Helwett Packard HP-38E User guide

HEWLETT-PACKARD
HP-38E/38C
OWNER’'S HANDBOOK
AND PROGRAMMING GUIDE

About Continuous Memory (HP-38C only)
If you purchased an HP-38C instead of an HP-38E, your calculator contains Con-
tinuous Memory—one of the most advanced memory systems available in a financial
calculator. Even when the calculator is turned off, the financial registers and the
storage registers save information such as cash flows, amortization data, or inter-
mediate answers for later updating or calculations. Continuous Memory also allows
you to save any programs you frequently find useful, whether short, like a checkbook
balancer, or longer, like a bond calculation, for as long as you want.
And, continuous memory helps save battery life! Much of the time a calculator is
switched on is spent holding information, waiting for the next computation. Continuous
Memory eliminates much of this unneeded battery usage by allowing you to switch
off the calculator when you have a prolonged pause or interruption between
calculations.
Note: Unless otherwise indicated, “HP-38E” is used throughout this handbook to
refer to both the HP-38E and the HP-38C.

HEWLETT |’!fi PACKARD
HP-38E/38C
Owner’s Handbook
and
Programming Guide
April 1979
00038-90038
Printed in U.S.A. © Hewlett-Packard Company 1979

Contents
The HP-38E Financial Programmable Calculator
The HP-38EMemory ......... ... ... i, 6
Functionand Key Index ............. ... ... ... . oo 6
Programming Key Index ... 10
A Financial Calculator
With Programming Capability! ........................... ... 12
Manual Problem Solving ............... ... i 12
Programmed Problem Solving .................... ... 13
Part I: Problem Solving .................................. 17
Section 1: Using Your Calculator ............................ 18
The Keyboard ....... ... ... 18
Clearing Prefixes ........ ..o 18
Arithmetic Operators (F](E)EJ(E] -+« vvvvevrvirrinanaraeinns 19
Percentage ........ooiiiiii 19
Net Amount (o) (73] 19
Percent Difference Between Two Numbers .............. 20
Percent of Total ... oot 21
LAST X 22
The Hidden Function (Mantissa) ................coooviinnin.. 22
Keying In Exponents of 10 ................cciiiiiiinnein... 23
Calendar ......... ... . 24
Date Format. ... 24
Days Between Dates ......oviiiiiiiiiiiii 24
Future or Past Dates .. vvvvvvvviiiia i 25
Section 2: The Financial Functions .......................... 28
The Financial Registers . ..., 28
Displaying Financial Values ................................ 29
Clearing the Financial Registers ............................ 29
Reentering Values ................ ... ... 29
The Payment Switch ........................cooiiiiiiii... 29
Financial Interest Calculations .................. e 30
Simple Interest ..., 32
Accrued Interest—360-Day Basis ...................oonnn. .. 32
Accrued Interest—365-Day Basis . ......................... 34
3

4 Contents
Compound Interest ...t 34
Solving for the Number of Compounding
or Payment Periods (0] . .........coviiiiiiiiii 34
Solving for the Periodic Interest Rate &) .................... 37
Solving for the Present Value ........................... 39
Solving for the Periodic Payment Amount ............... 42
Solving for the Future Value ............................ 43
Amortization (AMORT] 45
Discounted Cash Flow Analysis ...................cc.ooo... 48
Net Present Value ... .o 49
Internal Rate of Return ... it 53
Changing Cash Flow Entries .................. ... ..ou 56
Reviewing Cash Flow Entries .............................. 56
Section 3: Mathematical Functions .......................... 58
ReCIProCals ... 58
Square ROOt ... 58
Exponentiation: Raising a Number to a Power (v).............. 59
Logarithms ... 61
Antilogarithms ... ... 61
Factorials (n] .. ... 62
Number Alteration . .......... .. . i 63
Rounding a Number ..o 63
Integer Portion of a Number ... ool 64
Fractional Portion of a Number (Frac)............... ... ... ... 65
Section 4: Statistical Functions .............................. 66
SUMMALIONS ... . 66
Viewing the Statistical Registers ............................ 67
Deleting and CorrectingData . .............. ...t 67
Mean (X)L . 67
Standard Deviation (s] ............. ... .. . . 69
Weighted Mean ... 70
Linear Regression .............c.coiiiiiiiiiiiii i 72
Correlation Coefficient ............ ... ... ... . .. 72
Linear Estimates X, ¥ . ......ovviioi i 74
Part II: Programming .................................... 79
Section 5: What Is a Program? .............................. 80
Why Write Programs? ........... ... ..o i 80
Three Modes of Operation ..., 81
Introductory Program . ...........o i 82
Keycodes . ... 82
Running a Program ............co i 84

Contents 5
[GT0) 00 . e et e e e 84
Automatic Memory Allocation ............... ... .. i, 85
Section 6: Writing a Second Program........................ 90
Displaying Each Step . ........... ... .o i 93
Displaying a Particular Step ... 93
Interrupting Program Execution ................ ... ... 94
Stopping Program Execution ............... ... ... ... ... 94
Pausing During Program Execution ......................... 97
Program StOPS .. ..ottt 99
Section 7: Decisions ...... ...t 102
FIOWChAMS ...ttt 102
Branching . ... 106
Unconditional Branching and Looping ...................... 106
Conditional Tests and Conditional Branching ................ 108
Section 8: Editing a Program........................ ... ... 118
Finding the Error ........... .. . 118
[SSTIEXECULION ..\ttt ettt 118
CUBA StOPS vttt 120
Changing One Instruction ........... ... it 120
Adding Instructions . ........ ... i 122
Multiple Programs . ... 124
Appendix A: Service and Maintenance...................... 126
Appendix B: More About IRR ............................. 136
Appendix C: Error Messages................ooovvviennn. 138
Appendix D: Continuous Memory ... ....................... 140
Index .. . . 141

The HP-38E/38C Financial
Programmable Calculator

Financial Registers
PMT
Fv CIn.
L Jn C I~
LT C I
C Jev CIw
L] :
1
R,
R,
R,
R,
R,
DMY MDY
OFF oN
|t seon I £
R,
AMORT INT NPV RND IRR
oooos| -
X % T A% R,
....
Rs
ey
PREFI X FIN
== x:y R,
Automatic Memory Stack
Registers
C_I7
L1z
C—Jy
C__1x
LAST X
L]
Storage Registers
M
M
™M
3
<
>
x
134
X
<
1000000000
Program Memory
00
o1
Y
02
1
=3 03
04
[ 05
C ) 06
07
08
Converted
from
storage
registers.
The calculator automatically converts one storage register into seven lines
of program memory, one register at a time as you need them, beginning
with R., and ending with R,.
Storage registers R, through R, are reserved for storage register
arithmetic. Refer to Your HP Financial Calculator for instructions on how
to use them.

Function and Key Index
orr T o
Power switch
(page 13).
D.MY MDY
BEGlN.HHHD END
Payment switch.
Selects timing of
payments in com-
pound interest
calculations (page
29) or selects date
format (page 24).
Shiftkey. Selects
alternate function in
gold above the func-
tion keys. Also used
in display format-
ting (page 18).
(9] shitt key.
Selects alternate
function in blue on
the slanted face of
the function keys
(page 18).
after
,[9], (s79), (REL),
or (GT0], cancels
that key (page 18).
is also the
mantissa function
(page 22).
Digit Entry
Enters a
copy of number
in displayed
X-register into
Y-register. Used
to separate
numbers . *
Changes
sign of number or
exponent of 10 in
displayed X-
register.”
[EEx] Enter expo-
nent. After pressing,
next numbers keyed
in are exponents of
10 (page 23).
(o] thru (@] Digits.
Used for keying in
numbers and display
formatting.*
(-] Decimal point.
Also used for
display formatting.”
Clears con-
tents of displayed
X-register to zero.”
* Refer to Your HP Financial Calculator.
6
Reviewing
Numbers
Exchanges
contents of X- and
Y-registers of stack.*
Rolls down
contents of stack for
viewing in displayed
X-register.”
Recalls
number displayed
before the previous
operation back into
the displayed X-
register (page 22).
Manual Storage
Store. Followed
by number key,
decimal point and
number key, or top
row financial key,
stores displayed
number in storage
register specified.
Also used to perform
storage register
arithmetic.”