Chapter 4

HARDWARE FOR EDUCATORS

Chapter 4

Chapter Objectives

Chapter 4: Hardware for Educators

2

Describe the system unitDefine the term bit and describe how a series of

bits are used to represent dataIdentify the major components of the system unit

and explain their functionsExplain how the CPU uses the four steps of a

machine cycle to process dataDescribe the four types of input as well as input

devices and pointing devicesList the characteristics of a keyboard and identify

various types of keyboards

Chapter Objectives3

Differentiate among the four types of outputIdentify different types of output devicesExplain differences among various types of printersDifferentiate between storage and memoryIdentify types of storage media and devicesDifferentiate between CDs and DVDs


The System Unit

System unit Boxlike case that

houses the electronic components of the computer that are used to process data

4Chapter 4: Hardware for Educators

Data Representation

Analog vs. Digital Analog

Uses continuous signals to represent data and information

Digital Computers as electronic devices

that are powered by electricity Therefore, digital devices only

understand two states on – represented by the

number 1 off – represented by the

number 0 Each off or on digital value is

called a bit (short for binary digit)


Data Representation6

Binary number systemCombination of ones and zeroes represent

characters


Data Representation7

Bit vs. Byte By itself a bit is not very informative Eight bits equals one byte A byte provides a combination of 0s and 1s to represent 256

individual characters (numbers, letters, punctuation marks)

The system of representing these characters are defined by patterns called a coding system ASCII - American Standard Code for Information Interchange ASCII system converts every keyboard stroke into a byte When processing of the stroke into bytes is completed the result is

numbers, letters, and special characters displayed on the screen Conversion takes place so quickly you don’t even realize they are

happening



The Components of the System Unit9

The Motherboard Contains many of the

electronic components Chip

A small piece of semiconducting material that is made up of many layers of circuits and microscopic components

Usually no bigger than one-half-inch square

Contains many microscopic pathways that carry electrical current

Contains many different types of chips, including the CPU




CPU A single chip inside the

motherboard Dual-core processor – a single

chip with dual processors Multi-core processor – a single

chip with multiple processors Interprets and carries out the

basic instructions that operate a computer

Microprocessor manages most of a computer’s operations



The Control Unit A component of the CPU that directs and coordinates

most of the operations in the computer Fetch - get the next instruction from memory Decode - translate the instruction Execute - carry out the command Store the result - write the result to memory Machine cycle



Image depicting the Machine Cycle


The Arithmetic/Logic Unit (ALU) Performs the execution part of the machine cycle Arithmetic (addition, subtraction, multiplication,

division) Comparison (greater than, equal to, less than) Logical (AND, OR, NOT)



The System Clock Synchronizes, or controls the timing of, all computer

operations Each tick is called a clock cycle Speed measured in gigahertz (GHz) Clock speed the speed at which a processor executes

instructions (measured in gigahertz GHz) Giga = one billion Hertz = one cycle per second 1 GHz = one billion ticks of the system clock in one

second Faster clock means more instructions the CPU can

execute each second



Memory Used to store data and instructions Memory chips on circuit boards store the data and

instructions Memory store three basic items:

The operating system and other system software Application software Data being processed by application programs

Bytes are stored at specific locations or addresses


Terms of Storage Size


17

Kilobyte (KB) = 1 thousand bytes 1,024 bytes ½ page of text= =

MEGABYTE (MB)1 MILLION BYTES1,048,576 BYTES500 PAGES OF TEXT

Gigabyte (GB)

1 billion bytes

1,073,741,824 bytes

500,000 pages of text

Terabyte (TB) 1 trillion bytes 1,099,511,627,776 bytes

500,000,000 pages of text

= = =

= = =

= = =

18

Seats in a stadium are similar to addresses in memory:

(1) A seat in a stadium holds one person at a time, and an address in memory holds a single byte

(2) Both a seat and an address can be empty

(3) A seat has a unique identifying number and so does an address



Memory Size of memory is measured by the number of bytes

available Volatile memory – contents are lost when the

computer is turned off Nonvolatile memory – contents are not lost when the

computer is turned off



Random Access Memory (RAM) The memory chips in the system unit When the computer starts, certain operating system

files are loaded from a hard disk into RAM Synchronous Dynamic RAM (SDRAM) Dual Inline Memory Module (DIMM)


The Components of the System Unit

Random Access Memory (RAM) RAM Chips

Smaller in size than processor chips

Commonly hold up to 4 gigabytes of memory



Random Access Memory (RAM) Configuring RAM

The more RAM, the more programs and files a computer can work on at once

Software usually tells you how much RAM is required For an application to perform optimally, you usually need

more than the minimum specifications



Read-Only Memory (ROM) Cannot be modified Contents not lost when the

computer is turned off These type of chips are also

installed on cars, home appliances, toys, educational games

Flash Memory Type of nonvolatile memory

that can be erased electronically and rewritten on

Example of how flash memory works: Computer changes from

standard time to daylight saving time



Expansion Slots and Expansion Cards Expansion slot

A socket on the motherboard that can hold an adapter card

Add new devices or capabilities to the computer Expansion card

Circuit board that enhances functions of a system component and/or provides connections to peripherals

Plug and Play



Removable Memory Devices Flash memory cards USB flash drives PC Cards ExpressCard modules



Ports and Connectors Port

Point of attachment to the system unit

Usually on the back and front of the system unit

Connectors Used to plug into ports

Male connectors Female connectors


The Components of the System Unit

Ports and Connectors USB USB 2.0 USB 3.0 FireWire Bluetooth


What is Input?28

Any data or instructions you enter into the memory of a computer Data – unprocessed items Programs - series of instructions that tells the

computer how to perform a task Commands - an instruction given to a

computer program User responses - responses to questions or

messages from the software



What are Input Devices?30

Any hardware component that: allows you to enter

data, programs, commands, user responses into a computer



The Keyboard Typing area Numeric keypad Toggle keys Status lights Arrow keys - arrow control keys Function keys Specialized buttons




Pointing Devices An input device that allows you to control a pointer on

the screen Block arrow I-beam Pointing hand


What are Input Devices?

Pointing Devices Mouse

One or two button mouse Scroll wheel Moving the mouse pointer Clicking Dragging Double-clicking Optical mouse Cordless mouse



Touchpad and Pointing Stick Touchpad – small, flat,

rectangular pointing device that is sensitive to pressure and motion

Pointing Stick – pressure-sensitive pointing device shaped like a pencil eraser



Pointing Devices Trackball

Like a mouse, but the ball is on top

Often used on portable computers



Pointing Devices Joystick

Uses the movement of a vertical lever

Often used with games Wheel

Steering-wheel type input device

Used to simulate driving a car or other vehicle



Pointing Devices Touch screen

Monitor has a touch sensitive panel

Used to issue simple commands or choose from a list of options

Kiosks



Optical Scanners Captures an entire page of text or images such as

photographs or artwork electronically Converts the text or image on the original document

into digital data that can be stored on a storage medium and processed by the computer



Pen Input Users write, draw,

and tap on a flat surface to enter input

Stylus – small metal or plastic device that looks like a tiny ink pen but uses pressure instead of ink

Digital pen – slightly larger than a stylus



Digital Cameras Allows you to take

pictures and store the photographed images digitally

Download, or transfer, pictures to your computer



Audio and Video Input Audio input

Entering speech, music, or sound effects Sound card Speech Recognition

Computer’s capability of distinguishing spoken words



Audio and Video Input Video input

Capturing a full-motion recording onto a computer and storing the video on a computer’s storage medium



PDAs, Smart Phones, and Media Players Input Navigation receiver Microphone Digital camera Data transfer Wireless keyboard Stylus


What is Output?

TextGraphicsAudioVideo


What are Output Devices?46

Any computer component capable of conveying information to the user

Commonly used output devices Display devices Printers Data projectors Facsimile machines Multifunction devices Interactive whiteboards Speakers, headphones, and earphones



Display Devices Screen housed in a plastic or metal case Variety of sizes Cathode ray tube (CRT) Pixels Flat-panel displays

LCD (liquid crystal display) monitors LCD screens Plasma monitors



What are Output Devices?

Plasma Monitors Some can measure more

than 150 inches wide Uses gas plasma technology,

which sandwiches a layer of gas between two glass plates



Monitor Quality Resolution (sharpness and clarity)

Expressed as number of columns and rows 1600 x 1200



Televisions Output device for game consoles Some came consoles include a small LCD screen Larger television displays are more preferable



Printers An output device that produces text and graphics on a

physical medium such as paper or transparency film Hard copy (printout) Portrait orientation vs. landscape orientation Printing requirements vary



Nonimpact Printers Do not strike paper Much quieter Ink-jet printers

Spray tiny drops of ink onto the paper

Both black-and-white and color

Photo printers Produce photo lab

quality pictures Many use ink-jet

technology



Nonimpact Printers Laser printers

High-speed, high-quality nonimpact printer

Very high quality resolution



Data Projectors Allows an audience to

view output LCD projectors Digital light processing

(DLP) projector



Facsimile (Fax) Machine Used to transmit and

receive an image of a document over a telephone line

Stand-alone Fax modem



Multifunction Devices Can print, scan, copy,

and fax Less space Lower cost than

separate units



Interactive whiteboards Touch-sensitive device,

resembling a dry-erase board

A presenter controls the computer program used to display the image by: Clicking a remote control Touching the whiteboard Drawing on or erasing

the whiteboard Writing on a special

tablet



Speakers, Headphones, and Earphones Voice output Audio output device Internal speaker


What is Storage?

The media on which data, instructions, and information are kept

The devices that record and retrieve data, instructions, and information

Similar to a filing cabinet


Storage Media and Devices61

Storage medium Also called secondary storage Physical material

Storage device Mechanism used to record and retrieve these items to

and from a storage medium Capacity measured in megabytes or gigabytes



Magnetic Disk Uses magnetic patterns to store data, instructions,

and information on the disk’s surface Formatting is the process of preparing a disk for

reading and writing by organizing the disk into storage locations called tracks and sectors



Hard Disks Provide large storage capacity Sizes range from 160 GB to 1.5 TB Consists of several inflexible, circular disks, called

platters Magnetic storage device Formatting



Miniature and Portable Hard Disks Miniature hard disks are found in consumer

electronics and have greater storage capacities than flash memory

External hard disks connect to a USB or FireWire port by a cable



CDs and DVDs Optical storage media Used to distribute software Laser reads pits on the surface Used on multimedia computers Several types



Care of Optical Discs Can last up to 100 years if properly cared for Never bend a disc Avoid extreme temperatures and humidity Keep away from contaminants Do not stack or touch discs Use a protective case


Storage Media and Devices

CD-ROM Compact disc read-only

memory Can contain text,

graphics, video, as well as sound

Can hold up to 1 GB Used to distribute

software



Picture CDs Stores digital versions

of a single roll of film using a .jpg file format

Most optical drives can read a Picture CD



CD-R and CD-RW Compact disc-recordable

Can write on each part of the disc only one time Cannot be erased

Compact disc-rewriteable Can write on multiple times Erasable disc



DVD and BD Digital video disc read-only memory (DVD-ROM)

Can store from 4.7 GB to 17 GB High quality DVD-ROM drives

BD (Blu-ray Disc) has storage capacities of 100GB, with expectations of exceeding 200 GB



Miniature Mobile Storage Media





USB Flash Drive Storage device that

plugs into a USB port on a computer or mobile device

Smart Card Similar in size to a

credit card Stores data on a thin

microprocessor embedded in the card


Chapter Summary74

Describe the system unitDefine the term bit and describe how a series of

bits are used to represent dataIdentify the major components of the system unit

and explain their functionsExplain how the CPU uses the four steps of a

machine cycle to process dataDescribe the four types of input as well as input

devices and pointing devicesList the characteristics of a keyboard and identify

various types of keyboards


Chapter Summary75

Differentiate among the four types of outputIdentify different types of output devicesExplain differences among various types of

printersDifferentiate between storage and memoryIdentify types of storage media and devicesDifferentiate between CDs and DVDs


HARDWARE FOR EDUCATORS

Chapter 4 CompleteChapter 4 Complete

Education

Chapter 4