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Date:      Tue, 30 Jan 1996 13:21:50 +1030 (CST)
From:      Michael Smith <msmith@atrad.adelaide.edu.au>
To:        terry@lambert.org (Terry Lambert)
Cc:        msmith@atrad.adelaide.edu.au, terry@lambert.org, hsu@clinet.fi, hm@altona.hamburg.com, freebsd-hackers@FreeBSD.ORG
Subject:   Re: Multi-Port Async Cards
Message-ID:  <199601300251.NAA12777@genesis.atrad.adelaide.edu.au>
In-Reply-To: <199601292056.NAA04426@phaeton.artisoft.com> from "Terry Lambert" at Jan 29, 96 01:56:26 pm

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Terry Lambert stands accused of saying:
> > No, it won't.  There is no hardware feature in the 8250-family UART that
> > deasserts DTR when the machine has crashed.  In fact, I know of no UART
> > family that meets this criteria.
> 
> There is a firmware feature.  It's called BIOS POST initialization, and
> it is dependent on you buying good hardware.  Your hardware should:
> 
> 1)	Do a hard reset, not a soft reset, on triple fault (this is the
> 	problem with not rebooting after shutdown on a machine with a
> 	buggered keyboard controller INT 19 interface).

This doesn't help if your system dies from another fault (eg. locked
hardware).

> If you are running a large site, invest $35 in a watchdog reset board.
> Do it, do it NOW.  There are BSD drivers for several of this type of
> board.

If you have a source for the $35 variant, I'd love to see it.  The only 
reference I managed to track down was for a $400 product, which unsurprisingly
failed to enthuse me.  Currently I install 8-port relay boards in a
nominated 'stable' system, and run lines from the motherboard reset pins
to the relays.  Crude, but _very_ effective.  (Until someone runs the 
'cylon' program I use to test the cards 8)

> Any BIOS that does PSOT initialization of UARTs will drop DTR.

As already observed, if you get far enough to have the POST happening,
you're fine, however this is _not_ the situation that's of interest here.

> This is really irrelevant.  What is the use of not answering the phone
> vs. bogusly answering the phone and not talking?  Long distance charges?

USERS.  Count yourself _fortunate_ that you don't have to deal with them.

> Most US LD companies (not TelAmerica) start charging after 6 seconds,
> answered or not.  Your customer is going to be pissed off by the fact
> that he did not get service, and won't really give a damn about the
> failure mode that caused him to not be serviced.

Observed behaviour here is much to the contrary, I'm afraid to say.

> 					Terry Lambert

-- 
]] Mike Smith, Software Engineer        msmith@atrad.adelaide.edu.au    [[
]] Genesis Software                     genesis@atrad.adelaide.edu.au   [[
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