Jake-S@cup.portal.com (Jake G Schwartz) (03/24/91)
The HP32S II - A Shift Towards Better Functionality
Hewlett-Packard's newest mid-line scientific calculator, the HP32S II,
is a direct replacement for the original HP32S RPN machine which has been
around for over a year now. Since HP's apparent attempts to move into the
lower-priced calculator market, we have seen a half dozen new scientific
machines ranging from the HP20S up to the HP48SX (with which most of us are
familiar). The HP20S, HP21S (statistics machine), HP22S and HP27S are
algebraic units, while the HP32S and HP42S are based on the "classic"
4-level stack RPN data entry and math. The new '32S II is also an RPN unit
but has had some significant changes built in which give the machine a much
tighter feel, as well as a fair-sized chunk of new capabilities at the same
price as its predecessor. (Additionally, the 16K ROM operating system was
packed sufficiently so no additional space was needed in order to shoehorn
in the enhancements.)
The presence of a single (gold-colored) keyboard shift key with only
one corresponding function name above each keyboard key is an ambitious goal
for simplifying the look of the entire line of HP machines. The HP41's
keyboard and XEQ/ALPHA method of reaching hidden functions may have been the
initial test for this "cleaner look" philosophy. The concept of LCD menus
and soft keys has now been in HP calculators for 5 years. The HP18C,
released in 1986 with its single shift, soft keys and LCD menus, began this
"new wave" (ahem). When the lower-end machines were being planned, it
probably was concluded that continuing the use of key menus would permit
reduction of keyboard clutter while simultaneously allowing more
functionality with a limited keyboard. The problem with this concept as I
see it, is that as more and more menus are used, a greater percentage of
functions become hidden from the fingertips. We must then remember in which
menu a desired function resides and it is much more difficult for key
sequences to become second nature. When all functions were out on the
keyboard deck, there was much more of a chance that a function's key
position could ultimately be memorized. (The old HP67 and HP34C may have
taken this concept to its practical limit with "f", "g" and "h" shift keys
along with four functions on most of the other keys on the keyboard.) Of
course, a finite number of keys and a practical limit to the number of shift
keys prevents any solution from being perfect for all calculators.
The folks who did the HP32S II seem to have learned from the original
32S that a "clean" keyboard isn't always the most useful one. A machine like
this, with 22 or so different menus (including 6 submenus) makes life
somewhat more difficult than necessary. For example, on the '32S if I wish
to find the mean of the X entries in a statistical sum, I must first press
the shift-STAT key. This takes me to a menu containing an "x-mean/y-mean"
key. Pressing this key reveals a submenu where the X-mean key is found, and
I can access it from here. This has been simplified on the '32S II. A second
(blue) shift key has been added and two shifted functions now reside above
most of the keyboard keys. A handful of functions which previously were
hidden in menus are now accessable on the keyboard deck. All menus are only
one level deep and there are only 14 of them. My latest count totals around
15-20 new functions which have been added to the machine, including
X-interchange-any-register, the Xth root of Y, roll up and four metric
conversions and their inverses. However, the two major functional
enhancements for my money are the addition of (1) algebraic equation entry
capability for solving and integrating; and (2) a new rational fraction
display and calculation mode.
Ever since the equation solver found its way into HP calculator
firmware (in June of 1986 with the HP18C), there have been attempts to weave
both scientific and business calculators around the HP Solve environment in
one form or another. With the algebraic-entry machines, this task was easier
since the entry format of equations was already supported in normal keyboard
calculations. However, to have a solver in an RPN machine such as the HP32S
which didn't support full alphanumeric capability (like the HP42S does), it
was necessary to require that solver "equations" be represented by RPN
programs which evaluate the desired expression and leave zero in the X
register as a result. Consequently, someone who purchased a '32S would have
to initially learn RPN programming even if he only wished to use the machine
to repetitively solve mathematical formulas. The algebraic entry capability
of the HP32S II (added to the original HP32S' RPN program solver) makes life
a lot simpler. Formulas are entered roughly as they are written, with
parentheses and equals symbols. Multiple formulas may be saved in the
machine at once, allowing the user to choose whichever one he needs at the
moment. The capacity for formulas is limited only by available RAM memory
(which is still around 390 bytes, presumably to keep the hardware design
unchanged from before).
Previously, the closest thing to a fraction feature on any HP
calculator has been the "->Q" key on the HP48SX. The HP32S II not only
allows fraction entry at any time, but also has a new "FDISP" key which
works similarly to the FIX, SCI or ENG keys to turn on full-time fraction
display mode. Entry of fractions is (not surprisingly) similar to the HP48
fraction calculator which was demonstrated by Bill Wickes on June 2, 1990 in
Chicago when he demonstrated it as an example of HP48 vectored ENTER
capability. To enter one and two-thirds, simply press "1.2.3". After
pressing "1.2" the display shows just that, however when the decimal point
is pressed a second time, the first displayed decimal point changes to a
blank space and a slash appears after the 2. Then, entering the 3 completes
the task. If the machine is currently in FIX, SCI, ENG or STD (called "ALL"
in this unit) mode, the value will be displayed as 1.6666... following
termination of numeric digit entry. However, if FDISP has been chosen, the
"1 2/3" will remain displayed. Numbers are maintained internally in
floating-point fashion, but will be displayed as rational fractions. By
modifying the status of two flags and using the "/c" function, one may also
control the value of the displayed denominator in the fraction.
Other enhancements to the '32S II include extending the number of user
flags from seven to twelve; adding population standard deviation of X and Y
statistical data as well as the sample standard deviation; and adding the
less-than-or-equal-to and greater-than-or-equal-to comparison tests to the
x-versus-y and x-versus-zero test menus. Conversions between polar and
rectangular coordinates, decimal hours and hours/minutes/seconds and degrees
and radians have been moved out of hidden positions in menus and placed on
the keyboard in shifted key positions. The additional shift key has also
allowed conversions between kilograms and pounds, degrees Celcius and
Fahrenheit, centimeters and inches and liters and gallons to be added. For
greater visibility, the numeric dot-matrix LCD digits are at least one-third
taller than their counterparts on the original HP32S.
Overall, the HP32S II has a much "tighter" feel to it, giving a better
command over keys and functions with fewer keystrokes required to do many of
the operations formerly hidden in the old '32S. The user is no longer
required to learn RPN keystroke programming if he needs to solve or
integrate expressions, but it's there when the need arises. The capability
to manipulate numbers as fractions adds icing on the cake for those who
frequently handle such quantities. I would highly recommend this machine to
those who desire a moderate-cost scientific calculator with HP's RPN entry
mode, keystroke programming and a significant number of mathematical
functions.
Jake Schwartz