Calculators

Well, Scott Kirkwood told me I should have a blog. I did not have many uses, but I have many ideas that I forget and then they revive over time. One is about calculotors:

As a 16 year old I bought an HP25 RPN programmable calculator. I was the first in school to have such a powerful computing machine. I'm afraid I threw it away, but it was a great machine. It prepared me for my career in computing and math -- access to computers was scarce at the time. If I am nostalgic I go to
http://www.hpmuseum.org/simulate/simulate.htm#java25

As a present to my PH.D I bought another HP, 32SII, but it has a problem with the display. I will try (once more) to get it fixed.

But recently I got fascinated with the HP12C, which all financial people use. As a mathematician I thought I needed to inderstand what the fuss is all about. I bought one second hand in order to play and figure out what it was all about. Well, its all about compound interest, i.e. $$$. But in practice I prefer making a spreadsheet for such calculations.

I know about three interesting links about the HP12C:
http://www.hpcalc.org/details.php?id=4345
Visually identical to the real machine. Whether the results are accurate I don't know.

http://www.hpcalc.org/details.php?id=4188
This one is visually ugly, but showes all the registers, which might be useful for understanding.

http://h10032.www1.hp.com/ctg/Manual/bpia5184.pdf
Solving financial problems with the HP12C

For my Windows PC I use the Excalibur software for scientific stuff.
I can't find the webpage, but google for Excalibur calculatot 32-bit

I also downloaded RPN Calc but never use it.

There are also JavaSCript implemenatations, as
http://www.arachnoid.com/lutusp/calculator.html
But I find the lay-out too ugly.

For cryptographic use, with big numbers, the following page is useful:
http://world.std.com/~reinhold/BigNumCalc.html