Centronics
Parallel poort ook wel Centronics poort genoemd werd gebruikt wordt gebruikt om printers aan te sturen, later verschenen de EPP en ECP variant welke bidirectioneel verkeer mogelijk maakten. Hierdoor werd de poort ook voor andere toepassingen zoals scanners gebruikt. USB heeft de parallele poort inmiddels grotendeels verdrongen.
| De aansluitingen van een 25 polige connector | ||
| 1 | STROBE | Strobe |
| 2 | D0 | Data Bit 0 |
| 3 | D1 | Data Bit 1 |
| 4 | D2 | Data Bit 2 |
| 5 | D3 | Data Bit 3 |
| 6 | D4 | Data Bit 4 |
| 7 | D5 | Data Bit 5 |
| 8 | D6 | Data Bit 6 |
| 9 | D7 | Data Bit 7 |
| 10 | ACK | Acknowledge |
| 11 | BUSY | Busy |
| 12 | PE | Paper End |
| 13 | SEL | Select |
| 14 | AUTOFD | Autofeed |
| 15 | ERROR | Error |
| 16 | INIT | Initialize |
| 17 | SELIN | Select In |
| 18 | GND | Strobe Ground |
| 19 | GND | Data bit 1 and 2 Ground |
| 20 | GND | Data bit 3 and 4 Ground |
| 21 | GND | Data bit 5 and 6 Ground |
| 22 | GND | Data bit 7 and 8 Ground |
| 23 | GND | Busy and Fault Ground |
| 24 | GND | Paper out, Select, and Acknowledge Ground |
| 25 | GND | AutoFeed, Select input and Initialize Ground |
Fig 1. 25 polige sub d connector.
| De aansluitingen van een 36 polige connector | ||
| 1 | STROBE | Strobe |
| 2 | D0 | Data Bit 0 |
| 3 | D1 | Data Bit 1 |
| 4 | D2 | Data Bit 2 |
| 5 | D3 | Data Bit 3 |
| 6 | D4 | Data Bit 4 |
| 7 | D5 | Data Bit 5 |
| 8 | D6 | Data Bit 6 |
| 9 | D7 | Data Bit 7 |
| 10 | ACK | Acknowledge |
| 11 | BUSY | Busy |
| 12 | PE | Paper End |
| 13 | SEL | Select |
| 14 | AUTOFD | Autofeed |
| 15 | Select IN | Daisy-Chain IN |
| 16 | Signal GND | Logic Ground |
| 17 | CHASSIS GND | Shield Ground |
| 18 | +5 V PULLUP | +5 V DC (50 mA max) |
| 19 | GND | Signal Ground (Strobe Ground) |
| 20 | GND | Signal Ground (Data 0 Ground) |
| 21 | GND | Signal Ground (Data 1 Ground) |
| 22 | GND | Signal Ground (Data 2 Ground) |
| 23 | GND | Signal Ground (Data 3 Ground) |
| 24 | GND | Signal Ground (Data 4 Ground) |
| 25 | GND | Signal Ground (Data 5 Ground) |
| 26 | GND | Signal Ground (Data 6 Ground) |
| 27 | GND | Signal Ground (Data 7 Ground) |
| 28 | GND | Signal Ground (Acknowledge Ground) |
| 29 | GND | Signal Ground (Busy Ground) |
| 30 | GNDRESET | Reset Ground |
| 31 | RESET | Cancel Current Job (May be called /PRIME) |
| 32 | FAULT | Fault with Printer (Low when offline) |
| 33 | 0 V | Signal Ground |
| 34 | n/c | Not used |
| 35 | +5 V | +5 V DC |
| 36 | SLCT IN | Select In; Taking low or high sets printer on line or off line |
Fig 2. 36 polige centronics connector.