RWMIRA01@ULKYVX.BITNET (Rob Miracle) (06/20/88)
First a brief description of VGA. VGA has all of the CGA, and EGA modes. It also supports a 640X480 16 color mode and a 320X200 256 color mode. There is also a 640X480 2 color mode. The 640X480 modes use a bit map identical to EGA expept for it being 640X480 instead of 640 X350. The 256 color mode is addressed at 0xA0000000 and one byte = one pixel. So you can access any pixel by 320*Y+X for the Offset and a Segment of 0xA000. The graphics mode here is 0x13. A really good book to get hold of if you want to learn how to do this is: Programmer's Guide to the PC & PS/2 Video Systems, Richard Wilton, Microsoft Press, ISBN 1-55615-103-9, Library of Congress QA76.8.I2594W55, 1987. It details the VGA, MCGA, EGA, CGA, MDA, and Herculeas cards. Most of the code examples are in MASM, but most people would not have a problem with it. Rob Miracle Programmer/Analyst-II University of Louisville RWMIRA01@ULKYVX.BITNET