It’s always been amazing to me the way that people don’t really care that they have no idea how their devices function, even if those people really rely on those devices. Of course we can’t understand every aspect of our worlds, but for those of you who are simply curious and enjoy an amazing tidbit of knowledge here and there, you may appreciate a brief synopsis on how exactly a hard drive operates. I won’t get too much into the physics or detail every aspect of how hard disk drives work, but here’s some info for those of you that want just a tiny slice of the world of computer engineering:

hard disk driveHard Disk Drive vs. Solid State Drive

These are the two mainstream products engineered to store data. Both can store from mere gigabytes to multiple terabytes, and both are viable options for anyone hoping to store from personal to commercial amounts of data. Today we will be talking about the Hard Disk Drive, named for its spinning platter(s) (magnetized-metal coated, glass or aluminum disk on which information is stored and from which information is read). “Solid state” drives are named for their lack of moving material; no power is necessary for information to be read off of them. Today we will just be talking about hard disk drives.

binary dataStoring and Reading the Information

Any information stored by or accessible to a computer can be broken down to a binary of 0’s and 1’s. For that information to be stored onto a hard disk drive, scientists discovered a method of either magnetizing or demagnetizing tiny areas of metal on the platter that correspond to that binary. Accordingly, when another magnet is dragged along these areas, it can transmit the presence and absence of magnification to the computer, which reads that presence and absence as a binary and is then able to display the relevant information.

Finding the Information

Anyone who has suffered from data loss and then opted into data recovery understands that having information stored on your hard drive is not equivalent to finding that information, and if you can’t find the information, it’s dead to you. Therefore it was important for scientists to engineer hard disk drives so that your computer could store information on them in a very orderly pattern on each platter. Bits of data are posited in concentric, circular tracks which are each broken up into smaller areas called sectors. Maps of the sectors are stored in another part of the hard drive. These maps supply information regarding what parts of the drive are in use storage-wise and which are free for new information. When you want to store new information, your computer accesses this map (called the File Allocation Table in the Windows operating system), locates a free sector, and instructs the read-write head to move to that sector and save your data there. To read information, your computer uses the map to access the targeted area and instructs the read-write heads to head there and pick up the information.