it essentials: pc hardware and software 1 module 1 information technology basics

IT Essentials: PC Hardware and Software 1

Module 1

Information Technology Basics


Computer Systems

• A computer system consists of hardware and software

components.

• Hardware is the physical equipment such as the case,

floppy disk drives, keyboard, monitor, cables, speakers,

and printers.

• The term software describes the programs that are used to

operate the computer system.

• Computer software, also called

programs, instructs the computer

on how to operate. These operations

may include identifying, accessing,

and processing information.


Computer Software

• There are two types of software: operating systems and

applications.

• Application software accepts input from the user and then

manipulates it to achieve a result, known as the output.

Examples of applications include word processors,

database programs, spreadsheets, web browsers, web

development tools, and graphic design tools.

• An operating system (OS) is a program that manages all

the other programs in a computer. It also provides the

operating environment with the applications that are used to

access resources on the computer.


Operating Systems

Examples of Operating Systems

• The Disk Operating System (DOS)

• Windows 98

• Windows 2000

• Windows XP

• Windows NT

• Linux

• Mac OS X (Apple Macintosh)

• DEC VMS

• IBM OS/400


Computer Types

• Mainframes - The mainframe model consists of centralized

computers, usually housed in secure climate controlled

computer rooms. End users interface with the computers via

"dumb terminals." These dumb terminals are low cost devices

that usually consist of a monitor, keyboard, and a

communication port to talk to the mainframe.


Mainframe Computers

•There are several advantages of mainframes:

•Scalability, the ability to add more users as the need arises

•Centralized management

•Centralized backup

•Low cost desktop devices (dumb terminals)

•High level of security


Mainframe Computers

• There are several disadvantages of mainframes:

• character based applications

• lack of vendor operating system standards and

interoperability in multi-vendor environments

• expensive, with a high cost for set up, maintenance, and

initial equipment

• potential single point of failure (non-fault tolerant

configurations)

• timesharing systems, which means that there is a potential

for a bottleneck


Personal Computers

• There are several advantages of PC computing:

• standardized hardware

• standardized, highly interoperable operating systems

• GUI interface

• low cost devices (when compared to mainframes), low cost

of entry

• distributed computing

• user flexibility

• high productivity applications


Personal Computers

• There are several disadvantages of PC computing:

• Desktop computers cost, on average, five times as much as

dumb terminals, according to some industry estimates.

• There is usually no centralized backup.

• There is usually no centralized management.

• Security risks can be greater (physical, data access, and

virus security).

• There is usually high management and maintenance costs,

although they are generally cheaper to maintain than

mainframes.


Birth of the Internet

• 1960’s - The U.S. Department of Defense (DoD) recognized

the need to establish communications links between major U.S.

military installations. The primary motivation was to maintain

communications if a nuclear war resulted in the mass

destruction and breakdown of traditional communications

channels.

• 1970’s - When the Advanced Research Projects Agency

Network (ARPANET) project began, no one anticipated that the

network would grow to the extent that it did. Throughout the

1970s, more nodes or access points were added, both

domestically and abroad.



• 1980’s - The Domain Name System (DNS) was introduced in

1984, providing a way to map "friendly" host names to IP

addresses. It was much more efficient and convenient than

previous methods.

• 1990’s - ARPANET evolved into the Internet, with the U.S.

government getting involved in pushing the development of the

so-called information superhighway.

• Today, there are millions of sites that exist on the World Wide

Web, with millions of host computers participating in this great

linking.


Starting and Restarting a Computer

• Starting a computer is also referred to as booting the system.

• A "cold boot" is performed when the PC is turned on using the

power button.

• Restarting a PC that has already been powered up is referred

to as a "warm boot." This can be achieved by pressing the

reset button on the front panel.


Shutting Down a Computer

• Three ways to shutdown a computer

• To shutdown the computer, click on the Start button on the

lower left corner of the Windows Taskbar and select Shut

Down.

• Pressing Ctrl+Alt+Delete, and click Shut Down from the

menu that displays.

• Pressing Alt+F4 at the desktop, and selecting Shut Down

from the menu that displays.

• Note: It is extremely important not to power off the computer

with the power switch. Most operating systems like Macintosh

and Windows have a specific method for turning the system

off.


The Desktop

• The main display screen in Windows is known as the desktop.

• Some of the icons on the desktop, such as My Computer,

Network Neighborhood (or My Network Places), Recycle Bin,

and My Documents, are shortcuts to those directories


The Desktop

• Located at the bottom of the desktop is the taskbar.

• The taskbar contains the Start button, quick launch buttons,

system tray, and the clock.

• The Start button, displays the Start menu. This menu

allows access to virtually every program and function on the

PC.

• Quick launch buttons are shortcuts to applications.


Windows Explorer (Windows 2000)

• To create a shortcut (icon), right-click the program or file

(in Windows Explorer) and select Create Shortcut.

• Explorer can be accessed in Windows 2000 by choosing

Start > Programs > Accessories > Windows Explorer,

from the Windows desktop.


Windows Explorer (Windows 9x)

• To create a shortcut (icon), right-click the program or file (in

Windows Explorer) and select Create Shortcut.

• With Windows 9x (95, 98, and Millennium), choose Start >

Programs > Windows Explorer from the menu that displays.


Switching Between Windows

• When more than one window is open, the user can switch

between windows by pressing Alt +Tab. While holding down

the Alt button, keep pressing Tab to find the desired window.

• Document windows can also be selected by clicking the

desired document on the desktop taskbar, which displays at

the bottom of the screen.


Viewing Basic System Information

• To view information about the system, go to the Start menu and

choose Programs > Accessories > System Tools > System

Information. Here you can view information such as the type of

operating system, the processor type, and the type and amount

of Random-Access Memory (RAM) that is installed.


Adjusting the Screen Display

• To adjust the screen display, first minimize all windows that are

open.

• Right-click on empty space on the desktop and choose

Properties to open the Display Properties window.

• Alternatively, from the Start menu choose Settings > Control

Panel > Display.


Start Menu Options


Start Menu Options

• The Help feature provides tips and instructions on how to use

Windows, along with an index and search function so

information can be found easily.


Start Menu Options

• Find/Search

• In Windows 95, 98, and Windows NT,

Find is used to locate files, folders, and

network connections to other computers

and peripherals.

• In Windows 2000, Find has been

renamed Search.

• Programs

• The Programs menu lists all of the

programs that are installed on the

computer.


Start Menu Options

• Documents

• The Documents menu shows a list of the most recent

documents that have been accessed or created.

• Run

• The Run feature is another method of starting a program,

instead of clicking the program's shortcut icon on the

desktop or on the list of programs within the Programs

directory.


Application Software

• There are several types of application software:

• Word Processor - an application that creates, edits, stores, and

prints documents.

• Spreadsheet - numerical data is stored in cells that are arranged on

a grid.

• Database - a collection of data that is organized so that its contents

can be easily accessed, managed, and updated.

• Graphics applications - used to create or modify graphical images.

• Presentation applications - permit the organizing, design, and

delivery of presentations in the form of slide shows and reports.

• Web browser - an application that is used to locate and display

pages from the World Wide Web.


Measurement-related Terminology

• Bit – The smallest unit of data in a computer. A bit can take the

value of either one or zero, and it is the binary format in which

data is processed by computers. 0’s and 1’s. Binary (base2)

• Byte – A byte is a unit of measure used to describe the size of

a data file, the amount of space on a disk or other storage

medium, or the amount of data being sent over a network. One

byte consists of eight bits of data.

• Nibble – A nibble is half a byte or four bits.



• Kilobyte (KB) – A kilobyte is 1,024 (or approximately 1,000)

bytes.

• Kilobit (Kb) – A kilobit is 1,024 (or approximately 1,000) bits.

• Megabyte (MB) – A megabyte is 1,048,576 bytes (or

approximately 1,000,000 bytes).

• Note that a capital B indicates bytes while a lower case b

indicates bits.



The following terms are standard measurements of theamount of data transferred over a network connection.

• Kilobits per second (Kbps) –Kbps is a data transfer rate of

approximately 1,000 bits per second.

• Megabytes per second (MBps) –MBps is a data transfer rate

of approximately 1,000,000 bytes per second.

• Megabits per second (Mbps) –Mbps is a data transfer rate of

approximately 1,000,000 bits per second.



• Hertz (Hz) – Is a unit of measurement of frequency. It is the

rate of change in the state or cycle in a sound wave,

alternating current, or other cyclical waveform.

Common measurement of the speed of a processing chip.

• Megahertz (MHz) – One million cycles per second. common

measurement of the speed of a processing chip.

• Gigahertz (GHz) – One billion (1,000,000,000) cycles per

second.


Boolean Logic Gates

• Computers are built from various types of electronic circuits.

These circuits depend on what are called AND, OR, NOT, and

NOR logic "gates."

• These gates are characterized by how they respond to input

signals.


Boolean Logic Gates

AND

• The AND gate acts as follows: if either input is off, the output is

off.

• AND is like multiplication

AND 0 1

0 0 0

1 0 1

Truth Table


Numbering Systems

• Decimal (base 10) uses 10 symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

• Binary (base 2) uses 2 symbols 0, 1

• Hexadecimal (base 16) uses 16 symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F


Numbering Systems

10^4 10^3 10^2 10^1 10^0 Decimal10,000 1,000 100 10 1

4 2 6 426

Base 10

2^7 2^6 2^5 2^4 2^3 2^2 2^1 2^0 Decimal128 64 32 16 8 4 2 1

1 0 0 1 1 19

Base 2

16^4 16^3 16^2 16^1 16^0 Decimal65,536 4,096 256 16 1

1 2 A 298

Base 16


Binary Counting

Decimal Binary Decimal Binary01

1011

100101110111

10001001101010111100

110111101111

100001000110010100111010010101101101011111000

0123456789

101112

13141516171819202122232425 11001


Decimal to Binary ConversionMethod 1

Convert the decimal number 192 into a binary number.

192/2 = 96 with a remainder of 0








Write down all the remainders, backwards, and you have the binary number 11000000.



Convert the decimal number 192 into a binary number. First find the largest number that is a power of 2 that you can subtract from the original number. Repeat the process until there is nothing left to subtract.192-128 = 64 128’s used 1 64-64 = 0 64’s used 1 32’s used 0 16’s used 0 8’s used 0 4’s used 0 2’s used 0 1’s used 0

Write down the 0s & 1s from top to bottom, and you have the binary number 11000000.



Convert the decimal number 213 into a binary number. First find the largest number that is a power of 2 that you can subtract from the original number. Repeat the process until there is nothing left to subtract.213-128 = 85 128’s used 1 85-64 = 21 64’s used 1*(32 cannot be subtracted from 21) 32’s used 0 21-16 = 5 16’s used 1*(8 cannot be subtracted from 5) 8’s used 0 5-4 = 1 4’s used 1*(2 cannot be subtracted from 1) 2’s used 0 1-1 = 0 1’s used 1

Write down the 0s & 1s from top to bottom, and you have the binary number 11010101.


Binary to Decimal ConversionMethod 1

27 26 25 24 23 22 21 20

128 64 32 16 8 4 2 1 1 0 1 1 0 1 0 1

From right to left, write the values of the powers of 2 above each binary number. Then add up the values where a 1 exist.

128 + 32 + 16 + 4 + 1 = 181


Binary to Decimal ConversionMethod 2

• Start from the left with the first 1 in the binary number. Write down a 1 below it.

• Then look at the next number to the right

• if it is a 0, double the previous number and write it down

• if it is a 1, double the previous number and add 1 to it, then write it down

• Continue this until you reach the last 0 or 1 in the binary number.

• The last number you write down is the decimal equivalent of the binary number.

128 64 32 16 8 4 2 1 1 1 0 1

Binary place value

Binary number

Conversion 1 3 6 13


Hexadecimal to Decimal Conversion

• Each number place represents a power of 16

• Given the hexadecimal number 12A

• 1 X 256 = 256

• 2 X 16 = 32

• A X 1 = +10 (A = 10 in hex)

298

16^4 16^3 16^2 16^1 16^0 Decimal65,536 4,096 256 16 1

1 2 A 298

Base 16


Hexadecimal to Binary Conversion

To convert a hex number to a binary number, each hex bit represents 4 binary digits

Given the hex number A 3

A is the decimal number 10

10 in binary is 1 0 1 0

8 4 2 1 (binary number places - 4 bits)

1 0 1 0

3 is the decimal number 3

3 in binary is 0 0 1 1

8 4 2 1 (binary number places - 4 bits)

0 0 1 1

hex A 3 = 1 0 1 0 0 0 1 1 in binary


Let’s see what you have learned . . .

• Q: What does it mean if I cannot move iconsaround on the desktop?

• A: Auto arrange is enabled.• Q: What maps host names to IP addresses?• A: DNS – Directory Name Service• Q: What is the Alt+Tab used for?• A: switches between the open applications• Q: Translate 30GB.• A: 30 billion bytes


• Q: How is one cycle per second, the unit offrequency CPU speeds measured?

• A: Hertz• Q: Should I clean my physical hardware

components with rubbing alcohol?• A: No, when you must clean, use isopropryl

alcohol.• Q: How can I find out my system information?• A: Start > Programs > Accessories > System

Tools > System Information• Q: What type of signal has an infinite number of

values?• A: Analog signals


• Q: What is the best way to protect my equipmentfrom ESD?

• A: Wear a wrist strap and ground yourself. • Q: What type of technology prevents hackers

from viewing data on the Internet?• A: Encryption and security policies • Q: How did the Internet evolve?• A: ARPANET evolved into the Internet, while the

U.S.government became involved in pushing thedevelopment of the so-called informationsuperhighway.

• Q: What is a relational database?• A: Relational databases are a collection of flat-

file databases, or tables, linked throughsome particular relationship.


• Q: What is the proper way to shut down yourcomputer?

• A: Start > Shutdown• Q: What is a multimeter used for?• A: used to test high-voltage devices • Q: Where on the desktop will you see a

display of the documents and applications?• A: on the Start menu• Q: What is another way to start an

application,other than clicking on the icon?

• A: Go to Start > Run