ASCII is very well defined. Control characters were needed at the time (and still are today, if you're using a terminal emulator).
It's easy to handle, just disallow < 32 and > 127, which are invalid or non-printable chars (but think about tab/cr/lf). Basically every font you can find can display all of the ASCII printable range without room for confusion.
It's easy to handle, just disallow < 32 and > 127, which are invalid or non-printable chars (but think about tab/cr/lf). Basically every font you can find can display all of the ASCII printable range without room for confusion.