip.htm |archive-date=2016-05-22}} (NB. NWDOSTIP.TXT is a comprehensive work on [[Novell DOS 7]] and [[OpenDOS 7.01]], including the description of many undocumented features and internals. It is part of the author's yet larger MPDOSTIP.ZIP collection maintained up to 2001 and distributed on many sites at the time. The provided link points to a HTML-converted older version of the NWDOSTIP.TXT file.)</ref>
<ref name="Paul_2001_NWDOSTIP">{{cite book |title=NWDOS-TIPs &mdash; Tips & Tricks rund um Novell DOS 7, mit Blick auf undokumentierte Details, Bugs und Workarounds |workid=MPDOSTIP |author-first=Matthias R. |author-last=Paul |date=2001-04-09 |edition=3 |version=Release 183 |language=de}}</ref>
<ref name="Paul_2001_CPSwitchFD">{{cite web |title=Changing codepages in FreeDOS |author-first=Matthias R. |author-last=Paul |date=2001-08-15 |access-date=2016-06-06 |url=http://www.freedos.org/technotes/technote/txt/141.txt |type=Technical design specification |url-status=dead |archive-url=https://web.archive.org/web/20160606182501/http://www.freedos.org/technotes/technote/txt/141.txt |archive-date=2016-06-06 |quote=[…] The […] active system codepage […] sometimes also called global codepage […] is the codepage currently in use for the [[DOS kernel]], for example the collating order and other [[I18N]] tables depend on this codepage. While in most cases the system codepage reflects the codepage used for devices such as console ([[DISPLAY.SYS]]), printers ([[PRINTER.SYS]]), and keyboard ([[KEYB.COM]]), this is not a requirement as there are means to switch the individual device codepages without changing the system codepage (for example using [[MODE (DOS command)|MODE]]). Further, in dealing with [[National Language Support|NLS]] issues, it is important to distinguish between the currently active, the hardware, and the [[primary code page|primary codepage]]s for any device and/or the system. The hardware codepage is the default codepage supported by a device after initialization of the hardware. It normally defaults to [[Code page 437|437]] for the console, but some European clones have [[Code page 850|850]] stored in the video font ROMs, and I have been told that some Czech [[Color Graphics Adapter|CGA]] and [[Monochrome Display Adapter|MDA]] cards had [[Kamenický encoding|Kamenicky]] codepage 867 (aka [[Wordperfect]] codepage 895) stored in their ROMs. Most printers default to [[Code page 367|367]] ([[ISO-646-US]] 7-bit) or 437 on power up, and the default system, or global, codepage for the system is always 437 under [[DR-DOS]] […] but under [[MS-DOS]]/[[PC DOS]] it reflects the codepage entry in [[COUNTRY (CONFIG.SYS directive)|COUNTRY]]=country,codepage,filespec where it must be one of the codepages valid for the given country as per [[COUNTRY.SYS]] filespec - this is 437 (or 850 on newer systems) in most cases, but not necessarily. The default country is 1 (USA), the default filespec is "\COUNTRY.SYS", and if no filespec is found the system will work with the statically pre-initialized data in the kernel which is the data for the USA in most cases. If no codepage is given with COUNTRY, the [[DOS BIOS]] will search for the first codepage entry for a given country (or 1), this is called the primary codepage. The codepage value of 0 is used internally to retrieve this codepage, and for the COUNTRY.SYS file parsers in the DOS BIOS and [[NLSFUNC (DOS command)|NLSFUNC]], a codepage value of zero means "match any codepage, whatever comes first for the given country code". So, it depends on the order of codepage entries in the COUNTRY.SYS file if the system will default to 437, 850, or something else. […] However, some Arabic and Hebrew [[Hercules Graphics Card|HGC]] and CGA cards have multiple hardware fonts, so called fontpages, […] so that a device may support multiple hardware codepages at the same time. The corresponding fontpage functions are INT 2Fh/AD41h and INT 2Fh/AD42h. […] COUNTRY.SYS and [[KEYBOARD.SYS]] contain only two codepage entries for a given country in Western issues of DOS. (In [[Arabic MS-DOS|Arabic]] and [[Hebrew MS-DOS|Hebrew]] issues there can be up to 8 codepages for one country […]) […] When you specify a line like: [[DEVICE (CONFIG.SYS directive)|DEVICE]]=…\display.sys con=(ega,437,1) […] DISPLAY.SYS is told that 437 should be assumed to be the hardware codepage of the display adapter. This is necessary to be known by DISPLAY.SYS because it will use different mechanisms to switch to the software [[prepared code page|prepared codepage]]s and the hardware codepage, and there is no way to retrieve the info about the hardware codepage by itself. When the requested codepage is equal to the hardware codepage declared here, DISPLAY.SYS will use the method to switch to the hardware codepage, otherwise it will attempt to look up the font info in its internal buffer. […]}} (NB. Based on fd-dev post [http://marc.info/?l=freedos-dev&m=99788711909602&w=2<!-- https://archive.today/20141001010931/http://marc.info/?l=freedos-dev&m=99788711909602&w=2 -->].)</ref>
<ref name="Paul_2002-09-05">{{cite web |title=Technical info on undocumented DOS country info for LCASE, ARAMODE and CCTORC records |author-first=Matthias R. |author-last=Paul |date=2002-09-05 |work=FreeDOS development list fd-dev at Topica |url=http://permalink.gmane.org/gmane.os.freedos.devel/364 |access-date=2016-05-26 |url-status=dead |archive-url=https://web.archive.org/web/20160527142512/http://permalink.gmane.org/gmane.os.freedos.devel/364 |archive-date=2016-05-27}}</ref>
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<ref name="Elliott_2012_HGCPlus">{{cite web |title=Hercules Graphics Card Plus: Notes |author-first=John C. |author-last=Elliott |date=2012-08-09 |work=Seasip.info |url=http://www.seasip.info/VintagePC/hercplus.html |access-date=2016-11-23 |url-status=live |archive-url=https://web.archive.org/web/20161123124757/http://www.seasip.info/VintagePC/hercplus.html |archive-date=2016-11-23}}</ref>
<ref name="Elliott_2012_InColor">{{cite web |title=Hercules InColor Card: Notes |author-first=John C. |author-last=Elliott |date=2012-08-05 |work=Seasip.info |url=http://www.seasip.info/VintagePC/incolor.html |access-date=2016-11-23 |url-status=live |archive-url=https://web.archive.org/web/20161123123816/http://www.seasip.info/VintagePC/incolor.html |archive-date=2016-11-23}}</ref>
<ref name="Elliott_2005_MDAElliott_2020_MDA">{{cite web |title=Monochrome Display Adapter: Notes |author-first=John C. |author-last=Elliott |date=20052020-1106-0608 |work=Seasip.info |url=http://www.seasip.info/VintagePC/mda.html |access-date=2016-11-23 |url-status=live |archive-url=https://web.archive.org/web/2016112313345920230920194518/httphttps://www.seasip.info/VintagePC/mda.html |archive-date=20162023-1109-2320 |quote=[…] Reading from port 03BAh returns vertical sync in bit 7, and a card ID in bits 6-4: 000: Hercules, 001: Hercules Plus, 101: Hercules InColor, 111: Unknown clone […] One card […] which appears to be a Hercules clone of Eastern European origin, has a further capability - two ROM fonts, selectable in software. These options are controlled in a similar manner to other extended features in the Hercules: Bit 2 of port 3BFh must be set to enable the feature, and then Bit 4 of port 3B8h selects which font to use. The card ID in bits 6-4 of port 03BAh has all three bits set. […]}}</ref>
<ref name="Ferraro_1994">{{cite book |title=Programmer's Guide to the EGA, VGA and Super VGA Cards |author-first=Richard F. |author-last=Ferraro |edition=3 |date=August 1994 |publisher=[[Addison-Wesley Publishing Company, Inc.]] |isbn=0-201-62490-7 |id={{EAN|9780201624908}}}}</ref>
<ref name="Paul_2001_COUNTRY">{{cite web |title=DOS COUNTRY.SYS file format |type=COUNTRY.LST file |author-first=Matthias R. |author-last=Paul |date=2001-06-10 |edition=1.44 |orig-date=1995 |url=http://www.columbia.edu/~em36/wpdos/MatthiasPaulCPI.zip<!-- not an official distribution archive, but contains an older version of COUNTRY.LST --> |access-date=2016-08-20 |url-status=live |archive-url=https://web.archive.org/web/20160420065252/http://www.columbia.edu/~em36/wpdos/MatthiasPaulCPI.zip |archive-date=2016-04-20}}</ref>