Linux and Laptop Screen Resolutions
A funny thing happened to me on the way to setting up my laptop with and external display under Linux. As I have mentioned before, neither Ubuntu nor Mandriva was able to handle this "properly". I have continued to test this through the latest Alpha and Beta releases, and now the situation has changed rather dramatically... and surprisingly.
First, the new release of Mandriva (2009.0), gets the screen resolutions exactly the way I want them, by default. What this means is that the laptop screen is 1280x800, always, and when the external screen is connected it is 1280x1024 and the two screens are set to "mirror", meaning they display the same content as far as possible, and the additional resolution of the external display is simply clipped off the bottom of the laptop display.
However, the Beta release of Ubuntu 8.10 (Intrepid Ibex) has added an interesting new twist. When the two displays are set to "mirror", as they are by default, it doesn't get the resolution right - it sets them both for 1024x768, which I think is the highest resolution they have in common - and which looks awful on both of them. But if I un-check "mirrored", it sets each of them up separately, I can choose the optimum resolution of each one, and I can position them adjacent to each other any way that I like. The desktop then becomes the sum of the two individual displays, and I move between them my simply moving the mouse around. Users of multiple displays will be familiar with this situation; I haven't used it in many years, but it turns out to be even nicer than I remember.
I then tried to un-mirror the displays in Mandriva, but it doesn't quite get it right. One or the other always falls back to 640x480 resolution and then tiles that to fill the display, and that is certainly not a useable situation. Too bad.
The result of all this is that Mandriva can do what I originally wanted and Ubuntu can't, but now Ubuntu is able to do something else which I like even more! What a pleasing development.
jw 13/10/2008