Timer (Gettin' in the mouse interrupt)

["Michael J. Kelly" <mjk1@intelsrv3.cs.uofs.edu>]

How exactly does one get the IIc/IIgs (et al w/cards) mouse interrupt
to start polling?  I know it polls 1/60Hz, but what are the memory
locations to address to start such a process?  (If I have a timer I want
to update at say, $0300, how can I poll it?)

-Mike