The Macintosh character set is illustrated on page I-247 of Inside Macintosh,
Vol. 1, copyright 1985. All characters that are not shaded in this illustration
can be generated on any Macintosh.
With System 4.1, the keyboard mapping changed. It now uses resources in the
System file for mapping dead keys. "Dead keys" are those that don't produce
a character until a second key is pressed. If the second character is one
that is recognized as a proper dead-key combination, then a character is
produced. For example, Option-n is a dead key that produces the n-tilde
character only if n is the next key pressed.
There are two omissions in the new keyboard maps for System 4.1. The
capital A with tilde and capital O with tilde are valid combinations that
were omitted from the key map.