6581 / 8580 SID pinout
DIP-28. Sound + paddle A/D
3-voice synth at $D400-$D41C. 6581 (NMOS) needs Vdd (pin 28) at +12 V and Vcc (pin 25) at +5 V. 8580 (HMOS-II) runs at +9 V on Vdd; same pinout. Do not put a 12 V rail on an 8580 without checking. Filter caps on pins 1-4.
Open the interactive SID pinoutPins
| Pin | Name | Type | Signal |
|---|---|---|---|
| 1 | CAP1A | audio | Filter capacitor pin, pair 1 (with CAP1B). Leave the external cap in place. |
| 2 | CAP1B | audio | Filter capacitor pin, pair 1 (with CAP1A). |
| 3 | CAP2A | audio | Filter capacitor pin, pair 2 (with CAP2B). |
| 4 | CAP2B | audio | Filter capacitor pin, pair 2 (with CAP2A). |
| 5 | /RES | ctrl | Reset. LOW clears the SID registers. |
| 6 | Φ2 | clock | Phase 2 system clock input. |
| 7 | R/W | ctrl | Read/write from the CPU. |
| 8 | /CS | ctrl | Chip select (address decoding). LOW enables SID registers at $D400. |
| 9 | A0 | addr | Register select bit 0. |
| 10 | A1 | addr | Register select bit 1. |
| 11 | A2 | addr | Register select bit 2. |
| 12 | A3 | addr | Register select bit 3. |
| 13 | A4 | addr | Register select bit 4. |
| 14 | GND | ground | 0 V. |
| 15 | D0 | data | Data bus bit 0. |
| 16 | D1 | data | Data bus bit 1. |
| 17 | D2 | data | Data bus bit 2. |
| 18 | D3 | data | Data bus bit 3. |
| 19 | D4 | data | Data bus bit 4. |
| 20 | D5 | data | Data bus bit 5. |
| 21 | D6 | data | Data bus bit 6. |
| 22 | D7 | data | Data bus bit 7. |
| 23 | POT Y | audio | Paddle A/D input Y. Control port pin 5. |
| 24 | POT X | audio | Paddle A/D input X. Control port pin 9. |
| 25 | Vcc | power | +5 V digital supply (sheet). |
| 26 | EXT IN | audio | External audio input, mixed or filtered with the SID voices. On the C64 it comes from pin 5 of the audio/video DIN. |
| 27 | AUDIO OUT | audio | Mixed audio output (to the board audio stage). |
| 28 | Vdd | power | Analog supply: +12 V on a 6581 (sheet). 8580 uses +9 V here. |
Fitted in
- Commodore 64 U18
- Commodore 128 U5