Hint to get TwinView up-and-running

[hajo]

Sorry folks, I've seen too many threads about problems with TwinView as to reply to each one individually. After struggling for months (with various driver & Linux versions) to get 2 outputs simultaneously, last night I found (my) solution by chance.

It appears that either the Linux drivers don't actively probe for connected CRTs/DFPs/TVs the way that the WIN drivers do, or they simply ignore it. While I always had CRT + TV flawlessly working under WIN, it never worked under Linux -- when turning on the TV, there was no picture on the CRT. Meanwhile I figured out that the picture disappearing from the CRT went to the DFP connector instead. Connecting my CRT via an adapter to the DFP connector now gives me
- boot screen (as the card detects the CRT @ boot-time)
- X-Image on the CRT
- TV-Out

Further, by scanning through so many "tutorials" & posts, I realized that others with the same GPU (GEF4 TI4200) seem to have exactly the same configuration I had yet do not encounter the same problems. I suspect that different board manufacturers assign the output ports of the GPU to different rear-panel connectors, creating a mess for driver developers not considering this fact.

Conclusion: If you have problems getting more than one signal out, try different combinations of connections of displays to your card or possibly try to fiddle around with the "ConnectedMonitors" string -- I guess changing from say "CRT,DFP" to "DFP,CRT" or to "CRT,CRT" etc might help...

Yet I would love to hear comments from the driver developers about the actual behaviour of the drivers, as I tend to be 100% convinced only by hard facts and not by my middle-of-the-night luck ;)

Enjoy,
HaJo

P.S.: Before doing this, of course make sure you have configured the TwinView feature correctly, as described in the driver's README....

[moksha]

Here's a working twinview for a laptop with an external LCD -- defined to let you switch between clone (mirror) mode and spanning mode. The external monitor has to be attached when you boot up. I need a modeline because of the unusual geometry of my laptop; try just removing it, or substituting your own.

Section "Monitor"
Identifier "Monitor[0]"
Option "UseEdidFreqs"
ModeLine "1280x854" 85.3 1280 1296 1552 1792 854 854 861 892 -hsync -vsync
Option "DPMS"
EndSection

Section "Device"
Identifier "nVidia[0]"
Driver "nvidia"
BoardName "NV17 GeForce4 420 Go 32M"
Option "NoLogo" "On"
BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "Screen[0]"
Device "nVidia[0]"
Monitor "Monitor[0]"
Option "TwinView"
Option "TwinViewOrientation" "LeftOf"
Option "MetaModes" "1024x768, 1280x854; 1024x768 @1280x854 +0+0, 1280x854 +0+0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1280x854" "1024x768"
EndSubSection
EndSection

The MetaModes line lets you switch between spanning (defined by 1024x768, 1280x854, where the second set is for the laptop screen) and mirroring (defined by 1024x768 @1280x854 +0+0, 1280x854 +0+0). The @1280 is added to get panning access to
a part of the screen that otherwise would be inaccessible -- and more importantly to avoid an imperfect mirroring mode, where the two screens get superimposed.

This is probably an unorthodox way of getting this effect -- using the +0+0 offsets to get mirroring -- but it works great.

To switch between spanning and clone mode, press CtrlAlt with the plus or minus sign on the number pad.

The only thing I don't know how to do is to get full control of where the second screen is logically positioned. If you had a graphical interface you could just move the external screen above the built-in screen. Anybody know how to do this?

Cheers,
moksha