In the variables, expressions, and monitors views, you'll notice an inverted black triangle in the title bar. Click on it to open a menu.
From that menu, select "Java Primitives..." and a dialog will open prompting for your "Primitive Type Display Options" and giving you 3 options with check boxes:
Display hexadecimal values
Display ASCII character Values
Display unsigned values
Check those boxes you want, and click OK.
You can now see the selected values in addition to the original value in the view.
Very useful at times -- thanks for making me go find it.