20 pin Apple HDI-20
connector at the Apple computer, looking into cable-side
connector.
This connector is present on the Macintosh Duo MiniDock and PowerBook Duo Floppy adapter. An HDI-20 1.4 MB drive can be connected to this port.
| Pin | Name | Description |
|---|---|---|
| 1 | GND | Signal Ground |
| 2 | GND | Signal Ground |
| 3 | GND | Signal Ground |
| 4 | GND | Signal Ground |
| 5 | NC | No connection |
| 6 | +5V | +5 volts DC |
| 7 | +5V | +5 volts DC |
| 8 | +5V | +5 volts DC |
| 9 | +5V | +5 volts DC |
| 10 | NC | No connection |
| 11 | PH0 | Phase 0: state control line |
| 12 | PH1 | Phase 1: state control line |
| 13 | PH2 | Phase 2: state control line |
| 14 | PH3 | Phase 3: register write strobe |
| 15 | WREQ | Write request |
| 16 | HDSEL | Head select |
| 17 | ENBL2 | External drive select |
| 18 | RD | Read data |
| 19 | WR | Write data |
| 20 | NC | No connection |