Following is a list of DOS versions since its inception in 1981:
Version Major new features
1.0 1981 8-sector 160KB floppy (SS).
1.05 Bug fix.
1.1 1982 8-sector 320KB floppy (DS).
2.0 1983 10M hard disk, 9-sector 360KB floppy,
directories, more batch commands.
2.1 1983 PCjr cartridge support and bug fixes.
3.0 1984 20MB hard disk, 1.2MB floppy, VDISK,
PATH, new commands.
3.1 1985 Network support, bug fixes.
3.2 1986 720KB floppy, new commands.
3.3 1987 1.44MB floppy, FDISK partitions.
4.0 1988 Menu and mouse support (DOS shell),
improved commands, EMS support,
512MB hard disks.
4.01 1988 Bug fix (4.0 rarely used).
5.0 1991 Major upgrade: new DOS shell, ability
to use high memory, task swapping,
online help, new text editor,
2GB hard disks, 2.88MB floppies,
enhanced commands.
5.02 1992 IBM version (PC-DOS 5.02), includes
ISO fonts for European compatibility,
power management and file transfer
6.0 1993 Includes built in disk compression
and various utilities for antivirus,
backup, undelete and file transfer.
6.1 1993 IBM version (PC-DOS 6.1), includes
different utilities than MS-DOS 6.0.
6.2 1993 MS version (MS-DOS 6.2), 6.0 bug fix.
6.21 1994 MS version (without DoubleSpace)
6.3 1994 IBM version (PC-DOS 6.3), upgrade.
6.22 1994 MS version with Microsoft's own
DriveSpace compression.
7.0 1995 IBM version (PC-DOS 7.0) includes
enhancements.
7.0 1995 The MS-DOS 7 in Windows 95