1. Lesson 3: Basic Parts and Functions of Computer
Comp1: Computer Concepts with Internet
Instructor: Sir Joshua Hernandez

2. Basic Parts

3. Basic Parts of a computer
Desktop computer system

4. Basic Parts of a computer
A. SYSTEM UNIT
The system unit is the core of a computer system. Usually it's a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU), or microprocessor, which acts as the "brain" of your computer. Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off.

5. Basic Parts of a computer
B. STORAGE
Your computer has one or more disk drives—devices that store information on a metal or plastic disk. The disk preserves the information even when your computer is turned off.

6. Basic Parts of a computer
B. STORAGE
1. Hard disk drive
Your computer's hard disk drive stores information on a hard disk—a rigid platter or stack of platters with a magnetic surface. Because hard disks can hold massive amounts of information, they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit.

7. Basic Parts of a computer
B. STORAGE
2. CD and DVD drives
Nearly all computers today come equipped with a CD or DVD drive, usually located on the front of the system unit. CD drives use lasers to read (retrieve) data from a CD; many CD drives can also write (record) data onto CDs. If you have a recordable disk drive, you can store copies of your files on blank CDs. You can also use a CD drive to play music CDs on your computer.

8. Basic Parts of a computer
B. STORAGE
3. Floppy disk drive
Floppy disk drives store information on floppy disks, also called floppies or diskettes. Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also retrieve information more slowly and are more prone to damage. For these reasons, floppy disk drives are less popular than they used to be, although some computers still include them.

9. Basic Parts of a computer
C. MOUSE
A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless.

10. Basic Parts of a computer
D. KEYBOARD
A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys:
The function keys, found on the top row, perform different functions depending on where they are used.
The numeric keypad, located on the right side of most keyboards, allows you to enter numbers quickly.
The navigation keys, such as the arrow keys, allow you to move your position within a document or webpage.

11. Basic Parts of a computer
E. MONITOR
A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures.
There are two basic types of monitors: CRT (cathode ray tube) monitors and the newer LCD (liquid crystal display) monitors. Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter.
CRT
LCD

12. Basic Parts of a computer
F. SPEAKERS
Speakers are used to play sound. They can be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.

13. Basic Parts of a computer
G. MODEM
To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher-speed modems are usually separate components.

14. The Computer System

15. Computer System = Hardware + Software
The Computer System
The computer system is defined as an arrangement of all-possible hardware and software installed to the computer, which will assist in carrying out its task efficiently.
The Computer System Equation:
Computer System = Hardware + Software

16. Components of a Computer System
The Computer System
Components of a Computer System

17. The Central Processing Unit (CPU)
The Computer System
The Central Processing Unit (CPU)
The CPU is most times referred to as the brain of the computer, because it controls and coordinates all the functions of a computer, similar to how your brain controls and coordinates the data and information which comes into your body. For smaller computers such as personal computers, the CPU is contained on a silicon chip called a microprocessor. On larger computers such as IBM mainframe, the CPU may consist of several circuit boards.
The three main manufactures of CPUs are: Intel Corporation, Advanced Micro Devices (AMD), Cyrix.

18. The Main Functions of the CPU
The Computer System
The Main Functions of the CPU
Fetching data and instruction from memory.
Coordinating and performing instructions received.
Sending the results of execution to memory.

19. The Main Components of the CPU
The Computer System
The Main Components of the CPU
Arithmetic Logic Unit (ALU)
This is a twin unit that performs all arithmetic calculations (arithmetic unit) and logical operations (logic unit) on data being processed.
Control Unit (CU)
The main function of the control unit is to decode and execute all instructions given to the computer. However other function includes:
Processing inputted information.
Controlling the output’s outcome and destination.

20. The Main Components of the CPU
The Computer System
The Main Components of the CPU
CPU clock
The CPU clock regulates the speed of the processor and it synchronizes all the parts of the CPU. The speed of the processor is measured in Mega Hertz (MHz) which means million of cycles per second.
Registers
Registers are high-speed storage areas in CPU that temporarily hold data and instructions.

21. The Main Components of the CPU
The Computer System
The Main Components of the CPU
Buses
The electrical path or channel along where bits are transferred. This information is transmitted in groups of bits and bytes. Bus width can be 8, 16, 32, 64, or 128 bits. An 8- bit bus moves 8 bits of data at a time. Bus width is the amount of data the CPU can transmit at any time. The speed of a bus affects the transfer of bits. A faster bus means faster transfer of information to and from the CPU.

22. Basic Functions

23. Main Functions of Computers
Input - In order for the computer to function, data and instructions have to be input into it in a suitable form. This is done via input devices. Examples of input devices are the keyboard, the mouse, and microphone. It involves receiving information from the environment, or from storage devices, through an input device.
Output – Presentation of data to the environment from main memory of the computer to media external to the CPU. Common output devices, like the printer and the monitor present the information to the user in a format he/she can immediately understand (e.g. printed on paper or displayed on screen)

24. Main Functions of Computers
Processing – Manipulation of data in a variety of ways applying rules of arithmetic and logic. This is commonly referred to as the “brain” of the computer system and is responsible for converting data and instructions into useful information.
Storing – recording of data in a relatively permanent form i.e. disk, CD and other storage devices for access later on.

25. References
Steinbeck, Dionne. (2007) Exploring Information Technology. Marie Rose Pittal p.
Shelly, Gary; Vermaat, Misty. (2013) Discovering Computers. Boston, Ma: Cengage Learning.
Parts of A Computer. © 2014 Microsoft. Date Retrieved: Nov 26, Retrieved from: parts#1TC=windows-7