| Address | Name | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 | Description |
|---|---|---|---|---|---|---|---|---|---|---|
| D400 | SID1FRELOW | FRE1LOW | Frequency voice 1 low byte | |||||||
| D401 | SID1FREHIGH | FRE1HIGH | Frequency voice 1 high byte | |||||||
| D402 | SID1PWDCLOW | PWDC1LOW | Pulse wave duty cycle voice 1 low byte | |||||||
| D403 | SID1PWDCHIGH | PWDC1HIGH | Pulse wave duty cycle voice 1 high byte | |||||||
| D404 | SID1CR | noise | pulse | sawtooth | triangle | test | ringmod V3 | synth V3 | gate | Control Register voice 1 |