Comparing raw performance of the Z80 and the 6502
May 21, 2022 · A lot has been said on the internet about the 6502, at 1MHz, being roughly equivalent in performance to the Z80, at 4 MHz. It is said the Z80 has a typical 4 clock ticks per instruction, while …
Where to buy a 6502 chip - Retrocomputing Stack Exchange
Jun 8, 2020 · I want to purchase a 6502 40 pin CPU in order to verify if my 6502 is faulty, I've seen I can buy from Hong Kong but would prefer closer (to the UK), RS and CPC don’t seen to have any. Most …
6502 - Why does the BRK instruction set the B flag? - Retrocomputing ...
Apr 24, 2024 · On the 6502, the brk instruction is a software interrupt. Like any other interrupt, it pushes the status word to the stack and then the program counter, before transferring control to an interrupt
Why did so many early microcomputers use the MOS 6502 and variants?
May 14, 2017 · Quite a few successful early microcomputers used the MOS 6502 CPU. This included, but was not limited to, systems like the Apple I, Apple II, Commodore PET, and Ataris. A followup …
How similar were the MC6800 and MOS 6502?
Sep 25, 2024 · When reading about the history of the 6502 CPU, it is regularly pointed out that Chuck Peddle had previously worked on the MC6800 CPU at Motorola. As well, it is stated that the goal …
Is there a standardised 6502 assembly syntax?
Mar 9, 2024 · 10 Is there an standardised 6502 assembly syntax? Not really. While MOS' own Cross-Assembler might have been a base, it was way too primitive to be be considered. Still, there is a line …
Were there 6502 revisions B and C, and what were they like?
Aug 13, 2023 · So this naming implies there ought to exist revisions B and C, which presumably were done to fix other problems, or add other features, but I can't seem to find much information about …
6502 - Why were there no 32-bit versions of 65xx CPUs, or 64-bit ...
Oct 29, 2020 · A RISC based implementation of the Apple II 6502 Processor: In mid ’85 I performed an analysis that showed a simple RISC style implementation of a 16‐bit binary compatible superset of …
assembly - "Paul's method" moniker for the 6502 RTS trick ...
Oct 21, 2025 · In 6502 assembly programming, there's a common trick (usually called the RTS trick) for performing indirect jumps by pushing the target address minus one on the stack and executing a …
What is the MOS 6502 doing on each cycle of an instruction?
Feb 7, 2021 · 11 Assuming you’re asking: what can the 6502 be seen to be doing by an external observer, then the data sheet has a full breakdown of bus activity per cycle per addressing mode; …