[Andy A.]

The 'wheel' input is in fact an analog 0-5v (0-255 increments) signal, just like the X&Y axis. It is typically the throttle in a flight sim. In FIRST it is almost never used on the joysticks. You can however use it, if you so choose, as a 'hip' or rudder axis.

On the old CH flight sticks it is the left most wheel and rotates something like 60 degrees. The other two wheels are trim. Some joysticks may use the 'wheel' as a 4 way 'hat' switch using a resistor network to get 4 distinct increments out of the analog. This is what I think you are referring to on your stick. The newer sticks they have been including in the kit probably use the hat switch in place of a real throttle wheel.

There is also a 4th analog on each joystick port that is also rarely used. The original design of the gameport intended for a y cable to be used to connect two joysticks to one computer. That never really happened, and the two other analogs usually were used for a throttle and hat switch. Then USB sticks came out and manufactures where no longer limited by the gameport and so you end up with a zillion buttons and axises.

There are many joysticks on the market that allow you to twist the stick about the z axis, usually to substitute for rudder pedals. They are probably all usb based however.

-Andy A.