Re: problem reading VGA text fonts

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Tue, 19 Nov 1996 19:12:25 +0100 (MET)

> After very long search the problem was pinned down on accesses to the
> BIOS ROM (the physical, not the shadowed image). These accesses cause
> memory corruptions with ViRGE (and some other S3 chips).

oh, very interesting.

> Are you accessing the (physical) VGA BIOS ROM somewhere to detect the
> type of board?

sure we do :-(
(mainly to determine the vendor and fix some vendor dependent bugs)

I just disabled reading the BIOS, started X11 100 times and, guess what ?
text font is still OK! (with this card almost every server startup corrupted
fonts before).

> Maybe the BIOS is not shadowed on the AXP machine?
no idea

now the interesting question is: how can we read the BIOS (esp. on AXP)
without currupting video memory ?

thanks a lot for this big hint (why didn't I ask earlier? :-(

Harald

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