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

From: Jules Richardson <>
Date: Fri Feb 18 05:01:45 2005

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 :)


Received on Fri Feb 18 2005 - 05:01:45 GMT

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