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From: jallen@netxcom.UUCP (John Allen)
Newsgroups: comp.sys.ibm.pc,comp.arch,comp.unix.wizards
Subject: Re: 386 demand paged virtual memory
Message-ID: <368@netxcom.UUCP>
Date: Fri, 4-Sep-87 23:18:15 EDT
Article-I.D.: netxcom.368
Posted: Fri Sep  4 23:18:15 1987
Date-Received: Sat, 5-Sep-87 23:27:01 EDT
References: <125@snark.UUCP> <299@nuchat.UUCP> <358@netxcom.UUCP> <268@etn-rad.UUCP>
Reply-To: jallen@netxcom.UUCP (John Allen)
Lines: 20
Xref: mnetor comp.sys.ibm.pc:7495 comp.arch:2095 comp.unix.wizards:4098

In article <268@etn-rad.UUCP> jru@etn-rad.UUCP (0000-John Unekis) writes:
>When they say that the 80386 "supports demand paged virtual memory", what 
>they mean is that since your operating system will have to manage tasks
>as a group of segments in memory anyway, why not make the segments a small
>fixed size and call them pages instead. Your operating system will still
>be doing all the work, but using segments to represent virtual pages 
>makes it look like intel had a reason for preserving segmentation beyond
>continued compatibility with the 8086.

This is incorrect and misleading.  A segment and a page a two very different
things.  The 386 will allow any number of pages within a segment which can
be up to 4 Gigabytes in length.  The paging mechanism is not dependent upon
the segmented architecture.

John Allen
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