From the blog "HLO projects"
Uno for the Atari 8-bit in Atari Microsoft BASIC
I wrote for the Atari 8-bit in Atari Microsoft BASIC. But I did later translate the program to the TI-99 (see Games/Mygame section).
Not a lot of people knew Microsoft wrote a BASIC for the Atari 8-bit line. Fact is Atari Microsoft BASIC was going to be 'the' BASIC for the Atait 8-bit line. The only thing that stopped from being the de-facto BASIC for the Atari was that Atari had a requirement that the BASIC had to fit in a 8k cartridge