INT 33 - MS MOUSE v1.0+ - DEFINE SCREEN REGION FOR UPDATING

	AX = 0010h
	CX,DX = X,Y coordinates of upper left corner
	SI,DI = X,Y coordinates of lower right corner
Note:	mouse cursor is hidden in the specified region, and needs to be
	  explicitly turned on again
SeeAlso: AX=0001h,AX=0002h,AX=0007h,AX=0010h"Genius MOUSE",AX=0031h