Here are the keycodes that I was able to uncover using showkey -k.
Unfortunately, the kernel logs don’t complain when I hit the unknown keys so there’s probably no point in setting up the extra scancodes (particularly since this Belkin MediaPilot keyboard is not the primary keyboard in the system, and the setkeycodes documentation suggests that it only works on the primary keyboard). I’ve tried to use useful codes out of linux/input.h, and can confirm that these actually feed through to MythTV, so that they can be used as JumpPoints, or whatever.
Into ~/.Xmodmap put (note that ‘!’ is the comment character) :
And in my ~/.xinitrc I’ve got :
Just for completeness, I’ve appended the following code to my ~/.bash_profile - this detects whether it’s running as the console on my second keyboard, and launches appropriately :