The Museum of HP Calculators


HP-25 Features

Features in optional ROMs are listed as Option.
Features in HP mag card or tape Application Pacs are listed as +.
Other software is not included.
Display and Keyboard HP-25
Display type LED
Display format 1 Line
FIXed number format Yes
SCIentific number format Yes
ENGineering number format Yes
STanDard / ALL number format -
Alpha messages and prompts -
Softkeys labeled by mag. card or overlay -
Softkeys labeled by display menus -
Softkeys with neither labeling system -
Status annunciators -
Redefinable keyboard -
Logic HP-25
Logic system RPN
Stack levels 4
Last x Yes
Undo -
Precedence -
Parentheses -
Storage Addition (STO +) Yes
Storage Arithmetic (STO +, −, ×, ÷) Yes
Storage Exponentiation (STO ^) -
Recall Arithmetic -
Named variables -
Multiple data types -
Directories -
Math HP-25
+, −, ×, ÷ Yes 
1/x Yes
Yes
x2 Yes
LOG x Yes
10x Yes
LN x Yes
ex Yes
yx Yes
π Yes
% Yes
% change -
INTeger truncation and ABSolute value Yes
Trigonometric functions (SIN, COS etc.) Yes
Hyperbolic trig. (SINH, COSH etc.) -
# of trig. modes (degrees, radians, grads) 3
Advanced Math HP-25
Solver / root finder -
Numeric integration -
Complex numbers -
Matrix operations -
Matrix writer -
Equation writer -
Symbolic operations -
Fractions -
Plotting and graphics (display) -
Plotting and graphics (printer / plotter) -
Statistical HP-25
Mean, standard deviation (# of variables) 1
Σ of n, x, x2 Yes
Σ of n, x, x2, y Yes
Σ of n, x, x2, y, xy Yes
Σ of n, x, x2, y, y2, xy -
Σ of lists -
Random number generator -
Linear regression, estimate  -
Curve fitting -
Correlation coefficient -
Normal distribution -
Factorial -
Gamma -
Combinations and permutations -
Scientific and Time HP-25
Polar / rectangular conversions Yes
Base conversions (2, 8, 10, 16) -
Arithmetic in bases 2, 8 and 16 -
Bit operations (AND, OR, XOR, ...) -
Selectable word size (1-64 bits) -
Selectable complement mode (1's, 2's, unsigned) -
Decimal hrs / hrs.min.sec. conversions Yes
Hrs.min.sec arithmetic -
Time of day clock -
Timer -
Dynamic calculations (timer × rate) -
Alarms -
Unit Conversions HP-25
Centimeters / inches -
Millimeters / inches -
Meters / feet -
Kilograms / pounds (mass) -
Newtons / pounds (force) -
British thermal units / joules -
Liters / gallons -
° Celsius / ° Fahrenheit -
Other -
User-defined units -
Time Value of Money HP-25
Number of payments (n) -
Interest rate (i) -
Present Value (PV) -
Payment (PMT) -
Future Value (FV) -
Cash Flow Analysis HP-25
Net present value (NPV) -
Internal rate of return (IRR) -
Amortization HP-25
Accumulated Interest (ACC INT) -
Balance (BAL) -
Depreciation HP-25
Straight line (SL) -
Sum of the years digits (SOYD) -
Declining balance (DB) -
Bonds and calendar functions HP-25
Bond price -
Bond yield -
Date arithmetic / calendar functions -
Memory and Programming HP-25
Programming language(s) RPN
RAM / Max # of variables or addressable registers 8 Registers
Max # of program steps 49
RAM / Max vars or regs with full optional RAM -
Max # of prog steps with full optional RAM -
Merged program steps  Yes
Manual register / program memory allocation  -
Automatic register / program memory allocation -
Overlapped register and program memory -
Continuous memory -
Flags -
Conditional tests 8
Subroutine levels -
Indexed looping (increment by +/- 1, end at 0) -
Indexed looping (choice of increment and end) -
Multiple index / loop registers -
Line number addressing Yes
Branching by relative line number -
Global program label addressing -
Local program label addressing -
Indirect / computed addressing and control -
Multiple indirection registers -
Pause Yes
Alpha messages and prompts in programs -
Alpha program listings -
Alpha string manipulation -
Program step insert / delete -
I/O and Expansion Features HP-25
ROM modules -
RAM modules or expansion option -
General expansion slots / connector -
Magnetic card reader/writer -
Tape drive -
Disk drive -
Upgradeable firmware -
Optical wand -
Serial port -
Infrared input -
Infrared output -
Printer -
Networking -
Other -
General HP-25
Sounds -
Self test -
Hard case (in addition to soft case) -
Additional Features -
Batteries Rechargeable
Length (inches) 5.1"
Width 2.7"
Height 1.2"
Weight (oz or lbs) 6 oz
Year of introduction 1975
Features in optional ROMs are listed as Option.
Features in HP mag card or tape Application Pacs are listed as +.
Other software is not included.

Unlim means limited only by available memory.
HP-25 notes:
  • The HP-25C has a separate features page.

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