Connect USB Joystick to Commodore C64 - Hackster.io
USBJoy2.0 - adapter. Connect your Atari Amiga C64 joystick to PC! Develop your own usb device! - Polish electronics for 3D printers, CNC, robotics, retro computers
Atari joystick port - Wikipedia
USB Joystick Adapters – breadbox64.com
Bluetooth Interface Adds Rumble Feedback To Commodore 64 Games | Hackaday
Commodore 64 Four Player Adapter | időrégész.hu
4 joystick adapter for C64/128 (CGA/Protovision)
USB Joystick Converter for Atari, Amiga, Commodore 64 – Electronics Projects Circuits