Zilog Z280

The Z280 was fabricated in CMOS,[1] added a memory management unit (MMU) to expand the addressing range to 16 MB, features for multitasking and multiprocessor and coprocessor configurations, and 256 bytes of on-chip static RAM, configurable as either a cache for instructions and/or data, or as part of the ordinary address space.

It has a huge number of new instructions and addressing modes giving a total of over 2000 combinations.

It is capable of efficiently handling 32-bit data operations including hardware multiply, divide, and sign extension.

The Z280 had many advanced features for its time, most of them never seen again on a Zilog processor:[2] In the early 1990s, a small number of single-board computers based on the Zilog Z280 were designed and produced by Tilmann Reh, but the CPU was never used in any commercially produced computer.

[3] In 2016, Lamar Owens contacted Tilmann Reh and obtained permission to have a small new run of the CPU280 system PCB's created, getting ten boards made and distributed to several beta builders.