To help out John and Robert, two kids working on a computer program for kids at a youth center I promised to put this link on my site. It's a link on the history The History and Significance of Software. You can find it here.

While I don't usually take requests for external links to this page, I understand that free pizza is involved this time, which is a good thing.

The most recent 25 added calculators (and other devices)

Currently my on-line museum has 291 calculators on display.

About this museum

One of my stranger hobbies is collecting calculators. I especially like programmable calculators, and of those I love the ones made by Hewlett Packard the most.

This hobby started somewhere in the late seventies. I was already very much interested in calculators (see below) when a friend of mine discovered that a local shop sold broken calculators for about $1.50 to $10. They would normally throw them away but if you asked nicely they would sell them cheaply.

That's when it started. Those broken calculators were usually very easy to fix, a broken print-track, a loose battery contact, a broken on/off switch - those were usually the problems. Some 'broken' calculators simply had flat batteries!

Later I was able to buy some of the calculators new, and sometimes people would donate me their old calculators. So if you want to see your old calculator on the web - I'm your man! :-)

Today producing a four function calculator is apparently extremely easy, you can buy a standard calculator for about $1.50. I've got the feeling that more work was put in the older calculators resulting in better products and peripherals. Today's super programmable calculators may have a abundance of functions and options, but also quite often stupid bugs, interface problems and omissions. However, the product expected life-time of modern calculators is probably much shorter also. There are exceptions however.

What do I collect?

There are a lot of calculators in this world and I can't collect the all. Therefore I've tried to find a subset that suits me. Therefore I've decided that I collect calculators that can run on battery (or solar) power. I therefore do not collect mechanical or mains powered calculators. Except for some of the older HP's which are so extremely beautiful. So, I try to collect ALL HP calculators and any other battery or solar powered calculators I can find.

Some remarks

©2009 Ernst Mulder