I believe MS has now officially released the sources to MS-DOS 1.x, 2.x, and 4; but most of 3.x and 6.x were leaked many years ago, so I wonder if that's the re

I believe MS has now officially released the sources to MS-DOS 1.x, 2.x, and 4; but most of 3.x and 6.x were leaked many years ago, so I wonder if that's the reason they skipped 3.