HP-34C Excitement


I recently picked up an HP-34C from TAS, believed unworking. I wanted at least one Spice in my HP collection (I like the Classics the most, any LED HP next, then the HP-41C, and recently enjoying a bargain HP-50G). When I received the 34C it was in overall good condition, but with a lot of tape residue on back. Battery contacts and bay in very good condition. Keyboard EXCELLENT - I had read the 34C keyboards could be really good, this one is like the best Classics, no rattle. Some white wear marks (?) around power switch, but otherwise clean. I was VERY doubtful that it would work, but I popped in a couple of alkalines and a paper clip to connect the cells, and I nearly fell off my seat when it powered up and worked PERFECTLY!! I am overjoyed! Everything seems to work wonderfully, and I'm really liking this little machine - based on combination of features (LEDS!, Continuous Memory, lots of keyboard functions, compact) I think it might become one of my favorites! Who knew??!! I'm going to give it a good cleaning, a battery pack and put it to daily use!


Hi, Mark;

I got my HP34C some years ago, and I use it whenever I have the chance to. Today I bought a 'spare box', an HP34C that seems to be a good spare parts supplier. It cost me R$88 (about US$45,00 I guess) and it is not in good shape. Now I think I can keep the first one, in very good condition, for as long as I can.

Good machines, these HP34C´s.


Luiz (Brazil)


Yup, the 34c was one of the better models made. Always worked great for me, even up to today.

It is/was one of my favorite machines in that generation.

(I started with 25->25c->34c->19c...)




Will you enjoy yours as much as Norm did his? KeR blIPPTY blippITY BLIP BLIP. I am envious!

Of my two Spices, the 32E and 33E, the 32E is my favourite and is a much more practical scientific/statistical analysis tool. The lack of continuous memory in the 33E makes it my least preferred calculator.

Norm's Memories of Cheerleaders

Jeff Kearns


As a scientist, I'm not convinced that using an HP-34C is better than sex, at least generally. But it is my opinion, with a reasonable degree of medical certainty (important legal phrasing), that people who experience the joy of using a 34C also experience greater pleasure in many other activities as well. This, of course, would be best confirmed with industry sponsored, prospective, randomized trials. Perhaps a grant proposal to HP might be in order, but now that the 34C is no longer marketed, they probably wouldn't be interested. Too bad... it would be a great advertising campaign.

"New study proves that using an HP-34C improves your sex life..."



Freud might have believed Norm was saying that a 34c is better than the expandable version of the HP-48. If so; what would he have believed he has just learned about you? Never mind. Freud would have used AOS. Now Jung; he would have been an RPL man.

Me; i like my 34c, it's red LEDs, and solve function - but it has no interface port. -db


Don't CMOS circuits operate gates using a "Tunnel Effect"? Freud would like that!


Ha! I'm not sure I'll enjoy it THAT much, but it's close! I've had a whole day with it now, and I do like it a lot. Wrote some simple programs, love the "A" and "B" keys!

Two questions for the experts:

1. The wear around the ON/OFF key shows WHITE, which is unlike any other HP calc I've cleaned up? Doesn't look like it will clean off, more like this is exposing light color underneath? Any ideas if this is fixable? It's the only wear showing, happily.

2. Once in a while (like 1/20) I get an "Error 9" when I do a STO-ENTER self test (the rest of the time I get all the -888888s). This will persist until I turn the calc off, when turn on it will pass self test again. Program and register contents don't seem to be affected? Any ideas?

Cheers, 34C lovers!


I know that with the Woodstocks, trying to clean the plastic with alcohol can cause whitish areas. I've had great luck with "Armor-All" vinyl conditioner. Rub a cloth lightly saturated with the stuff on the whitish areas. It might take a bit of time, but it should fix it. Then use a dry cloth to remove most of the Armor-All and buff it up. You can apply this lightly to clean the entire calculator. It's been discussed here previously. I've never seen it do any harm, even years after the application. I use it to polish up every calculator I restore.


Hi, Mark;

about the first question, I have an HP33E 'carcass' that has the white 'back' around the ON/OFF switch as well. I believe the keyboard faceplate is of some sort of white plastic (acetate?), it is not made of aluminum, as we see in other calculators.

The 'Error 9' tells me that your unit is one of the 'solderless' type, i.e., the IC´s are not soldered in a 'regular' PCB, instead they are 'sandwiched' pressed over a flexible PCB. Hence, some (or one) of the chips may be with a bad contact. Chances are that you may have a soldered unit with cold (broken) soldering, but I´d bet the first possibility.

I´m not an expert, and I actually love the HP calculators, but I still prefer a good female company, and, if all´s well, good s*x... 8^D


Luiz (Brazil)

Edited: 22 May 2010, 6:02 p.m.

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