But what you need to type on the PC side depends on what program you are using to communicate with cattell. The file will appear on your desktop. The file will transfer to cattell. Kermit 5a can display file transfer progress using your whole screen in a rather nice way. Fill these items in, ignoring any other fields.
Fetch is very fast, and very convenient.
These is no need to disconect from cattell or even to quit any other programs to run it. Remember, you can have a number of program running at once on a Mac, and you can have as many programs communicating with cattell as you want.