Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!spool2.mu.edu!uunet!bria!mike
From: mike@bria
Newsgroups: comp.unix.msdos
Subject: Re: VPIX compatability questions
Message-ID: <399@bria>
Date: 27 Jan 91 19:51:47 GMT
References: <6025@spdcc.SPDCC.COM> <1991Jan17.041520.24159@tmsoft.uucp> <2546@westmark.WESTMARK.COM> <392@bria> <868@csource.oz.au>
Reply-To: uunet!bria!mike (Michael Stefanik)
Organization: Briareus Corporation, Los Angeles, CA
Lines: 35

In article <868@csource.oz.au> csource.oz.au!david (david nugent) writes:
|| Yes, and it depends on what context.  If you're a DOS program and you
|| want to determine if you're in a VP/ix environment, just have that
|| program try to create a temporary file on the C: disk.  Since VP/ix
|| requires that pseudo-disk to be read-only (if you're going to boot from
|| it) then the create will succeed under real DOS, and fail under VP/ix.
|
|No, there is no such requirement.  Certainly the C: drive I run VP/ix
|from is not read only.

That is true, if only one vpix process is "booted" from that pseudo-drive.
Multiple sessions under VP/ix preclude write access except for the *first*
session.  Essentially, what you're pointing out *is* correct ... It's not
a terrbily good solution.

However, another solution would be to look for "strange" filenames
that you would expect to find under VP/ix, but not DOS (such as something
like Z:\ETC\ENVIR~~A or whatever) since VP/ix collapses long filenames
using some arcane method that I'm not bothering to lookup at this
moment.

Disclamer: What's arcane for me may be perfectly normal for you.

|I'm sure there must be a simple way of doing this.  Some of the DOS
|programs supplied with VP/ix use a number of pseudo I/O ports to
|communicate with vpix itself, such as "rundos" and "rununix".
|Obviously there isn't a documented way though.

True 'nuff.
-- 
Michael Stefanik, Systems Engineer (JOAT), Briareus Corporation
UUCP: ...!uunet!bria!mike
--
technoignorami (tek'no-ig'no-ram`i) a group of individuals that are constantly
found to be saying things like "Well, it works on my DOS machine ..."