I have now received another calculator for the "harem": an HP 19bII with the back door.
I have fond memories of the HP 19bII. While my first calculators were HP (spice models, beginning with the 33c), I did my last 3 years in university with a Casio pocket computer. At the time, I did not have the funds for the HP41cx - which was the model to have. However, for all practical purposes, the Casio was a better calculator: it could be programmable in Basic and I could do any numerical programming I was asked in my engineering courses. While I missed the powerful Basic of the HP85, with which I made my first money, it was good enough for me.
When I finished engineering I started an MBA. I then got some more money, and I bought the then best available financial calculator - the HP19bII. I enjoyed it during 2 years. It had all the financial tools, plus a good set of statistical and mathematical tools. However, at the middle of my second year in the MBA, it fell to the floor and the battery door went off. I was not able to fix it properly. Tired of sticking it with tape every now and then, I left it in a drawer (from where it was picked up by my sister) and got an HP 17bII instead. A classy machine as well, but missing key features like trigonometrics. Well, it was more than good enough, but it market my end as a self-respecting engineer.
Several years later, when at a covneience store in Madrid, I saw a stack of blister packed HP19bII. They looked blacker than I remembered, but at that time I was not looking for another calculator, and I passed by. I did not know at the moment that I was looking at the back door HP 19bII.
When I started collecting calculators again, the 19b was one of the first to get. I knew what to expect: a well specified calculator, with all the functions I could need for a non-academic environment (seriously, how many times are you inverting matrixes in real life?), but I knew as well that it should rest on my desk most of the time, unless I wanted to have another battery door casualty.
I have just bought a back-battery door HP19bII. I guess that many of you would like to see both kinds compared:
Front view: the back battery door on the right. It shows a darker colour, but the difference is not too big.
Here is the reason for getting it: the back door:
The batteries were set in place with the door, but there was pressure on the door all the time. Whoever changed a set of batteries onthese machines know what I am referring to. This design change solves the problem (at least, this problem!)
The keys have the same good key feel - totally different from any other HP but very satisfactory. This sample was made in Indonesia.
The keys are much blacker than the original:
A closer look:
Now that I think about it, I have not tested it for speed differences - and I will not do it today. I keep most of the claculators in the collection without battery, to avoid corroding the terminals, and to do these tests I would have to go through the painful exercice of changing the batteries again...