I remember that MS carried a special version of MSDOS
for people who need to
modify the code for specific hardware. Certain portions of DOS are provided
as source and the rest as object code.
Does anyone have a copy of this?
No, but I think you can get such stuff from Annasoft (a spinoff of Annabooks).
I think Micros~1 licensed them to sell the embedded versions of DOS,
Windows, etc.
http://www.annasoft.com/