Timeline of DOS operating systems

This article presents a timeline of events in the history of x86 DOS operating systems from 1973 to 2016. Other operating systems named "DOS" are generally not part of the scope of this timeline.

DOS releases have been in the forms of:
 * OEM adaption kits (OAKs) – all Microsoft releases before version 3.2 were OAKs only
 * Shrink wrap packaged product for smaller OEMs (system builders) – starting with MS-DOS 3.2 in 1986, Microsoft offered these in addition to OAKs
 * End-user retail – all versions of IBM PC DOS (and other OEM-adapted versions) were sold to end users. DR-DOS began selling to end users with version 5.0 in July 1990, followed by MS-DOS 5.0 in June 1991
 * Free download – starting with OpenDOS 7.01 in 1997, followed by FreeDOS in 1998

1973–1980: Hardware foundations and CP/M

 * 8-bit CP/M : First licensed release

1.3

1.4

2.0

3.0

1980–1995: Important events in DOS history
1980

81

82

83

84

85

86

87

88

89

1990

91

92

93

94

95