(At the Computer)
(At the Joystick cable)
9 PIN D-SUB MALE at the Computer. 9 PIN D-SUB FEMALE at the Joystick cable.
The Amstrad CPC 464, 664, and 6128 provide a single 9-pin DE-9 joystick port based on the Atari digital joystick standard, introduced with the CPC 464 in 1984. Signals are active-low: pressing a direction or fire button shorts the relevant pin to ground. Unlike a standard Atari port, the CPC shares one connector between two joysticks — pin 8 (Common1) is ground for joystick 1, and pin 9 (Common2) is ground for joystick 2, with the second joystick connected via a pass-through socket on the first. The port supports two fire buttons: FIRE2 (pin 6) is the primary button used by most games, and FIRE1 (pin 7) is the secondary button found on CPC-specific controllers; pin 5 is not connected.
Digital Joystick 1
| Pin | Name | Dir | Description |
|---|---|---|---|
| 1 | UP | IN | Up |
| 2 | DOWN | IN | Down |
| 3 | LEFT | IN | Left |
| 4 | RIGHT | IN | Right |
| 5 | n/c | - | Not connected |
| 6 | FIRE2 | IN | Fire button 2 |
| 7 | FIRE1 | IN | Fire button 1 |
| 8 | GND | - | Ground |
| 9 | GND | - | Ground |
Digital Joystick 2
| Pin | Name | Dir | Description |
|---|---|---|---|
| 1 | UP | IN | Up |
| 2 | DOWN | IN | Down |
| 3 | LEFT | IN | Left |
| 4 | RIGHT | IN | Right |
| 5 | n/c | - | Not connected |
| 6 | FIRE2 | IN | Fire button 2 |
| 7 | FIRE1 | IN | Fire button 1 |
| 8 | GND | - | Ground |
| 9 | n/c | - | Not connected |
Notes
- Direction is Computer relative Joystick.
- The connector is a 9-pin DE-9 (sometimes called DB-9); the host provides a male socket, and the joystick cable terminates in a female plug.
- Two joysticks share the single port. Joystick 1 uses pin 8 (Common1/GND) as its ground return; joystick 2 uses pin 9 (Common2/GND) and is connected through a pass-through socket on joystick 1.
- Standard Atari-compatible joysticks work for directions and a single fire button (pin 6 / FIRE2); the second fire button (pin 7 / FIRE1) is specific to CPC controllers.
- Joystick inputs are read by the PSG (AY-3-8912) I/O port via the 8255 PPI and scanned by the Key Manager as though they were keyboard keys.
Signals
- UP — active-low direction input; pressing grounds pin 1 via Common1 or Common2
- DOWN — active-low direction input; pressing grounds pin 2
- LEFT — active-low direction input; pressing grounds pin 3
- RIGHT — active-low direction input; pressing grounds pin 4
- n/c — pin 5; not connected on the CPC
- FIRE2 — primary fire button (active-low); used by the majority of CPC software
- FIRE1 — secondary fire button (active-low); CPC-specific, not present on standard Atari joysticks
- GND (Common1) — ground return for joystick 1 (pin 8)
- GND (Common2) — ground return for joystick 2 (pin 9); not connected on joystick 2’s own table entry where pin 9 is n/c, as joystick 2 receives Common2 from the host port