FireWire wasn't trying to support mice and keyboards. Nor was it trying to be all things to all users. It was trying to be an ultra-fast interface. And FireWire

FireWire wasn't trying to support mice and keyboards. Nor was it trying to be all things to all users. It was trying to be an ultra-fast interface. And FireWire absolutely was backwards-compatible with an adapter. Still is. I never had any compatibility issues with FireWire.