Hewlett-Packard Company
16399 West Bernardo Drive
MS 8-600
San Diego, CA 92127-1899
HP part number F2215AA-90001
Edition 1, February 2007
Read 2007 October 17 – December 11
Reviewed 2007 December 24
Somewhere, maybe it was online, maybe it was in IEEE
Spectrum, I saw an ad for a modern version
of the HP 35, the HP 35s. This was
marketed directly to me, the guy who was there when that calculator was
invented but could never afford the big one.
When I was a senior in High School (1973-4) dad bought an
SR-10 (Texas Instruments ÒSlide RuleÓ), the first four-function calculator with
a square-root. It came with a
booklet describing all sorts of other things you could do (cube roots, logsÉ)
using repeated algorithms from the available functions. It had no register memory. RobÕs dad bought him an SR-50 in
anticipation of his science career at Rice University. Mr. Aanstoos was floored when they
received a partial refund before the products were even shipped, prices were
dropping so fast.
At Baylor, HP35Õs were for sale but I was a music major and
had no calculator of my own until after I had graduated. (I did play around with an HP-25 in one
of Sam WilsonÕs labs and got a little familiar with it RPN and programming from
that.) After I had a job and
money, I bought the competing TI-59 because it had card programmability and a
printer that would go with it, and because it was a little cheaper. But I was always the rebellious reverse
polish notation typeÉ. Finally I have
gotten away from buying clearly inferior products (like PCs) just because they
are a little cheaper.
So, here is the HP-35 again. It is LCD rather than red, power hungry, LEDs. It will run months off of a hearing
aide battery rather than a few hours from a rechargeable Ni-Cd, and it
incorporates everything HP has learned about programmability in over thirty
years.
It comes with a User Guide of about 200 pages. I decided to go through it at ten pages
per day to make sure I didnÕt miss any features. (Now that IÕm done with the calculator manual, this has
morphed into reading Knuth three pages at a time. While writing this, I decided to change it from five to three,
Knuth being rather dense in places.)
I already knew all about HPÕs X Y Z T stack and how to use it (kind of
like a raw microprocessor does) and now I also know about programs,
subroutines, functions, integration, solving for any variables, or even linear
equations, various modes of display, selected bases, and so forth. It has several dozen built in
constants, though one might have to refer to the book to know what they
are. It has 26 alpha-labeled
memories. Programs go by letter
labels as well rather than just straight numbering, meaning they are easier to
view and maintain. There is no
card or printing but the machine does maintain all program and state when
powered off so that this isnÕt such an issue. This calculator has a little bit more smarts than youÕd want
to use manually, but there it is.
Interestingly, it can even be put into ÒalgebraicÓ mode,
although there are distinctions in the algebraic usage from what I learned on
TI calculators and am used to on generic calculators, which are all
algebraic. This might be a problem
if I ever intended to use algebraic mode but this is only required in equation
generation and equations need not be highly complicated.
The most fun was working the examples. There are several short to moderate
length program listings in the text, designed to illustrate the various
concepts being demonstrated. In
order to really get familiar with the calculator and any idiosyncrasies, I
entered each of these and ran them.
This is aided by the memory count and checksum given per
subroutine. Most of these were
fine, but some checksums and even a few of the actual programs had errors in
them. I made corrections in my
text where appropriate when I discovered them.
There are many built-in features such as linear analysis,
simultaneous equations, and integrations and these can be called from user
programs. All operations can be
performed in complex arithmetic where that makes sense.
Most of the features are straightforward and intuitive, for
those of us from the RPN, microprocessor machine-language past. Rather than special codes, it puts up
words or alphanumeric labels in many cases. This greatly improves understandability. Some features, such as the eleven flags
or the conventions for using other numeric bases, are just the opposite. They are clumsy and can even require
the reference manual at the ready for effective use. This is surprising for HP. Seems like those flags could have had names rather than
numbers.
The whole package was about $70 and came with a nice
carrying case and a DVD. The DVD
is basically a flattering history of HP calculators including this one and
including the ÒHippo Story.Ó (Yep,
the Hippo Story is basically what you would think it is: A Hippo ate an HP calculator and the
calculator still worked after it came out the other end, 42 days later!) ItÕs a quarter hour of entertainment
that makes you feel good about your purchase.
Issues notwithstanding, I hope that this is my hand
calculator indefinitely. I know
how to use these older machine and my imagination and needs are tuned to what
they can do. Anything that is
bigger than its 32K memory (and many calculations one might need to do are lots
smaller) can be done on a real computer.
(Of course, a ÒrealÓ computer with a desktop calculator of any desired
style will soon be bundled in cellphone software, if not already.) Still, I havenÕt enjoyed a new
calculator this much since my TI-35 (scientific) that quit working some years
ago. The TI was not programmable
but had most of the keystroke features that the HP 35s does, which is what I
liked about it. This one is much
more powerful, looks to be much more durable, and is RPN.