UPDATE] Converting the “Competition Pro Extra USB” to C64/Amiga/Atari DB9 – pagetable.com
Amiga joystick USB adapter (HID) - Retro32
Classic Atari Joystick to USB Adapter - YouTube
BYDOT USB Adapter Controller Conveter for SEGA MD/NES/SNES/PCE/CD32 Game Consoles - Walmart.com
USB Adapter For DB9 Joysticks Atari / Amiga / Commodore / MSX / SMS / emulators | eBay
USB Joystick Adapters – breadbox64.com
USB Atari RetroPort - retroUSB
Retronics USB Joystick Adapter and Other Coolness with V-USB | Code and Life
9 Pin Joystick to USB Adapter
Amazon.com: Retro USB Adapter for Atari Joysticks and Paddles - 4 Port/Players : Electronics
USB Joystick Adapters – breadbox64.com
USB adapter for DB9 joysticks (Amiga, Commodore, Atari) | eBay
Dual 9 Way Atari/Commodore USB Joystick Adaptor
Build a USB Adapter for Retro Joystick and use it on your PC, MiSTer or Amiga A500 Mini - YouTube
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 Joystick USB Adaptor – Waiting for Friday
Retronicdesign - New USB DB9 Joystick Adapter for your 30... | Facebook
C64 Joystick Adapter | Hackaday
Atari Retro Joystick USB adapter – Make or Buy – 2 and 4 ports
Amiga Joystick to USB Adapter Cable - English Amiga Board