HP 25 User Manual

92 Programming
tions
one at a time. When you hold themJkey down in RUN
mode , the program step number and keycode are displayed.
When you release themJkey, the instruction is executed . Use
mJ on the simple area of a circle program shown below to
familiarize
yourself with its operation.
Example Program. This program calculates the area of a
circle using
the formula: A = 'TTr2 where r is the radius. Set the
PRGM-RUN switch to PRGM PRGM~RUN and press
I PI<GM I to clear program memory and display step 00. Then key
in the list of keys shown below.
Press Display
m 0
1 01
15 02
m El
1 02
15 73
0 1 03
61
The program assumes that a value forr has been keyed into the
X-register. To run the program, set the PRGM-RUN switch
back to RUN PRGM" RUN and press D ~ . Now step
through the program in slow motion using a value of 10 for r.
Press
10
miD
Display
1 10.
1
01 15 02
1 100.00
1 02 15 73
3.14
03 61
1 314.16
When you hold mJdown, the
first instruction
is displayed.
When you release mJ, the first
instruction
is executed.
Again holdingmJdown displays
the second instruction.
Again
releasingmJexecutes the
second instruction.
HoldingmJdown displays the
third instruction this time.
And releasing mI executes the
third instruction.
You can see that it would be easy to spot a mistake in your pro-
gram using
themJkey .

HP 25 Specifications

General

Power Source	Rechargeable battery pack
Programming Steps	49
Release Year	1975
Functions	Trigonometric, logarithmic, statistical
Type	Scientific
Dimensions	148 x 80 x 14 mm