back to article Ten classic electronic calculators from the 1970s and 1980s

Until sometime in the early 1980s, when you reached secondary school you were handed a slim book full of numbers during a maths lesson and taught how to use log tables. Sines, cosines, tangents, square roots - they were all in there too. While it made a change from long division, it caused its own share of headaches. But, to a …


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  1. dervheid

    Still working

    My 36 year old Commodore SR416 still works perfectly.

    1. Anonymous Coward
      Anonymous Coward

      Re: Still working

      So does my 32 year old Casio FX-602P

      1. skswales

        Re: Still working

        Alas, my 32-year old FX-601P died in Sep 2013 - it is greatly missed.

      2. Dazed and Confused

        Re: Still working

        So does my 32 year old Casio FX-602P

        Somehow I managed to kill my 602 years ago, but a couple of years back my father gave me my FX-502P back, which I'd given him when I'd bought the 602. The first software I ever sold was for the FX-502P. I also won £10 off my maths lecturer who bet I couldn't write a framework stress analysis program on a calculator.

        Of course the only thing wrong with them was that they didn't use RPN.

    2. Refugee from Windows

      Re: Still working

      I did replace the internal rechargeable batteries a while back, but still going strong.

      1. Graham Marsden
        Thumb Up

        Re: Still working

        Alas the on/off switch on my FX-81 died a long while ago, but I still have an FX-350 by my side here and an FX-570 in the other room which are kept working by dint of leaving the power switch "on" and just using the AC button to switch it on and letting the auto time-out to switch it off.

        1. Charlie Clark Silver badge

          Re: Still working

          While still at school I upgraded from an FX81, which had taken quite a bashing, to an 180p which could just about be programmed to solve quadratic equations, which is indeed what I used for at O level. That was probably my first ever functional test! It wasn't cheating as marks were awarded for demonstrating how the result was achieved.

          It's still going strong and is what I use any time I need to tot some numbers or double check some mental arithmetic.

          1. gareth husk

            Re: Still working

            The FX-180P was my 3rd calculator that I bought in 81 following a Rockwell 4 function for O-level and an SR 4912 for A-level. It's still on my desk at work and still used every week (normally to prove that my mental arithmetic is correct to the disbelievers). Every 6-7 years the display dims and I think it has died and then remember that it might need batteries.

        2. Jonski

          Re: Still working

          @ Graham Marsden: My FX-82 died that way too, until I cleaned the switch contacts with a bit of isopropyl alcohol. That worked fine for a while longer, and upon its ensuing re-death, a judicious application of emery paper to the metal contacts worked a treat.


    3. Oh Homer

      Still missing

      Not exactly state of the art, but I sadly miss my long-lost, self-assembly, Sinclair Radionic calculator, circa 1978.

      At least I still have my beloved HP48GX.

    4. Jim 59

      Re: Still working

      The first silicon chip in most peoples' homes was probably inside a calculator, as they predated digital watches by a year or two.

      In out house it was a Rockwell in 1977. I remember being confised about the funny "4".

    5. Joe H.

      Re: Still working

      My beloved Casio fx-7000g is still working, last time I checked a few years ago when I pulled the batteries out, and I still have the manual. Business calculus in 1990 was the last time I really needed it for anything, ah, good times.

  2. Peter Mount
    Thumb Up

    Ah the FX-1000G

    The FX-1000G got me through my A-Levels during the late 80's. I can't remember what happened to it after that but it was a good calculator.

  3. Tanuki
    Thumb Up

    RPN FTW!

    I still have my H-P 33E which gets used occasionally.

    Its only fault is that because of the odd way that H-P built it [some of the chips are not soldered to the flexible PCB but are kept in place using a piece of spongy foam!] sometimes you need to twist the case a bit to 'improve' the chip-to-PCB contact and get all the LED segments to light.

    1. Dunstan Vavasour

      HP 33E

      I had a HP 33E at Uni. I dropped it crossing the road and, before I could retrieve it, it had been run over by a car. Apart from a crack in the bottom corner of the case, it was unscathed.

    2. Stoneshop

      Re: RPN FTW!

      The "spongy foam" stuff was pretty common for connecting LCD screens to a circuit board back then. It saved having to add pins, or a piece of ribbon cable to the LCD. If you take one of these constructions apart, you'll find that the foam has black 'channels' running vertically. The problem is that over time the contact between the pads, the channels and the screen deteriorates, but moving things around a bit sufficiently cleans the contact spots again. Oh, and if you have the screen misaligned with the pads on the circuit board, you can get pretty weird displays.


        Re: RPN FTW!

        As memory serves, it was called Zebra Strip.

        1. Stoneshop

          Re: RPN FTW!

          There were basically two types of zebra strip: a silicone tube with narrow conductive rings on the outside, and a rectangular strip with carbon channels inside, running vertically. ISTR the latter ones usually being pink-ish

      2. Charles Manning

        Fixing the foam problem.

        You should be able to fix the problem with this stuff...

        It is tape that conducts in the Z axis. Should be able to replace zebra connectors etc quite well.

    3. PhilBuk

      Re: RPN FTW!

      Still have mine, bought in 1978 on a journey to the States. Never got a UK charger for it but just used AA cells in it which have worked fine over the years. Had to strip and clean the keyboard about 10 years ago but it still works fine. Also have a HP16C which does multiple bases and machine code arithmatic. Great calculators.

      Of course, the fault with the HP33E was that you could enter quite complex programs in it which disappeared when it was switched off. The HP33C came out one year after I bought mine.


    4. Andus McCoatover

      Re: RPN FTW! Springy foam connector

      Yep, at leat one of the early Nokia phones had this (?910?).

      I used to work miracles to my friends by giving them a quick twist to restore a missing segment or two...then retighten the case screws for a longer-lasting fix.

  4. Sandpit

    No early casio?!?

    Where is the green digitron tube featured on the great casio FX-39, 105 or my favorite the 120. Really high quality feel to these with sweet buttons and I loved the way the tube "sang" when you switched it on.

    1. Anonymous Coward
      Anonymous Coward

      Re: No early casio?!?

      They aren't Nixies, they are Vacuum Fluorescent Displays.

    2. Anonymous Coward
      Anonymous Coward

      Re: No early casio?!?

      check em under a magnifying glass to see the slightly glowing red anode lines...


      1. Hugh Pumphrey

        Re: No early casio?!?

        "check em under a magnifying glass to see the slightly glowing red anode lines..."

        cornz 1, your post inspired me to put some batteries in my 1975(ish) casio fx31, just to see the turquoise glowing display light up again. You can indeed see the anode lines glowing; I can't remember if I ever noticed this before.

        1. Anonymous Coward
          Anonymous Coward

          Re: No early casio?!?

          "slightly glowing red anode lines..."

          I think those are actually the cathode (filament), the anode is the green glowing bit.

          FX-29 in the drawer here (dates to about '76), still working ok though the black vinyl cover is getting a bit brittle. I'd forgotten how small the little green digits were, but in the days before mobile phones it could double as a handy under-bedclothes torch (88888888). Don't ask.

          I use LCD models now, and not in the dark, but still the same scientific buttons get the wear - pi, log, ln, 1/x, sqrt.

    3. anonoomouse

      Re: No early casio?!?

      Spot on. Fx39 was revolutionary. Mine died 10 years ago. I miss it.

  5. MacroRodent

    TI-59 memories

    My father got a TI-59 from work around 1978 or 1979, and it was the first device on which I tried any kind of programming. Felt like using technology from the future! Unfortunately magnetic card reader was not too reliable, and eventually stopped working. There were also swappable ROM modules of programs. The calculator came with one, but others were supposedly available for special tasks. There was also a cheaper version TI-58 that lacked the magnetic card feature, but was otherwise similar.

    1. Evil Auditor Silver badge

      Re: TI-59 memories

      So I wasn't the only one who started programming with the TI-59.

      I also had, still have somewhere, both of them, the TI-58C - no card reader but at least constant memory.

    2. Number6

      Re: TI-59 memories

      I have a TI-58 somewhere, it worked last time I tried it, although the rechargeable batteries will need replacing. It had one bit error in its RAM, somewhere near the top, I had to make sure that when programming, I only stored even op-codes in that location.

      I got it to play noughs and crosses - it could have been invincible but I deliberately left one way it could be beaten.

    3. Bilious

      Re: TI-59 memories

      Classical or classical. I had the SR-52, the precursor to Ti59 (

      Read errors on the magnetic cards were a nuisance, and battery life was so-so - but space permitted me to program anovas on it. Made me a local statistics expert in the late 1970s.

      The printer was very helpful for documentation purposes. There were occasional contact problems, but wriggling usually solved it.

  6. Edwin

    Ahhh... memory...

    My first programming experience was on a LED display HP. A game involving landing a lander on the moon, IIRC.

    Still have an old FX-something lying around, but when I need a calculator, I reach for my HP48. None of that pansy smartphone stuff.

    1. Anonymous Coward
      Anonymous Coward

      Re: Ahhh... memory...

      > when I need a calculator, I reach for my HP48. None of that pansy smartphone stuff.

      My two 48GXs are missing in action, while my 42S has been stolen (back) by a member of my family, and dad keeps his 41s well hidden, so I have to resort to smartphone stuff:

      Binaries available at the usual places, including until recently from F-Droid.

    2. Dazed and Confused

      Re: Ahhh... memory...

      > but when I need a calculator, I reach for my HP48. None of that pansy smartphone stuff.

      You can get a HP48 app for Android, and a HP16C one too.

      But it doesn't have the tactile delight of the real 16C, so my wife lets me use her 16C.

      I've an 41CX too, but it feels more plasticy.

  7. Himalayaman

    I still have an HP-28C... incredible machine.

  8. Josco

    My first calculator

    I had left school and was working for Berni Inns as a trainee manager on the princely sum of £4 per week. My mother came home one day with the first electronic calculator I had ever seen. It was a Sharp and it could add, subtract, divide and multiply with an eight character screen! It also had a button on the side to increment the display count by one so it could be used as a rudimentary counter. At £15 it was nearly a months wage!

    Sadly it has been lost.

  9. Bob Starling

    HP calculators rewired my brain for RPN so thoroughly that I am almost incapable of using a regular calculator. I was ridiculously pleased when I found a HP11C emulator app for my smartphone.

    1. Spanners Silver badge


      I had a Sinclair Scientific Reverse Polish Notation device. The best thing about it was that almost nobody borrowed it twice! My maths teacher figured it out and explained some of the things that it could do beyond straight arithmetic.

      I too now have an calculator app on my phone that does RPN if I want. Now I get confuse a whole new bunch of people...

      1. Evil Auditor Silver badge

        Re borrowing RPN calculators

        I remember when once in a post grad lecture the nice lady next to me borrowed my HP-48. At first, she was puzzled for a few seconds - I can only guess: "where the heck is equal?". Then she pressed some keys, waited another few seconds, pressed some more keys and silently passed it back to me. It had some weird numbers on the display :-)

      2. Bronek Kozicki

        Re: RPN

        I was familiar with RPN since youth (some 20 years ago - I think my father had some HP variant) but didn't use them much, until few years ago when I purchased newer HP model. The fun part is that I got accustomed to it from using a simulator rather than the real thing. Now I install this simulator on all computers I expect to need a calculator. And I still have (and use) the real thing, obviously - under 5 years, it's almost new anyway!

  10. Fading

    Still use

    my fx-7000GA purchased for my A-levels. Have the 7700 (I upgraded for university) as well but it eats batteries at an alarming rate (and I don't need the additional functions in my day job).

    1. AndrueC Silver badge

      Re: Still use

      You could supposedly reduce battery consumption by turning down the contrast on the FX-7000G. Meant you had to tilt it to read it though.

      I'll have to dig mine out tonight and see if it still works. It was working a couple of years ago.

      1. Great Bu

        Re: Still use

        I still have my FX7000G, I didn't realise it still worked until I saw my wife sitting at our computer filling in her finances spreadsheet and using the calculator to add up some numbers. I made no comment.*

        *Do I get a prize for restraint ?

    2. Dances With Sheep

      Re: Still use fx-7000

      My fx-7000G is just to the right of my mouse as I'm typing this :-)

      It's been in use daily since my GCSE days mumble years ago. I think I'd be stuffed without it.

      (And yes, batteries can be made to last by turning down the contrast)

    3. GitMeMyShootinIrons

      Re: Still use

      Four CR-2032 batteries on the 7700 (one for memory, the rest for the calculator) - and it does like batteries like a fatman likes cakes!

  11. Tom 7

    Ah the skills one forgets

    that RPN seems to have hidden itself away in my brain - but funnily enough I can feel the keyboards of some of these in my memory!

    And I can also remember the smell of the log tables!

    1. Admiral Grace Hopper

      Re: Ah the skills one forgets

      Log tables are a whole different area of nostalgia. I've still got mine tucked away somewhere, hopefully with some slide rules close by.

    2. Michael Wojcik Silver badge

      Re: Ah the skills one forgets

      And I can also remember the smell of the log tables!

      I've never had to use a slide rule in anger - I learned how to use one from one of those "how things work" books, but by the time I was doing sufficiently-ambitious arithmetic in school, four-function calculators were widely available.

      They did teach us to use log tables and interpolation, though. Interesting at the time, and an understanding of logarithms came in handy years later when I started working with probabilities, which are often computed in log space to prevent underflow. (Of course in underflow becomes negative overflow in log space, but you get a lot more room to work in.)

  12. hammarbtyp

    Programming was a challenge

    I seem to of owned most of these once in my life, especially the Casio's

    The greatest challenge with the Casio programmable model was fitting a simultaneous equation solver in the available memory. I was well pleased when I managed it and in hindsight started pushing me to the career in embedded programming I have now

  13. J.G.Harston Silver badge

    I did my I O level exams with a RPN HP calculator borrowed from my Dad. Until then I did trig by remembering the SIN of 0, 30, 45, 60, 90 and interpolating between the points and calculating COS and TAN from SIN.

    I saved up my pocket money to buy a solar-panel Casio fx911 for my A levels, which I still have in perfect working order. I was doing my tax return with it just a couple of days ago. :)

  14. MrTivo

    Casio MG 880 - match the numbers game

    Surely one of the most used calculators when I was at school. Played an annoying version of "When the Saints go marching in", plus that really addictive match-the-numbers-and-make-multiples-of-10-to-get-a-bonus-n-character-game. We used to play, highest score for 1 or 3 waves of numbers, and those who really couldn't stop playing disconnected the speaker so they could play during class.

    Finish 10 waves of numbers and the screen shifted to the left by one segment for the next 10 waves, then back for the next, as the speed increased. I am pretty sure there were 99 waves before the game reverted back to where it started.

    People could walk and play the game at the same time, ISTR. Those +/= buttons got a good pounding. Picked one up a at a boot sale, just for the memories. I still suck at the game.

    Then there is the boxing match calculator, BG-15.....

  15. Admiral Grace Hopper

    Happy and sad memories

    My TI-59 didn't survive being run over and was replaced by a fx-550 which saw me through to university when I replaced it with a Prime (it wasn't, strictly speaking, my Prime, but I loved it nonetheless).

    I couldn't find my old Casio when I came to guide my nephew and niece through their GCSEs and A-levels so I was a little pleased to find myself shopping for a scientific calculator once more.

    I'd lambast you for shameless nostalgia, but well, when I were a lass it were all mainframes with discrete components round here ...

    1. Anonymous Coward
      Anonymous Coward

      Re: Happy and sad memories

      > My TI-59 didn't survive being run over

      Should have bought an HP. :-)

  16. Anonymous Coward
    Anonymous Coward

    Casio FX-82

    Joining secondary school in the mid 90s I remember one of the requirements was a Casio FX-82.

    It looked like it had barely changed in 15 years, but if it did the job then it was ripe for the job.

    I also remember in the 80s in primary school, someone had a calculator that had a vivid red LED display, it was a thing of beauty.

    Remember teachers saying that mental arithmetic was important?

    That we wouldn't be carrying calculators with us everyday?

    I look at my mobile phone, with calculator, spreadsheet and internet connectivity functionality, and laugh to myself.

    1. LaeMing

      Re: Casio FX-82

      We got to use calculators from year-8 with the 2xAA battery-powered FX-82 as the standard. Even better was when my younger brother go to year 8 and I offloaded my '82 on him and got myself a FX-115m (that is the one in the article photo, though not in the article!). Had all the binary, octal and hex modes that a budding computer geek needed (at least that is what I convinced my mum of).

      It also had solar cells running the display but an internal button-cell running the actual chip, so when smart-arses covered the solar cells while walking past my desk, I didn't loose what I was in the middle of. Suckers!

      Still have it right here and last used it just 2 days ago. It is on its third button-cell in [redacted] decades!

  17. Dr Trevor Marshall

    My smartphone emulates my beloved HP41

    I have Andsens HP41 simulator on my android smartphone. I use it almost daily. ( a41CV.apk ). It even runs my old programs...

    1. Phil O'Sophical Silver badge

      Re: My smartphone emulates my beloved HP41

      There's a TI5x emulator for Android as well, emulates the TI 58/59 family.

      I highly recommend a read of Ken Shirriff's blog on reverse engineering and emulating the origiinal Sinclair Scientific, as well:

    2. KA1AXY

      Re: My smartphone emulates my beloved HP41

      I have one of those emulators on my PC at work...and still own my HP41C, as well as the HP25 it replaced. The HP25 is a nice little unit: solid, LED readout and programmable. Runs on two AA cells. It got me through grad school. Before that, I had a Bowmar 4-banger and a slide rule for the trig functions.

    3. Zolko Silver badge

      Re: My smartphone emulates my beloved HP41

      I prefer the HP-15c, and it has it's Android andro11c emulator also (the HP-11C actually, but they're nearly identical)

      Then there is also the HP-15C emulator for computers.

      These have put my real HP-15C to rest, even though it still works perfectly (aaahh, those keys were a pleasure to type on)

  18. John Styles

    FX 502-P

    For me it was the FX 502 P with the strange yellow LCD, whatever happened to them? Unlike the 602P you had to look at the program as its mnemonics - the digits and the letters C,E,F and P, IIRC.

    Who remembers Dick Pountain's column in PCW? There were strange tricks you could do to exploit a bug in the firmware to display some of the letters and put the digits 1 to 4 in the first character of the exponent i.e. you could display 1 E 499.

    1. Steeev

      Re: FX 502-P

      Ah the FX-502! And its cassette cradle. And the Kraftwerk track, supposedly composed on one. ("I am the operator of my pocket calculator")

      In order, I learned programming on: the Sinclair Cambridge, TI-57 and finally the FX502-P before graduating to "real" computers. I remember being shocked at the 6502 processor in a SYM-1 not having multiply and divide instructions (not to mention trig) while the lowly TI-57 had.

      O tempora, o mores!

      1. Ancientbr IT

        Re: FX 502-P

        I'd forgotten the cradle - thanks for reminding me - and those music overlays for the keypad to help in composition. I wrote some almost-melodic sequences for mine and then set it off while I strummed along with my electric guitar and multi-tracked onto a stereo cassette tape deck.

        Ah, nostalgia. Although I don't know where my nost is, I'm happy to experience the algia it gets whenever I trek back mentally some 35 years.

    2. Ancientbr IT

      Re: FX 502-P

      Extracting from (dusty) archives...

      YES! Dick Pountain - the man who published my first "real" program and fed my ego :) I think he offered me seventy quid for the accompanying article, achieved by sticking a cheque for the same in with the letter that asked me if I minded if he published, and as I recall the issue in which it was published arrived the same day in the mail.

      The program was a version of Tic-Tac-Toe for the Casio fx502P and Dick seemed to think it was worth examining the code (he made nice comments, which fed my ego even more :)). I've long since lost the issue of PCW (rest in peace) in which it appeared but it was a treasured relic for many years. If I could find a scan of the article online that would be great - I could show my wife what I've been boasting about all these years :) - but it still eludes me.

      Truth be told, what got me started in my ongoing addiction to programming was the Sinclair Cambridge. An hour after I bought it (at Boots, in Oxford, I think), while I was buried deep in the manual the bus I was riding was hit head-on by a truck carrying 12 tons of road gravel - one way to have a baptism of fire, so to speak. Some programmers are born, some are made, some have it hammered into them at 50 mph.

      I owned or used at work some of the great machines discussed here - Sinclair Cambridge and a couple of other models whose manufacturers' names I can't recall, Casios 201p, 502p, and 702p; an HP 97c (the one with the programmable strips and inbuilt printer and that wonderful RPN that confused an entire department at the University of Oxford but yours truly cracked it :)) and a bunch of others after that (again, memory fails me) until I transitioned into "home computers" - a whole other saga :)

      But, all hail Dick Pountain. Also Paul Liptrot for different reasons, and Wendy Wilson/Hunter and Trevor Hood at what was Castle House Publishing, for even more different reasons. One of these days I'll raise a monument to them all (and the countless others who helped me become what I am today - - homeless and unemployed in Los Angeles. But still addicted to programming :)).

      1. Dazed and Confused

        Re: FX 502-P

        > Dick Pountain - the man who published my first "real" program and fed my ego :) ... The program was a version of Tic-Tac-Toe for the Casio fx502P

        I'm not worthy, truly you are a god amongst programmers!

        I remember the article well, but no I don't have a copy. That was a remarkable piece of code, if I'd owned a hat I'd have taken it off for you then.

  19. Pen-y-gors

    Sad, sad, sad...

    In 1972 I was doing A-levels, and I asked for (and got) a set of 7-figure log tables for Xmas. Man, was I a rebel! They're still around somewhere.

    Then went to Uni in 1974 and got a Sinclair Scientific (the log tables were easier to use...)

    Mid 80s got a Casio fx451 (the one that could handle Hex) and it's still in my desk drawer and still works.

    1. Boothy

      Re: Sad, sad, sad...

      Casio fx451 here also.

      The Hex mode was very useful while doing assembly code courses and similar.

      1. Simon Harris

        Re: Sad, sad, sad...

        I had the fx450 - all the same functions as the 451, but with more primitive solar cells that seemed to require the sun to go supernova before you got any decent contrast on the display.

  20. spider from mars


    I think I've still got mine in a drawer somewhere - don't know if it still works though. I coded up a very simple drawing program to entertain myself in boring lessons, and the program function was excellent for cheating in exams, as the "program" slot could be used to store useful formulae instead :)

    1. Tascam Holiday

      Re: FX-7000G

      My FX-7000G is still going strong, I think I got in 1986 or 1987. There was a depressing point a couple of years ago when a colleague pointed out that he was younger than my calculator though.

      1. Simon Harris

        Re: FX-7000G

        Hadn't used mine in a while, but the other day I remembered i'd seen some CR2032s in my girlfriend's battery collection and thought 'hey, wonder if it still works'.

        Works perfectly and my girlfriend lost me to calculator nostalgia for a few hours.

        1. Anonymous John

          Re: FX-7000G

          Your girlfriend collects batteries?

          1. Admiral Grace Hopper

            Re: FX-7000G

            Your girlfriend doesn't?

          2. Paul Crawford Silver badge

            Re: FX-7000G

            I though most girls did, but of the 'AA' size.

          3. Anonymous Coward
            Anonymous Coward

            Re: FX-7000G

            > Your girlfriend collects batteries?

            It's better than needing them.

        2. Evil Auditor Silver badge

          Re: FX-7000G

          @Simon Harris

          Don't you have your own battery collection? Or are you and your girlfried that far into the relationship that you united your battery collections? Congratulations! That's something not even all married couples would do!

  21. Anonymous Coward

    All these comments...

    and no one has mentioned the simple schoolboy pleasure you got in your maths lessons in the early 80s of typing 58008 and turning the calculator upside down

    1. Erudite Luddite

      Re: All these comments...

      Beat me to it! Although I recall the apposite numerical plural being 5318008


    2. Simon Harris

      Re: All these comments...

      Of course 58008 works just as well without turning it over as 80085, but 58008618, 5318008 etc only work upside down.

      I remember getting a Casio fx450 which did base convertion and logic functions and had a new kind of fun working out what naughty words you could make with the hex digits - even without turning it over b00b5, b19b00b5, b00b1e5, etc. Bonus points for working it out and entering it in decimal and then pressing the hex conversion key

  22. Rich 11 Silver badge

    Simpler days...

    My fx-550 finally gave up the ghost six or seven years ago. The modern calculator I bought to replace it just doesn't seem as intuitive.

    I've still got my log tables, though. I used to be able to make good approximations purely with mental arithmetic, having memorised the logs of 2, 3 and 5, working by interpolation between those and their multiples (but I can only remember log 2 now). I've also got my dad's slide rule tucked away in a box somewhere, although I never really taught myself to use it properly.

    1. Paul Crawford Silver badge

      Re: Simpler days...

      Indeed, I still have (and prefer) my fx-570c to a newer model that tries to do things in some sort of procedural way (i.e. you have to enter 'sin' '0.5' '=' and not that stack-based '0.5' 'sin' sort of way).

      I prefer the stack-style as often you compute something, and then want its log, etc, and it is annoying not to just press 'log' and get the result of computing it on what is currently on display.

    2. Number6

      Re: Simpler days...

      2 and 5 are easy to remember, especially if you're involved with electroncs. 3dB is x2, so log(2) is 0.3, and you can remember 5 because it's 10/2, or (1 - 0.3). The 3 can't be deduced from simple short-cuts, so you have to remember it's 0.477.

  23. Tony S

    I'd bought a slide rule (10 shillings with the discount we were allowed as students) in '67 for my first year at the grammar school. (4 weeks pocket money!) I used this throughout the next 5 years; although I still had to use log tables.

    I remember when the first of the Casio calculators was brought in by someone; we actually organised some tests to see who could do the calculations quicker, those with slide rules or the electronic device. (Damn, we were sad!) Because of complexity in operations, slide rules tended to win to begin with, but as people became more familiar with the set-up, they started to get faster.

    After I started work, it was mostly mental arithmetic and manual addition. 8-(

  24. Inspector71
    Thumb Up

    It Will Not Die

    HP still sells the vintage HP 12C Financial Calculator after 30 odd years. You will have to pry it out of the cold dead fingers of a couple of accountants I know.

    1. Steven Jones

      Re: It Will Not Die

      "You will have to pry it out of the cold dead fingers of a couple of accountants I know."

      The difficulty will surely be establishing if an accountant is alive or dead...

    2. Mayhem

      Re: It Will Not Die

      I swear accountants tend to be cold blooded ... their fingers are cold and clammy whether alive or dead.

    3. DC509

      Re: It Will Not Die

      I had a number of 12C's, which are truly fabulous financial calculators. I also had the other 2 HPs in the list but my favourite was the HP67, because of the sheer number of buttons and the integrated magnetic strip reader.

  25. Anonymous Coward
    Anonymous Coward

    Not only the TI-59, but also...

    "If the all-singing, all-dancing card-reading TI-59 was the Fred Astaire of programmable calculators"

    then what does that make its junior family members, the TI-58 and TI-57?

    1. Dazed and Confused

      Re: Not only the TI-59, but also...

      > then what does that make its junior family members, the TI-58 and TI-57?

      Thanks for the link.

      The Ti-57 is where I started programming, The lab where my father worked had one and he'd borrow it for me to play on.

      Then my brother got a CBM programmable calculator which had more "steps" and memories so I'd beg that from him.

  26. Anonymous Coward
    Anonymous Coward

    First "banned" calculator...

    ...was the Casio FX-7000G.

    You weren't permitted to take it into any Scottish O grade or higher maths exam unless it had been factory reset prior to entering the exam room. The calculator was very popular up until that time as you could program in all the "harder to remember" formulae before entering the exam.

    This was kind of amusing as you could do the same to some extent with the FX-550 (which I used for 15 years or so) but the graphing functions on the FX-7000G freaked the examiners/invigilators out enough to ban it :)

    1. Anonymous Coward
      Anonymous Coward

      Re: First "banned" calculator...

      No it wasn't.

      When I did my O/A-Levels well, well before the 7000G came out no programmable calculators were allowed in the exam room. And before that not even basic calculators were allowed. So it wasn't a case of banning calculators but more of allowing them.

      1. Anonymous Coward
        Anonymous Coward

        Re: First "banned" calculator...

        Here's a tiny clue for you - O grades/highers are not the same as o levels/a levels. Its not even the same educational system so I repeat it WAS the first "banned" calculator in Scotland. Edit - it was specifically named as such along with a TI calc added about a month later.

        1. Anonymous Coward
          Anonymous Coward

          Re: First "banned" calculator...

          Repeat as much as you like. The de facto standard was no calculators either in scotland or england and in some exams scottish or otherwise calculators of any description are still not allowed.

          1. El Zed

            Re: First "banned" calculator...

            Repeat as much as you like. The de facto standard was no calculators either in scotland or england and in some exams scottish or otherwise calculators of any description are still not allowed.

            weird that,

            from Google, the fx-7000G came out in '85.

            At that point, I'd been an escapee from the drudge that was the Scottish secondary education system for a couple of years, but during the fun time I had, I'd used various Ti. HP and Casios (including programmables)* in exams from around '78 onwards, though they insisted that any programmable had it's batteries taken out and reinserted before the start of the exam...old school thinking at it's best.

            My last school Casio, a fx-3600P purchased in '82 a couple of days before my CSYS exams as a replacement for the sadly unremembered model HP programmable calculator which inconveniently attained the blessed state of fubar. The Casio survived almost daily use up till the late 90's, in fact, it may still be working somewhere out there, but as some fscker 'borrowed' it from my workbench circa '98, I'll never know.

            I've currently got a couple of el-cheapo Olympia scientific calculators from Lidl lying around at work for those occasions when I need one, I really must invest in a decent calculator again for home use.

            *I'm not including either the Texets (I spit at the memories) or National Semiconductor Novus calculators I had, the Novus calculators were great fun (my first one was a Mathbox 650 back in '74-75) but you had to be careful, as they weren't that stable (some of the factory rejects made for great practical joke items, with all sorts of fun faults like multiplying any number by a decimal setting the calculator into a countdown from a large random number, 2+2=7 etc.)

          2. mickey mouse the fith

            Re: First "banned" calculator...

            I remember having my Casio calculator watch taken off me before a maths exam in the mid 80`s. Calculators were not allowed in the exams for the city & guilds maths modules i did.

            You were allowed them in other subjects like physics or engineering though, just not maths (which stands to reason really).

            Apparently the school had problems with people using sharp (and other) programmable watches to cheat in exams by loading them full of likely answers via the address book functions, and so calculator (or any funky looking) watches were always comfiscated before (or during if you managed to hide it under your sleeve and teach noticed it later) exams as you couldnt remove the battery and the teachers had no idea what functions the watch had hidden upon it. Calculators were inspected for cheating potential beforehand and a bunch of roving teachers scanned the room constantly looking for cheats during the exam.

  27. Malcom Ryder 1

    I got my first scientific calculator in 1975, it was a Texas instruments model. It was previously $75.00, but buy buying it in bulk with some other people at work, I got it for $50.00. That was when I was making $3.20 an hour.

  28. Roger Jenkins


    I had a RPM calculator back in the late 70's, it was a Novus. I've never seen or heard of them since.

    1. Andy The Hat Silver badge

      Re: Novus

      "I had a RPM calculator back in the late 70's, it was a Novus. I've never seen or heard of them since."

      Hooray! Another person in the world who had one of these.The big advantage was the rest of the kids never borrowed my calculator as it didn't have an equals sign! Mine still works ...

    2. Number6

      Re: Novus

      Now, of course, an RPM calculator is what you use to determine which other software packages you need to install on your RedHat system before you can install the one you actually want...

  29. Neil Barnes Silver badge

    I used nothing but slipsticks - including circular and tubular types - and the fabled book of tables, until my O-levels in 1976. Got a Sinclair Scientific sometime between then and the A-levels a couple of years later; no-one *ever* borrowed that calculator a second time. It ended up wired in as a maths co-processor on a 6502 system, driving the switches with CMOS contacts and reading the multiplexed display... absolutely no use whatsoever but it did, just, work.

    Got an HP11 mid-eighties (I had to change the batteries last year, shock), but it's still my reach-for calculator, and I have an HP41 at home, and another HP whose number I forget but which eats really unusual batteries - HP31 perhaps? LED display...

    Stack logic is built in so much now I can't even drive these 'show the equation' calculators; anything with an equals key throws me! I don't use the programmability of them these days, but for general use, there's nothing to beat an HP calculator.

    1. Stoneshop

      I have an HP29C somewhere: LED display, RPN of course, and programmable (and one of the example programs in the manual is that moon lander one). At some point the batteries wouldn't hold charge anymore, to the point where it wouldn't even power up running off the mains adapter. But after a brief interlude with a pocket knife, two AA NiCads and some glue, it was fully functional again. I'll probably have to redo that trick when I find it.

    2. GrumpyOldMan


      Found my log tables book in the loft and showed my kids. Bit bigger than A5, grey cover, logs, inverse logs, etc, when they stopped laughing at me they did actually look interested. For a nano second...

  30. Phil O'Sophical Silver badge

    I remember all of these...

    Didn't get to own many of them, though. I still have my (built from kit) Sinclair Scientific. my original (LED) TI-30, and a TI-51-III programmable. Also a later LCD TI one, can't remember it's model. They all still work.

    Although the article mentions HP's love affair with RPN it doesn't mention the other big classroom disagreement of the late 70s/early 80s: the Casio sequential operation versus TI's "real algebraic" operation.

    Enter 2*3+8*4+3*7 on a Casio and it would perform each operation as encountered, so the result would be 413.

    A TI calculator would respect associativity, and 'stack' partial results, thus giving you 59. On a Casio you'd have to explicitly enter it as (2*3)+(8*4)+(3*7) to get the "algebraically correct" result. Oh, the arguments about which was better... :)

    1. Simon Harris

      Re: I remember all of these...

      Are you sure about that? It's a long time since it bit the dust (err, my inquisitiveness to find out what was inside), but I'm pretty sure I remember my Casio FX-39 having proper operator precidence back then.

      1. Phil O'Sophical Silver badge

        Re: I remember all of these...

        I have to admit that I can't remember which Casio(s) we tried, but at that time TI was the only manufacturer (at least among those affordable to sixth formers) which had the feature.

        I've just tried on my desktop systems. The Windows 7 calculator shows proper precedence, the Gnome 2 calculator on Solaris doesn't, so they still aren't all consistent!

  31. terry 15

    I bought an fx-P401 either for my GCSE's or A-Levels (I don't remember which) but I've had it and used it for many years since. I loved the fact that you typed the calculation you wanted (brackets included) then hit 'exe'cute to perform the calculation. It performed the calculation in the order you expected rather than having to second guess order of execution and had all various standard casio functions (include hex/binary/decimal modes).

    It was advanced enough to do what I needed but not too advanced so it was allowed during my university exams. (eg the FX-1000G graphical calculator that replaced it and was banned!)

    I still use it now in work, I'm not entirely sure how many years ago I replaced the batteries but they keep going and going!

  32. dav3car

    IBM mainframe people HAD to have a TI Programmer don't know the model number. It could do math in hex.

    1. Dick Head

      Still have mine...

      ...TI Programmer LED from the early 1970's. Plus the LCD follow-on from around 1980. And finally the grail: the HP 16C from around 1984. I still use the 16C, and have two spares in case it ever goes tits-up.

  33. Mr Hubris

    I had one of these in about 1976 - (Prinztronic - i.e. Dixons)

    We were poor. But it got me through my A-Levels.

  34. Neil 44

    Sinclair Scientific

    Haven't you got a picture of a Sinclair Scientific? RPN (which confused people who borrowed it!) and it was *almost* accurate :)

    If you want a picture, I'll dig the one I built from a kit out and take a couple....

  35. Aristotles slow and dimwitted horse

    If only I'd spent more time learning maths...

    Than using my calculator to write fun terms such as:

    5318008 or 71077345

    (the 4 doesn't work as well on a PC though)

  36. Smudged


    I still have a HP-41CV at home somewhere (probably in a drawer with my Newton). I remember putting all the mnemonics and formulas I needed for my A levels into it, since no teacher at the time (1981) realised a calculator could do anything but a few sums.

    Now this has reminded me, I might stick it on ebay if I can find some batteries for it.

    1. Dazed and Confused

      Re: HP-41CV

      How did an article on calculators miss out the HP-41CV, the calculator used on the space shuttle.

      In terms of batteries it should take Duracell "N" cells. One reference I saw online mentioned some other batteries which where about 10 times the price and didn't work :-(

  37. AndrueC Silver badge
    Thumb Up

    I had an FX-82 clone bought from Tandy. Chiefly remembered for the fact it took four or five seconds to calculate 49 factorial.

    I also had (still have) a Casio FX-7000G. I don't use it these days but I programmed it to display a 2D rectangle that rotated about either vertical or horizontal axis. It flickered a bit but worked. I also used it to help with exams (ahem). I didn't bother programming the formula though - it was more memory efficient to use it as a text pad with appropriate 'short hand' :)

    My favourite calculator was probably my FX-350. Rather surprised El Reg hasn't mentioned that model.

    Ah happy memories - apart from the fact you've reminded me it was so long ago. Where did the years go?!?

    My biggest complaint about calculators these days is that so few offer easily accessible hex/bin/logic facilities. If a calculator has them they are usually buried away in a special mode somewhere :-/

    1. Nigel Whitfield.

      There were loads we could have mentioned; the fx350 isn't so different to the 550, though. And having limited myself to ten, I didn't want to end up with huge numbers of Casios; they were pretty ubiquitous, but there were the other brands as well.

    2. Rusty 1

      49 factorial?

      Isn't the magic number 69? Well it was for the 2 digit exponent Casio-toting people. There was a Sharp around at the time that had 3 digit exponents. Oh the numbers that beauty could factorialise :-)

      1. AndrueC Silver badge

        Re: 49 factorial?

        Isn't the magic number 69?

        You're right. I blame my mistake on senility :)

    3. This post has been deleted by its author

  38. Steve Davies 3 Silver badge

    Rockwell 8R Calculator

    That got me through my degree in Control Eng 1972-75. Ti Calculators were specifically prohibited in exams.\

    1. Anonymous Coward
      Anonymous Coward

      Re: Rockwell 8R Calculator

      For me the 8R was a lifesaver. I worked for an insurance company when it came out. My desktop mechanical calculator would go into fits everytime I tried to do division on it. I ended up having to do division from the other side (multiplication). My dad, who worked for Rockwell Autonetics at the time, got an 8R for me at a steeply discounted price, $35. Problem solved! And much quieter too.

  39. chizz

    unfortunately, [enter]

    in RPN [enter]

    I only think! [+][+]

  40. Anonymous Coward
    Anonymous Coward

    FX80 early lesson in marketing?

    if iremember correctly the FX80 was an FX81 without the stats functions, however they were the same machine with just the screeenprint changing, if you used the keystokes from an 81 on an 80 it performed the correct calculation. Got to admire casio for trying to segment the market.

    1. sorry, what?

      Re: FX80 early lesson in marketing?

      I think it was the FX-80, black, that had the SD functions and the 5 quid cheaper FX-81, white/cream, that didn't. I had the cheaper one and my friend had the expensive one. He paid for the printed functions above the keys and an LCD that said "SD" in small letters when in SD mode. I didn't have the printing and the LCD said "ERROR" where "SD" should be if you used the key sequence to access SD mode. As you mentioned, it all still worked though!

      Laugh? Oh, you bet. As soon as I'd copied down what the functions were on which key ;)

    2. Mike Kennelly

      Re: FX80 early lesson in marketing?

      On the FX-81, the difference being that if you pressed the two-key combination required to initiate Standard Deviation mode, the FX-81 would indicate "ERROR" rather than "SD", if I remember rightly - but as you say it would otherwise function exactly as the more expensive model. I put little sticky labels under the keys on mine so I could easily access the hidden functions.

  41. Anonymous John

    The first one I bought had no keyboard, just metal pads and a stylus.And probably still in a box in the attic.

  42. Minophis

    I had a Casio FX-7000G, the battery started dying during my Physics A-level exam. I had to switch it off for a minute just to be able to calculate the log of a number. Other than that I loved it. I still have it somewhere.

    1. Simon Harris


      Going into an A-level with flat batteries. That really is a schoolboy error!

  43. chizz

    Classic HP clones still available


    they are a good bit smaller than the originals, identical functionality, plus some minor additions, USB upgradeable.

    Disclaimer . I have no connection, but I do use their DM16 daily.

  44. baz rowlingson

    At school I remember there were two popular but similar Casio models, one with statistical functions and a cheaper one without. The cheaper one actually had the stats functions, only they weren't marked on the machine and when you went into stats mode the LCD had an 'ERROR' show rather than 'SD'. With a judicious application of ubiquitous 80s schoolboy huff-fluid of choice, Tippex, and a quick scribble and you had a free upgrade.

    I had a Sharp EL506H because it could do hexadecimal, a vital tool for any programmer back in the late 80s. It went missing when someone did a sweep of the shared PhD office and probably got about 20 calculators.

  45. Anonymous Coward
    Anonymous Coward

    Sharp EL-509A

    My EL-509A from 1983 is still going strong. My PhD supervisor was using one a decade ago too.

  46. WaveyDavey

    Happy days. Most of the students in my huge 1980-81 6th form (18 upper and lower together) had TI-30's and I recall you could turn them on by pressing a combination of 2 keys on left hand column, and one on right.

    I had a casio (can't remember model but had stats, hyperbolics, dec/oct/hex) which lasted me well past Uni, and it was much faster in the "factorial calculator challenge" we sad students had. I think the limit was 69! before it exploded / error'ed.

    I can still remember the "new electronics" / "new calculator" smell when I first took it out of its packaging.

    Fanboi icon 'cos I was a Casio Fanboi back in the day.l

  47. SJG

    Casio FX-602P

    My 602P is still working well and sits happily in the top drawer of my desk.

    I probably learned more about the basics of programming from the 602p than my early days with Basic. It's assembler like commands with a total of just 512 available 'steps' taught me to be a very lean programmer. At least it did have a GOSUB which started me thinking about subroutines very early on.

    Together with a few friends, we managed to write some games, even an adventure game which ran in a 9x9 grid and an interactive game based on 'hitting' numbers which progressed across the screen.

    It's a fantastic pity that today's super-powerful smartphones just don't provide the same type of easy opportunity for learning the basics of programming. I spent many hours of free lessons programming on the 602P, I'm not sure that anyone really does that with a smartphone.

    There is, however, a nice simulation of the 602P that's available for android, so it is possible to simulate the environment, but it's just not quite the same.

    Here's the link :

  48. Boris the Cockroach Silver badge

    no mention

    Of the Casio FX-6000G ? :(

    I got that as a 18th birthday present to help out wiff ma edukashun.

    And its had a long and varied career , mostly consisting of sitting in my toolbox at work and doing various amounts of trig/rotational geometery for which is was programmed in some cases.

    It had 7 yrs of torment in a graphite foundry, where it had to be cleaned nearly every week or the dust would short everything out.

    But now, its reached a happy retirement sitting on my deck at home after the battery box no longer holds the batteries in tight enough to mantain a decent contact with the result the memory goes screwy.

    Still good enough though to help out with Kerbal Space Program calculations.

    But thats when stuff was built to last..... can anyone see an iPhone lasting 30 odd years?

    1. jake Silver badge

      Re: no mention

      I use an abacus to calculate critter nutrition needs in my feedbarn almost daily. Normal calculators die in a matter of weeks in that environment. I still use sliderules, where applicable (aircraft & "back of the envelope" calculations for ranching needs).

  49. Steve Todd

    Commodore factory - happy memories

    I used to live near this. Some bin diving at the weekend and a knowledge of how to use a soldering iron let me build working calculators out of rejects. I managed to put together a working SR100 at one point, which was about the most powerful non-programable ever made (90 functions IIRC).

  50. Richard Lloyd

    Odd Commodore choice

    Considering it's placed inbetween two programmable calculators in El Reg's list, picking the non-programmable 1976 F4146R instead of the far superior programmable 1977 PR-100 is a mystery to me. I had a PR-100 and it was a great calculator for its time (even the manual had some nifty programs you could type in, including one for showing which date Easter Day fell on, which until then I had no idea was based on an algorithm!).

    The PR-100 may even be the last programmable calculator that Commodore made, if this page is to believed:

    1. Stuart Palin

      Re: Odd Commodore choice

      > the far superior programmable 1977 PR-100

      I still have my PR-100 though the rechargeable battery needs replacing. I was really pleased with myself when I discovered how to crash it (locks up and needs to be power cycled to recover). Probably explains way too much about my subsequent interests.

  51. GrumpyOldMan


    Y'know, kids these days don't know they'e born! Our first calc was a big fat Casio something that we did the usual 80085 and 07734 and other stupid stuff on (how many commentatds going "Yep - I dd that" and how many going "Er- Wot?") cos we were so cool! I still have my Casio FX something from the mid-80's - still works perfectly.

    1. Sporkinum

      Re: Ahhhhh

      Aside from a mechanical adding machine, our first calc was a Casio mini. It could only show 6 digits at a time on a blue florescent display. If the answer was more than 6 digits, you could hit a button to display the other digits up to 12. I had forgotten about the Casio Fx81 until I saw the picture.

  52. Drew 11

    Big casio programmable?

    I remember in the 80's using a Casio programmable that was about 5 inches wide and an inch deep, and had a fluorescent display with more digits than normal.

    Corners were quite rounded IIRC. Style was similar to the FX-102 but a lot bigger and a lot more keys. What the hell was the model number?

    I wish I still had it, it was great.

    1. Drew 11

      Re: Big casio programmable?

      Found it.


  53. Jock in a Frock

    Casio fan here....

    I had an uncle (very clever chap), who recognised my knack for maths & computers, bought me my first calculator (basic arithmetic green VFD model, can't find it on t'web), and let me learn programming on his Sharp calculator.

    Through my schooling I had a series of Casios (FX82, FX100, FX451 - loved the form factor of that one!). and got a Casio FX7000G for my FE studies.

    My son is currently doing GCSE Maths, and I got him a Casio FX-83GT Plus (which his school not only recommend, but sell at a premium!). It's a lovely machine, a throwback to the classics of the '80s. I liked it so much I bought myself one, even though I have no real need of a calculator nowadays.

  54. xeroks

    fx7000 fail

    I splashed out £50 (a load of money for me at the time) on an fx7000a, at the start of my first open university course. It'll be worth it, I thought, as I'll make a lot of use of it over next 6 years.

    It was really good, and quite fun to play with too. I knew someone - a non-programmer - who wrote a game on it.

    However, when I started my next course I discovered that I couldn't take it into any further OU exams because it was programmable. Thanks for that.

    I ended up buying the cheapest scientific calculator I could find, for about £3. It did me fine, and was also far cheaper for batteries than the 7000.

    1. Neil Barnes Silver badge

      Re: fx7000 fail

      Interesting - I bought the HP11 specifically for the OU maths foundation course, which at the time had a section on programming and required you to write the program in the exam. I made sure I told them it was reverse polish...

      I think it's been into every OU exam I did since then, though...

  55. davemcwish

    Way back when I were a youth

    I (like John Naismith) sat my 'O' grades one of which was Arithmetic - a completely separate exam to 'Mathematics' and all we were allowed was the little grey paper book of log tables.

    As for devices I still have my Casio 7000G & 8000G and a Ti-89 Titanium all working.

  56. returnmyjedi

    No Little Professor?

    It might have been a backwards calculator, but the little guys moustache used to wiggle when you got an answer correct. Sir Clive's efforts couldn't compete with that!

  57. BobChip

    A vote for the HP 15C

    I persuaded my employer to get me a HP 15C in the early 1980s. Although I have used many other calculators since, the HP still works perfectly, and remains my "go to first" calculator to this day.

    And of course, because so few people (I think) use RPN these days, anyone who tries to pinch it will quickly curse and throw it back at me. Happy days.

    1. Zolko Silver badge

      Re: A vote for the HP 15C

      did you try the Android emulator of it on your phone ? With a 5'' screen, it's nearly the correct size.

      Or the PC emulator for your desktop.

  58. gaz 7

    when I were a lad

    Calculators were banned in Maths, but allowed in Physics and Chemistry.

    TI-30 was the default choice, we could not afford on so I had a bog-basic Sharp who's most advanced function was a percentage key.

    Spent a weeks wage from summer job(about £20) to buy a TI-21 for college when I was 16, which I still have and it still works.

    I think children should still be forced to learn log tables. character building for starters...

  59. Dave P 1

    The TI-59

    Before the calculator I used a slip-stick in high school. It was followed by one of the first scientific calculators. In university I purchased a TI-59. It was wonderful. It came with one subroutine module, but several others were available for specialized purposes. I believe there were also pre-programmed cards available. The memory set-up may have been unique to the TI-5x family; the memory was banked as data or program, and you were able to divide the memory as you wished. So depending on you needs at the moment you could re-partition the memory to increase data space at the expense of program space or vice versa. Marvelous! With the optional printer as shown in the photo, you did not need to worry about battery life, and you could print out results. I remember writing an iterative program that successively honed in on a set of values for a simulation. While most students would do a few iterations manually, I set it to run overnight with a few hundred iterations, printing out the results of each iteration. It could be used as a mini computer. I don't recall any other calculator that was as capable as the TI-59, nor do I recall ever programming scientific routines on anything but a mainframe (using Fortran) after that.

  60. Spoonsinger

    Still got my FX-550.

    Which wasn't what I wanted to take through my A-Levels. The FX-570 was my tool of choice, but the left most digit on the display only displayed half it's character, (much to the amusement of the stat's teacher), so had to plumb for the FX-550 as emergency fallback. (Mind it's still working on the original battery).

    1. maguffyn

      Re: Still got my FX-550.

      My FX-100 is still running on the original AA batteries. It's still my main calculator I'm really quite proud of the length of time that the batteries have lasted (and I do still use it!)

  61. Anonymous Coward
    Anonymous Coward

    Back when the INV button was a puzzle...

    I got a red LED calculator which ran off a PP3 9v battery, Texas I think but long since thrown away and forgotten about - in preference to the Casio I got a year later - because each button only did one thing. When I was 11 I didn't understand how other calculators worked with so many functions for each key, I didn't understand about the INV button, LOL

    Fast forward to today and I'm baffled by my daughter's calculator. Fancy dot matrix and stuff, but try finding the Square of -3 .... it comes out as -9! Something's changed somewhere along the line since my day!

    1. Simon Harris

      Re: Back when the INV button was a puzzle...

      Just checked the keyboard on my fx-7000G. With various combinations of shift, alpha and mode, some keys have 5 functions. Not sure that even Uncle Clive beat that!

  62. willi0000000

    now i feel old

    my first "calculator" when i got to university was a K+E Log Log Decitrig and i still have it somewhere. several years in, someone showed up with a four-function beauty from TI and it's been downhill ever since.


  63. -tim


    It was great as you could do '1*2+3' 4 x <enter> and have it do the right thing.

    It is also the only one on the list that could still be built today. The casing tooling is still in use and the CPU was recently still being made for a finance calculator.

    I still have two that work fine but they take 3 "N" batteries and soon I may need to start pulling apart 9V cells to get them.

    I think the date is wrong on the 28-C, My first was a birthday present at the start of the year in 1986 and I had been asking for one for a while.

    1. Anonymous Coward
      Anonymous Coward

      Re: HP28

      > It is also the only one on the list that could still be built today. The casing tooling is still in use and the CPU was recently still being made for a finance calculator.

      Unfortunately not. The Saturn processor is no longer made (and in fact stopped a long while ago - HP just had large stocks). The 12C (which I assume is the financial model you refer to), switched to a different processor a while back and the Saturn code is emulated. (After a spell trying a 're-written in C' version which is sold as the 12C Platinum.)

  64. Richard Pennington 1

    Those were the days

    I went to university in 1978, using a TI-58 and a TI-59 for everyday work (I had to have two as sometimes I would put a program on one and have it running for literally weeks). You could run either one continuously with its mains adapter (I never bought the printer). Eventually the rechargeable batteries would, die, but I suspect that if I rigged up the right power supply I could have both machines working again. I also had a TI-30 - the early version with LED display. Unfortunately the TI-30 would silently give wrong answers when the battery was low. One reason for the TI-30 was that the TI-58 / TI-59 program modules were banned in University exams.

  65. Richard Pennington 1

    TI calculators

    Texas Industries may be better known for chips than calculators (at least in the UK), but a quick trip over the Channel shows many TI models on sale in France.

  66. Outcast

    No Sharp Elsimate ?

    I went to school just south of Perth WA in the 70's and this was the "Must-Have".

    Pretty wierd considering I couldn't afford one and even if I could no-one was allowed to use them anyway !

  67. Anonymous Coward
    Anonymous Coward

    IIRC, to turn off a Casio with no off button

    you can trigger the auto power off by hitting zero, AC ,divide, minus, and M+ all at once.

    No idea how I found this out, but it always worked on my FX115m and FX450 (both were the c-power ones with half battery half solar power).

  68. Quantum Leaper

    I still have my Dad's Unisonic 840, it still works too. He bought in September 26, 1975, the date is on the warranty card in that in the leather case. I even have a power supply somewhere for it too. I remember my next one was programmable Sharp 5100 or something like that, but the display cracked and you can't see the numbers anymore, I might even have another Sharp somewhere too, I have two case but only one calculator. I still remember in my math class when people saw the Sharp, everyone had to have one. A couple stores had a run on those calculators, the other students from the class.

  69. Anonymous Coward
    Anonymous Coward

    If you were a swot, you went for the FX-100 ...

    It still is a damn fine calculator.

  70. Will Godfrey Silver badge

    Casio fx-31

    Still going strong and in regular use after all these years. A bit of the case broken away in the top corner by the DC input (never used) when I dropped it. Didn't even make it blink!

  71. Paul Hovnanian Silver badge

    I have a number of these. An FX-550 got me through an EE degree (on one battery). I have a collection of HPs, including the HP-41C, HP-28S (which I carry today along side a slide rule). I have a few TI-59s in the collection as well. Then there's my HP-16C, excellent for doing binary/hex math and bit manipulation. Plus a pile of 'lesser' calculators and slide rules.

    I'm keeping my eyes open for an HP-9100A or B. Desktop rather than pocket sized, but worthy of my collection. Also a Curta would be nice.

  72. Peter X

    Sharp EL-506P

    I still have (and use) my old Sharp EL-506P from the 1980s and the thing that really surprises me is that it's still running on it's original batteries!

  73. Stephen W Harris


    The first calculator I used was a PYE P-630 ( I wonder what happened to it...

  74. James Wheeler

    Casio CM-100 Programmer's Calculator

    I bought one of these for everyone on my team in 1986. Solar powered with binary, octal, decimal and hex conversions and arithmetic, Does bit shifts, XOR, AND, etc.. Still the only calculator that I regularly use.

    1. deshepherd

      Re: Casio CM-100 Programmer's Calculator

      Had one of those .... solar power idea was great ... until I needed to work for a few days in the "layout office" which was a windowless room only lit by the glow from the (at that time) huge 20" monitors - clearly this was way before the "VDU working environment" directives!

  75. This Side Up
    Thumb Up

    Well I'd certainly have included the Texas Ti Programmer. I can't remember if it had a model number, but it was the first one I came across that could work in octal, decimal and hexadecimal. I'm sure I had something like the black Sinclair for a long time - red led display but oblong keys. My first calculator was a Hemmi Sun which I have in my hand right now.!

    1. jake Silver badge

      Re: Hemmi

      Me too :-)



  76. kittens

    How about the TI's SR 50?

    Had one of these in college. I had a x, y, and a z register. I made a enough "mistakes" with when it fetched from the z register that I finally went out and got a HP (15C). Both still work, but I trust the HP.

  77. jake Silver badge

    No mention of the 1977 HP-01?

    Mine still works. I only used it for about two months ... Too clunky for words, but a definite hint at what was to come in miniaturization. No, I didn't purchase her, she was a gift from HP.

  78. oiseau

    Hewlett-Packard HP-41C (1979)


    Had one of these as a first year architecture student.

    Cost me the bundle I had saved during a year and was delighted with it.

    Unfortunately, HP made any and all accessories availablr for the HP-41 ridiculously expensive (the card reader was notoriously pricey) so after a while I had to sell it as I really could not get the most of it and typing in the program steps soon got old.

    But yes, it was a wonder.


  79. Anonymous Coward
    Anonymous Coward

    Two Things...

    In between those booklets full of numbers and the electronic calculator comes the slide rule.

    I still have the one that I got in about 1961, when I was a bout nine. I bought it because I was a duffer at learning "my tables."

    The other thing is a bit if a nitpick, but shouldn't this be titled "scientific" calculators? I'm sure that those of us who were content with +-*/ were catered for quite cheaply, at least as early as the mid 70s?

  80. Adrian 4


    I know people today are at least as attached to their phones as we once were to our calculators. But they change models far more frequently .. I wonder if they'll remember what they owned (or even hoard them) in 30 years time ?

  81. Snar


    My first boss had an HP-28C and I loved using it, so bought one myself. Sadly the LCD got damaged my some detritus that came flying out of a motor that I was testing. So I ended up trading it in for an HP48GX which never had the same feel as the 28. I still use the 48 today and also have the HP-48 emulator on my iPhone.

    Before that, I had the Sharp PC-1403 Pocket Computer which I still have and used to store formula's for when I took my exams at Poly. I should put some new batteries in it and see if it still works after all these years.

    RPN IMO works well. I've always liked it.

  82. GrantK

    Uses for an HP 41c

    Back in the early 90s we used the HP 41c as a (backup) fire control computer for the Artillery.

    Young army recruits and Reverse Polish notation did not always gel easily.

    I remember my dad using one of these in the 80s too, he was a land surveyor at the time.

  83. foxpak

    No silicon heaven?

    But where do all the calculators go?

  84. Vociferous

    One of my most prized possessions... a 70's Commodore 796M pocket calculator. Gotta love those nixie tubes.

  85. bart

    Is it just me, or does it at all seem plausible that Mr. Ive may have "borrowed" some design cues from a Sinclair Executive that his daddy may have owned in the 70's? Apple has sued others over form factor - particularly for slightly rounded corners on a slim flat body . . .

    Maybe Sinclair should lawyer up and collect some Apple goodness . . .

  86. Anonymous Coward
    Anonymous Coward

    Fuck man. The Register just out-nerded itself while also dually outing the biggest nerds on the planet in this comment section.

    Heaven help us all.

  87. pierce

    how did the HP 65 from 1974 not make this list? it was the gold standard for programmable calculators for years and years.

    ====> because you needed kinda big pockets.

    1. IvyKing

      HP65? How about HP35?

      I remember first reading about it in the March 1972 issue of Popular Electronics - in the Mac's Service Shop that was a carryover of when Electronics World was folded into PopTronics. Figured the slide rule was soon to be history.

      For the Usains, the Bowmar Brains were another classic line.

  88. OldPalmFan

    I remember when...

    ...I used to get Practical Electronics. They had a project (about 6 months long if I remember rightly) to build your own electronic calculator complete with nixie tubes for the display; it was the size of briefcase! The rule with PE was to wait till the end of the project series and then the next edition to get all the corrections to their circuits etc. However around the 2nd or 3rd item in the series Clive Sinclair brought out his pocket calculator and suddenly the article was history.

    I've always been a fan of RPN. My first was a HP-33E that I still have in a drawer somewhere. I used to write some great programmes for it, only to see them disappear of course when it was switched off.

    My current calculator is a HP 32SII and I have RPN calculators on my phone, tablet and (Windows) desktop. And of course I used to have an RPN calculator on my Palm.

    As others have noted, the best way to not loose a calculator is to have an RPN one as they are always returned about 10 seconds after being borrowed.

  89. hackmule

    SR-10 missing

    hey what about the beloved SR-10. The first in the TI line of slide rule calculators. I spent many hours with that one.

  90. Frank Rysanek

    69 Factorial on a TI-25 - those were the days...

    When I was a pre-school kid, in the early eighties in the then commie Czechoslovakia, my father (a graduated machinery engineer) used to have a TI-25. God knows how he got it - probably as a gift from some foreign supplier. I still remember how I was attracted to the magical green button on the otherwise black keyboard, while I couldn't count at al yet. I guess it was even before digital wrist-watches and colour TV sets (in our household anyway). I knew where my dad kept the calculator, but the shelf was too high for me to reach (and tampering was forbidden). Then gradually, as I got my wits together, my father used to let me use it a bit. And I had to protect it from my younger sisters. Then I used to carry it along to school every day, during later eightees and throughout the nineties (after the wall came down). Even throughout the nineties its all-black design (now noticeably battered) looked slim and cool, compared to the grey Japanese mainstream that flooded our market by then. I don't recall exactly anymore how and when I lost it, I guess it was in about 2004 when I lost my briefcase on the job to a random thief... Brings about a lot of childhood memories. 69 Factorial took about 6 seconds.

  91. GoodOldie

    Sharp EL-8109

    Bought my Sharp EL-8109 in '77 for my B App Sc. It still works fine, as my grand kids know!

  92. Hannibal Lecter


    I still have what may have been the very first TI-59 "in the wild", which was donated by TI to the Dallas public TV station for a fundraising auction and purchased by yours truly several weeks before they were publicly announced. I actually thought I was bidding on a 57, as there was no such as a 59. :-)

    But it's my HP-41CV that's sitting on my desk and gets used every day. You just can't beat RPN.

  93. Proud Father

    Geeting old :(

    I think that I have owned most of those during my lifetime.

    I had a TI-53. I loved the challenge of trying to do big things with 32 steps programming. I think there was even a book of program steps you could buy. Dunno where that is now :(

    I keep a TI-85 on the shelf behind me. It can do 449! with only a slight pause (< 1s).

  94. Jim 59

    Nice article

    Misses out calcs with electroluminescent displays (ie. green) and those with paper only. But to include everything and it would go on forever.

    Personally I liked the slim wallet scientifics, more attractive than today's chunky efforts.

  95. The Man Himself Silver badge


    "Until sometime in the early 1980s, when you reached secondary school you were handed a slim book full of numbers during a maths lesson and taught how to use log tables. Sines, cosines, tangents, square roots - they were all in there too"

    I remember that lesson well. Towards the end, one of the girls in the class started crying...when asked what was the matter, she replied "I'll never be able to memorise all of these!"

  96. Shafted by Big Blue

    HP Calculators

    I've only ever used HP RPN calculators in my role as an electronics engineer and latterly as an accountant. I have an HP48G and HP12C and use an HP11C emulator on my iPhone and iPad. Never really understood the bodmas thing.

  97. DC509

    I am so sad that...

    I was actually a professional programmer of the HP41C for a while in 1981/2 (they were used extensively by petroleum engineers in the oil companies). I wrote several complex analytical tools for reservoir engineers and geologists using that little puppie!

  98. GM--

    Has nobody ever heard of the ANITA range of electronic calculators - by far the grand daddy of all by years. They beat HP Texas and others and there designs were ripped of by all before Rockwell took them over - just Google them.

  99. Pirate Dave Silver badge

    HP 20S

    Being a cheap bastard, I only sprang ~$30 for an HP 20S in 1990, but it served me well through two years of calculus and a year of physics. And it's still my go-to calculator at home, although these days it rarely does anything more complicated than simple addition. I had others along the way as well - graphing TIs and Sharps, but when it came time for heads-down calculations, I always went back to the 20S.

  100. Anonymous Coward
    Anonymous Coward

    What was the first calculator watch?

  101. lambda_beta

    You missed the most important one

    The HP-35!!

    1. Dazed and Confused

      Re: You missed the most important one

      > The HP-35!!

      The grandaddy of scientific calculators. The product the marketing guys said would never sell, no one would ever want to be able to carry around a tool like that, but Bill Hewlett over rode them and pushed it through.

  102. John 62

    Sharp EL-531GH Represent

    Direct Algebraic Logic was awesome. Type in a trig function and use brackets the same as the equation was written!

    Our secondary school sold them when we started in 1st year. None of the shops have Sharps anymore, but I was relieved to see Sharp still sells new and updated versions that are the same colour as your iPhone 5C!

  103. Donald Becker

    I expected to see a Novus (National Semiconductor) calculator on the list. They were cheap and widely sold in the mid-1970s. The 650 was one of the earliest products with a resin-covered bare die directly mounted to the circuit board, but had only 6 digits and used RPN. The 850 had more digits (8?) and established the basic 4-banger feature set. A common 9V battery lasted long enough to not be a noticeable expense.

    The HP-41C was like a bicycle hauling a camper. I had one with a motorized card reader and printer on which I constructed elaborate programs, such iterative refinement loops to figure out the operating point of op-amps. it somehow managed to feel professional and worth the expense even as the crappiest 6502 consumer toy beat it on all fronts.

    The Sinclair scientific calculator deserves a mention only as a bad imitation of a calculator. Accurate to half a digit, and you never knew which half. Perhaps good as a trainer, but completely untrustworthy.

  104. Hughb


    Ive used my trusty Casio FX-451 almost once every day since i bought it in the 80s. What tech from today will still be fully operational in another 30 years??

  105. MHE

    Sharp PC-1201

    My first number cruncher was a 1978 Sharp PC-1201, an (as the brochure says, capitals included) "Computer-Like 10-Digit Scientific Calculator with 128-Step Programming". It featured a very readable blue-greenish VFD display and ran on either 2 AA-cells or the included rechargeable battery pack, retaining the 128-step program when turned off (it even included a backup coin cell).

    Such was its power that I astonished the guy who had to calculate the mortgage payments for my first house by having the results for the full 30-year period ready when he was still skipping through his "professional" paper tables ! I still have the machine, and the original brochure that was forwarded at my request straight from Sharp/Osaka.

    A few years later the PC-1500 blew its predecessors away, especially because it was so well documented (both its hardware and the machine language used "underneath" its very comprehensive Basic).

  106. Anonymous Coward
    Anonymous Coward


    Have two of them, and an HP41CX iPhone app so I don't have to risk the now very valuable Real Hardware.

    1. lunatik96

      Re: HP41CX

      I use an emulator for any desktop work beyond simple addition/ multiplication

  107. Shale

    On-Off weakness on my fx-100 too. I blobbed some solder across the switch so it's now permanently on (no problem, as it's auto power-off still works a treat) and I've had to gaffer tape the back as I've long since lost the battery cover. Been with me through GSE / A / Uni + jobs. Even with all this it's still on the original batteries!!

    Brought an fx-83GT Plus as I now teach maths, but I much prefer the fx-100. Where is my favourite X <--> Y button on these new improved versions?!

    1. Zot

      I think my FX-100 still has the same batteries from the mid 1980s. Magical rejuvenating batteries, although I recently had to clean the dried up leakage on the contacts.

  108. lunatik96


    My HP 28 got me through the worst of my Electrical Engineering and Physics classes in late 80's. I put new batteries in a few weeks ago and still works great. When I returned to school for a Math Degree, the TI 83/84 was standard. It is a great calc, but cant compare to RPN entry. My first calc, unsurprisingly not mentioned, was a National Semiconductor 4640 that had 4 level stack - perfect for rectangular to polar and vice versa as needed in Complex calculations. I think I loved that calc more than any other. I bought another when the first was stolen.

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