Interactive Connector Diagram
Click or tap any pin in the diagram below to inspect its signal assignment, electrical specification, and wire colour standard.
Supported Systems / Found On — Retro Machine Hubs
This connector is used on the following retro computer systems. Click any colour-coded badge below to open its full board-level repair, diagnostic, and schematic Machine Hub:
Connector Specifications
Full Pin Assignment & Wiring Reference
| Pin | Signal Name | Direction | Electrical Spec / Role | Wire Colour / SCART / Adapter Target |
|---|---|---|---|---|
| 1 | UP ( / Mouse V ) | In | Digital UP switch (Active-Low to Pin 8) | Amiga/ST Mouse: V-Pulse | White |
| 2 | DOWN ( / Mouse VQ ) | In | Digital DOWN switch (Active-Low to Pin 8) | Amiga/ST Mouse: VQ-Pulse | Blue |
| 3 | LEFT ( / Mouse H ) | In | Digital LEFT switch (Active-Low to Pin 8) | Amiga/ST Mouse: H-Pulse | Green |
| 4 | RIGHT ( / Mouse HQ ) | In | Digital RIGHT switch (Active-Low to Pin 8) | Amiga/ST Mouse: HQ-Pulse | Brown |
| 5 | POT Y (C64) / MID BTN (Amiga) | In | C64: Pot Y (SID) | Atari: Pot B | Amiga: Middle Mouse Btn | CPC: Joy 2 Right | Yellow |
| 6 | FIRE 1 / LEFT MOUSE BTN | In | Primary Fire Button / Left Mouse Button ( + Lightpen Strobe on C64/Amiga) | Orange |
| 7 | +5V DC ( / CPC Fire 2 ) | Pwr | +5 V DC Supply (50–100 mA max for paddles/mouse/autofire; Fire 2 on CPC!) | Red (+5V) |
| 8 | GND (0 V Common) | GND | 0 V Common Switch Return (Note: Driven low by PSG Pin 8 Strobe on MSX!) | Black (GND) |
| 9 | POT X (C64) / RIGHT BTN (Amiga) | In | C64: Pot X (SID) | Atari: Pot A | Amiga: Right Mouse Btn (Paula) | CPC: Joy 2 Common | Purple / Grey |
System-Specific DB9 Quirks (Amiga Right Mouse, CPC Splitter & MSX Pin 7)
Introduced on the 1977 Atari VCS (2600), the 9-pin D-Sub male (DE-9M) connector became the universal joystick port for 8-bit and 16-bit computers. While Pins 1 (Up), 2 (Down), 3 (Left), 4 (Right), 6 (Fire 1), and 8 (Ground) are identical across nearly all standard systems, Pins 5, 7, and 9 carry completely different signals (Analogue Paddles on C64/Atari, Right/Middle Mouse Buttons on Amiga, Secondary Joystick Splitter on Amstrad CPC, and Pin 8 Strobe on MSX!).
- Amiga Right Mouse Button Not Working: On the Amiga, the Left Mouse Button (Pin 6) goes to CIA-A, X/Y movement (Pins 1–4) goes to Denise, and the Right Mouse Button (Pin 9) goes to Paula Pin 33 (POT0Y)!
- Amstrad CPC 464/6128 Dual Joystick Y-Splitter: The CPC maps Joystick 2 onto the same single DB9 port by using Pin 9 as Joystick 2 Common Ground and Pins 1, 2, 3, 5, 7 for Joy 2 directions/fire.
- MSX 2-Button Gamepad Wiring: On an MSX, Pin 6 is Trigger A, Pin 7 is Trigger B, and Pin 8 is an active-low strobe output driven by the AY-3-8910 / YM2149.