Parallel Port Pin-Out
EPP was created in 1991 to permit up to 2 Mbps data transfer, and was intended primarily for non-printers.

 

ECP was created in 1992 to permit higher speed printer communications.

 

IEEE1284 was created in 1994 to combine EEP and ECP, and relies on the host to determine which standard to use.

Standard Parallel Port (SPP)   Enhanced Parallel Port (EPP)   Extended Capabilities Port (ECP)
Signal Name Centronics

(36-pin)

 DB-25

(25-pin)

 Signal Name DB-25

(25-pin)

 Signal Name DB-25

(25-pin)
Strobe 1 1 Write 1 Host CLK 1
Data 0 2 2 Data 0 2 Data 0 2
Data 1 3 3 Data 1 3 Data 1 3
Data 2 4 4 Data 2 4 Data 2 4
Data 3 5 5 Data 3 5 Data 3 5
Data 4 6 6 Data 4 6 Data 4 6
Data 5 7 7 Data 5 7 Data 5 7
Data 6 8 8 Data 6 8 Data 6 8
Data 7 9 9 Data 7 9 Data 7 9
Acknowledge 10 10 Interrupt 10 Periph CLK 10
Busy 11 11 Wait 11 Periph ACK 11
Paper End 12 12 Spare 12 Ack Reverse 12
Select 13 13 Spare 13 X-Flag 13
Auto Line Feed 14 14 Data Strobe 14 Host ACK 14
Error 32 15 Spare 15 Periph Request 15
Initialize Printer 31 16 Reset 16 Reverse Request 16
Select Input 36 17 Address Strobe 17 1284 Active 17
Strobe Return 19 18 Ground 18 Ground 18
Data 0 Return 20 19 Ground 19 Ground 19
Data 1 Return 21 19 Ground 20 Ground 20
Data 2 Return 22 20 Ground 21 Ground 21
Data 3 Return 23 20 Ground 22 Ground 22
Data 4 Return 24 21 Ground 23 Ground 23
Data 5 Return 25 21 Ground 24 Ground 24
Data 6 Return 26 22 Ground 25 Ground 25
Data 7 Return 27 22
Acknowledge Return 28 24
Busy Return 29 23
Paper End Return 28 24
Select Return 28 24
Auto Line Feed Return 30 25
Error Return 29 23
Initialize Printer Return 30 25
Select Input Return 30 25
Shield 33 N/C
N/C 34 N/C
N/C 35 N/C