Resolution, mode, dotclock problems

Peter Jay Salzman p at dirac.org
Wed Jan 11 11:18:30 PST 2006


Hi all,

For my system, lspci reports:

   0000:00:02.0 VGA compatible controller: Intel Corporation 82865G
      Integrated Graphics Controller (rev 02)

And I use the i810 driver:

   Section "Device"
      Identifier   "Intel Corporation 82865G Integrated Graphics Device"
      Driver       "i810"
   EndSection

Here is the screen section:

   Section "Screen"

   Identifier  "Default Screen"
   Device       "Intel Corporation 82865G Integrated Graphics Device"
   Monitor      "Generic Monitor"
   DefaultDepth 24

   SubSection "Display"
   Depth 24
   Modes "1280x1024" "1152x864" "1024x768" "800x600" "640x480" "320x200"
   EndSubSection

   SubSection "Display"
   Depth 16
   Modes "320x240" "800x600" "1280x1024" "1024x768" "1280x960" "800x600"
   #Virtual 1024 768
   EndSubSection

   EndSection



The first problem is that there are certain modes, like 320x200 and 320x240,
that I would really like to use, but the X server reports they're unusable:

   (1152x864,Generic Monitor) mode clock 100000MHz exceeds DDC maximum 140MHz
   (320x200,Generic Monitor) mode clock 100000MHz exceeds DDC maximum 140MHz
   (1600x1200,Generic Monitor) mode clock 162MHz exceeds DDC maximum 140MHz

How is it possible that 320x200 needs a dotclock of 100 GHz?  How can I get
320x200 (and 320x240) to be available modes for my system?




The second problem is that setting different resolutions on my screen yields
"fake" resolutions.  For example:

   $ xrandr -q
    SZ:    Pixels          Physical       Refresh
   *0   1280 x 1024   ( 325mm x 260mm )  *75  
    1   1024 x 768    ( 325mm x 260mm )   75  
    2    800 x 600    ( 325mm x 260mm )   75  
    3    640 x 480    ( 325mm x 260mm )   75  
   Current rotation - normal
   Current reflection - none
   Rotations possible - normal 
   Reflections possible - none

If I want to choose 640x480, I can do:

   $ xrandr -s 3

but what happens is that I see a rectangular "view port" surrounded by a
thick black margin.  It appears that the portion of the screen I'm looking
at in the small viewport is actually 1280x1024, but only the "center" of the
1280x1024 screen.   Hope that's clear.




The third problem is that when I run xdpyinfo, it reports:

   dimensions:    1280x1024 pixels (325x260 millimeters)

but those physical dimensions are incorrect.  When I measure the actual
width and height of the monitor's viewable screen I measure 355x285 mm.  I
inserted the following line in my xorg.conf file:

   Section "Monitor"
      Identifier	"Generic Monitor"
      HorizSync	31.5-75.0
      VertRefresh	48-80
      DisplaySize 355 285        <---------
      Option		"DPMS"
   EndSection

But it doesn't seem to do any good.  xdpyinfo keeps reporting 325x260 mm,
and my specification appears to be ignored.




Can someone please help me out?  My wife and I would dearly love to play
scummvm, but SDL is displaying the game in a very small rectangular box
surrounded by a large black border.


Many Thanks!
Pete



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