Was gifted some old HP's today... questions

[tppytel]

I'm a HS math teacher in the States with an interest in old calculating devices. Most of my colleagues are too young to recognize anything older than a TI-30 or TI-83, much less a slide rule. I was puttering around with my 50g at school the other day and showed it to one older colleague - not a hardcore math/engineering guy, but I figured he might be interested nonetheless. He's like... "Yeah, I've got a box of old calculators like that a friend gave me. I'll bring those in for you." Um... sure, OK!

He shows up today with a bag full of calculators and manuals, all in near-pristine condition...

45 + Manual (no charger)
10C + User Manual
15C + User Manual + Advanced Functions Handbook
28C + User Manual + Advanced Functions Handbook + 4 books of examples
48S (dead) + 2 vol User Manual
A few random old TI's and less interesting things

So... score? I told him some of this was fairly valuable, but he was just trying to clean out his closets and keep the stuff out of landfills. The 45 is going to live in my classroom with some of my other display objects for its vintage charm. The 28C I wasn't particularly interested in myself but a quick eBay search indicated that it should be worth something with all those extra manuals included, so I gave those back and told him to eBay them. If anyone here is interested, PM me and I can put you in touch with him.

I've been wanting a small, handy desk calculator for quick calculations that's not just a TI-30, and I think the 10C or 15C will be great there. I generally use my Prime for serious work, but sometimes that's upstairs in my briefcase and I don't feel like fetching it. Clearly the 15C is more powerful but the 10C already does everything I would need for quick calculations. Are there are any other important usability considerations between the 10C and 15C? I'm thinking of selling the 15C and getting a Swiss Micros 15 or 42 clone just to play with and to have more interesting calculators to share with kids.

I could also use a fresh case for the 10C/15C. The bag of HP goodness came with one slipcase that seems original (my stepdad had a 12C with the same case) but the lining is separating from the shell and the shell is deteriorating and leaving dust inside the case. I was looking at this leather slipcase here. Any other suggestions?

[Steve Simpkin]

On the non-working HP-48S, try applying pressure to the metal bezel between the display and top row of keys while trying to turn it on.

[johnb]

(11-22-2022 12:33 AM)tppytel Wrote:  ...
10C + User Manual
15C + User Manual + Advanced Functions Handbook
...

I've been wanting a small, handy desk calculator for quick calculations that's not just a TI-30, and I think the 10C or 15C will be great there. I generally use my Prime for serious work, but sometimes that's upstairs in my briefcase and I don't feel like fetching it. Clearly the 15C is more powerful but the 10C already does everything I would need for quick calculations. Are there are any other important usability considerations between the 10C and 15C? I'm thinking of selling the 15C and getting a Swiss Micros 15 or 42 clone just to play with and to have more interesting calculators to share with kids.
...

That 10c -- while the least powerful of the Voyager series -- may be the most valuable in terms of sales price, due to how few were made. You might want to more deeply investigate those prices versus the 15c if you're thinking of selling.

Interesting you mention keeping one close at hand. Personally, I find that the 11c hits the sweet spot between functionality and ease of use. Both the 11c and 15c have a digit-at-a-time backspace key that the 10c lacks, and if you use any one of this series of calculator a lot, you'll appreciate having it. The 15c can handle complex numbers and small matrices, which the 11c and 10c cannot, but for those, you'll probably prefer using your 50g or your Prime. I find the layout is simply better on the 11c --- but if you told me I could only ever carry either a 10c or a 15c from now on instead of my 11c, I'd definitely pick the 15c, not for the additional power, but for that doggone backspace key!

(The other HP that really hits a sweet spot between functionality and accessibility is the 32sII, but I digress...)


Just my highly opinionated... er... opinion. ;-D

[Dave Britten]

(11-22-2022 04:03 AM)johnb Wrote:  Interesting you mention keeping one close at hand. Personally, I find that the 11c hits the sweet spot between functionality and ease of use. Both the 11c and 15c have a digit-at-a-time backspace key that the 10c lacks, and if you use one any of this series of calculator a lot, you'll appreciate having it. The 15c can handle complex numbers and small matrices, which the 11c and 10c cannot, but for those, you'll probably prefer using your 50g or your Prime. I find the layout is simply better on the 11c --- but if you told me I could only ever carry either a 10c or a 15c from now on instead of my 11c, I'd definitely pick the 15c, not for the additional power, but for that doggone backspace key!

(The other HP that really hits a sweet spot between functionality and accessibility is the 32sII, but I digress...)


Just my highly opinionated... er... opinion. ;-D

I agree, I've always felt like the 11C was HP's most elegant scientific model. Maybe not the most powerful, but it really nails the balance of features, size, performance, power consumption, etc. Also mostly agreed regarding the 32SII, but I think they should have given it at least 2 KB of RAM for it to really shine. It's a great calculator otherwise.

To the OP, regarding the HP 45, you can probably get it working with a fresh set of batteries. Search ebay for "Rechargeable HP Calculator Battery Classic CASE", get a set of Eneloop AAAs and a charger, and there's a good chance you'll be up and running. I have a few of these battery cases for my 45, 80, 55, and 65. The old "Classic" models were relatively bulletproof, so there's a good chance it will work fine once you've got a power source. You might need to open it and clean the key contacts, though (pretty easy to do).

[Thomas Klemm]

(11-22-2022 01:58 PM)Dave Britten Wrote:  I agree, I've always felt like the 11C was HP's most elegant scientific model.

I third this opinion: We had this question before.

[tppytel]

@Steve - Sadly, the 48S got tossed already. It didn't seem rare or valuable enough to be worth troubleshooting and I'm happy just having my 50g at home. If I really wanted a 48 at some point, I'd hunt down a GX. But thanks for the suggestion.

@John - Completed eBay listings for the 10C seem to be about the same as the 15C, ~$200 for a near mint one with the manual.

@Dave - The 45 works. It had some kind of battery pack already installed and I just popped in some AAA's. The wiring looked dodgy and there was some foam padding in there to keep the batteries in place on the contacts, but I figured that's fine for what's mostly just a display piece.

Interesting comments on the 10C vs 11C vs 15C. I'll have to think about that. I do like the simplicity of the 10C for quick calculations - it's not often that I need hyperbolics, matrices, or complex numbers and I'd have the Prime for those. But I see what you're saying about the Backspace. Hmm... I might have to consider a SwissMicros DM11L.

[johnb]

Something else you should consider... don't toss those old HP's! Not even the broken ones!

I think most of us here are interested in preserving as many of these as possible, so they don't disappear off the face of the Earth. Even broken ones are valuable for scavenging for parts. Even if someone won't pay very much for a "bad" or broken one, someone will at least pay shipping (and maybe a small bonus) just to keep these out of the trash bin.

[Mark H. Shin]

Just received the 15C...

This is as pristine it gets! It looks like it was taken out of packaging, and then stored away...

S/N# 2250A00200

If I'm not mistaken... It is a 1982 model (week 50 production; and unit #00200). That's unit# 200 (exactly) produced in 1982, week 50 (December 10-16, 1982; and made in the U.S.A.). That makes it 40 years old next week! And still functioning perfectly, I might add!

How appropriate for this time of year!

Excellent! I'm extremely pleased.

[johnb]

(12-03-2022 02:10 AM)Mark H. Shin Wrote:  Just received the 15C...

This is as pristine it gets! It looks like it was taken out of packaging, and then stored away...

Nothing quite like holding something classic or antique in mint condition!

Did you buy this from @tppytel?

[tppytel]

Yes, the 15C was the one I mentioned above. Mark made a generous offer, so I sold it on behalf of my friend and am passing the funds back to him. I'm keeping the 10C for my own use. I tried to pay my friend for that but he wouldn't accept it - he just asked me to buy our math team kids nicer pizza at their next party.

He still has that 28C if anyone's interested. I know it's not as popular as the Voyagers but it does have two manuals and all four application books, which might be of interest to collectors. We didn't have any N-cells handy to test it out, though.

[johnb]

(12-03-2022 05:00 PM)tppytel Wrote:  Yes, the 15C was the one I mentioned above. Mark made a generous offer, so I sold it on behalf of my friend and am passing the funds back to him. I'm keeping the 10C for my own use. I tried to pay my friend for that but he wouldn't accept it - he just asked me to buy our math team kids nicer pizza at their next party.

Nice! Glad it has gone to someone who will truly appreciate it. And nice to hear that the offer was generous.

(12-03-2022 05:00 PM)tppytel Wrote:  He still has that 28C if anyone's interested. I know it's not as popular as the Voyagers but it does have two manuals and all four application books, which might be of interest to collectors. We didn't have any N-cells handy to test it out, though.

I would normally be interested (I've got a 28S and a 48GX so it would help round out the RPL portion of my collection), but JUST this past week, I had an unexpected major expenditure. (It put the kibosh on getting a nice, gently used 50g!)

Hopefully someone else will step up for the 28c!

Not as capable as the 28s but it was notably the FIRST calculator in the world to be able to handle symbolics. Also, their book-like form factor is just plain cool.