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Analog Computers

blog.degruyter.com

11–20 of 107 posts

Re: Analog Computers

#11
post #7

The author's so called analog computers can be built by using FPGAs. And the term he might be reaching for is called data-flow programming.

The author's so called analog computers

Why do you say "so-called"?

can be built by using FPGAs.

Also, FPAA's (Field Programmable Analog Array)[1]

[1]: https://en.wikipedia.org/wiki/Field-programmable_analog_arra...

Re: Analog Computers

#14
post #7

The author's so called analog computers can be built by using FPGAs. And the term he might be reaching for is called data-flow programming.

Not really. FPGAs are fundamentally digital and pretty much give you a bunch of logic gates to work with ("Field-Programmable Gate Array"). The author's proposed architecture would instead provide an array of components that perform analog operations, such as summing, multiplication, and integration or differentiation, over analog voltages.

Re: Analog Computers

#15
post #7

The author's so called analog computers can be built by using FPGAs. And the term he might be reaching for is called data-flow programming.

The author's so called analog computers Why do you say "so-called"? can be built by using FPGAs. Also, FPAA's (Field Programmable Analog Array)[1] [1]: https://en.wikipedia.org/wiki/Field-programmable_analog_arra...

Maybe it was the wrong term. My point was we have them and they are used, but they are not cost efficient in general. So saying that they will be the future of computing, is a bit ridiculous imo.

Re: Analog Computers

#16
A good summary of analog computers can be found on the wikipedia article:

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

Takeaway: Analog computers are limited in precision and by "analog noise"; the precision of the components used determine the precision of the output. Usually no more than 3 or 4 decimal places are possible, at least with the tech that was used in their heydey. I would say that is still close to the case even today. Of course, one could do things like cryogenic cooling or such, but it becomes a cost factor at that point.

Something else that wasn't mentioned:

The ADALINE/MADALINE memister technology is an analog component, and is a hardware component equivalent to a McCulloch–Pitts neuron model (perceptron).

The memister is NOT to be confused with the memristor, which is a different technology; the memister was a 3-terminal device (memory transistor):

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

...whereas a memristor is a two terminal device ("memory resistor"):

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

Re: Analog Computers

#17
I'm hoping that analog computing will come back in the form of photonic analog computing. This would be more powerful than quantum digital computing (you know the things that people are wasting time on).

Fun fact, with analog computing, one could imagine achieving Real Computation (https://en.wikipedia.org/wiki/Real_computation) which is above and beyond Turing. completeness.

Note the fun sentence "If real computation were physically realizable, one could use it to solve NP-complete problems, and even #P-complete problems, in polynomial time. ".

We are on a wrong evolutionary branch of computing. Bits are lame-o-rama, whereas differentiable signals are pure unadulterated flavortown.

Re: Analog Computers

#18

If any of you guys are into analog computing, just as an FYI, there's a sub-reddit dedicated to the topic (full disclosure, I started this particular one). analogcomputing.reddit.com There's not a ton of content there yet, but please feel free to add anything you come across. I'm a fan of the idea and suspect, like the author of this piece, that there is "something there".

How long have subreddits been accessible through a subdomain? Is this something the subreddit mods have to turn on?

Re: Analog Computers

#19
post #18

If any of you guys are into analog computing, just as an FYI, there's a sub-reddit dedicated to the topic (full disclosure, I started this particular one). analogcomputing.reddit.com There's not a ton of content there yet, but please feel free to add anything you come across. I'm a fan of the idea and suspect, like the author of this piece, that there is "something there".

How long have subreddits been accessible through a subdomain? Is this something the subreddit mods have to turn on?

It's been this way since I started using the site in 2009.

Re: Analog Computers

#20

I'm hoping that analog computing will come back in the form of photonic analog computing. This would be more powerful than quantum digital computing (you know the things that people are wasting time on). Fun fact, with analog computing, one could imagine achieving Real Computation ( https://en.wikipedia.org/wiki/Real_computation ) which is above and beyond Turing. completeness. Note the fun sentence "If real computat…

What you're describing is generally accepted to be physically unrealizable. In fact, the sentence that follows your quoted sentence cites two commonly known physical limitations that prevent the existence of your "computational class above and beyond Turing".

Whether or not there exist physically realizable computations that are not computable by a turing machine is an open question, but most physicists and computational complexity theorists seem to believe there does not exist such a class.

https://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis

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