The Museum of HP Calculators

This Hewlett-Packard advertisement, originally published in Scientific American, is used by permission. If errors crept in during the scanning process, please contact Dave Hicks

The new HP-27 Scientific/Plus from Hewlett-Packard.

Gives you every scientific function offered in a preprogrammed calculator-plus the added power of statistics and finance.

Now you can work exponential, log and trig problems--plus statistics, business and finance--all in one powerful preprogrammed calculator.

HP-27 makes short work of a wide range of problems you face every day.

The new HP-27 Scientific/Plus is the most powerful preprogrammed pocket calculator Hewlett-Packard has ever built.

Its highly sophisticated design effectively integrates every significant scientific and financial function--and thus eliminates the need for two separate calculators.

The extraordinary versatility of the HP-27 will be extremely valuable to any scientist or engineer whose responsibilities extend into targeting, budgets, cost analysis and other financial and forecasting considerations.

New statistical and financial functions greatly expand your calculating power.

The HP-27 gives you all the most-used statistical and financial functions, including five new functions never before made available on an HP pocket calculator--variance, correlation coefficient, normal distribution, net present value and internal rate of return for uneven cash flows.

With the remarkable HP-27, you can handle not only scientific calculations but other vital calculations you need to arrive at intelligent financial decisions and recommendations.

All the fundamental scientific, statistical and financial functions are preprogrammed and permanently stored in the HP-27. All you have to do is key in your data, press the appropriate function keys and see your answer displayed in seconds.

And for added convenience, the HP-27 provides an exceptionally large memory capacity, flexible display controls and selective clearing options.

Perhaps the most useful calculator ever designed for scientists and engineers.

The enormous variety of preprogrammed functions on the new HP-27--more than Hewlett-Packard has ever made available in one pocket calculator-gives you solutions to virtually every calculation required in science and business management.

28 exponential, log and trig functions--all preprogrammed:

The HP-27 gives you all the most-used exponential, log and trig functions-including sines, cosines, tangents and their inverses in three angular modes; natural and common logs and anti-logs; pi; related arithmetic functions; coordinate conversions; angle conversion, angle addition and subtraction.

15 important statistical functions--all preprogrammed:

Many statistical functions useful in both science and business are provided by the HP-27-including three new functions: variance, correlation coefficient and normal distribution. Summations of data points are stored for easy access. What's more, you can adjust or correct input data without having to repeat an entire calculation. Once your data is keyed in, you can calculate the means, standard deviations and variances for two variables. You can also calculate linear regression, linear estimates and the correlation coefficient for two variables. In addition, you can calculate the density function and upper-tail area under a normal distribution curve.

10 valuable financial functions all preprogrammed.

For convenience in solving both personal and job related business problems-such as mortgages, compound interests and sinking funds-all fundamental financial functions are preprogrammed into the HP-27 to eliminate the need for bulky books of equations and interest tables. Two new preprogrammed functions--net present value and internal rate of return for uneven cash f lows--facilitate capital budgeting and resource allocation. I n addition, the HP-27 provides three separate percentage functions for ease in calculating margins, markups, discounts, percents of totals, etc.

RPN--the professional logic system--gives added flexibility, speed and confidence.

Compared to algebraic logic, the RPN logic system is faster, more efficient and more versatile in solving the complex problems faced by today's professionals in science and finance. For most calculations, it requires fewer keystrokes. You don't need parenthesis keys and you don't need to keep track of complicated hierarchies. Intermediate answers are displayed and stored automatically in an operational stack of four memories--so you never need to write them down and risk errors. And because only intermediate results are stored, the size and complexity of problems that can be handled with RPN logic are virtually unlimited.

Exceptional memory capacity and versatile operating options for even greater convenience.

The HP-27 Scientific/Plus gives you all the advantages of expanded memory capacity, selective memory clearing and three display modes. 20 memories help simplify your most difficult calculations. In addition to the 5 financial memories, the 4 operational stack memories and a last-x memory, the HP-27 provides 10 addressable memories for data storage. This large memory capacity lets you make highly complex and lengthy calculations with ease and assurance. Displayed values may be stored in any addressable memory and later recalled to the display. In addition, register arithmetic can be performed on all ten addressable memories.

6 clearing options give you flexible use of memories.

With the CLx key, you can clear the display only. You can clear all four memories of the operational stack with the STK key. The last six addressable memories, which are used for statistics, are cleared with the Sum key. The REG key clears all ten addressable memories, all five financial memories and the last-x memory Or you can clear the status of the financial memories with the RESET key. In addition, you can clear the prefix keys with the key labeled PREFIX.

You can display fixed decimal, scientific or engineering notation.

In fixed decimal, the most commonly used notation, you can display between 0-9 places to the right of the decimal point. Whenever the value is too large or too small to be displayed in fixed notation, the display automatically changes to scientific notation. In scientific notation, useful when working with very large or small numbers, values are displayed with a single digit to the left of the decimal point followed by up to seven digits to the right, and a two-digit exponent. In engineering notation, useful in working with many units of measure, such as kilo (103), nano (10-9), etc., values are displayed with exponents that are multiples of 3.

The HP-27 Scientific/Plus Pocket Calculator comes complete with:

Optional Accessories (Details sent with HP-27)

Full one year warranty.

The HP-27 is warranted against defects in materials and workmanship for one year from the date of delivery. During the warranty period, Hewlett-Packard will repair, or at its option, replace at no charge components which prove to be defective, provided the calculator is returned shipping prepaid, to Hewlett-Packard's Customer Service facility.

This warranty does not apply if the calculator has been damaged by accident or misuse, or as a result of service or modification by other than an authorized Hewlett-Packard Customer Service facility. No other express warranty is given by Hewlett-Packard. HEWLETT-PACKARD SHALL NOT BE LIABLE FOR CONSEQUENTIAL DAMAGES.

Hewlett-Packard Quality.

HP pocket calculators are designed and built for you-the business or professional person-who needs a calculator rugged enough for day-in, day-out use and as up-to-date as tomorrow.

HP pocket calculators meet these requirements-and more-because they're the most advanced pocket calculators in the world.

Every key is double injection molded. The symbol on the face of the key goes through the entire key, so it won't wear off--no matter how often the key is pressed.

Every key is tested twice. A quality control inspector presses the keys to make sure they feel right, then a specially designed machine exercises them to make sure they function right.

Under the keyboard is a moisture-proof polyethylene barrier to help protect the inside of the calculator from coffee spills and similar hazards.

The heavy gauge plastic case is contour-designed to fit the hand comfortably, and rugged enough to withstand a tumble to a hard floor. (One HP pocket calculator even withstood an accidental journey through a snow blower.)

Uncompromising quality, innovative design, high quality components and precision assembly combine to produce calculators that are second to none.

Hewlett-Packard reserves the right to make changes in materials, specifications or accessories without notice.

The HP-27 Scientific/Plus Pocket Calculator Features and Specifications.

Mathematical Functions:
sin, cos, tan --Trigonometric functions
sin-1, cos-1, tan-1 --and their inverses
DEG, RAD, GRD --Degrees, radians, and grads mode
ln, ex --Natural log and antilog
log, 10x --Common log and antilog
yx, x2 --Exponential functions
->R, ->P --Rectangular/polar coordinate conversion
H.MS+, H.MS- --Time (angle) addition and subtraction in hours, minutes and seconds
->H.MS, ->H --Time (angle) conversion in hours, minutes and seconds to decimal hours (degrees).
1/x. sqrt(x), pi --Convenient math functions
+, -, x, ÷ --Arithmetic functions

Statistical Functions:
Sum+ --Accumulates x, y, x2, y2, xy, n
Sum- --Deletes unwanted data
L.R. --Linear regression coefficients
y^ - Linear estimate
r --Correlation coefficient mean
x bar --Mean--two variables
s --Standard deviation--two variables
VAR --Variance
N.D. --Normal distribution
n! --Factorial

Financial Functions:
n --Number of periods
I --Periodic interest rate
PMT --Periodic payment amount
PV --Present value of money
FV --Future value of money
NPV --Net present value
IRR --internal rate of return
% --Percent
delta% --Percent difference
%sum --Percent of total

Data Manipulation; display control, clearing options; storage functions:
ENTER --Separates numerical entries
x!=y --Exchanges contents of x and y stack registers
R dn --Rolls down contents of stack registers
CHS --Changes the sign of a number
EEX --Enter exponent
LASTx --Recalls last entry after an operation
FIX --Sets fixed decimal notation display
SCI --Sets scientific notation display
ENG --Sets engineering notation display
CLx --Clears display
CLEAR STK --Clears stack
CLEAR REG --Clears addressable registers, financial registers and LASTx
CLEAR Sum --Clears summation registers
CLEAR PREFIX --Clears prefix key
RESET --Clears financial status for a new problem.
STO --Stores displayed value into addressable register.
RCL --Recalls a number to the display from an addressable register.
f --Gold shift key; selects functions printed in gold on keyboard.
g --Black shift key; selects functions printed in black on front face of keys.

Physical Specifications:

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