Computer Fundamental

1. Fundamental of
Computers

2. What is a Computer?
A computer is an electronic device used to process data.
• A computer can convert data into information that is
useful to people.
• A complete computer system includes four distinct
parts:
Hardware
Software
Data
User

4. • A computer's hardware consists of electronic
devices; the parts you can see and touch.
• The term "device" refers to any piece of hardware
used by the computer, such as a keyboard,
monitor, modem, mouse, etc.
Hardware

6. • Software – also called programs – consists of organized
sets of instructions for controlling the computer.
• Some programs exist for the computer's use, to help it
manage its own tasks and devices.
• Other programs exist for the user, and enable the
computer to perform tasks for you, such as creating
documents.
Software

7. •
•
•
Data consists of raw facts, which the computer can
manipulate and process into information that is
useful to people.
Computerized data is digital, meaning that it has
been reduced to digits, or numbers. The computer
stores and reads all data as numbers.
Although computers use data in digital form, they
convert data into forms that people can
understand, such as text, numerals, sounds, and
images.
Data

8. • People are the computer's operators, or users.
• Some types of computers can operate without
much intervention from people, but personal
computers are designed specifically for use by
people.
Users

9. Computer Architecture
•
•
•
•
•
•
Types of Hardware
The CPU
Memory
How Memory is Measured
Input and Output Devices
Storage Devices

10. A computer's hardware devices are categorized as
follows:
•
•
•
•
Processor
Memory
Input and output (I/O) devices
Storage devices
Types of Hardware

11. 01101010
01001010
01101101001111
10000000

12. CPU
The procedure that
transforms raw data
into useful
information is called
processing. This
function is divided
between the
computer's processor
and memory.
The processor
is also called
the central
processing
unit (CPU). It
manages all
devices and
performs the
actual
processing of
data.
The CPU consists of one or more chips attached to the
computer's main circuit board (the motherboard).

13. • Memory also consists of chips attached to the
motherboard.
• Memory holds data and program instructions as
the CPU works with them. This memory is called
Random Access Memory (RAM).
• The CPU can find any piece of data
in RAM, when it needs it for processing.
• RAM is volatile, meaning it holds data
only when the power is on. When the power
is off, RAM's contents are lost.
Memory

14. • The smallest usable unit of measure for memory is
the byte – the amount of memory required to hold
one character, like the letter A or the numeral 2.
• Computers work with larger chunks of data,
measured in multiple bytes, as shown below:
Unit Approx. Value
(bytes)
Actual Value
(bytes)
Kilobyte (KB) 1,000 1,024
Megabyte (MB) 1,000,000 1,048,576
Gigabyte (GB) 1,000,000,000 1,073,741,824
Terabyte (TB) 1,000,000,000,000 1,099,511,627,776
How Memory is Measured

15. • Input devices accept data and instructions from the
user or from another computer system. The keyboard
and mouse are examples of input devices.
• Output devices return processed data back to the
user or to another computer system. The printer and
monitor are examples.
• Communications devices (such as modems and
network interface cards) perform both input and
output, allowing computers to share information.
Input and Output Devices

17. • Storage devices hold data not currently being used
by the CPU. Data is commonly stored on a magnetic
or optical disk. Each type uses a special medium for
storing data on its surface.
• A disk drive is a device that reads data from and
writes data to a disk. Most new computers feature a
floppy disk drive, a hard disk drive, and an optical
disk drive.
• The most common optical storage devices are CD-
ROM and DVD-ROM drives.
Storage Devices

19. Software
• Software is a set of electronic instructions that tells
the computer how to do certain tasks. A set of
instructions is often called a program.
• When a computer is using a particular program, it is
said to be running or executing the program.
• The two most common types of programs are system
software and application software.

21. • System software exists primarily for the computer
itself, to help the computer perform specific
functions.
• One major type of system software is the operating
system (OS). All computers require an operating
system.
• The OS tells the computer how to interact with the
user and its own devices.
• Common operating systems include Windows, the
Macintosh OS, OS/2, and UNIX .
System Software

22. •
•
Application software tells the computer how to
accomplish tasks the user requires, such as creating a
document or editing a graphic image.
Some important kinds of application software are:
Word processing programs
Database management
Graphics programs
Web design tools and browsers
Communications programs
Entertainment and education
Spreadsheet software
Presentation programs
Networking software
Internet applications
Utilities
Multimedia authoring
Applications Software

23. Computer Classifications

24. Super Computers

25. Mainframe Computers

26. Mini Computers

27. Workstation

28. Micro Computers (PC)

29. •
•
•
•
Binary Numbers
The Binary Number System
Bits and Bytes
Text Codes
How Computers Represent Data

30. Binary Numbers
• Computer processing is performed by transistors,
which are switches with only two possible states: on
and off.
• All computer data is converted to a series of binary
numbers– 1 and 0. For example, you see a sentence as
a collection of letters, but the computer sees each
letter as a collection of 1s and0s.
• If a transistor is assigned a value of 1, it is on. If it has
a value of 0, it is off. A computer's transistors can be
switched on and off millions of times each second.

31. Base 10 Base 2
0 0
1 1
2 10
3 11
4 100
5 101
6 110
7 111
8 1000
9 1001
10 1010
• To convert data into strings of
numbers, computers use the binary
number system.
• Humans use the decimal system
(“deci” stands for “ten”).
• The binary number system works the
same way as the decimal system, but
has only two available symbols (0 and
1) rather than ten (0, 1, 2, 3, 4, 5, 6, 7,
8, and 9).
The Binary Number System

32. A single unit of data is called a bit, having a value of 1
or 0.
• Computers work with collections of bits, grouping
them to represent larger pieces of data, such as letters
of the alphabet.
• Eight bits make up one byte. A byte is the amount of
memory needed to store one alphanumeric character.
• With one byte, the computer can represent one of 256
different symbols or characters.
.
How Computers Represent Data - Bits and
•
Bytes

33. 1 0 1 1 0 0 1 0
1 0 0 1 0 0 1 0
1 0 0 1 0 0 1 1
1 1 1 1 1 1 1 1

34. • A text code is a system that uses binary numbers (1s
and 0s) to represent characters understood by humans
(letters and numerals).
• An early text code system, called EBCDIC, uses eight-
bit codes, but is used primarily in older mainframe
systems.
• In the most common text-code set, ASCII, each
character consists of eight bits (one byte) of data.
ASCII is used in nearly all personal computers.
• In the Unicode text-code set, each character consists of
16 bits (two bytes) of data.
How Computers Represent Data - Text Codes

35. Code Character
00110000 0
00110001 1
00110010 2
00110011 3
00110100 4
00110101 5
01000001 A
01000010 B
01000011 C
01000100 D
01000101 E
Examples from the
ASCII Text Code

36. Where Processing Occurs:
•
•
The Control Unit
The Arithmetic Logic Unit
• Machine Cycles
• The Role of Memory in Processing
• Types of RAM
How Computers Process Data

37. • Processing takes place in the PC's central processing
unit (CPU).
• The system's memory also plays a crucial role in
processing data.
• Both the CPU and memory are attached to the
system's motherboard, which connects all the
computer's devices together, enabling them to
communicate.
CPU

39. The two main parts of a CPU are the control unit and the
arithmetic logic unit (ALU)
• The control unit directs the flow of data through the
CPU, and to and from other devices.
• The control unit stores the CPU's microcode, which
contains the instructions for all the tasks the CPU can
perform.
The Control Unit

41. • The actual manipulation of data takes place in the
ALU.
• The ALU can perform arithmetic and logic
operations.
• The ALU is connected to a set of registers—small
memory areas in the CPU, which hold data and
program instructions while they are being processed.
The Arithmetic Logic Unit

42. Arithmetic Logical
Operations Operations
+ Add ,  equal to, not equal to
 Subtract >, >
than
greater than, not greater
x Multiply <, < less than, not less than
 Divide ,  greater than or equal to,
not greater than or equal to
^ Raise by a power ,  less than or equal to,
not less than or equal to
ALU Operations List

43. • RAM stores data and program code needed by the
CPU. The contents of RAM change rapidly and often.
• Read-only memory (ROM) is nonvolatile (or
permanent). It holds instructions that run the
computer when the power is first turned on.
• The CPU accesses each location in memory by using a
unique number, called the memory address.
Memory

44. There are two basic types of RAM: static and dynamic
• Dynamic RAM (DRAM) chips must be recharged
with electricity very frequently, or they will lose their
contents.
• Static RAM (SRAM) does not need to be recharged
as often as DRAM, and can hold its contents longer.
Another type of RAM, called flash memory, can store its
contents after power is turned off. Flash memory is used
in digital cameras to store pictures.
Types of RAM

45. More RAM = Better Performance!

46. • Cache memory is high-speed memory that holds the
most recent data and instructions that have been
loaded by the CPU.
• Cache is located directly on the CPU or between the
CPU and RAM, making it faster than normal RAM.
• CPU-resident cache is called Level-1 (L1) cache.
External cache is called Level-2 (L2) cache.
• The amount of cache memory has a tremendous
impact on the computer's speed.
Cache Memory

48. • The operating system manages all the other
programs that run on the PC.
• The operating system provides services to programs
and the user, including file management, memory
management, and printing
• To provide services to programs, the OS makes
system calls—requesting other hardware and
software resources to perform tasks.
Operating system

49. • Multitasking is the capability of running multiple
processes simultaneously.
• A multitasking OS lets you run multiple programs at
the same time.
• Through multitasking, you can do several chores at
one time, such as printing a document while
downloading a file from the Internet.
• There are two types of multitasking: cooperative and
preemptive.
Operating System - Multitasking

51. • The operating system keeps track of all the files on
each disk.
• Users can make file management easier by creating
a hierarchical file system that includes folders and
subfolders arranged in a logical order.
Operating System - Managing Files

52. • The OS uses interrupt requests (IRQs) to maintain
organized communication with the CPU and other
pieces of hardware.
• Each hardware device is controlled by a piece of
software, called a driver, which allows the OS to
activate and use the device.
• The operating system provides the software
necessary to link computers and form a network.
Operating system - Managing Hardware

54. • Graphical User Interfaces
(GUIs)
• Command-Line Interfaces
The User Interface

55. • Most modern operating systems, like Windows and
the Macintosh OS, provide a graphical user interface
(GUI).
• A GUI lets you control the system by using a mouse
to click graphical objects on screen.
• A GUI is based on the desktop metaphor. Graphical
objects appear on a background (the desktop),
representing resources you can use.
Graphical User Interfaces (GUIs)

56. Start menu
Start button
T
D
a
i
s
a
k
l
o
b
g
a
r
b
o
x
Icons
Program
Deskrtuonpningin
a window
Window control buttons

57. • Some older operating systems, such as DOS and
UNIX, use command-line interfaces.
• In a command-line interface, you type commands at a
prompt.
• Under command-line interfaces, individual
applications do not need to look or function the same
way, so different programs can look very different
.
Command-Line Interfaces

58. • The Difference between Databases and DBMSes
• Database Basics
• DBMSes Basics
Databases and Database Management
Systems

59. •
The Difference between Databases and
DBMSes
A database is a repository for collections of related
data or facts.
• A database management system (DBMS) is a
software tool that lets users add, view, and work
with the data in a database.
• Large databases and DBMS’ are commonly used by
companies, but many productivity applications are
built around database concepts.

60. The two primary types of databases are flat-file
databases (with only one table) and relational databases
(with multiple, related tables).
• Fields, which store various pieces of data related
to a single entity.
• Records, or collections of fields relating to an
entity.
• Tables, which are collections of related records.
Databases use three main structures for organizing
data:
Databases and DBMSes - Database Basics

61. Field
Record

62. Table
PROFESSIONAL ADDRESS BOOK

63. • Entering data into the database.
• Sorting (rearranging) the data in the database.
• Obtaining subsets of the data for use.
A DBMS allows users to access and manage the data
collected in a database.
Data management tasks (all done through the DBMS)
can be divided into three categories:
Databases and DBMSes - DBMS Basics

64. • Simultaneous Access
• Shared Peripheral Devices
• Personal Communication
A network connects computers so they can communicate,
exchange information, and share resources.
The main benefits of using a network are:
Computer Network

65. • In organizations, many people may need to use the
same data or programs. A network solves this
problem.
• Shared data and programs can be stored on a
central network server. A server that stores data
files may be called a file server.
• Managers may assign access rights to users. Some
users may only be able to read data, others may be
able to make changes to existing files.
The Uses of a Network - Simultaneous Access

66. • Because peripheral (external) devices like printers
can be expensive, it is cost-effective to connect a
device to a network so users can share it.
• Through a process called spooling, users can send
multiple documents (called print jobs) to a
networked printer at the same time. The documents
are temporarily stored on the server and printed in
turn.
The Uses of a Network -Shared Peripheral
Devices

67. • One of the most common uses of networks is for
electronic mail (e-mail).
• An e-mail system enables users to exchange written
messages (often with data files attached) across the
local network or over the Internet.
• Two other popular network-based communications
systems are teleconferencing and videoconferencing.
The Uses of a Network - Personal
Communication

68. 1 2 3 4

69. • A LAN is a network whose computers are located
relatively near one another. The nodes may be
connected by a cable, infrared link, or small
transmitters.
• A network transmits data among computers by
breaking it into small pieces, called packets.
• Every LAN uses a protocol – a set of rules that
governs how packets are configured and
transmitted.
Type of Networks – Local Area Networks
(LANs)

70. •
Type of Networks – Wide Area Networks
(WANs)
Multiple LANs can be connected together using
devices such as bridges, routers, or gateways, which
enable them to share data.
• A WAN is two or more LANs connected together.
The LANs can be many miles apart.
• To cover great distances, WANs may transmit data
over leased high-speed phone lines or wireless links
such as satellites.

71. LAN 1
WAN
LAN 2
Type A
header
Payload Type A
header
Payload
Type A
header
Payload
Significant
geographical
distance
ROUTER ROUTER
SERVER SERVER

72. • In client/server computing, individual nodes share the
processing and storage workload with the server.
• Client/server networks require specialized software
that enables nodes and the server to collaborate on
processing and storage, but no special type of network
hardware.
Networks Structure – Client/Server Networks

73. 1
2
3

74. • In a peer-to-peer network, all nodes have an equal
relation to one another.
• Each node usually has access to some resources on
other nodes, so users can share files, programs, or
devices on other users' systems.
• Some peer-to-peer networks use a server, but some
do not.
Networks Structure – Peer-to-Peer Networks

75. A network's topology is the layout of the cables and
devices that connect the nodes. The four most common
network topologies are:
• Bus. Each node is connected in series along a
single conduit.
• Star. All nodes are connected to a central hub.
• Ring. Nodes are connected in a circular chain,
with the conduit beginning and ending at the
same computer.
• Mesh. Each node has a separate connection to
every other node.
Network Topologies for LANs

76. • In a network, the media are the wires, cables and other
means by which data travels from its source to its
destination.
• The most common network media are twisted-pair
cable, coaxial cable, fiber-optic cable, and wireless
links.
• Each node uses a special device, called a network
interface card (NIC). The card connects to the
network media and controls the flow of data.
• NICs must use a common network technology to
communicate. The most popular network technologies
for LANs are Ethernet, Fast Ethernet, and Token Ring.
Network Media and Hardware

77. • Word processors provide tools for creating, editing,
and formatting text-based documents.
• You can use a word processor to create virtually any
type of document, from a simple letter to a complete
book.
• A word processor's formatting tools let you create
professional-quality documents easily.
Word Processing Programs and Their Uses

78. Word processors provide tools to produce
professional looking documents.

79. • Document area
• Menu bar
• Toolbars
• Rulers
• Scroll Bars
• Status Bar
Most Windows-based word processors offer a similar
set of tools, which you use to navigate, edit, and format
documents:
The Word Processor's Interface

80. Menu bar Toolbars
Ruler
Document area
Status bar
Scroll bar
Scroll boxes

81. • Spreadsheets provide tools for working with
numerical data.
• You can use a spreadsheet program to create
budgets, balance sheets, and other types of
number- baseddocuments.
• You can display your information in a traditional
row-and-column format, or in a chart.
Spreadsheet Programs and Their Uses

82. Classic row and column
format
Report using
color and graphics

83. • In a spreadsheet program, you work in a document
called a worksheet. You can collect multiple
worksheets into a file called a workbook.
• Most Windows-based word spreadsheets offer a
similar set of tools, including a formula bar, where
you can enter and edit data.
• Data is displayed in cells. A cell is the intersection
of a row and column.
• Each cell has a cell address – the combination of
the cell's column letter and row number.
The Spreadsheet's Interface

84. Menu bar
Tool bars
Column
Row
Status bar
Scroll boxes
Cell
Formula bar