Only 3 methods come to mind,
Wire coin switch to a button
set replay very low
replace MPU with an aftermarket board that supports freeplay like Alltech or weebly.

Replay and board have the advantage of being easily undoable.

At the Rocky Mountain Pinball Showdown what a lot of owners did for games that don't have a freeplay option is to set the replay score as low as possible (basically a single target would hit it) and then add like 40 credits to the game. I don't think any of them had any problems with running out of the credits.

An option I’ve used is to set one of the replay settings to something really low .. like 10k so most people will win a free game. Also leave the match setting on to make up for the couple that don’t make the free play mark. I did this on an eight Ball at SFGE and it lasted for the whole show without adding credits

Mike V

I seem to remember a solution for adding another leaf switch to the start button and wiring it to the coin-in switch wires so that every time you press start it also adds a credit.

PinWiki also says that Free Play ROMs are available for all Bally/Stern SS games, has anyone ever tried that?

This is the easiest solution, if you have working batteries or NVRAM in the game. The only thing that stinks is that on -17 games, the score increases sooooo slowly to come back around to "0". On -35 games, it's not that bad.

I have tried them when repairing a game. They work but using them assumes that you have an original board in the game (or a newer Weebly board that uses original rom sockets) and the ability to burn those roms correctly AND properly jumping the MPU AND that the DIPS on the MPU are working properly. It's a lot to take in for people that are just getting their feet wet, not well versed in MPU work.

^^^^ this works perfectly.
1. No need to change the replay value (changing the replay low makes the knocker go off- it is more fun to earn the knock)
2. Very cheap (no expensive new board or chip replacement)
3. Totally reversible and easy to install.
4. Fool proof option- works every time.

Absolute pain in the ass to add switches on a machine where they were not meant to be. Easiest solution is to press the coin door button and set replay low. Takes 90 seconds. Earn a replay with the second and third scores, nothing changes. Points 2-4 above hold true for this solution and it's also faster. With most games I work on the customer doesn't even want the knocker to go off at all and they ask me to disconnect it or, it's already disconnected.

One person plays a kick-ass game and wins four credits??

It really is pretty easy. You are only stacking one leaf switch to a already existing leaf switch. Then moving 2 wires (which does require soldering.)
This era Bally has the start button on the door- makes it fairly simple. No drilling, no additional wires.
It does take a little experience in wires and soldering, this might be a great time to learn if you want too.

What I have done in the past is use one of these micro switch holders from newer games - https://www.marcospecialties.com/pinball-parts/545-5121-00

The mount holes are the same spacing as those that hold the leaf switch for the start button. Bend the actuator from the micro switch so that it is activated before the start button leaf makes contact. Either wire the new micro switch to the coin switch of just use some alligator clips for a temporary free play setup.

Each time the start button is pressed, it'll add a credit and immediately remove it to start the game.
188b37aa37b93cace37e0983bf7762d8c518070d (resized).jpg

Yes- or if you get a switch with the white plastic nub on it- you can adjust the so they contact at the same time.
I really like the looks of the above switch also(never tried one like that)
I just used some old leaf switches from old parts that I had laying around.

Double post on accident.

I have done it more than 50 times both ways. I’ve been fixing games for 20 years. Trust me, changing Replay is easier.

Totally agree!!!- changing replay is way easier!!!
But....... the OP made it pretty clear in the ORIGINAL post that he did not want the option of lowering the replay.
So, using your 20 years experience, what would your best solution be for the OP’s original problem? (Please, try very hard to remember- lowering the replay is NOT a answer to his question)

PS- the replay knocker has a long history in pinball and is such a fun feature to hear and earn. It is sad that you disconnect or don’t fix them for your customers. I understand if the customer asks to disable it- but I wonder if it wasn’t going off all the time because of your minimal effort of lowering the replay, that they may enjoy the thrill of hearing the game knock for a skilled player.

I always vote for free play roms, and if possible turn off the credit display as well, I've found even with free play roms if people see 00 in the credits display they don't even try to start a game.

I greatly dislike the free play rom variety that always shows an 01 in the credit display, though.

My preference is for the credit display to show nothing *only* when credits are zero. The curious mind will press the start button. And also to have the credits reset to none at the start of a game to give players added incentive of seeing how many replays they can rack up in a single game.

There is a board made by a guy Dave2084 in the UK that plugs onto the 32 pins at the top of the MPU it has many of the freeplay roms on it. It's way cheaper than buying a new MPU, and can be easily taken off if you sell the game on.

I don't know the guy, but seems like a really top bloke and was very helpful, answering my questions.

I'm not sure if he's on Pinside, but I found his boards here:

https://www.pinballinfo.com/community/threads/bally-35-stern-mpu-rom-multigame-pcbs.39531/

pasted_image (resized).png

Does anyone have copies of Olivers Freeplay Bally roms? I have downloaded the batch files that he has on his site and run those, but I just keep getting error messages in the log1 file and cant create a freeplay custom rom.

I have placed the u6 file 720-2832.u6 in the same folder as the all of the files from the unzipped p-72832fn that I downloaded from his site.

I have run the custcre.bat as instructed but then the log just keeps flaggin errors:

romadd:create one large 64k rom (bdat-900.BIN) for early bally / stern pinball eproms add u6
by okaegi v1.01
cant open bdat-900.BIN, we will create it...
cant open u6

gencust bdat-900.BIN 7-2832f.pat 7-2832fu.bin
gencust:based on orignal rom (bdat-900.BIN) and patchfile (7-2832f.pat) custom rom ist created 7-2832fu.bin
by okaegi v1.2
gencust read crc-32 from 7-2832f.pat -> 58e144b4
gencust bdat-900.BIN calculated crc-32 d7978eeb
gencust bdat-900.BIN is not original rom file, please dump again

fsp 7-2832fu.bin bdat
fsp:splitfile 7-2832fu.bin to bdat-nn (2048 bytes each) by okaegi v1.00
cant open 7-2832fu.bin

copy /b bdat-2 + bdat-10 7-2832fuN.U2
The system cannot find the file specified.

copy /b bdat-3 + bdat-11 7-2832fuN.U6
The system cannot find the file specified.

gencrc32 7-2832fun.U6
gencrc32 from file (7-2832fun.U6) and file ((null))
by okaegi v1.01
cant open 7-2832fun.U6...

I have also tried for the 720-3032.U6 rom and I get all of the same errors

if anyone already has working freeplay versions of the U6 rom files I'd hugely appreciate it as I can't get past this point with the batch files.

The instructions on his web site state you need to use the merged U1/U2 2732 ROMs from the "bly2732.zip" file on the web.
https://arcarc.xmission.com/Pinball/Roms/Pinball/Bally/bly2732.zip

His batch files do not work with the standard 2716 ROM files.

Hi quench.

Solved

I found another thread that explained that the U6 Rom needed to be named U6 not .U6 Just U6 with no file extension. I tried that and it worked first time.