Setting X display to 1800 x 1440 screen mode

(includes information provided by Xi Graphics)


  1. Deleted /usr/X11R6/bin/X and made link x --> XF86_SVGA. It is important to use the correct XF86_SVGA, since a newer one from Sunsite did not work, giving the message 
    /usrX11R6/bin/Xwrapper: error loading shared libraries: 
undefined symbol: __rawmemchr
    This meant that the X server could only be run as root (in which case Xwrapper is bypassed). This server recognized the Matrox Millennium G400 32MB AGP2 board. Setting 1800x1440 mode required manual editing of /etc/XF86Config to fix errors made by the X configuration program, xf86config:
    1. The 'SubSection "Display"' ... 'Modes' lines were set to 1800x1400 instead of 1800x1440, while the 'Modeline' which sets the monitor timings was set to 1800X1440 (the correct value).
    2. The upper-case X in the 'Modeline' prevented the server from recognizing "1800x1440" as a valid mode. Changing it to lower case x allowed X to start up.
  2. It was not possible to set the Xi Graphics AcceleratedX server to 1800x1440 without modification. User support at Xi Graphics gave the advice listed below, by email. 
    (1) Edit your /usr/X11R6/lib/X11/AcceleratedX/etc/Xtimings
file, and paste the information below into it.

[PREADJUSTED_TIMING]
PreadjustedTimingName = "1800x1400 @ 70Hz";

HorPixel              = 1800;
VerPixel              = 1400;
PixelWidthRatio       = 4;
PixelHeightRatio      = 3;
HorFrequency          = 101.942;
VerFrequency          = 69.967;
ScanType              = NONINTERLACED;
HorSyncPolarity       = NEGATIVE;
VerSyncPolarity       = POSITIVE;
CharacterWidth        = 8;
PixelClock            = 252.000;
HorTotalTime          = 9.810;
HorAddrTime           = 7.143;
HorBlankStart         = 7.143;
HorBlankTime          = 2.667;
HorSyncStart          = 7.683;
HorSyncTime           = 0.794;
VerTotalTime          = 14.293;
VerAddrTime           = 13.734;
VerBlankStart         = 13.734;
VerBlankTime          = 0.559;
VerSyncStart          = 13.744;
VerSyncTime           = 0.029;  

(2) Edit your boards .xqa file to include 1800x1400 in all
[RESOLUTION] sections.  The name of the .xqa file for your
board can be found in /etc/Xaccel.ini, and it is located
in /usr/X11R6/lib/X11/AcceleratedX/boards/YourBoardVendor/.

(3) Similarly, edit your monitor's .vda file to include
"1800x1400 @ 70Hz" in the [ESTABLISHED_TIMINGS] section.  The .vda
file is in /usr/X11R6/lib/X11/AcceleratedX/monitors/YourMonitorVendor/
    This also required creating files cpdg400.vda and mga-mil2a32.xqa in the appropriate directories and adding the 1800 lines.
  3. Unfortunately, it turned out that, despite this helpful advice, AGP-2 cards (which have 2 notches instead of 1 notch in AGP cards) do not yet work in AcceleratedX, giving the message 
    Can't probe display.
    No screen mode worked in AcceleratedX with this card while the older Matrox Millennium G200 AGP card worked perfectly. Hopefully, these cards will work in the near future. Card vendors will also hopefully stop changing the configuration of the video bus every couple of months.

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