The Dawn of the Solid-State Era

The Dawn of the Solid-State Era
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The Dawn of the Solid-State Era
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The Dawn of the Solid-State Era
Published on
September 20, 2018
Updated on
September 20, 2018
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A huge thanks to Dennis Kriesel of the Eclectic Gamers Podcast for this interesting article on The Dawn of the Solid-State Era! Check out the Eclectic Gamers Podcast here, and their Facebook page here!


The 1970s witnessed a major transition in pinball manufacturing, as the rise of solid-state (SS) technology took hold and forced the arguably biggest transition the hobby ever saw. Electromechanical (EM) games fell by the wayside as SS games hit the marketplace, offering greater capabilities for the playing experience (particularly around multiplayer games and maintaining “game state” from player to player). Boards and chips replaced what took sizable banks of relays and switches, with an end result that more bang for the buck could now fit inside the dimensions of a pinball cabinet.

The Big Three (Bally, Williams, and Gottlieb) each entered this new era of technology with their own approach. How they tackled the changing landscape not only influenced their sales at the time, but also laid the groundwork for what happened to each of them as the technology evolved.

This article will focus on the very first production board sets (commonly referred to by the MPU or system designation) of the major U.S. manufacturers. A simple summary of the features and capabilities will be listed, and each overall setup explored. This is not a repair guide (there are plenty of those online), but rather an attempt to explain just what these systems could do in a way that matters to players of the games.

First Production-Used Solid-State Systems (Big Three)Bally AS-2518-17Williams System 3Gottlieb System 1Date of first production gameDec-76Sep-77Dec-77Date of last production gameJun-78Aug-78Dec-80MicroprocessorMotorola 6800Based on Motorola 6800Rockwell PPS4/1Switches (max)406440Controlled lamps (max)606436Solenoids via driver (max)15 momentary4 continuous16 solenoid lines6 special solenoid lines8Displays6-digit (gas plasma)6-digit (gas plasma)6-digit (vacuum fluorescent)SoundChimesChimesType 1 SoundChimesChime BoardSound Board

Each manufacturer will be covered in the order they got their SS board set to market.


Bally was seizing the lead in the pinball market early in the 1970s, and worked quickly to develop a SS system, allowing them to be the first major player on the market with one. Freedom was the first game out to feature their AS-2518-17 board set. The AS-2518-17 relied on the follows boards to complete the system:

  • An MPU board
  • A rectifier board
  • A lamp driver board
  • A solenoid driver/power regulator board
  • The displays

The MPU board is powered by a Motorola 6800 series chip, which is an eight-bit microprocessor. Bally decided to drive all their lamps and solenoids directly, rather than using a matrix. With the AS-2518-17, Bally could control up to 60 lamps and 19 solenoids (15 that were momentary in use and four that were continuous).

Bally did use a 5×8 matrix for their switches, thereby allowing their system to use up to 40 switches in the playfield. As for score displays, Bally took advantage of gas plasma, a high-voltage solution. All scores were limited to six digits with the AS-2518-17 board set. Bally also stuck with a chime unit for sound effects for the entirety of the board’s use.

Bally produced eight games using the AS-2518-17 board set. They transitioned to the AS-2518-35 with the release of Lost World in August 1978.

Bally AS-2518-17 Games

Game (Date, Produced Units Sold)

It should be noted that Stern Electronics used functionally identical SS boards to Bally. While Stern refers to their first board as the M-100, and the layout of the components on their boards did have some differences, there is no practical difference in the systems. The reason for this is interesting. Gary and Sam Stern purchased the failed manufacturer Chicago Coin to help start up Stern Electronics, but they also acquired Universal Research Laboratories (URL). URL produced printed circuit boards, and once acquired was tasked with reverse engineering the Bally board set (an easy feat given URL originally produced circuit boards for Bally) to create the Stern board set so that Stern could enter the SS era. Bally did sue for this, and ultimately Stern had to pay Bally a royalty on each system sold.


Williams was next to enter the SS market with the reveal of their System 3 board set in September 1977. Williams internal development was prototyping solutions for quite a while beforehand (hence why the production of SS games starts with System 3; System 1 and System 2 were used internally before they felt their SS solution was production ready). System 3 relied on the following boards to complete the system:

  • An MPU board
  • A driver board
  • A power supply board
  • A display driver board
  • The displays
  • A sound board (on some)

The MPU board used a microprocessor based on the Motorola 6800 series (the chip type used by Bally), and is thus an eight-bit microprocessor. System 3 relied on DIP switches to control game settings. The driver board handled the lamps (via an 8×8 matrix, so 64 controllable lamps total), the switches (also an 8×8 matrix, so 64 total possible switches), and the solenoids and sound selection.

Williams’ solenoid approach with the System 3 driver board could control 21 solenoids. Sixteen of these are traditional (though with System 3 five of those were dedicated to handling sound/speech), and six are special (special solenoid lines permitted the solenoid to be fired from the MPU or a switch on the playfield; the MPU in System 3 was not fast enough to process the ball hitting things like pop bumpers, so this method allowed a switch hit to fire such a device but also permitted the MPU to control the features in testing).

The first two Williams System 3 games used chimes for sound (and even included a device Williams called the noisemaker to emulate the sound of EM score reels). After that Williams moved over to their Type 1 Sound board (which could do modern sound effects or digital versions of chimes, depending on what the operator wanted). As for displays, the Williams approach was similar to Bally, using six-digit score displays driven by high voltage, gas plasma technology.

Williams produced five games with their System 3 board set. They transitioned to System 4 with the release of Pokerino in October 1978.

Williams System 3 Games

Game (Date, Produced Units Sold)


Gottlieb was the last major U.S. pinball manufacturer to transition over to SS technology. They farmed out responsibility for their system to Rockwell International (versus developing their own system internally), and the end result was something dramatically different than what is seen with Bally and Williams. System 1 relied on the following board sets to complete the system:

  • A CPU board
  • A power supply board
  • A driver board
  • A sound board (on some)

The MPU (or CPU) board uses the Rockwell PPS4/1, which is a four-bit processor. Similar to Bally, Gottlieb went with a 5×8 switch matrix (meaning a maximum of 40 switches), but Gottlieb’s System 1 is limited to controlling 36 lamps maximum, significantly fewer than Bally or Williams saw their first SS board sets handle.

Another significant limitation, comparatively speaking, is regarding solenoid drivers. Gottlieb System 1 is limited to just eight. However, five of those were used on all System 1 games (one for a knocker, one for the outhole, and three for chimes/sounds), meaning only three solenoids were left for other functions (like resetting a drop-target bank). Note that devices like flippers and pop bumpers bypassed the driver board entirely and operated as they had in the EM era. It was possible for Gottlieb to use a lamp transistor to “pre-drive” an additional transistor under the playfield, so some System 1 games artificially gained one additional solenoid driver via that approach.

System 1 used traditional chimes for the first three games, and then a three-tone digital chime board for the next six titles. A sound board was ultimately employed as of Totem in August 1979. As for displays, Gottlieb ran with six-digit scoring like the other companies, but instead of using gas plasma they turned to vacuum fluorescent (a low voltage solution that is safer for operators and also allowed the displays to last longer than gas plasma can).

Gottlieb released 16 games on System 1. They transitioned to System 80 with the release of The Amazing Spider-Man in May 1980. Gottlieb did produce Asteroid Annie and the Aliens well after the switch to System 80, for the explicit purpose of using their remaining supplies of System 1.

Gottlieb System 1 Games

Game (Date, Produced Units Sold)


Looking at how each major manufacturer began their foray into the SS era, one can see the groundwork being laid for how things worked out. Bally beating all their competitors to market with their SS games was rewarded with continued sales dominance. Williams, a smaller player than the other two, showed the most advanced capabilities of any via their System 3 (with more controllable lamps, solenoid drivers, and switches… not to mention the quick adoption of a sound card) and likely partially explains why they started to shift into a dominate position as the SS era advanced. Gottlieb, last to enter the SS arena, did so with a terribly antiquated setup compared to its peers (a four-bit processor, extremely limited solenoid drivers, not to mention fewer controllable lamps), and chose to stick with the same system far longer than Bally or Williams did.

While one cannot pin the rise and fall of all these companies solely on how their first production board sets played out, one can note it was a very important transition, each company handled it in a different way, and those that seemed to handle it better often fared better for it (at least for a little while).

The author extends special thanks to Bruce Nightingale (of The Slam Tilt Podcast and The Silverball Saloon) for proofing this article for accuracy and his additional insights regarding the first board set by Stern Electronics.