PC History: Floppy drive

The PC floppy disk drive is a type of disk drive that reads and writes data to and from a floppy disk, which was a common data storage medium from the 1970s to the early 2000s. Floppy disks were so common in late 20th-century culture that many electronic and software programs continue to use save icons that look like floppy disks well into the 21st century, as a form of skeuomorphic design. While floppy disk drives still have some limited uses, especially with legacy industrial computer equipment, they have been superseded by data storage methods with much greater data storage capacity and data transfer speed.

A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. The first floppy disks, invented and made by IBM in 1971, had a disk diameter of 8 inches (203.2 mm). Subsequently, the 5¼-inch (133.35 mm) and then the 3½-inch (88.9 mm) became a ubiquitous form of data storage and transfer.

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

Floppy Disk Types
8-inch Floppy Disks: The original size, these disks could hold about 80-500 KB of data.
5.25-inch Floppy Disks: These were more common in the 1980s, with capacities ranging from 160 KB to 1.2 MB.
3.5-inch Floppy Disks: Introduced in the mid-1980s, they became the standard in the 1990s. These disks had a hard plastic shell and could hold 720 KB to 1.44 MB of data, with some high-density versions holding up to 2.88 MB.

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

How Old School Floppy Drives Worked

The genius engineering of the 3½ inch floppy disk

Why the floppy disk just won’t die
A surprising number of industries, from embroidery to aviation, still use floppies.
https://www.wired.com/story/why-the-floppy-disk-just-wont-die/

We Spoke With the Last Person Standing in the Floppy Disk Business
https://eyeondesign.aiga.org/we-spoke-with-the-last-person-standing-in-the-floppy-disk-business/

Where are floppy disks today? Planes, trains, and all these other places
No, really! Floppy drives still live on in many surprising places, and not just the homes of die-hard techies.
https://www.zdnet.com/article/where-are-floppy-disks-today-planes-trains-and-all-these-other-places/

5.25-inch floppy disks expected to help run San Francisco trains until 2030
“We have a technical debt that stretches back many decades.”
https://arstechnica.com/gadgets/2024/04/5-25-inch-floppy-disks-expected-to-help-run-san-francisco-trains-until-2030/

German Navy to replace aging 8-inch floppy drives with an emulated solution for its anti-submarine frigates
https://www.tomshardware.com/pc-components/storage/german-navy-aims-to-replace-aging-8-inch-floppy-drives-with-an-emulated-solution-for-its-anti-submarine-frigates

The floppy disk refused to die in Japan – laws that forced the continued use of floppies have finally hit the chopping block
News
Officials won’t ask for CD media either.
https://www.tomshardware.com/pc-components/storage/the-floppy-disk-refuses-to-die-in-japan-laws-that-forced-the-continued-use-of-floppies-have-finally-hit-the-chopping-block

Japan declares victory in effort to end government use of floppy disks
https://www.reuters.com/world/asia-pacific/japan-declares-victory-effort-end-government-use-floppy-disks-2024-07-03/
“Japan’s government has finally eliminated the use of floppy disks in all its systems, after scrapping over 1,000 regulations governing their use — Japan’s government has finally eliminated the use of floppy disks in all its systems, two decades since their heyday, reaching a long-awaited milestone …”

After 60 Years the 4-Pin Molex Connector Is Finally (Almost) Dead
For whom the bell tolls.
https://gizmodo.com/google-search-seo-leak-reveal-gatekeeps-internet-1851508410

German Navy to replace aging 8-inch floppy drives with an emulated solution for its anti-submarine frigates
News
Das Boot Disk
https://www.tomshardware.com/pc-components/storage/german-navy-aims-to-replace-aging-8-inch-floppy-drives-with-an-emulated-solution-for-its-anti-submarine-frigates
https://www.heise.de/en/opinion/Floppy-disk-drive-wanted-Why-the-Navy-defends-the-country-with-floppy-disks-9796441.html

Airlines still order floppy disks, “the last man standing in the business” explains why
Vintage or smart?
https://interestingengineering.com/transportation/airlines-still-order-floppy-disks-the-last-man-standing-in-the-business-explains-why

Boeing 747s still get critical updates via floppy disks / A rare look inside a 20-year-old airliner
https://www.theverge.com/2020/8/11/21363122/boeing-747s-floppy-disc-updates-critical-software
“Boeing’s 747-400 aircraft, first introduced in 1988, is still receiving critical software updates through 3.5-inch floppy disks.”

Obsolete, but not gone: The people who won’t give up floppy disks
https://www.bbc.com/future/article/20240510-floppy-disks-why-some-people-are-still-in-love-with-this-obsolete-computer-storage-technology

San Francisco’s Train System Still Uses Floppy Disks—and Will for Years
Three 5.25-inch floppy disks help keep Muni running every morning. A tech upgrade could take until 2030.
https://arstechnica.com/gadgets/2024/04/5-25-inch-floppy-disks-expected-to-help-run-san-francisco-trains-until-2030/
“The San Francisco Municipal Transportation Agency, which runs the city’s Muni Metro light rail, claims to be the first US agency to adopt floppy disks. But today, the SFMTA is eager to abandon its reliance on 5¼-inch floppy disks—just give it about six years and a few hundred million dollars more.”

5.25-inch floppy disks expected to help run San Francisco trains until 2030
“We have a technical debt that stretches back many decades.”
https://arstechnica.com/gadgets/2024/04/5-25-inch-floppy-disks-expected-to-help-run-san-francisco-trains-until-2030/

Update Complete: U.S. Nuclear Weapons No Longer Need Floppy Disks
The Defense Department has transitioned away from a 1970s-era nuclear command and control system that relied on eight-inch floppy disks. The “modernizing” effort was quietly completed in June.
https://www.nytimes.com/2019/10/24/us/nuclear-weapons-floppy-disks.html
https://www.cnet.com/science/us-military-retires-floppy-disks-used-by-nuclear-weapons-system/

U.S. Military To Replace 1970s Floppy Disks Controlling Nuclear Missiles
19 Oct 2019 — The U.S. finally calls time on “nuclear war controlled by eight-inch floppy disks.”
https://www.forbes.com/sites/zakdoffman/2019/10/19/us-military-to-replace-1970s-floppy-disks-controlling-nuclear-missiles/

Each generation of floppy disk drive (FDD) began with a variety of incompatible interfaces but soon evolved into one de facto standard interface for the generations of 8-inch FDDs, 5.25-inch FDDs and 3.5-inch FDDs.[1] For example, before adopting 3.5-inch FDD standards for interface, media and form factor there were drives and media proposed by Hitachi, Tabor, Sony, Tandon, Shugart and Canon.

https://en.wikipedia.org/wiki/Floppy_disk_drive_interface

The de facto standard 5.25 inch FDD interface is based upon the Shugart Associates SA400 FDD. The signal interface uses a dual in-line 34-pin PCB edge connector which mates to a flat ribbon cable connector; a separate connector is for DC power. 3.5-inch and 5.25-inch drives connect to the floppy controller using a 34-conductor flat ribbon cable for signal and control; a separate cable provides d.c. power.

The de facto standard for 3.5 inch drives uses a dual in-line pin style connector mating to a socket connector, collectively slightly smaller than the PCB edge pin connector and mating socket used for the 5¼ inch standard but with the same 34 pin definitions as the 5¼ inch standard.

Technical information on interfacing to floppy drives:
https://en.wikipedia.org/wiki/Floppy_disk_drive_interface
https://old.pinouts.ru/HD/InternalDisk_pinout.shtml

Disk drives were once used widely for all kinds of hardware hacks that needed small stepper motors driving. The disk drive drive boards contain all the circuitry you need to control them in a ready-made assembly, complete with connectors. You merely need a PC power supply and its connectors to connect them up. If you research the FDC interface you will find the details of the control signals which can be fairly directly connected to an Arduino or other micro-controller board. For read/write head positioning control, you typically have one signal for sending step pulses and other pin that tells to which direction to move the motor.

https://forum.arduino.cc/t/getting-floppy-drive-stepper-motors-to-talk-to-arduino-uno/296141

https://www.reddit.com/r/arduino/comments/gv0asm/arduino_controls_floppy_drive_stepper_motor/

https://www.instructables.com/floppy-drawbot/

https://www.epanorama.net/circuits/diskstepper.html