1.0 -- 1981 -- Supported 8088 CPUs using 160K single sided floppy disks. Only the 7 bit ASCII character set was built into the OS although the eighth bit in the byte was carried along and displayed/saved/etc.
1.25 -- 1982 -- Supported floppy drives with heads on both sides of the disk. MSDOS 1.0 required modifying the disk by cutting a second locator notch and manually flipping the floppy disk to get to the second 160K. Supported non-IBM hardware.
2.0 -- 1983 -- added support for 360K floppies and 10mb hard drive. Incorporated optional file-handle based file IO. Added IO redirection and piping.
2.11 -- 1983 -- support for 8 bit characters (i.e. for languages using characters with values 128-255)
3.0 -- 1984 -- support for 1.2MB floppies and hard drives to 32MB
3.1 -- 1984 -- allowed "drive letters" to reference external (network) storage (Network Redirector)
3.2 -- 1986 -- allowed an extended disk partition up to 32MB in addition to the primary partition. 720K floppy support
3.3 -- 1987 -- PS/2 support. 1.44MB Floppies. Code Pages. Multiple disk partitions.
4.0 -- 1988 -- FAT16 (disks to 2.14GB). Extended Memory support. Code Pages (alternate national character sets). Graphical User Shell. The release had annoying bugs and excessive memory footprint.
4.1 -- 1988 -- Bug fixes (lots of them)
5.0 -- 1990 -- Many more bug fixes. High/Upper Memory Support. 2.88MB Floppies. Disk caching. Disk file undelete. EDIT replaced EDLIN
5.0a -- 1991/2 -- Bug fixes for CHKDSK/UNDELETE
6.0 -- 1993 -- Disk Compression. Anti-Virus and Backup utilities. MOVE command. Graphical Shell shipped separately.
6.2 -- 1993 -- Compression bug fixes. Upgrades to disk handling -- SCANDISK, DISKCOPY, Smartdrive
6.21 -- 1993 -- Disk Compression temporarily removed because of legal issues
6.22 -- 1994 -- Disk Compression returned with a slightly altered name (DRVSPACE vs DBLSPACE).
7.0 -- 1995 -- Released as part of Windows 95. Long File Name Support. Some utilities (e.g. UNDELETE) removed.
7.1 -- 1997 -- Released with Windows 95 OSR2. Support for FAT32.
8.0 -- 2000 -- Released with Windows Me. Removes support for SYS command and other features removed in Windows Me.
There are/have been several MSDOS clones and extensions -- Freedos, QDOS(ndos), DRDOS, 4DOS, OpenDOS, PCDOS. OS/2 and Windows NT/2000/XP support and sometimes expand upon most MSDOS capabilities.
Return To Index Copyright 1994-2017 by Donald Kenney.