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 …
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 example of these …
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 …
memory - Was the Commodore 128 movable zero page / stack and …
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, and …
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 …
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 - 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 operations is 16-bits. …
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.
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 …