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Episode 2 - EM Pinball Resources

EM Pinball Journeys·podcast_episode·30m 31s·analyzed·Dec 15, 2024
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Analysis

claude-haiku-4-5-20251001 · $0.028

TL;DR

Technical deep-dive into 1976 Harry Williams Aztec EM machine architecture and game logic systems.

Summary

A detailed educational episode from EM Pinball Journeys examining the internal mechanics of a 1976 Harry Williams Aztec electromechanical pinball machine. The host provides an in-depth technical walkthrough of how scoring, playfield targets, relays, solenoids, and the score motor work together to create game logic without integrated circuits, tracing pinball's evolution from mechanical games through the early electronic era.

Key Claims

  • David Gottlieb designed Baffle Ball in 1931, widely regarded as the first commercially successful pinball game

    high confidence · Host discussing pinball history; this is widely documented historical fact in pinball community

  • David Gottlieb and company introduced electromechanical flippers in 1947's Humpty Dumpty

    high confidence · Host citing historical milestone in pinball development

  • Harry Williams released Aztec 29 years after Humpty Dumpty (placing it around 1976)

    high confidence · Host contextualizing Aztec's place in pinball history

  • The Aztec machine featured a fake sixth digit on its score display to inflate the appearance of scores

    high confidence · Host showing the mechanical score reel mechanism with dummy digit printed on underside

  • Harry Williams pioneered jet bumpers in 1948

    high confidence · Host discussing bumper mechanism development

  • Aztec uses a score motor with eight cams and switch stacks as its central control mechanism, functioning similarly to a CPU

    high confidence · Host demonstrating and explaining the score motor's sequential operation

  • Only the bumpers and slingshots on Aztec are powered by DC current (via rectifier), while everything else including flippers runs on 24V AC

    high confidence · Host explaining power systems and showing bridge rectifier installation on playfield

  • Flipper coils use a center-tap design to operate at two power levels: full power initially, reduced power when held to prevent overheating

    high confidence · Host explaining three-terminal flipper coil design and demonstrating voltage drop

Notable Quotes

  • “pinball machines are a fascinating tribute to humanity—artists musicians game designers and even voice actors work alongside machinists Fabricators Crafts People and Engineers to manufacture these elaborate Contraptions made purely for our Amusement”

    Host (EM Pinball Journeys) @ Early intro — Establishes thematic framing of pinball as collaborative art form; sets respectful, appreciative tone for technical analysis

  • “this Rat's Nest of wires and stuff...somehow that's all being accomplished with this Rat's Nest of wires and stuff how why it's easy just look at the schematic I'm sure you can figure it out I'm kidding of course”

    Host @ Mid-content — Humorous acknowledgment of the complexity being analyzed; signals the host will make this understandable

  • “Pinball is called pinball because in the earliest days it was a simple game of balls and pins an evolution of the French game Bagatelle”

    Host @ History section — Etymology and origin of pinball naming convention

  • “This would be useless the moment any 100 point target were hit the relay would lock itself on and be stuck but that circuit path travels through a switch on the score reel called the end of stroke switch”

    Host @ Explaining relay logic — Demonstrates understanding of self-powering relay circuits and their control mechanisms

  • “It takes two to tango, and to make something happen, the machine performs a dance where it constantly rewires itself on the fly. And what does it use to make that happen? That's right: relays.”

    Host @ Score motor section — Key insight explaining why relay-based systems require constant reconfiguration; central to EM game logic

  • “with the exception of the motor run switch, the rest of these switches aren't connected to anything. Even when the game is on and in play, they're just there clicking away without accomplishing a thing”

    Host @ Score motor explanation — Critical clarification about how EM logic works—switches are inactive until relays connect them dynamically

Entities

Harry WilliamspersonDavid GottliebpersonAztecgameHumpty DumptygameBaffle BallgameBagatellegame

Signals

  • ?

    historical_signal: Host provides authoritative historical context tracing pinball evolution from French Bagatelle through mechanical games (1931 Baffle Ball), electromechanical flippers (1947 Humpty Dumpty), jet bumpers (1948), to 1976 EM systems; establishes lineage of design innovation

    high · Comprehensive historical narrative with specific dates and designer attributions

  • ?

    design_innovation: Score motor design featuring eight cams with sequential switch stacks functioning as primitive CPU—demonstrates how EM manufacturers solved game logic without microprocessors through mechanical sequencing and relay-based dynamic rewiring

    high · Host explaining score motor: 'the machine performs a dance where it constantly rewires itself on the fly...the rest of these switches aren't connected to anything. Even when the game is on and in play, they're just there clicking away without accomplishing a thing'

  • ?

    design_innovation: Center-tap flipper coil design using three terminals to operate at two power levels—high power for initial activation, reduced power when held to prevent thermal damage; example of elegant thermal management solution predating modern electronics

    high · Host demonstrating coil design: 'flipper coils have three terminals...when the Flipper is at rest the button sends power through the center tap...once it reaches the end of its travel it opens this switch...current must now travel through the entire length of the solenoid wire'

  • ?

    design_innovation: Mechanical score reel displays using ratcheting mechanisms and solenoid-driven drums; dummy reel with printed top/bottom digits to create illusion of six-digit display from five physical reels

    high · Host showing score reel mechanism: 'the last digit of the readout is in fact fake and is only there to inflate the score but Harry Williams went through the trouble of printing the bottom of the nine and the top of the one on the dummy reel'

Transcript

youtube_mirror_subs · $0.000

0:12
welcome to the theater of magic I love pinball the sights The Sounds the physical nature of actual stuff happening in front of you and not just on a video screen have long appealed to me in fact for as long as I can remember of course a big draw to me is that these machines are well machines and wondrous machines at that a pinball machine is a fascinating tribute to humanity artists musicians game designers and even voice actors work alongside machinists Fabricators Crafts People and Engineers to manufacture these elaborate Contraptions made purely for our Amusement well and to gobble up our quarters with so much going on inside one of these even just sitting idle you might have wondered how they work luckily somebody gave me the keys to this machine so we can look [Music] inside it's it's a computer there's a computer in here it keeps track of where the ball is shows you your score on this display plays music and sound effects through speak speakers and lights up all the various light bulbs when they need to be lit how very modern but pinball goes back much further than this and not even 20 years prior to this machine leaving the factory pinball machines didn't feature any integrated circuits of any kind this is Aztec by Williams built in 1976 this machine hails from the tail end of the electromechanical era it wouldn't be long before manufacturer started tinkering with electronic controls in fact 10 copies of this very game were built as prototypes for the Williams system 2 microprocessor unit this one though well it's a little more old school and today I'm going to show you what makes it tick seriously why is it ticking to find out we'll have to look inside this time it opens from the back and once you remove this panel you won't see anything that looks like a computer in fact you'll find an Unholy mess of wires linking quite the assortment of Oddball assemblies together and this isn't even the half of it inside the main cabinet under the Playfield there's even more we get in there by opening the coin door pulling this lever which releases the lockdown bar that's this large metal piece at the front edge of the cabinet then once we remove the lock down bar by lifting up on it we can slide the glass out and the Playfield will simply lift right up there's even a handy prop rod now that we're in we see even more wires and even more stuff and that's not even the whole of it some of the control mechanisms are attached to the underside of the Playfield each and every one of these devices is critical for the function and logic of this game while this is nowhere near as complex as theater of magic there's still a lot going on there's a full-on rule set and series of goals in this game different targets light the letters a z t e and C light them all up and there's a chance for an extra ball there's a bonus added for hitting certain targets which is awarded at the end of each ball and if you hit the right targets you can double the bonus value there's more too if you complete Aztec and fill the bonus ladder up to 50,000 points that lights a special which Awards a free game and which outlane is lit will flip back and forth as you hit other targets you can also win replays based on on your score and that's configurable some of the rules can even be changed winning a special can award an extra ball instead of a replay and there are even three difficulty settings which change how many targets need to be hit before other opportunities are awarded but aside from rules and features the machine also needs to keep track of which ball is in play and thus how far you are along the game oh and by the way you can choose whether you want three balls per game or five it it has to end the game when it's over and disable the Playfield and when a new one is started it needs to reset the scores to zero plus up to four people can play this game it's fun to compete so it needs to keep track of which player is up and only change that player's score when it's their turn somehow that's all being accomplished with this Rat's Nest of wires and stuff how why it's easy just look at the schematic I'm sure you can figure it out I'm kidding of course and even if you studied this for hours it's not going to make any sense unless you understand what these parts are doing and how they work together so since you're all watching I suppose it's my job to explain what these parts are doing and how they work together we'll start with the basics and work our way up and we're going to go way back to basics with a bit of history but just a bit I promise pinball is called pinball because in the earliest days it was a simple game of balls and pins an evolution of the French game Bagel early games were very simple marbles rolled down a board set at an angle with pins nailed into the face those pins would create obstacles that deflected the motion of the rolling balls and would often form goals worth points games like this were made going back to the 18th century but they would remain obscure toys for the wealthy for many years then sometime around the Great Depression some clever folks devised ways to automate the game and turn it into a machine albeit a very simple one David gotle designed baffle ball in 1931 which is widely regarded as the first commercially successful pinball game I don't have one to show you but I do have Microsoft pinball arcade baffle ball was a simple baseball themed I guess marble game with the twist of Bean coin operated when the coin slide was pushed in trap doors in the goals would open allowing the balls to fall down into the machine and collected the ball shooter then the player had their fund these early games were purely mechanical featured manual scoring Were Meant To Go a top a table or other such surface and started showing up in bars and parlors all across the country and plenty of gambling based on your score occurred too but that's a story for a different time baffle ball was so successful that it spawned plenty of imitators such as Bal who which by the way was so successful that the company that produced it would rename itself Bali with a variety of games for players to choose from companies making pinball machines scrambled to add new features in order to make theirs Stand Out features like bumpers electric lights automatic scoring and eventually movable bumpers in the players control it was none other than dgot Le and company that introduced electromechanical flippers in 1947's Humpty Dumpty while the arrangement of the flippers on the Playfield is certainly odd by modern tastes this machine set new and enduring standards for pinball and 29 years later one of got Le's main Rivals Williams would release this machine Aztec the one I'm standing behind and that this video is principally about that one first let's look at what the player sees the Playfield is still just a wooden board with things attached to it that A ball rolls around on but now a variety of targets obstacles bumpers plenty of lights and let's not forget flippers make the game fast-paced visually interesting and addictive as with most pinball machines the Playfield is slightly off center as the right hand side of the machine is taken up by the shooter Lane that sends the ball up to the top of the Playfield using a player operated plunger just like the earliest games a simple gauge is printed on the shooter to help the player hit the ball with consistent Force depending on the game's design the strength of the initial plunge may be important and many games feature a deliberate element known as a skill shot where extra points are awarded if you get the plunge strength just right now you'll notice that there are fairly large obstacles which block off off parts of the Playfield this is done mainly to Define paths the ball might or in some cases must take these can be created in a number of ways but the most common is plastic posts fastened to the Playfield which are then fitted with rubber rings large rings may be stretched across two or more posts to create a linear barrier but you'll find plenty of individual posts with their own rings too the rubber rings make the ball bounce off these obstacles often un predictably and some of the larger barriers will award 10 points when hit to fill the otherwise blank areas of the play field created by the obstacles decorative plastic pieces printed with Graphics matching the game's theme are placed at top the posts this also helps visually Define the shape of the off-limits areas underneath the Plastics you'll find small incandescent light bulbs this is the only safe place to put them since the ball can't hit them and they illuminate the play field to allow for play in a dark room all things considered this is a pretty simple layout with a small number and variety of targets aside from the various 10-point bumpers this game features three rollover buttons eight rollover Lanes six standup targets one spinning Target one Kickback lane two slingshot kickers and three pop bumpers though Williams would prefer you call them jet bumpers for trademark reasons all of these award points when they're hit but they often do something else too or change how many points they award but for now let's just focus on the points the game shows you your score on the back class with these mechanical readouts called score reels oh by the way this back glass isn't in very good shape but I've got a reproduction replacement I've just not gotten around to ordering the right piece of glass for it yet anyway see if you can spot a fun little trick manufacturers were doing around this time look at the front and now the back do you see what's off look at the front again there are six digits in the score but look at the back and there are only five score reels per player the last digit of the readout is in fact fake and is only there to inflate the score but Williams went through the trouble of printing the bottom of the nine and the top of the one on the dummy reel which makes it quite convincing here's a spare score reel or drum unit as Williams calls it we can look at up close it's a fairly simple device just a large plastic drum with the digits 0 through 9 printed on its edge and a ratcheting mechanism to advance the position of the drum by 1/10th of a rotation a small solenoid a type of electromagnet pulls on a plunger when electric current runs through it and that advances the mechanism by one step by the way I hope you like electromagnets cuz this machine is chalk full of them the game's circuitry runs on 24 volts ac produced by this lump of a transformer sitting in the bottom which also produces 6 Volts for all the lamps all of the targets the ball can hit that award points are merely simple switches when the game is on and in play those switches become wired to the scoring mechanism take these 100 Point rollover buttons for example they literally are buttons and beneath the Playfield two electrical contacts become pressed together when the button is depressed by the weight of the ball you might guess that these 100 Point buttons are wired to the score reel in the hundreds position and sure enough when I press it that reel advances by one step but that's not all that happened a bell rang at the same time sitting in the cabinet near the coin door is the chime unit this is a unit with Chimes each of its three Chimes has a solenoid sitting below it and when power is sent to the coil it flings a plunger up into the chime which gives it a right
Theater of Magic
game
Gottliebcompany
Ballycompany
EM Pinball Journeysmedia
Microsoft Pinball Arcadeproduct
Straight Down The Middle: a pinball showmedia
  • ?

    design_philosophy: EM era design philosophy emphasized mechanical solutions, relay logic, and clever use of electromagnetic principles to create complex game systems without semiconductor integration; celebrates craftsmanship and engineering ingenuity

    high · Host's framing: 'pinball machines are a fascinating tribute to humanity—artists musicians game designers and even voice actors work alongside machinists Fabricators Crafts People and Engineers'

  • ?

    technology_signal: Aztec uses hybrid power delivery: AC 24V for most systems (relays, flippers, motors) but DC power (via bridge rectifier) for bumpers and slingshots to achieve stronger solenoid performance; indicates manufacturer optimization choices

    high · Host: 'the bumpers and the slingshot solenoids are provided with DC power...Harry Williams began tinkering with them around this time...solenoids powered by DC can be stronger than AC powered ones'

  • ?

    manufacturing_signal: Evidence of standardized component approach: multiple relay types, modular switch stacks, solenoid standardization across functions; suggests organized manufacturing practices and component inventory management

    medium · Host cataloging components: 'three rollover buttons eight rollover lanes six standup targets one spinning Target one kickback lane two slingshot kickers and three bumpers'

  • ?

    content_signal: EM Pinball Journeys represents high-quality educational content focused on technical documentation of electromechanical machines; Episode 2 focuses on machine resources and internal systems; suggests growing audience interest in EM preservation and understanding

    high · Episode structure, depth of technical explanation, apparent facility access suggesting established platform

  • ?

    restoration_signal: Host mentions reproduction backglass replacement for Aztec machine; suggests aftermarket parts availability for restoration of 1970s machines

    medium · Host: 'this back glass isn't in very good shape but I have a reproduction replacement I just haven't gotten around to ordering the right piece of glass for it yet'

  • ?

    historical_signal: Discussion of mylar protective sheets around jet bumpers to prevent wood damage; notes that 'this wasn't always standard practice though so many older games exhibit severe wear around the bumpers'—indicates wear patterns in historical machines

    medium · Host: 'a mylar protective sheet is installed around the bumper to minimize damage this wasn't always standard practice though so many older games exhibit severe wear around the bumpers'

    • 13:13
    smack that certainly rings a bell since two solenoids were fired with one switch solenoids that draw a lot of current and are located in two very different places the switch on the Playfield isn't what's powering them instead the Playfield switch Powers a relay specifically Al the 100 Point relay which lives in the backbox relays are switches that are actuated with wait for it an electromagnet a coil of wire creates a magnetic field when it's energized which pulls on an Armature and that in turn actuates a series of switches sometimes relays are simple and sometimes they're not in pinball machines like this they're not pinball pushes relays to their conceptual limit using them to create the game logic and do countless other tasks but that's a big part of why I like these machines so much notice that some of these switches are normally open and the contacts close when the relay is energized but some of them are just the opposite there's even a third option make brake switches we'll see some of those later in this case the switch on the Playfield since it was worth 100 points completed a circuit to energize the 100 Point relay when that pulled on its Armature these two switch contacts closed which completed a circuit both to the hundreds position score reel and the small chime all of the targets worth 100 points have their switches wired in parallel so that they'll all activate this relay when hit and all that arcing we see is precisely why the game uses a relay and not the switches on the Playfield seems simple enough but there are many more switch es on this relay than just the two that bump the score reel and chime in fact there are six one of these additional switches is there to ensure the score reel actually moves solenoids are fast but they're not instantaneous if the ball just brushes up against a Target the contact time may have been too brief for the solenoid in the score reel to pull completely on the plunger and actually Advance it to the next number so these two contacts actually provide a way for the Relay to power itself if I Bridge them with a screwdriver you'll see it pull in on its own this would be useless the moment any 100 point target were hit the relay would lock itself on and be stuck but that circuit path travels through a switch on the score reel called the end of stroke switch this is normally closed allowing power to flow through but opens once the solenoid has reached the end of it travel at that point it breaks the circuit powering the relay so the relay lets go here's what that looks like on the schematic for the machine uh full disclosure I've made some alterations to this and hidden a fair bit because some of what's visible here is very confusing without context I haven't given you yet and it's not important right now when reading the schematic power flows across the page and a circuit is active when there's a complete path from the left to the right though it's AC so it flows in both directions the 100 Point relay coil is right here it will become energized when any of these switches close they're labeled to indicate what and where they are and sure enough those are things worth 100 points but this switch is labeled 100 Point relay that means it's a switch within that relay and the symbol means it's a normally open switch so it closes when the relay energizes and since it also provides power to the relay coil it provides that bypass which keeps the coil energized even when input from the other switches is lost but that switch is it swi in series with all of these normally closed switches on the score reels those are the end of stroke switches we were just looking at so once the solenoid on whichever reel it's trying to fire has actually fired the re will lose that bypass signal and de energize another contact in the relay has to do with the number nine the score reels are not mechanically linked each one operates entirely independently of the others but if you have 900 points and score an additional 100 according to the laws of math you'll have 1,000 so two reels have to move in order to display that sum they do and did you know notice that two Bells rang this
    18:07
    [Applause] time this switch in the 100 Point relay will actually cause the 1,000 Point relay to energize as well but only when the 100 Point score reel is on the number nine look back at the score reel and you'll find a stack of switches which we call a switch stack oddly enough sitting near the top this switch is normally open but a pivoting mechanism actuates the switch stack at the nine position and closes that switch when it's closed an interlock is created between the 100 Point relay and the 1,00 point relay take a look at the schematic again these are the ninth position switches on the score reels and you'll see that they connect to that switch within the 100 Point relay if the score reel switch on the player that's up is closed meaning the 100 point score reel is showing a nine then the next time the 100 Point relay fires power will also get sent through to this switch and up to the 1,000 Point relay coil therefore the two relays will fire together all of the succeeding score reels have this interlock so a score of 99,99 will correctly roll to 100,000 when a single 10-point bumper is
    19:30
    hit speaking of of the 10-point bumpers now is a good time to go over the various Target Types on the Playfield when a rubber ring is stretched across two posts so long as the distance is sufficient a switch will be tucked behind that ring the contacts are slightly separated but will get pushed together when the ball stretches the ring sending power to the 10-point relay which advances the 10-point score reel rings a bell and also steps the number match units don't worry about that yet uh there's a lot going on in here the standup targets throughout the Playfield are essentially the same thing as all the 10-point bumpers but one of the switch contacts is attached to the face of the target the gap between the contacts here is important a wider Gap will require the ball to hit the target with more force in order for that hit to register but if they're too close simply brushing against the target will register as a hit so it's generally best to be somewhere in the middle the rollover lanes are essentially the same thing as the rollover buttons but instead of a button a formed piece of wire sticks up through a slot in the Playfield when that wire is depressed by the ball switch contacts below the Playfield are pushed together which adds the points generally the ball can travel over these in either direction but you'll notice that the designers had an evil streak with the out lanes those have their trip wires formed such that it will only allow the ball to travel down towards the drain should you happen to get very lucky and have the ball bounce off the apron and roll up the outlane which does happen occasionally unless it's going very fast it will just Bonk into this and fall back down Boo the spinning Target while very different in its execution is similar to the rollover Lanes the metal plate that the ball hits is attached to an eccentric axle I guess and a wire linkage connected to the right hand side goes below the Playfield through a small hole when the target rotates that linkage is repeatedly pulled up and down which in turn pulls on a leaf switch repeatedly connecting and disconnecting the two contacts as it spins when this target is hit just right it's quite the
    21:57
    show but not quite the show that the pop bump I mean jet bumpers can put on pioneered by Williams in 1948 these jet bumpers repel the ball at high speed when they're hit they're triggered by a circular platform known as the skirt this is attached to a stick resting in a bow below the Playfield while rather silly at first glance this Arrangement means that no matter where the ball should hit the skirt the stick will pivot which in turn pushes the bull downward thereby pushing these two switch contacts together that provides power to the solenoid beneath the Playfield which pulls down on this angled metal ring that floats above the skirt when that occurs the ball finds itself between that ring and the skirt solenoids are quite fast so the ring immediately comes crashing down and makes contact with the ball since the ring is angled at roughly 45° the ball gets flung away from the bumper this is a very rough process and since the Playfield is made of wood a myar protective sheet is installed around the bumper to minimize damage this wasn't always standard practice though so many older games exhibit severe wear around the bumpers if you noticed the second switch down below the jet bumper that is what actually registers points it's just like the targets we've been looking at but hidden away and activated by the movement of the bumper ring and not the ball itself not all games work like this though sometimes a pop bumper relay is used activated by the skirt which locks on in a similar fashion to the points relays we looked at earlier a contact within that pop bumper relay Awards points and this switch serves as an end of stroke switch to release the relay after the bumper has fired that approach has pros and cons and Williams opted to power the solenoid directly from the bumper skirt switch the main downside of this approach is that occasionally the ball will just brush against the bumper so it kind of sort of half fires and it doesn't award points and finally we have the slingshots these dastardly things are hardly a Target worth hitting as they only score 10 points and they have a nasty habit of flinging the ball right into the out lanes they're made up of three posts arranged in a triangle with a large rubber ring stretched across all three in the center of the long Edge is a kicker just behind the rubber ring the kicker is flanked on either side by two switch contacts when the ball hits the rubber ring and either of those switches close power is sent to a solenoid below which pushes the kicker outward stretching the rubber ring and flinging the ball away just like the pop bumpers it's a switch below the Playfield that actually registers points when the kicker has moved and the switches behind the rubber only provide power to the solenoid oh right I forgot about the kickback Lane here this thing is sort of a combo of the slingshot kicker and a rollover Lane the ball lands on a trip wire and after points are awarded a solenoid below the Playfield fires which Bonks the ball back up an interesting twist with this machine is that the pop bumpers and the slingshot solenoids are provided with DC power a bridge rectifier and capacitor are attached to the underside of the Playfield which means that there is in fact a single Semiconductor in this machine or four depending on how you want to Define things it turns out that solenoids powered by DC can be stronger than AC powered ones and Williams began tinkering with them around this time only the pop bumpers and slingshots are powered through the rectifier though as you can see in the schematic everything else including the flippers is powered by 24 BTS AC and why don't we talk about the flippers as with pretty much everything that moves they're powered by a solenoid but in this case they're controlled by the player with buttons on the sides of the cabinet those buttons simply push the contacts of a leaf switch together which sends power to the flipper coils then they pull on a linkage and The Flipper bat pops up flipper coils though are unique see a strong solenoid needs quite a lot of power power that means they get hot over time for every other solenoid in the machine that's not much of a problem because they're only activated in short bursts but the flippers are controlled by the player and that player might just want to hold the flippers up in order to catch the ball that could cause the coils to overheat and coils that overheat tend to get melty then Smoky and on rare occasions fiery Slow blow fuses throughout the cabinet should prevent a serious problem like a fire in the event that a coil becomes locked on which can happen but we want the flippers to be able to stay up without causing any trouble so if you look carefully at the flipper coil you'll see that it has three terminals the long coil of wire that actually makes the solenoid has a connection in its middle which allows it to function at two power levels when The Flipper is at rest the button sends power to the coil through the center tap this bypasses half of the coil's length reducing the number of turns of wire that current flows through which makes the solenoid more powerful that might seem backwards but that's just how solenoids work but once it reaches the end of its travel it opens this switch another end of stroke switch that removes power from the center tap meaning current must now travel through the entire length of the solenoid wire this reduces the current flowing through and the strength of the solenoid and allows it to stay energized without burning up and for a demonstration of this principle observe the change in sound as I force The Flipper bat down while holding in the
    28:22
    button the lights in the machine even dim while I do this it's a lot of current at this point we've looked at how everything on the Playfield Works we've seen how the machine shows you your score and we've seen how points get added to it but the machine is doing a heck of a lot more than simply adding Point values together which you might have been able to tell by all the stuff inside there are layers and layers of complexity built at top the basic scoring functions for instance the machine has to know how to count you get three balls per game and then it ends it also needs to know how many players there are and change which set of score reels is active after each ball but also not do that if the current player scored an extra ball and gets to shoot again then there's the bonus ladder I referenced earlier which always starts at 5,000 points but can be Advanced when you hit certain Targets in increments of 5,000 and I think that's a good place to move to next the number five here watch this [Music] how on Earth do you suppose that happened I hit a switch just once but the score reel moved five times all on its
    29:43
    own well remember that ticking it was doing in the beginning perhaps you noticed it happened in groups of five listen
    29:58
    again turns out the number five appears all over the place this target is worth 500 points this Lane scores 5,000 as does the kickback Target the bonus values increment in steps of 5,000 points and then there's this thing's name Aztec that has five letters in it and some of the targets will award points based on how many of those five letters are lit how how is it doing all that and why does everything happen in fives well it's time I introduce you to the score motor this wonky looking Contraption is the closest thing this machine has to a central processing unit the score motor consists of an electric motor which through a speed reduction gearbox slowly rotates a series of eight cams upon which rest a ridiculous number of switches in eight Stacks the stacks from left to right are called index 1 2 3 4 5 impulse and impulse forward incidentally impulse forward just has a single switch which is used only in the reset sequence ah sequence what a good word that is pretty much the whole idea of the score motor it allows things to happen automatically in a sequence on every one of the eight cams there are a series of divots or bumps these will actuate the switch Stacks as the cam rotates either the stack will briefly fall into the divot and the switches within will make or break contact as they move or in the case of the two impulse cams at the far right a series of bumps will push up on the switch stack which accomplishes the same thing the cams 1 through five are all offset such that the switches they actuate will be bumped in sequence 1 2 3 4 5 and impulse and impulse forward are bumped five times with every rotation the index cam on the far left is critical for the score motor's functions the switch on the top of this stack is the motor run switch it's much like the self-powering interlocks we've been looking at in other relays when closed it provides power to the motor and thus it will run and crucially that switch is closed whenever the motor is out of its parked position once it gets back to the park position the switch stack falls into the divot that switch opens and the motor St stops in practice this means that if anything should cause the motor to start moving it will keep itself moving until it's made a complete cycle it even works if I just push on
    32:48
    it but you'll notice that when I did that nothing happened this is what's both very confusing and completely critical to understand about electromechanics mechical systems like this with the exception of the motor run switch the rest of these switches aren't connected to anything even when the game is on and in play they're just there clicking away without accomplishing a thing because the wires they're connected to hit dead ends it takes two to tango and to make something happen the machine performs a dance where it constantly rewires itself on the Fly and what does it used to make that happen that's right relays that's why there are so many of them in this machine to actually make something occur you need a relay to connect these bouncing switches to other things in the machine that way they'll you know do stuff take this rollover worth 5,000 points as an example you'll never guess what the 5,000 Point rollover switch completes a circuit to it's none other than the 5,000 Point relay which lives on the underside of the Playfield this relay has three switch contacts which all connect to the score motor the switch on the right sends power to the motor to start it turning which you can observe when I Bridge the
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    contacts the switch on the left is yet another relay interlock the rollover switch is what sends the initial power to the relay coil to energize it but once once these contacts are touching the relay keeps itself powered if I Bridge these contacts you'll see the relay pull in and lock itself on if this feels familiar well it's doing the same thing as the switches on the points relays in the back box it keeps the relay energized until its task is actually complete and right now I've disabled the score motor since it's not moving this relay cannot complete its task and the Machine is locked up in this State its task remember is to add 5,000 points to the score and the middle contact in the relay is what makes that possible when closed this connects the 1,000 Point relay in the back box to this switch on the top of the impulse cam of the score motor when I plug the score motor back in the cams begin rotating and since the impulse cam actuates its switch stack five times the 1,00 point relay will receive five pulses through this
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    switch and right after it sends the fifth pulse the relay lets go that's because the relay's interlock is connected through a normally closed switch on cam 5 once cam 5 is actuated that switch is broken so the relay releases and now the machine is at rest this happens very quickly L which is incidentally the point so it's kind of hard to keep track of however I can slowly rotate the score motor by hand so we can observe each individual action occur once the 5,000 Point relay becomes energized it locks on by keeping itself powered through a switch on cam 5 it also connects the impulse switch through to the 1,00 point relay as I turn this we hear the machine dinging and buzzing every time this switch stack pops up but the relay is still locked on because cam 5 hasn't been actuated yet when that switch stack falls into the divot we hear a click as the relay loses power and lets go [Music]
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    as you can imagine the timing here is critical and the cams are aligned so that the fifth bump of the impulse switch happens just before cam 5 actuates its switches which also happens just before we get back to the start point and the index switch actuates with the score motor re-enabled this happens quickly and automatically I hope you can appreciate how amazingly Bonkers this is and that was one of the simplest relays in the machine causing it to do one of the simplest automated tasks it can do we've still got a bajillion relays to look at plus a solid 32 other switches in the score motor and we're how long into this video yeah I can't cover how everything works in this machine let alone in a single go so there will definitely be a second part but before we conclude here let's talk about the Aztec targets how they light up their respective letters and why that changes what other targets do by now I hope you know what the switches in these targets send power to say it with me now relays and Williams was kind enough to mount them in order on this support below the Playfield here's the a relay the Z relay the T relay the E relay and the C relay for now let's just focus on the a relay this single relay features all three kinds of switch contacts the three leftmost switches are normally open and as the relay pulls on its Armature the contacts are pushed together then we have a normally closed switch this one does just the opposite but the two on the right are make break switches the relay moves the center blade and instead of turning something on or off it redirects the flow of power from one place to another like the 5000 Point relay we just looked at this relay will power itself once it has been actuated as soon as the left hand switch makes contact it provides a power bypass and the relay becomes locked on and this relay will stay locked on until the end of the ball in play the next three switches have to do with the center Target and a kickback Lane I'll get back to those in a moment the two switches on the end the make brake switches change the machine's behavior and appearance once the a target has been hit the a rollover Lane is marked lights a 1000 and lights spinning Target obviously that means it lights some things up but it also makes this light go out it's this make brake switch that changes which lights are lit before I hit the target 6 volts was sent to the right hand contact which illuminated the lamp above the lane but once I hit it and the relay locked on power was redirected to the contact on the left which leads to the 2 a lamps as well as the spinner lighting the spinner Target changed its point value from 100 to 1,000 points how well that's what the other make brake switch did it disconnected the spinner from the 100 Point relay and connected it instead to the 1,000 Point relay now I could just tell you that but you might have noticed that the wires in this machine are colorcoded so you can trace where they go let's follow their path this is the SP spinning Target switch when closed it sends power out this gray wire with a red stripe it ends up bundled in the harness and comes back out right here at the relay there it's sent out either through the white wire with a red trace on the right or the brown wire with a yellow trace on the left those wires reenter the harness split out towards the back into this small bundle that's connected through a Jones plug to the back box and sure enough those two wires eventually end up at the coils of the 10 1,000 Point relays which one is connected depends on whether or not the relay is energized and here's what it looks like on the schematic power is sent through the spinner switch on the gray and red wire that ends up at the make brake switch in the a relay the normally closed contact connects over to the 100 Point relay so the spinning switch will send power there when closed but when the a relay is energized power is redirected to the brown and yellow wire which connects up to the 1,00 point relay but the spinning Target is only one of three targets that the a relay will change in value there's also the center Target and the kickback Lane those targets are worth a set value when none of the letters are lit but if even a single letter is lit they're worth more points in fact more for every letter that's lit in the case of the center Target is 1,000 points for each lit letter and the kickback Lane award WS 10,000 points for each lit letter that means that technically the targets have six possible values each how can this sort of circuitry possibly manage that well it's actually simpler than it might seem let's look at the center Target first the center Target switch sends power to the center Target relay of course which is similar to the 5,000 Point relay we looked at earlier once powered it locks itself on starts the score motor spinning hooks the 100 Point relay up to the impulse switch on the score motor and releases just after the fifth pulse of the 100 Point relay thus it adds 500 points to the score but look at the circuit path on the schematic power comes through the impulse switch here then we have to follow a gray and white wire down to b19 uh here it is and then it has to go through all of these normally closed switches before it makes it to the 100 Point relay if they're all closed then we're fine the 100 Point relay will be pulsed five times and we get those 500 points added to the score but if any one of the Aztec letter targets has been hit its respective switch in its relay is open and since all those switches are wired in series this circuit path is broken so it no longer works ah but we get 1,000 points for every letter that's lit and we just have to move a little ways up on the schematic to see how that works here again we see switches in the a z t e and C relays these are normally open but close when the respective relay is energized and right above them we see switches in a circle this is how the schematic tells us those are in the score motor and the notation tells us where in the score motor those switches are the a lay is connected through the index stack switch B that's the second switch from the bottom the Z relay through stack one switch a the bottom switch in the stack the T relay through switch stack two switch a the E relay through stack three switch a and the C relay through stack four switch a we already know that those switch Stacks are actuated by the score motor one at a time in order so you can imagine what's happening here as a sort of scanning sequence when the center Target is hit and its relay is energized each of the letter relays receives a pulse of power at the respective switches the a relay receives its pulse immediately as it's connected through a normally closed switch at the index position but as the motor turns that switch opens and then the following relays get pulsed one at a time whichever relays are energized will have this this switch closed so its respective pulse makes its way through the center Target relay and to the 1,000 Point relay coil thus it adds 1,000 points for every lit letter this is pretty wild right despite just being a tangled mess of wires relays switches a motor and some cams we have a machine which methodically checks whether each of the felet targets has been hit and and Awards points if it has been this results in a unique pattern of dings depending on which targets are lit I won't waste your time any further by going through every possible combination but here are a
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    [Music] few you probably noticed that right alongside the center Target relay in the schematic was the shooter relay that's what I've been calling the kickback Lane Williams decided to refer to this as the shooter which is very confusing since you know this is also the shooter but anyway that Target Works in essentially the exact same way as the center Target but it pulses the 1,000 Point relay through the impulse switch when no letters are lit thus awarding 5,000 points and pulses the 10,000 Point relay for every lit letter the only other difference is that the shooter coil gets fired at the end of the sequence through switch 4E in the score motor to kick the ball back out of the target while I covered a lot of what this machine does in this video it's probably pretty obvious based on all the other stuff in here that there's a lot more to see in part two we'll take a look at how the machine manages to do some of its more complex automated sequences like this one
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    [Music] yep it added 25,000 points to the score all on its own then changed with a ball inpl light from one to two apparently it can count and it also knows your score cross 350,000 points and you've won a replay stay tuned for how that all works it's just as nuts as everything you saw here thank you very much for watching I hope you enjoyed it and that I've been able to help you understand all this nonsense the thing is though it's not nonsense it's logic and that's part of why I like machines like this so much you can actually look at them pick it apart and understand what it's doing and why it blows my mind how folks of the past figured all this out and got these things manufactured in math and perhaps even more mind-blowing while this machine is from 1976 most of the tech in here existed in some form back in the 1930s it just got built up in layer after layer until we arrived at this and to be honest this machine isn't that complex there are plenty of electromechanical pins out there which have much deeper rule sets and many more Targets in fact 20 years prior to this one getting manufactured B introduced a game with multiball yeah maybe one day we can take a look at a more complex machine but for now I need to go to bed good night [Music] everybody you didn't know this but I'm even wearing [Music] PJs you never know what I've got on below the desk or behind the pinball
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    in fact 10 copies I slightly ooh the left-handed teleprompter control is going to throw me off I was going to need to pick this up quite the assortment of weird God we can slide the glass out and the Playfield will simply lift right up I botched the word simply to F and just a bit I promised promised that's not the what large rings may be stretched across two or more posts to create a linear barrier but sometimes that sounds weird and I'm going to start over but you'll find plenty of individual rings with their own rings too well this Line's not going great and that advances the mechanism by one step it or it would if I weren't so clumsy [Music]
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    a [Applause] [Music] [Applause]