Retro Review: HP 22S
HP 22S 
Pioneers: 10B, 10bII+ (updated), 14B, 17bII+ (updated), 20S, 21S, 22S, 27S, 32SII, 42S 
Essentials
Company: Hewlett Packard
Years: 1988  1991
Type: Scientific, Formula Programming
Memory: 371
Operating
System: Algebraic
Memory
Registers: 26 (AZ)
Number of Built
In Equations: 16
Batteries: 3 LR44, 3 A76, 3 357
Features
The HP 22S is
an algebraic calculator that shares the similar style with the HP 20S, 21S,
32S, and 42S. The top row of keys ([ √x
], [ e^x ], [ LN ], [ y^x ], [ 1/x ], [ Σ+ ]) act not only as function keys but
soft menu keys.
The standard
variety of functions are present:
* Trigonometric,
hyperbolic, exponential, and logarithmic functions
*
Conversions: kg/lb, °C/°F, cm/in,
ltr/gal, H/HMS, DEG/RAD
* Probability: nCr, nPr, n!
(the factorial function only accepts integer)
* Integer part,
fractional part, absolute value, round to fix setting
*
Statistics: 1 Variable and Linear
Regression (y = mx + b)
* Storage
arithmetic
* Base
conversions: Binary, Decimal, Octal, Hexadecimal. Decimal mode is floating decimal mode.
* This is
really cool: the rectangular (xCOORD,
yCOORD) and polar (RADIUS, ANGLE) conversions get their own keys (well,
shifted functions of [ 1 ], [ 2 ], [ 3 ], and [  ], respectively)
* Percent
Change: old [INPUT] new [(shift)] [1/x]
(%CHG) (nPr and nCr work the same way)
Overall the
keys are really easy to work with and the calculator is a pleasure to use. I like the crisp display. Plus, if blue is
your favorite color like me, the light blue font against the dark background is
a plus.
There are two
manuals with the HP 22S: the User
Manual, and the excellent Science Student Applications for the HP 22S.
Equations
You can either
use one of the 14 builtin equations (listed below) or create your own. While you are creating your own, you can use
either the [STO] or [RCL] keys to call up a letter. All variables are one letter and global.
Equations that are longer than the 12 character display can be scrolled by the
[ √x ] and [ Σ+ ] keys.
Equations can
be evaluated (evaluate the right side of the equation) or solved (a menu will
show the variables to be solved for).
Equations are solved in a reasonably amount of time.
The 16 built in
equations, which are displayed by the equations themselves (no titles):
(Source: HP 22S
manual)
Title

Equation

Length of a
Line/Vector

R=SQRT(X^2+Y^2+Z^2)

Roots of a
Quadratic Equation

X=(B+J*SQRT(B^24*A*C))÷2÷A
Real roots
only, J = 1 or 1

Equation of
Motion (Position)

X=S+V*T+.5*A*T^2
X = position,
V = velocity, A = acceleration

Equation of
Motion (Final Velocity)

F=V+A*T

Kinetic
Energy

E=.5*M*V^2

Force Between
Two Objects (Physics or Electric Force)

F=K*A*B÷R^2
K =
6.67408E11 m^3 kg^1 s^2 (gravitational force)
K =
1.602176621E19 J (electron charge)

Joule’s Law

P=I^2*R

Ideal Gas Law

P*V=N*R*T

Gibb’s Free
Energy

G=HT*S

Pressure of a
Fluid

P=I+D*G*H
G = 9.80665
m/s^2

Radioactive
Decay

K*T=LN(N÷I)

Thin Lens
Equation

O*F+I*F=O*I

Diffraction

A=ASIN(M*L÷D)

Exponential
Growth and Decay

Y=F+(IF)*EXP(K*T)

Root Mean
Square

R=SQRT(Σx^2÷n)
Σx^2 and n
come from statistical data

Time Value of
Money
(End of
Period payments/periods assumed)

(P*100÷IF)*(1+I÷100)^NP*100÷I=B
N = number of
payments/periods
B = present
value
I = periodic
interest rate
P = payment
F = future
value

Final Verdict
The HP 22S is a
great calculator to own. I love the
rectangular/polar conversion set up. The
display is great.
My only criticism
is that I wish the 22S had more memory.
371 bytes can store a handful equations, but data points that are used
in the statistical calculations and storing values in the variables AZ eat up
the memory as well.
4 out of 5
stars.
Eddie
This blog is
property of Edward Shore, 2017
Coming soon (tentative): a review of a favorite Texas Instruments calculator, TI68.
Coming soon (tentative): a review of a favorite Texas Instruments calculator, TI68.