In today’s tech savvy world, it is very improbable that an educated adult person has no knowledge of about a Hard Disk Drive. The device is technically a mass storage for digital data and is used in a wide range of electronic gadgets and appliances including computers, phones, tablets etc. Physically, it consists of multiple platters with magnetic heads organized on a moving actuator arm which stores and retrieves data. The rapid rotation of the platter is the signal that data is being either stored or retrieved by the user. There can be multiple numbers of platters inside a device depending on the capacity of the device. For example, a laptop usually has 4 platters while an iPhone has 2. Data is stored in a random access manner which indicates that while work is in progress, data can be saved anywhere in the HDD randomly and not in a sequential order. The typical Hard Disk Drive retains the data stored even when the power is disconnected.

Although a part of our daily life in recent times, there are facts about the Hard Disk Drive that most of us are oblivious about. Some of these are presented as follows:

• Hard Disk Drives were developed by IBM for the first time in 1956 and were intended to be used as a secondary storage device.

• This initial IBM drive, named the 350 RAMAC, was the size of two refrigerators and had stacks of 50 disks.

• Till now, more than 200 companies have developed and modified the Hard Disk Drives. Amongst these are Seagate, Toshiba and Western Digital.

• Standard interface cables keep the Hard Disk Drives connected to the system. Some of these are SATA, USB and SAS cables.

• The first ever PC to use an HDD was the Apple Macintosh which used the secondary storage device as an external memory and had to be bought exclusively.

• Although the platters are coated with a shallow layer of magnetic material about 10-20 mm in depth, the platters themselves are made of non-magnetic materials like ceramic or aluminium alloys.

• The magnetic attributes of the drive are at risk of being lost when the drive heats up. To counter this possibility, two parallel layers of magnet are coated on the platters separated by a layer of non-magnetic element.

• The Hard Disk Drives of the first generation would spin at a speed of 1200 rpm. The most modern version of drives rotates at a maximum speed of 15000 rpm.

• The amount of natural error has been reduced with the development of Low-Density-Parity-Check Codes.

• The average seek-time of a Hard Disk Drive is under 4 ms in modern drives while the first generation of drives had a seek-time of about 600 ms.

These are only some of the lesser known facts about the HDD. Keeping in mind the extensive use of this device in almost all the gadgets we use today, more such interesting facts are there that would astound readers. The HDD is changing every day and someday it might happen that it is completely replaced from the face of the earth by some better technology.