From:	<SANDMANN AT clio DOT rice DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: CWSDPMI for Gb of VM?
Date:	Sun, 26 Jan 1997 22:47:13
Organization:	Rice University, Houston, Texas
Lines:	19
Message-ID:	<32ebdef1.SANDMANN@clio.rice.edu>
References:	<5cgtcp$3hs AT newton DOT pacific DOT net DOT sg>
Reply-To:	SANDMANN AT clio DOT rice DOT edu
NNTP-Posting-Host:	clio.rice.edu
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> When you write 2Gb of virtual memory, what is the ratio RAM/HD in this case?

This would be 2Gb of disk based storage in addition to the RAM you have.  But
I just did some calculations, and it seems the small model will break at
around 1.3Gb of disk based storage (due to data+bss+stack > 64K).  Since I
find it highly unlikely anyone would want to suffer through that much 
paging, I won't worry about fixing it (which wouldn't be too hard).  The
page tables themselves would also start paging at over around 500Mb of total
memory space, which will slow things down also.

> And is it easy to change dalloc.h?

Change a documented constant, and rebuild everything.  Since the larger
sizes haven't been tested in over a year, things may have been broken.
In particular, the latest versions don't link to the borland libraries at
all, so a long integer operation call may be missing, or may be coded with
assumptions in start.asm which don't apply.  So great care would be advised.
I suspect an increase to 255Mb of disk based storage wouldn't cause many
problems, since long integer arithmetic would be avoided.

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