Hardware ROM Hack GBA How to play Pokemon Green US on a repro cartridge

[yohuchiha]

Hello there!

I was doing nothing this Saturday, so I decided to make something new.

I have a copy of a repro cartridge Pokémon Green from Aliexpress, so I was wondering if I could make It work on my N64.



I open up the cartridge and look at the PCB looking for solutions. The battery is missing but the game saves it on the cartridge.



Besides some bugs working okay, but the ROM is just a regular Blue version, and I want my haking ROM with sprite Japanese 1 gen art.

My idea was to re-write the ROM file like I saw it on Bennvenn, into the cartridge and put my custom ROM on it using my GBxCart-Rw.



On the first try, I didn't find the ROM, and I think the cartridge wasn't attached to the PCB, but on the 2nd try it worked and I could back up the ROM.

It backs ad a '.sgb'. The file works normally on VBA, but the ROM save file is inside the ROM. (I guess)



Ignoring it, I tried to write the new ROM into this cartridge, got some errors on 3.3V to 5V, and ended up writing on 3.3V.

But It worked, my ROM was on the cartridge and playing.



However, It is not saving progress.



I tried soldering an old battery, but Its voltage is very low, and I'm not sure if I ended up soldering very well or messed up the positive and negative.

In the middle of the cartridge, there is a connector that energizes the board, and I'm not so sure if I need to energize it as well.

Well, I want to know if you guys know something and give me any ideas to finish this project.