[comp.graphics] VGA Card Programming

LMS5@psuvm.psu.edu (03/15/90)

   I am currently writing a program that will utilize my entire display
memory. The image will have a 700x700 resolution and I wish to use my
screen as a 640x480 window to scroll and pan around this image. Changing
the value in my Start Address Register (without touching the Offset Register),
will allow me to scroll and pan a 640x480 image. But, when I try to load a
90 byte offset into my Offset Register my screen will split. I doubled checked
the index of the Offset Register and I am using 13h index value. Any hints and
suggestions on how to solve my problem or another better way to accomplish my
goal would be appreciated.

P.S. When I try and load an 80 byte offset value into my Offset register the
screen will split, making me believe that I do not have the correct index
value. I am new to VGA Card Programming.


Laurie m. Salopek       LMS5 @ PSUVM