Monday, April 9, 2007

HOWTO: config 915resolution to have widescreen resolution

Overview
There is a problem with Intel Graphics chipsets to where where it doesn't know about wide screen resolutions. I don't know about the back story but I would like to be able to use 1440x900 with my monitor. The good thing is that someone has created a solution that gets around this issue.

My system is a 2007 ASUS P1-P5945G that uses the INTEL 945G CHIPSET. I have a 19" (widescreen) Viewsonic monitor that supports up to 1440x900 resolution. This system was purchased from http://www.mwave.com/ for a pretty good price.

Disclaimer
What works for me might not work for you. Ensure you know your hardware before you try this. It may be possible to toast your system (motherboard/monitor/mind) in attempting this. Just be careful and sure.

Technique
The idea it to change one of the preset resolutions in the Intel Graphics chip from its default to your preferred resolution. The good part is that there is a command for it but the change is not permanent. To get around this, someone created an init script that ensures your change happens at boot :-) Here is what you do....Assuming FC6.

1. Install 915resolution: yum install 915resolution
2. Get a list of Resolutions and pick one to replace: 915resolution -l

  • this will give you a long list of all the supported resolutions and bit levels
  • in front you will see a hex value (5a, 5b,...). Look for ones you will not be able to use with your monitor.
3. Edit config file and add RESOLUTION="..." statement: vi /etc/sysconfig/915resolution

  • If you want 5a to be 1440x900 at 32bit set RESOLUTION="5a 1440 900 32"
4. Run FC6 setup from xterm

  • Turn on System Service "915resolution" so it sets RESOLUTION=".." each time you boot.
5. Reboot.

  • When you come back up, you should be able to select 1440x900 (or whatever you picked) as your Preference->Screen Resolution.
When you boot your linux system next, you will be able to go into the GNOME Preference->Screen Resolution and see 1440x900 (or whatever you set) in the list.

What to Check
On my monitor, I have a little button that tells me the current resolution and refresh rate. Ensure this matches what your monitor can support.

I would also look at your /var/log/xorg.log and see if you got any errors. If so, do a little reading to ensure there is nothing bad happening.

GDM
I have run into an annoying thing with the "greeter" for Gnome. If your /etc/X11/xorg.conf has resolutions higher then the resolution you wish to use, it might pick the highest supported one in the list. This will give you a login screen that scrolls when you move your mouse around.

The only way I have found to fix this is to edit the /etc/X11/xorg.conf and remove any resolution higher then you desired (1440x900 for me) by you. This quick edit will correct that problem.

Final Thoughts
This concept seems to work. I have not read anything that says that this is dangerous or damaging. Still, do your research to ensure your hardware is safe.

If you use UBUNTU, check out this link for a good overview. Much of my information came from there.
http://www.ubuntuforums.org/showthread.php?p=1808047


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2 comments:

Matt Hauck (郝柏昇) said...

I think you forgot the Ubuntu link.

uuklanger said...

Looks like I did. It here here now.