Computers and Computer Systems

Day 2

What impact do computers have on our lives?

Computers

Education enhanced instruction Video game systems transport you to an

imaginary world ATMs allow you to access bank accounts Television and Movies Mobile computing, text messaging, e-mail,

and online audio/video conferencing allow you to communicate with people all over the world

Understanding the Importance of Computers

First computers developed in the late 1940s and early 1950s.

Massive machines with names like UNIVAC and ENIAC

Designed for use by the military and government

Less processing power than an iPhone but occupied small buildings or entire city blocks and cost millions of dollars

Brief History of Computers

Computers in mid-1950s through early 1970s somewhat smaller and more powerful.

1971, Dr. Ted Hoff developed a microprocessor.

Steve Jobs and Steve Wozniak built the first Apple computer in 1976.

In 1980, Bill Gates worked with IBM to develop the disk operating system (DOS), which quickly became the PC of choice for businesses.

History Continued

A computer is an electronic device that receives data (input), processes data, stores data and produces a result (output).

Computer system includes:◦ Hardware : The actual machine – wires,

transistors, and circuits. Includes peripheral devices such as printers and monitors.

◦ Software: Instructions or programs for controlling the computer

Defining a Computer

Receives Data Processes Data Outputs Information Stores Data

Description of Computer System

Inputs Data Outputs Data

Processes Data

Stores Data

1. Desktop Computers2. Laptops3. Mobile Devices

◦ PDAs, calculators, cell phones, handheld games

4. Tablet PC5. Mainframe Computer6. Supercomputer7. Portable music and media players (MP3 and

DVD)8. Electronic book readers9. Computer game systems

Types of Computers

Motherboard – a circuit board that contains many important components.◦ Central Processing Unit◦ Memory◦ Basic Controllers◦ Expansion ports and slots

Identifying System Components

The central processing unit or CPU, also called the microprocessor, is the brains of the computer.

The CPU contains a chip with millions of switches and pathways that help your computer make important decisions.

Programs help tell the computer which switches to turn off and on to control the activities of the computer.

Central Processing Unit

As electricity passes through the processor pathways, the turning off and on of switches represents 1s and 0s in a computer. ◦ 1 = electricity present◦ 0 = absence of electricity

A single zero or a single 1 is called a bit. 8 bits are equal to 1 byte. A byte is a single character.

◦ Example : Letter “A”

Recognizing How a Computer Represents Data

TERM ABBREVIATION

NUMBER OF BYTES

Kilobyte KB About 1,000

Megabyte MB About 1 million

Gigabyte GB About 1 billion

Terabyte TB About 1 trillion

Measurement Terms

Memory is also found on the motherboard. RAM (Random Access Memory)

◦ Short-term memory that is erased after you turn off the computer.

ROM (Read Only Memory)◦ Long-term memory used to store specific

instructions that are needed for computer operations.

Memory

Think about what you have learned in this lesson. Your goal is to purchase a computer. 1. Where would you shop – online, or through a local

computer dealer, retail store or other? 2. How much memory would you need? 3. Would you purchase a desktop, notebook or other

type of computer?

Write a 1-2 paragraph essay answering the above questions and outlining your thoughts about what other technologies you would include.

Explain why you made these selections.

Critical Thinking

Input, Output and Processing Devices

Day 3

Allow you to enter data and commands into the computer.◦ Example:

Keyboard Mouse Trackball Touchpad Pointing Stick Microphones

Input Devices

Used for specialized applications.◦ Digital Cameras◦ Game Controllers◦ Scanners/Bar Code Readers◦ Touch Display Screen ◦ Stylus◦ Security Devices

Specialized Inputs

Enables the computer to give you the results of the processed data.◦ Examples:

Monitors Printers Speakers Headphones Projectors Fax Machines

Output Devices

As data is entered in the computer and processed, it is stored in RAM. If you want to keep a permanent copy of the data, you must store it on some type of storage device. ◦ Three types of storage devices.

Magnetic Technology Optical Technology Solid-state Storage

Storage Devices

Use oxide-coated plastic storage media called Mylar.

Examples:◦ Hard Disks◦ Magnetic Tape◦ Floppy disks◦ Zip Disks

Magnetic Storage Devices

Use laser technology to read and write data on silver platters.◦ Examples:

CDs DVDs Blu-ray

Optical Storage Devices

Referred to as removal media◦ Examples:

Memory Cards USB Flash Drive

Solid-State Storage Media

Software Fundamentals

Day 3

Software is divided into two classes.◦ System Software◦ Application Software

Software

Application Software is the end-user programs that allows the user to tell the computer what to do.

Microsoft Office Suite is an example of application software.◦ The Suite includes Word, Excel, PowerPoint and

Access.

Application Software

Word is the word-processing software. Use this software to create, edit and print

documents. Examples of documents:

◦ Reports◦ Letters◦ Resumes◦ Memos

Word

Excel is the spreadsheet software. Use to evaluate, calculate, manipulate,

analyze and present numeric data. Examples of documents:

◦ Budgets◦ Spreadsheets◦ Grade Sheets◦ Invoices

Excel

PowerPoint is the presentation software. Used to organize and present information,

normally in the form of a slide show. Examples of Documents

◦ Slides◦ Outlines◦ Speaker’s notes◦ Audience Handouts

PowerPoint

Access is the database software. Used as a collection of related information

organized in a manner that allows for rapid search and retrieval.

Examples of documents◦ Addresses◦ Schedules◦ Inventory

Access

Utility programs help you perform computer housekeeping chores.

Examples◦ Antivirus programs◦ Defragmentation◦ Backup program

Utility Programs

Operating system is system software that enables the computer hardware to communicate and operate with the application software.

Most widely used system software is Windows XP.

System Software

Networks Fundamentals

Day 4

A network is a group of two or more computers linked together.

The biggest network of all is the Internet.

Network

Instant Communication Information Sharing Collaborative Environment Hardware sharing Software sharing Enhanced Communication

Network Benefits

Many weaknesses and risks to networks.◦ Data security and unauthorized access◦ Equipment malfunctions◦ System failures◦ Computer hackers

Hackers are people who break into computer systems to steal services and information.

◦ Virus attacks◦ E-mail not necessarily private

Risks of Networks

Networks are divided into two main types.◦ Local Area Network (LAN)◦ Wide Area Networks (WAN)

Types of Networks

Most LANs connect personal computers, workstations and other devices such as printers in a limited geographic area, such as an office building, a school or a home.

Wireless networks are a type of local area network.

LANs

A wide area network covers a large geographic area and communicate links across cities, regions or national boundaries.

The largest WAN is the Internet. Most WANs consist of two or more LANs and

are connected by routers. WANs can be connected through channels

like telephone systems, fiber optics, satellites, microwaves or any combination of these.

WANs

Firewall – special hardware to protect a network from outside networks

Intranet – designed for the exclusive use of people within an organization.

Extranet – similar to Intranet but it allows specific users outside of organization to access Intranet.

Internet – worldwide system composed of thousands of smaller networks.

Other Network Terms

Log onto wikispace. Answer the Computer Purchase Questions

and Social Networking questions on one Word document.

Make sure you save and send it to me through Moodle when you finish.

Questions

Electronic Communication

3rd Quarter

Internet provides many communication services.◦ Electronic mail◦ Instant messaging◦ Text messaging◦ Online conferencing◦ Chat rooms◦ Social networking sites◦ Blog postings/comments◦ Message boards and newsgroups

Electronic Communication Categories

Communication requires the following components:◦ Sender: The person sending the message◦ Receiver: The person receiving the message◦ Channel: The media that carries or transports the

message◦ Protocols: The rules that govern the transfer of

data and ensures that information created by one system can be interpreted and read by another

Components of Communication

An e-mail address consists of three parts:◦ The user name of the individual◦ The @ symbol◦ The user’s domain name

E-mail Addresses

When you compose an e-mail message, it should contain four main components.◦ Address of the person you are sending the

message.◦ Subject Line, which should grab the reader’s

attention◦ Body of the Message◦ Attachments if needed

Parts of an E-mail Message

A virus is a program that has been written, usually by a hacker, to cause corruption of data on a computer.

Usually they are attached to a file and spread from one file to another.

Viruses

Worm – a virus that makes copies of itself, resulting in the consumption of system resources that slows down or actually halts tasks.

Time Bomb – a virus that does not cause its damage until a certain date or until the system has been booted a certain number of times.

Types of Viruses

Logic Bomb – a virus triggered by the appearance or disappearance of specified data.

Trojan horse – a virus that does something different from what it is expected to do.

Types (Cont).

Use antivirus software and update this software regularly.

Be careful in opening e-mail attachments. Do not access files copied from USB drives,

other media or downloaded from the Internet without scanning the files first.

Protect Your Computer

The Web actually began in 1990, when Dr. Tim Berners-Lee wrote a small computer program for his own use.

It wasn’t until 1993 the number of people using the Web increased significantly when Mark Andreessen released Mosaic, which was the first graphical browser.

Mosaic is similar to what Firefox and Internet Explorer are now.

History of the World Wide Web

The web sites at www.ibiblio.org/pioneers contains a profile of 10 Internet pioneers. Complete the following:

Visit the www.ibiblio.org/pioneers Web site and select one of the pioneers.

Read the biography of the pioneer you selected.

Copy a photo of the pioneer to Word document and write a paragraph describing his or her contributions to the Internet.

Project 27-2

Web Content3rd Quarter???

Web pages and Web sites Blogs

◦ Authors post comments and readers can comment on entries.

Wikis◦ A collaborative website that can be edited by anyone

with access. Social Networking Sites

◦ Groups of people who share similar interests Podcasts

◦ A collection of multimedia files that can be downloaded from the Internet to other devices.

Web Content You can Create

Technology today is integrated into almost every facet of life and influences how you work, use computers at home and learn about the world outside your doors.

Using Computers

Collecting Information Organizing Information Evaluating Information Communicating Information Increasing Productivity Collaborating with Others and Solve Problems Creating Communities Facilitating Learning Promoting Creativitiy Supporting Critical Thinking Supporting Daily Life

Impact of Computers

How do computers impact our daily life?

Computers in Everyday Life

ATMs – Teller machines allow use to get money.

Credit Card – Pay for something without money.

Automated Processes – robots on assembly lines.

Point-of-Sale Systems – buy something and it is scanned into the computer system

Living Online

Weather Predicting – severe weather reports Computers in Appliances – built in clocks,

automobiles, cell phones GPS – provide location and directions Security Systems – protect home and cars

Living Online

E-Commerce – buying and selling things online

Media – news and information can be communicated much quicker now

Online Learning – people can take classes online

Robotics – assembly lines and dangerous tasks

Telecommuting – working from home Online Communities – Social networks

Transform Daily Life

Social networking online is a recent technology that has become very popular. Research this technology and then prepare a report defining what you consider the definition of a social network site, list at least four examples of social networking sites and then discuss why you think this technology has become so popular. Select one site (other than Facebook or MySpace) and describe the differences between the network site you selected and Facebook or MySpace.

Lesson 30 Online Discovery