Emulated keyboard issues
On macOS, when I was messing around in the test menu of La Keyboard and the arcade version of The Typing of the Dead, I've noticed a couple of issues. Left Ctrl and Shift are mapped to their right sides, and the Left Command key does not emulate the S1 key.
macOS doesn't distinguish between left and right modifier keys. This is a limitation of the OS. The S1 key isn't mapped on any platform. I don't think it is used for any game.
macOS doesn't distinguish between left and right modifier keys. This is a limitation of the OS. The S1 key isn't mapped on any platform. I don't think it is used for any game.
Some emulators for macOS use both left and right modifier keys individually.
The S1 key can be used for Keyboard-supported Dreamcast games that use button remapping, like Quake III Arena and Unreal Tournament.