In message <x77l93leue.fsf@pasillo.wsrcc.com>, Wolfgang Rupprecht writes:
>How does one enable the wheel on a usb wheel mouse to send z-axis X11
>events?  All I could find on google is how to make Xfree86 emulate
>buttons 4 and 5 from the wheel.  That seems like a shameful waste.  (I
>have a 3-d program I'm writing that I'd really like to get a true
>third axis of info into.)

That's all there is, so far as I can tell.  You then turn buttons 4 and 5
into an axis.

-s