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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."

32 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 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".

    3. 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.

    4. Re:The future of RPN calculators... by exp(pi*sqrt(163)) · · Score: 4, Informative

      That is the chain rule. Sheesh! Doesn't anyone know any mathematics these days. There's more than one type of notation for writing derivatives: f'(g(x))g'(x) is the same thing as df/dg dg/dx.

      --
      Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
    5. Re:The future of RPN calculators... by pclminion · · Score: 5, Informative
      First, what he posted is the Chain Rule, written in Leibniz notation.

      Second, you've committed the atrocious sin of mixing Leibniz notation with Newton prime notation. What a horrific mess you've created.

      The proper way to write it would be:

      h(x) = f(g(x))
      h'(x) = f'(g(x))*g'(x)

      I think this should help explain why the Leibniz notation is so popular, because in the Newtonian notation, a prime can only bind to a name, not an arbitrary algebraic expression. Hence you are required to introduce the additional function h(x) just to allow the notation to work.

      Anyway, you're hardly qualified to school us in calculus.

  3. Qonos???? by AKAImBatman · · Score: 4, Funny

    Q'onos? Isn't that like the Klingon homeworld or something?

    1. Re:Qonos???? by nytes · · Score: 4, Informative

      Hoo-boy. I'm labeling myself as uber-geek.

      The reason the 'r' comes and goes is because the 'Q', in Klingon, is sort of like an over done 'k' in English. It's pronounced toward the back of the mouth. The net effect is vaguely like a "kr" sound in English.

      So "Kronos" is sort of a phonemic transcription of what "Qo'noS" would sound like.

      --
      -- I have monkeys in my pants.
  4. Re:My survey response by DonServo · · Score: 4, Interesting

    Inconvenient? I can perform complex calculations MUCH faster using RPN than I can with an algebraic calculator. No worries about misplaced parantheses!

  5. maxima by John+Meacham · · Score: 5, Informative

    maxima.sf.net is a truely awesome symbolic algebra program, it is derived from one of the first ever 'modern' computer algebra systems and was recently made open source.

    If it could be put into a calculator, that would rock.

    --
    http://notanumber.net/
  6. Bad title by Decaff · · Score: 5, Funny

    Surely it should be

    RPN Calculators Future of the

    1. Re:Bad title by Chester+K · · Score: 4, Funny

      Surely it should be RPN Calculators Future of the

      Well, more accurately it should be "Calcuators RPN Future the of", but if I were to point that out I'd be basically admitting how much of a geek I am.

      --

      NO CARRIER
  7. 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
  8. Linux based RPN calculator ... by YetAnotherName · · Score: 5, Funny
    Sort of like putting a Saturn V on a pair of inline skates? This device certainly blurs the line between PDA, notebook, and calculator. Although programming wise, linking it to /usr/bin/dc ought to be a no-brainer. Waiting for your caculator to boot-up might get a bit annoying after awhile.

    Other obligatory comments:
    • But, does it run Linux?
    • Imagine a Beowulf cluster of those!
    • In Soviet Russia, Polish notation reverses you!
    • I am Polish, you insensitve clod!
  9. More details and pictures by Warlock48 · · Score: 5, Informative

    There's more details and pictures on hpcalc.

    Quote:

    Operating system:
    eCos, running in 512KB SRAM and providing one month of battery life
    Linux, running in 64MB of SDRAM and providing considerably more than a day of battery life

    Other software:
    Emulation of both the HP 49G and the TI-89
    Advanced math software: Gnuplot, Giac/Xcas (supposedly better than Maple), MathsExplorer
    PDA software: calendar, tasks, notes, time management
    Datalogging capabilities

    Processor:
    Intel PXA 263 XScale processor, running at 400 MHz
    32MB of on-chip flash memory
    32-bit data bus

    Display:
    Grayscale 3" 320x240
    Full support already exists for a color screen to be offered at a later date

    Other hardware:
    Mono speaker and microphone
    Stereo audio input and ouput ports
    Keyboard with tactile feedback designed for fast, accurate data entry
    Compact Flash Type II slot
    SDIO slot
    IrDA port
    USB client and host ports, supporting external keyboards, webcams, and other devices

    Optional sled:
    Vernier probe compatible
    8 analog I/O channels
    16 digital/sonic I/O channels
    Extra high-capacity lithium ion battery
    DB-9 serial port

    Price:
    Over US$350

  10. 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?
  11. 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
  12. "Linux-based calculator" by leshert · · Score: 4, Funny
    Linux-based calculator


    Is it just me, or does that have the same ring as "fuel/air explosive-based cigarette lighter"?

  13. No one ever forgot to return my RPN calculator by Anonymous Coward · · Score: 5, Funny

    As a high school student, I loved my HP "Reverse Polish Notation" calculator. Whenever someone would ask to borrow it, I would say, "Sure, you just have to remember that if you want to add 4+2 you have to enter '4', 'Enter', '2', 'Plus'."

    This scared everyone away, and they went on to borrow someone else's calculator. I didn't have any trouble with people "forgetting" to return the calculator, I still have it to this day. Thanks, HP!

  14. 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.
  15. Re:My survey response by nkh · · Score: 5, Funny

    I've got a hp48gx and always suffer from this kind of situation:
    - hey, can you lend me your calculator?
    - no, you won't know how to use it.
    - yes I will.
    - ok, if you really want.
    - [1] [+]: + Error: Too Few Arguments hey it's not working!
    - I told you...

  16. 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?

  17. ??? - More Detail, please. by students · · Score: 4, Interesting

    I am going to start calculus next year as a softmore. Can you explain this in more detail, with out actually using calculus? I want to know because I would like to buy a new calculator this summer, and I want to share this with my calculus teacher. I've tried RPN on my TI-83 plus (with RMN III and CABAMAP applications), and found it to be minorly surperior.

    1. 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.

    2. Re:??? - More Detail, please. by shobadobs · · Score: 5, Interesting

      I would suggest getting the HP-49G+. (I am a 49G user.) RPN might only be "minorly better," but the real question comes down to the operating system's user interfaces. The 49G's is simply far better. In RPN mode, the user can use all the calculator's features without having to jump through dialogue boxes all the time. For example, say I wanted to graph a sine curve. Instead of having to go to the "Y=" menu and such, with which we're all familiar, I merely need to type X [SIN] EQ [STO] [PLOT] [F4] [F5] [F6]. (and I can press F4 F5 F6 in very quick succession) It is really nice to use.

      After having used a TI-89, then an HP-49G, when I try going back to the TI-89 for some purpose (maybe a game, or a program i once made), I really start to notice how annoying and slow the 89's UI is.

      The HP is also much more customizable. The ability to remap the keyboard is quick, easy, and built in. There are 128 system flags for changing user settings, accessible via the MODES menu. The HP has no limit to the depth of the directory tree. Its menus are better -- they are at the bottom of the screen, somewhat like the TI-85 and Ti-86's menus, rather than having to type Shift MATH 4 4 every time you need to use a specific function.

      One of the neatest things is programming. Its programming language, Reverse Polish Lisp, is simple yet powerful. Plus, it has a built-in compiler for System Reverse Polish Lisp, and ASM.

      Plus, text-editing on the HP 49G/G+ is much, much easier. When in ALPHA mode, one can type both letters and numbers because the number pad has no letters on it.

      I used it for BC Calculus this year, and it easily served my needs.

    3. Re:??? - More Detail, please. by TastyWords · · Score: 4, Interesting

      Big hint: even if calculators are permitted, do your best to see if you can do it long-hand. If you punch everything in, you aren't actually doing the work and you aren't actually learning the process, no matter what someone says ("The only way you can punch the right keys is if you understand what you're doing.") longhand provides better comprehension of the problem. Besides, if you get an answer you don't trust, it's easier to look through what you've done and trace your work. Punch it into a calculator and you may or may not have gotten it right - if nothing else, use it for verification if you are so inclined. But be careful - I had a prof in Advanced Calc and DiffEq who loved to give problems whose answer would be "2" or "3.7" - something which would instill doubt in most minds - "How can it have such a simple result?"

      There is a real-world situation for this: to learn to walk a tight-rope, bring it down until it's 6" off the floor. Most people have no problems practicing that way. But it's the same rope. The only difference is in your mind.

      The only "real math" classes I took in college were Calc III, Advanced Calc, and DiffEq. I hated real math that much. Having studied under Hofstadter and Erdos while in high school made me realize I needed to be open & free in my thinking - abstract algebra, group theory, and Galois' work made me realize how much more suited I was for "pure math". It's so open and you can create anything you want to with your imagination.
      I just wish the regular high school classes taught students something other than "real math" algebra and calculus so students could see a difference and which is better suited for them.

  18. Re:My survey response by Tumbleweed · · Score: 5, Funny

    No worries about spelling, either. :)

    The modern calculator should be able to handle easy RGB triplet to hex conversion, as well as IP xxx.xxx.xxx.xxx 'Bruce' format (I can't remember what that format is called, so I just refer to it as Bruce to save confusion) to 32-bit format.

    Oh yeah, and a built-in function for calculating the air speed velocity of laden and unladen African and European swallows, based on various factors such as wind speed, elevation (density of air, ya know), age & weight of birds and any burden they may be carrying. Granted, even with that, it won't be all THAT accurate, but it's better than clacking two coconuts together

    Oh, it should also have built-in 802.11g WiFi & IEEE1394.b. :)

    And If I can use it to control the TV remotely, that'd be great, thanks.

    I still prefer the physical format of my trusty HP11C, but then again, I don't need graphing ability in my calculator. Graphing's for nerds.

  19. 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.

  20. Re:This is very good for the student by JonathanBoyd · · Score: 4, Informative
    Right now most math and science students are given or required to own a graphic calculator.

    Here in the UK, they're forbidden in exams (up to and including university level) and frowned upon as a distraction and hindrance to being able to visual graphs yourself.

  21. 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?
  22. 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