A system and method for incrementally recording blocks of data such as servo
information
on magnetic media such as hard disks, flexible disks or tapes. The system comprises
a master element with permeable features configured according to the block of data
and corresponding to a small fraction of the area of the medium. A predetermined
portion of the medium is advanced and brought in proximity to the master element.
An electromagnet applies a localized field to copy the data to the selected portion
of the medium. The field of the electromagnet is decreased before the next predetermined
portion of the medium is advanced thereby avoiding damage to previously recorded data.
