A magnetic memory system is provided that includes magnetic domain data chips having a block replicate organization wherein the system may include data chips having one or more defective minor loops. A dedicated minor loop is provided on the chip to store a redundancy map for locating the defective minor loops. The dedicated minor loop also provides for storing a synchronization pattern for initializing the system by having each minor loop properly addressed for transferring magnetic domains. The dedicated loop can only be accessed by a separate swap pin preventing a write operation by the user thus preserving the data stored therein.