Calculator blog

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.

I 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+ ?)

With 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!

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

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/

Now that I am frequently opening the calculator to put new firmware types I enjoy having the 3D-printed Voyager battery covers. We have it for the original calculators (the small door for three button batteries) but we also have it for the new models (compatible from the 2007 model onwards, including HP12c and HP15c CE). This is an advantage because it does not need the ugly screw, and you can just open it and reset it if needed. Much more comfortable !!

Why not? In my case it is easier than in others for obvious reasons. However, lately I had to do several conversions from Hexadecimal to Decimal - and while I can do them in the "Base" menu of the HP Prime, it is actually easier to use the HP16c to add, subtract and calculate.

However, every time I do it I need to reset the memory and programs of my HP15c. So far there are not that many - but I hate to rewrite them every time. So I took another HP15c, this time in HP16c mode, running with the DECbug patch and the HP16c overlay. I even have a different leather case for each. The HP16c is using the Bordeaux leather case - just to make sure that I reach for the right one in each case. Voilà!

At least one of our customers has done it too. You may read his comments in HPmuseum.org. Makes full sense if you load your HP15c with lots of programs as we do!! 

[You can ask us to have it patched and tested for 25€ before shipping - please remember to order the Flashing Voyager article when ordering yours]

We offer a flashing service for calculators using the POGO connector. These include the HP12c, HP15c and HP10bII+. There are community patches available for the HP15c. This patch solves the DEC bug in the non-manufacturer-supported HP16c mode, from a solution devised by a well-known community member. The second picture shows a calculator without the bug. In a calculator with the bug, it would show 105 instead. You'd need to send the calculator back and we will patch it and send it back. 

 The DEC bug is just a display bug that affects the HP16c mode: the values are still correct in the registers. If you do not have the overlay, you may as well forget about it because you will never experiece it: it does not affect any of the two HP15c modes. 

If you order the HP15c Computer Science edition, which includes the overlay, you can also order the patching together when you buy it. You will receive the calculator already patched, working perfectly. This serves as well to weed out the odd defective unit, since we have to test thoroughly the unit before shipping.

An image is worth 1000 words: as you know, in the NOMAS HP16c this screen was not possible. When you keyed 111, you got 105 !! This was called the "DEC" bug. You could not complain: it was a gift and it was Not manufacturer supported feature. Now "someone" (we don't know if he wants his name mentioned) has created a patch that we are testing. As it only patches a couple of bytes in the HP16c ROM, it should not impact on 15 or 15.2 performance. We've been using it during 15 days with no issues whatsoever.

We have found finally a producer that has access to pogo pins at the same picth as the one in the HP calculators. It is a different pitch from the industry standard 2.54mm - which makes it difficult to find a replacement.

Now we are discussing the prices - prior to this, we did not even know with whom to discuss! Let's hope to strik an agreement and be able to have a product for Christmas.

Here are some pictures now drawn by the factory: