wheel mouse + kvm switch

Trevor S. Cornpropst tcornpropst at cox.net
Sun May 11 19:34:23 PDT 2003

On Sunday 11 May 2003 02:16, Nicolas Galler wrote:
> I have found a lot of problem report about this on google but no solution
> :( So is there a way to use the wheel mouse on freebsd with a kvm switch?
> My mouse (and the wheel) works fine when plugged directly. The win2k
> machine on the switch works fine (as fine as windows can go anyway).
> But when I plug the mouse through the switch freebsd doesn't see the wheel
> anymore. Somehow psm decided to discard the mouse wheel data? I tried
> reading the data from /dev/psm0, and get nothing for the wheel when the
> mouse is in the switch (it shows data if it's plugged directly). So this
> seems to be a problem with the psm driver, not the moused or X.
> Well the mouse model is detected the same way (Mouse 4D+) whether or not
> the switch is there, so maybe the switch is translating data, but freebsd
> fails to probe the difference, so is there a way to force the driver to
> intellimouse or something? The switch is of the plainest nameless kind so I
> don't think it's doing something so obscure that only windows can handle
> it. This seems to be quite a common problem so I hope there is a solution
> (other than going wild on psm.c myself)
> Thanks
> Nicolas Galler


I experienced the same problems you mention. My configuration was a Logitech 
Wheel Mouse and a Linksys 4 port KVM. I suspect the reason this works for 
Windows and not FreeBSD is Windows has an option in the hardware properties 
for your mouse "Wheel Detection: Assume wheel is present".

The cause of this problem comes from the KVM switch itself. I say this because 
I have seen the wheel work with some KVMs and not with others. Obviously, I 
was aware some hardware is better than others but I thought mine was good 
enough ;-) Strangely, my Linksys 2 port switch worked fine.

I tried several configuration options in FreeBSD and X with no success. I 
finally purchased a KVM switch that advertised "keyboard and mouse emulation" 
and that it worked with wheel mice. You can get around the keyboard and mouse 
emulation problem with a psm option or running moused. But, I never found a 
way to make the wheel work without buying a different switch. FYI, I replaced 
the 4 port Linksys with the IOGear mini KVM. Works great and has the cables 
built in.


Trevor Cornpropst

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