The HP-35: Consumer Electronics, an Origin Story(codex99.com)
codex99.com
The HP-35: Consumer Electronics, an Origin Story
http://codex99.com/design/the-hp35.html
45 comments
The HP calculators were so well designed. In college, a HP salesman stood before the engineering class and hurled a TI calculator at the cement wall. It exploded. Then he threw the HP calculator against the wall. It bounced off the wall. He picked it up and followed up with…. “Ok give me two numbers…”
Back in my school days, I found that TI's calculators had crap keyboards that inevitably failed at the worst moment. I decided to try an HP instead (HP-11C in my case), and I still have that calculator. It still works beautifully, but these days I just fire up Free42 on my phone.
[deleted]
Early/mid-80's, I was employed as a "junior operator" in a pretty well outfitted computer operations center, the kind with raised tiles and an on-duty human available 24/7 to service international offices' other computer operations .. so as a teenage programmerhacker whose codes mere presence was highly odious to the senior operators, that meant I was really only allowed to be the tape monkey and the halon test subject, the crawl-space cable stuffer, the 30-minute bus-ride to another office' midnight switch-flicker, anything really, to have kept me logged off so the operators could do their operate.
So .. this one time, I was involved in a project to replace a thousand dumb terminals RS232 lines with ethernet throughout a labyrinthine maze of inner ducts and panels and routing networks and old-school inter-building telecoms cable channels, and so on. A job considered worthy of me, per the senior operators, since I had failed to find the bugs in the RS232-link that had necessitated (triggered) this upgrade to ethernet in the first place, greybeard grin. I didn't write the RS232 code they were using, I just complained about it too loudly this one time and it was, therefore, forever mine.
As a result of those bastard operators and their fetish for overalls, I can still do base-T muscle memory in the dark, and .. this one particular time .. finding myself buried deep in some dusty fan-duct that had required circus-like machinations to get into, stringing cables in the guts of the building .. my only flashlight falls out of my mouth and breaks itself on one of the thousands of sharp pointy things keeping building tiles from falling on us in places like banks with high ceilings and hospitals with low, dense ones, and so on.
So for a second I glimpse darkness and ponder the future 15 minute ordeal getting back across the ducts and to our exit-spot mostly blind and having to follow my new cable run by hand and make sure everything was set.
I foolishly yell back to my fellow duct-puller colleague, a relatively untrustworthy teenager like me at the time, who - doing an apprenticeship "network operation" at 3am in the morning, sitting there waiting for us to immediately leave after this - has absolutely no time for my shit and wants to get down from the ladder we have wisely put on top of another ladder in the depths of the basement, in order to get access to this ceiling hell-hole in which I was in danger of inhabiting permanently.
He sticks his head barely through the ceiling tile, up at me, and throws the only thing he has at hand with a light, his HP calculator, somehow chucking it right at my general direction long enough that I can see the thing and reach it before he stops letting dim light in around his neck, and so .. I type in 8888888 and use its feeble display light to crawl my way back through the ducts, a foot at a time .. to check my cable run .. by hand.
And, inevitably, those little dinky LED's help me find a kink in this one particular 'infamous' RS232 bundle which, unawares to us dopey copper tuggers, had been a key link in the chain leading to our brand new ethernet cable going in at an angle, cable shield cut open on a steel duct blade edge, which also had remnants of the old RS232 bundle, the missing trunks. WTF.
So .. by law .. we had to pull another length of cable, so back I go, down the precarious ladders bearing super bad news, past the fuming fellow dungeon crawler and our boss, getting wind of the troubles our ladders were in, and so we got the spare flashlight out of the van, another hour or so off schedule before the early-birds come to work .. and back into the depths, one more time, dagnabit.
Well, for weeks after that, I thoroughly loved annoying the greybeard operators that I, geniously, debugged the network problems with a calculator. Fellow junior op got his HP back, but I still don't think he'll know how to use it.
So .. this one time, I was involved in a project to replace a thousand dumb terminals RS232 lines with ethernet throughout a labyrinthine maze of inner ducts and panels and routing networks and old-school inter-building telecoms cable channels, and so on. A job considered worthy of me, per the senior operators, since I had failed to find the bugs in the RS232-link that had necessitated (triggered) this upgrade to ethernet in the first place, greybeard grin. I didn't write the RS232 code they were using, I just complained about it too loudly this one time and it was, therefore, forever mine.
As a result of those bastard operators and their fetish for overalls, I can still do base-T muscle memory in the dark, and .. this one particular time .. finding myself buried deep in some dusty fan-duct that had required circus-like machinations to get into, stringing cables in the guts of the building .. my only flashlight falls out of my mouth and breaks itself on one of the thousands of sharp pointy things keeping building tiles from falling on us in places like banks with high ceilings and hospitals with low, dense ones, and so on.
So for a second I glimpse darkness and ponder the future 15 minute ordeal getting back across the ducts and to our exit-spot mostly blind and having to follow my new cable run by hand and make sure everything was set.
I foolishly yell back to my fellow duct-puller colleague, a relatively untrustworthy teenager like me at the time, who - doing an apprenticeship "network operation" at 3am in the morning, sitting there waiting for us to immediately leave after this - has absolutely no time for my shit and wants to get down from the ladder we have wisely put on top of another ladder in the depths of the basement, in order to get access to this ceiling hell-hole in which I was in danger of inhabiting permanently.
He sticks his head barely through the ceiling tile, up at me, and throws the only thing he has at hand with a light, his HP calculator, somehow chucking it right at my general direction long enough that I can see the thing and reach it before he stops letting dim light in around his neck, and so .. I type in 8888888 and use its feeble display light to crawl my way back through the ducts, a foot at a time .. to check my cable run .. by hand.
And, inevitably, those little dinky LED's help me find a kink in this one particular 'infamous' RS232 bundle which, unawares to us dopey copper tuggers, had been a key link in the chain leading to our brand new ethernet cable going in at an angle, cable shield cut open on a steel duct blade edge, which also had remnants of the old RS232 bundle, the missing trunks. WTF.
So .. by law .. we had to pull another length of cable, so back I go, down the precarious ladders bearing super bad news, past the fuming fellow dungeon crawler and our boss, getting wind of the troubles our ladders were in, and so we got the spare flashlight out of the van, another hour or so off schedule before the early-birds come to work .. and back into the depths, one more time, dagnabit.
Well, for weeks after that, I thoroughly loved annoying the greybeard operators that I, geniously, debugged the network problems with a calculator. Fellow junior op got his HP back, but I still don't think he'll know how to use it.
I need more of these stories.
I enjoyed writing it, took me back to a much more adventurous era, both personally and professionally.
You might find BOFH a worthy soak of attention if you haven't already:
https://bofh.bjash.com
https://en.wikipedia.org/wiki/Bastard_Operator_From_Hell
You might find BOFH a worthy soak of attention if you haven't already:
https://bofh.bjash.com
https://en.wikipedia.org/wiki/Bastard_Operator_From_Hell
I devoured those when they were first coming out.
This seems to be a summary of the story at http://www.hp9825.com/html/the_9100_project.html, written by people who do know what a Q-meter is, have heard of Olivetti, and cite their sources.
That is a desktop calculator, which was the ancestor of the pocket calculator described in the parent article.
I see no overlap between the stories, even if they are about the same people.
On the same site, there is
http://www.hp9825.com/html/osborne-s_story.html
with what Tom Osborne says about the history of HP-35. That gives additional details, but it is also distinct from the parent article.
I see no overlap between the stories, even if they are about the same people.
On the same site, there is
http://www.hp9825.com/html/osborne-s_story.html
with what Tom Osborne says about the history of HP-35. That gives additional details, but it is also distinct from the parent article.
You need the historical context of the desktop calculator to really understand the pocket calculator.
Short summary: "I want that in my pocket"
Short summary: "I want that in my pocket"
The parent article tells the story starting from before the desktop calculator in question and devotes several paragraphs to it, and I didn't mean just that one web page. The parent article doesn't seem to have any information that isn't presented on hp9825.com.
The several paragraphs in the parent article corresponding to specifically that web page start at:
> Tom Osborne, a Berkeley-trained electrical engineer, wasn’t one of those 9000 employees. In his Bay-area apartment, he had built a floating-point electronic calculator he called the Green Machine (after the color of the automotive touch-up paint he used on the balsa wood case). He tried shopping it around but no one was interested until he showed it to HP in June, 1965.
The several paragraphs in the parent article corresponding to specifically that web page start at:
> Tom Osborne, a Berkeley-trained electrical engineer, wasn’t one of those 9000 employees. In his Bay-area apartment, he had built a floating-point electronic calculator he called the Green Machine (after the color of the automotive touch-up paint he used on the balsa wood case). He tried shopping it around but no one was interested until he showed it to HP in June, 1965.
Swiss Micros make some decent RPN calculators inspired by the legendary HP ones.
https://www.swissmicros.com/products
I have always wanted one, but they are too expensive sadly. But they are definitely very good gifts for engineers.
DM-42N is cheaper than HP-42S was originally, and an order of magnitude cheaper than the HP-35 was at its time.
Definitely, but back then calculators are luxuries such as personal computers in the 70s/80s.
Maybe the HP15C would suit? That's back in production.
I keep hoping against hope they will release a 50G clone. Instant buy for me.
People take ubiquitous calculating power for granted today. But back in the day, a portable or semi-portable machine able to do math in milliseconds was magical. It was as cutting-edge as ChatGPT, something that came straight from Science Fiction.
I am thankful my father-in-law gave me his HP-35 purchased in the early 1970s. With it came a metal case with a lock and a base you would bolt to your desk. It was a precious item back then.
Thankfully the power supply still works so I can take it out every so often and enjoy the history of it.
Thankfully the power supply still works so I can take it out every so often and enjoy the history of it.
If you have an old calculator and you find the buttons are sticking, you can sometimes fix it with a bath in isopropanol. I have revived 2 old HPs this way.
1. take out batteries
2. fill a shallow container with IPA (70% or 90% is ok)
3. immerse buttons, but try and keep the display out of the IPA as much as possible (if liquid gets in the display it takes forever to dry and can leave a ring)
4. work the buttons until you feel improvement, IPA will turn brown
5. let dry for a few days before you put batteries back in.
1. take out batteries
2. fill a shallow container with IPA (70% or 90% is ok)
3. immerse buttons, but try and keep the display out of the IPA as much as possible (if liquid gets in the display it takes forever to dry and can leave a ring)
4. work the buttons until you feel improvement, IPA will turn brown
5. let dry for a few days before you put batteries back in.
I was a sophomore EE student when these came out. There were debates about whether to allow calculators in the classroom, somewhat irrelevant to me, since the price was out of reach anyway. Then the ME department made a deal to order in bulk, answering the debate, and making the marvelous machine somewhat affordable. I begged my father, and he fronted me the $271.40 (the HP-45 had just come out, so the 35 came down in price). Glorious days!
""I have a last-generation HP-35, which, according to the serial number, was built in the second week of 1973. It was given to me by a friend who used it in the field when he was a surveyor and it shows: the silver bezel is worn, the face has the tell-tale crosshatch pattern of over-agressive cleaning, there is mildew (or something) in the battery compartment, the contacts are corroded, and the battery pack is, obviously, years beyond dead. I’m sure it has been decades since it was last used, but I plugged it into the wall, cycled the on/off switch a few times and there it was—a bright, red 0. The calculator is now 45 years old, but it still works.
Of course it still works.""
Computers don't get old. Their users do.
It doesn't matter how old the computer is, there is a user out there, somewhere.
(Disclaimer: kept every computer I've ever used/owned/developed-for since 1978.. I know for sure my HP is in some hallow box, somewhere..)
Computers don't get old. Their users do.
It doesn't matter how old the computer is, there is a user out there, somewhere.
(Disclaimer: kept every computer I've ever used/owned/developed-for since 1978.. I know for sure my HP is in some hallow box, somewhere..)
I've got my HP 32SII on my desk right now. Nothing beats a physical keypad with RPN.
> I’m sure it has been decades since it was last used, but I plugged it into the wall, cycled the on/off switch a few times and there it was—a bright, red 0. The calculator is now 45 years old, but it still works.
Ah, so you could connect this pocket calculator to mains power? Guess it shows that I'm from the generation who grew up with LCD-equipped calculators, which could run for years with two button cells...
Ah, so you could connect this pocket calculator to mains power? Guess it shows that I'm from the generation who grew up with LCD-equipped calculators, which could run for years with two button cells...
Since he mentions a bright red 0, that indicates a calculator with a LED display.
The early calculators, which had either LED or vacuum fluorescent displays, could use either a few R6 cylindrical batteries or an external power supply, like a laptop today.
When close to a wall plug, it was normal to use it, because the lifetime of the batteries was modest, mostly due to the high power consumption of the display.
While this was a disadvantage, bright and fast VFD displays were much more appealing than the dull and slow LCD displays that have replaced them a few years later.
I believe that HP has used only LED displays at that time and not VFDs, because they manufactured the LED themselves, unlike other calculator vendors.
The early calculators, which had either LED or vacuum fluorescent displays, could use either a few R6 cylindrical batteries or an external power supply, like a laptop today.
When close to a wall plug, it was normal to use it, because the lifetime of the batteries was modest, mostly due to the high power consumption of the display.
While this was a disadvantage, bright and fast VFD displays were much more appealing than the dull and slow LCD displays that have replaced them a few years later.
I believe that HP has used only LED displays at that time and not VFDs, because they manufactured the LED themselves, unlike other calculator vendors.
>The early calculators, which had either LED or vacuum fluorescent displays
nickel-cadmium has entered the chat, installed first in the HP-35!
nickel-cadmium has entered the chat, installed first in the HP-35!
This story took place when I was in high school. At university, my electronics professor had one of these. He adored that little thing, and all the students were jealous, but they were really expensive so we all used slide rules. At a point, the Sinclair Scientific came out, and my parents bought me one for Christmas. It was a great little machine, very comfortable to use in one hand if you were in the lab. But the switches stopped working after a while. I bought some casio or other machine (no idea what -- it was brown is all O can recall) and that was okay but again the switches got bouncy and then stopped working.
When I got to grad school, I bought an HP (forget the number) and it was trash. I had spent all that money and it was no better than the cheap foreign junk. I was so angry I gathered folks in the lab at a certain point and threw it against a wall to smash it. I wrote to HP, enclosing some of the pieces and telling pretty much this story, and telling the how disappointed I was in their calculator. This was the old days, so somebody actually wrote back with a candid answer that told me that they realized they had a poor design process, but that I should buy one of the new generation. (I was hoping for a discount price, but no go on that!)
So I bought an HP15C. I still have that thing, and it works perfectly. (I've had 2 other HP calculators since, and of course they are better in lots of ways, but I like my old HP12C more.)
I would have none of this attraction but for the RPN feature. The physical aspects of the machine were great and all, but it was really RPN that let me calculate correctly without always thinking I had got lost.
Nowadays I always have a laptop handy and just type in a REPL to do a lot of simple calculations.
PS. before I do any calculation, I do it in my head so I have a very rough idea of the answer. I do that in class quite a lot, and I think my students view this as some kind of magic trick.
When I got to grad school, I bought an HP (forget the number) and it was trash. I had spent all that money and it was no better than the cheap foreign junk. I was so angry I gathered folks in the lab at a certain point and threw it against a wall to smash it. I wrote to HP, enclosing some of the pieces and telling pretty much this story, and telling the how disappointed I was in their calculator. This was the old days, so somebody actually wrote back with a candid answer that told me that they realized they had a poor design process, but that I should buy one of the new generation. (I was hoping for a discount price, but no go on that!)
So I bought an HP15C. I still have that thing, and it works perfectly. (I've had 2 other HP calculators since, and of course they are better in lots of ways, but I like my old HP12C more.)
I would have none of this attraction but for the RPN feature. The physical aspects of the machine were great and all, but it was really RPN that let me calculate correctly without always thinking I had got lost.
Nowadays I always have a laptop handy and just type in a REPL to do a lot of simple calculations.
PS. before I do any calculation, I do it in my head so I have a very rough idea of the answer. I do that in class quite a lot, and I think my students view this as some kind of magic trick.
An HP15C or HP12C app is the perfect companion for your mobile phone.
Turn the phone on its side, and it's even about the right size.
Here is a relatively recent review of the main Android options: https://www.hpmuseum.org/forum/thread-22091.html
Here is a relatively recent review of the main Android options: https://www.hpmuseum.org/forum/thread-22091.html
previous submission https://news.ycombinator.com/item?id=17050732
Still use my original 42S and 15C here all the time.
I carry Free42 on my phone for day-to-day use, and the physical 42S is safely on a shelf because I love it too much to use it. And I think the keyboard finally succumbed to the rot and needs fixing.
The 15C is a true classic. I used to be a land surveyor, so the 48GX with the COGO card was my fave.
I had the legendary 15C during my college. That little thing was a workhorse. But I’ll admit I was jealous of the HP35 when it came out.
[deleted]
Anyone know why it was called the HP-35 if it was the first?
The usual explanation is that it’s got 35 buttons. Whether that’s the true reason I don’t know, but at least the button count checks out!
Now, if someone could explain to me the logic behind the naming of the HP-10, HP-10b, HP-10C and HP-10s, I’d be most grateful...
Now, if someone could explain to me the logic behind the naming of the HP-10, HP-10b, HP-10C and HP-10s, I’d be most grateful...
Such amazing devices
RPN was what folks used before FP was created, to make other folks feel dumb.
About the decision to use RPN in HP-35, Tom Osborne said this:
"I was a bit concerned about the stack architecture and RPN notation, but that all went away when I demonstrated one of the first prototypes to my mother-in-law, who is anything but a mathematician. After I had done some fairly complex operations, Fran said, "How many things can you stack up in that machine?" With that comment, my worries disappeared."
"I was a bit concerned about the stack architecture and RPN notation, but that all went away when I demonstrated one of the first prototypes to my mother-in-law, who is anything but a mathematician. After I had done some fairly complex operations, Fran said, "How many things can you stack up in that machine?" With that comment, my worries disappeared."
What's "FP"? Nothing comes to mind.
As for myself, I had a Texas Instruments TI-30, I think it was, in my higher studies - it was a price revolution at the time. That was a fine simple calculator, but when somebody let me try their HP calculator a year or two later I was sold and I never looked back. RPN is just so much easier when you want to do long calculations - just begin, no need to plan things in advance.
I took it to mean "Functional Programming".
For those who struggle with RPN (postfix), it is really just a linearized tree.
Starting with the infix a+bc
The tree form of that is:
Starting with the infix a+bc
The tree form of that is:
+
/ \
a *
/ \
b c
a b c * +