How to get a Joystick work with KDE?
My Linux-Kernel (2.4.20) is compiled with Joystick-Support...

well, I use 2.4.19 and did:
modprobe joydev

If the joystick is USB, make sure uhci or ohci (whichever fits your mobo) is moduled/compiled in. That done, it should "just work". As a matter of fact, it's kinda hard to turn off once you get it started without pulling the plug. :-?

The answers you need have already been given but as a bonus here are some tools that come with the joystick driver that can help you test things out or even correct some issues:

jstest /dev/js0
jscal -c /dev/js0

and if your controller is NOT a USB one:

jsattach <your hex headache goes here> /dev/js0

My joystick is all calibrated and nice, but it's WAY too sensitive.
I can't find a single setting in vendetta that has anything to do with "Joystick Deadzone" and when I click "Calibrate" it does nothing.
It's really unusably sensitive. I can't even fly in a straight line. IMPOSSIBLE to chat more than two-word lines of I'd spinn out of course and hit a roid.
Getting in to hidden sectors is a no-go too... :/
I hope I don't have to go back to mouse and keyboard, cuz it's sweet with the stick in every aspect but the deadzone.

(Logitech Wingman Foce 3D USB joystick on Debian GNU/Linux Sid)

Try out this tool:

http://wolfpack.twu.net/libjsw/