Background

Computers do not string together the letters of the
alphabet to make words or use the ten decimal numbers
to make endless number combinations. Rather, they use
a binary numbering system with two symbols (‘0’ and
‘1’) to represent alphanumeric characters. This system
is universally used in all computers and computer-based
devices. Data stored in a computer’s memory or on
magnetic storage devices are combinations of Bits (a
‘0’ or a ‘1’) and Bytes (eight ‘0’s and ‘1’s). Each letter,
number, or character can be represented by a combina-
tion of Bytes. For instance, the binary number for the
capital letter ‘A’ is ‘01000001’ which represents 8 Bits
of data stored by the computer as 1 Byte. There are 256
combinations that can be made using eight ‘0’s and ‘1’s.
Although computer data and file size is measured in
binary code using the binary numbering system, prefixes
for multiples are actually based upon the metric system.
For example, the nearest binary number to 1,000 would
be 2^ 10 or 1,024. Thus 1,024 Bytes is called a ‘Kilo-
byte.’
The previous column discussed the amount of data
represented by 1 Byte (a single typed character) through
1 Zettabyte (one billion Terabytes or approximately 36
million years of stored HD video). It also mentioned that
there are currently more than 35 billion devices con-
nected to the Internet, with the potential of more than
one trillion devices being able to connect to a network!
An incredible amount of data is produced yearly by these
devices, about 75% of which is generated by individuals
and includes not only text files, but also multimedia files
(audio, video, and images). All this data has to be stored
somewhere and it generally resides on millions and mil-
lions of hard drives. The ubiquitous hard drive was and
still is the most prevalent device in use today for both
short and long term data storage. Hard drives provide
an efficient and cost-effective means to manage large
amounts of data. However, we should remember that
throughout the history of data storage, current media
technology only lasts a short time (i.e., the floppy disk)
before being replaced by some newer, bigger, better, and
faster method of storing data.

The Hard Drive Continues “Spinning” into the
Future

To increase hard drive storage capacity, manufacturers historically have been able to continually decrease the size of the magnetic grains which comprise the data bits. This allows for a greater number of bits of data to be recorded per square inch per platter. However the microscopic magnetic grains are so small that they can potentially interfere with each other. Should this occur, it would diminish their ability to maintain assigned magnetic orientations and the data would become corrupted, leading to an unreliable and unusable hard drive.