From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: dpmi
Date:	Tue, 31 Dec 1996 00:24:38 -0800
Organization:	Two pounds of chaos and a pinch of salt
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Message-ID:	<32C8CDC6.6145@cs.com>
References:	<32C8A3A6 DOT 47B3 AT dmv DOT com>
Reply-To:	fighteer AT cs DOT com
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Pyro Technic wrote:
> 
> is it posible to compile dpmi support N2 a program. i've created
> several file utils, but to keep the user from having 2 learn about DPMI
> they must run it in the win95 MS-DOS shell. NE help greatly
> apppreciated.

In order to get DPMI support for DJGPP programs, you must find a way to
obtain DPMI services on the host computer.  This is a requirement of all
32-bit compilers, not just DJGPP.  Here are the things you can do:

- Distribute cwsdpmi.exe with your programs.  It's about 20k, so adding
that to a 50k program (the smallest you can make that really does
anything under DJGPP) makes a 70k distribution unzipped.  It's a bit big
for a simple utility, but try comparing that to the size of any other
32-bit compiler's files when bound with a DPMI host.

- Use the PMODE stub, which is bindable to your programs.  PMODE has
drawbacks, however, in the form of incomplete DPMI 0.9 support;
particularly no virtual memory.

- Require that your users run the program in a DPMI environment, and
give them pointers on where to obtain cwsdpmi.

- Distribute cwsdpmi, but inform your users that they can put it in a
common directory in the PATH to save space.

- Use a dinky 16-bit compiler to make your small programs.  There are
plenty of freeware 16-bit compilers out there... but reliability is
another issue.

Remember, before you balk at the idea of distributing cwsdpmi with your
programs, that many popular commercial programs, particularly games,
come with DOS extenders, particularly DOS4GW.  So it isn't all that
unusual to do so yourself.

There is a final option, available to true nuts... er, enthusiasts <g> :

- Get the sources to cwsdpmi from Charles Sandmann or SimTel and modify
it to be bindable to the executable.  I figure that somebody will
eventually break down and take this route, and we will all be much
happier.  ;)

Good luck!

-- 
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| John M. Aldrich, aka Fighteer I  |        fighteer AT cs DOT com         |
| Plan:  To find ANYONE willing to |   http://www.cs.com/fighteer   |
| play Descent 2 on DWANGO!        | Tagline: <this space for rent> |
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