NAME
       SetRast - Set an entire drawing area to a specified color.

   SYNOPSIS
       SetRast( rp, pen )
                a1  d0

	void SetRast( struct RastPort *, UBYTE );

   FUNCTION
       Set the entire contents of the specified RastPort to the
       specified pen.

   INPUTS
       rp - pointer to RastPort structure
       pen - the pen number (0-255) to jam into bitmap

   RESULT
       All pixels within the drawing area are set to the
	selected pen number.

   BUGS

   SEE ALSO
	RectFill() graphics/rastport.h