Abstract: A storage media is disclosed and comprises a storage body and a readable indelible mark formed in the body such that portions thereof are indelibly altered. The mark is read by writing first data to the body in the region of the mark, and reading second data from the body in such region. The written first data is not accepted where the portions of the body are indelibly altered. Accordingly, the read second data corresponds to the written first data with segments thereof missing. The missing segments of the first data correspond to the portions of the body indelibly altered. In a preferred embodiment, the storage media comprises a magnetic rotatable disk having a substantially planar substrate and a magnetizable layer deposited thereon. The reading and writing are therefore performed magnetically.

Abstract: A storage media is disclosed and comprises a storage body and a readable indelible mark formed in the body such that portions thereof are indelibly altered. The mark is read by writing first data to the body in the region of the mark, and reading second data from the body in such region. The written first data is not accepted where the portions of the body are indelibly altered. Accordingly, the read second data corresponds to the written first data with segments thereof missing. The missing segments of the first data correspond to the portions of the body indelibly altered. In a preferred embodiment, the storage media comprises a magnetic rotatable disk having a substantially planar substrate and a magnetizable layer deposited thereon. The reading and writing are therefore performed magnetically.

Abstract: A storage media is disclosed and comprises a storage body and a readable indelible mark formed in the body such that portions thereof are indelibly altered. The mark is read by writing first data to the body in the region of the mark, and reading second data from the body in such region. The written first data is not accepted where the portions of the body are indelibly altered. Accordingly, the read second data corresponds to the written first data with segments thereof missing. The missing segments of the first data correspond to the portions of the body indelibly altered. In a preferred embodiment, the storage media comprises a magnetic rotatable disk having a substantially planar substrate and a magnetizable layer deposited thereon. The reading and writing are therefore performed magnetically.

Abstract: The current invention substantially removes particulate waste materials or debris from the floptical medium after laser etching. A low-temperature gas containing ice crystals is applied at a predetermined angle while the floptical medium is being rotated to improve the cleaning effect. The temperature of the disk is maintained above freezing to maintain the cleaning effect.