The definition of VIC-20

The Commodore VIC-20 computer sold millions of units and is generally considered to have been the first affordable home computer. It features a ROM-based BASIC and uses it as a default "OS". It is based on the 65xx family of processors. VIC (in case you are wondering) can stand for either video interface c or video interface computer. The VIC-20 is the precursor to the C64/128.