CODE
call      main,0
exit
PROCBEGIN  main
	alloc	1
1:	inp	_0
	beq	_0, 0, 0

	outp	_0
	param	@_0			; pass number by reference
	call	Fib, 1

	outp	_0			; answer is passed back in _0
	newl
	goto	1
0:	free	1
PROCEND


PROCBEGIN	Fib
	alloc	2			; allocate 2 local variables on 
					; the call stack

	;; test for base cases Fib(1) and Fib(2)
	beq	^%0, 1, 2
	beq	^%0, 2, 2

	;; calculate Fib(n-1)
	sub	^%0, 1, %1
	param	@%1
	call	Fib, 1
	
	;; calculate Fib(n-2)
	sub	^%0, 2, %2
	param	@%2
	call	Fib, 1

	; calculate Fib(n)
	add	%1, %2, ^%0
	goto	3

	; exit with the base case
2:	move	1, ^%0

	; clean up the call stack
3:	free	2	
PROCEND