evermeer@cs.ruu.nl (Erik Vermeer) (05/06/91)
Hello folks, I'm writing a program about graphical real-time animation on an IBM-XT (e.g. a rotating cube). My strategy is to draw a picture on an hidden, virtual screen and when the drawing is finished to place the virtual screen onto the actual screen. After that the drawing is rotated a bit, and the drawing starts again (on the hidden screen). I know it is easy to do when you use an EGA or VGA graphics card. The only problem is, my computer has a CGA graphics card. I wrote a machine-code routine for the copying of the virtual screen onto the actual screen (it is a simple block move in memory). The only problem is, I don't know the memory addresses of the pointers (I assume there are several) to the start of the actual screen (the screen is placed at hex B8000). I need to know them, because I want to redirect the making of the drawing to the virtual screen. My intention was to write the program is BASIC. When I succeed, I will think of writing the same program in a more structured language. I use Microsoft GW-Basic and Borland Turbo-Basic. I think the addresses needed are different for GW-Basic and Turbo-Basic. Can anybody help me with my problem !! Erik Vermeer University of Utrecht, the Netherlands. e-mail: evermeer@cs.ruu.nl Sorry for my poor English !!!!