Microsoft, continuing in their streak of open sourcing software from the early days of the IBM PC and its platform, has open sourced 86-DOS 1.00, as written by Tim Paterson. They have provided both the source code files and, possibly more interesting to many here, Mr. Paterson has uploaded the original source code listings, some hand-annotated!
The announcement:
The code:
The scans:
As the Microsoft announcement points out, these artifacts provide a window into not only how we see the development of early software today, but also how it was done at the time, by including source code, source for development tools such as the assembler, and physical artifacts of the development process. This includes notes, assembler output, and ephemera.
The physical artifacts themselves were donated to the Interim Computer Museum and will apparently be available for viewing at some point in the future.