scroll

From ArchaicPixels: HuC and PCEAS Documentation

scroll(char num, int x, int y, char top, char bottom, char disp);

     Define screen window 'num'. Up to four window can be defined.
     'top' and 'bottom' are the screen top and bottom limits
     of the window (limits are included in the window area).
     'disp' controls the type of the window, if bit 7 is set
     background graphics will be displayed in this window,
     and if bit 6 is set sprites will also be displayed.
     If none of these bits are set the window will stay blank.
     'x' and 'y' are the top-left coordinates of the area
     in the virtual screen that will be displayed in
     the window.