14 pin Apple AAUI male connector to the Macintosh
15 pin D-SUB female connector to the transceiver (AUI)
Apple’s AAUI (Apple Attachment Unit Interface) is a compact 14-position, 0.050-inch-spaced ribbon-contact connector introduced with the Macintosh Quadra 700 and 900 in October 1991. It carries the same four differential-pair circuits as the IEEE 802.3 AUI — Data Out (DO), Data In (DI), and Control In (CI, collision detect) — but omits the Control Out (CO) circuit entirely and replaces the standard DA-15 shell with a smaller Micro-D style housing. AAUI was used on Macintosh Quadra, Centris, PowerBook 500, and Power Macintosh models through approximately 1997, as well as on certain NuBus Ethernet cards and the Apple LaserWriter IIg.
| Description | AAUI | AUI |
|---|---|---|
| control in circuit A | 5 | 2 |
| data out circuit A | 9 | 3 |
| data in circuit shield | shell | 4 |
| data in circuit A | 2 | 5 |
| voltage common | 4 | 6 |
| control out circuit shield | shell | 8 |
| control in circuit B | 6 | 9 |
| data out circuit B | 10 | 10 |
| data out circuit shield | shell | 11 |
| data in circuit B | 3 | 12 |
| voltage plus | 1 | 13 |
| voltage shield | shell | 14 |
Notes
- AUI pins 7 (CO-A) and 15 (CO-B) have no AAUI equivalents; the CO circuit is not implemented in AAUI.
- AUI pin 8 (CO-S, Control Out shield) maps to the AAUI shell rather than to a numbered pin.
- Most Apple products with an AAUI connector supply only +5 VDC on pin 1 (AAUI pin 1 / AUI pin 13); standard AUI transceivers require +12 VDC at 500 mA, so an external supply is needed when using non-Apple transceivers.
- The maximum AUI drop cable length is 50 m for 10BASE-5 and 1.33 m for 10BASE-2, per IEEE 802.3.
- The electrical requirements of AAUI signals are governed by IEEE Standard 802.3-1988 CSMA/CD, paragraph 7.6.3.