The 25-pin standard Sub-D female connector LPT on the rear panel of the CMU is intended for connecting a printer. The interface is CENTRONICS compatible.
Pin assignment of the LPT connector
| Pin | Signal | Input (I) Output (O) |
Description |
| 1 | STROBE | O | Impulse for transfer of a data byte, 1µs pulse width at minimum (active LOW) |
| 2 | D0 | O | Data line 0 |
| 3 | D1 | O | Data line 1 |
| 4 | D2 | O | Data line 2 |
| 5 | D3 | O | Data line 3 |
| 6 | D4 | O | Data line 4 |
| 7 | D5 | O | Data line 5 |
| 8 | D6 | O | Data line 6 |
| 9 | D7 | O | Data line 7 |
| 10 | ACK | I | Indicates that the printer is ready to receive the next byte (active LOW) |
| 11 | BUSY | I | Signal active if the printer is unable to receive data |
| 12 | PE | I | The signal is activated if no printer paper is available (active HIGH). |
| 13 | SELECT | I | The signal is activated when the printer is selected (active HIGH). |
| 14 | AUTOFEED | O | If the signal is active the printer inserts a line feed after each line (active LOW). |
| 15 | ERROR | I | The signal is activated if no printer paper is available or an error occurred (active LOW). |
| 16 | INIT | O | Initializing the printer (active LOW) |
| 17 | SELECT IN | O | If the signal is active the codes DC1/DC3 are ignored by the printer (active LOW). |
| 18 - 25 | GND | Connected to ground |