The Friden EC-130, one of the world's first electronic calculators | Hacker News Reader

The Friden EC-130, one of the world's first electronic calculators

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50 pointskens18 comments

Another very notable bit of history about this calculator in the linked Old Calculator Museum article (which also has pictures of the full device):

> The Friden 130 pioneered the use of Reverse Polish Notation (RPN), a method of entering math problems using a multi-register stack. RPN logic made complex calculations easier to perform without having to write down intermediate results and re-enter them into the calculator when needed. Friden continued the use of this stack-based method of calculating in its second generation of calculators (an example being the Friden 1162), but for some reason the principle was never patented by Friden.

https://www.oldcalculatormuseum.com/friden130.html

I test drove one of these as a youngster when my father brought a demo home from the salesman.

Nobody had seen anything like it, and I did want to keep it because the registers looked so promising, but otherwise it really didn't do that much.

For most things it could be outperformed by an unpowered slide rule or Magic Brain Calculator. Or a printing adding machine when you need the output document.

Plus it was about the same price as a new Volkswagen beetle which was about the cheapest car and about the only import you would usually see. People were still not very comfortable driving a foreign car across the US because there were virtually no available tires, parts, qualified mechanics, or metric tools in many states at all, and seldom until you got to a big city, most often close to a port of arrival at a factory dealer.

A new Ford Falcon could be had for only a few hundred dollars more.

I really wanted to work with the Friden extensively but we could not keep it, though I was really looking forward to seeing what they came up with next even more. Well, within a couple years at school we were very fortunate to get a Wang 370 which you could program with the same kind of blank computer cards as the IBM 360 at the university.

But only one card at a time almost like it was a toaster.

The future was going to be great, we were going to the moon!

Cool way to store the bits. I saw the other day a video about an old eletronic calculator that stores itens in memory usinglike a piano wire, and microfones, and small speakers, to make the cord vibrate, and store the value.

It was the Friden ec-132 https://www.youtube.com/watch?v=2BIx2x-Q2fE&t=2s&ab_channel=...

Where are those solar-powered credit-card-sized calculators from the 80s? And why haven't they evolved into more powerful systems (solar-powered credit-card-sized phones for example)?

I'm not an electrical engineer, however I suspect that RF is expensive in terms of energy. So battery issues, and solar energy conversion efficiency I expect. And these days the phone has evolved into a fully blown computer, so yeah - energy requirements. But those little credit card solar calculators were cool, I remember the one I had well... There are some amazingly small phones these days approaching that form factor... google worlds smallest phones etc. Anyhow - maybe a real engineer can comment further?

You also need at least a little bit of analog electronics (mic and speaker). Assume you can power it with a solar panel that covers the back of the phone though. (I'm not sure you can for reasonable talk times.) What now? You can't hold the phone in your hand because you're covering the solar panel. You're probably also going to be a little bit thicker than a credit card because of the audio.

And why haven't they evolved into more powerful systems (solar-powered credit-card-sized phones for example)?

Those calculators have a 4-bit CPU running at a few kHz (actually frequency may depend on how much power the solar cell outputs.) You may have noticed they have a pretty substantial delay on input and computation. Hard to do anything but simple arithmetic with that limited amount of power.

There are credit-card-sized phones, but they have a traditional battery (and are a bit thicker than a credit card.)

They are of course right here, on AliExpress [1] and they're $0.70 which seems a pretty sensible price development. No idea how much they were in the 80s, but probably a little bit more. :)

I do think the actual design is the same, the image slots right into my mind's idea of how a solar-powered credit card-sized calculator looks, down to the color scheme (black and gold, yeah) and font.

[1] https://www.aliexpress.com/item/32652366421.html

I'd love to know if that's a real solar panel or if the calculator has a coin cell in it.

I have a calculator that looks just like this one, and the calculator stops working if I block the solar panel with my hand.

Now if they would make a credit-card sized solar scientific calculator, and while I'm dreaming can it be a clone of the HP-15C?

How about a credit card sized HP15C clone made of titanium?

https://www.swissmicros.com/product/dm15

People who want solar power on everything don't understand how shitty the sun is as a source of energy compared to a small pot of chemicals. The real thing you should be going for: small hydrocarbon fuel cells (theoretically much higher energy density than lithium). Or I guess, very well programmed, very energy efficient microprocessors; good luck with that in current year.

It turns out I have one in my desk drawer and the display definitely goes off if you cover the solar panel. It's possible there's also a battery but I doubt it because this is some long-ago (90s?) cheap knick-knack and I'd be surprised if any battery still had a charge.

I don't know what those calculators are using but last time I played with this it's pretty hard to power an MCU off even a phone sized solar panel from indoor light (you have to play crazy games with sleeping and have a special supervisor task that monitors how fast you're draining backup capacitors etc.) I feel like most of those were only powering the display with the solar panel and had a watch battery running the electronics. But it could have been that the flash and ram were eating a lot of the power in my experiments.

It does sound still doable. Low-power mcus can be really low power these days, I checked a random one and they advertise 25uA/MHz active mode, and for a pocket calc you dont need many MHz.

https://www.microchip.com/wwwproducts/en/ATSAML11E14A

On the other hand, these small solar cells are rated 5V/30mA, but I think they'll be more in the uA range when used indoors.

https://www.amazon.com/AOSHIKE-Electric-Materials-photovolta...

So might be bit of a stretch, but not too far off

Ambiq has chips that can draw as little as 6uA/MHz and soon will reach 3uA/MHz:

https://ambiq.com/apollo4/

I like that they interleaved the digits, least significant first, so each digit showed up when it was needed for computation.

I think it means the screen had to be refreshed top to bottom, right to left, so the display could use the digits as they come in.

Edit: looks like bottom to top!

Frien, Anita, these are both very Swedish sounding names. And yet the company behind Friden were from New York it seems.

The founder was born in Sweden, moved to the US at 25.

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

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