I am using a Kensington "Expeert Mouse" trackball. SUSE v9.1 has identified it correctly, and I find the appropriate lines for it in XF86Config. Two things mystify me:

1) This is a four-button device. Why does XF86Config call out the number of buttons as five?

2) Seeing the the deivice is already configured to use all four buttons, how does one go about assigning specific functions to buttons 3 and 4 (aka 4 and 5, in the parlance of XF86Config)?

is it a wheel mouse? if so, those will be buttons 4 and 5. if there are extra buttons, they should be 6 and 7...meaning you'll need to change your config accordingly.

No, there is no wheel. Kensington "Expert Mouse" is a trackball with four buttons. From your reply, I understand that, as far as Linux is concerned, what I have is in fact a seven-button mouse with a phantom wheel which would occupy (if it were real) buttons 4 and 5.

So, if I configure a seven-button mouse (with the funny order of numbers) the trackball's buttons 3 and 4 will occupy which driver buttons? 3 and 6, or 6 and 7?

Interestingly (for people who think highly of the "man" system), I searched the entire system for "mouse", "input device", and several other keywords, and never made a hit. No doubt all this is documented, but nobody will find it unless he already knows where it is.

The same is true of my other question: Once I have the seven button configuration, how do I assign functions to the newly-configured buttons? I have asked this question twice on Usenet and two or three times on LQ, so far without any reply.