>Tried booting NetBSD on a Power Computing PowerCenter Pro.  Any
>ideas what could be going on?

Try "bootfloppy-980715.fs".


>NetBSD 1.3F (INSTALL_FLOPPY) #0: Wed Jun 24 20:38:49 JST 1998
>    tsubai@powermac:/c/0620/src/sys/arch/macppc/compile/INSTALL_FLOPPY
>CPU: 604ev (Revision 202)
>real mem  = 201326592
>kmem_suballoc: bad status return of 3.

You have too much memory :-).  Removing some DIMMs may solve the problem.
I'm sure this bug is fixed on the new floppy.