Xref: news2.mv.net comp.os.msdos.djgpp:7685
From: "John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: buffer -> screen transfers
Date: Tue, 20 Aug 1996 20:00:24 -0700
Organization: Three pounds of chaos and a pinch of salt
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Message-ID: <321A7BC8.27F4@cs.com>
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To: "Tony O'Bryan" <root AT ursa DOT smsu DOT edu>
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Tony O'Bryan wrote:
> 
> Will __crt0_nearptr_enable allow a pointer to linear address 0xa0000 to
> directly access the video screen?

Yes, but you have to reference all your direct memory writes with
__djgpp_conventional_base to get the *correct* pmode address to write to.
So, the correct address for the VGA screen would be the following:

char *VGAscreen = (char *) (0xA0000 + __djgpp_conventional_base);

Read the description of the __djgpp_nearptr_enable() function for more
info, including a complete example (using the text screen, but the
technique is the same).

John

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