Helwett Packard HP-55 User guide

HEWLETT-PACKARD
ElRR:SIS

How to Use This Handbook
This handbook is organized so that it can be used in either of
two ways:
= A logical arrangement of topics lets you read it straight
through if desired.
= Major topics are self-contained, wherever possible, so
that it is not necessary to read an entire section to extract
one idea.
Sections 1, 2, and 3 show you how to calculate with your HP-55;
section 4 (edged in blue ) describes the operation of the digital
timer and section 5 tells you how to program your HP-55.
If you are a beginner, you will appreciate the step-by-step
explanations in this handbook. But if you are already familiar
with Hewlett-Packard pocket calculators, you may find that the
supplementary Quick Reference Guide is all that you need.
Whenever you require additional information about a particular
operation, you can refer back to this handbook.
Before using the calculator you may need to
charge its battery pack as described in appendix A.
The calculator can then be operated while the bat-
tery is charging or, later, on battery power alone.

HEWLETT@PACKARD
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Owner’s Handbook
February 1975
00055-90001 Rev. B 2/75
PRINTED IN U.S.A. © HEWLETT-PACKARD

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Figure 1. Keyboard Layout

Display
Mode Switch
——— OFF-ON Switch
xsY x=Y
——— Programming Keys:
Prefix Keys: i@ [@
inZmm fti=m gal=|
Metric Conversions: — ——— ———
Ibm=kg Ibf =N °Fz°C
1 1
Btu=J
—
——— Arithmetic Keys: |
——— Timer and Program Control Key:

Contents
Versatility Is Everything ............................ 7
Section 1: Getting Started
Power On ... 9
Keyboard ... ... . . . 9
Gold Operations .......... i 9
Blue Operations .............. ... . ... 9
Initial Display ... .. 10
Keying In and Entering Numbers ..................... 10
Simple Arithmetic ....... ... .. .. . 12
Arithmetic and the Stack .............. ... ... ... ..., 15
Left to Right Execution .......................... 18
Constant Arithmetic .......... ... ... ... ... ... 21
Manipulating Numbers in the Stack .................. 21
Rotating the Stack ........... . ... ... 22
Exchanging Xand Y ............ ... 23
Storing and Recalling Numbers ...................... 23
Storing Numbers ......... ... . 24
Recalling Numbers ... ... .. ... ... ... ... 24
Storage Register Arithmetic ...................... 25
Clearing Operations ............. ... ... ... 27
Clearing Storage Registers and the Stack ........ 27
Clearing Prefix Keys ......... .. ... . . 27
Section 2: Fundamental Operations
The Display Format .......... ... .. ... i, 29
Negative Numbers ................... ... ... ... ..... 31
Entering Exponents ........... ... .. 32
Powersof Ten ... ... ... ... ... . ... 32
Negative Exponents ................. ... ... .. 32
Pi 33
Last X . 33
To Avoid Reentering Numbers ................. .. 33
To Correct Input Errors ... o i 34
Basic Functions ........ ... .. .. 34
Reciprocal .......... .. . 34
Square and Square Root ................. ... .. .. 34
Percentage ........... ... 35

Summations ...
Accumulating Results ...........................
DeletingData ...................................
Sums of Products .................. .. ... .. ....
RCL =+
Section 3: Keyboard Calculations
Logarithms ... . .
Natural Logarithms . ..... .. ... ... ... ... ....
Common Logarithms ............................
Exponentials ........ ...
Roots ... ... .
Factorial ... ... ... .. . .
Angular Functions .......... ... ...
Angular Modes .............. ... . oo
Trigonometric Functions ........................
Angle Conversion ............ ... ... .. .. ..
Angular Mode Conversion .......................
Angle Arithmetic in Degrees, Minutes, and Seconds. .
Conversions ... ...
Coordinate Conversion ..........................
English/Metric Conversion .......................
Statistics ...
Mean ... ...
Linear Regression ...............................
Linear Estimate ...................... ... ... ....
Section 4: Using the Timer
Starting the Timer ........... ... ... ... .. ..........
Stopping the Timer ..................................
Changing the Display ................................
Taking Splits ......... ... .
Adding and Subtracting Times .......................
Converting Times ...
Section 5: Programming
What Is a Program?
Program Memory
42
42

Writing a Program ......... ... .. .. i 71
Setting the Program Pointer ..................... 72
Keying Ina Program ............................ 73
Endinga Program .......... ... ... ... .......... 74
Running the Program ............................... 75
Single Step and Back Step .......... ... 75
Changing or Correcting a Program ................... 76
Branching ....... .. ... ... 78
Simple Branching ........... ... ... ............ 78
Conditional Branching .......................... 80
Debugging Your Programs .......................... 82
Program Stops ............. 82
Single-Step Execution .................. ... ...... 83
Common Mistakes .......................... .. ... 83
Appendix A: General Information
ACCESSOIIeS ... i 85
Standard Accessories ............... .o 85
Optional ACcessories ............coeiiuuuennno.. 85
Battery Operation ........... ... ... ... ... ... ... 85
Recharging and AC Line Operation .................. 86
Battery Pack Replacement ........................... 87
Appendix B: Additional Operating Information
Automatic Stack Lift ................... 90
Calculating Range .......... ..o 91
Underflow ... 91
Overflow ... 91
Temperature Range ................ ... ... ... 91
Appendix C: Calculator Troubleshooting
Blank Display ... 92
Multiple Decimal Point Display ....................... 92
Blurring Display ........ooiiii i 92
Flashing Display ..., 92
Battery Failure ....... .. .. . 92
Warranty ... 93
Shipping Instructions ................. ... .. 93
Index .o 95