Atari Microsoft BASIC

The Atari Microsoft BASIC and Atari Microsoft BASIC II variants of the 6502-version of Microsoft BASIC ported to the Atari 8-bit machines. The first version, released 1981, required 32 KB of RAM and was supplied on floppy disk. The second version, released the next year, had most of the code on a ROM cartridge with additional functions on an optional floppy.

Atari Microsoft BASIC was highly compatible with contemporary BASICs like AppleSoft BASIC and Commodore BASIC, in contrast to their own Atari BASIC which was a somewhat different dialect and incompatible in many ways. Like Atari BASIC, Atari Microsoft BASIC included a number of new commands and features to take advantage of the Atari platform. These were only partially compatible with the similar features of Atari BASIC.