                   RUN-TIME ERRORS IN OVERLAYS
                   ---------------------------


     Run-time  errors occurring in overlays are found  as  usual,
and  an  address  is issued by the error  handling  system.  This
address,  however,  is  an address within the overlay  area,  and
there  is no way of knowing which overlay subprogram was actually
active when the error occurred.
     Run-time  errors  in overlays can therefore  not  always  be
readily  found  with  the Options menu's  'Find  run-time  error'
facility.  What 'Find run-time error' will point out is the first
occurrence of code at the specified address. This, of course, may
be  the place of the error,  but the error may as well occur in a
subsequent subprogram within the same overlay group.
     This  it not a serious limitation,  however,  as the type of
error  and  the way it occurs most often will indicate to you  in
which subprogram the error happened.  The way to locate the error
precisely is then to place the suspected subprogram as the  first
subprogram of the overlay group.  'Find run-time error' will then
work.
     THE BEST THING TO DO IS NOT TO PLACE SUBPROGRAMS IN OVERLAYS
UNTIL THEY HAVE BEEN FULLY DEBUGGED!


