Code page 866

Code page 866 (CP 866) is a code page used under DOS and OS/2 to write Cyrillic script. It is based on the "alternative character set" of GOST 19768-87. The code was widely used during the DOS era because it preserves the pseudographic symbols (unlike Windows-1251) and maintains alphabetical order (although non-contiguously) of Cyrillic letters (unlike KOI8-R).

Each character is shown with its equivalent Unicode code point and its decimal code point. Only the second half of the table (code points 128–255) is shown, the first half (code points 0–127) being the same as ASCII.

IBM code page 808 is a variant of code page 866; the only difference is the euro sign (€) in position FD_hex (253) replacing the universal currency sign (¤).

Before Microsoft's final code page for Russian MS-DOS 4.01 was registered with IBM by Franz Rau of Microsoft as CP866 in January 1990, draft versions of it developed by Yuri Starikov (Юрий Стариков) of Dialogue were still called code page 900 internally. While the documentation was corrected to reflect the new name before the release of the product, sketches of earlier draft versions still named code page 900 and without Ukrainian and Belarusian letters, which had been added in autumn 1989, were published in the Russian press in 1990. Code page 900 slipped through into the distribution of the Russian MS-DOS 5.0 LCD.CPI codepage information file.

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