SunOS 4.1.1 v's The Printer

[tony at cosc.canterbury.ac.nz]

After many hours Reading TFM, soldering up new cables, etc, I worked out
how hardware flow control for printers works on SunOS 4.1.1  I tried this
out on a SS2 and an SLC, and they both worked.  A Flame for Sun: why do
they make it so hard to figure out their tty ports?  Maybe I'm just stupid
:-)

Anyway, the information I gleaned might help someone else:

1. The cable (Sun Workstation end):

Pin 2 = Transmit data from Sun (and to the printer :-)

Pin 3 = No Connection; BAD, BAD crosstalk from TxD happens if you leave
this line connected on long cables, as I found out :-(

Pin 5 = Clear To Send from the printer.  Positive (> 3V) = OK to send
data, Negative (< -3V) = Stop sending data.

Pin 7 = Signal ground

Pin 8 (Carrier Detect) is strapped to Pin 20 (DTR from sun)  The effect of
this is to make CD permanently "on".  EVEN IF YOU "stty clocal" YOU NEED
THIS.  Another 2 hours to find this out :-(  Pin 8 won't work for flow
control, BTW

2. Here is the "ms" (tty settings) field from my /etc/printcap.  The
important fields are crtscts and -ixon (see stty(1V)):

	ms=cs8,clocal,-parenb,cread,crtscts,ignbrk,ignpar,cstopb,\
	-ixon,-tabs,onlcr,-echo:

Hope all this is useful to someone.

= 		Tony Dale (tony at cosc.canterbury.ac.nz) 			=