On Monday 17 February 2003 11:34 am, David Laight wrote:
> > XFree86 -configure probably did not correctly identify the
> > electrical characteristics of your monitor and is using an
> > incorrect ModeLine.
> >
> > Determine the range of horizontal and vertical sync rates your
> > monitor is capable of handling.  That information should be in the
> > manual which came with the monitor, or you probably can get the
> > specs from the manufacturer's web site.  Then edit the XF86Config
> > file to include those values:
> >
> > Section "Monitor"
> >         Identifier   "Monitor0"
> >         VendorName   "CPQ"
> >         ModelName    " P70"
> >         HorizSync    30.0 - 92.0
> >         VertRefresh  48.0 - 150.0
> > EndSection
>
> This is an LCD panel, they work somewhat differently and the
> refresh rates are not that relevant.
>
> I've run panels with very low refresh rates!  You get some surprising
> results!  I've also dynamically changed the pixel clock (by a factor
> of about 5) in order to stop the display DMA underrunning when doing
> slow IO cycles on the same bus.

Sorry, I got into this late.

In that case a specific ModeLine can be created.  The log file should=20
show which ModeLine is being used.  In this case the dot clock would=20
need to be increased in order to put all the dots on the screen during=20
the vertical refresh period, providing that the monitor is capable of=20
accepting the faster dot clock.  Again the specs for the monitor are=20
required.

I'm running Linux right now but the same file should be in NetBSD,=20
/var/log/XFree86.0.log, and the last lines show the dot clock and=20
ModeLine values:

GetModeLine - scrn: 0 clock: 157500
GetModeLine - hdsp: 1280 hbeg: 1344 hend: 1504 httl: 1728
              vdsp: 1024 vbeg: 1025 vend: 1028 vttl: 1072 flags: 5

This ModeLine would look like this:

 ModeLine  "1280x1024" 157.50 1280 1344 1504 1728 1024 1025 1028 1072

The ModeLine is placed in Section "Monitor".