The Last Scientific Calculator?

There was a time when being an engineering student meant you had a sword. Well, really it was a slide rule hanging from your belt, but it sounds cooler to call it a sword. The slide rule sword gave way to calculators hanging from your belt loop, and for many engineers that calculator was from HP. Today’s students are more likely to have a TI or Casio calculator, but HP is still in there with the HP Prime. It is hard to call it a calculator since the latest variant has a 528 MHz ARM Cortex A7, 256 MB of RAM, and 512 MB of ROM. But if you can’t justify a $150 calculator, there are some cheap and even free options out there to get the experience. To start with, HP has a free app that runs on Windows or Mac that works just like the calculator. Of course, that’s free as in no charge, not free as in open source. But still, it will run under Wine with no more than the usual amount of coaxing.

You might wonder why you need a calculator on your computer, and perhaps you don’t. However, the HP Prime isn’t just your 1980s vintage calculator. It also has an amazing number of applications including a complete symbolic math system based on xCAS/Giac. It is also programmable using a special HP language that is sort of like Basic or Pascal. Other applications include plotting, statistics, solvers, and even a spreadsheet that can hold up to 10,000 rows and 676 columns.

Portability

It is easy to think that HP provides the free PC software so you’ll go out and buy the real calculator, and that may be part of it. However, you can also get official apps for Android and iOS. They aren’t free, but they are relatively inexpensive. On iOS the cost right now is $25 and on Android it is $20. There are also “lite” versions that are free.

It appears that these apps are not emulating the actual calculator hardware, but are ports of the calculator code. So this isn’t a case of someone just writing a pretend calculator, these apps act like the real calculator because it is running the same source code. For example, there is an application, HP Connectivity Kit, that lets you talk to a real calculator over the network. The PC and phone versions will also connect just like a real device.

Programming

You can write programs on the device or if you have the HP Connectivity software (also free) you can write programs on your PC. You can even find some from the Internet. If you miss your old calculator, there is a define feature that lets you program like a key macro recording.

The programming language isn’t hard to pick up. Here’s a short snippet:


EXPORT AREAVOL()
BEGIN
LOCAL N1, N2, L1;
CHOOSE(N1, "Area or Volume?", "Area", "Volume");
IF N1 == 1 THEN
CHOOSE(N2, "Choose shape", "Rectangle", "Triangle", "Disk");
ELSE
CHOOSE(N2, "Choose solid", "Prism", "Cylinder", "Cone", "Pyramid", "Sphere");
. . .

Hacking and What’s Next?

You’d think that the real hardware would be a prime platform for hacking, but so far that’s still on the to-do list. The only really good hardware hack for the real calculator adds a Samsung battery with a higher capacity to the machine. There are also some enticing pads on the PCB that appear to support a buzzer and I2C communications, but there’s no firmware for it. There have been a few attempts to load alien firmware into the device, but there’s no full-blown development system. Getting to the JTAG port looks pretty intense. There’s also been the inevitable hacking of the communication protocol.

History is replete with products that seemed amazing for their day but turned out to be just a stopgap for something better. Cassettes gave way to CDs and then CDs gave way to digital music. Telephone answering machines gave way to voicemail. Calculators have that feel to them. How much longer will we need them? Are the virtual HP Prime applications going to overshadow the physical device?

Regardless, the Prime is state of the art and would shame a personal computer from a few years ago. You can only wonder if it will be the last great calculator, or if there are more yet to come. And a calculator still makes a nice project. Not all homemade calculators are simple.

100 thoughts on “The Last Scientific Calculator?

  1. Of course I need a culculator on my computer. I use one all the time. No real interest in this one though.

    Anything beyond simple math I jump to a real programming language.

      1. I’m well covered between Google, speedcrunch and NumWorks (I use the emulator don’t own the actual thing).

        Rarely I use Sagemath and Octave.

        Very rarely numpy etc.

        1. bc is particularly nice because it has arbitrary precision. I rarely need 60 decimal digits of accuracy, but when I do, bc is free and not hard to learn and use.

  2. I was very curious about that claim that the language is like Basic or Pascal, since those languages aren’t much like each other (although the late 80’s DEC VAX Basic and Pascal were nicknamed Pasic and Bascal). It’s not an “or” it’s more of “What if Basic and Pascal had a baby and they fed it crack all the time”: Basic’s statement-oriented syntax, Pascal’s Begin and End and semicolons. What a mess.

      1. What’s wrong with GOTO? it’s just an unconditional jump. If you save the return address [push to stack], you use it to CALL a subroutine.
        If your code has subroutines, it has GOTO in it.

        1. GOTO is great if you have an IDE where you can right-click the goto and instantly jump between the label and the goto statement.

          Unfortunately, IDEs with that option only came about 30 years after developers who were experts in the use of GOTO statements were deemed an evolutionary dead-end and it was decided to let them go extinct.

          Apparently some distant relative of them was able to survive the extinction event. So maybe now the GOTO statement could make a comeback, and we can save the developers who diet on those GOTO statements. Maybe we can put them in a zoo and start a breeding program?

          :P

      1. I’ve found their HP-16L to be invaluable whenever I’m playing with code at a really low level … I don’t think any other calculator out there comes close to that level of convenience for doing “computer math”.

        (I think TI had a model called the “Programmer” at one point, but I’ve never seen one)

          1. Swissmicros calcuators seem to be superior to the original HP’s.
            My HP is a tad slow, just slow enough that you have to wait for an answer, if you want to use the graphical stuff, 20s of compute time can be needed. Display contrast is also barely acceptable, as most LCD’s of that era were.

            Swissmicros also have more memory and (I think) direct USB (Although I’m not sure what you can do with that. Can it push answers to a PC as a HID device, or used as external keyboard?
            But standalone calulators mostly shine when you’re not sitting behind your PC.

        1. I guess you meant the HP-16C. :) Here I am now, with my HP-16C in front of me. This is the one ‘computer’ that I have kept throughout the years from something like 1985 until now. Never had a better calculator/computer for software development work. I even ported over the ‘nonpareil’ emulator to iOS to be able to always have it with me on my iPhone (for personal use only of course :)).

          I also have a TI Programmer. It’s also kind of useful, it can convert dec/hex/oct, and do some logic operations, and can shift bits. But it’s buttons are crap, it’s display is LED, tiny and dim, and the HP-16C can just do a hundred things more than the TI programmer.

          The great thing about the HP-16C is the layout of it’s keyboard. Just about all of the necessary functionality is only one click away, and all other slightly less common functionality only takes 2 clicks.

          And it supports word sizes of up to 64 bits, which means that it’s still useful in this day and age.

          Too bad there are not so many software developers as there are financial advisors in this world. Otherwise we would have had a remake of the HP-16C as well. But to be honest, this was the best buy I’ve ever made, because: which computer you’ve owned still works flawlessly after 35 years? Mine even survived our dog chewing on it! Just a few scratches, that’s all it got.

    1. Why buy another calculator? If the HP-48G still serves you well then just download the emulator. The last I checked HP themselves were hosting emulators and ROMs for this so it’s not even stealing.

      1. I like the feel of the physical keys, the fact that it’s always sitting on my desk, and it doesn’t steal focus away from whatever app I working with on my PC. I love my calculators.

        Smartphones can do everything, but their UIs are inferior to dedicated devices’ – even when they’re emulating the dedicated device. That goes for calculators, cameras, flashlights, game consoles, etc.

        1. I have to agree. I have my real HP-16C, and a port of ‘nonpareil’ on my iPhone. They are exactly the same, same ‘UI’ and UX, even the speed is the same. But I keep using my real HP because it has a real keyboard. That cannot be beaten by any touch screen, barring touch screens with tactile feedback (if they will ever become mainstream).

        2. Physical keys do have a feel advantage. I’ve got to disagree on the interface comparison though. A smartphone has some advantages too. I don’t know about other apps but the emulator I use, Droid48 really takes advantage of it.

          For example, do you ever use your 48 for plain old arithmetic? I do because I have gotten used to typing my problems in RPN order. The app has a mode where the on-screen keyboard has just the keys necessary for this. The recovered space is used by making the keys bigger. It’s much easier to type on than either the app in normal mode or as I remember it my actual physical HP48G was! It takes two physical calculators to get that.

          Or maybe you are using all those wonderful graphing abilities. I suppose that shiny new graphing calculators probably have better screens than I grew up with. But, so long as we are comparing to the 48G (which is the calc I grew up with) even the crappiest smartphone of a decade ago is capable of so much better a display! The emulator is of course still limited to the resolution of the original. I could have sworn however that Droid48 had a feature where you could hide the keyboard, all except the arrow and function keys and expand the display to use most of the screen. That’s a lot of area for the graph. Unfortunately haven’t had a reason to graph anything lately so I just double-checked to make sure I wasn’t posting misinformation. It seems to be making a liar of me. I can’t find that feature today. Maybe it’s skin dependent or maybe I used to have a different emulator app.

          Anyway, the minimal keyboard option is pretty great and even with all the keys showing on my S9 the buttons are bigger than the physical buttons on any calculator I have ever seen. And besides, if I ever wanted to do any large amount of typing on my “calculator” I could always get a bluetooth keyboard or even plug in a full-sized USB desktop keyboard via USB-C.

          If a person REALLY did a LOT of calculating I could even see building a dedicated calculator with a Pi, an LCD and a full-sized keyboard. Just make a skin where the screen is nothing but display and use the keyboard for everything.

      1. The issue with the DM-XX calculators is that the HP equivalents just keep on running and running, even 35 years later. Maybe in 20 years those HP calculators will finally start to fail, and Swissmicro will start to gain some momentum. :)

        For sure, if my HP-16C dies, I will buy a DM-16L. But not going to shell out $150 if my HP-16C is still going strong.

    2. I have a HP-48 emulator on my phone, that has the great advantage, that I have it with me anyway. And it takes much less space than the real thing. I have the Excalibur RPN calculator on my PC. So there is not much use any more for the physical ’48. Although I really loved it during my university time.

  3. I think calculators are still fundamentally important for education. They provide physical keys are efficient and error free input and low power consumption and reliability which are key for testing systems that cannot tolerate the single digit percentage IT issues of computers.
    Also, the limited mathematical capabilities provides focus and a level playing field for the topics explored by the student. Very few people in college will be academically impressed by a student who can mentally easily factor polynomials mentally, but in high school that is still an important skill to build up and so having a CAS which can either do that or be used to automate the process easily to someone who is good at programming is not good as it could mask students with legitimately rare mathematical talents from those who are just familiar with software engineering fundamentals. Those students need to be put on the right trak as soon as possible in their education. Likewise, hacker types who may be struggling at really understanding analytic geometry even though they can tell their computer to do vector math for them might need to stay after class a bit to brush up, and shouldn’t let their computer mask that need.

      1. Which way is “weird”? Adding two numbers once you know what they both are, or…

        Writing down one number, then typing “plus” and hoping that the next thing to come along is a number – and if it’s not, making up an arbitrary system of operator precedence to disambiguate the ensuing trainwreck, and then throwing in parentheses for when that fails.

        Granted, we learn the second way pretty early on, so it seems “normal”. But calling that mathematical system reasosnable is a stretch.

        “1 2 +” for lyfe!

        1. I’m still ticked off at HP for putting support for ‘algebraic entry’ in that recent 35s model. FFS there’s a whole key wasted for parentheses, while STO is relegated to a 2nd function on RCL? Rubbish! (That 35s was a near miss in so many ways, don’t let’s get started)

    1. Back in the day everybody had a TI because they were affordable (sort of ) but when saw saw a HP on somebody’s desk you and everyone else just looked and did not dare touch. Just bragging rights “I saw an HP RPN today” was good enough. I still have and use mine.

        1. The language dates from the 1980s, many programs for HP calculators are written in this language.

          Let’s turn this question around: what excuse is there to throw away a perfectly good language with a proven implementation? Let’s say I’m a mechanical engineer and I have this CAS program that I wrote a long time ago to determine the proper thickness of a gusset plate. Why do you insist that I re-write my program that has worked so well for me? Really, I have to toss it out, re-code it and re-test it??? Why can’t I have an environment on my computer where I can run my program? Because you are too lazy to learn another language?

          1. I’ve learned more than a dozen different programming languages, dozens more if you count variants of languages.
            Why does HP have to stick with their cobble for their new calculator when there are better languages out there now?
            Keep in mind, this calculator is used by kids. Is it better for them to start using a good, logically consistent language based on modern principles or a hot mess from the 80s?

          2. But also, no language ever thought useful for teaching kids, Basic, Logo et al, has had much use or relevance in the real world some 15 years later. So tell me what you pick, I want to short all companies having any investment in it.

          3. I wouldn’t mind their choice of language so much if their twist on it didn’t have so many bugs and inefficiencies. Things such as hard limited max array lengths of ~9999/10k (I think, I stuck to using 2^13 as my cap for sanity and efficiencies sake. 2^14 didn’t work) Or requiring independent heap objects for every element of the array, preventing efficient arrays of ints, or any other numeric (In testing it used ~16 bytes per int element in an array iirc. about 4x what was actually being used). The calculator has so much horsepower and memory, but the vast majority of its potential is crippled by horrendous inefficiencies in it’s software implementation.

            My calculator has been plagued by crashes and reboots, after I wrote a program that needed to use about 10% of the ram. I chained multiple arrays of ints together, and the program ran, but it screwed up something that appears to persist even across wipes, and the ram dumps everything I have saved whenever it decides to give me ‘The calculator had a problem and will reboot in 3 seconds’ on startup (which is about every time I turn the calculator on after any significant period of time). If they just let us compile and upload native code, the thing would be orders of magnitude more functional, but the suggestion is just met by threats from hp employees on the forms to further lock down and cripple the platform.

            The CPU they have is a full fledged 32 bit CPU, there is no reason they couldn’t leverage the MMU to give us a sandboxed space for user code that couldn’t interfere with their sacrosanct ‘Exam Mode’. I don’t get why they put such nice hardware into a calculator that they seem determined to keep programmers and power users out of. The student market that they seem to be targeting are capable of working just fine with a Z80 or 68K instead of an ARM Cortex A7. And as for Ram, you would need more than 1.5k max size numeric arrays to fill the ram (and even using a small portion of it seems to cause instabilities in their OS/language layer).

    1. I think at the time the slide rule hanging from a belt was “cool”, if you were in the right circles. Calling it a sword didn’t matter within those circles, and it woukdn’t make yiu cool outside that circle.

      I missed most of that. I did get a sliderule about 1974, from some who did get an HP-35 very early on. But I don’t think the short slide rule he gave me was what he used at work before the HP.

      I do have a foot longslide rule, it came in a box from a neighbor a few years after. I still have that one, nit sure where the shorter one went. Unfortunately the belt loop on the long sliderule’s case is broken, so I.won’t be wearing it on my belt.

      I did know the rudiments of using one, but it was a brief time long ago so I’d need a book to use it today.

      I always thought circular sliderules were cooler than straight ones.

  4. Interesting, but I’ll stick to my ‘real’ HP-15 (scientific), HP-16 (computer science), and HP-12 (accounting) calculators with good o’ RPN. Anything more than that and I’ll jump to python or C on a workstation. At work I always have a handy calculator on the desk or pocket for quick calculations. Oh course same at home. My phone works fine when on the road for those minor calcs.

    1. Your approach pretty close mirrors mine. However, I seem to have a calculator hoarding system, as I have a HP-41CX, HP-11C, HP-48G, HP WP34S that has been reflashed, and a SwissMicros DM42 . I have all the calculators sprinkled around my desks so they can be easily used.
      As for my phone… I find it annoying to unlock it everytime I need to do a few calculations.

      1. I had an HP-11C, but I gave it to my sister when she needed a calculator for college. By ten, I had moved to the HP-15, so why not? Now (for nostalgic purposes) I wish I still had it ;) . My HP-16 is my second as the first one got stolen early in my career… I missed it, so finally bought one years later like new in box….

        I also wrote a ‘simulator’ for the HP language to write programs with on the PC expanding the functionality a bit…. Was a fun project to play with. More like ‘assembly’ language :) .

      2. Forgot to mention I also have my dad’s hp-65. Still works but the red segment led’s are acting up. Sometime I’d like to dig into it and see if anything I can do to fix it. I believe this was the model of HP calculator used for later Apollo missions (HP-35 as well). The HP-41 was used on the Shuttle missions.

        1. Yous hould stop using it until is fixed, a recap at least. The leds are driven with the high voltage spike from a flyback converter, and if it’s not working properly it can fry them.

          1. Yep, it is ‘not’ in use. I only fired it up when my dad gave it to me and only a couple of times since. I thought I had read that the capacitors may need replacing. Thanks for the heads up.

          2. I am not sure, if the one from my father is a HP-35 or HP-65, but for sure with red LEDs and PMOS logic chips which operate at something like 25 to 30V. They rely on the NiCd batteries to smooth the voltage from the charger. If batteries or battery contacts are bad, then the display goes crazy. I do not know at the moment, if and how many electrolytic caps are used inside it.

  5. I have an HP-11 that I bought new in the early 80s to replace a TI-58 that went bad after about 2 years of use. The HP-11 still works perfectly and has only required 3 battery changes in the almost 40 years I have owned it. I took a calculus class as a refresher about 8 years ago and bought a HP-48sx and the keyboard lasted about a year. When manufacturing went to Singapore or wherever, they lost the recipe.

    Is this new device equipped with a decent keyboard?

  6. I too have kept my HP-15, more out of nostalgia than anything. For half the price of the current HP offering one can get a modest android tablet and free apps that will do pretty much everything else including word processing and photo retouching. For a pushbutton calculator I use very capable, solar powered ones costing less than $20. Will they do a 3D rendering of the shuttle? Nope. Will the batteries ever give out? Nope. Will I cry my eyes out if I drop it and it smashes to bits? Nope.

    The big market for “scientific calculators” unfortunately, lies in our academic system that requires a non-communication device to take exams with and these are often from a very specific list, which (coincidentally, I’m sure) have unreasonably high price tags.

    XKCD called this out as usual:

    https://imgs.xkcd.com/comics/1996.png

  7. I still use physical calculators. I love my HP-97 desktop calculator because it’s massive enough that it stays next to my computer and doesn’t move around. It’s always there when I need it. Then I have my HP-16C for hexadecimal calculations. And for balancing my checkbook, I have my restored Wang calculator from the 1960s that I altered to use RPN (https://www.galacticstudios.org/a-modern-electronic-package-for-the-wang-300-series-calculator/).

  8. My first sliderule was an aristo scolar, after that there was a (mandatory at my school in those days) TI-25 but I quickly discovered RPN and spent all my money on an new HP-41 in 1983
    I still use my HP-15 and HP-41 also have a HP-48G but never got used to the crazy keyboard where the most used functions are under a purple or green shift key. For the same reason I don’t think I I will like the prime. Maybe I buy a swiss micro 41 clone, they look cool. Don’t know how to use any non RPN anymore.
    On linux I have a HP-15 emulator, never found a really good 41 emulator, there is a good windows one but I dumped windows 5 years ago.

    For most problems I use octave and jupiter notebook nowadays but i always keep a HP at hand.

  9. Last calculator? There will never be a last calculator until there are the last humans.

    As hobbyists and engineers we can do it all on a phone app or a computer application and probably do it better. Once you graduate you may have bought your last calculator. But students will always have to have dedicate calculators.

    It’s all about cheating. They need to be able to show whoever runs the test that they cleared the memory. Nobody wants to do that to their phone. Also they can’t have access to the internet or other networks for looking up answers.

    No doubt HP understands this and that’s why they offer emulators. If you can get away with running an app on a general purpose device then you aren’t in their market anyway. But… if they can keep you in their ecosystem with the free app you just might influence the next generation of students into choosing their overpriced little dedicated black boxes of mathematics.

    And that’s an ok deal. I for one don’t need better than my old HP 48 that I spent years with in High School and College. But since it died years ago, I’d move on to a free program like Octave or something if I couldn’t just keep using the 48 as an app on my phone. But so long as that’s free I have no reason to study up on another app. I even still have the big paperback manual! How many apps on your phone can you say that about?

    1. There are in use and becoming more widespread, secure locked down environments running on windows laptops/PCs such as “secure-exam” which offer version of other applications to be used in the exam, with no access to the outside world enabled, beyond what the environment allowed (download of exam, upload of answers, specific online references) I would imagine that that will eventually spread to high level math/science courses with equivalent calculators applications embedded in it, and that will be the end of hardware calculators in education.

      1. But then a school/university needs a computer/laptop/PC for everybody who takes part in the exam. Because I can not imagine how a privately owned computer could be locked down that way.
        At worst you need some modified boot code, which pretends to cold boot the machine, but boots the locked down environment into a kind of sandbox, where it can feel happily locked down, but can not prevent other applications outside the sandbox in the real OS from doing whatever they are supposed to do.

        1. Possibly you can still stream your cheat sheet in morse code through the capslock light, but that be how it be, BYOD, test and verify secure-exam is working before attending exam.

      2. Yuck!

        It takes effort to learn the higher functions of a graphing calculator or application. It’s been a while. I don’t know how the kids are doing it now but we bought our calculators (our parents bought them) then used them at home for homework and in class. If it was a TI the teacher would help you in class. If it was an HP then you spent all that time that the teacher was going over how to do it twice, first for TI-83 then again for TI-85 madly flipping through the HP manual trying to figure out how HP does it.

        So, if the school is providing the environment then do the students only see it on exam day? If so did they dumb down the classes so nothing would be too complicated to figure out on the spot? Or is every family just forced to buy a PC, Mac or Chromebook in order to match what the school has so they can use the same software at home.

        Yay for vendor lock in!

  10. I prefer a hard calculator to an app. Simply because it sits on my desk just waiting for me to press it’s buttons. It doesn’t do anything else so won’t be repurposed at the time I need it. It buttons don’t move it will never have a software/firmware update that will alter its operation.

    It’s a bit like a 13mm open spanner Vs. an adjustable spinner. An adjustable one is more versatile but if I know the nut is 13mm i can just grab the 13mm spanner and it fits and the job is done the adjustable one needs, well, adjusting every time I use it.

    There’s nothing wrong with soft calculators it’s just a matter of the right tool at the right time.

    1. This is my problem. I like the physical calculator, even when I’m sitting at a computer, b/c it doesn’t take you out of the flow of what you’re doing. Plus, the buttons just feel nice. (RIP old 48G!)

      That said, I use Python / R / dc / bc / vim / units all the time. Whatever’s at hand, honestly.

      But do I miss a dedicated calculator? Yup. It’s just the right tool.

      1. The buttons on the real calculator are fine. But the App (PC or phone) lets you “Ctrl-C”. And on the PC you do not need to grab it out of the pocket, it’s just a click away.

    2. Agreed, when I want to use a calculator there’s nothing like my trusty old HP-41C. When I’m somewhere with my laptop where the actual calculator isn’t handy, an HP emulator on my phone will work, but it just isn’t as comfortable an experience without the tactile feel of the keys. Either way, having a fully independent device beats the distraction of using a calculator app on a device that you’re already using.

  11. I loved my HP calculators starting with the HP-65 I thought I died and went to heaven…
    Then two HP-41s a 41CV and a 41CX, used them until they wouldn’t work anymore.
    As an RF tech back in the 80s I got a hell of a lot of use out of them with my own apps…
    The HP programming language is easy to learn.
    For those of you who want more, there is HP synthetic programming on the HP-41 series…. You do it at the machine language level. Programs run like a scared animal in that mode and when they crash…. You are screwed five ways to next week if you didn’t back up your stored programs and data. You have to remove the batteries for a few minutes in order to get the calculator to boot again.
    The HP-41CX the most kick ass calculator on the planet. (unless the HP Prime is better)

  12. I made an app for Android (Soft84) to try to provide most of the functionality I actually used on my HP48, but it’s not really complete and I’m still not happy with the UI and anyways I’m not crazy about hunting down my phone just to do some math.

    I use dc all the time. But sometimes I need trig. I’ve used rpncalc in the past, but Debian doesn’t package it anymore. The best I’ve found in terms of an RPN full-featured scientific calculator is orpie, but I don’t use it often enough to remember how to get around the counter-intuitive UI (they over optimized it for minimal keypresses, at the cost of considerable astonishment).

    Anyways, I say all this because I’m still looking for something that ideally would be the same as dc (RPN, line terminal interface), except with some provision for scientific calculator functions: trig and fractional exponents. Sometimes I want units too, but I’m not sure that’s worth the complication. I have just this week been really leaning towards actually writing it myself, but maybe you all can save me the time with some advice?

    1. Consider – the Teensy series. Used by many, to drive a custom mechanical keyboard.
      If you added a small LCD screen, I’m sure the Teensy would have enough grunt to work as a calculator.
      Then you just need a hotkey to enter calc “mode” – and you have your device.

      It could probably work as a dumb terminal, too.

  13. “For example, there is an application, HP Connectivity Kit, that lets you talk to a real calculator over the network.”

    For when the original’s screen…needs work. ;-)

  14. The keyboard is the thing I love about my HP 48GX (and older HP calculators.) The keys have just the perfect spacing, travel and give without any tendency to stick. I still use my 48GX quite frequently but when I was using it a lot I could almost touch-type on it.

  15. As a child I saved up to by a TI-59 and the plugin maths module and later bought the dedicated printer. The magnetic strips were great to save programs. All very treasured, enjoyed and introduced me into programming. I have since bought the HP Prime and just love it. I have the App on an Android which is my goto (rather than gosub) calculator. But, to use the HP Prime as a dedicated machine just can’t be beaten. The manual is huge and I am still working through it. Perhaps I don’t get out enough, but when I do, I’ll sit on a train figuring out new things with the HP Prime.

    Living the life!

  16. I wondered why no television manufacturer ever thought of incorporating a basic 4 function calculator into the remote. It already has the buttons. Move the switch to Calc, it turns on the display and changes the volume up and down and channel up and down to + – * / and three other buttons to . = C

    BS (Before Smartphones) there was many a time I wished for such a combo device.

    Some years ago I bought a new in the box HP 41C from a thrift store for somewhere around $4 or $5. It had all the original papers, even had the original Energizer N cells in their little box, only one of which was dead. The flexible circuit contacts in the battery compartment were pristine without a mark. The box had its original $250 Oregon State University Bookstore price tag.

    The only reason I bothered to buy it was a friend had been showing me his old 41CV and the 41CX his father was still using for his job in the Oregon Department Of Transportation – in the early 2000’s. The formulas in the surveying cartridge still applied the same circa 2004 as they did in the mid 1980’s.

    So I put it on ebay with a pretty low starting price. The bidding was fast and furious, ending at $450. :) Probably still on some collector’s shelf with its virgin battery compartment. Makes me wonder how much the value drops once a set of N cells have been inserted?

    1. Some years ago I built my own remote control. It has:
      * Atmega328 (none of that arduino rubbish)
      * Nrf24L01+ (I really do not like that chip, want to switch to HopeRf 9…
      * “Nokia” monochrome LCD.
      * 32 buttons
      * “Book” like flipping method, so each button can have 4 (or more) funcions.

      By flipping over the thin cardboard pages you get other text over the buttons, and on one of the pages I Implemented a simple RPN calculator. The other pages are for “lights”, “curtains”, “Audio”.

      I never bothered to put the project on the Internet. It also never got far beyont the prototyping stage, but it does work. It may even be Hackaday worthy.

      1. Idk why no one builds a phone that can blast out 2.45GHz enough that, if you set it on top of a frozen burrito, it could cook it for you. Seems doable. Might need better battery tec, though

  17. One of my engineering mentors from decades ago use to say: if you need more than a plain scientific calculator to figure something out, STOP! You’re probably doing something wrong. Someone has developed an approximation that should get you close enough. Once you know what the rough number should be, you can decide if you really need to get fancy.

    Too many people immediately reach for the modeling software. STOP! If you can’t approximate where you think you should be, how will you know whether you have a reasonable answer?

    This is why we still have calculators.

  18. The calculator on my PC and smartphone work, but not the same as having that handheld friend.
    Nothing matched the usefulness of my solar powered Casio CM-100 Computer Math Calculator.
    I lacked transcendental functions, but performed binary functions, and could convert to any radix instantly,
    even in the middle of a calculation. Indispensible for developing software for avionics,
    where a lot of the documentation and old code was in octal notation.

  19. Oh Lord. Good old civilized times, when people didn’t say nu to old ladies.
    I had (have, still working) a brand new HP41CX, with a card reader (yup, still working) and an Engineering Whatever extension.
    Time passes, online tools sucks, now replaced the good old calculator by offline really smart linux stuff.
    BTW occasionally using an HP41CX emulator on Android.

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