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Bally & Stern General Game ROM Chip & Jumper Info

Many of the Technical Articles on our site contain information and directions involving electronics and circuit board repair. They are authored with the assumption that the reader has adequate experience and knowledge required to do the work being described.

If you do not feel qualified, or are in any way uncomfortable doing any of the work described in any of the articles, then we strongly recommend enlisting the help of a qualified repair person or shop who can do the work for you. It may save you cost, time, and further repair work.

We (Action Pinball & Amusement, LLC) are not responsible for any damage to you, your game, or your property, from doing any work on your game related to any of the articles listed on this site.
  • Parts & Supplies: Free free to contact us if you have any questions about parts that we sell which are mentioned in any of our Technical Articles.

  • Technical Help & Questions: We do not provide remote assistance with diagnosing and repairing games. We are mainly a parts supplier and do not have the time or resources to provide such services. Here are some other options you can explore for help:


Bally and Stern games made between 1977 and 1989 used several different types of ROM chips on the MPU and sound boards in their games.

When replacing ROM chips in these games, new chips must be the same type as the old chips you are replacing, or your game won't work.

An alternative is to change the wire "jumpers" on the board so that it is configured for the type of new chips you are installing.

  • What are ROM chips?
    ROM chips hold the game's data (or "code"), which tells the game how to work, or what sounds to make. The MPU board uses "game" ROM chips, and sound board uses "sound" ROM chips, etc. Game ROM chips go in locations U1 through U6 on the MPU board (not all games use chips in all locations). Sound ROM chips will vary in placement and # of chips, depending on the game, and type of sound board it uses.

  • What are jumpers?
    Jumpers are small bare-wire connections that go between two separate "jumper points" on your board. Jumper points are typically labeled "E1", "E2", "E3", etc., and are printed in white ink on the board, next to each jumper point.

    Connections (jumpers) are made between various jumper points in order to basically "re-wire" the board, so that the processor chip can "see", or communicate with, the types of ROM chips that are installed on the board.

    Different types of ROM chips require different jumper settings so that the processor chip can communicate with them properly, and make your game work.

    Here is a picture of two jumper locations on a late-model pinball MPU board- W1 and W2. (Late model boards use "W" for their prefix instead of "E", and use what look like resistors instead of bare wire, for the jumpers):

    Or, more clearly:
    A jumper connection between either set of two points is considered "IN", or "set". A set of two points that doesn't have a connection between them, is considered "OUT", or "not set".

  • Do I need to make any changes?

    Some new ROM chips can be installed and run without any changes. Others may require jumper changes, or using a specific type of ROM chip, in order to work.

    Most sound boards do not require jumper changes in order to use replacement chips. We do not address sound board jumper changes in this article since they are rarely required, but you can e-mail us if you have any questions (please include name of your game and what ROMs you want/need to replace).
    1. What MPU Board Do You Have?
      To determine if you need anything special, you'll first have to determine what type of MPU board you have. Early Bally and Stern boards had their board ID number printed in the lower right corner of the MPU board, in white ink. Later boards may have the ID number elsewhere. Sometimes labels or stickers were put over the number, so you may need to remove a sticker or two to find the number:
      • Bally MPU Boards (1977-1985): "AS-2518-17", "AS-2518-35", or "AS-2518-133".
      • Bally/Midway MPU Boards (1985-1989): "A084-91786-AH06" (see game list below).
      • Stern MPU Boards: "MPU-100" or "MPU-200"

    2. What type are your old ROM Chips?
      Next, you'll have to determine what type of ROM chips you have on your board. Chips will have a number printed on them indicating the type/size of the chip. (If the chip you're looking at has a label stuck on it, you may have to remove the label to find the number underneath.)

      Look for any of the following numbers on your chips: 2516, 2532, 2716, 2732, 27128, 27256, 9316A, 9316B, or 9332.

    3. What type are your new ROM Chips?
      If you have your new ROM chips, you'll have to determine what type they are as well. If you purchased ROM chips for your vintage Bally or Stern game from us, the chip number should be printed on the label. Look for "2532", "2716", "2732", "27128", "27256", or "27512".

      If you haven't purchased from us yet, the type of chips we supply for your particular game should be listed on the web page where you are purchasing them (or "adding to your cart"). For example, Bally Eight Ball: click here for example.

      If you did not purchase your chips from us, or number is not on the label, you can peel back the label on the top of the chip to find the chip number. Again, look for any of the above chip numbers.
    If your old chips are the same as your new chips, then you're set- no changes are necessary. Just replace old with new ("plug and play").

    If your old chips are different than your new chips, you still may not need to make any changes. The following chips are compatible and don't require any changes:

    Old Chip:   New Chip:
    2516Uses same jumpers as:2716
    9316BUses same jumpers as:2716
    9332Uses same jumpers as:2532
    27128Uses same jumpers as:27256 and 27512
    27256Uses same jumpers as:27128 and 27512
    27512Uses same jumpers as:27128 and 27256

    If what you have is still different, then you will either need to make jumper changes to your board, or possibly acquire different ROM chips which are "plug-and-play" compatible with your old chips.

    Special Note: 9316A chips have no modern compatible counterparts. If your board has these chips, your board will have to be modified to use new replacement chips. There are no alternatives.

    See the next section on making changes to your board to accomodate your new ROM chips.

  • What changes do I make?

    If you've reached this point in the article, then you've got old ROM chips which are different than your new ROM chips (ie: not "plug-and-play" compatible) and will have to either acquire different new ROM chips which are compatible (e-mail us), or make some changes to your MPU board to accomodate your new chips.

    Important Note: If you're uncomfortable doing any of the circuit board work described below, we strongly recommend leaving it to someone who is experienced. If you don't have experience working electronic circuit boards, it can be too easy to make a mistake, or damage something beyond repair. It's better to send the board out to have the work done, rather than risk damaging it yourself. If you need assistance with your board, e-mail us- we may be able to help.

    To make changes to your MPU board, jumpers will have to be set according to the type of ROM chips you are installing, or your game won't work. This is where the process gets technical. To change jumper settings, you'll need a soldering iron, some solder, de-soldering wick (or "braid"), or a de-soldering tool, and possibly a small piece of wire to use for making new jumpers.

    Use care when desoldering and soldering on these fragile circuit boards- too much heat from a soldering iron can lift solder pads and traces, and can damage the board. Excess solder can short the jumper to other connections nearby. Again, if you're not experienced with this type of work, or are uncomfortable doing it, enlist the help of an expert.

    Early Bally/Stern MPU Boards (AS-2518-17 & MPU-100) - Configuration Details:

    Bally AS-2518-17 and Stern MPU-100 boards will not only need jumper configuration, but will also need to have some physical modifications done to the board in order for it to use modern replacement ROM chips.

    These early boards were designed strictly for what are now "obsolete" masked PROM chips only. So in order to use modern replacement ROM chips, they must be physically modified, or "altered", in order to work properly with new ROM chips.

    Bally games that used the early "-17" board were: Freedom, Evel Knievel, Night Rider, Eight Ball, Power Play, Mata Hari, Black Jack, and Strikes & Spares.

    Stern games that used the early "MPU-100" board were: Pinball, Stingray, Stars, Memory Lane, Lectronamo, Wild Fyre, Ted Nugent, Dracula, Trident, Hot Hand, Magic, and Cosmic Princess.

    Your game may not necessarily have it's original board still in it after 30+ years! So be sure to properly ID what board you really have (despite what game it's in) and what ROM chips it has on it, before proceeding.

    Click the link below for a listing of common jumper settings/configurations for Bally AS-2518-17 and Stern MPU-100 MPU boards.

    Early Bally & Stern MPU Configuration/Jumper Settings

    Late Bally/Stern MPU Boards (AS-2518-35, AS-2518-133, & MPU-200)- Configuration Details:

    Bally AS-2518-35, AS-2518-133, and Stern MPU-200 boards will require only jumper changes to configure them for the particular type of ROM chip you are installing. No additional board modifications are necessary.

    Click the link below for a listing of common jumper settings/configurations for Bally AS-2518-35, AS-2518-133, and Stern MPU-200 MPU boards.

    Late Bally MPU Configuration/Jumper Settings Late Stern MPU Configuration/Jumper Settings

    Late Bally/Midway '6803' MPU Boards (A084-91786-AH06)- Configuration Details:

    Bally/Midway A084-91786-AH06 boards utilized the 6803 processor chip and were used between 1985 and 1989 (see game list below). Boards in these games were more standardized for ROM chips and usually do not require any jumper changes to use new ROM chips. However, if new ROM chips are a different type than your old chips, e-mail us with the name of your game, type of chip(s) you have, and we may be able to provide matching plug-and-play replacement chips.

    The 6803 series of games includes these titles:

    Atlantis, Beat the Clock, Black Belt, Blackwater 100, City Slicker, Dungeons & Dragons, Eight Ball Champ, Escape From Lost World, Hardbody, Heavy Metal Meltdown, Hot Shotz, Karate Fight, Lady Luck, Motordome, Party Animal, Ramp Warrior, Special Force, Special Force Girls, Strange Science, Truck Stop

    The above information should be enough to familliarize you with what is required for installing new ROM chips on your particular MPU board, and possibly get you started on changing jumpers and doing board modifications on your own, if you so desire.

  • If you require more in-depth technical information, please see the other articles available on our Technical Articles page.
  • If you would like to find a qualified repair shop to configure your MPU board for you, see our Game Service & Repair page.
  • If you are searching for replacement ROM chips, see our ROM Chips page.

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