My print copy of 2001: A Space Odyssey (A.C. Clarke) has disappeared, but I seem to recall that in an early chapter when Floyd was the sole passenger on a shuttle to the moon he read the latest news on a portable device that strongly resembled today's internet-connected tablets.
Robert A. Heinlein described a CAD system called "Drafting Dan" in his novel "The Door into Summer". But he was a little off-target in "Have Space Suit: Will Travel" where space flight to the moon happens (first prize in a soap contest), but slide-rules are still in use. Can't predict everything, but still good calls...
Of course it is possible that RAH stuck with the slipstick concept because this was one of his "juvenile novels" written to encourage youngsters to get into what we now refer to as "STEM"; and slide rules were the only computational resource available at the time.
While he's better known for A Room with a View and A Passage to India, my favorite E. M. Forster work is "The Machine Stops" (1909), which IMO quite accurately describes the Internet, especially social networking.
Jules Verne also invented (unless someone can point me to prior art) full-motion holograms in The Carpathian Castle (1892) and IMO steampunk in The Steam House (1880), which features a giant steam-powered mechanical elephant :-)
Jerry Pournelle: "By the turn of the century, you will be able to use your computer to get any piece of information that exists." Probably not the exact quote, but he wrote it in the early 1980's or late 1970's, in his column in Byte Magazine.