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Data Storage: Synchronized at the 'Write Time'

A microscopic image of a bit-patterned recording medium.

A scanning electron microscope image of a bit-patterned recording medium, with ordered arrays of magnetic islands.

Credit: A*STAR Data Storage Institute

A*STAR researchers say they have established several important design principles to consider when developing bit-patterned media recording (BPMR), a potential high-density magnetic recording system.

The BPMR technique offers much higher storage capacity than conventional hard disk drives because it records the data in a regular array of single-grain magnetic islands that can be much smaller than the multiple grain bits in continuous media, says A*STAR researcher Maria Yu Lin.

"Ideally, bit-patterned media [will] achieve one grain per bit because the magnetic cells are patterned in isolated and ordered arrays known as 'islands,'" Lin says.

However, variations in disk-spinning speed and vibrations can cause temporal misalignment, which in turn causes writing errors. The researchers solved this problem by adding information to the disk that tells the writing head its exact position.

"The analysis indicates that the total additional information needed for synchronization and error correction for a motor with a medium rotation variation is 11.75 percent," Lin says. "Compared to the potential gain in terms of data density that this technology enables, such a total overhead is acceptable."

From A*STAR Research
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Abstracts Copyright © 2013 Information Inc., Bethesda, Maryland, USA


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