The Commodore VIC-20 was an 8-bit home computer first released in 1980.  The "Video Interface Chip" (MOS Technology 6560/6561) was responsible for both the audio and visual graphics of the machine.  On the audio side, the VIC chip had 3 square wave channels and 1 white noise channel and a global volume control.  Each square wave had a range of 3 octaves, but were tuned an octave apart from each other.  This gives the chip a five octave range total.