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From: jlowrey@skat.usc.edu (John 'Fritz' Lowrey)
Newsgroups: comp.os.msdos.programmer
Subject: Overlay usage...
Message-ID: <31248@usc>
Date: 21 Mar 91 09:42:31 GMT
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Originator: jlowrey@skat.usc.edu


	I am an experienced DOS programmer using C and PASCAL to 
create applications for myself and my office mates.  Recently I have
been porting a very large program from UNIX to the PC AT, this program
when compiled with MSC 6.0 (max optimizations + exepack) is still very
large and I would like to utilize overlays to reduce memory consumption
for lesser used modules.
	The theory behind overlays and their implementation using the 
linker is not difficult.  What I would like to know is:

	1:  Once the overlay module is no longer needed, is the memory
		allocated to it freed to the data segment?

	2:  In a related question, I assume procedures from one overlay
		module may call those in anther (which seems fairly 
		inefficient, but logical), how is the memory for these
		overlay functions dealt with?

Any clarifying responces would be appreciated.

					Fritz (jlowrey@skat.usc.edu)