I have asus_acpi module loaded (acpi4asus) but changing the value of /proc/acpi/asus/disp file nothing works....
here is a Cut&Paste from redme file os acpi4asus 0.29:
4.1.1 Display switching
Note: the display switching code is currently considered EXPERIMENTAL.
Switching works for the following models:
L5800C (M I N E ! ! !)
W1000N (albeit with some glitches)
Switching doesn't work for the following:
L2X00D (locks the laptop under certain conditions)
To switch the displays, echo values from 0 to 7 to /proc/acpi/asus/disp. The
significance of those values is as follows:
0 - no display
1 - LCD only
2 - CRT only
3 - LCD + CRT
4 - TV-Out only
5 - LCD + TV-Out
6 - CRT + TV-Out (not tested)
7 - LCD + CRT + TV-Out (not tested)
I change the value with : "cat 4 > /proc/acpi/asus/disp"