386/ix Applications Platform - CHEAP!

[Dick Dunn]

ron at ron.rutgers.edu (Ron Natalie) writes:
> Nearly all the System V's for the 386 are Interactive Systems' port
> anyway.  It's just repackaged in various ways for end user sales.

True to a first approximation...each seller (including Interactive) will
add some features, but right about the base of the system.

> It runs DOS applications pretty well under the UNIX (it's really
> the 80386 that makes this easy, not the UNIX).

This is not quite fair.  The 386 makes it possible, by providing an 8086
mode that can look like a real 8086 to a program, yet be protected and
caged in so it doesn't stomp on the rest of the universe.  The hardware
really provides a LOT of support for doing this.  HOWEVER, there's a lot of
software work involved in making things work with the UNIX world (so you
can share files, the screen, etc.)  That is, once you have the hardware
mechanism to box in the 8086 program, you have to supply the software to
reconnect the beast to reality.  Well-behaved programs are easy, but there
are various DOS program which are quite popular but quite ill-behaved--
they go around rewriting interrupt vectors, writing directly to device
registers, etc....all the things you'd never even contemplate in the UNIX
world.  They have to run, and that presents some hard problems--particu-
larly hard if you want them to run efficiently, since you can't just
emulate everything.

There's more than one 8086 DOS under UNIX gadget.  VP/ix is the one
Interactive and Phoenix (see next) did; it also shows up in some other
vendors' systems under other names.

>...They've adapted the Phoenix BIOS.

Por supuesto...but because Phoenix and Interactive were partners in the
development of VP/ix, this kind of begs the question.  (Would Phoenix use
somebody else's BIOS?)

Disclaimer:  I speak for myself, etc...but I work for Interactive, so I
might know what I'm talking about here.
-- 
Dick Dunn      UUCP: {ncar,nbires}!ico!rcd           (303)449-2870
   ...Just say no to mindless dogma.