[ Fibonacci sequence
  ==================

  A program for the EDSAC

  Calculates the nth Fibonacci
  number and displays it at the
  top of storage tank 3

  The default value of n is 10

  To calculate other Fibonacci
  numbers, set the starting value
  of the count to n-2

  Works with Initial Orders 2 ]


        T56K  [ set load point  ]
        GK    [ set theta       ]

[ Orders ]

[  0 ]  T20@  [ a = 0           ]
        A17@  [ a += y          ]
        U18@  [ temp = a        ]
        A16@  [ a += x          ]
        T17@  [ y = a; a = 0    ]
        A18@  [ a += temp       ]
        T16@  [ x = a; a = 0    ]

        A19@  [ a = count       ]
        S15@  [ a -= 1          ]
        U19@  [ count = a       ]
        E@    [ if a>=0 go to θ ]

        T20@  [ a = 0           ]
        A17@  [ a += y          ]
        T96F  [ C(96) = a; a = 0]

        ZF    [ halt ]

[ Data ]

[ 15 ]  P0D   [ const: 1        ]
[ 16 ]  P0F   [ var: x = 0      ]
[ 17 ]  P0D   [ var: y = 1      ]
[ 18 ]  P0F   [ var: temp = 0   ]
[ 19 ]  P4F   [ var: count = 8  ]
[ 20 ]  P0F   [ used to clear a ]

        EZPF  [ begin execution ]