Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
What are you trying to accomplish? No matter you will need a serial to usb adaptor, and the original Newton software (which should run in Classic).
 
Check out the archives at Newtontalk.net for your answers. I'm currently working on getting my eMates hooked up to my iBook. Good luck!
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.