[CentOS] Problem with widescreen display

Sun Nov 2 12:26:56 UTC 2008
William L. Maltby <CentOS4Bill at triad.rr.com>

On Sat, 2008-11-01 at 22:08 +0000, Marko Vojinovic wrote:
> I have a dual boot CentOS 5.2 / FC4 machine, and recently I have bought a new 
> widescreen tft monitor. I used to use a plain 4:3 crt, and after plugging the 
> 16:9 tft naturally X needed reconfiguring. This was easy in FC4, and seemed 
> as easy in CentOS, but with a wrong result.
> 
> Basically, what I did was to run system-config-display to reconfigure for the 
> new monitor and resolution. All goes well, but after X restarts, I see a 
> strange picture: the resolution indeed goes to 1680x1050 as is supposed to, 
> but is squeezed/shrinked/scaled horizontally to match a 4:3 aspect ratio, 
> leaving two (unequal) black bands on the left and right side of the monitor.

This sounds like the "Modes" line in the "Subsection Display" may not
have the right settings. The manual/CD for the monitor should have the
right settings. I would compare those against what the configuration
process generated and manually edit if needed. Why the difference
between FC4 and CentOS, I can't guess.

I don't have the URL, but some time ago I googled and found a very
detailed description of the modes, their effects, "blanking" (the "black
bands") and the relationship of all those. Go googling if you think if
might help.

> <snip>

> Btw, this is on an nVidia GeForce 4 using the default nv driver. The vesa 
> driver doesn't support widescreen resolutions, while nvidia binary driver 
> crashes X completely on start (but this is a known motherboard problem common 
> to FC4 as well).

Have you tried the nvidia drivers from rpmforge? It has drivers for both
the older and newer nVidia cards, all ready for CentOS. I'm using the
older driver now (standard CRT though, not a newer LCD/TFT wide-aspect
screen) and it works flawlessly.

I've also used the stuff from the nvidia site, but abandoned it as soon
as I found the older driver on rpmforge. So I can't say if that's a
better way to go. Several on the list have espoused that route and had
good results.

> 
> Is there some kernel setting or whatever that might "force" the graphics card 
> to 4:3 aspect irrespective of X configuration? Some "filter" between what X 
> tries to display and the actual signal to the monitor? What else can I try?

All I can think of is that "Modes" line I mentioned above.

> 
> Any advice appreciated!
> 
> Best, :-)
> Marko
> <snip Sig stuff>

HTH
-- 
Bill