Where to buy a 6502 chip - Retrocomputing Stack Exchange
Jun 6, 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 …
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 …
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 …
Why didn't the 6502 have increment/decrement opcodes for A?
Dec 11, 2019 · In 6502 Assembly, we can use INX and INY to increase the value stored in X and Y. They can be decreased with DEX and DEY. However, it seems that there are no such instructions for …
How similar were the MC6800 and MOS 6502?
Sep 25, 2024 · 5 While the 6800 and the 6502 are quite similar at a basic technology level, their different levels of commercial success suggest that the better-optimised ISA of the 6502 was an advantage. …
Why does MOS 6502 require an external clock if it has an internal ...
Oct 20, 2022 · The 6502 includes internal circuitry which, given a single square-wave clock input, will produce phi1 and phi2 signals which meet the specified requirements. Some members of the family, …
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 …
Why does the 6502 have the BIT instruction?
May 25, 2019 · The 6502 has a bit instruction which copies two of the bits into the N and V flags, pretends to and the byte with the accumulator, but discards the result and only affects Z. I'm having 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; …
Why didn't Commodore run the 6502 at 2 MHz? [closed]
Jun 19, 2024 · The Atari 800, in 1979, ran the 6502 at 1.79 MHz. That rounds to 2, and was presumably a 6502A rated for 2 MHz, underclocked. Why did Commodore keep running their 6502 computers at …