HP 15c - Manual (Page 87)

Section 7: Program Editing 87
Insertions and Deletions
After an insertion, the display will show the instruction you just added.
After a deletion, the display will show the line prior to the deleted (now
nonexistent) one.
If all space available in memory is occupied, the calculator will not accept
any program instruction insertions and
Error 4 will be displayed.
Initializing Calculator Status
The contents of storage registers and the status of calculator settings will
affect a program if the program uses those registers or depends on a certain
status setting. If the current status is incorrect for the program being run,
you will get incorrect results. Therefore, it is wise to clear registers and set
relevant modes either just prior to running a program or within the program
itself. A self-initializing program is more mistake-proof—but it also uses
more program lines.
Calculator-initializing functions are: ´ CLEAR ∑, ´ CLEAR
M, ´
CLEAR
Q, | D, | R, | g, |
F, and | ".
Problems
It is good programming technique to avoid using identical program labels.
(This shouldn't be hard, since the HP-15C provides 25 different labels.) To
ensure against duplication of labels, you can clear program memory first.
1. The following program is used by the manager of a savings and loan
company to compute the future values of savings accounts according
to the formula FV = PV (l + i)
n
, where FV is future value, PV is
present value, i is the periodic interest rate, and n is the number of
periods. Enter PV first (into the Y-register) and n second (into the X-
register) before executing the program. Given is an annual interest
rate of 7.5% (so i = 0.075).