Re: MDA video detection request.

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Sun Jul 09 2000 - 13:40:12 EST


> > Hercules Graphics Adapter
>
> This is not good enough, since there are non-hercules mda cards.
> Also, vga cards might emulate that port io aliasing as well.

The reliable way to detect an HGA card is to run through the VGA/EGA detect
and only if VGA/EGA fails then check that the light pen port is changing value
as you would expect. The light pen port check is used heavily - clone Herc
cards emulate its behaviour even if they dont have one

This is well documented in some of the PC video books

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Jul 15 2000 - 21:00:10 EST