-extern void DDScrollBuffer_Cls(int BackColor);
-extern long DDScrollBuffer_CreateAtSize(long Width, long Height, long hWndViewPort);
-extern long DDScrollBuffer_Get_DestXOff();
-extern long DDScrollBuffer_Get_DestYOff();
-extern int DDScrollBuffer_Get_Height();
-extern DirectDrawSurface7 DDScrollBuffer_Get_Surface();
-extern long DDScrollBuffer_Get_Width();
-extern void DDScrollBuffer_Let_DestXOff(long NewVal);
-extern void DDScrollBuffer_Let_DestYOff(long NewVal);