Great video, I really enjoyed how down to earth it was. It reminded me of The Secret Life of Machines [1], where we get to peek behind the curtain and see how seemingly "magical" machines (in your case a digital computer) emerges from simple fundamental concepts.
I don't know if he mentioned, the name doesn't show up in the transcript, it but this seems to be very close to an unrolled Curta, the main difference being that it doesn't use 9s complement for subtraction so it has a more complex bidirectional carry mechanism. Otherwise the function is very similar down to shifting the turns and output accumulator to multiply the entry number. The big drum he makes many of is just one in the Curta that actuates every output dial through a full rotation.
9s complement makes subtraction extremely satisfying on the Curta because it causes a carry on (almost) every single output and turn accumulator dial.
Hi, I made the calculator and this video. As I discuss throughout and particularly towards the end of the video, my design is based on Thomas de Colmar's Arithmometer (~1820-1860) and Leibniz's Stepped Reckoner (late 1600s), both of which predate the Curta (1930s). Or rather, the Curta is a super cool and elegant refinement of those (and other) designs. I think it is more accurate to say the Curta is like a rolled up version of those (and my) calculator.
The "big drum" you mention is sometimes called a Leibniz Wheel, though this naming convention is misleading in some ways: http://journals.cambridge.org/abstract_S0007087414000429. As that article argues (though I disagree with some points), the history of calculating machines is more nuanced than a linear progress narrative suggests. So, I tried to keep my narrative a little tighter and not go much into the calculators of the late 19th century and the designs in the 20th century like the Curta. Also, the Curta's (awesome!) story has been told many times, so I did not feel the need to go into it. Sorry to go on this long, but I think this history is fascinating and how we tell it speaks to how we understand how technology changes through time.
The carry propagation hardware is the hardest to make work right. The low-digit add has to power the entire chain of carries. As the number of digits increases, it gets harder to do that, because so much mechanism has to be pushed.
There are carry mechanisms which use an external power source for carry propagation. Babbage's Difference Engine has one.[1] All the pending carry values are stored in a latch for each number wheel. Then a cam system applies the carries one at a time. This scales to large numbers of wheels.
I love thinking about the "what if?" universe where we never figured out semiconductors and transistors, but still had roughly the same level of human progress. Would everything be clockwork like Syberia [1]? Would we have something akin to iPhones but done entirely with electro-mechanical stuff with antennas? I guess this is sort of the appeal of something like Steampunk.
Mechanical calculators are ridiculously cool to me. If I ever become an eccentric billionaire, I really want to buy an original Curta calculator [2], just because I respect the genius and engineering required to design such a thing.
The one in this video is also very cool. Very satisfying to watch all the gears turn at once.
£850 is actually cheaper than I thought it was, but it's still a bit much for me to justify right now. If I spent a grand on a fidget toy, I think my wife would be pretty mad at me.
Whatever patents that they had have to be expired, I kind of wish someone would make reproductions. I know there's the 3D printed ones, which are cool in their own right, but since 3D printers aren't super precise the parts have to be huge to compensate. I want as close to a one-to-one reproduction as possible, but I guess there's not much money in it.
It doesn’t help that they made an absolute ton of them: something like 140,000! That means that they’re not particularly rare, and it holds the price down.
Add in the fact that authenticity is part of the appeal, plus the fairly expensive process to make a decent replica, it’s not shocking that no replicas have emerged, even though cheap-ish CNCs mean it’s probably easier to do than it ever has been.
I'm sure they would not have been less than £850 in whatever currency it was sold in back then, inflation adjusted. But the justification was much better than being a fidget toy.
Update it with USB so that it can take input and return results. Hook it up to a cash register for something like an antique store. Ideally one selling small items so that the customer can marvel at the display adding things up.
I also have always wanted one of those mechanical vintage cash registers, for the same reason I have always wanted a Curta. They always seemed like they would be fun to play with.
I could probably get one of those cash registers to play with for not a ton of money, but my house isn't huge and it's hard to justify the space.
I have had an interest in building a mechanical computer for a long time. It has not ever gotten farther that some research into what route to take. There are lots and lots of simple logic mechanisms (many, many in use in real world applications). It can go as far and be as capable as you have time for.
Great video, I really enjoyed how down to earth it was. It reminded me of The Secret Life of Machines [1], where we get to peek behind the curtain and see how seemingly "magical" machines (in your case a digital computer) emerges from simple fundamental concepts.
[1] https://en.wikipedia.org/wiki/The_Secret_Life_of_Machines
I don't know if he mentioned, the name doesn't show up in the transcript, it but this seems to be very close to an unrolled Curta, the main difference being that it doesn't use 9s complement for subtraction so it has a more complex bidirectional carry mechanism. Otherwise the function is very similar down to shifting the turns and output accumulator to multiply the entry number. The big drum he makes many of is just one in the Curta that actuates every output dial through a full rotation.
9s complement makes subtraction extremely satisfying on the Curta because it causes a carry on (almost) every single output and turn accumulator dial.
Hi, I made the calculator and this video. As I discuss throughout and particularly towards the end of the video, my design is based on Thomas de Colmar's Arithmometer (~1820-1860) and Leibniz's Stepped Reckoner (late 1600s), both of which predate the Curta (1930s). Or rather, the Curta is a super cool and elegant refinement of those (and other) designs. I think it is more accurate to say the Curta is like a rolled up version of those (and my) calculator.
The "big drum" you mention is sometimes called a Leibniz Wheel, though this naming convention is misleading in some ways: http://journals.cambridge.org/abstract_S0007087414000429. As that article argues (though I disagree with some points), the history of calculating machines is more nuanced than a linear progress narrative suggests. So, I tried to keep my narrative a little tighter and not go much into the calculators of the late 19th century and the designs in the 20th century like the Curta. Also, the Curta's (awesome!) story has been told many times, so I did not feel the need to go into it. Sorry to go on this long, but I think this history is fascinating and how we tell it speaks to how we understand how technology changes through time.
Just wanted to say, fantastic work and video. I really enjoyed watching it.
The carry propagation hardware is the hardest to make work right. The low-digit add has to power the entire chain of carries. As the number of digits increases, it gets harder to do that, because so much mechanism has to be pushed.
There are carry mechanisms which use an external power source for carry propagation. Babbage's Difference Engine has one.[1] All the pending carry values are stored in a latch for each number wheel. Then a cam system applies the carries one at a time. This scales to large numbers of wheels.
[1] https://youtu.be/vdra5Ms__9s?t=247
I love thinking about the "what if?" universe where we never figured out semiconductors and transistors, but still had roughly the same level of human progress. Would everything be clockwork like Syberia [1]? Would we have something akin to iPhones but done entirely with electro-mechanical stuff with antennas? I guess this is sort of the appeal of something like Steampunk.
Mechanical calculators are ridiculously cool to me. If I ever become an eccentric billionaire, I really want to buy an original Curta calculator [2], just because I respect the genius and engineering required to design such a thing.
The one in this video is also very cool. Very satisfying to watch all the gears turn at once.
[1] https://en.wikipedia.org/wiki/Syberia
[2] https://en.wikipedia.org/wiki/Curta
Maybe without semiconductors we would stumble upon something better sooner.
Maybe optical/biological/quantum computing.
You don't have to be a billionaire, I got a Curta mark I for ~£850 on ebay and it's like the world's greatest fidget toy.
£850 is actually cheaper than I thought it was, but it's still a bit much for me to justify right now. If I spent a grand on a fidget toy, I think my wife would be pretty mad at me.
Whatever patents that they had have to be expired, I kind of wish someone would make reproductions. I know there's the 3D printed ones, which are cool in their own right, but since 3D printers aren't super precise the parts have to be huge to compensate. I want as close to a one-to-one reproduction as possible, but I guess there's not much money in it.
It doesn’t help that they made an absolute ton of them: something like 140,000! That means that they’re not particularly rare, and it holds the price down.
Add in the fact that authenticity is part of the appeal, plus the fairly expensive process to make a decent replica, it’s not shocking that no replicas have emerged, even though cheap-ish CNCs mean it’s probably easier to do than it ever has been.
I'm sure they would not have been less than £850 in whatever currency it was sold in back then, inflation adjusted. But the justification was much better than being a fidget toy.
Oh definitely, prior to having cheap computers that can compute gigaflops, I would definitely have bought one to do number crunching.
The problem is that if I bought one now, it would simply be a toy and nothing else. That's just a bit more than I'm willing to spend.
Update it with USB so that it can take input and return results. Hook it up to a cash register for something like an antique store. Ideally one selling small items so that the customer can marvel at the display adding things up.
I also have always wanted one of those mechanical vintage cash registers, for the same reason I have always wanted a Curta. They always seemed like they would be fun to play with.
I could probably get one of those cash registers to play with for not a ton of money, but my house isn't huge and it's hard to justify the space.
What is the simplest way to do mechanical logic? Without all those fancy looking gears. I wonder how far it can go if you actually optimize it.
I have had an interest in building a mechanical computer for a long time. It has not ever gotten farther that some research into what route to take. There are lots and lots of simple logic mechanisms (many, many in use in real world applications). It can go as far and be as capable as you have time for.
the madness of cutting hundreds of gears by hand, many with a 45 degree bevel, I couldn't even imagine.
madness!
You can just continue the division by inputting the remainer i think?
Great work, excellent video.
Great work !