Disabling BRK signal

[Brent Welch]

My two-cents worth on the BREAK signal that aborts a Sun is that this is a
software feature, not an intrinsic hardware feature.   The serial line
driver in SunOS sees the BREAK and call the PROM abort routine.  I haven't
actually looked at the SunOS code that does this.  However, our Sprite OS
that runs on Suns does this same sort of thing, and it is done in
software.  Hmmm, reexamining a Sun-Spots message imlies that the BREAK
signal seems to cause a Watchdog Reset, not a mere abort-to-monitor.
That's a little puzzling, but I still maintain that it is software because
I've yanked the console line on our Sprite machines with impunity.  (The
Sprite kernel interprets a BREAK-followed-by-'a' as ABORT,
BREAK-followed-by'd' as enter the debugger, etc. etc.  We map a bunch of
special keystrokes like this so we can poke at lifeless machines.)

	Brent Welch
	University of California, Berkeley
	brent%sprite at gingner.Berkeley.EDU