Floppy Disks

The US company IBM made a great breakthrough in the storage and retrieval of computer information in 1970. 

The IBM 3740 system could be used with a "floppy disk" - a thin, flexible plastic disc 8 inches across, covered with magnetic iron oxide.

The "floppy" was designed to be inserted into a slot in the computer which could copy data on to it or read information from it.

Floppy disks were slower in operation, stored less information, and were less reliable than hard disks, but could easily be inserted in or removed from a computer and provided an inexpensive form of portable computer media. They were also far faster than the reel to reel magnetic tapes used by older systems.

Two types were in use - The 5.1/4-inch disks, which really were floppy, and the 31/2-inch disks, which had a rigid plastic jacket with a sliding metal shutter. 

The surfaces of the disk were divided (formatted) into areas on which information could be stored and the disk was held in a disk drive which rotated it inside its cover.

The computer stored information on the disk, or retrieved information from the disk (known as ''writing'' and ''reading'' operations respectively) by a fixed magnetic head within the disk drive.

Floppy disks were also known as "diskettes".