DOS (Disk Operating System) Remember de C: prompt
C:\> .
1973
Gary Kildall writes a simple operating system in his PL/M language. He calls it CP/M (Control Program/Monitor).
(Control Program for Microcomputer)
1979
February
Apple Computer releases DOS 3.2.
July
Apple Computer releases DOS 3.2.1
1980
April
Tim Patterson begins writing an operating system for use with Seattle Computer Products' 8086-based computer.
          Seattle Computer Products decides to make their own disk operating system (DOS), due to delays by Digital Research in releasing a CP/M-86 operating system.
August
QDOS 0.10 (Quick and Dirty Operating System) is shipped by Seattle Computer Products.  Even though it had been created in only two man-months, the DOS worked surprisingly well.  A week later, the EDLIN line editor was created.  EDLIN was supposed to last only six months, before being replaced.
September
Tim Patterson shows Microsoft his 86-DOS, written for the 8086 chip.
October
Microsoft's Paul Allen contacts Seattle Computer Products' Tim Patterson, asking for the rights to sell SCP's DOS to an unnamed client (IBM).  Microsoft pays less than US$100,000 for the right.
December
Seattle Computer Products renames QDOS to 86-DOS, releasing it as version 0.3. Microsoft then bought non-exclusive rights to market 86-DOS.
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1981
February
MS-DOS runs for the first time on IBM's prototype microcomputer.
July
Microsoft buys all rights to DOS from Seattle Computer Products, and the name MS-DOS is adopted.
August
IBM announces the IBM 5150 PC Personal Computer, featuring a 4.77-MHz Intel 8088 CPU, 64KB RAM, 40KB ROM, one 5.25-inch floppy drive, and PC-DOS 1.0 (Microsoft's MS-DOS), for US$3000.
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1982
May
Microsoft releases MS-DOS 1.1 to IBM, for the IBM PC.  It supports 320KB double-sided floppy disk drives. Microsoft also releases MS-DOS 1.25, similar to 1.1 but for IBM-compatible computers.
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1983
March
MS-DOS 2.0 for PCs is announced. It was written from scratch, supporting 10 MB hard drives, a tree-structured file system, and 360 KB floppy disks.
October
IBM introduces PC-DOS 2.1 with the IBM PCjr.
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1984
March
Microsoft releases MS-DOS 2.1 for the IBM PCjr.
Microsoft releases MS-DOS 2.11.  It includes enhancements to better allow conversion into different languages and date formats.
August
Microsoft releases MS-DOS 3.0 for PCs. It adds support for 1.2 MB floppy disks, and bigger (than 10 MB) hard disks.
November
Microsoft releases MS-DOS 3.1. It adds support for Microsoft networks.
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1986
January
Microsoft releases MS-DOS 3.2. It adds support for 3.5-inch 720 KB floppy disk drives.
Microsoft releases MS-DOS 3.25.
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1987
April
IBM announces DOS 3.3 for PCs, for US$120.
August
Microsoft ships MS-DOS 3.3.
November
Compaq ships MS-DOS 3.31 with support for over 32mb drives.
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1988
Digital Research transforms CP/M into DR DOS.
June
Microsoft releases MS-DOS 4.0, including a graphical/mouse interface.
July
IBM ships DOS 4.0. It adds a shell menu interface and support for hard disk partitions over 32 MB.
November
Microsoft releases MS-DOS 4.01.
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1990
April
Microsoft introduces Russian MS-DOS 4.01 for the Soviet market.
May
Digital Research releases DR DOS 5.0.
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1991
June
Microsoft releases MS-DOS 5.0. It adds a full-screen editor, undelete and unformat utilities, and task swapping.
GW-BASIC is replaced with Qbasic, based on Microsoft's QuickBASIC.
September
Digital Research Inc. releases DR DOS 6.0, for US$100.
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1993
March
Microsoft introduces the MS-DOS 6.0 Upgrade, including DoubleSpace disk compression. 1 million copies of the new and upgrade versions are sold through retail channels within the first 40 days.
November
Microsoft releases MS-DOS 6.2.
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1994
February
Microsoft releases MS-DOS 6.21, removing DoubleSpace disk compression.
April
IBM releases PC-DOS 6.3.
June
Microsoft releases MS-DOS 6.22, bringing back disk compression under the name DriveSpace.
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1995
February
IBM announces PC DOS 7, with integrated data compression from Stac Electronics (Stacker).
April
IBM releases PC DOS 7.
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In August of 1995 Microsoft introduces Windows 95, it includes MS DOS 7.0 but it's clear that DOS is going to die a slow death.

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