SR-56 Sinking Fund Program - Interest Rate Unknown
This program is taken from the SR-56 Applications Book, by Texas Instruments.

This will solve for the periodic interest rate given the N, FV, and PMT components of the Time Value of Money equation. This program deals with problems that have a future value in them rather than a present value.
Remember: The periodic interest rate is NOT the annual rate. For TVM problems involving a present value, see: SR-56 Present Values

Instructions:
1) Clear memories. 2nd Cms.
2) Load known values (you need to enter three of these) into data memories. Future Value STO 2, Payment per period, STO 3, Number of periods STO 4.
3) Calculate the periodic interest rate by pressing RST, R/S. The rate is automatically calculated and displayed.

Program Listing:
```Line  Keycode  Instruction
00      56       CP
01      15       CLR
02      34       RCL
03      02       2
04      54       /
05      34       RCL
06      03       3
07      54       /
08      33       STO
09      05       5
10      34       RCL
11      04       4
12      43       X^2
13      74       -
14      34       RCL
15      05       5
16      20       1/X
17      94       =
18      37       X = T
19      09       9
20      02       2
21      33       STO
22      01       1
23      52       (
24      01       1
25      84       +
26      34       RCL
27      01       1
28      53       )
29      45       Y^X
30      34       RCL
31      04       4
32      74       -
33      01       1
34      74       -
35      33       STO
36      06       6
37      34       RCL
38      01       1
39      64       *
40      34       RCL
41      05       5
42      94       =
43      54       /
44      52       (
45      34       RCL
46      06       6
47      54       /
48      34       RCL
49      01       1
50      93       +/-
51      84       +
52      34       RCL
53      04       4
54      64       *
55      52       (
56      01       1
57      84       +
58      34       RCL
59      01       1
60      53       )
61      45       Y^X
62      52       (
63      34       RCL
64      04       4
65      74       -
66      01       1
67      94       =
68      12       INV
69      35       SUM
70      01       1
71      28       | X |
72      74       -
73      04       7
74      93       +/-
75      19       10^X
76      94       =
77      47       X >= T
78      02       2
79      03       3
80      34       RCL
81      01       1
82      49       FIX
83      06       6
84      44       EE
85      12       INV
86      44       EE
87      33       STO
88      01       1
89      64       *
90      02       2
91      19       10^X
92      49       FIX
93      02       2
94      94       =
95      41       R/S
96      42       RST
```

Visitors since 6/21/97