1. Chapter 3- Computer Hardware
Chapter Three
Computer Hardware
Chapter 3- Computer Hardware

2. Chapter 3 - Computer Hardware
Objectives
System Unit and Motherboard
Central Processing Unit
Memory
Input / Output Devices
Storage Devices
Expansion Cards
Chapter 3 - Computer Hardware

3. Chapter 3- Computer Hardware
Definition Hardware
Hardware H/W: The physical components of the computer (touchable), either Electronic or Mechanical parts.
Chapter 3- Computer Hardware

4. The System Unit (Case or Chassis)
The "system unit" is the name given to the main PC box that houses the various elements that go together to make up the PC.
For instance, within the system unit is the computer system's motherboard, which contains all the main components, such as the CPU and Primary memory.
Chapter 3- Computer Hardware

5. The System Unit (Case or Chassis)
The system unit also houses items such as the hard disk, the floppy disk and CD-ROM and DVD drives etc.
One of the important component is the power supply.
System units come in two basic forms:
The tower version,
Desktop version.
Chapter 3- Computer Hardware

6. The System Unit (Case or Chassis)
Tower Box
Desktop Box
Chapter 3- Computer Hardware

7. Chapter 3- Computer Hardware
Power Supply
Chapter 3- Computer Hardware

8. The System Board (Motherboard)
The main circuit board in the computer.
It provides the electrical connections by which the other components of the system communicate.
It contains the following:
CPU
Primary Storages(RAM and ROM)
Buses – metal lines or cables that appear on the motherboard - used to connect the parts on board with each other
Expansion Slots(Sockets)
Ports
Chapter 3- Computer Hardware

9. Chapter 3- Computer Hardware
Essential Skills for Digital Literacy
Computing Fundamentals
Motherboard
RAM Slots
AGP Slot
CPU Slot/ Microprocessor
Expansion/PCI Slots
Pg 15
Descriptions of the components labeled here are on the next slide.
Input/Output Slots
Chapter 3- Computer Hardware 9
© CCI Learning Solutions Inc.
Recognizing Computers – Slide 9

10. diagram for the Computer's Hardware
Chapter 3- Computer Hardware

11. Central Processing Unit (CPU)
The CPU is the brain of your computer.
It is microchip that consists of hundreds of millions of transistors.
It performs the following:
Mathematical calculations.
Logical Operations.
Chapter 3- Computer Hardware

12. Central Processing Unit (CPU)
It is responsible for executing user instructions that are given in a form of programs and direct commands.
Example: operating system (Unix), Application (Spreadsheet).
The CPU carries out program instructions in sequence, one at a time.
Chapter 3- Computer Hardware

13. Central Processing Unit (CPU)
CPU's speed: Number of basic operations executed in one second
It determines how fast your computer will run.
Its measured in Hertz units.
CPU speed is measured in Mega Hertz (MHz) or Giga Hertz (GHz).
Chapter 3- Computer Hardware

14. Central Processing Unit (CPU)
To give you some indication of how PCs have advanced over the years, the original IBM PC released in 1981 ran at 4.77 MHz while modern PCs run at speeds above 2.8 GHz or higher!
Chapter 3- Computer Hardware

15. Chapter 3- Computer Hardware
Components of CPU
Chapter 3- Computer Hardware

16. Arithmetic and Logic Unit (ALU)
The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all arithmetic and logical operations.
The arithmetic/logic unit can perform four kinds of arithmetic operations, or mathematical calculations: addition, subtraction, multiplication, and division.
Chapter 3- Computer Hardware

17. Arithmetic and Logic Unit (ALU)
As its name implies, the arithmetic/logic unit also performs logical operations.
Example of logical operations is: a=b, a<b, a>b, a>=b.
Chapter 3- Computer Hardware

18. Chapter 3- Computer Hardware
Control Unit
It carries out the following tasks:
Reading and interpreting program instructions.
Directing and controlling data flow within the CPU and between the CPU and Primary Memory.
Note: The control unit does not execute program instructions; rather, it directs the ALU to do so.
Chapter 3- Computer Hardware

19. Chapter 3- Computer Hardware
Registers
Registers are very high speed, immediate access storage locations where program instructions are decoded and data stored temporarily before and after execution by the ALU.
Note: Registers are not part of the Main memory; rather they are special additional storage locations within the CPU.
Chapter 3- Computer Hardware

20. Chapter 3- Computer Hardware
Examples of CPUs
Intel
Pentium, Celeron, Xeon
AMD
Athlon, Opteron
IBM
Power3
Cyrix
6x86MX  
Chapter 3- Computer Hardware

21. Chapter 3- Computer Hardware
Measuring Memory
1 bit=1 binary (0s and 1s) digit 
1 byte=8 bit 
1 kilobyte=1024 bytes  (210 B)
1 megabyte=1024 kilobytes (220 B)
1 gigabyte=1024 megabytes  (230 B)
1 terabyte=1024 gigabytes (240 B)
 In video or tapes, an "exabyte" or "exobyte" is up to about a year straight of recording. 
Chapter 3- Computer Hardware

22. Calculating Memory Capacity
How many Bytes in 8 GB?
8 * 1024 * 1024 * 1024 or
8 * 210 * 210 * 210 = 233
How many KB in 4 GB?
4 * 1024 * or
4 * 210 * = 222
How many bits in 2 TB?
2 * 1024 * 1024 * 1024 * 1024 * 8 or
21 * 210 * 210 * 210 * 210 * 23= 244
Chapter 3- Computer Hardware

23. Primary Storage (Main Memory) RAM and ROM
RAM (Random Access Memory )
RAM is a volatile memory(when the computer is turned off, all of the data is lost) used by the system to store data for processing by the computer CPU.
As a rule, computers with a larger RAM capacity is often faster than a computer with a smaller RAM capacity.
Functions of RAM
Store data and programs before being processed in the CPU
Store results of processing before being transmitted to the output unit
Chapter 3- Computer Hardware

24. Chapter 3- Computer Hardware
ROM
Read Only Memory (ROM) a special type of memory chip that holds software(ROM-BIOS) that can be read but not written to.
It is a non-volatile memory.
ROM-BIOS (Basic Input and Output System)
It is the first program that is executed by CPU when the computer turned on.
Functions of ROM
Booting
Searches the OS from storage devices and loads it into RAM
Chapter 3- Computer Hardware

25. Chapter 3- Computer Hardware
ROM
Other types of ROM:
PROM (Programmable ROM)
It can be programmed using PROM programmer.
EPROM (Erasable PROM)
Data can be erased using ultraviolet light.
EEPROM (Electrically EPROM)
Data can be erased using electricity only.
Chapter 3- Computer Hardware

26. Chapter 3- Computer Hardware
Cache Memory
Is a high speed memory that allows the CPU to access data in a very short access time.
Used to store frequently used instructions or data.
Levels of Cash Memory:
L1 on-chip (embedded in the CPU)
L2 and L3 are off-chip (resides on motherboard)
Chapter 3- Computer Hardware

27. Chapter 3- Computer Hardware
Secondary Storage
Hard Disc Drives
Flash Memory
Memory Cards – SD(Secure Digital) Cards
CD (Compact Disc)
CD-R
CD-RW
Can hold up to 700MB
Chapter 3- Computer Hardware

28. Secondary Storage (Continue..)
DVD (Digital Versatile Disk)
Can hold 4.7GB – GB
BD (Blu-ray Disk)
Can hold GB
Blu-ray Disk refers to the “blue-laser” used to read the disk
Chapter 3- Computer Hardware

29. Chapter 3- Computer Hardware
Input Devices
Keyboard (Wired, Wireless)
Mouse
Touchpads and Touch Screens
Scanners
Webcams
Joysticks
Barcode Readers
Finger Print Readers
Microphones
Digital Cameras
Chapter 3- Computer Hardware

30. Chapter 3- Computer Hardware
Output Devices
Monitor
CRT (Cathode Ray Tube)
LCD (Liquid Crystal Display)
Plasma(Colour Plasma Display)
Printer
Laser (Color, Black and White)
Inkjet (Color, Black and White)
Speakers
Projectors
Plotters
Chapter 3- Computer Hardware

31. Chapter 2 - Computer Hardware
Expansion Cards
is an electronic board that can be inserted into the expansion slot of the mother board.
Examples:
Modem(MODulator/DEModulator)
Modulation is the Process of Converting Digital to Analogue Signal)
Demodulation is the Process of Converting Analogue to Digital
NIC(Network Interface Card)-To connect to a Network
Video Cards-built in with motherboard to display images from computer
Sound Card—built in with motherboard to produce sound from computer
Chapter 2 - Computer Hardware

32. Chapter 3 - Computer Hardware
Summary
You should be able to
Define the Hardware
Differentiate between hardware components
Their uses and Limitations
Chapter 3 - Computer Hardware