I am a beginner in mainframe and I am trying to make a connection between rational developer for system z and mainframe. In host connection, I am able to make a connection and it is showing the screens of mainframe. But when I tried to make a connection in remote systems for zos, I am not able to establish a connection and download my data sets. It asks for z/os unix files, which I am not sure what it is. Can anybody tell me how to download the datasets from mainframe to windows 7 through rational developer for system z. I tried the steps mentioned in the documentation of rational developer, but am not successful in that and thought that I am missing something.