The HP-35

[gioscarab]

I think the article misses that the HP 9100A was developed after HP acquired the patent of Olivetti Programma 101 and its italian r&d electronics laboratory. Programma 101 was the first personal computer ever made and the first to actually fit on a desktop. It was also the first to use the magnetic card that was able to read and save programs, the precursor of cassettes and floppy disks or the first memory format based on "magnetic paint". The patents and the laboratory sold to HP were fundamental to fuel the revolution of the following years and to make the HP 9100A. Italians won that race at the time, more than a decade before Gates and Jobs. I had the luck to become friend of one of the engineers of the machine, Gastone Garziera, his funniest quote when he finishes to describe his masterpiece is "Very very easy, as americans say".

[ChickeNES]

> Programma 101 was the first personal computer ever made and the first to actually fit on a desktop.

It's not, the Mathatronics Mathatron was sold nearly a year before the Programma 101: https://www.oldcalculatormuseum.com/c-math8-48m.html

[pinewurst]

That’s not at all true. The 9100A was a descendant of a prototype developed by Tom Osborne in 1964. There was a later lawsuit from Olivetti that certain features (especially the mag card) overlapped their 1965 P101 patents, which was settled for ~$900K. No insult to Olivetti’s great achievements but this was hardly cause and effect.

[TheOtherHobbes]

Magnetic cards appeared in later HP calculators - starting with the HP-65 - and were copied by TI.

These calculators look a bit clunky and retro today compared to modern phones, but they were unbelievably futuristic in the mid-70s.

The idea that you could have a programmable microcomputer in your pocket which could load applications from plastic cards was jaw-dropping.

[kensai]

Is it known why was it sold? Why couldn't the Olivetti team capitalize on such a formidable invention itself?

[goatinaboat]

What is great about this story is the way that Hewlett, an engineer himself, was able to use his intuition to achieve product-market fit, you cannot imagine an MBA who came up through the finance department having his sort of insight, he would never had taken on that risk in 1971.

There is a modern reboot of this, the HP-35s, LCD display but the same curved case.

[microtherion]

Several details of this story stuck out to me:

An engineer who lives across the street from the CEO and carpools with him. Not so common anymore, though I seem to recall that Java started with an engineer who played hockey with Scott McNealy.

The CEO having a consulting company do a market survey and the deciding "ah, whatever, I want one of these, let's go ahead".

I think especially the latter story seems typical for Hewlett, in that he was neither a by-the-book corporate drone, nor an utterly reckless damn-the-torpedoes type, but somebody who was willing to trust his instincts and take calculated risks at times.

[EarthIsHome]

I have the HP-35s. I really like it, but the batteries die in around 2 years even if you don't use it. Other than that, it's a really fun, tactile calculator that I find myself pulling out for simple calculations.

Here's a bug list tracker: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.c...

[abhinav22]

I would have to respectfully disagree. I think this can come across as stereotypical, and it may play well to an audience of engineers, scientists and programmers.

Individuals themselves possess brilliance, there are good MBAs as much as there are bad MBAs and the same for STEM professionals.

Rather we should say Hewlett had exceptional insight at the time, vs. attributing it to his upbringing and then making a sweeping statement on MBAs coming through a finance department.

[hpcjoe]

I loved my HP calculators. I used them in college in the 80s, and grad school in the early 90s. Mostly HP15, 41, and 42. My last 42 is sitting in a drawer nearby, with a relatively fresh battery, and it works well.

I recall writing "programs" that performed some of the calcs I needed in the physics curriculum. I also recall being amused that I could calculate 1/3 (or 1/7) and add it to itself until I got (nearly) 1. From there this led me to study what fixed and floating point were, and think about the implications for the code I was writing (precision, truncation/roundoff error, etc.) to do longer calcs.

This eventually led me to skipping a postdoc, and working in the high performance computing industry. Where I am today.

They were/are awesome tools.

[dhimes]

I have the hp 41 cv app on my iPhone and it's fantastic. I paid once many years ago and have never been asked to pay again. A great group of enthusiasts keep it going.

That said, I've had recent occasion to do some programming for celestial navigation on a handheld- and the TI is a lot easier to use for that.

[idatum]

I credit the HP-41CV I had in in high school for growing my interest in programming. Through college it was an HP-48G. My father-in-law recognized my love for these devices later by giving me his old HP-35, complete with manuals and a couple accessories.

One of the more interesting accessories was his special HP-35 hardcore looking security lock. You would securely bolt the base of the lock to your desk, place the HP-35 inside, and connect and lock the cover with a key. Precious device back then!

[madengr]

I had a Radio Shack scientific calculator about that same timeframe. It was stolen during a lab. I then bought a 32Sii. Just wanted to thank the thief, as I likely never would have been a lifelong RPN user.

[todd8]

HP calculators were great. I’ve owned several of the postfix based ones. (I.e. one enters 12, 30, + instead of 12 + 30)

The article may not make it clear how many efforts were going on in that timeframe to manufacture calculators. The first electronic calculator I saw at MIT was a desktop system by Wang; it had a Nixie tube display, see [1,2,3].

The first handheld calculator I ever came into contact with was in 1971 when I saw a student with a Bowmar Brain.

[1] https://peoplaid.com/2020/08/12/the-story-of-an-wang-develop...

[2] https://en.m.wikipedia.org/wiki/Wang_Laboratories

[3] https://en.m.wikipedia.org/wiki/Nixie_tube

[4] http://www.vintagecalculators.com/html/bowmar_calculators.ht...

[sllabres]

"postfix based" == RPN (reverse polish notation)

https://en.wikipedia.org/wiki/Reverse_Polish_notation

If one wants to try out on an android mobile go to:

https://play.google.com/store/apps/details?id=org.ab.x48

or

https://play.google.com/store/apps/details?id=org.emulator.f...

[ghaff]

One interesting thought that occurs to me is that a mid-1970s vintage HP-35 would still be a perfectly good calculator for a typical engineer. (Leaving aside battery life because of the LED display.) That's not true of a lot of electronics of the era, especially any digital electronics.

(Amps etc. would be another example if you stick to purely analog inputs, but that's not digital.)

[GeorgeTirebiter]

If you just loved the HP-35, try http://culver.net/hp35

I did NOT write this code; but you might want to View Source to see the JS that implements it, as it's clean, lean, and easy to understand.

[ncmncm]

Not strictly on topic, but...

Right about the time IBM came up with their PC-AT (16-bit 80286, 10MB hard disk, yes: MB) HP came out with their version, same price, same specs, name started with a "V".

Over the course of the following year, each and every hard disk in every PC-AT failed. IF and ONLY IF you had paid $200 extra for a service contract (about the price of the drive) then, WHEN it failed, you could pack up and drive your PC-AT to whichever city had the nearest IBM service office, and they would replace the disk while you waited. Sorry about your data.

The HPs came with disk drives that didn't fail.

Guess which company ended up with the better reputation -- for "excellent service".

It is said the failed drives (made by Conner, IIRC) became an artificial reef offshore of Boca Raton.

[throw0101a]

I find it amusing that one of the sections has "Electronic slide rule" in the title. I guess that was the reference mark to beat at the time.

The YouTube channel of "Professor Herning" has some good videos if one is curious on slide rules:

* https://www.youtube.com/c/ProfessorHerning/videos

Both their use:

* https://www.youtube.com/c/ProfessorHerning/playlists

and comparisons between different models. There's a still lively trade for them on eBay that seems to go on for aficionados and the curious.

[apricot]

Most buyers of early scientific calculators bought them to replace their slide rule. Early TI calculators had model numbers of SR-xx, which stood for "slide rule".

[bitminer]

I remember pestering my father for one back in 1973.

He managed to get a demonstrator from the local office of HP, for iirc CAD$695, which was a lot of money in those days.

I would push a few number keys and the log button, and, like magic, 10 significant figures. Beyond magic.

The other mystery was this: on the label at the bottom on the reverse side, it said "Made in Singapore".

To me, in the early 1970s Canada, that was as mysterious a place as you could imagine.

(I'm sure it was assembled there, not manufactured, but still.)

[gyc]

My dad bought one as a student at Stanford at the time and he passed it down to me for use in high school >20 years later. An amazing piece of technology.

[idatum]

Related to this history is how calculators used CORDIC, COordinate Rotation DIgital Computer, to compute trigonometric functions in real time with minimal hardware. CORDIC was originally developed by Jack Volder working at Convair corporation in 1959.

Here is a nice explanation (PDF): https://www.qc.cuny.edu/Academics/Degrees/DMNS/Faculty%20Doc...

EDIT: in the HP-35 article it is mentioned in section III. The PDF here goes in to the math and implementation of CORDIC.

[JohnJamesRambo]

> HP typically priced their equipment at the cost of the material list × π (or in an especially competitive market, list × e)

Were they just being cute or is there some mathematical basis to these numbers being used to price things?

[nemo44x]

I’m not sure but it seems irrational.

[ImaCake]

I suppose it would make the math of calculating profits a bit easier in a age with much less fancy calculating equipment. Especially if sales were distributed exponentially or normally with respect to some variable like time or location.

[pzone]

Just being cute.

[tibbydudeza]

Their calculators was awesome and later bought only HP computers and printers but then things changed not for the better sadly.

[abhinav22]

If you have an iphone, try out this awesome, free RPN calculator.

Link:

https://apps.apple.com/ae/app/rpn-30/id1451413517

Reviews:

https://appgrooves.com/ios/1451413517/rpn-30/ashok-khanna/po...

Note: I am the Author, but this is not spammy, I already have 10,000 users and don’t charge for it anyway :)

[mongol]

Where did HP step out of the path that changed their reputation? Was there a crucial decision where they made the "wrong choice"?

[throw0101a]

Meta: perhaps add (2015/2018) to the title?