7 ms·

Computational Duplo train track layouts

215 points by amenghra 8y ago

jeffwass 8y ago
Ian Stewart wrote about calculational train circuits like these in an article in Scientific American in 1994 : “A Subway Named Turing” Subscription-required link : https://www.nature.com/scientificamerican/journal/v271/n3/pdf/scientificamerican0994-104.pdf https://www.nature.com/scientificamerican/journal/v271/n3/pd... Love the closing line (as the train passengers discussing the concept of train logic circuits realise they haven’t come to a station in awhile): >“This isn't any touring machine," the guard said indignantly. "This is a personnel commuter, buddy." >At least, I think that's what he said.
- garethrees 8y ago
  Ian Stewart's article in Scientific American was based on "Train Sets" by Adam Chalcraft and Michael Greene (Eureka 53, pp. 5–12), which also provides the basis of the Duplo constructions. (But note that Duplo has linked points as well as sprung and lazy points, which allows for more compact constructions.) http://www.monochrom.at/turingtrainterminal/Chalcraft.pdf http://www.monochrom.at/turingtrainterminal/Chalcraft.pdf
- M2Ys4U 8y ago
  >Subscription-required link : https://www.nature.com/scientificamerican/journal/v271/n3/pd.. https://www.nature.com/scientificamerican/journal/v271/n3/pd.... Of course you can always access academic papers using sci-hub ;) https://sci-hub.tw/10.1038/scientificamerican0994-104 https://sci-hub.tw/10.1038/scientificamerican0994-104
wiredfool 8y ago
I remember doing stuff like this when the kids were little. I only got one good gadget tho, pretty much the a set of flip flops chained together.
amelius 8y ago
These must be the most expensive logic-gates I've seen so far ...
stackola 8y ago
Semi-related, here's a binary full adder build from trains in Open Transport Tycoon https://www.reddit.com/r/programming/comments/2se36e/binary_full_adder_using_trains_in_openttd/ https://www.reddit.com/r/programming/comments/2se36e/binary_...
twic 8y ago
Okay, now i want to see this used to build a circuit implementing the shunting-yard algorithm: https://en.wikipedia.org/wiki/Shunting-yard_algorithm https://en.wikipedia.org/wiki/Shunting-yard_algorithm
kennydude 8y ago
> Duplo is a train set system made by Lego®. I thought Duplo was just the Lego for babies?
- lqet 8y ago
  My thoughts exactly [1]. [1] https://en.wikipedia.org/wiki/Lego_Duplo https://en.wikipedia.org/wiki/Lego_Duplo
- Tomte 8y ago
  Yes, the author expressed it a bit clumsily. Duplo is the oversize brick line for smaller children. And it has train sets. Lego used to have train sets, several systems, in fact, but they stopped doing that. Well, always, the Lego City line has some trains with tracks, but it‘s not really a train system like the old ones.
- progers7 8y ago
  Duplo are blocks twice the size of Lego. There are also Quatro blocks which are twice the size of Duplo. These have been discontinued: http://lego.wikia.com/wiki/QUATRO http://lego.wikia.com/wiki/QUATRO
- dragonwriter 8y ago
  Duplo is the brick line by Lego with twice the linear dimension of Lego per “dimple”. This does make them more suitable for younger kids (because they are less likely to be choking hazards and require less fine motor skills)
  - deleted 8y ago
    [deleted]
joering2 8y ago
On of my on-the-list-when-i-get-old project: build a lego train system with HD camera in the cockpit that users can visit my website and navigate said train online :) something tells me there is a buck or two in such project :)
- jstanley 8y ago
  Do you mean it would make you lots of money or cost you lots of money? If the former, where does the money come from?
  - jonsen 8y ago
    Maybe just a spelling error: ...theres is a bug or two...
btown 8y ago
Somewhat related to computation and train tracks (though using train tracks for binary state is really awesome!): "Introductions to Monads" are a dime a dozen, but this one, which uses train track analogies (a monad is just an adapter that changes a noncomposable function into a composable segment for a path), was the one that got the entire concept to click for me. Highly recommended. https://fsharpforfunandprofit.com/rop/ https://fsharpforfunandprofit.com/rop/
robaato 8y ago
Desmond Bagley's novel "The Enemy" features a model train set whose layout/timetable was used by the ex Russian spy also a genius, to encode his research and leave for posterity. Haven't read for years but enjoyed it!
Aardwolf 8y ago
Easy to miss but the link is to just one page of the site late in a series, the whole series begins here: http://www.cr31.co.uk/stagecast/trains/tt0_intro.html http://www.cr31.co.uk/stagecast/trains/tt0_intro.html
sceadu 8y ago
https://youtu.be/psvTTNOJgfA https://youtu.be/psvTTNOJgfA (see the second half of the video)

215 points by amenghra 8y ago

Ian Stewart wrote about calculational train circuits like these in an article in Scientific American in 1994 : “A Subway Named Turing” Subscription-required link : https://www.nature.com/scientificamerican/journal/v271/n3/pdf/scientificamerican0994-104.pdf https://www.nature.com/scientificamerican/journal/v271/n3/pd... Love the closing line (as the train passengers discussing the concept of train logic circuits realise they haven’t come to a station in awhile): >“This isn't any touring machine," the guard said indignantly. "This is a personnel commuter, buddy." >At least, I think that's what he said.

garethrees 8y ago
Ian Stewart's article in Scientific American was based on "Train Sets" by Adam Chalcraft and Michael Greene (Eureka 53, pp. 5–12), which also provides the basis of the Duplo constructions. (But note that Duplo has linked points as well as sprung and lazy points, which allows for more compact constructions.) http://www.monochrom.at/turingtrainterminal/Chalcraft.pdf http://www.monochrom.at/turingtrainterminal/Chalcraft.pdf
M2Ys4U 8y ago
>Subscription-required link : https://www.nature.com/scientificamerican/journal/v271/n3/pd.. https://www.nature.com/scientificamerican/journal/v271/n3/pd.... Of course you can always access academic papers using sci-hub ;) https://sci-hub.tw/10.1038/scientificamerican0994-104 https://sci-hub.tw/10.1038/scientificamerican0994-104

wiredfool 8y ago

I remember doing stuff like this when the kids were little. I only got one good gadget tho, pretty much the a set of flip flops chained together.

amelius 8y ago

These must be the most expensive logic-gates I've seen so far ...

stackola 8y ago

Semi-related, here's a binary full adder build from trains in Open Transport Tycoon https://www.reddit.com/r/programming/comments/2se36e/binary_full_adder_using_trains_in_openttd/ https://www.reddit.com/r/programming/comments/2se36e/binary_...

twic 8y ago

Okay, now i want to see this used to build a circuit implementing the shunting-yard algorithm: https://en.wikipedia.org/wiki/Shunting-yard_algorithm https://en.wikipedia.org/wiki/Shunting-yard_algorithm

kennydude 8y ago

> Duplo is a train set system made by Lego®. I thought Duplo was just the Lego for babies?

lqet 8y ago
My thoughts exactly [1]. [1] https://en.wikipedia.org/wiki/Lego_Duplo https://en.wikipedia.org/wiki/Lego_Duplo
Tomte 8y ago
Yes, the author expressed it a bit clumsily. Duplo is the oversize brick line for smaller children. And it has train sets. Lego used to have train sets, several systems, in fact, but they stopped doing that. Well, always, the Lego City line has some trains with tracks, but it‘s not really a train system like the old ones.
progers7 8y ago
Duplo are blocks twice the size of Lego. There are also Quatro blocks which are twice the size of Duplo. These have been discontinued: http://lego.wikia.com/wiki/QUATRO http://lego.wikia.com/wiki/QUATRO
dragonwriter 8y ago
Duplo is the brick line by Lego with twice the linear dimension of Lego per “dimple”. This does make them more suitable for younger kids (because they are less likely to be choking hazards and require less fine motor skills)
- deleted 8y ago
  [deleted]

joering2 8y ago

On of my on-the-list-when-i-get-old project: build a lego train system with HD camera in the cockpit that users can visit my website and navigate said train online :) something tells me there is a buck or two in such project :)

jstanley 8y ago
Do you mean it would make you lots of money or cost you lots of money? If the former, where does the money come from?
- jonsen 8y ago
  Maybe just a spelling error: ...theres is a bug or two...

btown 8y ago

Somewhat related to computation and train tracks (though using train tracks for binary state is really awesome!): "Introductions to Monads" are a dime a dozen, but this one, which uses train track analogies (a monad is just an adapter that changes a noncomposable function into a composable segment for a path), was the one that got the entire concept to click for me. Highly recommended. https://fsharpforfunandprofit.com/rop/ https://fsharpforfunandprofit.com/rop/

robaato 8y ago

Desmond Bagley's novel "The Enemy" features a model train set whose layout/timetable was used by the ex Russian spy also a genius, to encode his research and leave for posterity. Haven't read for years but enjoyed it!

Aardwolf 8y ago

Easy to miss but the link is to just one page of the site late in a series, the whole series begins here: http://www.cr31.co.uk/stagecast/trains/tt0_intro.html http://www.cr31.co.uk/stagecast/trains/tt0_intro.html

sceadu 8y ago

https://youtu.be/psvTTNOJgfA https://youtu.be/psvTTNOJgfA (see the second half of the video)