Amiga 4 Player adapter released as open source hardware.
Available on github.
A drop in replacement pcb for the Arcade joystick, using inexpensive ebay microswitches. As a feature, a 555 timer can be added to supply autofire functionality.
We’ve created a simple adapter which makes it easier to bridge the connections between the Amiga, Bluepill and GOTEK drive.
More info on Keir Frasers github: https://github.com/keirf/FF_OSD