The Selection Accumulator; a Jukebox's Brain

[@TechnologyConnections]

Astute viewers will notice that it's been much longer than a week since the last video. In light of everything going on in the real world right now, I hope this can serve as a meaningful distraction. I, as I'm sure is the case for many of you as well, am unsettled by a lot and it's hard to work, or even just think. I have never felt that I've been an anxious person, and now I'm learning what real anxiety is. This pinned comment surely doesn't mean much, but to everyone watching; please be safe. Make as many technology connections with loved ones as you can, and keep your chin up.

[@Leo9ine]

Thank you for those words and for this video. Listening to you talk about the inner workings of dated technology is exactly the soothing and familiar comfort I (and all of us) need right now. It brings a sense of peace and normalcy amid the anxiety. Stay safe

[@JoeHamelin]

You stay safe too, buddy.

[@RSpudieD]

It's a crazy world out there. We don't blame you at all for the delay and wouldn't mind either if it took even longer. Stay safe!

[@TechGorilla1987]

You mean the complete media driven insanity?

[@GRBtutorials]

I... didn't notice it, probably 'cause I was at home and time passed faster (and on regional holidays, which happened to coincide with quarantine, so no remote school/work either, we start tomorrow).

[@DanielBrownsan]

If I could bring my dad back, it would be to sit with him and watch - and talk about - this video. When I was young, he would sit and explain things to me just like this. We dismantled an entire pinball machine and he showed me how every piece of it worked. Thank you for the walk down memory lane...

[@carlosmontgomery4178]

pinball or flipper? :) old-school or electronic? :) :)

[@tobywarren6151]

HEY DONT MAKE ME CRY!

[@Courtj3st3r33]

My dad has a jukebox, he's watching this next time I see him!

[@raydunakin]

That's awesome. He must have been a cool guy.

[@NotCerius]

Whoa. This really hits home, because I used to do the same with my dad. I should give him a call. And I'm sorry. :(

[@NickJabbour]

I bought out the remnants of a TV and radio repair shop whose hay day was ca 1960s and 70s. Get in touch and I’ll get you those springs and relay, no charge. Lots of resistors and switches and solenoids. This could be the distraction I need.

[@Earthstar_Review]

This needs more visibility.

[@calvinthedestroyer]

@@Earthstar_Review bumping

@@calvinthedestroyer Bump up

[@aggrotits.thunderbelch]

⬆️⬆️

[@SamHarrisonMusic]

Amazing! when you find exactly the person you need through youtube :) what a star Nick!

[@AlRoderick]

Fun fact, this mechanism makes it impossible to queue up more than one playing of What's New Pussycat by Tom Jones in a row.

[@nullvoid3545]

FALSE!!! you assume i have only 1 copy of What's New Pussycat by Tom Jones!

[@liquidsleepgames3661]

Did that once. Banned from the bar for a week.

[@liquidsleepgames3661]

@Michael Persico some who knew a good troll song

[@Jdp313]

John malney

[@khatharrmalkavian3306]

You can re-queue the currently playing song, but there's no way to get any of the other songs to be queued more than once, since the queuing signal is a single bit.

[@gretarreynisson3280]

“Charmingly ugly and stylistically repressed” How did you find my Tinder bio

[@CurtisDensmore1]

👏

[@teaser6089]

Haha

[@bsadewitz]

Isn't that the title of a song by Morrissey?

[@aronrad]

Just kept right swiping the contact pads until someones solenoid had current going through. Classic electromechanical pick up technique from the 70s.

[@HaydenX]

@@aronrad Wait..."pick up"...you dirty, dirty punner you.

[@Asphesteros]

Love how this implies Fonzie’s power to make a jukebox play by hitting the side is actually kind of maybe plausible. With so much done with little leaf switches, maybe for some designs a vibration from a good smack could momentarily close a circuit that’d register a credit or start a chain that powers an operation. Neat!

[@xaenon]

A mercury switch wired into the credit mechanism could do it easily

[@RipOffProductionsLLC]

I wouldn't be surprised if such a critical design flaw existed in some early coin-operated machines, and I'd hate to be the engineer responsible when such an issue was discovered...

[@ghostmantagshome-er6pb]

Heyyyyyyyyy

[@Shadow81989]

I particularly like one thing you glossed over: The "perfect-alignment-pin", in addition to aligning the record holding wheel, also mechanically locks it into place! This is a very important safety mechanism, because over time, relais will start to "stick" when energized, as the electricity heats the contacts (mainly when they become a bit dirty and rough), and thereby welds them together. In that case, the electrical interlock switch (which should stop the motor) would fail, and it would still turn with the disk-grabby-arm in there! This additional mechanical blockade will make sure this can not happen, even if the relay "breaks" at some point, and is an (almost) 100% certain way to protect your valuable disks.

[@SpikeOriundo]

"You thought the last video was complicated?" I dunno honestly, I just like listening to how technology works, understanding it is a whole other level that I don't really try to dabble on.

[@potterfanz6780]

10:40 "I don't know. I've been staring at these schematics for hours, and my brain hurts." Ah, the joy of working on EMs.

[@Darxide23]

There's a difference between complex and complicated. This thing is complex, but it isn't very complicated.

[@ChaunceyGardener]

He went from the toaster straight to this. I heard next video is commercial aircraft hydraulics.

[@IstasPumaNevada]

@@ChaunceyGardener Maybe he'll do a collab with Wendover Productions. ;D

[@admthrawnuru]

"this jukebox is what turned me into the weirdo that I am today" Omg, my grandma was right about that rock music!

[@perrybrown4985]

A shame we never had hydraulic computers - "numeric overflow" would have been so much more obvious.

[@two_number_nines]

isn't the valvebody in automatic transmissions exactly that?

[@MattMcIrvin]

en.wikipedia.org/wiki/MONIAC

[@MattMcIrvin]

and: en.wikipedia.org/wiki/Water_integrator

[@MattMcIrvin]

(Terry Pratchett put a nod to MONIAC in one of his late Discworld books, "Making Money")

[@nthgth]

@@two_number_nines Good point. At least before electronically controlled transmissions

[@avlisk]

What I learned: "Out of Order" is the normal condition of this machine. It is a miracle if it's working at all.

[@deathstrike]

Wurlitzer is well known for making complex EM machines. It is somewhat similar to EM (electromechanical) pinball machined. I have a few of them and maintenance is a pain due to corroded, worn, and bent contact pins. You also have to have precise feeler gauges to measure the distance between contacts and switches. And the motor assemblies have to have a strict oiling schedule to maintain proper lubrication and to check for wear, dirt, and corrosion. Ugh it's harsh and Rowe and other manufacturers went to simpler mechanisms and transistor components to ease the workings.

[@harrisonernst2990]

@@deathstrike is Seeburg comparable to Wurlitzer in terms of complication or Rowe?

[@deathstrike]

@@harrisonernst2990 To be honest? There isn't much difference tech wise between Seeburg, Rowe, and Wurlitzer. The bulk of the "juke era" machines from the late 30s to the late 60s incorporated tube amplifiers, mechanical sun and moon gears, and a ton of copper switches. It is not unlike the early pre electronic phone systems and EM pinballs. So is one more complicated or harder to work on? Depends. Seeburg actually had a really cool console jukebox that was similar in size to a home stereo cabinet from the 50s, great little box, until it breaks. Ugh, a huge headache due to compact wiring and tighter fitted switches and gears. So the only one I would say would be more "complicated" to work on is Wurlitzer especially the "bubble tube" systems. But as the solid state era ensued relays were replaced with transistor switching, tubes and heaters were replaced by solid state amps and selectors simplified with electronic board and optical sensors. So no particular one was easier or harder to work on per se but given a choice? I'd take solid state, much easier than the pain of insuring proper gear meshes and synchronization of selector switches.

[@harrisonernst2990]

@@deathstrike thanks for the info! Very cool to learn about these machines! I have an old seeburg wallbox and I got it to work with a jukebox emulator. I found an ice cream place by my school with a seeburg jukebox and tens of wallboxes, all working! Ever since then I’ve been obsessed.

[@deathstrike]

@@harrisonernst2990 Awesome!! One word of advice, old jukes and pinball machines just be patient with them. Takes a lot of time honored elbow grease and enjoying the hobby. There is a massive amount of data on many old machines and with time, you can restore even the worst machine.

[@AlanCanon2222]

I really like how conversational your manner is, gentle humor but not straying too far from the subject. All carefully written, too, obviously. Your craft as a writer/performer shows to those of us with some experience along those directions. It's nice.

[@watchm4ker]

"Deterministic Pushdown Automaton" is the term you're looking for. It's a step below a computer, as it takes instructions, and has memory, but lacks the functionality for true computation, such as branching instructions.

[@KarimElHayawan]

+

[@MrGardenofeden]

Are you sure this cannot be achieved with a finite state machine? The number of LPs in fixed, so there is a finite number of possible states the machine can be into.

[@andrewmicone99]

Finite-state machine, a DPDA has a stack, a finite state machine doesn't have a stack. This machine doesn't have a stack.

[@Stoney3K]

@@andrewmicone99 And a "mechanical finite state machine" is just a fancy name for a cam-driven sequencer. You can also find these in washing machines as well as old VCRs where the cam operates a mode switch.

[@buddyclem7328]

@@andrewmicone99 I would argue that the machine has a kind of stack, but not a sequential one, like FIFO or FILO. The sequence follows the order of the records selected, until all the selections have been played and cleared.

[@rabidpb]

10:29 RY1 is turned on by a pulse to 47. One of the contacts of RY1 itself then holds 47 high from the voltage on 32, making RY1 self-latching. The low side of RY1's coil is normally held low through RY3 to 22. When RY3 is activated, that low side is switched to 52, which continues to keep RY1 active. Near the end of the cycle, 52's ground connection is interrupted by the stepper, de-energising RY1 and releasing it.

[@grn1]

Liking and commenting to hopefully push this up to where he'll see it.

[@deathkiller008]

here to help him see this even if it is a year late!

[@bhull242]

Here to help him see it even if it’s _two_ years late!

[@TEAserOne]

Helping I guess

[@raydunakin]

This whole machine is so insanely complex I can't even imagine how someone was able to invent it.

[@overloader7900]

How did developers developed spagghetti code?

[@cmelton6796]

@@overloader7900 They tangled the wires and chaos ensued

[@control_the_pet_population]

@Isaac Eiland-Hall I agree... the individual tasks aren't terribly complex, it's more the integration into the coherently operating whole that's the tricky part.

[@ponocni1]

Welcome back, sethbling here. Today we are making electromechanic jukebox. Its quite simple. All you need is bunch of redstone, pistons, redstone torches, repeaters, comparators. and thats about it.

[@LuisMendoza-pp9qi]

Engineers back then were far more inventive, imaginative and smart than the overpaid entitled techies coders that you can find at startups this days....

[@Bobrogers99]

Way, way back in my teens, I fed in my coins and made my selections, and I never realized what a complicated process was being initiated. The jukebox was quite a large number of complex electromechanical machines which interacted with each other to play my music. I marvel at the engineers who planned it all, but also the mechanical wizards who put all the pieces together to make it work!

[@Pyrolonn]

I always thought, "what a ripoff! Pay 10 cents for something you could play at home for free!" What I didn't understand at the time, you're paying for the delivery system, not the record. And of course the value isn't in hearing the music it's for boys and girls to meet and interact, and that of course is priceless.

[@boobah5643]

Modern equivalents are certainly no less complex; it's just you can't take the cover off and watch them 'think.'

[@sharedknowledge6640]

Bob Rogers this thing is a marvel. I’m sure they must have been interesting to service as well. I suspect a lot of the service was done under a contract at x dollars a month or year which gave the manufacturer incentive to make them reasonably reliable and do things like put light bulbs in them.

[@Bobrogers99]

It would require a well-trained service agent to keep them running smoothly and to troubleshoot problems, so I agree that most were probably under a service contract. So many little switches and relays, and so many little mechanical widgets to wear out!

[@Zigfried207]

Now learn how a microcontroller works🥱

[@R_C420]

Bought a beat up statesman, at a second hand store Didn't know how to solder, but he knew for sure That one servo, felt good in his hand Didn't take long, to understand Just one relay, pinned way down low Was one one-trip circuit, to a selection row So he started probing, and never gonna stop Gotta keep on testing, someday gonna make that record pop And be a jukebox hero...

[@dashcamandy2242]

*NICE!*

[@shelby3822]

A tip of the cap sir

[@BEM684]

I'm pretty sure that's the best comment this video will get.

[@shannonrhoads7099]

You win an Internet.

[@TheNebulon]

This comment needs a donate button

[@narcoleptic8982]

As an electrician, the amount of engineering behind this is absolutely mind blowing. I have training and experience with relays\contactors and their wiring, but this is just taking it to a whole other level. Absolutely fascinating. Thanks for taking the time to pore over those wiring diagrams and service manuals. Troubleshooting these things must have been a nightmare.

[@xaenon]

It was not for the timid.

[@DillonStrichman]

Currently working as a lab technician for the electrical engineering department of my community college. In an era of embedded systems, it can be so easy to forget the painstaking effort put in by the engineers of days past. The Mechatronics students loved these videos -- Your presentation is just so endearing, inquisitive, and informative -- a surefire way to cultivate a nascent fascination, and an attitude I have always tried to demonstrate in the lab :) Always looking forward to new videos!

[@isaacspradling2777]

"This is literally a side note" You are always a source of comedy gold, good sir.

[@gamingmusicandjokesandabit1240]

15:10

[@Schplatnel]

I find it very nice how almost everything in the machine is labeled, with full words & numbers and not just shortenings that you’re supposed to figure out. Probably makes maintenance a less confusing task... though how complex the machine is probably makes maintenance very difficult in the first place.

[@zorgatron8998]

This is mesmerizing. This satisfied my brain in a way similar to the TV show "How It's Made" on the Science channel.

[@SquishyZoran]

Same but I wish they would make new episodes and wonder why they don’t.

[@nuvan83]

dum... dum dum de-dum... whee-woo

[@SpydersByte]

used to love that show!

[@PhilipSmolen]

New Mind is an independent channel in the spirit of "How It's Made". kzbin.info/door/5_Y-BKzq1uW_2rexWkUzlA He does a pretty good job.

[@pomonabill220]

Yes it is satisfying. "How it's made" though doesn't go into the detail that these two videos went into. Of course, they don't have the time to do alot of detail, and sometimes is frustrating.

[@GlobexCorpOfficial]

"I've been staring at these schematics for hours, and my brain hurts." So very relatable.

[@sammiller5509]

makes one glad that we have Grafcet now😂👍

As an electronics and computer science major, yes. If it's someone else's code or electronic schematics, looking for faults can be *absurdly* exhausting.

[@rationalmartian]

LOL. Yeah I grew up with one of our toilet walls having constantly changing schematics/wiring diagrams. My old fella was an Electrician down the Pit. Whenever any new equipment was installed or he moved to a district with different tackle he would pin up the drawings and smoke a few cig's while he had a dump and bone up on the diagrams until he knew them. I can still hear him. "Diagrams are allreet and sometimes needed. But it's up theer theh wants it. He had a thing about sussing out the problem while he was walking to where the problem was. And down a shithole coal mine, buggering around with big paper drawings was a pain in the arse. I should know. I ended up as a Engineer/Fitter down the same Pit. I had to do the same with hydraulics schematics and drawings on occasion. Though I wasn't as conscientious as my Dad. He was known for it.

[@dstone1701]

That's the story of my entire career as an electronics tech.

[@nightcat7741]

same feels which makes me kinda thankful I'm not currently studying this in school 😅

[@TheRealMikeWilly]

I never intended on knowing this much about how and why a jukebox works. Now it's 6:34 am and my alarm went off 4 minutes ago and it's time to get up and go to work. Thank you for keeping me up and not getting any sleep. I can always depend on your channel any time I'm craving a "KZbin rabbit hole" experience while actually learning something.

[@carlosdanielcruz3597]

Read your comment at that exact same time. Makes two of us bro 😆

[@musickid43]

After seeing part 1, I went to my Aunt and Uncle's house where they have an old Rock-Ola 433 GP Imperial (my best guess of name based on research) jukebox that I haven't seen in years. It still works. My uncle started talking about how he hasn't heard these songs in years, I started analyzing how the selection works, yes I opened it. I'm in a same spot where seeing this machine as a kid has lead me to my current career as a programmer. Thank you for the video.

[@Caramelldanson]

15:14 It's probably so that the side selection in the documentation could be consistently referred to regardless of how the user oriented the records in the carousel.

[@I_Santos_]

You, good sir, are a gem. Your explanations are so detailed and your passion for this stuff permeates your delivery. And don’t get me started on your sense of humour. One of the most entertaining channels about “boring” things. I’ve actually learned quite a lot here, thank you.

[@WookieFragger]

I feel like a dork for how hard I laughed at "This is a literal side note", but that was just way too funny

[@sevilleandcoarthouse2960]

Ha dork

[@BaghaShams]

Imagine being the person who slaved over engineering these mechanical marvels, and then witnessing the digital age come around where all this can be done in a few lines of code embedded in a $0.50 chip.

[@grn1]

I imagine quite a few of those guys now program said 50 cent chips. These old electro-mechanical systems are what led to the creation of the first micro-controllers which led to computers as we know them today. The new chips are easier in many ways to use but actually designing them is a whole other story.

[@bobbuilder3748]

I imagine most of them are dead by now.

[@MrDuncl]

I'm sure they found other similar things to design. Ever seen a pen potter in operation ? kzbin.info/www/bejne/fZLOYoimmtZ6otE In the 1980s we had one at work that was bigger (A0) and an awful lot faster (and I would guess more expensive). The 21st century equivalent would be a 3D printer.

[@shackman9566]

They still need some sort of mechanical mechanism to control. And it's been my experience that those old time engineers did alot better job of building the mechanical systems. They are much more reliable and robust. Everything today is disposable.

[@DOCTOR_SONG]

Yeah !! TELL ME ABOUT!!!!! This chippy stuff just too tempremenral

[@mr.johnson3844]

If I were one of your parents, I would feel very, very proud after watching this video.

[@BoopyTheFox]

Technology Connections is the only youtuber that can completely occupy your attention yet put you to sleep when brain shuts of trying to understand everything.

[@EdwardMillen]

This! I watched the first part of this last night but only got a few minutes into this second part before I had to give up and go to bed, but I wanted to get straight back into it today because it was so interesting. And I'm pleased to say I actually feel like I understand how it all works now!

[@KarlaO711]

Yeah I fall asleep too on his videos. He has such a nice tone to his voice while explaining things. :)

[@meathead585]

And such a relaxed and just wonderful sleep it turns out to be. Nothing like it.

[@adnamamedia]

I love how absurdly complicated electro-mechanics are. I could only imagine how long it took to engineer this thing

[@aleksandersuur9475]

Engineering is not a one man job, it's typical for a team or several to work on a design for a few months or longer. Without modern engineering aids everything takes longer and has to be done in a simpler fashion, but in general this thing is fairly typical machine for the era. And I highly doubt they started from a blank sketch, for sure the company had previous experience with similar and progressively simpler machines and they might have outsourced bits of it. What really boggles the mind is the economics, it must have cost a fortune to make it back in the day even after amortizing the engineering costs and it had to earn it's keep by collecting coins at the corner of a bar. I'd really like to know what it might have cost back in the day and how that made any sense.

[@rickc303]

@@aleksandersuur9475 exactly, because the whole purpose of this thing was to make money from playing songs lol

[@BaddeJimme]

@@aleksandersuur9475 It could be regarded as a loss leader. It gives your customers music and is much cheaper than having a resident DJ, and if the DJ would spend most of the night playing requests the quality of the music will be mostly the same. That said, you should not underestimate the earning potential of a machine collecting small change in the corner. If it's playing a record every 5-10 minutes, it will collect a heck of a lot of small change over several years.

[@aleksandersuur9475]

@@BaddeJimme Yeah that makes sense, good point. The point of a bar is to sell drinks not music, music just helps the drinks flow.

[@raygunsforronnie847]

@@BaddeJimme I wouldn't characterize a juke box as a loss leader, but as another way for a tavern, restaurant, pool hall or skating rink to generate a little more "revenue per guest." The cost of designing and building an industrial-strength coin operated record player gets amortized across the 20+ year commercial life expectancy of the machine. In tavern location rentals often the coin equipment owner is also the land lord. The business pays weekly rent on the juke box, pool tables, pinball machines and other amusements from the cash boxes on those machines. Any money remaining is split between the tavern and the coin operator. If the amusements don't make their rental the tavern has to make up the difference. The whole coin operated machine biz has an interesting organized crime back story, too.

[@TheJacklikesvideos]

I can't thank you enough for taking me on this tour through all the questions I had as a child in bars.

[@scaper8]

Not goning to lie, as conventionally "ugly" as that thing is, with the purple under the nameplate and amber around the selection buttons, is has a certain beauty to it.

[@eternalephemera]

It’s really awe inspiring to think of the work that must have gone into its design for it to be so ugly.

[@herzogmeow5596]

Not that different from computer programs, things are most likely very ugly behind the scenes

[@BixbyConsequence]

Designed to be unobtrusive for toned-down bars and restaurants, as opposed to the flashy ones in diners.

[@TheTerribleUsername]

*"g o n i n g"*

[@scaper8]

@@TheTerribleUsername Ah yes, I missed a typo. The shame.

[@allmycircuits8850]

Sorry for another comment, just can't stop :) These two motors and solenoids are THE FIRST EVER USELESS BOX and what a magnificent box it is! One rotating arm opens switches while another one closes them one at a time.

[@Pcat0]

If you consider this a useless box then it would be far from the first.

[@snaj9989]

@@Pcat0 Well its usefull afterall.

[@xm1193]

“Wurlitzer’s way ahead of you...” sounds like a fabulous slogan.

[@WillowEpp]

1940s - Various "computers" are "programmed" using direct wiring and switches. Engineers do this in order to avoid the tabs vs spaces debate.

[@superdingo9741]

@@tthung8668 4 spaces beats tabs.

[@drwahnsin6867]

@@superdingo9741 4 tabs!

[@someonerandom9939]

@@cmmartti I don't use spaces because it only takes one backspace to make a potentially hard to see problem in a language that is ugly enough to use indentation to dictate bodies of control statements

[@DeeSnow97]

Anyone who uses tabs is objectively wrong for A. assuming everyone else's editor is configured the same way as theirs, and B. mixing two different types of invisible characters. The only acceptable use of tabs in all of programming is the Whitespace language.

[@DeeSnow97]

@@someonerandom9939 did you just call python ugly

[@imajeenyus42]

That is just incredible! Incidentally, the technique of using lots of pins that pop up to stop something at specified positions is exactly the same as the tab stops in a mechanical typewriter.

[@josephgaviota]

And rather like the keyboard of a Linotype machine.

[@therealcaldini]

Thank you for an absolutely wonderful pair of videos. My six year old son and I have sat transfixed through both films. I once heard someone say (of the Moulton folding bicycle) that beauty is inherent in anything that is entirely functional. I would also say that nothing is more captivating than a person talking about something that they know and love. Both are applicable to this feature. Once again, thank you.

[@kirbymarchbarcena]

@26:49 "This jukebox is actually what turned me into the weirdo I am today" Thanks, Jukebox!!!!

[@XanthinZarda]

Bitten by a radioactive jukebox, Alex had transformed in one instant!

[@waynenocton]

Dude, I’m thoroughly impressed by your ability to describe these things so well. I was a VCR repairman and have always just had to know how things work, and am pretty sure you are the same. Keep up the great work.

[@CarriageHouseCompany]

2 years later and I wanted to let you know how fantastic these videos are. I just got a Wurlitzer 3300 and am grateful for these videos to learn how these jukeboxes work. Well done!

[@millomweb]

"Somebody has rigged this machine so it behaves as though it always has a credit." You mean, at 5:41 they operated the "Free play switch" far right !

[@Stefan-]

Ha ha, that might be it...

[@DanBowkley]

I wonder if that's also totally bypassing the credit accumulator, making it appear dead when it's actually very much not dead yet...

[@UnacceptableViews]

@@DanBowkley you're probably right..

[@millomweb]

@@DanBowkley Probably - so coins are instantly returned.

[@Doktor_Calamari]

@@DanBowkley I feel like Alec would have tried that already. I mean, he's been swapping out relays and such.

[@Stoney3K]

"So, let's say you selected C-5." Great, now you sunk my battleship.

[@KSPAtlas]

Have a time to throw him and the man

[@KingdaToro]

If you select C-4, the jukebox explodes.

[@mapifisher]

@@KingdaToro happens in chess sometimes

[@tracyh5751]

Selecting A1 prepares an unreasonably well seasoned steak.

[@galxieranger8277]

C-9: the machine walks away from the payload losing the round. K-9: you've just selected Baja Men's one-hit wonder V-8: the vending machines start dispensing tomato juice.

[@biggityboggityboo8775]

Geez Louise! The designer of that should be given a Nobel prize!

[@BetaKeja]

The reason they're labelled side 1 & 2 might be because you can load the records either way. Side 1 could be side A or B depending on the record.

[@fungi331]

big brain moment

[@joest1231]

IIRC Jukebox discs were specially pressed, i.e. because of the limited capacity they did not have "B-sides" in the regular sense, they were all double A-sides. Also, I think the discs were actually supplied in packs, with pre-printed selection cards.

[@vyratron839]

joest1231 "double A sides" is confusing but I guess you mean they put hit songs on both sides so the jukebox wouldn't be half full of bad music.

[@joest1231]

​@@vyratron839 Yes, I started typing a description, but this explains it much better: en.wikipedia.org/wiki/A-side_and_B-side#Double_A-side . Jukebox disks were specially pressed though, so I guess referring to "Side 1" and "Side 2" on these discs avoided the offense of putting an artist on the "B-side".

[@stefankrause5138]

@@joest1231 year 2796: Archeologist: "Yes, they called it B-side, but there were also B-sides, that they have called double-A..." other Archeologist: "Fascinating!"

[@Celcius1]

If you speak to James the bald engineer at Add Ohms, might be able to provide you with guidance on how to repair the coin mechanisms electronics

[@Ender06]

or Clive from bigclivedotcom

[@Uzwel]

Or on EEVBlog

[@migkillerphantom]

No electronics in this device

[@michaelwarren2391]

@@migkillerphantom Except for the amplifier

[@christo930]

NO! There are jukebox collectors who understand these systems very well. There are jukeboxes from 1907! /watch?v=F8y2XXLRAcA There is a huge wealth of knowledge about old jukeboxes out there. Since jukeboxes were almost entirely unchanged from the beginning, at least conceptually up until the early 80s, there is a very good chance that these are known problems that are relatively easy to fix.

[@bborkzilla]

I was in a diner one night and the jukebox kept playing Sinatra's My Way over and over again until I unplugged it - much to the relief of the waitress who said it had been playing that all afternoon. Complex mechanical systems can have some pretty funny failure modes!

[@MisterNohbdy]

5:15 - Instructions: "Jukebox is on permanent free play." Maybe if you use White Out on that sentence, the credit accumulator will work again.

[@bjfincher773]

Those are labels I'm 99.9% sure Alec added himself.

[@White-Wolf1969]

@@bjfincher773 being the fact that they name Alec in them I pretty sure of it as well.

[@renakunisaki]

"I have no idea what this light is for" 😁

[@THE_CARBON]

Lol

[@jamescarl861]

Hello. I'm a computer engineer. When someone says "computer" these days, they're usually thinking of something along the lines of a Turning Machine. What you have here is a state machine. Even more simple than a state machine is combinational logic. Every one of these is considered a type of computer in my field. So in my personal opinion, I would say that yes, this is a computer. But no, it is not a turning machine.

[@sergeant5848]

It's a computer Captain, but not as we know it!

[@KaiCalimatinus]

Are you meaning Turing machines? I assume autocorrect had its way. Just helping any budding comp sci enthusiasts look it up easier, named after Alan Turing, the famed codebreaker and early computer scientist famous for work at Bletchly Park. Indeed, not every computer is Turning complete (able to theoretically run any program), but anything that computes logic is a computer I agree

[@npgabriel]

@@KaiCalimatinus Hah it happened to you as well

[@MaxBrix]

@@npgabriel Computers apparently do not like Alan Turing.

[@acidemperor]

Shouldn't that be Turing machine?

[@KermodeBear]

I am constantly amazed at how engineers so long ago were able to accomplish so much with so little.

[@K-o-R]

5:35 Rigged the machine by flicking that useful-looking "Free play" switch"?

[@TechnologyConnections]

As far as I can tell that doesn't do anything at all. I suspect someone has modified the credit accumulator in some fashion - I've tried moving that switch back and forth and nothing changes.

[@MostlyPennyCat]

@@TechnologyConnections But you're tracing lines with a multimeter, right?

[@TechnologyConnections]

@@MostlyPennyCat Honestly no, since I have no need for the credit accumulator to work in the first place other than for novelty's sake

[@Stoney3K]

@@TechnologyConnections I'd suspect somebody just jumpered the switch or bypassed the switch in the credit accumulator so it's on free play regardless of the switch position. After all, the credit accumulator only provides nothing but a contact to the latch board that says "You can accept another selection input".

[@Ugly_German_Truths]

@@Jtzkb It honestly sounds like TC will need a whole SEASON to finickle that out :D

[@chasecochran2173]

Modern Jukeboxes: yea sure ill play the song from my internal computer Old Jukeboxes: SPINNY CHOICE WHEEL GO BRRRRRRRR

[@MrDuncl]

Modern Jukeboxes. I've 5000 songs on my hard drive but I won't play any of them without a subscription. Old fashioned Jukeboxes. Load me up with 45s and I'll play them.

[@BrennanYoung]

These days we can just FTP the album tracklist directly from the artist's BBS to the daisy wheel printer if we want to see what song is coming up next

[@asj3419]

Modern jukebox: On-chip MOSFET Q3209 (used to allow bit x2 from main bus into ADC and thus playing music) has failed because a voltage fluxuation caused a signal to be in the illegal voltage range by 0.5 volts, allowing a direct path from Vcc to ground through the MOSFET and burning it out in the process. Old jukebox: Well of course all of my logic accepts AC as well as DC with transients as far as the eye can see, what bloody difference does that make?

[@sovietelectioncollidingtro6231]

_BRRRR AND THE TING GOES SKRAAA_

[@MarkMcCluney]

My Dad was a vending machine service engineer back in the sixties and his favourite part of any machine was the coin mech. I can confirm that they are/were endlessly fascinating and satisfying.

[@GermanBeez]

this man's sarcasm is on the level of a fine aged wine. remarkable.

[@Sharonmxg]

totally why I keep watching. His delivery gets me laughing every time. Really great informative content is like a bonus!

[@18000rpm]

"Hey I need you to design something that can accept different coin denominations, calculate number of songs based on the total of the different coins inserted, have a user-friendly UI for users to select the calculated number of songs allowed, keep those songs in a list and play them in a queue. And no CPU, microcontroller or memory allowed. GO!"

[@moconnell663]

Tiny man in a box. I win :)

[@SyncViews]

Define "memory" though. This does have a form of memory for selection and credits, the main thing is they can be much smaller (so can store a queue in a reasonable physical space), and logic gates make dealing with numbers easier.

[@jayands]

*Mumbo Jumbo has entered the chat*

[@Cypeq]

@@SyncViews hands down this is a memory, it stores data, that's all that is required of memory by definition.

[@RedwoodRhiadra]

@Michael Persico But it's sequential access, not random!

[@jakel.1724]

I am impressed how you’ve fought yourself to make these. A lot of smarts in your brain sir. Thank you

[@Magmafrost13]

That service manual must be a godsend. I feel like you'd never see something like that these days

[@cr4zyj4ck]

@@00O3O1B you dont need a manual showing you the internal controls of every chip and microcontroller, a circuit diagram alone can be extremely useful, as well as instructions such as "this module requires programming, or the device will not function." While the manual for electromechanical devices needs to be excessively complex to allow you to actually repair the machine, with modern devices the vast majority of the complexity is inside chips that no repairshop can fix. Desoldering such a chip from a board and soldering on a replacement is something you can do, however, and instructions on how the components of a board actually plug in to each other will allow you to repair it. You say that modern devices are endlessly more complex than these old electromechanical ones, but you can design a jukebox today to run off a mere fraction of the number of physical components that the old ones had, retaining most of the complexity for the computer programming.

[@SeanBZA]

Instead of calling it a computer call it a state machine, which runs from one state to another, with the ability to modify the output as required.

[@coder0xff]

Even modern computers are state machines. The theoretical turing machine, which has infinite storage capacity, doesn't actually exist in physical form.

[@quietone610]

If this were a pinball, it'd be called "electromagnetic". "Solid State" would be chips and cards; this is timing wheels, relays, and lots of little push-switches.

[@MattMcIrvin]

@@quietone610 I've always thought it was interesting that pinballs, unlike computers, never went through a vacuum-tube-logic or even a discrete transistor era. Tubes replaced relays as the logic elements of digital computers in the late 1940s and early '50s; but pinballs stayed entirely electromechanical until 1976-77, when they went straight to microprocessor-based systems. (It makes sense because of the different requirements--pinballs have to be as rugged and cheap as possible, but logic speed is not of paramount importance.)

[@belg4mit]

Non-programmers wouldn't know what he was referring to though.

[@quietone610]

@@MattMcIrvin I think it was because the companies who MADE pinball machines were few, and at each technical stage asked themselves: can we significantly improve the machine with this? Pinball also draws most of its appeal from physical toys, and there isn't much you can change about them until you get to seven-segment display and actual sound. You're also right about durability. Can a 50-year-old set of vacuum tubes take a slap and a punch? Not very well, they can't.

[@Jobobn1998]

I love mechanical logic, and the series on this jukebox just bounced that up to a new level.

[@adrian_veliz]

I think it is technically a mechanical implementation of a Finite State Automaton (FSA).

[@coder0xff]

Even modern computers are state machines. The theoretical turing machine, which has infinite storage capacity, doesn't actually exist in physical form.

[@TVarmy]

@@coder0xff yes but some state machines are more finite than others, so they're easier to diagram/describe that way

[@recklessroges]

Yes, but I think we can agree that its not Turing Complete. Hence, not a computer.

[@xplinux22]

@@recklessroges Was just about to comment on the lack of Turing completeness as well. This is an FSM, not a full general-purpose programmable computer.

[@Corey_Brandt]

What are you nerds talking about?

[@dashcamandy2242]

01:25 - Of course! Most folks don't know there is usually a hidden "REJECT" button somewhere on the device, for the times when the needle gets stuck in a scratch and you get the extra-extra-extra-extra-long-play version of "MacArthur Park." The button triggers the tonearm return, but I don't know if your particular model has it. You can probably find replacement springs at a mom-and-pop hardware store... I suppose the Big Box Home Improvement Chains might have them too, check the bulk nuts 'n' bolts ("Fasteners") section. Probably in those plastic drawer organizers where you have to pick your own and write the price-per-piece on the little baggie. They have almost everything in that section - car trim panel retainer clips, replacement hardware for assemble-it-yourself furniture... Even replacement incandescent bulbs and knobs for slightly-vintage audio gear. As a child, I spent some time with a friend of my mother's and her family. Her husband worked for an emergency lighting manufacturer in the 80s, and his hobbies included jukebox restoration, pinball machine restoration, and later on, a 1-armed-bandit and a pachinko machine -- and then he got into neon. His living room boasted a massive neon display and a retired traffic light hanging from the ceiling, 4 jukeboxes (mostly Seeburg and Wurlitzer, and often he'd trade models with other collector/restorers), and a front-projection TV. To say the family was... eccentric... would be a slight understatement. At one point, they even drove a Citroen, and at another point, a Gremlin. Being the proud geek he was, he would show off the guts of each individual machine and show off its quirks. I was too young to understand half of what was going on under the hood, but it was still fascinating. (I remember he had a credenza-style model once where you dialed a rotary phone to make your selections, he didn't keep that one for very long.) Last time I saw a jukebox in real life was the last time I was in a bar - 2008 maybe? - and it was a touchscreen digital media player (128k MP3s judging by crap audio quality) with gotta-be-hip RGB LEDs, a bill validator, a credit card reader, and internet access to download more songs if the bar owner wanted to pay per track. It made me long for the days of those fugly faux-dark-walnut-veneered beasts in Pizza Hut.

[@builderdex]

McMaster-Carr online distributor has springs galore!

[@marscaleb]

When I was a kid, one day I found an old tape recorder but found it wasn't working right. I decided to try to fix it, even though I had no idea how the thing worked. I took it apart and found it was gummed up with a bunch of dust bunnies and dirt and the like. I cleaned it all out and it was working properly again. And I spent a lot of time watching all the mechanisms inside, seeing how they all worked together, noting the subtle and clever designs, like the bar arm that moved when I hit certain buttons (like "stop") that disengaged the other buttons and caused them to pop up. As a child, I began day-dreaming about becoming an expert on how tings like this worked, and pulling apart all sorts of appliances. I never became an engineer. Maybe I should have have. But despite the love I had for seeing how these things worked, I never did. I just want to thank you for amazing videos like this that spark that same joy I felt as a kid. You are absolutely right; delivering all this functionality through a circuit board and processor, while still cool in its own right, just isn't as amazing as this.

[@joshua43214]

Rube Goldberg: "Ima make a thing to play records..." Wurlitzer: "Hold my beer."

[@zohaibamir1252]

Beer was then held on by a set of latching relays and solenoids

[@buddyclem7328]

@@zohaibamir1252 More beer was automatically ordered using a POTS land line, a rotating magnetic drum, a mechanically controlled magnetic pickup, an amplifier, and much more mechanical automation. Before hanging up, it tells the beer distributor the current time, since the mechanism was harvested from a 1940s era time annunciator. Thanks to this clever mechanism, the beer supply is uninterrupted.

[@Torchedini]

But this is not rube goldberg levels. It would be if you would put microcontrollers everywhere. But as is everything in there is needed and has function. Where as with rube goldberg machines you could delete most of the operation/logic.

[@JMPDev]

Fun fact: Mr. Goldberg was a cartoonist. He only ever drew his machines.

[@abc-ni9uw]

God sake 🥱

[@SomePotato]

I wish some of the engineers who built this are still alive and get to see the love you are giving their creation.

[@kentswan3230]

All in all a fascinating analysis of a complex electromechanical system. Thanks. An observation. This machine can be considered to be a set of fixed programmed, multi-state sequencers. The interesting thing is that if you have ever dived deep into how computers are actually implemented, there are similar fixed programmed, multistate sequencers buried deep inside the CPU silicon. This buried layer is typically called micro-code is fixed read-only memory where each microcode step is only responsible for activating and routing data to various logic functions. The higher-level language programs you may write, are converted eventually converted into a sequence of assembly statements which is converted to machine code. Each machine code instruction is tied to a specific hardcoded sequence of microcode. The microcode operates much like the cams doing one sequence of things exactly. The things the microcode does are activating selected logic (comparators, incrementors, arithmetic units, decision logic, etc and selecting data paths (these are like some of the relay's routing power). The net of this is the high-level instructions you write eventually execute blocks of microcode that control the CPU's silicon machinery. Admittedly the above analogy has been simplified. If you go back to the olden days, early relay logic computers were programmed' by using patch panels and data value switches. These would allow the operators to chain different calculation blocks together and supply different input settings to obtain calculated output from different complex arithmetic and logic functions. They were incredibly slow (but orders of magnitude faster than hand or mechanical calculation), not terribly flexible. Additionally, they were typically designed for a very specific class of calculations but even so, they served their purpose well at the time they were constructed. As a side note, The first working programmable computer was the relay-based Z3, designed by Konrad Zuse and completed in 1941. This computer was implemented with telephone relays and had a master clock of 5.3 Hz. It could perform additions in 0.8 seconds and multiply in 3 seconds. Blazingly fast... NOT.

[@rthsw]

Yes, thats so correct, dude! This was my 2nd thought. The first one was: I'm so lucky to have navision, and not a soldering iron!!!. Until today, at least a big part of most programs are state machines (Player has still live, Sprite B is collision with sprite B, Item X has enough stock for delivering). And this Jukebox is a massive state machine! The Memory and the bus-clock is the rotating arm and so one...

[@bleutz]

I started out my electronics career in 1977 on 1963 vintage F-4 Phantoms. The whole plane worked like this!

[@do_d_dola_d_dan5105]

Fascinating! I always thought that jukeboxes were neat but you've shown me that I had absolutely no idea just how neat! I'll never look at a jukebox the same way.

[@odunarr]

This is the most hectic "how do they do it" episode yet! It is funny how hard to follow, but yet easy to listen to this man is! I watch your stuff befor bed (to go to sleep) and I the morning to get my brain switched on again! Very entertaining, and very educational!

[@erikharrie3477]

Thank you for these great videos! Another bit of title controversy for you. This machine was never called a jukebox. COIN OPERATED MULTI SELECTOR PHONOGRAPH Old man Wurlitzer felt the term jukebox implied a machine in a juke joint where immoral behavior was taking place. Not until the model 1050 in the early 1970's was the term "jukebox" ever on a Wurlitzer. Ironic, the company went under while that model was being produced. From what I've read, the problems with the new mechanism cost them money to repair and hurt sales at the same time. I have a few 1967 models (3100 & 3110) they run the old 1950's era mechanism and are crude but reliable. I love the mechanical noises it makes between songs.

[@superdrummergaming]

I can't even imagine the engineering that went into this for the first time. "How are we gonna do this?" "MORE SWITCHES!"

[@atimholt]

“And what do we use apart from (s)witches?”

[@johndoe1909]

This they way automation was done back in the days. It was common everywhere in the industry. Our telephone system back in the days made these mechanisms look trivial.

[@rubiconnn]

@MrClassiccarenthusia That makes sense for a multimillion dollar manufacturer. This was a jukebox in a dive bar somewhere.

[@Lawrence330]

They technically still do. The entire idea of PLCs is that instead of completely rewiring a relay board every time you have a configuration change on the line, you can simple place as many relays "virtually" as possible. (Much of) the "internal wiring" is done with simple code or even with a drag/drop interface with various plant elements tied into the controller rather than to discrete relays.

[@markpenrice6253]

I'd say for the complexity of the machine that's a remarkably low number of relays. They did a fine job of pulling off the functionality it has with only, what, six relays? That's the equivalent of just six transistors, after all. These days you can get a solid state discrete logic chip that's the size of your pinky nail and costs a matter of cents with eight transistors on it, and that's considered a pretty stoneage thing unless you need to switch relatively high currents and/or voltages. Even the first ever microprocessors had a few thousand, and the first microcontrollers were based upon the second or third generation of those.

[@tizio5103]

3:15 Aah the old infamous "I have no idea what this light is for" indicator.

[@MichaelAStanhope]

Its amazing that we could put a man on the moon when we were still using electro-mechanical devices like this! What a logistical nightmare these things are, but cool as hell to watch.

[@venge1894]

You could do quite alot with electro-mechanics, but of course they took up far more space than modern computers. I would imagine being a astronaut nowadays is much more comfortable.

[@benjammin2020]

Also, the NASA engineers did all their math on slide rules! Of you don't know what a slide rules is, look it up.

[@d2factotum]

The Apollo Guidance Computer was one of the first machines to actually use silicon logic, albeit it was a few thousand discrete chips rather than the single integrated circuit you get in a modern computer.

[@MisterTalkingMachine]

CuriousMarc restored an AGC last year and has a series of videos on it up on youtube.

[@benjammin2020]

@@d2factotum wasn't the memory a grid of copper wire with looped magnets hand woven, and magnet on one diagonal vs the other diagonal were ones and zeroes?

[@mcb187]

28:02 “Oh sh*t (mumbling) oops, I said a bad word.” Best blooper ever.

[@EdwardMillen]

Wow, that was interesting! I'm seeing a lot of similarities between how this does things and how things have to be done in computer programming sometimes to handle certain edge-cases etc (like the way relay 2 has to be wired slightly differently from relay 1, and based on it, even though they both work the same way apart from that... and the way it does an extra rotation to make sure there's nothing else selected before stopping... oh and the extra switches needing to be activated by the latch solenoid, to prevent people activating things by just holding down the buttons without paying) I sometimes feel like I must be doing things wrong/inefficiently by having to write extra bits of code (or add extra variables) to handle things like that, that perhaps it wouldn't be necessary if the whole thing worked a different way (although I can't find any better way to do it), but now I'm thinking that's probably just what you have to do sometimes to make sure things function reliably in all possible situations (which is what I always aim for).

[@DaveZeichner]

Writing an extra bit of code to handle an edge case is nothing compared to what they had to do mechanically. (Although, logically, the same things.)

[@atlbrysco6198]

So first of all, let me say thanks so much for hosting this amazing video! When I gained my Electrical Engineering Degree (way back in 198humph humph humph) the field was on the cusp of Digital transformation and most things were electromechanical ("EM") with digital only being implemented into *seriously* delicate work that required finesse (which EM couldn't do well). This takes me back through to my 20's, when you had to have spit, band-aids, a good multi-meter and garage toolbox to get you through the days... good times! However, I will say one thing - your "disclaimer" at the end - it may not be something that someone today considers a "computer," but remember the original definition of computer did not include "digital" (it was around in the 1890's when the coin was termed) - it simply was a device that could work through a mathematical equation of Boolean Algebra (yes or no, 1 or 0, true/false) - these machines fully qualified that definition through positive and negative electrical surges, just as computers do today. Your argument would be better served by qualifying between "digital" and "analog" computers and I would argue that your strawman comparison of a combustion engine to a computer is not fair - combustion engines don't solve binary problems - they simply "open or close" on a set sequential pattern. It can't change that pattern depending on inputs and other variable relays that can affect or change that "open or close" pattern. Beyond that, great job! Thanks so very much again!

[@Vincent_Sullivan]

ATLBrysco; Regarding this disclaimer at the end: Not so fast! I agree that the camshaft in an ICE is not a computer but I think Alec chose the wrong component. The carburettor is indisputably an analog fluidic computer. It takes in various analog inputs such as accelerator pedal position, rate of accelerator pedal position change (accelerator pump) temperature (choke control), air pressure (bowl vent), engine rpm (via air speed through the venturi) and performs a computation that results in the output of an analog quantity of fuel fed to the engine and possibly a digital output to the transmission (if it is an automatic) that gives the transmission the signal to "kick down" to a lower gear to increase engine RPM to get the engine higher up on its power curve if high acceleration is required.

[@theowinters6314]

Honestly, I love how this thing is built, it's both wonderful simple and beautifully complex. It really is just a specialized state machine (no surprise there really), and the accumulator is elegant.

[@gregakinson2800]

And to think I was born in 1963 and used these things so many times! Incredible mechanical and electrical minds came up with this and it is very impressive! Over all it was a very good presentation and now I present another good idea since you are so good and hopefully you will do it. Back in the eighties for a while I was a "pin setter machine mechanic" for an alley full of Brunswick A-2 pin setter machines (30). I was SO impressed by how they actually worked having been a bowler for many years prior. Care to take this on if you find a way? I am sure you would do great with it given the chance.

[@henninghoefer]

I laughed out loud at the "literal side note" 😂

[@orifox1629]

Hey, hang in there, I know this time is rough, we'll get through it, I promise. Also, I did actually really like your button explanation from the first video, it really made sense to me and clarified so much and contextualized a lot of things in my life. Loved this series. Thank you thank you. Once again, thanks for your work, I love learning the things your interested in and I love your passion

[@KiwiMaker]

I love how everything is actually labeled inside the machine, anybody can actually have a look inside and have somewhat of an understanding of what it does, although insanely complex how it does it!

[@welcomestranger]

Holy shitballs that thing is so amazingly complicated! So fascinating to watch every little part serving it's own little function.

[@thomasconrow5980]

When this machine was manufactured, computer was a profession - not a device.

[@stefansynths]

There were definitely computers in 1970. There weren't home computers yet, but businesses, universities, and spacecraft had computers.

[@SpaceManRD]

...there were definitely computers in the 70s, Tom.

[@Nicholas_Steel]

People are devices though...

[@buddyclem7328]

When the machine was designed, that was definitely true. Computer components were still very expensive in the 1970s, so mechanical devices persisted for many years, despite the labor involved in maintaining them.

[@user-tm3fz7qx3s]

100th like

[@DavidAndrewsPEC]

This was bloody interesting ... thank you! And - Alec's mum and dad ... thank yous two too! Your allowing of Alex to indulge in his technology passions has given the world a very interesting chap to watch and listen to as he introduces us all to really deep insights and (often) interesting nuances about stuff. Yous done good! ;)

[@FennecTECH]

Imagine the time it took for someone to design this thing.

[@kakwa]

Also image the time took to manufacture this thing. The amount of errors possible when wiring these is incredibly high, and troubleshooting errors not that trivial...

[@DinoRowan]

Right! It's insane! I think about the same stuff when watching manufacturing/how it's made videos as well. The logistics are astounding.

[@Rizzy1634]

Pierre-Francois CARPENTIER cost to build this thing today would be huge.

[@waldoppen]

Also imagine showing them Spotify streaming service after they had finished building it.

[@momentary_]

They basically wrote a large program with wires.

[@MisterTalkingMachine]

I relate personally to the story at the end, for me it started with my dad letting me take apart a broken VCR when I was arond 5 years old. Also if you want replacement springs you could try the ones you get from taking apart CD drives.

[@slave288]

Being someone who has designed and built circuits like this, I took one look at your wiring diagram and could answer your question on what keeps the relay coil energized for a moment once the contacts feeding it are opened. The capacitors. You will notice in the diagram there are 20 uF capacitors wired across the relay coil. Some may think this serves as some sort of filtering capacitor but it's not. When the relay coil is energized the capacitor charges instantly and then when the switch is opened the capacitor slowly discharges, continuing the coils magnetism for a brief second until the capacitor discharges and the contacts eventually drop out. Have designed many circuits like this over the years.

[@AjinkyaMahajan]

It Fascinates me the efforts you put in understanding those old manuals and explaining it in the best possible way 👌✨ Thanks as always.👍

[@cheeto4493]

I sure am glad you have the service manual for that. Just imagine the puzzle of figuring it out from just poking, prodding and tracing wiring.

[@grn1]

I don't know, sometimes poking, prodding and wire tracing is actually easier to understand than the dang manuals.

[@Voreoptera]

29 minutes of pure complex well explained, how does this work again. Mechanical computer. Thankyou for your story at the end, and you have put many hours into this to give us the explanation of chaos. Thankyou. This is all too much for anyone.

[@davidchidester5463]

Amazingly complex, yet something about all the designs makes perfect sense. Clever clever engineers.

[@TheOtherBill]

Old time telephone switchmen giggle when you say this is complicated.

[@gljames24]

Oh, I bet!

[@SuperFranzs]

Don't give him any ideas. I don't think he can fit a telephone switch in his studio.

[@EVPaddy]

@@SuperFranzs there are small ones that were used in businesses. My father had one in my room when I was a child ;)

[@JoseSilveira-newhandleforYT]

You betcha! I'm an old Strowger technician, first trained at the manufacturer (Plessey) and later a PSTN company (also did some freelance work on a few jukeboxes), many moons ago :-) Just the operations than went on since you lifted the handset at home and you got a dial tone from the PSTN it was connected to, would make many good people cringe, and this was a simple circuit...

[@JoseSilveira-newhandleforYT]

After posting the above, made a quick search online and found an overview of the Strowger system - you can have a look here: dougkerr.net/Pumpkin/articles/SXS_Overview.pdf

[@Jxdizzle6969]

I've seen some of your videos through KZbin's suggestions over several months occasionally and after a few videos I decided to subscribe. Well after powering through many of your videos over several days (all of which i enjoyed) I found this two video series to be my favorite by far. From the actual item in question to the flow and descriptions these just stood out to me and became my favorites. Keep doing what your doing!

[@Robb403]

It's a very interesting video and you do a good job of simplifying the technology. I don't know if anyone has pointed this out. But, the Wurlitzer electromechanical rotary selector is base on telephone switching technology from the days when phones had dials, period, before there was touch tone. Automated phone switching centers were once big buildings full of electromechanical rotary switches that connected your call based on the number of pulses from your phone. Electronic switching didn't come in until after transistors were perfected the 1950's and many switching systems didn't go electronic until the 1980's. Wurlitzer didn't invent the technology. They just modified it suit their needs. Those electromechanical phone switching centers could also be quite temperamental, especially as they got older, and they required a lot of servicing.

[@richardhunter9995]

I remember when the phone switching center in the town I grew up in changed from mechanical to electronic. With the mechanical one you only had to dial the last 4 digits, electronic you had to dial all 7. The mechanical ones would also withstand the EMP from a nuclear blast, the electronic ones not so much.

[@andylinton2798]

Yes, I thought it was kinda similar to a Strowger switch.

[@grn1]

@@richardhunter9995 A sufficiently strong EMP will fry any electronic device including electro-mechanical ones. They may not be as sensitive but all those transformers and relays may amplify the EMP/generate a very strong current when hit.

[@jerbearx1]

Instead of "computer" you could think of this as an electro-mechanical State Machine.

[@electron8262]

What would it need to become a computer? Would it need to be general purpose or programmable?

[@seraphina985]

I'd probably still argue this is a somewhat primitive computer as it is not that dissimilar to a modern application-specific integrated circuit. Even a modern computer system has a bunch of these sure the input data for them is controlled by the more general-purpose processors like the CPU, GPU or other general-purpose processors connected to the network. But they do still execute hardwired functions on arbitrary input data so long as the input data is within the scope of the specifications. That said it's a tricky distinction as there is a spectrum to this sort of thing just look at the GPU for evidence of that, a graphics card is practically a fully functioning computer mounted on it's own motherboard as it relies very little on the host to actually work mostly the system motherboard is just a bridge to access secondary storage in order to load programs from. With some fast flash chips and a high-end microcontroller, you could emulate that and feed software to it directly and it would probably work why you would want to do this other than as a project just to show it could be done is debatable but...

[@chrismanuel9768]

I mean... it computes though

[@TallinuTV]

State machine is the perfect description for this actually.

[@TheToric]

@@seraphina985 id argue the opposite. Specialist IC's are not computers (im assuming your talking about ASIC's, not microcontrollers/fpgas) in order for something to be a computer, something must: Take some input data Process it Output some other data based on the prossesing And be reprogrammable. You need to be able to change what step 2 does. For a turing complete machine, this includes some some sort of conditional jumping/looping and branching. This machine has the first three, but not the third.

[@robsta1980]

You're a brave guy attempting to explain how these work. I worked on a 59 Wurlitzer 2300s about 10years ago and it's hands down THE most complicated machine I've ever laid eyes on. Thankfully all the selection stuff worked, but I still had to take it all out to replace one of the take out arms. It blows my mind how the engineers even planned something like this, never mind actually do it. The microchip has got a lot to answer for.

[@jackdaniels8898]

Great video. A couple of years ago I restored my first (and last electro-mechanical pinball machine). It was an early 70’s model. One thing was apparent and probably the same with jukeboxes is that they evolved in sophistication over time. .... From what I observed, am I correct that the order in which songs were selected was not maintained? It seems not but rather the next raised pin in the carousel is what gets played next.

[@harryhall5092]

same way all the time, lower to higher number as pins stop the readout arm!

[@KurosakiYukigo]

Actually I think Alec explained that with why the carousel makes a full rotation back to the "start" position before fully engaging the switch that starts the feeler contact looking for its next record. This way the machine functionally ignores the next records queuing to be played until it can reset to zero state, and then it looks. If the next record to be played was numerically before your first selection, good news, it'll pick it up! It hasn't been missed! If your next selection was numerically after your first selection, well it plays after, like intended, it just had to be sure you didn't cue it out of order.

[@aevangel1]

As Mr. Spock would say: "Fascinating"

[@phtitzy]

This was absolutely surreal to see and learn about. Working with electronics now it's amazing to see how complex electro-mechanical used to be, let alone how someone even had the ingenuity to come up with it. Amazing explanation, thank you

[@MedveSzarny]

I've always loved this channel, but i still can't imagine how he can deliver top quality videos every time!