A made a little boo-boo.  When describing the MCT ADR local bus shared 
interrupt (and the pica_iointr handler), I should've said INT1, *not* INT0.
Sorry.  INT0 is the only irq on the R4000SC that has it's own pin, so I had
a brain fart.  I may have made this same mistake on the list previously,
I apologize.  In fact, I'm not sure if INT0 is even used on the Magnum.
Hopefully if Jason is able to get Magnum docs, we'll be able to shed light
on what the Magnum interrupt assignments are, if they differ from the Pica
at all.

Cheers,
-Mark