MS-DOS

Logo of MS-DOS

MS-DOS (Microsoft Disk Operating System) is an operating system for x86 based personal computers. It was based on 86-DOS (Quick and Dirty Operating System), also known as 86-DOS, which was made by Tim Paterson and purchased by Microsoft. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for personal computers during the 1980s and 1990s. It was preceded by M-DOS (also called MIDAS), designed and copyrighted by Microsoft in 1979. MS-DOS was written for the Intel 8086 family of microprocessors, particularly the IBM PC and compatibles. An MSX port was also made, called MSX-DOS.

It was gradually replaced on consumer desktop computers by operating systems offering a graphical user interface (GUI), in particular by various generations of the Microsoft Windows operating system. It is still used by a tiny market niche where legacy DOS applications are still required, but no modern version is available.

Microsoft and IBM both had their own versions of MS-DOS. There are not many differences between the two versions before the split up, when IBM started developing PC-DOS independently of Microsoft. IBM distributed their version of MS-DOS first as IBM DOS (prior to version 5.0), and later on as IBM PC-DOS.

Known versions

MS-DOS 1.x

• MS-DOS 1.11 - Internal version from 1981
• MS-DOS 1.12 - Internal version from 1981
• MS-DOS 1.13 - Internal version from 1981
• MS-DOS 1.20 - Internal version from 1981
• MS-DOS 1.21 - Internal version from 1982
• MS-DOS 1.22 - Internal version from 1982
• MS-DOS 1.23 - Unknown OEM
• MS-DOS 1.24 - Unknown OEM
• MS-DOS 1.25 - Corona (BIOS 1.03 and 1.07), Zenith (command.com 1.19 for the Zenith Z-100 PC Compatible series from 1984 and 1.20 for the Zenith Z-100 from 1982) and Sanyo OEM, Seattle Computers OEM (command.com 1.17 as part of the released MS-DOS 1.1 source package), and Columbia OEM (Rel. 2.11)

MS-DOS 2.x

• MS-DOS 2.00 - Olivetti (M20 with 8086 add-on), NCR, Apricot, Tandy, Seequa and Eagle OEM
• MS-DOS 2.01 - Wang OEM
• MS-DOS 2.02 - Compaq OEM
• MS-DOS 2.05 - DEC OEM
• MS-DOS 2.11 - AT&T, BULL, TeleVideo, Olivetti, Toshiba, Apricot, NEC for PC-98xx, NCR, Tandy and ITT OEM
• MS-DOS 2.11D - Ericsson OEM
• MS-DOS 2.12 - Compaq OEM
• MS-DOS 2.13 - Zenith OEM (Z-100)
• MS-DOS 2.21 - Zenith OEM (Z-100)
• MS-DOS 2.25 - Same as 2.11, but has better support for Japanese and Korean character sets. Released in October 1985, as stated in a Croatian computer magazine "Moj Mikro".

MS-DOS 3.x

• MS-DOS 3.00 - Apricot and Compaq OEM
• MS-DOS 3.06 - Apricot OEM
• MS-DOS 3.10 - Seiko Epson, Phoenix, Tandon, Apricot, Sperry, Fujitsu, Olivetti, Compaq and Multitech OEM, NEC for NEC PC-98
• MS-DOS 3.10C - RM Nimbus and Ericsson OEM
• MS-DOS 3.10L24 - Japanese, for Fujitsu FM-Towns
• MS-DOS 3.20 - HP, Amstrad, Apricot, AT&T, Tandy and Seiko Epson OEM
• MS-DOS 3.20E - BULL OEM
• MS-DOS 3.21 - Hyosung, KayPro, Zenith, Goupil, and Compaq OEM
• MS-DOS 3.22 - Twinhead OEM
• MS-DOS 3.30 - Amstrad, HP, Dell, NEC, Tulip, AT&T, Tandy, Olivetti, Tandon, Seiko Epson for PC-98xx and Toshiba OEM
• MS-DOS 3.30+ - Zenith OEM
• MS-DOS 3.30A - DTK OEM, also retail
• MS-DOS 3.30B - Schineider OEM and for NEC PC-98
• MS-DOS 3.30C - for NEC PC-98
• MS-DOS 3.30D - for NEC PC-98
• MS-DOS 3.30T - Tandy OEM
• MS-DOS 3.31 - Compaq and Olivetti OEM
• MS-DOS 3.31D - Compaq OEM
• MS-DOS 3.4 - Mentioned in the September 1988 issue of Serbian computer magazine "Svet Kompjutera" as well as PX00006

Multi-tasking MS-DOS 4.0

• MS-DOS 4.00 - A rare OEM version, capable of multi-tasking. Only released by some European OEMs, a working copy can be found online. (Unnamed OEM and Goupil OEM)

MS-DOS 4.x

• MS-DOS 4.00 - An extremely rare version which was quickly replaced by 4.01 due to bugs. Dated 06/10/1988, a Sampo OEM without disk 6 can be found online.
• MS-DOS 4.01 - Olivetti, Amstrad, Nokia, Tulip, HP, Toshiba, Zenith and VEGAS OEM
• MS-DOS 4.01A - Nokia OEM
• MS-DOS 4.02 - Unknown stage, mentioned in PX05132
• MS-DOS 4.10.20 - International Computer Ltd. OEM version

MS-DOS 5.x

• MS-DOS 5.00.070 - Beta, existance suggested by ROM-DOS 5.00.070 mentioned in PX05132
• MS-DOS 5.00.112 - Beta, mentioned in PX05132
• MS-DOS 5.00.217 - Beta, German claims to have it but existence unconfirmed
• MS-DOS 5.00.224 - Beta, leaked and also mentioned in PX05132
• MS-DOS 5.00.225 - Beta, mentioned in PX05132
• MS-DOS 5.00.226 - Beta, mentioned in PX05132
• MS-DOS 5.00.227 - Beta, mentioned in PX05132
• MS-DOS 5.00.333 - Beta, leaked and also mentioned in PX06476
• MS-DOS 5.00.409c - Beta, leaked - includes INFER (MSD prorotype), and where.exe, neither made it to the release.
• MS-DOS 5.00.432 - Beta, leaked and also mentioned in PX05243
• MS-DOS 5.00.460 - Beta, mentioned in PX08857
• MS-DOS 5.00.480 - Beta, mentioned in PX05243
• MS-DOS 5.00.481 - Beta, mentioned in PX03447
• MS-DOS 5.00.490 - Beta, leaked
• MS-DOS 5.00.500 - Beta, mentioned in PX05243
• MS-DOS 5.00.1180 - Unknown stage, mentioned in PX07621
• MS-DOS 5.00 RC1 - Release Candidate 1, mentioned in PX05243
• MS-DOS 5.00 RC3 - Release Candidate 3, mentioned in PX09027 with a date of 5th March 1991, also mentioned in a BBS list but hasn't been found yet
• MS-DOS 5.00 RC3A - Release Candidate 3A, incomplete leak
• MS-DOS 5.00 RC10 - Release Candidate 10, leaked
• MS-DOS 5.00 - HP, Dell, Compaq, Tandy and PC Kenitec OEM, Epson OEM (PC-98xx) - last common version with IBM.
• MS-DOS 5.00a - The 1991.11.11 release including the fixes previously released separately.
• MS-DOS 5.00a - Toshiba OEM
• MS-DOS 5.00A - for NEC PC-98
• MS-DOS 5.00A-H - for NEC PC-98
• MS-DOS 5.50 - The DOS in Windows NT is based on MS-DOS 5.00 code, some files directly copy this.

MS-DOS 6.x

The base versions are listed as including 'Enhanced Tools', this means what the retail upgrade is, was sold to OEMs as two packages. A separate disk is available of the supplemental files. These are mainly DOS 5 files removed, and random add-ons.

• MS-DOS 6.00.0015 - Beta, leaked and also mentioned in February 1993 issue of Serbian computer magazine "Svet Kompjutera"
• MS-DOS 6.00.0018 - Beta, mentioned in a BBS list but hasn't been found yet and thus can't be confirmed to exist
• MS-DOS 6.00.0108 - Beta, mentioned in a BBS list but hasn't been found yet and thus can't be confirmed to exist
• MS-DOS 6.00.0204 - Beta, references found in leaked MS-DOS 6.0 source code. Dos5 help renamed to doshelp, later renamed as fasthelp
• MS-DOS 6.00.0305 - Beta, mentioned in February 1993 issue of Serbian computer magazine "Svet Kompjutera"
• MS-DOS 6.00.0405 - Beta, mentioned in a BBS list but hasn't been found yet and thus can't be confirmed to exist
• MS-DOS 6.00 - HP, Packard Bell, Fujitsu and NEC OEM, Compaq OEM
• MS-DOS 6.20.3002 - Beta, Step-Up, leaked
• MS-DOS 6.20.RC1 - Release Candidate 1, leaked
• MS-DOS 6.20.RC2 - Release Candidate 2, leaked
• MS-DOS 6.20.RC3 - Release Candidate 3, leaked
• MS-DOS 6.20.RC5 - Release Candidate 5, Upgrade, leaked
• MS-DOS 6.20 - Retail, NEC OEM (PC-98xx)
• MS-DOS 6.20L10 - Japanese, for Fujitsu FM-Towns
• MS-DOS 6.20-V - Japanese MS-DOS 6.20
• MS-DOS 6.21 - Beta, Chinese Simplified leaked
• MS-DOS 6.21 - OEM, Retail, DBLSPACE removed, crosses Stac's licencing.
• MS-DOS 6.22 - Retail, Step-Up, additional download to read DBLSPACE backups.

MS-DOS 7.x

• MS-DOS 7.00 - Only released as part of Windows 95 RTM and OSR1
• MS-DOS 7.00 - A DOS spun off the Windows release, with shell, https://www.betaarchive.com/forum/viewtopic.php?f=59&t=39495
• MS-DOS 7.10 - Only released as part of Windows 95 OSR2, OSR2.5, Windows 98 and 98SE

MS-DOS 8.x

• MS-DOS 8.00 - Only released as part of Windows ME - XP to Windows 7 inclued a boot-disk in diskcopy.dll