Parallel Interface; Serial Interface, Powered And Non-Powered - HP dc7900 - Convertible Minitower PC Service & Reference Manual

Parallel Interface

Connector and Icon
Pin Signal
1 Strobe
2 Data Bit 0
3 Data Bit 1
4 Data Bit 2
5 Data Bit 3
6 Data Bit 4
7 Data Bit 5
8 Data Bit 6
9 Data Bit 7

Serial Interface, Powered and Non-Powered

Connector and Icon
214 Appendix A Connector Pin Assignments
Pin Signal
10 Acknowledge
11 Busy
12 Paper End
13 Select
14 Auto Linefeed
15 Error
16 Initialize Printer
17 Select IN
18–25 Signal Ground
Pin Signal
1 Carrier Detect (12V if powered)
2 Receive Data
3 Transmit Data
4 Data Terminal Ready
5 Signal Ground
6 Data Set Ready
7 Request to Send
8 Clear to Send
9 Ring Indicator (5V if powered)