[ltp] Using the T40 with video projectors?

[Dave Ackley]

I seemed to get inconsistent behavior when connecting external LCD
panels to my T40p, depending on factors I couldn't completely nail
down, from plausible things like whether or not the external panel was
connected when X was started, to I'm sure I don't know what else.

Playing with the 'Clone' options to the radeon driver seems to be
helping.  I now seem able to start X with no external monitor, then
plug in the panel later and have it sync up okay.  I don't understand
all this stuff, but without the 'clone' options XF86 seemed to pick
hsyncs up around 85MHz, but my external panel only goes up to 80.

In case any of this is related to the projector issues you're having,
here's the device section I'm currently using for external video:

Section "Device"
        Identifier  "Videocard1"
        Driver      "radeon"
        VendorName  "Videocard vendor"
        BoardName   "ATI Radeon Mobility M9"
        VideoRam    65536
                                                                                
        Option      "DDCMode" "on"
        Option      "CloneDisplay" "2"
        Option      "CloneMode" "1280x1024"
        Option      "CloneHSync" "30-80.0"
        Option      "CloneVRefresh" "50.0-75.0"
EndSection
                                                                                
I'm not sure the DDCMode on is worth anything.  I got the
hsync/vrefresh numbers from the XFree86.0.log file from starting up X
with the external panel connected.

2373G1U Redhat 9 stock XF86 4.3.0

         -Dave


   From: "Theodore Ts'o" <tytso@mit.edu>
   Phone: (781) 391-3464
   Sender: linux-thinkpad-admin@linux-thinkpad.org
   X-BeenThere: linux-thinkpad@linux-thinkpad.org
   X-Mailman-Version: 2.0.8
   Precedence: bulk
   Reply-To: linux-thinkpad@linux-thinkpad.org
   List-Help: <mailto:linux-thinkpad-request@linux-thinkpad.org?subject=help>
   List-Post: <mailto:linux-thinkpad@linux-thinkpad.org>
   List-Subscribe: <http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad>,
           <mailto:linux-thinkpad-request@linux-thinkpad.org?subject=subscribe>
   List-Id: This list for users of Linux on IBM Thinkpads. <linux-thinkpad.linux-thinkpad.org>
   List-Unsubscribe: <http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad>,
           <mailto:linux-thinkpad-request@linux-thinkpad.org?subject=unsubscribe>
   List-Archive: <http://mailman.linux-thinkpad.org/pipermail/linux-thinkpad/>
   Date: Tue, 15 Jul 2003 22:57:13 -0400

   Hi all,

   I wonder if any of you with T40p's (or other Thinkpads that have a
   1400x1050 resolution displays) have run into this particular problem.
   The issue, of course, is that the projectors can't deal with the extra
   resolution.

   The problem, though is that even when I bring the resolution down to
   1024x768, or even 800x600, the projector is still not able to sync with
   the video.  It only shows part of the screen (generally the left 30% of
   the screen in 1024x768 mode is simply not shown by the video projector).

   Has anyone seen this, and come up with a workaround?  I've enclosed the
   XFree86 config file which I use to try to force my T40p into 1024x768
   mode....

                                           - Ted
 ..