[ltp] Dual-head non-scrolling viewport

[Alex Deucher]

On Thu, 17 Feb 2005 16:39:49 -0800, John Locke <mail@freelock.com> wrote:
> Hi,
> 
> Finally got my coffee-drowned laptop back from the service depot a
> couple days ago, and after reading through the very helpful thread
> "thinkpad with external monitor howto" from a couple of weeks ago,
> finally started to tackle getting dual-head working on this machine,
> something I had gotten quickly accustomed to on my backup laptop.
> 
> So now, I have a few things I'm trying to figure out.
> 
> Basic configuration: T41, merged FB, 1400x1050 on the laptop, 1024x768
> on an external flatscreen panel monitor connected to the VGA port. I'm
> using Xorg 6.8.1 and the Radeon driver on a brand-spanking new Mandrake
> 10.1 install.
> 
> I got the dual head to work by adding these lines to the device section:
> 
>     Option "MetaModes" "1400x1050-1024x768 1024x768-1024x768 1400x1050
> 1024x768"
>     Option "CRT2Position" "LeftOf"
>     #Option "MergedFB" "On"
>     Option "MonitorLayout" "LVDS, CRT"
> 
>  ... and put this Modes line in a Display subsection:
> 
>         Modes "1400x1050-1024x768" "1024x768-1024x768" "1400x1050"
> "1024x768"
> 
> I tried adding some custom Modelines using a modeline generator somebody
> mentioned in the earlier thread, but they didn't work. When I went back
> to just the default modelines in the Mandrake xorg.conf file, it worked
> mostly fine--none of the modelines seem to reflect my actual
> configuration.
> 
> So here are my issues:
> 
> 1. The external LCD has a couple of slightly fuzzy bands. I've seen this
> before when I've set the monitor on another computer to Mandrake's
> settings for a generic monitor, and they went away when I selected a
> generic flat panel monitor. It's a Samsung 15" Syncmaster 570S. I have
> no idea what the difference is between the "Generic" monitor and "Flat
> Panel"--is this a different Modeline added to the file? Mandrake's
> wizards don't help configure a second monitor...

Try changing the hsync and vrefresh (crt2hync and crt2vrefresh if
using mergedfb) settings for your external monitor.  Many LCDs support
70Hz refresh rates, but look MUCH better at 60Hz.

> 
> 2. KDE loads the task bar on the external monitor, not the laptop
> screen. Is there a way I can force the task bar to the laptop instead?

try:
Option "MergedXineramaCRT2IsScreen0" "true"
see the radeon man page for more.  However, you may be able to switch
it within KDE (in GNOME, you can just drag it to whichever head you
want).

> 
> 3. Here's the tricky one. I'm finding it extremely annoying to have the
> viewport on the external monitor scroll. I've found I can use the krandr
> applet to change both screens to have the same height, at 1024x768. Is
> it possible to set up my system so that I can have two screens at
> different resolutions, without one of them scrolling? I'm thinking this
> isn't possible with MergedFB--can I do it with two separate screens,
> using Xinerama? If I don't use Xinerama, can I set it up so that I can
> still move the mouse between screens and get the keyboard to work on
> both screens? If somebody could point me to a good how-to on how to set
> this up, that would be great!

It's not really possible with mergedfb.  There are some patch floating
around that lock the viewport at a particular offset, however, hte
mouse and potentially windows can still end up in the offscreen areas.
 What you want to do is definitely possible with regular dualhead and
xinerama.

Alex

> 
> Thanks,
> 
> --
> John Locke
> "Open Source Solutions for Small Business Problems"
> published by Charles River Media, June 2004
> http://www.freelock.com