The planet probably was a world of the Old Empire In the Dune Universe that had long been occupied by the Thinking Machines. Its main city was Quadra City. It was used as a major supply depot and manufacturing center. After its conquest by Omnius it was surrounded by several military battle stations.
One of the human slaves was Borys, a former Ginaz Swordmaster, who begun spreading his plans among the cowed humans and gauging the other prisoners. He had carefully culled out those willing to fight for their freedom and his handpicked lieutenants were dispersed across Quadra.
Quadra was one of the final targets of the Great Purge, although it posed a significant challenge, being more heavily fortified than most other Synchronized Worlds. The Purge fleet group commanded by Vorian Atreides first attacked the artificial moons before the atomic launch. Borys and his followers were filled with hope and begun the rebellion, destroying machinery and attacking robots, preparing the way for the fleet's rescuers.
However according to the plan of the Great Purge, Quadra was rendered void of both biological life and AI presence.
Sources: Dune: The Battle of Corrin?