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Mail Archives: djgpp/1996/05/06/13:46:55

From: kagel AT quasar DOT bloomberg DOT com
Date: Mon, 6 May 1996 13:34:35 -0400
Message-Id: <9605061734.AA01848@quasar.bloomberg.com >
To: MOLESWORTH DOT THOMAS AT bryanston DOT co DOT uk
Cc: djgpp AT delorie DOT com
In-Reply-To: <000000137472914242915@bryanston.co.uk> (message from Bryanston School on Mon, 06 May 1996 16:55:15 +0100)
Subject: Re: Pointer Arithmetic + physical address mapping
Reply-To: kagel AT dg1 DOT bloomberg DOT com

   From: Bryanston School <MOLESWORTH DOT THOMAS AT bryanston DOT co DOT uk>
   Date: Mon, 06 May 1996 16:55:15 +0100

   Does pointer arithmetic only work with ints in DJGPP? I tried using
   pointer arithmetic on unsigned ints and longs, and my program gave
   a whole list of runtime errors; when I called a subroutine with a pointer
   to a variable, it could not access the correct area of memory (the actual
   pointer passed to the function was wrong; the value printed in the main
   procedure and the function were different)


This all should work.  Submit some code snippets and someone will comment.


   Also, is it possible to map an area of physical memory (a reserved area of
   extended memory at about 1.25 Mb, 1 Mb in size) to a logical address in
   DJGPP v1? I found some code which adds 0xE0000000 to the address, is this
   right and if so how does it work? The docs say that the 0xE0000000 address
   is simply a copy of the first 1 Mb.

See a previous posting in the last few days.

-- 
Art S. Kagel, kagel AT quasar DOT bloomberg DOT com

A proverb is no proverb to you 'till life has illustrated it.  -- John Keats

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