Atari 5200:Controller Adapters

During its lifetime and especially in recent years, the Atari 5200 became notorious for its complex and unreliable stock controller. It is no surprise then that a number of controller adapters have been developed for the 5200, allowing for all sorts of controllers to be used.

Masterplay Interface
Sold by Electra Concepts in 1984, the Masterplay Interface is the only controller adapter released for the 5200 during its heyday. It is a small box that connects to the 5200 and has three ports. One of them is a DB9 port for 2600-compatible joysticks and another is a DB15 which is a passthrough for an original 5200 controller, which is needed for the Start/Pause/Reset buttons and keypad; a switch is also included to completely enable the 5200 controller for games which require its analog joystick. The third port is a simple 3.5 mm jack located in between the two controller ports, intended for an additional fire button that could be adhered onto the controller of one's choice.

MegaPlay
The MegaPlay adapter is compatible with Sega Genesis/Mega Drive controllers and goes a step farther than most other adapters in that it uses button combinations to simulate both keypads, meaning that it can totally replace the 5200 controller (except for games which need the analog joystick). Though it is not commercially available, the PCB project is available on OSH Park. It is based around an Arduino Nano and a couple of 4052 multiplexers.