FYI Just ran across this looking for info on a Z-World Z80 ISA coprocessor card made in Davis, CA http://books.google.com/books?id=4SkqFozu80MC&pg=PA37&lpg=PA37&… page 37 in "Embedded systems design using the Rabbit 3000 microprocessor" gives a short history of Rabbit, which traces it's roots to Decmation, who made Z80 cards for DEC machines. Decmation -> Z-World -> Rabbit