Epub Blog says the oldest digital book dates from 1964-65 when Dr. Joseph Raben of Queens College, NY, digitized John Milton’s Paradise Lost, probably using IBM punch cards. There was a rather odd-ball segment of the humanities back then devoted to vocabulary analysis of different writer’s works. The fact that a computer text could permit you to figure out exactly how many times Milton used “fall” in his works held out a tantalizing (if no doubt illusory) hope that such facts would allow us to make decisive judgements about style. I can remember having to deal with monster books printed out from a computer file when I was an editor in the early 1970s, in particular a massive breakdown of Vondel’s Bespiegelingen. Computer analysis of this sort has perhaps not lived up to the hopes of its founders, but it has found a place in the identification of authorship via analysis of word frequencies. I don’t think too many people sat at their terminals or even their computer printouts reading these e-books straight through though.