Mike van Bokhoven wrote:
   Cromemco
DPU? Z80 and 68000 on one S-100 card; add an IOP Serial I/O
 card, and you've got another Z80... 
 How about the Sega MegaDrive/Genesis? That ran a 68000 and Z80.  
 
 That's only two, though :) I'm mainly curious as to which vendors managed to
 produce and market a system with more than two out of the box (rather than
 relying on add-on boards from third parties, or even optional extras from the
 manufacturer). I don't think there could have been many. 
A copule that have not been mentioned yet, although relying on optional
extras :
Xerox Daybreak. It has the bit-slice MESA processor board, an 80188 for
I/O, and an optional MS-DOS processor board that I've never seen, but
which prexumably contained an 80x86 or 8088 chip.
DEC Rainbow. 8088 and Z80 as standard, there's a 7220 graphics processor
on the colour card (well, if the Tiger can count that chip :-))
-tony