rts/cts on 3b2 tty ports (flow control)

Gene Spafford spaf at gatech.CSNET
Tue Jun 4 09:16:27 AEST 1985


It's been a while since the last posting on this subject, but I thought
some of you might be interested.

We have gotten UUCP working over an Ungermann-Bass Net/One virtual
circuit using the "g" protocol.  It took a bit of struggle, but it
works great.  In short, we define the port at each end so it ignores
the ^P (used by UB as an escape) and so it ignores ^S/^Q.  The
port is flow controlled using ^S/^Q but the buffers are set to around
150 characters -- the UUCP "g" protocol uses 64 byte packets with
"acks" -- so there is never any danger of triggering the flow control
mechanism.

Under regular terminal use, if the computer output threatens
to overrun the buffer, the ^S/^Q protocol damps the flow in a manner
transparent to the user.  In this mode, users typing ^S/^Q see it
work normally for them too.

The lack of an "escape" character doesn't seem to be a major loss
to the average user.  And we can direct connect any two Unix systems
on campus this way if their ports are configured correctly.

That still doesn't solve Robert's 3b2 problem, but....
-- 
Gene "3 months and holding" Spafford
The Clouds Project, School of ICS, Georgia Tech, Atlanta GA 30332
CSNet:	Spaf @ GATech		ARPA:	Spaf%GATech.CSNet @ CSNet-Relay.ARPA
uucp:	...!{akgua,allegra,hplabs,ihnp4,linus,seismo,ulysses}!gatech!spaf



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