HARDWARE
Hardware is the most visible part of any information system: the equipment such as
computers, scanners and printers that are used to capture data, transform it and present it
to the user as output. Although we will focus mainly on the personal computer (PC) and the
peripheral devices that are commonly used with it, the same principles apply to the complete
range of computers:
• Supercomputers, a term used to denote the fastest computing engines available at any given
time, which are used for running exceptionally demanding scientific applications.
• Mainframe computers, which provide high-capacity processing and data storage facilities to
hundreds or even thousands of users operating from (dumb) terminals.
• Servers, which have large data storage capacities enabling users to share files and
application software, although processing will typically occur on the user’s own machine.
• Workstations, which provide high-level performance for individual users in computationally
intensive fields such as engineering.
• Personal computers (including laptop/notebook computers) have a connected monitor,
keyboard and CPU, and have developed into a convenient and flexible business tool capable of
operating independently or as part of an organizational network.
• Mobile devices such as personal digital assistants or the latest generation of cellular
telephones, offer maximum portability plus wireless connection to the internet, although
they do not offer the full functionality of a PC.
And we are already moving into the age of wearable computers for medical or security
applications, embedded computers in appliances ranging from motor cars to washing machines,
and the smart card which will provide identification, banking facilities, medical records
and more!
Input devices
Data may enter an information system in a variety of different ways, and the input device that is most appropriate will usually depend on the type of data being entered into the system, how frequently this is done, and who is responsible for the activity. For example, it would be more efficient to scan a page of typed text into an information system rather than retyping it, but if this happens very seldom, and if typing staff are readily available, then the cost of the scanner might not be justified. However, all of the input devices described in this chapter have at least one thing in common: the ability to translate non-digital data types such as text, sound or graphics into digital (i.e. binary) format for processing by a computer. Hardware refers to the physical elements of a computer. Also referred to as the machinery or the equipment of the computer. Examples of hardware in a computer are the keyboard, the monitor, the mouse and the processing unit However, most of a computer's hardware cannot be seen; It's inside the computer case.I/O lets the computer talk with the world around it. Sometimes it’s necessary to add functionality to a computer to keep it up to date, or make it better. The amount of I/O a computer has can be changed, by adding expansion cards that support I/O. A graphics card can be added to a computer to let it talk with a display, or a WiFi card can be added, which will let a computer talk to other computers without a connecting wire. Sometimes functionality can be added through a universal port, a port that supports multiple kinds of I/O. USB, FireWire, and Thunderbolt (Types of I/O) support multiple data types. Your keyboard, mouse, and monitor all connect to a computer's I/O.
CPUs or processors perform computations. They do the math for your calculator application, they compare the size of numbers; people have likened the CPU to the "brain" of a computer. Memory is what allows a computer to remember things. Similar to human memory, there's long term memory (a hard disc or optical media (like a CD)) and short term memory (RAM). When a computer is turned off, it forgets everything in the RAM, so the computer saves everything it knows it will need later on in the long term memory. The short term memory is easier to use because it can do I/O faster, so when a data is needed by the CPU, it's sent from the hard disk drive (HDD) to the RAM. The short term memory lives on RAM, while the long term memory is in the hard disk drive (HDD). Optical disks let you change certain parts of the memory, it's kind of like having a book or notebook that you might read and get information from.
The motherboard is a piece of hardware that makes connections in the right places between all of the other components in a computer. It tells data where it should go. When the CPU is finished processing some data, it might say to the CPU, OK, put this in the HDD, and the motherboard will figure out where the HDD is and send the data there.