Storage devices come in a variety of shapes, sizes, and media. The most common storage devices are Magnetic Storage devices. For instance, a Floppy disk or Hard drive (with the magnetic strip). Zip disk and Magnetic strips are used in credit cards and ATM cards, but microchips in many commercial applications have replaced them. Magnetic Storage devices can still be found on desktops with old computers using floppy disks. We can use them to store and access large amounts of data. They are easy to use but are mostly obsolete due to the advanced technology.

Structure and design:

The magnetic storage device contains iron oxide or ferrite elements surrounded by a thin film of plastic or Mylar. The magnetic material is magnetised in one direction, making it a magnetisation medium with parallel magnetic lines of force. The information is stored in the form of small spots on the disk’s surface. When the disk rotates, the spots pass under a read-write head. The magnetic properties of the medium are modified by the nature of the pattern of magnetic lines recorded on its surface. The magnetic Storage device is used to store data and information.

Storage capacity:

The storage capacity of a magnetic storage device is usually measured in bits or bytes. The word bit is short for binary digit and has a value of either 0 or 1. A byte is a multiple of 8 bits, giving a value from 0 through 255 for each position in memory or storage devices. Thus the storage capacity of a magnetic storage device could be given in bits or bytes.

Classification:

Magnetic storage devices can be divided into two categories, Digital storage devices and analogue storage devices.

  • Digital storage devices store data digitally and can only be read by the computer it was written to and can only be processed when the computer is turned on. These are commonly used for non-critical data sent to the computer for processing or being read. These devices may be memory cards like SD cards, CF cards, MMC cards and hard drives of computers, pen drives, etc.
  •  Analogue storage devices store data in an analogue form, which means different wavelengths of light store them. These can be optical disks, CD-ROM, DVD-ROM, and Blu-ray discs, wherein CD-ROM is not an optical medium like others but an electronic one. 

Applications:

Magnetic storage devices are used by all industry sectors, including computers, communication and information technology, transportation, security and identification, retailing, medical equipment, and others. Their most common usage includes:

  • Fluorescent lamp- Used in calculators or in the display of Time and Date.
  • Transistor- Used in digital watches, audio oscillators, amplifiers, audio controls, and auto-ignition.
  • Vacuum tube- Used in audio equipment, microwave ovens, and radios.
  • CRT- Used for television images, monitors (evolution of display tubes), digital watches, and calculators.
  • CD ROM or CD player- Used for playback of digital music files recorded on CD media. A standard disc allows storage capacity from 650 MB to 10 GByte per disc side.

Floppy disk- Used to store and retrieve small amounts of data. It contains a magnetic strip on the periphery of the disk, which is read and written by a floppy disk drive.

Hard drive- Used in computer systems, networks, and industrial equipment. HDD contains hard disks, which are made up of many hard rigid plastic disks with several platters and read/write heads mounted on rails to be moved relative to the platters to read discs or transfer data between discs.

Zip disk and magnetic strip- Zip disk and magnetic strip storage device are the steps of evolution in magnetic storage devices. A zip disk is a magnetic disk on which digital information can be stored and retrieved. It has 80 MB, 100MB, or 250MB capacity and is used to transfer data between computers. It requires an external drive to access data that is stored on it.

Advantages and disadvantages of the Magnetic Storage device:

Advantages of the Magnetic Storage Device are:

  • It is a comparatively cheap storage media.
  • It can store a large amount of data.
  • It offers a fast and efficient user interface. This media can be easily carried and moved from one device to another.

Disadvantages of the Magnetic Storage device are:

  • We cannot access the data stored unless a computer is available with a suitable reading device.

A better alternative to floppy disks is portable storage devices.

  • The storage media available has a finite capacity which limits the amount of data it can store.
  • We cannot use it for storing information that requires high-speed access, like financial market data.

Conclusion: 

Magnetic storage devices are used in various applications such as data storage, data transfer, voice and image recognition, audio recording, and playback. Besides these uses, magnetic storage devices are also used for security purposes like credit card and debit card numbers, ATM cards, etc. The magnetic storage device has advantages over other storage media like floppy disks, hard drives, and CD-ROMs. It has plenty of space to store huge amounts of information between the two recording surfaces, which is especially useful when transferring or processing huge amounts of data such as computer, audio, or video files.