Hi everyone! I’m a new member of the community, but I had my eyes on Planet VB for years and had thought about participating in it for a while.

I’m a programmer with experience in both C and some assembly languages, so I’m feeling confident I could learn about VB games development. But for now, I aim at a small project: I just want to do a very simple Mario Tennis ROM hack.

I just want to change some sounds and maybe some graphics in the game. I’m wondering what are the tools I would need for that. Basically, where could I find a reliable ROM of Mario Tennis, what software should I use to modify it, and so on.

I know this is a broad request, and I’d be super thankful to anyone who can guide me in the right direction!

I mostly use 3 emulators:
1. Reality Boy with the debug features enabled. It allows you to look at the charmem, bgmaps and so in a very convenient way.
2. Medanfen. The build in debugger allows you to read the asm rather easily and you can do stuff like changing the memory during runtime.
3 planetvb emulator. It has a very good breakpoint system and allows you to see bgmaps and so on as well. On top it will show you addresses for everything which is really handy. With a little work this could become the only emulator you would need.

There are a few other tools like David Tucker’s disassembler and Horvats MV810ASM but I rarely use them.

I often use the VB tech scroll (https://www.planetvb.com/content/downloads/documents/stsvb.html), as a reference. It pretty much contains all the information that has been collected from several sources over the lifetime of this community.

What I usually do is reverse engineering a game using the emulators I mentioned above. I write down my findings and then write specific tools for each game. I’m in the middle of writing a tool that can replace images in many virtual boy games (so far I have Innsmouth, Space Invaders, Gundam and Faceball). However, it is very hardcoded right now and could not be used without changing the actual code.

You can hit me up in discord if you have any questions. You can also see what I’m talking about if you look into the thunderstruck-projects channel on the planetvb discord.