I check out the 12$ Super Card SD, a cheap Chinese SD card solution for the Game Boy Advance.
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DISCLAIMER: I mention at the end that it only plays GBA ROMs which is incorrect. Thank you to commentor Cestus Fr for pointing that out. If you create a folder called gb on the SD card and place Game Boy ROMs in there, it will play them without needing a patch. Same goes for NES ROMs. Create a folder called nes in the root of the SD card and place your NES ROMs in there.

Find the Supercard SD on eBay: https://www.ebay.com/sch/i.html?_nkw=supercard+sd&_sacat=0
2.71 software: https://bit.ly/2KcmRWr
1.85 firmware: https://bit.ly/2JKRIdj

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