hits since 2020-09-25.
Power
| Pin Number | Signal |
|---|---|
| 1 | +12V |
| 2 | -12V |
| 3 | GND |
| 4 | +5V |
Printer (SK1)
| Inner row | Pin | Outer row | |
|---|---|---|---|
| D6 | 1 | 2 | GND |
| D7 | 3 | 4 | GND |
| D4 | 5 | 6 | GND |
| D5 | 7 | 8 | GND |
| D2 | 9 | 10 | GND |
| D3 | 11 | 12 | GND |
| D0 | 13 | 14 | GND |
| D1 | 15 | 16 | GND |
| BUSY | 17 | 18 | GND |
| /STROBE | 19 | 20 | GND |
Keyboard (SK2)
| Inner row | Pin | Outer row | |
|---|---|---|---|
| D0 | 1 | 2 | +5V |
| D1 | 3 | 4 | GND |
| D2 | 5 | 6 | GND |
| D3 | 7 | 8 | GND |
| D4 | 9 | 10 | GND |
| D5 | 11 | 12 | GND |
| D6 | 13 | 14 | GND |
| N/C | 15 | 16 | GND |
| /STROBE | 17 | 18 | GND |
| /RESET | 19 | 20 | -12V |
Serial Ports (SK3 (Serial 1) and SK4(Serial 2))
| Pin Number | Signal |
|---|---|
| 1 | GND |
| 2 | TxD |
| 3 | RxD |
| 4 | /RTS |
| 5 | /CTS |
| 7 | GND |
| 11 | +5V |
| 25 | -12V |
Floppy disk (SK5)
| Inner row | Pin | Outer row | |
|---|---|---|---|
| GND | 1 | 2 | N/C |
| GND | 3 | 4 | N/C |
| GND | 5 | 6 | N/C |
| GND | 7 | 8 | Index |
| GND | 9 | 10 | Select 0 |
| GND | 11 | 12 | Select 1 |
| GND | 13 | 14 | N/C |
| GND | 15 | 16 | Motor On |
| GND | 17 | 18 | Direction |
| GND | 19 | 20 | Step |
| GND | 21 | 22 | Write Data |
| GND | 23 | 24 | Write Gate |
| GND | 25 | 26 | Track 0 |
| GND | 27 | 28 | Write Prot |
| GND | 29 | 30 | Read Data |
| GND | 31 | 32 | N/C |
| GND | 33 | 34 | N/C |
EPROM Disc or GPIO (SK6)
| Pin Number | Signal |
|---|---|
| 1 | PA4 |
| 2 | PA3 |
| 3 | PA5 |
| 4 | PA2 |
| 5 | PA6 |
| 6 | PA1 |
| 7 | PA7 |
| 8 | PA0 |
| 9 | GND |
| 10 | PC7 |
| 11 | PC6 |
| 12 | PC5 |
| 13 | PC4 |
| 14 | PC0 |
| 15 | +5V |
| 16 | PC1 |
| 17 | PB7 |
| 18 | PC2 |
| 19 | PB6 |
| 20 | PC3 |
| 21 | PB5 |
| 22 | PB0 |
| 23 | PB4 |
| 24 | PB1 |
| 25 | PB3 |
| 26 | PB2 |
TTL Video (SK8)
| Pin Number | Signal |
|---|---|
| 1 | GND |
| 2 | /TTLVID |
| 3 | /HSYNC |
| 4 | /VSYNC |
Composite Video (SK9)
Composite video and GND.
Expansion (SK10)
| Inner row | Pin | Outer row | |
|---|---|---|---|
| +5V | 1 | 2 | +5V |
| GND | 3 | 4 | GND |
| BA0 | 5 | 6 | IC19 pin 6 |
| /BRTS | 7 | 8 | BA1 |
| BD1 | 9 | 10 | BD0 |
| BD3 | 11 | 12 | BD2 |
| BD5 | 13 | 14 | BD4 |
| BD7 | 15 | 16 | BD6 |
| BA2 | 17 | 18 | BR/W |
| BA4 | 19 | 20 | BA3 |
| 16MHz | 21 | 22 | BE |
| WDS | 23 | 24 | Q |
| RTC | 25 | 26 | LPEN |
| /IO2 | 27 | 28 | /RDS |
| /IO1 | 29 | 30 | /IOBUFF |
| /NMI | 31 | 32 | RST |
| /FIRQ | 33 | 34 | /IRQ |
| /TTLVID | 35 | 36 | VSYNC |
| GND | 37 | 38 | GND |
| -12V | 39 | 40 | +12V |
I have no idea why IC19 pin 6 (which is part of the parallel keyboard/printer interface) is on this connector. LPEN is pin 21 of the uPD7220 (not labelled in the schematic).
hits since 2020-09-25.