[R-sig-Debian] [OT] What file can I use to change Ubuntu 9.10 display characteristics?

[Dirk Eddelbuettel]

On 4 December 2009 at 13:24, Douglas Bates wrote:
| This question is vaguely related to R in that I have managed to wedge
| the netbook computer that I use for demonstrations of R and I would
| like to know how to un-wedge it so I can continue to give lectures
| about R.
| 
| I have an ASUS eee PC running the netbook-remix version of Ubuntu
| 9.10.  The X server in 9.10 is a little different from earlier
| versions in that it does not require an explicit configuration file
| for the X server ( /etc/X11/xorg.conf, IIRC) as it can autoconfigure.
| That it did fine.
| 
| When I attached the netbook to the VGA input for the video projector
| in a lecture hall I found that it dropped the resolution to 640 x 480,
| which is undesirably coarse.  I decided to tinker and see if I could
| get it to 800 x 600 on both the built-in display and the video
| projector.  I used the GUI application accessed through the menu
| sequence System -> Preferences -> Display.
| 
| I believe that at one point I actually got things working that way
| but, of course, I couldn't leave well-enough alone and decided to try
| to get a resolution with 768 lines as I knew the projector supported
| that.  That was when it all went south.  The system froze with a blank
| screen and blank projector output.  I needed to do a hard power-down
| and reboot without the projector plugged in.  Fortunately I didn't
| lose the disk (I run ext2 file systems as a journaled file system puts
| too much wear on the solid-state disk) and I can use the computer
| without an external display.
| 
| Now I can use the netbook when it is not connected to an external VGA
| display but as soon as I connect the external VGA it freezes,
| presumably because it is trying to use an unsupported video mode.  The
| information on the video modes I selected must be stored somewhere but
| I can't find out where.  Does anyone know where that GUI application
| caches its information?  All this GUI configuration is great unless
| the thing you are trying to configure is the display and you can't get
| that working.  In the old days when you needed to edit a text-based
| configuration file you had a fighting chance of doing that even if you
| could only get the barest of systems, a text console device, running.

Try the 'randr' frontends.  I have used both xrandr (from a package of the
same name) and the KRandR frontend in KDE on both my older laptop (where I
learned about xrandr during UseR :) and my netbook which has a nice but
non-standard 'hd' resolution of 1366 x 768. The last time I connected it to a
projector I think I simply selected a lower (and more standard) resolution
from the KRandR applet in the panel.  Oh, and that was with a pre-release of
Ubuntu 9.10.  Gnome appears to have packages 'gnome-randr-applet' and
'grandr'.

And as I understand it, there is no configuration.  X11 now does everything
dynamically.  But I could be wrong.  In fact, that is quite likely as I
hardware and I usually try our best to ignore each other ...

Dirk

-- 
Three out of two people have difficulties with fractions.