Date: Thu, 19 Feb 1998 20:24:09 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Anthony DOT Appleyard AT umist DOT ac DOT uk
cc: djgpp AT delorie DOT com
Subject: Re: overlaying
In-Reply-To: <1573BE346B2@fs2.mt.umist.ac.uk>
Message-ID: <Pine.SUN.3.91.980219202053.13131A-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk


On Thu, 19 Feb 1998, Anthony.Appleyard wrote:

> > ABC.CC reserves(_go32_dpmi_allocate_dos_memory() etc) some conventional
> > memory, whose address it sends to XYZ.CC as hex chars as a call argument,
> > and XYZ.CC can leave information in that area for ABC.CC to read.
>   but I was told "no, ABC's conv mem is swopped out while XYZ.CC is running".

Whoever told you that was dead wrong.  If ABC.CC allocates DOS memory, it
stays allocated until ABC.CC exits.  DOS memory is almost *never* swapped
out (because DOS lives there too, and you cannot swap DOS).  Even if it
*is* swapped out, it will be swapped in when you try to access it. 

Actually, DJGPP uses this technique all the time to pass long command 
lines to child programs.  So you can safely use it as well.