The Cosmic Computer by H. Beam Piper
Originally published as “The Junkyard Planet” in 1963, and based on a short story (“Graveyard of Dreams”) first published in 1958. This is the story of a planet down on its luck. Poictesme experienced a boom when it was a major military HQ during the System States War. When the war ended, the Terran Federation couldn’t even afford to ship their gear home. Bases and Logistical centers were sealed up and all the military personnel left packed on transports. The planet’s economy takes a major hit. They are reduced to two major exports. The first is a local mellon prized for the brandy made from its juice. They can sell it for centa-credits a barrel, which is what the rare interstellar trader will pay for it. The brandy made from the juice sells for several credits a glass on Terra. Their other export is military surplus they dig out of old Terran Federation bases, which they are also paid in single digit centi-credits on the credit. A group of leading citizens pool their money together and send one of their own, young Conn Maxwell, to far off Terra. He is to study computer systems at a major university and learn all he can about the legendary Terran Federation military super computer, Merlin. After being told by impeachable sources that Merlin was a myth, Conn returns home with a plan to bootstrap the economy with a search for Merlin. His hope is that by the time the planet is producing its own starships and engaging in interstellar trade (instead of having middlemen dictate prices to them), the group of ‘leading citizens’ will realize that they don’t need Merlin. Then the unthinkable happens and throws a giant monkey wrench in Conn’s plans.