The HP12C, a buyer's guide


Hi everyone!

I was hoping that someone out there could help me to understand something. Over the past few weeks, I have purchased three 12Cs on eBay. My goal is to find one that is in nice shape, then I'll sell the others (it's funny...I guess one person's description of "mint" isn't the same as mine!!!)

At first, I was just going to buy one of the new, sealed ones from a dealer, but then I read an article in this message board that said that the new ones aren't as well made as the older ones...I also read articles mentioning that newer ones have 1x3.3V cell vs 3x1.5V cells, and another article that discussed the # of ICs...

Can anyone out there describe the various "varities" of 12C, when they were manufactured and how you can identify them? Also, are there any performance differences between them?

Ideally, I'd like to find a nice, mint 12C that's one of the "good old" ones. Unfortunately, I don't know how to tell!



I purchased a new made-in-China HP 12C at Staples, and it is just fine. However, I had to return two before I got this one on the third try. The first two had serious defects in their key action. But Staples is gracious in accepting returns within 30 days.

I had a similar experience buying a slightly older made-in-Malaysia HP 12C on clearance at WalMart. The first one had a slight defect in the action of two keys, but the second one is excellent. Again, WalMart was good about exchanging.

Statistics can do funny things, and it is possible that 99.9% of the new HP 12C's have perfect key action even though 3 out of 5 in my experience were imperfect. But personally I would be hesitant to buy a new HP 12C from anyone who did not provide easy exchange in case of defect.

So far as I can see, the two that I am left with are of very high quality, perhaps almost as good as my 1982 made-in-USA HP 15C. Or maybe I am getting carried away ...


Thanks Tom!

What sort of defects did you have in the calcs? Did the keys not function at all? Did they fail the keyboard test?

3 out of 5, not very good odds I must say, but I'm glad that you found two that function perfectly!



Yes, indeed, it's difficult to find a correct 12C.

I own several of these. I purchased one here on a local auction side that I paid $15 I think. It's a 86 USA made and though it has several scratches it's really solid and works perfectly. I'm using it on a daily basis.

I purchased one 2 years ago on ebay, when the 12C were far less popular, to a PhD. Advertised as mint, I was delighted to see that it had never been used and was very complete in its box, with the pink foam protect slip. Only the box whowed shelf wear.

I do have several other 12c's NIB -unopened that are malaysian made, and these are far worse than my 2 other US mades. Though they are mint, the plastic is not as glossy and the key response seem far softer. I don't like the touch feeling of these, but at least I do have some stock should my other 12c fall apart... or should they reach "leoglyph's " prices on ebay !



I didn't get as far as trying an official keyboard test. In fact, I would have to consult the manual to know what that is!

In the first Chinese calc, when I pressed the zero key I could get anywhere from no zeros to four or five depending on how I pressed the key -- or perhaps depending, from all I could tell, on which way the wind was blowing.

In the second Chinese calc, two other number keys gave trouble; I believe one of them was a seven, I forget the other. It was not quite as bad as the first.

As you may guess, by this time I was trying all keys of a new calc for function -- many times -- before accepting it. I would enter a succession of zeros, then ones, etc., clearing the display as necessary before continuing.

In the first Malaysian unit, the trouble was with the blue "g" shift key and the RCL key. If I were not watching the display as I worked, I could feel the key click, but not necessarily have the function work, which caused me consternation in writing programs. The unit was workable, but not really acceptable -- at least from HP. When a prefix key of this sort is pressed, the display will blink when the key is effective; I could press the key, feel the spring, but have no response from the display, and find out that the g-shift or RCL function had not worked. Press the key a different way, and everything would work -- but there was not a reliable relationship between the spring feel and the working.

When I think back to my slide-rule days, to log and trig tables, etc., I can wonder at how spoiled I have become. Think what Ptolemy or Kepler could have done with any of the calculators that I took back! (though they would have preferred one with trig functions!) I would have given most anything in the 1950's to have had that lousy calc with the mis-firing zeros! But Hewlett Packard has led us to expect perfection, and we are disappointed when we no longer find it at first try.


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