Reading a GBA save game
To read or write a savegame from/to a GBA cartridge you must first make sure you have the GBA.txt copied to your SD card. You can download it here: https://raw.githubusercontent.com/sanni/cartreader/master/sd/gba.txt
Then setup the config switches like so:
Next plug the GBA cartridge into the GB/GBA slot of the cartridge reader.
Then you can choose Read save to dump the save to the sd card.
If the cartridge is not recognized try cleaning the contacts with rubbing alcohol.
There might be still errors in the GBA database so be sure to check an online database like http://www.advanscene.com/ if you encounter any errors.