[HN Gopher] Show HN: Roons - Mechanical Computer Kit
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       Show HN: Roons - Mechanical Computer Kit
        
       I built a mechanical computer kit: https://whomtech.com/show-hn
       tl;dr: it's a cellular automaton on a "loom" of alternating bars,
       using contoured tiles to guide marbles through logic gates.  It's
       not just "Turing complete, job done"; I've tried to make it
       actually practical. Devices are compact, e.g. you can fit a binary
       adder into a 3cm square. It took me nearly two years and dozens of
       different approaches.  There's a sequence of interactive tutorials
       to try out, demo videos, and a janky simulator. I've also sent out
       a few prototype kits and have some more ready to go.  Please ask me
       anything, I will talk about this for hours.  -- Jesse
        
       Author : uncial
       Score  : 121 points
       Date   : 2025-05-01 15:57 UTC (7 hours ago)
        
 (HTM) web link (whomtech.com)
 (TXT) w3m dump (whomtech.com)
        
       | proaralyst wrote:
       | This is cool! The simulator was useful for understanding what was
       | going on, I hadn't realised until I watched a few that the roons
       | can push marbles out in between squares.
        
         | uncial wrote:
         | Thanks! Glad to hear the simulator was worthwhile, took me ages
         | to hack it into shape. I did actually experiment with adding
         | markings on the edges of the path roons, so that when you put
         | them together, the "phantom channel" becomes visible. Ended up
         | looking pretty cluttered though so I scrapped it.
        
       | shafoshaf wrote:
       | All with a reference to the Rockwell Turbo Encabulator! Awesome.
        
         | uncial wrote:
         | I'm grateful to Rockwell for their excellent research, but I
         | think they really dropped the ball on side fumbling -- any
         | competitive encabulator in 2025 really needs to be using
         | bifurcated resonance.
        
       | sriram_malhar wrote:
       | Good God! This is marvelous!
        
       | Johnbot wrote:
       | This is really neat.
       | 
       | Is there any use for something like a hopper that dispenses new
       | marbles continuously?
        
         | uncial wrote:
         | Absolutely yes! I prototyped a hopper peripheral that doubled
         | as marble storage. It hooked into the gear grid and used the
         | rotation to drive a helical lift to carry the marbles up to the
         | surface, where they'd enter the edge of an adjacent disk. I
         | ended up setting it aside for 2 reasons: 1) Lack of time -- sad
         | to say but I had to focus on getting the roons core ready. Too
         | much to do! 2) The HDD peripheral -- this is a WIP that
         | compactly stores and emits bitstreams. The way it's designed,
         | it can be set to "reservoir" mode, which emits the continuous
         | marble bitstream like you suggest. I figured it'd be redundant
         | to have both a hopper and HDD, so I scrapped the hopper for
         | now.
        
       | convolvatron wrote:
       | you implied that there were scaling problems. it would be really
       | fun and indstructive if one could use enough nodes to bulid a
       | simple store and von neuman machine with instruction decode. but
       | this seems like it would take a 10x10 array of your panels. do
       | you think you can push this architecture that far?
        
         | uncial wrote:
         | Yes, fantastic question! 10x10 is actually way more than we
         | need -- don't know the minimum but I suspect 2x2 is possible.
         | The interactive tutorials sketch out an approach to this. My
         | instinct is to use SAM with timers for memory/program, then
         | there's a couple of approaches in the tutorial for the
         | instruction processor. Toying with the idea of an OISC to
         | minimise space requirements. Tho we can always add a motor to
         | the encabulator if we need to drive a larger grid!
        
           | anthk wrote:
           | Would subleq work on this? Also, the 'ascii' output
           | array/grid would be like a whiteboard, and a Forth on this
           | would look like the computers from "Slouching towarsf Bedlam"
           | text adventure.
           | 
           | Maybe it would need 5 minutes to show a prompt, but, if it
           | works, it would be the greatest homage to computing (and
           | Chuck Moore) ever.
           | 
           | There's Eforth for subleq, and the muxleq version feels
           | almost like a native Forth on speed.
           | 
           | https://github.com/howerj/muxleq
           | 
           | The muxleq repo has the original subleq too. You can set the
           | options for floating point and the do...loop (among others)
           | in the Forth file and then you could just recompile the DEC
           | file.
           | 
           | With the do...loop it's closer to the standards. And, yes, I
           | can mimic for...next with ease with most ans forths such as
           | pforth.
           | 
           | If any, I can link an already recompiled and more featured
           | DEC file here.
           | 
           | BTW: You would like the book from the author too.
           | 
           | https://howerj.github.io/subleq.htm
        
             | uncial wrote:
             | I'm absolutely going to need a few hours to properly digest
             | this, but here are my preliminary thoughts:
             | 
             | You could almost certainly do a subleq in roons! Tbh it may
             | end up being a practical approach to making a compact full
             | computer -- though seems like it might compromise
             | legibility. This is way outside my wheelhouse, thank you
             | for the links, I have a lot of reading to do.
             | 
             | Re: an ASCII grid -- I explore this a little bit in the
             | tutorials, but because of the up/down nature of the loom,
             | each marble only occupies 25% of the surrounding
             | whitespace, so this kind of display doesn't end up very
             | visible. This is why I'm leaning more towards the
             | peripherals approach for rendering stuff.
        
               | anthk wrote:
               | Or just send the keys to a typewriter, as some guy did
               | with a ZMachine, Asterisk and the mentioned device. But
               | it would need a microcontroller, or a way to roll a ball
               | in a precise way to type down a letter.
        
       | uticus wrote:
       | > ...the gears have a layer of phase baffles (I don't know the
       | technical term). These physically block the gears from connecting
       | until they're perfectly synced up...
       | 
       | perhaps the correct term is "key" [0]? only thing i could find to
       | contribute to this masterful project, by pointing out unimportant
       | details like this.
       | 
       | [0] https://en.wikipedia.org/wiki/Key_(engineering)
        
         | uncial wrote:
         | That sounds like the right general category, but maybe not
         | specific enough? We could call it an Uticus Key and see if we
         | can get the name to stick, that might be funny. (Thanks for the
         | kind words!)
        
       | uticus wrote:
       | btw love the about page
       | 
       | > Do you want to work with a company servicing 6,000 Clients
       | across 8 Different Countries, with turnover of more than 125
       | Million USD?...Are you looking for a Proven Track Record
       | delivered by an Award-Winning Multinational Conglomerate with
       | over Two Hundred Years of Business Experience?...If not, whomtech
       | has you covered.
        
       | BlimpSpike wrote:
       | How loud is it? Would it disrupt the whole office if I had it on
       | my desk and occasionally played with it?
       | 
       | Very cool, I'll check back for the Kickstarter!
        
         | uncial wrote:
         | With the FDM-printed prototype version there's a noticeable "a
         | mechanism is occuring" sound, largely due to layer lines. Tbh
         | it's not too loud rn but I'm confident we can get it smooth and
         | whisper-quiet using any vaguely sane manufacturing technique
         | (defaulting to injection moulded ABS but we have some options).
         | The marbles/roons themselves are silent, it's just a question
         | of getting the barrel cams to play nice.
        
         | thenthenthen wrote:
         | The first idea that came to mind was, how to trigger sounds
         | with these functions! Would be a mesmerising synth! Well done!
        
       | cuken wrote:
       | This is really really cool! The physicality of it is special and
       | can be a huge help with some people to gain an understanding of
       | whats actually happening on the micro scale. Reminds me very much
       | of "Spintronics", a game that holds a special place in my heart
       | as I could teach a traditionally conceptual topic to my kids.
       | 
       | Are the designs you've come up with 3D printed? I feel like
       | there's a huge possibility of community advancement into this
       | ecosystem (fully appreciating you should make a return on all of
       | your time and creativity).
       | 
       | Thanks again for sharing something so cool.
        
         | uncial wrote:
         | Thank you! Yeah, I was trying to lean into the idea of "shrink
         | yourself down into a computer and physically manipulate the
         | bits", think it's the best way to understand what computers are
         | actually doing.
         | 
         | Spintronics is really wonderful, not just for its cleverness
         | (which is extreme) but also the total concept and aesthetics --
         | absolutely something I'm aspiring to.
         | 
         | And yeah these are all 3D printed. Agree with your sentiments
         | around community stuff, I don't have any fixed ideas there but
         | I would be absolutely delighted to see how people can build on
         | this. There are _so many_ possible physical cellular automata
         | to explore; this is just one.
        
           | cuken wrote:
           | If you ever open up the designs or want another set of eyes
           | to print on some other devices / take a crack at generating
           | new components, please let me know (looking forward to the
           | kickstarter).
        
       | sneha_tamal wrote:
       | that is awesome, how do you see this evolving for practical use
       | cases? Is it just for education and experimentation, or could
       | something like this scale for more complex tasks?
        
         | uncial wrote:
         | So I don't think _this specific_ implementation has practical
         | use cases (someone prove me wrong!), but there 's a really
         | really cool general point here--
         | 
         | We've had this technology for centuries.
         | 
         | Seriously. This doesn't need transistors or clever materials.
         | Mechanically, it's much less complicated than what (say) 18th
         | century clockmakers were doing -- it's just bars going up and
         | down!
         | 
         | So if you'd asked me 200+ years ago, I'd say: this device can
         | compute nautical charts, calculate differential equations, and
         | some third incredibly useful thing. Nowadays we can do all that
         | much better with silicon etc, and I don't see this competing
         | practically on that playing field...
         | 
         | ... but I think it's useful mental technology to _notice_ that
         | there were simple ways to perform arbitrary computations,
         | accessible much earlier on in the tech tree, that sort of got
         | skipped for some reason. So while roons is probably siloed to
         | education /experimentation/fun, I really hope it inspires
         | someone to go -- what else are we missing?
        
       | duncancarroll wrote:
       | This is the coolest thing I've seen in a long time. I've always
       | wanted to see this visualized and the marbles make it so tactile
       | and real.
        
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       (page generated 2025-05-01 23:01 UTC)