Hi !

If you want to have Soft-Scrolling on your VGA, you have to change some 
intern registers of the CRTC. But it is a little bit difficult to explain, 
so I would suggest, you take a look at "The Programming of the 
EGA/VGA-Adapter" by Addison-Wesley. You will find all useful descriptions 
for every available VGA-Register.

-Boris
