[lug] Screen res and modes

[Scott A. Herod]

I'm guessing that your horizontal sync range is set too low.
In /etc/X11/XF86Config you should have a line that looks
something like:

    HorizSync  
30-97                                                           

The high number that you have set is probably on the order of
37.  The lowest acceptable 1280x1024 standard modeline requires
the upper number to be at least 64.2.  If you've got a multi-sync
monitor that's not more than a few years old, you will probably
be ok setting you HorizSync high enough to get there.

One thing you can do if you are worried about over clocking the
monitor is turn X off.  ( Kill it, not just escape out to a
tty. )  And run "X -probeonly > /tmp/CONFIG_REPORT".  
In the tmp file you should see a report of what modelines X saw
and what horizontal sync is required for each.  Then you can go
tweak the HorizSync range to get the mode you want.

Scott

John Starkey wrote:
> 
> Hello again.
> 
> I've been thru the archives looking for an answer to this and I only found
> some old threads about setting screen res in general.
> 
> Last night on a fresh install I had everything working great except I
> couldn't get out of 1280x1024. So I tried to do a reinstall and
> specify 1024x768 as the default but that didn't work. Now I'm stuch
> with 800x600 and can't even get 1280x1024 back. My luck.
> 
> I've been all through the XF86Config trying multiple things but I keep
> getting "No valid modes found". I assume it's referring to the ModeLine
> statements in the monitor section. I'd prefer not to blow up the monitor
> so I'm hesitent to make any changes to the sync data.
> 
> Anyone know what I can do. I know 1280 worked, why can't it find a
> modeline for that atleast?
> 
> Thanks,
> 
> John