HP-15c: Why so popular?

[Peter Klein]

Pardon me if I question Doctrine here ;-). I’m curious why the 15c is so popular. Don’t get me wrong, it’s a very nice machine. HP managed to cram maximum possible goodness into a limited but lovely, elegant, durable package with a beautifully readable display. And I used an 11c as my daily driver for a dozen years, so I have some idea of how it feels. *

But the 42s is much more easily usable for complex numbers and matrices. Solving equations and programming is much easier on the 32s, 32sii and 42s. And then there’s the equation list, which the 32sii and its red-headed stepchildren the 33s and 35s do and the 15c doesn’t.

So, in 25 words or more, tell us, “Why I love my 15c, despite all that’s come after it.”

* My opinion may be colored by the fact that my hands are too big to comfortably “touch type” numbers on a Voyager.

[vaklaff]

Without taking sides and just looking logically, the answer as already in your question, isn't? If one doesn't need the post-Voyager features then it all goes down to "lovely, elegant, durable package with a beautifully readable display". Your words, sir :-)

[John Garza (3665)]

Oh... there are SO many variables to this equation.

Personally, I dislike LCD displays.
And programmables without mass storage.
( continuous memory is not an effective substitute for those who write a lot of programs )
Though I have a 15C simply for the collections sake.

-J

[JanS]

Also, the golden ratio as discussed here https://www.hpmuseum.org/cgi-sys/cgiwrap...read=71057 - but that holds true for all the v'gers

[John Garza (3665)]

Yes, everyone in industrial design (and architecture) learns about the golden ratio in college.
I'm sure the HP designers of the earlier machines knew of it as well.

But other factors came into play for pre-Voyager machines.
Like the requirement to be hand held.
Which resulted in the vertical 2:1 ratio we see in Classics and Woodstocks.
Voyagers are desk top machines ideally.

-J

[Maximilian Hohmann]

Hello!

(10-26-2023 08:27 AM)Peter Klein Wrote:  I’m curious why the 15c is so popular.

Is it really so popular? As far as I am concerned, the first one I ever saw was the one I bought on eBay for my collection maybe in 2005. At school, university and work I saw colleagues and coworkers use all brands and kinds of calculators, but really never a 15C, or any other of the Voyager series. Back when one could still find calculators at flea markets - this used to be my main source for many years - I managed to get exactly one, an HP-11C, from this series. Nothing else.
So around here Germany/Europe the HP-15C was never a popular calculator. I guess, as usual with HP products from that era, because it cost two or three times as much as similar products from the competition. The high prices that Voyager series calculators, with the exception of the 12C, fetch on places like eBay reflect their relative rarity and lack of popularity...

Personally I agree with John Garza: I don't like LCD displays and for a handheld thing, which in my eyes a pocket calculator should be, the landscape layout is not ideal. Therefore I will never "love" an HP-15C ;-)

Yes, the 15C has an incredible amount of functionality crammed into such a small unit - and I admire it's designers for that - but this is about it. The functions are mainly impractical and counter-intuitive to use (e.g. my trusted old Ti59 has a much better way for entering and editing matrices) and therefore prbably don't really get used by many people in real life. Sometimes less is more and as a matter of fact, I have an 11C lying on my desk next to my computer and not a 15C.

Regards
Max

[ebs]

I confirm that in Europe was/is not popular, even I would say that the entire HP line of calculators isn't either, I have never seen an HP calculator in the school, college, nor in work places. And I have never, never seen an HP-12C used by financial people (or any other people) in the past or present. Here Casio is the king. I have only seen very low end HP models in physical shops, not even the Prime.

That said, I think that "popular" in this context could be read as "popular in the HP calculator community" and I think that if we are talking about the HP15C so much now is because from time to time HP launches a limited or collection edition and that raises the hype around it.

[OlidaBel]

naïve answers:
- beautiful looking, the colors (black, white yellow, blue)
- small in hands and nice form factor
- LCD screen segments are clear
- all functions on the keyboard
- nostalgia (first HP years on 11c and 15c)
- keyboard feeling
- the "running" ;-)

[Maximilian Hohmann]

Hello!

(10-26-2023 11:51 AM)ebs Wrote:  That said, I think that "popular" in this context could be read as "popular in the HP calculator community" and I think that if we are talking about the HP15C so much now is because from time to time HP launches a limited or collection edition and that raises the hype around it.

Certainly! But they didn't choose the 15C as the base model for deriving special editions from it because of it's popularity among collectors and afficionados. But because the 12C is still in production and all they have to do is to print 10.000 different faceplates and flash 10.000 procesors with a different firmware.

My impression is, that the 41C, 42S, 71B or the HP-25 are much more popular around here than the 15C ever was. But making a collectors edition for any of these models, as much as we would like to see one!, would mean to recreate the entire production line from scratch.

Regards
Max

[Johnh]

Well I think our hp15c 's are appreciated due to their classic status, and the timeless and very functional design of what they do best. That's the basic functionality with a very clear simple display, outstandingly clear tactile buttons and a lot of functionality. The human stories of those engineers and scientists who created it, and those who used it to work on the world's greatest endeavours all add to the legend.

You don't have to use everything it can do to make it worthwhile. The basic number crunching, with some programming, plus 'solve' and 'integrate' are all useful for me.

So many later models add lots more capability. But they also get complex and harder to read and that detracts from the basics.

That being said, I like my hp35S too. It's a worthy descendent and it adds some very useful things, but its not quite as good in its own time as the hp15C was in its time.

[rawi]

Peter Klein wrote:

Quote:I’m curious why the 15c is so popular.

I love that machine and in my case it is nostalgia and the effectivity with which I can use it.

My first HP calculator when being a student was a HP 33E, rather powerful, excellent manuals, really nice, but with just 49 programming steps and without constant memory...

My next one was the HP 34C. What an advantage! More programming space, more registers, constant memory and something no other handheld machine had: Solve- and integrate-functionality. It was so easy to use (e.g. exactness of integration just by setting the display format) and worked very reliable! No tables of statistical distribution needed any more! I used it heavily, perhaps too heavily. After about three years it was broken.

At that time I was no longer student but an assistant at a university chair for statistics. As a university employee I had access to a mainframe computer and as well to a PC. But I had to share these with many colleages, so access was limited. Furthermore there were no packages that could easily be used for integrating, for matrix computation etc. You had to write your own routines, by then in Fortran, to get the job done.

I replaced the broken HP 34C with a HP 15C. What a progress! So much registers! So much programming space! So much functionality! And it had again the solve and integrate functionality and additionally matrix functionality (complex numbers I did not need). There it was ahead even of the HP 41 family, which was much more expensive (at that time there was no advantage module yet). I had to prepare little exercises for students. All could be computed within seconds without going to a computer. I loved the display. Very easy to read, and energy saving, so there was no clumsy power supply needed. And the machine itself was very small and light-weighted. I used it heavily. Batteries were very long lasting. For me it was the feeling of having arrived at the ideal machine.

Yes, there was a learning curve. But there was an excellent manual as well, that helped a lot and was fun reading. Yes, the display information when programming was something you had to get used to. But after some weeks I knew that 43 32 meant g RTN. So in the daily usage those problems soon disappeared.

Perhaps nowadays many collectors can't understand how easy the handling got after some weeks of daily usage. If you switch all the time between different calculators of your collection you cannot get that familiarity I had (and still have after more than 30 years using other machines, because this one got broken as well after six years or so).

Best

Raimund

[Dave Britten]

I think the 15C just hits the sweet spot of size, convenience, durability, elegance, and capability for a lot of people. It was also the first really affordable option for a device that can solve, integrate, do matrices, and do complex numbers, so I'm sure there's a lot of primacy bias and nostalgia from the early adopters too. It's true that the Pioneers are considerably more powerful, the 42S in particular can do anything the 15C does but better. But the 42S screen visibility is quite frankly crap compared to the nice bold segmented display of the Voyagers. Even the 32SII, while much easier to read than the 42S, doesn't quite stack up to the Voyager LCD. So it makes a nice calculator to keep on the desk for quick problem solving (though the 11C or 12C do just as well in this regard). The Voyagers are also considerably more durable than the Pioneers (which are certainly no slouch themselves).

[Massimo Gnerucci]

(10-26-2023 12:06 PM)Maximilian Hohmann Wrote:  My impression is, that the 41C, 42S, 71B or the HP-25 are much more popular around here than the 15C ever was. But making a collectors edition for any of these models, as much as we would like to see one!, would mean to recreate the entire production line from scratch.

Make it so!

[ctrclckws]

In my case, fond memories of my first HP.
A 15C, purchased in the 80's new, during or just after undergraduate school.

Later on, when my needs were more financial, got a 12C.

Both of those original calcs disappeared due to life events.
Had never heard of the 10c, 11c, or 16c until I started looking at sites like this. Could have used the 16C for some classes and work, but had not heard of it.

The 12C was replaced, and I have several of the variants.
The 15C was replaced from TAS, and now the CE.
And just because, I have a complete set of Voyagers now.

Relatively easy to use, a nice size, very long battery life, nostalgia, are my reasons

[carey]

As a young college prof in the early 80's, our college offered each faculty member an office computing choice: either a deeply discounted IBM PC jr or an HP15c. I was the only one who chose the 15c.

For me, the clincher was the HP15c Advanced Functions Handbook's two sections on Contour Integrals and Complex Potentials with a fluid streamlines example. I still recall the sense of exhilaration in knowing that in the palm of my hands I held a tool that could (numerically) solve such "complex" problems!

[KeithB]

(10-26-2023 02:37 PM)carey Wrote:  As a young college prof in the early 80's, our college offered each faculty member an office computing choice: either a deeply discounted IBM PC jr or an HP15c. I was the only one who chose the 15c.

You clearly got the better end of the deal!

[Jlouis]

For those who says it was not so popular, I must remember you that the HP 15C was reissued two times, since its ended production in 1989, the first time with a petition for HP with thousands signatures. If it's not popularity, you name it.

Tell me another calculator that did this.

As for the reason for its success, among others already mentioned here, the landscape form factor is very important. By the way, the popularity of the 12C is not coincidence too.

Cheers

JL

[Jlouis]

(10-26-2023 11:58 AM)OlidaBel Wrote:  naïve answers:
- beautiful looking, the colors (black, white yellow, blue)
- small in hands and nice form factor
- LCD screen segments are clear
- all functions on the keyboard
- nostalgia (first HP years on 11c and 15c)
- keyboard feeling
- the "running" ;-)

Yes, very true

[BillBee]

Like others, I picked one up when starting engineering in college in the mid 80s and became a RPN believer. Powerful, compact and tough.
-Bill

[floppy]

Since I started with HP41 and due to prog storage outside the calculator, no way for me to go into HP15 (I had one 2-3 years ago, resold it immediatly). I suppose this is something non explicable ;-)
Perhaps it would have been different if I started direct with an HP15.