
Section 4: Programming 269



Press


Comment



4000


STO 1


Initial downpayment





STO 2


($4000).




1.005


STO 3


Monthly inflation factor







(1.005).




2000


STO 4


Initial savings





STO 5


($2000).




185


STO 6


Monthly savings







($185).




1.01


STO 7


Monthly interest factor







(1.01).




Note that the initial downpayment is stored.in both R1 and R2. This is because
in our program r1 will remain the same as the initial value but R2 will contain
the downpayment in successive months. We can at will reset R2 to the initial value saved in
R1 and start over again. The same reasoning holds for R4 and R5 containing
the initial savings.


One final word before we actually start our program. Normal procedure is to write the entire program
sequence, enter it, and then test it. For the sake of greater understanding, we will write one label
at a time and obtain the answers for that segment of the problem as we go along.


Programming Label A : Monthly Total Downpayment


1.

Switch to W/PRGM.


2.

Press fPRGM to clear memory.


3.

Key in the sequence of steps below.



KEY ENTRY

CODE SHOWN

COMMENTS

LBL

23


A

11


RCL 2

34 02

Dnpmt

RCL 3

34 03

Inflation factor

×

71


STO 2

33 02

New dnpmt

RTN

24




KEY ENTRY

CODE SHOWN








Dnpmt × 1.005 = New Dnpmt









