Calculator blog

Musings and comments about our common interest


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Shady Calculator Stories

Some sad stories in Ebay.

As many of you, I have been purchasing items in Ebay for both my own collection and for the shop. Most of the times you get good material - never a bargain, but what it is advertised. Then you find some guys that are quite liberal with adjectives - in particular, “working condition” and “good shape”. But in most cases they try to help.

But then you have a third type: those that give you a crappy product and then play with you. The aim is to dance with you until the 45 days period since the purchase has elapsed. A recent case comes to my mind. I bought an HP41c calculator sold as working. It took some time to arrive, in a plastic envelope, without any protection, dirty, battered, and, of course, not working. I paid for it “working” price, and it was in such a poor state that I did not venture into repairing it - I could have not sold it in such a state. I arranged the return of the calculator, which took some other days, since the delivery address was wrong, and then wait…and wait… and wait for the refund. “Do you want it in your account or in Paypal” “if in Paypal, then I need to put funds in it”. And then silence… the 45 days had elapsed.

Just in case you find him: the name is Pablo Alvarez Llinas, and his Ebay user name is beaviisb. In today’s world, anonymity is impossible. In linked he appears as working for HP Delivery Services.

I have another case, concerning an HP85 - but that’ll be the object of another installment of “shady calculator stories”

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Calculators for the Iphone 5

i41cx review

My former telephone died and my wife got me an iPhone 5. Then I set to get some calculators to work with in the system. In particular, I downloaded all the free ones. Here's what I got:

I did not load the HP15c in any of its versions, since i always carry one with me. I find that it is the finest device ever made for personal calculations, only rivaled by the mighty HP42s - but this is a completely different discussion...
I took the free version of the HP42s, Free42. It is built for the smaller screen of the previous iPhone versions

I got RPN25 calc. When you need a simple, RPN calculator, this is a nice alternative, since there are not too many keys and it has the basic set of functions. Also for smaller screens, but it is a pleasure to use.

I got a very simple RPN calc, iRPN Calc, which is as simple a calculator as you may find anywhere, with a very nice twist: you can change the items in the stack by moving them around with your fingers. Also for smaller screen.


I48. not built for the iPhone 5 - there is a wide white band in the lower part of the screen - it is in need of an adaption or at least a recompiling, in order to be livable with in the iPhone 5.

PowerOne SL: does not try to mimic the original HP calculators, and it is the first one that does fill the whole screen. It opens as an algebraic model, but when going to the settings page, you can change it into RPN. It has several pages for different functions, from numbers, angle functions, other transcendental functions, and memory registers. This is a fine addition to the screen.


The i41CX+

One of the calculators that has marked my scientific life was the HP41cv. This was a machine that offered a young engineer the promise of doing anything - from controlling peripherals to all kinds of calculators. I have been following with attention the HP41cl developments, and I find extremely interesting the old, loved 41c body with throughly modern innards - and sometime I will get one. But it just does not fit in my pocket.

Therefore I took the plunge and download the full version i41CX+, with CAS. Let me state first that I have not been able to delve into the CAS, since I have been exploring the different modules available (the CAS is one of them). It works basically as the original one, and it has been adapted to the longer screen of the iPhone 5. Lest I forget, it is not free, but close to 25 € (once bought, you cannot see the price in the store). Let me say that it fully justifies the purchase.