NewtKey 1.2! - Use Apple's Newton Keyboard, with any standard keyboard layout 

Small window which can be dragged off the edge of the screen. Optional on-screen Caps Lock indicator, Up to 10 user defined macros, save on typing, Automatic sleep can optionally be disabled when the keyboard is in use. NewtKey is the only Newton Keyboard driver will work on any Newton, from the first to the most recent. It only lets you connect to Apple's Newton Keyboard. You can't connect to Macintosh or PC keyboards. They use different interfaces, and require hardware interfaces. NewtKey is very simple to use. To connect your Newton Keyboard. Turn on your Newton 

Open the Extras Drawer, and tap NewtKey. Tap "C" in the NewtKey window to enable the keyboard.