how to kludge a 486 PC into thinking it has a video card?

[Gary Fisher]

I have convinced old PC's to run minus a keyboard by setting the "don't stop on POST error" or some such variant setting in the BIOS.  I think most AMI etc. bioses have that setting.  Hopefully the lack of a video card can fall into that former category rather than refusing to boot at all.

Gary Fisher 
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ORIGINAL MESSAGE BELOW:
Message: 19
Date: Fri, 18 Feb 2005 11:01:45 +0000
From: Jules Richardson <julesrichardsonuk at yahoo.co.uk>
Subject: how to kludge a 486 PC into thinking it has a video card?
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <1108724505.9518.31.camel at weka.localdomain>
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slightly oddball question for this list (but then I specialise in
those :)

Anyone know of a good way of convincing an old 486-based PC's BIOS that
it has a video board present when in fact it doesn't? 

Far as I know the BIOSes of the time would check for MDA / CGA / EGA /
VGA adapters at boot time, but 'not fitted' wasn't usually an option. I
wonder if there's a clever way involving a minimum of circuitry in such
a case for the BIOS checks to work...

(I was wondering what to do with a pile of 486 boards at Bletchley and
figured I'd build a cluster out of them... :-)

If I have to fit video boards to every one them I will, but it looks
kinda ugly and just sucks power for something that isn't needed... (I
still need to fit network cards of course, so unless I can find a
handful of right-angle ISA adapters I can't just build a rack full of
flat boards anyway)

madness :)

ta

J.