back to article HP's beloved 12c calculator turns 30

One of the most durable examples of mobile electronic goodness is turning 30: the HP 12c Financial Calculator. Learning the Reverse Polish Notation entry system of the HP 12c has been a rite of passage for Wall Street moneymen since 1981, when the HP 12c was introduced along with such other calculating classics as the HP 15c …


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  1. Neil Barnes Silver badge

    Still got my 11c...

    Still used every now and again, on the same batteries since 1987.

  2. Steve X


    I still have a working Sinclair Scientific, built from a kit around 1975(?). It's RPN as well. I remember trying to show school teachers how to use it. Fun times...

    1. Charles Manning


      A big problem with HPs is that all the scientifics are programmable and thus cannot be used for some exams. That really sucks for anyone who is used to RPN and needs to use a Casio etc.

      Sinclair Scientific sounds like an option.

      1. bhtooefr

        Non-programmable HP scientifics...

        ...there's always the HP-35 (not the 35S), or the HP-45.

        Of course, those are ancient, ancient pieces of hardware...

    2. Mephistro

      @ RPN

      When I was 15 (1980), I got hold of an HP33E RPN scientific programmable calculator. Scientific calculators were the fashion of the day back then. I remember our teacher writing formulae in the blackboard and asking for the results. I usually had the correct answer while everybody else was fumbling with the parentheses. It got so conspicuous that the teacher asked me to go to the blackboard and explain how I was doing it. He purchased an HP 33E the next week.

      Nowadays, I make most of my calculations with my computer, using an HP33E emulator. I miss the buttons feel, though.

  3. Rob 5

    I had one of those.

    Got it at a car boot sale, for 50p, just to muck about with.

    Years later, I flogged it on fleabay for $50. Result!

  4. ponder

    How about the 15c bring it back HP

    I want my HP 15c back

    1. atragon

      It might well be back...

      Look here;

  5. Anonymous Coward
    Anonymous Coward

    Programmer's calculator?

    No mention of the HP16c from the same family. It worked in decimal, hex, and octal notation and would convert from one base to another. It would also perform 1's and 2's complement operations and you could set the word size to match the word size of the computer system you were working on.

  6. jake Silver badge

    I lusted after that calculator when I was at Berkeley ...

    ... but being a starving student 30 years ago, I couldn't afford one :-)

    However (and the real reason for this post), 30 years later, and owning a winery, I'm here to tell you that "buttery" and "oak" do NOT belong in a proper Chardonnay, the opinions of my fellow Californian heathens notwithstanding ...

    1. Anonymous Coward

      tsk tsk

      Malolactic intolerance?

      1. jake Silver badge

        No, AC 21:15

        Good taste.

        1. Anonymous Coward

          Dear Jake

          Well, for what it's worth, I was starving at Cal a decade before you ('70).

          I guess you're not partners with Dario (also ex-Cal), Sir Peter, Kerner, Bo or any number of other California vintners who seem to have no problem catering to those who DO like controlled amount of butter/oak in their Chard.

          If I want citrus/flint, I'll take a bag of lemons to Yosemite so I can lick the juice off a rock.

          De gustibus non est disputandum.

          1. jake Silver badge

            @the old-fart known as AC 22:54

            1) Go Bears!

            2) My partner is my Wife, so no. The Foreman and the field hands also own stock in the company, and have a say in day-to-day & year-to-year operations. None of us like "big, buttery, oaky" California Chardonnays. We prefer citrusy, melony, somewhat floral, a hint of berry ... I have one leased 75 acre Chardonnay vineyard in Sonoma's Carneros AVA that tastes just like Pinot Grigio after a couple years, but we can't sell it as that ... so it's called "<Vineyard> White Table Wine" when we bottle it. It flies off the shelves ...

            3) Not much flint in Yosemite, if any ... and I've walked every inch of the trail system at least four times. Ever eat a pine tree? Many parts are edible ... [1][2]

            4) Indeed. But "the Judgment of Paris", which put California on the world's wine map, had nothing to do with "big, oaky, buttery & high in alcohol" ... it had to do with proper Chardonnay.

            [1] STR

            [2] No, I'm not green & granola ... but I do know how to live off the land ;-)

    2. Eddy Ito


      I never could understand why someone would purposefully try to combine the flavors of whiskey and churned milk.

      1. jake Silver badge

        @Eddy Ito

        There is a VERY good reason that Charles Shaw's "two buck Chuck" Chardonnay won a gold medal at the California State Fair in 2007 ... It was the only true Chardonnay that actually tasted like Chardonnay! Not a perfect bottle of wine, perhaps. But it's mass-produced, cheap, and drinkable. And you can cook with it. I usually have a couple dozen cases in my wine cellar ... I can't make a decent, drinkable, cooking wine cheaper than Fred Franzia does :-)

  7. Herby

    For the true calculator geek...

    Only an original HP-35 calculator will do. As one who bought one in 1972 at full retail ($395.00 as I remember) it was wonderful. It originally had the goof in it (exp function), but I did get it fixed. Alas, I sold it when I got my next calculator (an HP-45).

    It DID get me a 100% on a thermodynamics quiz when the next lowest grade was in the 30% range. Those were the days!!

    1. Disco-Legend-Zeke

      HP-35 Serial #19

      I didn't have the 2.02 antilog error fixed. Making it all the more rare.

      I recall i used it when i designed some components for the World Trade Center.

    2. Lewis Mettler

      HP-80 anyone

      Yes, my 12C still sits on the desk today. But, the HP-80 was the original financial calculator in the day. I saw a HP-35 when it first came out. End of the slip stick. But, the HP-80 was financial.

      I was selling real estate at the time. The Wall Street Journal had a full page ad introducing the HP-80. Sent off the $395 right from the ad.

      I was really impressed. Ended up buying a HP-81 too. (Remember the HP-36? A desktop version of the 35?) Also sent off to HP for more info on desktop systems. A brochure on the HP-9830A came back. Desktop, programmable in BASIC. 4kRam. 32 Character Display. Learned how to program by reading the user manual. All of that in 1972. You can still see it at

      Finally sold the Hp-81 a few years ago for $500 on eBay. Turns out some guy repaired HP calculators and just had to have an 81. 81 was the desktop version of the 80, precursor to the 12C.

      1. jake Silver badge

        End of the slipstick? I think not ...

        I still use the one that my Father bought in the late '50s. It's an ivory-on-bamboo Sun. Got him his three Engineering degrees ... and me my several. It's more accurate than "back of the envelope" for calculating materials needs here at the ranch. I also have circular models in each of the aircraft. And there is an abacus in the feed barn for calculating nutritional, medical & supplement needs of the critters (calculators only last a couple weeks in that environment).

  8. Fazal Majid

    Not the same

    My HP-15C is one of my most prized possessions (I also own the iPhone app version), and I use a HP-12C as an inferior substitute at the office. The current Chinese-made 12C is a pale shadow of the Corvallis or Singapore-made originals in terms of build quality, specially the keypad, and the Platinum edition is completely different under the hood, with a number of bugs introduced along the way.

  9. Version 1.0 Silver badge
    Thumb Up

    RPN - kicking algebraic arses for nearly 60 years.

    I still have my 16C which has been on my desk since the day it came out - and they think there's no market for these? I dread the day that it stops working.

    I discovered in school that the primary advantage of RPN over algebraic notation was that nobody ever stole your calculator.

  10. Adrian Challinor

    I suddenly feel old

    Old - that is all.

    Mines the one with "2's complement arithmetic" in the pocket. I'll stagger off to my cardboard box now.

    1. nyelvmark

      I know how you feel

      I felt very old 10 years ago when I realised that it was near-impossible to persuade 30-ish system analysts / software management experts to believe that a person over 40 could actually understand how to program a computer.

      I still occasionally write software as a hobby, but I can't compete with the authorised-by-god Java programmers (You know that Java is better than C because it has automatic garbage collection, right?).

      Sometimes I hear of someone who needs a real programmer (e.g, someone who doesn't blow a fuse when faced with Polish Notation: 2,2,+ =4 instead of 2+2=4), but they always want to pay peanuts, so for the moment I'll stick with teaching English to Hungarians (Hungarian notation is another kettle of fish, lol).

  11. Anonymous Coward
    Thumb Up

    I love my HP-35s

    I've never had a "proper" vintage HP, but my new 35s is ace. Yes, I only run it in RPN mode.

    RPN makes absolutely no sense whatsoever for the first 5 minutes, then suddenly you realise it's so easy, logical, fast and wonderful.

  12. Anonymous Coward
    Thumb Up

    For those with Android....

    ...there is an excellent calculator available that mimics an HP RPN (or algebraic) calculator called RealCalc. Have a look on the Market....

    1. Chris Miller
      Thumb Up

      or for those of us still in the Palm 5.0 stone age

      Power48 is an amazing emulator of 48SX and 48GX models. Stunning is the only word.

      My first HP calculator was an HP-35, followed by a -10C and (my current model) a 32S - over 20 years old and still going strong (on its second set of batteries).

  13. Anonymous Coward
    Anonymous Coward

    A 32e and 16c

    I have a really old 31e and a 16c.. the latter of which seems to have sprouted legs.. but it'll turn up. They are fantastic little beasts. I especially like the old 31e with its red LED display. That one got run over and it still works as it did in 1978. Classmates would borrow my calculator once... and not seeing an equals sign, would never ask for it again. Ahhhh.

  14. MLR
    Paris Hilton

    I /still/ use my HP 15C

    ... almost every day. It's a great calc and even though it's about 30 years old (older than many of the people I work with), it has never failed me.

  15. kissingthecarpet
    Thumb Up

    HP were way out of my price range

    I used to have a TI programmable(among several others) at school(not sure now which one - TI-57 perhaps). They were great for Statistics - you could construct tables, so you could "show the working" & vary the partition between LOC & memories. The late 70's has to be the golden age of calculators IMHO.

    The point in exams was to have at least 2 or 3 just in case. I sat London (& 1 AEB) GCEs & they didn't really seem to have rules for calculators(maybe you weren't allowed alpha displays)

    Also had a CBM 9190(??) that had 90 maths functions including numerical integration, perms & combs, Gaussian,Poisson etc etc. This all seemed hugely impressive at the time. Both had a red LED display of course, none of that poncy LCD rubbish.

  16. Dazed and Confused

    Consigned to a bottom desk draw ?

    My wife's 16C is on my desktop where it's been since I persuaded her to let me have it.

  17. Peter 39
    Thumb Up


    The original 16c is the real ticket.

    Still have mine - won't part with it

  18. MajorTom

    Still have three old hp calculators

    And I've only had 4 calculators since I was in high school*. All were hps. The 15c is in a box somewhere in the basement. The 28c...god I adored that one...I lost when I was an engineering student. And the 48SX I got as a replacement was larger, and somehow slower than the 28C, but that's the beast that carried me through the rest of university including grad school and I keep it handy even today.

    Definitely the RPN entry method keeps the unworthy away from my calculators.

    *I stole my little brother's 42S about 16 years ago and have it in the drawer next to me at work as I write this.

  19. PJI


    You can practise RPN on UNIX, using dc(1). At least, it is still on OS X (BSD derived), complete with the man page.

  20. sT0rNG b4R3 duRiD
    Thumb Up

    For great justice

    (This last one is the only calc app I run on my droid)

  21. Bruce Hoult

    A quarter century of HP28S

    I still use my HP 28S, bought in 1986, almost every day. I recently had to put in its 4th set of batteries.

    It's a far far better machine than the 12C! Rather than 20 memories and 99 program steps it's got 32 KB of memory, and the stack is as deep as you want it to be, not just a puny 4 levels. Plus it supports complex numbers, binary operations with a selectable word size, strings, vectors, matrices, lists, and algebraic expressions in addition to the native RPN.

    It's my 3rd and last calculator. Previous ones were some Casio scientific in 1977, and a Texas Instruments TI57 programmable (8 memories an 50 program steps) in 1979.

  22. Dick Head

    Who's got the oldest?...

    ...I have 3 HP 16Cs, the oldest from 1983 (as best I remember). The instruction book has a 1982 copyright.

    It replaced a TI LCD Programmer, which my wife had pretty much taken over anyway. And that replaced a TI LED Programmer, which is still around somewhere. The red LEDs are still the coolest.

    I programmed my first HP 16C to help me disentangle the various fields in the long microcode word used by the embedded controller I was working on then, which used AMD 2900 series chips, as far as I remember.

    Doesn't seem like it was so long ago. I grow old, I grow old, I shall wear the bottoms of my trousers rolled.

  23. Anonymous Coward

    HP12c - superb

    Amazing that HP has not only kept this brilliant calculator going, but that the build quality is still pretty good; my one is fairly new and the keys have an excellent feel that you don't get with a Casio, TI, or for that matter, any other HP calculator either.

    Let's hope HP also bring back the HP16c too.

    @atragon - thanks for - excellent site, now safely in my geek folder.

  24. Matt Bryant Silver badge

    Erm, swapped mine for a Casio.

    In 1983 or so, a mate was going off to do nasty Maths stuff at Uni, so I gave her mine and she bought me a Casio fx-100 as a present. I still have the Casio, it still works faultlessly. She admitted to me a while back she sold my 12c to a colleague for a tidy profit! The Casio saw me through years of service and one of my kids used it through school, and now it still sits on my desk and gets the occassional use. Whilst I probably won't get any geek-points for saying it, in my view the Casio has proved just as good as the 12c.

  25. Stuart Dole


    I still have my red LED HP-25, second battery. When I got it, friends were hacking theirs (adding magnetic stick readers, etc.). I programmed it to run simulations of cancer cell migration for my thesis - a run would go all weekend. The feel of the keys is still wonderful. Old? yep. I also still have a wonderful circular sliderule in my top drawer that sees occasional use.

    RPN vs. Algebraic: anyone remember the tee shirts that said "ENTER > EQUAL"?

  26. Anonymous Coward
    Anonymous Coward

    Just a me too ...

    I have a HP16C that I still use several times a week. It no longer stays on my desk at work though, in case someone permanently borrows it.

  27. atragon

    I fell in love with rpn straight away

    I own 8 original HP calculators all bought between '81 and '89, among those three of the "10" series (11, 12, 15), the last being the 48sx. But my first professional calculator wasn't an HP, it was a TI 57. Good calculator, but when one of my friend let me handle for 5 minutes his HP 33C I just fell in love with it. Yes, HP were more expensive, but the build quality was definitely superior, you just needed to press a couple of keys to realise it, and for me RPN was well worth the price premium. I now immensely regret i didn't buy the 16C, I was an earth scientist at the time, so I really didn't need it. But as pointed out in other comments, it is really a remarkable and unique calculator. I don't know much about the current HP calculators, the HP 35s looks nice, but I have read mixed reviews and a few have had problem with the keyboard. It is sad that these new calculators also come with a packaging that seem more appropriate for those cheap toys in newsagents than for a professional calculator.

  28. Ben Cooper

    LCD screens? Pah...

    It might not be RPN, but I wear my HP-01 quite a bit - okay, three batteries and a solid case mean I walk a bit squint, but it can do running calculations with the date or time as an input - very cool.

    It makes the HP-25 on my desk seem normal.

  29. J 3


    My comparatively juvenile (1992) 20S raises a glass.

    It was funny when I first heard that the guys who made my trusty calculator were making computers, years later...

  30. Ron1
    Thumb Up

    What about HP28C and HP48S/SX?

    Being El Reg is supposed to be a tech journal, I am surprised there is no mention of HP28C and HP48S/SX calculators with graphs and solver, turning 25 this year...

  31. Blue eyed boy

    HP rules K Enter O

    That was my contribution to the many variations on this graffiti theme back in my student days (bid 70's). I still have a HP97 (desktop model with printer) which is my machine of choice for instant calculations. An "old 97" that is no "wreck".

    We needconfigurable text on this icon so I could write R/S.

    1. kissingthecarpet
      Thumb Up

      I remember them

      I thought they were the coolest calculator in the late 70's. You weren't too poor then, eh? HP were well expensive in those days

  32. John Aislabie

    Still going

    My HP12c has been used most (work) days since it was issued to me in July 1986. It currently shares bag space with an iPad . It is scratched and dented but the only thing missing is three(out of four) rubber feet.

    The handbook is a great reference resource and lives on my desk. I always wondered why the note on "Potential for Radio/television Interference" is "for USA only"

  33. David Beck

    A lot of 16C owners here

    Another 16C owner and a note to the author, anyone who has a 16C unused in a desk drawer can sell it for at least 2x the original price. In the old days this would indicate that HP could sell a few of these if they wanted to make a bit of money. But in the new marketing model if you can't rule the world, there is no reason to build it. Gone are the days that established companies built niche products.

  34. Malcolm 2

    16C still going strong

    Still have my HP 16c and it is still in (almost) daily use. Love it. Get really confused if I have to use a "standard" calculator (although that could also have someting to do with my age. I seem to remember that it cost me a small fortune at the time.

  35. atragon

    Bring the HP-16 C back petition?

    There is a petition to bring the HP 15C back:

    Apparently, HP might have listened to it and bring it back although in a limited number.

    Considering the praise the 16 C is receiving in these comments, maybe The Register could host a similar petition for the 16 C? Financiers are enjoying their ever lasting ad-hoc calculator, maybe we, IT geeks, should be too.

  36. wiggers
    Thumb Up


    This was my workhorse for many years, at uni and early working life. Wrote loads of programs for it and used the Byte Grabber hack to get access to additional registers and functions.

  37. QrazyQat

    nostalgia is sometimes good

    Still have mine (the one I have must actually be nearly 30 years old by now). Great key action on that thing. And I did find that RP was a much more sensible way to do even simple math with a calculator than the usual method.

  38. Anonymous Coward


    Have two that I use all the time (one at home, one at work).

    Flogged an SR50A for years, till the keyboard literally wore out from hundreds of thousands of key presses (1/2 the price of HP, poor college studs just can't afford the good stuff like an old line HP, you know, the real HP before HP split into pieces and the bad piece started peddling PCs).

    Got an HP33C (or something like that) keyboard failed just after the warranty ran out, then I found that HP was quietly replacing every single one that failed in warranty with no questions due to a FAIL in keyboard materials design. No, they never replaced mine and no, I never forgave them for taking my money and returning a finger.

    Still, the HP41CX works well and RPN is so much better and more natural than the alternative. Would like to buy a spare one, but the fleabay prices are, well, stratospheric and rising.

  39. Anonymous Coward

    15c was better

    Bought mine in 85 or 86 while at uni.

    It was required for a subject I took. It cost $240. Bank balance after that transaction was less than $240!

    Ouch, that really, really hurt at the time.

    It's paid for itself many times over, and is still going strong now although it doesn't get used as much as it used to.

    I can't think of *any* technology or gadget that has lasted that long, or current technology that will. Those things were built properly.

    1. Anonymous Coward

      15c still going strong

      I got it for free from a yard sale (about 20 years ago) 'cause the seller didn't know RPN and couldn't get the calculator to give the right answers.

      Still using my HP 41, too but GPS has taken all the fun out of the Navigation module.

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