[ On Sun, April 19, 1998 at 08:22:23 (-0400), der Mouse wrote: ]
> Subject: Re: Sparc serial console
>
> > I have a sparc1 attached via null modem to my main server.  When I
> > shut down the main server.. it immediately drops the sparc to the
> > boot prom.  I'm wondering if there is a way to prevent this behavior
> > from the sparc.
> 
> The only way I know of is, don't use the console port on the sparc for
> your inter-machine link. :-(  Or, arrange for the "main server" to not
> generate a break condition on that line when it's shut down....

Once upon a time I had a tiny circuit that would hold the lines steady
on an RS-232 port such that you wouldn't get a BREAK when you unplug or
reconnect them, but I don't seem to have it around any more, and the
only ideas that come to mind right now involve electronic switching.

I happen to have a sparcstation-1 here that's currently attached to the
serial console port on an NCD HMX.  I've just tested unplugging it
several times and it seems stable.

Perhaps the serial ports on your main server have some strange
electrical behaviour as they lose power that causes a signal somewhat
like a BREAK to occur.

-- 
							Greg A. Woods

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