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 …
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 …
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 …
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 …
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 …
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 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 …
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 …
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's the convention for < > low/high-byte in 8-bit assembler?
Aug 16, 2023 · In contrast the 6502 had to load and store each byte separate, making those operators almost mandatory. 'Almost' as the original MOS Cross Assembler (*2) did not feature either.