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4418 Pack Saddle Pass
Austin, TX 78745
512-447-8888 Voice
512-447-8895 Fax
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JUMPER COMBINATIONS for BALLY MPUs


If the battery has leaked on your Main Processor Board you can buy a brand new DASH 35 MPU board here!

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From 1977 until 1984, Bally used only two circuit boards as the main processor unit (or MPU board) in every model of their pinballs. From 1977 through 1979, this board is designated the 2518-17 MPU or 'early' board. The following games were shipped from the factory with early MPU boards:

These games can be made to run on any Bally MPU board, early or late.


Beginning in 1979, Bally expanded the capability of their MPU board and introduced the 2518-35 or 'late' MPU board. Games produced after this date CAN NOT BE MADE TO RUN on the early MPU board! The late board was capable of running all of the early games (listed above) as well as:

This list is in chronological order


Both the early and the late MPU boards use JUMPER wires which can be moved to change the way that the processor chip addresses the information contained in the ROM chips. These READ-ONLY-MEMORY chips contain the maps of the playfield and the switch matrix, the layout of the solenoid coils, as well as the 'rules of the game'. When these games were first produced, it was cost effective to have the ROMs produced in large numbers with the program imprinted permanently on the chip. These devices, called MASKED ROMS, can not be erased or re-programmed. They require a particular JUMPER combination to run. If any one of the jumpers is missing or misplaced, the board simply will not work. To confuse matters, it is now possible to purchase replacement ROMs on EPROM, or ERASABLE-PROGRAMMABLE-READ-ONLY-MEMORY. The only difference between the MASKED ROM and the EPROM is the ADDRESSING neccessary for the computer to read the chip. Therefore, it becomes neccessary to change the JUMPERS when changing chips, whether you are putting a different game on a particular board, or simply replacing failed original chips. The following JUMPER CHART explains how to get any particular device to run in any given MPU board. NOTE: Connection points on the circuit board all have the prefix "E".


BALLY 2518-17 EARLY MPU WITH:

*9316A in U2 & 9316A in U6 USE JUMPERS 1-2, 3-4, 6-7

*2716 in U2 9316A in U6 USE JUMPERS 1-2, 3-4, 6-7
BECAUSE THE EARLY BOARD DID NOT HAVE JUMPERS FOR 2716 EPROMS, YOU MUST PERFORM THE FOLLOWING MODIFICATION TO THE BOARD:
Component side of board: Cut the trace from {U2 pin 18} to {U3 pin 18} where it passes between sockets U2 & U3. Solder side of board: Run a jumper from {U2 pin 18} to {U17 pin 11}. Cut the trace going to {U2 Pin 21}. Jump from Pin 21 to Pin 24 (+5 Volts) on U2.

*2716 in U2 2716 in U6 = 1-2, 3-4, 6-7
PERFORM THE FOLLOWING MODIFICATION:
Component side of board: Cut pin 4 away from U18;
Solder side of board: Short pin 4 to pin 5 on U18 with a solder blob; Cut the trace at Pin 21 on both U2 & U6. Run a jumper from Pin 21 to Pin 24 on both.


BALLY 2518-35 MPU WITH:


Note: When connecting jumper 13A to 14 or 19, be certain to cut 13-15.


If you own any good working 2518-35 (Dash 35) MPU board, we can send you the ROMs to make it work in any of the games listed above. All GAME ROMs sell for the same price:


Unfortunately, many of these original boards have battery leakage corrosion damage. We work on these board every day, and we give free repair estimates if you'd like to send your board to us. CLICK HERE to read more about it.


Pinball ROMs

Part number Description price comments location Open a picture
in a new window
BUY it NOW!
ROMProgrammed GAME ROM from our archives
$25. for any one chip
These are the 'personality chips' which contain the GAME PROGRAM
YOU NAME THE GAME!

Available for MPU boards, sound boards, displays, ANYWHERE a programmable device was used in your game:

WE KEPT A COPY FOR YOU IN OUR ARCHIVES!

ROMs
RM2Programmed GAME ROMs from our archives
$45. for two from the same game
set of 2
YOU NAME THE GAME!
ROMs
RM3Programmed GAME ROMs from our archives
$60. for three from the same game
set of 3
YOU NAME THE GAME!
ROMs
RM4Programmed GAME ROMs from our archives
$70. for four from the same game
set of 4
YOU NAME THE GAME!
ROMs
RM5Programmed GAME ROMs from our archives
$80. for five from the same game
set of 5
YOU NAME THE GAME!
ROMs

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Two-Bit Score Amusements
4418 Pack Saddle Pass
Austin, TX 78745
512-447-8888 Voice
512-447-8895 Fax

e-mail to: Sales@Twobits.com

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