In cooperation with the excellent Computer History Museum in Mountain View, Microsoft released the source code to MS-DOS 1.1, MS-DOS 2.0, and Microsoft Word for Windows 1.1a.
Here’s hoping that this is a sign of things to come and Microsoft will also release the source code to historic versions of Windows 1.x, 2.x and 3.x, further versions of MS-DOS—and maybe even OS/2 1.0!
The poor CHM server is currently suffering from a severe overload so actually looking at the goodies will have to wait…
Later: Yes, it’s the real thing. There’s the MS-DOS source code, and even more—someone left in a few WordStar overlay files. Somehow I doubt Microsoft is legally allowed to redistribute files with “COPYRIGHT (C) 1982, MICROPRO INTERNATIONAL” in them… oh well.
The DOS 1.1 source code seems to be a somewhat random collection of files saved by Tim Paterson, as used by SCP.
The 2.0 source code appears to have been taken from a MS-DOS 2.0 OAK… which means no useful IO.SYS source code. On the other hand, there is a smattering of documentation.
All in all, fun stuff!
Why not simply using the included SCP 8086 assembler or easier the MASM 1.10? And don’t ask which machines where used for building.
Regarding io.sys, I’d be willing to create a new one, but my x86-fu isn’t good enough.
I’ve rolled msdos.sys and command.com from 1.25, though, didn’t take a lot of work but it did take an ancient MASM.
I try compile MS-DOS 1.25 Source Code but Microsoft MASM give errors. I do not know Microsoft MASM it work with. I did anybody compile MS-DOS 1.25 Source Code.