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.
it has 4 voices that have a limited but wide tuning range, and like the SN76489 and T6W28, the last voice is dedicated to playing noise.
the 3 pulse wave channels also have different octaves that they can play notes on:
these channels are not referred as "square" wave channels since a technique to play 15 additional pulse-like waveforms has been discovered long after the VIC-20's release.
10xx
: switch waveform. range is 00
to 0F
.this chip uses the VIC instrument editor.
the following options are available in the Chip Manager window: