The Commodore Vic-20 Resource Page


From Wikipedia: The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore’s first personal computer, the PET. The VIC-20 was the first computer of any description to sell one million units. It was described as “one of the first anti-spectatorial, non-esoteric computers by design…no longer relegated to hobbyist/enthusiasts or those with money, the computer Commodore developed was the computer of the future.”

The Commodore Vic 20 was my first computer and many others from Generation X (born late 1970s to early 1980s) will likely tell you the same thing. Some may have jumped in late in 1982 and bought a Commodore 64 ($595 at the time), or a competitor machine like the Atari 400/800, Apple II, Texas Instruments TI-99/4 or a Tandy TRS-80. Regardless, the Vic 20 was well known as an early home computer that was easy to use, had great games and was relatively inexpensive ($300 in 1980). Not only could you connect to local BBS boards, but you could write your own programs and games.


The machine came with a Basic Interpreter with 20 KB ROM + 5 KB RAM (expandable to 32 KB), a keyboard with micro-switches and several ports and interfaces. These interfaces included an Atari Joystick port, a cartridge port (most 4-16k), a serial CBM-488 bus for drives and printers, TTL-level “user port” with both RS-232 and Centronics signals, a video output port and a power switch.

All of the features of the Commodore Vic 20 were included in the Commodore 64 to the extent that side-by-side, both machines appear to be almost identical barring a second joystick port on the 64.

The graphics capabilities of the VIC chip (6560/6561) include two different 256 character sets, a 4:3 width to height ratio, 22 columns and 23 rows of 8-by-8-pixel characters.

The 6560/6561 VIC chip

The startup screen shows 176×184 pixels and there is a fixed-color border to the edges of the screen. There is a higher-resolution mode which boosts the columns to 27 with each character being 8×8 pixels in size and they use one color. There is no true bitmap mode but the Vic 20 allows for programmable custom character sets. The Vic graphics chip can also support a light pen through the joystick port and outputs Luma+Sync and Chroma video signals through the composite video output.

A Super Expader cartridge was available that added expanded Basic programming commands, 3k of RAM, and a graphics mode using a resolution of 160×160 pixels.

The Vic 20’s Super Expander Cartridge

The Commodore 1530 C2N-B Datasette provided inexpensive external storage for the VIC-20. Users could store data with common and inexpensive audio cassettes with this device. Datasettes can typically store about 100 kByte per 30 minute side but this can be boosted to 1000 kByte with the use of turbo tape and other fast loaders.

The 1530 Dataset Storage Device




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