Int 33 Fn 0003  - MS Mouse V1.0+ - Return Position And Button Status       [M]

   AX = 0003h

Return: BX = button status
      bit 0  left button pressed if 1
      bit 1  right button pressed if 1
      bit 2  middle button pressed if 1 (Mouse Systems/Logitech mouse)
   CX = column
   DX = row

Note:  in text modes, all coordinates are specified as multiples of the cell
     size, typically 8x8 pixels

See Also: AX=0004h,AX=000Bh,INT 2F/AX=D000h"ZWmous"