AoE x-Chapters is down to the wire

The door is close to slamming shut on the new Art of Electronics, x-Chapters book. We appreciate all the comments and advice given so far. Paul enjoyed reading much of it too, that I pasted to appropriate places in the draft text. We made many dozens of changes and additions; a few more are still underway. Thank you all! Any last-minute thoughts, get 'em in now.