Praise for the HP-34C


I was an undergrad when the HP-34C and the rest of the Spice series were released. I had purchased a 29C about a year earlier, which I was very impressed with, and somehow I thought the spice series calcs looked cheaper than previous HP's. I distinctly remember passing over the new functionality because I thought the build quality had gone to pot at HP. (Strange to think of that now, knowing what HP passes for calculators these days!)

Anyway, I recently obtained one of these from a surplus house, dirty and in unknown operational condition. Happily, it cleaned up pretty well and works perfectly with a rebuilt battery. I've been playing around with it, and I think this must be a really under-rated calculator, at least by me. The solver and integrate functions work very well - not as fast as the most modern calculators, but quite acceptable. It has a ton of nice features, including a factorial function which works with non-integer numbers, so it can be used to compute the gamma function. My 41C can't do that!

It's a lot of fun in a small package, and I wonder if there are other fans of this fine little calculator out there. I perceive that it doesn't get a lot of attention, but I am enjoying mine... and by the way, the build quality seems just great!

best regards,


I really like the 34C too and agree with you that it's somewhat underrated. I've got two of them and the build quality on both is excellent, but that seems to be an exception to the rest of the Spice line. The 34C was the last of that line so perhaps HP had learned enough from the poor reliability of the earlier ones to make the 34C consistently better.

My only complaint is that it's hard to remember the location of all 3 shift functions of each key without looking at them. I suppose that if I stuck to this machine and didn't switch calculators every few days, I'd remember them :)


A 34c was my first HP, at university. I fell in love with it. I knew all four functions of each key, without looking at them. Knowing key codes for each function, and with aid from the led display allowed programming in darkness. My unit was a very early brazilian made. It developed defects from the first construction technique, but HP traded it for a later design. I praise the 34c, but I also felt woodstocks look and feel better.


This was the first scientific calc I learnt to use in 1982. Although I prefer the 15c now, really it's a great calculator.



It is a great calculator, and one of the best LEDs ever made. In some limited side by side testing, it was faster (computational loop, solver) than the 15C by a good 25%.



Of course I'm a great fan of the spice series. My only complaint is that the battery terminals are very weak.


I've got one recently, came in dead. Someone has opened the case playing with the hard plastic backbone and mixed the logic chips up. The battery flexcable has been ripped off also. It's a real pain to make it works again.

But seemed to be a little bit fragile due to the mechanical design on early models. Without a battery pack in place, the battery cover falls off easily and lost.

The HP-34C is a great calculator. However, my favorite still be the HP-25 (not C)- I don't know why.

Thanks to all who helped me to wake the HP-34C up again.



I bought the 34C in 79 to replace my broken 25. ( It was my fault that the 25 went dead). I like it pretty much but after a week I returned for the 41C with full credit.


Just read your praise for the 34C and could not agree more! I had one in the early '80s and loved it. Moved up to a 41c and sold the 34(now with regrets). Recently I've come across two "dead" 34Cs and have managed to make one fully functional again ( by swapping out keypads, cleaning contacts and making a new battery pack.) I'm proud of myself for being able to sucessfully perform such delicate surgery! I even have a manual with I bought from a local calculator store. However, I need a charger for it. Anyone know where I can get one for a reasonable price ($25 or less)?


Chargers show up regularly on Ebay. Finding one for $25 or less should not be a problem.

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