The Museum of HP Calculators


HP-48S 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-48S
Display type LCD
Display format 8Line
FIXed number format Yes
SCIentific number format Yes
ENGineering number format Yes
STanDard / ALL number format Yes
Alpha messages and prompts Yes
Softkeys labeled by mag. card or overlay -
Softkeys labeled by display menus Yes
Softkeys with neither labeling system -
Status annunciators Yes
Redefinable keyboard Yes
Logic HP-48S
Logic system RPN/RPL
Stack levels Unlim
Last x Yes
Undo Yes
Precedence Yes
Parentheses Yes
Storage Addition (STO +) Yes
Storage Arithmetic (STO +, −, ×, ÷) Yes
Storage Exponentiation (STO ^) -
Recall Arithmetic -
Named variables Yes
Multiple data types Yes
Directories Yes
Math HP-48S
+, −, ×, ÷ Yes 
1/x Yes
Yes
x2 Yes
LOG x Yes
10x Yes
LN x Yes
ex Yes
yx Yes
π Yes
% Yes
% change Yes
INTeger truncation and ABSolute value Yes
Trigonometric functions (SIN, COS etc.) Yes
Hyperbolic trig. (SINH, COSH etc.) Yes
# of trig. modes (degrees, radians, grads) 3
Advanced Math HP-48S
Solver / root finder Yes
Numeric integration Yes
Complex numbers Yes
Matrix operations Yes
Matrix writer Yes
Equation writer Yes
Symbolic operations Yes
Fractions Yes*
Plotting and graphics (display) Yes
Plotting and graphics (printer / plotter) Option
Statistical HP-48S
Mean, standard deviation (# of variables) Multiple
Σ of n, x, x2 -
Σ of n, x, x2, y -
Σ of n, x, x2, y, xy -
Σ of n, x, x2, y, y2, xy -
Σ of lists Yes
Random number generator Yes
Linear regression, estimate  Yes
Curve fitting Yes
Correlation coefficient Yes
Normal distribution Yes
Factorial Yes
Gamma Yes
Combinations and permutations Yes
Scientific and Time HP-48S
Polar / rectangular conversions Yes
Base conversions (2, 8, 10, 16) Yes
Arithmetic in bases 2, 8 and 16 Yes
Bit operations (AND, OR, XOR, ...) Yes
Selectable word size (1-64 bits) Yes
Selectable complement mode (1's, 2's, unsigned) -
Decimal hrs / hrs.min.sec. conversions Yes
Hrs.min.sec arithmetic Yes
Time of day clock Yes
Timer Yes
Dynamic calculations (timer × rate) -
Alarms Yes
Unit Conversions HP-48S
Centimeters / inches Yes
Millimeters / inches Yes
Meters / feet Yes
Kilograms / pounds (mass) Yes
Newtons / pounds (force) Yes
British thermal units / joules Yes
Liters / gallons Yes
° Celsius / ° Fahrenheit Yes
Other Yes
User-defined units Yes
Time Value of Money HP-48S
Number of payments (n) -
Interest rate (i) -
Present Value (PV) -
Payment (PMT) -
Future Value (FV) -
Cash Flow Analysis HP-48S
Net present value (NPV) -
Internal rate of return (IRR) -
Amortization HP-48S
Accumulated Interest (ACC INT) -
Balance (BAL) -
Depreciation HP-48S
Straight line (SL) -
Sum of the years digits (SOYD) -
Declining balance (DB) -
Bonds and calendar functions HP-48S
Bond price -
Bond yield -
Date arithmetic / calendar functions Yes
Memory and Programming HP-48S
Programming language(s) RPL
RAM / Max # of variables or addressable registers 32K Bytes
Max # of program steps Unlim
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 Yes
Overlapped register and program memory -
Continuous memory Yes
Flags 128
Conditional tests Many
Subroutine levels Unlim
Indexed looping (increment by +/- 1, end at 0) Yes
Indexed looping (choice of increment and end) Yes
Multiple index / loop registers Yes
Line number addressing -
Branching by relative line number -
Global program label addressing Yes
Local program label addressing Yes
Indirect / computed addressing and control Yes
Multiple indirection registers Yes
Pause Yes
Alpha messages and prompts in programs Yes
Alpha program listings Option
Alpha string manipulation Yes
Program step insert / delete Yes
I/O and Expansion Features HP-48S
ROM modules -
RAM modules or expansion option -
General expansion slots / connector -
Magnetic card reader/writer -
Tape drive -
Disk drive Option
Upgradeable firmware -
Optical wand -
Serial port Yes
Infrared input Yes
Infrared output Yes
Printer Option
Networking -
Other -
General HP-48S
Sounds Yes
Self test Yes
Hard case (in addition to soft case) -
Additional Features -
Batteries 3 AAA
Length (inches) 7.1"
Width 3.2"
Height 1.1"
Weight (oz or lbs) 8oz
Year of introduction 1991
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-48S notes:
  • Fractions were input as algebraic objects like '4 + 7/8' and output using the →Q function.
  • To start the continuous self test with the calculator turned on, press and hold ON and press E. This will continuously test internal ROM and RAM and generate patterns in the display. OK-48 will be shown on each pass if all is well. To exit, press and hold ON and press C.
  • To start the keyboard test with the calculator turned on, press and hold ON and press D. Press E. KBD1 will appear in the display. Starting with the upper left key (A), press each key moving right to left and then down until you get to the + key. KBD1 OK will then be displayed. The calculator will beep between each keystroke. If the calculator displays a hex number, either there is a keyboard problem or you pressed the key in the wrong order. To exit, press and hold ON and press C.
  • To start the IR loop back test with the calculator turned on, press and hold ON and press D. Press D. Press EVAL. The calculator should display IRLB OK. To exit, press and hold ON and press C.
  • To start the serial UART loop back test with the calculator turned on, press and hold ON and press D. carefully connect pins 2 and 3 (send and receive) of the serial port. Leave the pins connected during the test. Press PRG. The calculator should display U_LB OK. If the test fails, make sure you shorted the correct pins and no others. To exit, press and hold ON and press C.
  • To display the CPU speed, with the calculator turned on, press and hold ON and press D. Press A. The CPU speed is displayed in hertz. To exit, press and hold ON and press C.

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