The protocol is documented in the SDK and is really simple to implement. You send commands to the Z7000 (or anything running the file transfer program) that do stuff like: listing directories, changing the current directory, sending a file, receiving a file, and some others. The file transfer protocol is similar to xmodem. If you don't mind using shareware, there is a program called ZoomCom in the Zoomer library here that does what you are trying to do.
PDC Chris
PDA Forum Consultant
Keyword: PDA