Matrox G550 fails dual-head, used to work

[Warren Block]

On Wed, 13 Aug 2008, Steven Friedrich wrote:

> Some time ago, xorg changed something and my dual-head stopped working on all
> my machines.
>
> I think the mga driver or xserver is having trouble detecting the second head,
> though it does display the same desktop as the first head.  Xinerama doesn't
> appear to work. I built a new xorg.conf, but xrandr only says there's a
> default output, not two.

If you want dual head on a Matrox card with the latest ported 
xorg-server, you need xf86-video-mga-1.9.100.  That version of the 
driver was in ports for a while, but people using modelines had trouble 
and it was backed out.  You can use portdowngrade to get 1.9.100.

Additionally, you need to patch xorg-server so it can read the Matrox 
video BIOS.

G550 with two VGA ports should work, I think.  G550 with DVI, maybe not.

Documentation here:

http://wonkity.com/~wblock/mgapatch/

-Warren Block * Rapid City, South Dakota USA