Hey folks,

Text mode and X windows display mirroring work nicely for the
ATI driver. Using the keyboard Fn-F8(CRT/LCD) screen swaps
between the displays, but many times you want to see the
output on both displays.

Text mode mirroring
Turn on the external display and
for text mode, go to an nice text console with CTRL-ALT-F2
and type:

Code:
atitvout detect
atitvout auto
See: man atitvout or the project page at http://software.freshmeat.net/projects/atitvout/

X Windows Mirroring
Edit the file /etc/X11/XF86Config-4
and add the following line in the right place
The line is
Option "Display" "Mirror"

and the context is, just inside the "Device" section. I just put it
after the "sw_cursor" option as follows:

Code:
Section "Device"
        ### Available Driver options are:-
# sw_cursor is needed for some ati and radeon cards
Option "sw_cursor"
Option "Display" "Mirror"
        #Option     "hw_cursor"
        #Option     "NoAccel"
        #Option     "ShowCache"
        #Option     "ShadowFB"
        #Option     "UseFBDev"
        #Option     "Rotate"
        Identifier  "Card0"
# The following line is auto-generated by KNOPPIX mkxf86config
        Driver      "ati"
        VendorName  "All"
        BoardName   "All"
#       BusID       "PCI:1:0:0"
EndSection
Then if you want a nice dangerous root X windows session, just type
CTRL-Left ALT-F2 for a root text console and then
Code:
startx -- :1
Since you have an X session already running on Knoppix as
DISPLAY :0.0 on the fifth virtual console (CTRL-Left ALT-F5) the :1
option starts the X Windows server on the next free virtual
terminal which is number six. So to switch to this session
use (CTRL-Left ALT-F6).