Commodore PET, January 1977. PET, or the Personal Electronic Transactor is the first Commodore computer. Designed by Chuck Peddle, PET is one of the very first user-friendly computers. It was designed around the MOS Technologies 6502 CPU, which eventually came to be used in many of the popular computers of the day - the Apple II, Atari 400/800, AIM-65, and others. It had built-in display, built-in cassette drive, and one of the worst keyboards at price US$795.