[CentOS] New monitor weirdnesses (CentOS 5.11)

Tue Dec 1 20:52:09 UTC 2015

On Tue, Dec 01, 2015 at 03:47:13PM -0500, Robert Heller wrote:
> I just got a new monitor for my desktop system (the old one died after *many* 
> years of service).  The new monitor is a high res 16:9 monitor, but the VESA video 
> driver insists on using 1024x768 (which was the resolution of the *old* 
> monitor).  It does seem to detect higher, 16:9 resolutions but it is not using 
> them.  I *think* I need to set some low-level video mode thing, but it has 
> been a long time since I have had to do that that I have totally forgotten how 
> to do it.  And I have been unable to find it with a websearch either.

Robert:

A few years back I had a similar problem when switching from an OLD monitor to a new one.

I found the problem to be that I was still attempting to use the OLD VGA cable which apparently
did not have the wires in it to pass the monitor capabilities back to the video card. As soon as
I switched to the cable that came with the new one the system properly detected the new monitor
and all was well.

Fred

> 
> >From /var/log/Xorg.0.log:
> 
> (II) VESA(0): Printing DDC gathered Modelines:
> (II) VESA(0): Modeline "1366x768"x0.0   85.50  1366 1436 1579 1792  768 771 774 798 +hsync +vsync (47.7 kHz)
> (II) VESA(0): Modeline "1360x768"x0.0   85.50  1360 1424 1536 1792  768 771 777 795 +hsync +vsync (47.7 kHz)
> (II) VESA(0): Modeline "800x600"x0.0   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz)
> (II) VESA(0): Modeline "800x600"x0.0   36.00  800 824 896 1024  600 601 603 625 +hsync +vsync (35.2 kHz)
> (II) VESA(0): Modeline "640x480"x0.0   31.50  640 656 720 840  480 481 484 500 -hsync -vsync (37.5 kHz)
> (II) VESA(0): Modeline "640x480"x0.0   31.50  640 664 704 832  480 489 492 520 -hsync -vsync (37.9 kHz)
> (II) VESA(0): Modeline "640x480"x0.0   30.24  640 704 768 864  480 483 486 525 -hsync -vsync (35.0 kHz)
> (II) VESA(0): Modeline "640x480"x0.0   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz)
> (II) VESA(0): Modeline "720x400"x0.0   28.32  720 738 846 900  400 412 414 449 -hsync +vsync (31.5 kHz)
> (II) VESA(0): Modeline "1024x768"x0.0   78.75  1024 1040 1136 1312  768 769 772 800 +hsync +vsync (60.0 kHz)
> (II) VESA(0): Modeline "1024x768"x0.0   75.00  1024 1048 1184 1328  768 771 777 806 -hsync -vsync (56.5 kHz)
> (II) VESA(0): Modeline "1024x768"x0.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz)
> (II) VESA(0): Modeline "832x624"x0.0   57.28  832 864 928 1152  624 625 628 667 -hsync -vsync (49.7 kHz)
> (II) VESA(0): Modeline "800x600"x0.0   49.50  800 816 896 1056  600 601 604 625 +hsync +vsync (46.9 kHz)
> (II) VESA(0): Modeline "800x600"x0.0   50.00  800 856 976 1040  600 637 643 666 +hsync +vsync (48.1 kHz)
> (II) VESA(0): Modeline "1280x720"x60.0   74.48  1280 1336 1472 1664  720 721 724 746 -hsync +vsync (44.8 kHz)
> (II) VESA(0): Searching for matching VESA mode(s):
> 
> Any of 1360x768, 1366x768, or 1280x720 would be fine.
> 
> Following this are a pile of blocks starting with 'Mode: ...' or '*Mode: ...'.
> I think these are the modes the driver is reading from some 'magic' place and
> maybe the stared ones are 'matches' to the DCC mode lines. I think what I need
> to do is update this 'magic' place with a low-level program (probably
> eventually run in /etc/rc.local or someplace like that) that will add in a
> 'Mode' -- I did this *years* ago with little machines with Intel video chips 
> and 16:9 monitors. But I am totally blanking on the command to use.  I find 
> using a 4:3 video mode on a 16:9 monitor somewhat unusable.
> 
> I running CentOS 5.11 w/Xen. The video chipset is a NVIDIA Corporation C77
> [GeForce 8200] (rev a2). I am using stock CentOS 5 drivers and libraries
> (slightly out of date).
> 
> 
> -- 
> Robert Heller             -- 978-544-6933
> Deepwoods Software        -- Custom Software Services
> http://www.deepsoft.com/  -- Linux Administration Services
> heller at deepsoft.com       -- Webhosting Services
>                                                                     
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-- 
---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
  "And he will be called Wonderful Counselor, Mighty God, Everlasting Father,
  Prince of Peace. Of the increase of his government there will be no end. He 
 will reign on David's throne and over his kingdom, establishing and upholding
      it with justice and righteousness from that time on and forever."
------------------------------- Isaiah 9:7 (niv) ------------------------------