How To Read Atari Controllers

Atari 2600 controllers use a standard DB-9 serial port.

DB-9 Pin Layout

The controller pins are as follows, looking face on to the (female) DB9 plug:

1. Input pin (UP), set by the controller.
2. Input pin (DOWN), set by the controller.
3. Input pin (LEFT), set by the controller.
4. Input pin (RIGHT), set by the controller.
5. N/A.
6. Input pin (FIRE), set by the controller.
7. N/A.
8. Ground.
9. N/A.

Classic Joystick

The classic joystick is comprised of five simple switches, each of which pulls the appropriate pin to ground when pressed.

Resources

• Atari 2600 joystick pinout