== Description ==
The Z80 microprocessor is an 8 bit [[CPU ]] with a 16 bit address bus capable of direct access of 64k of memory space. It has a language of 252 root instructions and with the reserved 4 bytes as prefixes, acceses an additional 308 instructions. The Z80 was modeled after the [[8080]] and contains the 78 - 8080 opcodes as a subset to it's language.
Programming features include an accumulator and six eight bit registers that can be paired as 3-16 bit registers. In addition to the general registers, a stack-pointer, program-counter, and two index (memory pointers) registers are provided. While not in the same leauge as the Intel 80x86 or the [[Motorola 68000]] series, the Z80 is extremely useful for low cost control applications. One of the more useful features of the Z80 is the built-in refresh circuitry for ease of design with DRAMs.