Microsoft has shared the source code for 86-DOS 1.00 on GitHub, putting online the 45-year-old precursor to MS-DOS that helped shape early PC software. [1]
86-DOS was built by Tim Paterson for an Intel 8086-based computer kit sold by Seattle Computer Products. Microsoft later licensed the system for the IBM PC 5150 and hired Paterson to keep working on it in 1981. [1]
The code was not kept in a digital archive. Instead, it survived in print-outs held by Paterson, which a team of historians and preservationists led by Yufeng Gao and Rich Cini located, scanned and transcribed to rebuild the source. [1]
Microsoft renamed the operating system MS-DOS in 1982, but it kept the 86-DOS version numbers. The company has also released source code for MS-DOS 1.25, 2.0 and 4.0 as open source. [1]
The newly published 86-DOS 1.00 code adds an earlier chapter to the software’s public record and lands on the operating system’s 45th birthday. [1]
