IIRC he figured out how far away the hacker was by putting an o-scope on the rs232 line and measuring the kermit protocol ack packet delay and that was a pretty amazing story.
It's been years since I've read it but recall it as a good read. He has another couple books as well but he admits he was wrong about various things in Silicon Snake Oil and the other book is sort of an ed-tech ant (about which he really wasn't wrong but not sure it brought a lot of new ideas.
The article could use some comments on alternative slide rule scales like the famous EE-specific slide rules and others.