Compatible controllers or adapters to be used on the original CV console?

[RockLobster]

I prefer the Super Action controllers to the originals but sometimes I want something less gigantic to use.

 

What other controller options are there now in 2023?   

 

How about adapters like the many that lets you use retro controllers as a USB HID device but reversed?

[RockLobster]

Apologies for not googling hard and long enough.  I've found this to answer part of my question:

 

http://www.colecovision.dk/joysticks.htm

 

I've since found other AA threads about using a Y-Splitter and 2-button games along with the apparent Atari 7800 compatibility.

 

I've also found some people mentioning how the 3-button Genesis/Megadrive gamepad has button B for both buttons.   This is fine for games like Cosmic Avenger to shoot and bomb but not for games that require separate use of each.

 

What are the pin-outs necessary to convert Sega Master System or Genesis/Megadrive controllers for distinct 2-button CV control?

 

Thanks.