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Don't understand what I'm writing? Look at my mini glossary of pinball terms! If you are looking for technical explanations or item terms ("what's a bumper?"), go to the "Operator's Stuff" section. Have a pinball term you don't know and can't find? Let me know.

The Internet Pinball Database has been upgraded with a big and possibly the most complete and detailed pinball glossary every written on the web. If you want extensive information that is not covered in my mini glossary, go there.

backbox
The vertically-installed wooden box on top of the rear end of the cabinet. This box includes the electronics of a solid state pinball game, including the processor, the MPU, power driver board, sound and display board. On EM machines, the backbox was full of switches and reels, and boy, those things are loud. The backbox is covered with a so-called backglass that is a glass with a motive on it to show the game's theme. Until the mid 80s, backglasses were printed with paint, i.e. the paint was directly on the glass and if it shattered, it was lost. Later, plastic translites were used because they were easier to produce and could be saved or easier replaced in case of the glass shattering. The backglass is normally lit by a number of bulbs and flashers behind it.

backglass
See "backbox".

ball trough
The queue at the bottom of the playfield, under the metal cover, where the balls are stored when they drain out of play. The ball trough stores all balls that the game needs to run (two to an amazing eight balls on Sega's Apollo 13). The first ball in the queue is spit out into the shooter lane where you launch the ball from.

Diamond Plate™
Diamond Plate is an especially hard sort of lacquer coating developed by Williams that protects the playfield even better than mylar since the transparent film often started getting scratches or bubbles after years - not so with DP. My Terminator 2 machine almost looked like on the first day with the DP playfield, and it was 13 years old at the time! Diamond Plate was introduced as a trademark by Williams in the late 80s when they experimented with it on a few games of a series, producing a limited number of playfields with Diamond Plate on it while the majority of games still came with mylar. Of course, these rare DP playfield are sought after! Terminator 2 was the first game to feature Diamond Plate on the full production run. The Diamond Plate coat on late 90s playfields is said to be of lower quality than that from the late 80s till the mid 90s.

end-of-stroke (EOS) switch
This switch is used in almost every modern pinball machine, however depending on its age and manufacturer, the design is different. In Williams' 80s machines, the flipper assembly has two leaf switches, one that is closed and the other being open when the flipper is not active. Once activated, the assembly moves the flipper up and accordingly closes the open switch (which is for the switch matrix) and opens the other, the end-of-stroke switch (that's why it's called EOS). The EOS switch cuts the high-power side of the coil and reduces the electrical power so the coil goes into low-power mode to hold the flipper up without getting hot and burning. So, the EOS switch is an important electrical switch that controls how much power the flipper coil gets. In the late System 11B and 11C machines by Williams, the first switch (switch matrix) was removed as it was controlled by the electronics. In Williams' Fliptronics machines from 1992 and later, the EOS switch changed to be a normally open (instead of closed) switch so the electrical arcing was reduced to a minimum. Also, these switches were changed to be made of gold-plated contacts for even longer lifetime. The Fliptronics EOS switch is not really necessary as the Fliptronics board in the machine can control the power change for the flipper solenoids by itself, but the EOS switch remained installed for optimal flipper operation and most precise gameplay. The Fliptronics board's ability to operate without the EOS switch is a double security feature because the coils cannot burn even if the switch is broken!
Learn more about the flipper assembly system under "Operator's Stuff".

flasher
A big lamp under or on top of the playfield which flashes very brightly. Flasher lamps cannot burn constant light, they can only flash for the blink of an eye when they are energized.

Fliptronics™
A trademark of Williams, this electronical system was introduced in 1992 and controls the flipper movement to prevent flipper assembly wear and make them more precise. The most important factor about Fliptronics is that flipper solenoid operation changed from analogue to digital - no longer is there any voltage running through the flipper button switches because these were discarded and replaced by optical (digital) switches. They send information to the Fliptronics board in the backbox when the flipper buttons are pressed, telling the board that the flippers have to be activated. The Fliptronics board has complete control of the high and low (EOS) power signals which it sends to the flipper coils. As mentioned in the EOS switch explanation, the board can control the power changes without an EOS switch if it's broken or missing. The board does read the EOS switch though if it's working for better precision and the familiar Williams flipper feel. Because the EOS switch was changed from normally closed to normally open and uses gold plating to transmit a low voltage instead of high coil power (like it used to be on old EOS switches), there is close to no switch wear, enhancing the digital flipper control of the Fliptronics board. This way, Fliptronics flippers are always strong and as precise as they can be.

fuse
Solid state pinball machines use fuses to secure safe operation of all solenoids. If a coil or a motor gets hot, the fuse blows and in return lames all connected solenoids. As an example, if one bumper coil has problems and the fuse blows, all three bumpers will not function anymore until the fuse is replaced.
In America, slow-blow fuses were installed in pinball games because medium-blow fuses are too sensitive to hold long enough (never-theless I had to cope with medium-blow fuses in my Space Station because I didn't find anything else in the area). Fast-blow fuses are rare and only used for low-power devices or display electronics.

GI
General illumination; the lamps on the playfield of a pinball game which light the whole game so that you can see everything even when playing in the dark. However, GI is not only for visibility, it also adds atmosphere (best example: the green GI on Space Station and also the completely white, cold GI on The Machine which makes for a nice space effect).

(lamp) insert
The transparent plastic that is glued into a hole in the playfield where a lamp sits under. Inserts are the coloured arrows, rectangles, circles and triangles (among other shapes) you see flashing and lighting on the playfield, showing you where to shoot and what you score. The insert is not the lamp under the playfield that lights it; the term insert only refers to the plastic shape above the lamp. Inserts most usually have text on them to describe what the lamp is telling you.

IPDB
The Internet Pinball Database; a site located at www.ipdb.org. This database is a searchable record of almost every existing pinball game in the world with detailed information on every game, for example the number of produced machines, the design credits, notable features, specialties, links to related sites and of course pictures made of photos, scans of flyers and the like. Inevitable if you're looking for information on a pinball game you know nothing about. The IPDB link on top of every game page on my site leads directly to the game's page in the database. The link in the media section does the same.

jet
Williams' short form for "jet bumper", also called "pop bumper" by Gottlieb and many players/collectors, referring to the bumpers on the playfield. Why jet? I don't know. Why pop? ;-)

knocker
The knocker is actually a coil that shoots a plunger against a metal plate. Commonly this coil is installed in the backbox, but I found it inside the cabinet on Gottlieb's Arena (where you could barely hear it). The hit of metal or hard plastic on metal creates this unique "bang" that you hear when getting a special, a replay or a match (all three meaning that you get a credit = a free game). On many newer machines, if the machine is set to award extra balls instead of credits for a special and/or replay, the knocker will also activate if you get a normal extra ball in play. It's a kind of reverse thinking by the software which is in fact incorrect since the knocker is meant to knock with special, replay and match (and highscore credit awards) and not the credit or extra ball itself, but still it happens.
Knockers sound different in each game. My Machine's knocker is extremely loud and has people jump all the time, and the sound is very much like the typical sound you know from computer pinball simulations. My Terminator 2 had a rather wooden sound and F-14's knocker had exactly the right sound. The Getaway which I once played in the nearby cinema was SO loud that everyone in the game room got a shock from it! It sounded more like a popping balloon though. Random info: back when knockers didn't exist yet, a big bell did the job. You can find such a bell on early 80s games, e.g. Space Shuttle. It's fun to hear it go wild when you make first place and get three credits! XD

MAME
Multiple Arcade Machine Emulator; this is a well-known emulator for the PC that simulates the environment of arcade machines so you can play game ROMs on your PC. PinMAME is the incarnation of MAME for pinball games. In conjunction with the PC pinball simulator Visual Pinball, PinMAME - in a special edition called Visual PinMAME or VPinMAME - can simulate complete pinball machines that are playable on your PC screen. Of course, the playfield and artwork have to be constructed first in Visual Pinball.

match
This is a feature that was introduced in the 50s, but sees prominent use with the solid state machines. At game end, the last two digits of the players' scores are taken and displayed. These last two digits will always be a multiple of ten since there are no pinball games that award single points, only ten points and up in ten, hundred, thousand or million steps! So, the final two digits can be 00, 10, 20, 30 and so on to 90. The game selects a random two-digit ten multiple in an animation sequence to make it more suspenseful. Once the final random number is shown, it is compared to all two-digit numbers of the players. In case one of the players' two digits match with the random number, a match award - a credit - is given. Matches will always give credits or tickets as selectable by the operator. No extra balls can be given by the match feature since the game is already over. Since this explanation was a little shaky, here's an example: you made 5,200,350 points at the end of the game. Your last two digits are 50 (there can be no 51, 52 etc.!). The game selects its own random two-digit number made of a ten multiple, i.e. 00, 10, 20, 30 and so on. If the game randomly selects 50, it matches with your two digits and you get a credit (or ticket).
Many people don't know what the machine is doing when it displays all the scrolling numbers at the end of the game, and keep asking what that is. Explaining the match feature to everyone of my friends is quite tough as it's not easy to explain (you can see that here). Hopefully this explanation and example cleared it up.

microswitch
A small switch that "clicks" on or off depending on whether it's pressed or not. Usually a microswitch is pressed by a metal blade that is connected to a wire the ball can roll over, pushing it down as it contacts the wire. This mechanism is especially found in lanes - just look at the outlanes and inlanes of a pinball game and you will see the wires.

Mylar®
Actually Mylar® is a trademark of Dupont since they invented it and gave it the name. Mylar is a plastic film that is extremely stable, hard to scratch, hard to tear, and that can protect the underlying surface for years. This is why pinball manufacturers started using mylar on their games' playfields because the normal lacquer and paint wore down after continuous play in the arcades. While the earlier machines of the 80s came with mylar for optional installation by the operator, the 90s introduced factory-installed mylar to guarantee a long life of the playfield. However, in 1991 the first series-made playfields using Diamond Plate were introduced in such machines as Terminator 2 and this was about the end of the mylar days except for some specially applied mylar in heavy-wear areas such as bumpers. See "Diamond Plate" for details.

Pinball 2000
The last system that Williams/Bally made before closing their doors to the pinball market. Pinball 2000 is featured in only two games; Star Wars: Episode 1 and Revenge From Mars. This system replaces the dot matrix display with a full colour monitor which is installed upside-down above the upper part of the playfield. This requires a much larger backbox which has "depth" above the playfield for the monitor to sit in. The upper part of the playfield glass has a layer of half-transparent mirroring which mirrors the monitor screen onto the playfield, making it look like it was three-dimensional. Using targets behind the mirrored picture, the game can score "video targets" which are displayed on-screen and thereby on the playfield. You can have the ball interact with the screen and change the playfield this way. Many people consider Pinball 2000 to be not real pinball (including me) because it's too much of a video game with too little mechanical interaction.

plunger
A plunger in the pinball world is a long metal cylinder which moves in an assembly. The two common types of plungers are the ball shooter plunger, which is the thing you pull back with your hand and release to shoot the ball into play (on all machines until the early 90s and some in the mid-90s), and the coil plunger which is the metal cylinder the coil pulls into itself when its energized. Most coils in pinball machines work with plungers, but the most obvious plungers can be seen in the flipper assemblies: the coil pulls the plunger in which moves the flipper up through a link. This is how the flippers work (in a basic sense). Check the "Operator's Stuff" section for more details on plungers and coils.

(star) post
A post is a vertically installed pole made of metal or plastic. The cone-shaped plastic posts you see on most machines are called star posts because they usually have zig-zag edges around their cone shape. Star posts often have a rubber ring on them or they hold a larger rubber (e.g. of a slingshot) together with other posts.

replay
Replay actually means that you can play again (replay) the game. A replay award gives you a credit or an extra ball depending on how the machine is set up (originally it's a credit and older machines don't have the extra ball option). The replay "level" is reached when you get a certain number of points while you play. For example, let the replay level be at 5 million and when you get 5 million points while playing, you get the replay award (credit or extra ball). The replay level is displayed by the machine in attract mode from time to time, and before you launch the third ball ("replay at <value>" or "extra ball at <value>"). This way you know what you need to gain for a replay award. Every machine from the later 80s up has an auto replay value feature which measures the skill of the player(s) by recording the game scores and the number of replays reached. After 50 games or so, the machine sets a new replay level depending on those statistics, and this level will be an exact percentage less or more of the previous level. The percentage is adjustable by the operator, but it's usually 7% or 10%. So, if the percentage is at 10% and the replay level raises from 5 million, it will be 5.5 million. There can be multiple replay levels (the second being double the first etc.).

ROM
The software that is burned into an EPROM or PROM chip (or several chips) that sit(s) on the boards in the backbox. Actually ROM stands for "read-only memory", but the software is often called ROM in the arcade language. The ROM files on the (E)PROM chips have the data for video, audio and game rules, kind of like the files and executable in a computer game, only that pinball ROMs interact with the hard-ware at all times.
I was informed by my netfriend Maverick that EPROM stands for "eraseable programmable read-only memory" and PROM means the same, only those are not "eraseable", meaning you can only program them once.

special
A special is originally a credit you are awarded in play. You will hear the knocker go off and get a credit for free to play again. However, specials can also be set to award an extra ball on modern machines.

switch matrix
The network of switches that connect to the processor. In the software of the machine the switches are controlled in the shape of a matrix, with rows and columns which are layed out similarly to the switch layout under the playfield. If there is a problem in the switch matrix, it can affect several switches at once, namely all switches in one row or column of the matrix. Shortening the matrix means death to the machine until the required switches, chips or transistors are replaced.

System 3/4/6/7/9/11
Williams' solid state electronics systems used from 1977 to 1990 when WPC followed. You can find detailed information about these systems on Marvin3m's pinball page.

tilt
A "tilt" in the pinball sense is a protection against cheating. The tilt is triggered if the player slams or shakes the machine too hard and too often, ignoring the warnings that most machines display before tilting. When the tilt occurs, either the whole game is aborted (slam tilt) or the current ball is forced to drain by deactivating all solenoids, switches and flippers (shake tilt). You can learn how the tilt is mechanically triggered in the "Operator's Stuff" section.

translite
See "backbox".

Visual Pinball
Created by Randy Davis, this software is the most attractive pinball construction and simulation software to date for the PC. It lets you build complete working pinball tables on your PC and plays them back in 3D with lighting and shadowing. Visual Pinball is used in con-junction with Visual PinMAME (see above) to emulate and simulate real-world pinball machines. Visual Pinball has gained a huge fan and designer community; see the "Links" section for details. Visual Pinball's homepage is www.randydavis.com/vp/. You can find information on it in the "Visual Pinball" section.

WPC
Williams Pinball Controller; the electronics and processing system that came after System 11. The first WPC machine was Dr. Dude though it was mostly still System 11 based, followed by "real" WPC games like The Machine: Bride of Pin*Bot and Terminator 2. WPC was extended with WPC-95 later on. You can find detailed information about WPC on Marvin3m's pinball page.