| $00 |
Voice 1 frequency low byte |
| $01 |
Voice 1 frequency high byte |
| $02 |
Voice 1 pulse width low byte |
| $03 |
Voice 1 pulse width high byte (bits 3-0) |
| $04 |
Voice 1 control (gate, sync, ring mod, waveform) |
| $05 |
Voice 1 attack/decay rates |
| $06 |
Voice 1 sustain level/release rate |
| $07 |
Voice 2 frequency low byte |
| $08 |
Voice 2 frequency high byte |
| $09 |
Voice 2 pulse width low byte |
| $0A |
Voice 2 pulse width high byte (bits 3-0) |
| $0B |
Voice 2 control (gate, sync, ring mod, waveform) |
| $0C |
Voice 2 attack/decay rates |
| $0D |
Voice 2 sustain level/release rate |
| $0E |
Voice 3 frequency low byte |
| $0F |
Voice 3 frequency high byte |
| $10 |
Voice 3 pulse width low byte |
| $11 |
Voice 3 pulse width high byte (bits 3-0) |
| $12 |
Voice 3 control (gate, sync, ring mod, waveform) |
| $13 |
Voice 3 attack/decay rates |
| $14 |
Voice 3 sustain level/release rate |
| $15 |
Filter cutoff frequency low byte |
| $16 |
Filter cutoff frequency high byte (bits 2-0) |
| $17 |
Filter resonance/control |
| $18 |
Filter mode/volume control |
| $19 |
POTX value (0-255), updated every 512 clock cycles |
| $1A |
POTY value (0-255), updated every 512 clock cycles |
| $1B |
Upper 8 bits of Oscillator 3 value (random number if noise waveform is selected) |
| $1C |
Upper 8 bits of Voice 3 envelope generator value |