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Mail Archives: djgpp/1999/09/01/15:22:43

Date: Wed, 1 Sep 1999 13:17:20 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Eric Rudd <rudd AT cyberoptics DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: Nearptr putpixel method?
In-Reply-To: <37CC1600.E9ABA4A0@cyberoptics.com>
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On Tue, 31 Aug 1999, Eric Rudd wrote:

> If one is using a linear frame buffer (usually located high in 32-bit memory
> space), one other option is to write a modified __djgpp_nearptr_enable() that
> opens the segment limit just wide enough to include the video card address.
> This at least prevents a stray pointer from wrapping and accessing DOS memory.
> Thus, a buggy program may crash, but at least it's unlikely to bring down DOS.
> I have been using this technique for several years now (both under DOS and
> under Win95), and have yet to have a problem with it.

Care to post some minimal code that demonstrates this?  It could be a
valuable addition to the FAQ.

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