The HP-35: Consumer Electronics, an Origin Story (opens in new tab)

An anecdote about the HP-35, from the HP Museum (http://www.hpmuseum.org/hp35.htm):

> The HP-35 had numerical algorithms that exceeded the precision of most mainframe computers at the time. [...] This forced time-consuming manual comparisons of results to mathematical tables. A few bugs got through this process. For example: 2.02 ln e^x resulted in 2 rather than 2.02. When the bug was discovered, HP had already sold 25,000 units which was a huge volume for the company. In a meeting, Dave Packard asked what they were going to do about the units already in the field and someone in the crowd said "Don't tell?" At this Packard's pencil snapped and he said: "Who said that? We're going to tell everyone and offer them, a replacement. It would be better to never make a dime of profit than to have a product out there with a problem". It turns out that less than a quarter of the units were returned. Most people preferred to keep their buggy calculator and the notice from HP offering the replacement.

And here is a scan of that recall notice: https://imgur.com/K1k0cSQ (original source: http://www.hpmuseum.org/forum/thread-2821.html)

Unfortunately, consumer electronics are not the same as the days of Braun. 70’s was the golden era.

I was extremely pleased with my DM42 from SwissMicros. All of their models either have a Titanium or Steel case. The heft and quality is just absolutely beautiful.

I spoke to Michael Steinmann and he seems to be a great guy passionate about what he does. I enjoyed our conversation about old school electronics.

Check out https://SwissMicros.com

How can you not love this:

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

It really is hard to over state the impact that scientific calculators had on industry. My great uncle who was an engineer at the Panama Canal company had log tables, these were tables of logarithmic values given a number, and the inverse. He needed the heavy tome because he couldn't get enough digits of precision out of his slide rule. He was one of those people who immediately bought an HP-35 when it came out and was thrilled.

My parents bought me the TI SR-52 when it came out and it was the coolest thing I could imagine. I wore the numbers off the keycaps on that thing.

I really really like HP calculators. The only one I have now is the HP-35s, a new version of HP-35.

Once you go RPN, you can never go back! I have PCalc (another piece of amazing software) on my phone for RPN.

It feels really stupid for others to see that I can't operate a normal calculator.

Some of these comments are "my first HP".

I bought an HP-28C in when I graduated from high school using my own money. It was $235 which was a lot of money for me. My parents thought I was crazy. I later upgraded to the 28S followed by the 48sx.

At college, I would enter and win the "Calculator Olympics". They would give you these super complicated algebraic expressions to evaluate. The TI people would lose track of all the parentheses and the older HPs would exceed the 4-level stack.

I was amused a couple years ago to discover many of my old programs are still preserved on the internet: https://www.hpcalc.org/authors/166 POLY was hugely popular at the time. I just wrote it to simplify my classwork.

While I am definitely fond of the HP-35 in a nostalgic sense, my real-life working calculator was the HP-48GX when I became a land surveyor. I added a COGO card that would calculate pavement design, storm water pipe modelling, and the area of a polygon after the coordinates of each point were given. And away I went. There wasn't much I couldn't do with that, graphing or calc-wise. Made my job so much easier in the field.

When they killed the HP-48GX, and replaced it with inferior models, it was a dark day in land surveying.

I bought a HP-42S in West Germany in 1989, my first trip to the West when I was 14 (I was Hungarian at the time, now that's fixed, I am Canadian). Oh the memories.

Later, 1995, I got a HP 48G via Usenet (eBay opened the month when it arrived from the USA so it's not like I could've bought it there). A friend of mine have soldered four 128K SRAMs in there, stacked, with most legs just ran together vertically with the few data legs separated. Dave Arnett himself told us it's possible to change a G into a GX... https://groups.google.com/d/msg/comp.sys.hp48/CS0lTpKkBHw/vn...

I still have it although I do not use it, it's one of the very few things I carried over when I immigrated.

Ps. Isn't the Internet fantastic? The easy communication with people you'd never be able to connect with otherwise and the astonishing archives allowing me to dig this 23 year old conversation up with ease.

A neighbor gave us one when he moved up to an HP-25 (lower number, but a later and better calculator). I used it in college. I remember running across campus on my way to a chemistry test, playing catch with my calculator (in the padded case) as I ran. I had confidence that, even if I dropped it, it would still work.

Amazing. I got a HP30s in 2003 as it was the only calculator approved by the university. Everybody I knew hated every single aspect of it. The arrow button was soft and imprecise, leading to long calculations being deleted by accident. The display was too short for longer expressions (compared to the competition). The display scratched easily. The buttons were round and didn’t give good tactical feedback. My jaw dropped when I started working in industry and people would guard jealously their ancient HP calculators with nice clicky buttons and crisp display.

HP has come a long way - down.

I'm in the age group that spans the end of the slide rule with the beginnings of calculators and personal computers. As a high school senior, trigonometry was the highest math class and we learned to use the slide rule in it. I still have the one my dad bought me for my birthday that year. In college freshman calculus, I remember one guy brought his HP-35 to class and everyone else being awed and amazed by it, including the professor. It was too expensive for me but I was able to buy a TI-50 the next year. Functional but it wasn't an HP.

I love this:

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

What an interesting story. My dad had an HP-35 that he used as a grad student at Stanford in the 70s, and he handed it down to me decades later for me to use in my high school math classes.

> HP’s own LEDs [...] the calculator needed 15 of them

> Osborne was able to get the price down to a dollar each

> HP typically priced their equipment at the cost of the material list × π [...] the LED display around 20 dollars

uh?

When I was growing up in the early 80s, my engineer father had an HP-35 that he adored. He ultimately added an HP-12c, too, and when I was in middle school I was gifted an HP-32sii. I was the only weirdo using RPN. :) I upgraded to an HP-48g in high school when everyone else was using Ti-82.

I can't really think of any other company or product line I've had such a longstanding relationship with. FWIW, I still have both of my HP calculators and they work great!

Oh, how I love old HP calculators. My HP 28s is 30 years old and still working great. - I learned programming in a Forth like language (stack based) with it. And it inspired me to learn Scheme and the Mathematica language. Love it. Although these days I rather use a version for my iPhone (HCalc)

wow... what an amazing article. Few interesting bits...

- HP was offering so many products that it took a four-pound, nearly 600-page catalog to describe them all.

- In what has to be one of the most famous design briefs in electronics history, Bill Hewlett asked Osborne and Cochran to shrink the 9100. “I want it to be a tenth of the volume, ten times as fast and cost a tenth as much.”

- At the time it seemed like an impossible request, but Hewlett didn’t let the idea go. Cochran, who for a time lived across the street from Hewlett, would occasionally give him a ride to work.

- It soon became clear that the entire project was going to cost around a million dollars.

- Stanford Research Institute did market survey and their conclusion was clear: “we don’t recommend that you go ahead with this.”

- Hewlett, despite the SRI report, decided he wanted one and thought his engineers should have one as well.

- For the log and exponential functions they used pseudo division and multiplication algorithms from Briggs’ 1624 Arithmetica Logarithmica. For the transcendental functions they used Volder’s CORDIC algorithm, originally developed for B-58 navigation.

- It took them more than a little finessing to fit everything into the 5140 bits (or 0.6 K).

- First industrial design featuring angled the display, a textured case, rubber feet serve as battery compartment latches.

- The entire project took 14 months, half of HP’s typical design cycle.

- Hewlett said the name would be the HP-35, after the device’s 35 keys. HP’s computerized inventory system only recognized four-digit names

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

- “We [had to worry about] sales per square foot on the first floor of Macy’s, vs. the second floor.”

- HP-35 “[was] something only fictional heroes like James Bond, Walter Mitty or Dick Tracy are supposed to own,” a device that Captain Kirk of Star Trek was supposed to own.

- climbers carried to the top of Everest to do altitude calculations; Apollo astronauts used it in space to calculate re-entry coordinates

- In all, 100,000 HP-35’s (or more than 10× their estimate) were sold in the first year—accounting for more than half of the company’s total profits

It's amazing the similarity between HP and Apple's success stories. And then the fact that Steve Jobs bought the property that summer and the site is now part of Apple’s new Pentagon-sized spaceship headquarters.

I think pretty much every thing you need to know why companies succeed and fail is in this story.

Oh yea. Those were the days those were.

HP 21, 29C, 41CX. Great introduction to computing.

> battery for 3 hours

Wow. How often people would replace batteries on this?

100K units in the first year, vs your king of consumer electronics today: the iPhone, which pre-sells and ships 100K units in what, several minutes?

I understand not everyone buys calculators, but that’s sort of the point of the article that this was marketed as a ‘consumer’ electronics product rather than scientific equipment.

Also there’s much less friction and much more marketing today, but it’s wild to imagine how millions of iPhones ‘move’ in a single weekend, every year for nearly the last decade and what is required to keep supply in pace with demand.