Z80B

The Z80B is a revision of the Zilog Z80 family introduced in the early 1980s. It is designed as a higher-performance successor to the original Z80 and the Z80A, while preserving software compatibility with existing Z80 code. The Z80B is used in a wide range of systems, including microcomputers, embedded controllers, and arcade hardware, where a familiar 8-bit CPU with a 16-bit address space was advantageous.

Technically, the Z80B shares the same basic architecture as its predecessors: an 8-bit data bus, a 16-bit address bus, a rich instruction set, and the same general-purpose registers and interrupt model. It is typically implemented in a 40-pin package and uses the same external bus signals such as MREQ, IORQ, RD, and WR, which facilitated easy integration into established designs. The key distinction of the Z80B lies in its timing and speed characteristics, offering higher clock rates and improved timing performance to support faster memory and peripheral interfacing than earlier Z80 versions.

In practice, the Z80B allowed systems to operate at higher frequencies while remaining software-compatible with existing Z80 software and development tools. This made it a popular choice for upgrading legacy Z80-based machines and for new designs that required reliable 8-bit processing with broad ecosystem support.

The Z80B was later succeeded by subsequent Z80 revisions and related processors from Zilog and other manufacturers. Its legacy is tied to the widespread adoption of the Z80 family in the late 1970s and 1980s, where it provided a dependable, extensible 8-bit computing platform.