[net.emacs] EMACS with Flow Control

tanner@ki4pv.UUCP (Tanner Andrews) (07/10/85)

While this has not yet been needed on this system, and so I haven't
implemented it, I have had to do this on many systems before.  At
times it is not a pain in the sensitive locations.

Many terminals and people can't process chars fast enough, &c., &c.
There was invented, therefore, flow control.  In the case of people,
this flow control is done by mashing some key (such as ^S).  In the
case of terminals, you frequently find them pretending to mash the
same key.

Most modern terminals, however, have another way to shut up the computer
or whatever they are talking to:  they wiggle an rs232 signal (such as
the one on pin 20).  Printers do the same thing, by the way.  If the
computer watches for this, and shuts up when the terminal says "not
ready", then you can pass all chars straight through to the application.

If your network or computer supports "hardware" flow control, sometimes
called "dtr" (among other things), throw the proper switches.  Your op
sys probably can handle ^S/^Q when applications are not running in "raw"
mode.
-- 
<std dsclm, copies upon request>	   Tanner Andrews, KI4PV
uucp:					...!decvax!ucf-cs!ki4pv!tanner

chris@umcp-cs.UUCP (Chris Torek) (07/15/85)

Unfortunately, DTR flow control often doesn't work through networks/
modems/whatever.  Sigh.

If we invent the Great American Data Rate Control Protocol, what're
the chances that we can get every manufacturer to abide by it?
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris@umcp-cs		ARPA:	chris@maryland