USB to RS232 Mini 4P Serial Adapter Cable for Uniden Bearcat BCT15X BCD996XT BCD996T BCD396T Scanner PC Programming Cable FT231XS Chip

I had a variant of this MP3 as a kid, and I believe it used the same cable as Action Replays for the Nintendo DS. https://www.reddit.com/r/nds/comments/yfn6vv/found_my_action_replay_from_2006_what_cable_do_i/ There's one Amazon link in that thread you may want to take a look at: https://www.amazon.com/Adapter-Bearcat-UBC3300XLT-Scanner-Programming/dp/B08CVKGLDD