EMZETT.Floppy disk
In short: The floppy disk (diskette) is a magnetic, removable data carrier made of a thin, flexible disk in a sleeve. From the 1970s to the 2000s it was the standard for carrying small amounts of data.
In more detail: A magnetizable plastic disk rotates in the drive, a read/write head magnetizes tracks and reads them back. The name “floppy” comes from the first flexible 8-inch and 5¼-inch disks. The 3½-inch variant already had a rigid case.
In Depth
| Format | Capacity | Era |
|---|---|---|
| 8 inch | 80 – 250 KB | 1970s |
| 5¼ inch | 160 KB – 1.2 MB | 1976 – 1990s |
| 3½ inch DD | 720 KB | 1984 |
| 3½ inch HD | 1.44 MB | from 1987, the classic |
| Zip disk (related) | 100 – 750 MB | 1990s |
How it works:
- Data lies on concentric tracks, divided into sectors (512 bytes each).
- The head touches the disk directly (unlike hard drives), hence slower and more prone to wear.
- The disk spins at ~300 rpm, transfer only about 50 KB/s.
- A write-protect slider on the edge prevents overwriting.
Problems: Small size (a photo hardly fits), sensitivity to magnetic fields, dust and heat, high failure rate.
Replaced by: CD-R, USB sticks, network and cloud. The last PCs around 2005 still had a floppy drive. Sony ended production in 2011.
What remains: The save symbol in many programs. In virtual machines (disk image .img) and retro computing. The 1.44 MB are the standard measure for “tiny files” and a classic comparison in exercises (a photo today is larger than 3 floppies).
See also: Hard drives, HDD: structure and operation, NAND flash