Commodore BASIC is also known as PET BASIC. It is a BASIC programming language. It was used in Commodore International's 8-bit home computers. It started with the PET computer in 1977. The last computer to use Commodore BASIC was Commodore 128 of 1985. The core was based on 6502 Microsoft BASIC. It shares many characteristics with other 6502 BASICs like Applesoft BASIC.