Signal assignments for the Apple Computers NuBus row A is listed below.
Refer here for NuBus Signal assignments row B, or NuBus pin out row A.
This interface is obsolete and should not be used for new designs.
| Pin # | Signal Name | Description |
|---|---|---|
| 1 | /RESET | Reset |
| 2 | - | |
| 3 | +5 V | +5 VDC |
| 4 | +5 V | +5 VDC |
| 5 | /TM0 | Transfer Mode 0 |
| 6 | /AD0 | Address/Data 0 |
| 7 | /AD2 | Address/Data 2 |
| 8 | /AD4 | Address/Data 4 |
| 9 | /AD6 | Address/Data 6 |
| 10 | /AD8 | Address/Data 8 |
| 11 | /AD10 | Address/Data 10 |
| 12 | /AD12 | Address/Data 12 |
| 13 | /AD14 | Address/Data 14 |
| 14 | /AD16 | Address/Data 16 |
| 15 | /AD18 | Address/Data 18 |
| 16 | /AD20 | Address/Data 20 |
| 17 | /AD22 | Address/Data 22 |
| 18 | /AD24 | Address/Data 24 |
| 19 | /AD26 | Address/Data 26 |
| 20 | /AD28 | Address/Data 28 |
| 21 | /AD30 | Address/Data 30 |
| 22 | GND | Ground |
| 23 | /PFW | |
| 24 | /ARB0 | Arbitration 0 |
| 25 | /ARB2 | Arbitration 2 |
| 26 | /ID0 | Slot ID 0 |
| 27 | /ID2 | Slot ID 2 |
| 28 | /START | |
| 29 | +5 V | +5 VDC |
| 30 | +5 V | +5 VDC |
| 31 | GND | Ground |
| 32 | /CLK | Clock |
The slash before each of the signal names indicate that the line is active low.
Back to the main NuBus page for a description of the bus and other signal assignments.
Additional pinout tables for other Apple protocols are listed on the
Apple Computer Buses
page.
Do not reference this bus in new designs, the NuBus has been obsolete for a number of years now. However, in it's day, NuBus was considered a fast interface bus.








