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.”
Recall.
Fol-
lowed
by
number
key,
decimal
point
and
number
key,
or
top-row
financial
key
recalls
value
from
storage
register
specified
into
the
displayed
X-register.”
CLEAR
[aLL]
Clears
contents
of
stack
(X,Y,Z,T),
all
storage
registers,
statistical
registers,
and
financial
registers.
Leaves
program
memory
untouched.*
Arithmetic
HEXME
Arithmetic
operators
(page
19).*
Percentages
Computes
x%
of
y
and
retains
the
y
value
in
the
Y-register
(page
19).*
4£%]
Computes
percent
of
change
between
number
in
Y-register
and
num-
ber
in
displayed
X-
register
(page
20).*
<7
|
Computes
percent
that
x
is
of
number
in
Y-register
(page
21).*
Calendar
Changes
a
date
in
the
Y-
register
by
the
number
of
days
in
the
X-register
and
displays
day
of
week
(page
25).
Computes
the
number
of
days
between
two
dates
in
the
Y-
and
X-registers
(page
24).
Compound
Interest
Clears
contents
of
financial
registers
(page
29).
(n]
Stores
or
computes
number
of
periods
in
financial
problem
(page
34).
Multiplies
displayed
X-register
by
12
and
stores
the
resulting
value
in
the
n-register
(page
28).
(i)
Stores
or
computes
interest
rate
per
compound-
ing
period
(page
37).
Divides
displayed
X-register
by
12
and
stores
the
resulting
value
in
the
i-register
(page
28).
*
Refer
to
Your
HP
Financial
Calculator.
7
Stores
or
computes
present
value
(initial
cash
flow)
of
a
financial
problem
(page
39).
Stores
or
computes
payment
amount
(page
42).
Stores
or
computes
future
value
(final
cash
flow)
of
a
financial
problem
(page
43).
|
Amortizes
x
number
of
periods
using
values
stored
in
[PMT),
(i),
(pv},
and
the
display.
Updates
values
in
and
[n]
(page
45).
7|
Calculates
simple
interest
(page
32).
v
|
Calculates
the
net
present
value
of
up
to
20
uneven
cash
flows
and
initial
investment
using
values
stored
with
(CFo],
(CR
],
and
(M)
(page
49).
(RR
]
Calculates
the
internal
rate
of
return
(yield)
for
up
to
20
uneven
cash
flows
and
initial
investment
using
values
stored
with
(cro],
(SR,
and
(N
(page
53).
Initial
cash
flow.
Stores
con-
tents
of
displayed
X-register
in
R,,
initializes
(n]
to
zero,
starts
auto-
matic
IRR,
sets
N,
to
1.
Used
at
the
beginning
of
a
dis-
counted
cash
flow
problem.
(page
49).
Cash
flow
j.
Stores
contents
of
displayed
X-register
in
R;,
increments
(n)
by
1,
sets
N;
to
1.
Used
for
all
cash
flows
except
the
initial
cash
flow
in
a
discounted
cash
flow
problem
(page
49).
[N
Stores
the
number
(from
1
to
99)
of
times
each
cash
flow
occurs
in
N;.
Assumes
1
unless
otherwise
specified
(page
49).
Mathematics
[~]
Computes
square
root
of
num-
ber
in
displayed
X-
register
(page
58).
Raises
number
in
Y-register
to
power
of
number
in
X-register
(page
59).
Computes
reciprocal
of
number
in
displayed
X-
register
(page
58).
(n']
Computes
factorial
[n
-
(n-1)...
3-2-1]
of
number
in
displayed
X-register
(page
62).
Natural
antilogarithm.
Raises
e
(approx.
2.718281828)
to
power
of
number
in
displayed
X-register
(page
61).
Computes
natural
logarithm
(base
e,
approx.
2.718281828)
of
number
in
displayed
X-register
(page
61).
Number
Alteration
(RND]
Rounds
mantissa
of
10-digit
number
in
X-
register
to
match
the
display
setting.
(page
63).
8
[INTGR
]
Leaves
only
the
integer
portion
of
number
in
dis-
played
X-register
by
truncating
fractional
portion
(page
64).
Leaves
only
the
fractional
por-
tion
of
number
in
displayed
X-register
by
truncating
integer
portion
(page
65).
Statistics
CLEAR
[£]
Clears
statistical
storage
registers
R,
through
Rs
to
zeros
(page
67).
(z+]
Accumulates
numbers
from
X-
and
Y-registers
into
statistical
storage
registers
R,
through
R
(page
66).
Subtracts
x
and
y
values
from
statis-
tical
storage
regis-
ters
R,
through
Re
for
correcting
2
accumulations
(page
67).
Computes
mean
(average)
of
x
and
y
values
accumulated
by
(Zt]
(page
67).
of
available
Program
Mode
Automatic
Run
Mode
Active
keys:
Go
to.
Fol-
lowed
by
a
decimal
point
and
a
two-
digit
number,
posi-
tions
calculator
to
that
step
number
of
program
memory.
No
instructions
are
executed
(page
93).
Single
step.
Displays
line
num-
ber
and
contents
of
next
program
mem-
ory
line
(page
93).
Back
step.
Displays
line
num-
ber
and
contents
of
previous
program
memory
line.
When
back
stepped
from
line
00,
goes
to
end
of
program
memory
as
defined
by
(eJ
(page
93).
Pressed
from
keyboard:
Go
to.
Fol-
lowed
by
a
two-
digit
number,
posi-
tions
calculator
to
that
step
number
of
program
memory.
No
instructions
are
executed
(page
93).
Single
step.
Displays
line
num-
ber
and
keycode
of
current
program
memory
line
when
pressed;
executes
instruction,
dis-
plays
result,
and
moves
to
next
line
when
released
(page
118).
Back
step.
Displays
line
num-
ber
and
keycode
of
previous
program
memory
line
when
pressed;
displays
original
contents
of
X-register
when
released.
Noinstruc-
tions
are
executed.
(page
119).
Any
key.
Pressing
any
key
on
the
keyboard
stops
execution
of
a
program.
Executed
as
a
recorded
pro-
gram
instruction:
Go
to.
Fol-
lowed
by
a
two-
digit
number,
causes
calculator
to
branch
to
the
specified
line
number
next,
and
resumes
program
execution
from
there
(page
106).
Pause.
Stops
program
execution
for
about
1
second
and
displays
con-
tents
of
X-register
then
resumes
program
execution
(page
97).
Conditional.
tests
value
in
X-register
against
that
in
Y-register.
tests
value
in
X-register
against
zero.
If
true,
calcu-
lator
executes
next
program
memory
line.
If
false,
calcu-
lator
skips
next
line
before
resuming
execution
(page
109).
11
A
Financial
Calculator
With
Programming
Capability!
Your
HP-38E
is
a
versatile,
handheld
financial
calculator
that
uses
the
powerful
Hewlett-Packard
logic
system
to
compute
answers
to
complex
financial,
statistical,
and
mathematical
problems
in
either
of
two
modes:
=
Manual
Problem
Solving.
You
work
step-by-step
through
the
toughest
of
problems,
choosing
from
among
the
dozens
of
availa-
ble
operations
to
calculate
the
correct
answer
quickly
and
easily.
=
Programmed
Problem
Solving.
The
HP-38E
memorizes
a
sequence
of
up
to
99
different
operations
as
you
press
them,
and
then
repeats
that
sequence
at
the
touch of
one key
as
often
as
you
wish
to
solve
a
particular
type
of
problem.
A
program
is
nothing
more
than
a
sequence
of
manual
keystrokes
that
is
remembered
by
the
calculator.
You
can
then
execute
the
program
as
often
as
you
like.
No
prior
computer
programming
experience
is
necessary
for
HP-38E
calculator
programming.
To
see
the
close
relationship
between
the
manual
solution
to
a
problem
and
a
programmed
solution,
let’s
solve
a
problem
manually,
and
then
use
a
program
to
solve
the
same
problem
and
others
like
it.
Manual
Problem
Solving
Example:
The
furniture
store
in
your
area
is
having
a
huge
clearance
sale:
25%
off
all
marked
prices
(before
taxes).
If
the
sales
tax
is
6%,
how
much
does
the
sofa
and
two
matching
armchairs
cost,
now
marked
$1,780
for
the
set?
12
A
Financial
Calculator
With
Programming
Capability!
13
First,
slide
the
calculator
power
switch
OFF
[l[[[[JoN
to
ON.
To
use
the
HP-38E
to
manually
compute
the
discounted
cost
of
the
sofa
and
armchairs,
press
the
following
keys
in
the
order
shown:
Keystrokes
Display
1780
(EnTERY)
1,780.00
Enter
marked
price.
25 445.00
Amount
of
discount
(25%
of
$1,780).
=
1,335.00
Price
less
discount.
6
80.10
Sales
tax.
1,415.10
Total
cost.
Programmed
Problem
Solving
If
you
want
to
compute
the
discounted
cost
plus
tax for
each
piece
or
set
of
furniture
you
are
interested
in,
you
could
repeat
the
above
pro-
cedure,
entering
a
different
marked
price
each
time.
However,
you
might
wish
to
write
a
program
that
would
calculate
the
discounted
price
plus
tax,
instead
of
pressing
all
the
keys
for
each
item.
To
calculate
the
discounted
price
plus
sales
tax
using
a
program,
you
should
firstwrite
the
program,
then
you
must
record
the
program
into
the
calculator,
and
finally
you
run
the
program
to
calculate
the
answer.
Writing
the
Program:
You
have
already
written
it!
A
program
is
nothing
more
than
the
series
of
keystrokes
you would
execute
to
solve
the
same
problem
manually.
Recording
the
Program:
To
record
the
keystrokes
of
the
program
into
the
calculator:
1.
Press
(9)[FR]
(programirun)
to
put
the
calculator
in
program
mode.
2.
Press[9)
(clear
program)
to
clear
the
calculator
of
previous
programs.
14
A
Financial
Calculator
With
Programming
Capability!
3.
Press
the
following
keys
in
order.
(When
you
are
recording
a
program,
the
display
gives
you
information
that
you
will
find
useful
later,
but
you
can
ignore
the
display
for
now.)
ENTER+
2
5
%
These
keys
are
the
same
keys
you
=
pressed
to
solve
the
problem
manually.
6
%
Running
the
Program:
Press
(9]
again
to
get
back
into
run
mode.
Now
all
you
have
to
do
to
calculate
the
discounted
cost
of
any
piece
of
furniture
is
key
in
the
marked
price
and
press
the
(runistop)
key.
When
you
press
,
the
sequence
of
keystrokes
you
recorded
is
auto-
matically
executed
by
the
calculator,
giving
you
the
same
answer
you
would
have
obtained
manually.
For
example,
to
calculate the
discounted
cost
plus
sales
tax
of
the
sofa
and
armchair
set:
Keystrokes
Display
1780
1,780.
R/S
1,415.10
Discounted
cost
plus
6%
sales
tax.
For
the
dinette
set,
marked
at
$950,
and
the
TV/stereo
home
entertainment
center,
marked
at
$1,925:
Keystrokes
Display
950
(rrs)
755.25
Discounted
cost
plus
6%
sales
tax.
1925
1,530.38
Discounted
cost
plus
6%
sales
tax.
A
Financial
Calculator
With
Programming
Capability!
15/16
Programming
the
HP-38E
is
that
easy!
The
calculator
remembers
a
series
of
keystrokes
and
then
executes
them
when
you
press
the
key.
If
you
are
new
to
HP
calculators
and
have
not
yet
read
Your
HP
Financial
Calculator:
An
Introduction
to
Financial
Concepts
and
Problem
Solving,
please
do
so
now.
We
want
you
to
feel
comfortable
with
your
HP-38E
and
we
want
to
show
you
how
easy
it
is
to
use.
Part
I
of
your
HP-38E
Owner’s
Handbook
and
Programming
Guide
reviews
the
function
keys
on
your
keyboard
used
in
manual
or
pro-
grammed
problem
solving
while
part
II is
a
complete
guide
to
HP-38E
calculator
programming.
This manual suits for next models
1
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