CS 8422 Advanced Computing Systems, Dr. Hoganson

The Origins of MS-DOS

Sui-Tung Ng

CS 8422, Spring 2003 Advanced Computing Systems

CS 8422 Advanced Computing Systems, Dr. Hoganson

Tim Paterson

• Tim Paterson- Original author of MS-DOS - graduated from U of Washington in 1978- worked as an engineer in Seattle Computer Products- designed an 8086 CPU card for S-100 Bus in May 1979- began designing DOS in 1980 after IBM had released their new 8086 microprocessor (16-bit)

• objectives in design of DOS- as simple as possible- make it fast and efficient

- written in 8086 assembly language• In college, Paterson wrote a multi-tasking operating system for the Z80

microprocessor as a term project. Therefore, Paterson had confidence in writing an OS for 8086 computer. Patterson spent half of his time working on Qdos from April to July, 1980. QDOS was completed in July, 1980.

CS 8422 Advanced Computing Systems, Dr. Hoganson

Tim Paterson

• took two man-months to create Quick and Dirty Operating System (QDOS)

• used Microsoft Stand-Alone Disk BASIC to handle file organization

• was hired in Microsoft in 1981• in and out of Microsoft in 1980s• joined Microsoft again in 1990

• QDOS could work with Microsoft Stand-Alone Disk BASIC that used a File Allocation Table (FAT).

CS 8422 Advanced Computing Systems, Dr. Hoganson

Seattle Computer Products

• located in Tukwila of Washington• manugacturer of S-100 memory cards• a hardware company, not software company, in

1980• worked with Microsoft and Digital Research• shipped its first 8086 cards with Microsoft Stand-

Alone Disk BASIC in Nov 1979• gave up to use Digital Research CP/M-86 as its

operating system in 1980• decided to create its own DOS

• Seattle Computer Products (SCP) gave up to use CP/M-86 as Digital Research could not promise when it would be completed. Finally, SCP decided to develop its own DOS.

CS 8422 Advanced Computing Systems, Dr. Hoganson

Seattle Computer Products

• QDOS - completed in July 1980• QDOS 0.10 - launched in Aug 1980• 86-DOS version 0.3 - released at the end of 1980• sold non-exclusive rights to Microsoft to market

86-DOS• released 86-DOS version 1.00 in Apr 1981• similar to the MS-DOS of today

• Seattle Computer Products (SCP)was a hardware company, therefore it was willing to sell the non-exclusive right for Microsoft to market its 86-DOS at that time.

CS 8422 Advanced Computing Systems, Dr. Hoganson

Microsoft

• Microsoft had been working with IBM on their personal computer project and advised IBM to Digital Research for the operating system. However Digital Research refused to sign a non-disclosure agreement. Finally, Microsoft offered IBM with DOS by buying the rights to market DOS from SCP.

• paid SCP $10,000 for the right to market 86-DOS and• paid SCP $15,000 for each OEM customer in 1981• got a secret customer for DOS - IBM• bought DOS from Seattle Computer by paying $50,000• plus a license to include DOS in their PCs in July 1981• named DOS as MS-DOS• provided 86-DOS1.14 as OS in IBM’s PCs• released MS-DOS version 1.24 to IBM• released MS-DOS version 1.25 to the public in Mar 1982

CS 8422 Advanced Computing Systems, Dr. Hoganson

Microsoft

• Microsoft kept improving and evolving DOS after buying the products completely from SCP. MS-DOS became a very popular Operating System in the PC markets.

• released MS-DOS version 2.0 to IBM new XT computer in Feb 1983

• settled the license dispute by buying the license back from SCP for $975,000 in 1986

• the total price for DOS ended up $1,050,000• launched MS-DOS to its OEM in 1982• kept improving and evolving DOS for 15 years• stopped updating DOS until Windows95 was

released in 1995

CS 8422 Advanced Computing Systems, Dr. Hoganson

MS-DOS Timeline

• Year DOS Version• 12/1980 QDOS• 07/1981 86-DOS• 09/1982 MS-DOS 1.25• 03/1983 MS-DOS 2.0• 11/1983 MS-DOS 2.01• 12/1983 MS-DOS 2.11• 09/1984 MS-DOS 3.0• 11/1984 MS-DOS 3.1• 04/1986 MS-DOS 3.2

CS 8422 Advanced Computing Systems, Dr. Hoganson

MS-DOS Timeline

• 04/1987 MS-DOS 3.3• 04/1988 MS-DOS 3.31• 07/1988 MS-DOS 4.0• 11/1988 MS-DOS 4.01• 04/1989 MS-DOS 4.01a• 04/1991 MS-DOS 5.0• 03/1993 MS-DOS 6.0• 11/1993 MS-DOS 6.2• 04/1994 MS-DOS 6.22• 08/1995 MS-DOS 7.0

• Above timeline shows that Microsoft spent time to develop and market the MS-DOS from 1980 to 1995. The development cost of MS-DOS was high over the past 15 years.

CS 8422 Advanced Computing Systems, Dr. Hoganson

Conclusion

• Tim Paterson was the original author in DOS • MS-DOS was an easy-to-use operating system • Microsoft successfully launched MS-DOS to IBM

and to the PC market• Microsoft kept improving and evolving the MS-

DOS over the past years• Microsoft integrated MS-DOS with its windows

operating system in 1995

• Without the efforts of Microsoft, DOS will not be the popular operating system in 1980s and 1990s. MS-DOS now is integrated in Windows 95, 98, NT, and 2000.

CS 8422 Advanced Computing Systems, Dr. Hoganson

References• A short history of MS-DOS. (2003). Retrieved

February 21, 2003, from http://www.patersontech.com/Dos/Byte/History.html.

• Conner, D. (1998). Father of DOS still having fun at Microsoft. Retrieved February 21, 2003, from http://www.patersontech.com/Dos/Micronews/paterson04_10_98.htm.

• DOS timeline. (2003). Retrieved February 21, 2003, from http://www.powerload.fsnet.co.uk/timeline.htm.

• Hunter, D. (2003). Retrieved February 21, 2003, from http://www.patersontech.com/Dos/Softalk/Softalk.html.

CS 8422 Advanced Computing Systems, Dr. Hoganson

References• MS-DOS review. (2003). Retrieved February 21,

2003, from http://www.michaelh.com/comp/msdos.shtml.

• Paterson, T. (2003). DOS. Retrieved February 21, 2003, from http://www.patersontech.com/Dos/Encyclo.htm.

• The Dross of the DOS. (1997). Retrieved February 21, 2003, from http://www.forbes.com/asap/1997/1201/070_print.html.