An early color home computer
The Strong National Museum of Play dates the VIC-20's appearance to the June 1980 Computer Electronics Show and North American household sales to 1981. Technical documentation describes 6502 operation at approximately 1.02 MHz for NTSC systems and 1.108 MHz for PAL systems, so regional timing is a real variant rather than a footnote. [1] [2]
Base memory and expansion
An unexpanded VIC-20 has 5 KB of RAM: 1 KB at addresses 0–1023 and 4 KB at 4096–8191. The latter area includes BASIC program data and screen memory. The programmer reference also documents expansion sufficient for up to 32,000 independent user-RAM locations, making memory configuration central to accurate compatibility discussion. [3] [4]
VIC-I graphics, sound, and connections
VIC-I combines display and sound functions. The documented baseline includes a 22-by-23 text layout, a 176-by-184 bitmap arrangement, 16 selectable colors, three square-wave voices, and one noise voice. Setup documentation identifies cartridge/expansion, game-control, video, user, cassette, and serial connections, with serial peripherals including printers and disk drives. [2] [5] [6]