Commodore Vic-20

The VIC-20 is an 8-bit home computer was released in 1981 by Commodore. The VIC-20 was Commodore’s first colour home computer and was the year’s best-selling home computer.

The VIC-20 was intended to be more economical than the PET computer. It was equipped with 5 KB of static RAM and used the same MOS 6502 CPU as the PET. The VIC-20’s video chip, was intended for use in inexpensive display terminals and game consoles. The VIC-20 used the 8 KB BASIC 2.0 used on earlier PETs.

  • NAME: VIC 20
  • MANUFACTURER: Commodore
  • TYPE: Home Computer
  • ORIGIN: U.S.A.
  • YEAR: May 1981
  • END OF PRODUCTION: January 1985
  • KEYBOARD: Full-stroke keyboard, 4 function keys, 66 keys
  • CPU: Commodore Semiconductor Group 6502A
  • SPEED: 1.0227 Mhz
  • CO-PROCESSOR: VIC-I (6560) for sound and graphics.
  • RAM: 5 KB (3583 bytes free), expandable up to 32 KB
  • VRAM: Screen memory shared with regular RAM
  • ROM: 16 KB
  • TEXT MODES: 23 rows x 22 columns
  • GRAPHIC MODES: 184 x 176
  • COLORS: 8 character colors, 16 background/border colors
  • SOUND: 3 voices / 3 octaves
  • I/O PORTS: 1 joystick port, 1 user port, 1 serial port, 1 cartrige port, Composite video output, tape interface
  • POWER SUPPLY: External power supply unit, 18 Watts

On the rear, there is the composite video socket, which provides a sharper, cleaner picture if a dedicated monitor is used. An external RF modulator was necessary to use the computer with a TV. There is also a standard Commodore cassette interface, serial port, a ROM cartridge slot, which took games and ultilities carts for instant loading, and also memory expansion packs up to 16K. There is also a user port for RS-232. The right side of the machine has a single joystick port, the on off switch and the power socket.

The VIC-20 went through several variations in its three-and-a-half years of production. First-year models had a PET-style keyboard with a blocky typeface while most VIC-20s made during 1981 had a slightly different keyboard also shared with early C64s. The rainbow logo VIC-20 was introduced in early 1983 and has the newer C64 keyboard with gray function keys and the Revision B motherboard. It has a similar power supply to the C64 PSU.
The machine’s keyboard-sized unit external design was later used by the Commodore 64 and C16.

VIC-20 sales exceeded one million units, making it the first computer to sell this many, and in total it sold over three million. In summer 1982, Commodore unveiled the Commodore 64, a more advanced machine with 64 KB of RAM and considerably improved sound and graphics. Initial sales of the C64 were slow but took off in mid-1983. The VIC-20 was widely available for under $90 by that time. Commodore discontinued the VIC-20 in January 1985.