How did floppy disks work?

Floppy disks, flexible disks, floppies. We know their history quite well, we know that they are an endangered species (unless a manufacturer brings them back), and we've come across very interesting replacements, but I think we haven't explored how they work. It's clear that the floppy disk is a magnetic storage medium, and that it had to deal with several limitations during its evolution, however, those are too superficial details, and don't fully explain how our data was saved on them…

Anyone who decides to review the history of floppy disks will see that they were developed in the late 1960s, with their first commercial variant debuting in 1971. Of course, I mean the eight-inch disk, which had unexpected media exposure when it was seen participating in the control of US nuclear weapons. From eight inches we went to 5.25, and from there to 3.5, with several experimental and alternative formats in between, used by other systems (such as Amstrad's three-inch disks).

Once the standards were set, the floppy disk lowered costs (and by extension, quality) until its virtual extinction. Today they can be obtained in the form of old stock or recycled drives, while Windows 10 doesn't even include a built-in driver for USB readers (although Windows Update offers one), but honestly, how many times did we stop to think about the way they work?

How Floppy Disks Work

It all starts with the external design of the floppy disk. The two marks on the bottom near the read window on 5.25-inch disks serve to relieve any type of additional tension generated by the drive. The small circle acts as an index, helping to determine the position of the disk in terms of its rotation, and the famous slot that is covered with tape allows us to establish whether the disk can be written to or not.

Despite the general fragility that has been associated with them in recent years, floppy disks have a more robust magnetic surface inside than old cassettes. The format on each floppy disk depends on the type of computer, but as a reference, IBM PC and compatible systems adopted a structure of 40 tracks divided into eight sectors (later nine), almost doubling those numbers when the disk is double-sided (80 tracks, 15 sectors). Although this is not the most efficient way to store data, its effectiveness was sufficient for the demands of the time.

The drives themselves are another story. Commodore's strategy was essentially to put a computer inside its historic 1541, and in other cases, the computer assumes a much stricter role by sending direct commands to the mechanism. Commodore's design seems better on paper, but as the video shows, it was hacks and last-minute changes that made the 1541 a real turtle, a problem that gave rise to the much-appreciated «Fast Load».

In summary, even with 50 years on its shoulders, floppy disks have several stories to tell. Time does not favor them in any way, and all enthusiasts recommend making backups in the form of images, but their nostalgic value is powerful. Do you still have floppy disks? Leave a comment.