Message-Id: <199806092100.XAA20689@legolas.mdh.se>
Comments: Authenticated sender is <dal97mlm AT mds DOT mdh DOT se>
From: "=?ISO-8859-1?Q?Magnus_Lindstr=F6m?=" <dal97mlm AT mds DOT mdh DOT se>
Organization: Gamla drakar
To: djgpp AT delorie DOT com
Date: Tue, 9 Jun 1998 22:58:44 +0100
MIME-Version: 1.0
Content-type: text/plain; charset=ISO-8859-1
Subject: Re: a tile engine question
In-reply-to: <000601bd93ce$155240a0$c34d08c3@arthur>
Content-Transfer-Encoding: 8bit
Precedence: bulk

> 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..

Magnus Lindström

_______________________________________
E-mail->   dal97mlm AT mds DOT mdh DOT se
WWW->      mds.mdh.se/~dal97mlm/
ICQ UIN -> 3959951
_______________________________________