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-38C HP-12C
Display type LED LCD
Display format 1 Line 1 Line
FIXed number format Yes Yes
SCIentific number format Yes Yes*
ENGineering number format - -
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-38C HP-12C
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-38C HP-12C
+, -, ×, ÷ Yes  Yes 
1/x Yes Yes
sq. root Yes Yes
x2 - -
LOG x - -
10x - -
LN x Yes Yes
ex Yes Yes
yx Yes Yes
pi - -
% Yes Yes
% change Yes Yes
INTeger truncation and ABSolute value Yes INT only
Trigonometric functions (SIN, COS etc.) - -
Hyperbolic trig. (SINH, COSH etc.) - -
# of trig. modes (degrees, radians, grads) - -
     
Advanced Math HP-38C HP-12C
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-38C HP-12C
Mean, standard deviation (# of variables) 2 2
Summation of n, x, x2 Yes Yes
Summation of n, x, x2, y Yes Yes
Summation of n, x, x2, y, xy Yes Yes
Summation of n, x, x2, y, y2, xy Yes Yes
Summation of lists - -
Random number generator - -
Linear regression, estimate  Yes Yes
Curve fitting - -
Correlation coefficient Yes Yes
Normal distribution - -
Factorial Yes Yes
Gamma - -
Combinations and permutations - -
     
Scientific and Time

HP-38C

HP-12C

Polar / rectangular conversions - -
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 - -
Hrs.min.sec arithmetic - -
Time of day clock - -
Timer - -
Dynamic calculations (timer × rate) - -
Alarms - -
     
Unit Conversions

HP-38C

HP-12C

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-38C HP-12C
Number of payments (n) Yes Yes
Interest rate (i) Yes Yes
Present Value (PV) Yes Yes
Payment (PMT) Yes Yes
Future Value (FV) Yes Yes
     
Cash Flow Analysis HP-38C HP-12C
Net present value (NPV) Yes Yes
Internal rate of return (IRR) Yes Yes
     
Amortization HP-38C HP-12C
Accumulated Interest (ACC INT) Yes Yes
Balance (BAL) Yes Yes
     
Depreciation HP-38C HP-12C
Straight line (SL) - Yes
Sum of the years digits (SOYD) - Yes
Declining balance (DB) - Yes
     
Bonds and calendar functions HP-38C HP-12C
Bond price - Yes
Bond yield - Yes
Date arithmetic / calendar functions - Yes
     
Memory and Programming HP-38C HP-12C
Programming language(s) RPN RPN
RAM / Max # of variables or addressable registers 20 20
Max # of program steps 99 99
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

Yes

Overlapped register and program memory - -
Continuous memory

Yes

Yes

Flags - -
Conditional tests 2 2
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 Yes
Alpha messages and prompts in programs - -
Alpha program listings - -
Alpha string manipulation - -
Program step insert / delete - -
     
I/O and Expansion Features HP-38C HP-12C
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-38C HP-12C
Sounds - -
Self test Yes Yes
Hard case (in addition to soft case) - -
Additional Features - -
Batteries Rechargeable 3 SR44
Length (inches) 5.6" 5.1"
Width 2.8" 3.1"
Height 1.2" 0.6"
Weight (oz or lbs) 6-8 oz* 4 oz
Year of introduction 1979 1981

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-38C 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.
HP-12C notes:
  • FIXed mode set by "f #". SCIentific mode set by "f ." with no choice of the number of digits.
  • Self test: with the calculator off, hold the × key and press ON. The calculator will display running for around half a minute and then activate the entire display to indicate success. The test my be done continuously by pressing + while holding 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.)

Go back to the feature comparison page
Go back to the main exhibit hall