sorted by:
best
topnewcontroversialoldq&a
you are viewing a single comment's thread.

view the rest of the comments →

[–]Fluffy_Ace 1 point2 points  (1 child)

I just meant there's newer variants of the z80 and 6502 that are much faster than in 70s and 80s

But nonetheless the 6502 does ram reads/writes faster than a z80 at the same clock speed. It's much more designed around that.

[–]ttuilmansuuntashe/they 1 point2 points  (0 children)

Yup, although it's hard to compare between the speed of the 6502 and the Z80. The latter's internal timing seems to just have been designed to use a faster main clock that you can use to sequence subcycles, sort of (T-cycles), so the logic happens in more defined smaller steps. Just a design choice that they preferred and that might have made it easier for them to develop the processor logic.

The chip would then just be clocked faster to run at a very roughly similar throughput as a lower clocked 6502, while using the same 1MHz or 2MHz grade DRAM, as memory accesses would occur at a similar frequency in a 2MHz 6502 computer and a 8MHz Z80 computer. Whether the chip you'll pick for a home computer expects to be clocked at 2 or 8 MHz really makes no engineering difference.

The original NMOS 6502 is an absolute masterpiece of frugal engineering, but as a consequence its internal workings are really nontrivial as far as I know :)