From: Till Harbaum Newsgroups: comp.os.msdos.djgpp Subject: Re: VGA question Date: 08 Feb 1997 17:19:00 +0100 Organization: TU Braunschweig, Informatik (Bueltenweg), Germany Lines: 24 Sender: harbaum AT logic Distribution: world Message-ID: References: <01bc14c1$4d90a520$0cb0f8ce AT 698130> NNTP-Posting-Host: logic.ibr.cs.tu-bs.de To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp > Does anybody know how to achieve double buffered animation in VGA (320x200 > 256 colors)? Specifically I need to know how to select the pixel to be > displayed in the upper left corner of the display. Do do the double buffering with both buffers inside vga memory you should use the appropriate vesa functions. There is no way to do this via the std vga registers (I assume this is what you meant by "the pixel in the upper left corner"). A second way to do double buffering is to use one buffer in the main memory. Some other people wrote you answers on how to do this. The first version may be the faster one, since it does not require to copy the video buffer at a buffer change. But perhaps accesses to video memeory are that slower than your access to main memory that its faster to build up a bitmap in main memory and copy it into the video memory than to build the bitmap inside video memory. This is true with isa vgas, but perhaps not with pci devices. Ciao, Till