Forty-five years ago, in April 1980, a young employee at Seattle Computer Products began developing a small disk operating system for the new Intel 8086-based board. Against all odds, this modest project evolved into software that would power the PC industry for over a decade: Microsoft’s MS-DOS.This is a story about development of 86-DOS, better known by its code name QDOS1 before it was sold to Microsoft.The two main sources I used are Tim Paterson's blogs from 2007 and Vintage Computer Federa...