Portable OS's (was: Re: Do OS's slow down with age?)

[David F. Carlson]

In article <978 at riddle.UUCP>, domo at 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 at ee.rochester.edu

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