External Connectors
Cartridge Slot
| Pin | Name | Explanation |
|---|---|---|
| 1 | VDD | Power Supply +5V DC |
| 2 | PHI | System Clock ~ 1.05 MHz (CGB Double-speed mode: ~ 2.10 MHz) |
| 3 | /WR | Write |
| 4 | /RD | Read |
| 5 | /CS | Chip Select |
| 6-21 | A0-A15 | Address Lines |
| 22-29 | D0-D7 | Data Lines |
| 30 | /RES | Reset signal |
| 31 | VIN | External Sound Input |
| 32 | GND | Ground |
Link Port
Pin numbers are arranged as 2,4,6 in upper row, 1,3,5 in lower row; outside view of Game Boy socket; flat side of socket upside. Colors as used in most or all standard link cables, because SIN and SOUT are crossed, colors Red and Orange are exchanged at one cable end.
| Pin | Name | Color | Explanation |
|---|---|---|---|
| 1 | VCC | - | +5V DC |
| 2 | SOUT | red | Data Out |
| 3 | SIN | orange | Data In |
| 4 | P14 | - | Not used |
| 5 | SCK | green | Shift Clock |
| 6 | GND | blue | Ground |
Note: The original Game Boy used larger plugs than Game Boy Pocket and newer. Linking between older/newer Game Boy systems is possible by using cables with one large and one small plug though.
Stereo Sound Connector (3.5mm, female)
| Pin | Explanation |
|---|---|
| Tip | Sound Left |
| Middle | Sound Right |
| Base | Ground |
External Power Supply
The Game Boy can be powered by an external supply through a coaxial (or barrel) power connector. The appropriate connector and supply depends on the model. The table below describes the physical connector (barrel outer and inner diameter) and the electrical requirements for each model:
| Model | Outer Dia. | Inner Dia. | Voltage | Load | Centre Polarity |
|---|---|---|---|---|---|
| DMG | 3.5 mm | 1.35 mm | 6 V DC | 0.7 W | Negative (-) |
| MGB | 2.35 mm | 0.7 mm | 3 V DC | 0.7 W | Positive (+) |
| CGB | 2.35 mm | 0.7 mm | 3 V DC | 0.6 W | Positive (+) |
- Polarity is listed as the sign of the inner/centre contact. The outer contact is always the opposite sign.
- The CGB and DMG specify the voltage and polarity on the case, near the connector. The MGB lists the voltage but not the polarity.
- The dimensions of the MGB/CGB connector match a Japanese standard connector (JEITA RC-5320A JSAP1, formerly EIAJ-01).
- The listed load in watts is taken from the back label of each model.