The Museum of HP Calculators


Calculator Comparison

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-10C HP-33E
Display type LCD LED
Display format 1 Line 1 Line
FIXed number format Yes Yes
SCIentific number format Yes Yes
ENGineering number format Yes 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 Yes -
Redefinable keyboard - -
Logic HP-10C HP-33E
Logic system RPN RPN
Stack levels 4 4
Last x Yes Yes
Undo - -
Precedence - -
Parentheses - -
Storage Addition (STO +) Yes Yes
Storage Arithmetic (STO +, −, ×, ÷) Yes Yes
Storage Exponentiation (STO ^) - -
Recall Arithmetic - -
Named variables - -
Multiple data types - -
Directories - -
Math HP-10C HP-33E
+, −, ×, ÷ Yes  Yes 
1/x Yes Yes
Yes Yes
x2 Yes Yes
LOG x Yes Yes
10x Yes Yes
LN x Yes Yes
ex Yes Yes
yx Yes Yes
π Yes Yes
% Yes Yes
% change - -
INTeger truncation and ABSolute value INT only Yes
Trigonometric functions (SIN, COS etc.) Yes Yes
Hyperbolic trig. (SINH, COSH etc.) - -
# of trig. modes (degrees, radians, grads) 3 3
Advanced Math HP-10C HP-33E
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-10C HP-33E
Mean, standard deviation (# of variables) 2 2
Σ of n, x, x2 Yes Yes
Σ of n, x, x2, y Yes Yes
Σ of n, x, x2, y, xy Yes Yes
Σ of n, x, x2, y, y2, xy Yes Yes
Σ of lists - -
Random number generator - -
Linear regression, estimate  Yes Yes
Curve fitting - -
Correlation coefficient Yes Yes
Normal distribution - -
Factorial Yes -
Gamma - -
Combinations and permutations - -
Scientific and Time HP-10C HP-33E
Polar / rectangular conversions Yes 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 Yes
Hrs.min.sec arithmetic - -
Time of day clock - -
Timer - -
Dynamic calculations (timer × rate) - -
Alarms - -
Unit Conversions HP-10C HP-33E
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-10C HP-33E
Number of payments (n) - -
Interest rate (i) - -
Present Value (PV) - -
Payment (PMT) - -
Future Value (FV) - -
Cash Flow Analysis HP-10C HP-33E
Net present value (NPV) - -
Internal rate of return (IRR) - -
Amortization HP-10C HP-33E
Accumulated Interest (ACC INT) - -
Balance (BAL) - -
Depreciation HP-10C HP-33E
Straight line (SL) - -
Sum of the years digits (SOYD) - -
Declining balance (DB) - -
Bonds and calendar functions HP-10C HP-33E
Bond price - -
Bond yield - -
Date arithmetic / calendar functions - -
Memory and Programming HP-10C HP-33E
Programming language(s) RPN RPN
RAM / Max # of variables or addressable registers 10 8
Max # of program steps 79 49
RAM / Max vars or regs with full optional RAM - -
Max # of prog steps with full optional RAM - -
Merged program steps  Yes Yes
Manual register / program memory allocation  - -
Automatic register / program memory allocation Yes -
Overlapped register and program memory - -
Continuous memory Yes -
Flags - -
Conditional tests 2 8
Subroutine levels - 3
Indexed looping (increment by +/- 1, end at 0) - -
Indexed looping (choice of increment and end) - -
Multiple index / loop registers - -
Line number addressing Yes Yes
Branching by relative line number - -
Global program label addressing - -
Local program label addressing - -
Indirect / computed addressing and control - -
Multiple indirection registers - -
Pause Yes Yes
Alpha messages and prompts in programs - -
Alpha program listings - -
Alpha string manipulation - -
Program step insert / delete - -
I/O and Expansion Features HP-10C HP-33E
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-10C HP-33E
Sounds - -
Self test Yes Yes
Hard case (in addition to soft case) - -
Additional Features - -
Batteries 3 SR44 Rechargeable
Length (inches) 5.1" 5.6"
Width 3.1" 2.8"
Height 0.6" 1.2"
Weight (oz or lbs) 4 oz 6-8 oz*
Year of introduction 1982 1978
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-10C notes:
  • Self test: with the calculator off, hold the × key down and press and release ON, then release ×. The calculator will display running for around half a minute and then activate the entire display to indicate success. The test may be done continuously by (with the calculator off) holding + down while pressing the ON key. To stop the continuous test at the end of the current iteration, press and hold − and then press ON.
  • There is also a keyboard test. With the calculator off, press and hold ÷ and press ON. Now press each key from the top left moving left to right and then down (the enter key gets pressed in both the third and fourth rows.) If all keys are pressed in the correct order and are working, the model number (without the C) is displayed. Otherwise, Error 9 is displayed. (The display will show a changing pattern of segments as keys are pressed.)
HP-33E notes:
  • Late versions were about 1.5 oz lighter than earlier versions.
  • Self test by pressing STO and then ENTER. At the end of the test, the entire display lights to indicate success.

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