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EM Tech: Score Motors and Bonus Counts in Electromechanical Pinball with Mark Gibson

Marco Pinball·video·43m 44s·analyzed·May 21, 2026
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claude-haiku-4-5-20251001 · $0.023

TL;DR

Technical deep-dive on EM score motors, bonus counting, and stepper mechanics with real game examples.

Summary

Mark Gibson from Fun with Pinball delivers an in-depth technical seminar on electromechanical pinball score motors, bonus counting mechanisms, and stepper units. He explains how cams, switches, and pulses interact to calculate and display points, demonstrating single, double, and triple bonus systems using real examples from Bally Wizard, Williams Stardust, and Gottlieb Humpty Dumpty. The session covers practical troubleshooting insights and design variations across manufacturers.

Key Claims

  • Gottlieb developed their unique score motor design around 1947-1948, first appearing in Humpty Dumpty

    high confidence · Mark Gibson stated this directly during the Gottlieb motor explanation segment

  • Both Bally and Williams initially used horizontal shaft designs similar to or directly copied from Gottlieb through the 1950s and into the early 1960s

    high confidence · Mark Gibson responding to audience question about Gottlieb's horizontal cam motor design

  • Bally Wizard uses a single/double bonus system that produces audible 'ding' patterns at different cadences depending on bonus multiplier

    high confidence · Mark Gibson demonstrated with audio examples during bonus explanation

  • Williams Stardust can award single, double, or triple bonuses using the same circuit with different relay configurations

    high confidence · Mark Gibson showed the circuit diagram and explained the relay switching logic

  • Score motor pulses are filtered through switch combinations to create variable point awards (e.g., blocking 4 of 5 pulses to generate different scoring)

    high confidence · Demonstrated with Gottlieb motor pulse-blocking examples and Royal Flush poker scoring

  • Williams used 'Long Dwell' cam designations to increase tolerance for worn switches by extending pulse width

    high confidence · Mark Gibson explained this as a manufacturing tolerance solution for switch wear

  • Mark Gibson runs free monthly online repair clinics teaching schematic reading and troubleshooting

    high confidence · Marco Pinball host mentioned this during introduction and endorsement

  • Mark Gibson conducted EM training classes at Pacific Pinball Museum and has another scheduled at Past Times Arcade in Girard, Ohio

    high confidence · Marco Pinball host stated this in the introduction

Notable Quotes

  • “It's not as scary as it might look.”

    Mark Gibson@ 2:10 — Sets accessible tone for complex technical material; addresses common intimidation around EM electronics

  • “So the stepper can be in any arbitrary position, but when I drain or I need to count that bonus, I need to get back down to zero before I can move on to the next thing.”

    Mark Gibson@ 11:28 — Core principle of how bonus counting works—explains why zero-position detection is critical

  • “I can use those wider pulses to either allow one of the smaller ones to pass, or I can block it. I can do it either way.”

    Mark Gibson@ 24:34 — Key insight into Gottlieb's elegant pulse-masking design philosophy

  • “For a single bonus, you hear ding, ding, ding, ding, ding. For a double bonus, you hear ding, ding, ding, ding, ding, ding.”

    Mark Gibson@ 17:56 — Translates mechanical complexity into audible player experience; makes abstract concepts tangible

  • “The whole reason for making one of them much wider is it's more tolerant of that kind of shifting around, and it's a tolerance that's built in.”

    Mark Gibson@ 39:28 — Reveals manufacturing pragmatism—design choices driven by real-world durability concerns

  • “Royal Plus... it has a computer chip or something because it's like it's thinking.”

    Audience member@ 36:24 — Illustrates how sophisticated EM scoring can appear AI-like; Mark explains it's all mechanical pulse filtering

Entities

Mark GibsonpersonMarco PinballpersonFun with PinballorganizationPacific Pinball MuseumvenuePast Times ArcadevenueBally WizardgameWilliams StardustgameGottlieb Humpty Dumptygame

Signals

  • ?

    educational_signal: Structured technical education in EM pinball mechanics through seminars, clinics, and online resources; indicates growing community investment in preserving and understanding electromechanical knowledge

    high · Mark Gibson's Pinball University seminar, free monthly online repair clinics, EM training classes at museum and arcade venue

  • ?

    historical_signal: Documentation of score motor design evolution across manufacturers—Gottlieb's 1947-48 innovation, Bally/Williams adoption and variation, manufacturing tolerance solutions (Long Dwell cams)

    high · Detailed technical comparison of Gottlieb horizontal cam vs. Bally/Williams adaptations; explanation of Long Dwell as design refinement for durability

  • ?

    design_philosophy: Gottlieb's pulse-masking approach reveals sophisticated design philosophy: using variable-width pulses to filter and create complex scoring without hardwired circuits; emphasizes tolerance and reliability

    high · Explanation of how wider pulses allow narrower pulses to pass/block selectively; connection to manufacturing tolerance and worn switch accommodation

  • ?

    restoration_signal: Discovery that Gottlieb score motor switch dogs can be positioned in two ways to correct subtle timing issues; one specific position differs from standard; repositioning errors are common during restoration

    high · Mark Gibson discussed switch dog sooner/later positioning as a critical assembly detail; noted only one position in the motor uses non-standard placement, creating rebuild errors

  • ?

    gameplay_signal: Score motor mechanics create distinctive audio patterns (cadence of 'dings') that players use to perceive bonus multiplier; different patterns indicate single vs. double bonuses in Bally Wizard

Transcript

youtube_groq_whisper · $0.131

0:00
All righty, everybody. Welcome to another session with Pinball University. We have a very special guest with us today, Mark Gibson with Fun with Pinball. Everyone give him a round of applause. Thank you, Mark, for being here. Mark just did EM training classes at the Pacific Pinball Museum a few weeks ago. And he has another one coming up soon at Past Times Arcade in Girard, Ohio, one of the largest public collections as well, too. And definitely check out his website. He also runs monthly online repair clinics that are free to go on. And it's like how I learned how to read schematics. Thank you.
1:19
Yeah, definitely, definitely write that down. It's an awesome resource to have. And now Mark is going to teach us a little bit more about troubleshooting score motors and bonus counts and learning how they work. So without further ado, let me take that off and go back to you. All right, Mark.
1:39
That's me. That's you. Yeah, so welcome. Thanks for coming. Anybody who needs a nap this afternoon, now is the time. We're going to talk a little bit about score motors and bonus counts and how they play together.
1:56
Helping people diagnose their games and stuff. I run into confusion quite a bit. And so I'm hoping this will help some of you grok your games a little bit better.
Royal Flush
game
Gottliebcompany
Ballycompany
Williamscompany
Godley Moon Valleygame
Starjetgame

high · Demonstration of Bally Wizard single vs. double bonus audio patterns; explained how pulse separation creates timing differences audible to players

  • ?

    design_innovation: Williams and Bally scoring circuits achieved single/double/triple bonus variation through relay-based switch configuration rather than mechanical design changes; same circuit, different relay activation patterns

    high · Williams Stardust circuit example showing how triple/double/single bonus switches control which pulses reach thousand-point relay; configuration determines payout without mechanical redesign

  • ?

    manufacturing_signal: Long Dwell cam design addresses real-world wear and shift tolerance; wider pulse windows accommodate aged switches and slight misalignment that develops over machine lifetime

    high · Mark Gibson explained Long Dwell as tolerance solution; wider pulses compensate for worn switch behavior and manufacturing variation

  • ?

    community_signal: Active community effort to document and teach EM electronics through seminars, websites, and clinics; addresses risk of knowledge loss as older technicians age and fewer people understand mechanical systems

    high · Mark Gibson's Fun with Pinball resource site, monthly free clinics, training at museums and public collections

  • ?

    restoration_signal: Schematic reading is critical skill for EM diagnosis; different manufacturers used different notational systems (Bally vs. Williams vs. Gottlieb); community resources emphasize schematic fluency as foundation

    high · Marco Pinball intro noted schematic reading as learned skill through Mark's clinics; Mark emphasized multiple representations of same information (Bally charts, Williams notation, aerial views)

    • 2:10
    It's not as scary as it might look. And let's ask questions as we go along, too. Thank you. A Dirty Table Thank you. The switches are all lined up across the top.
    4:20
    And on the right side is another representation of the same information. And this is usually on your Williams schematics as well. So these are the cams on this side here, running down the side.
    4:35
    And attached to each cam is a set of switches. And these bumps tell you when that switch stack will activate relative to its neighbors. Thank you. The impulse came on the end is stepping in between them and filling out the five pulses in between the other sets of cams. They're interleaved that way.
    5:56
    So it's the same information I showed you before with Bally, just a different way of showing it. And let's see the way Bally did it. So if you've got a Bally schematic, you may have seen one or both of these or all three of these charts. A little bit of a twist. On the left here, this is the aerial view of your score motor from the top looking down. And something I find that confuses people is that these things here, these are not the switch stacks. These are actually the cutouts in the frame that are folded up to hold the switch stacks. So that means that your switch stacks are actually mounted there.
    6:31
    So as you're looking for your switches on a score motor from the schematic, Thank you. How many of the switch, cam, or peg are you following? This motor shown here has five levels and the switches can be mounted at any of those five levels. And so the first one, the motor 1A switch, would be in a stack in this quadrant at this compass point, but it would be the stack that's mounted to the bottom following the bottom cam. And this information here is essentially the same that the others were showing you. When does each switch stack activate relative to its neighbors as time is passing? So as I put that in motion, you can see that as the motor is turning, I get different sets of switches that are activating in a very specific repeatable order. And this repeats as the motor goes around. It's got three copies of this. It repeats three times for one complete revolution.
    7:53
    Okay. Often, this chart ends up being really important for troubleshooting, Thank you. So, let's move over to talk about bonuses.
    8:35
    So one common thing that you, these five pulses that I've circled in the Godly Moon Valley charts, that pattern is often used not only for reset, for example, but maybe for scoring 50 points, right? The same cadence, dot, dot, dot, dot, dot, dot, dot, dot, dot, dot, that's 50 points, right? For each set of five pulses that you get. Thank you. I just keep the motor running until I get to the end. I've counted off as many points as I need to. So the top one, I'm counting 20,000 points, for example, and the bottom one, I'm counting just 15,000. But I'm still using those chains of five pulses, groups of five pulses.
    9:46
    But I'm not just adding points. When I'm counting a bonus, I also need to count down. I'm counting off a certain number of points that you've earned as you've played that ball. Thank you. So this is what a stepper unit looks like. This is a ballet stepper, but they all function essentially the same way.
    10:32
    And it has two coils on it. One coil is for setting, for walking forward or adding bonus, and the other is for resetting or counting off the bonus or subtracting. And when this thing is in motion that little peg that little red peg rotates Okay so here I am adding bonus as I playing the game and as I drain and get to the out it will start counting off the bonus and subtracting So it turns what is that That clockwise It turning clockwise when you adding bonus during the ball and it rotates backwards counterclockwise to count down to the zero point And what's interesting about zero, well I need to know when to stop counting bonus and to start playing the next ball, right? So somewhere there has to be a switch that recognizes that I've counted down to zero from wherever I happen to be. So the stepper can be in any arbitrary position, but when I drain or I need to count that bonus, I need to get back down to zero before I can move on to the next thing. And that's the mechanism that most of them use. If there's a peg somewhere that's going to open a switch, then this thing walks all the way back down to zero.
    11:43
    And that's typically a make-break switch, but it doesn't always have to be. It'll vary from game to game. But basically that make break switch is telling you whether I still have to count or whether I'm done counting. And the position of that make break switch is going to activate different circuits telling me whether to keep going or whether to stop and move on to the next thing.
    12:06
    Any questions? You still with me? I hope so. So let's look at a real circuit and pick it apart I'm going to start and figure out how you might count a single bonus using the things I've described so far.
    12:23
    So on the left side here, I've got a score chart. This is from a Williams game. And this is going to show me what pulses are firing when as this motor starts turning. Up here, this is the out-hole switch that lives at the bottom of the play field under the out-hole. And the first thing it's going to do, assuming I have earned a bonus, I'm going to fire this bonus relay as soon as that out-of-hole switch closes.
    12:52
    Over here, I've got the bonus unit, which right now has stepped up to position 7, which tells me maybe I owe you 7,000 points when you drain. And this is one of the score wheels. Right now, let's just say it's at 0. So when I drain, I need to count off those 7,000 points and move them over to the score wheel. So the first step here is I'm going to presume the ball lands in the out-hole switch. Now suddenly this switch has closed, and because my bonus unit is not a zero, I'm going to come down this path and fire my bonus relay. Somewhere in the game there's a bonus relay that says we still owe this player points. The bonus relay in turn has closed these two switches, which now has enabled these two circuits. Thank you. I'm getting the first pulse out of the chain of five. And that impulse switch, there's a whole stack of switches on that impulse cam, that has closed both of these switches, this switch here and this. And the bonus relay had already closed these switches for me. So now I've got my 1k point relay, the thousand point relay is fired now using that circuit. And the one above it is the circuit that's going to, is the solenoid that's going to subtract one step from my bonus stepper. So they're happening simultaneously. I'm effectively using the same position here to accomplish two different things. So as soon as this, so these solenoids are activated, but they don't actually advance until the power relaxes. A
    15:31
    The fifth pulse has walked me down. So now I'm down to two on my bonus stepper. I still owe this person 2,000 points, and I've gotten five on the score reel. So now I have to start a second cycle. I've only got five pulses to work with. I've got to get another set of five to finish out that bonus.
    15:50
    So that puts me down here, and I've done the very same process. And right now I've given away the 6,000 points. I've still got one more point on my bonus stepper. But I've got both of these now active again and this is going to step down to zero and that's what's going to change this switch up here, the zero position switch. So when I get down to zero, this switch now flips and says we're done counting bonus, my bonus is at zero, the score reels up to seven, and I can fire the out-hole relay which is going to return the ball to the shooter lane and bop your uncle, you're on your way.
    16:28
    That was the simple case. So how do we do a double bonus? In the single bonus case, we use essentially copies of the same pulse to accomplish the step down and the add points. And if I keep doing that in lockstep, I'm going to have to subtract.
    16:47
    I can only give 1,000 points for every time I step down. Well, some games have a double bonus where they give you 2,000 points for every step down. Well, how is that accomplished?
    16:57
    Well, I can pick a different set of pulses to do that kind of thing, right? In the previous example, I used some set of five on a different machine, but I used a set of five that came one, two, three, four, five, one after the other. Well, in this situation, maybe I pick these two, and I send both of those pulses to my thousand-point relay. So 2,000 points, and nothing has stepped down. The next cycle, maybe I step down my bonus unit. So I got 2,000, and I take a single step. And then I can repeat that. I can take the next two and add points, and then I take a stat.
    17:37
    Right? And what I end up with, in one cycle, I've gotten 4,000 points, but I've only taken two steps down. I'm effectively getting 2,000 points every time I take a stat. So that's how you get a double bonus out of a game.
    17:52
    And here's a live example. If you've ever played a Bally Wizard, this is how they do it. A single bonus on a valley, I think what you hear is ding, ding, ding, ding, ding, ding as it's counting. And for a double bonus, you hear ding, ding, ding, ding, ding, ding.
    18:11
    That's because they're using the pulses that I showed. So the first pulse on the number three cam closes this switch, and that's going to come down and fire 1,000 points. So that first pulse gives me 1,000 points.
    18:29
    The next one down closes this switch, and I can fire the 1,000-point relay, but only if I'm counting a double bonus. If I'm not counting a double bonus, that gets blocked there, and it never gets through. So this is configurable, if you will. The third pulse on the number 5 cam is going to be the one that's going to step my subtract Subtract my step unit, right? So I've awarded either 1 or 2,000 points, and then I'm going to subtract my step unit down.
    19:02
    And then I repeat the thing again. So we're back, and remember I said that the cams are numbered, and the number reflects the order. Well, we went, what did we do? We did 3, 4, then 5 was over here, and now we're doing 6 down here, right? As we're working our way down this chart. Alright so I'm getting another thousand points there and optionally I'm getting a second thousand points if I'm doing the double bonus and then the last one down is stepping my stepper again. So I'm getting either a single or a double based on whether or not I've got a relay that says I've got a double bonus coming to me. This is an example from a Williams Stardust where they can do single, double or triple. In the box is our zero position switch.
    19:57
    And I don't know the rules well enough to tell you what earns you a double or triple bonus, but this is how they pull it off in the game. I'm not showing you the relays for the single, double, or triple. Assuming they work, all I end up with are switches down here that are showing me triple, double, or single bonus for a given bonus count. So the first thing that happens, let's see, so let me walk through this a bit. This is a score motor switch. This is going to throw out five pulses.
    20:31
    And in this Whizzy Williams notation, those pulses jump through the arrow down to here like in hyperspace. Thank you. At the same time, I've got a switch that looks just like this one down here at the bottom.
    21:17
    The same switch stack, same five pulses, different switch. Those five pulses go right through to my thousand point relay. I'm sorry, this was the subtract, and this is the thousand point relay. The point is they're getting the same pulse at the same time. They're in lockstep, right? So it's a single bonus. There's nobody getting ahead of the other one. So that's the single bonus scenario. This is the double bonus scenario using the very same circuit. And instead of closing the single bonus switch we using the double bonus switch which means now we using this thing this four cam number four to step down my subtract And that guy comes out way out here, right? The number four cam we showed earlier only fires relatively late in the cycle. www.fastpinball.com And for the triple bonus situation, we have the same thing where we're stepping down here on the fourth cam. So this hasn't changed. This is when I'm subtracting the stepper down. But now I'm using a switch on the triple bonus relay. There's one here and there's another one right below it. And they're letting three pulses through. There's one here on the 1C switch and the 2 and the 3. A
    23:40
    Let's take a minute and talk briefly about what Godley did with their score motor because it's a little unique and it will help us understand the final example.
    23:50
    So Godley built this score motor that threw out pulses represented by this chart. And some people think this was just sneezed on the page, but there's actually a lot of meaning to when these pulses are happening to each other. So we've talked already quite a bit about these five pulses that everybody has. So these are five per cycle. But every one of them, if you look closely, has a matching longer pulse that sits below it somewhere.
    24:25
    All five of those have a mate that's wider than it is. And what I can do is I can use those wider pulses to either allow one of the smaller ones to pass, or I can block it. I can do it either way. So as a simple example, if I were to put a switch on this pulse and another one on this pulse that's normally open, that would allow just the first pulse to pass through. And I can illustrate that here. This is the trivial example. So motor 1A is the top row of this chart. He's going to close five times as the motor rotates through a cycle.
    25:10
    Well, I'm going to get five pulses coming out of there along this wire through that first switch, right? But motor 1D is an open switch that only closes right here, right? So that switch is only closed, meaning when this pulse, when it's coincident with the first pulse in that chain. So only this pulse actually gets through. The rest of these four are all blocked because this switch here opens up.
    25:44
    So I've got five pulses coming into one side, but I'm only letting the first guy through and the other four end up being blocked.
    25:51
    So what I end up with in this coil is just the first, down here, the first of the five possible pulses that might get through. A
    26:29
    Thank you. The first coil, coil A, it's only going to see two of those five because it's using a switch on 1D and 2C. So these two pulses, the first one gets through the 1D switch this way,
    27:13
    and the second pulse gets through the 2C switch because that's lined up in time, right? So these first two will get through to the bottom and fire that coil. The next three are all going to be blocked because both of these switches are closed. I'm going to show you how to get through the circuit to the coil.
    27:32
    So I've only allowed two of the five to get through. If I configure the switches this way that are normally closed, what ends up happening is that the five pulses that come through this way, the first one is blocked here by this motor 1D switch, and the second one is blocked by the 2C switch, and only the last three get through. So I've got three pulses coming through in that second scenario.
    28:06
    And then the last one, there's no switches in all five get through. So is that the difference between like 300 points and 500 points? Yeah. Is that where that would be used? That would be one way that you could generate 300.
    28:21
    So the Godly Motor was developed in 1947, 48, something like that, Humpty Dumpty. Thank you.
    29:27
    A little bit about the game. This is the 1000 point relay coil. So every time this coil fires, I'm going to get 1000 points.
    30:05
    Right next to it, I've got another switch that's on the bonus score relay. So this whole circuit is dead until they're counting bonus. So it's not working for 500 points, it's not working for reset. It's only working when I'm counting bonus. That kills the whole circuit unless we're counting bonus. This piece of it is just a small stepper that's going to examine all five hands. So this double arrow here is going to walk across and evaluate all five or zero to four positions to figure out whether or not you earned that hand and whether or not you deserve points for that hand. Okay?
    30:50
    And then the next step, although on the other side we have our favorite five pulses coming in, right? So I'm using the motor 1A switch, which is using the top row of the chart that we saw earlier. And it's feeding five pulses in into the circuit.
    31:07
    And I get five pulses on this wire here. Right? Well, what's going to happen here when I go through these motor switches, right? Well, each one, if you look carefully, is peeling off one of those five pulses, right? So I get five pulses on this wire, but this switch is going to knock off, like a shooting gallery, it's going to pick off one of the ducts, right? It's taking off one of the pulses and only let four of them get to here.
    31:39
    And then I go through another switch, only three of them get to here, Thank you. And the 5B indicates you've gotten two kings down. Well, that's a pair, right? So if I have a pair in this game, one of these switches will close, and that one pulse is going to find its way out to the L relay and give me 1,000 points. So all I get for a pair is 1,000 points on a royal flush, right? Then the next step is I need to move this the stepper will take a step over and now we going to look at the second hand so that double arrow moves over to position one And we already established that I only getting two pulses into this wire But now I've got these same two switches but instead of being in parallel they're in series.
    33:01
    So I need both of those switches to be closed. So if I have two jacks and two kings, so two pair, right, I'm going to get the two pulses through to my thousand point relay.
    33:15
    Yeah? My arrow moves again and we're going to evaluate three of a kind. So this relay here elsewhere in the game is going to close activated switches if I can have the three queens dropped on this game. I've got my three pulses that come through and all I need is that one switch to close because I've gotten all three queens and that will give me 3,000 points.
    33:47
    The next one is full house, so I need three of a kind and a pair, right? So the three of a kind we saw before, this is the six relay, so that gives me the three queens. Thank you. So that's what I've got. Can I clarify any of that for you? So is that not showing the coil on the disc that actually rotates?
    34:59
    Or, you know, the relay disc? This here? No, that's the step unit and I'm not showing you how that advances. Right, so every time the motor takes a third of a turn, it's looking at... Right, right. So it will take the five pulses and give you points, but then it's going to take another late pulse late in the game and walk that stepper forward to the next one. So it's doing the math, you know, how many points do you get and then step. And then doing the math, how many points do you get and then step. Similar to what we saw earlier where you're getting so many points and then a step and you're separating them out, right?
    35:44
    Does it make sense when you walk through it slowly? It does now to me. It does now? It does. Good, thanks.
    35:52
    So a few things that we've talked about. There's lots of good reference material online that's available. These are URL links that you can pull up or you can just find them on my website, Fun With Pinball, where I go into a lot more detail about how these things work and not just bonus circuits. I've pulled apart all kinds of other circuits and other devices too.
    36:19
    So that's what I have unless you have questions for me. The Royal Plus because if anybody has seen that game or watched it play, it's like it has a computer chip or something because it's like it's thinking. It's interesting because, yeah, it has a different point value for every step through the stepwork.
    36:52
    It has to, one at a time, yeah, yeah. And it's the score motor that's driving all that, right? It's throwing out the pulses and the rest of the circuit is filtering out how many of those actually get to the score reel to give you points.
    37:06
    Question? So we've got the score reel and you have the two in series, the short pulse and the long pulse.
    37:13
    The thing is you can just make two and the other one comes with the short pulse because you have to roll to the series. Ah, excellent question. I want to make a simplified audio one. Let me back up to that slide. That's a next level question.
    37:34
    This one. Right. So the question is, so the chain of five pulses are all very small relative to the pulses that are used for the masking or blocking, right? Why aren't they the same width? If you're going to put them in series. No? Why don't you just use, I want one pulse, 1D, I don't know. Oh, if you just want one pulse, you don't go through all the trouble. Some of these are contrived examples, right? But the Royal Flash, it does have to block four of them just to let the one through for the, what was it, a pair, right? So if you're going through the whole, the full range of possibilities, you go through the complication. If you just need one pulse, yeah, you don't need all the series switches and all that. The masking. Williams did a little bit of it. Not very much, but if you've ever seen on a Williams game, what do they call the cam? Long Dwell.
    38:37
    Some cams are labeled 1, 2, 3, 4, 5. Some are labeled 5, Long Dwell. And what that means is that the stack activates for a longer period of time than it might normally. www.fastpinball.com Suddenly I can get a little sliver of pulse to slip through, right? If they're not exactly lined up and they've just shifted a little bit, then I'm going to get a little sliver of pulse over here on the end. So the whole reason for making one of them much wider is it's more tolerant of that kind of shifting around, and it's a tolerance that's built in, right? So if my switches start to get mangled or worn or whatever, I've got that much more margin where I can tolerate the thing I'm not behaving exactly the way it was the day it left the factory, right?
    39:51
    Question? I have a question. The Gottlieb's four motor, I call it the pancake style, is seen in a value game called Starjet from 1963. Do you know of any other instances where the value waves have used that? And why was that? So the question is that there's a ballet game that has a pancake or horizontal cam motor like similar to the Gottlieb. Ballet and Williams both had horizontal cam motors early on.
    40:27
    Some were direct copies of Gottlieb, some were very similar to Gottlieb. They all had the vertical shaft horizontal cam design through the 50s, I think, and early 60s perhaps. And then both Ballet and Williams went and did their horizontal shaft design, Thank you.
    41:11
    Yes. Yes. Question. The switch dogs. The switch dogs. I don't know if I have a picture of that. Yes. So the cam followers on a Godleaf score motor that are following the platters, the cams, and not the ones that are activated by the pins. The It affects the relative timing of that whole switch stack. I refer to it as the sooner and later position, because you can put it in one position, and as the gap in the cam comes by, it can open and activate your switch either sooner or later based on the position where you put that cam, that switch dock. And that solved for them a subtle timing problem that I don't have my thumb on. There was some very subtle, tricky little timing issue that they corrected by having that switch dog have two positions. That's one of the few modifications they made to the motor since the late 40s. And there's only one position in that whole motor that actually uses...
    42:52
    I'll get it wrong if I say it out loud. They all use the same position except for one, which uses a different position. And it would be spelled out in your table. And it never changes. They're all the same. And it's a headache for you to take your stormwater apart and put it back in the wrong place.
    43:25
    When you figure it out, you make the victory dance. Last call? Well, thanks for coming out. I appreciate it. Thank you so much, Mark.