Floppy Disk

In 1967 at IBM, David Noble was tasked with solving an apparently trivial problem: finding a way to load programs into the new System/370 computers at startup. The semiconductor memories equipping these machines lose their content as soon as they’re powered off, unlike the older magnetic core memories. An external, reliable medium was therefore needed.

Noble’s team, which included Alan F. Shugart, Herbert Thompson, Ralph Flores, and Warren L. Dalziel, began by exploring magnetic tape cartridges. But Noble had another idea: why not use a flexible disk? The first experiments bordered on amateurism. The team bought a 45 RPM vinyl record player from a store and jury-rigged a magnetic read head mounted on the arm. The flexible disk rested on a foam-lined platter.

These experiments quickly revealed a nightmare, as the slightest speck of dust or stray hair caused data loss. Worse, these impurities literally “crawled” across the disk, pushed by the read head. The brilliant idea emerged from an evening work session between Herbert Thompson and Ralph Flores. Frustrated with the turntable approach, they abandoned this path and rushed to a grocery store to buy pink absorbent paper, the kind used for cleaning.

By cutting a file folder to the right size and gluing this pink paper to it, they created the first protective envelope. They cut openings for the read head and the central mounting system. The dust problems disappeared instantly. This pink paper would later give way to a specialized white material, but the principle remained unchanged for decades.

The first IBM floppy disk drive, dubbed “Minnow”, hit the market in 1971. It was read-only and equipped the IBM 3330 hard disk controllers as well as certain System/370 models. The following year, Memorex made a major breakthrough with the 651, the first OEM drive capable of both reading and writing. Wang Laboratories and DEC eagerly adopted it to replace their aging punched tape readers.

The real turning point came in 1973 when IBM launched its 3740 data entry system equipped with the 33FD drive. A single floppy disk could now store the equivalent of 3,000 punch cards, drastically reducing paper consumption. Its 80-kilobyte storage capacity revolutionized working habits. The industry adopted this format as a de facto standard. Shugart Associates, the company founded by Alan Shugart, took the lead in the compatible drive market.

In 1975, the market was organized around well-defined segments. Data entry accounted for 12,500 units sold, intelligent terminals 10,200, minicomputers 3,100, word processing 800 units, not to mention other emerging applications. A drive cost about $380, a considerable sum.

The year 1976 marked the arrival of the 5.25-inch format, born from an informal conversation at Shugart Associates. Customers complained about the bulkiness of the 8-inch drives, which weighed 17 kg each. The team developed a prototype the size of a cocktail napkin in six weeks. This innovation preserved the technical performance of the 8-inch format in a case adapted to the emerging desktop computers.

IBM responded in 1977 with the 53FD model, the first double-sided drive that doubled capacity while maintaining compatibility with single-sided disks. Adapting this technology proved to be an uphill battle. Shugart Associates nearly went bankrupt with its double-sided read heads inspired by Winchester hard drives. It was ultimately Tandon that found the viable solution with one fixed head and one mobile head.

This year 1977 also saw the birth of the Apple II, the first mass-produced personal computer equipped with 5.25-inch floppy disk drives. Personal computers adopted this configuration as a standard that helped standardize storage media. The software industry could finally take off.

The genesis of the 5.25-inch format reveals entertaining anecdotes. Wang Laboratories dreamed of a desktop computer with a $100 drive. Steve Jobs, unknown to the general public, regularly showed up at Shugart Associates seeking an affordable drive to replace the audio cassettes Apple used for data storage. Don Massaro and Jimmy Adkisson’s team deliberately chose the 5.25-inch dimension because it was the smallest size that didn’t allow the diskette to slip into a pocket, thus avoiding damage from carelessness.

The 8-inch format experienced its golden age in the early 1980s with 1.5 million units produced annually. The industry comprised 25 American manufacturers, 11 Japanese, and 8 European. Margins eroded in the face of fierce competition, dropping from 55% to 40%. Japanese manufacturers, obsessed with production quality, gradually dominated the global market.

The decline of the 8-inch format began with the success of the 5.25-inch, but production continued until the late 1990s. IBM maintained contracts with YE Data in Japan to deliver 5,000 to 10,000 drives per year, exclusively for maintaining old systems still under contract.

The 1980s saw most personal computers accommodate both a 5.25-inch drive and a 3.5-inch drive. The latter format eventually became the new standard. The 1990s marked the peak of the 3.5-inch floppy with over five billion units sold each year. But the arrival of rewritable CDs, DVDs, and then USB flash drives spelled the end for this technology. In 2011, Sony, the last global manufacturer, closed the book on floppy disk production.

The floppy disk saga implicitly tells the story of the complete transformation of computer storage media. From a simple program loading tool, it evolved into a versatile peripheral that heralded modern removable storage. Without it, neither the software industry nor the democratization of personal computing would have reached the scale we know today.