This novel had its genesis in a much shorter story called "Graveyard of Dreams" (Galaxy, 1958) Piper expanded it to book length, and it appeared in 1963 as Junkyard Planet. Ace later renamed the book The Cosmic Computer for its paperback appearance. This edition returns the book to Piper's original title, Junkyard Planet.

Conn Maxwell returns from Terra to his home world of Poictesme, dubbed "The Junkyard Planet" because of all the military equipment left behind after the last war. Conn claims he has found the location of Merlin, a military super-computer rumored to have been left behind. But is Merlin real, or just a myth? And will Conn’s knowledge of the computer save Poictesme -- or tear his world apart?