Microsoft open-sources "the earliest DOS source code discovered to date"
Microsoft has released the earliest known source code for DOS, dating back to the original 86-DOS operating system created by Tim Paterson. The release includes documentation and notes transcribed by the DOS Disassembly Group.
Microsoft is releasing the earliest DOS source code discovered to date, tracing back to the original 86-DOS operating system developed by Tim Paterson. The DOS Disassembly Group painstakingly transcribed and scanned the code from paper printouts due to difficulties with modern OCR software. This release follows previous open-source releases of MS-DOS versions from 2014, 2018, and 2024…
Imagine a really old computer game that started it all – MS-DOS. Tim Paterson made the very first version, called 86-DOS. Microsoft bought the rights and made it into MS-DOS, which became super popular. Now, a group of people found old paper copies of the game’s instructions (the source code). They carefully copied them down, because computers weren’t good at reading old paper. Microsoft is sharing these instructions so people can learn how MS-DOS was made. They’ve done this before with other old Microsoft programs, like a game called Zork and a movie maker. It’s like finding the original blueprints for a famous building – it helps us understand how it was built!
Analysis
Microsoft has released the earliest known source code for the 86-DOS operating system, predating the MS-DOS branding. This release, spearheaded by the DOS Disassembly Group led by Yufeng Gao and Rich Cini, represents a significant step in preserving the history of early PC computing. The group painstakingly transcribed and scanned the code from paper printouts provided by Tim Paterson, the original creator of 86-DOS. According to the article, modern OCR software struggled with the quality of the decades-old printouts, highlighting the challenges involved in recreating this historical artifact. Microsoft has previously released source code for MS-DOS versions in 2014, 2018, and 2024, alongside other projects like Zork and 3D Movie Maker. The open-source remake of the old MS-DOS Editor isn't a direct replacement for the original EDIT.COM, but it aims to provide a modern equivalent. The discovery of this code follows a similar event in 2024, when the earliest known version of 86-DOS was rediscovered and uploaded to the Internet Archive, further demonstrating the ongoing efforts to preserve this critical piece of computing history. The release is part of a broader trend of Microsoft open-sourcing historical software projects, allowing researchers and enthusiasts to study and understand the evolution of its operating systems.
Key points
- Microsoft released the earliest known source code for 86-DOS, predating MS-DOS.
- The DOS Disassembly Group painstakingly transcribed the code from paper printouts.
- This release follows previous open-source releases of MS-DOS versions.
- The project highlights the importance of preserving computing history.
