Zilog’s Z-BUS Backplane Interconnect

Z-BUS backplane

Zilog’s Z-BUS backplane interconnect

We never did any design work with the Z-BUS backplane. It was given to us when we visited Zilog in California in 1983, and was used in their System 8000 Unix computers. We include the pictures in here to show the distributed termination resistors, the multi-layer layout and compact nature compared to later VME backplanes. Zilog did not attract a robust board market, and were a lot smaller than Intel or Motorola who were nuturing Multibus and VME respectively. There were a few Multibus 1 vendors with Z8000 processors, which also did not help to make Z-BUS popular. (We are not sure if the specification was published or made freely available).

See Zilog’s System 8000 Unix box for some more details and photos of the boards.