Taking books from the various piles on the floor and putting them snuggly on their new shelves, I have encountered the other 50s UK computing book: "Automatic Digital Calculators" by Booth and Booth, Butterworths Scientific Publications, 1956 (2nd ed, 3rd reprinting) While it only has four plates, it is *full* of circuit diagrams, element descriptions, and much advanced maths :) in connection with the fundamentals of the devices. I am accumulating material for a marathon scanning session, as I said in the previous post on this subject. It's a stack about 2 meters high right now. Hmmmm.... Cheerz John