I am not sure which version of the debugger you are using. It was designed for ASCII printable characters. However if you highlight any line in the body of the debugger it will show you, in the text line labeled "W/CC" (for with Control Codes) the standard mneumonic for each ASCII control character that appears in that line. I did that for the obvious reason. All the ASCII control characters have values below 32. I show them as (NUL), (STX), (ETX), (ACK), (CR), (LF) and so on.

If you are interested in that sort of stuff download a copy of the free Textpad text editor. One of its features is that it has a window you can keep open that shows all the ASCII coding. It is the only text editor I use for many reasons.

Hope that helps