8.   USER ABORTS AND LOST CARRIERS

        If a user enters one of the characters following the /R:  in
        the  DOORWAY command  line,  then the  program will  abort.
        "EXTERNAL  USER  ABORT"  will be  displayed  on  the Sysop's
        screen for a couple of seconds.   Note that if the user does
        an EXTERNAL  ABORT when  the program  is in  a CRITICAL  DOS
        function, the abort could crash the system.  Therefore, if a
        critical  DOS function is being performed, the abort will be
        delayed (but remembered)  until it is safe to abort.  If the
        user does an  external abort  during a drop  to DOS  (REMOTE
        session),  the  function  or  program  in  process  will  be
        aborted,  and the user will be  dropped back to DOS, and the
        message "EXTERNAL ABORT IN DOS" will appear on both ends.

        If a carrier is lost, the  program will abort, or if in  DOS
        an EXIT will  be performed, and  control will return to  the
        HOST  program  automatically.   The  message  "CARRIER  LOST
        >>>>>  RETURNING  TO  BOARD" will  flash  up  on  the HOST's
        screen.  If carrier is lost  during a critical DOS function,
        DOORWAY  will attempt to abort  the program for 255 seconds.
        DOORWAY  goes to great lengths  to abort a program which was
        previously unbreakable.   It will resort to hooking  the dos
        interrupts to gain control, and sending the program carriage
        returns, ESC characters, and   .  If unable to  break the
        program for 255 seconds,  then the system will reboot.   The
        only  way  I know  for this  to  happen, is  if  the program
        running under  DOORWAY hangs up,  but timer ticks  are still
        functioning.  If this  happens, and the user hangs  up, then
        the system  would be  hung until  the Sysop  noticed it  and
        rebooted.  Therefore, Doorway will reboot the system.
        If a User or keyboard timeout occurs, then DOORWAY will send
        the  appropriate  message  and  return  to  PCBoard.    If a
        keyboard timeout  occurs in DOS (/C:DOS), then the bell will
        be rung,  but it will not return to the BBS.