Returns the status of the system, or the status of a file handle.
If no parameter is given, the card status is returned. e.g. If a card is not inserted,
E08 is returned. If no error, a single
«sp» is returned.
If a file handle is given, the status of the file handle is returned. e.g. If the file handle is pointing to the end of the file,
E07 is returned.
«sp» | Enn