About The Calculator 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
What do I collect?
There are a lot of calculators in this world and I can't collect them
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.
The very first calculator I have ever touched is still in my
possession. My father bought it on one of his visits to the US of A
when I was about ten years old. It is the Realtone Model 8414.
The second calculator in my life is still used by my father!
The first calculator I ever owned was given to me by a friend
of my father, and is probably the one that started it all. It was
the Triumph 81C. My original 81C doesn't
work anymore but I put it on display in this on-line museum anyway.
The first calculator I ever bought myself was the TI 30. That was when I was about
12 years old (1977). Well, actually that was the second one, I had
bought a four-function model myself, and when I showed it to my
father he said I should bring it back and get a "real" calculator.
The calculator I bought had a "flaw" (√-9 = -3) which was
enough to get my money back. He then tried to explain all the
scientific functions to me but I didn't quite understand them!
My most favourite calculator designs are the HP 15C,
and the HP 41CX. The most usable programmable
calculator ever, in my opinion, is the Casio
fx-602p (I'm not including the basic programmable pocket-computers).
And my reward for the best school calculator goes (with much praise)
to the Casio
My reward for the worst keyboard design goes to the
When I get a new calculator I first examine whether it's still fully
operational. If necessary and possible I repair it. Then the
calculator is thoroughly cleaned. Except for a few (two, so far)
exceptions, all calculators in my collection are fully functional.
The calculator's picture is taken by scanning the calculator using a
desktop scanner. All pictures were scanned using the same scanner
and resolution settings (safeguarding the picture's relative
proportions). All calculator pictures were painstakingly retouched
to remove dust spots and scratches and such.
For those looking for manuals, I hardly have any, so please don't
ask for copies. Today the best place to look for calculators are
flea markets, and most of them sell their calculators without
manuals and such. If you're looking for HP manuals, try hpmuseum.org
(link valid 2022-12-30).
Mny other manuals can be found using Google or by visiting sites of
other calculator collectors. The manuals of a number of pocket computers
can be found on PockeMul's website pockemul.com (link valid 2022-12-30).
Please email me if you've got
a calculator you are about to throw away. I'd be delighted to add it
to my collection. Anyone donating a calculator will get their name
referenced on the calculator's webpage.
©2023 Ernst Mulder