From:	"Charles Sandmann" <sandmann AT clio DOT rice DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Memory amount and PMODE
Date:	Sun, 8 Oct 2000 11:32:46
Organization:	Aspen Technology, Inc.
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Message-ID:	<39e05b5e.sandmann@clio.rice.edu>
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> Is there a way to make sure [PMODE] cannot be changed [to support more
> than 64Mb] with run/compile-time variables [first question]. 

PMODE needs to be modified in the code to support the BIOS call for
more than 64Mb memory sizing (for use without HIMEM.SYS) and modified to
support extended XMS calls (Win 95+ HIMEM.SYS).  It's all assembler code
which needs lots of examination and testing to make sure it doesn't break.

> Or maybe somebody know alternative DPMI
> server - stub that can be bound to the executable without this limitation.

Per my other post, CWSDPMI r5 is embedded in a stub which is currently
in pre-beta testing.

> Agreed, and I know that it doesnt support virtual memory, but imagine
> that the program _must_ be a single execuable (it depends not on me - 
> I would rather tune CWSDPMI parameters). The problem with virtual memory
> is even deeper: this program starts from floppy to repair file system on
> the local hard drive, so i cannot use default c:\cwsdpmi,swp, It would
> be nice to have ability to enable/disable swap and change swap file path
> (if there's a network drive for example) in the run-time (e.g to have
> select_file_box() with checkbox "enable/disable swap" :). Because
> I dont know if it possible with CWSDPMI or any other appropriate 
> DPMI server [second question] I have no arguments to convince the 
> customer, because to have additional executable is a very big minus
> for him.

You could not do it at run-time from DJGPP code (you are running in the 
DPMI server at the time...).  But this information is stored in the 
executable itself - so you could modify the image and re-start, or hack
the embedded stub to let you change it in-memory before invoking the DPMI 
server (before you make the change from real mode to PM).  You could also 
have it be a command line argument (the original CWSDPMI command line
argument code for setting swap location is currently compile time disabled
in the embedded stub so it would not confict with arguments passed to 
DJGPP code).

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