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.
cheers
Jules