The Commodore VIC-20 was Commodore's major attempt at making a personal home computer, and is the percursor to the Commodore 64. The VIC-20 was also known as the VC-20 in Germany, and the VIC-1001 in Japan.
The 3 pulse wave channels also have different octaves that they can play notes on. The first channel is the bass channel, and it can play notes from octave 1. The next is the 'mid/chord' channel, and it plays notes from octave 2. And rather obviously, the 3rd pulse channel is typically the lead channel, can play notes from octave 3.