HP HP-65 - Page 71

come). We shall accomplish this by manually storing all of the
values in registers prior to performing the calculations using the
program. Assume that the following registers are used:
Initial downpayment ($4000) ST0 (1]
STO [2]
Monthly inflation factor (1.005) STO (3]
Initial savings ($2000) [sTO [4]
sTO (5]
Monthly savings ($185) [sT0 [6]
Monthly interest factor (1.01) 19
Note that the initial downpayment is stored in both R; and R..
This is because in our program r, will remain the same as the
initial value but R, will contain the downpayment in successive
months. We can at will reset R, to the initial value saved in R,
and start over again. The same reasoning holds for R, and R;
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 [[§ : Monthly Total Downpayment
1. Switch to W/PRGM.
2. Press[fl to clear memory.
3. Key in the sequence of steps below.
‘COMMENTS
} Dnpmt X 1.005 = New Dnpmt