WEBVTT Kind: captions Language: en 00:00:06.014 --> 00:00:06.860 [click] 00:00:07.079 --> 00:00:10.389 ♫ intense music ♫ [Welcome to the Theatre of Magic!] 00:00:10.389 --> 00:00:13.128 I love pinball. 00:00:13.128 --> 00:00:14.921 The sights, the sounds, 00:00:14.921 --> 00:00:22.326 the physical nature of actual stuff happening in front of you and not just on a video screen have long appealed to me. 00:00:22.326 --> 00:00:25.305 In fact, for as long as I can remember. 00:00:25.305 --> 00:00:29.635 Of course, a big draw to me is that these machines are... 00:00:29.635 --> 00:00:31.196 well, machines. 00:00:31.196 --> 00:00:34.176 And wondrous machines at that! 00:00:34.176 --> 00:00:37.840 A pinball machine is a fascinating tribute to humanity - 00:00:37.840 --> 00:00:42.061 artists, musicians, game designers and even voice actors 00:00:42.061 --> 00:00:46.750 work alongside machinists, fabricators, craftspeople, and engineers 00:00:46.750 --> 00:00:53.278 to manufacture these elaborate contraptions made purely for our amusement. 00:00:53.278 --> 00:00:56.745 Well, and to gobble up our quarters. 00:00:56.857 --> 00:00:59.240 [dramatic organ music] With so much going on inside one of these, 00:00:59.240 --> 00:01:01.109 even just siding idle, 00:01:01.109 --> 00:01:03.574 you might have wondered how they work. 00:01:03.574 --> 00:01:09.731 Luckily, somebody gave me the keys to this machine so we can take look inside. 00:01:18.188 --> 00:01:19.282 [music stops] It’s… 00:01:20.448 --> 00:01:22.102 it’s a computer. 00:01:22.102 --> 00:01:23.975 There’s a computer in here. 00:01:23.975 --> 00:01:26.038 It keeps track of where the ball is, 00:01:26.038 --> 00:01:28.132 shows you your score on this display, 00:01:28.132 --> 00:01:30.671 plays music and sound effects through speakers, 00:01:30.671 --> 00:01:34.866 and lights up all the various light bulbs they need to be lit. 00:01:34.866 --> 00:01:37.009 How very modern. 00:01:37.009 --> 00:01:40.603 But pinball goes much further back than this. 00:01:40.603 --> 00:01:44.714 And not even twenty years prior to this machine leaving the factory, 00:01:44.714 --> 00:01:50.076 pinball machines didn’t feature any integrated circuits of any kind. 00:01:50.076 --> 00:01:52.881 This is Aztec by Williams. 00:01:52.881 --> 00:01:58.759 Built in 1976, this machine hails from the tail end of the electromechanical era. 00:01:58.759 --> 00:02:02.938 It wouldn’t be long before manufacturers started tinkering with electronic controls, 00:02:02.938 --> 00:02:10.274 in fact 10 copies of this very game were built as prototypes for the Williams System 2 microprocessor unit. 00:02:10.274 --> 00:02:13.436 This one, though, well it’s a little more old-school. 00:02:13.436 --> 00:02:16.401 And today, I’m gonna show you what makes it tick. 00:02:16.401 --> 00:02:18.405 [ticking sounds, five-at-a-time] 00:02:18.405 --> 00:02:20.604 Seriously, why is it ticking? 00:02:20.604 --> 00:02:23.122 To find out, we’ll have to look inside. 00:02:23.122 --> 00:02:29.224 This time it opens from the back, and once you remove this panel you won’t see anything that looks like a computer - 00:02:29.224 --> 00:02:35.980 in fact you’ll find an unholy mess of wires linking quite the assortment of oddball assemblies together. 00:02:35.980 --> 00:02:38.070 And this isn’t even the half of it! 00:02:38.070 --> 00:02:42.230 Inside the main cabinet under the playfield there’s even more. 00:02:42.230 --> 00:02:44.693 We get in there by opening the coin door, 00:02:44.693 --> 00:02:47.703 pulling this lever which releases the lockdown bar 00:02:47.703 --> 00:02:50.926 (that’s this large metal piece at the front edge of the cabinet), 00:02:50.926 --> 00:02:53.942 then once we remove the lockdown bar by lifting up on it, 00:02:53.942 --> 00:02:58.135 we can slide the glass out and the playfield will simply lift right up. 00:02:58.135 --> 00:03:00.000 There’s even a handy prop rod! 00:03:00.800 --> 00:03:04.727 Now that we’re in, we see even more wires and even more stuff. 00:03:04.727 --> 00:03:06.940 And that’s not even the whole of it! 00:03:06.940 --> 00:03:11.531 Some of the control mechanisms are attached to the underside of the playfield. 00:03:11.531 --> 00:03:18.340 Each and every one of these devices is critical for the function and logic of this game. 00:03:18.340 --> 00:03:27.845 While this is nowhere near as complex as Theatre of Magic, there’s still a lot going on. There’s a full-on ruleset and series of goals in this game: 00:03:27.845 --> 00:03:31.712 different targets light the letters A, Z, T, E, and C. 00:03:31.712 --> 00:03:34.346 Light them all up and there’s a chance for an extra ball. 00:03:35.026 --> 00:03:39.656 There’s a bonus added for hitting certain targets which is awarded at the end of each ball. 00:03:39.656 --> 00:03:43.302 And if you hit the right targets you can double the bonus value. 00:03:44.031 --> 00:03:45.219 There’s more, too. 00:03:45.219 --> 00:03:49.577 If you complete AZTEC and fill the bonus ladder up to 50,000 points, 00:03:49.577 --> 00:03:52.662 that lights a Special which awards a free game. 00:03:52.662 --> 00:03:58.025 And which outlane is lit will flip back and forth as you hit other targets. 00:03:58.025 --> 00:04:03.086 You can also win replays based on your score, and that’s configurable. 00:04:03.086 --> 00:04:04.865 Some of the rules can even be changed - 00:04:04.865 --> 00:04:08.456 winning a special can award an extra ball instead of a replay, 00:04:08.456 --> 00:04:16.328 and there are even three difficulty settings which change how many targets need to be hit before other opportunities are awarded. 00:04:16.328 --> 00:04:18.785 But aside from rules and features, 00:04:18.785 --> 00:04:25.027 the machine also needs to keep track of which ball is in play and thus how far you are along the game 00:04:25.027 --> 00:04:29.515 (oh and by the way you can choose whether you want three balls per game or five). 00:04:29.515 --> 00:04:33.490 It has to end the game when it’s over and disable the playfield, 00:04:33.490 --> 00:04:37.496 and when a new one is started it needs to reset the scores to zero. 00:04:37.496 --> 00:04:39.857 Plus, up to four people can play this game. 00:04:39.857 --> 00:04:41.357 It’s fun to compete! 00:04:41.357 --> 00:04:44.675 So it needs to keep track of which player is up, 00:04:44.675 --> 00:04:49.407 and only change that player’s score when it’s their turn. 00:04:49.407 --> 00:04:52.822 Somehow that’s all being accomplished with… 00:04:53.234 --> 00:04:56.713 this rat’s nest of wires and stuff! 00:04:57.301 --> 00:04:58.214 How? 00:04:58.214 --> 00:05:00.937 Why, it’s easy - just look at this schematic. 00:05:00.937 --> 00:05:02.744 I’m sure you can figure it out! 00:05:04.166 --> 00:05:07.746 I’m kidding, of course - and even if you studied this for hours, 00:05:07.746 --> 00:05:14.025 it’s not gonna make any sense unless you understand what these parts are doing and how they work together. 00:05:14.025 --> 00:05:16.344 So, since you’re all watching, 00:05:16.344 --> 00:05:20.799 I suppose it’s my job to explain what these parts are doing and how they work together. 00:05:20.799 --> 00:05:23.915 We’ll start with the basics and work our way up. 00:05:23.915 --> 00:05:27.416 And we’re gonna go way back to basics with a bit of history. 00:05:27.416 --> 00:05:29.688 But just a bit, I promise. 00:05:29.688 --> 00:05:36.518 Pinball is called "pinball" because in the earliest days it was a simple game of balls and pins. 00:05:36.518 --> 00:05:41.238 An evolution of the French game bagatelle, early games were very simple. 00:05:41.238 --> 00:05:46.462 Marbles rolled down a board set at an angle with pins nailed into the face. 00:05:46.462 --> 00:05:53.621 Those pins would create obstacles that deflected the motion of the rolling balls and would often form goals worth points. 00:05:53.621 --> 00:05:56.803 Games like this were made going back to the 18th century, 00:05:56.803 --> 00:06:01.071 but they would remain obscure toys for the wealthy for many years. 00:06:01.071 --> 00:06:08.215 Then, some time around the great depression,  some clever folks devised ways to automate the game and turn it into a machine 00:06:08.215 --> 00:06:10.591 (albeit a very simple one). 00:06:10.591 --> 00:06:18.811 David Gottlieb designed Baffle Ball in 1931 which is widely regarded as the first commercially-successful pinball game. 00:06:18.811 --> 00:06:23.980 I don’t have one to show you but I do have Microsoft Pinball Arcade! 00:06:23.980 --> 00:06:31.695 Baffle Ball was a simple baseball-themed (I guess) marble game with the twist of being coin-operated. 00:06:31.695 --> 00:06:36.041 When the coin slide was pushed in, trap-doors in the goals would open 00:06:36.041 --> 00:06:40.415 allowing the balls to fall down into the machine and collect at the ball shooter. 00:06:40.415 --> 00:06:42.587 Then the player had their fun. 00:06:42.587 --> 00:06:45.191 These early games were purely mechanical, 00:06:45.191 --> 00:06:47.028 featured manual scoring, 00:06:47.028 --> 00:06:50.122 were meant to go atop a table or other such surface, 00:06:50.122 --> 00:06:54.240 and started showing up in bars and parlors all across the country. 00:06:54.240 --> 00:06:58.504 And… plenty of gambling based on your score occurred, too, 00:06:58.504 --> 00:07:01.434 but that’s a story for a different time. 00:07:01.560 --> 00:07:07.257 Baffle Ball was so successful that it spawned plenty of imitators such as Ballyhoo - 00:07:07.257 --> 00:07:11.989 which, by the way, was so successful the company that  produced it would rename itself 00:07:11.989 --> 00:07:13.303 Bally. 00:07:13.303 --> 00:07:16.607 With a variety of games for players to choose from, 00:07:16.607 --> 00:07:22.617 companies making pinball machines scrambled to add new features in order to make theirs stand out. 00:07:22.617 --> 00:07:27.351 Features like bumpers, electric lights, automatic scoring, and eventually 00:07:27.351 --> 00:07:30.717 moveable bumpers in the player’s control. 00:07:30.717 --> 00:07:38.476 It was none other than D. Gottlieb & Company that introduced electromechanical flippers in 1947’s Humpty Dumpty. 00:07:38.476 --> 00:07:44.064 While the arrangement of the flippers on the playfield is certainly… odd by modern tastes, 00:07:44.064 --> 00:07:48.103 this machine set new and enduring standards for pinball. 00:07:48.103 --> 00:07:54.805 And, 29 years later, one of Gottlieb’s main rivals, Williams, would release this machine. 00:07:54.805 --> 00:07:55.824 Aztec. 00:07:55.824 --> 00:07:59.323 The one I’m standing behind and that this video is principally about. 00:07:59.323 --> 00:08:00.735 That one. 00:08:00.735 --> 00:08:03.711 First, let’s look at what the player sees. 00:08:03.711 --> 00:08:10.819 The playfield is still just a wooden board with things attached to it that a ball rolls around on. 00:08:10.819 --> 00:08:15.402 But now a variety of targets, obstacles, bumpers, plenty of lights, 00:08:15.402 --> 00:08:22.008 and let’s not forget flippers make the game fast-paced, visually interesting, and addictive. 00:08:22.008 --> 00:08:23.883 As with most pinball machines, 00:08:23.883 --> 00:08:29.899 the playfield is slightly off-center as the right hand side of the machine is taken up by the shooter lane. 00:08:29.899 --> 00:08:36.720 That sends the ball up to the top of the playfield using a player-operated plunger, just like the earliest games. 00:08:36.720 --> 00:08:42.365 A simple gauge is printed on the shooter to help the player hit the ball with consistent force. 00:08:42.365 --> 00:08:46.798 Depending on the game’s design, the strength of the initial plunge may be important, 00:08:46.798 --> 00:08:55.453 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. 00:08:55.453 --> 00:09:01.140 Now you’ll notice that there are fairly large obstacles which block off parts of the playfield. 00:09:01.140 --> 00:09:07.674 This is done mainly to define paths the ball might or, in some cases, must take. 00:09:07.674 --> 00:09:16.367 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. 00:09:16.367 --> 00:09:21.289 Large rings may be stretched across two or more posts to create a linear barrier, 00:09:21.289 --> 00:09:25.637 but you’ll find plenty of individual posts with their own rings, too. 00:09:25.637 --> 00:09:34.376 The rubber rings make the ball bounce off these obstacles, often unpredictably, and some of the larger barriers will award 10 points when hit. 00:09:34.376 --> 00:09:39.205 To fill the otherwise blank areas of the playfield created by the obstacles, 00:09:39.205 --> 00:09:45.192 decorative plastic pieces printed with graphics matching the game’s theme are placed atop the posts. 00:09:45.192 --> 00:09:50.013 This also helps visually define the shape of the off-limits areas. 00:09:50.013 --> 00:09:54.480 Underneath the plastics you’ll find small incandescent light bulbs. 00:09:54.480 --> 00:09:58.116 This is the only safe place to put ‘em since the ball can’t hit them, 00:09:58.116 --> 00:10:02.197 and they illuminate the playfield to allow for play in a dark room. 00:10:02.197 --> 00:10:08.302 All things considered, this is a pretty simple layout with a small number and variety of targets. 00:10:08.302 --> 00:10:10.754 Aside from the various 10 point bumpers, 00:10:10.754 --> 00:10:13.377 this game features three rollover buttons, 00:10:13.377 --> 00:10:15.222 eight rollover lanes, 00:10:15.222 --> 00:10:17.092 six stand-up targets, 00:10:17.092 --> 00:10:18.633 one spinning target, 00:10:18.633 --> 00:10:20.059 one kickback lane, 00:10:20.059 --> 00:10:21.818 two slingshot kickers, 00:10:21.818 --> 00:10:23.319 and three pop bumpers 00:10:23.319 --> 00:10:28.179 (though Williams would prefer you call them Jet Bumpers for trademark reasons). 00:10:28.179 --> 00:10:30.919 All of these award points when they’re hit, 00:10:30.919 --> 00:10:35.880 but they often do something else, too - or change how many points they award. 00:10:35.880 --> 00:10:39.197 But for now, let’s just focus on the points. 00:10:39.197 --> 00:10:44.954 The game shows you your score on the backglass  with these mechanical readouts called score reels. 00:10:44.954 --> 00:10:50.784 Oh, by the way, this backglass isn’t in very good shape but I’ve got a reproduction replacement. 00:10:50.784 --> 00:10:54.479 I’ve just not gotten around to ordering the right piece of glass for it yet. 00:10:54.479 --> 00:11:00.114 Anyway, see if you can spot a fun little trick manufacturers were doing ‘round this time. 00:11:00.114 --> 00:11:01.910 Look at the front. 00:11:01.910 --> 00:11:03.842 And now the back. 00:11:04.462 --> 00:11:06.197 Do you see what’s off? 00:11:06.197 --> 00:11:07.545 Look at the front again. 00:11:07.545 --> 00:11:10.418 There are six digits in the score. 00:11:10.418 --> 00:11:15.266 But look at the back and there are only five score reels per player. 00:11:15.266 --> 00:11:19.140 The last digit of the readout is, in fact, fake 00:11:19.140 --> 00:11:21.725 and is there only to inflate the score. 00:11:21.725 --> 00:11:27.256 But! Williams went through the trouble of printing the bottom of the 9 and the top of the 1 on the dummy reel 00:11:27.256 --> 00:11:28.880 which makes it quite convincing. 00:11:30.000 --> 00:11:35.800 Here’s a spare score reel, or drum unit as Williams calls it, we can look at up close. 00:11:35.800 --> 00:11:37.409 It’s a fairly simple device: 00:11:37.409 --> 00:11:42.237 just a large plastic drum with the digits zero through nine printed on its edge 00:11:42.237 --> 00:11:47.536 and a ratcheting mechanism to advance the  position of the drum by one tenth of a rotation. 00:11:47.536 --> 00:11:53.748 A small solenoid (a type of electromagnet) pulls on a plunger when electric current runs through it, 00:11:53.748 --> 00:11:57.449 and that advances the mechanism by one step. 00:11:57.449 --> 00:12:03.121 By the way, I hope you like electromagnets ‘cause this machine is chock full of ‘em. 00:12:03.121 --> 00:12:12.815 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. 00:12:12.815 --> 00:12:18.151 All of the targets the ball can hit that award points are merely simple switches. 00:12:18.151 --> 00:12:23.665 When the game is on and in-play, those switches become wired to the scoring mechanism. 00:12:23.665 --> 00:12:27.234 Take these 100 point rollover buttons for example. 00:12:27.234 --> 00:12:33.292 They literally are buttons and beneath the playfield two electrical contacts become pressed together 00:12:33.292 --> 00:12:35.973 when the button is depressed by the weight of the ball. 00:12:36.229 --> 00:12:41.613 You might guess that these 100 point buttons are wired  to the score reel in the hundreds position, 00:12:41.613 --> 00:12:43.561 and sure enough when I press it 00:12:43.561 --> 00:12:47.267 [clack/ding] that reel advances by one step. 00:12:47.267 --> 00:12:49.030 But that’s not all that happened. 00:12:49.030 --> 00:12:51.419 A bell rang at the same time. 00:12:51.419 --> 00:12:55.658 Sitting in the cabinet near the coin door is the chime unit. 00:12:55.658 --> 00:12:58.491 This is a unit with chimes. 00:12:58.491 --> 00:13:03.672 Each of its three chimes has a solenoid sitting below it and when power is sent to the coil 00:13:03.672 --> 00:13:08.143 it flings a plunger up into the chime which gives it a right smack. 00:13:08.143 --> 00:13:10.421 [Three dings, a la the NBC theme] 00:13:10.421 --> 00:13:12.580 That certainly rings a bell. 00:13:12.580 --> 00:13:21.887 Since two solenoids were fired with one switch - solenoids that draw a lot of current and are located in two very different places - 00:13:21.887 --> 00:13:25.312 the switch on the playfield isn’t what’s powering them. 00:13:25.312 --> 00:13:28.749 Instead, the playfield switch powers a relay. 00:13:28.749 --> 00:13:33.391 Specifically, the 100 point relay which lives in the backbox. 00:13:33.391 --> 00:13:36.263 Relays are switches that are actuated with 00:13:36.263 --> 00:13:37.547 - wait for it - 00:13:37.547 --> 00:13:39.471 an electromagnet! 00:13:39.471 --> 00:13:44.520 A coil of wire creates a magnetic field when it’s energized which pulls on an armature, 00:13:44.640 --> 00:13:48.143 and that in turn actuates a series of switches. 00:13:48.143 --> 00:13:51.737 Sometimes relays are simple, and sometimes they’re not. 00:13:51.737 --> 00:13:53.616 In pinball machines like this, 00:13:53.616 --> 00:13:55.154 ** they’re not ** 00:13:55.154 --> 00:13:58.215 Pinball pushes relays to their conceptual limit 00:13:58.215 --> 00:14:02.867 using them to create the game logic and do countless other tasks, 00:14:02.867 --> 00:14:06.393 but that’s a big part of why I like these machines so much. 00:14:06.393 --> 00:14:12.838 Notice that some of these switches are normally open and the contacts close when the relay is energized, 00:14:12.838 --> 00:14:15.292 but some of them are just the opposite. 00:14:15.292 --> 00:14:18.970 There’s even a third option - make/break switches. 00:14:18.970 --> 00:14:21.214 We’ll see some of those later. 00:14:21.214 --> 00:14:25.527 In this case, the switch on the playfield,  since it was worth 100 points, 00:14:25.527 --> 00:14:29.593 completed a circuit to energize the 100 point relay. 00:14:29.593 --> 00:14:34.152 When that pulled on its armature, these two switch contacts closed 00:14:34.152 --> 00:14:40.016 which completed a circuit both to the hundreds position score reel and the small chime. 00:14:40.016 --> 00:14:47.579 All of the targets worth 100 points have their switches wired in parallel so that they’ll all activate this relay when hit. 00:14:47.579 --> 00:14:55.481 And all that arcing we see is precisely why the game uses a relay and not the switches on the playfield. 00:14:55.481 --> 00:15:03.812 Seems simple enough, but there are many more switches on this relay than just the two that bump the score reel and chime. 00:15:03.812 --> 00:15:06.552 In fact there are six. 00:15:06.680 --> 00:15:11.541 One of these additional switches is there to ensure the score reel actually moves. 00:15:11.541 --> 00:15:15.173 Solenoids are fast, but they’re not instantaneous. 00:15:15.173 --> 00:15:18.195 If the ball just brushes up against a target, 00:15:18.195 --> 00:15:27.706 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. 00:15:27.706 --> 00:15:33.622 So, these two contacts actually provide a way for the relay to power itself. 00:15:33.622 --> 00:15:37.321 If I bridge them with a screwdriver you’ll see it pull in. 00:15:37.321 --> 00:15:46.436 On its own this would be useless - the moment any 100 point target were hit the relay would lock itself on and be stuck. 00:15:46.436 --> 00:15:52.876 But that circuit path travels through a switch on the score reel called the end-of-stroke switch. 00:15:52.876 --> 00:16:00.144 This is normally closed allowing power to flow through but opens once the solenoid has reached the end of its travel. 00:16:00.144 --> 00:16:05.172 At that point it breaks the circuit powering the relay, so the relay lets go. 00:16:05.172 --> 00:16:08.732 Here’s what that looks like on the schematic for the machine. 00:16:08.732 --> 00:16:14.181 Full disclosure, I’ve made some alterations to this and hidden a fair bit 00:16:14.181 --> 00:16:21.627 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. 00:16:21.627 --> 00:16:29.953 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 00:16:29.953 --> 00:16:33.555 (though it’s AC so it flows in both directions). 00:16:33.555 --> 00:16:37.002 The 100 point relay coil is right here. 00:16:37.002 --> 00:16:41.574 It will become energized when any of these switches close. 00:16:41.574 --> 00:16:48.522 They’re labeled to indicate what and where they are, and sure enough those are things worth 100 points. 00:16:48.522 --> 00:16:52.727 But this switch is labeled "100 point relay." 00:16:52.727 --> 00:16:59.102 That means it’s a switch within that relay, and the symbol means it’s a normally open switch. 00:16:59.102 --> 00:17:02.416 So, it closes when the relay energizes, 00:17:02.416 --> 00:17:06.089 and since it also provides power to the relay coil, 00:17:06.089 --> 00:17:13.398 it provides that bypass which keeps the coil energized even when input from the other switches is lost. 00:17:13.398 --> 00:17:20.604 But that switch is itself wired in series with all of these normally-closed switches on the score reels. 00:17:20.604 --> 00:17:28.254 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, 00:17:28.254 --> 00:17:32.918 the relay will lose that bypass signal and de-energize. 00:17:32.918 --> 00:17:37.557 Another contact in the relay has to do with the number 9. 00:17:37.557 --> 00:17:44.344 The score reels are not mechanically linked - each one operates entirely independently of the others. 00:17:44.344 --> 00:17:52.271 But if you have 900 points and score an additional one hundred, according to the laws of math you’ll have 1,000 00:17:52.271 --> 00:17:56.295 so two reels have to move in order to display that sum. 00:17:56.295 --> 00:18:01.312 [dings]  They do - and did you notice that two bells rang this time? 00:18:01.312 --> 00:18:04.734 [ding… ding… ding… 00:18:05.609 --> 00:18:08.161 dongs] 00:18:08.161 --> 00:18:14.961 This switch in the 100 point relay will actually cause the 1,000 point relay to energize as well - 00:18:14.961 --> 00:18:20.461 but only when the 100 point score reel is on the number 9. 00:18:20.461 --> 00:18:24.407 Look back at the score reel and you’ll find a stack of switches 00:18:24.407 --> 00:18:27.093 (which we call a switch stack, oddly enough) 00:18:27.093 --> 00:18:28.895 sitting near the top. 00:18:28.895 --> 00:18:36.904 This switch is normally open, but a pivoting mechanism actuates the switch stack at the nine position and closes that switch. 00:18:36.904 --> 00:18:43.906 When it’s closed, an interlock is created between the 100 point relay and the 1,000 point relay. 00:18:43.906 --> 00:18:45.953 Take a look at the schematic again. 00:18:45.953 --> 00:18:49.195 These are the 9th position switches on the score reels, 00:18:49.320 --> 00:18:53.995 and you’ll see that they connect to that switch within the 100 point relay. 00:18:53.995 --> 00:19:01.000 If the score reel switch on the player that’s up is closed,  meaning the 100 point score reel is showing a 9,   00:19:01.000 --> 00:19:04.252 then the next time the 100 point relay fires, 00:19:04.252 --> 00:19:13.096 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. 00:19:13.096 --> 00:19:16.746 All of the succeeding score reels have this interlock, 00:19:16.746 --> 00:19:22.054 so a score of 99,990 will correctly roll to 100,000 00:19:22.054 --> 00:19:24.381 when a single 10-point bumper is hit. 00:19:24.381 --> 00:19:28.303 [three chimes and a loud clack] 00:19:28.303 --> 00:19:30.212 Speaking of the 10-point bumpers, 00:19:30.212 --> 00:19:34.613 now’s a good time to go over the various target types on the playfield. 00:19:34.613 --> 00:19:42.901 When a rubber ring is stretched across two posts, so long as the distance is sufficient a switch will be tucked behind that ring. 00:19:42.901 --> 00:19:48.132 The contacts are slightly separated but will get pushed together when the ball stretches the ring, 00:19:48.132 --> 00:19:53.842 sending power to the 10 point relay which advances the 10 point score reel, rings a bell, 00:19:53.842 --> 00:19:58.907 and also steps the number match unit... 00:19:58.907 --> 00:20:00.393 Don’t worry about that yet. 00:20:00.393 --> 00:20:02.924 Uh, there’s a lot going on in here! 00:20:02.924 --> 00:20:08.395 The stand-up targets throughout the playfield are  essentially the same thing as all the 10-point bumpers, 00:20:08.395 --> 00:20:12.969 but one of the switch contacts is attached to the face of the target. 00:20:12.969 --> 00:20:16.111 The gap between the contacts here is important; 00:20:16.111 --> 00:20:22.397 a wider gap will require the ball to hit the target with more force in order for that hit to register. 00:20:22.397 --> 00:20:27.413 But if they’re too close, simply brushing against the target will register as a hit. 00:20:27.413 --> 00:20:30.617 So it’s generally best to be somewhere in the middle. 00:20:30.617 --> 00:20:34.828 The rollover lanes are essentially the same thing as the rollover buttons, 00:20:34.828 --> 00:20:40.394 but instead of a button, a formed piece of wire sticks up through a slot in the playfield. 00:20:40.394 --> 00:20:47.610 When that wire is depressed by the ball, switch contacts below the playfield are pushed together which adds the points. 00:20:47.610 --> 00:20:51.297 Generally the ball can travel over these in either direction, 00:20:51.297 --> 00:20:55.975 but you’ll notice that the designers had an evil streak with the outlanes. 00:20:55.975 --> 00:21:02.819 Those have their trip-wires formed such that it will only allow the ball to travel down towards the drain. 00:21:02.819 --> 00:21:10.520 Should you happen to get very lucky and have the ball bounce off the apron and roll up the outlane, which does happen occasionally, 00:21:10.520 --> 00:21:16.517 unless it’s going very fast it will just  bonk into this and fall back down. 00:21:16.517 --> 00:21:18.035 Boo! 00:21:18.035 --> 00:21:24.357 The spinning target, while very different in its execution, is similar to the rollover lanes. 00:21:24.357 --> 00:21:30.055 The metal plate that the ball hits is attached to an eccentric… axle? I guess? 00:21:30.055 --> 00:21:36.424 And a wire linkage connected to the right hand side  goes below the playfield through a small hole. 00:21:36.424 --> 00:21:42.262 When the target rotates, that linkage is repeatedly pulled up and down which in turn pulls on a leaf switch, 00:21:42.262 --> 00:21:46.574 repeatedly connecting and disconnecting the two contacts as it spins. 00:21:46.574 --> 00:21:50.648 When this target is hit just right, it’s quite the show. 00:21:50.648 --> 00:21:54.936 [rapid clacking and dinging] 00:21:54.936 --> 00:21:57.238 But not quite the show that the pop bump- 00:21:57.238 --> 00:21:59.885 I mean jet bumpers can put on. 00:21:59.885 --> 00:22:06.710 Pioneered by Williams in 1948, these jet bumpers repel the ball at high speed when they’re hit. 00:22:06.710 --> 00:22:10.811 They’re triggered by a circular platform known as the skirt. 00:22:10.811 --> 00:22:15.877 This is attached to a stick resting in a bowl below the playfield. 00:22:15.877 --> 00:22:22.255 While rather silly at first glance,  this arrangement means that no matter where the ball should hit the skirt, 00:22:22.255 --> 00:22:30.044 the stick will pivot which in turn pushes the bowl downward thereby pushing these two switch contacts together. 00:22:30.044 --> 00:22:38.791 That provides power to the solenoid beneath the playfield which pulls down on this angled metal ring that floats above the skirt. 00:22:38.791 --> 00:22:44.021 When that occurs, the ball finds itself between that ring and the skirt. 00:22:44.021 --> 00:22:51.157 Solenoids are quite fast so the ring immediately comes  crashing down and makes contact with the ball. 00:22:51.157 --> 00:22:54.381 Since the ring is angled at roughly 45 degrees, 00:22:54.381 --> 00:22:57.358 the ball gets flung away from the bumper. 00:22:57.358 --> 00:23:06.861 This is a very rough process and since the playfield is made of wood, a mylar protective sheet is installed around the bumper to minimize damage. 00:23:06.861 --> 00:23:08.919 This wasn’t always standard practice, though, 00:23:08.919 --> 00:23:13.515 so many older games exhibit severe wear around the bumpers. 00:23:13.515 --> 00:23:19.752 If you noticed the second switch down below the jet bumper, that is what actually registers points. 00:23:19.752 --> 00:23:22.491 It’s just like the targets we’ve been looking at, 00:23:22.491 --> 00:23:28.473 but hidden away and activated by the movement of the bumper ring and not the ball itself. 00:23:28.473 --> 00:23:35.345 Not all games work like this, though - sometimes a pop bumper relay is used, activated by the skirt, 00:23:35.345 --> 00:23:40.019 which locks on in a similar fashion to the points relays we looked at earlier. 00:23:40.019 --> 00:23:43.484 A contact within that pop bumper relay awards points, 00:23:43.484 --> 00:23:49.890 and this switch serves as an end-of-stroke switch to release the relay after the bumper has fired. 00:23:49.890 --> 00:23:56.868 That approach has pros and cons and Williams opted to power the solenoid directly from the bumper skirt switch. 00:23:56.868 --> 00:24:02.212 The main downside of this approach is that occasionally the ball will just brush against the bumper, 00:24:02.212 --> 00:24:07.112 so it kinda-sorta half-fires and it doesn’t award points. 00:24:07.112 --> 00:24:10.379 And finally, we have the slingshots. 00:24:10.379 --> 00:24:16.070 These dastardly things are hardly a target worth hitting as they only score 10 points, 00:24:16.070 --> 00:24:21.884 and they have a nasty habit of flinging the ball right into the outlanes. 00:24:21.884 --> 00:24:28.817 They’re made up of three posts arranged in a triangle with a large rubber ring stretched across all three. 00:24:28.817 --> 00:24:33.935 In the center of the long edge is a kicker just behind the rubber ring. 00:24:33.935 --> 00:24:37.555 The kicker is flanked on either side by two switch contacts. 00:24:37.555 --> 00:24:41.647 When the ball hits the rubber ring and either of those switches close, 00:24:41.647 --> 00:24:46.063 power is sent to a solenoid below which pushes the kicker outward, 00:24:46.063 --> 00:24:49.954 stretching the rubber ring and flinging the ball away. 00:24:49.954 --> 00:24:56.467 Just like the pop bumpers, it’s a switch below the playfield that actually registers points when the kicker has moved, 00:24:56.467 --> 00:25:00.761 and the switches behind the rubber only provide power to the solenoid. 00:25:00.761 --> 00:25:04.301 Oh, right, I forgot about the kickback lane here. 00:25:04.301 --> 00:25:09.164 This thing is sort of a combo of the slingshot kicker and a rollover lane. 00:25:09.164 --> 00:25:18.041 The ball lands on a trip wire, and after points are awarded a solenoid below the playfield fires which bonks the ball back up. 00:25:18.041 --> 00:25:27.103 An interesting twist with this machine is  that the pop bumpers and slingshot solenoids are provided with DC power. 00:25:27.103 --> 00:25:31.737 A bridge rectifier and capacitor are attached to the underside of the playfield 00:25:31.737 --> 00:25:36.741 which means that there is in fact a single semiconductor in this machine! 00:25:36.741 --> 00:25:39.920 Or four depending on how you wanna define things. 00:25:39.920 --> 00:25:45.388 It turns out that solenoids powered by DC can be stronger than AC-powered ones, 00:25:45.388 --> 00:25:49.184 and Williams began tinkering with them around this time. 00:25:49.184 --> 00:25:54.839 Only the pop bumpers and slingshots are powered through the rectifier, though, as you can see in the schematic. 00:25:54.839 --> 00:25:59.743 Everything else, including the flippers, is powered by 24 volts AC. 00:25:59.743 --> 00:26:02.151 And why don’t we talk about the flippers? 00:26:02.151 --> 00:26:06.867 As with pretty much everything that moves, they’re powered by a solenoid. 00:26:06.867 --> 00:26:11.978 But in this case they’re controlled by the player with buttons on the side of the cabinet. 00:26:11.978 --> 00:26:18.082 Those buttons simply push the contacts of a leaf switch together which sends power to the flipper coils. 00:26:18.082 --> 00:26:22.192 Then they pull on a linkage, and the flipper bat pops up. 00:26:22.192 --> 00:26:25.020 Flipper coils, though, are unique. 00:26:25.020 --> 00:26:29.175 See, a strong solenoid needs quite a lot of power. 00:26:29.175 --> 00:26:32.116 That means they get hot over time. 00:26:32.116 --> 00:26:38.880 For every other solenoid in the machine, that’s not much of a problem because they’re only activated in short bursts. 00:26:38.880 --> 00:26:41.575 But the flippers are controlled by the player, 00:26:41.575 --> 00:26:47.334 and that player might just want to hold the flippers up in order to catch the ball. 00:26:47.334 --> 00:26:50.366 That could cause the coils to overheat. 00:26:50.366 --> 00:26:53.368 And coils that overheat tend to get melty, 00:26:53.368 --> 00:26:55.076 then smoky, 00:26:55.076 --> 00:26:58.416 and on rare occasions, firy. 00:26:58.416 --> 00:27:07.377 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) 00:27:07.377 --> 00:27:12.437 but we want the flippers to be able to stay up without causing any trouble. 00:27:12.437 --> 00:27:17.845 So, if you look carefully at the flipper coil, you’ll see that it has three terminals. 00:27:17.845 --> 00:27:25.904 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. 00:27:26.000 --> 00:27:31.418 When the flipper is at rest, the button sends power to the coil through the center tap. 00:27:31.418 --> 00:27:34.179 This bypasses half of the coil’s length, 00:27:34.179 --> 00:27:40.720 reducing the number of turns of wire that current flows through which makes the solenoid more powerful. 00:27:40.720 --> 00:27:44.952 That might seem backwards but that’s just how solenoids work. 00:27:44.952 --> 00:27:51.160 But once it reaches the end of its travel, it opens this switch: another end-of-stroke switch. 00:27:51.160 --> 00:27:58.641 That removes power from the center tap, meaning current must now travel through the entire length of the solenoid wire. 00:27:58.641 --> 00:28:06.006 This reduces the current flowing through and the strength of the solenoid and allows it to stay energized without burning up. 00:28:06.006 --> 00:28:08.142 And for a demonstration of this principle, 00:28:08.142 --> 00:28:13.301 observe the change in sound as I force the flipper bat down while holding in the button. 00:28:13.814 --> 00:28:15.071 [buzz 00:28:15.071 --> 00:28:15.571 BZZTTZZTTZZZ 00:28:15.571 --> 00:28:16.071 buzz 00:28:16.071 --> 00:28:16.571 BZZTTZZTTZZZ 00:28:16.571 --> 00:28:17.071 buzz 00:28:17.071 --> 00:28:17.788 BRRRRRGGGGGHHH 00:28:17.788 --> 00:28:18.337 buzz 00:28:18.337 --> 00:28:19.257 BRRRRGHHHHH 00:28:19.257 --> 00:28:20.000 buzz] 00:28:20.510 --> 00:28:24.948 The lights in the machine even dim while I do this - it’s a lot of current! 00:28:26.479 --> 00:28:30.238 At this point, we’ve looked at how everything on the playfield works, 00:28:30.238 --> 00:28:32.816 we’ve seen how the machine shows you your score, 00:28:32.816 --> 00:28:35.979 and we’ve seen how points get added to it. 00:28:35.979 --> 00:28:40.768 But the machine is doing a heckuva a lot more than simply adding point values together. 00:28:40.768 --> 00:28:44.466 Which you might have been able to tell by all the stuff inside. 00:28:44.466 --> 00:28:50.271 There are layers and layers of complexity built atop the basic scoring functions. 00:28:50.271 --> 00:28:53.789 For instance, the machine has to know how to count. 00:28:53.789 --> 00:28:57.097 You get three balls per game and then it ends. 00:28:57.097 --> 00:29:04.392 It also needs to know how many players there are and change which set of score reels is active after each ball— 00:29:04.392 --> 00:29:10.750 but also not do that if the current player scored an extra ball and gets to shoot again. 00:29:10.750 --> 00:29:16.058 Then there’s the bonus ladder I referenced earlier which always starts at five thousand points, 00:29:16.058 --> 00:29:20.561 but can be advanced when you hit certain targets in increments of 5,000. 00:29:20.926 --> 00:29:24.056 And I think that’s a good place to move to next: 00:29:24.056 --> 00:29:26.190 the number five. 00:29:26.190 --> 00:29:27.703 Here, watch this. 00:29:27.703 --> 00:29:29.828 [bell rings five times] 00:29:30.411 --> 00:29:33.013 How on earth do you suppose that happened? 00:29:33.013 --> 00:29:39.535 I hit a switch just once, but the score reel moved five times all on its own. 00:29:39.827 --> 00:29:42.206 [ding ding ding ding ding] 00:29:42.206 --> 00:29:45.436 Well, remember that ticking it was doing in the beginning? 00:29:45.436 --> 00:29:48.841 Perhaps you noticed it happened in groups of five. 00:29:48.841 --> 00:29:50.389 Listen again. 00:29:50.389 --> 00:29:55.053 [clacking noises in quintuplets, plus a humming sound] 00:29:55.334 --> 00:29:59.726 Turns out the number 5 appears all over the place. 00:29:59.726 --> 00:30:02.103 This target is worth five hundred points, 00:30:02.103 --> 00:30:06.349 this lane scores 5,000, as does the kickback target. 00:30:06.349 --> 00:30:09.452 The bonus values increment in steps of 5,000 points. 00:30:09.452 --> 00:30:12.613 And then there’s this thing's name: AZTEC. 00:30:12.613 --> 00:30:14.269 That has five letters in it. 00:30:14.269 --> 00:30:20.621 And some of the targets will award points based on how many of those five letters are lit. 00:30:20.834 --> 00:30:23.279 How... how is it doing all that? 00:30:23.279 --> 00:30:26.613 And why does everything happen in fives? 00:30:26.613 --> 00:30:31.297 Well, it’s time I introduce you to the score motor. 00:30:31.297 --> 00:30:37.472 This wonky looking contraption is the closest  thing this machine has to a central processing unit. 00:30:37.798 --> 00:30:42.840 The score motor consists of an electric motor which, through a speed-reduction gearbox, 00:30:42.840 --> 00:30:50.869 slowly rotates a series of eight cams upon which rest a ridiculous number of switches in eight stacks. 00:30:50.869 --> 00:31:00.000 The stacks, from left to right, are called index, one, two, three, four, five, impulse, and impulse forward. 00:31:00.000 --> 00:31:05.755 Incidentally impulse forward just has a single switch which is used only in the reset sequence. 00:31:05.755 --> 00:31:09.625 Ah, sequence - what a good word! 00:31:09.625 --> 00:31:13.462 That is pretty much the whole idea of the score motor. 00:31:13.462 --> 00:31:17.007 It allows things to happen automatically in a sequence. 00:31:17.007 --> 00:31:22.039 On every one of the eight cams there are a series of divots or bumps. 00:31:22.039 --> 00:31:25.798 These will actuate the switch stacks as the cam rotates: 00:31:25.798 --> 00:31:32.864 either the stack will briefly fall into the divot and the switches within will make or break contact as they move, 00:31:32.864 --> 00:31:35.882 or, in the case of the two impulse cams at the far right, 00:31:35.882 --> 00:31:42.069 a series of bumps will push up on the switch stack which accomplishes the same thing. 00:31:42.069 --> 00:31:48.976 The cams one through five are all offset such that the switches they actuate will be bumped in-sequence, 00:31:48.976 --> 00:31:50.732 one two three four five, 00:31:50.732 --> 00:31:56.594 and impulse and impulse forward are bumped five times with every rotation. 00:31:56.594 --> 00:32:01.686 The index cam on the far left is critical for the score motor’s functions. 00:32:01.686 --> 00:32:06.139 The switch on the top of this stack is the Motor Run switch. 00:32:06.139 --> 00:32:10.985 It’s much like the self-powering interlocks we’ve been looking at in other relays. 00:32:10.985 --> 00:32:16.551 When closed, it provides power to the motor and thus it will run - and crucially, 00:32:16.551 --> 00:32:21.351 that switch is closed whenever the motor is out of its parked position. 00:32:21.351 --> 00:32:23.428 Once it gets back to the park position, 00:32:23.428 --> 00:32:28.802 the switch stack falls into the divot, that switch opens, and the motor stops. 00:32:28.802 --> 00:32:37.607 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. 00:32:37.607 --> 00:32:40.084 It even works if I just push on it. 00:32:40.084 --> 00:32:45.884 [rapid clicking and motor noise] 00:32:45.884 --> 00:32:47.858 But you’ll notice that when I did that… 00:32:47.858 --> 00:32:49.266 [chickachickachickachickachickachunk] 00:32:49.266 --> 00:32:51.366 nothing happened. 00:32:51.366 --> 00:32:59.920 This is what’s both very confusing and completely critical to understand about electromechanical systems like this. 00:32:59.920 --> 00:33:02.989 With the exception of the motor run switch, 00:33:02.989 --> 00:33:09.944 the rest of these switches aren’t connected to anything even when the game is on and in-play. 00:33:09.944 --> 00:33:19.221 They’re just… there, clicking away without accomplishing a thing  because the wire's they're connected to hit dead ends. 00:33:19.221 --> 00:33:28.630 It takes two to tango, and to make something happen the machine performs a dance where it constantly rewires itself on the fly. 00:33:28.630 --> 00:33:31.534 And what does it use to make that happen? 00:33:31.534 --> 00:33:33.847 That’s right, relays! 00:33:33.847 --> 00:33:36.655 That’s why there are so many of them in this machine. 00:33:37.056 --> 00:33:47.656 To actually make something occur, you need a relay to connect these bouncing switches to other things in the machine that way they’ll, y’know, do stuff. 00:33:47.656 --> 00:33:51.464 Take this rollover worth 5,000 points as an example. 00:33:51.464 --> 00:33:56.174 You’ll never guess what the 5,000 point rollover switch completes a circuit to. 00:33:56.174 --> 00:34:01.495 It’s none other than the 5,000 point relay which lives on the underside of the playfield. 00:34:01.495 --> 00:34:06.602 This relay has three switch contacts which all connect to the score motor. 00:34:06.602 --> 00:34:12.544 The switch on the right sends power to the motor to start it turning which you can observe when I bridge the contacts. 00:34:12.544 --> 00:34:18.369 [motor runs in bursts] 00:34:18.369 --> 00:34:22.285 The switch on the left is yet another relay interlock. 00:34:22.285 --> 00:34:26.880 The rollover switch is what sends the initial power  to the relay coil to energize it, 00:34:26.880 --> 00:34:27.501 [CLACK] 00:34:27.501 --> 00:34:31.447 but once these contacts are touching, the relay keeps itself powered. 00:34:31.447 --> 00:34:36.597 If I bridge these contacts, you’ll see the relay pull in and lock itself on. 00:34:36.597 --> 00:34:42.949 If this feels familiar, well it’s doing the same thing as the switches on the points relays in the backbox: 00:34:42.949 --> 00:34:48.012 it keeps the relay energized until its task is actually complete. 00:34:48.012 --> 00:34:51.639 And right now, I’ve disabled the score motor. 00:34:51.639 --> 00:34:58.858 Since it’s not moving, this relay cannot complete its task and the machine is locked up in this state. 00:34:58.858 --> 00:35:03.252 Its task, remember, is to add 5,000 points to the score. 00:35:03.252 --> 00:35:07.317 And the middle contact in the relay is what makes that possible. 00:35:07.317 --> 00:35:11.858 When closed, this connects the 1,000 point relay in the backbox 00:35:11.858 --> 00:35:15.818 to this switch on top of the impulse cam of the score motor. 00:35:15.818 --> 00:35:19.919 When I plug the score motor back in, the cams begin rotating 00:35:19.919 --> 00:35:24.116 and since the impulse cam actuates its switch stack five times, 00:35:24.116 --> 00:35:28.454 the 1,000 point relay will receive five pulses through this switch. 00:35:28.673 --> 00:35:35.431 [five clacks and dings] 00:35:35.431 --> 00:35:40.125 And right after it sends the fifth pulse, the relay lets go. 00:35:42.749 --> 00:35:48.768 That’s because the relay’s interlock is connected through a normally-closed switch on cam five. 00:35:48.768 --> 00:35:53.555 Once cam five is actuated, that switch is broken so the relay  releases. 00:35:53.555 --> 00:35:56.206 And now the machine is at rest. 00:35:56.206 --> 00:36:02.372 This happens very quickly (which is incidentally the point) so it’s kind of hard to keep track of. 00:36:02.372 --> 00:36:09.515 However, I can slowly rotate the score motor by hand so we can observe each individual action occur. 00:36:09.515 --> 00:36:16.914 Once the 5,000 point relay becomes energized, it locks on by keeping itself powered through a switch on cam five. 00:36:16.914 --> 00:36:21.649 It also connects the impulse switch through to the 1,000 point relay. 00:36:21.649 --> 00:36:28.967 As I turn this, we hear the machine dinging and buzzing every time this switch stack pops up. 00:36:28.967 --> 00:36:35.547 But the relay’s still locked on because cam 5 hasn't been actuated yet. 00:36:35.547 --> 00:36:42.215 When that switch stack falls into the divot, we hear a click as the relay loses power and lets go. 00:36:42.215 --> 00:36:43.242 [buzz/ding.... 00:36:43.242 --> 00:36:44.385 clunk] 00:36:47.519 --> 00:36:48.074 [ding] 00:36:48.074 --> 00:36:48.724 [clunk] 00:36:52.223 --> 00:36:53.913 [ding/buzzzzz] 00:36:53.913 --> 00:36:54.771 [clunk] 00:36:55.464 --> 00:36:57.055 [click] 00:36:57.565 --> 00:37:00.922 As you can imagine, the timing here is critical 00:37:00.922 --> 00:37:09.380 and the cams are aligned so that the fifth bump of the impulse switch happens just before cam 5 actuates its switches 00:37:09.380 --> 00:37:15.320 (which also happens just before we get back to the start point and the index switch actuates.) 00:37:15.320 --> 00:37:20.908 With the score motor re-enabled, this all happens quickly and automatically. 00:37:20.908 --> 00:37:25.411 I hope you can appreciate how amazingly bonkers this is. 00:37:25.411 --> 00:37:33.337 And that was one of the simplest relays in the machine causing it to do one of the simplest automated tasks it can do. 00:37:33.337 --> 00:37:39.889 We’ve still got a bajillion relays to look at, plus a solid 32 other switches in the score motor, 00:37:39.889 --> 00:37:42.653 and we’re how long into this video? 00:37:42.653 --> 00:37:48.394 Yeah, I can’t cover how everything works in this machine, let alone in a single go. 00:37:48.394 --> 00:37:50.998 So there will definitely be a second part. 00:37:50.998 --> 00:37:55.143 But before we conclude here, let’s talk about the AZTEC targets, 00:37:55.143 --> 00:37:57.283 how they light up their respective letters, 00:37:57.283 --> 00:38:00.800 and why that changes what other targets do. 00:38:00.800 --> 00:38:06.125 By now, I hope you know what the switches in these targets send power to. 00:38:06.125 --> 00:38:07.666 Say it with me now, 00:38:07.666 --> 00:38:09.077 relays! 00:38:09.077 --> 00:38:14.326 And Williams was kind enough to mount them in order on this support below the playfield. 00:38:14.326 --> 00:38:15.773 Here’s the A relay, 00:38:15.773 --> 00:38:16.978 the Z relay, 00:38:16.978 --> 00:38:18.032 the T relay, 00:38:18.032 --> 00:38:19.332 the E relay, 00:38:19.332 --> 00:38:21.168 and the C relay. 00:38:21.168 --> 00:38:24.553 For now, let’s just focus on the A relay. 00:38:24.553 --> 00:38:28.907 This single relay features all three kinds of switch contacts. 00:38:28.907 --> 00:38:36.397 The three leftmost switches are normally open, and as the relay pulls on its armature the contacts are pushed together. 00:38:36.397 --> 00:38:40.823 Then we have a normally closed switch - this one does just the opposite. 00:38:40.823 --> 00:38:44.202 But the two on the right are make/break switches. 00:38:44.202 --> 00:38:48.742 The relay moves the center blade, and instead of turning something on or off, 00:38:48.742 --> 00:38:53.006 it redirects the flow of power from one place to another. 00:38:53.006 --> 00:38:59.453 Like the 5,000 point relay we just looked at,  this relay will power itself once it has been actuated. 00:38:59.453 --> 00:39:05.978 As soon as the left hand switch makes contact, it provides a power bypass and the relay becomes locked on. 00:39:05.978 --> 00:39:10.939 And this relay will stay locked on until the end of the ball-in-play. 00:39:10.939 --> 00:39:17.762 The next three switches have to do with the center target and the kickback lane - I’ll get back those in a moment. 00:39:17.762 --> 00:39:26.560 The two switches on the end, the make/break switches, change the machine’s behavior and appearance once the A target has been hit. 00:39:26.560 --> 00:39:33.799 The A rollover lane is marked “Lites A,” 1000, and “Lites Spinning Target.” 00:39:33.799 --> 00:39:36.380 Obviously that means it lights some things up, 00:39:36.380 --> 00:39:39.737 but it also makes this light go out. 00:39:39.737 --> 00:39:43.820 It’s this make/break switch that changes which lights are lit. 00:39:43.820 --> 00:39:50.658 Before I hit the target, 6 volts was sent to the right-hand contact which illuminated the lamp above the lane. 00:39:50.658 --> 00:39:52.935 But once I hit it and the relay locked on, 00:39:52.935 --> 00:40:00.123 power was redirected to the contact on the left which leads to the two A lamps as well as the spinner. 00:40:00.123 --> 00:40:05.133 Lighting the spinner target changed its point value from 100 to 1,000 points. 00:40:05.133 --> 00:40:06.337 How? 00:40:06.337 --> 00:40:09.522 Well, that's what the other make/break switch did. 00:40:09.522 --> 00:40:16.299 It disconnected the spinner from the 100 point relay and connected it instead to the 1,000 point relay. 00:40:16.299 --> 00:40:18.794 Now, I could just tell you that, 00:40:18.794 --> 00:40:24.612 but you might have noticed that the wires in this machine are color-coded so you can trace where they go. 00:40:24.612 --> 00:40:26.498 Let’s follow their path. 00:40:26.498 --> 00:40:28.712 This is the spinning target switch. 00:40:28.712 --> 00:40:33.096 When closed, it sends power out this gray wire with a red stripe. 00:40:33.096 --> 00:40:38.274 It ends up bundled in the harness and comes back out right here at the relay. 00:40:38.274 --> 00:40:46.260 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. 00:40:46.260 --> 00:40:48.320 Those wires re-enter the harness, 00:40:48.320 --> 00:40:54.265 split out towards the back into this small bundle that's connected through a Jones plug to the backbox, 00:40:54.265 --> 00:41:01.669 and sure enough those two wires eventually end up at the coils of the 100 and 1,000 point relays. 00:41:01.669 --> 00:41:06.295 Which one is connected depends on whether or not the relay is energized. 00:41:06.295 --> 00:41:08.765 And here's what that looks like on the schematic. 00:41:08.765 --> 00:41:12.727 Power is sent through the spinner switch on the grey and red wire. 00:41:12.727 --> 00:41:16.743 That ends up at the make/break switch in the A relay. 00:41:16.743 --> 00:41:20.641 The normally closed contact connects over to the 100 point relay, 00:41:20.641 --> 00:41:24.428 so the spinning switch will send power there when closed. 00:41:24.428 --> 00:41:27.118 But, when the A relay is energized, 00:41:27.118 --> 00:41:32.880 power is redirected to the brown and yellow wire which connects up to the 1,000 point relay. 00:41:32.880 --> 00:41:38.520 But the spinning target is only one of three targets that the A relay will change in value. 00:41:38.520 --> 00:41:41.978 There’s also the center target and the kickback lane. 00:41:41.978 --> 00:41:49.436 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 - 00:41:49.436 --> 00:41:52.401 in fact, more for every letter that’s lit. 00:41:52.401 --> 00:41:56.099 In the case of the center target, it’s 1,000 points for each lit letter, 00:41:56.099 --> 00:42:00.432 and the kickback lane awards 10,000 points for each lit letter. 00:42:00.432 --> 00:42:06.056 That means that, technically, the targets have six possible values each. 00:42:06.421 --> 00:42:10.566 How can this sort of circuitry possibly manage that? 00:42:10.566 --> 00:42:13.576 Well, it’s actually simpler than it might seem. 00:42:13.576 --> 00:42:16.001 Let’s look at the center target first. 00:42:16.001 --> 00:42:20.952 The center target switch sends power to the center target relay, of course, 00:42:20.952 --> 00:42:24.719 which is similar to the the 5,000 point relay we looked at earlier. 00:42:24.719 --> 00:42:32.673 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, 00:42:32.673 --> 00:42:37.491 and releases just after the fifth pulse of the 100 point relay. 00:42:37.491 --> 00:42:40.162 Thus, it adds 500 points to the score. 00:42:40.880 --> 00:42:43.848 But look at the circuit path on the schematic. 00:42:43.848 --> 00:42:50.984 Power comes through the impulse switch here, then we have to follow a grey and white wire to B-19 - 00:42:50.984 --> 00:42:52.416 uh, here it is, 00:42:52.416 --> 00:43:00.348 and then it has to go through all of these normally closed switches before it makes it to the 100 point relay. 00:43:00.348 --> 00:43:03.308 If they’re all closed, then we’re fine - 00:43:03.308 --> 00:43:05.934 the 100 point relay will be pulsed five times 00:43:05.934 --> 00:43:09.346 and we get those 500 points added to the score. 00:43:09.346 --> 00:43:14.288 But if any one of the AZTEC letter targets has been hit, 00:43:14.288 --> 00:43:17.720 its respective switch in its relay is open, 00:43:17.720 --> 00:43:20.509 and since all those switches are wired in series, 00:43:20.509 --> 00:43:22.558 this circuit path is broken. 00:43:22.558 --> 00:43:24.615 So it no longer works. 00:43:24.615 --> 00:43:29.156 Ah, but we get 1000 points for every letter that’s lit. 00:43:29.156 --> 00:43:33.850 And we just have to move a little ways up on the schematic to see how that works. 00:43:33.850 --> 00:43:39.522 Here again we see switches in the A, Z, T, E, and C relays. 00:43:39.522 --> 00:43:44.479 These are normally open, but close when their respective relay is energized. 00:43:44.479 --> 00:43:48.129 And right above them we see switches in a circle. 00:43:48.129 --> 00:43:51.860 This is how the schematic tells us those are in the score motor. 00:43:51.860 --> 00:43:56.439 And the notation tells us where in the score motor those switches are. 00:43:56.439 --> 00:44:02.761 The A relay is connected through the index stack, switch B  (that’s the second switch from the bottom). 00:44:02.880 --> 00:44:07.916 The Z relay through stack one, switch A (the bottom switch in the stack). 00:44:07.916 --> 00:44:11.178 The T relay through stack 2, switch A. 00:44:11.178 --> 00:44:14.147 The E relay through stack 3, switch A. 00:44:14.147 --> 00:44:17.572 And the C relay through stack 4, switch A. 00:44:17.572 --> 00:44:24.124 We already know that those switch stacks are actuated by the score motor one at a time in order. 00:44:24.124 --> 00:44:29.289 So you can imagine what’s happening here as a sort of scanning sequence. 00:44:29.289 --> 00:44:32.729 When the center target is hit and its relay is energized, 00:44:32.729 --> 00:44:38.609 each of the letter relays receives a pulse of power at their respective switches. 00:44:38.609 --> 00:44:46.657 The A relay receives its pulse immediately as it’s connected through a normally closed switch at the index position. 00:44:46.657 --> 00:44:50.285 But as the motor turns, that switch opens 00:44:50.285 --> 00:44:54.142 and then the following relays get pulsed one at a time. 00:44:54.142 --> 00:44:58.462 Whichever relays are energized will have this switch closed, 00:44:58.462 --> 00:45:06.066 so its respective pulse makes its way through the center target relay and to the 1,000 point relay coil. 00:45:06.066 --> 00:45:10.652 Thus it adds 1,000 point for every lit letter. 00:45:10.652 --> 00:45:13.128 This is pretty wild, right? 00:45:13.128 --> 00:45:20.517 Despite just being a tangled mess of wires, relays, switches, a motor and some cams, 00:45:20.517 --> 00:45:26.842 we have a machine which methodically checks whether each of the five letter targets has been hit 00:45:26.842 --> 00:45:29.985 and awards points if it has been. 00:45:29.985 --> 00:45:35.088 This results in a unique pattern of dings depending on which targets are lit. 00:45:35.088 --> 00:45:39.335 I won’t waste your time any further by going through every possible combination, 00:45:39.335 --> 00:45:41.015 but here are a few: 00:45:41.525 --> 00:45:42.920 [ding ding / ding ding] 00:45:44.378 --> 00:45:45.631 [ding / ding / ding] 00:45:47.308 --> 00:45:48.654 [ding/ ding ding ding] 00:45:50.221 --> 00:45:51.382 [ding ding ding / ding] 00:45:52.585 --> 00:45:58.730 You probably noticed that right alongside the center target relay in the schematic was the shooter relay. 00:45:58.730 --> 00:46:01.768 That’s what I’ve been calling the kickback lane - 00:46:01.768 --> 00:46:06.661 Williams decided to refer to this as the shooter which is very confusing since, y’know, 00:46:06.661 --> 00:46:08.330 this is also the shooter. 00:46:08.330 --> 00:46:13.577 But anyway, that target works in essentially the exact same way as the center target, 00:46:13.577 --> 00:46:18.860 but it pulses the 1,000 point relay through the impulse switch when no letters are lit 00:46:18.860 --> 00:46:20.928 (thus awarding 5,000 points) 00:46:20.928 --> 00:46:25.047 and pulses the 10,000 point relay for every lit letter. 00:46:25.047 --> 00:46:35.469 The only other difference is that the shooter coil gets fired at the end of the sequence through switch 4-E in the score motor to kick the ball out of the target. 00:46:35.469 --> 00:46:39.750 While I covered a lot of what this machine does in this video, 00:46:39.750 --> 00:46:46.178 it’s probably pretty obvious based on all the other stuff in here that there’s a lot more to see. 00:46:46.178 --> 00:46:52.456 In part 2, we’ll take a look at how the machine manages to do some of its more complex automated sequences 00:46:52.456 --> 00:46:53.699 like this one: 00:46:54.246 --> 00:46:55.301 [ding ding ding ding ding / 00:46:55.481 --> 00:46:56.334 ding ding ding ding ding / 00:46:56.476 --> 00:46:57.267 ding ding ding ding ding / 00:46:57.434 --> 00:46:58.333 ding ding ding ding ding / 00:46:58.501 --> 00:46:59.368 ding ding ding ding ding 00:46:59.368 --> 00:47:01.235 tuck click clack ka-chunky shwhup] 00:47:01.235 --> 00:47:05.783 Yep, it added 25,000 points to the score all on its own, 00:47:05.783 --> 00:47:10.000 then changed the ball-in-play light from one to two. 00:47:10.000 --> 00:47:12.075 Apparently it can count. 00:47:12.075 --> 00:47:17.115 And it also knows your score - cross 350,000 points and... 00:47:17.115 --> 00:47:19.003 [ding ding *clunk* ding ding] 00:47:19.003 --> 00:47:20.989 you’ve won a replay. 00:47:20.989 --> 00:47:23.738 Stay tuned for how that all works. 00:47:23.738 --> 00:47:27.428 It’s just as nuts as everything you saw here. 00:47:27.428 --> 00:47:29.864 Thank you very much for watching. 00:47:29.864 --> 00:47:35.535 I hope you enjoyed it and that I’ve been able to help you understand all this nonsense. 00:47:35.535 --> 00:47:39.488 The thing is, though, it’s not nonsense - it’s logic! 00:47:39.488 --> 00:47:43.331 And that’s part of why I like machines like this so much. 00:47:43.331 --> 00:47:49.583 You can actually look at them, pick it apart, and understand what it’s doing and why. 00:47:49.583 --> 00:47:54.214 It blows my mind how folks of the past figured all this out 00:47:54.214 --> 00:47:57.479 and got these things manufactured in mass. 00:47:57.479 --> 00:48:02.634 And perhaps even more mind-blowing, while this machine is from 1976 00:48:02.634 --> 00:48:08.416 most of the tech in here existed in some form back in the 1930’s. 00:48:08.416 --> 00:48:13.545 It just got built up in layer after layer  until we arrived at this. 00:48:13.545 --> 00:48:14.827 And to be honest, 00:48:14.920 --> 00:48:16.814 this machine isn’t that complex. 00:48:16.814 --> 00:48:23.721 There are plenty of electromechanical pins out there which have much deeper rulesets and many more targets. 00:48:23.721 --> 00:48:28.005 In fact, twenty years prior to this one getting manufactured, 00:48:28.005 --> 00:48:31.785 Bally introduced a game with multiball. 00:48:31.785 --> 00:48:33.413 Yeah. 00:48:33.413 --> 00:48:37.813 Maybe one day we can take a look at a more complex machine but for now… 00:48:37.813 --> 00:48:39.709 I need to go to bed. 00:48:40.000 --> 00:48:41.668 G’night everybody. 00:48:42.568 --> 00:48:45.126 ♫ coin-operatedly smooth jazz ♫ 00:48:46.301 --> 00:48:49.720 You didn’t know this but I’m even wearing PJs. 00:48:52.162 --> 00:48:54.955 You never know what I’ve got on below the desk. 00:48:54.955 --> 00:48:56.551 Or behind the pinball… 00:48:59.540 --> 00:49:01.060 In fact, 10 copies… 00:49:01.060 --> 00:49:01.954 I… 00:49:02.793 --> 00:49:04.206 slightly… 00:49:04.206 --> 00:49:08.520 ooh, left handed teleprompter control’s gonna throw me off. 00:49:08.520 --> 00:49:10.329 Just gonna need to pick this up. 00:49:10.329 --> 00:49:13.035 Quite the assortment of weird ob… 00:49:13.035 --> 00:49:14.093 ahhhh! 00:49:14.093 --> 00:49:17.868 We can slide the glass out and the playfield will simpy lift right up. 00:49:17.868 --> 00:49:20.039 I botched the word “simply” 00:49:20.039 --> 00:49:22.510 To find… de ber da ka ta ka da bakatakaww 00:49:22.510 --> 00:49:24.401 And just a bit, I promised. 00:49:24.401 --> 00:49:25.815 Promised? 00:49:26.070 --> 00:49:27.713 That’s not the… what? 00:49:27.968 --> 00:49:33.251 Large rings may be stretched across two or more posts to create a linear barrier, 00:49:33.251 --> 00:49:37.011 but sometimes that sounds weird and I’m gonna start over. 00:49:37.011 --> 00:49:40.814 But you’ll find plenty of individual rings with their own rings, too. 00:49:42.017 --> 00:49:44.646 Well, this line’s not going great! 00:49:44.646 --> 00:49:47.404 And that advances the mechanism by one step. 00:49:47.951 --> 00:49:51.067 It, or it would if I weren’t so clumsy. 00:49:52.853 --> 00:49:56.209 Ever since I was a young boy, I've played the silver ball. 00:49:56.209 --> 00:49:59.077 But sadly I got started long into its downfall 00:49:59.077 --> 00:50:02.411 and you really couldn't find 'em in many amusement halls 00:50:02.411 --> 00:50:06.109 but that wouldn't stop me: just hadda play pinball! 00:50:06.109 --> 00:50:08.238 [imagined guitar riff clashes with soprano sax]