Modelines for Montiors

Declan Moriarty declan.moriartyt at
Tue Feb 24 01:19:55 PST 2004

On Tue, Feb 24, 2004 at 12:11:42AM -0800, Arindam Dey enlightened us thusly
> > Try adding something like this to your XF86Config:
> > 
> > Section "Monitor"
> >   Identifier	"Gateway CM751"
> >   VendorName	"Gateway"
> >   ModelName  	"CM751"
> >   HorizSync  	30-95
> >   VertRefresh  	50-160
> >   DisplaySize 	360 270
> > EndSection
> > 
> > XFree tends to use the maximum values given. With
> > analog
> > monitors quality of what is displayed tends to be
> > reduced
> > when you get close to the hardware limits.
> > So i would be a little conservative on the maximum
> > numbers,
> > maybe start out with "HorizSync 30-85". That should
> > give
> > you about 88Hz when running at 1280x960.
> > 
> > --
> > Michael
> Thanks Michael.
> I already have that relevant portion in my XF86Config
> file. My fuax pas should have posted the relevant
> XF86Config but had forgotten to get it. Even then it
> is displaying only 640x480. Hmm try giving it less
> (30-85) so that it does more....does this work never
> tried it will try it later when I reach the pc. Don't
> have it here right now.
> And this is a LCD monitor so thats why I thought it
> needs the modeline.

The above section gives a monitor section. not a modeline.. Here's a
# 1024x768 @ 70 Hz, 56.5 kHz hsync
Modeline "1024x768" 75 1024 1040 1176 1296   768  771  777  786 -hsync -vsync

You are getting 640x480 because X can find no valid modes to display, so
falls back to 640x480 at 60hz, which every pc has to do anyhow for dos.

Those figures after "1024x768" mean: Dotclock speed (controlling writing
speed, and therefore refresh); right edge of visible; right edge of
invisible portion; left invisible (time between 1040 & 1176 is flyback);
left edge of visible; and a similar 4 figures for the vertical.

The modelines are increasingly extinct as all the Vesa modes are already
in X these days. My XF86Config has 640x480, 800x600, 1024x768, 1280x1024
but X tries 1152x960 and all sorts of strange things also.

I would disregard concerns about horizontal speed and maximums. Monitors
these days do not freak if you go a little over the top, and X never
does, except for rounding errors. If your monitor can do what you say,
I'd consider it safe at that.

Don't forget the Display section, which is basically last. Here's mine:

    Subsection "Display"
        Depth       24
        Modes       "800x600" "640x480"
        ViewPort    0 0

You repeat that for every colour depth you want. These are the things
you can jump around with Ctrl_Alt_+/-. I want to come up in 800x600, and
don't want 1280x1024 at all, even though my monitor can do it, as I like
800x600 and am not bothered farting with the screen size.

As a rule, have your densest resolution first, because X sets a screen


	With best Regards,

	Declan Moriarty.

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