... in response to earlier discussion ...
Reading more, you *do* mention internal modems and the need to disable
an internal COM port in the "Getting the Right Hardware" chapter --
Modems, p 154.
There's also a typo (at least I think it's a typo) in the "Burn-In"
section of the same chapter: "A god idea is to put a smoke detector
abvoe the machine...". Hmm... Playing God with your hardware?
Good book, BTW, and fun to read.