ASCII is a 7-bit character set code with values ranging from 0 to 127.
Binary data uses the 8-bit character set, with code values ranging from 0
to 255.
A/UX supports 8-bit binary files, which are usually executable applications
and binary data files. A/UX 2.0.1 recognizes only 7-bit filenames, which
means you can't create filenames with character values greater than 127.
Special characters prohibited by 7-bit ASCII include '/', '|', and so on.
However, Macintosh HFS filenames can use the 8-bit character set.