This has many comments on passages in my book as well as new material and links to other websites which relate his work to present-day developments. I would like also to thank the many readers of my book whose messages have helped me to build up this material. Meanwhile I am continuing to build up the detailed textual comments in this Update. The 2000 edition You are also invited to explore the material about Alan Turing in other parts of the website. The guide to the website is on the Alan Turing Home Page.
Suggestions are always welcome.