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Musings and comments about our common interest

 


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tricks for units use in HP Prime

Some tricks regarding using units in HP Prime.

Units are one of the main differences between scientific and graphical calculators. The aim of a good teacher is that students know what they are doing. When studying together with my sons, we always stress that they need to understand what the result is. “The answer is 50”, they would say. “50 what?”, I retort. This is the ultimate understanding of the problem being solved. Many times, a student fails to comprehend what he has obtained, applying the rules he has been given to solve the problems.

Graphical calculators have that: they allow you to dimension correctly your problem.

(in the discussion that follows, we will assume that we are in the home section of the calculator, and that RPN entry has been selected).

You enter the distance in meters, you enter the time in seconds, you divide both and you get the speed in m/s. (To get the units on the numbers in the Prime, you just write the number, go to the units menu, units submenu, the type of unit you want (length, for example), and the specific unit you need (km, m, cm, in, etc.). It’s that simple!)

Once you have your result in the right units, you can interpret what it is, and then change units if needed. To do so, you just need to supply the unit you want (just select the units menu, the units submenu, the type of unit you want and the specific unit you want to convert to. The prime will add the 1 in front, and you will get 1_km/h in the lower register of the stack.

To perform the conversion, you just need to go to the units menu, then tools, then convert. The Prime understand that you want to convert the quantity in the y register (level 2) to the units in the x register (level 1).

In some cases, you end up with a complex unit, having force, mass, time, whatever. What is it? The best you can do in this case is to have the Prime find the international system equivalent of whatever you have in X, using the MKSA function in the units/tools menu. Then you can understand what the hell is that!

One last thing: and now, how to remove the units from the number? you just obtained what you wanted, and now want to continue calculating with it, but you don’t want to continue keeping track of units. You can divide it by 1_the unit you just obtained - but it can take some time to write it, and you’d better rewrite the number instead!

The other (best?) alternative is to use the CAS.left() function on you previous result. It leaves the number without the unit!

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More about: HP prime, Units
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A Casio in HP livery - the HP300s+

300sA Casio in HP300s+ livery.

The friends at tiplanet.org, which is a French website devoted to Texas instruments machines, but that has several HP users that also post in hpmuseum.org, 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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More about: HP300s+
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Function library in the HP Prime - very similar to the HP50g's

One of the things that I was missing of the HP50g in the HP Prime is the ability to keep many functions available for solving - something like the function library.

One alternative is to create multiple copies of a solver app - each with a different function. This is not good for organizing your functions!

Another alternative is to enter them into variables - but then you need to have a very good memory to know what each variable does.

But there is a “proper” solution too. Eddie W. Shore (whose blog we have mentioned many times before) has created a free application that handles 47 well used functions. You just run the app, and then choose among the different functions. These are stored in variable E1, and prior to that, you get a description of what each component of the function does.

You can find and download the application here:

https://drive.google.com/file/d/0B7R8x9Yi26yGeURROW5OZkQ5ZTQ/view

Enjoy!

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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.

35s_1big

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HP Financial calculators

There is now a forum thread in hpmuseum.org about which is the best financial calculator made by HP. It is curious how every model has its proponents - except the original 10b.

Most old timers swear by the 12c. No one mentioned the CP version - all of them are used to the RPN entry method and no one values the ALG entry method available in the 12cp; and the numbers in its screen are taller, with worse readability in my opinion.

There was a couple of proponents of the HP30b. If you look at the raw capabilities and speed, it is by far the best of them all. It has a huge quantity of scientific functions, absent in most other financial calculators; but both its keyboard (the worst of all of the units discussed) and its many system put it in the back in my opinion. Only the 20b, with its rubber keyboard, fares worse. The best feature in my opinion, is that it can be converted in a wp34s…

Tim Wessman, the HP calculator designer, chimed in to praise the HP10bII+. And if I had to recommend a financial calculator for someone that doesn’t want RPN, and is not willing to shell out 90 bucks for a HP17bII, this is the one I would push forward. It has everything: functions that can be accessed directly from the keyboard, without menus; a panoply of scientific functions, much wider than that of the HP17bII, and including trigonometrics; a breakeven point calculation; percentage functions well designed; and a clear screen and fantastic keyboard. As true as it is that I don’t recommend the HP10bII “old” for anyone but the most jaded collector, the HP10bII+ is a must for any calculator lover, and a safe recommendation for any economics student not willing to learn RPN.

Existing the hp10bii+ and the HP12c, there is no point in getting a 12cp - except for hardcore collectors. It is of good quality, but the choice of keyboard color is just awful. Quality is identical to the 12c, for that matter; but, as said, the screen is worse. And it is much slower than the latest, ARM-based 12c.

We have then the different versions of the HP17bII. Keyboard quality of the old versions is better, IMHO, than the new; but the screen quality of the latter is miles ahead than that of the old; so much so that I can’t stand the old screen for long periods, once accustomed to the new.

It has to be mentioned that everything within the HP17bII+ is different from the HP17BII. The processor, the machine code, the algorithms - everything is different. In fact, the solver is based on a different paradigm - the original one being far more advanced than the latter. And it is not 100% compatible: the functions L() and G() (which turn the hp17bii solver in a true programming language) don’t work in the newer model.

From the aspect point of view, it is a tie between the 12c and 17bii+; the superior portability of the 12c against the silver cover and nice, ample slanted keys of the 17bII.

Then there is the 19bii, which is the best ever made; but then you come into reliability problems - that damned battery door…

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Shady Calculator Stories

Some sad stories in Ebay.

As many of you, I have been purchasing items in Ebay for both my own collection and for the shop. Most of the times you get good material - never a bargain, but what it is advertised. Then you find some guys that are quite liberal with adjectives - in particular, “working condition” and “good shape”. But in most cases they try to help.

But then you have a third type: those that give you a crappy product and then play with you. The aim is to dance with you until the 45 days period since the purchase has elapsed. A recent case comes to my mind. I bought an HP41c calculator sold as working. It took some time to arrive, in a plastic envelope, without any protection, dirty, battered, and, of course, not working. I paid for it “working” price, and it was in such a poor state that I did not venture into repairing it - I could have not sold it in such a state. I arranged the return of the calculator, which took some other days, since the delivery address was wrong, and then wait…and wait… and wait for the refund. “Do you want it in your account or in Paypal” “if in Paypal, then I need to put funds in it”. And then silence… the 45 days had elapsed.

Just in case you find him: the name is Pablo Alvarez Llinas, and his Ebay user name is beaviisb. In today’s world, anonymity is impossible. In linked he appears as working for HP Delivery Services.

I have another case, concerning an HP85 - but that’ll be the object of another installment of “shady calculator stories”

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Available Fourier Probes

I have received queries now for some very specific probes. In general, one thinks about the typical educational items: current, voltage, temperature, pH…

But the person doing the enquiry was asking for some more specific: Calcium, Chlorhide and Ammonia. I even did not know that they existed. The HP Prime may be useful for profesional duties after all!

in fact the whole list of the available probes in our supplier stock is amazing. I have not put all of them in the web, but here is the list you can get right now if wanted:

 

Part Number Description
AC020 Ammonium Electrode
AC021 Ion Selective, Electrode Adapter, (ISE Adapter)
AC012A Anemometer
DT098 Blood Pressure/Heart Rate
DT040A Carbon Dioxide Gas, CO2
AC019 Calcium Electrode
AC021 Ion Selective, Electrode Adapter, (ISE Adapter)
AC018 Chloride Electrode
AC021 Ion Selective, Electrode Adapter, (ISE Adapter)
DT035 Conductivity Sensor Adapter
DT111 Control Switch 
DT110 Control Switch 
DT006 Current 
DT020-1 Distance (for NOVA5000, MultiLogPRO and NOVA LINK)
DT187A Distance (for EcoLogXL)
DT254 Flow Rate
DT272 Force
DT116 Geiger Muller
DT155A Heart Rate (Pulse)
DT298A Heart Rate (Exercise)
DT014 Humidity (5% Accuracy)
DT009-1 Light
DT009-4 Light Multi-Range
DT156 Magnetic Field
DT036 Dual Axis Magnetic 
DT008 Microphone
DT222 Oxygen Sensor Adapter
DT016A pH Electrode + pH Sensor Adapter
AC008 Potassium Electrode
DT015 Pressure 
DT015-1 Pressure 
AC013A Rain Collector
DT148A Rotary Motion
DT122A Smart Pulley
DT171A Soil Moisture
DT320 Sound Level 
DT037A Spirometer
DT029 Temperature (for NOVA5000, MultiLogPRO and NOVA LINK)
DT025 Temperature 
DT241 Temperature (for EcoLogXL)
DT002 Voltage 

 

You can get more detailed specs for any of them on demand.

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HP50g Blue no more!

No more HP50g blue!

As I have run out today of my last units of Hp50g blue, I have contacted my sources - only to discover that all stocks of any kind of HP50g have disappeared!

In a way, it has been a stupidity on our side not to build sufficient stock, now that it has been announced that the hp50g is going to be discontinued. All distributors are giving good prices on their black units - but apparently there are no more blue units.

Here you have a picture comparing both. While the black model has a more professional look, the blue had a much better contrast, and it was more in line with the style a student needs nowadays. From the functional point of view, both were exactly equal. I think that different versions of this model had different cases going with it - some in faux leather, some in different fabric qualities. I have one of each, but you cannot know it from the model number.

DSC_7756small

All of them could be connected (and can be connected, in the case of the black HP50g) with the StreamSmart 410 and its probes. I see this feature being advertised for the HP Prime, which is HP’s current interest - but there were other calculators that could use it, and which already had software developed for it.

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Clarification on HP41CL pricing

A few comments regarding the pricing of the HP41CL units (for which I have received several enquiries)

The price is based on an assembled HP41C/CV units with the latest CL module from Systemyde. On top of that, there may be other options:

For a “plain” HP41CL, the cost is 609 €. This price includes VAT in European Union.

If a serial module + cable is added, the price is 649 €

If the calculator includes an original box with manuals, then the price is 725 €. The amount includes the serial module + serial cable.

Finally, if we’re able to locate a Time Module, with a typical standalone price of 150 €, you can buy it for 725 € for the base model, 774 with serial cable.

Be aware that this price can be valid for the current circuit lot!: the currency exchange ratio with USD will make future purchases much more expensive.

You need to take also into account that these units work perfectly, and have the original battery connector, with no signs of rusting, and sport all ports. When you buy a second hand calculator, you will find that some just don’t work - or you can’t make them to work, or you need to replace the battery connector with a repaired one, or the original case has deteriorated and produces the “black dust” that gets everywhere… We think that if you pay north of 600 €, you should only have excellent units - but we need to factor in all the units that were not so good and were left behind. This is roughly 30% of units!

IMG_1679

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More about: HP41cl
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New units coming in

Several news in our products:

  • There is a new boxed HP41CL in pristine state. The screen is not yellowish, the box comes with all manuals and even the stickers for your overlays are there! Pictures will follow.

  • We have also a very good, side-battery door HP19bII, with original manual in French.

  • And a new HP42S, just received. The bezel has some nicks, but barely appreciable. I have been playing with it, and it has warmed again my heart to it. RPN at its best, without its problems (try to use matrixes in any other RPN calculator, except the HP15c)

I will post all three in the website as soon as I can take the corresponding pictures.

On a different subject: we are quite sad to not being able to offer a good transport arrangement to our overseas customers. Even shipping outside the European Union is getting increasingly complicated for small shipments like ours. In the past, we were used to close to no paperwork. Now, with tax administrations trying to get resources from wherever they can, procedures are much stricter and therefore expensive. We will have to increase substantially shipment costs to the US

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