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. 
The IBM IS/390 came with three by default.  A PC processor running OS/2,
a mainframe processor running a mainframe OS (commonly VM or VSE) and a
channel processor with an i960.
Peace...  Sridhar