From: schultz@schultz.kgn.ibm.com (Karl Schultz) Subject: Re: VESA standard VGA/SVGA programming??? Reply-To: schultz@vnet.ibm.com Organization: IBM AWS Graphics Systems Keywords: vga Lines: 45 |> 1. How VESA standard works? Any documentation for VESA standard? The VESA standard can be requested from VESA: VESA 2150 North First Street, Suite 440 San Jose, CA 95131-2029 Ask for the VESA VBE and Super VGA Programming starndards. VESA also defines local bus and other standards. The VESA standard only addresses ways in which an application can find out info and capabilities of a specific super VGA implementation and to control the video mode selection and video memory access. You still have to set your own pixels. |> 2. At a higher resolution than 320x200x256 or 640x480x16 VGA mode, |> where the video memory A0000-AFFFF is no longer sufficient to hold |> all info, what is the trick to do fast image manipulation? I |> heard about memory mapping or video memory bank switching but know |> nothing on how it is implemented. Any advice, anyone? VESA defines a "window" that is used to access video memory. This window is anchored at the spot where you want to write, and then you can write as far as the window takes you (usually 64K). Windows have granularities, so you can't just anchor them anywhere. Also, some implementations allow two windows. |> 3. My interest is in 640x480x256 mode. Should this mode be called |> SVGA mode? What is the technique for fast image scrolling for the |> above mode? How to deal with different SVGA cards? This is VESA mode 101h. There is a Set Display Start function that might be useful for scrolling. |> Your guidance to books or any other sources to the above questions |> would be greatly appreciated. Please send me mail. Your best bet is to write VESA for the info. There have also been announcements on this group of VESA software. -- Karl Schultz schultz@vnet.ibm.com These statements or opinions are not necessarily those of IBM