Differences in the Z80 processors?

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sun Jul 27 14:35:21 2003

> I have seen z80, z80a, and z80b processors, and I'm curious about what the
> differences are between the different versions of the processor? Is each
> newer version faster than the earlier model, like a 486-33/66/100 or are the

The only difference berween those processors is the maximum clacok
frequency you can use :

Z80 : 2.5MHz
Z80A : 4MHz
Z80B : 6MHz
Z80H : 8MHz

There are, AFAIK, no extra instructions in any of the versions.

> Also, can I use a Z80a or Z80b in place of the original Z80 if I want to
> replace a bad CPU?

That should work fine

-tony
Received on Sun Jul 27 2003 - 14:35:21 BST