The information below is based partly on the information he sent me
and my own experimentation on linux and windows.
(Any errors here are my fault. I welcome corrections.)
In what follows 'Fn' refers to the function key next to Ctrl on the left.
'Fn-Left' refers to the action of holding down the Fn key, then pressing the Left Arrow key (on right of keyboard.)
NOTE ADDED 13 Jul 2010:
On Matthew's suggestion I checked out behaviour in Windows 7 and found that I had previously misdescribed the situation.
I now think there is a bug in the linux software handling the fn+key combinations on E6410 (and perhaps other machines).
REVISED INFORMATION (13 Jul 2010): Fn-Left: toggle ambient light sensor On-Off INTENDED behaviour (as found in windows 7) When On it controls screen brightness When Off it lets user determine screen brightness as below. ACTUAL behaviour (at least on my machine with Fedora 13): When ON the ambient light sensor controls display brightness, and the user can also control brightness, but sometimes the user's setting is overridden by changes in sensed ambient light. This can be very annoying. BUG: When OFF the brightness is set at a fixed value (quite dim on my machine, possibly a setting I selected for the bios), and in that state neither the light sensor nor the Up/Down key actions cause screen brightness to change. THIS IS A SERIOUS BUG Fn-Down: dim the screen Works only when ambient light sensor is in the On state (toggled by Fn-Left) (See bug above) Fn-Up: brighten the screen Works only when ambient light sensor is in the On state (toggled by Fn-Left) (See bug above) Fn-Right: toggle keyboard backlight setting This switches between three states: 1. Backlighting off (whatever the ambient light level) 2. Backlighting controlled by ambient light level and whether typing is in progress. Backlighting comes on when typing starts, if the ambient light level is low. Backlight goes off after no typing for some interval. 3. Backlighting stays on (whatever the ambient light level) (In Windows 7 it is also possible to set the brightness level for the backlighting. I have not found a way to do this on linux.) I hope that eventually Dell will provide a linux version of their DCP (Dell Control Point) package (minus the security stuff). OTHERS (Windows only?) Fn-8: cycle through display devices As far as I know this does not work on linux. On Linux: Try using the lxrandr tool for much more precise control, including selecting resolution of laptop and external display. Fn-7: launch DCP Dell Control Point (Windows only) May not be installed: included in one of the Dell CDs. If present this is also in the TaskBar tray. Useful for setting brightness levels, keyboard backlighting, and ambient light sensor behaviour (among other things). The Dell manual for users of the 'Dell Control Point' package is here (PDF). Fn-F3: display battery state On windows only For linux do cat /proc/acpi/battery/BATT0/state or try the gnome power controls. Unchanging information about the battery: cat /proc/acpi/battery/BATT0/info In GNOME, this pops up a status window? Fn-F2: toggle battery charging control Windows only: There are two states that can be controlled in the bios settings. This may give access to those states while windows is running: When charging toggle 'Express charge' On or Off When AC power is connected, toggle battery charging On or Off Fn-F1: Sleep Does not work for me on linux, unless programmed separately, e.g. via window manager settings. (Works in Gnome.)
If you have more detailed information or corrections, please let me know, if possible with links to sources of information. Thanks A.Sloman [AT] cs.bham.ac.uk
This web site was first created in July 2010
Last updated:13 Jul 2010