From: sje@xylos.ma30.bull.com (Steven J. Edwards)
Subject: A review of the 1992.08 _Byte_ Coherent 4.0 review
Reply-To: sje@xylos.ma30.bull.com
Organization: Bull HN, Worldwide Information Systems, Billerica, Mass., USA
Distribution: comp
Date: 22 Jul 92 15:46:06

The 1992.08 issue of _Byte_ magazine has a "First Impressions" review
of Coherent 4.0 by regular contributor Ben Smith.  The article is
found on pages 37 and 38 and is based on Smith's evaluation of a beta
copy of the just released version of the operating system.

I suspect that the "First Impressions" items are reviews of those
products where there is just not enough lead time to produce a
comprehensive and fully accurate evaluation.  It's certainly
challenging to produce a proper review in the first place, let alone
with the multi-month publishing lag time.  Even so, I was surprised at
the number of minor inaccuracies Smith had in the two page piece; he
is usually more careful in his writing.  Therefore, I have decided to
post this little note about some of the article's disreprencies.

The first problem is a misleading generalization concerning the phrase
"looks and acts like Unix" and also later comparisons of Coherent with
various Unix and Unix-like implementations.  Although some of these
are favorable to Coherent, particularly those concerning price, Smith
is a bit lax when defining what he exactly means by "Unix".  There are
so many implementations of Unix and Unix-like operating systems that
an undifferentiated reference to "Unix" is so broad to be nearly
meaningless.  Indeed, in the third paragraph the author strongly
inplies that Coherent is just one of any number of "other Unix
systems" that support Common Object File Format.

A second problem is a lack of precision when delineating the
differences in the supplied development utilities between Coherent 3.x
and the 4.0 version.  A reader could easily conclude that nroff, ms,
tar, and cpio (among many other utilities mentioned) are not included
in the 3.x version.  Also, it is later implied that 3.x would run only
on 286 systems.  I think that these minor faults may be due to a lack
of experience with 3.x; perhaps there was some confusion in the
author's reading of the 4.0 release notes.  This also would have been
a good place to mention the MWC device driver kits.

Thirdly, the author states that Coherent 4.0 has demand paging and
virtual memory.  I am sure that this comes as a big surprise to the
MWC development crew.

A fourth area of concern is the unrepresentative benchmark comments.
Smith writes, assumingly accurately, that the Dhrystone benchmark
(tight loop iterative integer arithmetic) runs faster on both DOS and
SCO Unix than it did with Coherent.  This is the only benchmark that
the author mentions.  Why?  Having developed software with Unix for
about fifteen years, I can tell you that such a becnhmark is nearly
meaningless because the real test of Unix development is the edit,
compilation, link, execute, and crash cycle; this needs a fast
character editor with good memory management support, a compiler that
spends more time compiling then shuffling files, and a linker that
doesn't take all day long to put together a 200 Kbyte program.  All of
these tasks require good file and disk management at either the driver
or kernel level.  It is for large tasks like these that a development
system is measured.

A fifth, and minor problem is the typo about Coherent's "100 page
manual".  I guess that either the printer dropped a zero or that Smith
got his manual printed on newspaper size pages.

Overall, the author gives a reasonable description and a conditional
recommendation of Coherent 4.0.  Let's hope that there is a full
follow-up review in an upcoming issue.

 [The above opinions expressed are my own; not necessarily held by others.]
      == Steven J. Edwards           Bull HN Information Systems Inc. ==
      == (508) 294-3484              300 Concord Road         MS 820A ==
      == sje@xylos.ma30.bull.com     Billerica, MA 01821          USA ==
"That Government which Governs the Least, Governs Best." -- Thomas Jefferson