Things We Used to Care About: the Graphing Calculators Edition

When I started college in 1989, I was going to school to get my Bachelor’s Degree in Electronics Engineering Technology. Graphing calculators were brand new; before that, we had Texas Instrument calculators as well as Casios, and my first weapon of choice for busting out math problems was an HP 28S. Do you remember?


Things We Used to Care About: the Graphing Calculators Edition

The image above, courtesy of the HP Calculator Museum, was the first HP Calculator I ever bought. This calculator made busting out math problems pretty easy.  I could graph out complex equations as well as trigonometry problems that I needed to work on while I was obtaining my degree. Unlike the other calculators, the HP used something called RPN to enter in the math equations.  RPN stands for Reverse Polish Notation. RPN meant you had to enter the numbers in first and put them on a stack. Then you hit the operators in.

For example, if you wanted to say 45+46, you’d type 45 enter 46 enter and then the plus sign to add them.  This seemed weird at first, but once you got the hang of it, it was simple. The 28S had an infrared output on the top of it, although I never used it then.  the 28S also made beeps when you used it, and it was programmable. the calculator was just cool to me then. However, like mobile phones today, calculators developed rapidly in this time, and the 28S soon wasn’t enough, so I went out and bought the HP-48SX to replace the 28S.

Things We Used to Care About: the Graphing Calculators Edition

The HP 48SX had a bigger screen, which was the main attraction for me, plus it had a much more traditional calculator design. It too could also make sounds, and it had a infrared port which I did take advantage of then by purchasing a HP 82240B infrared printer. This helped me do math home work because I could print my graphs instead of sketching them down on paper. You could really do some amazing things with the grey-scale screen of the 48SX back then.

Things We Used to Care About: the Graphing Calculators Edition

HP Graphing Calculators Today

Things We Used to Care About: the Graphing Calculators Edition

HP still makes calculators today, in fact, they have a modern version of the 48SX in the HP 50G.  The 50G runs on an ARM based processor like many smartphones today, and it still has a greyscale screen.  In many ways it’s just like the 48SX, except that it has USB cable to connect it to your computer to offload and load equations.  In many ways, it’s superior to the 48SX, however the old HP calculators were mechanically solid with keys that would never give out, and they were built to take a beating.

The new graphing calculators aren’t near as solid as the those of old, but they are still being used in many programs today — although it’s MUCH easier to simply use your phone to do a lot of the same functions.  You can even install a HP calculator app for your phone and do a lot of the same things you could do on the 48SX and now the 50G. The 50G is still available direct from HP for $129.99.  I also found the infrared printer on Amazon for $159.99.

Things We Used to Care About: the Graphing Calculators Edition

HP also has made a newer, more advanced calculator in the HP Prime Graphing Calculator. This calculator has a color touch screen on it and is rechargeable.  It also comes with a USB connection kit.  It can be had for $149.99 direct from HP.

Why should I (or you) care about these today?

Well, I don’t need one for my job or my everyday life — and you probably don’t either — but there may be a few reasons it might be something we’d want to have.  Similar to e-ink based devices like the Kindle, there’s little distraction to the work at hand when you use one of these. There are no other apps to distract; no messaging, just calculating. So if you are trying to concentrate on crunching some numbers then one of these may be something you’d want. Then you have to consider that the battery life on these calculators is many times better than using a smartphone or computer for doing calculation work. Finally, devices like this are made for calculating; it’s all they do. In some ways they can be better than an app on your smartphone, and of course they will last much longer than your phone at this point.  I read in a forum that someone just retired their 48SX last year and replaced it with a 50G. That is over 20 years of service for one device if they bought the calculator in 1990 when it was released! Try doing that with a smartphone.

Sadly, for most it’s just not relevant today. Alton Brown has a dislike of monotasking devices in the kitchen, and in the class room and engineering spaces that is exactly what these would be. So I don’t see HP selling bunches of these … but if you need a reliable calculating device, then you should look no further.

For more on HP calculators check out the HP Calculator Museum and

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About the Author

Joel McLaughlin
Joel is a consultant in the IT field and is located in Columbus, OH. While he loves Linux and tends to use it more than anything else, he will stoop to running closed source if it is the best tool for the job. His techno passions are Linux, Android, netbooks, GPS, podcasting and Amateur Radio.

5 Comments on "Things We Used to Care About: the Graphing Calculators Edition"

  1. nickcornaglia | August 24, 2014 at 7:25 pm |

    My son’s new High School required him to purchase a calculator. We just bought the TI Nspire-CX calculator.The school does not allow the use of phones during school hours, so I guess the use of an app is out.

  2. thenikjones | August 25, 2014 at 12:44 pm |

    I bought my Hp28S in 1990 and use it at work to this day – total overkill, but no-one borrows it as no-one understands RPN. You are the only fellow 28S owner I am aware of!

  3. Heatwave316 | August 25, 2014 at 1:19 pm |

    I know I still use mine, but mainly just to balance the checkbook. But I love the big screen. I think mine is a TI-82. I just don’t understand why they are still so expensive. It seems like all tech gets cheaper over time, but these have the same price as when I bought it in high school many years ago.

  4. Actually when you look at the cost of the current HP Calculators they are HALF the cost that they were in the 90’s. The original cost on the 48SX was $350 but the 50G which is a better device in a lot of ways is now $149.99. So HP doesn’t charge near as much. I think this may be because HP now uses off the shelf hardware with an ARM chip versus doing the R&D on their own processors. The 48SX used a HP Saturn processor. The 50G uses an ARM derivative. Much different costs. I am guessing that TI still uses custom processors….but then they were never as high as HP was back in the day.

    As for not being able to use an APP….I get that. Perfect reason for these to still exist. Less distraction. 🙂 In my day this is the equivalent of asking for a 4 banger on a test. What’s a 4 banger? A calculator that does addition, subtraction, multiplication and division as it’s main functions. It MIGHT do square roots and percentages…MAYBE Sine, Cosine and Tangent as well but that’s the extent of it.

  5. I also had a HP28S that I got as a graduation present (I had used a 15C for years), and bought myself a 48S a few years later. Very powerful, and I absolutely loved them.

    But what killed them for me? The HP200LX – it has the HP Calc built-in, along with the numeric keypad so I had a full PDA and HP Calc all in one. I still use a HP48-like calculator on my phone 🙂

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