Friday, 3 July 2015

Controlling Bally Sound Boards

As i have produced 2 sound board remakes now i decided to write a test software program for my 2 bally compatible boards. The idea being that you can specify the board type in the program and it will then play the full set of sounds for you. I also thought of having an input where you can specify the sound id directly. I like this idea also for the purpose of using with some of my other projects such as my custom pinball controller and also for recording high quality samples of all bally sounds.

Whilst developing the software I came across something that was interesting whilst working out how to access sounds from later games like gold ball and xenon which are 7 segment games and use a larger 2732 rom. It also provides supplemental information on the tech information written regarding how the later sound boards (namely the Squawk & Talk) receives information.

Before the 7 segment on Bally games was introduced the control line was using a sound address line 5 to allow upto 32 sounds to be played. When the 7 segments came out this line was then used to drive the 7th segment and so if the sound access program remained the same then only 16 sounds would have been possible. At this point I believe that the double 4 bit nibble process was introduced (yet to confirm this through tests though) to allow upto 256 sounds to be played. This would mean that this system was in place as soon as 7 segment games came out (Skateball onwards?) rather than from the introduction of the Squawk & Talk Sound board.

Also, as mentioned in the technical documentation by Clive Jones 

"Strangely, the schematics that I'm checking against show a *fifth* solenoid select line wired to PA4 (if the "EE" jumpers are installed, which, we'll come to shortly) or IO4 of the PSG. Maybe Bally kept their options open by keeping this fifth solenoid select line available on S+T?"

The 5th select line is still connected on a S&T board, but on closer inspection of the manual schematics and wiring diagrams, this line is tied to ground through a looped connector so the signal is purely used on the display front here. Also on games such as Xenon the manual states sound address line 5 as Not Used. This rules out some sort of possible multiplexing for both signals, and i'm not sure how that would have even been possible with the current design.

I will update here with more information as i find it

Wednesday, 6 May 2015

Custom Pinball Controller

About a year ago i started work on a life long ambition of mine: to build a fully featured pinball control system for early bally and stern games with the goal in being able to produce a board set and software framework for other like minded people to modify and create new games from old play fields. I also wanted to be able to create new rules and sounds for a game i made back in the college days some 25 years ago.

I developed a double board set and had some protos made. 1 controller board and 1 driver board, that are designed to work together, and replace all other bally boards except the power section on the old power driver board.

I wanted to create a board set that would work together and include additional options on the boards so that people could add extra features to games should they wish, but also be a direct plug in to the games original wiring. The main features of the board set are:

 - Control Original Segment Displays, or use low cost serial Led displays
 - Control Original Switch Matrix
 - Control Original 16 Drivers plus Solenoid expanders
 - Control Original 64 non-matrixed lamps
- Additional 16 mosfet drivers for flashers, motors, magnets etc
- Additional RGB Lamp Control for extra lamps
- Large SD card sound/music storage capabilities
- Multiple Channel Sound with background music
- Sound line out for connection to external amps/audio setups

The hardware is one side of the project, but the software framework is the other. I have been working on creating a pinball library framework which people can use to get their own project off the game in conjunction with this hardware. The framework is made up classes for all the major pinball items, so lamps, switches, drivers, displays and sounds. The game itself then has various other files including feature modes and base modes to make the game playable. I have based my design concepts on the work of other more complex pinball frameworks, such as pyprocgame. This is the framework that i use for my rewrites of Indiana Jones and Whirlwind (see my other blog posts). Without the ideas from this software i wouldn't be here. :)

The framework is all written using the arduino code language and C++. I am making sure that you can still use the standard arduino ide to modify the files to create your own game from. The framework is very modular and i'm pretty happy with it so far.

Here is an example game play video with the latest game framework . I currently have 32 of the 64 lamps connected. Notice the fast attract patterns. This is to show the power of the system and what may be possible in future with more complex effects. Original game attract patterns were very slow and basic. Some of the game features are now coded into the framework to so look out for the kickback lamps progressing during the vid and some of the bonus triangle lamps lighting up.

Also, the sound system is now set to produce optimal sound volume and quality. Its taken awhile to get the hardware correct here. I will be adding the 2nd channel - background music in soon. I'm very happy with the sounds i've found especially the coin up, start and drop hit sounds. Enjoy the vid :)

Thursday, 5 February 2015

Testing the Squawk & Talk Sound Board Redesign

The first proto boards arrived from the manufacture just before Christmas, so i set about assembling one to test the design and iron out any issues /errors. I have documented the assembly process below with videos and descriptions of each stage.

Update 1

First part of the board is assembled and tested. I am assembling the digital section in stages, following the diagnostic led sets of parts to check everything is working ok. I have assembled upto both pia chips so far and have a flicker and 3 flashes   It was great to see that led start blinking!

Below is a quick video showing the status led blinking at power up. Note that the first flicker is now more like a flash as i am using a reset chip ic.

Next i will be assembling the ay sound generator section, then the speech section and then the op amp, filtering and power amp sections

Update 2

Update on development. All five flashes are now working with the speech chip section installed. Moved on to the amp side and populated the main amp and speech pre-amp/filtering section. Also added my Elektra roms, tested the jumper dipswitch configs and all working from the test button. 

After christmas and holiday break i will be moving onto the final population of the dac and sound amp section and the data input section.

Update 3

Back on with assembling the remaining parts on the s&t sound board now christmas is over.

A question for interested people: A friend of mine mentioned the idea of adding into the board the centaur reverb circuitry as an optional extra. The idea here would be to use the holtek guitar effects chip replacement circuit that can be bought separately and add it into the design as an optional population section. The circuitry would be enabled or disabled with dipswitches. This would mean any game could have the echoey sounds  

Please let me know what you think

Update 4

Update: New video. All sections are now tested and working (sound amp & filtering, dac and data input). The first proto board is now fully assembled and it all went rather well   A few things to alter for the next revision, but its time now to try it in a few different games. Very happy with the sound quality so far and am looking at the reverb/echo addition to. I think it's the best i've ever heard these games sound  

New video of the board running in my partially complete Elektra restoration here:

The self test now includes the sound effect as well as all the speech calls. I also tried out the mpu to sound board data flow from in game. There are some great 80s sounds that this board can generate  

Update 5

Update: New video. I created a test echo/reverb circuit and connected upto to my proto board. All tested very nicely. Video here of my Elektra with echo! Very cool to hear this! I set the reverb pretty high for testing.

I'm now finalising the changes for the production board and building another proto board to test in a few other games/locations. I'm thinking of creating the echo board as a separate plug on daughter card option for the J2 connector (rhs) instead of additional parts on the main board. This means it can be easily plugged onto boards in the future, require no additional wiring and will keep costs down for the main board. I will be looking to create this daughter board as an optional extra after the first run of standard boards is under way.

Update 6

Some new videos of additional testing with the proto boards in a friends centaur yesterday. Working really nicely

Sound Board Test

Game Play

Pre-Ordering is now open for the first run of 25. The cost for an assembled and tested standard board will be £149 inc. VAT plus postage to your country. The pre-order process will run like my other board and mod projects with 50% upfront and then the remaining 50% once your board is ready to send. I am aiming to have the boards ready within 2 months, all being well.

Please contact me now if you'd like to get in on the first run. Thanks, or click here

You are also welcome to purchase the blank pcb or a kit from me if you want to assemble it yourself.

The summary of updates for my board are:

- Reduced component count
- Test point pads for common signals and voltages
- Leds for power voltages and diagnostic led
- Improved and simplified reset section
- On board reset button
- Dip switch config for rom settings
- Fully compatible with all stock roms
- Dip switch config for inclusion of sound generator ic
- Expanded J2 connector to allow future plug on daughter cards such as echo/reverb board.
- Option via J2 for external amp hook up and multiple speaker usage
- Higher power amp on board for stock speaker connection
- Socketed ICs
- Plate through design

The board is designed to work in the following games:

Beat The Clock
Centaur II
Eight Ball Champ
Eight Ball Deluxe
Eight Ball Deluxe Limited Edition
Fireball II
Flash Gordon
Mr. & Mrs. Pac-Man
Rapid Fire

As normal, visit my full website over at or contact me directly at or tweet @mypinballs to say hi