Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.i386
Subject: Re: Binary Compatibility
Message-ID: <1989Dec16.055834.3043@virtech.uucp>
Date: 16 Dec 89 05:58:34 GMT
References: <338@denwa.uucp>
Organization: Virtual Technologies Inc.
Lines: 53

In article <338@denwa.uucp>, jimmy@denwa.info.com (Jim Gottlieb) writes:
> and because it seems that more software and hardware specifically lists
> SCO as a system that it runs on (though often it says "SCO Xenix").

Since release 3.2 of unix (Interactive 2.0.2) for the 386, the capability to 
run xenix software has existed.  In fact, since I sometimes have to develope
software that links with xenix libraries, I have copied my xenix file system
to a file system on my interactive system and just do a chroot() to run
in a xenix environment (xenix compiler, libraries, system programs, etc).

I have not yet found a piece of application software that will run under
xenix that will not run under Unix.  

> What I wonder is:  Are they that different that software must be
> separately compiled for SCO, ISC, AT&T, ESIX...?  If so, this strikes me
> as awfully stupid.  How can we ever hope to persuade most of the major
> software companies to support Unix under this scenario.  Does this mean
> that I can't use SCO's software (or software written for SCO Unix)
> under 386/ix?  I guess if it is written for "Xenix" I can use it under
> SVR2's Xenix compatibility.

As long as the software does not use any special system calls that are not
present under UNIX (but are under xenix) the same binary software can
be used on all of the listed systems.  There are only a few little used 
xenix system calls that do not appear in Unix and a smart product manager
should ensure that these system calls are t used.

> One last question is, for products like Wordperfect, what are the
> advantages (if any) of buying the native Unix version versus buying the
> MS-DOS version and running it under vp/ix or Merge?

There are three major considerations:

	1. since dos is single user, most products for dos do not have
	any real support for multi user systems (for example, there may be
	no way to share documents, but limit different access (i.e only you
	can update the doc but others could read it)).

	2. vpix is a cpu hog.  Running 4 or 5 simultaneous vpix sessions 
	can really eat up the cpu and kill performance.

	3. Since the product was developed for dos, it's user interface under
	unix may not be as nice or user friendly. 

If the interface under unix is acceptable, I would recommend getting the unix
version of the software.  You should be able to support more users on the
same machine and get better performance.

-- 
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| Conor P. Cahill     uunet!virtech!cpcahil      	703-430-9247	!
| Virtual Technologies Inc.,    P. O. Box 876,   Sterling, VA 22170     |
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