Amazon.com: Tangxi 3D Game Joystick for Atari 2600,Retro Classic 3D Analog Mobile Gaming Joystick Controller Replacement for Atari,Compatible with Atari 7800 Console : Video Games
HOWTO - Atari 7800 Controller ST Compatibility Modification - ctrl.alt.rees
Amazon.com: Hakeeta Game Controller, Joystick Controller with an Operation Button and a Four-way Control, Compatible with Atari 7800, Suitable for All Atari 2600 Systems. : Video Games
Atari 7800 Gamepad compared to a Master System controller : r/atari7800
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Atari 2600 / 7800 Controller CX78 | eBay
Atari 7800 Controller Joystick IH 254 Used - guaranteed to work | eBay