1. What a Floppy Disk Is and Why the "Save" Icon Shows It
The square picture on the "Save" button shows a storage device called a "floppy disk." The current 3.5-inch version comes in a hard plastic case, but inside is actually a soft disk. The word "floppy" means "flexible" in English, named for the softness of the disk inside the case [1].
The surface of the disk is thinly coated with a magnetic material, such as iron oxide. You can picture this material as something like iron filings. Data is recorded by changing the direction of the magnetism in this material. A magnetic head changes the magnet direction to write data, then reads the changes to retrieve information as a sequence of 0s and 1s [1].
The recording surface of the disk is divided into many concentric rings called "tracks." Like a record player, the entire disk rotates while the magnetic head moves over the necessary track to read and write data [1].
2. How Floppy Disks Shrank from 8 Inches to 3.5 Inches Since 1971
The floppy disk was born in 1971. IBM announced an 8-inch (about 20 centimeters) disk. However, this first model was read-only, with a capacity of only about 80 kilobytes [2].
In 1972, IBM announced the "33FD," which allowed writing. Its capacity was 400 kilobytes before formatting (250 kilobytes after). Later, the double-sided "43FD" reached 800 kilobytes before formatting, and the "53FD," with a new recording method, grew to 1.6 megabytes before formatting [3].
In 1976, a company founded by Alan Shugart, who had worked on the 8-inch floppy, developed a smaller "5.25-inch" floppy [4]. Capacity started at about 90–113 kilobytes, growing to 360 kilobytes in 1978 and exceeding 1.2 megabytes by 1984 [5].
Sony in Japan aimed for an even smaller disk. They started a development team in 1979 with a goal of "about 3 inches," but settled on 3.5 inches. They released it worldwide in 1981, ahead of others [6]. The 3.5-inch size became widely known when Apple’s new computer, the "Macintosh 128K," adopted it in 1984. At the launch event, Steve Jobs dramatically pulled a floppy disk from his shirt pocket and inserted it into the Macintosh [6].
A standard capacity was eventually set. In 1987, the "1.44 megabyte" capacity adopted by IBM’s PS/2 series became the industry standard [6]. About two years later, a "2.88 megabyte" standard appeared, but it required a special drive and was not adopted by most computers [5]. Despite higher-capacity technologies existing, 1.44 megabytes became the widespread standard.
3. How Large Software Was Split Across Many Floppy Disks
It may be hard to imagine how small 1.44 megabytes is. It is said to be too small to even hold a single photo taken with a modern smartphone [13].
Because of this limit, large programs could not fit on one floppy disk. In the mid-1990s, the popular operating system "Windows 95" was sold in retail packages on 13 floppy disks. Later revised versions increased to 26 disks, and eventually, the floppy version was discontinued in favor of CD-ROM only [7].
Swapping disks one by one during installation was a normal method for distributing large software. They were split into multiple disks because of capacity limits, not because it was a failure [7]. As a rough guide, one CD-ROM from that era (about 650 megabytes) was equivalent to about 450 floppy disks of 1.44 megabytes [8]. Because of this huge difference in capacity, many software programs switched to CD-ROM as it became widespread.
4. How Computers Used Floppy Disks to Start Up
When you turn on a computer, it first goes to a small area at the very beginning of the disk to find out "what to do first." This area is called the "boot sector" [9].
The computer follows the instructions written there to become usable. This process is called "booting." In the era before hard disks, the first place the computer looked was the floppy disk [10]. After booting was complete, it was common to remove that floppy and insert a different one containing the application you wanted to use [10].
This is not a special mechanism. Today, when computers boot from hard disks or SSDs, they also read and execute the very first sector in exactly the same way. The floppy disk was not special; it was just the medium used for the same system back then [9].
5. Why Floppy Disks Disappeared from Computers
In 1998, Apple released the new "iMac" computer. It was a controversial decision at the time because it did not include a floppy drive, which had been standard until then [11].
This decision helped pave the way for the spread of USB flash drives. USB flash drives became common in the early 2000s, replacing Zip drives used for portable storage. So, the iMac removing the floppy came first, and USB drives becoming standard came after [12].
As optical discs like CD/DVD-ROMs, USB drives, and SD memory cards became widespread, and as the internet developed allowing files to be sent directly, the need to exchange data on physical media decreased [1]. The floppy disk’s own weaknesses also played a role. It had small capacity, slow read/write speeds, and was vulnerable to humidity, magnetism, and aging [13].
Manufacturers began withdrawing from production. By the end of March 2009, Hitachi Maxell and Mitsubishi Chemical Media withdrew from production [18]. Sony, which continued making them until the end, announced the end of sales in April 2010 and stopped domestic sales of all 6 models of 3.5-inch floppies by the end of March 2011 [14]. Sony, the company that first sold 3.5-inch floppies worldwide, was also the last to make them.
6. Where Floppy Disks and the Save Icon Still Remain Today
Even after floppy disks disappeared from stores, they remained in one place: Japanese government rules. In December 2022, the Digital Agency found about 2,100 clauses in national laws and regulations that specified the use of media like floppy disks [15].
In March 2024, the then-Minister for Digital Affairs, Taro Kono, reported on social media that 969 out of 1,024 regulations requiring submission on floppies had been changed to allow online submission [16]. The counting methods differed between surveys, so the two numbers cannot be directly compared, but a significant number of rules remained.
On June 28, 2024, all regulations requiring the use of floppy disks were abolished from administrative procedures. The Digital Agency announced this completion on July 19 of the same year [15]. If floppy disks disappeared from shelves around 2011, it took another 13 years for their name to disappear from laws as an "allowed medium."
One thing remains today: the square "Save" icon seen at the beginning. Many software save icons still use the floppy disk image. This is said to be the result of a design method called "skeuomorphism," which imitates the look of real objects to make the design easier for users to learn [17]. Changing an established icon creates a burden for everyone to relearn it, so the image still communicates "save" to generations who have never seen the real object [17].
7. How to Investigate Save Icons on Your Own Devices
Open an app on your computer or smartphone and look for the "Save" icon. See if it looks like a picture of a small square disk. It is also interesting to look for other icons or marks that keep the shape of old tools no longer in use.
If you are curious, try reading these two sources. The Wikipedia article "Floppy disk" summarizes the mechanism of magnetic recording and the history of its decline [1]. The article "Why is the 'Save Icon' still a floppy disk picture?" explains why the icon has not changed [17].