Monday, 11 January 2021

Commodore VIC-20 (1981)

Launched January 1981

Microcomputers had been on a rollercoaster ride since the launch of the holy trinity of the Commodore PET, Apple II and Tandy TRS-80 in 1977. These early computers were expensive and limited in capabilities, so take-up was somewhat limited – especially in the home. But if there was one machine that finally brought the micro into living rooms and bedrooms all over the world, it was probably the Commodore VIC-20.

Commodore VIC-20



Selling more than a million units in its first year of production, the VIC-20 was based on the familiar (and Commodore-owned) MOS Technology 6502 CPU combined with a graphics-and-sound chip called the VIC which MOS had designed but had yet to find a market for.

Graphics were a fairly blocky 176 x 184 pixels in a maximum of 16 colours, with a fairly ungainly text resolution of 22 x 23 characters (at a time when business computers would have up to 80 columns)
Sound was a slightly more impressive three channels plus a noise generator. A tiny 5Kb of RAM left just 3.5Kb for BASIC applications, but it could be expanded to 32Kb.

BASIC itself was a cut-down version of the one in the PET – a smaller codebase was needed because of the limited ROM and RAM in the VIC-20. Unfortunately this meant that the VIC-20 lacked any commands to control graphics or sound in BASIC which had to be done through a series of POKES and PEEKS. The later VIC Super Expander cartridge helped, but BASIC programs written using it could only be used by people owning the expander cartridge.

Everything was packaged in an attractive and durable single box costing a shade less than $300 which would need to be connected to a domestic TV set (via an external modulator) or composite video monitor… which wasn’t included in the price. Nor included was the almost-essential “datasette” cassette drive needed for storage, but even taking all this into consideration the price was a steal compared to the previous generation of computers. And in a bare-minimum configuration you could use the family TV and a software cartridge plugged into the back.

It was an expandable system – floppy disks and joysticks being a common option, but the built-in serial port and CBM-488 bus allowed a variety of other add-ons including the sub-$100 VICMODEM which sold over a million units.

VIC-20 plus peripherals


About a year-and-a-half later, the VIC-20’s successor was launched – the Commodore 64. Almost identical in exterior design, the C64 was a much more complex and expensive beast. The VIC continued to be sold alongside the C64, by the time it was discontinued in January 1985 (four years after launch) it was priced at less than $100.

The VIC-20 cemented Commodore as one of the key players in the early 80s microcomputer market, but of course that position wouldn’t last. Today a Commodore VIC-20 in very good condition can sell for up to £400, the VIC-compatible floppy disk units are much in demand and can also sell for hundreds of pounds. Alternatively, the Linux-based THEC64 includes a VIC-20 emulation mode in convincing replica hardware for much less.

Image credits:
Science Museum Group - CC BY 4.0
Marcin Wichary / MagentaGreen via Wikimedia Commons -  CC-BY-2.0




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