[Coco] Utility of large MPI (was: Re: ROM Cart registers)

[RETRO Innovations]

Hmm, I think I am beginning to understand why folks are looking more for 
an all-in-one cart for the Coco.  It's a shame, but it looks like the 
utility of a 8 slot MPI is marginal.

If you are using a GCCC or sIDE, al of $ff5x is dedicated
$ff6x-$ff7e must be dedicated, because none of those addresses are gated 
by the MPI.
$ff4x is really the only place to share the bus.  16 bytes is not a lot 
of space to share.

Jim