FromCharacterCode[n] gives a string consisting of the character with integer code n.
FromCharacterCode[, , ... ] gives a string consisting of the sequence of characters with codes .
FromCharacterCode[, , ... , , ... , ... ] gives a list of strings.
FromCharacterCode[ ... , "encoding"] uses the specified character encoding.
The integer n must lie between 0 and 65535, as returned by ToCharacterCode.
For n between 0 and 127, FromCharacterCode returns ASCII characters.
For n between 129 and 255, it returns ISO Latin-1 characters.
For other n it returns characters specified by the standard Mathematica encoding based on Unicode.
InputForm[FromCharacterCode[n]] gives the full name assigned to a special character with character code n.
Whether a particular character generated by FromCharacterCode can be rendered on your output device will depend on what fonts and drivers you are using.
Encodings supported in FromCharacterCode[ ... , "encoding"] are listed in the notes for $CharacterEncoding.
See The Mathematica Book: Section 2.7.7.
See also: ToCharacterCode, CharacterRange, $CharacterEncoding.
Related package: Utilities`BinaryFiles`.