Writing A Second Program - HP -25 Owner's Handbook Manual

The illustration on the left shows program memory immediately
after pressing [l Prcv Jin PRGM mode or turning the HP-25
ON. The illustration on the right shows program memory after
recording the three-step example program.
A (0] [0] instruction in the program tells the calculator to
go to step 00 and execute the automatic stop instruction there
next. If is pressed again in automatic RUN mode, the calcu-
lator will begin executing instructions from step 00 as it did the
first time. Each time the calculator executes the program, it
ends execution at step 00, ready to begin again.
If you had recorded a 49-step program, after executing step 49
the calculator would execute the automatic stop instruction
stored in siep 00. Then you would have to press to execute
the program again.
Now try an example.
Example. Calculate the surface area of a spherical ''cat's-eye"'
(marble) with a diameter of 1.3 centimeters. Then calculate the
surface area of a baseball with a diameter of 2.5 inches.
Press Display
1.3 Area of the marble in square
centimeters.
2.5 19.63 Area of the baseball in square
inches.
Each time you press the calculatorexecutesthesequence of
keystrokes you have recorded. You calculate the same answers
you would obtain if you did each problem manually, but without
the time or the tedium.
Writing a Second Program
Now let's write a second program and use it to further explore
the programming capability of your HP-25 calculator. Suppose
you want to write a program that will calculate the increase in