The Vinesauce ROM Corruptor is THG’s tool of choice. It’s an easy-to-use interface that let’s you get right into.
From what I have found, a lot of essential data for NES games is near the front, or the lower numbers, so you don’t want to corrupt those or the game will jam. I usually start from the back of the cartidge, where less important data is stored, and make my way forward.
The corrupting itself is just random, and you will get a few for it. You will find what Nathan and I call “hotspots”, which are areas with a lot of weird that you can explore by tweaking the amount of corruption. You’ll also get an eye for things that may tip you off. “Hmm, that jammed, but it almost worked. What if I corrupt every 13th byte instead of every 10th?” or “Hey, that one was mostly normal, but a little off. What if I cranked up the what-the-fuck?” Little tricks like that.
I will say two things about it:
- There are plenty of people on the Vinesauce forums who have A LOT of time invested into this. I would look around there for tips for NES games.
- You WILL NOT get a lot of results. Each 5-6 video Nathan and I make is cut from approx. 2-3 HOURS of raw footage. When you are dealing with a random factor, you just basically have to buckle in and hope for the best.
Hope that helps! I am by no means the expert, but feel free to let me know if you have any other questions!