9 PIN D-SUB MALE at the Atari
9 PIN D-SUB FEMALE at the joystick cable
The Atari 2600 VCS (1977) uses a 9-pin DE-9 connector for its two controller ports (J202 and J203 on the motherboard), establishing what became a widely adopted de-facto digital joystick standard. All directional and button signals are active-low: pressing a direction or the fire button shorts the corresponding pin to ground (pin 8) via a normally-open switch, which the console’s 6532 RAM-I/O chip reads as a logic-low input. Pin 7 carries +5V from the console’s power rail and is used by paddle controllers, which wire a 1 MΩ potentiometer between pin 7 and pin 8; the TIA chip then reads the resulting analogue voltage on pins 5 and 9. The CX40 digital joystick cable leaves pins 5, 7, and 9 unconnected, but the console socket itself carries live +5V on pin 7 at all times.
| Pin | Color | Dir | Description |
|---|---|---|---|
| 1 | WHT | IN | Up |
| 2 | BLU | IN | Down |
| 3 | GRN | IN | Left |
| 4 | BRN | IN | Right |
| 5 | n/c | - | Not connected |
| 6 | ORG | IN | Button |
| 7 | n/c | - | +5V (50 mA) |
| 8 | BLK | - | Ground(-) |
| 9 | n/c | - | Not connected |
Notes
- Direction is Computer relative Joystick.
- Connect Direction/Button to Ground for action.
- Pin 7 carries +5V from the console’s power rail; paddle controllers use this line to energise the potentiometer divider. The standard CX40 joystick cable does not connect pin 7, but the socket is live.
- Pins 5 and 9 carry analogue POT signals to the TIA chip for paddle controllers; they are unused (effectively not connected) when a standard digital joystick is attached.
Signals
- Up — active-low; grounded when joystick is pushed forward
- Down — active-low; grounded when joystick is pulled back
- Left — active-low; grounded when joystick is moved left
- Right — active-low; grounded when joystick is moved right
- Button — active-low; grounded when the fire button is pressed
- +5V — console power rail (+5 V DC); used by paddle controllers (pin 7)
- Ground — signal and power return (pin 8)