Survey: How do you keep your calculators?


Hi everybody.

I need some advice on how to keep my calculators safe. I begin to have a respectable number of them (about 30, I know this may make you laugh if you have hundreds of them), and I'm wondering how to store them: in a closet? in some folders? without batteries? or with batteries for fast checking? and how frequent must this checking be? in a show-room? on some shelf?

How do you store your calculators? I'd like to know.

Of course, I've read what Philippe on MyCalcDB says about keeping calculators. But I'd like to know your opinion.


-- Antonio

Edited: 23 June 2006, 9:45 a.m. after one or more responses were posted


Hi, Antonio:

I'm not saying that what follows is the best way to do it, it's just how I do it:

  1. *all* batteries removed
  2. inside their own covers, leather cases, or whatever, but not their boxes
  3. each one individually stored in a teflon or similar plastic bag (to reduce whatever friction, i.e., wear, to a minimum)
  4. each bag is then thermally sealed, so that no gasses, liquids, or dust can enter it.
  5. the sealed bags are kept in a suitable place, i.e., inside some drawer, so that they're safe from light, moisture, etc.
  6. once a year or so, I remove them from their sealed bags, putt batteries back on, and test them for a little while, then to the bag again.

I also check pouch disintegration, as the original ones for the HP7-1B have the nasty habit of turning their insides into acrylic dust with time, which must be washed out. If the pouch develops or can
develop this problem, it's best to have the calculator out of it
or at least enclosed in a plastic bag of its own. Checking card readers is a must, too.

Anyway, I think most of this is overkill, actually. My HP-11C was in the open for more than 20 years of (careful) daily use, and it's in the same nearly mint good shape as most of my other models.

Best regards from V.


I remove batteries if they aren't wired in. If they are hard-wired in I remove them only if I see leakage.

With Unisonic calculators I find it is best not to store them in their carryig case. The cases have a way of sticking to the calculator so that you have to slip a thin blade down between the calculator and case in order to free the calculator.


Personally I prefer to use them as regularly as possible, as that is why I brought them in the first place. I have replaced the batteries in all of them and (so far) havn't had a modern rechargeable cell leak but still check every so often.

Mike T.


It goes without saying that I keep a number of them in regular use (HP-71B, HP-15C, SHARP PC-1350, etc), and not subject to the proceedings I described.

That only applies to the models put away for storage, which I understand is what Antonio was asking in the first place. The models in use are just, that, simply there to be (carefully) used. But using 80-100 valuable and mostly expensive models "as regularly as possible" is entirely out of the question, there are simulators and such if the need ever arises, which it rarely does.

Best regards from V.

Edited: 23 June 2006, 12:21 p.m.


Well, 30 is a goodly number. You have now surpassed me (I have roughly 20).

I keep most of mine up and running. I put silver oxide cells in them.

The once I worry about most are the 48 series with the alkalines.

I don't have any batteries in my RED LED (zeppelin) model, nor in my 41CV.

I have half my collection at home, half at the office. That way, I always have a good one close at hand! And they all get used alot that way too.

Valentin is right for the long term storage.

I do keep them in drawer, to keep dust, spills etc off, and in their sleeves. I bought sleeves for the ones that didn't have them.


How do you store your calculators? I'd like to know.

Heck, I just leave them in their slipcovers with batteries installed, and keep them in a clean drawer away from sources of dust, heat, and odors.

I'm not too worried about battery leakage on the Voyagers and Pioneers (13/44/76/357 button cells). The ones that have clocks (17, 27, 48, 49, 71) slowly but surely discharge their batteries, which get replaced. I also use the 41's extensively enough that they need periodic battery replacement. That leaves the two 28C's, which I ought to check periodically for leakage.

Few of my calc's are in near-mint condition, and I bought most of them used. I just try to prevent careless damage or degradation.

-- KS

Edited: 24 June 2006, 4:29 p.m.


I like to use my calculators, so I have them in a display case, so that I can get to them quickly. This means that they have to have batteries and I check them from time to time to make sure they all work.



Vassilis; what are the "things" on the 2nd, third, and 4th levels? you know which things the things are. everyone here knows what the normal things are. it's the 4 thing-y things that i'm curious about.


db (martinez, ca.) wrote:

> what are the "things" on the 2nd, third, and 4th levels?

OK, since I am not sure which ones you mean, here is the index for the entire display case:


* HP98549 is the "low cost graphics adaptor" for the HP 9000/345 workstation (I put it there for decoration)

** TI-BA this is a Texas Instruments Business Analyst (or smth). It looks much better without the ugly exterior. It runs on a 9V battery which also serves to prop the keyboard at a convenient angle. Here is a closer view of it:

*** HP-98625A this is the high speed HP-IB adaptor for the HP 9000/345 workstation. I had to remove this one, because it has a conflict with the SCSI adaptor on the 345 (you may have one or the other, but not both). Good thing that the 345 has a "low-speed" HP-IB adaptor built-in so I can use a SCSI hard drive and still be able to access HP-IB peripherals. BTW this 345 runs OpenBSD.


PS I got the display case from IKEA.

Edited: 25 June 2006, 3:52 a.m.


I have them piled on a shelf in the garage.
Except for the 48G and the 12c, 15C and 16C which I have
piled on my desk...

Warning! gloat follows:
Today I bought a 29C, a couple of second generation 35's,
one of which is in a locked security cradle (no key!) at
a school tag/garage/rummage sale for $1US each. The 29C and
the 35 in the security cradle both work. I haven't tried
to power up the other 35 as it is missing the battery pack.
I found the battery cover to the 35 about 50 feet from it!
I missed out on another 29C by just minutes!

dona nobis pacem


running the 35 on the ac adapter/charger w/o a battery is ok.


But then I'll need to open up the security case on the other HP 35
to use its charger/adapter. (No key)

dona nobis pacem


I have a security cable without a key. I asked a locksmith about making a key and he gave me a cost estimate that was more than I was willing to pay. I can see how to replace the lock but haven't been able to find one that will fit. Does anyone know where I could purchase a replacement lock mechanism?


Palmer O. Hanson, Jr. wrote:

> I have a security cable without a key. [...] I can see how to
> replace the lock but haven't been able to find one that will fit.

If you can take out the lock you may want to disassemble it and remove the cylinders (and associated springs). Then your lock will not need a key, you'll be able to open it with a flat blade screwdriver, or in fact anything that will fit in the lock (e.g. another similar key).

Obviously this works only if you can remove the core of the lock and do not care to actually lock the calculator (i.e. do not expect any kind of security from the modified lock).

I did this procedure on a docking station for my IBM laptop. I lost the keys and in any case the docking station is at home, anybody who breaks in, can take the whole thing so locking the laptop to the docking station is merely a nuisance.


Edited: 26 June 2006, 12:54 a.m.


Hi Antonio,

I keep my most valuable calculators (or the ones I paid the most money for - which probably dosen't make them automatically valuable ...) in my wardrobe, between socks, T-Shirts and sweaters. But this is only possible, because there aren't so many valuable calculators yet, less than 10 maybe :-(

The majority lies piled up in shoe-boxes in a dry room, removable battries removed and built-in recharchable batteries removed, in case they started leaking already. I leave good batteries inside and try to check them reguarly. If I have boxes and manuals, I try to keep them as close together as possible, apart from HP manuals, for which I have reserved a special place in my bookeshelf.

There are also some larger cardboard boxes in the garage with bigger stuff like desktop calculators and all the accessries and software packages of my HP-150 personal computer (which itself, together with daisy-wheel printer and flatbed-plotter must also be somewhere in the garage, but I must confess, that I have lost sight some years ago).

Then there are about 50 or so that I really like to use regularly, they are kept in various drawers.

And finally there is pile of maybe 50 calculators below and on top of our dinner table that I have not ctalogued yet (or tried to repair in case of defective ones). Dont talk to my wife about those, however ;-)

Greetings, max


Ah, your wife too complains? Same destiny...

-- Antonio


Ah, your wife too complains? Same destiny...

I think we all share this sad fate!




I think we all share this sad fate!

Well, at times, it can also be funny: Our little son is in his first year at school. Recently, my wife talked to his teacher about his progress, and was told, that he is doing quite well, but curiously a bit reluctant to learn math and he even said to her once: "why should I bother, I can use a calculator any time!".

So my wife had to tell her that her husband has calculators lying everywhere around the house ... and she understood :-)

Greetings, Max

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