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Musings and comments about our common interest

 


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The function key program trick for HP15c

Now that we have so many program steps in the new HP15c CE, we need to orgaize the programs. In many cases, you need to input several variables to run the program (say TVM, with 5 variables: n, i, PV, PMT and FV; but there may be several other programs)

It consists in using one label to store the value and solve for that variable when pressing R/S. An example:

f LBL A
STO 1 Stores the value in X in R1
R/S            Stops. Here you can press another function key or R/S to solve for A
 
... some code here to solve for this variable
 
STO 1
g RTN
 
Same with other labels of the first row, each using with another register to store the value: 2, 3, 4, 5.
 
Now, this is typically used for a main program, say TVM; but you can use these labels to enter the variables in registers 1, 2, 3, 4, 5, and then press GSB another label to run other program with solve. In my current set up, I use the "solver loader" in 4 different programs (not all variables - but for sure the first three). When you enter it once in a program in your calculator, you can use it to fill in R1 to R5 in any other program (if these are the ones you set it for). Just make sure of not pressing R/S but the initial label of whatever program you want to run. 
 
A nice trick that saves programming steps and makes an easier number entry for your programs!
 
 
 
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HP Robots 2

The HP Robot is called Otto. There are robot machines, different body options, STL drawings to be 3D printed (in 3D-printing companies or the 3D-printer of the school), programming tools (in modules and translation to Python). Quite interesting if you want to introduce youngsters into procedural programming, in a way quite similar to Apple's playgrounds but with a real machine that is loaded a program through USB. 

We have not taken a decision yet on whether to carry this line - our customer base has zero intersection with the intended HP Robot customer profile!!

More information about prices and options in the coming weeks.

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HP Robots !!!!

You saw it first here! A new product line for education with the HP brand: HP Robots !! Intended squarely for the educational market, with several complexity levels and many options, allow children to learn about 3D printing, assembling, reading manuals, and object programming and python:

Captura_de_pantalla_2024-01-08_a_las_23.44.32

More information about it in the coming days!!!

 

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The HP15c and HP16c in HP Journal of May 1983

If you have time for an interesting read, please take a look at the two last articles on May 1983 issue of HP Journal:

Captura_de_pantalla_2024-01-07_a_las_19.54.00

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More about the reprogramming cable

Continuing with the programming cable: I received pictures of some parts as they were being produced by the manufacturer. These are the circuits used for the two buttons in the cable: the Reset and Erase buttons.

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The clip was also extensively desgined and tested in several materials and shapes before finally commiting to a mould. The producer estimated that the 0,4mm diameter pin was too thin for repeated use, se we brought it up to 0,6mm. I concur: in the past some pins in 0,4mm were easily bent and I destroyed a couple of cables.

The head of the cable is asymetrical so there is one way only to insert it.

WhatsApp_Image_2023-12-21_at_10.15.15

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Cable for HP15c CE reprogramming

As you know, we have designed a cable for the newest Voyagers' reprogramming. The calculator side has a POGO 6-pin connector, and the computer side has an USB A connector. (maybe too early for an USB C connector?). We have had several redesigns to improve connectivity, useability and resistance - all which has delayed the delivery until now. We expect to receive the initial units around January the 15th, and these will be sent to the customers that placed an order before. 

With the cable you can reprogram the HP12c and HP15c CE of latest versions. You can alter the firmware, or, most likely, fix bugs. The only "important" bug we know about in the hp15c is not in the supported HP15c 99 register mode - it is in the HP16c unsupported mode. This bug is quite nasty - it renders the DEC mode completely unusable. Fortunately a member of the hpmuseum.org forum found a simple fix, which implies just 3 byte changes. I have been using a prototype of the cable to fix more than 120 units for my customers and I have to report that I have not "bricked" any calculator in the process. For comparison, I have bricked beyond recovery many calculators HP15c Limited Edition or HP30b financial calculator. The new modules are much more robust.

Pricing will be depending on whether the customer buys a HP15c from us: 40€ if he doesn't, 20€ if he did and 10€ in a special package with the calculator.

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The HP16c mode

IMG_1048I am beginning to learn the HP16c through the HP16c mode in the latest HP15c CE. It is very expensive to get an original HP16c!

Unfortunately, the HP16c mode has a very nasty bug whereby the DEC screen mode does not represent well the X register's contents. The register contents are OK - it is the screen view that is wrong. It happens with some values only - but enough to be unuseful for real life use.

A member of the hpmuseum.org community developed a change in three positions of the original ROM. It is not that the original ROM was wrong - it was the emulator (which was designed for calculators that just use numbers in BCD) that could not manage some of the hexadecimal higher values. With reference to the original ROM memory space, the changes are the following:

06ef:000 (was:346)
06f0:000 (was:1cb)
0718:3ac (was:17a)
(addresses are the 10-bit word addresses expressed in the 16c ROM space - beware that you need to add the offset from the beggining of the firmware to the beginning of the HP16c ROM, and that the HP15c firmware is arranged in bytes, so that two bytes make a "nutbyte" of 10bits. You also need to consider that the memory is arranged "little endian".

We are now patching the HP15c CE calculators for the customers that ask for it. We are also offering the patching service for calculators in our customer's hands - in this case for a fee.

We will also receive soon a patching cable, valid for the HP15c CE, the latest HP12c (after 2015) and the HP10bII+ (anyone considering adding RPN to the HP10bII+ ?)

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Battery door for new voyagers

IMG_1648With the new voyagers you don't need to open the battery door for a long time. I am a heavy user of the HP15c Collector's Edition, and I have been using it from April when I received my test unit. It is still running on the original set of batteries (at least 7 months of testing and heavy use)

However, I am now using a lot its POGO connection in order to try new things firmware and other projects (of which you will know if they succeed), and I have to say that it is a real pain to use the screw all the time. It is also a little bit protruding and marking the nice leather cases we have.

We designed several years ago a battery door that never saw a lot of sales (as opposed to the battery door for the original HP12c - it seems that a sizeable number of them was lost and required replacement). Now I am travelling and unable to do any change since I have not a screwdriver with me - next time I will fit one of our doors instead of the screwed one!

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Black Friday 2023

Now we have the Black Friday campaign at full speed. We have created a specific page with all the offers. you can find it here: Black Friday Offers

Among them you can find what is probably the most interesting item in our website (basically because we are the only ones that can offer it: the HP15c CE "Black Friday Edition", which includes:

  •  HP15c CE
  • Overlay HP16c 
  • Firmware patch to avoid the "DEC bug" that is only appearing in the NOMAS HP16c feature of the HP15c CE

For the Black Friday period, it is sold at the same price of the HP15c "nude": 107,43 € + VAT (none if you are from outside the EU) + shipping

HP15c CE Black Friday

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The best link you can add today to your browser

I think this is the best link you can add to your browser if you are a HP calculator lover: all the manuals in all the languages that the site owner has been able to get/scan !!

literature.hpcalc.org/

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