I've been using New Super Ultimate Injector to overhaul my virtual console library of games on my 3DS, and have found that there's lots of information to be learned and understood if you want to do it properly. The problem is, this information isn't always readily available or easy to find, and is rather niche, so I've had to do some of my own research on things. There are still lots of people asking questions or seeking help with NSUI without getting an answer. And although I don't know everything, I thought I'd just share here what I've learned and maybe it can help other people who are also trying to use NSUI. This guide assumes the use of Beta 28, as that is the latest (and likely the last) version. If any of my information is straight up incorrect, or this guide would better belong in a different forum, please let me know.
For starters, the download links for both Beta 27 and Beta 28 (on this site, at least) are disabled for unknown reasons. But you can find NSUI on Gamebrew or archive.org in either of those versions.
This guide will exclusively cover injecting NES, SNES, GB, GBC, and GBA games. Game Gear is also very straightforward so I won't need to cover it. I'm not sure how Famicom Disk System injection works unfortunately.
Credit to Asdolo, of course, for making this great software.
