trouble getting dual monitors set up
 

i am running ubuntu linux with the latest X.org on my 15" powerbook. i would really like to be able to have an external monitor set up to mirror the image on my laptop, or possiby even span my desktop across both monitors. i've tinkered with x a little with some guidance, but have failed miserably. i have a radeon 9600 pci card with svga out. any help is much appreciated! thanks.

What have you tried? Post the x conf file and lets have a look.

i've tried a number of different things, using various howtos, but nothing's worked. first i'll list my current xorg.conf, and then a couple of my various attempts:

current:
an attempt:
another attempt:
and i seem to have deleted some other attempted confs, where i made separate sections for the other monitor and duplicated the section for my graphics card. when i did that, i got a desktop that was four times too big for my laptop screen, although my external monitor was white with the following output in the upper left:
but i was able to move my cursor across to it, which was very strange. however, i could not get anything else to appear on it. thanks very much for your help!

I will post my dual screen conf file when I get home from work. Until then, if anyone has a dual screen (in clone view) conf file utilizing an ATI card please post it. It would probably be closer to what is needed here.

For what it is worth.
 

Here is the video section of my working xinerama based config file. Granted xinerama and twinview are Nvidia functions, but the monitor and device setup has to be similar. Anyone who knows different please follow up.

#Section "Device"
# Identifier "fx5200nvdriver"
# Driver "nvidia"
#EndSection

# The next two entries are for the dual head FX5200 card
Section "Device"
Identifier "Device[0]"
BoardName "0x0321"
Driver "nvidia"
BusID "3:0:0"
Screen 0
Option "Rotate" "off"
VendorName "NVidia"
EndSection

Section "Device"
Identifier "Device[1]"
BoardName "0x0321"
Driver "nvidia"
BusID "3:0:0"
Screen 1
Option "Rotate" "off"
VendorName "NVidia"
EndSection

Section "Monitor" # Phillips 109B
Identifier "Monitor[0]"
HorizSync 28-97
VertRefresh 50-160
Option "DPMS"
VendorName "PHILLIPS"
ModelName "109B (109B2)"
EndSection

Section "Monitor" # LG Flatron 1720P
Identifier "Monitor[1]"
HorizSync 28-64
ModelName "1280X1024@60HZ"
Option "DPMS"
VendorName "--> LCD"
VertRefresh 50-60
EndSection

Section "Screen"
Identifier "Screen[0]"
Device "Device[0]"
Monitor "Monitor[0]"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "800x600" "640x480"
EndSubSection
EndSection

Section "Screen"
Identifier "Screen[1]"
Device "Device[1]"
Monitor "Monitor[1]"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "800x600" "640x480"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Layout[all]"
Screen "Screen[0]"
Screen "Screen[1]" LeftOf "Screen[0]"
Option "Clone" "off"
Option "Xinerama" "on"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
InputDevice "Generic Mouse"
EndSection

great, thank you very much. i will give it a try tomorrow sometime. you mentioned that the monitor set ups have to be similar - do you mean the refresh rates and everything, or just color depth and resolution? im a little worried because my laptop has a stretched widescreen and my externam monitor is a typical 19" monitor. i've had this working with os x before with the monitors on different resolutions - is this just a quirk of X? thanks again for all your help.