1. Chapter Three
Computer Hardware
Chapter 3- Computer Hardware

2. Topics Covered System Unit and Motherboard
Central Processing Unit (CPU)
Primary Memory
Secondary Memory
Input / Output Devices
Expansion Cards
Chapter 3 - Computer Hardware

3. What is Computer Hardware?
Abbreviated as H/W
Physical components of the computer
Touchable parts
maybe Electronics or Mechanical parts
Chapter 3- Computer Hardware

4. The System Unit (Case or Chassis)
The main PC box that houses the various elements:
motherboard, which contains all the main components, such as the CPU and primary memory.
Hard disks, the floppy disk, CD-ROM, DVD drives etc.
Also contains Power Supply.
System units come in two basic forms:
The Tower
The Desktop
Chapter 3- Computer Hardware

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

6. Power Supply
Chapter 3- Computer Hardware

7. The Motherboard
Chapter 3- Computer Hardware

8. The System Board (Motherboard)
Is the main circuit board
Provides electrical connections/ communication channels to components
It contains the following:
CPU
Primary Memory (RAM and ROM)
Buses
Expansion Slots (Sockets)
Ports
Chapter 3- Computer Hardware

9. Motherboard RAM Slots AGP Slot CPU Slot/ Microprocessor Pg 15
Essential Skills for Digital Literacy
Motherboard
Computing Fundamentals
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
© CCI Learning Solutions Inc.
Recognizing Computers – Slide 9

10. 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:
Arithmetic/Mathematical calculations
Logical Operations
Chapter 3- Computer Hardware

11. Components of CPU
Chapter 3- Computer Hardware

12. CPU Speed Number of basic operations executed in one second
Measured in Hz (Hertz)
It determines how fast your computer will run.
IBM PC of 1981 runs at 4.77 MHz
Present day PC runs at 2.8 GHz or faster
Chapter 3- Computer Hardware

13. Arithmetic and Logic Unit (ALU)
Also known as ALU
contains the electronic circuitry that executes all arithmetic and logical operations
Arithmetic Operations include Multiplication, Division, Addition, Subtraction
Logic Operations include comparison like a=b, a<b, a>b, a>=b
Chapter 3- Computer Hardware

14. 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

15. Registers
Registers are very high speed, immediate access storage locations
where program instructions are decoded
where data are temporarily stored 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

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

17. Measuring Memory 1 bit=1 binary (0’s and 1’s) 1 byte=8 bits
1 kilobyte=1024 bytes = (210 B)
1 megabyte=1024 kilobytes= (220 B)
1 gigabyte=1024 megabytes= (230 B)
1 terabyte=1024 gigabytes = (240 B)
Chapter 3- Computer Hardware

18. Calculating Memory Capacity
How many Bytes in 8 GB?
8 * 1024 * 1024 * 1024 or
23 * 210 * 210 * 210 = 233
How many KB in 4 GB?
4 * 1024 * or
22 * 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

19. Primary Memory (Main Memory)
RAM (Random Access Memory )
RAM is a volatile memory
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
Store results of processing before being transmitted to the output unit
Chapter 3- Computer Hardware

20. ROM
Read Only Memory (ROM) a special type of memory chip that holds software
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

21. Other Types of 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

22. 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

23. Secondary Memory 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

24. Secondary Memory (con’t.)
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

25. Input Device

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

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

28. Expansion Cards an electronic board inserted into the expansion slot
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)
Video Cards
Sound Card
Chapter 2 - Computer Hardware

29. Summary What is Hardware? What is System Unit? Motherboard?
What is Central Processing Unit (CPU)?
What is Primary Memory?
What is Secondary Memory?
What are Input / Output Devices?
What are Expansion Cards?
Chapter 3 - Computer Hardware