The Zilog Z8000 is a 16-bit microprocessor introduced in 1979.
Initial versions were the Z8001 with a 23-bit external address bus in a 48-pin DIP, and the Z8002 which supported only 16-bit addressing but fit in a 40-pin DIP.
The series was later expanded to include the Z8003 and Z8004, updated versions of the Z8001 and Z8002, respectively, which improved support for virtual memory.
The Z8000 was not very successful commercially, being quickly overtaken by the faster 16/32-bit Motorola 68000 introduced later the same year.
- Zilog Z8000 @ Wikipedia