VERSION - Versions of DOS
Version Date Changes
PC-DOS 1.0 Oct 1981 original release, single sided drive
PC-DOS 1.1 Jun 1982 bugfix, double sided drive support
MS-DOS 1.25 Jun 1982 for early compatibles
PC-DOS 2.0 Mar 1983 PC/XT, added (hard drive &UNIX features)
PC-DOS 2.1 Oct 1983 PCjr & portable mods, fixes for 2.0
MS-DOS 2.11 Oct 1983 compatible equivalent to 2.1
PC-DOS 3.0 Aug 1984 support for 1.2 Mb drive (AT)
PC-DOS 3.1 Nov 1984 added network support, fixes for 3.0
MS-DOS 2.25 Oct 1985 compatible; foreign language support
PC-DOS 3.2 Jul 1986 720k 3½" drive support for Convertible
MS-DOS 3.2 Jul 1986
MS-DOS 3.21 May 1987
MS-DOS 3.3 Jul 1987
PC-DOS 3.3 Apr 1987 PS/2, 1.44 disk support, mult. partitions
MS-DOS 3.30a Feb 1988
CPQ-DOS 3.31 Oct 1988 Compaq DOS for disk partitions > 32MB
PC-DOS 4.00 Aug 1988 Larger DOS partitions, EMS support (bugs)
MS-DOS 4.00 Oct 1988
MS-DOS 4.01 Nov 1988
MS-DOS 4.01a Apr 1989
PC-DOS 4.01 ??? ???? Fixes for major bugs in 4.0
- release dates vary between OEM versions
- IBM was supposedly responsible for most changes in DOS 4.x
- DOS 4.01 reports version 4.0, except in some vendor versions
- DOS 5.0 is primarily a Microsoft developed version