| SIDE A (Solder side) | I/O | Pin number | I/O | SIDE B (Part side) |
|---|---|---|---|---|
| GND | - | 1 | - | GND |
| GND | - | 2 | - | GND |
| +5V | - | 3 | - | +5V |
| +5V | - | 4 | - | +5V |
| AB0 | O | 5 | - | EXTRXRDY |
| AB1 | O | 6 | - | - |
| AB2 | O | 7 | I | MWAIT |
| AB3 | O | 8 | I | INT4 |
| AB4 | O | 9 | I | INT3 |
| AB5 | O | 10 | I | INT2 |
| AB6 | O | 11 | I | FDINT1 |
| AB7 | O | 12 | I | FDINT2 |
| AB8 | O | 13 | O | DB0 |
| AB9 | O | 14 | O | DB1 |
| AB10 | O | 15 | O | DB2 |
| AB11 | O | 16 | O | DB3 |
| AB12 | O | 17 | O | DB4 |
| AB13 | O | 18 | O | DB5 |
| AB14 | O | 19 | O | DB6 |
| AB15 | O | 20 | O | DB7 |
| RD | O | 21 | O | MEMR |
| WR | O | 22 | O | HIGH |
| MREQ | O | 23 | O | IOW |
| IORQ | O | 24 | O | IOR |
| M1 | O | 25 | O | MEMW |
| RAS0 | O | 26 | ? | DMATC |
| RAS1 | O | 27 | ? | DMARDY |
| RFSH | O | 28 | I | DRQ1,2 |
| MUX | O | 29 | O | DACK1,2 |
| WE | O | 30 | O | 4CLK |
| ROMKILL | I | 31 | I | NMI |
| RESET | O | 32 | I | WAITRQ |
| SCLK | O | 33 | - | +12V |
| CLK | O | 34 | - | -12V |
| V1 | ? | 35 | ? | V1 |
| V2 | ? | 36 | ? | V2 |
| Signal | Function |
|---|---|
| MWAIT | Add 1 wait to memory cycle (same function as setting with dip switch) |
| ROMKILL | Prohibits the main unit device from responding to accesses from 0000h to 7FFFh |
| 4CLK | 15.9744 MHz |
| SCLK | 76.8 kHz ? |
| CLK | 3.9936 MHz |
| HIGH | Pulled up to +5V |
| Ports | Functions |
|---|---|
| 90h-9Fh | CD-ROM I/F |
| A0h-A3h | LAN, PSG |
| B4h-B5h | Video Art Board |
| BCh-BFh | Parallel |
| C2h-C3h | SIO |
| C4h-C7h | PSG |
| D0h-D8h | GP-IB, PSG |
| DCh-DFh | Modem |
| F3h-F7h | 8'FDD |