DOS Fn 3300H: Query Break-Check Flag

                                                         Compatibility: 2.0+ 
 Expects: AX    3300H
 Returns: DL    current break level (0=OFF, 1=ON)
    Info: DL is returned with the current Ctrl-Break checking state.

          When Break is ON, DOS checks for Ctrl-Break (or Ctrl+C) from the
          console during most functions (except 06H and 07H).  When
          detected, INT 23H is executed (if INT 23H has not been
          intercepted, this will abort the process).

          When Break is OFF, DOS checks for Ctrl-Break during standard I/O,
          standard printer, and standard AUX operations

See Also: Fn 3301H (set break-checking state)
          Fn 0bH (get input status)
          INT 23H
          DOS Functions