Psi-Computers were gigantic forms of super computers that were created by the Guardians of the Universe and were located on their adoptive homeworld of Oa. The Oans made use of these machines to solve complex problems that challenged their attempts at enforcing order upon the cosmos. Once a new mysterious incident emerged, the Guardians inputted that information to their Psi-Computers which made calculations on the nature of the problem whereupon it provided to its makers a full story on events that led to it manifesting in the first place. This allowed the Oans to quickly discover dangerous threats to not only their own existence but to the universe itself.