1. 1

2. 2
COMPUTER SYSTEM
• Combination of components designed to
process data and store files
• Consists of four major hardware
components  input devices, output
devices, processor and storage devices
• Needs hardware, software and a user to
fully function

3. 3
*input devices
*processor
*output devices
*storage devices
COMPUTER
HARDWARE

4. 4

9. Inputdevices
Outputdevices
hardware
software
Computer system

10. COMPUTER HARDWARECOMPUTER HARDWARE
BLOCK DIAGRAMBLOCK DIAGRAM
Input
devices
processor
Storage
devices
output
devices

11. An Input device feeds raw data to the
processor.
A processor processes raw data and turns it
into useful information.
A storage device keeps or stores both
process and unprocessed data for later
usage.
An output device shows or display the
processed data
11

12. 12
Any questions
so far?

13. 13
Human uses the brain to think,
make decisions and process
information. A computer has a brain
too, and the brain of a computer is
the processor or the central
processing unit (CPU) that
processes information

14. THE CENTRAL
PROCESSING UNIT
All processing activities are done in
the CPU
It utilizes the computer memory to
execute instructions from the
application software and accomplish
a task
The processor must be connected to
input devices, output devices and
storage devices to carry out the tasks
14

15. 15
THE INFORMATION
PROCESSING CYCLE
Input processor
Storage
output

16. User will input the data to be
processed by the processor.
The storage holds databases, files
and programs. The output of the
processed data will be displayed
by the output devices present as
useful information products for
the user
The Information Processing Cycle

17. 17
Draw the computer hardware
block diagram and the
information processing cycle.
Explain briefly each diagram

18. 18
Information processing cycle
Any data or instructions that
we enter into the computer
system for processing
Input
A location which data,
instruction and information are
held for future use
Storage
Data that has been processed
into a useful form
information
Output

19. 19
Machine cycle that consist four
basic operations, that’s are fetching,
decoding, executing and storing
Process
Fetching
DecodingStoring
Executing

20. 20
Fetching
The process of obtaining a
program instructions or data item
from memory
Decoding The process of translating a
program instruction into signals
that the computer can execute
Storing
The process of writing the result to
the storage or memory
Executing The process of implementing the
instructions in a program.
process

21. 21
Any
questions?

22. 22
DATA
REPRESENTATI
ON

23. 23
Computers recognize only two
discrete states  on & off
These states can be represented by
two digits  0 & 1
Each 0 or 1 is called a bit in the
binary system.

24. 24
BINARY DIGIT
 The smallest unit of data a computer can process
 The binary system has a base of 2 with the two
digits (0 and 1)
 Combinations of 0s and 1s represent larger
numbers

25. 25
BYTE
• Unit of information
built from bits
• 1 byte = 8 bits
• One byte represents a
single character (3, B
or #)
• Unit of information
built from bits
• 1 byte = 8 bits
• One byte represents a
single character (3, B
or #)
CHARACTER
• One byte represents
one character such as
A, 7, 9 and +
• F = 01000110 (binary
code)
• One byte represents
one character such as
A, 7, 9 and +
• F = 01000110 (binary
code)
00111001 = 9
00101011 = +

26. 26
æThree character codes to
represent characters
æASCII, EBCDIC, Unicode

27. 27

28. 28

29. 29

30. 30
* ASCII (American Standard Code for Information Interchange)
* Proposed by ASA (American Standard Association)

31. 31
 To achieve compatibility between various types
of data processing equipment making it
possible for the components to communicate
with each other successfully
 Enables manufacturers to produce components
that are assured to operate correctly in a
computer
 Enables human to interact with a computer
 Enables users to purchase components that are
compatible with their computer configurations
FUNCTIONS OF ASCII

32. 32
HOW ASCII WORKS IN A COMPUTER
SYSTEM?
When you press a key, for example the letter D
on your keyboard, the electronic signal is sent
to the CPU for the computer to process and
store in memory. Every character is converted
to its corresponding binary form. The computer
the processes the letter as a byte, which
actually a series of on and off of electrical
states. When the computer is finished
processing the byte, the software installed in
the system convert the byte back which is then
displayed in the screen. Example, the letter D is
converted to 01000100

33. 33
DATADATA
MEASUREMENTMEASUREMENT
 Bit
 Bytes
 Kilobytes (1 KB = 210
bytes)
 Megabyte (1 MB = 220
bytes)
 Gigabyte (1 GB = 230
bytes)
 Terabyte (1 TB = 240
bytes)

34. 34
EVOLUTION OF
COMMUNICATION
Computer’s “speed = how fast computer
can process data
Every microprocessor contains a system
clock
The system clock controls the speed of all
the operations within a computer
The speed of the clock = how many cycles
per second the clock makes
CLOCK SPEED MEASUREMENT

35. 35
The units of clock speed measurement
Hertz (Hz)
æ The clock speed unit is
measured in hertz
æ A hertz is one cycle per
second
Megahertz (MHz)
æMega = million
æMegahertz (MHz) = 1
million cycles of the
system clock
æA computer that operates
at 933 MHz has 933
million clock cycles in
one second

36. 36
Gigahertz (GHz)
æGiga = billion
æ1GHz = 1000 MHz
æE.g. a microprocessor that runs at 200 GHz
executes 200 billion cycles per second
The units of clock speed measurement

37. Processing Speed
37
» The system clock  major factors that influence
the computer speed
» CPU with a higher clock speed can process
more instructions per second than a CPU with a
lower clock speed
» E.g. A 1 GHz CPU is faster than a CPU operating
at 800 MHz

38. Speed and path
38

The combination of speed and number of paths
determines the total processing speed or
channel bandwidth

Different processors often use different
architectures

e.g. a 1.4 GHz Pentium 4 performs better than a
1.4 GHz Pentium 3, but it is not as fast as a 1.4
GHz Power PC G4 processor.

39. 39
A Pentium 4 running at 2.4 GHz is
one-third faster than
a Pentium 4 running at 1.8 GHz

40. 40
Input devices

41. 41
Any data or instructions that
we enter into the computer
system for processing
Input
text
audio
Graphic
video

42. 42

43. 43
OUTPUT
DEVICES

44. 44
Data that has been processed
into a useful form
information
Output

45. 45

46. 46
MOTHERBOARD

47. 47
 Motherboard main circuit board of the system
unit
 Consist of some electronic components attached to
it and others built into it

48. 48
CPU
Expansion
slot
RAM
Components of a Motherboard

49. 49
RAM
•Memory of the computer
•Placed on the RAM slot
expansion card
•Plugged into an expansion slot
•Used to add new devices or capabilities to a computer
Components of a Motherboard

50. 50
Ports and connectors
• The point at which a peripheral attaches to a system unit so that
the peripheral can send data to or receive information from
the computer
• Serial port
• Parallel port
• Universal Serial Bus (USB) port
• FireWire port
• Spécial purpose ports
- MIDI port
- SCSI port
- IrDA port
Components of a Motherboard

51. 51
PORTS AND
CONNECTORS

52. 52
Serial port A socket on a computer used
to connect a modem, data
acquisition terminal or other
serial devices via a slow-speed
serial interface
Connect a device to the
system unit by transmitting
data one bit at a time
Example = COM
(communication) port
A socket on a computer used
to connect a modem, data
acquisition terminal or other
serial devices via a slow-speed
serial interface
Connect a device to the
system unit by transmitting
data one bit at a time
Example = COM
(communication) port

53. 53
Parallel port
A devices by transferring information more than
one bit at a time socket on a computer used to
connect
Transfer eight bits of data (one byte)
simultaneously through eight separate lines in a
single cable
Many printers connect to the system unit using a
parallel port
A devices by transferring information more than
one bit at a time socket on a computer used to
connect
Transfer eight bits of data (one byte)
simultaneously through eight separate lines in a
single cable
Many printers connect to the system unit using a
parallel port

54. 54
USB port • A socket on a computer
or peripheral devices
into which a USB cable is
plugged in
• Can connect up to 127
different peripherals
together with a single
connector
• Transfer data to a speed
of 12 megabits per
second

55. 55
Fire Wire
port
• Previously the FireWire port is called IEEE 1394 port, a
personal computer (and digital audio/video) serial bus
interface standard
• Similar to a USB port in that it can connect multiple types of
devices that require faster data transmission speeds
• Data can move across the port at up to 400 megabits per
second

56. 56
Special
purpose
port
MIDI port
connect the system unit to a
musical instrument
(electronic keyboard)
SCSI port
special high-speed parallel
port used to attach
peripheral devices
IrDA port
transmit data via infrared
light waves

57. 57
CENTRAL
PROCESSING
UNIT

58. 58
CPU
an integrated circuit chip that is
capable of processing electronic
signals
CPU interprets instructions
given by the software and
carries out those instructions
by processing data and
controlling the rest of the
computer’s components
Control
Unit (CU)
Arithmetic
Logic Unit
(ALU)
subcomponents

59. 59
Control Unit
(CU)
æMain function  to
direct the CPU to
process data
æExtracts instructions
from memory and
decodes and executes
them
æManages a four-step
basic operation 
machine cycle @
processing cycle

60. 60
Arithmetic Logic
Unit (ALU)
• Perform all arithmetic and
logical operations
• Arithmetic operation is an
operation that forms a
function of two numbers
• Logic operation is an
operation on logical values
• 16 logic operations over
one or two operands
(AND, OR, NOT, NAND,
NOR, XOR and
equivalence)

61. 61
STORAGE

62. 62
FUNCTIONS OF COMPUTER STORAGE
1.Store programs and data to be used at a later
time
2.Keep current data while being processed by the
processor until the information is saved in a
storage media
3.Stores instructions from a computer program
Primary
storage
Secondary
storage

63. 63
Primary storage
• main memory in a computer
• stores data and programs that can be accessed directly by the processor
• Installed inside
computers
• The data in RAM can be
read (retrieved) or
written (stored)
• RAM is volatile the
programs and data in
RAM are lost when the
computer is powered
off
• Stores data during and
after processing
RAM
• Permanently stored
inside the computer
• ROM is non-volatile
• Programs in ROM have
been pre-recorded (It can only
be stored by the manufacturer  once it is
done, it cannot be changed)
• Many complex functions
• All the contents in ROM
can be accessed and read
but cannot be changed
ROM

64. 64

65. 65
Secondary storage
• alternative storage to keep work and documents
•useful to store programs and data for future use
•non-volatile
Magnetic Medium
•Non-volatile
•Can be any type of
storage medium that
utilizes magnetic
patterns to represent
information
• Magnetic disk (floppy
disk, hard disk)
•Magnetic tape (video
cassette, audio storage
reel-to-reel tape etc)
Optical Medium
•Non-volatile
•Holds content in
digital form that
are written and
read by a laser
(CDs, DVDs, CD-R,
DVDR etc)
Flash Memory
•Solid-state, non-
volatile, rewritable
memory that functions
like RAM & a hard disk
drive combined
•Store bits of electronic
data
•Fast reading access
times
•Thumb drives, pen
drives, flash drives etc

66. COMPUTERSOFTWARE
A program which
consists of a set
of instructions
that tells the
computer how to
perform specific
tasks APPLICATION
SOFTWARE
SYSTEM
SOFTWARE

67. SYSTEM
SOFTWARE
Any software used to control
and manage computerdevices
and operations
APPLICATION
SOFTWARE
Any software used to help
userperformspecific tasks
OS, Utility program
Spreadsheet, web browser

68. Usage
Need
Number
Of software
Dependency
Function
Systemsoftware Application software
Enable computer to
function properly
Enable user to work
efficiently
Compulsory Optional
One More than one
Independent
Provides
environment for
application to run
Dependent
Provides environment
enable user to do
specific tasks

69. SYSTEM
SOFTWARE
OPERATING SYSTEM
A set of programthat
coordinates all the
activities among the
computerhardware
devices
-LINUX
-Mac OS
-UNIX
-Windows XP
UTILITY PROGRAM
A type of system
software that allows user
to perform maintenance
type tasks to manage a
computer, devices orits
program
-Antivirus
-Screen savers
-File manager

70. Function oF oS
Starting a computer
Providing userinterface
Managing data and programs
Managing memory
Configuring devices

71. Starting a computer
OS function
❋ Booting – Loading and initialize OS
into the computer’s memory
❋ Two ways of booting
Warmboot Cold boot
- Restarting a computerthat is
already on
- After installing new software
orhardware /after
application stops working
- Starting a computerthat is
already off
- Computerthat is completely
powered off

72. Providing userinterface
OS function
- Controls how userenters data and
instructions and how information
is displayed
- Interface enables users to;
- start an application program
- manage disks and files
- shut down computersafely
Command Line
Menu-Driven
GUI

73. Command
Line
➤Requires user to type command or press special
keys on the keyboard to enter data and
instructions to tell the OS what to do
➤Typed one line at a time
➤Difficult to use  exact spelling, syntax or a set
of rules of entering commands
➤Advantage  helps user to operate computer
quickly after memorizing the keywords and
syntax

74. Menu-Driven
➤ No need to memorize
keywords and syntax
➤ Provide menu to enter
commands
➤ shows all the option
available at a given point
in a form of text based
menu
➤ Easy to learn

75. GUI
• Friendly user, commonly used
• Operates after OS finishes loading into
memory
• Interacts with the menus and visual
images to issue commands
• On desktop  can initiate many actions
by clicking icons that represents
computer resources

76. THE IMPORTANCE OF
USERINTERFACE
✺Assists userto interact with OS
✺Control how userenters data and
instructions
✺Control how information is displayed

77. OS function
Managing data and programs
- CPU loads the application fromstorage into
memory
- Multitasking OS  enable users to work
with two ormore application at the same
time

78. Managing memory
OS function
- Optimizing the use of RAM
- Allocating data and instruction to an area
of memory while being processed
- Monitoring the contents of memory
- Releasing data and instructions from
being monitored in memory when the
process is done

79. Configuring devices
OS function
- Handling input/output as
well as enabling
communication with i/o
devices
- Most OS comes with
drivers forpopular
i/o devices

80. OS PLATFORMS
• manufacturers produce unique
software version for each platform
Apple
PlatformOS
PC
Platform OS
Cross-platform
OS

81. Apple
PlatformOS
• Used on Apple platform
- Mac OS
- Mac OS X
• Closed source software
• For use with home desktop and
workstations

82. Apple
PlatformOS

83. • Used in IBM compatible computers
• Examples:
- Disk Operating System (DOS)
- Microsoft Windows XP
• Closed source software
• DOS - use command line interface
• MS Windows XP – GUI interface
PC
PlatformOS

84. PC
PlatformOS

85. • UNIX  Multitasking OS
» Most versions of UNIX use GUI and some use
command line
Cross-platform
OS
• LINUX  Multitasking OS
» Open source software
» Free and UNIX-like GUI OS
» Best known for its support of IBM-Intel PC-
based hardware

86. Cross-platform
OS

87. APPLICATION
SOFTWARE
WORD PROCESSING
SPREADSHEET
PRESENTATION
GRAPHICS EDITING

88. • An office application enables user to create, edit,
format and print textual document
WORDPROCESSING

89. • A program that processes information in the form of grid
of columns and rows (table)
• Holds values or mathematical formulas
• Indispensable if working with numbers
SPREADSHEET

90. • Enables user to create transparencies, slides and
handouts for presentation
• Create visual aids for presentation to communicate
ideas, messages and other information to a group
PRESENTATION

91. • A program that can edit digital representation or
non-text information (drawings, charts or
photographs)
GRAPHICS EDITING

92. APPLICATION
SOFTWARE
WORD PROCESSING
SPREADSHEET
PRESENTATION
GRAPHICS EDITING
SOFTWARE SUITE
• A collection of individual programs sold as a single package
• Designed to enhance workperformance
• Word processing, spreadsheet,
presentation and e-mail
• Microsoft Office

93. • closed source software
• stable system with support if the
software fails or malfunctions
PROPRIETARY
SOFTWARE

94. • Provided for use, modification and redistribution
• Can download from the Internet for free and
modify into better quality software
• The only qualification  changes can't be
copyrighted
OPEN SOURCE
SOFTWARE

95. OPEN SOURCE
SOFTWARE
OpenOffice.org, PHP-Nuke, The
GIMP, Mozilla, ClamAV,
OpenLDAP, Audacity and
RedHat
LINUX version