RCEU540-Amiga-4-Player-Adapter
An adapter that plugs into the Amiga's parallel port to grant 3rd and 4th joystick port.
BOM
2x db9 male (for wires)
1x db25 male (for wires)
Optional
2x 1x2 2.54mm/0.1" SIL header
2x jumpers
The optional part is to enable 5v supply to the joystick (i.e. autofire etc)
Casing
An adapter case is available on Thingiverse
Notes
The adapter is quite stable plugged into the amiga and 2 joysticks connected to it.