During the kickstart installation of the CentOS 4.3 systems I recently built, anaconda probed for the video card (Intel 945) and monitor (NEC MultiSync 2070NX). The optimal setting for this monitor is 1600x1200 @ 60Hz. The X server is configured to use 1600x1200, but it is using a higher refresh rate, which causes the monitor to display an error message, and it also locks you out of the on-screen- menu. How do you translate a 60Hz refresh frequency into the appropriate horizontal sync and vertical refresh frequencies in the xorg.conf file? I can't find anything to change in system-config- display. Any suggestions?
Thanks, Alfred
On Mon, 2006-06-26 at 09:55 -0400, Alfred von Campe wrote:
During the kickstart installation of the CentOS 4.3 systems I recently built, anaconda probed for the video card (Intel 945) and monitor (NEC MultiSync 2070NX). The optimal setting for this monitor is 1600x1200 @ 60Hz. The X server is configured to use 1600x1200, but it is using a higher refresh rate, which causes the monitor to display an error message, and it also locks you out of the on-screen- menu. How do you translate a 60Hz refresh frequency into the appropriate horizontal sync and vertical refresh frequencies in the xorg.conf file? I can't find anything to change in system-config- display. Any suggestions?
Here is some information I have used as background.
http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html
The above seems thorough, but is murky in some ways - refs to apply the previous formula when there are more than one. I also seem to recall that Brian J. Smith had posted something on this. Maybe searching the archives? I hope my memory's not wrong, searches can *eat* time. He also has a blog and it would be referenced in archives too I think.
I seem to remember that there was a post of a very easy formula posted in the LinuxFromScratch archives long ago. Googling there with
site:linuxfromscratch.org
as one of the args might find that as well.
Thanks, Alfred
<snip sig stuff>
HTH
Bill:
Here is some information I have used as background.
http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html
Thanks, there is some interesting information there. I did some more googling since my previous post, and I found some examples on how to *increase* the refresh frequency. However, in my case I want to set the refresh frequency to exactly 60 Hz. I think I also found that the refresh frequency (usually what you configure in Windows, i.e., 1024x768@75Hz) corresponds to the VertRefresh entry in the xorg.conf file. However, when I set that to 60 (instead of the monitor's 56.0 - 85.0 range), the problem didn't go away. I probably also have to adjust the HorizSync entry, but I don't know to what exactly.
Alfred
On Mon, 2006-06-26 at 10:40 -0400, Alfred von Campe wrote:
Bill:
Here is some information I have used as background.
http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html<snip>
However, when I set that to 60 (instead of the monitor's 56.0
- 85.0 range), the problem didn't go away. I probably also have to
adjust the HorizSync entry, but I don't know to what exactly.
Using that HOWTO, I've been sporadically working on a script to generate the params, but haven't quite finished it. So I'm no further help ATM. If/when I get back to it and get something workable, I'll post. By playing with the params mentioned in that doc in the fixed frequency portion, I have managed to set various ranges, image move left/right, gets chopped, etc. I'll power up that machine and take a look and see if anything that looks like it might b e useful jumps out at me.
But I really think the postings on LFS or by Brian will be most useful, or postings somewhere else on the WEB.
Alfred
<snip sig stuff>
On Mon, 2006-06-26 at 11:08 -0400, William L. Maltby wrote:
On Mon, 2006-06-26 at 10:40 -0400, Alfred von Campe wrote:
Bill:
Here is some information I have used as background.
http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html<snip>
However, when I set that to 60 (instead of the monitor's 56.0
- 85.0 range), the problem didn't go away. I probably also have to
adjust the HorizSync entry, but I don't know to what exactly.
Using that HOWTO, I've been sporadically working on a script to generate the params, but haven't quite finished it. So I'm no further help ATM. If/when I get back to it and get something workable, I'll post. By playing with the params mentioned in that doc in the fixed frequency portion, I have managed to set various ranges, image move left/right, gets chopped, etc. I'll power up that machine and take a look and see if anything that looks like it might b e useful jumps out at me.
But I really think the postings on LFS or by Brian will be most useful, or postings somewhere else on the WEB.
As I remembered, the only complete and usable one is for vga frame buffer setup and only for a test resolution, not what you are hunting for. I can't say if it is good for many combos of video dot clocks and monitor constraints.
<snip>
-
Alfred von Campe -
William L. Maltby