HP 9100 Calculator


The HP 9100A and 9100B are programmable, electronic calculators which perform operations commonly encountered in scientific and engineering problems. Their log, trig and mathematical functions are each performed with a single key stroke, providing fast, convenient solutions to intricate equations. Computer-like memory enables the calculator to store instructions and constants for repetitive or iterative solutions. The easily-readable cathode ray tube instantly displays entries, answers and intermediate results.


Direct keyboard operations include:

addition, subtraction, multiplication, division and square-root.
log x, ln x and ex.
sin x, cos x, tan x, sin-1 x, cos-1 x and tan-1 x. (x in degrees or radians)
sinh x, cosh x, tanh x, sinh-1 x, cosh-1 x and tanh-1 x.
Coordinate transformation:
polar-to-rectangular, rectangular-to-polar, cu­mu­lative addition and subtraction of vectors.
other single-key operations include taking the absolute value of a number, extracting the integer part of a number, and entering the value of π. Keys are also available for positioning and storage operations.


Times for total performance of functions, including worst-case decimal-point placement and carrying:

Add, subtract   2 milliseconds
Multiply, divide   35 milliseconds
Square-root   40 milliseconds
Sin, cos, tan   354 milliseconds
Coordinate transformation    332 milliseconds
ln x   56 milliseconds
ex   141 milliseconds

Numerical Format

The operator can select either FIXED point (eg. 1234.567890) or FLOATING point (scientific notation); eg. 1.234567890 x 10³) for display of entries and answers. The calculator’s dynamic range is 10-98 to 1099 with up to 10 significant digits.
In FIXED point mode, the operator selects the number of decimal places desired between 0-9 on the decimal wheel. Whenever more digits are placed left of the decimal point than the decimal wheel will allow, the calculator automatically reverts to FLOATING point notation to allow completion of the calculation, with no loss of information.

HP 9100A/B Keyboard

HP 9100A/B Keyboard


The calculators are programmed either by use of the keyboard or by magnetic cards. The program mode allows entry of program instructions, via the keyboard, into program memory. Programming consists of pressing keys in the proper sequence. Any key on the keyboard is available as a program step. The program capacity o the 9100A is 196 steps and the capacity of the 9100B is 392 steps. No language or code conversions are required.
The self-contained magnetic card reader/recorder can record programs from program memory onto wallet-size magnetic cards. The reader/recorder can also read the magnetic cards back into program memory for repetitive use. Two programs fo 196 steps each may be recorded on each reusable card. Cards may by cascaded for longer programs.

Program Instructions

Conditional Branching:
IF statements make the comparisions – less-than, equal-to, greater-than – and can be programmed to branch to any of the program addresses.
Unconditional Branching:
GO TO statement can be programmed to branch to any of the program adresses. (Also used for manual addressing and correction of individual program steps.)
A true subroutine capability permitting instant access to subroutines from any point in a program. By using SUB/RETURN instruction, subroutines may be nested up to 5 deep. (9100B only)
Provides conditional branching dependent on manual or programmed setting of flag.
Halts the program for data entry or display.
Brief display of interim results in computation.
Step Program:
Operator may step through program for visual verification of instructions. A ‘dual display’ feature on the 9100B greatly simplifies program editing and modification. It allows the program step and the succeeding one to be displayed simultaneously.


Magnetic core memory includes:
3 display registers (keyboard, accumulator, temporary).
9100A has 16 storage registers with capacity for 196 program steps plus 2 constants. Total of 2208 bits of core memory.
9100B has 32 storage registers with capacity for 392 program steps plus 4 constants. Total of 3840 bits of core memory.
Register accommodates floating point number with 12 significant digits (including 2 undisplayed guard digits) and 2 digit exponent. Alternately, register accomodates 14 program steps.
Contains over 32,000 bits of fixed information for keyboard routines.


Operating range, 0-45°C.
Net 40 lbs. (18,1 kg), Shipping 65 lbs. (29,5 kg).
115 or 230 V ±10% (slide switch), 50-60 Hz, 70 watts.
8¼” high by 16″ wide by 19″ deep. (210 mm. x 406 mm. x 483 mm.)

Accessories furnished no charge

For 9100A:
For 9100B:
  Operating and Programming Manual.
Additional copies – $2.50 each.
For 9100A:
For 9100B:
  Program Library binder containing sample programs.
Additional copies – $30.00.
  Box of 10 magnetic program cards.
Additional box – $10.00.
For 9100A:
For 9100B:
  Pad of 100 program sheets.
Additional pads – $2.50 each.
For 9100A:
For 9100B:
  Magnetic card with pre-recorded diagnostic program.
Additional card – $2.50.
For 9100A:
For 9100B:
  Pull out instruction card mounted in calculator.
Additional copies – $5.00.
  Plastic dust cover.
Additional cover – $2.50.

Additional accessories available

5000-5884   Single magnetic card, $2.00.
09100-90000   Box of 5 program pads, $10.00.
09100-90007   200 magnetic cards without envelopes, $80.00

Purchase Plans

Purchase:     HP 9100A, $4400.
  HP 9100B, $4900.
Rent: HP 9100A, $260.00 per month
  HP 9100B, $285.00 per month
Lease: HP 9100A, $115.00 per month
  HP 9100B, $128.00 per month

Service Contracts Available

9100A and 9100B Comparision

ITEMS    9100A      9100B
Storage Registers     16   32
Program Steps   196   392
Price   $4400   $4900

The 9100B also includes:

  • An additional positioning instruction X←( ) for more convenient data recall.
  • A dual program display for more convenient program edification.
  • A greater subroutine capability.

Program Library

The Program Library furnished with the 9100’s include programmed solutions to practical problems in a wide range of scientific and engineering fields. It serves both as an illustration of programming techniques and as a source of ready-to-use programs. Program Library holders also receive the Hewlett-Packard KEYBOARD, a periodic publication which provides updating information and a forum for the exchange of programs by 9100 users. Program categories include:

  • Business
  • Chemistry
  • Electronics
  • Fluid Mechanics
  • Life Sciences
  • Mathematics
  • Mechanics
  • Physics
  • Statistics
  • Structures
  • Surveying
  • Thermodynamics

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