[lug] How to select video mode for dapper drake installation?

[D. Stimits]

siegfried wrote:

> Thanks Mr. Stimits!
>
> We are stuck on the “Configuring xserver-xorg” page of the ubuntu 
> installation. It says “if there are some resolutions you would not 
> like the X server to use even if your hardware is capable of them, 
> removed them form the list below”.
>
Not sure what to say about ubuntu, all I ever do is edit the xorg.conf 
with vi. Or if you have hardware accel nvidia drivers, there is a tool I 
sometimes use with that. There is a section or subsection in 
/etc/X11/xorg.conf (perhaps located differently on ubuntu, but likely 
the same), for "Display". In that there is a space delimited set of 
modes, e.g., "1280x800". It makes all of them available, I believe it 
tries to start with the first one on the left, although there is 
probably some sort of default you can set. Personally I'd just set 
inittab to run only to console mode, edit that value to be soley 
"1280x800" (you know it works in windows, should be ok in linux assuming 
color depth and scan rates and so on are compatible), and then manually 
"init 5" (or whichever runlevel is graphics mode for ubuntu...I'm 
guessing it'll be the same as debian, but I've never run 
debian...someone might be able to answer that). If it works, edit 
/etc/inittab back to graphics level as default...if not, it boots to 
console mode, so you can easily edit again.
...

> When booted in windows, windows uses 1280x800. Should we select this 
> mode? We tried once the xserver would not start.
>

For 1280x800 to work, several things must happen. First, your video card 
must support that resolution at the requested color depth and scan 
rates. Second, your monitor must be able to display that color depth, 
resolution, and scan rate combination. When you are in windows, you 
might want to find out what color depth it claims, and what scan rate it 
uses. Lastly, none of your driver software should disbelieve that those 
modes are possible. When you boot windows, generally it'll be a driver 
that knows how to query the video card fully, and possibly the monitor 
if it's recent enough. Under linux, I'm not so sure that the software 
drivers are fully capable of this. For nvidia video cards, the hardware 
accel "nvidia" driver provides far more feedback from the hardware than 
does the software "nv" driver. There are cases where the software driver 
will refuse to run at a mode that it thinks will damage things, but in 
which the hardware accel driver with more knowledge will allow it. Most 
of the xorg.conf files have comments in them which describe what you're 
looking at, and as long as your inittab is set to console mode (and you 
sudo init 5 or whatever to get to runlevel 5 temporarily), then you're 
safe to have it fail while testing.

D. Stimits, stimits AT comcast DOT net