In 1971, IBM introduced the first "memory disk", as it was called then, or the "floppy disk" as it is known today.
8-inch Floppy Disk
The first floppy was an 8-inch flexible plastic disk coated with magnetic iron oxide; computer data was written to and read from the disk's surface.
The nickname "floppy" came from the disk's flexibility. The floppy disk was considered a revolutionary device in the "History of Computers" for its portability which provided a new and easy physical means of transporting data from computer to computer.
Inventor Alan Shugart
The "floppy" was invented by IBM engineers led by Alan Shugart. The first disks were designed for loading microcodes into the controller of the Merlin (IBM 3330) disk pack file (a 100 MB storage device). So, in effect, the first floppies were used to fill another type of data storage device. Overnight, additional uses for the floppy were discovered, making it the hot new program and file storage medium.
How Does a Floppy Work?
A floppy is a circle of magnetic material similar to other kinds of recording tape such as cassette tape; one or two sides of the disk are used for recording. The disk drive grabs the floppy by its center and spins it like a record inside its housing. The read/write head, much like the head on a tape deck, contacts the surface through an opening in the plastic shell, or envelope. The first Shugart floppy held 100 KBs of data.
* First-hand account of how the operating system for the 8-inch disk was written.
5 1/4-inch Floppy Disk
In 1976, the 5 1/4" flexible disk drive and diskette was developed by Alan Shugart for Wang Laboratories. Wang wanted a smaller floppy disk and drive to use with their desktop computers. By 1978, more than 10 manufacturers were producing 5 1/4" floppy drives that stored up to 1.2MB (megabytes) of data.
One interesting story about the 5 1/4-inch floppy disk is how the size was decided. Engineers, Jim Adkisson and Don Massaro were discussing the size with An Wang of Wang Laboratories. The trio just happened to be doing their discussing at a bar. An Wang motioned to a drink napkin and stated "about that size" which happened to be 5 1/4-inches wide.
3 1/2-inch Floppy Disk
In 1981, Sony introduced the first 3 1/2" floppy drives and diskettes. These floppies were encased in hard plastic, however, the name stayed the same. They stored 400kb of data, and later 720K (double-density) and 1.44MB (high-density).
Post Floppy Disk
For the most part, recordable CDs and DVDs, and flash drives have replaced floppies as the means of transporting files from one computer to another computer.