Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!ll-xn!cullvax!drw
From: drw@cullvax.UUCP (Dale Worley)
Newsgroups: comp.sources.d,comp.emacs
Subject: Gnu Emacs and ^S/^Q flow control
Message-ID: <1284@cullvax.UUCP>
Date: Tue, 16-Jun-87 10:48:32 EDT
Article-I.D.: cullvax.1284
Posted: Tue Jun 16 10:48:32 1987
Date-Received: Sun, 21-Jun-87 07:15:50 EDT
Organization: Cullinet Software, Westwood, MA, USA
Lines: 30
Xref: mnetor comp.sources.d:852 comp.emacs:1165

gwyn@brl-smoke.ARPA (Doug Gwyn ) writes:
> Railing against the use of DC3 and DC1 for flow control by some terminals
> is pointless -- they need to throttle incoming data, especially at high
> bit rates and when performing complex actions such as line insertion, and
> the DC3/DC1 method was chosen as the best way to do this, given that most
> modems don't correctly handle control-line (out of band) flow control.

Amusingly, despite the fact that RMS (the author of Gnu Emacs) finds
^S/^Q completely loathsome, he provides the best way to avoid the
problems that I've ever seen:  The input stage of Emacs can map any
character to any other.  Normally this is just the identity map, but
for flow-control situations, he recommends mapping ^^ to ^S and ^_ to
^Q (or perhaps vice-versa).  This makes life slightly less convenient
for the user, but is absolutely transparent to customizations which
check for ^S and ^Q for special meanings.

I believe also that special uses of ^S and ^Q in Gnu Emacs are
controlled by variables, so you can redefine which character activates
the feature (like repeating incremental search (search-repeat-char)
and quoting search characters (search-quote-char)).

It's not *that* painful to get around using ^S and ^Q, if your Emacs
is fully customizable.

Dale
-- 
Dale Worley	Cullinet Software		ARPA: cullvax!drw@eddie.mit.edu
UUCP: ...!seismo!harvard!mit-eddie!cullvax!drw
"President Nixon has just lowered the speed of light to 55 mph.  At what
speed can 2 colliding VW's of mass m = (number) produce a 3rd VW?"