I think you're still missing the point.
The entire FILE is non-printable characters!
The file is not a "document" as much as it is a "drawing".
AutoCAD contains vector data.
the definition of lines, arcs, circles, dimensions include
arrowhead type, size, extension length, all sorts of GRAPHICAL data.
It just so happens that within the graphical context, we insert
some text. AutoCAD doesn't save the text in one way, but encrypt
everything else.. it encrypts it all.
I opened an autocad DWG file in a text editor.. there is not a single
recognizable word in the whole file.
The fact is that the file is NOT ASCII.. therefore, opening it as if it WERE
an ASCII file won't do any good.
Ever tried opening a .jpg file with a text editor?
Try it... you KNOW that somewhere in the file is a word.. but you won't find
it in the text editor!!!