This transfers a file using ZMODEM Binary, which tells the receiver not to change anything. Use this to send text without converting line endings, or send raw data that a different operating system can understand, such as a .WKS format spreadsheet.
This transfers a text-only file using the ZMODEM Text option, which automatically converts line endings to the convention of the receiving system. Select this if you are sending a text file to a non-Macintosh system, like DOS or UNIX.
MacBinary II is the standard format for transferring Macintosh files. If the file is intended to be used on a Macintosh, even if it may be stored on a different system in the meantime (such as most BBSes), this option should be selected.
