A report on Floppy disk and Group coded recording

8-inch, 5¼-inch, and 3½-inch floppy disks

8-inch, 5¼-inch (full height), and 3½-inch drives

A 3½-inch floppy disk removed from its housing

8-inch floppy disk,
inserted in drive,
(3½-inch floppy diskette,
in front, shown for scale)

3½-inch, high-density floppy diskettes with adhesive labels affixed

Imation USB floppy drive, model 01946: an external drive that accepts high-density disks

Front and rear of a retail 3½-inch and 5¼-inch floppy disk cleaning kit, as sold in Australia at retailer Big W, circa early 1990s

Different data storage media (Examples include: Flash drive, CD, Tape drive, and CompactFlash)

A floppy hardware emulator, same size as a 3½-inch drive, provides a USB interface to the user

Screenshot depicting a floppy disk as "save" icon

Disk notcher converts single-sided 5¼-inch diskettes to double-sided.

Rear side of a 3½-inch floppy disk in a transparent case, showing its internal parts

How the read-write head is applied on the floppy

Visualization of magnetic information on floppy disk (image recorded with CMOS-MagView)

A box of about 80 floppy disks together with one USB memory stick. The stick is capable of holding over 130 times as much data as the entire box of disks put together.

The others are different mainframe hard disk as well as floppy disk encoding methods used in some microcomputers until the late 1980s.

- Group coded recording

There were competing floppy disk formats, with hard- and soft-sector versions and encoding schemes such as differential Manchester encoding (DM), modified frequency modulation (MFM), M2FM and group coded recording (GCR).

- Floppy disk

3 related topics with Alpha

IBM DemiDiskette media and Model 341 FDD

Floppy disk variants

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A Maxell-branded 3-inch Compact Floppy Disk

A 3" floppy disk by Amstrad. This format was used by their CPC and Spectrum lines and in some systems by other manufacturers.

3-inch diskette of Nintendo Famicom Disk Systems

3-inch diskette from Smith Corona labelled 2.8-inch for the diameter of the magnetic disc itself

A write-notch puncher for 5 1⁄4-inch disks

The pictured chip, codenamed Paula, controls floppy access on all revisions of the Commodore Amiga as one of its many functions

The floppy disk is a data storage and transfer medium that was ubiquitous from the mid-1970s well into the 2000s.

Both took turnable diskettes named CE-1650F with a total capacity of 2×64 KB (128 KB) at 62,464 bytes per side (512 byte sectors, 8 sectors/track, 16 tracks (00..15), 48 tpi, 250 kbit/s, 270 rpm with GCR (4/5) recording).

Floppy-disk controller

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5-1/4 Diskette Drive Adapter found on the IBM PC. This card is based on the NEC D765AC, the large chip at the top of the image.

Block diagram showing FDC communication with the CPU and the FDD.

A setup disk of Japanese Microsoft Office 4.3, provided with 3.5" 1.2 MB and 1440 KB formats.

A floppy-disk controller (FDC) is a special-purpose integrated circuit (IC or "chip") and associated disk controller circuitry that directs and controls reading from and writing to a computer's floppy disk drive (FDD).

Translate data bits into FM, MFM, M²FM, or GCR format to be able to record them

Physical layout of sectors in a zone-bit disc: As distance from the centre increases, the number of sectors in a given angle increases from one (red) to two (green) to four (grey).

Zone bit recording

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Method used by disk drives to optimise the tracks for increased data capacity.

Commodore 1541 floppy disk (combined ZBR, ZCAV and GCR for 17–21 sectors á 256 bytes in 4 writing speed zones)