from the man page : ) The control–\ character is a local escape. It prompts with >>>. Legitimate responses to the prompt are ... q Exit.
i suppose the trick is find it on your keyboard, in the spanish keyboard is ctrl+ç, and under drawterm X11 i need to type ctrl+altgr+1 try to find \ whithout configure your local map, then use that key to exit con. slds. gabi