Dwight Watt - Newspaper Article #204 6/12/2013

Question: What is a hard drive?


The hard drive is where your information is stored inside the computer. It is where you permanently store information in the computer that says there when the computer is turned off, but the data can be changed.

The hard drive is a component in the computer that is normally in a case about 3 by 5 inches or 1.5 by 3 inches depending on whether in a desktop or laptop computer. It looks like just a sealed unit with a circuit board on it but inside it has a circular platter that is flat that turns at about 7200 rpm (rounds per minute. On that surface your information is stored at magnetic dots. The drive cannot be opened as dust or dirt will cause the read write head to crash. A destroyed unit can be opened to see the parts,

There is a read write head (similar to the read write head that drags across a cassette tape to read the magnetic store information). However the hard drive read write head floats just a fraction above the disk reading and writing. It is closer that the size if a hair on your head, but never touches the disk. If it touches, it digs a groove in the disk and destroys it. This is why you do not want to drop computers.

The disk in a hard drive is a physically hard platter that does not bend. The disk in a floppy drive is a thin piece of Mylar usually and does bend. Those that have seen the 5.25 inch floppy diskettes that were used in the 80s know they could be bent as they did not have a hard cover. The ones inside the 3.5 diskettes are also floppy but have a hard cover.

Hard disks have gotten much bigger over time and much cheaper. If you look at hard disks now you will find them available commonly in sizes up to 2 terabytes (trillions of bytes of storage for just over $100.

The hard disk is what you will usually see referenced as C drive (or can be other letters above C, but the first is normally C. The floppy drives (if your computer has floppy drives, USB thumb drives have replaced them) are letters A and B.