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

From: Gary Fisher <GFisher_at_tristonecapital.com>
Date: Fri Feb 18 11:53:11 2005

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
This e-mail and any attachments may contain confidential and privileged information. If you are not the intended recipient, please notify the sender immediately by return e-mail, delete this e-mail and destroy any copies. Any dissemination or use of this information by a person other than the intended recipient is unauthorized and may be illegal. Unless otherwise stated, opinions expressed in this e-mail are those of the author and are not endorsed by the author's employer.




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>
Content-Type: text/plain


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.
Received on Fri Feb 18 2005 - 11:53:11 GMT