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From:	CBFalconer <cbfalconer AT yahoo DOT com>
Organization:	Ched Research
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Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: memory image
References:	<Pine DOT SUN DOT 3 DOT 91 DOT 1020228192554 DOT 7029C-100000 AT is> <002101c1c092$4b43fe70$770510ac AT inf DOT umcc DOT cu>
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Date:	Fri, 01 Mar 2002 01:18:16 GMT
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To:	djgpp AT delorie DOT com
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Jade wrote:
> 
> As u know EXE files include some header info like the stack size,
> PSP etc. They are not memory image.
> COM executables does not include this info at the header so they
> are usefull for doing things like boot loaders. That's why I need
> to compile a COM file. I need to make a boot loader for a sample
> system I'm writting.

Com files start executing with CS=DS=ES=SS at 0100h.  They are 16
bit systems only, and own the complete DOS memory arena at start
up.  The stack is set to point to the top of the 64k segment. 
They can't be made with the DJGPP system - you need to use an
assembler or older compilers set for the 'tiny' model.  The exe is
then converted with exe2bin, which comes with your DOS system (or
maybe used to come).


-- 
Chuck F (cbfalconer AT yahoo DOT com) (cbfalconer AT XXXXworldnet DOT att DOT net)
   Available for consulting/temporary embedded and systems.
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