Converting the “Competition Pro Extra USB” to C64/Amiga/Atari DB9 – pagetable.com
9 Pin Joystick to USB Adapter
USBJoy2.0E adapter - Extended Version. Connect your Atari Amiga C64 joystick to PC! Develop your own usb device! - Polish electronics for 3D printers, CNC, robotics, retro computers
Atari 2600 USB Joystick (Retro-link) - Stone Age Gamer
USB Adapter for Atari Joystick, Paddle, Driving by iCode, Dual DB9 Ports Converter, Pro Plus Edition
TheC64 mini
Commodore 64 Joystick USB Adapter | C64Joy - Hackster.io
C64 Joystick Adapter - Share Project - PCBWay
USB Joystick Adapters – breadbox64.com
Dual 9 Way Atari/Commodore USB Joystick Adaptor
USB Joystick Adapters – breadbox64.com
Joystick USB Adapter – 64KB.DE
Retronics USB Joystick Adapter and Other Coolness with V-USB | Code and Life