Neo Geo to NES Controller Adapter with Mapping Options
4This is a video showing off my homemade Neo Geo to NES controller adapter, which I made mostly for use with the Analogue Interactive NT Mini. It has the added functionality of being able to map up and/or down to face buttons in addition to using the stick. This is to provide an advantage in games that use up/down to do unusual things like jump or accelerate.
As a kid, I tended to dislike games that did that, and moved on to titles that were more fun for me, so this adapter has helped me enjoy a number of titles I didn't have much experience with. Unfortunately, since I didn't spend much time with games with odd controls, I have trouble remembering the names of games that worked that way. If you can think of a good one, drop me a comment.
Controller adapter is nothing fancy, just a padhack.
For Atari/Commodore systems with standard 9-pin controllers, the below link is to a commercial product that will help you connect a multi-button controller to your old system, with options like mapping up/down to extra buttons. Not a paid advert in any way, just another way to accomplish this with minimal work.
https://www.64hdd.com/64jpx/64jpx.html