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The Future of RPN Calculators

Noksagt writes "HP's recent release of the 33s won't be the last RPN calculator. Former HPers at Hydrix are hyping an impressive Linux-based PDA/calculator, named Qonos. They have a survey up regarding features, etc. More information can be found at comp.sys.hp48 or The Museum of HP Calculators. A new open hardware project called OpenRPN has also begun. Their mission is to produce horizontal and vertical format scientific RPN calcs and later a graphing calc."

26 of 301 comments (clear)

  1. Re:TI Rocks by 0x0d0a · · Score: 4, Insightful

    HP calculators might be more competitive today if Carly hadn't decided that it would be a really good idea to dump the HP calculator engineering team to "save money".

  2. The future of RPN calculators... by JessLeah · · Score: 4, Insightful

    ...is to be a teeny-tiny niche market, like Linux handhelds (compare and contrast: Number of Zauruses sold vs. number of iPaqs sold).

    The Masses don't understand RPN, don't understand why anyone would want to use a "backwards" syntax, and aren't interested in listening to us nerds when we explain the very real benefits of grokking stack-based systems.

    1. Re:The future of RPN calculators... by capt.Hij · · Score: 5, Insightful

      You are probaly right which is a shame. When I was just a lad everybody used hp calculators with rpn. In our calculus class I do not remember anyone having a problem with the chain rule. The idea of a composite function was almost inate partly because of the way you enter equations into an rpn calculator.

      I teach calculus to students who use the TI, and so many more students just do not get the chain rule. It is amazing. Moreover, it is damn near impossible to try to connect the idea to the way they think about functions and the way they key them into the calculator. The tools we use really can constrain the way we think, and rpn calculators really make you back up and rethink what a function is.

    2. Re:The future of RPN calculators... by dillon_rinker · · Score: 3, Insightful

      The chain rule??? Why would anyone have a problem with the chain rule? And what does RPN have to do with it? It's an intuitively obvious rule to anyone who has completed sixth grade:

      dx/dy = dx/dt * dt/dy

      Since you teach calculus, I'll point out that this is a serious question - what's not to understand?

    3. Re:The future of RPN calculators... by Jerf · · Score: 4, Insightful

      It's an intuitively obvious rule to anyone who has completed sixth grade:

      LOL.

      Spoken like somebody who has only taken the advanced math classes.

      I mean that mostly in a good way, but you have obviously not examined the "normal" student in detail. A lot of people (scarily, possibly even the majority) graduate high school without really being able to add 17/28 + 87/98. Of those who can, few of them can explain it correctly. Of those who can, most of them lose it quickly.

      I wish it was an "intuitively obvious rule to anyone who has completed sixth grade".

    4. Re:The future of RPN calculators... by John+Whitley · · Score: 3, Insightful

      ...is to be a teeny-tiny niche market, like Linux handhelds

      The market probably won't be huge, but that has nothing to do with it's RPN-ness or Linux-ness. That has to do with relatively small numbers of folks who need a powerful math appliance.

      On the other hand, this has the potential to be the iPod of the Mathematically Inclined. If the software and industrial design are done well, it has serious hope to be a hit on college campuses, as well as with a variety of technical professionals.

    5. Re:The future of RPN calculators... by |/|/||| · · Score: 2, Insightful
      Exactly. And figuring out how to express an equation as a set of nested functions is like figuring out how to punch it into an RPN calculator.

      --
      [javac] 100 errors
    6. Re:The future of RPN calculators... by Tablizer · · Score: 4, Insightful

      The Masses don't understand RPN, don't understand why anyone would want to use a "backwards" syntax, and aren't interested in listening to us nerds when we explain the very real benefits of grokking stack-based systems.

      The benefits are quantitative in that it is less keystrokes to evaluate a given expression. Don't sell it in terms of "grokking", because that gets into personal psychology which cannot be easily measured. Instead, count keystrokes. "You can finish more of your exam in the given time-space" for example.

    7. Re:The future of RPN calculators... by shobadobs · · Score: 3, Insightful

      The real benefit to RPN is not the number of keystrokes or the speed at which it can be used (although it is superior for those reasons). The real advantage is that evaluating expressions with RPN makes it feel like you are evaluating the expression, whereas using "algebraic" mode is more like typing in the expression and getting an answer. RPN feels more natural, because you evaluate the expression as you would with mental math.

      Interestingly, I have noticed that after having adopted RPN and used it for two years, my mental math ability has dramatically increased. It is as if RPN use forged new connections in my brain. For instance, once, during a competition, I got a simple problem: f(x) = x^2 + 5, g(x) = x/2 - 3. Evaluate g(f(5)). It took one second to evaluate that and hit the buzzer. The reason i was able to do it so quickly is that internally, I thought of the functions as RPN routines - X SQUARED 5 PLUS 2 DIVIDE 3 MINUS.

      I didn't realize it until I just wrote this now, but my mental image of functions has dramatically changed because of RPN (I was just fine with them before, though).

    8. Re:The future of RPN calculators... by dillon_rinker · · Score: 3, Insightful

      Second, you've committed the atrocious sin of mixing Leibniz notation with Newton prime notation

      (whine)
      But DAD! This is how ALL the cool calculus textbook writers are doing it these days!
      (/whine)

      Leibniz notation is introduced in all the calc textbooks I've read with the STUPID idea that even though it LOOKS like a fraction, you can't TREAT treat it like a fraction. I suppose this is done to preserve rigor, but it is a STUPID pedagogical technique. End rant.

      The functional notation f'(x) is useful, as is the differential notation dy/dx. Mixing them gives you the worst of both worlds.

      Just to pick a nit - IIRC, Newton used a dot notation, which this screen is too limited to display. Here's an attempt at explanation. If x were a function, then x with a dot over it would be the first derivative, and x with two dots over it(like an umlaut) would be the second derivative. I don't recall where the 'prime' notation came from.

      Anyway, you're hardly qualified to school us in calculus.
      Now, don't be hard on the boy, just because his teacher is everything we've come to expect from the public education system...

  3. Re:My survey response by .com+b4+.storm · · Score: 4, Insightful

    Seriously, why are we worried about the "future" of inconvenient input formats?

    How is RPN inconvenient? Sure, it requires a change of thinking initially, but the gains are traditionally a lot more than the initial effort required. Even just in my limited use of RPN in a college environment, I have seen the benefits as far as speed and yes, convenience.

    In one of my recent math classes, the instructor spent 20 minutes helping people to enter a semi-complex formula with parenthetical notation. With RPN, I didn't have to deal with messy parenthesis, I just got the work done. As an added bonus, I got to spend those 20 minutes practicing my written Chinese. :)

    --
    "Wow, you're like some kind of superhero able to ward off happiness and success at every turn."
    -- Ryan Stiles
  4. Natural it isn't by 14erCleaner · · Score: 4, Insightful
    RPN obvious isn't. Backwards to people it seems. (Star Wars I've watched times many, true.)

    On the other hand, RPN does inspire near-religious devotion in some, especially those who used the early HP calculators back in the 70's. My engineer dad would have killed for one of those back in '74 or so, but they were too expensive at the time.

    --
    Have you read my blog lately?
  5. Integration in PDA/Calculator by beatleadam · · Score: 5, Insightful

    From the OpenRPN Project Website
    Here is a short list of some planned features:
    *Philips LMC210x ARM7 CPU
    *Flashable ROM
    *MMC/SD expansion card support
    *20 digit accuracy
    *USB connectivity
    *Several forms of I/O
    *3"x5" PCB for internal expansions/modules
    *Hi-Resolution LCDs
    *All aluminum watertight body
    *Molded-through keytops (customized sets will come standard)
    *High-durability anodized finish
    *Customizable keyboard overlays
    *Positive tactile keys
    *Reverse RPL compatability
    *A nice thick manual

    This sounds just like the PDA I would Love to have which is of course the point here.

    My single question is one of integration in that I do not want to carry a full-featured Calculator and a PDA I just want the PDA itself yet with this awesome calculator function integrated. Where does the line exist anymore between PDAs and Calculators especially Linux powered devices?

    --
    I have a theory that the truth is never told during the nine-to-five hours. -- Hunter S. Thompson
  6. Re:TI Rocks by Anonymous Coward · · Score: 1, Insightful

    Especially knowing that the calculator division was self-funded, and one of the most profitable in HP... It was just too small a profit overall, and TI is crushing HP in terms of sales. Carly's motto was "we're only staying in business where we're the first"... Was hasn't she dumped PCs then? :-P

  7. Re:My survey response by localhost00 · · Score: 2, Insightful
    inconvenient input formats?

    RPN is NOT inconvenient if you get used to it.

    I actually prefer RPN.

    --

    Calling atheism and agnosticism a religion is like calling bald a hair color.

  8. For HP to sell more RPN calculators by I+kan+Spl · · Score: 4, Insightful

    they need to fix those buttons. I mean, the old style buttons on the 32SII and the 48GX rocked. Why, or why did they ever have to change to those evil plastic buttons? Was this a cost-saving thing, or just a tatic to make sure the calcuators died out?

    --
    My UID is prime and so is this number: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0.
  9. My $2E-2 by eaolson · · Score: 5, Insightful
    I'm a scientist, and I use my HP 32S daily. I probably couldn't function without it. It's RPN, doesn't graph anything, and has fairly limited memory and programming abilities. But I like it. I have to say that I hate the idea of this calculator/PDA thing.

    I don't want my calculator to be my PDA. I have a PDA for that. They're different devices with different interfaces and should be used for different things. I put an RPN calculator on my Palm and, although I can use it, it's awkward and clunky. I use it only when I have no other choice.

    I don't want a graphing calculator. I like my one line of text. If I need to graph anything, then I'm probably doing it for a complicated reason, and I'll fire up Matlab or Origin at my desktop. My calculator is for, just that, calculating.

    The website brags that this thing has a whole month of battery life in it's low-power mode. Big fricking deal. I bought my HP in about 1990. I have replaced the batteries in it exactly ONCE. There's nothing more useless than a calculator that you've picked up and realized you forgot to plug it in last night to recharge it, and it's dead.

    I don't want a fold-out keyboard that's probably fairly fragile and won't last too long. I want something sturdy that will stand up to significant, continuous use for years to come.

    Why can't someone just build a good calculator that does what it's supposed to, and not some calculator / PDA / laptop / Borg monstrosity?

    1. Re:My $2E-2 by dwhitman · · Score: 3, Insightful
      Another scientist chipping in, and I couldn't agree more. I've been using a HP15C for about 20 years now and live in terror of the day it dies, because I can't replace it. I had and loved a HP32 that died; but I like the form factor of the 15C better.

      I don't want my calculator to do mediocre graphing or mediocre symbolic logic or mediocre numerical analysis or mediocre monte carlo simulation, yadda yadda yadda - for anything complicated, I'm going to use my workstation with a big display and high end software. I don't even need programability in a calculator, although it's useful (I wrote a nonlinear regression package for an HP41C that deconvoluted NMR spectra for my thesis - today I'd just do it on my workstation).

      I want an RPN calculator with good buttons, enough of them to expose all the functions I need without plowing through nested menues, but not so many that I need to go hunting to find things. I want a good solid-segment LCD or LED display for high contrast and wide viewing angle; I don't need or want alphabetic characters or graphics. One display line is plenty, but make the segments big - my eyes aren't as good as they used to be. I want a small form factor so it'll fit in my pocket, and essentially infinite battery life so I don't have to worry about whether it's charged.

      I want the HP-15C to go back into production. I'd buy three or four immediately and scatter them about so there's always one in reach.

    2. Re:My $2E-2 by starseeker · · Score: 2, Insightful

      "Why can't someone just build a good calculator that does what it's supposed to, and not some calculator / PDA / laptop / Borg monstrosity?"

      Because stable and reliable doesn't convey "status" like the "latest IN gadget", and thus marketers don't know what to do with it.

      When's the last time you saw an ad for anything that featured detailed description of the actual merits of the product, as opposed to pretty people having fun/doing work/both? I've never heard a commercial for a car say, for example, talk about the technical details of the car and the manufacturing process. It's always a picture of the vehicle doing things no ordinary sane driver would ever do, and then a price and a lot of fine print. Or an annoying used car salesman shouting to get your attention.

      Marketing drives EVERYTHING. And there's nothing exciting about basic, solid and reliable. Plus, if you buy a basic, solid, reliable product the company doesn't see any more of your money for ten years. Hence, the trend is away from long term products, however wasteful that might be.

      Maybe I'm stuck in cynical mode, but quality sure doesn't seem to be the driving force nowadays.

      --
      "I object to doing things that computers can do." -- Olin Shivers, lispers.org
  10. Re:My survey response by ChuckleBug · · Score: 5, Insightful

    People just freak out over RPN for no reason. I taught several college friends, none of whom were math wizards, about the joys of RPN and every one of them became hooked. RPN just seems backwards because everything is fed to us in a linear, "algebraic" way. But the fact is, RPN is actually much more intuitive once you get past the initial "wall." With RPN, you do calculations the way you would with a pencil and paper - or in your head: Break the problem into chunks so you get intermediate values, then operate on those intermediate values, and so on until you're done.

    Just starting at the left and working your way to the right, all the while keeping track of parentheses is NOT intuitive. It's just familiar.

  11. Obvious answer. by raehl · · Score: 2, Insightful

    Because that calculator has already been built, and you already own it.

    Thus, building it again isn't likely to be profitable.

  12. Re: ??? - More Detail, please. by gidds · · Score: 4, Insightful
    I don't think this is anything you have to worry about, really. As someone with an honours degree in mathematics, I can't really see the connection between RPN and the chain rule, either :)

    I wouldn't worry too much about a flash calculator, either. The important things in mathematics go on in your head, and on paper. The basic arithmetic functions are jolly useful, and the trig functions (ideally including hyperbolic ones) can be quite handy, but if you can't work out the graph of a function yourself, then a calculator isn't really going to help you.

    What I found helpful when learning calculus was to think of it in mechanical terms where possible. Functions and graphs can be a bit abstract, but calculus is really about rates of change, and I found that thinking in terms of speeds and accelerations tended to give me a good mental picture of what was going on, at least to start with.

    --

    Ceterum censeo subscriptionem esse delendam.

  13. Re:12 C replacement by Anonymous Coward · · Score: 1, Insightful

    Well, real COMPUTER geeks may want a 16C (which featured convenient HEX entry, etc.). The 15C or the 42S are probably the best scientific calculators ever made.

  14. this needs linux? by pedantic+bore · · Score: 4, Insightful
    I think it's a bit weird that people are building linux-based calculators. Doesn't that seem like a bit of overkill? The memory required to boot linux is at least 1,000 times the memory of my trusty old HP.

    Everyone in the Slashdot community seems so worried about the Microsoft monoculture, and yet here we are pushing linux into every possible niche. It can't be optimal to have the same OS running on both our calculators and our supercomputers.

    --
    Am I part of the core demographic for Swedish Fish?
  15. The future of RPN calculators...Mass miss. by Anonymous Coward · · Score: 2, Insightful
    "The Masses don't understand RPN, don't understand why anyone would want to use a "backwards" syntax, and aren't interested in listening to us nerds when we explain the very real benefits of grokking stack-based systems. "

    And YET the "masses" use RPN all the time and don't realize it.

    When the masses do a math problem.
    123
    426
    +
    ---
    549
    In other words we're presented with the numbers FIRST, then told what to do with them (ADD).

    When the masses do math in their head, it's the same way. Intermmediates (mental scratch memory) is for carries.

    We think RPN is dead because most people don't actually conciously THINK about what they do when they do math. This becomes even more obvious when doing a more complicated problem. Try doing the quadratic formula for example.

    Bet we do that RPN with the precedence rules already memorized (remember your teacher going through those?).

    So NO it's not a geek thing. It's just that geeks are more obvious about certain aspects that the masses may not be conciously aware of.

    ---
    "Sorry, but according to [the] tests [we turn on and off], you are trying to post from an open HTTP proxy."
  16. The future of RPN is in the past by cdw3423 · · Score: 4, Insightful

    The HP 15C may well be the ideal pocket calculator for today, when more complex calculations are done on a desktop computer. Bring Back The HP 15C