Calculator blog

Musings and comments about our common interest


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Price Reduction for new HP calculators


We have recently reduced the price of most HP calculators, due to higher volume:

Now prices are more competitive - in particular the HP Prime that is clearly the best calculator there is now!



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Speed tests for the HP12c


As promised, here you will have some tests on the HP12c - old and new. 

We will not compare arbitrary tests, since these are very unlikely to happen for a typical HP12c user (the image I have of a HP12c is a no-nonsense business or banker user, who will not spend his life programming mathematical converging algorithms. He will instead compute net present valuers or internal return rates, and calculate the interest required for an objective monthly payment for a loan. So we will not focus on programming loops, but long financial calculations. :

We will too compare three units: the HP12c original (3 LR44 button batteries), HP12c Platinum (current version) and theHP12c current version (ARM Atmel-based, two cell)

1st test: Amortization calculation: monthly payment during 50 years

  • Loan: 200.000€, monthly payment
  • Interest: 5% yearly.
  • 50 years, 600 payment periods.
  • Full payment (FV = 0)

Amort calculation for 400 periods: f 400 amort.


  • Initial amount: -100
  • Cashflow 1: 26 (20 times)
  • Cashflow 2: 126 (1 time)
  • (IRR should be exactly 26%) seed: 10%

Here are the results:

  HP12c Orig. HP12c Plat. HP12c ARM  
Loan 102 9,5 1,0 seconds
NPV 2,5 instant instant seconds
IRR 21 2,7 instant seconds

As you can see, the difference in speed is amazing. You can argue that these type of calculations are better handled in a computer, and therefore the comparison is worthless. However, these kind of calculations are often discussed in meetings, where you don't have your computer in front - and there you may have to perform such calculations. I'd say that it is easy to live with the Platinum delays.

The platinum has another two big advantages. One, it can do algorithmic entry, as well as RPN. Not a selling point for me, but for others is a Yes/no issue. I can get my children to appreciate TPN - they have been using graphical calculators since the start and they don't see the need for RPN.

Second: it has a backspace for errors in data entry. This is a little bit of a pain in the ass in the HP12c "gold" when entering a long number: if you get it wrong, you have to start it from scratch again. I'd say this was more of a problem with previous versions where repeated keys and missed keys were normal - not the case with this latest one where no keys are missed or repeated.

On the other hand, I much prefer the smaller numbers of the HP12c over the tall, thin digits of the HP12c - also I don't like the garish color of the f, g keys and the alternate lettering. But tastes are so subjective...

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Several days ago we informed that the HP12c is out of stock and it will be for several months due to the current scarcity of chips. What is available for the time being is the HP12C Platinum. 

12cp_4bigThis is a different beast altogether. Issued as a development of the HP12c, it had several advantages over it and also several drawbacks:

  • 1.5 times faster than the original due to a different processor and firmware in the Platinum version (a development of the 6502 processor of Atari and Apple II fame). The newer, ARM based versions of the HP12c are stil around 50 times faster than the HP12c Platinum, though.
  • much more memory - up to 400 program steps instead of the 100 of the plain HP12c
  • both RPN and algebraic numer entry
  • backspace - you just need to compare the old HP12c and the HP15c to know that this feature was sorely missing from the former!
  • A different LCD screen with different digit formats: taller and slimmer. (I prefer the former)
  • the bezels are silver instead of gold - just like the scientific Voyagers.
  • The colors of the keys and lettering are a much brighter orange-red and electric blue

We have enough stocks of this version and we are able to supply black leather cases for it too!

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New HP12c set

There is a new product for the HP12c fanatics: a set of 4 different versions of the long-lived, standard setting financial calculator. It consists of:

  • A used, bright keys HP12c
  • A new, current HP12c
  • A HP12c Platinum
  • The last, HP12c 30th Anniversary edition

The combined price of all is 312 €, but the collector’s set sells for 280 - a 32 € off. It also includes free shipping within the European Union - and additional estimated 25 €. All in all, close to 20% off!

It’s your opportunity to enter in the HP12c area with a full collection from scratch.

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Types of current HP12c

Current HP12c family of calculators.

There are three models available for sale nowadays (we mean, models that can be bought off stock at many places). These are:

  • HP12c “plain”: Two batteries, ARM processor, golden bezel, extremely fast. Apparently there are two types as well, and you can tell them by the elongated “%” sign in one of the types. These are supposed to have the worst keyboard. It runs the original firmware running on an emulation layer on the ARM processor. 100 programming steps.
  • 12cHP12c Anniversary: De Luxe box, slightly smaller than that of the HP15c LE, but with a better keyboard. These can be identified by the “Anniversary Edition” in the golden bezel. Same processor and speed as above; same firmware too. Apparently there was a better perceived keyboard quality.
  • HP12c Platinum. Silver bezel, alternate keys on much brighter colors (to the point of making it seem “unprofessional”), slower 8502 Processor, completely different firmware (it is said that it is binary based, compared with the BCD (binary coded decimal) that had been the hallmark of all HP calculators until then, and for which a huge amount of scientific theory had been written).

The processor speed, while much slower than the ARM-based calks, is still 8 times faster than the original HP12c. There are some significant improvements: 400 programming steps, algebraic and RPN number entry, and backspace key. The numbers are longer than in the 12c, and some say that readability is better - I tend to think the opposite.

If you want to give a present to someone in the financial world, and if that someone is young, you’d be safe getting the 12c Platinum, since you don’t know if that person is conversant with RPN entry mode; moreover, the backspace key (although a shifted one), is of great help when keying in big numbers. This was a big failure in the original 12c, that HP corrected in the much better HP15c (but which is not a financial calc!).


HP12c_Platinum_-_4But if that person has a long experience, you can bet that he would be happy with a HP12c Anniversary, that will replace his worn out, battered original model. I have seen many of them in the field, and these 25 years old calculators have held their ground nicely - but for these user, the Anniversary is like refreshing their old workhorse.


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The HP12c Platinum

The HP12c Platinum

While we run a company 100% devoted to HP calculators, old and new, and have been carrying the HP12c Platinum since day one, I had never opened one of the boxes and actually used it. I figured out that it would be too close to the 12c to be of any interest. But today I have tried!


First of all, these are quite new! This is not the old model with a single CR2032 battery; it has TWO CR2032 batteries, and the box is the very same one used by the newer, ARM-based hp12c Anniversaries. You can see it in the interior of the battery bay. The only difference is the lack of connector to reprogram the ARM Atmel processor. The covers, by the way, are completely exchangeables.


The back side in silver is similar to that of the hp15c. There is room for engraving your name in it.

The main difference between this calculator and the plain HP12c is the twin entry method: algebraic (with parenthesis) and RPN. This implies reassigning some keys (the parenthesis and the equal sign). Additionally, the designers took the opportunity to add the much used x2 key. But for sheer usability, the main drawback of the HP12c was the fact that it did not have a backspace key. This model has it! I would not have made it as a g-shifted key, but on the upper key position. The designer wanted instead to keep the front keys exactly as the original hp12c.


Other feature is the undo key. There is a sign in the screen that shows that the last keystroke can be undone, and there is a g-whited key that allows it.

These new features required a different LCD screen. The screen is grey, as opposed to the greenish tint of the new hp12c, and the digits are taller and thinner. If I have to choose, I would take the 12c's one. There are as well indicators for RPN.

I think that the enclosed pictures tell the story very well, despite the low quality.


When it comes to programming, the main difference is the memory space: 400 steps instead of 100. Bearing in mind the limited memory size of the original calculator, I adapted my needs to it and never used the full memory; when I needed more complex programs, I always reverted to the HP15c - my main calculator, together with the HP42s. Now you can think about bigger programs: 400 steps give a lot of room.

I do not like the stronger color of the f- and g- keys, and the red color of the f-shifted functions, compared with other Voyager calculators. But seeing them together, now the others seem quite shy and bleached!

Used to the HP15c, it shocks to leave f-shifted positions empty. Only two more are used (ALG and RPN)

The key feel is excellent, as we have learned to expect from the old HP calculators and the new Kinpo-made HP calculators. It is a pleasure to use. Good as it is the new HP10bII, this one (and the Kinpo-made Voyagers) is several level above.

There is a leather-like pouch, sturdier and thicker than the one provided with the 12c. It comes with room to place your business card. On the other hand, the main advantage of this calculator is that you can carry it on your jacket pocket, and the thicker case partially defeats this feature.

Many prospective users are attracted by the professional look of the Voyager family, but are put off by the RPN entry method. This may be an attractive option for them!


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