How did the Z80 instruction set differ from the 8080?
Oct 26, 2016 · The Zilog Z80 microprocessor, known for its use in the ZX Spectrum, was designed to be a backwards-compatible extension to the Intel 8080 processor. It introduced several new instructions …
Comparing raw performance of the Z80 and the 6502
May 21, 2022 · The Z80's fastest memory fetch — the first half of an operation fetch — takes two cycles. That's always paired with another two cycles for refresh though, so the shortest instructions are four …
Why did the Z80 with 4-bit ALU out-perform the fully 8-bit Intel 8080?
Feb 16, 2020 · However, the Z80 out performed the Intel version and nearly displaced it completely in the CP/M market. How did Zilog design their ALU to both out-perform and save cost? Clarification: …
Z80: asymmetric use of B in DJNZ (B is a low byte) vs. BC in LDIR ...
Aug 18, 2022 · Z80 registers are specialized. Much like A, X and Y have different features on a 6502. Inherited Basics Most of this is inherited straight from the 8080: A - General purpose accumulator HL …
Managing registers/memory effectively on the Z80
Feb 17, 2023 · The Z80 assembler unified the mnemonics to a great extent. Its rather abstract angle simplifies first steps. In contrast 8080 mnemonics are more diverse, if not chatty, presenting more of …
What was the last commercial Z80-based computer sold?
Jul 13, 2025 · AFAICT, the last Z80 desktop computer sold was the TRS-80 Model 4, in production until late 1991. If you include notebook computers, the Amstrad NC200 was released in 1993.
Did any computers use the Z80B? - Retrocomputing Stack Exchange
Jan 10, 2018 · The Z80 was one of the most popular CPUs of the seventies and eighties. In almost all cases that I know of, the version used was the Z80A, rated for 4 MHz, sometimes clocked a little …
assembly - The proper way to shift a byte using a Z80
Jun 20, 2021 · The Z80 also includes instructions to move rotate ranges of memory four bits at a time. Unfortunately, there are no register-based equivalents.
Did anyone ever use the extra set of registers on the Z80?
Oct 1, 2018 · The Z80 has the surprising feature of a second set of registers. I suppose these were intended to be used for rapid task switching or interrupt handling, though I think if I were …
Could a Z80 address a total of 128 KB of ROM and RAM?
Nov 16, 2020 · The Z80 has total memory address space of 64kB, so the answer to your question would be no. However it can be filled with ROM and RAM as you see fit, and with some extra hardware to …