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Calculator blog

Musings and comments about our common interest

 


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latest HP15c LE vs. HP41CL

DSC_8393_062I have been using the HP15c (did I tell you that I have one for sale?) during this last two days, after some time of being using the HP41CL. In general terms, I prefer the latter, due to a better keyboard, a more informative screen and a more comfortable viewing when on a table.

However, when you’re traveling, the HP41cl is heavy, you need to pack it in your suitcase, and you risk having it damaged.

Instead, the HP15c can be carried in your jacket pocket, and you can use it in the airplane without resorting to your suitcase. I have to fly a lot lately, and i can use it this way. Incidentally, this can be done with the HP42s too - it is just that I prefer the “landscape” orientation for using the calculator with a single hand (typical when you’re sitting in a low cost airplane seat!) Apart from that, I got used to the better screen contrast of both the HP41cl and the HP15c, and then, reading the HP42s with bad light conditions and a worsening sight is tiresome.

But next week, I am returning to the HP41CL! I will investigate modules with statistical distributions.

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A new watch - and an old one...

Today we have seen announced the new Apple Watch. Impressive.

hp_blingBut many years ago, the clock to aim to was the HP01 digital clock. That was impressive at its time. It included a calculator, and it was a “tour de force” at the moment when hand-held calculators were starting to be used by engineers and high level students.

These machines command enormous prices nowadays - north of $1000 for good samples. These are purely collector’s items, since this machine has been improved upon by many orders of magnitude in all areas - except perhaps battery duration (when comparing with smartphones, that is)

You know that HP has issued a couple of years ago a number of anniversary devices. Some of them were new items called as the original one; but some others were real replicas of the real thing: the HP15c Limited Edition and the HP12c 30th Anniversary. These were nice niche products and, in the case of the HP15c Limited Edition, even though it was bug-ridden and memory limited (but same as the original), it has been outsold everywhere. Only 25000 units were produced (as far as I know, according to the serial numbers I have seen)

What if the HP 01 digital clock was produced again, as a collector item? (A very serious collector item - forget the $1000 level - think much higher…)

You’ll have to remember that you saw it here first…

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New Prime

Just received and opened the new HP Prime.

Yes, I said new: this is the new, improved, G8X92AA model, which supersedes the former NW280AA. This new one will work with the wireless dongle, and works flawlessly with the Stream Smart 410.

The previous model, NW280AA, won’t work with these add-ons.

prime_codesThere is no way to tell one from the other in the calculator body - everything is exactly the same. No difference at all. I agonized to find any difference, but I could not. Even the writings in the back plastic half were completely identical in both cases. When starting up, the firmware looks different (and simpler) in the new one.

You can tell one from the other by the box. In the lower right side of the back of the box, you can see the model number. See enclosed picture

We guarantee you that, having already finished our stock of old NW280AA units, you will only get from us the new model.

We also received the Smartstream 410 data gathering information, and a couple of Fourier probes to perform some experiments. Being an EE, I set for a multi-range voltage probe and a Ampere probe. There are many - and you will see the list of them in our product list when we have finally received all of them in our stock. To name a few, there are pressure probes, PH meters, accelerometers, …

While I write, I had to leave the SmartStream on charge for about 5 hours. The power it receives from the calculator is not enough - and it would drain the Prime’s battery in no time. I suppose that the system is designed so that the Prime can only get power through its nano-USB connector, not provide it.

I am now going through the SmartStream user manual, which begins by calling the device MCL, standing for Mobile Calculating Laboratory. The SmartStream can accommodate up to 4 simultaneous probes. These probes can supply data sampled at several thousand samples per second. The user manual is not specific enough about it, but the data sheet says “5000 and more”. So you can see that this cannot act as an oscilloscope - except for very low frequency analysis, like temperature, voices (and that forgetting the upper harmonics). It can also be set to specific periods of time. It is intended to fill the HP Prime memory (for example, in the statistics app) with data from the 4 sensors, and then the student can perform different analysis, model fitting, graphing, etc., with the HP Prime workhorse.

stream_smart_1

Streamsmart_2

spreamsmart_3

streamsmart_4

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HP and the educational market

 

I have received the training materials of the HP educational meeting in Geneva. It is clear for me that there is a strong push of HP in the educational market - something that did not happen before.

 

Until now, HP had been the calculator of the professional: engineers, economists, accountants. Now, the computer has changed completely the way they perform their job. In most occasions, they have their computer open, and they can perform whatever calculation they need with Excel - and perform “what if” analysis much better than anyone could dream with a calculator. So there is not a real need for a calculator while for a professional anymore - unless he’s in a meeting and needs to give a fast answer far from a computer.

 

Now, a student cannot have access to a computer during class (can you picture the distractions with games and, above all, internet?), and even less so while in a math test. Then, the only help he can have is a calculator.

 

This evolution had been seen by Texas Instruments long ago, and was missed sally by HP. Apparently, they have seen it now, and they are into a multi-legged strategy for the educational market, where they join computers, calculators, multimeters to interface with them, and software to join everything.

 

Let me go through the material and update you in the coming days.

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One more HP15c

15c_3smallThere is only one unit left of HP15c. I found a couple of units in the back of the warehouse, and one has been sold already. Beyond this last unit, nothing else, unless HP reissues it, once again.

The concept of a “Special Edition” or “Anniversary Edition” of a calculator is a concept completely strange for anyone outside our hobby. They see the calculator as a fungible item. They don’t understand how a calculator can cost over 10 €, let alone more than 100.

These same guys may wear a watch one or two orders of magnitude more expensive than that 100 € calculator. I tell them, then, “why do you buy an expensive watch? It won’t go faster than the cheapest quartz-driven digital clock. In fact, it will be less accurate and will require higher maintenance.”

Or they write a Mont Blanc, Parker or Omas fountain pen. Leaky (don’t dare to flight with it in your jacket pocket), requiring frequent cleaning and refill, these have some things in common with our beloved calculators: you can use them for your day job, you can have several of them for different occasions, and you derive your pleasure (also) from their handling: the way a fountain pen slips through the page, or the click of an HP41c keyboard when calculating. But, still, they don’t get it.

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More units of HP41CL

 

3 new units of HP41cl

 

We have three decent hp41c calculators and 3 hp41CL circuit ready for assembly. I know that some of you were waiting for the new batch of circuits to arrive - so, you can already order them.

 

These differ from the previous models just in the additional modules Monte has entered since. Let’s be honest - all the important ones were in long ago - the new ones being included are at the very end of the rarities camp.

 

While the HP-produced modules were the most useful models at the beginning, there have been some user-produced modules that I feel are even better. Let’s agree that probably the best module from HP was the Advantage module, which effectively made a new calculator of the HP41c - with all the features that then were missing from the HP 15c.

 

For programmers, though, the most useful one has to be the CCC module. However, this is very heavy in programming and less useful for general users.

 

In my opinion, Angel Martín’s Sandmath modules are the best companions you may have if you have any scientific work to do (among the Sandmath modules, the better the latter). In my HP41CL, I have “plugged” the Advantage module and the Sandmath module. I don’t feel I need more for what I do. And with that power at hand, I don’t need any of the next calculator models.

 

Another issue is when you teach your children. There, a Prime can come handy.

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More about: HP 41cl
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The Prime for solving problems at school - one example close to me

Math classes in my children school are split by levels, so that children can advance at their own pace. In a 66-strong year, there have been established 4 levels. The top level holds just 4 children. I had access to the admission test for that level, and the problems were easy but interesting. We’re talking about 11-year old kids, in a British system school. 
 
I sat with my eldest child and reviewed some of the problems. The first one I came across was about squares drawn with small lightning sticks. 
 
The order 1 has just 4 sticks.
 
The order 2 (2 sticks per side) has 12 sticks in total.
 
The order 3 (3 sticks per side) has 24 sticks.
 
You are asked to tell the 4 side and the 5 side. Then, you are asked to find a rule, and calculate how many sticks are in the 100 per side figure.
 
The point here is counting in the right way, so that you can draw the rule from it. My son found it quite fast - at least faster than me.
 
You first count the vertical sticks: there are 5 columns of 4 sticks each = 20; the horizontals are the same: 5 rows of 4 sticks each. Total 40.
 
For the order 5: there are 6 columns of 5 sticks, and 6 rows of 5 sticks too - therefore 60 sticks.
 
In general, for a side with n sticks: (n+1)*n*2.
 
(This my son called “the template”, which I liked as a definition. They have not learned yet to use functions or variables, so that was his first encounter with them. He then proceeded to apply the template to the case n=100)
 
Then I said, “it would be good to have the template applied automatically to any number you want - without having to calculate it all the time”. “Yes!”, he replied.
 
So we opened up the Prime, and entered the formula in the Function app. I changed the integer variable “n” for the standard “X” used there. Then I showed to him how to enter a formula in the system. As it is easy, he was able to do it quite fast. 
 
“And now?” he asked.
 
We clicked on the table buttons. Very fast we came to the right “zooming” and he was able to see the value of the template for any integer. He then proceeded to check the values he hard found, and found them right. But now he had learn to enter “templates” and how “templates” could help him to solve real problems. 
 
The second question was to imagine the tridimensional case. We will discuss it the next day. Again, the key to it was to count it properly.
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SmartStream 410 and HP Prime training program

During the last days of August, there will be a meeting in Geneva, organized by HP for the European network, so that professors and educators can be trained in the use of the SmartStream 410 and the Fourier Probes with the HP Prime.

As I have said several times before, this combination is the current equivalent of what we had at the beginning of the eighties with the HP41c and its HP-IL interface. The only thing is that while the interface was extremely slow, the instruments it could connect with were totally professional. I still have before myself a HP 3468A multimeter, a portable device that can be used standalone, but that can be connected through HP-IL to automate readings. I have not used it that way - as I have a similar HP 3478A machine with HP-IB interface, I prefer to connect it with my HP-85A, which has a much friendlier interface, a proper keyboard and a very simple BASIC language. I can even plot graphs of the variable evolutions, which would require yet another device - and give much lower quality.

(When I was at Engineering college I managed to get an HP7225A plotter to be used with the HP85. While it is now regarded as an inferior device compared with the ubiquitous HP7470 (of which I have a unit pending refurbishment), it is the one that stays in my memory. I remember looking at it, mesmerized, while it was plotting the labels with its ugly fonts, at handwriting speed, much noisier than a dot-matrix ribbon printer. I managed to create a small lab in HP-IB, and wish I had kept the plotter too)

The devices associated with the Prime are intended to prepare experiments to be shown in class. I can’t picture a field engineer using these devices in professional use - you can buy hand multimeters and oscilloscopes with much better precision than these. However, for the DIY that needs to do some automated readings, it can be of help, and at a much lower cost than professional alternatives.

My main gripe with the specs is the low sampling rate. We’re not talking megahertz, we’re talking (low) kilohertz, around 5. This precludes it being used as an oscilloscope.

But, as a tool for school teachers to show maths and physics to their kids. I have not received my test samples yet…

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Which calculator to take with you on a 2 weeks' holiday?

Leaving for holiday in a beach location. Still some work to do, but having been warned by “home management” that there are lots of things to pack from our children, and therefore I need to “travel light”.

Hearing “travel light” from my wife is at least surprising: she does not know what “travel light” means. My bags will will always be half of her’s - but let’s do the exercise anyway.

Which for the sake of this blog means which calculator(s) to carry with me. I have already decided not to take with me the HP41CL, although is the one I like best. It would be my solitary island choice - but not for a summer travel to a sun and beach destination. Too risky for its high value. So I have left it in Oslo.

I am taking with me the HP Prime. Now the question is whether I should take with me an HP15c - the HP42s suffers the same precautions as the HP41CL.

The main thing against the HP15c is that I will lose 1 hour with it at the beginning. Why? Because it lost all of the programs I wrote in it (235 steps of ugly code to fill in, with a lot of chances of getting some of it wrong). And I am used to my programs when working. I have it anyway on my Iphone.

And why the HP Prime and not the HP50g (with the promised comparison between both)? First, if we have to travel light, the Prime is thin and light. With its plastic cover, is probably the best protected calculator I ever had. What’s more, I can try to use it to get some of my children interested in maths (through calculators)

Then, why not both? That’s a question that I still need to answer to myself. After all, we’re only leaving next wednesday morning!

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HP 50g vs HP Prime (I)

I am seeing several comments in various forums about whether the HP Prime is better than the HP50g for engineering work.

In reality, the best calculator for engineering work ever is the HP42s - provided you don’t need to interface anything. In that case, it is the HP41c daily that takes the lead. IMHO!

Any graphic calculator is a waste of screen size in my opinion (always talking about engineering work - NOT engineering studies). The only place where the bigger screen makes sense is when you’re entering a matrix (which can be entered in a more “pedestrian” way in both the HP41c and HP42s. The HP15c can also do it, and that’s the engineering calculator for someone on the road.

Once said the above, it is true that the HP50g has a more professional feel than the HP Prime. The latter has been designed to appeal to younger students. I would go as far as to say that the objective market is high school level (baccalauréat , bachillerato, Gymnasium, depending on which country you are). It has colors, tactile screen and test modes and wifi communications totally unneeded in engineering.

But the discussion is so interesting that we will try to go deeper in this subject in a couple of future blogs, so that you can decide which one suits you.

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More about: HP 50g, HP prime
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