To access a storage location and obtain previously recorded data. To sense the presence of flux reversals on magnetic media. Usually implemented such that a dynamic flux amplitude will cause a proportional electrical output from the transducer. A digital input signal level which causes the drive circuitry to recover data. A form of memory which cannot be changed in formal operational modes.
Many different types are available.
RAM used for permanent information storage. The recording element which writes data to the magnetic media and reads recorded data from the media. The action of moving the head of a disk drive to cylinder zero. A read error, transient or otherwise, falling within the capability of an ECC mechanism to correct, or able to overcome by rereading the data in question. The amount of delay in obtaining information from a disk drive attributable to the rotation of the disk.