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VIC logo2.jpg
The Commodore VIC-20. Known also as the VC-20 in Germany and the VIC-1001 in Japan.
VIC-20 side view
VIC-20 back view
VIC-20 case badge, first North American version
VIC-20 case badge, first European version
VIC-20 case badge, second version (used world-wide)

Development & Marketing

The VIC-20 (written alternatively as the VIC20, Vic-20, Vic 20 and VIC=20 and sold also as the VIC-1001 and VC-20) is an 8-bit computer manufactured by Commodore International from 1981 to 1985. It was Commodore's first exclusive foray into the home-computer market and as such, was intended to be more affordable than the PET computer (which had been marketed towards a more professional clientele). The VIC-20's video chip, the MOS Technology VIC was a general-purpose color video chip designed by Al Charpentier in 1977 and intended for use in inexpensive display terminals and game consoles, but Commodore couldn't find a market for the chip. With Apple II gaining momentum with the advent of VisiCalc in 1979, Jack Tramiel wanted a product out that would compete in the same segment, to be presented at the January 1980 CES. For this reason Chuck Peddle and Bill Seiler started to design a computer named TOI (The Other Intellect).

The TOI computer failed to materialize, much due to the fact that it required an 80-column character display which in turn required the MOS Technology 6564 chip, which could not be used since it required very expensive static RAM to operate fast enough. In the meantime, freshman engineer Robert Yannes at MOS Technology (then a part of Commodore) had designed a computer in his home dubbed the MicroPET and finished a prototype with some help from Al Charpentier and Charles Winterble. When Jack Tramiel was confronted with this prototype he immediately said he wanted it to be finished and ordered it to be mass produced following a limited demonstration on the CES, since the TOI had not yet been finished.

The very hackish prototype produced by Yannes had very few of the features required for a real computer, so Robert Russell at Commodore headquarters had to coordinate and finish large parts of the design under the codename Vixen. The parts contributed by Russell included a port of the operating system (kernel and BASIC interpreter) taken from John Feagans design for the Commodore PET, a character set with the characteristic PETSCII, an Atari 2600-compatible joystick interface and the cartridge port. The serial IEEE 488-derivative interface was designed by Glen Stark. Some features, like the memory add-in board, were designed by Bill Seiler. At the time, Commodore had an oversupply of 1Kbit×4 SRAM chips, so Tramiel demanded that these be used in the new computer. The end result is arguably closer to the PET or TOI computers than to Yannes prototype, albeit with a 22-column VIC chip instead of the custom chips designed for the more ambitious computers.

In April 1980 at a meeting of general managers outside of London, Jack Tramiel declared that he wanted a lowcost color computer. When most of the GMs argued against it, he said, "the Japanese are coming, so we will become the Japanese." This was in keeping with Tramiel's philosophy which was to make "computers for the masses, not the classes." The concept was championed at the meeting by Michael Tomczyk, newly hired marketing strategist and assistant to the president; Tony Tokai, General Manager of Commodore-Japan, and Kit Spencer, the U.K.'s top marketing executive.

When they returned to California from that meeting, Tomczyk wrote a 30 page memo detailing recommendations for the new computer and presented it to Tramiel. Recommendations included programmable function keys, full size typewriter style keys, built-in RS-232. Tomczyk insisted on "user friendliness" as the prime directive for the new computer and proposed a retail price of $299.95. He recruited a marketing team and a small group of computer enthusiasts, and worked closely with colleagues in the U.K. and Japan to create colorful packaging, user manuals, and the first wave of software programs (mostly games and home applications). Scott Adams was contracted to provide a series of cartridge-based adventure games. Tomczyk's account of the story is told in his 1984 book, The Home Computer Wars.

While the PET was sold through authorized dealers, the VIC-20 primarily sold at retail, especially discount and toy stores, where it could compete more directly with game consoles. It was the first computer to be sold in K-Mart. Commodore took out advertisements featuring actor William Shatner of Star Trek fame as its spokesman, asking, "Why buy just a video game?". Television personality Henry Morgan (best known as a panelist on the TV show What's My Line?) became the ironic voice on a series of clever Commodore product ads.

The VIC-20 start-up screen

The VIC-20 had 5K of Ram, which netted down to 3.5K on startup, which is the equivalent to the words and spaces on one sheet of typing paper. The computer was expandable to 32k with an add-on memory cartridge. A major aspect of its "friendliness" was that, with included RF Modulator, a common home television could be used as the computer's display. Although the VIC-20 was criticized in print as being underpowered, the strategy worked: in 1982 it was the best-selling computer of the year, with 800,000 machines sold, and in January 1983 it passed the 1 million unit mark—a first in computer history. At its peak, 9,000 units per day were produced, and a total of 2.5 million units were sold before it was discontinued in January 1985, when Commodore repositioned the C64 as its entry-level computer due to the forthcoming release of the C128 and Amiga (the latter taking Commodore into the 16-bit world).

In 1981, Tomczyk contracted with an outside engineering group to develop a direct-connect modem-on-a-cartridge (the VICModem) which at $99 became the first modem priced under $100. The VICModem was also the first modem to sell over 1 million units. VICModem was packaged with $197.50 worth of free telecomputing services from the Source, CompuServe and Dow Jones. Tomczyk also created an entity called the Commodore Information Network to enable users to exchange information and take some of the pressure from Customer Support inquires, which were straining Commodore's lean organization. In 1982, this network accounted for the largest traffic on CompuServe, which, it can be argued, was an early implementation of Internet-style user groups.

The VIC-20 was also sold as the VIC-1001 in Japan and the VC-20 in Germany.


Length (depth) 216mm
Width 404mm
Height 75mm
Power Consumption Original model - 18 Watts, Revision C (also known as VIC-CR) - 7 watts
Video Standard NTSC, PAL, SECAM (by special modification)
Processor MOS 6502
Random Access Memory


5K built-in of which 3.5k (3583 bytes) available for BASIC language programming
Random Access Memory


Up to 37k of additional RAM with 27.5k (28159 bytes) available for BASIC language programming
Display area 23 rows x 22 characters, 176x184 pixels with one bit per pixel depth, 88x184 with two bit per pixel depth
Colors 16
Sound Monaural, 3 square wave voices & 1 noise channel
Ports Cartridge port, User port, Cassette tape port, Serial bus, Joystick Connector, Audio/Video port
Keyboard 62 normal keys plus 4 function keys

Hardware Modifications now has its own page.




Manuals / Documentation

VIC-20 User manual.

All VIC-20s came with an User manual and leaflets, price lists and some other commercial literature.

Commodore also published a Programmer's Reference Guide, a BASIC introduction course (in two parts) and some other books and courses on programming languages.


Because of the VIC's many connector ports, a whole range of devices could be attached to the computer. This allowed the VIC-20 to expand its abilities and usefulness far beyond that of the basic stock model. Article: Peripherals.



Promotional/Magazine Materials

Byte Magazine, May 1981 VIC-20 Review Media:Bytemay81.pdf


Original Commodore VIC-20 Wikipedia article

Denial Commodore VIC-20 Community