Subject: Differences in the Z80 processors?

From: "Ernest" <[email-masked]>
Date: Sat Jul 26 19:29:23 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
differences more along the lines of additional commands (or something like
that?) Or a combination of both?

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

Thanks.

E.

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From: [email-masked] (Tony Duell)
Date: Sun Jul 27 14:35:21 2003

> 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

That should work fine

-tony