Int 2A Fn 81  CU - Network - End DOS Critical Section                      [D]

   AH = 81h
   AL = critical section number (00h-0Fh) (see AH=80h)

Notes: normally hooked rather than called
   the handler should reawaken any tasks which were suspended due to an
     attempt to enter the specified critical section

See Also: AH=80h,AH=82h,AX=8700h