I have bought a secondhand graphics card (it worked in the shop) to use instead of the onboard graphics (Intel 82845G/GL) in Fedora Core 4, and if that works, SUSE 10.1. Working in complete ignorance, I have inserted the card into the PC, and it shows up in lspci as:

VGA compatible controller: S3 Inc. 86c764/765 [Trio32/64/64V+] (rev 54)

However, if I plug my monitor into the S3 card, and turn on the PC, the monitor does not respond at all - "no signal".
There is a great deal of information around concerning drivers, but I do not know how to proceed from here, as I suspect there is no point if the monitor does not react at all. Is there a detailed guide anywhere? Or can someone give me a pointer?

Try going into BIOS and switching off integrated video card.

That woke up the monitor, but both my installed Fedora Core 4 and live DVD SUSE 10.1 had kernel panics. I tried variations on the two settings that seem to apply (Award BIOS); Initial Display and Graphics Aperture Size, but no go.
The settings that I thought should work were Initial Display set to PCI and the Graphics Aperture Size set to Disabled.
A great deal has been written about kernel panics but I cannot tell what might apply in this case.

Reinstall or boot with init=/bin/sh and try to investigate (if you don't understand the second, it's not for you..)

I attempted a reinstall of SUSE 10.1, which failed previously due to a bug in the installer (bug 188839, cannot cope with my onboard graphics - fixed for 10.2 - the reason I was trying this) and it was unable to reach the hardware configuration stage.
My thanks for your assistance, but I have spent quite long enough on 10.1 one way or another, I shall wait until 10.2 or go Kubuntu.