| pin | direction | function |
| 1 | out(oc) | -STROBE (shows transmission?) |
| 2 | out | D0 |
| 3 | out | D1 |
| 4 | out | D2 |
| 5 | out | D3 |
| 6 | out | D4 |
| 7 | out | D5 |
| 8 | out | D6 |
| 9 | out | D7 |
| 10 | in | -ACK (accepted previous character), IRQ! |
| 11 | in | BUSY |
| 12 | in | PE (paper empty) |
| 13 | in | SELECT (printer online) |
| 14 | out | AUTO FEED (automatic CR after LF) |
| 15 | in | -ERROR (data transmission error) |
| 16 | out | -INIT (reset printer) |
| 17 | out | -SLCT IN (select input / switch printer online) |
| 18 | - | GND (ground) |
| 19 | - | GND |
| 20 | - | GND |
| 21 | - | GND |
| 22 | - | GND |
| 23 | - | GND |
| 24 | - | GND |
| 25 | - | GND |
Out means PC output.
-VALUE means hardware inverted logic.