| Pin | Name | Description |
|---|---|---|
| 1 | SOUND C | Sound C (Can be tied together with A & B) |
| 2 | PORT | ? |
| 3 | VCC | +5 VDC |
| 4 | SOUND B | Sound B (Can be tied together with A & C) |
| 5 | SOUND A | Sound A (Can be tied together with B & C) |
| 6 | GND | Ground |
| 7 | PORT | ? |
| 8 | PORT | ? |
| 9 | PORT | ? |
| 10 | PORT | ? |
| 11 | PORT | ? |
| 12 | PORT | ? |
| 13 | PORT | ? |
| 14 | CLOCK | ? |
| 15 | CLOCK | ? |
| 16 | RESET | Reset |
| 17 | A8 | Address 8? |
| 18 | BDIR | ? |
| 19 | BC2 | ? |
| 20 | BC1 | ? |
| 21 | D7 | Data 7 |
| 22 | D6 | Data 6 |
| 23 | D5 | Data 5 |
| 24 | D4 | Data 4 |
| 25 | D3 | Data 3 |
| 26 | D2 | Data 2 |
| 27 | D1 | Data 1 |
| 28 | D0 | Data 0 |
