This is not my area of expertise, but I believe this is the section of Mame source that was referred to:
https://github.com/mamedev/mame/blob/master/src/mame/nintendo/popeye.cpp
The encrypted version uses the tpp2_state function, while the unencrypted version uses the tpp2_noalu_state...
This physical switch from page 2 of the 19in1 PCB manual I sent you is the one I mistakenly called a service switch. It allows you to access the service menu. The manual calls it a test switch. Potato/Tomato
While this is innovative and accurate, I do not think it necessary for this instance. Admittedly there are definitely other workarounds for this, but OP expressed to me via email that he does not want to solder anything to make this revision.
I'm also not sure that the test and service wires...
That adapter will work, but you don't need it if you are only wanting robotron and smash TV.
The 19in1 board has (software) dip switches to allow you to use the player 1 buttons to control shooting, which is exactly what Smash TV uses. You just need to connect your player2 joystick to those...
I'm not sure what to tell you. I'd guess I've plugged in several thousand Male Jamma boards into my switchers by now. I've never failed to insert or remove a Jamma edge connector, and haven't broken anything. I personally think my EZ Jamma gameboard interfaces are easier to grip and therefore...
If you want to use the player 2 joystick as the button inputs for player 1, you just have to connect that player 2 joystick to the player1 button inputs on your Jamma harness.
Alternatively, you could daisy chain the P1 buttons with your P2-joystick so it triggers both simultaneously... But...
Great Pricing, fully transferrable lifetime (mine) warranty on all RiddledTV PCBs.
FYI, the devices you have called Jamma adapters -> I call them EZ Jamma Cabinet Interface.
1 Jamma Extension = EZ Jamma Cabinet Interface + EZ Jamma Gameboard Interface + cables
I'm placing this applicable diagram here: https://riddledtv.com/MultiFighterCondenserConnectionDiagram.pdf
The only difference here from that diagram is the # of games, and the Jamma to Chamma adapter.
A Jamma switcher + Multifighter Condenser + 2 condenser cables would make this a plug and play solution. as best I can tell, you already have a Chamma adapter there.
Please feel free to contact me if you would like me to email a quote for you.