These are know as fixed length record files. No EOL characters are used. A DOS file will display correct on both Macintosh and Unix except for the presence of an extra character that may or may not be displayed at the beginning or the end of a line. There are many public domain programs that will convert between these format. In DOS there is no way to convert without having a special program.
Printing is done correctly.
No conversion is done. There are many other Macintosh third party products for this function. Most are marketed as being able to read and write DOS diskettes and floppies. These programs do the conversions invisible to you. Unix Unix comes with many commands and filters that will do the conversions in any direction.