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

   AX = 0003h

Return: BX = button status (see #2839)
   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"

Bitfields for mouse button status:
Bit(s) Description (Table 2839)
 0 left button pressed if 1
 1 right button pressed if 1
 2 middle button pressed if 1 (Mouse Systems/Logitech/Genius)