Turing 201: Turing Machine Explained! (More than you ever needed to know...)

There aren't many modules as iconic as the Turing Machine - for a long time it was the the go-to for starting to explore generative music. It may have been eclipsed somewhat by Mutable Instruments Marbles, but Turing Machine is still my mainstay. When I started using the Monome Teletype for generative stuff, it made sense that I'd want to recreate the Turing Machine in that environment. The next video in my Teletype series is going to be about that - but in order to tell people how to recreate it, I first have to explain how the original works. That's where this video comes in.
Lots of videos will tell you how to use Turing Machine, but I haven't seen anyone really dig deep into how it works. So come along with me and learn more than you ever needed to know about one of the coolest uses of just a few logic ICs there is.
To get your own Turing Machine, head on over to Thonk: www.thonk.co.uk/
The (many, many) slides from this video are available at: bit.ly/turingmachine201
00:00:00 - Introduction
00:01:47 - Usage review
00:05:28 - Shift Registers
00:07:36 - Making a repeating pattern
00:08:18 - The Pulse output
00:08:31 - The Write switch
00:09:12 - Flipped bits & the double length trick
00:10:28 - Randomness & probability
00:11:19 - Output voltage
00:14:53 - The whole picture

[@tombola2004]

This is GREAT, thank you so much for doing this.

[@SoundVoltage]

My pleasure Tom - and you did all the hard work, I just made a video about it. :)

[@chitlun]

You’re THE MAN Tom, cheers!

[@rayderrich]

Very useful talk about one of my favorite things to do in modular. Thank you.

[@obsidiananvil9719]

Three minutes in, and I'm grinning-like-an-idiot. Excellent presentation. The pace, the knowledge, the hands-on timing, and your voice are spot on. Well done.

[@SoundVoltage]

LOL, thanks so much! I'm hope it's helpful!

[@stumptownsculptor]

Panel and boards just came in the mail today. So glad to hear about how it works before putting it together. I doubt I’ll really understand it but, every little bit helps. Thanks so much for this video!

[@SoundVoltage]

You're really going to enjoy it I bet. 5 years on and I still come back to mine regularly. Welcome to the Turing club! (Also, it's a pretty reasonable build!)

[@MirlitronOne]

At last I understand this module! Thank you!

[@sound.workshop]

Fantastic video. Now I want to buy a Turing machine because it s such a beautiful circuit. Thanks for sharing!

[@bill77]

This was very well done! The Turing Machine is still one of my most favorite modules. It is great there is still so much interest in it. Your presentation was so excellent that I think I'll have to check out your Teletype videos just to see what that is all about.

[@MrMarcLaflamme]

After watching Mylar Melodies’ video on how awesome the TM is (plus expanders) this is exactly what my curious brain needed! Adding my +1 to cover the Volts add on. That one still makes my head hurt. I wish the panel had notches on the scale knob so you knew when you were setting 1 or 2 v(oct) limit.

[@SoundVoltage]

Hope it was helpful! So, Volts isn't too hard to explain. The first 5 stages of the Turing Machine are connected to the 5 knobs on Volts. If that stage is active (the LED is on) then it adds that voltage to the output. So if you have each of the knobs dialed to 1 volt and stages 1, 3 & 5 are lit up, then it will output 3 volts. (It's more interesting if you have different settings for each, obviously) The big trick is that each knob goes all the way up to 8V or so, and the whole module tops out at 8V. So you really have to keep everything dialed down to like 25% or so or it just maxes out most of the time. If you remember the part from my video where I talk about voltage output, and one stage adds 4.22V and one adds 2.11V and 1.05V, 0.52V, 0.26V, etc. It's like that except the value it adds isn't fixed, it's set by the knobs.

[@MrMarcLaflamme]

@@SoundVoltage starting to make more sense now. I think what was missing was understanding exactly how the base TM worked. I didn’t know how on/off bits translated to different voltages but after seeing you equate it to binary it made sense. I wonder if TM mk3 could have a switch to toggle the voltages to a v/oct range so you don’t need a quantizer? Also a slew knob on the output would be awesome.

[@DCBMusic]

Definitely the most informative video I've seen on this. Good job demystifying the Turing Machine!

[@omnidivergence9846]

Wow!!! Fantastic detailed information here. I have been interested in understanding shift registers so that was very helpful. What a fascinating system.

[@chemicalBR0]

This was superb, I've had a turing machine for years (and built about 6 of them) and I was always curious exactly how it does what it does

[@axeman2638]

so you built them but didn't bother to find out how they worked?

[@chemicalBR0]

@@axeman2638 I know how to use them I just wasn't exactly sure of how it did what it did. I'm sure you've put together a plastic model kit at some point.... do you understand how injection moulding works and how those kits are made? or you've built some pre packed furniture. do you know how to make a pre packed furniture kit and all the steps involved? putting a kit together and using it is completely different from understanding how the module does what it does and the design of the circuit. the video is titled (more than you ever needed to know). in other words you don't need to know how it does what it does to build and use them the ONLY thing you need to know to build a turing machine is how to solder and follow simple instructions. as with most things in life we don't care how a thing does what it does we just care that it does the thing it's designed to do.

[@axeman2638]

@@chemicalBR0 "as with most things in life we don't care how a thing does what it does we just care that it does the thing it's designed to do." oh dear, failure of curiosity, this sort of attitude is a big part of why the world is in the mess it is in.

[@Sam-do4oj]

Fascinating!

[@garaughty]

A seriously brilliant tutorial !

[@SoundVoltage]

Thank you! The Turing Machine is a really remarkable module and I'm glad to have a chance to really get to know it and try to teach others!

[@dmikalova]

Thank you so much for all of your videos!

[@scrampop3353]

This is a great presentation, not that I'll ever code a Turing machine, but I do like playing with it.

[@EfeuWinterfest]

Great! I got my Turing Machine + expanders today and try to understand what happens 😃

[@SoundVoltage]

It's great fun! Welcome to the club :)

[@Psionetics]

Excellent work!

"Eventually, I cracked the code." I see you

[@hoofjaw]

This is ace. Thank you.

[@nothingness.emptiness]

This is a great explainer resource for understanding the Turing machine in more detail. I think I will recreate it in code for fun maybe run it on a microcontroller.

[@SoundVoltage]

It's a surprisingly simple algorithm. I have a video coming where I implement it on the Monome Teletype and it can be done in, literally, 7 lines of script. It's totally worth doing to explore the idea and expand on it

[@briankokernak2804]

This was excellent, thank you so much. I was wondering why I was always seeing voltage on a step that didn't have an LED lit.

[@projeto-inutilimages4027]

Great class,

[@kostantinosmag2986]

Very nice 🎉🎉🎉🎉🎉

[@MeeBilt]

Great video!

[@SoundVoltage]

Glad you enjoyed it!

[@atorgon]

Excellent work! I was also intrigued by the working details of this module and so I also had studied the schematics and done the same kind of experiments that you did, although only on the emulated version of the module by Stellare Modular for VCV. The interesting thing is that I found a small disagreement with respect to your experiment. On VCV, when I set a single bit at 1 and let it shift through, instead of an ascending series of steps doubling the voltage every time, I get exactly the opposite thing: a descending series of steps at half the voltage every time. It puzzled me at first, because the active bit is circulating from LSB to MSB on the DAC, so I expected the kind of behavior that you observed. However, I noticed in the schematic that the output is connected to the Iout_bar pin, and looking at the datasheet of the DAC0800 it seems that this is equivalent to inverting the weights between the bits (LSB MSB). So I was reassured. Now that I see your video I wonder: if you build your module yourself, could it be possible that you connected the output to the Iout pin instead of the Iout_bar? Otherwise, maybe it is the VCV implementation of the module that could be wrong... In any case, I feel that the descending notes give a more conclusive, satisfying melody than an ascending series of tones. I would be glad to hear your opinion on this point, and also on the detailed workings of the Volts extension (shouldn't the pots on the bits at 0 take some current and modify the output tension?)

[@SnoopLazeranake]

This was really interesting! May I ask, when can we expect to see the video on programming it into Teletype? That’s something I’m very interested in trying.

[@SoundVoltage]

Actually, it's probably my next video! (Or maybe second, I think I have another silly short video about Teletype first) But it's coming soon! I have a lot of the code already written.

[@SnoopLazeranake]

@@SoundVoltageExcellent to hear! Can’t wait to see it.

[@henriquematias1986]

Love the arpeggio pattern running on the background from the very start! was That generated with the turimg machine as well?

[@SoundVoltage]

I believe that it was!

[@dfpratt09]

Super cool. I was not entirely sure how the Turing Machine actually generated patterns, beyond reading that it had something to do with shift registers. Sort of a side note, but Have you seen the newish Xaoc Devices Leibniz Binary Subsystem? It took me a little bit to wrap my head around, but now I really want to build a little satellite system based around it, and binary information in a modular.

[@Quark.Lepton]

Very very cool and totally useful! 🫵🏻😃 Thanks! What I’d like to try is to feed local weather data as voltage sources into it as a kind of random sequence driver 😆🎉

[@Trippsy05]

I have no idea what this is or why it's in my recommended but it's really cool despite being way outside my ability to understand. Is this how HOME made their music?

[@SoundVoltage]

Thanks for watching even if it came out of the blue. :) It might be what HOME used, or something similar. Semi-random/generative techniques come up in weird places :)

[@flaminggarlic]

This is great. What did you use for the visualiztions? I need to make something like this to explain my module Aristotle.

[@SoundVoltage]

Many of the slides are just Google Slides, but for animations I've built my own animation library in Javascript that I then do a screen capture of. Do you have a link to your module yet?

[@mightymike1978]

1 Word: Mega!!!

[@mortensmodules]

Great video! This is really well explained! I love the Turing Machine - It's always my goto when I need to fire som random MI Rings for ambient stuff. But one question! Why does the Volts expander have 5 outs?... Why 5? What are their relation to the shift register values? - Am I missing someting essential here?

[@SoundVoltage]

Hey @mortensmodules, thanks, I appreciate it! I had to go find the Volts schematic to see what it was doing. Remember from my video that TM takes the first 8 steps of the shift register and gives them different voltage levels, and then adds them all up? Those voltage levels are fixed and one is half the level of the previous. In Volts, it takes the first 5 steps of the shift register, and instead of adding up fixed values like the TM, the 5 pots on the Volts decides how much each step adds. And then it sums those all up, and that's the output from that expander.

[@mortensmodules]

​Thank you very much for your time and reply - it was great to have this cleared up. I myself have Volts, and use it a lot, but I have never been able to fully figure out the connection between TM and Volts output. It still surprises me a little that it's 5 pots and not 4 or 8 (which would fit better with a register), but it's maybe a sweet spot that the output won't be very small or very large on average, due to the associated volt values . The Turing Machine is probably my absolute favorite module, and am still considering getting an extra one. Kind regards Morten

[@mastermachetier5594]

What version of the touring machine is the on You built?

[@SoundVoltage]

Just the standard version that is sold by Thonk. I built it, the expanders, and then mounted them all behind the custom panel.

[@ryushogun9890]

I'm obsessed with electronic looks, but I'm not too smart so I can't understand the relationship of memory and energy being put in.. Is it like a mathematical formula that is used for most of the possibilities?

[@studio48nl]

@4:45 with more LEDs turned on, how do you know at which step it is? Or is that a totally wrong idea of how it works? I understand the 'new value' will fall out of the end of the register, but what is the use of the 'one LED' advancing in the beginning of the video?

[@jordanmuller4735]

No code? So are you saying this module is analog?

[@SoundVoltage]

@jordanmuller4735 - There are a couple of shift registers in there, just simple ICs with flip-flop circuits. They are effectively storing on/off 'bits', but that's as digital as it gets.

[@jordanmuller4735]

Ah good to know, thank you. My curiosity is mainly about module placement in my rack, ie put it on the filtered bus board with the rest of the analog stuff or keep it with the digitals. Sounds like I can treat it like an analog module.

[@Bishka100]

Right at the end, I thought, "Sense not make you"... Then I realized it was yada yada yada, not yoda yoda yoda. Sometimes I astound myself with my own idiocy.

[@Soundbrigade]

"Thanks Bob!" 😂 Are you debunking flatearthers too?? (Bob being Bob Nodel of the Flat Earth Society) I like those "music generation machines" and before I heard about the Turing Machine I bought me a pcb for Cat Girl's iNfinity Melody that are sorted in the same cathegory but works a bit different as the random signal (noise) is fed into the look, not clocking it.