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From: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Newsgroups: comp.sys.ibm.pc,comp.unix.questions
Subject: proprietary OSs
Message-ID: <5254@bsu-cs.UUCP>
Date: 20 Dec 88 15:44:47 GMT
References: <205@imspw6.UUCP> <4330119@hpindda.HP.COM>
Reply-To: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Followup-To: comp.unix.questions
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 57

(Moving this from comp.sys.ibm.pc to comp.unix.questions.)

In article <4330119@hpindda.HP.COM> hardin@hpindda.HP.COM (John Hardin) writes:
>While I agree with your prediction of
>the role of Unix in the next few years, I can also see why there continue
>to be propietary OSs.  One reason is the inefficiencies of Unix.  I am no
>Unix kernel expert, so I don't pretend to know why, but I have seen that
>a propietary OS can support many more time-sharing users than Unix when
>both are run on the same hardware.

Counterarguments are possible.  For example:

o    Proprietary OSs often support more users than UNIX by restricting
     what these users can do.  For example, they may not allow job
     control (only one active job) or make it inconvenient;  they may
     not allow pipes (got to go via disk files, slowing things down,
     so it seems like more people are doing work but each person
     is getting less done);  they may not have many of the UNIX
     utilities like mail, wc, grep, awk, etc., so you just don't
     do those things at all

o    Proprietary OSs probably don't have Usenet software, which
     may mean a lighter load on the machine.  So you read news from
     your home machine, and post an article saying that the proprietary
     OS at work is more efficient :-)

o    Proprietary OSs may require a special terminal with
     local intelligence (e.g., IBM) thus offloading much work to a
     $2,000 terminal, rather than letting you use a $500 terminal for
     the same purpose.   Thus, to support 100 active users, you might
     need an additional investment of $2000 * 100 = $200,000 (in
     addition to the cost of the central machine).  The proprietary OS
     may appear more efficient if you only looked at the cost of the
     central machine and forgot about coaxial cables, front-ends,
     terminal multiplexors, intelligent terminals, and other
     paraphernalia that the proprietary OS may *require* rather than
     just *allow*

o    UNIX is less efficient than many proprietary OSs because it is
     written mostly in C.  An individual vendor is welcome to rewrite
     more of the kernel and utilities in his own proprietary
     machine-dependent language and speed up UNIX, or a proprietary
     UNIX clone in such a machine-dependent language, without
     sacrificing compatibility with UNIX applications

o    It is possible to have a proprietary OS emulate most of the
     UNIX system calls, allowing both efficiency and portability

o    Hardware is cheap enough that the additional hardware cost to make a
     UNIX-based system as efficient as one with a proprietary OS is
     probably smaller than the additional cost in software and
     inconvenience of using a proprietary OS

By the way, UNIX itself is a proprietary OS.  Perhaps we should be talking
about "portable" and "unportable" operating systems. 
-- 
Rahul Dhesi         UUCP:  <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi