The RetroFreak is a great little emulation machine that uses physical carts, similar to the Retron5.
Under standard conditions, it is possible to let the RetroFreak copy the cart contents to an SD card, but they're always encrypted.
However, by using custom firmware and a few configurations to two files, you can get unencrypted dumps of your carts onto your SD card.
Will this brick your system? Hopefully not. Proceed on your own risk.
Get the binaries
Start by grabbing the release of hissori's retrofd: https://github.com/hissorii/retrofd/releases Make sure you grab the release that's smaller than your SD card. If your SD card is 16GB, grab the 8GB one, and so on.
Unpack it, and then use something like Etcher to transfer the contests onto an empty SD card.
There are two edits that you need to do. To make it simple, you can replace the existing files on your SD card with the ones below.
Boot up your RetroFreak with the new SD card, and you should be able to use and play your carts like normal.
Once you insert a cart, let RetroFreak install it to the SD card. Now start the game for a few seconds.
After you've started a game, the unencrypted dump will be copied onto your SD card under
You can now exit the game, and continue with your next cart.
Once you've turned off the RetroFreak, you can take out the SD card and look the contents,
hopefully your unencrypted dumps will be there.
They should have names such as
Needs verification: You can also use the above method to dump an unencrypted BIOS of your Famicom Disk System. Just plug in the RAM adapter and follow the instructions above to save the encrypted BIOS on your SD card. Then start an FDS game that you have loaded onto the SD card.