Install the latest drivers from http://dri.freedesktop.org/snapshots/ (I used the 20050718 snapshot). You'll need three packages: the common, i810 and i915.

Extract each one to the same directory in the above order. Enter the dripkg subdirectory, execute install.sh and follow directions (you'll need to be root, and should not have X running while doing this).

Choose whether you wish to clone the display, ie have the same image on both screens. This would be useful for hooking up to a projector for presentations use etc. It is also the simpler version to configure, as you will only need to add a couple of lines to /etc/X11/xorg.conf, as below:

Section "Device"

        Identifier  "i810"

        Driver      "i810"

        VendorName  "Acer"

        BoardName   "Intel 852"

        VideoRam    32768

        Option      "VBERestore" "yes"

        Option      "DevicePresence" "yes"

        Option      "CheckDevices" "yes"

        Option      "MonitorLayout" "CRT,LFP"

        Option      "Clone" "on"

        Option      "CloneRefresh" "60"

        BusID       "PCI:0:2:0"

EndSection

Note that XVideo overlays (ie, Totem, MPlayer, Xine etc video playback) will work on only one display. There may be ways to choose which one, but by default it will be the external display.

Should you wish to have a different image on both displays, a more complicated configuration is needed. This configuration has two problems that hopefully will be resolved with time: first, more serious one is that if 2D acceleration is enabled, Xorg is likely to lock up freezing the console (the latest test driver seems to fix this). Second, with Acer's BIOS version 1.07, both displays must be at the same resolution (1024x768). The relevant parts of the xorg.conf are below:

Section "ServerLayout"

        Identifier     "Multihead"

        Screen      0  "Builtin" 0 0

        Screen      1  "Desktop" LeftOf "Builtin"

        InputDevice    "Synaptics" "AlwaysCore"

        InputDevice    "Keyboard0" "CoreKeyboard"

        InputDevice    "USBMouse" "CorePointer"

        Option      "Xinerama" "On"

EndSection

Section "Device"

        Identifier  "i810a"

        Driver      "i810"

        VendorName  "Acer"

        BoardName   "Intel 852"

        VideoRam    32768

        Option      "VBERestore" "yes"

        Option      "DevicePresence" "yes"

        Option      "CheckDevices" "yes"

        Option      "MonitorLayout" "CRT,LFP"

        Option      "noaccel" "true"

        BusID       "PCI:0:2:0"

        Screen      0

EndSection

Section "Device"

        Identifier  "i810b"

        Driver      "i810"

        VendorName  "Acer"

        BoardName   "Intel 852"

        BusID       "PCI:0:2:0"

        Screen      1

EndSection

Section "Screen"

        Identifier "Builtin"

        Device     "i810b"

        Monitor    "Monitor0"

        DefaultDepth     24

        SubSection "Display"

                Viewport   0 0

                Depth     24

                Modes    "1024x768"

        EndSubSection

EndSection

Section "Screen"

        Identifier "Desktop"

        Device     "i810a"

        Monitor    "Monitor0"

        DefaultDepth     24

        SubSection "Display"

                Viewport   0 0

                Depth     24

                Modes     "1024x768"

        EndSubSection

EndSection

Comment by sulka on Thu, 18 Aug 2005 11:00:41:
Heh, I just don't understand how you bother fiddling with your laptop like that. :)

Comment by oa on Fri, 19 Aug 2005 13:35:51:
well, sheesh. at least I'm not taken on a leash from one place to another without any control like some cupertino fans :)