[CentOS] CentOS 7, PS-2 moose

I just built a workstation, CentOS 7, fully updated. My user requires his
three-button mouse, telling me that imaging software is written for
three-button mice (so *please* don't tell me to tell him to get a new
mouse).

Anyway, no cursor. In both /var/log/messages and journalctl, I see "unable
to enable mouse".

What I read in messages and manpages is that PS-2 is default standard...
anyone have any ideas? I need to resolve this asap... so I can get onto
making sure his research imaging software running on CentOS 7.

       mark