Chapter 7 Storage.

Chapter 7 Storage

Chapter 7 Objectives Explain how a compact disc stores data
Differentiate between storage and memory Understand how to care for a compact disc Identify various types of storage media and storage devices Differentiate between CD-ROMs, CD-RWs, and DVD-ROMs Explain how a floppy disk stores data Identify the uses of tape Identify the advantages of using high-capacity disks Understand how an enterprise storage system works Describe how a hard disk organizes data Explain how to use PC Cards and other miniature storage media Identify the advantages of using an Internet hard drive Next Identify uses of microfilm and microfiche p. 7.2

Memory Versus Storage What is storage?
The media on which data, instructions, and information are kept, as well as the devices that record and retrieve these items Next p Fig. 7-1

Memory Versus Storage What is memory?
A temporary holding place for data and instructions Consists of one or more chips on the motherboard Sometimes called primary storage Nonvolatile memory Does not lose its contents when power is removed from the computer Volatile memory Loses its contents when the computer’s power is turned off Most memory is volatile Next p. 7. 3

Memory Versus Storage How does storage differ from memory?
Storage also called secondary storage, auxiliary storage, permanent storage, or mass storage Storage holds items such as data, instructions, and information for future use Storage is nonvolatile When you want to work with a file, you remove it from storage and place it in memory When you are finished with the file, you remove it from memory and return it to storage Next p. 7. 4

Memory Versus Storage How does volatility compare? ON OFF
State of Computer ON OFF Screen Display Volatile Contents of Storage Nonvolatile Contents of Memory (most RAM) Volatile C6578 print cartridge $30.25 per cartridge 2 cartridges $60.50 total due Contents of storage retained when power is off Screen display and contents of most RAM (memory) erased when power is off Next p Fig. 7-2

Memory Versus Storage What is a storage medium and a storage device?
The computer hardware that records and retrieves items to and from a storage medium storage medium The physical material on which a computer keeps data, instructions, and information Next p. 7. 4

Memory Versus Storage What is reading and writing? Reading
Process of transferring data, instructions, and information from a storage medium into memory Serves as a source of input Writing Process of transferring items from memory to a storage medium Serves as a source of output Next p. 7. 4

Memory Versus Storage What is access time?
cost less expensive more expensive speed faster slower The amount of time it takes the device to locate an item on a disk Defines the speed of a disk storage device Memory (RAM) Hard Disk Compact Disc Floppy Disk Next Tape p Fig. 7-4

Memory Versus Storage What is capacity?
Storage Term Number of bytes Abbreviation The number of bytes (characters) a storage medium can hold Manufacturers use many terms to define the capacity of storage media Kilobyte KB 1 thousand Megabyte MB 1 million Gigabyte GB 1 billion Terabyte TB 1 trillion Petabyte PB 1 quadrillion Next p Fig. 7-3

Technology Trailblazer
Al Shugart Joined IBM as a customer engineer in 1951 Supervised a team in 1967 responsible for developing a removable, portable data storage device Founded Shugart Associates in 1973 and Seagate Technology in 1979 Click to view Web Link then click Al Shugart Next p. 7.7

Floppy Disks What is a floppy disk?
A portable, inexpensive storage medium Consists of a thin, circular, flexible plastic disk with a magnetic coating Enclosed in a square-shaped plastic shell Today’s standard disk is 3.5” wide Next p. 7. 7

Floppy Disks What are the parts of a floppy disk?
A thin circular flexible film is enclosed between two liners A piece of metal called a shutter covers an opening to the recording surface liner shutter metal hub Click to view Web Link then click Floppy Disks magnetic coating flexible thin film shell Next p Fig. 7-5

Floppy Disks What is a floppy disk drive (FDD)?
A device that can read from and write on a floppy disk Most personal computers have a floppy disk drive, in which you insert and remove a floppy disk floppy disk floppy disk drive Next p Fig. 7-6

Floppy Disks How are floppy disk drives designated? One floppy drive
drive A Two floppy drives drive A drive B Next p. 7. 6

Floppy Disks How does a floppy disk store data?
A type of magnetic media Uses magnetic patterns to store items such as data, instructions, and information on a disk’s surface Able to access (read) data from and place (write) data on a magnetic disk any number of times The read/write head in the floppy disk drive is the mechanism that actually reads items from or writes items on the floppy disk Next p. 7. 8

Floppy Disks How does a floppy disk drive work?
Step 1: When you insert the floppy disk into the drive, the shutter moves to the side to expose the recording surface on the disk. Step 1 Step 2: When you initiate a disk access, the circuit board on the drive sends signals to control movement of the read/write heads and the disk. Step 2 Step 3: If disk access is a write instruction, the circuit board verifies whether the disk can be written to or not. Step 3 Step 6: The read/write heads read data from and write data on the floppy disk. Step 6 Step 4: A motor causes the floppy disk to spin. Step 4 Step 5: A motor positions the read/write heads over the correct location on the recording surface of the disk. Step 5 Next p Fig. 7-7

Floppy Disks What is density?
Downward compatible Able to recognize and use earlier media Floppy disk drives are downward compatible What is density? The number of bits in an area on a storage medium A floppy disk drive must support that floppy disk’s density Most floppy disks today are high density (HD) with a capacity of 1.44 MB Upward compatible Able to recognize newer media Floppy disk drives are not upward compatible Next p. 7. 7

Floppy Disks What are tracks and sectors?
Track: a narrow recording band that forms a full circle on the surface of the disk Pie shaped sections break the tracks into small arcs called sectors A sector can store up to 512 bytes of data A typical floppy disk stores data on both sides of the disk sector 18 per track track 80 per side Next p Fig. 7-8 80 tracks per side X 18 sectors per track X 2 sides per disk X 512 bytes per sector = 1,474,560 bytes

Floppy Disks What is a cluster?
The smallest unit of disk space that stores data Also called an allocation unit 2 to 8 sectors depending on the operating system Each cluster holds data from only one file One file can span many clusters cluster 2 to 8 sectors Next p. 7.8

Floppy Disks What is formatting?
The process of preparing a disk for reading and writing Formatting marks bad sectors as unusable Next p Fig. 7-9

Floppy Disks How do you care for a floppy?
A floppy disk can last at least seven years Proper care helps to maximize a disk’s life Avoid exposure to heat and cold Avoid exposure to magnetic fields Avoid exposure to contaminants such as dust, smoke, or salt air Never open the shutter and touch the disk’s recording surface Keep disks in a storage tray when not using them Next p. 7.9

Floppy Disks What is a write-protect notch?
A small opening with a cover that you slide up or down Protects floppy disks from accidentally being erased notch open means you cannot write on the disk write-protected not write-protected notch closed means you can write on the disk Next p Fig. 7-10

High-Capacity Disks What is a high-capacity disk drive?
A disk drive that uses disks with capacities of 100 MB and greater SuperDisk™ drive Uses a 120 MB or a 250 MB SuperDisk™ Developed by Imation HiFD™ (High-Capacity Floppy Disk) drive Uses a 200 MB HiFD™ disk Developed by Sony Electronics, Inc. Zip® drive Uses a Zip® disk that can store 100 MB or 250 MB of data Developed by Iomega Corporation built in Zip® drive Click to view Web Link then click Zip® Drives Next p. 7.9

High-Capacity Disks What is a backup?
A duplicate of a file, program, or disk that you can use if the original is lost damaged, or destroyed High-capacity disks are often used to back up important data and information data instructions information Next p. 7.9

Hard disk installed in system unit
Hard Disks Consists of several inflexible, circular platters that store items electronically Also called a hard disk drive or a fixed disk A platter is coated with a material that allows items to be recorded magnetically on its surface The components of a hard disk are enclosed in an airtight, sealed case to protect them What a hard disk? Hard disk installed in system unit Next p Fig. 7-12

Hard Disks How does a hard disk work?
Step 1: The circuit board controls the movement of the head activator and a small motor Step 1 Step 2: A small motor spins the platters while the computer is running Step 2 Step 3: When software requests a disk access, the read/write heads determine the current or new location of the data Step 3 Step 4: The head actuator positions the read/write head arms over the correct location on the platters to read or write data Step 4 Next p Fig. 7-13

Hard Disks What is a cylinder?
track What is a cylinder? The location of a single track through all platters A single movement of the read/write head arms can read all the platters of data Click to view animation Next p Fig. 7-14

Clearance is approximately two millionths of an inch
Hard Disks What is a head crash? Occurs when a read/write head touches the surface of a platter The platters of the hard disk rotate at a high rate of speed while the computer is running The spinning creates a cushion of air that floats the read/write head above the platter hair Clearance is approximately two millionths of an inch read/write head dust smoke Next gap p Fig. 7-15 platter

Hard Disks How does access time compare for a hard disk and a floppy disk? A hard disk’s access time is significantly faster than a floppy disk The hard disk spins much faster than a floppy disk A hard disk spins constantly, while a floppy disk starts spinning only when it receives a read or write command Hard disk Approximately 5 to 11 milliseconds Floppy disk 84 milliseconds or approximately ½ a second Click to view Web Link then click Hard Drives Next p

Hard Disks What is a disk cache?
A portion of memory that the processor uses to store frequently accessed items A cache controller manages cache and thus determines which items cache should store processor hard disk disk cache second request for data — to hard disk first request for data — to disk cache processor hard disk disk cache first request for data — to disk cache processor hard disk disk cache Next p Fig. 7-16

Designation for second partition on the hard disk
Hard Disks drive C Designation for first partition or for a single partition on the hard disk What is a partition? You can divide a formatted hard disk into separate areas called partitions Done by issuing a special operating system command Each partition functions as if it were a separate hard disk drive drive D Designation for second partition on the hard disk Next p

Hard Disks What is a disk controller?
USB port Used as interface for many external hard disk drives What is a disk controller? A special purpose chip and associated electronic circuits that control the transfer of data, instructions, and information from a disk to the rest of the computer Sometimes called an interface A hard disk controller (HDC) is the interface for a hard disk May be part of the disk drive or a separate card inside the system unit Enhanced Integrated Drive Electronics (EIDE) One of the most widely used controllers Supports up to four hard disks small computer system interface (SCSI) Supports multiple disk drives, as well as other peripherals You can daisy chain devices together Next p

Hard Disks What is a removable hard disk?
A disk drive in which a plastic or metal case surrounds the hard disk so you can remove it from the drive A popular, reasonably priced, removable hard disk is the Jaz® disk by Iomega Next p Fig. 7-17

Company on the Cutting Edge
Kingston Technology The world’s leading independent manufacturer of memory products of computers, servers, digital cameras, and other electronic devices Founded by John Tu and David Sun in 1987 Markets more than 2,000 products Designated as one of the 100 Best Companies to Work for in the United States by Fortune magazine Click to view Web Link then click Kingston Click to view video Next p

Hard Disks What is RAID? Redundant array of independent disks
A type of hard disk system that connects several smaller disks into a single unit that acts like a single large hard disk More reliable than a traditional disk system but quite expensive Next p Fig. 7-18

Hard Disks How does RAID work?
RAID duplicates data, instructions, and information to improve data reliability Level 1, called mirroring, has one backup disk for each disk Levels beyond level 1 use a technique called striping, which splits data, instructions, and information across multiple disks in the array Mirroring (RAID Level 1) Striping Next p Fig. 7-19

Hard Disks What utilities maintain a hard disk drive?
Windows provides many maintenance and monitoring utilities for a hard disk on the System Tools submenu Click to view Web Link then click Utilities Next p Fig. 7-20

Hard Disks What is an Internet hard drive?
A service on the Web that provides storage to computer users Sometimes called online storage Many offer storage free of charge Revenues come from advertisers Next p Fig. 7-21

Hard Disks What are advantages of an Internet hard drive?
Large audio, video, and graphics files can be downloaded to an Internet hard drive instantaneously Files can be accessed from any computer or device that has Web access Others can be authorized to access data from your Internet hard drive Allows offsite backups of data Next p

CD-ROM CD-RW CD-R DVD-ROM
Compact Discs What is a compact disc (CD)? CD-ROM A flat, round, portable, metal storage medium that usually is 4.75 inches in diameter and less than one-twentieth of an inch thick Most personal computers today include some type of compact disc drive Also called an optical disc Available in a variety of formats CD-RW CD-R DVD-ROM Next p

Insert disc, label side up Push button to slide out the tray
Compact Discs How do you use a compact disc? Insert disc, label side up CD drives can read compact discs, including audio discs Most CD drives include a volume control button and a headphone jack The drive designation of a CD drive usually follows alphabetically after that of the hard disk Push button to slide out the tray Push the same button to close the tray Next p Fig. 7-22

Compact Discs How does a laser read data on a compact disc?
Items are stored using microscopic pits (indentations) and land (flat areas) that are in the middle layer of the disk A laser light reads items from the compact disc Step 2 Compact disc label lens prism laser diode pit land Step 3 Compact disc label lens prism laser diode Light-sensing diode 1 pit land Compact disc label Compact disc label lens prism laser diode Step 1 Compact disc label lens prism laser diode Step 1: A laser diode shines a light beam toward the compact disc. Step 2: If light strikes a pit, it scatters. If light strikes land, it is reflected back toward the laser diode. Step 3: Reflected light is deflected to a light-sensing diode, which sends digital signals of 1 to the computer. Absence of reflected light is read as a digital signal of 0. Next p Fig. 7-23

Single track spirals to edge of disc
Compact Discs How is data stored on a compact disc? A compact disc typically stores items in a single track It spirals from the center of the disc to the edge of the disc The track is divided into evenly sized sectors in which items are stored Single track spirals to edge of disc Next p Fig. 7-24 Compact disc sectors

Compact Discs What is a jewel box?
A protective case for a compact disc Place a compact disc in a jewel box to protect data Next p Fig. 7-25

Compact Discs How should you care for a compact disc?
1: Do not expose the disc to excessive heat or sunlight. 2: Do not eat, smoke, or drink near a disc. 3: Do not stack discs. 4: Do not touch the underside of the disc. 5: Do store the disc in a jewel box when not in use. 6: Do hold a disc by its edges. Next p Fig. 7-26

CD-ROMs What is a CD-ROM?
A silver-colored compact disc that uses the same laser technology as audio CDs for recording music Can contain text, graphics, audio, and video The manufacturer writes, or records, the contents of standard CD-ROMs You cannot erase or modify the contents A CD-ROM drive or CD-ROM player is used to read items on a CD-ROM Next p

CD-ROMs What is the storage capacity of a CD-ROM?
A typical CD-ROM holds about 650 MB of data, instructions, and information Manufactures use CD-ROMs to store and distribute today’s multimedia and other complex software Click to view Web Link then click CD-ROMs Next p Fig. 7-27

40X 40 X 150 KB per second = 6,000 KB per second or 6 MB per second
CD-ROMs What is the data transfer rate of a CD-ROM drive? The time it takes a drive to transmit data, instructions, and information from the drive to another device Slower CD-ROM drives produce choppy images or sound Drive speed measured relative to original CD-ROM drives (150 KB per second) 40X 40 X 150 KB per second = 6,000 KB per second or 6 MB per second range of current rates 75X 75 X 150 KB per second = 12,250 KB per second or MB per second Next p. 7.20

CD-ROMs What is a PhotoCD?
A compact disc that contains digital photographic images saved in the PhotoCD format Based on a file format developed by Eastman Kodak Used by commercial and professional users A multisession disc, which means you can write additional data, instructions, and information to the disc at a later time Next p Fig. 7-28

CD-ROMs What is a Picture CD? A single-session disc offered by Kodak
Stores digital versions of photographs for consumers Single-session means all items are written to the disc at one time Film developers create the images on the disc from photographic negatives at the time a roll of film is developed Click to view Web Link then click Picture CDs Next p

CD-R and CD-RW What is a CD-R (compact disc-recordable)?
A multisession compact disc onto which you can record your own items such as text, graphics, and audio You write on the CD-R using a CD recorder or a CD-R drive and special software The CD-R drive can read and write both audio CDs and standard CD-ROMs You cannot erase the disc’s contents Most CD-ROM drives can read a CD-R Next p

CD-R and CD-RW What is a CD-RW (compact disc-rewritable)?
An erasable disc you can write on multiple times You must have CD-RW software and a CD-RW drive Discs can be read only by multiread CD-ROM drives Drives that can read audio CDs, data CDs, CD-Rs, and CD-RWs Most recent CD-ROM drives are multiread Click to view Web Link then click CD-RWs Next p

CD-R and CD-RW How is an audio CD created? 1 2a 2b 3a 3b 4 5 1 2a 2b
Step 1: Artist composes a song and creates a CD. Step 2a: Song is stored on audio CD and purchased by the user. Step 2b: Song is compressed and stored on the Internet. Step 3a: User inserts audio CD into CD-ROM drive, plays song, and copies it to the hard disk. Step 3b: User downloads song as audio file to hard disk. Step 4: User copies file to CD-RW disc. Step 5: User listens to song on personal computer or removes CD and listens to song on portable CD player. Next p Fig. 7-29

DVD-ROMs What is a DVD-ROM (digital video disc-ROM)?
An extremely high capacity compact disc capable of storing from 4.7 GB to 17 GB You must have a DVD-ROM drive or DVD player to read a DVD-ROM Looks just like a CD-ROM but data, instructions, and information is stored in a slightly different manner to achieve a higher storage capacity Click to view video Next p Fig. 7-30

DVD-ROMs How does a DVD-ROM store data?
Three storage techniques used to store DVD-ROM data Pits are packed closer together to make the disc more dense Two layers of pits are used, where the lower layer is semitransparent so the laser can read through it to the upper layer Some are double-sided, which means you can remove the DVD-ROM and turn it over to read the other side Next p Fig. 7-31

DVD-ROMs What are other various DVD formats?
Digital motion picture DVD Used to play a movie on your television set or view on the computer DVD-RAM A rewritable DVD that allows you to erase and record on the disc multiple times DVD-R (DVD-recordable) A recordable DVD that you can write on once and read from many times DVD+RW A competing technology to DVD-RAM Click to view video Next p

Technology Trailblazer
Mark Dean Designs microprocessors, improvements in architecture, and hardware innovations for IBM First African-American to receive an IBM Fellowship, the company’s highest technical ranking Inducted into the National Inventor's Hall of Fame Click to view Web Link then click Mark Dean Next p

Company on the Cutting Edge
EMC2 A provider pf storage systems for some of the world’s largest corporations Founded in 1979 by Richard Egan and Roger Marino to fill a demand for add-on memory boards in the minicomputer market Click to view Web Link then click EMC Next p

Tapes What is tape? A magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost A tape drive reads from and writes data and information on a tape Older computers used reel-to-reel tape drives A tape cartridge is a small, rectangular, plastic housing for tape used in today’s tape drives Click to view Web Link then click Tapes Next p Fig. 7-32

Tapes Where is tape used?
Used by business and home users to backup personal computer hard disks Both external and internal tape units for personal computers Larger computers use tape cartridges mounted in a separate cabinet called a tape library Three common types of tape drives Next p Fig. 7-33

Tapes What is sequential access versus direct access?
Method used for tape Reading and writing data consecutively You must forward or rewind the tape to a specific point to access a specific piece of data Much slower Utilized most often for long-term storage and backup Direct access Method used for floppy disks, hard disks, and compact discs Also called random access You can locate a particular data item or file immediately, without having to move consecutively through items stored in front of the desired data item or file Faster Used as the primary method of storage Next p

Enterprise Storage Systems
What is an enterprise storage system? A strategy that focuses on the availability, protection , organization, and backup of storage in a company Goal is to consolidate storage so operations run as efficiently as possible RAID SAN servers tape library NAS device CD-ROM jukeboxes Internet backup tape library NAS device CD-ROM jukeboxes Internet backup NAS device Internet backup NAS device NAS device CD-ROM jukeboxes Internet backup Next p Fig. 7-34

What storage techniques are used in an enterprise system? Network-attached storage (NAS) device An easy way to add additional hard disk space to the network Tape library A high-capacity tape system that works with multiple tape cartridges for storing backups of data, information, and instructions RAID system Ensures that data is not lost if one drive fails Internet backup Stores data, information, and instructions on the Web CD-ROM jukebox Holds hundreds of CD-ROMs that can contain application programs and data Also called a CD-ROM server Server Stores data, information, and instructions need by users on the network Storage area network (SAN) A high-speed network that connects storage devices Next p

How do organizations handle storage? Enterprise storage system managed in house Data warehouse A huge database system that stores and manages historical and current transaction data Storage management offloaded to an outside organization or online Web service Next p

PC Cards What is a PC Card? A thin, credit card-sized device
Fits into a PC Card slot on a notebook other personal computer Different types and sizes add storage, additional memory, communications, and sound capabilities to a computer Click to view Web Link then click PC Cards Next p Fig. 7-35

PC Cards What are the uses of PC Cards? Three types of PC Card
Advantage of a PC Card for storage is portability between systems Next p Fig. 7-36

Miniature Mobile Storage Media
What is miniature mobile storage media? Handheld devices use miniature mobile storage media to augment internal storage Storage Capacity Device Name Type, Use Clik! Disk 40 MB Cartridge Digital cameras, notebook computers CompactFlash 2 to 256 MB Memory Card Digital cameras, handheld computers, notebook computers, printers, cellular telephones Microdrive 1 GB Memory card Digital cameras, handheld computers, music players, video cameras SmartMedia 2 to 128 MB Memory Card Digital cameras, handheld computers, photo printers, cellular telephones Next p Fig. 7-37

How is miniature storage media used? Handheld devices, such as players and wallets, read or display the contents of miniature storage media such as memory cards Next p Fig. 7-38

What is a smart card? Stores data on a thin microprocessor embedded in the card Similar in size to a credit card Read smart card with a specialized card reader Information on the smart card can be read and updated Next p Fig. 7-39

What are the types of smart cards? Intelligent smart card contains a processor and has input, process, output, and storage capabilities Memory card has only storage capabilities Store data such as photographs, music, books, and video clips Store a prepaid dollar amount that is updated when the card is used Store patient records, vaccination data, and other healthcare information Store tracking information such as customer purchases or employee attendance Next p

What is electronic money? A means of paying for goods and services over the Internet Also called digital cash A bank issues unique digital cash numbers that represent an amount of money When you purchase digital cash, the amount of money is withdrawn from your bank account To use the card you swipe it through a card reader Next p

Microfilm and Microfiche
What are microfilm and microfiche? Store microscopic images of documents on roll or sheet film Images recorded onto film using a computer output microfilm (COM) recorder Images can only be read with a microfilm or microfiche reader Microfilm Uses a 100- to 215-foot roll of film Microfiche Uses a small sheet of film, usually about four inches by six inches Next p Fig. 7-40

Microfilm and Microfiche
How do life expectancies of various media compare? Microfilm and microfiche are inexpensive and have the longest life of any storage medium Next p Fig. 7-41

Summary What are suggested storage devices for computer users? Home
Large Business Home Mobile Small Office/Home Office Power Large Business Home Mobile Small Office/Home Office Power 3.5-inch HD floppy disk drive 1 GB PC Card hard disk 10 GB hard disk Internet hard drive DVD-ROM drive or 40X CD-ROM drive Mobile Home 3.5-inch HD floppy disk drive 250 MB Zip® drive 30 GB hard disk Internet hard drive DVD-ROM drive CD-RW drive Large Business 3.5-inch HD floppy disk drive 75 GB hard disk DVD-ROM drive CD-RW drive Microfilm or microfiche Smart card reader RAID Tape drive Enterprise storage system Large Business Small Office/Home Office 3.5-inch HD floppy disk drive 40 GB hard disk Internet hard drive DVD-ROM drive CD-RW drive 2 GB Jaz® drive 3.5-inch HD floppy disk drive DVD-ROM drive CD-RW drive 75 GB hard disk Internet hard drive 2 GB Jaz® drive Power Next p Fig. 7-42

Summary of Storage Memory versus storage Floppy disks
High-capacity disks Hard disks Compact discs CD-ROMs CD-R and CD-RW DVD-ROMs Tapes Enterprise storage systems PC Cards Miniature mobile storage media Microfilm and microfiche Next

Chapter 7 Complete

Chapter 7 Storage.

Similar presentations

Presentation on theme: "Chapter 7 Storage."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Chapter 7 Storage.

Similar presentations

Presentation on theme: "Chapter 7 Storage."— Presentation transcript:

Similar presentations

About project

Feedback