Calculator blog

There are already several beta users of the new firmware. I am not one of them, but what I have heard is that there are several features that were in the initial planning for the Prime, and it will help a lot in establishing it in the school market. I am now referring, in particular, to the wireless dongle.

I have been told that the initial samples of the wireless dongle will be sent within this month. The machines have been shipped to distributors, but not released yet to shops. It will be done together with the new firmware.

The wireless dongle will allow the professor to set up and control the students' calculators remotely. It can send tests, apps, control progress, and see all screens in the professor screen. This is a revolution in maths learning!

I look forward to receive as well the Smartstream and the voltage and ampere probes. Apparently, it does not have the same level of accuracy as a main-brand multimeter - like those of Agilent or Fluke, but there is not comparison on price between them. It allows to take up to 5000 samples per second, and therefore may serve as a very simple and slow oscilloscope - so that children can learn how waweforms are. With such computer power at hand, it will probably allow for a FFT app, so that a student could see how a waveform can be decomposed in different sinusoidal frequencies. Of course, with such a slow sampling frequency, there are not any professional uses that can be thought about it. However, there are other probes that could lead to professional use, while it was never the initial intention for the calculator.

As soon as we get our hands on both of these, you will be the first to know about it!

I am slowing down the production of HP41CL these days. I am tired of buying HP41 units in such bad condition in Ebay that we're not able to make them work. It is a pity that I must be losing so much money in these calculators, bringing the HP41c conversion program to basically breakeven on variable costs alone.

I am still doing conversions on user-submitted units. The pleasure of reading again the "MEMORY LOST" message when a new HP41CL sees the light compensates the time spent in it. But then there is a slighly tedious work to configure it properly, initializing all services so that the user can load their modules from the beginning, without having to figure out how to do it.

It is a pity too that one has to spend so much to get a Time Module. There is no way now that you can get it from less than 120-140 €  (getting it for less in the US is a mirage - you will end up paying more between taxes and handling) I look forward to the moment Monte is able to offer it integrated in the main board! Then you'd have a supercomputer in the shape of a humble HP41c.

If you have a HP41c and you want to have it converted to CL status, please drop me a line to sales@thecalculatorstore.com.

There are few weeks left until the new HP Prime firmware arrives. We have informed about it recently, and we have given the main advantages it will come with. But let’s elaborate on a couple of new features that make the HP Prime, at last, a professional tool.

The first one is the new available numbering formats. This has long been a problem for me. I use calculators everyday in my financial work; and we are using big integers (like 123456789, as opposed to one- or two-figure numbers as would be used in a class). You just can't read big numbers properly if there is not a) a separation between numbers in groups of three, and b) an alignment with a fixed number of decimals, so that you can make sense of which numbers are big and which are small.

Without these features, I always folded back to my HP41CL or HP15c. Curiously, I don't get out the best of them, the HP42s - maybe I don't want to damage it for fear of losing it. In a way, I seem to think that there will always be 41cs to modify, but not 42s

The a) thing was so simple to do that even the first HP RPN calculators were able to make it right. Even the already old HP50g was able to do it. It was a pain for me when using the Prime in a professional environment. (The second part was irrelevant in the past, since there were no additional lines - but now there are. However, it worked fine from the first firmware release)

The second thing to fix was to get consistency from app to app on how the GUI should work with finger gestures. It was surprising that the behaviour was not the same in all apps. This apparently is also mostly fixed in the new version. We look forward to increase the number of gestures available in most apps, so that we don't miss our smartphones when using the calculator.

Apparently, support for the wireless dongle and the Smartstream machinery has also been improved. This will be the object of the coming blog issues.

Due to our work in converting HP41c into HP41CL, we have had to buy many calculators in internet. This has resulted in a number of calculators that were in less than pristine state. In fact, many of them had been repaired, and had fallen in the same traps again and again (by the way, the same traps I fell myself when starting, until a friend took me out of that ignorance!)

The typical part that always breaks first in a HP41 is the lower screw posts. The second is -guess it?- the upper screw post, but this time not the support in the main body of the calculator, but the part that supports the head of the screw in the back side of the calculator.

The third part that tends to be damaged is the battery bay contacts - but we have discussed it already - see our Repair kit page for more detail and how to solve the problem.

And when the problem happens, everyone retorts to the typical glue these days: a Cyanoacrylate compound, that dissolves plastic and makes a mess of the rest (apart from not being too good in resistance once dried, due to the damaging of the plastic used by HP. Here is an example on our right: you can see the state in which the posts are now. 

In the versions of the HP41c that can be converted in HPCL, these posts are abosolutely critical to ensure that the board and the main body of the calculator make good contact. 

On the other hand, a calculator that seems to be completely broken can in many cases be repaired with just putting good attention in fixing the posts, so that even pressure is achieved.

It is good practice not to tighten too much the screws once repaired. No only due to the possibility of breaking them beyond repair (you need to be aware that these calculators are 30 years old already!), but because it affect the much-loved HP keyboard feel! The difference can be appreciated between keys in the middle of the keyboard and keys just above the posts. This is not too agreable!

Coming back to the repair. The key for avoiding the problem just cited is to use a "hybrid" type of glue. Here below you can see an example that works well:

This product does not dissolve the plastic and creates a lasting bond. Test it!

I have received news that a new firmware for HP Prime is coming! Klaas Kuperus gave the information below in his website:

New Functionality (Connectivity Kit)

1. A horizontal skin has been included for use with monitors that are restricted in the vertical pixel range.est

This is just to inform that we have received a new lot of HP41c battery bay repair kits!

The production lots take some time to produce, but still it is a magnificent product that allows your loved calculator to have a new lease of life. It also can give you the feeling of achievement when you are able to revive a 30-year old workhorse instead of disposing of it and buying one new - as it is the case with the rest of the electronics nowadays.

I will continue writing about the HP17bII+. There are some features that, while useful, have been terribly outdated with time. When the original HP17bII and HP19bII were created (around 1987, if I remember well), there were basically no mobile phones, let alone smartphones. Therefore, there was no device that could be used as an organizer, keeping your dates and alarms in a single place.

The HP41c with the time module was able to do that - but to set it up would have been seen as programming by most business users ( enter message in Alpha, enter day and hour (and something else I don’t remember now) and execute XYZALM. It even allowed the user to launch a program at the programmed time. I am using it from time to time: is faster to set than the HP17bII+’s method, albeit less user friendly, but you can program a user key to automate its use; I acknowledge that the iphone’s alarm or timer are still much more user friendly. That’s just our freakiness at play.

Coming back to the HP17bII, you can set a number of alarms in the system (up to 6), and define if they have to be repetitive or not, whether they show a message or not, etc. A use where it could be competitive is when passing a test in an environment where mobile phones are not allowed (like most!). This is a way of recalling you how much of the exam time is left.

Another function where the HP17bII is still competitive, is regarding time calculations. In business, there are many times where you need to calculate how many days have elapsed from a given data, or which week day will it be in 90 days time. This part is handled with ease by the HP17bII+, in an intuitive, easy way. You use it as a solver formula. You have three basic keys (Date1, Date2, and Days), and you just need to enter 2 of them - whichever - and press the soft key of the other, to get an instantaneous result. You can too select whether you want real days, 365 days or 360 days calculation; but the fact is that it is the most convenient way around, short of opening your Excel (which is like killing flies with machine guns)

When it comes to statistics, it is not at the same level of newer financial calculators, even from HP. There are now two models (the HP30b and the HP10bII+) that can perform diverse operations with statistical distributions; and while the function fitting capabilities of the HP17bII+ are good, they are no better than those of the above calculators.

But what really sets apart the HP17bII+ from the competition and its siblings, is the solver. It is surprising that no more companies have come up with elegant solver solutions during these 25 years! Even the HP30b and HP12c Platinum (both of them newer designs) cannot match the HP17bII+ in that respect.

And the solver allows some subtleties that are very similar to programming! You can have branching (a formula is applied if a key is pressed; a different formula if you press another, for example), and you can have extended sums (sum this formula from this variable changing from 1 to 200, for example). It is been a long time since I don’t use it, but there were several interesting things that could be done. Business types don’t typically program; but this could be the solution of many a math exam in university!

Regarding speed, this machine originally was running on a Saturn processor; the last redesign (by a taiwanese company) made it work on a 8502 processor (if I remember well). Some operations are faster, but others are not; and newer calculators like the HP30b, which run on ARM technology, are around 100 times faster!

Algorithms for business functions are quite optimized, and therefore these speed differences don’t hurt like on scientific areas, where loops and long procedures are much more common.

It really surprises me that the HP17bII+ does not have more success among the business students and professionals. It is a very comprehensive machine, that has been extraordinarily thought out for daily work. 

Today I have forgotten at home my HP Prime, the one I use most lately. While I am at home, I prefer to indulge on my HP41cl, and I don't take the latter out - the loss in case of damage or steal would be too high, and the pepasure I derive from using it when I am at home has no parallel. Therefore, it is the Prime for day to day work at the office. But as I said, today I also forgot it.

Looking into the drawers of my workplace I found an HP17bII+ - the silver version pictured beside.

Apart from looking gorgeous and totally at home with modern Apple-like computers, I thoroughly enjoyed its use for the day.

With the HP Prime you have to carefully consider what you want to do with it. It is a little bit of "problem solving", be it to prepare it to handle currency conversions, to prepare it to solve functions, etc. Once the "problem" is "solved", then it is incredibly fast and convenient.

With the HP17bII+, everything is pre-programmed, and the user interface is the best there is for a financial calculator (having used all of them)

I had to do some currency exchange. As a departure from the old HP17bII, the HP17bII+ has an additional menu for currency exchange, and it allows you to set up 6 currency combinations in a soft menu. You choose these conbnations from a menu where the most used currencies appear. You select the pair, enter the rate and store it.

Another menu that I often use is the BUS (business) menu. -you have several options (% of a total, % of increase, margin on sales, mark up on costs, etc.) These menus are made of the three components. You enter two of them and pressing on the third button, you get the answer. And if that variable appears in another menu, you can still use it. This is extrmely good to perform repeated calculations. For example, when analyzing a balance sheet or and P&L, you may want to enter a total, and calculate which percentage of it are the other figures that appear there. You enter the total once, and then you enter the components, find the %T, and enter the following component, etc. Very convenient - and you don't need to enter the total anymore.

Next week, we will talk about the solver.

Information for HP Prime

I have found a post in HPmuseum where a lot of links to information and tutorials to the HP Prime is posted. I enclose here several of them.

0) Official HP Prime Graphing Calculator User guides. In English:
http://h10025.www1.hp.com/ewfrf/wc/manua...ct=5367461

1) Excellent beginners math tutorial for the Prime. In French:
http://www.calculatrices-hp.com/uploads/...ime_v2.pdf
And pls check page 128 - it even covers the DataStreamer usage on a number of experiments, like reading pH!

2) This one is an overview of the HP Prime "advanced graphing calculator":
http://www.hpgraphingcalc.org/uploads/9/...t_nctm.pdf

3) The Maths Zone - Exploring Maths at Advanced Level:
https://www.derekenwinkel.nl/index.php/l...p39gii.pdf

4) HP Prime workshop materials 1.3:
http://www.hpgraphingcalc.org/uploads/9/...p_v1_3.pdf

5) The Maths Activities Pack:
http://www.hpgraphingcalc.org/uploads/9/...p39gii.pdf

6) Eddie's Math and Calculator Blog series
6.1) HP Prime Programming Tutorial #1: LOCAL, RETURN:
http://edspi31415.blogspot.com.es/2013/1...local.html
6.2) HP Prime Programming Tutorial #2: MSGBOX, IF-THEN-ELSE, PRINT, FOR
http://edspi31415.blogspot.com.es/2013/1...sgbox.html
6.3) HP Prime Programming Tutorial #3: WHILE, INPUT, KILL, REPEAT, GETKEY
http://edspi31415.blogspot.com.es/2013/1...while.html
6.4) HP Prime Programming Tutorial #4: CHOOSE and CASE, Tip about INPUT
http://edspi31415.blogspot.com.es/2013/1...hoose.html
6.5) HP Prime Programming Tutorial #5: STARTAPP, STARTVIEW, RGB
http://edspi31415.blogspot.com.es/2013/1...ial-5.html
6.6.1) HP Prime Programming Tutorial #6: Subroutines
http://edspi31415.blogspot.com.es/2013/1...ial-6.html
6.6.2) HP Prime Programming Tutorial #6: TEXTOUT
http://edspi31415.blogspot.com.es/2013/1...xtout.html
6.7) HP Prime Programming Tutorial #7: ARC, LINE, and Placement of Graphics
http://edspi31415.blogspot.com.es/2013/1...7-arc.html
6.8) HP Prime: CAS Commands in Home Mode
http://edspi31415.blogspot.com.es/2013/1...-mode.html
6.9) HP Prime: Drawing Pixelated Pictures (DRAWICON4, DRAWICON6)
http://edspi31415.blogspot.com.es/2013/1...tures.html
6.10) HP Prime Tip: RPN and Created Programs
http://edspi31415.blogspot.com.es/2013/1...grams.html
6.11) Program: Operations with Large Numbers (HP Prime)
http://edspi31415.blogspot.com.es/2013/1...mbers.html
6.12) HP Prime Program: Sampling Without Replacement
http://edspi31415.blogspot.com.es/2013/1...thout.html
6.13) HP Prime Tip: Changing the Color of a Function
http://edspi31415.blogspot.com.es/2013/1...ction.html
6.14) HP Prime Tip: Setting Up User Keys
http://edspi31415.blogspot.com.es/2013/0...-keys.html


7) Han's How To Guides:
7.1) HP Prime Programming: An Introduction
http://www.hpmuseum.org/forum/thread-216.html
7.2) HP Prime Programming: Variable types and their priorities
http://www.hpmuseum.org/forum/thread-215.html
7.3) HP Prime Programming: Newton's Method
http://www.hpmuseum.org/forum/thread-455.html
7.4) Example: creating icon menus
http://www.hpmuseum.org/forum/thread-315.html
7.5) Scrolling examples
http://www.hpmuseum.org/forum/thread-234.html
7.6) QPI: convert decimal to p/q, ln(p/q), p/q*pi, e^(p/q), or sqrt(p/q)
http://www.hpmuseum.org/forum/thread-18.html


8) Joe Horn's How To Guides:
8.1) PDQ Algorithm: Infinite precision best fraction within tolerance
http://www.hpmuseum.org/forum/thread-61.html
8.2) How to Avoid Streaks in photos on your HP Prime
http://holyjoe.net/Prime/Pix/color-reduction.htm
8.3) "hex": exact internal form of reals in CAS
http://www.hpmuseum.org/forum/thread-720.html

9) Carl's HP Prime Calculator Learning modules, by CR Haeger:
9.1) CAS solve()
https://docs.google.com/document/d/1eTfT...OffKb4/pub
9.2) Define User Function, Function App
https://docs.google.com/document/d/1kPO_...hUswUI/pub
9.3) Spreadsheet App, CAS Calculus
https://docs.google.com/document/d/1GUVZ...TKpvug/pub
9.4) Statistics 2Var App: Manual and MAKE Data
https://docs.google.com/document/d/1fq1M...JrSGcY/pub
9.5) Statistics 2Var App: MAKELIST, L1 and Spreadsheets
https://docs.google.com/document/d/12Kjg...SGd5KE/pub

10) CAS (XCAS) Programming Reference Materials
10.1) Symbolic algebra and Mathematics with Xcas (Renée De Graeve, Bernard Parisse)
http://www-fourier.ujf-grenoble.fr/~pari...cmd_en.pdf
10.2) Calcul Formel avec la calculatrice HP Prime (Renée De Graeve)
http://www-fourier.ujf-grenoble.fr/~pari...hprime.pdf
10.3) An introduction to the Xcas interface
http://www-fourier.ujf-grenoble.fr/~pari...iel_en.pdf

Special mention has to be made to Eddie B. Shore blog. Eddie is a maths professor, but he has a gift to explain different aspects of various calculators in its blog. He got an HP Prime and started working with it. I have linked a page to his blog here.

There are other interesting series - namely the ones written by Han and Joe Horn, and the interesting CAS series written by old HP calculate acquaintance Bernard Parisse and others.

It is clear that a completely new calculator will only succeed if there is enough information for kids to ease their learning. Let’s forget about us technical users - we have other tools for ourselves. Now calculators are a thing of students and of professors - and those only because of the former. And there is a huge installed base of Texas Instruments calculator families.

And the fight is not about RPN. We need to accept that RPN has lost in the marketplace, although not in our minds. We just can appreciate that a calculator comes with it, but it is only for heritage users - youngsters can’t give a damn provided they have an algebraic entry mode where they can enter the whole formula. (Some of us would argue that this does not mean that they understand the formula they have entered - while if they have to “translate” it to RPN, this forces them to analyze it, and sometimes find the traps and irregularities that it can imply (like division by zero and other kinds of discontinuities). As for me, there are many times when I am working out a problem as I think, taking consequences as I progress, and RPN is best suited to this way of reasoning. But I digress. for all practical purposes, RPN is not anymore a sales argument except for the mature technical person like us. It is the school market that will make succeed or fail a calculator. And enough support information is required for it to succeed. These writers are showing us the way!