Quixote said;
-And image 43 shows a tower with seven added Zorro slots, the bottom of which is occupied with a card that I don't recognize. At least the lower of these slots are in line with PCI slots. Very interesting, indeed.

Sorry to rain on the parade (I
am awaiting delivery of an A1) but image 43 contrasted, in my mind, with the uncluttered (cables hidden) interior of the NEW Mac TwinG5 Case so recently displayed! :-(
The Mac platform has "clearly" jumped ahead on this one aspect!