Universal DB9 to USB joystick adapter module by Retronic Design

• https://www.retronicdesign.com/en/

Some users reported needing to upgrade the firmware to this recent update to get their adapters working:

• https://www.retronicdesign.com/en/modified-firmware-atari-sega-genesis-joysticks-c64mini-proper-buttons-mapped/?fbclid=IwAR23FhgS30gHlP8yRpdlrsTXm4nANtu-p_gOUwGiWpLguH2EBp1QvngP0b4