What is a floppy disk

What is a Floppy Disk? Definition, Uses, and Types

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If you are one of the people interested in the history of the computer world, then you must have surely heard about floppy disks. And even if it is not so, then this article will undoubtedly be able to introduce you to the world of floppies. So, let’s get started with the question – What is Floppy disk?

What is a Floppy Disk?

A Floppy Disk is a type of disk storage coated with a magnetic material such as iron oxide. It is also known as a floppy or diskette.

It was invented by Alan Shugart of IBM (International Business Machines Corporation) in the year 1967 for storage of non-volatile, permanent secondary memory, to be interpreted by a floppy disk drive (FDD). Floppy diskettes composed of flexible (hence called floppy), thin, circular magnetic disks, are majorly available in three sizes 8 inches, 5.25 inches, and 3.5 inches.

floppy disk

The 8-inch floppy can store up to 80 KB of data, the 5.25-inch floppy can store 160 KB of data if coated on a single side (hence, 320 KB if double-sided), and the most widely used in the past, the 3.5-inch floppy can store up to 1.44 MB data. In diskettes, data is written and stored in a series of sectors. But floppies were replaced in the early 2000s by various other storage devices which were smaller in size and had more storage capacity.

Uses of Floppy Disk

Early computers did not have CD-ROM drives or USBs, and floppy disks were the only way to install a new program on a computer or to back up your information.  If the program was small (less than 1.44 MB for a 3.5″ floppy disk), the program could be installed from a single floppy disk.

However, most programs were larger than 1.44 MB and hence required multiple floppy diskettes. For example, version 13 of Windows 95 came on a DMF diskette and one diskette had to be installed at a time.

While compact discs (CDs) and universal serial bus drives (USB) replaced disks extensively in the 2000s, there are still several uses for floppy disks today. The aviation industry to some extent, still relies heavily on floppy disks, primarily for updating systems.

You would be surprised to know about specialized, high-end embroidery sewing machines, which are dependent upon floppy disks for programming. Files are transferred between computers by means of a 3.5-inch floppy disk which is said to be the Universal Standard for file transfer between different computers.

One of the most important applications of 3.5-inch floppy disks was to deliver programs and services, including important drives and software updates. Floppies can be easy tools to update drivers and software. 

Types of Floppy Disks

8-inch floppies 

As we told you above that in the late 1960s, the first floppy disk was introduced with a diameter of 8 inches. This floppy disk was designed only in read-only format.  But as it was upgraded over time, it became capable of reading and writing. 

Have you ever wondered how the floppy disk got its name? In fact, Floppy got its name because of its physicality as its physical structure looks like a floppy folder. After which all the subsequent versions were also named taking the same name as the base.

5.25-inch floppies 

After the invention and launch of the world’s first floppy disk in 1967, a new version of it was launched in the 1980s, whose diameter was 5.25 inches. This floppy disk drive was the most widely used drive for computers at that time. The ability to store data on this floppy disk drive ranged from 360 KB to 1.2 MB.  Some of the 5.25 versions also had floppy disks that allowed data to be written on both sides and to modify that data again. After this floppy disk was further upgraded, after which it was developed as a double-sided drive.

3.5-inch floppies

Soon another floppy disk came on the market, which in comparison with the earlier floppy disk drive was smaller. Its diameter was 3.5 inches. Its upper part was made of plastic and it could store up to 1.44 MB of data in it. Apart from this, data up to 730 KB could be stored on its double-density disk.

Parts of Floppy Disks

Floppy includes the following parts-

Read/Write Heads: are placed on both sides of a floppy diskette, they move together on a common congregation. The two heads are not positioned directly opposite to each other. Reading and writing are done on the same head while a second, wider head is used for erasing an input just prior to it being written.

Drive Motor: A very small spindle motor is attached to the metal hub at the center of the diskette, spinning on an average of 360 rotations per minute (RPM).

Stepper Motor: This motor makes accurate revolutions to move the head assembly to the proper track location. The input writing head assembly is further fastened to the stepper motor shaft.

Mechanical Frame: A  lever system that opens the protective window on the diskette to allow the input recording heads to touch the double-sided diskette media. A  button installed in the outer region allows the diskette to be ejected, at the point where the spring-loaded protective window closes.

Circuit Board: works as a base for the electronic stuff required to handle the data read from or written to the diskette. It also manages the circuits controlling the stepper motor used to move the read/write heads to each track, as well as manages the movement of the read/write heads toward the exterior of the diskette.

Working of Floppies

  • The computer program instructs the computer hardware to provide input for the floppy disk.

  • The floppy-disk-drive controller begins the motor movement in the diskette drive to spin the floppy disk which has multiple concentric tracks on each side with every track divided into tiny segments called sectors.

  • The stepper motor turns a worm-gear shaft in minute increments matching the spacing between tracks. The time taken to detect the correct track is said to be the “access time.” The action partial revolutions of the stepper motor move the read/write head setting. The floppy-disk-drive electronics know how many steps the motor has to turn to move the read/write heads to the accurate track.

  • The input head settings stop at the track. The read head enquires about the prewritten address on the formatted diskette to confirm it is using the right side of the diskette and is at the correct track.

  • Before the incorporation of the data on the diskette by the write head, an erase coil “clears” a large sector called the “clean slate” sector. The clean slate sector is always wider than the sector written by the read/write head.

  • The energized write head commits data to the diskette by magnetizing minuscule bar-magnet particles embedded in the diskette surface.

  • The diskette ceases to spin and leaves the floppy disk drive to wait for the next command.


Floppy disks prove to be more appropriate for short-term data storage and data transfer. They are susceptible to malfunctions and can hold only a small amount of data in comparison to newer storage devices, such as USB devices and CDs.

The above article provides decent information about floppies which can prove to be useful for anyone who desires to acquire knowledge about the same.

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