Pinout
Using 96 position (3x32) DIN 41612 connectors; right angle male on expansion cards, vertical female on the backplane side. The management card uses a 48 position (3x16) DIN 41612 (C2) right angle male connector, with the corresponding vertical female on the backplane side.
CPU Board
| A | B | C | |
| 1 | +5V | GND | +12V |
| 2 | +5V | GND | +12V |
| 3 | I2C_SCL1 | /I2C_IRQ1 | I2C_SDA1 |
| 4 | GND | GND | GND |
| 5 | GND | D8 | D13 |
| 6 | D9 | D11 | D15 |
| 7 | D10 | D14 | D12 |
| 8 | D7 | D5 | GND |
| 9 | D6 | GND | D3 |
|
10 |
GND | D4 | D1 |
| 11 | D2 | D0 | GND |
| 12 | GND | GND | A22 |
| 13 | A23 | GND | A19 |
| 14 | GND | A21 | A17 |
| 15 | A20 | A15 | A18 |
| 16 | A13 | A16 | A12 |
| 17 | A14 | A10 | GND |
| 18 | A11 | GND | A8 |
| 19 | GND | A9 | A6 |
| 20 | A7 | A4 | A2 |
| 21 | A5 | A3 | A1 |
| 22 | R/W | /LDS | /UDS |
| 23 | GND | /DTACK1 | /AS1 |
| 24 | CLK | GND | |
| 25 | FC1 | FC0 | FC2 |
| 26 | |||
| 27 | |||
| 28 | /EXT5 | /BG1 | /HALT14 |
| 29 | /RESET34 | /BR1 | /BGACK1 |
| 30 | /IACK1 | /IRQ | /BERR14 |
| 31 | GND | GND | GND |
| 32 | SNDR | GND | SNDL |
Note that the data and address bus, as well as most control signals (those in rows 1-25) are driven through buffers, whose direction is controlled by the bus request lines as to allow external bus masters to access CPU board peripherals. These buffers can be on the backplane or the CPU card.
Any empty cells are not currently used and considered reserved for future use.
Remarks:
- Pulled up on CPU board
- Pulled down on CPU board
- Asserted by processor to reset all peripherals. To reset the processor, you must simultaneously assert /HALT for at least 1ms.
- This signal is open drain.
- Asserted when the currently decoded address is valid and is not decoded on the CPU board. Can be used as part of external buffer logic.
Management Card
This provides power input to the rest of the backplane, and provides connectors for the mixed audio from the backplane.
| A | B | C | |
| 1 | +5V | +5V | +5V |
| 2 | +5V | +5V | +5V |
| 3 | +5V | +5V | +5V |
| 4 | GND | GND | GND |
| 5 | +12V | +12V | +12V |
| 6 | GND | GND | GND |
| 7 | GND | ||
| 8 | GND | ||
| 9 | GND | ||
|
10 |
GND | ||
| 11 | GND | ||
| 12 | GND | ||
| 13 | GND | I2C_IRQ | |
| 14 | I2C_SCL | GND | I2C_SDA |
| 15 | GND | ||
| 16 | SNDR | GND | SNDL |
Any empty cells are not filled in are considered reserved for future use, and should be left unconnected.
Remarks:
- SNDL/SNDR refers to mixed audio from all cards (CPU + expansion) in the system.
- EXTRST: when asserted, the CPU board (and with it, all peripherals on the backplane) are reset. This is equivalent to pushing the reset button on the CPU board, if it has one.