Article View: comp.os.msdos.programmer
Article #1554Re: 286 Protected mode
From: Bob Pendleton
Date: Fri, 06 Jul 1990 20:06
Date: Fri, 06 Jul 1990 20:06
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1405 bytes
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.
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Path: arc1-ca.pugleaf.net!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