Open sourcing MS-DOS 4.0 - Microsoft Open Source BlogTen years ago, Microsoft released the source for MS-DOS 1.25 and 2.0 to the Computer History Museum, and then later republished them for reference purposes. This code holds an important place in history and is a fascinating read of an operating system that was written entirely in 8086 assembly code nearly 45 years ago. Today, in partnership with IBM and in the spirit of open innovation, we're rele
