Editing Zilog Z8000 (section)

{{Short description|16-bit microprocessor}}
{{Use dmy dates|date=March 2020|cs1-dates=y}}
{{Infobox CPU architecture
| name        = Zilog Z8000 architecture
| designer    = [[Zilog]]
| bits        = 16-bit
| introduced  = {{Start date and age|1979|df=yes}}
| version     = 
| design      = CISC
| type        = Register–Memory
| encoding    = 
| branching   = Condition register
| endianness  = 
| page size   = 
| extensions  = 
| open        = 
| predecessor = 
| successor   = [[Zilog Z80000|Z80000]]
| registers   = 16 × 16-bit general purpose<br>24-bit PC<br>16-bit status
| gpr         = 
| fpr         = 
}}
{{Infobox CPU
| name          = Zilog Z8001
| image         = M20 mb cpu.jpg
| image_size    = 180px
| alt           = 
| caption       = Z8001 on the motherboard of an Olivetti M20 computer
| designfirm    = Zilog
| produced-start = {{Start date and age|1979|df=yes}}
| version       = 
| type          = 
| encoding      = 
| endianness    =
| page size     = 
| instructions  =
| extensions    = 
| data-width    = 16 bits
| address-width = 23 bits
| open          = 
| registers     = 
| gpr           =
| fpr           = 
| pack1         = 48-pin DIP (8001)
| pack2         = 40-pin DIP (8002)
| transistors   = 17,500
}}

The '''Zilog Z8000''' is a [[16-bit computing|16-bit]] microprocessor architecture designed by [[Zilog]] and introduced in early 1979. Two chips were initially released, differing only in the width of the address bus; the Z8001 had a 23-bit bus while the Z8002 had a 16-bit bus.

Bernard Peuto designed the architecture, while [[Masatoshi Shima]] did the logic and physical implementation, assisted by a small group. In contrast to most designs of the era, the Z8000 does not use [[microcode]], which allowed it to be implemented in only 17,500 transistors. The Z8000 is not [[Zilog Z80|Z80]]-compatible, but includes a number of design elements from it, such as combining two registers into one with twice the number of bits. The Z8000 expanded on the Z80 by allowing two 16-bit registers to operate as a 32-bit register, or four to operate as a 64-bit register.

Although it saw some use in the early 1980s, it was never as popular as the Z80. It was released after the 16-bit [[Intel 8086|8086]] (April 1978) and the same time as the less-expensive [[Intel 8088|8088]], and only months before the [[Motorola 68000|68000]] (September 1979) with a 32-bit [[instruction set architecture]] and which is roughly twice as fast. The [[Zilog Z80000|Z80000]] was a 32-bit follow-on design that made it to a test sampling phase in 1986 without ever being released commercially.<ref>{{cite web |url=https://www.kranenborg.org/z8000/ |title=The Z8000 / Z80,000 / Z16C00 CPU homepage |accessdate=2024-11-10}}</ref>