Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!helios.ee.lbl.gov!hellgate.utah.edu!uplherc!esunix!bambam!bpendlet
From: bpendlet@bambam.UUCP (Bob Pendleton)
Newsgroups: comp.os.msdos.programmer
Subject: Re: 286 Protected mode
Message-ID: <1737@bambam.UUCP>
Date: 6 Jul 90 20:06:16 GMT
References: <15154@reed.UUCP>
Organization: Evans & Sutherland Computer Corp., Salt Lake City, Utah
Lines: 24
X-Local-Date: 6 Jul 90 13:06:16 PDT

From article <15154@reed.UUCP>, by minar@reed.bitnet (Nelson Minar,(???)):

> What exactly is 286 protected mode? ...

> I also understand that MS-DOS doesn't function in protected mode. Does the
> BIOS? Are there MS-DOS like OSs that will work in protected mode?

Ray Duncan has a new book out entitled "Extending DOS." Pick up a
copy.  It gives a good overview of the answers to all you questions
and points you at sources for more detailled answers. 

But the basic answer is that in protected mode a segement value is
actually a pointer into a table of 24 bit pointers. (Grossly over
simplified!) And there are things called DOS extenders that let you
program in protected mode and still use DOS. 

Read the book. It's a good place to start.

			Bob P.
-- 
              Bob Pendleton, speaking only for myself.
UUCP Address:  decwrl!esunix!bpendlet or utah-cs!esunix!bpendlet

                      X: Tools, not rules.