Master System:Connector Pinouts
AV Out
Note: Connector is the female end at the console. This connector is not present on the NTSC and PAL Master System II.
| Pin # | Description |
|---|---|
| 1 | Composite Video Out (SMS and Mark III) / Unused (French SMS and French SMS II) |
| 2 | Ground |
| 3 | Audio Out |
| 4 | Green |
| 5 | 5V |
| 6 | Composite Sync |
| 7 | Red |
| 8 | Blue |
Cartridge Port (Mark III and Japanese SMS (MK-2000))
Note: Pins A1 through A22 are towards the back and numbered from left to right. Pins B1 through B22 are towards the front and numbered the same way.
| Pin # | Description | Pin # | Description |
|---|---|---|---|
| A1 | A0 | B1 | 5V |
| A2 | A1 | B2 | 5V |
| A3 | A2 | B3 | CSRAM |
| A4 | A3 | B4 | EXM1 |
| A5 | A4 | B5 | RD |
| A6 | A5 | B6 | WR |
| A7 | A6 | B7 | Mark III: Unused
MK-2000: RST |
| A8 | A7 | B8 | Unused |
| A9 | A8 | B9 | Mark III: Unused
MK-2000: MREQ |
| A10 | A9 | B10 | Mark III: MREQ
MK-2000: CE4 |
| A11 | A10 | B11 | CONT |
| A12 | A11 | B12 | Unused |
| A13 | A12 | B13 | Unused |
| A14 | A13 | B14 | Unused |
| A15 | D0 | B15 | Unused |
| A16 | D1 | B16 | Unused |
| A17 | D2 | B17 | Unused |
| A18 | D3 | B18 | A14 |
| A19 | D4 | B19 | EXM2 |
| A20 | D5 | B20 | Unused |
| A21 | D6 | B21 | Ground |
| A22 | D7 | B22 | Ground |
Cartridge Port (Export SMS)
Note: Odd numbered pins are towards the back and numbered from right to left. Even numbered pins are towards the front and also numbered from right to left. This table is oriented so the front of the port is facing left.
| Pin # | Description | Pin # | Description |
|---|---|---|---|
| 50 | NMI | 49 | CSRAM |
| 48 | KBSEL | 47 | Clock |
| 46 | Reset | 45 | BUSACK |
| 44 | BUSREQ | 43 | KILLGA |
| 42 | INT | 41 | WAIT |
| 40 | HALT | 39 | REFSH |
| 38 | IOREQ | 37 | M1 |
| 36 | A15 | 35 | 5V |
| 34 | CONT | 33 | A12 |
| 32 | A7 | 31 | A6 |
| 30 | A5 | 29 | A4 |
| 28 | A3 | 27 | A2 |
| 26 | A1 | 25 | A0 |
| 24 | D0 | 23 | D1 |
| 22 | D2 | 21 | Ground |
| 20 | Ground | 19 | Ground |
| 18 | D3 | 17 | D4 |
| 16 | D5 | 15 | D6 |
| 14 | D7 | 13 | CE3 |
| 12 | A10 | 11 | EXM2 |
| 10 | A11 | 9 | A9 |
| 8 | A8 | 7 | A13 |
| 6 | A14 | 5 | EXM1 |
| 4 | RD | 3 | MREQ |
| 2 | WR | 1 | 5V |
Controller Port
Note: Female is connector at the console. Male is connector at the controller. Diagram pictured is of the connector at the controller end. This pinout is mostly identical to the SG-1000.
| Pin # | Description |
|---|---|
| 1 | Up |
| 2 | Down |
| 3 | Left |
| 4 | Right |
| 5 | Unused |
| 6 | Button 1 |
| 7 | TH/Light Phaser trigger (Master System) / Ground (Mark III, console side only) |
| 8 | Ground |
| 9 | Button 2 |
Mark III Expansion Port
This expansion port is only found on the Mark III and is mostly identical to the one in the SG-1000 and SG-1000 II.
Note: Pins are numbered from left to right with the edge of the connector facing forward.
| Pin # | Description |
|---|---|
| 1 | Ground |
| 2 | Ground |
| 3 | Ground |
| 4 | Ground |
| 5 | A2 |
| 6 | Unused |
| 7 | IOREQ |
| 8 | CONT |
| 9 | WR |
| 10 | RD |
| 11 | KBSEL |
| 12 | D7 |
| 13 | D6 |
| 14 | D5 |
| 15 | D4 |
| 16 | D3 |
| 17 | D2 |
| 18 | D1 |
| 19 | D0 |
| 20 | A1 |
| 21 | A0 |
| 22 | KILLGA |
| 23 | 5V |
| 24 | 5V |