This is a freely downloadable version of a computer gain based on Spider Robinson book, Callahan’s Crosstime Saloon.
I enjoy Spider Robinson’s books, although they can get old fast if you read too many of them in a row.
Here is something to think about. Robert Heinlein consistently predicted the future and was usually about 20-30 years off. If you consider his book, The Door into Summer, you’ll see Autocad and many other engineering inventions that showed up about 20-30 years later. Robert Heinlein wrote I Will Fear no Evil around 1969 (published 1970). It is the story of a man who has his brain transplanted. About 20 years later, this guy Spider Robinson appears who reads uncannilly like R. A. Heinlein. Heinlein died in 1988. What happened to Heinlein’s brain? Read Spider Robinson’s books and you be the judge.