Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rice!sun-spots-request
From: gjh@tybalt.caltech.edu (Greg J. Hiscott)
Newsgroups: comp.sys.sun
Subject: Hardware Handshaking
Keywords: Hardware
Message-ID: <5268@brazos.Rice.edu>
Date: 24 Feb 90 01:01:50 GMT
Sender: news@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Sun-Spots-Digest: Volume 9, Issue 56, message 14

I have a question for you unappreciated and talented Sun SysAdmins out
there:

What hacks do you use to accomplish hardware handshaking on RS232 ports?
In more detail, I want to use hardware handshaking with HP plotters on Sun
SS1s and a 4/110.  Has anyone done this?  Can you save me the time of
writing a filter program to do it?

In the 4.0.3 manual pages:

c_cflag field can take on the values:
          CRTSCTS 020000000000  Enable RTS/CTS flow control.

If CRTSCTS is set, and the terminal has modem control  lines associated
with it, the Request To Send (RTS) modem control line will be raised, and
output will occur only if the Clear To Send (CTS) modem status line is
raised.  If the CTS modem status line is lowered, output is  suspended
until  CTS  is raised.   Some  hardware  may not support this function,
and other hardware may not permit it to be disabled;  in  either of these
cases, the state of the CRTSCTS flag is ignored.

Please advise.

+-------+    Greg Hiscott            gophers = gophers - 18;
|+-----+|    gjh@ligo.caltech.edu
|+-----+|    Disclaimer: Caltech has nothing to do with this message.
+-------+    (818) 356-2974    FAX:(818)304-9834