I don't see any credit being given to Digital Equipment Corporation (DEC) upon whose work this is based [1] [2] [3].
The quotes below only talk about OS source code, but they found language interpreter source code as well, see register story.
> "So, for a few years that is where I spent my time. I'd skip out on athletics and go down to this computer center. We were moving ahead very rapidly: BASIC, FORTRAN, LISP, PDP-10 machine language, digging out the operating system listings from the trash and studying those. Really not just banging away to find bugs like monkeys[laughs], but actually studying the code to see what was wrong." [4]
> "While his parents were concerned with his slipping grades, there was no slowing him down. He and Bill would go “dumpster diving” in C-Cubed’s garbage to find discarded printouts with source code for the machine’s operating system"
The quotes below only talk about OS source code, but they found language interpreter source code as well, see register story.
> "So, for a few years that is where I spent my time. I'd skip out on athletics and go down to this computer center. We were moving ahead very rapidly: BASIC, FORTRAN, LISP, PDP-10 machine language, digging out the operating system listings from the trash and studying those. Really not just banging away to find bugs like monkeys[laughs], but actually studying the code to see what was wrong." [4]
> "While his parents were concerned with his slipping grades, there was no slowing him down. He and Bill would go “dumpster diving” in C-Cubed’s garbage to find discarded printouts with source code for the machine’s operating system"
[1] https://en.wikipedia.org/wiki/BASIC-PLUS#Comparison_to_MS_BA...
[2] https://everybasic.info/doku.php/basics/decbasic#influence_f...
[4] https://americanhistory.si.edu/comphist/gates.htm
[3] https://www.theregister.com/2000/06/29/bill_gates_roots/
[5] https://paulallen.com/Futurist/Microsoft.aspx