I found a Keyspan USB to Serial adapter brand new in the box at a flea market, and used it and NCX to connect my 2000 to my Mac running 10.6. Since I hadn't used my Newtons in years I forgot about the Y2010 bug, so my date was way off. NCX kept crashing every time I tried to back up, then I found this page and installed Avi Drissman’s Fix2010 package. I corrected the date and time and ran NCX again and it worked great!