Calculator blog

We are putting together two new items:

• A new HP41cl, coming from a version 41C, but boxed and with English manuals. It is already available as an option in the website. It is more expensive than the rest - but it is not so easy to get boxed units in good ...

I think you all know that there was a black version of the HP17bII. You can find a comparative picture besides this text. But does anyone know where was it produced? When? Does it have the same quality as the rest? (As I don’t have my sample anymore, I can’t recall whether there was any differ...

Back in 1973, Fischer Black and Myron Scholes published a paper, "The Pricing of Options and Corporate Liabilities”, where they derived a differential equation to try to model the value of some kinds of options, initially only European type. The term “Black and Scholes” was coined by R...

How to effectively use the solver for your own equations

I consider the solver model of the hp17bII - hp19bII families the best there is. It allows you to perform normal calculations, but you still have the possibility of entering data at any time in on of the variables.

When using the HP48-hp50 family of calculators, this is one of the missing features for my daily operation. So I began exploring alternatives to mimic the behavior of the solver I love the most...

Upon some comments from Don Shepherd about the speed of the solver of the different versions of hP17bII

A=SIGMA(I:1:5000:1:1)

HP 17bII original: 80 seconds, serial number ID90700765, made in Indonesia

HP 17bII black: 80 seconds, serial number ID11400944, made in Indonesia

HP 17bII+ gold: 80 seconds, serial number CNA 43000634, made in China

HP 17bII silver:173 seconds, serial number CNA 04401226, made in China

Don made me doubt about the gold versi...