any harm in allowing only ctrl-Q to restart output?

[Guy Harris]

> The only thing you want to make sure of is that even if output is stopped,
> the interrupt and quit functions must turn it back on (when the terminal
> is not in "raw" mode).

Well, err, umm... System III did this, but System V doesn't, and 4.xBSD
never did.  I don't know about TOPS-[12]0 or VMS or any DEC operating
systems.  I suspect they don't, because it gives VT100s the ****fits.
The VT100 has a very small buffer between the comm line and the screen
updating code, so it demands *very* strict XON/XOFF flow control, especially
in smooth-scroll mode.  I have seen a fair amount of output get scrambled
by hitting the interrupt key in the middle of output; it stopped happening
when we had interrupt and quit not affect the flow control state.  (UNIX
can cause XON/XOFF problems even when working correctly; its habit of
surrounding every critical region with spl5() (or whatever) and running all
interrupt service routines at interrupt priority all the time means it
doesn't always respond to an XOFF in time.)

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy