Floppy Disk Drive

lntroduction

A floppy disk drive (FDD) is a device designed to read from and write data to floppy disks, a type of removable magnetic storage. These drives were standard in PCs from the late 1970s until the early 2000s

Types of floppy Drives & Disks

Types of Floppy Drives & Disks

8‑inch – the first widely used format (introduced 1971)
5¼‑inch – dominant in the late 1970s–1980s, used in early IBM PCs
3½‑inch – the most common, rigid plastic shell, metal shutter, capacities up to 1.44 MB (HD)

Proprietary variants – for Macs, Amiga, etc. (e.g., 400 KB, 800 KB, 1.4 MB)

Capacity & Physical Sizes

Disk Type	Size (Physical)	Typical Capacity
8‑inch	~200 mm diameter	Up to ~1 MB
5¼‑inch	~133 mm diameter	360 KB (DD), 1.2 MB (HD)
3½‑inch	90 × 94 × 3.3 mm cartridge	1.44 MB (HD), also 720 KB (DD), 2.88 MB (ED rarely)

Function & How it Works

Insert the disk – into the slot; on 3½″ disks, the metal shutter opens automatically.
Spin & position – a spindle motor rotates the disk; a head moves radially to access tracks .
Read/write data magnetically – soft or hard sectoring, encoding determines data format
Drive head – floats just above disk surface, precise and similar to a hard drive but slower.
Eject & protect – pressing the eject button disengages the disk; plastic casing (and shutter on 3½″) protects media.

Functions & Use Cases

Storage: Hold small files, documents, installation software.
Backup: Save configuration files or critical data.
Software distribution: Disks often shipped with OS or software.
Bootable disks: Many systems used these to boot or recover PCs.
Portability: Easy to share between computers.

By the late 1990s, they were phased out in favor of Zip drives, CD-ROMs, USB flash drives, and external hard disks.

External USB Floppy Drives(Modern)Revival

External USB FDDs act like typical drives and are still sold to access old disks. They use a USB‑A cable and are plug‑and‑play, powered entirely via USB.
The images show typical compact models supporting 1.44 MB (HD) or 720 KB (DD) disks.

Summary

What it does: Reads/writes data to flexible magnetic disks.
Main types: 8″, 5¼″, 3½″ (most popular).
Capacities: Up to 1.44 MB for 3½″ HD.
Mechanism: Spin + magnetics + movable read/write head.

Typical use: Software, backup, boot disks, portable files.