Need 15C advice.


After months of reading about the greatness of the 15C, I decided to spend $400 and get a neat new 15C from the local ebay broker.

The calc arrived in perfect condition. No a scratch or blemish anywhere to be found. No dust under the lens. Even the rubber feet look unused. It practically defines "museum" quality, and because of that I put it in a plastic zip loc bag, and have only calculated maybe 10 things on it, without taking the bag off.

I must have some sort of disease.

Anyway, the question for the group is... should I sell it for the 250-350 that it is really worth (I can't imagine ANYONE would be dumb like me and pay $400). Or keep if in my drawer for the next ten-twenty years and hope that the price for “Mint Condition” will at the very least recover my "investment".

I would like to use it, but it is just too darn sexy. At the very, very least, I know think I have a small understanding of what it must have been like when they first came out. Great form factor/great keys.

Pinch yourself, I am crazed... I will keep it, my preciousssss…


Keep it and buy a not so nice one for day to day use. I am in a similar position concerning HP16C's. I have two MINT in box ones. One was sold that way, the other was supposed to be used. I bought the "used" one to actually use, but the seller was quite dishonest and sold me a brand new one (for quite cheap). Buyer beware...


I think I remember seeing that auction!

See, all it takes is one exuberant bidder to create a run-up ;-0 . How long berfore calculators outstrip tulips in value... ;-)

Seriously, if you use your calculator kindly, alway cover it to keep dust out of it, don't eat and drink aroun it, have clean hands etc, and of course don't pound on the keys, then I believe you will have a great machine for use, and collecting---it won't wear out if you are not hard on it.

But here is one question: I bought a nice 11-c, and was amazed to discover that it still had the original factory smell! I couldn't beleive it! You know how smells are the strongest memories. At any rate, I put it in ziplock when not using it to preserve the smell---and amazingly, I can smell it outside the ziplock! That factory smell can permeate LDPE quite easily.

Any super HP geeks know what that factory smell really is?

Best regards,



Since you asked and I say use it. I won't buy anything unless I can use it. If you want to make a profit in the far future I think other investment would serve you better.


Put it away and let it increase in value and get an emulator for your PDA. See

its only $12.99 and looks great on my HP 5550!


aha! you have the 15c emulator.

do you know if it truely emulates the original or is it a re-make (ie reverse engineered). ive yet to see a proper 15c emulator. even most of the 12c emulators are, in fact, logical copies which, incidently, get different answers from a real 12c.

another thing i'd really want (apart from the lemony smell) is a high-speed 15c. that was the one thing i found a drawback to the original model.

best wishes and thanks,


I think you are right, all the Lygea's are logical simulators and in fact they may have additional features.

I also believe that Nelson Sicuro, contributor to this forum, and some other esteemable personalities as well, are working to crack the ROM out of the keep your eyes out!


Yep, I do remember the smell of a new HP. Not just HPs though, I seem to remember the smell with just about any new electronics - mostly from the 80's era. It seemed to permeate the books especially though - and that's part of the reason why I dislike the CD's and the brochures that pass for manuals these days. Limited tactile satisfaction - VERY limited olfactory satisfaction. (*sigh* - I know - I must seek help for "HAS" - HP acquisition syndrome)



I suspect the smell of electronics in general is about the same as "new car" smell.

What you are enjoying are the fumes emitted by all the plastic as it outgasses. It smells even better when it warms up because even MORE gas comes out.

Perhaps you shouldn't breath too deeply, but given all the other crap in the air nowadays, it's probably no worse than whatever you breath most of the time.


Yeah, I know about the outgassing of the plastics, etc. Even so, I still enjoy the new car smell, and I still enjoy the smell of an HP. (But, I also enjoy bacon!)



the 15c is one of my all time favourite calculators. i still use the one i bought over 20 years ago. its battered now, of course :-)

so if you bought this one for 400, you must want it. it seems to me that you have two options. (1) sell it for ~400 and buy a less perfect one. (2) use it. keeping it for an investment might backfire.

in your place, i would use it. but i would acquire a special case for it. the original case on mine has gradually worn the metal face will the many many times it had been used. a hard case or a quality leather case would be cool.

i recently saw an excellent protective leather case for a hp75. does anyone else know the one i mean. it was a true hp case, or did all 75's have one? something designed like that for a voyager would be awesome.

best wishes and good luck,


I would suggest that you preciously keep it, and even use it from time to time, even if it is just to enjoy its sheer engineering quality.

Altough I think you paid it way too much (I bought a really mint one, leatherette case included, for $225 on eBay, and the two HP-15C books for $30), yours will increase in value with time.

To me, it is the same as owning and daily enjoying a $15,000 Krell or Mark Levinson hi-fi system : of course you don't absolutely need it, but isn't life just more beautiful and enjoyable with it?

Just my two cents ;-) Happy calculating !


Use it, though carefully. Maybe keep it in a plastic baggie and use it sparingly, if you prefer, and be careful not to "pound" on the keys. The thing is, it won't last forever. My 11C just mysteriously died one day without any abuse or cause-of-death - it happens. No sense in letting it just sit around waiting to die in its sleep.


Send it to Randy so that it may someday become alive again!


The 11C? I multimetered the traces inside and confirmed the keys were working, but the only response to the "on" key was most of the LCD segments stuck "on" one time, otherwise no response. I'm assuming one of the IC's is shot, since there isn't much else inside. I didn't cut off the 111 plastic rivets that hold the PCB in place to check the LCD connection, though.


I advise you to make sure it is in an anti-static bag with silica gel dessicator.

An ordinary plastc bag may cause static damage, particularly if you are using it in the bag.

Personally, I would not be able to resist using it (carefully!).

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