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  1. 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 …

  2. 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 …

  3. hardware - How exactly do all control signals in 6502 work ...

    Jun 4, 2019 · I'm trying to make a 6502 replica in Logisim. I want to know what exactly each control signal in 6502, how the clock cycles work and additionally I would like to see an …

  4. 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 …

  5. memory - Was the Commodore 128 movable zero page / stack …

    Apr 1, 2020 · The Commodore 128 hardware allowed two things that weren't possible on the C64: Moving the 6502 zero page and 6502 stack to another place in RAM besides pages 0 and 1, …

  6. 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 …

  7. Why did so many early microcomputers use the MOS 6502 and …

    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 …

  8. 6502 - PDP-8 transistor count - Retrocomputing Stack Exchange

    Mar 2, 2018 · The 8008 and 6502 use a data width bus of 8-bits because they support bytes as a data type, and they use the data bus twice (i.e. taking longer) if the memory transfer …

  9. 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 …

  10. 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 …