Abstract: Each face of a magnetic disc memory is divided into sectors of a circle and into concentric tracks on which are recorded or from which are recovered binary data transferred between a central processing unit and the disc memory. Each sector of each track includes an address. One or more sectors on each track is a salvage sector, i.e., a sector where data are stored if a sector on the track is faulty. Faulty sectors on a track are detected and the order in which the faulty sectors are detected is indicated. In response to the detected faulty sectors and the indication of the order in which the faulty sectors are detected, as well as in response to addressing means for sectors of the memory, a number of replacement sectors equal to the number of detected faulty sectors is assigned at the end of a track address by the addressing means.