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From: gdmr@cstvax.UUCP (George D M Ross)
Newsgroups: net.arch
Subject: Re: Page size and the meaning of life
Message-ID: <7@cstvax.UUCP>
Date: Tue, 29-Oct-85 04:53:47 EST
Article-I.D.: cstvax.7
Posted: Tue Oct 29 04:53:47 1985
Date-Received: Sun, 3-Nov-85 07:25:58 EST
References: <926@decwrl.UUCP> <931@lll-crg.ARpA> <7459@watdaisy.UUCP> <939@lll-crg.ARpA> <406@unc.unc.UUCP>
Reply-To: gdmr@cstvax.UUCP (George D M Ross)
Organization: Comp. Sc., Edinburgh Univ., Scotland
Lines: 14

If the operating system allows you to modify page protection, catch access
violations and define the VM-to-disc mapping on a per-page basis, all from
a user program, then it is possible to do quite a nifty implementation of
differential files (and such-like things).  You need a reasonable page size
do make it work sensibly; a {base, limit}-type segment is pretty useless
from this point of view.

(VMS will let you do all the necessary, BTW.)

-- 
George D M Ross, Dept. of Computer Science, Univ. of Edinburgh
Phone: +44 31-667 1081 x2730
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