Skip to main content
The Commodore VIC-20 was Commodore’s major attempt at making a personal home computer, and is the precursor to the Commodore 64. It was also known as the VC-20 in Germany, and the VIC-1001 in Japan.

​
Sound Capabilities

The VIC-20 has 4 voices with a limited but wide tuning range. Like the SN76489 and T6W28, the last voice is dedicated to playing noise. The 3 pulse wave channels have different octaves:
  • Channel 1: Bass channel, plays notes from octave 1
  • Channel 2: Mid/chord channel, plays notes from octave 2
  • Channel 3: Lead channel, plays notes from octave 3
These channels are not referred to as “square” wave channels since a technique to play 15 additional pulse-like waveforms was discovered long after the VIC-20’s release.

​
Effect Commands

  • 10xx: Switch waveform (range: 00 to 0F)

​
Chip Configuration

PAL: Run at 1.10MHz instead of 1.02MHz Disable filtering: Bypasses the hardware’s lowpass filter

Build docs developers (and LLMs) love

Get started for freeTalk to us