Microsoft’s 6502 BASIC Is Now Open Source

By Amber Ankerholz

The historically significant language was used by millions.

Microsoft has officially released its 6502 BASIC programming language under the open source MIT license.

“Microsoft BASIC began in 1975 as the company’s very first product: a BASIC interpreter for the Intel 8080, written by Bill Gates and Paul Allen for the Altair 8800,” says Scott Hanselman, Vice President, Developer Community at Microsoft. 6502 BASIC was later licensed by Commodore for a flat fee of $25,000. “That decision put Microsoft’s BASIC at the heart of Commodore’s machines and helped millions of new programmers learn to code.”

This newly open-sourced version is “BASIC M6502 8K VER 1.1, the 6502 BASIC lineage that powered an era of home computing and formed the foundation of Commodore BASIC in the PET, VIC-20, and the legendary Commodore 64,” Hanselman says.

According to the project’s GitHub page, “this assembly language source code represents one of the most historically significant pieces of software from the early personal computer era.”

Learn more at Microsoft.