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From: root@bu-cs.UUCP (Barry Shein)
Newsgroups: net.emacs
Subject: Re: emacs under flow control
Message-ID: <466@bu-cs.UUCP>
Date: Fri, 5-Jul-85 18:59:31 EDT
Article-I.D.: bu-cs.466
Posted: Fri Jul  5 18:59:31 1985
Date-Received: Sun, 7-Jul-85 04:41:36 EDT
References: <2899@cornell.UUCP>
Organization: Boston Univ Comp. Sci.
Lines: 59

>Subject: emacs under flow control
>Date: Thu, 4-Jul-85 10:25:21 EDT
>From: jqj (J Q Johnson)
>
>This question is specifically oriented towards GNU emacs, but is applicable
>to all Emacs-like editors; it's been raised before.  The question:  what
>does one do if he has to support Emacs in a flow-controlled environment?
>
>...
>
>What have other sites done when faced with this problem?  Has any standard
>arisen?  How many users would scream "bloody murder" if ^\ were mapped on
>input to ^Q and ^] to ^S?

At Boston University we run an Ungermann/Bass broadband terminal network
(you might at Cornell also if I remember correctly) and *yes*, the
network assumes it owns ^S/^Q for flow control and things like
mismatched ends (eg. all of our hosts are 9600, even if you come in at
1200.)  Also ^P (DLE) and ^T is not very good either (^T is the
default hangup tho this is user settable.)

We have so far attacked this with a vengeance (not just with EMACS.)
The first thing I did was 'fix' all that when I got my source copy of
CCA Emacs, first making it use CBREAK correctly (current versions do,
this was quite a while ago) and then re-binding keys all over the place.

The big problems was when these chars were magically embedded in the
software (like a check for a ^S directly in ^R Incremental Search rather
than via the current binding), this sort of stuff kept haunting us (tho
again, the latest CCA version seems to fix about everything, I think all
I needed was to install my Keys files and we were done.)

Now we are doing the same with GNU emacs, trying to use similar
bindings.  Yes, ^\ and ^] seem to be good replacement candidates for
^S/^Q (funny, of course we chose the exact opposite order you did.)

I think it is not a major issue so long as the designers/coders keep to
their 'promise' that every command is re-bindable and just kinda keep it
in the back of their mind as they implement. Yes, it would be nice if
there were a note for a 'standard' re-binding for flow controlled sites.
I suspect this does come up quite a bit and will come up more so in the
future.

The real nuisance is not EMACS (which has a well worn path for fixing
this) but things like XMODEM and UUCP especially people with binary only
XMODEM versions for their PCs and look at us like we just killed their
pet dog when we try to explain the problem. I try to give them Kermit
for free if they ask.

Again, it's not a huge issue but, to appeal to egos, a truly sophisticated
software designer would take this kind of thing into account.

Yes, let's standardize a flow controlled key bindings and try to use it.
A choice of two with a mention in the manual should calm down users.

Some things just aren't worth fighting, clever software adapts where it
can.

	-Barry Shein, Boston University