How Does
How Do Floppy Disk Drives Work?
Origins
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Floppy disk drives were first used in the early part of the 1970s. While they have since become obsolete and are seldom used in new computers, for more than 20 years they were the dominant medium for mobile computer storage. Floppy disks were available in different sizes, but the most popular was the 3.5-inch floppy disk. These 3.5-inch floppy disks could hold what was, at the time, massive amounts of data. By today's standards, however, that capacity is less than perfect. 1.44 MB was the most that a 3.5-inch floppy disk could hold. The real stars of the floppy disk era, though, were the drives themselves. Marvels of engineering, the floppy drive was installed in most computers, and the science behind them was very straightforward.
Mechanics
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Each floppy disk drive included several parts, all of which were vital to the successful usage of the unit. The frame of the drive was designed to be grounded into the computer's case to avoid accidental electrical discharge. It was commonly secured with at least four separate screws to ensure that it was steady and didn't wobble, as even the slightest movement of the drive housing would cause the read and write heads to impact the diskette, possibly causing irreparable damage.
The read and write heads were located within the drive so they would rest both above and below the inserted floppy disk. The heads were offset from one another, since they would interfere with the operation of the other were they to be directly aligned.
The stepper motor was the method used to move the read and write heads across the surface of the disk. The stepper motor was married to a worm gear that rotated and controlled both the rate and amount that the read and write heads moved. The operation of this motor and the accompanying gear had to be measured in extremely small increments, so that the gear could direct the heads to the proper sector on the drive.
The drive motor was designed to spin the disk when inserted into the drive, and the revolutions per minute dictated how quickly the drive could write or read data. This is called the seek time, and is still used today in modern CD and DVD drive technology. The drive motor was one of the sturdiest parts of the floppy drives, since it had the highest duty cycle and had to be constantly in motion when the drive was in operation.
The circuit board was responsible for the hard-wired electronic commands that governed the internal workings of the drive. The hardwired commands input on the circuit board were responsible for the control of the read and write heads and controlled which tracks of the inserted diskette were used. It also served to catalog which sectors had been used to store data, so that they wouldn't be overwritten accidentally.
Present Day
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Floppy drives are still manufactured, though in much smaller numbers than even a decade ago. The top four computer manufacturers--Dell, Gateway, Acer and Hewlett Packar--don't put floppy drives into their computers anymore, unless a drive is specifically requested by the customer. Today's storage is typically held on optical media, such as CD or DVD, Blu-ray, or even on solid-state drives such as the increasingly popular USB storage drives. Each of these is capable of storing several thousand times the amount of data that could be stored on an old-style floppy disk.
eHow Article: How Do Floppy Disk Drives Work?
