Brett Davis - Pinball Expo 2023 - Pinball News

Pinball News (Pinball Expo 2023)·video·21m 35s·analyzed·Oct 20, 2023

Analysis

claude-haiku-4-5-20251001 · $0.026

TL;DR

Brett Davis discusses legacy pinball electronics integration challenges and XPin board design solutions.

Summary

Brett Davis, designer of XPin display and control board products, presents on the challenges of interfacing modern electronics with legacy pinball machine hardware spanning 1977–present. He discusses voltage incompatibilities, component obsolescence, signal integrity issues between old and new logic families, and design strategies (pull-down resistors, test buttons, isolation jumpers) to improve troubleshooting and reliability. Davis emphasizes testability and operator-friendly diagnostics as core design philosophy.

Key Claims

Gas plasma displays required ±90V (Williams), ~200V (Bally), 60V/42V (Gottlieb Futaba tubes); these components stopped manufacturing in the 1990s
high confidence · Direct technical specification from presenter; foundational to his argument about component obsolescence
Dot matrix displays from 1990s required -110V, +65V and are no longer manufactured; associated driver ICs (for glass plasma DMD) were discontinued when displays stopped production
high confidence · Technical specification integral to display evolution discussion
The 74154 IC is currently manufactured by only one company in DIP package format, making it a critical failure point in Williams 1980s games and Valley/Midway titles
high confidence · Specific component bottleneck identified; states some developers now source surface-mount versions and repackage to DIP
Pinball schematics frequently do not match actual wiring; Davis has found missing documented wires, undocumented reroutings, and prototype boards never mentioned in manuals
high confidence · Personal engineering experience; positions schematic unreliability as a core troubleshooting challenge
XPin display boards use pull-down resistors and low-power Schottky logic to bridge incompatible voltage signaling thresholds between old (CD 4050: 0–1.5V = low, >4V = high) and new logic (0.8V = low, 2.2V = high)
high confidence · Technical design rationale for XPin board compatibility approach
Davis has been designing electronics professionally for ~35 years, started Pinscore designs in 2008, and launched X-Pen brand in 2010–2011
high confidence · Personal background statement at talk opening
XPin boards feature test button isolation mode allowing displays to be tested without MPU involvement, and include test/play jumper selection for 100% isolation diagnostics
high confidence · Product feature description; Davis emphasizes this as response to common troubleshooting support calls
Davis has not entered his competition's products negatively but does conduct 'competitive intelligence' by purchasing and evaluating competitor designs

Notable Quotes

“Electronics with pinball, it's almost forensic engineering, trying to figure out what is going on in the game itself.”
Brett Davis@ 0:51 — Frames the core challenge of legacy hardware integration as detective work; sets tone for technical discussion
“Sometimes the schematics do not match what is going on in the game itself, or how they're hooked up. I have found missing wires that were never documented in the manuals.”
Brett Davis@ 1:26 — Establishes unreliability of factory documentation as foundational troubleshooting problem
“I don't want to add anything into the system that doesn't already exist. If I have a 5-volt supply... I wanted to make sure that my displays could operate in that 5-volt rail without causing a reset.”
Brett Davis@ 11:23 — States core design philosophy: minimize power draw to respect original electrical budgets
“The most standard calls I get is that they will say that they have replaced the display because they have some missing segments... I said, 'Push the test button. All the segments come on.'”
Brett Davis@ 12:10 — Demonstrates practical value of test button feature in isolating display vs. upstream failures
“I will never say I did something it was perfect. I've been doing this for long enough that let me tell you I constantly get surprises from people.”
Brett Davis@ 17:55 — Emphasizes humility and openness to discovering edge cases; positions continuous learning as driver
“I don't design a board unless I have a game for it to go into.”

Entities

Brett DavispersonXPincompanyPinscorecompanyPinball Expo 2023eventWilliamscompany Ballycompany Gottliebcompany AtaricompanyValleycompany

Signals

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business_signal: Sourcing of critical legacy components (74154 DIP, gas plasma display ICs, Futaba tubes) has collapsed to single-manufacturer or informal supply chains. Community developers responding with repackaging/workarounds, but long-term viability uncertain.
high · 'Only one manufacturer in the world currently making a DIP socket or DIP package for the 154'; high-voltage IC families discontinued in 1990s; necessity of buying 'new' pulls from salvage boards
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community_signal: Davis actively solicits customer feedback, monitors Pin Wiki troubleshooting threads, and incorporates real-world failure modes into product design. Positions booth presence and technical discussions as core community contribution.
high · 'I spend a lot of time getting guidance and information on pin wiki from people who have gone through troubleshoot'; encourages visitors to booth for technical discussions and beer
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community_signal: Davis frames technical support calls as opportunity for continuous innovation; welcomes edge cases and surprises as drivers of product improvement; positions troubleshooting guidance and booth presence as core contribution to hobby.
high · 'I constantly get surprises from people... this is what keeps me going back into the development'; 'testability and troubleshooting are features that I value'
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design_philosophy: Compatibility and non-invasive integration: XPin boards designed to operate within original 5V power budgets without causing resets; never adds features beyond what system already supports; emphasis on reverse-compatibility across multi-decade hardware span (1977–2023).
high · 'I don't want to add anything into the system that doesn't already exist'; careful power budget calculations to prevent voltage regulator resets on vintage games

Topics

Component obsolescence and sourcing challengesprimaryVoltage compatibility between legacy and modern electronicsprimaryDiagnostic and testability features in aftermarket boardsprimaryDisplay technology evolution (plasma → DMD → LED)primarySchematic inaccuracy and reverse-engineering pinball hardwaresecondaryLow-power design and power budget managementsecondaryCompetitive landscape and board design philosophysecondaryOperator/hobbyist support and troubleshooting guidancesecondary

Sentiment

positive(0.75)— Davis is passionate, self-confident, and optimistic about problem-solving. He praises the pinball community ('I love talking to you guys'), expresses excitement about returning to Pinball Expo after 5 years, and frames technical challenges as 'fascinating' and 'what drives me.' Tone is collaborative rather than defensive; he acknowledges competitors respectfully and positions his work as service to the community. Slight friction noted around frustrations with alligator clip testing and overfusing, but these are presented as motivations for better design, not complaints.

Transcript

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I'm Brett Davis. Is this one on? Okay, good. I can't hear myself, but that's okay. I'm the designer of all the XPin products that are on the market. I've been doing this since I started off doing Pinscore designs back in 2008, and then I broke off in 2010, 2011 to start focusing on X-Pen, my own brand name. A little bit about me, I've been doing electronics professionally for about the last 35 years and it's been an exciting ride as far as all the changes in technology that are out there. There's challenges. One of the things I often joked about early on is that, you know, electronics with pinball, it's almost forensic engineering, trying to figure out what is going on in the game itself. The circuit boards, the schematics. Okay, great, thanks. Schematics, because how many of you have ever looked at the schematics from these pinball machines? How many of you have found that they're actually what they represent? in the pinball machines. I can, it's a rough go, because sometimes the schematics do not match what is going on in the game itself, or how they're hooked up. I have found missing wires that were never documented in the manuals. I have found reroutings going on. I've found boards that no one even knew existed. They were in the prototype phases. So it was fascinating. It's one of those things that, for me as an engineer, and that is exactly it. I'm a professional engineer and been doing a variety of technologies for this time in my career. But I've always come back to the pinball electronics because it is fascinating. It's fun. It's what drives me to do this. Now, I can spend hours talking about how difficult it is to troubleshoot between old technology. And when I say old technology, I'm talking 1977 classic ballet games, some of their boards, and having it made up to technology from now in the 21st century. And that's one of the reasons I came up with the logo I did was evolution evolved because we are taking steps forward and making things happen that normally couldn't happen. and so i'm going to focus really on first one part of this one of the things that i get the most tech calls on support calls ask me what is it that's going on here why is it doing this and there is a fundamental reason in the designs from pre from 30 years ago to what there is now what we can do with it now and so i'll focus on that and then when i wrap up i'll also lead into some of the other things that I am doing to try to make sure that I'm mating up to the technologies because there's a lot of parts that are no longer manufactured mating up the technologies and what I'm doing to make sure that they the boards I'm producing you can utilize use the troubleshoot your games to help you fix them and maintain them to me that's what it is keeping the game alive making sure that it runs and runs for a long period of time So, I'm going to focus on displays because displays are what I have done, I started with 15 years ago and I still am working on and still evolving. And that, looking at the original displays, we're talking the technology was gas plasmas. We had the gas plasmas in the classic Bally's. We had the gas plasmas in the classic Williams. We had plasmas in Dot Matrix in the 90s. We had Futaba tubes in Gottlieb games. I mean, Atari was the only one really that went down the path of LEDs at that time. We started looking at those. But a couple of things about it, if you think about the world we live in today, your Williams games, they required plus and minus 90 volts to light up those scores, those segments. Valley Games, they were looking at 200 volts. Your Gauleeps, they needed 60 volts and 42 volts for their Futabas. Technologies that we no longer can get, the 6118s, the 7180s, they stopped manufacturing the high voltage versions of those back in the 90s. So if you see, if someone says, I got brand new ones, always raise the hand and say, wait a minute, Where'd you get them from? And they'll probably say, well, we took them off some boards. They're new to us. I ran into that. So you have to be looking at that. Now we look at dot matrix displays from the 90s. They needed minus 100 They needed minus 110 They needed plus 65 some outrageous voltages that we have to deal with And then not just that on the devices on those dot matrix displays because dot matrix is a big thing right now, because they stopped manufacturing the glass plasma dot matrix displays. For the ICs that they were used predominantly on the back of those boards to make them run, they stop manufacturing them when they stop manufacturing the dot matrix display. So why is this important? Because we're talking LED technology now, 5 volts. I got huge voltages here, got to deal with 5 volts. But voltage aside, there's a signaling aspect, communicating back and forth through the technologies to get the displays functioning correctly. Some people may think it's easier than it is, but you have to be careful of what you're dealing with. So I pulled this out. This is a typical Williams display circuit matchup. Easy enough. You can see this. On the left-hand side, this is what the MPU is putting out to the display, something very simple. You've got that beautiful 6821 that also is not manufactured anymore, but you can get them for 75 cents on Alibaba. and so you have that old technology feeding in we're going through some standard a little SIP resistor network going out to the display great that's what I have to deal with I look at what's there and then I look at the J1 which is J1 on the original displays and you have this list of inverters in the CD series of devices. There are so many product families out there as far as technologies goes. You have the CD, you have your TTL, you have your LS, you have your HC, HCTT, you have AC, you have numerous others, LS devices. But they're logic. It's digital. It's circuitry. But there's something interesting about going on with these things. Now, the 6821, when it drives the signal to the display, It's driven, driving it out, it's an OC display, so it's open collector. Now for those of you who are, you know, in the electronics industry, it's simply this. They're driving a transistor, when it's a zero, when you want a zero logic level out, it's going to be, it's going to be ground. Zero. When you want a one on the output, it's high impedance, very high resistance, and so you have to put a resistor there to pull it up to 5 volts if that's the case great straightforward kind of standard TTL not a big deal but then you look at the other side the other side is a CD device a 4050 device and this is on the original boards this is before you get to the 61 18s and the 71 80s you have a a 40-50 device where zero is no longer zero volts. Zero is now anything from 1.5 volts down to zero. That's a zero. And as far as the one goes, it has to be greater than four volts. Why is this important? Because in most standard digital logic devices, your low is 0.8 volts or less, not 1.5. 1.5 is in that metastable area. You don't know what you're going to get depending on the devices. And a high, depending on the device, has to be a minimum of 2.2 volts before it can be considered a high. So you get this gray area that's going on here. How can you guarantee to make sure that you're going to respond to it the way you need to? That's some of the challenges associated with dealing with electronics right now, especially with all the aftermarket stuff going on. I'm not the only one making displays. I don't talk bad about the other players. Competitive intelligence-wise, yeah, go out and buy their products and take a look to see what they're doing and seeing if I'm better or worse. They do their designs. They have their reasons for doing the choices they do. I have the reasons I do mine. nothing said there's more than one way to accomplish the same task but it's good to know how other people are thinking and looking evaluating things so what i did and can be to combat this uh come to for salute solving this and making it easier because i ended up with some great features i get some great features on this is that i created my I started looking at it and how I can make things better for everybody. Came up with this simple solution, and it works. I need a ground, but I can't count on ground coming from the CPU, NPU board, so I made sure I had a low zero value. So I pulled down resistors. That's basically from the signal going to ground. So when I needed a zero it was going to be a zero if the system was putting out 1 volts I still come down to zero for me The logic chip would see that Now I use standard LS devices low power Schottky Again it also about power It talks about power We one of the basic design guidelines I always had for the years I been doing this is that I don want to add anything into the system that doesn already exist If I have a 5-volt supply, Williams games, you had a 3-amp voltage regulator for 5-volt rail in those early games. I wanted to make sure that my displays could operate in that 5-volt rail without causing a reset. So I've designed it to make sure it's always operating lower power than what was required. and electrical engineers they have means to go ahead and calculate the power budget and figure out how much power they need for any given display so or product so that's how they keep things in in control so that's why i chose the low power shopkey devices and because of the design i ended up with a great little feature that allows me to turn on all the segments without having the NPU involved to test it. One of the most standard calls I get is that they will say that they have replaced the display because they have some missing segments. And then they put their display in, then they say it's outgassing or something's happened with the plasma tube. and I said, well, are you still missing the segments? Well, yeah, I'm still missing the segments. What's the deal? That's just tubes. What else is going on? I said, push the test button. I gave them a test button. Push the test button. All the segments come on, and what do they say? Well, heck, that means the display is working. So now the next step is start figuring out what isn't working. But at least you have confidence that the display is working. If a segment's needing to be on, it's going to be on the way it's supposed to be. So not going to happen there. And then on top of that, I have this, and this is just a cutout from my graphic, but you're starting to see these more on my boards where I have a test and a play jumper selection. Okay. What that does is that with that test, if you put the jumper in the test, you can hook up you can disconnect everything except your displays and the power push the test button and it'll come on that means that that will tell you that you are 100 isolated from the mpu system and you know that that display is functional and that's what that's what people are enjoying about this is that okay taking the step this is part of the technology interfacing bringing things out because when something has failed in your game what is it that's happening say i got to replace something i got to fix something well i don't know about you when i got my first pinball machine yeah i'm an electrical engineer but my first pinball machine heck it was missing it had wires all over the place and that it was it had been started to be parted out by the local coin knob for miscellaneous parts it's like oh my gosh what is this wire going to and why is it soldered like this not in the harness so me i was able to do that but from a lot of the new people to the hobby that are looking at getting these games to play and enjoy a little bit of nostalgia they don't have the background i do but they still would like to work on their games this is a great step to start that. If you have your display and you know your display is working but you're getting some garbage maybe, at least you can start looking for the garbage. And that's why it is, in this particular case, you can remove that ribbon cable from the, you know, connecting you to the NPU. You can remove everything and so you know the problem is further upstream. It's a great starting point. So as I said, also when I push the test button, yes, all segments are functional. I have matched and successfully interfaced between old technology and new technology. I've verified all my LED blocks are functional and good. And if there still display issues you go upstream you kind of fight figure out where it's at one point the 74 154 guess what that is a bugger of a device to figure out and now to replace because there is only one manufacturer sorry about that guys there's only one manufacturer in the world currently making a dip socket or a or a DIP package for the 154. So we have some other developers that have gone through and taken the surface mount put it on a DIP package so that you can still carry that out because that is such a common failure in these games That 154 is used in Williams all the 80s Williams games. It's used in some of the, it's used in the Bally Midway games. So it was well used. It's one of those components that, you know, it's like, okay. It is what it is. We understand it. So that's one of the challenges associated with interfacing technology. because technology is changing. It's constantly changing. When you think about what you've got to do, you've got to see how it is, and you basically go and talk to the people to find out. Me, personally, I love talking to you guys. I love getting the phone calls saying, hey, I've got a problem. Can you help me with this? And yes, they'll buy my board. Great. But now they call me back and say, hey, I put your board in. It looks great. It's working great, but I'm still missing a segment. Or, hey, how come I'm still popping this fuse? Or something else is happening. Why is this solenoid still locked on, but I'm not smoking it and everything else? So there's a variety of things that can be done. Now, on my side, I'm still doing a lot more stuff. as i said a little bit more about me just summarize because the rob only gave me a half hour that's okay i've been very busy downstairs but compatibility for me is always been a driving factor i will test it in as many games as i can i will never say i did something it was perfect I've been doing this for long enough that let me tell you I constantly get surprises from people that are saying this is going on in their game what can I do about it and when we talk about it it's like I've never heard of that I want to look into this this is exciting this is what keeps me going back into the development you can always count on me for one thing that testability and troubleshooting are features that I value I've been in your position I've been trying to troubleshoot a game I wish I could do that I have my driver boards that I'm coming out with right now I'm putting buttons on the solenoid drivers so that you can push the button and fire a solenoid without having to go in and search through a menu in very obscure diagnostic features it was one of those things that pin wiki and they say you can test your solenoids. Get a set of alligator clips, clip it to ground, touch the tab to the transistor with the other end, and you'll fire that solenoid. No, I'm not big on alligator clips. I'd rather just push the button. And you'll be seeing that in a lot of my designs now, coming through that way. Keep it simple. LEDs, great indicators. LEDs under fuses are wonderful. People love that because if the LED is lit, obviously you've got power. But if it's not lit, you immediately know you've got a fuse problem. Something happened. Some place to go, start looking and say, what is this about? And just a typical plug, do not overfuse games. It causes more nightmares than you can believe. I spend a lot of time getting guidance and information. on a pin wiki from people who have gone through a troubleshoot. And so I will add features based around their troubleshooting techniques and verification. So you're seeing that a lot in my products. And I can only say, stop by my booth. Talk to me. I've been adding boards. You know, Rob has been great, and he's lent me some games, and I'm putting boards in his games that have a lot of these features so I can demonstrate and show you how these features work to make your life better and easier in supporting your games. This is what pinball is about. It's about gameplay. It's about what you're passionate about. Me, I'm passionate more about the engineering. I don't have a big pinball collection. I only have seven pinball machines. Want more? Wife says no. But that doesn't stop me. I cycle games through all the time because I've solved it I don't design a board unless I have a game for it to go into and that's where it's at so granted my time is out is there any questions that I can answer for you right now or you can meet me downstairs in my booth I'm back by the concession stand and we're serving beer I'd probably say if you want to get into technical discussions have a few drinks before you start talking to me because we'll have a great conversation so that's it glad I'm here have fun at the show this is an awesome place I've been gone for five years I'm back and I'm going to be here again next year thank you