"[6] As the Apple II gained momentum with the advent of VisiCalc in 1979, Jack Tramiel wanted a product 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).

[7] Radio Shack had been achieving considerable success with the TRS-80 Model I, a relatively low-cost machine that was widely sold to novices and in 1980 released the Color Computer, which was aimed at the home and educational markets, used ROM cartridges for software, and connected to a TV set.

In the meantime, new engineer Robert Yannes at MOS Technology (then a part of Commodore) designed a computer in his home dubbed the MicroPET and finished a prototype with help from Al Charpentier and Charles Winterble.

With the TOI unfinished, when Jack Tramiel was shown the MicroPET prototype, he immediately said he wanted it to be finished and ordered it to be mass-produced following a limited demonstration at the CES.

The prototype produced by Yannes had 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.

It served several purposes, including costing substantially less than the IEEE-488 interface on the PET, using smaller cables and connectors that allowed for a more compact case design, and also complying with newly imposed FCC regulations on RFI emissions by home electronics (the PET was certified as Class B office equipment which had less stringent RFI requirements).

Commodore founder Jack Tramiel initially gave Tomczyk the title VIC Czar and later appointed him product manager.

[9] According to one of the development team, Neil Harris, "[W]e couldn't get any cooperation from the rest of the company who thought we were jokers because we were working late, about an hour after everyone else had left the building.

As the amount of memory on the VIC-20's system board was very small even for 1981 standards, the design team could get away with using more expensive SRAM due to its lower power consumption, heat output, and less supporting circuitry.

In April 1980, at a meeting of general managers outside London, Jack Tramiel declared he wanted a low-cost color computer.

[12] 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.

Tomczyk insisted on "user-friendliness" as the prime directive for the new computer, to engineer Terakura,[13] and proposed a retail price of US$299.95.

He recruited a marketing team and a small group of computer enthusiasts and worked closely with colleagues in the UK and Japan to create colorful packaging, user manuals, and the first wave of games and home applications.

With help from a Commodore engineer who came to Longwood, Florida, to assist in the effort, five of Adams's Adventure International game series were ported to the VIC.

It is also possible to fill a larger area of the screen with addressable graphics using a more dynamic allocation scheme if the contents are sparse or repetitive enough.

[citation needed] The VIC chip has readable scan-line counters but cannot generate interrupts based on the scan position.

The two VIA timer chips can serve this purpose through an elaborate programming technique, allowing graphics to be mixed with text above or below it, two different backgrounds and border colors, or more than 200 characters for the pseudo-high-resolution mode.

Unlike the PET, the VIC-20 does not include a machine language monitor, but Commodore offered them on disk, tape, or cartridge, with several different executables to load into various memory locations.

[16] Most expansion cartridges featured hardware DIP switches, allowing the RAM to be enabled in user-selectable memory blocks.

PEEK and POKE commands from BASIC can be used to perform data acquisition from temperature sensors, control robotic stepper motors, etc.

[22] Before the computer's release, a Commodore executive promised it would have "enough additional documentation to enable an experienced programmer/hobbyist to get inside and let his imagination work".

[24] Because of its small memory and low-resolution display compared to some other computers of the time, the VIC-20 was primarily used for educational software and games.

This software was distributed via online services such as CompuServe, BBSs, as well as offline by mail order and by user groups.

The VIC's low cost led to it being used by the Fort Pierce, Florida, Utilities Authority to measure the input and output of two of their generators and display the results on monitors throughout the plant.

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 game show I've Got a Secret) became the commentator in a series of Commodore product ads.

[24] While also noting the small screen size and RAM, BYTE stated that the VIC 20 was "unexcelled as low-cost, consumer-oriented computer.

This is a remarkable achievement, almost unbelievable considering the price of the entire unit"), graphics, documentation, and ease of software development with the KERNAL.