[comp.sys.zenith.z100] Follow-up to Z-100 tinkering

koziarzw@LONEX.RADC.AF.MIL (Walter Koziarz) (07/19/89)

Well, continued tampering with PC-DOS 3.2 (attempts to 'graft' its 
[equivalent] MSDOS.SYS and COMMAND.COM to Z-100 IO.SYS) have lead me to 
conclude that this is possible; but in the realm of:  "Why bother????".

I saw no tangible benefit other than satisfying curiosity as to the
'machine-independence' of MSDOS.SYS and COMMAND.COM.  Most commands DID work
and the system booted, ran WatchWord and other Z-100-specific applications.

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.

More to follow as I proceed.

Walt K.

krvw@sei.cmu.edu (Kenneth Van Wyk) (07/19/89)

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>