Microsoft is continuing its efforts to release early versions of DOS as open source, and today we’ve got a special one.
We’re stoked today to showcase some newly available source code materials that provide an even earlier look into the development of PC-DOS 1.00, the first release of DOS for the IBM PC. A dedicated team of historians and preservationists led by Yufeng Gao and Rich Cini has worked to locate, scan, and transcribe the stack of DOS-era source listings from Tim Paterson, the author of DOS.
The listings include sources to the 86-DOS 1.00 kernel, several development snapshots of the PC-DOS 1.00 kernel, and some well-known utilities such as CHKDSK. Not only were these assembler listings, but there were also listings of the assembler itself! This work offers rare insight into how MS-DOS/PC-DOS came to be, and how operating system development was done at the time, not as it was later reconstructed.
↫ Stacey Haffner and Scott Hanselman
It’s wild that the source code had to be transcribed from paper, including notes and changes. You can find more information about the process on Gao’s website and Cini’s website.
Scott is a very good “ambassador” at Microsoft. I don’t know what his title is, but he is the one that pushed for .Net becoming open source and reaches out with these kinds of projects.
It is nice to see there are some teams over there really invested in being “librarians” of computer history. Wish more companies have teams dedicated to this.
Less than 4k lines of assembly code…wow that’s nothing.
Then again, I think IBM PCs were sold with 64k of RAM so the OS had to be slim!
The 8088 had 20 bit addressing for 1MB support, but this had to be shared with BIOS, video memory and was probably unobtainium in 1980, haha. Now 8GB is considered low end and my home computer has a million times more ram!