ATARI Joystick CONNECTORS (4) DB-9M PCB 2600/7800/800 NEW (NO display package) | eBay
General Purpose port - MSX Wiki
Amazon.com: Retro Classic 3D Analog Joystick Controller for Atari 2600 Joystick, for Atari Flashback Game Control with Operating Button/Four-Way Joystick, for Atari Joystick with Games for Atari 2600 Systems : Video Games
2 NEW 10 Foot 10FT Extra long Extension cable for ATARI 2600 Controller Joystick | eBay