On September 3, 2025, Microsoft released version 1.1 of its 6502 Basic as open source. This code formed the basis for Applesoft Basic on the Apple II series as well as Commodore Basic on all of Commodore’s 8-bit computers, including the C-64. It was the same code that Jack Tramiel licensed for a flat $25,000 and then included in more than 15 million computers.
The code could be built into ROM or it could load from tape or disk and execute from RAM. One of the reasons this code proved so influential was because millions of Commodore computers booted straight into it from ROM.
David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.
