Thought I'd also mention "The ZX Spectrum ULA".
https://www.amazon.com/ZX-Spectrum-Ula-Microcomputer-Compute...
The book remains on the shelf behind me when most others have gone.
For me it's these https://www.flickr.com/photos/nathanchantrell/6446816275
Godspeed, Sir Clive. Your projects were all bonkers in the best possible way.
http://www.primrosebank.net/computers/zxspectrum/docs/Comple...