Some DOS history........
In May 1979, the American company 'Seattle Computer Products' made a plug-in printcard to the S-100 bus computer, that used the Intel 8086 processer.
One of the first of these cards, was placed at the disposal of Micro$oft.
This small company was known for their BASIC for the CP/M operating system.
About two weeks later, at the
National Computer Conference in New York, they showed a BASIC
version for the Intel 8086 processer.
In november 1979 the sale of these cards began.
Seattle Computer Products now waited for
Digital Research (actually, they had the somewhat pretentious name
of "Intergalactic Digital Research" at the time), to release a new
version of their operating system - CP/M.
Half a year later the
release of a new CP/M was not in sight, so Seattle decided, in
April 1980, to make its own operating system.
In August 1980,
Seattle started selling the first version of that new O/S, named
It was fast and dirty, but it worked.
(QDOS=Quick'n'Dirty Operating System.)
In about October 1980, IBM
began searching the market for an operating system for the
yet-to-be-introduced new IBM PC.
IBM had originally intended to
use Digital Research's CP/M - then the industry standard operating
system - you either ran a BASIC with disk functions, someone's OS,
Folklore reports various stories about the rift between
DRI and IBM.
The most popular story claims Gary Kildall or DRI
snubbed the IBM executives by flying his airplane when the meeting
Another story claims Kildall didn't want to release
the source for CP/M to IBM, which would be odd, since they released
it to other companies.
One noted industry pundit claims Kildall's
wife killed the deal by insisting on various contract changes.
suspect the deal was killed by the good ol' boy network.
to imagine a couple of junior IBM executives giving up when ordered
to a task as simple as licensing an operating system from a vendor.
It wouldn't look good on their performance reports.
It would be
interesting to hear IBM's story...
Well IBM then talked to
Micro$oft. Micro$oft was a language vendor.
Bill Gates and Paul
Allen had written BASIC and were selling it on punched tape or
Micro$oft had no real 8086 operating system to sell, but
quickly made a deal to license 'Seattle Computer Products', now
newly released 86-DOS v0.30 (QDOS was renamed to 86-DOS) operating
system to IBM.
86-DOS v0.30 was approximately 4000 line of code.
This code was quickly polished up and presented to IBM for
IBM found itself left with Micro$oft's offering of
"Micro$oft Disk Operating System 1.0".
An agreement was reached
between the two, and IBM agreed to accept 86-DOS as the main
operating system for their new PC.
Micro$oft purchased all rights
to 86-DOS in July 1981 (Now at 86-DOS v1.0, released by Seattle in
April 1981) and "IBM Personal Computer DOS 1.0" was ready for the
introduction of the IBM PC in October 1981.
IBM subjected the
operating system to an extensive quality-assurance program,
reportedly found well over 300 bugs, and decided to rewrite the
This is why PC-DOS is copyrighted by both IBM and
Some early OEM versions of DOS had different names,
such as Compaq-DOS, Z-DOS, Software Bus86, etc.
By version 2.0
Micro$oft managed to persuade everyone but IBM to refer to the
product as "MS-DOS". Although everyboby refers to IBM DOS as
PC-DOS, this is not correct.
Incidentally, IBM refers to its DOS
as "The IBM Personal Computer DOS." The term "PC-DOS" is a
trademark of IBM's rival DEC.
It is sometimes amusing to reflect
on the fact that the IBM PC was not originally intended to run
The target operating system at the end of the development
was for a (not yet in existence) 8086 version of CP/M.
other hand, when DOS was originally written the IBM PC did not yet
Although PC-DOS was bundled with the computer, Digital
Research's CP/M-86 would probably have been the main operating
system for the PC except for two things - Digital Research wanted
$495 for CP/M-86 (considering PC-DOS was essentially free) and many
software developers found it easier to port existing CP/M software
to DOS than to the new version of CP/M.
The IBM PC shipped without
an operating system.
IBM didn't start bundling DOS until the
second generation AT/339 came out (PC-DOS v1.1 = MS-DOS v1.24).
You could order one of three operating systems for your PC,
assuming you popped for the optional disk drive and 64K RAM upgrade
(base models had 16K and a cassette player port).
systems were IBM Personal Computer DOS 1.0, a version of the UCSD
P-System, which was an integrated Pascal operating system something
like the souped-up BASIC operating systems used by the Commodore 64
and others, or Digital Research's CP/M-86, which was officially an
option although you couldn't buy it until later.
$39.95 DOS was far cheaper than anyone else's alternative, darned
near everyone bought DOS.
The first buyable MS-DOS version is
v1.25 from July 1982.
Micro$oft sold this version to every
computer producer who showed interest. v1.25 is the same as
PC-DOS v1.10 and MS-DOS v1.24.
Allthough the O/S offered by
Micro$oft to IBM was called MS-DOS v1.00, it was never released to
MS-DOS v1.00 is 86-DOS v0.3.
The upgrade from DOS 3.3 to 4.0 was done in-house by IBM.
was a completely IBM product, later licensed back to Micro$oft.
early 1990 IBM announced that it was ceasing development of DOS and
all further work would be done solely by Micro$oft.
was long considered to be the "standard" version of DOS.
MS DOS 5.0 is a commercial product most developers will probably
write for it.
The version history of Micro$oft DOS. Includes QDOS, 86-DOS,
MS-DOS and PC-DOS.
Sorted by release date and year.
Version|| Name|| Release Year|| Notes|
|0.1 || QDOS || August 1980 || Made by Seattle Computer.|
|0.3 || 86-DOS || December 1980 || Made by Seattle Computer.|
|1.0 || 86-DOS ||April 1981|| Made by Seattle Computer.|
|1.00|| PC-DOS|| August 1981|| IBM first release, basicly the
same as 86-DOS|
|1.05 || PC-DOS || - - || IBM internal.|
|1.10 || PC-DOS || June 1982|| Bugfix, double sided floppy drive
|1.24 || MS-DOS || June 1982|| The same as PC-DOS v1.10.|
|1.25 || MS-DOS || July 1982|| The same as PC-DOS v1.10, first
non-IBM release of DOS|
|2.00 || PC-DOS|| March 1983 || For PC/XT, Unix-type subdirectory
support, installable device
drivers, I/O redirection,
subdirectories, harddisk support,
|1.85 || PC-DOS || April 1983|| IBM internal, extended v1.10.|
|2.01|| MS-DOS || May 1983|| First support for individual
country formats, Kanji [ ? ].|
|2.10 || PC-DOS|| October 1983|| For IBM PCjr, bugfixes for 2.0.
No country support.|
|2.11 || MS-DOS || December 1983 || Basically a cross of PC-DOS 2.10
and MS-DOS 2.01.|
|2.12|| MS-DOS || - 1983 || Special version for TI pro.|
|3.00 || PC-DOS|| August 1984|| 1.2 meg drive for PC/AT, some new
system calls, new external
programs, 16-bit FAT, specific
support for IBM network.|
|3.05|| MS-DOS|| November 1984|| First Non-IBM release of version
|3.10 || PC-DOS|| November 1984 || Bugfix for 3.0, implemented generic
|2.25 || MS-DOS|| October 1985 || Extended foreign language
|3.20|| PC-DOS|| January 1986|| 720k 3.5 inch drive support,
special support for laptops
(IBM PC Convertible), XCOPY.
Several localized versions
released, both MS-DOS and PC-DOS.|
|4.00 || MS-DOS|| April 1986|| Multitasking (Europe only) -
withdrawn from market after a
very short run.|
|3.30 || PC-DOS|| April 1987|| For PS/2 series, 1.44 meg support,
multiple DOS partition support,
code page switching, improved
foreign language support, some
new function calls, support for
the AT's CMOS clock.|
|3.31 || MS-DOS || November 1987|| Over-32 meg DOS partitions.
Different versions from different
OEMs (not Micro$oft). Compaq and
Wyse are most common.|
|3.40 || PC-DOS|| - 1988 || Internal IBM - not released (4.0
|2.11R || MS-DOS || - 1988|| Bootable ROM DOS for Tandy
|4.00|| PC-DOS || August 1988|| 32mb disk limit officially
broken, minor EMS support, more
new function calls, enhanced
network support for external
commands. PCjr support dropped.|
|4.01 || MS-DOS || December 1988|| Micro$oft version with some
|3.21R || MS-DOS || September 1989 || DOS in ROM, Flash File System for
|3.3R || MS-DOS|| - 1990 || DOS in ROM, introduced for TI
|5.00 || MS-DOS || June 1991 || High memory support, uses up to 8
hard disks, command line editor
and aliasing, 2.88 floppies,
ROMable OEM kit available.|
|5.02 || PC-DOS || August? 1992|| Version that can run on other
computers then IBM build.
V MS-DOS February 1993 Japanese-market version of 5,
with double byte Kanji character
|6.00 || MS-DOS || March 1993|| Disk compression (Doublespace),
multiple configurations in
CONFIG.SYS and AUTOEXEC.BAT.|
|6.00|| PC-DOS|| August? 1993 || -|
|6.20|| MS-DOS|| September 1993 || Rewrite of Doublespace.|
|6.21 || MS-DOS|| - 1994 || -|
|6.22|| MS-DOS || May 1994 || New disk compression (Drivespace).|
|6.30 || PC-DOS || - - || -|
|7.00 || MS-DOS || August 1995 || This version is included with
|7.00 || PC-DOS || 1996 ||PC-DOS 2000 zawiera dużo usprawnień i dodatków. Działa dużo lepiej niż MS|
Zobacz dodatkowe opisy do PC-DOS
|7.10 || MS-DOS|| August 1996 || This version is included with
Windows95b OSR2. |