Operating System

When you turn on your computer, it's nice to think that you’re in control. There's the trusty computer mouse, which you can move anywhere on the screen, summoning up your music library or Internet browser at the slightest whim. Although it's easy to feel like a director in front of your desktop or laptop, there's a lot going on inside, and the real man behind the curtain handling the necessary tasks is the operating system. All desktop computers have operating systems. The most common are the Windows family of operating systems developed by Microsoft, the Macintosh operating systems developed by Apple and the UNIX family of operating systems (which have been developed by a whole history of indivi¬duals, corporations and collaborators). There are hundreds of other operating systems available for special-purpose applications, including specializations for mainframes, robotics, manufacturing, real-time control systems and so on.

Even if a particular computer is unique, an operating system can ensure that applications continue to run when hardware upgrades and updates occur. This is because the operating system not the application - is charged with managing the hardware and the distribution of its resources.

Input and output devices

We use input devices every time we use computer. Simply speaking, it is these devices which allow us to enter information. Without them, the computer would not know wha we want it to do. Most likely in front of you right now are two of the most popular input devices the keyboard and the mouse. And instead of a mouse on a laptop computer you normally have a touchpad. Different people prefer different input devices for doing same task. To input devices we can also include the devices as camera, compact disc, digital camera, drawing tablet, microphone, scanner, joystick, and ect.

Camera - transmits a picture from one computer to another, or can be used to record a short video.

Compact Disc(CD) – CDs store information. It can then be pub into another computer and the information can be opened and added or used on the second computer. A CD-R or CD-RW can also be used as an OUTPUT device.

Digital Camera – can be used to take a pictures. It can be hooked up to computer to transfer the pictures from the camera to the computer.

Drawing Tablet – is similar to a white board, except you use a special pen to write on it and its connected to the computer. Then the word or image you draw can be saved on the computer.

Microphone – is used to record sound. The sound is then saves as a sound file on the computer.

Scanner – is used to copy pictures or other things and save them as files on the computer.

Joustick – is used to move the cursor from place to place, and to click on various items in programs. It is used mostly for computer games.

Output devices – devices that convert information from the machine language in a form accessible to human perception.

Monitor(Display) – a universal visual display unit information of all kinds.

Printer – a device for displaying information in hard copy text or graphics.(laser, inkjet, dot matrix printers)

Plotter – device that draws graphs, drawings and diagrams under computer control.

Speakers and headphones – a device to output audio information.