Unknows S-100 System
dkelvey at hotmail.com
Sat Sep 22 23:34:53 CDT 2007
> From: cclist at sydex.com> > On 22 Sep 2007 at 19:35, Barry Watzman wrote:> > > It would have been extremely difficult to have done that with a Z-80,> > it was trivial with an 8085 (using a Z-80 would probably have taken an> > additional almost 2 dozen ICs ... the external hardware and bus> > interfaces and signals were just totally different). Further, the> > performance of the 8085 was (ok, arguably) higher > > Was using an NSC800 ever discussed?>
I saw someone mention the NSC800. I don't think it was mentioned
that the NSC800 runs Z80 instructions but has the exact same
pins and interface as the 8085.
I don't recall if the NSC800 had the serial instructions of the 8085
but in this case, I don't think that is an issue.
It was true that the 8085 had just about as fast an execution
as the Z80, without the extra instructions of the Z80. This
was true for all but the tightest loops using some of the
special Z80 instructions. I recall when I was working at Intel,
we looked at many of the Z80 instructions and found them
to not be anything but code efficient with comparable speeds.
I have a couple NSC800s but not as separate packages. They
are in MA2000 modules.
The NSC800 also has the advanges of being CMOS. This means
lower power than either the 8085 or Z80.
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