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Mail Archives: djgpp/1995/01/27/17:36:45

From: Charles Sandmann <sandmann AT new-orleans DOT NeoSoft DOT com>
Subject: Re: V2
To: A DOT APPLEYARD AT fs2 DOT mt DOT umist DOT ac DOT uk (A.Appleyard)
Date: Fri, 27 Jan 1995 09:56:47 -0600 (CST)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

> > ... Under VCPI, it is possible to guarantee that physical memory gets mapped
> > to E0000000--EFFFFFFF, etc. Under DPMI, this is no longer possible, which is
> > a problem to several bits of code, especially those pertaining to graphics.
> 
> Please! I have an important Gnu C++ program that absolutely depends on knowing
> what addresses the text screen gets mapped to, as well as in a few places
> needing to know what addresses the physical memory (at least the lowest
> megabyte of RAM) gets mapped to.

The right answer (and only answer in V2) is to use one of these methods:
1) <sys/farptr.h> functions.  They make very, very good code.
2) memmove in go32.h
3) dosmem*() routines

Using any of the above your code will work under VCPI, DPMI, or V2.  Don't
wait, do it now.  Search for all references to 0xe00xxxxx type addresses
and remove them *NOW*.

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