From: "Ultima" <ultima AT game-master DOT com>
Subject: Re: a tile engine question
Newsgroups: comp.os.msdos.djgpp
References: <199806092100 DOT XAA20689 AT legolas DOT mdh DOT se>
Message-ID: <01bd9574$f7d7c560$d7f360cf@ultima>
Date: Thu, 11 Jun 1998 20:26:05 GMT
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NNTP-Posting-Date: Thu, 11 Jun 1998 16:26:05 EDT
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To: djgpp AT delorie DOT com
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Magnus Lindström <dal97mlm AT mds DOT mdh DOT se> wrote in article
<199806092100 DOT XAA20689 AT legolas DOT mdh DOT se>...
> > From:          "Arthur" <arfa AT clara DOT net>
> > To:            "DJGPP Mailing List" <djgpp AT delorie DOT com>
> > Subject:       Re: a tile engine question
> > Date:          Tue, 9 Jun 1998 17:44:27 +0100
> 
> > You have your standard screen memory reserved by the system. The
address of
> > this screen is pointed to by a dword in low memory. Now the clever bit:
by
> > changing this pointer, you can change the area of memory the computer
thinks
> > is the screen. Now you can have two or three screen buffers, which you
can
> > swap to the screen in one ASM instruction.
> > 
> > Is there any way you can do this on th PC, or more specifically DJGPP?
> > 
> > James Arthur
> > jaa AT arfa DOT clara DOT net
> > 
> > 
> Yes there is.. but I'm not going to explain exactly how you do it 
> here.. it would take to long. What you want to do is called page 
> flipping and is supported by the vbe function 07h. With this function 
> you select which pixel to be displayed in the upper left corner of 
> the display. Any Vesa spec should show you how to implement it..
You got it wrong. He means changing the offset of the BUFFER, 
not the offset of video memory!