{"id":47308,"date":"2025-04-03T15:06:43","date_gmt":"2025-04-03T19:06:43","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=47308"},"modified":"2025-05-05T09:33:34","modified_gmt":"2025-05-05T13:33:34","slug":"altair-basic-source-code","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2025\/04\/03\/altair-basic-source-code\/","title":{"rendered":"Altair Basic Source Code"},"content":{"rendered":"

Bill Gates<\/a> (via Slashdot<\/a>):<\/p>\n

\n

It feels like just yesterday that Paul and I were hunched over the PDP-10 in Harvard’s computer lab, writing the code that would become the first product of our new company.<\/p>\n

That code remains the coolest code I’ve ever written to this day—and you can see it for yourself at the bottom of this page.<\/p>\n

[…]<\/p>\n

Paul and I set out to create a BASIC interpreter, which would translate code into instructions the computer understood line by line as the program runs.<\/p>\n

[…]<\/p>\n

Paul and I decided to divide and conquer. We didn’t have the Intel 8080 chip that the Altair computer ran on, so Paul got to work writing a program that would simulate one on Harvard’s PDP-10 mainframe. This allowed us to test our software without needing an actual Altair. Meanwhile, I focused on writing the main code for the program while another friend, Monte Davidoff, worked on a portion called the math package. We coded day and night for the two months to create the software we had said already existed.<\/p>\n<\/blockquote>\n\n

Richard Speed<\/a>:<\/p>\n

The source code is provided as a 157-page PDF [link<\/a>] of scanned fan-fold paper rather than as source in a convenient repository<\/a>. An annotated disassembly of Altair BASIC 3.2 can be found on GitHub<\/a>.<\/p><\/blockquote>\n\n

Previously:<\/p>\n