The magnetic disks
The magnetic disks are typically made of aluminum. There are also experiments with disks made of glass.
The disks are covered with an ultra thin magnetic coating. With improved coating technologies, an
increasing number of micro magnets can be placed on the disk. Currently, there more than 2000 tracks per
inch disk radius. There are only 135 on a floppy disk. The narrower the tracks are, the bigger the disk
capacity gets. At the same time the magnetic signals get weaker and weaker. Therefore, the read/write
heads must get closer to the disk. This requires even smoother platters, etc.
An other improvement in modern disks is the employment of a technology called Multiple Zone Recording.
This allows for about twice as many sectors (120) in the outermost track as in the innermost. Thus, outer
tracks, which are much longer, can hold much more data than inner tracks. Previously, all tracks had the
same number of sectors, which was not very efficient.
The magnetic disks are typically made of aluminum. There are also experiments with disks made of glass.
The disks are covered with an ultra thin magnetic coating. With improved coating technologies, an
increasing number of micro magnets can be placed on the disk. Currently, there more than 2000 tracks per
inch disk radius. There are only 135 on a floppy disk. The narrower the tracks are, the bigger the disk
capacity gets. At the same time the magnetic signals get weaker and weaker. Therefore, the read/write
heads must get closer to the disk. This requires even smoother platters, etc.
An other improvement in modern disks is the employment of a technology called Multiple Zone Recording.
This allows for about twice as many sectors (120) in the outermost track as in the innermost. Thus, outer
tracks, which are much longer, can hold much more data than inner tracks. Previously, all tracks had the
same number of sectors, which was not very efficient.
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