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The Analog Thing: An open source, educational, low-cost modern analog computer
- Schiphol 5y agoSlightly OT: Does anyone know of a textbook or other resources where (dis(advantages of analog vs digital computing are discussed?
- mindcrime 5y agoI looked a while back, and it seems that most books on the topic fall into one or the other of two categories: 1. Really old, and really expensive or 2. Somewhat modern, and also pretty expensive FWIW, here's an Amazon List on this topic that I put together a while back. Looks like there are one or two that can be had for fairly cheap, if used copies are acceptable. https://www.amazon.com/hz/wishlist/ls/1ZGZWA01QFE1V?ref_=wl_share https://www.amazon.com/hz/wishlist/ls/1ZGZWA01QFE1V?ref_=wl_... I wound up snagging a couple off of a pirate e-book site but haven't had time to really dig into the whole thing yet.
- carapace 5y ago"Why Analog Computation?", oldie but goodie unclassified NSA document. > An introduction to analog computation containing a brief description of the analog computer and problems in which it can be advantageously applied. Both analog computers and systems combining analog and digital techniques are discussed in order to show why the Agency's interest in this computation area has increased. https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/tech-journals/why-analog-computation.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla...
- lambdatronics 5y agoThere's a fairly simple reason for the superiority of digital computing, which is that error accumulation in analog is impossible to avoid, so the accuracy of results is limited by the quality of the components, which makes them large/expensive and even then maybe only 1% accurate. Programming them is less flexible, too. The applications are pretty niche. The analog advantage is that you can directly implement differential equations, so they can be more power-efficient and faster than the equivalent digital simulation.
- Schiphol 5y agoThanks for this. I am most interested in mathematical comparisons. That is to say, ways in which optimal analog computation (idealizing away from noise propagation, among other things) might be sometimes better than its digital counterpart. Your last point about diff equations is directly relevant to this.
- smoldesu 5y agoI love devices like this, buying a Behringer Neutron completely opened my eyes to the possibilities of patching on a bigger level than just music. I do have to wonder who would buy this though. Analog computers like this are virtually useless unless you have some particularly applied use-case for them. I'd be interested to hear some user testimony if anyone owns one of these!
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- jpm_sd 5y agoThe name is not great and it seems like the target market is probably already served by breadboards?
- detaro 5y ago> it seems like the target market is probably already served by breadboards? I doubt it, assuming the analog groups are well-designed that's not trivial to just replicate in a DIY breadboard circuit.
- JKCalhoun 5y agoBecause it is an analog computer it is a kind of breadboard though, isn't it? ;-) No, having all the Op-Amps wired up for me, powered for me, "nulled" for me is a huge improvement over the mess I would have to make on a breadboard to replicate even a part of it. I only wish it had more than one output (meter) component so I could observe steps along the way.
- madengr 5y agoI’d prefer an analog meter.
- retrac 5y agoThe site emphasizes the educational aspect. I think they have a point. Nothing teaches mathematical relationships like hands-on instant feedback from a physical system. Patching your program and turning knobs in a literal sense jives well with the naive mental physics model some of us rely heavily on for reasoning and learning.
- motohagiography 5y agoThis is amazing. I use the MakeNoise Maths module on my synth to experiment with similar ideas, as I think the next leaps in scaling quantum computing are going to come from a generation of kids who developed a musical level intuition for wave dynamics playing with their parents' analog synths. Digital has been cool and interesting, but when young hackers have the tools and incentives to become de-facto physicists, they're going to tear holes in the fabric of reality. This is such a cool product.
- jnovek 5y agoOK, this is increasingly off-topic, but I’m just getting into Eurorack and I’ve been become curious about analog computers… not because I know anything about them, but because they share a user-interface style. Can you speak to similarities between them? You seem to know a bit about both topics.
- motohagiography 5y agoThanks! With the caveat that I profoundly lack depth on both, and am a bit artsy craftsy in my intuitions, I did buy the Maths module precisely because it was an analog computer. The intent was to create some generative music, and seeing if I could use it to create 1/f noise, and exploring self-similarity using a musical ear instead of in code. Still working on it. When you look at what you can do with magnets hooked to a synth with a ferrofluid, e.g. https://youtu.be/Q3oItpVa9fs https://youtu.be/Q3oItpVa9fs , the sound and your ear helps to develop an sense for what kinds of waves can be used to yield physical effects. If you can functionally suspend and maipulate a ferrofluid with waves, there are likely analogies to laser pulses and electrons for quantum computing. Waves gonna wave, etc. The other piece that grabbed me recently was "analog fractals," (https://hackaday.com/tag/analog-fractals/ https://hackaday.com/tag/analog-fractals/ + that rabbit hole) where if you can get those artifacts instantaneously as the effect of physical feedback instead of rendering them computationally, there are likely faster functional approaches to a lot of other problems, only a subset of which we use ASICs and FPGAs to implement today. It's speculative based on laughably incomplete understandings on my part, but that's hacking.
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- pvitz 5y agoThe last time this came up, I spent some time investigating the use of analog computers for Monte Carlo simulations and it is absolutely fascinating how differential equations or stochastic differential equations are being implemented with analog components. There are already some chips available that integrate these components similar to FPGAs and some toy examples show promising results, but it looks like we are not completely there yet. Nevertheless, if these chips get further developed, they could have a huge impact on neural networks (at least in terms of power consumption) and maybe Monte Carlo.
- buescher 5y agoThat would be really interesting - how do you generate the randomness? Every so often when Matlab or Simulink won't integrate something simple, probably because of something I did, I wish I had an analog computer to compare to.
- pjc50 5y agoRandomness is impossible to eradicate from the analogue world, so you just take an existing noise source like a semiconductor junction and connect it to an amplifier. Some care is needed to get something that works across a wide temperature range, and avoids being easy to overwhelm with outside noise sources, but it's a problem with lots of existing solutions.
- buescher 5y agoI mean in a practical way for a monte carlo simulation - usually in analog setup you set parameters with discretes, so you are going to need to do things like feeding a transconductance amplifier with your noise source. You're also going to worry about shaping and otherwise parameterizing your distribution - do you need uniformly distributed noise? gaussian noise? what are your limits? I can imagine a lot of practical pitfalls and awkward half-solutions to trying to do an analog monte carlo; I was wondering how the OP went about it.
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- PavleMiha 5y agoThis looks really cool, I found the line "inherently safer than digital computing in the face of cyber threats" pretty funny. There's no analog internet so what could the cyber threats even be?
- jaywalk 5y agoThe quote is saying that digital computing faces cyber threats, which makes analog computing inherently safer. Not that analog computing faces cyber threats.
- spicybright 5y agoI feel like that's a silly claim though. If you have no networking, wireless, interface for loading code, or really any code at all, then of course it's more secure. You're not doing the same tasks as a digital computer though. Paper is more secure than digital computing.
- mdp2021 5y agoExactly. And the claim stands, that if you can effectively compute («model dynamic systems») through an analog computer, you expand your toolbox with items that are beyond a framework involving security issues. (Yes, like paper, but paper, while it helps the computer, does not compute.) Another rephrasal of the concept they are proposing: "Don't be the man with a hammer" [not all problems are to be treated as nails - including the health and safety related concerns nails demand].
- pjmorris 5y agoI've joked for a number of years that I expect to see boutique professional offices (lawyers, doctors, dentists, etc) springing up that offer 'paper records only' as a feature.
- md2020 5y agoThis looks awesome, but as someone who knows nothing about analog computing, what’s a good educational resource to go along with this so that I can use it to actually learn?
- amelius 5y agoAny beginner's book about OpAmps will get you started.
- buescher 5y agoAnalog computing is about making analogs (today we would say usually say simulations) usually of physical systems, usually with operational amplifiers. Learn to model physical systems with differential equations first (and in 2021 you will probably also learn to solve/integrate them numerically on a computer in the process) then go to op amps. Here are some other interesting problems you can solve with analog computers that aren't really modeling problems, though: http://dataphys.org/list/dewdneys-analog-gadgets/ http://dataphys.org/list/dewdneys-analog-gadgets/
- jsilence 5y agoInstall VCV Rack and watch Omri Cohens videos. Warning: you might fall deep into this magnificen beautiful rabbit hole.
- mdp2021 5y ago> With "The Analog Thing", you can model dynamic systems including: ° market economies; ° the spread and control of diseases; ° population dynamics; ° chemical reactions; ° mechanical systems; ° a variety of mathematical attractors
- glitchc 5y agoWhile this is a cool idea, it's not terribly useful for anything more complex than a toy example. The fact that I need to physically wire the components and manually adjust coefficients every time I create a new program means that I can only really leave one complex program configured at a time. How do I switch between programs? Do I buy new THATs then? It would be much more practical if the analog components could be configured digitally through a script, so that multiple programs could be constructed and run on the same compute platform. A hybrid platform of sorts.
- throwawayboise 5y agoOne of the features listed: "An interface for controlling THAT digitally to develop analog-digital hybrid programs"
- buescher 5y agoA permanent analog computer is just an analog circuit. You can build a PCB with op-amps after you've proved it out.
- mpfundstein 5y agoso in your mind, are FPGAs also only useful for toy examples? also, how often do you think a pcb of an electrical product changes once deployed?
- djur 5y agoFPGAs are certainly far more useful due to the fact that you can design and simulate them digitally and then mass produce them from that design. You can work on as many FPGA designs as you want in parallel without having to physically set up and tear down each one in turn. They also don't cost $350 a pop.
- nereye 5y agoFrom a mainstream perspective, there are mixed mode ICs that contain a bunch of analog components (op amps, comparators, etc.) and allow you to configure them digitally. E.g. the whole PSoC series from Cypress (formerly, now Cypress is part of Siemens). Slightly less mainstream, there is the concept of FPAA (field programmable analog array), which is the equivalent of an FPGA but for analog instead of digital. E.g. see https://www.anadigm.com/fpaa.asp https://www.anadigm.com/fpaa.asp.
- atoav 5y agoSo you are telling me this is a synthesizer?
- munificent 5y agoWithout any oscillators. :(
- jsilence 5y agoDoes the filter ring?
- Animats 5y agoIt's cute, but, having used analog computers, it lacks some important things. Analog computers are usually reset to initial conditions, then started. As time goes on, the outputs change. This thing has integrators, so it will generate time-varying outputs. You need some way to watch those time-varying outputs, such as a plotter or an oscilloscope. This needs a graphical display. Something like one of those US$20 digital oscilloscopes available on Alibaba.
- Stampo00 5y agoThis is so fascinating. I'll be keeping an eye on this. I've been doing binary computing all my life, so it's kind of mind bending to think of computing using analog circuitry without immediately trying to turn it back into binary again.
- friendly_chap 5y agoPretty cool. Typo on frontpage > As digital computing approaches the limit of Moore's Law, analog computing offers a strategy to diversity today's digital monoculture. s/diversity/diversify ? s/today/in today ?
- the_only_law 5y ago> As digital computing approaches the limit of Moore's Law, analog computing offers a strategy to diversity today's digital monoculture. What sort of industrial roles/domains is analog computing particularly fit for. And whats the cancer that we see them adopted either replacing or alongside digital computers in those roles.
- analognoise 5y agoI am super excited to buy one of these.
- mycall 5y agoThis is way better than my Radio Shack 200-in-1 for understanding the logic part better than jumping directly to resistors/capacitors/diodes/etc. What a time to be alive.
- giardini 5y agoWhy wouldn't someone write a digital simulation of "The Analog Thing" and sell it?