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#2305

From: peter
Date: Wed, 19 Sep 1990 15:01

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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                |

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Date: 19 Sep 90 15:01:14 GMT
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