Lecture 5

Operating System

• Is the core software component of your computer
• It performs many functions and is, in very basic terms, an interface between your computer and the outside world
• Provides an interface to these parts using what is referred to as “drivers”.
• Is the most important program that runs on a computer.
• Perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.

The System Unit Parts and Functions

Power Supply – Regulates the flow of electric current to the motherboard and drives

Ports – allow data cables of devices to be connected to the   system unit so that data and information can pass in and out of the unit.

Motherboard Contains all the components that controls the computer – the microprocessor , the memory chips, and many other chips.

Microprocessor or the CPU (Central Processing Unit) – Processes all the data that flow through the system unit.

Random Access Memory (RAM) – Temporarily stores data and instructions entered from the keyboard, the disk drive, or other input devices.

Read- Only Memory (ROM) – Stores programs permanently. This means, these programs cannot be changed nor erased; they can only be read. These programs are already present in the computer when it was bought. They are used by the computer to start and to function.

Expansion Slots – Allows you to connect additional circuit or expansion boards to the motherboard.

Floppy Disk drive – Allows the computer to read the data on floppy disks and write data into the disks.

Hard Disk Drive – stores large amount of data and information. The hard disk is usually inside the system unit. It contains non-removable disks.

CD – ROM Drive –  Allows compact disks (CDs) or optical disks to be read.

Components of the Windows Desktop

ICONS – are pictures that represent programs, files, folder and other items.

DESKTOP – This is the area that takes up  the entire background of the csreen.

MOUSE POINTER – The on-screen pointer (usually an arrow) that you use to select items and choose commands.

THE START BUTTON – The start button is found at the bottom of the desktop. This shows the available programs found in your computer.

THE TASKBAR  – The taskbar is found at the bottom of the screen beside the start button. It shows programs currently running in your computer. When you start a program, a button appears on the taskbar that represent the program that you are using.

MY COMPUTER – This icon gives you access to a window in which you can browse through the contents of your computer.

RECYCLE BIN – It is the electronic trash can.

CLOCK – A clock at the right end of the Taskbar displays the current time.