Compaq LA36 - Manual (Page 152)

D-4
Interface Information
Pin Direction Signal Description
31 To printer Init L Set to high for Reverse Channel operation
32 From printer DataAvail L Reverse channel: Data 0 and 4
33 Not used
34 Not used
35 Not used
36 To printer SelectIn L Set to high for Reverse Channel
Serial Interface
Use the cable that comes with the printer or the Digital BC16E cable or equivalent. If you
prepare a cable separately, the cable connector at the printer side should be a male Modified
Modular Jack (MMJ) or the equivalent that conforms to EIA standards.
The following table shows the pin assignments. In the table:
• “Input” denotes a signal from the computer to the printer.
• “Output” denotes a signal from the printer to the computer.
• The signal level for mark state (logical 1) is -5 V to -6 V; for space state (logical 0), it is
+5 V to +6 V.
Pin Signal Direction Description
No. Name
1 Ready Out Output Data Terminal Ready
2 Transmit Data + Output This pin carries information from the printer to
the computer.
3 Transmit Data - Output Common signal level. This pin carries
information from the printer to the computer.
4 Receive Data - Input Common signal level at the computer side.
This pin carries information from the computer
to the printer.
5 Receive Data + Input This pin carries information from the computer
to the printer.
6 Ready In Input Optional (available as Data Set Ready)