On Mon, 8 Jan 2024, 'Jay LaBonte' via Pick and MultiValue Databases wrote:
> Correct me if I’m wrong, but didn’t Microsoft purchase CP/M-80 aka QDOS in 1981 which was licensed to IBM as PC-DOS.
>
Not even close. :)
"QDOS" was developed by Tim Patterson at Seattle Computer Products in
1980. It used the same calling convention as CP/M-80 in order to make
porting programs a lot easier. It was later renamed 86-DOS (1980/81) and
Bill Gates got wind of it, bought it and renamed it MS-DOS in order to
provide IBM with an OS for the IBM PC. Both MS-DOS and PC DOS started
from 86-DOS.