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Appendix C: Interface Pin Outs

Parallel Interface

Pin Name Function
1 STROBE Goes low for
≥
0.5
µ
s when active.
2 DATA0 These signals represent information for the 1st through 8th bit of parallel data,
respectively. Each signal is HIGH when data is logical 1, and LOW when logical
0.
3 DATA1
4 DATA2
5 DATA3
6 DATA4
7 DATA5
8 DATA6
9 DATA7
10 ACK 10
µ
s low to acknowledge receipt of data.
11 BUSY Printer sets line low when ready to receive data.
12 PAPER High when paper runs out.
13 SELECT High when printer is on-line.
14 AFXT Printer ignores this signal.
15 Not used.
16 SIGNAL GND Signal ground
17 CHASSIS Chassis ground (isolated from signal ground)
18 +5V +5V DC output from printer
19 - 30 GND Twisted pair ground return
31 RESET Printer is reset when this signal goes low.
32 ERROR Low when printing cannot continue due to error.
33 EXT GND External ground
34 - 35 Not used
36 SELECT IN Printer ignores this signal.

Optional Serial Interface

Pin Name Function
1 GND Printer chassis ground
2 TXD Data from printer
3 RXD Data to printer
4 RTS Always space
5 CTS Space when computer is ready to send data. Printer ignores this signal.
6 Not used.
7 GND Signal ground
8 - 10 Not used.
11 RCH Pr inter sets line to space when ready to receive data. Same signal as Pin 20.
12 - 19 Not used.
20 DTR Printer sets line to space when ready to receive data.
21 - 25 Not used.