Communicating Applications Spec - Get queue status

        Entry:
          AX = CB11h
          DL = queue to get status of
              00h task queue
              01h receive queue
              02h log queue
        Return:
          AX >= 0 total number of changes made to queue, modulo 32768
                  BX = number of control files currently in queue
                  CX = number of received files (zero for task and log queues)
             < 0  error code (see AX=CB01h)