Calculator blog

Musings and comments about our common interest


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A Casio in HP livery - the HP300s+

300sA Casio in HP300s+ livery.

The friends at, which is a French website devoted to Texas instruments machines, but that has several HP users that also post in, have uncovered that the HP300s+ share the very same firmware as the Casio fx–92 college 2D+.

You know that the lower level of HP scientific calculators are not 100% HP designs. To begin with, they don’t have RPN data entry mode; but we needed proof that they were designed by someone else. The tiplanet team had also seen the same firmware in a cheap Auchan calculator (Auchan is a french hypermarket chain, like Tesco in the UK, Aldi in Germany or Walmart in the US) However, apparently the quality of the circuit board in the latter was much lower than that of both Casio and HP models.

But there are additional functionality in the HP300s+, not accessible in the Casio. There is a menu for Hyperbolics through the Hyp key, a unit conversion menu via f–8, and with which units can be chosen based on rules written on the back of the calculator. These are functionalities that only appear in higher level Casio. So apparently the HP300s+ would not be an exact match of any particular Casio.

However, the tiplanet team opened up the diagnostics mode using the same key combinations. Both units showed the same firmware, “GY–468 VerA”, fully identical since both share the same checksum!

This means that all the functionality in the HP300s+ is also hidden in the Casio - it is just that the maker has decided to not make it available. How I hate equipment that has been deliberately clamped-down to adjust to market product roles!

By the way, it is also said that the HP10s+ is a Casio fx–85 clone…

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HP current scientific calculators

10splus_1_lrgWe have discussed several times hp financial calculators, but we have not talked about scientific calculators for a long time.

We have 4 models in the roster - although one of them is difficult to find. I even don’t have a unit of it, and I think I’m not missing too much.

These models are the 10sII+, the 300sII+, the hp30s and the hp35s. It is a pity that the hp15c LE, which was built in limited numbers, is not anymore in production. Used models sell for over 150€.

If you are in the market to buy a scientific calculator, you should also consider graphical calculator alternatives. They can do so much more, and for not so much money, when you consider the offers you can get for older models.

Let’s start with the cheaper ones: the hp10sII+ and hp300sII+. And let’s get it out from the beginning: THESE MACHINES ARE NOT RPN. Moreover, the logic in the machines has been seen in at least another two brands- it seems to be a rebadged design. This doesn’t mean that these are bad - far from it. I would have recommended against the previous units (hp10s and hp300s): they had basically the same logic, but they were cases in extremely ugly bodies, and the screen quality was not fantastic, to say the least. But these two units are much better: the screen has much more contrast, and the casing shows iphone 5 traits of design. You can see the pictures and judge for yourself. The 300sII+ is more advanced and has a greater range of functions, and, at 15€, is a safe bet.

The HP30s we do not carry. We don’t think it is good enough to bear the HP logo - and the price is not rock bottom. Pass.

The HP35s is one of the most beautiful calculators ever produced. Its black background, its clever use of colors for the different key functions, its legible screen with two lines of dot-matrix text, and its cursors to operate calculator and navigate the menus, make it really appealing. And it has real RPN and algebraic entry, and all the important scientific functions you may need, including complex and solving simple equation systems.


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An emulator for the new HP300s+

If you want to know the feel of using the new HP300s+, there is a free emulator in the product page. It is extremely small in size, and good enough for a first ride.

Here is how the screen looks like:


It even includes a mirroring effect, like the original!


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