Saturday, June 25, 2022

Retro Review: Hewlett Packard HP 33S

Retro Review:   Hewlett Packard HP 33S








The calculator with the Chevron Keyboard!

Quick Facts

Model:  HP 33S
Company:  Hewlett Packard
Years:  2003-2007
Type:  Scientific
Batteries: 2 x CR-2032
Operating Modes:  RPN, ALG
Memory:  31,277 bytes
Number of Registers: 27, A-Z, i
Display:  2 stack levels

Features

*  standard scientific calculator functions: trig, logs, power, absolute value, integer and fractional part, combinations, permutations, random numbers, hyperbolic functions, and more
*  factorial function that allows real numbers;  Γ(x) = (x - 1)!
*  polar and rectangular conversion functions,  very popular (for good reason) 
*  40 scientific constants
*  8 sets of SI-US conversions
*  base conversions 
*  algebraic mode (which I don't know anyone who would use this calculator in algebraic mode, but it's there)
*  linear regression  (y = mx + b)
*  fraction display mode ( [ ←| ] [ . ] (FDISP))
*  storage and recall arithmetic

We can store equations for evaluation, solving, and integration.  

Full list of conversions:

Polar (→θ,r) - Rectangular (→y,x)
Hours (→HR) - Hours-Minutes-Seconds (→HMS)
Degrees - Radians
Kilograms - Pounds
Degrees Celsius - Degrees Fahrenheit
Centimeters - Inches
Liters - Gallons

Programming

The HP 33S has keystroke programming and the set of commands similar from the HP 32SII:  

*  INPUT var
*  VIEW var  (views the variable without putting the variable's value on the stack)
*  Subroutines and Return
*  Comparison tests between x and 0, x and y.  If the test is true, execute the next step, otherwise skip the next step
*  ISG:  Increment and skip if greater
*  DSE:  Decrement and skip if equal or less than

The HP 33S designates one register, lower case i, for indirect addressing.  The absolute integer value of i determines where storage, recall, label, subroutine, integration variable, exchange, and function designation.  Use (i) to use indirect addressing.  Indirect registers can also access statistical sums:

(i) = 27,  i 
(i) = 28,  n
(i) = 29,  Σx
(i) = 30,  Σy
(i) = 31,  Σx^2
(i) = 32,  Σy^2
(i) = 33,  Σxy

The HP 33S has 26 labels, which restrict programs to 26.  Hence, LBL A instead of LBL A0001.   At first, I didn't like the restriction, but I learned to live with it and don't mind it as much.  

Let's Talk About the Chevron Keyboard

The HP 33S is a unique calculator it's keyboard style:  the keys take a slanted quadrilateral shape, with the center column of keys taking a chevron style shape.   At the top there is a directional pad.  Hewlett Packard took a chance with the design from the standard calculator shape, and it was not a homerun.   

The beginning production of the HP 33S was not successful. Keys had bad responses, the display was not up to par, and some keys are hard to press.   It took Hewlett Packard several production runs to get the keyboard working right, which unfortunately killed the reputation of the HP 33S.  Towards the end of its run, the keyboards were fixed.

I don't mind the unique keyboard, my biggest issue was the spacing the keys where sometimes the shifted functions and alpha characters did not have much space.  This made the keyboard busy.  I also do not like the black arrows on the green and purple backgrounds on the shift keys, I use HP used a lighter font for those arrows.  

A Phoenix of Calculators  

When the HP 33S first hit the market, the calculator was disliked.  Now, it is a sought after calculator.   The original price for the 33S was about $50 US dollars, now if you want one, be prepared to pay at least $75 US dollars, sometimes triple digits.  Make sure you are buying the HP 33S from later in the run (towards 2007).  

Another factor of why the HP 33S is becoming a collector's calculator, the successor, the HP 35S, had several shortcomings such as the number of mathematical bugs and the lack of the rectangular and polar conversion functions.   The HP 33S is closer to the classic style, like the HP 32S and HP 32SII.  

I don't expect to ever be an anniversary edition of the HP 33S but it was an underrated calculator and has its place in calculator history.

Tomorrow I have a list of programs and an integer demonstration.  

Eddie

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