Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!pt.cs.cmu.edu!sei!krvw
From: krvw@sei.cmu.edu (Kenneth Van Wyk)
Newsgroups: comp.sys.zenith.z100
Subject: Re: Follow-up to Z-100 tinkering
Message-ID: <3657@fy.sei.cmu.edu>
Date: 19 Jul 89 12:59:21 GMT
References: <8907191150.AA16732@lonex1.radc.af.mil>
Organization: Carnegie-Mellon University (Software Engineering Institute), Pgh, PA
Lines: 24
In-reply-to: koziarzw@LONEX.RADC.AF.MIL's message of 19 Jul 89 11:50:07 GMT


In article Follow-up to Z-100 tinkering of 19 Jul 89 11:50:07 GMT koziarzw@LONEX.RADC.AF.MIL (Walter Koziarz) writes:

>The 10MHz clock-rate tinker seems (from my fractal-image oriented perspective)
>to be much more worth pursuing.  The only real question I am still uncertain
>of with regard to 10MHz is whether the PALs on the 8087 board can keep-up.

Another serious consideration here is the 8087 itself, which is
particularly prone to heat (hence speed) related problems.  When I
increased the speed on my 100 from 5 to 8 Mhz, I found that the
machine would lock up at odd times, unpredictably.  I put in an 8088-2
(8 Mhz model) and that improved the situation slightly, then I put in
an 8087-2 (when the prices were ~$100) and voila - no more lockups,
ever.  The PALs, while probably not rated for 8 Mhz operation, had no
problem whatsoever.  My H-100 continues to run at 8 Mhz with 100%
reliability (knock on wood...).

Ken

Kenneth R. van Wyk
Technical Coordinator, Computer Emergency Response Team
Software Engineering Institute
Carnegie Mellon University
Internet: <krvw@SEI.CMU.EDU>