INT 33H 0001H: Show Mouse Pointer

 Expects: AX    0001H
 Returns: none
    Info: This unhides the mouse pointer.  It actually increments an
          internal counter used by the mouse support to determine when to
          show the pointer.

          That counter starts as -1 (after an INT 33H 0000H or 0021H
          reset).  This call increments it to 0.

          Whenever the counter is 0, the mouse pointer is displayed and
          tracked on-screen.  When the counter is 0, subsequent Show
          Pointer calls are ignored.  Calls to INT 33H 0002H (hide pointer)
          decrement the counter.

          This logic relieves programs of the burden of global tracking of
          the hidden/displayed state.  A subroutine may always use
          INT 33H 0001H at the beginning and INT 33H 0002H at the end,
          without affecting the shown/hidden state of the calling routine.

          This function also resets the "exclusion area" set via
          INT 33H 0010H.

See Also: INT 33H: Mouse Support
          Interrupts and BIOS Services