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This is the character set and the ROM font of the Soviet VT52-compatible text terminal 15ИЭ-00-013, notably used with the PDP-11-compatible workstation computer Электроника 60, on which the original version of #Tetris was made in 1985.

There are two parallel ASCII-derived character sets that may co-exist on the screen but (AFAIK) need special control codes to switch between. Each alphabetic character has a unique pixel shape, so it is possible to visually distinguish e.g. a Latin A from a Cyrillic A.

Source: original documentation linked to by the Russian Wikipedia page of the 15ИЭ-00-013.