Microsoft makes 86-DOS 1.00 open source on its 45th birthday

History painstakingly preserved.
Tom's Hardware on MSN

45 years later, earliest DOS source code transcribed from a stack of old printouts found in garage

Microsoft VP confirms transcribed document “is perfect and recompiles byte for byte to the original binaries.” ...

Microsoft open-sources 86-DOS 1.00, the ancestor of Windows

The source code for 86-DOS 1.00, the OS that eventually became MS-DOS and Windows, is now available on GitHub.

Microsoft open-sources “the earliest DOS source code discovered to date”

For students of early PC history, this isn’t even the first piece of 86-DOS history that has been newly rediscovered this ...