routine HARBOR.UPDATE given PORT                ''display SHIPs in HARBOR
   define PORT and WAITING.SHIP as integer variables
   define LAST.X.LOC, LAST.Y.LOC as real variables

   let LAST.X.LOC = PORT.X.ENTRANCE(PORT)
   let LAST.Y.LOC = PORT.Y.ENTRANCE(PORT)

     '' line up ship in the harbor
   for each WAITING.SHIP in PORT.HARBOR(PORT)
   do
       display WAITING.SHIP at (LAST.X.LOC, LAST.Y.LOC)
       subtract 15 from LAST.X.LOC
       add 7 to LAST.Y.LOC
   loop
''   display PORT.SHIP.COUNTER(PORT)

end   ''HARBOR.UPDATE
