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 …
z80 - What is R register and DRAM refresh internal operation ...
Apr 14, 2024 · The Z80 CPU has a built-in feature to support refreshing DRAM memory, by keeping a 7-bit refresh counter in the register R. The refresh counter is increased by 1 after every instruction …
z80 - Decoding Logic and Memory Systems for 8-bit computer - 64K ...
Apr 27, 2020 · 8 I have solved a similar problem when reworking my 8085-based OMEN Alpha computer for the Z80 CPU. The memory part is really simple: You have two memories, 32k each, and you …
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 …
z80 - How do I Interface a PS/2 Keyboard without Modern Techniques ...
Mar 21, 2019 · It's a part of standard Z80 family chips and has two channels. I used it for PS/2 keyboard and USB connection to my breadboard Z80 computer running at 2.4576 MHz. Z84C40 can divide …
What's the convention for < > low/high-byte in 8-bit assembler?
Aug 16, 2023 · For the 8080/Z80 part it might be noteworthy that the original CP/M ASM did not provide an operator to select either byte. And I can't come up with any genuine (*1) 8080/Z80 that does, …
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 …
z80 - What languages are better fit for generating efficient code for ...
May 30, 2020 · For Z80 and 6502 it wouldn't matter what the language is, because the specifics of the language are far away and dissolved by the time the intermediate representation gets to the …