Quick Disk

A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium encased in a rectangular plastic carrier. It is read and written using a floppy disk drive (FDD). Floppy disks were an almost universal data format from the late 1970s into the 1990s, used at first as a primary data storage mechanism, and later mostly as a file transfer system as part of what became known as "sneakernet".

Work on a drive that led to the world's first floppy disk and disk drive began in 1967 at a San Jose (CA) IBM facility, and introduced into the market in an 8-inch format in 1972. The more conveniently sized 5¼-inch disks were introduced in 1976, and became almost universal on on dedicated word processing systems and personal computers. This format was more slowly replaced by the 3½-inch format, first introduced in 1982. There was a significant period where both were popular. A number of other variant sizes were introduced over time, with limited market success.

Floppy disks remained a popular medium for nearly 40 years, but their use was declining by the mid-1990s. The introduction of high speed computer networking and new formats like the USB thumbdrive led to the eventual disappearance of the floppy disk as a standard feature of microcomputers, with a notable point in this conversion being the introduction of the floppy-less iMac in 1998. After 2000, floppy disks were increasingly rare and used primarily with older hardware and especially with legacy industrial computer equipment.

In 1967, IBM tasked their San Jose, California development laboratory to develop a reliable and inexpensive system for loading microcode into their System/370 mainframes in a process called Initial Control Program Load (ICPL). The System/370 was IBM's first computer system family to make extensive usage of volatile read/write semiconductor memory for microcode, so for most models, whenever the power was turned on, the microcode had to be loaded (System/370's predecessor, System/360, generally used non-volatile read-only memory for microcode). IBM also wanted inexpensive media that could be sent out to customers with software updates.

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