Computer Concepts

Computer Concepts A Brief Introduction

CAS 133 – Basic Computer Skills/MS Office XP

Russ Erdman - Instructor

“Oh drat these computers! They’re so naughty and so complex, I could pinch them!”

Computer Concepts

Where can you find computers?

Computers are everywhere

Computer Concepts

What is computer literacy?

Knowledge and understanding of computers and their uses.

Computer Concepts

WHAT IS A COMPUTER? A device that follows

instructions, processes data arithmetically and logically, produces output, and stores the results for future use.

Accepts data (input) Manipulates data Produces results

(output) Stores results

Computer Concepts

Computer ConceptsWhat are data and information?

DataRaw facts,

figures, and symbols

InformationData that is organized,

meaningful, and useful

SoftwareInstructions that

tell hardware how to perform tasks

HardwareElectronic and

mechanical equipment

What are hardware and software?Computer Concepts

Computer ConceptsHardware, Software and the

Computer

Without SOFTWARE the computer HARDWARE is just a giant PAPER WEIGHT!

What are common computer hardware components?

printer

scanner

speakerPC camera

microphonedigital camera

system unit

keyboard

modem

monitor

mouse

speaker

Computer Concepts

What is an input device?

Hardware used to enter data and instructions.

scanner

microphone

keyboard

mouse

PC camera

digital camera

Computer Concepts

What is an output device? Hardware that conveys information to a user.

printer

monitor speakers

Computer Concepts

What is the system unit?

Box-like device containing electronic components connected to motherboard hard

disk drive(inside case)

CD-RW drive

CD-ROM or DVD-ROM drive

Zip® drive

floppy disk drive

Computer Concepts

Processor Memory module

Processor Memory module Expansion cards

• Sound card• Modem card• Video card• Network

interface card

Ports and Connectors


• Sound card


• Sound card• Modem card


• Sound card• Modem card• Video card


• Sound card• Modem card• Video card• Network

interface card

Processor

What are common components insidethe system unit?

Computer Concepts

What is the motherboard? Main circuit board

in system unit Contains

chips,integrated circuits,and transistors

Also calledthe system board

Computer Concepts

Memory (RAM & ROM)• Temporary holding place for data

and instructions

What are two main components on the motherboard?

Central Processing Unit (CPU)

• Also called a processor

• Carries out instructions that tell computer what to do

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Central Processing UnitCentral Processing UnitWhat is a microprocessor?

Single processor chip foundin personal computers

Computer Concepts

Computer Concepts

volatile memoryLoses its contents when Loses its contents when the computer's power is the computer's power is

turned offturned off

volatile memoryLoses its contents when

computer's poweris turned off

MemoryMemoryWhat are two types of system unit memory?

nonvolatile memory

Does NOT lose its contents when

computer’s power is turned off

p. 4.16

RAM

ROM

MemoryMemoryWhat is random access memory (RAM)?

p. 4.16

Memory chips that can be read from and written to by processor

Most RAM is volatileThe more RAM a computer has, the faster it

operates

memory module

Computer Concepts

What is storage? Holds data, instructions, and information for future use.

StorageDevice

• Records and retrieves items to and froma storage medium

Storage Medium

• Physical material on which data, instructions, and information are stored

Click to view Web Linkthen click Storage Devices

p. 1.7

Computer Concepts

CD-RW drive

hard disk drive

CD-ROM or DVD-ROM drive

ZIP® drivefloppy disk drive

What are common storage devices or drives?

p. 1.7 Fig. 1-3

Computer Concepts

What is a floppy disk?

Thin, circular, flexible disk enclosed inrigid plastic

A Zip® disk is a higher capacity disk

Computer Concepts

Computer Concepts

p. 7. 10 Fig. 7-12

What is a hard disk? High-capacity

storage Consists of

several inflexible, circular platters that store items electronically

Components enclosed in airtight, sealed case for protection

hard disk installed in system unit

4: Head actuator positions read/write head arms over correct location on platters to read or write data

Step 4

2: Small motor spins platters

Step 2

3: When software requests disk access, read/write heads determine location of data

Step 3

1: Circuit board controls movement of head activator and small motor

Step 1

p. 7.11 Fig. 7-13

Hard DisksHow does a hard disk work?

Computer Concepts

Computer Concepts

p. 7. 17

Compact DiscsWhat is a compact disc (CD)?

Storage medium

Most PCs include some type of compact discdrive

Available invariety offormats

CD-ROM

CD-RCD-RW

DVD-ROM

DVD+RW

Computer ConceptsCompact Discs

A CD-ROM’s layout.

Computer ConceptsComputer SoftwareWhat is a computer program? A series of instructions that tells the

computer what to do

p. 1.10

Computer ConceptsAdvantages of a computer

SpeedReliabilityAccuracyStorageCommunications

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SpeedOperates at close to the speed of light –

186,000 miles/second! Consider word processing (typing) over

writing by hand. Reliability

Hardware seldom failsWhen the bank says the computers are

down it may not be true.

Advantages of a computer

Computer Concepts

AccuracySoftware – GIGO (Garbage In Garbage Out) Humans make 1 error every 300 characters

typed, computers make 1 error every 3,000,000 characters processed.

StorageConcept of bits (1s & 0s), bytes (8 bits),

kilobytes (1024 bytes), megabytes (1024 KB), gigabytes (1024 MB), terabytes (1024 GB).

All the works of Shakespeare can fit on one CD… with much room to spare!


Five basic types of data are represented in the computer.NumericCharacterVisualAudio Instructional

Computer ConceptsStorage

Data RepresentationData Representation

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Data RepresentationData RepresentationHow do computers represent data?

Most computers are digital

Recognize only two discrete states: on or off

1 1 1 1 1

0 0 0 0 0

on

offp. 4.13

Storage

Computer Concepts A digital computer’s circuits are binary. The circuits can exist in either one of two

electrical states, normally represented by 0 and 1, that is, OFF or ON.

Each 1 or 0 is called a binary digit or bit and are the basis for measurement of storage.

Each character (letter, number, etc.) equals one byte.

These bytes can add up, especially when representing images (graphics).

Storage

Computer Concepts

Consider the math – 1 byte = 1 character, 5 characters per word, 400 words per page, 200 pages per book.Floppy Disk = 1,440,000 bytes = 3.6 booksZip Disk = 100,000,000 bytes = 250 booksCD = 700,000,000 bytes = 1,750 booksDVD = 4,200,000,000 bytes = 10,500 booksHard Drive (small in lab) = 6,000,000,000

bytes = 15,000 booksHard Drive (newer) = 100,000,000,000 bytes =

250,000 books

Storage

Computer ConceptsStorageRepresenting Symbols and Text

Each letter and symbol in a text document must be translated into a binary number for storage in the computer.

Symbols and Text Includes characters, punctuation,

symbols representing numbers. Each symbol can be assigned a

numeric value Two standardized sets of codes for

symbols: ASCII (American Standard Code

for Information Interchange) EBCDIC (Extended Binary Coded

Decimal Interchange Code) Developed by IBM for use on

their mainframe computers.

The ASCII code, or simply ASCII, is used by virtually all other computers in the United States and Europe as well. All personal computers use the ASCII code.


0 - 0110000

1 - 0110001

2 - 0110010

3 - 0110011

4 - 0110100

5 - 0110101

6 - 0110110

7 - 0110111

8 - 0111000

9 - 0111001

: - 0111010

A - 1000001

B - 1000010

C - 1000011

D - 1000100

E - 1000101

F - 1000110

G - 1000111

H - 1001000

I - 1001001 J - 1001010 K -

1001011

a - 1100001 b - 1100010 c - 1100011 d - 1100100 e - 1100101 f - 1100110 g - 1100111 h - 1101000 i - 1101001 j - 1101010 k - 1101011

Ctrl+@(NULL) - 0000000 Ctrl+A - 0000001 Ctrl+B - 0000010 Ctrl+C - 0000011 Ctrl+D - 0000100 Ctrl+E - 0000101 Ctrl+F - 0000110 Ctrl+G(Bell) - 0000111 Space - 0100000 Delete - 1111111

A partial listing of the ASCII character set

Computer ConceptsStorage A new coding system has recently been developed

called UNICODE.

Unicode provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language.

Why UNICODE? No single encoding could contain enough

characters: for example, the European Union alone requires several different encodings to cover all its languages and what about Asian languages with all there characters.

Even for a single language like English no single encoding was adequate for all the letters, punctuation, and technical symbols in common use.


Digitized picture of a tiger.

Representation of Images


Black and white pixels are either 0 or 1.000100000000000000000000000000000000000001010101000000000000001000000000000000000000000001010110000000000000100000000000000000000000000011101010100000000001000000000000000000000000001110010000000000001011000000000000000000000001010100010000000000011110000000000000000000000111010010010000000001111101010101110000000000001100010000000000001111011101111111010000000010110000101001000001101111101111110110000000001111000001010000000011111011110101110100000000011100000101001000111010101010110100000000000101110000001010100000011101010101101010100000011111000001011000000101010010000000000000000000111000000000000110010101000000000000000000000011110000000000010110010100000000000000000000101111001001010101010010010101000000000000000101111110000011111101001011011101010110000000101101111001001111010111111111110101101101011111111111011001011111011111111111111111110111111011111110101011011111111111111111111111111111111111111010000111011111111111111111111111111111111111010101001111111111111111111111111111111111111101100001010111111111111111111011111100111101010101111011111111111111111111111011010101110101101010101111111111111111101011011110111101111100000010111111111111010111011010011111101010100000001011111111111101111111110010111101101010000000011111101011111011101110100111111010101000000001111111111111110101111111011111101110110000101111101101010110000101111111111111101011



Gray-Scale:Each pixel contains a value representing

some shade of gray.The more shades of gray possible, the more

memory will be needed. 4 shades of gray needs 2 bits per pixel:

00, 01, 10, 11

8 shades of gray needs 3 bits per pixel: 000, 001, 010, 011, 100, 101, 110, 111

64 shades of gray needs 6 bits per pixel: 000000, 000001, … 111110, 111111


Representing colors in pictures takes even more bits than gray-scale.

The more colors the more bits and thus more:

Memory is required

Processing power is requiredA better graphics card is required



Fact: All types of information are stored in binary form.

Problem: The computer has no way of discerning between types unless a file is marked in some manner for identification by the operating system.

Files are marked as to type with unique icons and have an extension that indicates file type. (e.g., .doc, .txt, .html, .xls, .ppt, .wav, .jpg and so forth)


Windows files showing their icons and extensions

Computer Concepts

CommunicationsAllows us to easily share data

NetworksEmailThe InternetThe World Wide WebModern Wireless Devices

Cell phonesWiFi and Bluetooth


Computer ConceptsTypes of Computer SoftwareWhat is system software? Programs that control the operations of the

computer and its devices

Operating System (OS)

Utility Programs

p. 1.12

Next

Computer Concepts

The operating system (OS) on the computers in the lab is Windows 2000 Professional.

Some other OS names are:DOS (Disk Operating System)Windows 98, Me, XPWindows 2000 Active ServerUnixLinuxMacintosh OS X and others

Types of Computer Software

Computer ConceptsTypes of Computer SoftwareWhat is application software?

Programs that perform specific tasks for users

Word processing

software

Spreadsheet software

Database software

Presentation graphics software

SuitePopular software applications bundled together as a single

unit

Office XP

Spreadsheet Database

Presentation graphics

Word processing

Computer ConceptsTypes of Computer Software

There must be some type of (OS) system software for application software to run on.

The application software must be compatible with the OS software.

The application software we will work with includes:Word (Word processing)Excel (Spreadsheets)Access (Databases)Internet Explorer (Web Browser)M.S. Paint (Graphics)Other

Computer Concepts

What is the user interface?

Controls how you enter data and commands and how information displays

Types of user interfaces include command line and graphical.p. 1.12

User Interface

Computer Concepts

p. 1.12

User InterfaceWhat is a graphical user interface (GUI)?

Uses visual images such as icons Icons represent

programs, instructions, or some other objects

icons

icons

p. 1.12 Fig. 1-13

Computer Concepts

p. 1.12

Computers are compared as to their:SpeedCostSizeComplexity

Super Computers

Mainframe Computers

Minicomputers

Microcomputers

Fast Expensive Complex Large

Slow Cheap Simple Small

The PC (Microcomputer) vs. Minis, Mainframes, Supercomputers

Computer Concepts

p. 1.12

Microcomputers: Are single-user systems (PCs) – only one processor.

Minicomputer: Most often used by several people (10 to hundreds of users). Usually faster

than a microcomputer but the difference is rapidly fading. May have more than one processor.

Mainframe: A powerful multi-user computer capable of supporting many hundreds or

thousands of users simultaneously. Has many processors

Supercomputer: An extremely fast computer that can perform hundreds of millions of

instructions per second. May have hundreds of processors

The PC (Microcomputer) vs. Minis, Mainframes, Supercomputers

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p. 1.12Computers have shrunk in size while getting more powerful

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p. 1.12

Harvard Mark I (IBM ASCC)

Constructed out of electromagnetic relays, rotating shafts, and clutches.

Described as sounding like a “roomful of ladies knitting”.

Contained more than 750,000 components, 50 feet long, 8 feet tall and weighed 5 tons.

ENIAC

ENIAC took 200,000 man-hours to build

Weighed 30 tons

Used 18,000 vacuum tubes (one went out every 12 minutes)

1,000 times faster than the Harvard Mark I

Computer Concepts

p. 1.12

Why do we say a computer has a bug? We owe that concept to Grace Hopper

A Naval officer, she was the third programmer on the Mark I

Considered the Mother of COBOL (Common Business Oriented Language)

Found first computer bug - a moth stuck in the computer’s electromagnetic relays and fouling it up.

Computer Concepts

p. 1.12

The invention of the transistor and integrated circuits led to: Smaller computers

Many more diverse capabilities and uses for computers

Today’s Intel Pentium 4 chip has 25 layers and 55 million transistors in a chip about 3/8th of an inch square

Computer Concepts

p. 1.12

“That’s all folks!”

Education

Computer Concepts