Power Macintosh 7200, 7500, 8500, 9500
14 pin Apple AAUI male connector at the card.
14 pin Apple AAUI female connector.
The Apple Attachment Unit Interface (AAUI) is a proprietary mechanical redesign of the standard IEEE 802.3 AUI (Attachment Unit Interface), introduced in October 1991 with the Macintosh Quadra 700 and 900. It uses a compact 14-position 0.050-inch-pitch ribbon contact connector in place of the DA-15 D-sub, primarily to avoid confusion with the DA-15 video ports found on contemporary Macintosh models. AAUI signals are electrically identical to standard AUI per IEEE 802.3-1990, Section 7, carrying the same Manchester-encoded 10 Mbit/s CSMA/CD Data Out, Data In, and Control In differential pairs. The port appeared on Macintosh Quadra and Power Macintosh computers, the Apple Ethernet NB Card, and LaserWriter IIg printers, and accepted interchangeable transceivers for 10BASE-T, 10BASE-2, and 10BASE-5 media; most hosts supply +5 V on the power pins rather than the +12 V used by classic AUI transceivers.
| Pin | Name | Description |
|---|---|---|
| 1 | FN Pwr | Power (+12V @ 2.1W or +5V @ 1.9W) |
| 2 | DI-A | Data In circuit A |
| 3 | DI-B | Data In circuit B |
| 4 | VCC | Voltage Common |
| 5 | CI-A | Control In circuit A |
| 6 | CI-B | Control In circuit B |
| 7 | +5V | +5 volts (from host) |
| 8 | +5V | Secondary +5 volts (from host) |
| 9 | DO-A | Data Out circuit A |
| 10 | DO-B | Data Out circuit B |
| 11 | VCC | Secondary Voltage Common |
| 12 | NC | Reserved |
| 13 | NC | Reserved |
| 14 | FN Pwr | Secondary +12V @ 2.1W or +5V @ 1.9W |
| Shell | Protective Gnd | Protective Ground |
Notes
- The AAUI connector is keyed so that it cannot be inserted inverted; the male plug clips into the female receptacle on the host board.
- Some Apple products supply only +5 V on the FN Pwr pins (1 and 14); transceivers designed for classic AUI may require +12 V and will not operate correctly from a +5 V AAUI host without a compatible power supply in the transceiver module.
- AAUI is strictly a 10 Mbit/s technology; it was phased out in favour of direct RJ-45 10BASE-T connectors from approximately 1998 onward.
- The AAUI connector is not electrically or mechanically compatible with the standard DA-15 AUI connector, although the signal definitions are identical per IEEE 802.3-1990, Section 7.
Signals
- FN Pwr — Transceiver power supply, +12 V at 2.1 W or +5 V at 1.9 W depending on host; present on pins 1 and 14
- DI-A / DI-B — Data In differential pair (Manchester-encoded receive data from transceiver to host MAC)
- CI-A / CI-B — Control In differential pair (collision presence signal from transceiver to host MAC, equivalent to the CO circuit in IEEE 802.3 terminology)
- DO-A / DO-B — Data Out differential pair (transmit data from host MAC to transceiver)
- +5V — +5 V supply from host to transceiver logic (pins 7 and 8)
- VCC — Voltage common / signal ground reference (pins 4 and 11)
- NC — Not connected; pins 12 and 13 are reserved and carry no signal
- Shell / Protective Gnd — Chassis ground via connector shell