Overview
- Microsoft, which released the trove Tuesday on its open‑source channels, posted the code on GitHub under an MIT license with original scans on Archive.org.
- The collection includes the 86‑DOS 1.00 kernel, several in‑progress PC‑DOS 1.00 kernels, classic tools like CHKDSK, and even listings of the assembler used to build them.
- Many files come from continuous‑feed printer listings preserved by 86‑DOS author Tim Paterson, whose garage printouts include handwritten notes that show fixes and feature adds as they happened.
- A volunteer team led by Yufeng Gao and Rich Cini has scanned and transcribed most of the material, with two of ten print bundles still in progress, and the project welcomes community help to verify and build using the original Seattle Computer Products assembler.
- The release centers on education and preservation, tracing the code that Microsoft licensed and later bought from Seattle Computer Products for the IBM PC, which became PC‑DOS and then MS‑DOS for clone makers.