Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!bfmny0!tneff
From: tneff@bfmny0.UU.NET (Tom Neff)
Newsgroups: comp.unix.i386
Subject: Re: Use a 386 unix as a home machine?
Message-ID: <15036@bfmny0.UU.NET>
Date: 27 Dec 89 20:12:20 GMT
References: <2910@infmx.UUCP> <207@comcon.UUCP>
Reply-To: tneff@bfmny0.UU.NET (Tom Neff)
Lines: 45

In article <207@comcon.UUCP> tim@comcon.UUCP (Tim Brown) writes:
>
>I would never buy unix specifically to run DOS.  You buy unix because it
>is better and use the capability to run DOS to get over the addiction.
>Bottom line, what could you need DOS for that unix can't do better
>anyway?   

If you write your own software and can afford all UNIX developer's kits,
this is theoretically correct.

However in the real world there are frequently DOS-hosted programs
which you must use for an important (if small) fraction of the time,
even though you want to overall convenience and flexibility of UNIX
for most of your work.

An example is a shop which develops embedded software for a variety of
different microprocessors and OS host environments, but does so on one
network of boxes.  Some of the vendor supplied compilers are hosted to
DOS, *period*.  Many of the others will run native under UNIX or
nearly-so with a special loader.  But the ability to shell transparently
down to DOS for a few cross compile and link phases is essential to the
smooth running of the shop.  This is where VP/ix shines.

>        Put a litle more diplomatically, If you *really* want to be
>ablt to run DOS, with no strings attached in so far as compatibility is
>concerned, run DOS. 

The adage is freshly demonstrated: diplomacy is the art of saying
nothing at length. :-)  VP/ix *does* run DOS.  It just runs it within
the "ghost PC" of a Virtual-386 task.  Raw CPU performance is not far
below what a native 86 mode 386 would see; DOS and I/O call overhead is
dictated by the care with which the Emulation Control Task (ECT) is
written.  Compatibility is limited by how much emulation the ECT wants
to do, and also by the subject program's "well behavior".

Finally, a 386 UNIX installation typically lets you allocate a bootable
DOS partition on your hard disk which can be accessed from VP/ix
as well as native-booted DOS.  So you can have the best of both worlds:
run DOS under UNIX for your mundane workday needs, but switch active
partitions and reboot under DOS on weekends when you'd rather be
playing Alien Space Zap. :-)

-- 
"Nature loves a vacuum.  Digital    \O@/    Tom Neff
  doesn't." -- DEC sales letter     /@O\    tneff@bfmny0.UU.NET