To all of you who arrived here to connect an Amiga 500/1000/2000/3000/4000 keyboard to an USB port on a modern PC/Mac/Raspberry Pi/whatever computer:
The Olaf-DrRemulak Arduino Leonardo script discussed here is quite obsolete now, since it missed the simpler functions from the Keyboard.h Arduino library, that are especially done for the purpose to convert old keyboards to USB ones.
Here is attached a better script from Janne Lof (I can't find anymore its original link on Internet, sorry).
I confirm this one works well with my A1000 keyboard and should work with all other Amiga keyboards with a controller onboard (so, all Amiga keyboards except the ones from A600 and A1200). I added a 'delay(300)' in the Caps Lock handling subroutine to make the caps lock comptatible with MacOS computers (and it still works with other computers).