Not true! ;) Murray Leinster featured both PCs and the Internet (not by those names, of course) in his short story "A Logic Named Joe", first published in Astounding Science Fiction in March, 1946.
Hmm, let's see what's on our shelves... the "Sector General" books my James White; collections of short stories by Zenna Henderson, Murray Leinster, and C.M. Kornbluth (all published by the SF Book Club, by the way); Slan and The Empire of Isher by A.E. van Vogt; the 6 Lensman books by E.E. "Doc" Smith (in two editions, btw); oh, and lots of other stuff by the Big Names that you're already familiar with.
That's the hardcovers...
Oh, a neat story collection you might look for (it's out of print I think, but might be found in a library) is Galactic Empires, volumes 1 and 2. It not only presents a lot of good Golden Age stories, it analyzes the different kinds of "Galactic Empire" stories that have been published over the years.