The Floppy Disk — Half a Century from IBM's 8-Inch Disk to Japan's Rulebook

The floppy disk is a storage medium in which a flexible, magnetically coated disk stays inside an envelope-like jacket and is slotted into a drive to be read or written. The first product was the 23FD, a read-only 8-inch drive code-named Minnow that IBM shipped in 1971, holding 80 KB. The disks then shrank to 5.25 inches and to 3.5 inches and became the standard way to carry software and data between personal computers. In Japan, provisions in laws and regulations that specified floppy disks for government procedures survived until 2024.

"Minnow", built for the mainframe

According to the Computer History Museum (CHM), in 1967 Alan Shugart, then a product manager at IBM San Jose, assigned David L. Noble to develop an inexpensive way to load microcode into the controller of the IBM 3330. IBM's own account says the team considered magnetic tape before switching to a flexible Mylar disk with a magnetic coating that could be inserted through a slot into a drive. Because the disks got dirty easily, they were packed in slim envelopes lined with a dust-wiping material.

Warren L. Dalziel was the lead inventor of the drive, and Ralph Flores and Herbert Thompson designed the protective jacket. A survey report published by Japan's National Museum of Nature and Science says IBM announced the 23FD in 1970 and brought it to market the following year, 1971. CHM gives its capacity as 80 KB, about 3,000 punched cards. IBM began selling floppy drives in 1971 and received US patents for the drive and the disk in 1972. IBM quotes Dalziel's recollection: "I had no idea how important it would become and how widespread."

The same report says IBM followed with writable 8-inch disks, raising capacity to 250 KB (33FD) in 1972, 560 KB (43FD) in 1976 and 1.2 MB (53FD) in 1977. New drives could read and write older disks, and that backward compatibility became a requirement for the 5.25-inch and 3.5-inch generations as well.

The 5.25-inch disk and the personal computer

Shugart moved to Memorex and in 1973 founded Shugart Associates. According to CHM, Gary Kildall used the company's SA800 8-inch drive to develop CP/M. The 8-inch disk was too large and too costly for word processors and personal computers, so in 1976 Shugart Associates introduced a 5.25-inch disk and drive.

The floppy changed the personal computer. The Apple II started out storing programs on cassette tape, and the Disk II followed in 1978. The IBM PC was also sold in a configuration with two floppy drives. IBM credits the floppy with making an independent software industry possible, since companies could now put programs on disks and sell them by mail or in stores.

Sony's 3.5-inch disk

The National Museum of Nature and Science report says Sony announced a 3.5-inch micro floppy disk (MFD) and drive in 1980. Its author, Hidetoshi Kamoto, worked on planning and developing that drive at Sony. According to the report, Sony had no prior experience with floppy disks but produced the product within a year. The disk sat in a rigid plastic case and was praised for being easy to handle; HP adopted it for the 9121D/S in 1982, Apple for the Macintosh in 1984 and IBM for the PS/2 in 1987, making it the world standard. The report describes this as the first time a Japanese manufacturer's proposal became the global standard in data storage.

The 3.5-inch figures are from the National Museum of Nature and Science report; the 5.25-inch 1.2 MB is from IBM.

For the most widespread capacity, 1.44 MB, English Wikipedia says a group of 21 companies settled on a 3.5-inch design improved from Sony's, and that 1.44 MB drives first shipped in 1986.

From 5 billion a year to the save icon

IBM says more than 5 billion floppy disks were sold each year at the peak in the mid-1990s. The National Museum of Nature and Science report estimates that in the roughly four decades from 1971 to 2009, when Sony stopped making 3.5-inch drives, 1.97 billion drives and 49.24 billion disks were shipped. The 3.5-inch format accounted for 1.71 billion of the drives (86.8%) and 35.5 billion of the disks (72.1%).

As software grew, the floppy became a burden. IBM notes that the diskette version of Windows 95 came on 13 diskettes that had to be installed one after another. The 1998 iMac shipped without a floppy drive. IBM left the floppy business and others soon followed; by the mid-2000s, IBM writes, floppies had gone the way of the punched card. A floppy-shaped icon still marks the save button in a great deal of software.

Computerworld reported in April 2010 that Sony would end floppy disk sales in Japan by March 2011. The Japanese market the year before was about 12 million disks, 70% of them Sony's, and many of the remaining customers were education and research users with legacy equipment.

Out of Japan's rulebook, 2024

The floppy disk's name stayed in Japanese law for a long time. Working with other ministries, the Digital Agency had been revising what it calls analogue regulations, and at a press conference on 14 June 2024 Digital Minister Taro Kono said there had been 1,034 regulations concerning floppy disks and that all but one had been revised. The remaining one fell under Article 27 of the End-of-Life Vehicle Recycling Act, which the Ministry of the Environment administers.

At the same conference Kono said the effort had become an international talking point, partly because the BBC had reported it. At his 2 July press conference he later confirmed that the last provision had been completed on 28 June. Across the whole programme, 4,332 of the 6,364 regulations based on laws and ordinances, about 70%, had been revised by mid-June.

Fifty-three years after IBM's 8-inch disk, the floppy left Japan's administrative procedures too. For the optical disc that followed in video, see DVD; for hardware generally, the hardware timeline.