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From: sassan@locus.com (Sassan Behzadi)
Newsgroups: comp.unix.msdos
Subject: Re: Dos App. Needs More Memory!!
Keywords: ODT-DOS EMS
Message-ID: <17246@oolong.la.locus.com>
Date: 12 Sep 90 19:25:04 GMT
References: <363@stephsf.stephsf.com>
Organization: Locus Computing Corp, Los Angeles
Lines: 31

In article <363@stephsf.stephsf.com> wengland@stephsf.stephsf.com (Bill England) writes:
>
>  While Merge allows allocation of 'simulated' expanded memory I could not 
>  find any provision for allocating extended memory.  

ODT-DOS (Merge) *does* simulate EMS, but you will not be able to run 
programs that go into protected mode in order to access Extended Memory.

>  On further thought
>  it seems like a difficult proposition to create this feature under
>  Unix.

Well it ain't easy.

A few companies (Microsoft, Quarterdeck, Lotus, Borland, Locus and IGC) 
are now working on "DOS Protected Mode Interface" (DPMI) which would
allow DOS programs to access Extended Memory through a set of "well
defined" calls. Operating Systems that support virtual DOS sessions
and DPMI (potentially: Windows, DesqView, UNIX, and yes - even OS/2) 
can allow these DOS programs to access Extended Memory without sacrificing
system security.

Of course DOS programs have to be re-written in order to use DPMI.
So don't expect your current DOS application that goes into protected 
mode to run under these Operating Systems.

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Sassan Behzadi                                                          
sassan@lcc.COM                                                     
Locus Computing Corporation                                            
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