From: Andrew Crabtree <andrewc AT typhoon DOT rose DOT hp DOT com>
Message-Id: <199706261619.AA233631987@typhoon.rose.hp.com>
Subject: Re: NEAR POINTERS
To: markoliv AT mercury DOT kosone DOT com (Mark Oliver)
Date: Thu, 26 Jun 1997 9:19:46 PDT
Cc: djgpp AT delorie DOT com
In-Reply-To: <01bc7f5e$2cc9b040$aa28bace@client.kosone.com>; from "Mark Oliver" at Jun 22, 97 10:43 pm
Precedence: bulk

> 
> Ok, quick question...I use __djgpp_nearpt_enable() so i  can write directly
> to video memory (it is so much faster than using memput or the poke
> functions). Anyway, i was wondering, what exactly this function does.
It sets the limit of your DS selector to -1 (0xFFFFFFFF).

>  Does
> it disable protected mode completely. 
It effectively does, since your limit is now 4 GB, and memory will wrap. 
This means that through DS you have access to the entire memory on the 
system.

Note that NT and Linux will not allow you to do this.

Andrew