On Wednesday, Microsoft released the complete source code for Microsoft BASIC for 6502 Version 1.1, the 1978 interpreter that powered the Commodore PET, VIC-20, Commodore 64, and Apple II through custom adaptations. The company posted 6,955 lines of assembly language code to GitHub under an MIT license, allowing anyone to freely use, modify, and distribute the code that helped launch the personal computer revolution.
"Rick Weiland and I (Bill Gates) wrote the 6502 BASIC," Gates commented on the Page Table blog in 2010. "I put the WAIT command in."
For millions of people in the late 1970s and early 1980s, variations of Microsoft's BASIC interpreter provided their first experience with programming. Users could type simple commands like "10 PRINT 'HELLO'" and "20 GOTO 10" to create an endless loop of text on their screens, for example—often their first taste of controlling a computer directly. The interpreter translated these human-readable commands into instructions that the processor could execute, one line at a time.
