Date:	Thu, 17 Nov 1994 10:44:26 +22305931 (WAUST)
From:	Ron Grunwald <rgrunwal AT bluering DOT cowan DOT edu DOT au>
Subject:	Re: Virtual memory and DPMI (and Win 3.1)
To:	DJ Delorie <dj AT stealth DOT ctron DOT com>
Cc:	MRMILLER AT delphi DOT com, djgpp AT sun DOT soe DOT clarkson DOT edu

On Wed, 16 Nov 1994, DJ Delorie wrote:

> > Normal DOS:
> > ===========
> >     default:    fails after allocating approx 4 Mb with the 
> >                   message "DPMI: Not enough memory"
> >     nodpmi:     ran sucessfully
> >  
> > Win DOS box:
> > ============
> >     default:    ran sucessfully
> >     nodpmi:     won't run at all with some message about being in V86
> >                   mode
> >  
> > Isn't virtual memory suppose to work, regardless of the presence of
> > dpmi (assuming you have the disk space)?  Is there some way to set GO32
> > so that the program would work whether or not it was run from a Windows
> > DOS box or not?
> 
> Virtual memory in DPMI mode is limited by the amount of virtual memory
> that the DPMI provider is willing to give you.  For qdpmi, this is the
> MAXMEM option.  I think it defaults to 4Mb.


I think that from previous queries on this list it was also specified that
QEMM's virtual memory management under QDPMI is incompatible with GO32.
From my own experiences this was found to be true, since the only memory
GO32 is given from QDPMI is actual memory. If more memory was required
than was physically available, the message "DPMI: Not enough memory"
would come up.


> 
> In Windows, the ONLY api available is DPMI, so if you disable dpmi,
> there is no way to enter protected mode.
> 

This works very well. Windows' DPMI host is compatible with GO32.



Regards, Ron.



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 | Author.............. Ron Grunwald                                | 
 | Internet............ rgrunwal AT bluering DOT cowan DOT edu DOT au              | 
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 | Department.......... Information Technology                      | 
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 | Location............ Perth, Western Australia                    |
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