The Selection Accumulator; a Jukebox’s Brain

The Selection Accumulator; a Jukebox’s Brain

Last week we explored the record changing
mechanism in this… charmingly ugly, stylistically repressed clunky buzzy disc jockeying gizmo
box of horrors. We looked at the mechanical bits that grab
the record, manipulate the tone arm and turntable, and all that jazz. We also created a circuit with a relay to
start and stop an action with two separate inputs. Also known as buttons. Yeah, I’m gonna try to explain that a little
better in this video, but anyway if you haven’t seen the video that I’m talking about right now, you should probably consider watching that first. In fact, here’s a card! I’m just kidding, there you go. And for all those situations where cards don’t
work, there’s a link in the description. Of course this is upside-down, but we’re
gonna roll with it. I left you with a devastating cliffhanger. You see, we covered how this machine is able
to take a record from the record carousel and play it, but we never covered how exactly
it knows what record to play. Well, that’s what we’re gonna cover in
this here video. Shocking, I know. So let’s consider what needs to be accomplished. We don’t have the luxury of a computer; we only have a few relays and whatever sort of mechanical contraptions we might devise. How could you design a sort of memory to store
a selection to be played given those limitations? Why with a ridiculously complicated electromechanical
solution, of course! And…. THIS is it! Exciting, huh? This is the Selection Accumulator. This device functions as the memory of the
jukebox. Calling it memory is a bit of a stretch, as you’ll soon see, but it does store selections to be played. Just, in physical space. Using physical objects. You’ll notice that all around the edge of
this are a bunch of little metal pins. They each have a spring attached to them, well most of them anyway, and they’re labeled just like the selections of the jukebox. See, each of these pins is a selection. There are 200 in total, starting at A1 and
ending with V0. By the way, if you noticed that the letters
I and O were missing, that was done just to prevent confusion between those two letters
and 1 and 0. Take a closer look at the springs and you’ll
see that they’re all under tension. Right now, these pins are just barely staying
held down. They’re really on the edge of their seats. If you push one ever so slightly towards the
center of the… let’s call it a basket, it will suddenly pop up. [click] That sounds like a click I’ve heard before! Anyway, thanks to the spring it will stay
in the popped up position until something pushes it back down, and then it will be caught
on the edge again so it stays down. So, let’s say you had selected C5. Well, in that case, the pin for C5 will be
popped up. And then the jukebox knows to play C5. If you have questions regarding how the pin managed to become in the popped up state, or how that translates into the jukebox actually playing C5, stay tuned because I’m about to answer them. But first, buttons! And I do mean buttons. The selection buttons up here on the top of
the jukebox are what makes those pins pop up. It’s really fascinating. So, firstly, recall from the last video that
when you push in these buttons, they stay held in until the selection accumulator has
done its thing. This serves two functions: One, it’s how the jukebox keeps you from
making selections unless you’ve put some money in it, and two it creates a circuit
across the letter and number patches. Hold that thought, we’ll get back to it. Way up here is the Latch Solenoid. This must be energized in order for a selection
to be made. If it’s not, as is the case when the jukebox is turned off, you’ll see that the buttons do not stay down. Unless the jukebox’s Credit Accumulator, which unfortunately does not work on this machine, registers a credit, this solenoid
will not be energized and you cannot make a selection. And before you think of getting all crafty
and just holding them in for a bit, the latch solenoid also moves these various leaf switches, setting up other circuits that come into play. So you cannot possibly make a selection unless
this solenoid is powered. The latch solenoid is held in by Relay 1,
one of four relays in this junction box. The junction box is mostly just a box that
a lot of things plug into. Basically it’s just a bunch of wires in here
going from socket to socket, but these four relays handle some of the various shenanigans we’re about to see. Anyway, relay 1 receives power from the
credit accumulator. This is the device that counts your money. Here’s a brief look at the credit accumulator. Again, it doesn’t work, I’ve not been
able to make it work, but what it’s supposed to do is add and remove credits from the machine based upon which selections you make and which coins you insert. Were it working it’s surprisingly versatile,
allowing you to set the number of credits each coin gives you, and even do things such
as require two nickels for one credit. It’s wired to the coin mechanism down here,
an equally fascinating bit of tech, which validates and sorts nickels, dimes, quarters,
and even half dollars, all done by gravity alone. Missing from the machine at the moment is
a blue plastic coin chute which would direct coins from the slot up above down to the top
of the coin mech. Anyway, depending on the coin it would fall
onto one of these four switches, and that would – or should anyway – make the credit
accumulator count up however many credits you set it to with these levers and junk. Anyway, again; it doesn’t work, which is a bummer,
but thankfully someone has rigged this machine to simply always behave as though it has a
credit. So, relay one is energized, and therefore
so is the latch solenoid, whenever it’s powered on. OK. So, back to the buttons. With the latch solenoid held in, press one
letter and the button will stay depressed. You can see the latch mechanism through this
hole in the top of the jukebox that definitely shouldn’t be there but it is anyway. By the way – don’t think of any funny
business and try to select two letters or two numbers at the same time. Wurlitzer’s way ahead of you –
the lower one will get priority. Anyway, press a letter, then a number. So again, C5. A lot is about to occur in the next two seconds. Strap in. Once both a letter and a number are selected,
these leaf switches will energize Relay 2, which is one of the relays here on the junction box. Interestingly, the junction box has different
names for these four relays, despite the fact that the service documentation only refers to them by numbers. Anyway, the closing of relay 2 completes the
circuit to the selection accumulator motor. That’s this guy! You may have noticed this weird thing sitting
in the middle of the basket. Well, when you make a selection, this goes
for a spin. A 180 degree spin, in fact. And you know what makes that happen? Why, Relay 3! Heyo, it’s time for that button demonstration
to come back into the fold. But this time – it’s not a button. It’s a circuit board. Notice what happens when I give the little
spinny thing a push. It suddenly starts moving, then stops again. How’s that happening? Well, notice these contact patches. You’ll see that there’s a break in them
on both sides. Well, this one’s not really a break but hey, let’s not get pedantic. That’s my job. On the bottom of this arm are four wiper contacts. These two here provide power to relay 3. Now, at rest, the circuit is broken. So, relay 3 is de-energized, and the motor
doesn’t get any power. But, if I push this far enough to where the
wipers touch the patches, relay 3 will close a switch contact inside itself, powering the
selection accumulator motor. The motor will stay powered through a 180
degree sweep, so it will keep spinning, but once the contacts make it off the patch, the
relay opens the switch, and the movement stops. Now, you saw that I needed to give this a
push to start it going. But after that point it completed its task
on its own. Relay 2 is what gives it that initial push. That happens as soon as both a letter and
a number button are pressed in. Once it’s moved from its starting position,
relay 3 takes over. And once it’s made it to the end of the
rotation, relay 3 is released, and the motion stops. Oh and by the way, all these other contact
patches did various things, including removing a credit from the credit accumulator (if it were working) and releasing relays 1 and 2. OK, now we are not getting deep into the specifics
here. This is how relays 1, 2, and 3 are represented
in the schematic. It’s nuts. This is very difficult to follow, especially since you have to go from one page to the next to make sense of anything, so for my descriptions of what’s going
on here I’ve been relying on the much more helpful Sequence of Operations section of this lovely service manual. Now, in regards to the red and green button
demonstration from before… well first let me acknowledge how unsatisfied with that explanation I am. I really should have been more specific about
what the buttons were accomplishing in the circuit, and a schematic would probably have
been helpful at least to some of you. So, this time, no buttons. Ah crap, but this all gets started ‘cause
of the selection buttons! Ugh. Well… Basically, and I’m not promising or even
trying to achieve perfect accuracy here, when both a letter and a number button are held
in, these weird linkages cause one of these here switches to energize relay 2. Inside relay 2, a pair of switch contacts closes
which provides power to the selection accumulator motor. So it starts spinning. Once it’s moved out of its park position,
this track here energizes relay 3. Relay 3 also has a pair of contacts inside of it that provide power to the selection accumulator motor. Now, relay 2 can be released without stopping
the motor. So, relay 2 got this going, but once it left
its park position, it could keep going on its own because of relay 3. Now, I’d love to get into more of the specifics
regarding these patches, but… unfortunately I can’t make any sense of how they relate to the other things that are going on. For example, remember relay 1? Well, that guy is supposedly powering the
latch solenoid, based upon whether or not there’s a credit in the credit accumulator. But power to the latch solenoid has to be
released briefly when the selection accumulator stops in order for the selection buttons to
pop back out, and I can’t say exactly what causes that. Does relay 1 momentarily get de-energized
thanks to one of these patches? Or is the solenoid itself powered through
here? I don’t know, and I’ve been staring at
these schematics for hours, and my brain hurts. All I’d like you to see here is how we can
make a bunch of things happen in sequence by running some contacts over some patches. This is yet another kind of program; I hesitate to say this but it’s a lot like a series of buttons that are getting pressed automatically in sequence. Yes, these aren’t buttons, but they’re
sets of contacts getting bridged as the wiper runs past them, one after the other. So, it can cause various actions to occur
at various times, depending on how and to what these contact patches are wired. This is what electromechanics are, people. It’s a buncha wires, all going to different
places, and all through different things. And now to the most important thing of all. The pins. So, this spinny thing is officially called
the Shaft and Magnet Assembly, and on both ends you’ll find a Selector Magnet. This is an electromagnet which travels just
behind each of the pins. You’ll notice that down here are a pair
of wiper contacts, and they are travelling over all of these teeny tiny patches. This is where the real magic happens. Each of these thick bars on the inner edge
is wired to one of the letter buttons. So we’ve got A over here, B is next to it,
and so on all the way through V. These teeny tiny patches along the edge are wired to numbers 1 through 0, and they repeat over and over again. Looking on the bottom you can see how there
are wire links connecting every tenth patch together. When two buttons are pressed, there’s power
across one of these letter patches, and twenty of the number patches. See where this is going? When you’ve selected C5, the C patch and
all of the 5 patches become a power source for the electromagnet. I’m not sure which one is live and which
is neutral, and in fact this is an AC circuit so it doesn’t really matter anyway, so let’s
just say there’s voltage across the two of them. As the magnet arm sweeps, the electromagnet
is just chillin’ doing nothin’. Sure, there’s voltage on all of these 5
patches, but there’s nowhere for that voltage to go. Except at C5. Right when the electromagnet is behind the
pin for C5, it gets a brief pulse of power, pulling the pin towards it, which causes it
to pop up with the help of the spring. Isn’t that just the coolest thing? With one letter and one number, there’s
only one spot on this entire board where a circuit is actually complete between the inner
and outer rings. The reason there’s an electromagnet on each end of the arm is that it only rotates 180 degrees per cycle. Now, the very last thing this mechanism
is responsible for is providing a pulse of power to the Override Magnet. That’s this guy. The override magnet pulls on a little latching
mechanism to close this leaf switch. This switch is essentially the master power
switch for the entire record changer. So long as it’s closed, the carousel, Wurlamatic,
and all their associated doodads now receive power, so it can start looking for the record
to be played. And how does it do that? Why, with the Readout Arm, of course! This is what I said connects to the black
bar underneath the record carousel in the last video. The readout arm is what actually translates
the popped up pin into a record to be played. You can see it has these little feeler levers
connected to two switches. When the selection accumulator is installed
in the jukebox, it hangs directly underneath the record carousel, and the feelers of the
readout arm travel right above the pins as the carousel rotates with the motivation provided by this motor You may have noticed already that every other
pin is shaped differently. All of the odd selection number pins have
a notch in the side facing the outside edge, and the even number selections are the opposite. That’s so the correct feeler is activated
depending on whether the selection is the A side or the B side of a record. See, these two pins are both the same record
in the carousel. That’s why readout number 2 is resting farther
forward than 1 – they need to stop the carousel in the same place, but the pin for side 2
is farther ahead in the rotation. Side-note; It annoys me greatly that Wurlitzer refers
to everything as Side 1 and Side 2 when it has long been established that 45’s have
an A side and a B side. In case you haven’t been doing so this whole time, please note that Side 1 corresponds to Side A,
and 2 corresponds to B. I don’t really know if Wurlitzer was trying to alleviate confusion with selections A and B, or if they
had some other reason for not calling these Readouts A and B, but here we are. Anyway… These two readout switches are connected to
this contact board up top via these feelers. Fun fact! These are my biggest source of problems with
this machine. You’ll notice that a few of them are all bent out
of shape, and only some of that was my doing. These contacts need constant cleaning in order
for the jukebox to work correctly, as the timing of when these feelers hit the pins
and thus stop the carousel needs to be fairly precise. Now, you may recall from the last video that
the side one and side two relays were what started the Wurlamatic mechanism and thus
pulled a record out of the carousel to be played. Well, these are what they’re wired to. If readout 1 gets tripped by a selection pin,
that energizes the side 1 relay, which stops the carousel, activates the Wurlamatic, and also energizes the side 1 solenoid so that the record takeout arm’s left pin gets caught
by this catch, and it pivots into position to play side one of the selected record. The same thing happens when the side 2 relay
is energized by readout 2, although the side 2 relay does not energize the side 1 solenoid,
therefore causing the take-out arm to pivot in the opposite direction. So then, here’s a question a few of you
have probably been asking by now; How does the pin go back down? Aha! Well, that’s not the job of the selection
accumulator. It has no ability to reset the pins. But, the readout arm does! There are a pair of small solenoids on top
that are attached to these little metal pusher things. Thanks to a switch buried deep within the
Wurlamatic mechanism, called the cancel switch, these solenoids briefly get power during the
course of its rotation and push the pins back down. One of the key components that I haven’t
mentioned yet is the Magazine Lock Solenoid. That loud buzzing it makes as the carousel
turns is coming from this. It probably shouldn’t be that loud, but
the machine is 50 years old, cut it some slack. The reason it’s important is that it aligns
the carousel whenever it’s stopped with this spring-loaded pin. This not only ensures ideal alignment with
the records and record take-out arm (and its grabby thing) but also with the cancel pins
of the readout arm. Ideally, the feeler switches will be adjust
so that the carousel stops a bit prematurely, and the lock solenoid pushes it a little bit
farther. This ensures the readout switches are firmly
against the pins and make consistent contact. Now, here’s where the cleverness of electromechanics
comes into play once again. You’ll notice that only one of these cancel
solenoids moves. And there is only one cancel switch inside
the Wurlamatic to make that happen. Why didn’t they both move? Well, because the current path between the
cancel switch and these solenoids goes through the side 1 and side 2 relays. Only the solenoid representing the side currently
being played receives power, thus only that selection is cancelled. It’s simply a matter of running the power
through one of the normally open contacts of the relay, so that whichever relay is currently
being energized (thus, the side that’s being played) will provide a current path to the
corresponding cancel solenoid. You might then ask, what happens if someone
selects both sides of the same record? Won’t the side one and side 2 relays both
be energized? Well, no! Why? Because side 1 takes precedence over side
two. How? Because the side 2 relay is wired through
a normally closed switch contact inside the side 1 relay. In this way, side one and two are interlocked. If both of the readout switches are activated
simultaneously, both relays 1 and 2 are receiving power. But, if relay one is energized, it cuts off
that power to relay 2. This in turn means that the Wurlamatic will
grab the record, pivot to play side one, and cancel the side 1 pin and the side 1 pin only. Because remember; Relay 2 is not powered whenever Relay 1 is. Relay 1 disconnects power from Relay 2. So, down comes the cancel solenoid, with its
power output being directed through relay 1, and now once the cancel solenoid is released
the side 1 readout is released as well. This now de-energizes the side 1 relay, which
means, now the side 2 relay can be energized by readout 2. The result of that is that once side one has
been played, the tone arm will hit the trip switch, the Wurlamatic restarts to put the
record back, but with the side 2 relay now energized, the transfer switch is out of the picture and it immediately takes the record back out again. This time it pivots to play the other side. Now, when the Wurlamatic hits the cancel switch
for the second time, the other cancel solenoid fires, and puts the side 2 pin back. Now neither readout switch is activated, and
so neither are relays 1 or 2. When side 2 is over, the trip switch is hit,
the Wurlamatic starts back up, and without the side 1 or side 2 relays in play anymore,
as soon as the record is put back, the transfer switch stops movement of the Wurlamatic, the record jaw thing hits the safety switch, and the carousel starts rotating, looking for
the next pin and thus the next selection. Once the carousel has made one complete rotation,
this catch on the end of the readout arm hits the latch mechanism near the override magnet. This doesn’t yet open the override switch. Instead, the carousel will go on for one more
rotation. This is done in case it was, say, playing
F3 and you then selected C2. C2 is behind F3 so it’s gonna hit this before
it gets there. Once it hits the override mechanism a second
time, that switch will open, and now the jukebox is back to its standby state. Did you get all of that? It’s simple, right? Let’s go through all this once again, just
for funsies. We begin with the latch solenoid. The latch solenoid is held in because the
machine thinks it has a credit so relay 1, which is different from the side 1 relay – why did Wurlitzer do that? – is energized. Pressing a letter button and a number button
closes these leaf switches which in turn activates relay two, which gets the selection accumulator
motor started. Once the magnet arm leaves its park position,
the wiper contacts will complete a circuit to relay 3, so it will keep going. The combination of letter and number puts
voltage across the letter and number patches on the board of the selection accumulator. Once the electromagnet is behind the corresponding
selection pin, the magnet fires, pulling the pin towards it, unseating the pin from its
catch, and it pops up. When the magnet arm is back at its park position,
the circuit to relay 3 is broken, which stops the magnet arm. At the same time, power is interrupted briefly
to the latch solenoid somehow (still not clear on that one) to pop the selection buttons back
out, and a pulse of power is sent to the override magnet, closing the override switch, thus
causing the carousel to be unlocked and begin rotation. Once either readout switch hits a pin, this
energizes its corresponding side relay. That will cut power to the magazine motor
and its lock solenoid, locking it in place. It also provides power to the main cam relay,
causing the Wurlamatic to remove the record from the carousel. Shortly after it’s moved, the transfer switch
keeps the main cam relay powered, which is important because the cancel switch will fire
the corresponding cancel solenoid, pushing the selection pin back down, and thus de-energizing the side one or side two relay. At this point, the carousel will not be able
to move because the safety switch is not being depressed now that the record take-out arm
is away from its parked position. Once the record take-out arm is in the play
position and the stylus has been moved to play the record, the play switch is depressed,
pausing the movement of the Wurlamatic by de-energizing the main cam relay. Now the record can play. When it’s over, it hits the trip switch,
bypassing the play switch and re-energizing the main cam motor once more. Now the record take-out arm will return to
the record carousel, and assuming the pin was successfully cancelled and thus neither
the side 1 or 2 relay is still being energized, the record grabby jaw thing will open up, hit the safety switch, and the carousel resumes movement. If another selection is stored in the selection
accumulator, it will of course stop once more and repeat the same sequence. However, if there are no more selections,
the carousel will hit the override assembly once, and make one more rotation. After completion of the second rotation, the
override switch is opened, stopping the carousel, and now the jukebox is back in standby mode. So. Is this neat or what? I mean, wow. I love the way this thing works. It’s endlessly fascinating to me, and even more
so when you remember that there is not a single programmable logic controller residing in here anywhere. Speaking of, I’d like to address a bit of
apparent controversy with the titling of the last video. And possibly this one. I don’t consider this device to contain
a computer. But, some people would say that it is a computer. I disagree, but first let’s acknowledge
that electromechanical computers are a thing! There’s no reason you can’t create a fully-functional computer using nothing but relays. But, I don’t see this device as computing
anything. It has a set of instructions, sure, and what
do computers do but follow said instruction sets? But at the same time, would you call an internal
combustion engine a computer? It has a cam shaft which opens its valves
in time with the movement of the piston. And in that sense it was programmed, but the actions
are entirely mechanical. There’s some nuance to be explored here,
but I would consider a sequence of operations to be separate from computing. Now, you could kinda argue that this machine
does multiplication in the selection process… but I don’t know if I’d agree. The one thing it does actually compute is
the value of coins. I would consider the credit accumulator to
be an electromechanical computer, although a very basic one. And even then, it really just counts up and
counts down, with each step being controlled with relay logic. And that’s where this gets messy. This machine is undeniably full of relay logic. In that sense this does have a programmable
logic controller. The programming was just done in what today
we would call a very unconventional fashion. Perhaps it would have been better to say silicon-free
computing, but let’s be honest. When you say the word “computer” these
days – this is not what comes to mind. Well, thank you so much for watching! I hope you liked this video. To answer a question I’m sure many of you
are wondering, yes. This is my jukebox, and I’ve had it for
years. It’s been at my parent’s home all this
time, and also kinda non-functional for the past half-decade, which is why I’ve never
featured it. One thing I do need to track down are suitable
replacement springs for the selection accumulator. A number of selections just don’t work because
the springs were broken, likely since the bottom panel of this machine has always been
missing. The broken springs are all on the side that
faces the rear, suggesting they were damaged through careless handling. This jukebox is actually what turned me into
the weirdo I am today. My parents let me buy this thing when I was
in – wait for it – middle school. Yeah. And I could afford it with my chores allowance
because it was very ugly and very broken. The person who owned it previously didn’t
have any interest in fixing it, so it went on eBay for cheap. I owe my parents a lot of thanks for things
that have happened throughout my life, but their willingness to let me buy a broken jukebox
at the age of 13 is certainly high up on my list. So, thanks mom and dad! And now, it’s time for me to end this video. But! There are a lot of interesting features of
this jukebox that we haven’t covered. Be on the lookout for a third jukebox video at some point, but for now, thank you. Thanks for watching. Thanks to everyone supporting this channel
on Patreon. And thanks again to my mom and dad. Cue the music! ♫ gratefully smooth jazz ♫ We’ll make one more take of that… then
we’re moving on. ‘Cause this is a LONG video. I left you with a devas… eugh. Gonna be doing this ‘till like 1:00 in the
morning. This… oh sh*t… sh-oops, I said a bad word… One more take of that. Ths only weights like 15 pounds, and has sharp
edges, no big deal at all That’s a longer line than I thought, my
word That’s so every corr… every? Where did that word come from? Well it was earlier but not there. From my descriptions of what’s going on
here, I’ve been relying on… And I forgot to put my finger in the thing. Ohhhh boooyyyyy… So, how confused are you? Seriously, I hope that wasn’t too bad. Also, totally wasn’t thinking about how much these captions would get in the way of some things on-screen. Pro-tip! On desktop, you can click and drag these captions around to wherever you’d like. So there’s that. Sorry, mobile users 🙁

Danny Hutson

100 thoughts on “The Selection Accumulator; a Jukebox’s Brain

  1. 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.

  2. Now the only question left to ask is which came first ;the actual kids ride /horse carousel or the jukebox carousel!My guess is the ride!

  3. We had a 1959 AMi when I was growing up. It was the most fascinating mechanical device I have ever seen. As far as I know, it's still around and functioning. It always reminded me of the robot from (Lost in space?) who says "Danger, Will Robinson !"

  4. I love these electro-mechanical marvels. Got a jukebox a little younger than this, but just as ugly.
    But regarding what constitutes a computer, it is only a device that does calculations, be it mechanically or electronic.
    I also have two gas pumps, the oldest is a clock dial type. This only showes the volume pumped and the price had to be manually calculated by a service station attendant. The other one, a 1957 Gilbarco has the two rows of rotating number wheels. The top row showing volume and the bottom showing the calculated price.
    The volume wheels are driven directly by the pump just like the dial pump, however the shaft goes through a large drum with adjustable gears. These gears can be set to the unit price and adjusts the turning ratio of the price wheels accordingly.
    In both service manuals and sales brochures this is refered to as the first computorized gas pump.

  5. I think it’s easier for you to think of all these relay contact points as transistor switches. I.e. on ore off. 😉

  6. It's hard to judge by watching a vid rather than seeing the actual object, but I can't help but to wonder if you couldn't modify springs from ball point pens to replace the missing/broken ones. There are also places like Grainger who sell springs, and if they don't have one that fits exactly, you may be able to modify something they have. And I'd wager that a sign store, you know… those little shops what make signs and stickers, should be able to make a replacement panel for that cracked piece on the front.

  7. By far one of your best videos yet. Your progress as a video creator since the beginning has been remarkable. Keep it up! We all appreciate it!

  8. My dad bought me parts to make a cable tv descrambler when I was in middle school and now as a parent I can’t see me doing the same. But it opened a whole door into tv production and RF and computers.

  9. Is the latch solenoid de-enrgised by the pin select coil being energized? Possably through the same curent limited suppy. As the latch solenoid needs to remain energized until the pin select coil is energised. As if you seketed 12345 and F you may get F1,F2 and passably F3 selected. Where as if you selected A B C D E and 1 you would only get A1.

  10. Technically, this is a computer. It's just not a general purpose computer (you may recall that this term used to be a thing). The fact that it uses mechanical latches is largely irrelevant. And it does multiplication, but it's again not arbitrary number multiplication – if you wanted that, you'd design it much smaller, but include two (or three, or four…) and interlock them. Please keep in mind that computer memory is also finite, so "arbitrary multiplication" isn't all that arbitrary… As for the final point – in terms of basic math, the coin counter is actually more sophisticated than the pricinple behind a computer, in that it can substract directly. 😉 CPUs add inverted values to substract – they just do it way faster than you can blink.

  11. Great video. What I want to know is how the machine kept track of multiple requests for the same song–there had to be counters for each selection on the carousel. Maybe if the counter wasn't zero, the pin reset wouldn't activate. I know this feature (multiple plays of same song) worked in at least some jukeboxes as early as 1964, possibly as early as 1962. Make that 1959. I once selected multiple plays of "Morgen" (a big hit in Germany) for a quarter. I was a kid at the time.

  12. Many thanks for these videos on the old Jukeboxes. Like it, I came into the world in 1970 and grew up loving the old Wurlitzer's and Rock-Ola's. Being a 1970's Juke, I believe the problem with it comes from all of the Disco it was forced to play for all those years just corroded and rotted the solenoids and relays.

    I look forward to your other videos on the inner workings.

  13. I have few hopefully basic questions that might make sense to answer on TCx:
    1. What happens if a user makes a selection of a record that is missing or has its lead-out groove too far in? I assume it gets stuck, but maybe there's a reset timer.
    2. What are those cogs on each record slot of the magazine? They seem to just be for organization but I have no idea what would need organizing since each slot is labeled properly.
    3. Is the magazine keyed so that you can't misalign it when reinstalling?

  14. Finite automata, a state machine. That's a class of computing machine. BTW great parents in supporting your interest in childhood. It's p/o how I become an engineer.

  15. Get out to your local harbor freight, they've got spring assortments. They're largely still open too.

    You flirted with it but should have actually gone into PLCs. Even with fully solid state controls, relay logic is still absolutely ubiquitous. — a controls engineer.

  16. Please make the 3rd episode! And once that's out, you can piece all 3 together and publish: Jukebox: The Movie .!!!!

  17. It seems like the accumulator cannot play the musical pieces in the order they have been "booked" but in alphabetical order.

  18. At least you weren't the kid who bought a mainframe off eBay and dragged it into your parents basement. That jukebox isn't that bad looking. I wish I had one in my man cave, I have plenty of 45s to go in one.

  19. It's a shame your service manual's schematics weren't arranged as a "straight-line" ladder diagram. You would have had a far easier time tracing the logic. But I suppose if a technician is about to fiddle with a rat's nest of wires, the diagram ought to be an honest preview.

  20. Damn! A pizza shop right around the corner from where I grew up had that exact jukebox, including the mountain scene marquee…

  21. It's amazing how EM machines have a rude Goldberg?
    Am I pronouncing his name right?

    It shouldn't work..but it does.
    With bells and whistles attached.

    I love mechanical machines compared to today's machines.
    With computer tech.

    I would also compare it to a Tesla car vs an Ford mustang in the 60's

    Yeah the TESLA car is neet to look at with the electronic bells and whistles.
    And electronic convenience attached.
    But how do you know personally how to fix it?
    Can you really go in to the engine of the Tesla car and fix it or go to a Tesla dealership and get it fixed?

    And what about those Tesla car batteries?
    Can you swap them out?
    Or have to go to a specified technician In Tesla cars and the bill for the car goes up and up.

    Or in a Ford mustang in the 60's go to a junkyard find the part.
    Put it in your mustang and hit go ..

    Seriously people are not understanding the concept of your new car is getting or will get expensive very fast.
    Electronics will never become cheep.
    And your new car can get hacked!
    And those self-driving cars!
    The term my car got hacked.
    Gets more scary!

    Seriously look think about it.
    You driving down the road and suddenly you have no control over your vehicle.

    Because a hacker hacked into your car Wi-Fi?
    Why is that a thing?
    And now has control of your car..
    Is under the whim of the hacker and running over pedestrians because of lols on Instagram YouTube and Facebook!

    And now you have to pay the price because your password on your car sucks.
    Welcome to reality!
    Didn't think about that scenario did you!
    But the mustang will never be hacked.
    And is running in peak performance!

  22. This is pretty cool. Hard to follow completely, even with your very helpful explanation (my main education is in computer science, not mechanical/electrical engineering), but still cool.

  23. I am a troll or throwing out hate at all.
    But people faith in technology right now is so concerning and a bad idea.
    In the age of coronavirus.
    Jesus people wake up!
    And need to wise up.

  24. Very entertaining stuff.
    Me I really respect electrical mechanical devices like pinball and jukeboxes.
    It's simple and confusing at the same time.
    But good job explaining it!
    2 metal horns merging together
    mm/ you rock!

  25. And me I would love to afford a jukebox pinball machine or arcade game.
    But my wishes can't catch up to my wallet: (.

    Oh well love the jukebox!

  26. This is an amazing job of reverse engineering and explanation. I'm inspired! I wonder if there's any old engineering manuals that talk about how to do the sequencing contacts.

  27. For really complex EM logic it can be helpful to redraw the circuit such that current flows from source to sink left to right. Relay and multi-pole switch contacts don’t have to be draw together — just use labels to associate them. Relay coils can stand alone with a label to associate them to their contacts. Let’s you lay out the circuit logically.

  28. I don't think you can consider a jukebox as a computer. You must be able to change how a computer processes input, or in other words, it must be programmable. You can make a jukebox program, which would be telling the jukebox to play a string of songs, but that does not change the way the jukebox processes your inputs, since that is hard wired.

  29. Your electro-mechanical jukebox is a robot, but not a computer. I has a large number of inputs, but you cannot alter that program to make it do something different. But that's just my opinion …

  30. It’s amazing how mechanically complex and ingenious things were. Modern technology while complex in a different way seems so simple in comparison. Amazing video, thanks for taking the time to tear down and explain all these time lost technologies. Keep up the great work!

  31. Statesman is actually a good looking jukebox. The water moving animation picture on top is amazing cool after a few cocktails…that is if you can get the animation motor to run. This model features an awesome amplifier and double 12" speakers only to be set back by a child's phonograph ceramic cartridge that tracks at 6 heavy grams. I changed my Statesman ceramic cartridge to a Shure SC35 magnetic cartridge, reduced the tone arm weight and added a preamp with an equalizer. Sounds better then just about any Seeburg jukebox after that respective upgrade. The Statesman had so many micro switch failures in smoky bars that operators could not keep them running. Wurlitzer had to keep repair men in local hotels in high bar populated areas to keep up with jukebox failures. A few years later Wurlitzer finally fixed most of the micro switch problems by the time the "SUPERSTAR" model was released…however by then few operators were going to take a risk on a high maintenance reputation brand jukebox. AMI was a reliable jukebox on the block and also offered 200 selections like Wurlitzer. With Seeburg you were down to 160 selections with high reliability. It is a fun game to keep these old Wurlitzers working. I really love the look of the "Zodiac" model. I remember one of those in a restaurant called the Crossroads that I worked at with my parents doing a family music act when I was 10 years old. I love the console "Cabaret" model too…but nothing but micro switch problems. When Wurlitzer jukeboxes work they are really the best sounding. I love this channel!! I gotta meet this host.

  32. Side 1 is one side of the record.
    Side 2 is the other side of the record.
    If you insert it one way, 1=A, 2=B.
    If you insert it the other way, 1=B, 2=A.

    That's why.

  33. This isn't a computer because it don't interpret data, it doesn't "compute" . Is cool, absolutely, is it doing anything with data, not really. (By it doesn't compute I mean the machine doesn't understand any terms, it is purely a binary function with no process to interpret. It receives power in different ways for different lengths but otherwise has no ability to "hang" on data or process it into new data) (p.s this was dumb and doesn't matter but electro mechanics is my jam)

  34. So, most early processors didn’t do multiplication either. It’s a super hard line to draw between “electro-mechanical device” “electro-mechanical computer” and “full-electric computer”. In fact, some ASICs used to do things like calculate blockchains are hard to really call a “computer” as well, since they’re just purely electrical pathways that are “programmed” by physical design, rather than through any semantic encoding. But then, the hardware that implements a semantic encoding is not really programmed through semantic encoding itself, except now they also kind of are, but the hardware that implements that semantic encoding is not programmable through semantic encoding either, but through physical design.

    So, it’s a bit like microevolution vs macroevolution. Is me getting O+ blood from my mother, and not B- blood from my father evolution? No one would really say “yes”, but really, it’s about matters of degrees. So, you end up with a situation similar to hills vs. mountains. The highest point in the country of the Netherlands is Vaalserberg, which is named a “mountain” but at just 322.4 m above… Normaal Amsterdams Peil? (Sure) it hardly counts as a “mountain” does it? But again, it’s the tallest point in the Netherlands. Despite really not being much more than a hill.

    So, we can argue about where the line should be drawn, that somethings are not “computers” but just “mechanical” devices enacting their “programming” through natural physical laws operating on the physical layout of their components. But I think most people understand a computer to be a sort of special-purpose device capable of consuming an arbitrary semantic encoding, and performing incredibly complicated tasks through emergent complexity of ordering from these semantics.

    I… got carried away. You’re right, I wouldn’t call it a computer either.

  35. It's like a beautiful work of kinetic art; all those different materials connected and synchronized 🤩
    For a short time I worked as a service engineer, maintaining jukeboxes back when CDs were the new thing. I never saw anything as fine as this in my travels. It was largely a case of switching the thing off and on, or cleaning the coin mechanism 😖

  36. I see a glitch in this design that could have come up in practical use:

    You cannot see what songs have already been selected-and a song cannot be selected more then once*, but it *would eat the credit for it.

    This machine is amazing, and if it where up to me, I'd clean up the innards as best I could, and then put clear plexi in so you could see it all.

  37. Well at least you have something to do while there craziness going on in the world. You do a wonderful job of explaining this all in the time you do. Also… I don't think I will be trying to fix one of those things anytime soon. I was thinking about getting a pinball machine, now I am not so sure… I bet they are also kind of hard to fix. PS don't go too crazy, we are all looking forward to future videos from you!

  38. IF you want to go just a little less crazy, get an upright piano and how how it works, and then if you want to go just a little crazier, talk about how you tune one, and if you really want to go crazy, show how a player piano works! Tuning a piano is more crazy than you thing, trust me on that one!

  39. Id imagine the reason they didnt refer to it as the "A" and "B" side is because it doesnt matter which way the disc goes into the machine?

    Id imagine you could theoretically put the A side of a record into the even numbered positions, thus naming it as 1 and 2 avoids potential confusion.

  40. 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.

  41. When I was in middle school my parents let me buy a pair of vending machines. One was a drink machine and the other a snack machine. That got me interested in purpose built machines in the same way that Jukebox did for you. I very nearly killed myself poking around in that drink machine poking around in the electronics because the outlets ground wasn't working.

  42. three questions: 1. why are the labels on the outside edge of the record carousel printed in "mirror" print? 2. it appears that selections are played in numeric/letter order, so if it's a popular night at the bar, and people are feeding this thing constantly, your selection could theoretically take a long time to come up, right? 3. what happens if you hit the same selection as has already been made? (or was that in video 1 that I have not watched) ?

  43. These two videos are even more fascinating than your usual excellent work! I am amazed at how much complex functionality can be achieved by purely electromechanical means, but really shouldn't be surprised – think about railway automatic signalling systems, inertial navigational systems in aircraft and gun firing 'computers' in WW2 warships, all devised and used successfully long before silicon chips came about. A while back you made a video on elevators, and I wonder whether something similar to the selection accumulator shown here has been used for remembering the requested floor numbers requested by elevator passengers?

  44. I've always been fascinated by electro mechanical devices. This is waaay more complex than I thought, but hey, it's no toaster!

  45. the selection accumulator is very similar to mechanism that dials phone numbers in an old mechanical phone exchange.

  46. So, it looks like the jukebox can only play songs in the order they are loaded in the jukebox, not the order selected.
    Am I right?

  47. Love everything you do, love electromechanics. There has always been a lot of debate around what is and is not a computer, for me most things are but what you think of as a "personal computer" has to have a programmable logic circuit, meaning that you have a machine that can do more then one set process.

    For mass produced parts you don't need in a hurry my goto is – like ebay but in china (make sure the seller has good reviews)


  48. I am in awe of how impressively complex this is. Probably the most complex way of making a jukebox by adding thingies that do thingies by connecting to thingies, which then do other thingies!

  49. I could never have imagined how complicated a damn record player could be. Who the hell invented this damn thing?!

  50. This isn’t that much different than that old pinball machine you looked at in your old old video on your old old channel. If you still have access to a machine like that you should go back and do a more thorough video on one of those

  51. These contacts are begging for CRC 2-26… seriously that would help a lot (just remember it's highly flammable).
    And no, it is not a computer — that word is these days used in the fixed sense of a general programmable computer (with emphasis on the "general" part); however it is a logic controller with hardwired logic — something that has long been used in industrial designs in various forms (i.e. before we had PLCs).
    The camshaft+disks that moves all the contacts up and down in the first video is akin to a ROM program even though it's made of hard plastic (the same way that early punch cards were used to old programs, and were essentially ROM devices).
    As for the coin machine, it's an adder (more like a primitive ALU in fact, and not a computer as that word is, again, used to mean a "general" programmable device).
    All combined, this machine is an automaton, to use an old fashion word that used to describe these mechanical contraptions performing a sequence of predetermined instructions.

  52. These 2 have been my absolute favorite videos of yours, I love learning about complicated electromechanics, and this has been the only cliffhanger I've been bothered by in a long time, so keep it up! You're honestly my favorite youtuber.

  53. Ok so I'm still not sure how the buttons work. Like does each button have its own set of wires? What does the whole buttons thing look like from the back? Unless it was already showed somewhere in the video. Like I get that it makes the thing with the solenoid and the levers activate the weird spinny thing but I don't know how.

  54. It is acting as a rotary switch, powered by being an electric motor itself, which is acting as a servo or stepper motor?

  55. The big difference between this and a computer is that while both run a "program", the jukebox is not "programmable" in the sense of what we consider a computer.

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