Revision as of 16:09, 26 January 2013


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1 Introduction

Williams System 8 Board Set

The Williams System 8 boardset was used in 1984 with only two games, the pitch and bat Pennant Fever and Still Crazy, a novelty game. Combining the driver board, sound board, and cpu directly onto one board eliminated several design deficiencies of the earlier System 3-7 boardsets; mainly the 40 pin interconnector, and extra wiring harness interboard connectors.

System 8 is very similar to its successor (System 9), but it is more of a "slimmed down" version. There are a total of 8 controlled solenoids versus the 16 used with the system 9 boardset. Another distinct difference is system 8 hardware does not utilize special solenoids. System 8 also lacks the connector for a speech daughterboard.

Although system 8 is capable of driving four 7-digit displays and one 4 digit display, only two 7-digit displays are used with Pennant Fever and one 7-digit display is used with Still Crazy. Therefore, master display boards are not used on either game. Both the lamp and switch matrices are 8 x 8 in size, but neither Pennant Fever nor Still Crazy use many switches in their matrices.

2 Games

Title	Date of Release	Model #	Other Boards	Notes
Pennant Fever	05-1984	526	CPU rev A	Pitch and Bat
Still Crazy	06-1984	534	CPU rev X1	Novelty Vertical Pinball

3 Technical Info

3.1 CPU Driver Board

System 8 CPU rev A (Pennant Fever)

System 8 CPU rev X1 (Still Crazy)

3.2 Power Supply

System 8 Power Supply

4 Problems and Solutions

4.1 Power Problems

4.2 MPU boot issues

4.2.1 Relocating the battery from the MPU board

4.2.2 Repairing Alkaline Corrosion

Remove the battery holder entirely from the MPU board and wash the board's affected areas with a 50/50 mix of vinegar and water. Scrub the corrosion with a soft toothbrush, rinse with water, then rinse with 91% or 99% isopropyl alcohol to displace the water.

4.2.3 Connecting a logic probe to the MPU

4.2.4 Using a PC Power Supply For Bench Testing

4.3 Game resets

4.4 Solenoid problems

this is a stub

4.5 Lamp problems

4.5.1 Lamp Matrix Row and Column Testing

4.6 Switch problems

4.6.1 Switch Matrix Row and Column Testing

4.7 Display problems

WARNING: This circuit uses high voltages. Don't continue, unless you are confident in your diagnostic abilities.

4.8 Sound problems

5 Repair Logs

Did you do a repair? Log it here as a possible solution for others.

@@ Line 47: / Line 47: @@
 === Connecting a logic probe to the MPU ===
-[[File:System8PowerOnTheBenchAnnotated.jpg|200px|thumb|left|Connect the +5V lead of your logic probe to the top of C6.]]<br>
-The System 8 MPU lacks test points. Argh!
-To connect a logic probe, pick up +5V at the top lead of capacitor C6 (a trace extends down from the larger electrolytic cap at C5). Pick up ground at pin 9 of 1J5.
-<br clear=all>
 === Using a PC Power Supply For Bench Testing ===
@@ Line 79: / Line 72: @@
 ==Sound problems==
-The System 8 MPU incorporates crude sound circuitry capable of making "FirePower" era sounds, tailored of course, for baseball as found in Pennant fever.
-Sound is produced on a section of the board containing a 6808/2 processor, 6821 PIA, 1408 DAC, and finally a TDA2002 amplifier. The sound ROM is located at U49.
-Pressing switch 3 at any time should cause the sound section to play various sounds over and over until power to the game is turned off.
-An 8 ohm speaker is connected at 1J15. Sound volume pot is connected at 1J16.
 =Repair Logs=
 Did you do a repair? Log it here as a possible solution for others.

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