This function will convert the complete file from ASCII to UTF-8. When the file is saved it will remain as UTF-8 unless specifically converted to another format by the user. The status bar will show "U8-" in front of the file type (DOS/UNIX/MAC) to indicate the file is UTF-8.
Internally the file will be in UNICODE format and converted back when the file is saved to UTF-8 encoding. In HEX mode the file will be shown with its current internal representation.