As described by The Register in 2001, around 1987 journalists and others started asking Bill Gates for a copy of the source code for the original version of Altair (eventually Micro-Soft) BASIC, written for the Altair 8800 and other 8080-based machines. This turned out to be fruitless, but a paper copy eventually was discovered at Harvard and copies of that now apparently reside in the Pusey library there and are available for public viewing. Ian Griffiths visited, read some of the code and write about his experience here. (There are various other copies of this page on the net.)

Since then the source for various derivatives of this BASIC has appeared on the 'net, apparently without major issues or takedown threats. BASIC-80 5.2 appears to contain substantial amounts of code from Altair BASIC, and the 6502 port also clearly has substantial reuse. Compare, for example, the PTRGET routine in those and you'll see that the header comment has the same structure and several identical phrases, many symbol names are identical, and the structure of the code is the same.

Why, though it's been preserved and bits of it are available through other versions anyway, does there seem to be an issue with making the early 8080 BASIC source code available? The reasons do not seem to be technical, since scanning paper documents from that era and making them available on-line is commonly done.

To be clear, I know that the object code and annotated disassemblies of it are widely available. I'm posting this question not becuase I'm looking for the details of how this BASIC works, but because I'm interested in the details of the original code (particularly naming conventions and comments) as written by Gates, Allen and Monte Davidoff.

  • 7
    Why not contact the Pusey library and ask them if there are any reasons not to make it available online? If anyone, they should know.
    – dirkt
    Commented Jul 26, 2019 at 14:26
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    I'm voting to close this question as off-topic because this is a question of permission or law, not of technology or history Commented Jul 26, 2019 at 20:30
  • 3
    Voting to leave open. I am willing to give it a chance, and would be happy to see an answer, but I suspect we won't get one. Editing it to "Is the source available" instead of why would avoid the concerns that this is a legal question.
    – DrSheldon
    Commented Jul 26, 2019 at 22:37
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    I also voted to keep this open, it is possible a person with direct knowledge of why could join this site at some point and provide a useful answer. Plus, I'm really curious too.
    – Geo...
    Commented Jul 27, 2019 at 0:40
  • 2
    Who is going to risk even a remote possibility of being attacked by a team of Microsoft lawyers? Commented Sep 30, 2021 at 2:01

1 Answer 1


The original code was sold to MITS before it was even completed and teams from MITS and Micro-Soft both worked on it simultaneously. Bill and Paul both moved to Albuquerque to continue work. It was housed on the Albuquerque Public Schools PDP-10 and edited/compiled there. I was one of 3 programmers at MITS who worked on it. We also created a version for the Altair 680 computer (Motorola 6800 based). Micro-Soft got a royalty on every copy sold. Pertec Computer Corp bought MITS in 1977 and after a lawsuit by the boys, they were given the right to sell it to other companies. Pertec was not really committed to the product and it was dis-continued after Pertec was sold to Triumph Adler. I had a copy of the source code for many years but threw it in the trash along with my Altairs in the early 80's.

  • Very interesting recollection of events. So I'm led to believe that either nobody has a copy of the source anymore (because it was felt to be obsolete and worthless), or people feel that Triumph Adler still holds the copyright and is looking for a reason to cash in?
    – bjb
    Commented Nov 30, 2022 at 19:33
  • "...but threw it in the trash along with my Altairs..." Ouch. The hardware you trashed is probably worth at least $10,000 today (perhaps even twice that), not to mention the priceless loss of the original source code. :-( But, of course, who would have thought at the time.
    – cjs
    Commented Dec 29, 2023 at 2:21

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