Microsoft has released the code to MSDOS 4.00 on GitHub; Dave takes you a tour of the code, builds it, and runs it on original hardware. For my book on life on the Spectrum: https://amzn.to/4bj29zo

For Clarity on the timeline:
Microsoft licensed (nonexclusively) 86DOS in Dec 1980 for $25,000
Paterson left SCP in April 1981 and worked for Microsoft from May 1981 to April 1982.
86DOS was purchased outright by Microsoft and renamed to MSDOS on 27 July 1981 for $50,000
In March 1982, MarkZ became the dev mgr for MSDOS 2

The Code:
https://github.com/microsoft/MSDOS

Remember that the code is opensourced, but trademark law still applies!

Any requests to contact me on Telegram, etc, are scams...

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