Introduction to Computers Chapter 1. 2 Hardware Hardware: The physical components of the computer, such as the monitor and system unit, are called hardware.

Introduction to Computers

Chapter 1

2

Hardware

Hardware: The physical components of the computer, such as the monitor and system unit, are called hardware.

3

Input/Output/Peripheral

Input Devices: Keyboard, mouse, scanner, etc.Output Devices: Printer, CD Burner, monitorPeripheral Devices: Expansion slots

4

Motherboard

Expansion boards Central Processing Unit Bus ROM (Read Only Memory) RAM (Random Access Memory)

5

Data Flow

6

Utility Program

A program Manages Files Disk Doctor CD/DVD Drive Driver needed for printing

7

Mobile Computing Devices

Notebook ComputersNotebook Computers

Tablet PCTablet PC

Handheld Computers (PDA)Handheld Computers (PDA)

SmartphonesSmartphones

Wearable Computers - MP3 Wearable Computers - MP3 PlayersPlayers

8

Cross-Platform Connectivity

The ability for one type of PC to link to and share data with a different type of PC

9

Programming Languages

Words Codes Symbols That allow a programmer to give

instructions to the computer

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Low/High Level Program Language

Low-Level: include machine language and assembly language

High Level: English-like instruction and are easier to use than machine language

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Complier/Interpreter

Complier: A program that converts an entire program into machine code before the program is executed.

Interpreter: Translates and executes an instruction before moving on to the next instruction in the program.

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Object-Oriented Language

Java C++ Visual Basic.Net

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Advantages of Networking

1. Allows users to reliably share and exchange data

2. Can reduce costs by sharing devices such as printers

3. Offers security options including password protection to restrict access to certain files

4. Simplifies file management through centralized software updates and file backups

5. Provides e-mail for network users

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Network Size

LAN: Local-Area Network WAN: Wide-Area Network

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Chapter 1

LAN Using a Bus Topology

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Chapter 1

LAN Using a Star Topology

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Chapter 1

LAN Using a Ring Topology

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NETIQUETTE

Network users should follow a certain etiquette referred to as netiquette:

*Do not attempt to access the account of another user without authorization.

*Do not share your password, and change it periodically

*Use appropriate subject matter and language, and be considerate of other people’s belief and opinions.

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Binary

The electrical circuits on a computer has one of two States, off or on. Therefore the binary number system(base 2), which only uses two digit (0 and 1), was adopted for use in computers.

Decimal Binary Base 2 Equivalent 0 0 =0×21+0×20 =0×2+0×1 =0+01 1 =0×21+1×20 =0×2+1×1 =0+12 10 =1×21+0×20 =1×2+0×1 =2+03 11 =1×21+1×20 =1×2+1×1 =2+14 100 =1×22+0×21+0×20 =1×4+0×2+0×1 =4+0+0

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Chapter 1

Storing Data in Memory

Computer memory is measured in bytes. MB - Megabytes which means 1,048,576 and GB – Gigabytes 1,073,741,820 bytes.c

Data stored in memory is referred to by an address. An address is a unique binary representation of a location in memory. Therefore, data can be stored, accessed, and retrieved from memory by its address.

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What is a File?

*Human-readable files are called text files, and computer readable files are called binary files.

Files type are distinguished by the extension that comes after the file name

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Extensions

.exe Executable .xls Excel

.doc Document .jpg Graphic

.class Complied java file

.gif GIF image file

.bmp Bitmap graphic .zip Compressed file

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Storage Devices

Storage devices use a persistent media to maintain files. These devices, which are also referred to as drives, mass storage, and auxiliary storage, can be categorized in three ways:

Internal or external

Removable or permanent media

Magnetic, optical, or solid state technology

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Storage Devices

Optical Technology - uses a drive with a laser and an optoelectronic sensor.

Solid State Technology - allows for the smallest, most portable storage

Magnetic Technology - allows for storage devices that range in capacity from 1.44MB to many gigabytes on hard disk drives.

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Chapter 1

Storage Devices

Storage media can be very sensitive. Care should be taken to avoid damaging files.

Never attempt to open a case containing a disk. Keep magnetic media away from magnets. Handel CD / DVDs by the center hole or by the

edges. Never bend CD / DVDs or other flexible media. Store CD / DVDs in a jewel case or sleeve to

prevent scratches. Keep media away from moisture and extreme

temperatures.

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Chapter 1

Intranet, Extranet, Internet

Intranet - is a network that is used by a single organization, such as a corporation or school, and is only accessible by authorized users.

Extranet - extends an intranet by providing various levels of accessibility to authorized members of the public.

Internet - Is the largest and most widely accessed network. The Internet, is a worldwide network of computers that is not controlled by any one organization.

27

Chapter 1

Telecommunications

Telecommunications - is the transmitting and receiving of data. Numerous telecommunications options are available, which vary in speed and cost:

Conventional Modem - Uses standard telephone lines to convert analog

signals to digital data. A conventional modem is a 56 Kbps modem,

which transmits data at 28.8 Kbps and 36.6 Kbps, and receives data at

56 Kbps. Home computers sometimes use a conventional modem.

DSL (Digital Subscriber Line) - DSL modem uses standard telephone

lines with data transmission up to 640 Kbps. Data receipt is from 1.5

Mbps to 9 Mbps. A DSL (Asymmetric DSL) is the most common form

used

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Telecommunications

Cable Modem - Transmits data through a coaxial cable television network. Data transmission is from 2 Mbps to 10 Mbps and data receipt is from 10 Mbps to 36 Mbps.

Leased / Dedicated Lines - are used by many businesses and schools for Internet access. They allow for a permanent connection to the Internet that is always active. The cost of a leased line is usually a fixed monthly fee. A T-1 carrier is a type of leased line that transmits data at 1.544 Mbps.

ISDN (Integrated Services Digital Network)- is a digital telephone network provided by a local phone company. ISDN is capable of transmitting and receiving data at up to 64 Kbps. ISDN requires the use of an ISDN terminal adapter instead of a modem.

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E-Mail

[email protected]@lpdatafiles.com

User NameUser Name Domain NameDomain Name

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E-Mail

Certain rules should be followed when composing e-mail messages

Use manners.Include “please” and “thank you” and also properly address people you do not know as Mr., Ms., Mrs., Dr., and so on.

Be Concise. Be professional, which includes using the proper spelling

and grammar. Re-read a message before it is sent. Always fill in the “To

Box” last to avoid sending a message before it is complete.

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E-Mail

E-mail messages are not private.

Send messages through your account only.

Use appropriate subject matter and language

Be considerate of other people’s beliefs and

opinions.

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Finding Information on the Web and Downloading Files

A search Engine - is a program that searches a database of web pages for keywords and then lists hyperlinks to pages that contain those keywords. Commonly used search engines include:

Yahoo!Yahoo! ((www.yahoo,com)) Google (Google (www.google.com))

MSN (MSN (www.msn.com)) AOL (AOL (www.aol.com))

Excite (Excite (www.excite.com)) Ask Jeeves (Ask Jeeves (www.ask.com))

Overture (Overture (www.overture.com)) Lycos (Lycos (www.lycos.com))

Web Crawler (Web Crawler (www.webcrawler.com)) Fast Search (www.Fast Search (www.

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Internet Privacy Issues

Online Profiling The collection of data a about consumers

visiting a website is a marketing technique. Example: Cookies or Web Beacons

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Internet Privacy Issues

Cookies: a text file created by the server computer when a user enters information into the website. Each time the user visits the website the server recognizes the user.

Web Beacons: are transparent graphics located on web pages or in e-mail messages that are used in combination with cookies to collect data about web page users or e-mail senders.

35

Internet Privacy Issues

Privacy Policy: is a legally binding document that explains how any personal information will be used.

Several laws have been passed to protect the consumers privacy.

Electronic Communications Privacy Act of 1986 Electronic Freedom of information Act of 1996 Children’s Online Privacy Protection Act of

1998 Safety and freedom through Encryption Act of

1999

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The Social and Ethical Implications of Computer Use

The society in which we live has been so profoundly affected by computers that the historians refer to

the present time as the Information Age.

37

Protecting Computer Software and

The society in which we live has been so profoundly affected by computers that the historians refer to the

present time as the Information Age.

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Protecting Computer Software and Data

As society becomes more and more reliant on digital information, copyright and exposure to malicious code have become two important issues among computer users. Copyright is protection of digital information.

39

Protecting Computer Software and Data

Three forms of malicious code are: Virus Trojan Horse Internet Worm

40

Careers

The growth of computers, the Internet, and the Web have created many new job opportunities in the IT field.

Data-entry Operator Systems Analyst Programmer Computer Engineer Technical Suppot Technician

41

The Social and Ethical Implications of Computer Use

Identity Theft is a growing crime where personal information is stolen electronically in order to make fraudulent purchases or loans.

42

MLA Citations

General citation for material located at a website:

Author’s Last Name, First Name MI. Site Title. Access date. Organization name. <URL>.

Example citation of a personal website:

Rawlings, Julie. Home page. 23 Dec. 2006. <http://www.lpdatafiles.com/jrawlings/index.htm>.

continued next slide

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MLA Citations, continued

Example citation of an article in an online magazine:Schiffman, Paula. "Making Vinegar at Home."

Vinegar Monthly. 4 May 2006. <http://www.lpdatafiles.com/ vinegarassoc/journal.asp>.

Example citation of a posting to a discussion list:Cruz, Anthony. "Are Orchestras Going

Downhill?" online posting. 10 Oct. 2006. Tuscon Annual Ballet Conf. <http://www.lpdatafiles.com/tuscontoes/downhill.txt>.