Is RPN still relevant?

[Matt Agajanian]

Hi all.

I’m gonna say yes. Since there’s SwissMicros, Panamatik, the developers of WP34S.

In addition, for the smartphone, there're Cuvee, the GO-2x series, i41CX. Plus, our beloved 15C has been resurrected.

As an added support, the HP-12C remains the pinnacle of financial calculators and has many upon many professionals using them and they're RPN proficient. Thus, I would think RPN survives to this day.

Yeah the direct formula entry systems from Casio, TI, Sharp, and Canon represent the most direct means to enter mathematical expression which seems to put RPN in a retirement hone. And yes, these manufacturers thrive on the educational market. Thus seeming to make RPN calculators fall off the popularity charts. BUT, there are those of us old enough to remember, experience and utilize RPN calculators from their earliest days. Also, there are those of us who've taught our kids how to use these RPN/HP beauties.

I'm thinking that the above paragraphs make a strong case that RPN and RPN calculators are still relevant.

[Garth Wilson]

Quote:the direct formula entry systems from Casio, TI, Sharp, and Canon represent the most direct means to enter mathematical expression which seems to put RPN in a retirement hone. And yes, these manufacturers thrive on the educational market.

...and that right there is the problem.  My answer is at https://www.hpmuseum.org/forum/thread-19...#pid166016 .

[Matt Agajanian]

My apologies for a somewhat repeat of a question from antiquity. Thanks.

[ttw]

Many years ago (in the 1970s), I would give a few nighttime seminars for students wanting to learn to use calculators. I found that most had algebraic calculators but that all of them found the RPN a bit more intuitive. This may seem funny but the difference is in looking at an expression and doing the operations. The RPN mimics one "evaluate from the inside out" rather well. Calculation isn't the same as notation.

With programmable calculators, we found (fooling around with expressions in early versions) that the number of keystrokes in RPN was around 1/2 to 2/3 that of algebraic; mostly because of not having to enter parethesis. I remember using (a now forgotten) continued fraction expression for estimating interest rates that took about 100 keystrokes in RPN but over 200 in algebraic.

[Albert Chan]

I think market already decided ... algebraic mode win.
Even modern HP-12C has algebraic mode as option.

[bxparks]

(12-17-2023 06:50 AM)Matt Agajanian Wrote:  In addition, for the smartphone, there're Cuvee, the GO-2x series, i41CX.

Funny, I've not heard of any of these, so I guess they are for iOS. My go-to recommendation for smartphones is Free42 because it works on all major platforms (Android, Linux, Windows, MacOS, IOS). It is used on the DM42, and of course, it's a superset of the real HP-42S. It is convenient to have the same UI on all my laptops and devices. Other notable RPN apps on my phone for fun and research are: Plus42, JRPN 15C, JRPN 16C, WRPN 16C, Droid48, 48sx, Emu48, WP34s. I cannot recommend the "Touch RPN" app anymore.

As for whether RPN is still relevant, I feel like this is similar to asking whether classical music is relevant compared to pop music. Obviously pop music is orders of magnitude more popular and successful than classical. But RPN is still useful and preferred by some people, for certain types of calculations, in certain situations. I am glad there is at least one company (SwissMicros) that is still making hardware for RPN.

[Edit: Removed unnecessary digression..]

[Maximilian Hohmann]

Hello!

(12-17-2023 06:50 AM)Matt Agajanian Wrote:  I’m gonna say yes. Since there’s SwissMicros, Panamatik, the developers of WP34S.

It all depends on your definition of the term "relevant". Panamatik sells spare parts for rare collector's items in (my guess!) numbers that don't surpass two digits, WP34S was ten years ago and about the sales figures of SwissMicros there has been quite a lot of spectulation on this forum. I can't imagine that they have buyers outside our forum here which limits the number somewhat.
For me personally, RPN was never relevant, simply because during the decade when I actually used a calculator (school and university), RPN models were out of reach for me. Now I collect them but apart from some trivial calculations I have no real use for a calculator.

In my view, the best (current) analogy to RPN is Super-8-film. It was introduced in the mid 1960ies, had it's peak around 1975 just like the HP35 and 65, and was still around throughout the 1980ies in rapidly diminishing numbers. It was simple to use, just like the afficiondos of RPN claim for their preferred calculator logic, but relatively expensive. In the end it lost against video which offered more for a lot less money (Texas Instrumets and Casio so to say).
But there are still manufacturers of Super 8 film in 2023, including Kodak (unfortunately they buried Kodachrome, the best film ever, for good and only continue to make Ektachrome). Prices are bordering on the insane, what could be said of Swiss Micros as well, but obviously there is still a niche market of fangirls and fanboys for whom this film format is kept alive!

Regards
Max

NB: I still have my Super 8 camera which, other than a calculator from HP I could afford as a student, but 35 Euros + development for a 3-minute film cartridge is a lot more than I want to spend.

[cdmackay]

Here in the UK, it seems that algebraic "won" simply because almost no-one learns about RPN. So whether RPN is better, easier etc isn't relevant.

Casio have a monopoly in schools; that's perpetuated by the schools, telling the students which calculator to buy, or even selling it to them. You don't want your child to be the only one in the class with a different model, let alone a different type.

[Thomas Klemm]

The standard calculator of the MacOS has RPN Mode.
You can also switch from Basic to Scientific or Programmer mode.

This probably makes it the most spread RPN calculator.
Well, maybe apart from dc on Unix systems.

[Commie]

(12-17-2023 06:30 PM)cdmackay Wrote:  Here in the UK, it seems that algebraic "won" simply because almost no-one learns about RPN. So whether RPN is better, easier etc isn't relevant.

Casio have a monopoly in schools; that's perpetuated by the schools, telling the students which calculator to buy, or even selling it to them. You don't want your child to be the only one in the class with a different model, let alone a different type.

The thing is though, you can't expect a school kid to start calculating in rpn, however you can sell rpn to graduates because of shear power of rpn. So long as the user understands the 4 level stack properly. There are 10's of hp45 on sale on Ebay fetching asking prices of around £150+ for full kit.In contrast to this the red led ti30 are asking around £20 for same era of calculator.

As far as Apple Mac/os is concerned, Apple obviously pay developers good sums of money for hp calculator apps in an attempt to bolster sales of Apple products.

[Garth Wilson]

(12-17-2023 06:30 PM)cdmackay Wrote:  You don't want your child to be the only one in the class with a different model, let alone a different type.

"Different" often meas "special," and seeing possibilities that others don't see.  Our two sons were required to get TI graphing calculators for math classes in high school in the early 2000's.  I had the first son take my old TI-59 (non-graphing, with the LED display) instead.  He aced the class.  My wife got the second son, three years behind the first, the prescribed calculator.  In spite of all the functions on it, he basically used it as a four-banger, and occasionally as a mid-1970's scientific.  Both sons said the main thing the kids used the graphic capabilities for was playing games.  This was of course before everyone had smartphones.  If they have to follow exact procedures in the textbook written for a particular calculator, it means they don't understand it, and they'll get moved along just because they followed instructions and turned the crank blindly without understanding. Not good.

Quote:you can't expect a school kid to start calculating in rpn

Why not?  That's the way we started in the early grades, with pencil and paper, writing one number down, putting the second number below it, then adding or subtracting or multiplying, or in the case of division, putting the second number off to the left before starting the operation.  The actual operation started after the numbers were written down, just as in RPN.

[Commie]

(12-17-2023 08:37 PM)Garth Wilson Wrote:  Why not?  That's the way we started in the early grades, with pencil and paper, writing one number down, putting the second number below it, then adding or subtracting or multiplying, or in the case of division, putting the second number off to the left before starting the operation.  The actual operation started after the numbers were written down, just as in RPN.

Rpn is simply too advanced for the average school kid, you make out that rpn is simple to use, it is not. Depending on your angle of view rpn has an automatic stack lift or stack drop and these need special thought before using, I myself thought I understood it given the stack operations printed on the back of the hp 45, but I did not until I designed a hp45 in an 8051 processor.

To give you an idea, the hp calculators stack algorithm, it seemed were doing stack operations before key presses, er?, behind the scenes as it were.

[dm319]

I don't think it's that hard. What helps is being able to see most of the stack. Then the function you press is simply applied to either the bottom number or the bottom two numbers. At the risk of kicking off an argument, I think the NSTK mode without the automatic stack lift is more intuitive to new users.

And with the recent BODMAS arguments, there's even more argument to having a calculator that doesn't take a side.

RPN is, IMHO, a more intuitive and better way of calculating. Sadly, schools tend to be set in their ways and have largely agreed on one input method and one brand. It doesn't help that there isn't a cheap one on the market.

[cjsuk]

Interesting this one. A recent observation...

I'm doing a mathematics (second) degree at the moment with Open University. The students are all told to use Casio fx-85. They changed the design recently and now none of the material works for the new calculators. This has caused a lot of struggles for both students and staff. If you teach people how to use specific calculators, this is what you get and I suspect that's the problem with the education system at the moment. As a social outcast of both an RPN calculator user and macOS user, I'm on my own because the tuition is specialised and the knowledge is not. And that dissuades people from using whatever machine works for them and propels the decline from generalised calculation into machine operators.

Throw back 25 years and the previous engineering degree didn't even mention a calculator. Just use whatever. And that whatever was an HP48!

Either way, RPN (and RPL) is still relevant but the education system is the market that drives trends in this space and it's breeding machine operators not mathematicians, engineers and generalised knowledge.

As for average school kids, my youngest, 11, doesn't use a calculator at school. They haven't got that far yet. She was hammering away on my 32Sii no problems at all in 2 minutes doing multi-stage calculations and worked out the stack. It's how you explain it that matters.

[John Garza (3665)]

It seems strange for a school to dictate what calculator to use. They should instead list requirements (like trig functions, graphing or not, etc.) I guess it's all part of our slow slide toward an authoritarian government. And since it's in early education, it also serves to indoctrinate our kids into blindly obeying authority figures. Be a rebel, use RPN.

I taught my daughter RPN at an early age. It definitely helped her in math. Then she wrote her first ever program (on any platform) on an HP-65 to hunt a wily wumpus.

-J

[rprosperi]

(12-17-2023 04:29 PM)Albert Chan Wrote:  Even modern HP-12C has algebraic mode as option.

Not correct. The HP-12C, in continuous production 1980-2023, has only RPN.

The 12C Platinum, introduced in 2003 primarily for European markets where Casio dominated with Algebraic models, does have an Algebraic option though.

[Roberto Volpi]

RPN in the '70s was a very efficient way to use the limited hardware resources available back in the day. It was actually never relevant for the biggest market share, but a niche of professionals and geeks.

Half a century after, hardware is more powerful, advanced and far cheaper, so it is hardly needed, especially if you take into account that the cheapest RPN calculator costs more than USD 100 and you cannot exactly buy it at the neighborhood's shop.

Today, less than 1% of world population has ever heard of RPN, and those who actually use RPN calculators are mainly readers of this forum.

It is of course unfortunate that schooling system never supported the diffusion of RPN, because it is a very efficient way of computing (if you know how to do it). Nevertheless it is delusional, and also a bit conspiracist, to blame it for that; schooling system, as far as math is concerned, is meant for giving a smattering of literacy to the bulk, and a student today with less than 50 bucks can buy almost everywhere an outstanding calculator with trigs, logs, stats and all stuff like that.

[Thomas Radtke]

I tought math and physics for half a year in school and always had the idea that learning algebraic precendece would profit from RPN since this entry system enforces thinking about it. One or two lessons with a concluding competition in getting the correct results from equations I'd write to the blackboard including troubleshooting could be sufficient to get this into the young minds. Not (only) about how to use RPN, but mainly to gain new insights in how to read and look at equations in general.

But of course, there were no affordable RPN calculators available, I was new to the job with no time for experiments, and then there was C, the students and teachers hell.

[carey]

RPN is intuitive in the sense that it mimics how calculations are done by hand where we start with numbers and then apply operations. However calculations aren't done by hand anymore so there's no need to mimic hand calculations and RPN's intuitiveness with numeric operations is offset by RPN's torturousness when working with equations without numbers. Math is idiomatic -- we visually recognize equation patterns (from the area of a circle \( \pi R^2 \) to a quadratic equation \( ax^2 + bx + c = 0 \) to a differential equation \( \frac{dN}{dt} = -kN \)). By inputting equations in RPN, our inherent equation pattern recognition skills become useless (imagine writing words in a sentence backwards).

HP wisely recognized this by adding equation mode in the RPN HP-32sii and the tick (') in the RPL HP28 and later RPL calculators so equations could be created algebraically. (Just to be clear, this is separate from adding algebraic mode to the HP49g and subsequent RPL models which was done for marketing). Equation mode in RPN calculators and the tick (') in RPL calculators was a necessary admission that RPN is backwards (literally!) for creating equations without numbers. I suspect that a good portion of the HP-32sii's popularity was due to its algebraic equation mode. It should be obvious to everyone why RPN is not taught in high school algebra classes and beyond, and would do students no favor if taught in earlier grades.

None of this detracts from RPN being fun, has nice workflow with chained calculations (though no longer unique since the Ans key and Ans() commands) and probably helps keeps a mind sharp into old age by engaging it to perform tasks that modern calculators can now perform on their own.

[Garth Wilson]

(12-18-2023 07:56 AM)carey Wrote:  However calculations aren't done by hand anymore

I guess you live in a world different from mine.

Quote:so there's no need to mimic hand calculations and RPN's intuitiveness with numeric operations is offset by RPN's torturousness when working with equations without numbers.

Only a small part of programming is math and equations though.

Quote:(imagine writing words in a sentence backwards).

It is my understanding that some spoken languages are indeed RPN, like that where we would say "put on shoes," in Korean it comes out more like "shoes, install."