Unix for a PC Compatible

[Jim Paradis]

In article <455 at sdiris1.UUCP> jjc at sdiris1.UUCP (Jim Carter) writes:
>[ description of Wendin's claims for "pcnx" ]

I'm posting my reply to the net because I think there are a lot of
people who are thinking of the same thing Jim Carter is...

You must be thinking of PCUNIX from Wendin (maybe they changed the name
to PCNX after being pressured from AT&T, I don't know...).  When I first
looked at it, it seemed too good to be true too... UNIX with source for
$99.  They also sell two other products: PCVMS (a VMS-like OS of all things
for the PC!!) and the Operating System Toolbox, which supposedly lets you
design your own multitasking PC kernels.  

Anyhow, when I called them up, they said that the source that comes with
PCNX is for the utilities only.  If I wanted kernel source, I'd have to
buy the Operating System Toolbox, which is another $99.  Well, I thought
to myself that an implementation of UNIX with source for $198 still couldn't
be all bad, so I sprung for it.

Big mistake.

First of all, PCNX runs ON TOP OF PC-DOS!  In fact, PCNX does not have
its own filesystem... it uses DOS as a filesystem.  Although this eliminates
the problem with transferring files between DOS and PCNX, it also means that
all of the restrictions of the DOS filesystem remain (i.e. filenames no longer
than 8 chars, required extensions, no links, limited protections...).

Second, it has a VMS-style kernel.  Turns out that Wendin's first OS products 
were PC/VMS and the Operating System Toolbox (OST).  Wendin's approach to doing
"kernels" for other OS's is to take the PC/VMS kernel and graft a user inter-
face on top of it.  What that essentially means is that PCNX is a VMS-like
kernel with a Bourne-shell-like CLI and a bunch of Unix-like utilities to go
with it.  So it's more like Eunice than UNIX.  The system calls are all
VMS system calls... to implement real UNIX-like facilities on top of these
system calls would require a LOT of twisting and contorting... with a
corresponding performance penalty.  Seeing as I was trying to run it on a
chop-suey XT clone, I needed ALL the compute power I could get.  I couldn't
afford to waste valuable compute cycles doing the translation back&forth
between UNIX and quasi-VMS (running on top of DOS, no less).

Third, the documentation is horrible.  The documentation for PCNX is a
couple hundred pages in a binder, and it mostly deals with command syntax
and system calls.  It contains a step-by-step installation procedure that
tries to be stupid-user-proof, but after doing the basic installation it
leaves you high and dry.  The console login refused to recognize anyone
other than root, for instance, even when I added entries for other users
to the password file.  Nothing in the documentation on how to handle this.

A number of utilities would hang the system if used.

Although it claims to be able to run well-behaved DOS software, I found
this capability lacking.  My Microsoft C compiler (version 4.0) wouldn't
run with it, for instance (their exec wouldn't pass arguments to subsequent 
passes).  PC/VI wouldn't work with it, since the console driver is strictly
a dumb-terminal... no ANSI.SYS here!  Needless to say, this kind of limited
its usefulness as a development environment!

Anyhow, my copies of PCNX (nee PCUNIX) and OST are gathering dust on my 
bookshelf now... if anyone still really wants them, I'd be glad to sell 
the both of them for real cheap (make an offer... anything over the cost 
of shipping will be gladly considered).  Right now I'm waiting for my copy of 
Tannenbaum's MINIX to come in... (note that MINIX is only $115, and comes
from a real UNIX person... certainly a better value than $198 for a
useless hack!)

   +----------------+  Jim Paradis             | Disclaimer: All opinions are
+--+-------------+  |  Encore Computer Corp.   | completely my own.  Encore
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|  +-------------+--+  Marlboro MA 01752       | opinions on most of these
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