
The HP-35: Consumer Electronics, an Origin Story - maxaigner
http://codex99.com/design/the-hp35.html
======
teraflop
An anecdote about the HP-35, from the HP Museum
([http://www.hpmuseum.org/hp35.htm](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](https://imgur.com/K1k0cSQ) (original source:
[http://www.hpmuseum.org/forum/thread-2821.html](http://www.hpmuseum.org/forum/thread-2821.html))

~~~
jacquesm
That letter should be required reading and the anecdote further cements the
'fish rots from the head' proverb as accurate. After all, without ethics at
the top there is no corrective action against such relatively minor nudges in
the wrong direction and over time that will accumulate until you get a
completely different version of the company. One that will never ever have the
kind of stature that HP enjoyed.

------
fermienrico
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](https://SwissMicros.com)

~~~
agumonkey
Talking about Braun, I've been disassembling all kind of devices for a few
monthes, and you can appreciate differences betweens brands a bit. Braun and a
few brands, do have better materials, better internals. I guess 90% of
consumers can't give a damn about that but it registered in my head. To the
point that I would even start a website about that, some sort of ifixit for
everything but phones.

~~~
ddingus
You should. Teardowns on ordinary things is appealing and informative.

I suspect more people than you think would find all that compelling.

~~~
agumonkey
Youtube is already filled with that, but it's random in quality.. maybe

~~~
ddingus
Really, I was speaking to quality. If it's good, informative, then heck yeah.
I like that stuff.

------
pjmorris
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)

~~~
Lio
The founders of HP were just so much cooler than the business school goons
like Fiorina who practically drove it into the ground.

That pricing formula is so playful, as is "well I want one and so do my
engineers".

Chapeau Bill Hewlett and Dave Packard.

~~~
madengr
Ha ha, practically? She did. Keysight is what’s left of the original HP.

HP is now known for garbage computers and shitty printers.

~~~
Splines
I feel that they're getting their legs back under their consumer division,
although I agree their laptops have been really mediocre.

However I have enjoyed using their enterprise workstations for the last 10
years are so (various models of Z4xx's) and haven't had any complaints.

~~~
Multicomp
I've had good experiences with their EliteBook lines. Solid machines, if you
are closer to the rugged notebook vs thin trophy book on the scale of laptop
thickness.

------
ChuckMcM
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.

~~~
analog31
I have my dad's slide rule, and his HP-35. He's a retired industrial research
scientist.

At my dad's workplace, every scientist had a Friden 55. The managers compared
the price of the HP to the annual service contract on the Friden, and bought
an HP to try out. They were going to let each scientist have it for a week,
then pass it on to the next person. Instead, after just a couple weeks, the
Fridens were all in the dumpster.

~~~
exikyut
Awesome.

It's proving a little tricky to find a picture and/or more info about the
Friden 55. All I'm getting is other models. Was it mechanical?

(Hopefully some of them ended up in attics, they sound mildly interesting even
if just from a historical-interest retrospective standpoint)

~~~
analog31
Aha, I found more hits when I entered "Friden STW." I don't know where I got
the "55" from.

[http://americanhistory.si.edu/collections/search/object/nmah...](http://americanhistory.si.edu/collections/search/object/nmah_690862)

It's fully mechanical and can do addition, subtraction, multiplication, and
division. I saw one of these things work, and it was quite an experience.
There's a YouTube here:

[https://www.youtube.com/watch?v=qKm9eM2BuM0](https://www.youtube.com/watch?v=qKm9eM2BuM0)

And a few people have published images of the service manual.

My dad said that while the Friden was accurate, it was not portable or quick,
and he usually used his slide rule, notebook, and graph paper. For a chemist,
slide rule accuracy was usually sufficient.

------
poyu
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.

~~~
setquk
As someone who switched away from RPN (well RPL) I disagree. I was an HP48/50
series fanboy since about 1995 and before that RPN on a HP41. I was the weird
kid at school who didn’t have a normal calculator and the teachers couldn’t
help me.

However I bought a Casio FX991EX recently after using my daughter’s unit which
has a modern entry system, solver, engineering units, conversions and dual
power. It’s pretty much perfect. Anything else more complicated, I roll out
python, scipy, sympy etc.

~~~
FractalLP
Yea, it's much easier to enter a matrix on a modern Casio than the HP calcs
and requires fewer keystrokes I believe. I guess navigation of the indices
takes up time on the Casio, but it is so intuitive.

------
wscott
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](https://www.hpcalc.org/authors/166) POLY
was hugely popular at the time. I just wrote it to simplify my classwork.

~~~
nealabq
My father worked at HP in the 70s in Tool&Die, and made some of the molds for
plastic pieces of the HP 35. He bought an HP 21 in '76\. It's now my son's.

It still works perfectly, except the battery is lost so we run a wire into the
battery compartment.

It's the most intuitive calculator I've ever used.

------
wyclif
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.

~~~
jwr
The HP-48G/GX was also my calculator of choice and I really disliked the later
HP49. However, I then tried the HP50G, and was instantly hooked. Once you get
over the differences in key layout, it's like a HP-48GX loaded with tons of
useful software, in a slightly better form factor. I now have a HP50G and a
HP-48G, but I never use the older model.

On iOS, I use the Emu50G app, which works, but could really use some
improvements and optimizations. It's a fork of emu48.

Incidentally, I think the HP-50G is the last good engineering calculator. I'm
puzzled as to how people get around without one these days: don't tell me
about python, scipy and other similar shells: there is nothing else out there
that can do so much, so efficiently.

~~~
vq
Have you tried Calc? It's loosely modelled after the HP-calculators and it's
my first choice of calculator when I have a full blown computer at my hands.

[https://www.gnu.org/software/emacs/manual/html_mono/calc.htm...](https://www.gnu.org/software/emacs/manual/html_mono/calc.html#What-
is-Calc)

------
chx
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...](https://groups.google.com/d/msg/comp.sys.hp48/CS0lTpKkBHw/vnJh61RXJpoJ)

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.

~~~
joezydeco
I'm a proud 42S owner as well. I keep it safe in a drawer and use the Free42
build on iOS in my pocket:

[http://thomasokken.nl/free42/](http://thomasokken.nl/free42/)

~~~
e3pi
I've a SKB case filled with HP calculators. It is your android FREE 42s I pack
in the kit. Other than 3-D just-so HP's haptic double-injected keys, it's
fantastic! Thank you Thomas for your phenomenal RPN gift to humankind!

~~~
chx
You are not replying to Thomas Okken, just FYI.

------
AnimalMuppet
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_.

~~~
Gargoyle
I accidentally sat on my HP-15C in college and broke the LCD. I wrote to HP to
see where I could get the LCD replaced. I was a college student and the thing
was like $125 1986 dollars, I wanted to fix it, not buy a new one.

They just sent me a new calculator for free. I was so amazed! Heh.

I repeated almost the same accident with an early kindle and Amazon did the
same free replacement. I don't think they do today.

------
pletnes
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.

------
sizzzzlerz
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.

------
jdblair
I love this:

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

------
gyc
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.

------
gcb0
> 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?

~~~
hinkley
Probably:

1 Display = 15 LEDs + X additional parts

------
eitally
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!

------
submeta
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)

------
sytelus
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.

------
MikeGale
Oh yea. Those were the days those were.

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

------
gcb0
> battery for 3 hours

Wow. How often people would replace batteries on this?

~~~
opencl
It uses a pack of rechargable AAs, I have an HP-45 (the immediate successor,
with the same battery pack) and replaced the original NiCD cells with NiMH.
When I got it the batteries were clearly already a few decades old. AAs NiCDs
were pretty common back then, I have an old TI and Soviet-made Electronika
calculator that also use them.

~~~
ghaff
Right. It mostly wasn't a problem so long as you remembered to charge them
before exams, etc. In college, I'd still bring a slide rule to final exams as
backup just in case something happened although I never had a problem.

I started college just as scientific calculators were appearing on the scene.
I had a TO for a couple of years because the HPs were still so expensive but I
was able to pickup an HP-55 after a bit for a relatively affordable price
(still probably talking about high 3 digits in today's dollars). That's what I
used until I bought an HP-41CV when I went back to school and needed a more
programmable calculator.

------
eltoozero
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.

~~~
jacquesm
That's Moore's law in action over the longer term. A device like the iPad back
when the HP-35 was introduced would have been (1) impossible to make and (2)
would have cost millions of $ given the number of transistors in the device
(besides the fact that the internet is what makes an iPad useful).

You really can't compare those numbers, yes, the HP was a consumer device, but
the manufacturer of _any_ consumer device back then would have been happy to
sell in those numbers.

The good news is now it can be yours for under $2 if you already have an
iPhone:

[https://itunes.apple.com/us/app/rpn-35-sd/id956224485?mt=8](https://itunes.apple.com/us/app/rpn-35-sd/id956224485?mt=8)

