Xref: utzoo comp.unix.questions:11479 comp.os.vms:11644
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!uhura.cc.rochester.edu!ur-valhalla!micropen!dave
From: dave@micropen (David F. Carlson)
Newsgroups: comp.unix.questions,comp.os.vms
Subject: Re: Portable OS's (was: Re: Do OS's slow down with age?)
Summary: MS-DOG VM
Message-ID: <645@micropen>
Date: 3 Feb 89 15:19:18 GMT
References: <209@imspw6.UUCP> <12872@steinmetz.ge.com> <370@siswat.UUCP> <978@riddle.UUCP>
Organization: Micropen Dirent Writing Systems, Pittsford, NY
Lines: 33

In article <978@riddle.UUCP>, domo@riddle.UUCP (Dominic Dunlop) writes:
! 
! [Fulminations against ``MESS-DOS'', comments on limits to VMS portability
! deleted]
! 
! It's a good idea to remember that there is a solution to this problem: make
! every machine look the same by implementing an emulator for some
! hypothetical standard machine architecture on top of each one.  Then write
! your operating system and applications in the machine code of the standard
! machine.  Presto!  It runs for any architecture on which you've implemented
! the emulator.  
! It's particularly easy if your hypothetical machine is simple, regular
! -- and dumb. 
! 
! Dominic Dunlop

To wit, there are several products on the market now that take an MS-DOS binary
and "compile" it into another operating system binary on a non-Intel machine.
Most of the commercial products produce output for Motorola CPU's running 
UNIX(tm).  This, coupled with the Intel VM-8086 mode that allows almost-native
execution of DOS binaries under UNIX/386 (several products exist) and under
OS/2 (when Microsoft supports the 386) is making the MS-DOS/PC architecture
real machine into a commonly available, through whatever means, virtual machine.

Although I personally wouldn't mind seeing less of MS-DOS, it does have more
software written for it than any other machine (virtual or not) in history.

"May you live in interesting times" -- Chinese curse.
-- 
David F. Carlson, Micropen, Inc.
micropen!dave@ee.rochester.edu

"The faster I go, the behinder I get." --Lewis Carroll