A)The Annotated Turing - Petzold B)Armchair Universe: An Exploration of Computer Worlds -- A.K. Dewdney The latter had many great ideas which inspired me to do interesting experiments on computers with minimal programming experience, it had a great chapter on recursion which really helped me understand recursion when it had no programming experience. I still go back and read sections of this book. Quite a joy IMHO
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