Is the hard disk store information as bits?

Internal Organization of Hard Disk

We all are known about bits, number series which contains 0s and 1s. So many people are known that information is stored as bits onto disk, which means 0s and 1s are embedded on platter surface. But exactly that’s WRONG. Even some people don’t know how data is saved in disk, they are used hard disk for data storage purposes. But they don’t know what the exact mechanism is. So, when your eyes on the last line of this article, you can get to know about the exact function of hard disk. Let’s move into it.

Each disk coated with a film of microscopic magnetized metal grains. Information is stored in binary format(0s and 1s) on a magnetic disk using the magnetic polarity of iron particles. So, data is recorded as a magnetic pattern. Data is written on to the platter by converting strings of bits into electrical current fed through an electromagnet (An electromagnet is a type of magnet in which the magnetic field is produced by an electric current). Electromagnet generates a field strong enough to change the direction, of metal grains magnetization. The electromagnet is situated in read/write head and it changes the polarity of these iron particles are used.

The polarity of the iron particles is set to same direction to store a value 0 and in opposing directions to store a value 1.

When a second bit is stored, the polarity of its first band is always the opposite of the band preceding it to indicate that it is beginning a new bit. Even the slowest drive takes only a fraction of a second (1/60) to create each band.

• Track– bits of data are arranged in concentric circular path on a magnetic disk
• Sector– Smallest physical storage unit on disk (Almost 512 bytes in size)
• Cluster/Block– Group of two or more contiguous sectors in a single track

The map of sectors is located at the very first sector on a disk, which is referred to as disk sector 0. In windows the map is called the File Allocation Table or FAT (FAT is a table for describing the allocation status of the clusters in the file system and link between the file contents).

When a computer wants to store new information, it takes a look at the FAT to find some free sectors. Then it instructs the read/write head to move across the platter to exactly the right location and store the data there. To read information, the same process runs in reverse. When the size of a file increases above the cluster size, it is stored in the consecutive cluster if it is free. If it is not free, it is stored in another available cluster. So files stored in non-adjacent sectors are called fragmented. Operating System is the responsible for defragmenting file with the help of FAT when it is needed to access (Defragmentation means rearranges and stores the files in adjacent clusters). Microsoft windows provides a proprietary defragmenting tool within its OS.

Finally, we can come up with a conclusion,the information is stored on the disk surface as magnetized iron particles, referred to as bits.

I think, after the completion of reading, you can get some knowledge on hard disk and how it functions. As an advice, just approach everything in a different way and learn additional things to enhance your knowledge. For the initiative, no need to learn huge and completely new things to you. Just realize what is exactly happening surrounding you, that’s enough to develop your knowledge.