Apple Desktop Bus Connector
(As used on Apple Macintosh keyboards and mice)
Pin number |
Description |
| 1 | Bidirectional data bus |
| 2 | Startup (grounded to pin 4 = on) |
| 3 | +5V |
| 4 | Ground |

Pictured looking into mating face of male plug.
(Note: non standard pin numbering)