The Zorro III bus has a number of electrical specifications that are very
important for PIC designers to consider, along with the  timing 
parameters of course.  It's extremely important to base designs on the
specification of the backplane, rather than the actual behavior of the
backplane.  New backplanes for new machines are designed to conform to the
specification, they are not necessarily based on previous designs.  This
is especially important with the Zorro III bus, since timing is far more
critical than in the past, and the bus controller is designed from this
specification, rather than the reverse, as in the Amiga 2000.

 expansion bus loading     temperature range     slot power availability