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3Hz Computer, Hold the Transistors (mcyoung.xyz)
199 points by ingve on Aug 7, 2022 | hide | past | favorite | 39 comments


I have a Type I Curta and it's amazing. I love the logo, but could never find an accurate vector version so I carefully measured it and made a DXF and SVG of it. Hopefully somebody finds this useful:

https://github.com/brettfo/curta


Another interesting mechanical computer, the Zuse Z1, apparently ran at 1 Hz.

"The first freely programmable computer in the world which used Boolean logic and binary floating-point numbers"

https://en.m.wikipedia.org/wiki/Z1_(computer)


I always look for them in thrift stores expecting the shopkeeper to say "someone just dropped off a box of stuff cleaning out their grandparent's place. I have no idea what it is. Looks like a spice grinder. It's probably broken, doesn't seem to want to open. Take it for $3"


Not in the same order of magnitude but this is how I bought my IBM Model M keyboard for 50 cents from a pile of those crappy "multimedia keyboards".


I keep hoping I'll find a Space Cadet keyboard this way, though I'm probably on the wrong side of the US for that to ever happen.


You can always make your own: https://www.thingiverse.com/thing:1943171


The assembly video for that is worth a skim: https://youtu.be/zh2Z11miQ0w


Heh, the end product strongly resembles a trash-can Mac Pro.


I have two stories like this:

One thrift store had a DEC TU-58 tape drive. I bought for $20 and immediately sold on eBay for $400 (I would have kept it, but have no DEC stuff to use with it at all).

Another thrift store had a late 60s / early 70s electronic calculator that used acoustic delay line memory and a CRT for display. I think I paid $100, played with it for a while, then sold it for $600. Unfortunately, it was damaged in shipping (it was well packed), and UPS had to pay up.

I bought a Curta recently, but is was not a good deal. Prices just keep going up on them.. I wish I had bought one in the early 2000s when they were still below $500.

Other mechanical calculators are reasonable. Aside from the Curta, only the really early ones are expensive.


Before I knew they were valuable, I saw a couple for sale somewhere for like $5 each.

I was like "oh God there's one of those mechanical computer thingies. I've got enough going on in my life. Figuring that thing out is not how I wish to spend my time"

Similarly I passed on the old model m keyboards: "the ergonomics on these things are wretched. They're heavy, noisy, and missing modern keys I use in my window manager"

Now I check, I always check


Lovely. I really admire the mechanical skills involved in making such a calculator. Mechanical devices seem intuitive. It’s almost as if you could grab a chisel and a few pieces of wood and build something similar yourself, and that’s when you feel the complexity of the design.



Why oh why are they making them from wood these days. So, no, not really. (Not me, anyway.)


There's a decent fan/reference/info page for these [1] on vcalc,net. edit to add, also a decent Wikipedia page [2].

[1] https://www.vcalc.net/cu.htm

[2] https://en.wikipedia.org/wiki/Curta


This was my grandfathers calculator, which he used for some business calculations (he was a "master ('Meister') craftsman" painter in East Germany, responsible for a team) into the 1990s even after he already had an electronic calculator.

https://i.imgur.com/jBDUHPp.jpeg

Does anybody have any information about this machine? I used to be able to do simple calculations with it, but nowadays I don't remember anything at all. I guess using trial and error I might be able to do additions and multiplications, but I would not be able to use even a fraction of that machine's capabilities. Sadly, there's no (surviving?) handbook.


There's a video of it on [1], and the page hosting it also has links to other resources. Might be helpful:

https://www.jaapsch.net/mechcalc/melitta.htm


There are plenty of resources for the Curta just a Google search away. Especially scans of the original manuals can be found. Try this one here: http://www.curta.de/kr34/


I have found all forms of mechanical calculators fascinating for years and have a few of these collected back in the days when they were cheap to find. Now most of them run a couple grand. They are wonderful little devices to play with. There are still a couple people in the US that will service them (it's a very tricky mechanism to reassemble).


That looks like a nice machine.

At school we were taught to use mechanical adding machines similar to this. Ours were made to sit flat on the desk, and had a crank-handle on the side. They were a lot scruffier than that Certa!

Within a year or two of those lessons, cheap electronic calculators became available.


You can spend many hours on Youtube looking at all the different desk calculators, they all are variations along these lines: https://www.youtube.com/watch?v=j88JslB67fU


If you like mechanical calculators, here's my FACIT: https://video.ploud.fr/w/6s76S5zfuBN5i1S35kMgHy


This makes me think about what are the principled requirements for artificial intelligence. It might be designed, it must have sensors and actuators, and it must have “goals” in some manner.

But, does AI require digital computers? Can you have AI with analog computers? Or, are even computers required? Perhaps AI only requires the (artificial) design of intelligent processes in the world.

For instance, the autopilot (known as “the Pilot’s Assistant) was invented in 1912, long before digital computers. If that’s an example of AI, then there is a need for conceptual reformulation…


> Can you have AI with analog computers?

Pattern-recognizing neural networks can certainly exist as analog computers. The very first perceptron-based image recognition systems were analog and optoelectronic. A grid of light sensors wired up in a network, with the weights set by potentiometers, self-adjusted by little stepper motors during training.

https://towardsdatascience.com/rosenblatts-perceptron-the-ve...

https://americanhistory.si.edu/collections/search/object/nma...


John McCarthy said of "artificial intelligence" that even his thermostat had beliefs. Sometimes it thinks the room is too hot, and sometimes it thinks the room is too cold.


In Cybernetics there's a result: every efficient self-regulating system must contain a model of itself. It's true even for the system of thermostat-and-room (although it's subtle.)

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


which explains consciousness: both why we are self-aware (because we're modelling ourselves) and why we aren't more self-aware (because the model is only accurate enough to be effective)...


I think so, yep. (Although I would say that it explains our subjective experience of mind, "what it's like to be a human", rather than the existence and nature of subjective experience itself, but that's getting into metaphysics.)

It seems to me that there's no good reason not to reuse the term "ego" for the cybernetic self-models in human minds.

This idea also has interesting ramifications when you think about the boundaries of "self" and "other". The self-model system is not just the human being: it includes all the aspects and entities around the human too. And in humans we have models of other people and their self-models, and they have models of us and our self-models, and in turn we have models of their models of our models, etc.


FWIW I believe the other-models are what have been strongly selected for, and the self-model is just an epiphenomenon arising from the relative ease of modelling one's self after having gained the ability to represent models of others' selves:

cf https://news.ycombinator.com/item?id=23475069


Sounds reasonable to me.

I appreciate the link to Shannon's paper. I've played a browser-based version of such a machine/game and it's pretty eerie.

Long ago a friend of mine had this cat, she liked to sit on your lap, but hated it when you got up, she would always jump down the instant you started to rise.

However...

She could tell from the pattern of muscle tensions in your legs whether or not you were really getting up or just moving a bit to rearrange your butt or whatever, and she would only jump if you were getting up. She was flawless at this. In fact, a few times she jumped down a split-second before I knew I was getting up. Like Bruce Lee, she could detect and respond to the intention to move, even before the motion was consciously known to the mover himself (me, in this case.)


Saying AI requires a digital computer is like saying biological intelligence requires a brain. If intelligence is substrate independent then it can run on anything.


It could use humans as actuators :-)

As for the autopilot - a plane autopilot is fundamentally a device to make the plane go straight; you don't need AI, or much processing power at all, to do that.


Not really a computer - there is no way to program it. At best it is a mechanical RAM with some operations.


you can't program it, but you can run programs on it.

it is not claimed to be an entire computer, but instead, an ALU and 1-2 registers. the article goes through this...


Curta Assembly! What a cool idea.


I can't be the only one wishing there was a video of it in action?!


You can find a couple of videos on YouTube, for example [1], at around 50 seconds.

[1] https://www.youtube.com/watch?v=fhUfRIeRSZE


Also a fascinating story behind the inventor Curt Herzstark (born in 1902 in Vienna).

From his very early years he was able to tinker in his father's workshop simply called "Austria" the first (mechanical) calculator plant in Austria-Hungary, back in 1905.

Because of his Jewish heritage the company was taken over by the Nazis in 1938 and he was later put in Buchenwald in 1943. An excerpt [0] taken from an interview [1] in 1987 (1 year before his death):

While I was imprisoned inside Buchenwald I had, after a few days, told the [people] in the work production scheduling department of my ideas. The head of the department, Mr. Munich said, 'See, Herzstark, I understand you've been working on a new thing, a small calculating machine. Do you know, I can give you a tip. We will allow you to make and draw everything. If it is really worth something, then we will give it to the Führer as a present after we win the war. Then, surely, you will be made an Aryan.' For me, that was the first time I thought to myself, my God, if you do this, you can extend your life. And then and there I started to draw the CURTA, the way I had imagined it.

After the war he was nearly ripped off by the Prince of Liechtenstein (i.e. his financial backers)[0]:

It was not long before Herzstark's financial backers, thinking they had got from him all they needed, conspired to force him out by reducing the value of all of the company's existing stock to zero, including his one-third interest. These were the same people who had earlier elected not to have Herzstark transfer ownership of his patents to the company, so that, should anyone sue, they would be suing Herzstark, not the company, thereby protecting themselves at Herzstark's expense. This ploy now backfired: without the patent rights, they could manufacture nothing. Herzstark was able to negotiate a new agreement, and money continued to flow to him.

One important "innovation"/"simplification" for miniaturizing the calculator to a single complemented step drum was the application of the nines' complement [2]:

The Curta calculator used the method of complements for subtraction, and managed to hide this from the user. Numbers were entered using digit input slides along the side of the device. The number on each slide was added to a result counter by a gearing mechanism which engaged cams on a rotating "echelon drum" (a.k.a. "step drum"). The drum was turned by use of a crank on the top of the instrument. The number of cams encountered by each digit as the crank turned was determined by the value of that digit. For example, if a slide is set to its "6" position, a row of 6 cams would be encountered around the drum corresponding to that position. For subtraction, the drum was shifted slightly before it was turned, which moved a different row of cams into position. This alternate row contained the nines' complement of the digits. Thus, the row of 6 cams that had been in position for addition now had a row with 3 cams. The shifted drum also engaged one extra cam which added 1 to the result (as required for the method of complements). The always present ten's complement "overflow 1" which carried out beyond the most significant digit of the results register was, in effect, discarded.

For playing around here [3] a Curta sim.

[0]https://en.m.wikipedia.org/wiki/Curta#History

[1]https://umedia.lib.umn.edu/item/p16022coll92:50

[2]https://en.m.wikipedia.org/wiki/Method_of_complements#Practi...

[3]https://satadorus.eu/x_ite/yacs_2_0/yacs_2_0.html


Yeah, great. But can it run Doom?! ;)


Pattern recognition, eh?




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