Atari ST joystick/joypad to Jaguar adapter

[Zerosquare]

Here's an adapter to use Atari ST (or compatible) joysticks/joypads on the Jaguar. The four directions of the joystick map to the Jaguar's D-pad, and the joystick button maps to the Jaguar's B button.

This is not a standalone device, it is meant to be added inside a standard controller (it can probably work on a Pro controller with minor modifications, but I don't have one so I can't test it).
All buttons of the controller remain functional whether or not there's a joystick plugged in.

The circuit taps signals from the controller's 74HC244 chip ("Axx" arrows) and from the controller's cable ("Bxx" arrows).
The dot on the 74HC244 package is next to pin #1 ; pins are numbered counter-clockwise.
To identify the correct wires on the cable, use a continuity tester, since wire colors may be different from controller to controller.

The parts you need are:
- One 74HC244 or 74HCT244 integrated circuit
- Five 10 kΩ ±5 % 0.25 W resistors
- Five 1N4148 diodes
- One 100 nF 25 V X7R capacitor
- One 9 pin male D-sub connector