I have a couple of SNES to NES controller adapters so I can use SNES controllers on my AV Famicom. SNES Y = NES B, and SNES B = MES A/
I want to know if a SNES controller can be modified so SNES X = NES turbo B, and SNES A = NES turbo A?
If it has any firmware you could probably re-flash it. But if you're willing to do that you could just modify a 9-pin pirate controller with turbo buttons.
I was wondering if the SNES X could be on the same data path as SNES Y, and SNES A could be on the same data path as SNES B (effectively having 2 NES A and B buttons in my case)?
Should be possible but I'm not knowledgeable in electronics and don't know exactly how these controllers work. Turbo controllers use an oscillator that is set up in such a way that it periodically toggles the button on and off at a certain frequency. You need some electronic skills to design such a circuit of course.
Yes, it's possible to create a turbo controller. You have to desolder one 4021ic from your snes gamepad or cut some traces if you have a third party globtop-type of gamepad. Then you have to construct and fit in a 555 timer rapidfire oscillator.
This tutorial is for mouse, but can be used in gamepads also.
http://www.instructables.com/id/Add-a-rapid-fire-button-to-your-mouse-using-a-555-/