CP866 is a Cyrillic codepage to be used with MS-DOS. It is based on the "alternative character set" of GOST 19768-87. The Cyrillic alphabet (or azbuka, from the old name of the first letters) is an alphabet used to write six natural Slavic languages (Belarusian, Bulgarian, Macedonian, Russian, Serbian, and Ukrainian) and many other languages of the former Soviet Union, Asia and Eastern Europe. ... Code page is the traditional IBM term used for a specific character encoding table: a mapping in which a sequence of bits, usually a single octet representing integer values 0 through 255, is associated with a specific character. ... Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ...

Codepage layout

Only the upper half (128–255) of the table is shown, the lower half (0–127) being plain ASCII. There are 95 printable ASCII characters, numbered 32 to 126. ...