Bally 6803
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1 Introduction
The Bally 6803 game system, and the games themselves, were developed with extreme cost consciousness in mind. Bally used particle board cabinets with minimal artwork, backglasses illuminated by a single 115VAC light bulb, cheaper materials and short cut techniques during these years of game development. Still, many of these games continue to be enjoyed by hobbyists now and will be for years to come.
2 Games
| Game Title | Game Number | Sound | Displays | Keypad Used | Notes |
|---|---|---|---|---|---|
| Eight Ball Champ | 0B38 | Squawk & Talk | 4 7-Digit / 1 6-Digit | Yes | |
| Beat the Clock | 0C70 | Squawk & Talk | 4 7-Digit / 1 6-Digit | Assumed Yes | |
| Lady Luck | 0E34 | Cheap Squeak | 4 7-Digit / 1 6-Digit | Assumed Yes | |
| Motordome | 0E14 | T. C. S. | 2 "Special" 14-Alphnumeric | Yes | |
| Black Belt | 0E52 | T. C. S. | 2 "Special" 14-Alphnumeric | Assumed Yes | |
| Special Force | 0E47 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | Yes | |
| Strange Science | 0E35 | T. C. S. | 2 "Special" 14-Alphnumeric | Yes | |
| City Slicker | 0E79 | T. C. S. | 2 "Special" 14-Alphnumeric | Yes | |
| Hardbody | 0E94 | T. C. S. | 2 "Special" 14-Alphnumeric | Yes | |
| Party Animal | 0H01 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | Assumed Yes | |
| Heavy Metal Meltdown | 0H03 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | Yes | |
| Dungeons & Dragons | 0H06 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | Yes | |
| Escape from the Lost World | 0H05 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | No | |
| Blackwater 100 | 0H07 | Sounds Deluxe | 2 "Special" 14-Alphnumeric | Assumed No | |
| Truck Stop | 2001 | D-11581-2001 | 2 "Special" 14-Alphnumeric | No | Uses a sound interface board to process signals for sound board |
| Atlantis | 2006 | D-11581-2006 | 2 "Special" 14-Alphnumeric | No | Uses a sound interface board to process signals for sound board |
Game model numbers provided by the Internet Pinball Database - http://www.ipdb.org
3 Technical Info
3.1 MPU Board
The Bally 6803 MPU incorporates all of the function of it's predecessors, the -17 and -35 MPUs, along with lamp driver and solenoid driver circuitry. The MPU is responsible for driving all game features other than sound, which is handled by one of several sound boards used in the 6803 game system run.
Architecturally, the board is similar to it's predecessors but employs the 6803 microprocessor along with two 6821 Peripheral Interface Adapters. It also contains what is essentially the entire lamp board circuitry along the left side of the board, including the familiar 4514 demultiplexers, 2N5064 SCRs and MCR-106 SCRs (silicon controlled rectifiers). Along the top of the MPU board, the solenoid driver circuitry of the older Bally Regulator/Solenoid Driver Board has been incorporated, including the typical 74LS154 4-to-16 decoder, CA3081 transistor arrays, and TIP-102 transistors. A "cube" relay is used to complete the power circuit for the flippers and is energized only when a game is in play.
3.1.1 CPU Board ROM Info and Jumper Settings
| Game | U2 | U3 | Jumpers |
|---|---|---|---|
| Eight Ball Champ | Not Used | 0B38-00803-0005 | 2, 4, 6, 8, 10 |
| Beat the Clock* | Not Used | 0C70-00803-0005 | 2, 4, 6, 9, 10 |
| Lady Luck | Not Used | 0E34-00803-0005 | 2, 4, 6, 8, 10 |
| Motor Dome | E14A-42AAE-BX40 | E14A-42AAE-CX4D | 2, 4, 6, 8, 10 |
| Black Belt | 0E52-00803-0001 | 0E52-00803-0002 | 2, 4, 6, 8, 10 |
| Special Force | 0E47-00803-0004 | 0E47-00803-0005 | 2, 4, 6, 9, 10 |
| Strange Science | 0E35-00803-0001 | 0E35-00803-0002 | 2, 4, 6, 9, 10 |
| City Slicker | 0E79-00803-0002 | 0E79-00803-0003 | 2, 4, 6, 9, 10 |
| Hard Body | E94A-12601-0000 | E94A-12602-0000 | 2, 4, 6, 9, 10 |
| Party Animal | H01A-12601-0000 | H01A-12602-0000 | 2, 4, 6, 9, 10 |
| Heavy Metal Meltdown | H03A-12601-0000 | H03A-12602-0000 | 2, 4, 6, 9, 10 |
| Dungeons & Dragons | H06A-12601-0000 | H06A-12602-0000 | 2, 4, 6, 9, 10 |
| Escape from the Lost World | H05A-12601-0000 | H05A-12602-0000 | 2, 4, 6, 8, 10 |
| Blackwater 100 | H07A-12601-0000 | H07A-12602-0000 | 2, 4, 6, 9, 10 |
| Truck Stop | H08A-12601-0000 | H08A-12602-0000 | 2, 4, 6, 9, 10 |
| Atlantis | 2006-12601-0000 | 2006-12602-0000 | 2, 4, 6, 9, 10 |
*Beat the Clock manual may state W8 in, W9 out. However, there was a service bulletin after the game was released stating the opposite.
3.2 Power Supply Board
The Bally 6803 game system power supply board provides all of the voltages necessary to operate the game. Solder joints, as shown on the right are subject to fracture on the power supply board, especially since it's a single sided board. Reflowing these solder joints will solve many power problems.
3.3 Sound Boards
3.3.1 Squawk & Talk
3.3.1.1 Cheap Squeak Sound Board
The Cheap Squeak was designed as a lesser expensive sound board. It only utilizes a 6803 microprocessor, which allows it to function without 6821 PIAs and external RAM memory. This sound board is only capable of simple tones and sounds, but not speech. Although the Cheap Squeak is used in a handful of -35 based Bally games, Lady Luck is the only 6803 based game which uses it.
At power up, the Cheap Squeak's LED will flicker briefly, then flash, flash again, then turn on and stay on. Once the LED stays on, it seems to turn itself off for certain sounds, and then turn back on. Likewise, it appears to idle with the LED on, when no sounds are playing. The LED May turn on and off when sounds are playing or idle, but this is not always the case.
With Lady Luck, upon pressing the self test button (SW1), the sound board will play an explosion type noise. The board will then reboot itself.
Board Theory of Operations
The 6803 (U1) microprocessor multiplexes A0-A7 with D0-D7, calling those signals AD0-AD7. The processor fetches information from the sound ROMs (both code to execute and sound clips) by placing address information on AD0-AD7 and strobing the processor's AS (address strobe) signal to the 74LS373 (U2), thereby latching the lower 8 bits of the address bus in the LS373. A8-A15 are used along with jumpers JW1 through JW12, to implement a memory mapped I/O scheme to address the 2 sound ROMs which can be 2532s, 2732s, or 2764s. A14 and A15 control the 74LS10 (a triple 3-input nand gate) to assert device selects to the ROMs.
Note that the processor does not use the traditional R/W signal as it never "writes" to memory. Besides placing instruction address and data on the address and data busses, the processor reads sound selects via P20-P24 and writes sound data to the DAC via P10-P17. Think of these lines as PA1-PA7 of a 6821 or 6532.
The 6803 is initialized by the MPU at power up into 6803 mode N. Once initialized and running, the sound ROM code running in the 6803 accepts sound signal commands and merely reads pre-formatted sound "clips" from the sound ROMs and then writes the data to the ZN429 (U6) digital-to-analog converter (DAC) 8 bits at a time. The DAC converts the digital data to an analog level which is presented to the amplifiers for output to the speaker(s).
The board creates 5VDC on board by regulating 12VDC down to 5VDC. Unregulated 12VDC enters the board at J1-10. It is filtered by C8, C9, and C10. The inductor at L1 smooths the voltage somewhat. D6 (VR332, equivalent to a 1N5402), D7, and D8 drop the voltage by .5 - .7 volts (normal voltage drop across a diode). The 7805 at U9 further regulates the voltage down to 5VDC which can be measured at TP2 (TP3 is ground).
This 5VDC is used as a reference voltage by the amplifiers as well as to power the TTL logic ICs. The ZN429 DAC also uses this 5VDC as a voltage reference. To prevent the sound volume from fluctuating over the range of operating temperatures, the reference voltage is held constant by a "voltage divider biasing circuit" comprised of resistors at R22, R23, and R24, and a 2N5305 NPN transistor at Q7. This reference voltage is presented at pin 5 of the DAC.
Test Points
- TP1 should measure about 11VDC.
- TP2 is 5VDC.
- TP3 is ground.
- TP4 is the clock signal, provided externally by the 6803 for the purpose of synchronizing address and data read cycles.
- TP5 is the reset signal, which is also present on pin 6 of the 6803.
Jumpers JW2, JW4, JW7, JW10, and JW11 should be installed when U3 EPROM is installed for Lady Luck.
3.3.2 Turbo Cheap Squeak (T.C.S.)
The Turbo Cheap Squeak sound board was used on games like Strange Science and Motordome. The sounds it can produce are pretty basic.
The board features a 68B09EP processor, a 6821 PIA, 16K of static ram, and 256K of ROM. It interfaces to the MPU similarly to the Bally Squawk and Talk board. Volume is controlled by the pot at VR1.
Note that the board is marked "T.C.S. FOR PINBALL". Some Bally / Midway video games also use a Turbo Cheap Squeak sound board. The T.C.S. sound boards used for video games and pinball are not 1-to-1 compatible between one another.
The following games use the Cheap Squeak:
- Motordome
- Black Belt / Karate Kick
- Strange Science
- City Slicker
- Hardbody
Normal boot up diagnostics via the LED for the T.C.S is as follows:
- 1st Flash - Determines if the external ROM (U7) is good.
- 2nd Flash - Checks if the external RAM (U6) is good.
- 3rd Flash - Checks the 6821 PIA (U8).
3.3.3 Sounds Deluxe
3.4 Accessing Bookkeeping, Settings, and Diagnostics
3.4.1 6803 Keypad
As easy as "A, B, C"...
Bally attemped to improve the operator's interface to the game system with this poorly constructed keypad. The keypad can be used to set free play, what kind of sounds are desired, balls per game, etc. See your game manual for game specific information.
4 Problems and Fixes
4.1 Power Problems
This is a stub
4.2 MPU Issues
4.2.1 Relocating the Factory NiCad Battery off the MPU
Like other Bally and Stern MPUs that employ a battery on the MPU to provide power to the volatile RAM, it's a good idea to remotely locate the battery. The 6803 MPU provides an excellent place to locate a blocking diode so that the MPU charging circuit is blocked from attempting to charge the alkaline batteries. In the picture at left, two holes were drilled in the fat trace leading from the positive battery connection to the northwest. That trace was severed under the diode where the black line is shown, and the diode soldered across the severed trace with the banded end pointing away from the positive connection on the board. Be sure to provide enough wire to allow the remote holder to reach the bottom of the head making it impossible for leaky batteries to drip on the circuit boards.
4.2.2 Leon's 6803 CPU Repair
Leon's 6803 repair procedure has been added to the PinWiki, and can be found here: http://www.pinwiki.com/wiki/index.php?title=Leon_Borre_Bally_6803_repair
4.2.3 Replacing header pins
Bally 6803 header pins are different from every other game system header pins. Bally used pins without a "carrier". Over time, the plating on these pins fails, creating conductivity issues. These header pins can be replaced fairly easily. Simply heat each pin individually and remove them. It's best to heat the pin itself vice the pin/board junction as quite a bit of heat is required to remove the pins, which are "jammed" into the board. Installing a new strip of .100 pins may require a bit of tapping with a hammer as the new pins are larger in diameter.
The same procedure may be used for .156 header pins on the MPU, as shown at left.
4.3 Solenoid Problems
4.4 Lamp Problems
4.5 Switch Problems
4.6 Display Problems
4.7 Sound Problems
4.7.1 Sounds Deluxe Board
This sound board has a common problem with DAC failure. AD7533 chip is easy and inexpensive to replace. You can prevent failure by removing C12 (47 uf) capacitor. It seems to have no adverse affect but prevents a voltage condition on power down that can destroy the DAC.
The LED with flash a check sequence on power up. 6 Flashes ROMS and RAM are OK.
4.8 Flipper Problems
4.9 Coins Register But Don't Credit Up
This is commonly seen on VPinMAME emulation, but applies to real life as well.
Coins drop OK, switch is good, game makes noise, but it remains on "Credits 0" and doesn't credit up.
Symptom is corrupted/blank NVRAM.
To fix, open coin door (make sure coin door switch is working, otherwise the keypad won't work), then do these steps:
Hit "Test", to enter operator mode.
Hit "A" until "Feature Options" is displayed.
Hit Enter.
It will say "Reset Factory Is".
Hit 6, then 5, then Enter.
Hit "Game" to return to attract mode. You'll know it worked because it will take longer than usual to reach attract mode, and the display will flicker slightly as the computer clears the memory (this is normal).
Intuitive and easy to remember, right? And Bally had the nerve to advertise "manual-free testing"....
5 Game Specific Problems and Fixes
Example would be servo controller on Independence Day pinball
6 Repair Logs
Did you do a repair? Log it here as a possible solution for others.