[ALUG] Hardware Issues (Display / X11 and Mouse)

[Tim Green]

On Mon, May 26, 2008 at 6:28 PM, Jan T. Kim <jtk at cmp.uea.ac.uk> wrote:
> Hi All,
>
> I've got two issues mainly concerning hardware:
>
> (1) I've recently bought an Asus W202S display (1680x1050) and connected
> that to my laptop (Asus X51, ATI Radeon Xpress 200M graphics, running the
> closed-source ATI X server).
>
> Things basically work, but it takes some sort of "warm-up time" before
> the picture stably settles in -- initially, areas with a checkerboard
> raster (e.g.  scroll bars of xterm and other Athena GUI applications,
> also the default meshwork pattern shown by X11 upon startup) are quite
> blurred. I can fix this by adjusting the "Phase" setting in the display's
> on-screen menu system, but the phase will drift, resulting in gradual
> build-up of blur, and it stabilises only after 20 minutes or so.
>
> I wonder whether there might be some Modeline hack or similar to generate
> a video signal that the display can lock on to reliably, regardless of
> some drift.
>
> In text (console) mode the display doesn't work ideally either, the display
> "sees" 1024 x 768 while the laptop's display shows 1280 x 800 (and
> presumably also sends that through the external monitor interface), so
> some amount of stuff is cut away from the margins. I've tried everything
> with the on-screen menus of the display (there isn't very much), to no
> avail -- so is there anything on the Linux side of this that I could try?

I'd like to think a modern distribution would be pre-configured to use
the "Preferred Mode" as reported in the monitor's EDID. Debian based
distributions have a package called read-edid. This allows you to run:
get-edid | parse-edid
which spits out some data including a mode line like this:
        Mode    "1600x1200"     # vfreq 60.000Hz, hfreq 75.000kHz
                DotClock        162.000000
                HTimings        1600 1664 1856 2160
                VTimings        1200 1201 1204 1250
                Flags   "+HSync" "+VSync"
        EndMode

Hope this helps!
Tim.