MS-DOS History
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Version Date Comments
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1.0 1981 The original version of MS-DOS. This was a renamed version
of QDOS which had been purchased by an upstart company called
Microsoft.
1.25 1982 This added support for double-sided disks. Previously the disk
had to be turned over to use the other side
2.0 1983 This added support for IBM's 10 MB hard disk, directories and
double-density 5.25" floppy disks with capacities of 360 KB
2.11 1983 Support for foreign and extended characters was added.
3.0 1984 Support for high-density (1.2 MB) floppy disks and 32 MB hard
disks was added.
3.1 1984 Network support was added.
3.3 1987 This release was written to take advantage of IBM's PS/2 computer
range. It added support for high density 3.5" floppy disks, more
than one partition on hard disks (allowing use of disks bigger than
32 MB) and code pages.
4.0 1988 This version provided XMS support, support for partitions on hard
disks up to 2 GB and a graphical shell. It also contained a large
number of bugs and many programs refused to run on it.
4.01 1989 The bugs in version 4.0 were fixed.
5.0 1991 This was a major upgrade. It allowed parts of DOS to load
itself in the high memory area and certain device drivers and
TSRs to run in the unused parts of the upper memory area
between 640K and 1024K. This version also added support for IBM's
new 2.88 MB floppy disks. An improved BASIC interpreter and text
editor were included, as was a disk cache, an undelete utility
and a hard-disk partition-table backup program. After the problems
with MS-DOS 4, it also provided a utility to make programs think
they were running on a different version of MS-DOS.
5.0a 1992/3 This was a minor bug fix which dealt with possibly catastrophic
problems with UNDELETE and CHKDSK.
6.0 1993 This was a catch-up with Novell's DR-DOS 6. It added a disk-
compression utility called DoubleSpace, a basic anti-virus
program and a disk defragmenter. It also finally included a MOVE
command, an improved backup program, MSBACKUP and multiple boot
configurations. Memory management was also improved by the addition
of MEMMAKER. A number of older utilities, such as JOIN and RECOVER
were removed. The DOS Shell was released separately as Microsoft felt
that there were too many disks.
6.2 1993 Extra security was built into DoubleSpace following complaints
of data loss. A new disk checker, SCANDISK, was also introduced,
as well as improvements to DISKCOPY and SmartDrive .
6.21 1993 Following legal action by Stac Electronics, Microsoft released
this version which had DoubleSpace removed. It came with a voucher
for an alternative disk compression program.
6.22 1994 Microsoft licenced a disk-compression package called DoubleDisk from
VertiSoft Systems and renamed it DriveSpace, which was included in
this version.
7.0 1995 This version is part of the original version of Windows 95. It
provides support for long filenames when Windows is running, but
removes a large number of utilities, some of which are on the Windows
95 CD in the \other\oldmsdos directory.
7.1 1997 This version is part of OEM Service Release 2 and later of Windows
95. The main change is support for FAT 32 hard disks, a more efficient
and robust way of storing data on large drives.
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