WWS Technology Wiki

The Hard Disk Drive or HDD and more commonly known as "The Hard drive" is the first and up until today the most successful way of storing data (information) for your use on a computer.  When we save things to our computer we are saving it to the Hard Disk Drive.  The hard drive described in its simplest form is composed of discs known as platters and an actuator arm, which is tipped with copper.  The platters are what store the data.  Each one can hold a given amount (depending on the size of the HDD) in the unit system of Megabytes, Gigabytes, Terabytes, ect.  There is most usually more than one disk in each HDD system (in the set up).  

The way the memory is transferred back and forth from the CPU (Central Processing Unit ) to the HDD is by the actuator arm.  The actuator arm finds the information it has been commanded to seek out on the HDD or puts data into it.  The reason the arm is copper tipped is magnetism.  In order for any of this to really work we need magnetism.  The way in which something is stored onto the platter is by the arm placing a ferromagnetic film onto it.  The film has the data and depending on how it is magnetized is how information is marked.  It is easier to think of it as the level of magnetization or demagnetization forming the data.  

By way of review, The Hard Disk Drive stores data for your computer.  The HDD has three main components, which are as follows: The Platters, the Actuator Arm and the copper wiring or the magnetic system.  When something like a file or application is opened on the computer the CPU sends a request for the data and the Actuator harm picks up the ferromagnetic film (using its magnetized copper wiring) right off the fiercely spinning platters.  Storing something is similar to finding something, it’s the same process between the CPU and the HDD only the data is going in and the ferromagnetic film is being demagnetized or moved to suit the data.  Since the Actuator arm doesn’t move, the disk spins incredibly fast to move to the arm, it can get quite hot in the system.  The Computers fan helps keep it at a safe and reasonable temperature.  

The HDD has been around for about sixty years (introduced in the fifties).  In the beginning it was a huge device about the size of a refrigerator stacked on top of an oven! It acted like a giant cassette tape and only stored about three to five megabytes on about fifty disks.  As time went on the system progressed.  As is the same with everything we create, we try to make it in its most elegant form.  Achieving elegancy wasn’t so easy as they were also trying to make more space on them.  However, people were able to fit about a million times more storage into a device about 15 times smaller.  Of course in the last decade or so of the 20th century (when they decreased size and increased storage) the material for the storage was extremely expensive bordering about ten to fifteen thousand dollars per megabyte!!! Luckily the economy shifted along with the accessibility of the material and that number decreased by tens of thousands!  Today we are seeing a steady decrease in HDD use although they are still very present.  The new kid in town is the Solid State Drive or SSD.  As far as competition goes the HDD will win out for a while longer until the SSD is permanently integrated into computers because as of now most computers have to be manually changed after purchase.