Low Function Terminal to System Keyboard Interface

The lft interface with the system keyboard uses an input ring mechanism.

The details of the keyboard driver ioctls, as well as the format and description of this input ring, are provided in Graphic Input Devices Subsystem. The keyboard device driver passes raw keystrokes to the lft interface. These keystrokes are converted to the appropriate code point using keyboard tables. The use of keyboard-language-dependent keyboard tables ensures that the lft interface provides National Language Support.