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From: GUBBINS@radc-tops20.ARPA (Gern)
Newsgroups: net.micro
Subject: Re: AT vs Z-100 - a myth
Message-ID: <11148@brl-tgr.ARPA>
Date: Thu, 30-May-85 09:48:47 EDT
Article-I.D.: brl-tgr.11148
Posted: Thu May 30 09:48:47 1985
Date-Received: Sat, 1-Jun-85 10:45:41 EDT
Sender: news@brl-tgr.ARPA
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The Z-100 and 8088/8086 machines will not suffer as you stated from 
150nsec memory needing wait states.   An 8088/8086 can run, in complete
spec, with room to spare, at 8MHz with 150Nsec memory (its not bizzare,
its a feature).   By design, Intel has 'relaxed' r/w strobing which make
this possible.   I do not think the same is true of the 80286.
A 5MHz 8088/8086 can run at 5MHz with no wait states needed.  Anyway, its
all in the spec books.

This fact allows a Z-100 (normally, until recently, a stock 5MHz machine,
now an 8MHz machine from ZDS) to be turboed to 7.5MHz with 200nsec memory
and remain totally in spec (do note that the Z-100 inserts 1 I/O wait state
which keeps the CRTC happy and continues to keep the other I/O happy).


The AT at 6MHz looses (according to accepted numbers) about 20-30% of
its speed due to the 1 memory wait state.  I now refer you to the
benchmark results posted by another person who ran the same machine
code on both machines.

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