Calculator blog

Here are some pictures of the complete cable:

Hopefully sent to customers by the end of the week.

There will be some sort of compensation for the delay to all.

The HP19bII is a fantastic calculator with one of the most complete function sets. It was the workhorse of the MBA I did at the beginning of the nineties. Most of my companions were using this calculator.

However, several years later most units had been damaged at the same point: the side door. Nearly all units after a long time become brittle and break over time.

Hewlett-Packard recognized this problem and redesigned the calculator, moving the battery door to the back. There were other minor changes, with a darker brown body and black keys instead of the grey of the past version. This model is much more demanded nowadays - because it lasts.

I bought one in a local second hand site, but it was missing the back door. So I designed one for it. I thought that there would be exactly one unit produced ever - this was not a piece that breaks, and it was difficult to lose too. So color me surprised when a customer asked me where such back door could be found. "It is here", I said. 

So I take the opportunity to offer it to you all. However, I still think that there will not be a lot of orders - rationale is the same as it was when I designed it.

Here is a picture of the complete cable:

What could be improved on the HP15c CE by changing the firmware?

• Back up: in my opinion, the ability to write down user memory (including memory disposition) would be fantastic. not only you save your hard-entered programs, but you could store different profiles (EE, algebra, finance, others...) and change them "on the fly"
• Memory is now far less important - we have enough! there are some methods to bring it to 224 registers, but what's the point?
• Debouncing time adjustment - a little like screen contrast?
• Any other that you can imagine?

We are offering theHP15c CE "Enhanced" at a 10€ premium over the standard price of the HP15c CE.

What makes it "enhanced"? 4 main items, in my opinion.

• We implement the latest firmware with a correction for the HP16c hidden mode, so that it is not affected by the DEC bug.
• We include a HP16c overlay so you can use the HP16c mode with ease.
• We include a programming cable so that you can change the firmware when new versions appear with more functions or solutions for yet unknown bugs. (In particular we are working on a back up feature - memory is big enough to save it just in case. Alternatively, you can have several profiles (finance, electrical, construction, algebra) that can be changed with the back up feature)
• My preferred: a proper QC done by me. I open the calculator, see whether the bezel has any spot, and test the keyboard. In particular, I test all keys for recording properly using the self test feature, for any hard key (is fair to say that this test does not test for rebounds, but our new firmware also changes debouncing to 100ms from 80ms in the original machine)

We have received news that the first batch of programming cables will be shipped late next week - this means typically one week more of delay compared to the latest Jan-15th schedule we published. We apologize for the delay and expect that all changes made on the design result in a better, sturdier cable. 

The head had to be redesigned some times so that a proper connection with the calculator could be made. The pins are sturdier than the original model. There was also a late change on the switchbox, to make it more resistant. 

The tests performed succeeded in reprogramming a unit with the latest firmware, and recovering the firmware from the machine too.

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:

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.

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:

More information about it in the coming days!!!

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