The Floppy Disk patent was granted today in 1972 — when 80KB took up 8 inches and were really floppy

The patent application for the floppy disk was granted to two IBM engineers on this day in 1972. U.S. patent number 3668658A was for a “magnetic record disk cover” that described a rotary magnetic medium housed in a protective cover that cleaned and protected the surface. These first floppy disks were a rather large 8 inches in diameter, but had a capacity of just 80 kilobytes. They were actually floppy, like the 5.25-inch disks that readers may be more familiar with, and in contrast to the rigid plastic-encased 3.5-inch ‘save icons.’

So, floppy disks are officially 54 years old, based on the patent application's grant and publication dates. However, work on this portable storage medium began in 1967 as part of IBM’s Project Minnow. This project proposed “a flexible Mylar disk coated with magnetic material that could be inserted through a slot into a disk drive mechanism and spun on a spindle” as a form of portable/removable media, instead of tape or punched cards. Big Blue was also targeting a device cost under $200 and a media cost under $5.

IBM put these first 8-inch floppies into production in 1971, a year ahead of the patent date we are commemorating, alongside compatible drives, to offer a full solution. So folks were using these for several months ahead of the patent. Both the floppies and drives received their U.S. patents in 1972, as our headline states.

Despite its ungainly size, this first floppy disk format would be rather short on capacity, even compared to later, smaller form factors. IBM notes that it was first marketed to customers as capable of holding the same amount of data as 3,000 punched cards. That fits the era in which it was launched. However, other sources note this was equivalent to 80 kilobytes.

The next floppy disk milestone came in 1977, according to the IBM blog, when the Apple II was launched with 5.25-inch floppy drives. Steve Wozniak developed a recording scheme known as Group Coded Recording, which allowed 140 kilobytes of storage, quite a lot more than the standard single-density 90 kilobytes. Then Tandon introduced a double-sided drive in 1978, with DSDD-format floppies offering up to 360-kilobyte capacity.

In 1984, IBM would trump that with the high-density format with up to 1.2 megabytes of data storage on a 5.25-inch disk. In the same year, Apple launched the original Macintosh with a 400-kilobyte 3.5-inch floppy disk mechanism from Sony installed. IBM would refine this much more pocketable, rigid, portable disk with its 1.44 megabyte standard 3.5-inch floppy disks in 1986.

Floppies had a superb run, as far as computer technologies go. At their peak, “more than 5 billion floppy disks were sold annually,” notes IBM. Apple was again instrumental in change when, in 1998, it left tech journalists aghast by not equipping the new iMac with a built-in floppy drive.

In 2026, floppies are mere nostalgia for most computer enthusiasts. Though from time to time we still uncover surprising niches that time and new tech have forgotten, like the San Francisco Muni Metro, in New Jersey prisons, and the German Navy.

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