This article details versions of MS-DOS, IBM PC DOS, and at least partially compatible disk operating systems. It does not include the many other operating systems called "DOS" which are unrelated to IBM PC compatibles.
Historical and licensing information
Originally MS-DOS was designed to be an operating system that could run on any computer with a 8086-family microprocessor. It competed with other operating systems written for such computers, such as CP/M-86 and UCSD Pascal. Each computer would have its own distinct hardware and its own version of MS-DOS, a situation similar to the one that existed for CP/M, with MS-DOS emulating the same solution as CP/M to adapt for different hardware platforms. So there were many different original equipment manufacturer (OEM) versions of MS-DOS for different hardware. But the greater speed attainable by direct control of hardware was of particular importance, especially when running computer games. So very soon an IBM-compatible architecture became the goal, and before long all 8086-family computers closely emulated IBM hardware, and only a single version of MS-DOS for a fixed hardware platform was all that was needed for the market. This specific version of MS-DOS is the version that is discussed here, as all other versions of MS-DOS died out with their respective systems. One version of such a generic MS-DOS (Z-DOS) is mentioned here, but there were dozens more. All these were for personal computers that used an 8086-family microprocessor, but which were not fully IBM PC compatible.
{| class="sortable wikitable" style="font-size: 85%; text-align: center; width: auto;"
|-
! style="width: 12em" | Name
! First public release date
! style="width: 11em" | Creator
! Owner or maintainer
! License
|-
! | 86-DOS 1.00
|
| Seattle Computer Products
|
| rowspan="2" , MIT License
|-
! | PC DOS 1.0
|
| rowspan="10" | Microsoft (for IBM)
| rowspan="13"
|-
! | PC DOS 1.1
|
| rowspan="13"
|-
! | PC DOS 2.0
|
|-
! | PC DOS 2.1
|
|-
! | PC DOS 3.0
|
|-
! | PC DOS 3.1
|
|-
! | PC DOS 3.2
|
|-
! | PC DOS 3.3
|
|-
! | IBM DOS 4.0<br/>(called PC DOS 4.0)
|
|-
! | IBM DOS 5.0<br/>(called PC DOS 5.0)
|
|-
! | PC DOS 6.1, PC DOS 6.3
|
| rowspan="4" | IBM
|-
! | PC DOS 7.0 (revision 0)
|
|-
! | PC DOS 2000<br/>(PC DOS 7.0 revision 1)
|
|-
! | PC DOS 7.10
|
|
|-
! | MS-DOS 1.25 (first version named "MS-DOS")
|
| Microsoft
| rowspan="16"
| , MIT License
|-
! | Z-DOS 1.25
|
| OEM Zenith Data Systems
|
|-
! | MS-DOS 2.0
|
| rowspan="15" | Microsoft
| , MIT License<!--outdated link? i.e. it seems to have unrelated content now, maybe right one is in archive.org-->
|
|
|-
! | DOS Plus 1.1, 1.2/1.2a
|
| rowspan="6" | Digital Research
| rowspan="7"
|-
! | DOS Plus 2.1
|
|-
! | DR DOS 3.31-3.35
|
|-
! | DR DOS 3.40-3.41
|
|-
! | DR DOS 5.0
|
|-
! | DR DOS 6.0
|
|-
! | Novell DOS 7
|
| Novell
|-
! | Caldera OpenDOS 7.01
| rowspan="2" |
| rowspan="3" | Caldera, Inc.;<br />Caldera UK, Ltd.
| officially;<br/>a derivative, Enhanced DR-DOS, was<br/>maintained by Udo Kuhnt until 2011
| rowspan="2" , free non-commercial use
|-
! | Caldera DR-OpenDOS 7.02
| rowspan="2"
|-
! | Caldera DR-DOS 7.02
|
| rowspan="4"
|-
! | Caldera DR-DOS 7.03
| 1999, 1998 prereleased
| Caldera Thin Clients, Inc.;<br />Caldera UK, Ltd;<br/>Lineo, Inc.
|
|-
! | DR-DOS 8.0
|
| DeviceLogics
| rowspan="2"
|-
! | DR-DOS 8.1
|
| DRDOS, Inc.
|-
! | FreeDOS 1.0
|
| rowspan="4" | Jim Hall, et al.
| rowspan="4"
| rowspan="4" , GPL
|-
! | FreeDOS 1.1
|
|-
! | FreeDOS 1.2
|
|-
! | FreeDOS 1.3
|
|-
! | PTS-DOS 6.4
|
| rowspan="5" | PhysTechSoft
| rowspan="5"
| rowspan="11"
|-
! | PTS-DOS 6.5
| rowspan="4" | ?
|-
! | PTS-DOS 6.6
|-
! | PTS-DOS 2000 (6.7)
|-
! | PTS-DOS 32 (7.0)
|-
! | PTS-DOS 6.51
| ca.
| rowspan="2" | Paragon Technology Systems
| rowspan="2"
|-
! | Paragon DOS 2000 Pro
| rowspan="4" | ?
|-
! | ROM-DOS 6.22
| rowspan="2" | Datalight
| rowspan="2"
|-
! | ROM-DOS 7.1
|
| NorthStar 87.5 KB<!-- SD/1S hard-sectored -->; Cromemco 90 KB<!-- SD/1S soft-sectored (WD1771) -->
| Cromemco/Tarbell 250.25 KB<!-- SD/1S (WD1771) -->;<!-- 500.5 KB SD/2S (WD1771); --> Tarbell 616 KB<!-- DD/1S (WD1791) -->; Tarbell 1232 KB<!-- DD/2S (WD1791) --><!-- 250 KB format also supported by Cromemco controller. Not sure if 500 KB format supported at all by Tarbell or Cromemco right now. -->
|
|
|-
! | MS-DOS 1.25<!-- 1.25 was the first MS-DOS release under this name. -->
|
| FAT12
|
| 160 KB; 320 KB
| 250.25 KB<!-- Since MS-DOS 1.25 already supported the 2S-format 320 KB, it appears likely that the 8" 500 KB format was supported as well, but I could not find this documented anywhere so far. Earlier versions of MS-DOS 1.1x did not support 2S-formats, whereas 86-DOS did. -->
|
|
|-
! | MS-DOS 2.0-2.11
| 16 MB (32 MB with third-party FORMAT)
| FAT12
|
| 160 KB; 180 KB; 320 KB; 360 KB
| 250.25 KB;
|
|
|-
! | MS-DOS 3.0
| 32 MB
| FAT12, FAT16
|
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 3.1
| 32 MB
| FAT12, FAT16
|
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 3.2
| 32 MB
| FAT12, FAT16
| 720 KB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 3.3
| 32 MB
| FAT12, FAT16
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 3.31
| 512 MB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 4.0
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 5.0
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB, 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 6.0
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 6.20
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 6.21
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 6.22
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 7.0 (Windows 95A)
| 2 GB
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 7.1 (Windows 95B/OSR2, Windows 95C/OSR2.5, Windows 98, and Windows 98SE)
| 124.55 GB with FAT32
| FAT12, FAT16, FAT16B, FAT32
| 720 KB; 1.44 MB, 2.88 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
|
|
|
|-
! | MS-DOS 8.0 (Windows Me and later Windows versions) (720 KB)
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB; Acorn 640 KB; Acorn 800 KB; CP/M 320 KB
|
|
|
|-
! | DR DOS 3.31-3.35
| 2 GB<!-- 512 MB why? -->
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
| <!-- DR DOS 3.31 is known not to support the 243 KB aka 250.25 KB format supported by at least 3.41 and higher. Versions 3.32-3.35 and 3.40 currently unknown. -->
|
|
|-
! | DR DOS 3.40-3.41
| 2 GB<!-- 512 MB why? -->
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
| (250.25 KB)
|
|
|-
| | DR DOS 5.0
| 2 GB<!-- 512 MB why? -->
| FAT12, FAT16, FAT16B
| 720 KB; 1.44 MB
| 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB
| (250.25 KB
</references>
External links
- Detailed timeline of DOS variants
- DR-DOS version dates