Holy cow; you're right. I always knew it as Atari BASIC, then later (apparently mistakenly) learned that it was made by Microsoft. I was referring to Atari BASIC above, not realizing my error.

Thank you!

I also had Basic-A+ from OSS. I seem to recall it had a few slight convenience items (and better disk commands), but that I wished I hadn't spent the exorbitant amount of money it cost me as a 12 year old.