Comparison of DOS operating systems


This article details versions of MS-DOS, IBM PC DOS, and at least partially compatible disk operating systems.

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 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 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.
NameFirst public release dateCreatorOwner or maintainer as of 2016License
86-DOS 0.421981-02-25Seattle Computer Productsrowspan="15" rowspan="16"
86-DOS 1.001981-04-28Seattle Computer Products--
PC DOS 1.01981-08-12Microsoft --
PC DOS 1.11982-05-??Microsoft --
PC DOS 2.01983-03-??Microsoft --
PC DOS 2.11983-10-??Microsoft --
PC DOS 3.01984-08-??Microsoft --
PC DOS 3.11985Microsoft --
PC DOS 3.21986Microsoft --
PC DOS 3.31987Microsoft --
IBM DOS 4.0
1988Microsoft --
IBM DOS 5.0
1991Microsoft --
PC DOS 6.1, PC DOS 6.31993Microsoft --
PC DOS 7.0 1995Microsoft --
PC DOS 2000
1998Microsoft --
PC DOS 7.102003Microsoft -
MS-DOS 1.25 1982Microsoftrowspan="16" , MIT License
Z-DOS 1.251982-05-??OEM Zenith Data Systems-
MS-DOS 2.01983-03-??Microsoft, MIT License-
MS-DOS 2.111983-12-??Microsoftrowspan="21" -
MS-DOS 3.01984Microsoft--
MS-DOS 3.11984Microsoft--
MS-DOS 3.21986Microsoft--
MS-DOS 3.31987Microsoft--
MS-DOS 4.01988Microsoft--
MS-DOS 5.01991Microsoft--
MS-DOS 6.01993Microsoft--
MS-DOS 6.201993Microsoft--
MS-DOS 6.211994Microsoft--
MS-DOS 6.221994Microsoft--
MS-DOS 7.0 1995Microsoft--
MS-DOS 7.10 1996Microsoft--
MS-DOS 8.0 2000Microsoft-
DOS Plus 1.1, 1.2/1.2a1985Digital Researchrowspan="7" -
DOS Plus 2.11986Digital Research--
DR DOS 3.31-3.351988Digital Research--
DR DOS 3.40-3.411989Digital Research--
DR DOS 5.01990Digital Research--
DR DOS 6.01991Digital Research--
Novell DOS 71993Novell--
Caldera OpenDOS 7.011997Caldera, Inc.;
Caldera UK, Ltd.		 officially;
a derivative, Enhanced DR-DOS, is maintained by Udo Kuhnt		rowspan="2", free non-commercial use
Caldera DR-OpenDOS 7.021997Caldera, Inc.;
Caldera UK, Ltd.		rowspan="2" -
Caldera DR-DOS 7.021998Caldera, Inc.;
Caldera UK, Ltd.		rowspan="4" -
Caldera DR-DOS 7.031999, 1998 prereleasedCaldera Thin Clients, Inc.;
Caldera UK, Ltd;
Lineo, Inc.		-
DR-DOS 8.02004DeviceLogicsrowspan="2" -
DR-DOS 8.12005DRDOS, Inc.--
FreeDOS 1.02006-09-03Jim Hall, et al.rowspan="3" rowspan="3", GPL
FreeDOS 1.12012-01-02Jim Hall, et al.--
FreeDOS 1.22016-12-25Jim Hall, et al.--
PTS-DOS 6.41993PhysTechSoftrowspan="5" rowspan="11"
PTS-DOS 6.5?PhysTechSoft--
PTS-DOS 6.6?PhysTechSoft--
PTS-DOS 2000 ?PhysTechSoft--
PTS-DOS 32 ?PhysTechSoft--
PTS-DOS 6.51ca. 1995Paragon Technology Systemsrowspan="2" -
Paragon DOS 2000 Pro?Paragon Technology Systems--
ROM-DOS 6.22?Datalightrowspan="2" -
ROM-DOS 7.1?Datalight--
Embedded DOS?General Software-
DIP DOS 2.111989DIP Research, Atari Corporation-
RxDOS1994Michael Podanoffsky, GPL
SISNE plus?Itautec, Scopus Tecnologia

Technical specifications