Unix on a PC

Chris Lewis clewis at mnetor.UUCP
Wed Apr 24 00:10:56 AEST 1985


In article <179 at geowhiz.UUCP> lm at geowhiz.UUCP (Larry McVoy) writes:
>called PCIX.  I was wondering if anyone has used it, and if so, what 
>their reaction was.  Is it slow?  Is it robust?  Do you need an onsite 
>guru?  

I used PC/IX for several months.  PC/IX is pretty good considering
the hardware that it runs on (XT).  I was rather impressed (as were
many other local UNIX gurus) with it's performance.   It was
pretty darn good - the response time was quite good, however,
large jobs did take a little longer than you'd probably see on
a 680x0.  Even so, it probably won't perform particularly well with
more than one user.

The system was pretty solid as far as quality of implementation and
robustness goes, except for one problem.  It is running on the 8088
with absolutely *no* memory protection between tasks (and no
automatic stack growth either - you have to specify a stack size, the
default is usually large enough however).  I used to have a couple 
crashes per week that could best be attributed to not having memory 
protection.  Crashes occured considerably less often (possibly
not at all) on machines not being used for program development.
Everything else seemed to work properly and as advertised.

Another, less major, problem is the problem of addressibility.
I'm pretty sure that PC/IX only supported the small 8088 model.
This limited programs to 64k text and 64k data (I think).
Then again, people lived with non-split-space pdp11's quite
well....

As an alternate big-blue route, I would suggest an AT with
XENIX instead because it does have memory protection and you get
somewhat more CPU horsepower than you would with an XT.  Choice
between XT/PCIX and AT/XENIX is basically a price/performance
(and probably partially robustness) tradeoff.  I have no information 
on AT/XENIX reliability.  PCIX on the AT has no memory protection
either (because it is running totally in 8088 compatibility mode), however
it is faster than PCIX on an XT - I also heard rumors that indicate
that it may be faster than XENIX on the AT.

UNIX gurus?  Well, depends upon what you want to do with it.  We
had several being totally run by non-UNIX-familiar people.  Count
upon a few calls to someone who knows UNIX reasonably well per 
month per system (particularly for software installs etc.).  
I don't think you need UNIX hackers tho.

Hard disk backup on floppies is a real pain.  Get a streamer if you can.

I'd still prefer a 680x0 system if I could afford it.
-- 
Chris Lewis, Computer X (CANADA) Ltd.
UUCP: {allegra, linus, ihnp4}!utzoo!mnetor!clewis
BELL: (416)-475-1300 ext. 321



More information about the Comp.unix mailing list