36 pin CENTRONICS female connector
at the printer.
| Pin | Description | Signal | Source |
|---|---|---|---|
| 1 | Data Strobe (low) | STROBE | Computer |
| 2 | Data Bit 1 (LSB) | D1 | Computer |
| 3 | Data Bit 2 | D2 | Computer |
| 4 | Data Bit 3 | D3 | Computer |
| 5 | Data Bit 4 | D4 | Computer |
| 6 | Data Bit 5 | D5 | Computer |
| 7 | Data Bit 6 | D6 | Computer |
| 8 | Data Bit 7 | D7 | Computer |
| 9 | Data Bit 8 (LSB) | D8 | Computer |
| 10 | Acknowledge (low) | ACK | Printer |
| 11 | Busy (high) | BUSY | Printer |
| 12 | Paper End (high) | PE | Printer |
| 13 | Select (high) | SEL | Printer |
| 14 | Supply Ground | - | |
| 15 | Oscillator Transmit | Printer | |
| 16 | Logical Ground | - | |
| 17 | Chassis Ground | - | |
| 18 | +5 Vdc | +V | Printer |
| 19 | Return Data Strobe | - | |
| 20 | Return Data Bit 1 | - | |
| 21 | Return Data Bit 2 | - | |
| 22 | Return Data Bit 3 | - | |
| 23 | Return Data Bit 4 | - | |
| 24 | Return Data Bit 5 | - | |
| 25 | Return Data Bit 6 | - | |
| 26 | Return Data Bit 7 | - | |
| 27 | Return Data Bit 8 | - | |
| 28 | Return ACK | - | |
| 29 | Return BUSY | - | |
| 30 | Return Input Prime | - | |
| 31 | Input Prime (low) | Computer | |
| 32 | Fault (low) | FAULT | Printer |
| 33 | - | - | - |
| 34 | - | - | - |
| 35 | - | - | - |
| 36 | - | - | - |
Signal Descriptions:
- STROBE: Active low pulse used to transfer data into the printer. Pulse with must be between 0.5 and 500 microseconds for most printers.
- ACK: Active low pulse indicates that data has been received and the printer is ready to accept more.
- BUSY: A high signal indicates that the printer cannot receive data.
- PE: A high signal indicates that the printer is out of paper (Paper End)
- SELECT OUT: A high signal indicates that the printer is on-line
- AUTO FEED: A low signal indicates to the printer that a line feed is required after each Carriage return. This signal is used as a ground line by some manufacturers.
- OSCXT: A 100-200 KHz signal used by true Centronics printers only.
- +5V: +5Vdc Not provided by all manufacturers
- PRIME: A low signal resets the printer to its power-up state and the printer buffer is cleared
- FAULT: A low signal indicates that the printer is in an off-line or error state
- LINE COUNT: Used by true Centronics printers only. Most of the time not used
- LINE COUNT: See 34
- SELECT IN: A high signal indicates to the printer that a DC1/ DC3 code is valid. This signal is used by a few manufacturers
- Host Logic High: A high signal indicates that the host is alive (turned on). Specific IEEE 1284 signal.
- Peripheral Logic High: A high signal indicates that the peripheral (printer) is alive (turned on). Specific IEEE 1284 signal.