From:	Nate Eldredge <neldredge AT hmc DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Fastest bitblt?
Date:	28 Feb 2000 14:00:58 -0800
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Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> writes:

> On Mon, 28 Feb 2000, Damian Yerrick wrote:
> 
> > Protected mode only provides a mechanism for memory protection; it
> > doesn't require that operating systems provide such protection.
> 
> Not true.  Memory protection is built into protected mode, at least to 
> some degree.  Access rights checking and segment-level protection are 
> always active, as they are inherent to PM.  Page-level protection is 
> optional.

True.  But actually having protection requires also that something set
what is to be protected.  I.e. you can set the segment limit to
0xffffffff.  Limit checking is still active, but I wouldn't consider
the resulting state to be "protection".

-- 

Nate Eldredge
neldredge AT hmc DOT edu

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