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
1STROBEStrobe
2D0Data Bit 0
3D1Data Bit 1
4D2Data Bit 2
5D3Data Bit 3
6D4Data Bit 4
7D5Data Bit 5
8D6Data Bit 6
9D7Data Bit 7
10ACKAcknowledge
11BUSYBusy
12PEPaper End
13SELSelect
14AUTOFDAutofeed
15ERRORError
16INITInitialize
17SELINSelect In
18GNDStrobe Ground
19GNDData bit 1 and 2 Ground
20GNDData bit 3 and 4 Ground
21GNDData bit 5 and 6 Ground
22GNDData bit 7 and 8 Ground
23GNDBusy and Fault Ground
24GNDPaper out, Select, and Acknowledge Ground
25GNDAutoFeed, Select input and Initialize Ground
25 polige sub d connector

Fig 1. 25 polige sub d connector.

De aansluitingen van een 36 polige connector
1STROBEStrobe
2D0Data Bit 0
3D1Data Bit 1
4D2Data Bit 2
5D3Data Bit 3
6D4Data Bit 4
7D5Data Bit 5
8D6Data Bit 6
9D7Data Bit 7
10ACKAcknowledge
11BUSYBusy
12PEPaper End
13SELSelect
14AUTOFDAutofeed
15Select INDaisy-Chain IN
16Signal GNDLogic Ground
17CHASSIS GNDShield Ground
18+5 V PULLUP+5 V DC (50 mA max)
19GNDSignal Ground (Strobe Ground)
20GNDSignal Ground (Data 0 Ground)
21GNDSignal Ground (Data 1 Ground)
22GNDSignal Ground (Data 2 Ground)
23GNDSignal Ground (Data 3 Ground)
24GNDSignal Ground (Data 4 Ground)
25GNDSignal Ground (Data 5 Ground)
26GNDSignal Ground (Data 6 Ground)
27GNDSignal Ground (Data 7 Ground)
28GNDSignal Ground (Acknowledge Ground)
29GNDSignal Ground (Busy Ground)
30GNDRESETReset Ground
31RESETCancel Current Job (May be called /PRIME)
32FAULTFault with Printer (Low when offline)
330 VSignal Ground
34n/cNot used
35+5 V+5 V DC
36SLCT INSelect In; Taking low or high sets printer on line or off line
36 polige centronics connector

Fig 2. 36 polige centronics connector.