UNIX and the Z8000 in a dual-processor co-operating system
David R. Phillips, Richard Mateosian · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1982
The UNIX operating system of the 16-bit world and the CP/M operating system of the 8-bit world can be combined into a co-operating system based on a Z8000/Z80 dual processor architecture. The Z8000 runs UNIX, which is the master operating system for the configuration. The Z80 and 64k bytes of dual-port ram are a shared resource for UNIX tasks needing to run CP/M programs. The Z8000 test and set instruction controls access to this shared resource. Communication between the Z80 and Z8000 is so arranged that a Z80 test and set instruction is unnecessary.