1 00:00:06,014 --> 00:00:06,860 [click] 2 00:00:07,079 --> 00:00:10,389 ♫ intense music ♫ [Welcome to the Theatre of Magic!] 3 00:00:10,389 --> 00:00:13,128 I love pinball. 4 00:00:13,128 --> 00:00:14,921 The sights, the sounds, 5 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. 6 00:00:22,326 --> 00:00:25,305 In fact, for as long as I can remember. 7 00:00:25,305 --> 00:00:29,635 Of course, a big draw to me is that these machines are... 8 00:00:29,635 --> 00:00:31,196 well, machines. 9 00:00:31,196 --> 00:00:34,176 And wondrous machines at that! 10 00:00:34,176 --> 00:00:37,840 A pinball machine is a fascinating tribute to humanity - 11 00:00:37,840 --> 00:00:42,061 artists, musicians, game designers and even voice actors 12 00:00:42,061 --> 00:00:46,750 work alongside machinists, fabricators, craftspeople, and engineers 13 00:00:46,750 --> 00:00:53,278 to manufacture these elaborate contraptions made purely for our amusement. 14 00:00:53,278 --> 00:00:56,745 Well, and to gobble up our quarters. 15 00:00:56,857 --> 00:00:59,240 [dramatic organ music] With so much going on inside one of these, 16 00:00:59,240 --> 00:01:01,109 even just siding idle, 17 00:01:01,109 --> 00:01:03,574 you might have wondered how they work. 18 00:01:03,574 --> 00:01:09,731 Luckily, somebody gave me the keys to this machine so we can take look inside. 19 00:01:18,188 --> 00:01:19,282 [music stops] It’s… 20 00:01:20,448 --> 00:01:22,102 it’s a computer. 21 00:01:22,102 --> 00:01:23,975 There’s a computer in here. 22 00:01:23,975 --> 00:01:26,038 It keeps track of where the ball is, 23 00:01:26,038 --> 00:01:28,132 shows you your score on this display, 24 00:01:28,132 --> 00:01:30,671 plays music and sound effects through speakers, 25 00:01:30,671 --> 00:01:34,866 and lights up all the various light bulbs they need to be lit. 26 00:01:34,866 --> 00:01:37,009 How very modern. 27 00:01:37,009 --> 00:01:40,603 But pinball goes much further back than this. 28 00:01:40,603 --> 00:01:44,714 And not even twenty years prior to this machine leaving the factory, 29 00:01:44,714 --> 00:01:50,076 pinball machines didn’t feature any integrated circuits of any kind. 30 00:01:50,076 --> 00:01:52,881 This is Aztec by Williams. 31 00:01:52,881 --> 00:01:58,759 Built in 1976, this machine hails from the tail end of the electromechanical era. 32 00:01:58,759 --> 00:02:02,938 It wouldn’t be long before manufacturers started tinkering with electronic controls, 33 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. 34 00:02:10,274 --> 00:02:13,436 This one, though, well it’s a little more old-school. 35 00:02:13,436 --> 00:02:16,401 And today, I’m gonna show you what makes it tick. 36 00:02:16,401 --> 00:02:18,405 [ticking sounds, five-at-a-time] 37 00:02:18,405 --> 00:02:20,604 Seriously, why is it ticking? 38 00:02:20,604 --> 00:02:23,122 To find out, we’ll have to look inside. 39 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 - 40 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. 41 00:02:35,980 --> 00:02:38,070 And this isn’t even the half of it! 42 00:02:38,070 --> 00:02:42,230 Inside the main cabinet under the playfield there’s even more. 43 00:02:42,230 --> 00:02:44,693 We get in there by opening the coin door, 44 00:02:44,693 --> 00:02:47,703 pulling this lever which releases the lockdown bar 45 00:02:47,703 --> 00:02:50,926 (that’s this large metal piece at the front edge of the cabinet), 46 00:02:50,926 --> 00:02:53,942 then once we remove the lockdown bar by lifting up on it, 47 00:02:53,942 --> 00:02:58,135 we can slide the glass out and the playfield will simply lift right up. 48 00:02:58,135 --> 00:03:00,000 There’s even a handy prop rod! 49 00:03:00,800 --> 00:03:04,727 Now that we’re in, we see even more wires and even more stuff. 50 00:03:04,727 --> 00:03:06,940 And that’s not even the whole of it! 51 00:03:06,940 --> 00:03:11,531 Some of the control mechanisms are attached to the underside of the playfield. 52 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. 53 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: 54 00:03:27,845 --> 00:03:31,712 different targets light the letters A, Z, T, E, and C. 55 00:03:31,712 --> 00:03:34,346 Light them all up and there’s a chance for an extra ball. 56 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. 57 00:03:39,656 --> 00:03:43,302 And if you hit the right targets you can double the bonus value. 58 00:03:44,031 --> 00:03:45,219 There’s more, too. 59 00:03:45,219 --> 00:03:49,577 If you complete AZTEC and fill the bonus ladder up to 50,000 points, 60 00:03:49,577 --> 00:03:52,662 that lights a Special which awards a free game. 61 00:03:52,662 --> 00:03:58,025 And which outlane is lit will flip back and forth as you hit other targets. 62 00:03:58,025 --> 00:04:03,086 You can also win replays based on your score, and that’s configurable. 63 00:04:03,086 --> 00:04:04,865 Some of the rules can even be changed - 64 00:04:04,865 --> 00:04:08,456 winning a special can award an extra ball instead of a replay, 65 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. 66 00:04:16,328 --> 00:04:18,785 But aside from rules and features, 67 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 68 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). 69 00:04:29,515 --> 00:04:33,490 It has to end the game when it’s over and disable the playfield, 70 00:04:33,490 --> 00:04:37,496 and when a new one is started it needs to reset the scores to zero. 71 00:04:37,496 --> 00:04:39,857 Plus, up to four people can play this game. 72 00:04:39,857 --> 00:04:41,357 It’s fun to compete! 73 00:04:41,357 --> 00:04:44,675 So it needs to keep track of which player is up, 74 00:04:44,675 --> 00:04:49,407 and only change that player’s score when it’s their turn. 75 00:04:49,407 --> 00:04:52,822 Somehow that’s all being accomplished with… 76 00:04:53,234 --> 00:04:56,713 this rat’s nest of wires and stuff! 77 00:04:57,301 --> 00:04:58,214 How? 78 00:04:58,214 --> 00:05:00,937 Why, it’s easy - just look at this schematic. 79 00:05:00,937 --> 00:05:02,744 I’m sure you can figure it out! 80 00:05:04,166 --> 00:05:07,746 I’m kidding, of course - and even if you studied this for hours, 81 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. 82 00:05:14,025 --> 00:05:16,344 So, since you’re all watching, 83 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. 84 00:05:20,799 --> 00:05:23,915 We’ll start with the basics and work our way up. 85 00:05:23,915 --> 00:05:27,416 And we’re gonna go way back to basics with a bit of history. 86 00:05:27,416 --> 00:05:29,688 But just a bit, I promise. 87 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. 88 00:05:36,518 --> 00:05:41,238 An evolution of the French game bagatelle, early games were very simple. 89 00:05:41,238 --> 00:05:46,462 Marbles rolled down a board set at an angle with pins nailed into the face. 90 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. 91 00:05:53,621 --> 00:05:56,803 Games like this were made going back to the 18th century, 92 00:05:56,803 --> 00:06:01,071 but they would remain obscure toys for the wealthy for many years. 93 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 94 00:06:08,215 --> 00:06:10,591 (albeit a very simple one). 95 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. 96 00:06:18,811 --> 00:06:23,980 I don’t have one to show you but I do have Microsoft Pinball Arcade! 97 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. 98 00:06:31,695 --> 00:06:36,041 When the coin slide was pushed in, trap-doors in the goals would open 99 00:06:36,041 --> 00:06:40,415 allowing the balls to fall down into the machine and collect at the ball shooter. 100 00:06:40,415 --> 00:06:42,587 Then the player had their fun. 101 00:06:42,587 --> 00:06:45,191 These early games were purely mechanical, 102 00:06:45,191 --> 00:06:47,028 featured manual scoring, 103 00:06:47,028 --> 00:06:50,122 were meant to go atop a table or other such surface, 104 00:06:50,122 --> 00:06:54,240 and started showing up in bars and parlors all across the country. 105 00:06:54,240 --> 00:06:58,504 And… plenty of gambling based on your score occurred, too, 106 00:06:58,504 --> 00:07:01,434 but that’s a story for a different time. 107 00:07:01,560 --> 00:07:07,257 Baffle Ball was so successful that it spawned plenty of imitators such as Ballyhoo - 108 00:07:07,257 --> 00:07:11,989 which, by the way, was so successful the company that  produced it would rename itself 109 00:07:11,989 --> 00:07:13,303 Bally. 110 00:07:13,303 --> 00:07:16,607 With a variety of games for players to choose from, 111 00:07:16,607 --> 00:07:22,617 companies making pinball machines scrambled to add new features in order to make theirs stand out. 112 00:07:22,617 --> 00:07:27,351 Features like bumpers, electric lights, automatic scoring, and eventually 113 00:07:27,351 --> 00:07:30,717 moveable bumpers in the player’s control. 114 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. 115 00:07:38,476 --> 00:07:44,064 While the arrangement of the flippers on the playfield is certainly… odd by modern tastes, 116 00:07:44,064 --> 00:07:48,103 this machine set new and enduring standards for pinball. 117 00:07:48,103 --> 00:07:54,805 And, 29 years later, one of Gottlieb’s main rivals, Williams, would release this machine. 118 00:07:54,805 --> 00:07:55,824 Aztec. 119 00:07:55,824 --> 00:07:59,323 The one I’m standing behind and that this video is principally about. 120 00:07:59,323 --> 00:08:00,735 That one. 121 00:08:00,735 --> 00:08:03,711 First, let’s look at what the player sees. 122 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. 123 00:08:10,819 --> 00:08:15,402 But now a variety of targets, obstacles, bumpers, plenty of lights, 124 00:08:15,402 --> 00:08:22,008 and let’s not forget flippers make the game fast-paced, visually interesting, and addictive. 125 00:08:22,008 --> 00:08:23,883 As with most pinball machines, 126 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. 127 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. 128 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. 129 00:08:42,365 --> 00:08:46,798 Depending on the game’s design, the strength of the initial plunge may be important, 130 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. 131 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. 132 00:09:01,140 --> 00:09:07,674 This is done mainly to define paths the ball might or, in some cases, must take. 133 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. 134 00:09:16,367 --> 00:09:21,289 Large rings may be stretched across two or more posts to create a linear barrier, 135 00:09:21,289 --> 00:09:25,637 but you’ll find plenty of individual posts with their own rings, too. 136 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. 137 00:09:34,376 --> 00:09:39,205 To fill the otherwise blank areas of the playfield created by the obstacles, 138 00:09:39,205 --> 00:09:45,192 decorative plastic pieces printed with graphics matching the game’s theme are placed atop the posts. 139 00:09:45,192 --> 00:09:50,013 This also helps visually define the shape of the off-limits areas. 140 00:09:50,013 --> 00:09:54,480 Underneath the plastics you’ll find small incandescent light bulbs. 141 00:09:54,480 --> 00:09:58,116 This is the only safe place to put ‘em since the ball can’t hit them, 142 00:09:58,116 --> 00:10:02,197 and they illuminate the playfield to allow for play in a dark room. 143 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. 144 00:10:08,302 --> 00:10:10,754 Aside from the various 10 point bumpers, 145 00:10:10,754 --> 00:10:13,377 this game features three rollover buttons, 146 00:10:13,377 --> 00:10:15,222 eight rollover lanes, 147 00:10:15,222 --> 00:10:17,092 six stand-up targets, 148 00:10:17,092 --> 00:10:18,633 one spinning target, 149 00:10:18,633 --> 00:10:20,059 one kickback lane, 150 00:10:20,059 --> 00:10:21,818 two slingshot kickers, 151 00:10:21,818 --> 00:10:23,319 and three pop bumpers 152 00:10:23,319 --> 00:10:28,179 (though Williams would prefer you call them Jet Bumpers for trademark reasons). 153 00:10:28,179 --> 00:10:30,919 All of these award points when they’re hit, 154 00:10:30,919 --> 00:10:35,880 but they often do something else, too - or change how many points they award. 155 00:10:35,880 --> 00:10:39,197 But for now, let’s just focus on the points. 156 00:10:39,197 --> 00:10:44,954 The game shows you your score on the backglass  with these mechanical readouts called score reels. 157 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. 158 00:10:50,784 --> 00:10:54,479 I’ve just not gotten around to ordering the right piece of glass for it yet. 159 00:10:54,479 --> 00:11:00,114 Anyway, see if you can spot a fun little trick manufacturers were doing ‘round this time. 160 00:11:00,114 --> 00:11:01,910 Look at the front. 161 00:11:01,910 --> 00:11:03,842 And now the back. 162 00:11:04,462 --> 00:11:06,197 Do you see what’s off? 163 00:11:06,197 --> 00:11:07,545 Look at the front again. 164 00:11:07,545 --> 00:11:10,418 There are six digits in the score. 165 00:11:10,418 --> 00:11:15,266 But look at the back and there are only five score reels per player. 166 00:11:15,266 --> 00:11:19,140 The last digit of the readout is, in fact, fake 167 00:11:19,140 --> 00:11:21,725 and is there only to inflate the score. 168 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 169 00:11:27,256 --> 00:11:28,880 which makes it quite convincing. 170 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. 171 00:11:35,800 --> 00:11:37,409 It’s a fairly simple device: 172 00:11:37,409 --> 00:11:42,237 just a large plastic drum with the digits zero through nine printed on its edge 173 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. 174 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, 175 00:11:53,748 --> 00:11:57,449 and that advances the mechanism by one step. 176 00:11:57,449 --> 00:12:03,121 By the way, I hope you like electromagnets ‘cause this machine is chock full of ‘em. 177 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. 178 00:12:12,815 --> 00:12:18,151 All of the targets the ball can hit that award points are merely simple switches. 179 00:12:18,151 --> 00:12:23,665 When the game is on and in-play, those switches become wired to the scoring mechanism. 180 00:12:23,665 --> 00:12:27,234 Take these 100 point rollover buttons for example. 181 00:12:27,234 --> 00:12:33,292 They literally are buttons and beneath the playfield two electrical contacts become pressed together 182 00:12:33,292 --> 00:12:35,973 when the button is depressed by the weight of the ball. 183 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, 184 00:12:41,613 --> 00:12:43,561 and sure enough when I press it 185 00:12:43,561 --> 00:12:47,267 [clack/ding] that reel advances by one step. 186 00:12:47,267 --> 00:12:49,030 But that’s not all that happened. 187 00:12:49,030 --> 00:12:51,419 A bell rang at the same time. 188 00:12:51,419 --> 00:12:55,658 Sitting in the cabinet near the coin door is the chime unit. 189 00:12:55,658 --> 00:12:58,491 This is a unit with chimes. 190 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 191 00:13:03,672 --> 00:13:08,143 it flings a plunger up into the chime which gives it a right smack. 192 00:13:08,143 --> 00:13:10,421 [Three dings, a la the NBC theme] 193 00:13:10,421 --> 00:13:12,580 That certainly rings a bell. 194 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 - 195 00:13:21,887 --> 00:13:25,312 the switch on the playfield isn’t what’s powering them. 196 00:13:25,312 --> 00:13:28,749 Instead, the playfield switch powers a relay. 197 00:13:28,749 --> 00:13:33,391 Specifically, the 100 point relay which lives in the backbox. 198 00:13:33,391 --> 00:13:36,263 Relays are switches that are actuated with 199 00:13:36,263 --> 00:13:37,547 - wait for it - 200 00:13:37,547 --> 00:13:39,471 an electromagnet! 201 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, 202 00:13:44,640 --> 00:13:48,143 and that in turn actuates a series of switches. 203 00:13:48,143 --> 00:13:51,737 Sometimes relays are simple, and sometimes they’re not. 204 00:13:51,737 --> 00:13:53,616 In pinball machines like this, 205 00:13:53,616 --> 00:13:55,154 ** they’re not ** 206 00:13:55,154 --> 00:13:58,215 Pinball pushes relays to their conceptual limit 207 00:13:58,215 --> 00:14:02,867 using them to create the game logic and do countless other tasks, 208 00:14:02,867 --> 00:14:06,393 but that’s a big part of why I like these machines so much. 209 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, 210 00:14:12,838 --> 00:14:15,292 but some of them are just the opposite. 211 00:14:15,292 --> 00:14:18,970 There’s even a third option - make/break switches. 212 00:14:18,970 --> 00:14:21,214 We’ll see some of those later. 213 00:14:21,214 --> 00:14:25,527 In this case, the switch on the playfield,  since it was worth 100 points, 214 00:14:25,527 --> 00:14:29,593 completed a circuit to energize the 100 point relay. 215 00:14:29,593 --> 00:14:34,152 When that pulled on its armature, these two switch contacts closed 216 00:14:34,152 --> 00:14:40,016 which completed a circuit both to the hundreds position score reel and the small chime. 217 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. 218 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. 219 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. 220 00:15:03,812 --> 00:15:06,552 In fact there are six. 221 00:15:06,680 --> 00:15:11,541 One of these additional switches is there to ensure the score reel actually moves. 222 00:15:11,541 --> 00:15:15,173 Solenoids are fast, but they’re not instantaneous. 223 00:15:15,173 --> 00:15:18,195 If the ball just brushes up against a target, 224 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. 225 00:15:27,706 --> 00:15:33,622 So, these two contacts actually provide a way for the relay to power itself. 226 00:15:33,622 --> 00:15:37,321 If I bridge them with a screwdriver you’ll see it pull in. 227 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. 228 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. 229 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. 230 00:16:00,144 --> 00:16:05,172 At that point it breaks the circuit powering the relay, so the relay lets go. 231 00:16:05,172 --> 00:16:08,732 Here’s what that looks like on the schematic for the machine. 232 00:16:08,732 --> 00:16:14,181 Full disclosure, I’ve made some alterations to this and hidden a fair bit 233 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. 234 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 235 00:16:29,953 --> 00:16:33,555 (though it’s AC so it flows in both directions). 236 00:16:33,555 --> 00:16:37,002 The 100 point relay coil is right here. 237 00:16:37,002 --> 00:16:41,574 It will become energized when any of these switches close. 238 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. 239 00:16:48,522 --> 00:16:52,727 But this switch is labeled "100 point relay." 240 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. 241 00:16:59,102 --> 00:17:02,416 So, it closes when the relay energizes, 242 00:17:02,416 --> 00:17:06,089 and since it also provides power to the relay coil, 243 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. 244 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. 245 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, 246 00:17:28,254 --> 00:17:32,918 the relay will lose that bypass signal and de-energize. 247 00:17:32,918 --> 00:17:37,557 Another contact in the relay has to do with the number 9. 248 00:17:37,557 --> 00:17:44,344 The score reels are not mechanically linked - each one operates entirely independently of the others. 249 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 1,000 250 00:17:52,271 --> 00:17:56,295 so two reels have to move in order to display that sum. 251 00:17:56,295 --> 00:18:01,312 [dings]  They do - and did you notice that two bells rang this time? 252 00:18:01,312 --> 00:18:04,734 [ding… ding… ding… 253 00:18:05,609 --> 00:18:08,161 dongs] 254 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 - 255 00:18:14,961 --> 00:18:20,461 but only when the 100 point score reel is on the number 9. 256 00:18:20,461 --> 00:18:24,407 Look back at the score reel and you’ll find a stack of switches 257 00:18:24,407 --> 00:18:27,093 (which we call a switch stack, oddly enough) 258 00:18:27,093 --> 00:18:28,895 sitting near the top. 259 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. 260 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. 261 00:18:43,906 --> 00:18:45,953 Take a look at the schematic again. 262 00:18:45,953 --> 00:18:49,195 These are the 9th position switches on the score reels, 263 00:18:49,320 --> 00:18:53,995 and you’ll see that they connect to that switch within the 100 point relay. 264 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,   265 00:19:01,000 --> 00:19:04,252 then the next time the 100 point relay fires, 266 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. 267 00:19:13,096 --> 00:19:16,746 All of the succeeding score reels have this interlock, 268 00:19:16,746 --> 00:19:22,054 so a score of 99,990 will correctly roll to 100,000 269 00:19:22,054 --> 00:19:24,381 when a single 10-point bumper is hit. 270 00:19:24,381 --> 00:19:28,303 [three chimes and a loud clack] 271 00:19:28,303 --> 00:19:30,212 Speaking of the 10-point bumpers, 272 00:19:30,212 --> 00:19:34,613 now’s a good time to go over the various target types on the playfield. 273 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. 274 00:19:42,901 --> 00:19:48,132 The contacts are slightly separated but will get pushed together when the ball stretches the ring, 275 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, 276 00:19:53,842 --> 00:19:58,907 and also steps the number match unit... 277 00:19:58,907 --> 00:20:00,393 Don’t worry about that yet. 278 00:20:00,393 --> 00:20:02,924 Uh, there’s a lot going on in here! 279 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, 280 00:20:08,395 --> 00:20:12,969 but one of the switch contacts is attached to the face of the target. 281 00:20:12,969 --> 00:20:16,111 The gap between the contacts here is important; 282 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. 283 00:20:22,397 --> 00:20:27,413 But if they’re too close, simply brushing against the target will register as a hit. 284 00:20:27,413 --> 00:20:30,617 So it’s generally best to be somewhere in the middle. 285 00:20:30,617 --> 00:20:34,828 The rollover lanes are essentially the same thing as the rollover buttons, 286 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. 287 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. 288 00:20:47,610 --> 00:20:51,297 Generally the ball can travel over these in either direction, 289 00:20:51,297 --> 00:20:55,975 but you’ll notice that the designers had an evil streak with the outlanes. 290 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. 291 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, 292 00:21:10,520 --> 00:21:16,517 unless it’s going very fast it will just  bonk into this and fall back down. 293 00:21:16,517 --> 00:21:18,035 Boo! 294 00:21:18,035 --> 00:21:24,357 The spinning target, while very different in its execution, is similar to the rollover lanes. 295 00:21:24,357 --> 00:21:30,055 The metal plate that the ball hits is attached to an eccentric… axle? I guess? 296 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. 297 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, 298 00:21:42,262 --> 00:21:46,574 repeatedly connecting and disconnecting the two contacts as it spins. 299 00:21:46,574 --> 00:21:50,648 When this target is hit just right, it’s quite the show. 300 00:21:50,648 --> 00:21:54,936 [rapid clacking and dinging] 301 00:21:54,936 --> 00:21:57,238 But not quite the show that the pop bump- 302 00:21:57,238 --> 00:21:59,885 I mean jet bumpers can put on. 303 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. 304 00:22:06,710 --> 00:22:10,811 They’re triggered by a circular platform known as the skirt. 305 00:22:10,811 --> 00:22:15,877 This is attached to a stick resting in a bowl below the playfield. 306 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, 307 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. 308 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. 309 00:22:38,791 --> 00:22:44,021 When that occurs, the ball finds itself between that ring and the skirt. 310 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. 311 00:22:51,157 --> 00:22:54,381 Since the ring is angled at roughly 45 degrees, 312 00:22:54,381 --> 00:22:57,358 the ball gets flung away from the bumper. 313 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. 314 00:23:06,861 --> 00:23:08,919 This wasn’t always standard practice, though, 315 00:23:08,919 --> 00:23:13,515 so many older games exhibit severe wear around the bumpers. 316 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. 317 00:23:19,752 --> 00:23:22,491 It’s just like the targets we’ve been looking at, 318 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. 319 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, 320 00:23:35,345 --> 00:23:40,019 which locks on in a similar fashion to the points relays we looked at earlier. 321 00:23:40,019 --> 00:23:43,484 A contact within that pop bumper relay awards points, 322 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. 323 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. 324 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, 325 00:24:02,212 --> 00:24:07,112 so it kinda-sorta half-fires and it doesn’t award points. 326 00:24:07,112 --> 00:24:10,379 And finally, we have the slingshots. 327 00:24:10,379 --> 00:24:16,070 These dastardly things are hardly a target worth hitting as they only score 10 points, 328 00:24:16,070 --> 00:24:21,884 and they have a nasty habit of flinging the ball right into the outlanes. 329 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. 330 00:24:28,817 --> 00:24:33,935 In the center of the long edge is a kicker just behind the rubber ring. 331 00:24:33,935 --> 00:24:37,555 The kicker is flanked on either side by two switch contacts. 332 00:24:37,555 --> 00:24:41,647 When the ball hits the rubber ring and either of those switches close, 333 00:24:41,647 --> 00:24:46,063 power is sent to a solenoid below which pushes the kicker outward, 334 00:24:46,063 --> 00:24:49,954 stretching the rubber ring and flinging the ball away. 335 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, 336 00:24:56,467 --> 00:25:00,761 and the switches behind the rubber only provide power to the solenoid. 337 00:25:00,761 --> 00:25:04,301 Oh, right, I forgot about the kickback lane here. 338 00:25:04,301 --> 00:25:09,164 This thing is sort of a combo of the slingshot kicker and a rollover lane. 339 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. 340 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. 341 00:25:27,103 --> 00:25:31,737 A bridge rectifier and capacitor are attached to the underside of the playfield 342 00:25:31,737 --> 00:25:36,741 which means that there is in fact a single semiconductor in this machine! 343 00:25:36,741 --> 00:25:39,920 Or four depending on how you wanna define things. 344 00:25:39,920 --> 00:25:45,388 It turns out that solenoids powered by DC can be stronger than AC-powered ones, 345 00:25:45,388 --> 00:25:49,184 and Williams began tinkering with them around this time. 346 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. 347 00:25:54,839 --> 00:25:59,743 Everything else, including the flippers, is powered by 24 volts AC. 348 00:25:59,743 --> 00:26:02,151 And why don’t we talk about the flippers? 349 00:26:02,151 --> 00:26:06,867 As with pretty much everything that moves, they’re powered by a solenoid. 350 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. 351 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. 352 00:26:18,082 --> 00:26:22,192 Then they pull on a linkage, and the flipper bat pops up. 353 00:26:22,192 --> 00:26:25,020 Flipper coils, though, are unique. 354 00:26:25,020 --> 00:26:29,175 See, a strong solenoid needs quite a lot of power. 355 00:26:29,175 --> 00:26:32,116 That means they get hot over time. 356 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. 357 00:26:38,880 --> 00:26:41,575 But the flippers are controlled by the player, 358 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. 359 00:26:47,334 --> 00:26:50,366 That could cause the coils to overheat. 360 00:26:50,366 --> 00:26:53,368 And coils that overheat tend to get melty, 361 00:26:53,368 --> 00:26:55,076 then smoky, 362 00:26:55,076 --> 00:26:58,416 and on rare occasions, firy. 363 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) 364 00:27:07,377 --> 00:27:12,437 but we want the flippers to be able to stay up without causing any trouble. 365 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. 366 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. 367 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. 368 00:27:31,418 --> 00:27:34,179 This bypasses half of the coil’s length, 369 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. 370 00:27:40,720 --> 00:27:44,952 That might seem backwards but that’s just how solenoids work. 371 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. 372 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. 373 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. 374 00:28:06,006 --> 00:28:08,142 And for a demonstration of this principle, 375 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. 376 00:28:13,814 --> 00:28:15,071 [buzz 377 00:28:15,071 --> 00:28:15,571 BZZTTZZTTZZZ 378 00:28:15,571 --> 00:28:16,071 buzz 379 00:28:16,071 --> 00:28:16,571 BZZTTZZTTZZZ 380 00:28:16,571 --> 00:28:17,071 buzz 381 00:28:17,071 --> 00:28:17,788 BRRRRRGGGGGHHH 382 00:28:17,788 --> 00:28:18,337 buzz 383 00:28:18,337 --> 00:28:19,257 BRRRRGHHHHH 384 00:28:19,257 --> 00:28:20,000 buzz] 385 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! 386 00:28:26,479 --> 00:28:30,238 At this point, we’ve looked at how everything on the playfield works, 387 00:28:30,238 --> 00:28:32,816 we’ve seen how the machine shows you your score, 388 00:28:32,816 --> 00:28:35,979 and we’ve seen how points get added to it. 389 00:28:35,979 --> 00:28:40,768 But the machine is doing a heckuva a lot more than simply adding point values together. 390 00:28:40,768 --> 00:28:44,466 Which you might have been able to tell by all the stuff inside. 391 00:28:44,466 --> 00:28:50,271 There are layers and layers of complexity built atop the basic scoring functions. 392 00:28:50,271 --> 00:28:53,789 For instance, the machine has to know how to count. 393 00:28:53,789 --> 00:28:57,097 You get three balls per game and then it ends. 394 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— 395 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. 396 00:29:10,750 --> 00:29:16,058 Then there’s the bonus ladder I referenced earlier which always starts at five thousand points, 397 00:29:16,058 --> 00:29:20,561 but can be advanced when you hit certain targets in increments of 5,000. 398 00:29:20,926 --> 00:29:24,056 And I think that’s a good place to move to next: 399 00:29:24,056 --> 00:29:26,190 the number five. 400 00:29:26,190 --> 00:29:27,703 Here, watch this. 401 00:29:27,703 --> 00:29:29,828 [bell rings five times] 402 00:29:30,411 --> 00:29:33,013 How on earth do you suppose that happened? 403 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. 404 00:29:39,827 --> 00:29:42,206 [ding ding ding ding ding] 405 00:29:42,206 --> 00:29:45,436 Well, remember that ticking it was doing in the beginning? 406 00:29:45,436 --> 00:29:48,841 Perhaps you noticed it happened in groups of five. 407 00:29:48,841 --> 00:29:50,389 Listen again. 408 00:29:50,389 --> 00:29:55,053 [clacking noises in quintuplets, plus a humming sound] 409 00:29:55,334 --> 00:29:59,726 Turns out the number 5 appears all over the place. 410 00:29:59,726 --> 00:30:02,103 This target is worth five hundred points, 411 00:30:02,103 --> 00:30:06,349 this lane scores 5,000, as does the kickback target. 412 00:30:06,349 --> 00:30:09,452 The bonus values increment in steps of 5,000 points. 413 00:30:09,452 --> 00:30:12,613 And then there’s this thing's name: AZTEC. 414 00:30:12,613 --> 00:30:14,269 That has five letters in it. 415 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. 416 00:30:20,834 --> 00:30:23,279 How... how is it doing all that? 417 00:30:23,279 --> 00:30:26,613 And why does everything happen in fives? 418 00:30:26,613 --> 00:30:31,297 Well, it’s time I introduce you to the score motor. 419 00:30:31,297 --> 00:30:37,472 This wonky looking contraption is the closest  thing this machine has to a central processing unit. 420 00:30:37,798 --> 00:30:42,840 The score motor consists of an electric motor which, through a speed-reduction gearbox, 421 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. 422 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. 423 00:31:00,000 --> 00:31:05,755 Incidentally impulse forward just has a single switch which is used only in the reset sequence. 424 00:31:05,755 --> 00:31:09,625 Ah, sequence - what a good word! 425 00:31:09,625 --> 00:31:13,462 That is pretty much the whole idea of the score motor. 426 00:31:13,462 --> 00:31:17,007 It allows things to happen automatically in a sequence. 427 00:31:17,007 --> 00:31:22,039 On every one of the eight cams there are a series of divots or bumps. 428 00:31:22,039 --> 00:31:25,798 These will actuate the switch stacks as the cam rotates: 429 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, 430 00:31:32,864 --> 00:31:35,882 or, in the case of the two impulse cams at the far right, 431 00:31:35,882 --> 00:31:42,069 a series of bumps will push up on the switch stack which accomplishes the same thing. 432 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, 433 00:31:48,976 --> 00:31:50,732 one two three four five, 434 00:31:50,732 --> 00:31:56,594 and impulse and impulse forward are bumped five times with every rotation. 435 00:31:56,594 --> 00:32:01,686 The index cam on the far left is critical for the score motor’s functions. 436 00:32:01,686 --> 00:32:06,139 The switch on the top of this stack is the Motor Run switch. 437 00:32:06,139 --> 00:32:10,985 It’s much like the self-powering interlocks we’ve been looking at in other relays. 438 00:32:10,985 --> 00:32:16,551 When closed, it provides power to the motor and thus it will run - and crucially, 439 00:32:16,551 --> 00:32:21,351 that switch is closed whenever the motor is out of its parked position. 440 00:32:21,351 --> 00:32:23,428 Once it gets back to the park position, 441 00:32:23,428 --> 00:32:28,802 the switch stack falls into the divot, that switch opens, and the motor stops. 442 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. 443 00:32:37,607 --> 00:32:40,084 It even works if I just push on it. 444 00:32:40,084 --> 00:32:45,884 [rapid clicking and motor noise] 445 00:32:45,884 --> 00:32:47,858 But you’ll notice that when I did that… 446 00:32:47,858 --> 00:32:49,266 [chickachickachickachickachickachunk] 447 00:32:49,266 --> 00:32:51,366 nothing happened. 448 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. 449 00:32:59,920 --> 00:33:02,989 With the exception of the motor run switch, 450 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. 451 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. 452 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. 453 00:33:28,630 --> 00:33:31,534 And what does it use to make that happen? 454 00:33:31,534 --> 00:33:33,847 That’s right, relays! 455 00:33:33,847 --> 00:33:36,655 That’s why there are so many of them in this machine. 456 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. 457 00:33:47,656 --> 00:33:51,464 Take this rollover worth 5,000 points as an example. 458 00:33:51,464 --> 00:33:56,174 You’ll never guess what the 5,000 point rollover switch completes a circuit to. 459 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. 460 00:34:01,495 --> 00:34:06,602 This relay has three switch contacts which all connect to the score motor. 461 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. 462 00:34:12,544 --> 00:34:18,369 [motor runs in bursts] 463 00:34:18,369 --> 00:34:22,285 The switch on the left is yet another relay interlock. 464 00:34:22,285 --> 00:34:26,880 The rollover switch is what sends the initial power  to the relay coil to energize it, 465 00:34:26,880 --> 00:34:27,501 [CLACK] 466 00:34:27,501 --> 00:34:31,447 but once these contacts are touching, the relay keeps itself powered. 467 00:34:31,447 --> 00:34:36,597 If I bridge these contacts, you’ll see the relay pull in and lock itself on. 468 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: 469 00:34:42,949 --> 00:34:48,012 it keeps the relay energized until its task is actually complete. 470 00:34:48,012 --> 00:34:51,639 And right now, I’ve disabled the score motor. 471 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. 472 00:34:58,858 --> 00:35:03,252 Its task, remember, is to add 5,000 points to the score. 473 00:35:03,252 --> 00:35:07,317 And the middle contact in the relay is what makes that possible. 474 00:35:07,317 --> 00:35:11,858 When closed, this connects the 1,000 point relay in the backbox 475 00:35:11,858 --> 00:35:15,818 to this switch on top of the impulse cam of the score motor. 476 00:35:15,818 --> 00:35:19,919 When I plug the score motor back in, the cams begin rotating 477 00:35:19,919 --> 00:35:24,116 and since the impulse cam actuates its switch stack five times, 478 00:35:24,116 --> 00:35:28,454 the 1,000 point relay will receive five pulses through this switch. 479 00:35:28,673 --> 00:35:35,431 [five clacks and dings] 480 00:35:35,431 --> 00:35:40,125 And right after it sends the fifth pulse, the relay lets go. 481 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. 482 00:35:48,768 --> 00:35:53,555 Once cam five is actuated, that switch is broken so the relay  releases. 483 00:35:53,555 --> 00:35:56,206 And now the machine is at rest. 484 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. 485 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. 486 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. 487 00:36:16,914 --> 00:36:21,649 It also connects the impulse switch through to the 1,000 point relay. 488 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. 489 00:36:28,967 --> 00:36:35,547 But the relay’s still locked on because cam 5 hasn't been actuated yet. 490 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. 491 00:36:42,215 --> 00:36:43,242 [buzz/ding.... 492 00:36:43,242 --> 00:36:44,385 clunk] 493 00:36:47,519 --> 00:36:48,074 [ding] 494 00:36:48,074 --> 00:36:48,724 [clunk] 495 00:36:52,223 --> 00:36:53,913 [ding/buzzzzz] 496 00:36:53,913 --> 00:36:54,771 [clunk] 497 00:36:55,464 --> 00:36:57,055 [click] 498 00:36:57,565 --> 00:37:00,922 As you can imagine, the timing here is critical 499 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 500 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.) 501 00:37:15,320 --> 00:37:20,908 With the score motor re-enabled, this all happens quickly and automatically. 502 00:37:20,908 --> 00:37:25,411 I hope you can appreciate how amazingly bonkers this is. 503 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. 504 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, 505 00:37:39,889 --> 00:37:42,653 and we’re how long into this video? 506 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. 507 00:37:48,394 --> 00:37:50,998 So there will definitely be a second part. 508 00:37:50,998 --> 00:37:55,143 But before we conclude here, let’s talk about the AZTEC targets, 509 00:37:55,143 --> 00:37:57,283 how they light up their respective letters, 510 00:37:57,283 --> 00:38:00,800 and why that changes what other targets do. 511 00:38:00,800 --> 00:38:06,125 By now, I hope you know what the switches in these targets send power to. 512 00:38:06,125 --> 00:38:07,666 Say it with me now, 513 00:38:07,666 --> 00:38:09,077 relays! 514 00:38:09,077 --> 00:38:14,326 And Williams was kind enough to mount them in order on this support below the playfield. 515 00:38:14,326 --> 00:38:15,773 Here’s the A relay, 516 00:38:15,773 --> 00:38:16,978 the Z relay, 517 00:38:16,978 --> 00:38:18,032 the T relay, 518 00:38:18,032 --> 00:38:19,332 the E relay, 519 00:38:19,332 --> 00:38:21,168 and the C relay. 520 00:38:21,168 --> 00:38:24,553 For now, let’s just focus on the A relay. 521 00:38:24,553 --> 00:38:28,907 This single relay features all three kinds of switch contacts. 522 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. 523 00:38:36,397 --> 00:38:40,823 Then we have a normally closed switch - this one does just the opposite. 524 00:38:40,823 --> 00:38:44,202 But the two on the right are make/break switches. 525 00:38:44,202 --> 00:38:48,742 The relay moves the center blade, and instead of turning something on or off, 526 00:38:48,742 --> 00:38:53,006 it redirects the flow of power from one place to another. 527 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. 528 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. 529 00:39:05,978 --> 00:39:10,939 And this relay will stay locked on until the end of the ball-in-play. 530 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. 531 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. 532 00:39:26,560 --> 00:39:33,799 The A rollover lane is marked “Lites A,” 1000, and “Lites Spinning Target.” 533 00:39:33,799 --> 00:39:36,380 Obviously that means it lights some things up, 534 00:39:36,380 --> 00:39:39,737 but it also makes this light go out. 535 00:39:39,737 --> 00:39:43,820 It’s this make/break switch that changes which lights are lit. 536 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. 537 00:39:50,658 --> 00:39:52,935 But once I hit it and the relay locked on, 538 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. 539 00:40:00,123 --> 00:40:05,133 Lighting the spinner target changed its point value from 100 to 1,000 points. 540 00:40:05,133 --> 00:40:06,337 How? 541 00:40:06,337 --> 00:40:09,522 Well, that's what the other make/break switch did. 542 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. 543 00:40:16,299 --> 00:40:18,794 Now, I could just tell you that, 544 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. 545 00:40:24,612 --> 00:40:26,498 Let’s follow their path. 546 00:40:26,498 --> 00:40:28,712 This is the spinning target switch. 547 00:40:28,712 --> 00:40:33,096 When closed, it sends power out this gray wire with a red stripe. 548 00:40:33,096 --> 00:40:38,274 It ends up bundled in the harness and comes back out right here at the relay. 549 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. 550 00:40:46,260 --> 00:40:48,320 Those wires re-enter the harness, 551 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, 552 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. 553 00:41:01,669 --> 00:41:06,295 Which one is connected depends on whether or not the relay is energized. 554 00:41:06,295 --> 00:41:08,765 And here's what that looks like on the schematic. 555 00:41:08,765 --> 00:41:12,727 Power is sent through the spinner switch on the grey and red wire. 556 00:41:12,727 --> 00:41:16,743 That ends up at the make/break switch in the A relay. 557 00:41:16,743 --> 00:41:20,641 The normally closed contact connects over to the 100 point relay, 558 00:41:20,641 --> 00:41:24,428 so the spinning switch will send power there when closed. 559 00:41:24,428 --> 00:41:27,118 But, when the A relay is energized, 560 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. 561 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. 562 00:41:38,520 --> 00:41:41,978 There’s also the center target and the kickback lane. 563 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 - 564 00:41:49,436 --> 00:41:52,401 in fact, more for every letter that’s lit. 565 00:41:52,401 --> 00:41:56,099 In the case of the center target, it’s 1,000 points for each lit letter, 566 00:41:56,099 --> 00:42:00,432 and the kickback lane awards 10,000 points for each lit letter. 567 00:42:00,432 --> 00:42:06,056 That means that, technically, the targets have six possible values each. 568 00:42:06,421 --> 00:42:10,566 How can this sort of circuitry possibly manage that? 569 00:42:10,566 --> 00:42:13,576 Well, it’s actually simpler than it might seem. 570 00:42:13,576 --> 00:42:16,001 Let’s look at the center target first. 571 00:42:16,001 --> 00:42:20,952 The center target switch sends power to the center target relay, of course, 572 00:42:20,952 --> 00:42:24,719 which is similar to the the 5,000 point relay we looked at earlier. 573 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, 574 00:42:32,673 --> 00:42:37,491 and releases just after the fifth pulse of the 100 point relay. 575 00:42:37,491 --> 00:42:40,162 Thus, it adds 500 points to the score. 576 00:42:40,880 --> 00:42:43,848 But look at the circuit path on the schematic. 577 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 - 578 00:42:50,984 --> 00:42:52,416 uh, here it is, 579 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. 580 00:43:00,348 --> 00:43:03,308 If they’re all closed, then we’re fine - 581 00:43:03,308 --> 00:43:05,934 the 100 point relay will be pulsed five times 582 00:43:05,934 --> 00:43:09,346 and we get those 500 points added to the score. 583 00:43:09,346 --> 00:43:14,288 But if any one of the AZTEC letter targets has been hit, 584 00:43:14,288 --> 00:43:17,720 its respective switch in its relay is open, 585 00:43:17,720 --> 00:43:20,509 and since all those switches are wired in series, 586 00:43:20,509 --> 00:43:22,558 this circuit path is broken. 587 00:43:22,558 --> 00:43:24,615 So it no longer works. 588 00:43:24,615 --> 00:43:29,156 Ah, but we get 1000 points for every letter that’s lit. 589 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. 590 00:43:33,850 --> 00:43:39,522 Here again we see switches in the A, Z, T, E, and C relays. 591 00:43:39,522 --> 00:43:44,479 These are normally open, but close when their respective relay is energized. 592 00:43:44,479 --> 00:43:48,129 And right above them we see switches in a circle. 593 00:43:48,129 --> 00:43:51,860 This is how the schematic tells us those are in the score motor. 594 00:43:51,860 --> 00:43:56,439 And the notation tells us where in the score motor those switches are. 595 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). 596 00:44:02,880 --> 00:44:07,916 The Z relay through stack one, switch A (the bottom switch in the stack). 597 00:44:07,916 --> 00:44:11,178 The T relay through stack 2, switch A. 598 00:44:11,178 --> 00:44:14,147 The E relay through stack 3, switch A. 599 00:44:14,147 --> 00:44:17,572 And the C relay through stack 4, switch A. 600 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. 601 00:44:24,124 --> 00:44:29,289 So you can imagine what’s happening here as a sort of scanning sequence. 602 00:44:29,289 --> 00:44:32,729 When the center target is hit and its relay is energized, 603 00:44:32,729 --> 00:44:38,609 each of the letter relays receives a pulse of power at their respective switches. 604 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. 605 00:44:46,657 --> 00:44:50,285 But as the motor turns, that switch opens 606 00:44:50,285 --> 00:44:54,142 and then the following relays get pulsed one at a time. 607 00:44:54,142 --> 00:44:58,462 Whichever relays are energized will have this switch closed, 608 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. 609 00:45:06,066 --> 00:45:10,652 Thus it adds 1,000 point for every lit letter. 610 00:45:10,652 --> 00:45:13,128 This is pretty wild, right? 611 00:45:13,128 --> 00:45:20,517 Despite just being a tangled mess of wires, relays, switches, a motor and some cams, 612 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 613 00:45:26,842 --> 00:45:29,985 and awards points if it has been. 614 00:45:29,985 --> 00:45:35,088 This results in a unique pattern of dings depending on which targets are lit. 615 00:45:35,088 --> 00:45:39,335 I won’t waste your time any further by going through every possible combination, 616 00:45:39,335 --> 00:45:41,015 but here are a few: 617 00:45:41,525 --> 00:45:42,920 [ding ding / ding ding] 618 00:45:44,378 --> 00:45:45,631 [ding / ding / ding] 619 00:45:47,308 --> 00:45:48,654 [ding/ ding ding ding] 620 00:45:50,221 --> 00:45:51,382 [ding ding ding / ding] 621 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. 622 00:45:58,730 --> 00:46:01,768 That’s what I’ve been calling the kickback lane - 623 00:46:01,768 --> 00:46:06,661 Williams decided to refer to this as the shooter which is very confusing since, y’know, 624 00:46:06,661 --> 00:46:08,330 this is also the shooter. 625 00:46:08,330 --> 00:46:13,577 But anyway, that target works in essentially the exact same way as the center target, 626 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 627 00:46:18,860 --> 00:46:20,928 (thus awarding 5,000 points) 628 00:46:20,928 --> 00:46:25,047 and pulses the 10,000 point relay for every lit letter. 629 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. 630 00:46:35,469 --> 00:46:39,750 While I covered a lot of what this machine does in this video, 631 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. 632 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 633 00:46:52,456 --> 00:46:53,699 like this one: 634 00:46:54,246 --> 00:46:55,301 [ding ding ding ding ding / 635 00:46:55,481 --> 00:46:56,334 ding ding ding ding ding / 636 00:46:56,476 --> 00:46:57,267 ding ding ding ding ding / 637 00:46:57,434 --> 00:46:58,333 ding ding ding ding ding / 638 00:46:58,501 --> 00:46:59,368 ding ding ding ding ding 639 00:46:59,368 --> 00:47:01,235 tuck click clack ka-chunky shwhup] 640 00:47:01,235 --> 00:47:05,783 Yep, it added 25,000 points to the score all on its own, 641 00:47:05,783 --> 00:47:10,000 then changed the ball-in-play light from one to two. 642 00:47:10,000 --> 00:47:12,075 Apparently it can count. 643 00:47:12,075 --> 00:47:17,115 And it also knows your score - cross 350,000 points and... 644 00:47:17,115 --> 00:47:19,003 [ding ding *clunk* ding ding] 645 00:47:19,003 --> 00:47:20,989 you’ve won a replay. 646 00:47:20,989 --> 00:47:23,738 Stay tuned for how that all works. 647 00:47:23,738 --> 00:47:27,428 It’s just as nuts as everything you saw here. 648 00:47:27,428 --> 00:47:29,864 Thank you very much for watching. 649 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. 650 00:47:35,535 --> 00:47:39,488 The thing is, though, it’s not nonsense - it’s logic! 651 00:47:39,488 --> 00:47:43,331 And that’s part of why I like machines like this so much. 652 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. 653 00:47:49,583 --> 00:47:54,214 It blows my mind how folks of the past figured all this out 654 00:47:54,214 --> 00:47:57,479 and got these things manufactured in mass. 655 00:47:57,479 --> 00:48:02,634 And perhaps even more mind-blowing, while this machine is from 1976 656 00:48:02,634 --> 00:48:08,416 most of the tech in here existed in some form back in the 1930’s. 657 00:48:08,416 --> 00:48:13,545 It just got built up in layer after layer  until we arrived at this. 658 00:48:13,545 --> 00:48:14,827 And to be honest, 659 00:48:14,920 --> 00:48:16,814 this machine isn’t that complex. 660 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. 661 00:48:23,721 --> 00:48:28,005 In fact, twenty years prior to this one getting manufactured, 662 00:48:28,005 --> 00:48:31,785 Bally introduced a game with multiball. 663 00:48:31,785 --> 00:48:33,413 Yeah. 664 00:48:33,413 --> 00:48:37,813 Maybe one day we can take a look at a more complex machine but for now… 665 00:48:37,813 --> 00:48:39,709 I need to go to bed. 666 00:48:40,000 --> 00:48:41,668 G’night everybody. 667 00:48:42,568 --> 00:48:45,126 ♫ coin-operatedly smooth jazz ♫ 668 00:48:46,301 --> 00:48:49,720 You didn’t know this but I’m even wearing PJs. 669 00:48:52,162 --> 00:48:54,955 You never know what I’ve got on below the desk. 670 00:48:54,955 --> 00:48:56,551 Or behind the pinball… 671 00:48:59,540 --> 00:49:01,060 In fact, 10 copies… 672 00:49:01,060 --> 00:49:01,954 I… 673 00:49:02,793 --> 00:49:04,206 slightly… 674 00:49:04,206 --> 00:49:08,520 ooh, left handed teleprompter control’s gonna throw me off. 675 00:49:08,520 --> 00:49:10,329 Just gonna need to pick this up. 676 00:49:10,329 --> 00:49:13,035 Quite the assortment of weird ob… 677 00:49:13,035 --> 00:49:14,093 ahhhh! 678 00:49:14,093 --> 00:49:17,868 We can slide the glass out and the playfield will simpy lift right up. 679 00:49:17,868 --> 00:49:20,039 I botched the word “simply” 680 00:49:20,039 --> 00:49:22,510 To find… de ber da ka ta ka da bakatakaww 681 00:49:22,510 --> 00:49:24,401 And just a bit, I promised. 682 00:49:24,401 --> 00:49:25,815 Promised? 683 00:49:26,070 --> 00:49:27,713 That’s not the… what? 684 00:49:27,968 --> 00:49:33,251 Large rings may be stretched across two or more posts to create a linear barrier, 685 00:49:33,251 --> 00:49:37,011 but sometimes that sounds weird and I’m gonna start over. 686 00:49:37,011 --> 00:49:40,814 But you’ll find plenty of individual rings with their own rings, too. 687 00:49:42,017 --> 00:49:44,646 Well, this line’s not going great! 688 00:49:44,646 --> 00:49:47,404 And that advances the mechanism by one step. 689 00:49:47,951 --> 00:49:51,067 It, or it would if I weren’t so clumsy. 690 00:49:52,853 --> 00:49:56,209 Ever since I was a young boy, I've played the silver ball. 691 00:49:56,209 --> 00:49:59,077 But sadly I got started long into its downfall 692 00:49:59,077 --> 00:50:02,411 and you really couldn't find 'em in many amusement halls 693 00:50:02,411 --> 00:50:06,109 but that wouldn't stop me: just hadda play pinball! 694 00:50:06,109 --> 00:50:08,238 [imagined guitar riff clashes with soprano sax]