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 …
16-bit comparisons setting both zero and carry flag on 8080/Z80
Jul 19, 2025 · 16-bit comparisons setting both zero and carry flag on 8080/Z80 Ask Question Asked 6 months ago Modified 6 months ago
Z80 Memory Bank Switching - Retrocomputing Stack Exchange
Oct 31, 2025 · WAITDRV_ – Drives Z80 WAIT during sound-memory transactions or when the row-write path is active, to meet timing. So IC69 ensures nSMOE, nSWEL, nSWEH only assert on the right …
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.
Long Term Prevalence of 8080 Code Over Z80 Code in Software …
Feb 20, 2023 · TL;DR: The Z80 was introduced not long after the 8080 and replaced it quickly and almost entirely for personal computing. Still, a large chunk of new software written stayed with 8080 …
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 …
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 …
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 …
Uses for the halt instruction? - Retrocomputing Stack Exchange
Jun 16, 2018 · Unlike 8080 and Z80 the 8085 also tristates all data, address and bus control signals. *3 - While the 6502 did not feature a halt instruction (not until the 65C02), Atari's TIA for the VCS did …