To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: INT 15 from protected mode 
Date: Wed, 25 Nov 92 09:14:14 -0600
From: Dan Bodoh <bodoh AT thor DOT xraylith DOT wisc DOT edu>

In your message of Tue, 24 Nov 92 22:30:32 CST, you wrote:

>Whee!  My first OBdjgpp!  What a concept!
>
>>lines of 'only some of the dv calls are supported in protected mode'.  
>>Does that mean it would be impossible to call most dv calls directly from
>>PM without changing go32 to switch to real mode to do it?  That is, could 
>>it be possible to write dv-specific apps with djgpp? (talking dv classic
>>here, and earlier ones than the one supplied with dv/x too)
>
>It is my understanding that you would have to make GO32 aware of INT 15
>in order to be able to use the DV API from inside of a DJGPP program.

Many of the DV API calls pass all their data back and forth via registers;
from what I understand these should be able to be caled directly in PM.
Some calls (the DV version of EXEC comes to mind) require a buffer
in the first 1 meg.  This should be relatively easy...

The hard part is the Message Sending functions.  This part of the DV API
is quasi-object oriented, in that windows, mailboxes, timers, etc. are
all objects.  The Message calls (which, for example, create, destroy, etc.
objects) require data to be pushed on the stack before the call and
popped off the stack after the call.  This is the hard part.

Some of these calls are implemented in SYS.LIB provided with the 
DVX DJGPP X lib.  
----
Daniel J. Bodoh, Elect & Comp Engr grad student at the University of Wisconsin
bodoh AT xraylith DOT wisc DOT edu   DECNET: cxrl::bodoh   FIDONET: Daniel Bodoh 1:121/99