Current and future RPN pocket calculators: WP34S, DM42, WP43S, C43, now C47

[Zucca]

Gentleman,

I would like to inform the community about what is currently happening in the RPN calculators development.
After some research, I think it is worth to point out in this blog that the RPN is far away from being abandoned and there is still a lot of development to create the perfect RPN calculator.

After HP slowly started to discontinued the RPN calc production, some people decided to continue to develop a RPN calculator.
It was a community base effort and those guys put togheter remarkable results by using the HP-20b and HP-30b hardware.
This is how the beautiful WP 34S was born.

After that the community started to look for a new hardware to overcome the two line display limitation.

At this point the Swissmicros company released the DM42 based on the Free42 software.

Seeing the beautiful big display of course the WP 34S community started to knock on the Swissmicros door, and here we go with the WP 43S project based on the DM42 hardware. The WP 43S claims to be the ultimate RPN calculator. This project is far from being concluded but some beta version is already running on the DM42 hardware.





The story is not over, user Jaymos who is a EE like us started a fork on the WP43S project, the C43. This WP 43S variation has some nice features for the EE world and uses the original DM42 keys (first layer). Since the C43 is depended on the WP43S project it is again far from being a finished product.
I even triggered Jaymos on the swissmicros blog.

Details can be found online, I just wanted to give a head's up.

[HighVoltage]

Nice information, thanks.

I love the old HP RPN calculators.
My favorite is the 11C but I also use the 42S on a daily basis.

I find it also amazing, how much they have increased in value over the years.

[Zucca]

First WP 43s prototype landed on this planet



https://forum.swissmicros.com/viewtopic.php?p=24811#p24811

[HighVoltage]

It is really nice to see SwissMicro to come out with new calculators.
I think the WP 43s will make it to my wishlist.

[Hawaka]

Very glad to see that there are still people developing RPN calc.

I daily drive a HP50G and when one of my colleague randomly said that HP wasn't doing RPN anymore I couldn't believe my hears. Had to look it up extensively before believing it.

I also own a DM42 and an HP35s, but still enjoy more the 50G. It might be because it's the one I have use the most, but also for it has the best key feeling (35s is also very good), the infinite stack, the space button and the key layout (ENTER bottom right feels way more natural for me)

[Zucca]

Just to let everybody know the WP43s will no longer go in production.
Decision was made 2 years ago, see here for details.

There is still the C43 C47 project!

[fzabkar]

I have always detested RPN. Algebraic notation is the only format that makes sense to me. Why should I readjust my brain to suit HP's calculator? A calculator should be designed to make computations easier, not harder. TI's calculators used an algebraic human interface and a hierarchical stack behind the scenes (which the user could access with a little hacking). I suspect that HP found the algebraic interface too challenging and then marketed their RPN deficiency as a feature.

As for RPN using less keystrokes, I could nearly always produce the same result with nearly the same amount of typing in algebraic notation. In any case, TI's calculators cost half as much as HP's and had twice the memory and features.

[Bobson]

I suspect that HP found the algebraic interface too challenging and then marketed their RPN deficiency as a feature.

Not true. Many desktop calculators were made previously which used RPN. And not only made by HP.

As for RPN using less keystrokes, I could nearly always produce the same result with nearly the same amount of typing in algebraic notation. In any case,

What is NEARLY?

TI's calculators cost half as much as HP's and had twice the memory and features.

BS! Just compare top TI N-Spire CX II with HP Prime G2: 64 vs 256MB RAM, 128 vs 512MB flash, 400 MHz Arm9 vs 528 MHz CotexA7 CPU. Build quality of HP is almost always higher than of TI.

[fzabkar]

I would say that for every 10 keystrokes in RPN, I could come within 12 in algebraic, and I wouldn't need to jump through mental hoops to get there.

As for the price difference, I remember that my 50-year-old TI59 cost me half as much as the HP-97 (?) and had twice the memory and performance, and a magnetic card reader, and optional ROM modules (one of which was included).

[artag]

All mechanical adding machines were RPN for addition/subtraction, so there used to be a huge user base ready for them. I'm not sure why algebraics became popular - the expressions are inherently ambiguous so you either need complex rules (which don't parse well) or a load of parentheses.

In the end, it's what you get used to. I won't go back to infix and I have plenty of saved 11/15/16/32/42/48 units to keep me going.

[bd139]

Both single entry RPN and Algebraic calculators are completely dead so it doesn't make sense to compare them to anything else. They are relics of technology limitation, nothing more. They both have two features which makes them pretty useless and dangerous for every day work, which is lack of visible calculation context and invisible context loss.  It is insane in 2024 not to delegate the work to either the computer or a more modern calculator which does not have those issues.

In my case that's an HP Prime G2. That can display the entire damn expression in one go so you can check where you futzed it because quite frankly, humans aren't perfect and RPN requires you to be.

Note: I own a few RPN calculators, a few algebraic calculators, a couple of books on RPN calculators and know how to use them. They are fun toys. But I'm not doing work on them. Why would you?!?!?!

[fourfathom]

[old RPN calculators]  They are fun toys. But I'm not doing work on them. Why would you?!?!?!

Because they work for me -- fast and familiar for the kind of work I use them for.  I still use my original HP 15-C in my office, and take the SwissMicro DM15L on the road with me.
Your reasons for not using them for your work are completely appropriate -- for you, and probably for most people.  I do use other tools for other jobs.

[bd139]

[old RPN calculators]  They are fun toys. But I'm not doing work on them. Why would you?!?!?!

Because they work for me -- fast and familiar for the kind of work I use them for.  I still use my original HP 15-C in my office, and take the SwissMicro DM15L on the road with me.
Your reasons for not using them for your work are completely appropriate -- for you, and probably for most people.  I do use other tools for other jobs.

Original 15C is definitely not fast. Sluggish as hell. (I have one). Evidence to support it...



Anyway the problem is not fast but safe. I have found I make (measurably) many more mistakes with the 15C/15CE than I do with the Prime which have a net effect of things taking longer on it. I am *very* familiar with the 15C.

[SiliconWizard]

Yes, the fact that you don't see the history of your calculations or even just the last one is very error-prone and frankly not comfortable.
Also, not being able to easily recall one of your past calculations and just change one or a few numbers is a major pain. Sure for repetitive calculations, you may define a custom program on these older calculators (for those that are programmable), but that's still sort of error-prone (especially when you only see one line at a time) and not as convenient.

That's something you get using a computer, or yes, a more modern pocket calculator.

[fzabkar]

These days I use Google's calculator, but of course you need an Internet connection.

For example, try to work out the average distance between two molecules of air:

https://www.google.com/search?q=cube+root+of+%28%2824.5+litres+per+mole%29+%2F+%28avogadro%27s+constant%29%29+in+nanometres

https://www.google.com/search?q=cube+root+of+%2824.5+litres+%2F+avogadro%27s+number%29+in+nanometres

[bd139]

Urgh sod google for a calculator. Seems counter intuitive.

You know calculators have nice constant libraries built in now and don't require internet connections

[Stray Electron]

I would say that for every 10 keystrokes in RPN, I could come within 12 in algebraic, and I wouldn't need to jump through mental hoops to get there.

As for the price difference, I remember that my 50-year-old TI59 cost me half as much as the HP-97 (?) and had twice the memory and performance, and a magnetic card reader, and optional ROM modules (one of which was included).

   Yeah, and how many TI-59s do you have that are still 100% functional?  I have four HP-97s and an HP-92 that still work like new (and a 67, 65, about 8 HP-41s, and a pile of 11Cs, 12Cs, 15Cs, 16Cs).  My TI-59 (bought new) was always marginal and I pitched out years ago. I was going to college 7 years after I bought the TI and it was so unreliable that I literally carried a small circular slide rule in the same case to use as an emergency backup to the TI.  One of my buddies convinced me to to spend the extra money and buy an HP-41 and I've never regretted it.

  The TI calcs are good enough for high school freshman and sophomore level math but anyone that intends to take any serious high school math or any college math should get a good HP calculator and learn how to use it.

[tggzzz]

Both single entry RPN and Algebraic calculators are completely dead so it doesn't make sense to compare them to anything else. They are relics of technology limitation, nothing more. They both have two features which makes them pretty useless and dangerous for every day work, which is lack of visible calculation context and invisible context loss.  It is insane in 2024 not to delegate the work to either the computer or a more modern calculator which does not have those issues.

In my case that's an HP Prime G2. That can display the entire damn expression in one go so you can check where you futzed it because quite frankly, humans aren't perfect and RPN requires you to be.

Note: I own a few RPN calculators, a few algebraic calculators, a couple of books on RPN calculators and know how to use them. They are fun toys. But I'm not doing work on them. Why would you?!?!?!

I own several calculators, too many are 1000inches long, some are mechanical, some electronic with barely comprehensible data entry requirements (e.g. "2*3=" gets the expected result, but to subtract numbers it is "2+3-", and if the mem switch is on, then then "=" also adds the result to the memory; go figure), one which is just about as accurate as a slide rule, some which don't get basic arithmetic correct, semi-RPN calculators, and RPN calculators.

I have, back in the early 70s, used a programmable calculator - probably a Sumlock 320G Scientist. That was easily understood and usable, but a sufficient pain that I decided to avoid programming a calculator if at all possible. Fortunately when I needed to do anything more complex, I was able to use BASIC or spreadsheets since desktop computers were available, e.g. HP9845C, HP85, and later PCs/Macs.

Hence since the early 80s, I have only used calculators as "better slide rules". (OK, OK, I know the HP9845C was sold as a calculator not a computer, but that was to avoid purchase requisitions stimulating corporate immune responses).

Currently, for simple calculations I use an HP15C emulator running under WINE. For anything where I might make a mistake and need to correct it, I use a spreadsheet.

[tggzzz]

You know calculators have nice constant libraries built in now

Always worth checking how many litres there are in a gallon, and how many pounds in a stone/hundredweight/ton.

Journalists usually don't.

[HighVoltage]

   Yeah, and how many TI-59s do you have that are still 100% functional?

I also had a TI-59 and it was cool at the time with the stripe reader. But sitting in a test and making the noise with the reader was pretty annoying. I even had made an interface for a PC to the TI-59. The TI-58C at least could remember it's programming after turning it off. 

The HP 41 was by far the more advanced calculator of those days.

But once the SHARP BASIC calculators came out, I just loved the PC1350 and later the PC1600.
Those had real RS232 interfaces and I used these to read the first instrument values automatically.
That was unheard of in those days.
I still have these SHARP calculators and they are still working perfectly.

These days I love my HP15C Limited Edition !

[RAPo]

I started studying maths at university in 1981. My dad taught me to always buy things so you can grow.

After saving for two years, I took the plunge and was the proud owner of an HP41CX (I had to live on peanut butter and pay a fine to the railroad company because I was so absorbed in studying the manual that I forgot to exit the train).  That same HP41CX is still on my desk and still working.

I became ingrained with RPN; it is in my finger memory. Over the years, I have had several other calculators, including non-RPN ones like TI-59. These are all in calculator heaven now.

Fast-forward to now: I have all the Swiss Micros, some of them converted to C47. But the HP15C, HP41CX, and HP12C are still the most used ones, both as physical calculators and as emulators on my phone.

[Sal Ammoniac]

I have only used RPN calculators, going back to my very first one in the mid-1970s: an HP-35. Since then I've had an HP-25C, an HP-67, an HP-41CX, an HP-48, and an HP-42S. All of them still work and I do use them occasionally, but what I use on a daily basis is an HP-41CX emulator that runs on my iPhone. It looks and operates exactly like the real thing, with two exceptions: it's a lot faster, and the tactile feedback of the real thing is missing.

[Zucca]

I became ingrained with RPN; it is in my finger memory. Over the years, I have had several other calculators, including non-RPN ones like TI-59. These are all in calculator heaven now.

Two things I envy you:

1) Studying Math at the university
2) You did jump on the RPN train when it was the right time.

I missed the RPN wave because my TI-68 was doing everything, and according to my standards, very well.
One night in we had a smart guy invited for dinner in our dorm and I remember him telling the others how HP RPN calc are so superior... his eyes were on fire...
I was involved in another conversation in the other room corner so I did not join them.

Fast forward 20 years later, I finally understood and was blown away by the RPN method, and I ate all my fingers because I wasted to much time pushing buttons during my EE study.

Currently I have Plus42 app on my phone, and loooove it.

PS: I also had a SM DM42, but it was not there and my phone was when needed, so I sold it.

[Zucca]

I have only used RPN calculators, going back to my very first one in the mid-1970s: an HP-35. Since then I've had an HP-25C, an HP-67, an HP-41CX, an HP-48, and an HP-42S.

Look for how much $ you can sell them on ebay... mind blowing.

[Peabody]

I go back to the HP80 in the late 70s.  Currently use a 38C and a 15C, along with a Casio fx-115 to do decimal/hex/binary conversions.

Of course if you use RPN calculators, you also have to code in Forth, which is RPP (Reverse Polish Programming).