Odp: Pd: Missing legacy Arabic encoding

[piotrunio-2...@wp.pl via Unicode]

The SEW subsequently explained that the actual reason is due to insufficient 
evidence of user community that would need to use the resulting mapping. 
Despite Win32 being a highly popular platform with plenty of backwards 
compatibility and native UCS-2 terminal support, the specific use cases of 
installing codepages into Windows NT and using terminal tiles from Windows 
3.1/95/98/ME are not sufficiently documented, making it difficult for any user 
communities to form around it. So it seems like the idea of standardizing 
legacy Arabic terminal BMP mappings is a dead end for now. Dnia 17 kwietnia 
2026 22:59    piotrunio-2...@wp.pl via Unicode  < unicode@corp.unicode.org 
>  napisał(a): The Recommendations in L2/26-100 claim that Microsoft's 
documentation of legacy Arabic encodings is available at 
https://learn.microsoft.com/en-us/typography/legacy/legacy_arabic_fonts. 
However, that article only demonstrates two encodings of TrueType fonts, which 
are used in Windows 3.1 but are completely different from the eight terminal 
encodings. Unlike the TrueType encodings which represent internal shaping 
mappings and are not used for text interchange, the terminal encodings have 
been demonstrated to be directly used in text interchange through int 10h and 
ReadConsoleOutputA/WriteConsoleOutputA as already demonstrated in L2/26-077. 
The Recommendations also claim that the proposal does not demonstrate any need 
for interchange or encoding, but the proposal actually demonstrated such a need 
due to the logical extension of the Win32 terminal API to the functions 
ReadConsoleOutputW/WriteConsoleOutputW, which are in Windows NT and may be used 
on the output of previously ran programs (including those that used the legacy 
Arabic terminal encodings), which given the CHAR_INFO structure, therefore 
implies a need for all the tiles to map to BMP for interchange. I'm not 
objecting to the SEW's conclusion of "Users are expected to use 
PUA.", which can indeed be used to provide a mapping even if not 
standardized, but the reasoning given was flawed.  Dnia 09 stycznia 2026 17:25  
 piotrunio-2...@wp.pl < piotrunio-2...@wp.pl >  napisał(a): The following 
Win32 C code will output 256 characters in system console codepage into the 
character grid, capture those character tiles in UCS-2 if possible, and then 
output the current console codepage number.   #include <windows.h>  
#include <stdio.h>  int main(){  HANDLE 
hConsole=GetStdHandle(STD_OUTPUT_HANDLE);  CHAR_INFO screen[256];  COORD 
size={16,16,};  COORD pos={0,0,};  SMALL_RECT rect={0,0,15,15,};  for(int 
i=0;i<256;i++){  screen[i].Attributes=0xF0;  screen[i].Char.AsciiChar=i;  }  
WriteConsoleOutputA(hConsole,screen,size,pos,&rect);  CHAR_INFO 
screenu[256];  if(ReadConsoleOutputW(hConsole,screenu,size,pos,&rect)){  
for(int i=0;i<256;i++) printf("%04X ",screenu[i].Char.UnicodeChar);  
}  else{  printf("error %08X\n",GetLastError());  }  
printf("codepage %u",GetConsoleOutputCP());  }   In most cases, 
whenever a legacy Win32 codepage is used, the application can run on Windows NT 
to capture the UCS-2 mapping of those character cells to the BMP (although for 
CJK codepages a more complex setup would be necessary due to thousands of 
fullwidth characters with 2-byte sequences).   However, in Arabic versions of 
Windows 9x (95/98/ME) the resulting character set has many presentation forms 
that are not in Unicode. This is the result when running on Windows ME:  
i.imgur.com https://i.imgur.com/QFm3SkI.png  in 10×20 font,  i.imgur.com 
https://i.imgur.com/KUbLQ0A.png  in 10×18 font (same result also appears in 
Windows 95/98). 5×12, 7×12, 8×12, 10×18, 10×20, and 12×16 bitmap fonts have 
been attested with that character set (VGAOEM.FON, 8514OEM.FON, DOSAPP.FON). 
The 10×20 font has slightly different mapping than the other sizes: 0x93 is ö 
instead of ô, and 0x97 is missing (causing the following characters on the same 
line to be drawn at the wrong position). It also claims to be using codepage 
720, but many characters differ from their CP720 mappings, including the 
bundled CP_720.NLS mappings (for example, ـ (U+0640 ARABIC TATWEEL) is 0x95 in 
CP720, but in the console 0x95 is ش instead, and the tatweel is at 0xFF). On 
Windows 9x, ReadConsoleOutputW is not supported so the UCS-2 mappings of the 
console character tiles cannot be captured (error 0x00000078 
ERROR_CALL_NOT_IMPLEMENTED).   When that program runs on Arabic versions of 
Windows NT, the visual output is of the CP437 character set if one of the 
bundled bitmap fonts is used ( i.imgur.com https://i.imgur.com/RxjtxMH.png ), 
or the CP720 set if Lucida Console is used, with the Arabic letters either 
having glitchy font substitution (NT 4.0, NT 5.0/2000) or the .notdef glyph (NT 
5.1/XP and up). In fact, it seems that the only Arabic bitmap fonts that occur 
in Windows NT are CP1256 fonts, which are not used in terminals. So this 
appears to be one of those permanent Windows compatibility regressions that 
occured when Windows 9x ended, where the terminals can no longer render legacy 
Arabic text. Even if the user managed to use registry hacks to set the font to 
Courier New or Simplified Arabic Fixed, it would still use the CP720 mapping 
which is not compatible with the Windows 9x set.   It appears that in the 
Windows 9x Arabic terminal character set, 244 characters ( 
ﺀﺁﺂﺃﺄﺅﺇﺈﺊﺋﺍﺎﺏﺑﺓ►◄↕ﺕ¶§ﺗﺙ↑↓→←ﺛﹰ▲▼ 
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ﺝﺟﺡéâﺣàﺥçêëèïîﺧﺩﺫﺭﺯôﺳûùﺷﺻ£ﺿﻁﻅﻉﻊﻋﻌ
 are already in Unicode, but 12 characters are not in Unicode:  • 6 of them are 
pieces of lam-alef ligatures (0xDD, 0xDE, 0xF9, 0xFB, 0xFC, 0xFD)  • 2 of them 
are shadda with fathatan ligatures without or with tatweel (0xD0, 0xD1)  — in 
some legacy Microsoft fonts, shadda with fathatan is mapped to private use 
U+E818  • 4 of them are disunifications of seen/sheen/sad/dad occuring either 
with or without tail  — ﹳ (U+FE73 ARABIC TAIL FRAGMENT) was originally encoded 
in Unicode 3.2 for CP864 compatibility; in that codepage, the forms of 
seen/sheen/sad/dad attach to the tail fragment  — forms with included tail: 
0x92, 0x95, 0x98, 0x8A  — forms without tail (attaching to tail fragment like 
in CP864): 0xF3, 0xF4, 0xF5, 0xF6   If someone tried to make a Win32 console 
implementation and tried to implement both Windows 9x Arabic terminal character 
set compatibility and wide string API (ReadConsoleOutputW) compatibility 
simultaneously, then they would run into the issue that there is currently no 
standardized mapping to handle that scenario. What should Windows 9x Arabic 
console compatible implementations do in that case?