Microsoft earlier today, in collaboration with IBM, announced that it is open-sourcing the MS-DOS 4.00 source code. The company has explained what was special about it and how to run it.
Ibm pc-xt RSS
The IBM PC-XT had a lot more expansion slots compared to the first IBM PC that launched in 1981, but it was not as big of a leap in other hardware specs. It also had a rival PC in the Compaq Portable.
