SmoothScrolling 

By setting the smooth scrolling flag the extended form of DisplayBitmap may be used
which allows the bitmap to be displayed at any offset. This enables the programmer
to scroll the portion of the bitmap being displayed. See BlitzMode programming
chapter for an explanation of hardware scrolling.


* Always use the extended form of DisplayBitmap with smoothscrolling set, even when
offset is 0,0.

* DisplayBitmap accepts quick types for the x offset and will position the bitmap in
fractions of pixels on AGA machines.

* The width of the display will be less than the default 320/640/1280 when smooth
scrolling is enabled.