6th November 1980
Microsoft signs contract with IBM to create MS-DOS

On 6 November 1980, Bill Gates signed a contract on behalf of Microsoft to create an operating system for IBM's new PC.

Rather than create the new operating system from scratch, Microsoft bought existing software, 86-DOS, from Seattle Computer Products and hired the author, Tim Paterson. 86-DOS was used as the foundation for Microsoft's operating system, which was released as MS-DOS and licensed first to IBM. In the following 12 months, Microsoft licensed MS-DOS to more than 70 other companies.

The revenues that resulted from licensing MS-DOS to multiple companies proved to be decisive turning point in Microsoft's fortunes, enabling them to evolve from a modest programming language company to a software industry leader.

Related information:

• Centre for Computing History: Microsoft

Images:

• MS-DOS command-line prompt
  Credit: Copyright Microsoft. Images remain the copyright of the original copyright holder. Used under fair use policy for educational purposes only.

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