2 ms·

Clock for clock 6502 was faster than Z80. I think 6502 was also cheaper. Of course Z80 did run at higher clock speeds. 6502 got practically 254 (6510) or 256 "

• deaddodo 3y ago
  Yes, clock for clock on the single-register subset of instructions you could directly compare. But A) z80s usually ran 4-8x faster, B) they had more registers which closed the gap on more complex instructions and C) they didn't have a special Zero Page that had to be juggled for maximal efficiency. The 6502 was great for it's economy and simplicity. But it wasn't some architectural marvel compared to it's peers.
  • naikrovek 3y ago
    > it wasn't some architectural marvel compared to it's peers. I don't think anyone is making that claim. it's just a good processor, especially for the era. it has weaknesses like any other processor.
  • flohofwoe 3y ago
    The Z80 takes 4 clock cycles for an instruction fetch (or simple instruction) and 3 clock cycles for a memory access (if no wait states are triggered), while the 6502 does a memory access in each clock cycle and a simple instruction in 2 clock cycles (in the end it's always been about memory speed). The Z80 may have been more convenient to work with because of the bigger instruction set and register bank, but a 2 MHz 6502 should easily be able to keep up with a 4 MHz Z80. The ingenous thing about the 6502 was its simplicity. It had around 3500 transistors compared to 8500 transistors of the Z80, essentially "small and elegant" vs "big and brute force". Disclaimer: I grew up on the Z80, but credit where credit is due ;)
    • deaddodo 3y ago
      > The 6502 was great for it's economy and simplicity. But it wasn't some architectural marvel compared to it's peers.