The 486 that [someyob] is restoring had the Turbo button, but sadly there was just a simple LED to show whether ... the state of the Turbo LED with an Arduino Pro Mini. Now to modern audiences ...

[Facelesstech] programmed an Arduino Pro Micro to fake controller button presses ... Hooking it up is easy—an on-the-go adapter allows the Switch’s USB-C port to connect directly to the ...