Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!diemen!ecc.tased.oz!peter
From: peter@ecc.tased.oz
Newsgroups: comp.os.msdos.programmer
Subject: DIR/ALL
Message-ID: <1990Sep19.151115.206@ecc.tased.oz>
Date: 19 Sep 90 15:01:14 GMT
Lines: 17

Can anyone describe neatly and succintly how 286 and 386 addressing works?

I understand that the 86 uses the low 20 bits of ((16 bit CS)*4 + (16 bit IP))
which specifies a physical memory address, but how do the others do it?

does a 286 use the low 24 bits of ((20 bit CS)*4 + (16 bit IP)), or what?
does this indicate a physical memory loction, or some kind of selector?

what does a 386 use, and therefore, what is its total virtual/physical address
space?

is addressing the only benefit of protected mode?
-- 
Peter Mayne (Systems Object)               Peter@ECC.TasEd.Oz.Au
Elizabeth Computer Centre                +-----------------------------
Link Rd, Claremont                       |VAXen don't use segments.
Tasmania, 7011, Australia                |