On Fri, May 16, 2003 at 03:44:21PM +0100, Francis Devereux wrote:
> On Fri, May 16, 2003 at 11:26:12PM +0930, Brett Lymn wrote:
> > On Fri, May 16, 2003 at 02:16:40PM +0100, Greg Matthews wrote:
> > > 
> > > On Fri, 2003-05-16 at 13:26, Marianne Spiller wrote:
> > > >   all kind of Sun hardware? Or only older machines (like my classic)?
> > > > 
> > > 
> > > hmmm... wouldnt like to say, maybe another lister would have more
> > > authority...?
> > >
> > 
> > By default, all Sun machines will drop to the OBP if a break is sent
> > to the serial console.  I believe that later machines allow you to
> > change the sequence to something less likely to occur (note, this
> > quite a new feature iirc).  
> > 
> > One method of avoiding inadvertant breaks when the terminal is powered
> > off is to put a resistor between the rx pin and dsr on the end of the
> > cable that plugs into the sun.  The idea is to ensure the rx is pulled
> > to the "idle" state if the power on the terminal goes away - in rs232
> > idle happens to be a logic "high".
> 
> Does this still allow deliberate breaks through?

I tried this on an Ultra2 running Solaris and it didn't work. If I remember
right SUN uses a short break (some msecs) and I was not able to suppress
short spikes while retaining the ordinary break.

On Solaris I use the alternate break sequence:
	/etc/kbd:  KEYBOARD_ABORT=alternate

NetBSD should do the same with sysctl -w hw.cnmagic = XX (CNMAGIC(9)).

-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)