Collecting Calculators

by Wlodek Mier-Jedrzejowicz Ph.D.


What do you do with your old calculator if you want to buy a new one, such as the HP48GX? Some people sell the old one to help pay for the new one. Others keep it; as a spare, to use while they learn the new one, or out of nostalgia.

A few HPCC members do more than keep their old calculators - they actually collect them. Even if you do not collect old HP calculators yourself, it is worth knowing about them - if you come across one it might be worth buying; it is a shame to see it thrown away, and you could sell it to someone who does collect them - though it will not get you 7 million pounds at Christie's!

If you do find an old HP calculator - in your office, maybe, or in a second-hand shop, or offered to you by someone who no longer needs it, you will have three questions. "Is it worth getting it?" "How much is it worth?" "How can I sell it if I don't want it?" I shall give general answers here to all three questions, but Les says a series of short articles about old HP calculators and their history would be useful for future issues of DATAFILE, so I shall write some such articles as well as this one; if you have a favourite old HP calculator and can write a article about it for DATAFILE then please do so!

The first question was "Is it worth getting it?" and the answer is nearly always "Yes". If you see an old HP calculator in a second-hand shop, try to buy it - for yourself or another HPCC member!

Naturally, the price demanded will affect your decision, but at a low price, say about #10 for a working calculator, or #5 for a broken one, it is definitely worth getting. Even the HP28C and HP18C which were both soon followed by improved versions, are worth getting if cheap enough; I am looking for a spare HP28C just now! Old manuals and accessories are worth getting too, though some HP-41 modules such as the Games module or normal memory modules are not worth much.

"How much is it worth?" is the most difficult question. No-one publishes a catalogue of prices, as is done for stamp or coin collectors! Too much depends on the condition, the rarity, how much the vendor wants, and how badly a potential customer wants it. If you have no idea of the value, try talking to one of the people named in the next paragraph. Some models particularly worth looking out for are as follows. The HP-01 calculator/watch is especially interesting, whether in a steel case or in a gold-plated one, because of the model number, and because it is a watch as well as a calculator. All the desktop and handheld models with a built-in printer are worth looking for, in particular the HP-97S which is a rare version of the HP-97, and the HP-95 of which some prototypes were made, but which never went
into mass production. If you find any of these, buy first and ask questions afterwards! Other models which seem to be hard to get include the HP-70 and the HP-22 (both are financial models), the HP-94 (any version) and the HP-10C.

Thirdly, "How can I sell it if I don't want it?" Colin Crowther who runs our library of books and old equipment can often help. So can I, because I write books about HP calculators, and therefore collect old ones. Colin and I also know other HPCC members who collect old HP calculators. You can also advertise in DATAFILE, or on The No Zone, or other electronic bulletin boards. So, check out that old HP calculator in your local junk shop and get in touch!


Just after I had written this article, I received a letter with the first issue of a small journal called "The International Calculator Collector". This is aimed at people who collect, or are interested in the history of, early handheld electronic calculators.

By "early", they mean calculators with displays of types earlier than the current LCDs (liquid crystal displays). They invite subscriptions (US$12 for airmail delivery of the journal outside the USA, $8 in the USA). They also invite articles about calculators.

The address is: International Association of Calculator Collectors, 1212 South Parton St., Santa Ana, CA 92707, USA. Maybe a collectors' catalogue will soon become available, contrary to the statement in my article!


This article is part of the WMJARTS file. This file contains a series of articles written by Wlodek Mier-Jedrzejowicz and published in DATAFILE, the journal of the HPCC. The article was reproduced with permission of the author.

Copyright Wlodek Mier-Jedrzejowicz Ph.D.