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Home , Disk storage, Floppy disk, Hard disk drive, Memory card

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

Memory Versus Memory Versus Storage Storage What is storage? How does • Media and devices used to store and storage differ retrieve data, instructions, and from memory? information • Stores items for When you want to work When you are future use, with a file, finished with rather than you read it the file, you from storage write it from temporarily and place it in memory into • Storage is memory storage nonvolatile, rather than volatile

Next Next p. 7. 2 Fig. 7-1 p. 7. 4

Memory Versus Memory Versus Storage Storage How does volatility compare? What is a storage device and a storage medium?

storage device Hardware that records ContentsContents of of storage and retrieves items to storage and from a storage retainedretained when when medium powerpower is is off off storage medium Physical material on which a Next Next keeps data, ScreenScreen display display and and contents contents instructions, and p. 7. 4 Fig. 7-2 ofof most most RAM RAM (memory) (memory) p. 7. 4 erasederased when when power power is is off off information

1 Memory Versus Memory Versus Storage Storage What is What is access time? and ? e • Amount of time v i f s a n s Memory t it takes device e e p r reading x (RAM) e

to locate item e r of transferring o on disk m data, instructions, Hard Disk and information from a storage medium writing • Defines speed cost speed into memory Process of of Compact Disc Serves as a source transferring items device e s v i lo of input from memory to a s w n e e r storage medium p x e Floppy Disk

Serves as a s s e source of output l Next Next p. 7. 4 p. 7.4 Fig. 7-4 Tape

Memory Versus Floppy Disks Storage What is capacity? What is a floppy disk? • Number Storage Abbreviation Number • Portable, of Term of bytes inexpensive (characters) storage storage KB 1 thousand medium medium can MB 1 million hold • Today’s GB 1 billion disk is 3.5” wide Terabyte TB 1 trillion

Petabyte PB 1 quadrillion Next Next p. 7. 5 Fig. 7-3 p. 7. 6

Floppy Disks Floppy Disks

What are the parts of a floppy disk? How are floppy disk drives designated? • Thin, circular, flexible film liner One floppy drive enclosed drive A between two shutter liners Two floppy drives hub drive A

drive B

Next magnetic Next p. 7.6 Fig. 7-5 shell flexible p. 7. 6 coating thin film

2 Floppy Disks How does a floppy disk drive work? Floppy Disks 1: Shutter moves to 2: Signal sent to control 3: If write instruction, circuit What are tracks and sectors? expose recording movement of read/write board verifies whether disk can surface on disk heads and disk be written to • Track is sector 18 per track 4: Motor causes Step 2 narrow track floppy disk to Step 1 recording 80 per side 5: Motor positions Step 6 band that read/write heads forms full over correct circle on disk location on disk surface

6: Read/write • Sector can heads read data Step 5 store up to from or write data on the floppy disk Step 4 512 bytes of Step 3 data Next Next p. 7. 7 Fig. 7-7 p. 7.8 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 Floppy Disks What is formatting? How do you care for a floppy? • Process of preparing disk for • Proper care helps reading and writing maximize disk’s Avoid exposure • Formatting marks bad sectors life Avoid exposure to heat and cold to magnetic as unusable • Floppy disk can fields last at least seven years Avoid exposure to contaminants such as dust, smoke, or salt air

Never open the shutter and touch the disk’s recording Keep disks in a surface storage tray Next Next when not using p. 7. 8 Fig. 7-9 p. 7.9 them

Floppy Disks High-Capacity Disks What is a What is a high-capacity disk drive? write-protect notchnotch open open • Uses disks with capacities of notch? meansmeans you you 100 MB and greater cannotcannot write write write-protected on the disk • Small opening on the disk • Primarily used to files with a cover and transfer files notch closed not write-protected that you slide notch closed meansmeans you you • Protects floppy cancan write write on on disks from thethe disk disk being erased ® ® accidentally drive built in Uses a Zip® disk that can store 100 MB or 250 MB of Next Next data p. 7. 9 Fig. 7-10 p. 7.9 Fig. 7-11

3 High-Capacity Disks Hard Disks

What is a backup? What is a hard disk? • Duplicate of file, • High-capacity program, or disk that storage you can use if original is • Consists of lost, damaged, or several inflexible, in s circular platters destroyed t ru that store items t io n electronically s • Components ta in a fo d enclosed in rm a airtight, sealed tio Next n Next hard disk case for p. 7.9 p. 7. 10 Fig. 7-12 installed in system unit protection

Hard Disks Hard Disks cylinder track 3: When How does a hard disk work? requests disk What is a cylinder? access, read/write 1: Circuit board controls 2: Small motor heads determine • Location of a single movement of head spins platters location of data activator and small motor track through all platters Step 2 4: Head actuator Step 1 • Single movement of positions read/write head read/write head arms arms over correct can read same track location on platters to read or on all platters write data

Next Step 3 Next p. 7.11 Fig. 7-13 Step 4 p. 7. 11 Fig. 7-14

Hard Disks Hard Disks What is a head crash? What is a disk ? • Occurs when read/write head touches platter • Portion of surface memory • Spinning creates cushion of air that floats read/write head above platter gapgap is is half half the the uses to processor diameterdiameter of of a a dustdust particle particle store clearanceclearance disk cache between head frequently between head hard disk andand platter platter is is hair accessed approximatelyapproximately items twotwo millionths millionths read/write head ofof an an inch dust first request for data — Next smoke Next to disk cache gap p. 7. 12 Fig. 7-15 p. 7. 12 Fig. 7-16 platter second request for data — to hard disk

4 Hard Disks Hard Disks What is a partition? What is a removable hard disk? • Formatted hard • Disk drive in which a plastic or metal case disk divided into drive C surrounds the hard disk so you can remove it from separate areas Designation for first the drive partition or for a single called partitions partition on hard disk • Used for backup or to transfer files • Each partition functions as if it were a separate one hard disk Peerless divided into stores up two partitions drive D Designation for second to 20 GB partition on hard disk Next Next Jaz stores p. 7. 12 p. 7. 13 Fig. 7-17 up to 2 GB

Hard Disks Hard Disks How does RAID work? What Windows • Disk system that duplicates data, instructions, and utilities information to improve data reliability maintain a hard • Mirroring has one backup disk for each disk disk drive? • Striping stores data across multiple disks

mirroring (RAID Level 1)

striping

Next Next p. 7. 14 Fig. 7-19 p. 7. 15 Fig. 7-20 System Tools

Hard Disks Hard Disks

What is an Internet hard drive? driveway.com What are advantages of an Internet hard drive? • Service on Web that provides storage to Large audio, video, and graphics files can computer users be downloaded to an Files can be • Most offer Internet hard drive accessed from any instantaneously computer or device free storage with Web access • Revenues

come from Others can be advertisers authorized to access Allows offsite data from your Internet of data hard drive

Next Next p. 7. 16 Fig. 7-21 p. 7. 16

5 Compact Discs Compact Discs M What is a compact disc (CD)? RO How do you use a compact disc? D- InsertInsert disc, disc, • Storage medium • CD drives can side up C C PushPush button button label side up D to slide out • Most PCs include -R read compact to slide out W CD thethe tray tray some type of compact -R discs, including disc drive audio discs • Available in +RW variety of DVD formats

PushPush the the same same Next OM Next buttonbutton to to close close p. 7. 17 -R p. 7. 17 Fig. 7-22 DVD thethe tray tray

Compact Discs Compact Discs How does a laser read data on a compact disc? How is data stored on a compact disc?

1: Laser diode shines light Compact disc • Typically stores items beam toward compact disc Step 123 label in single track

2: If light strikes pit, it • Track divided into scatters. If light strikes land, it is reflected back evenly sized sectors toward laser diode. pit land that store items lens lens 3: Reflected light deflected to light-sensing 0 1 diode, which sends digital signal of 1. prism prism Absence of reflected light read as digital Light- Light- sensing sensing Single track spirals signal of 0. diode diode to edge of disc Next laser laser Next diode diode p. 7. 18 Fig. 7-23 p. 7. 18 Fig. 7-24 Compact disc sectors

Compact Discs Compact Discs What is a jewel box? How should you care for a compact disc? • Protective case 1: Do not expose to excessive for compact heat or sunlight disc 2: Do not eat, smoke, or drink near a disc 3: Do not stack 4: Do not touch underside 5: Store in jewel jewel box box when not in use 6: Hold disc by its edges

Next Next p. 7.19 Fig. 7-25 p. 7.19 Fig. 7-26

6 CD-ROMs CD-ROMs What is a CD-ROM? What is the data transfer rate of a CD-ROM • Compact disc that uses drive? same laser technology as audio CDs for recording music 40X 40 X 150 KB per second = • Cannot erase or modify 6,000 KB per second or 6 MB per second contents • Typical CD-ROM holds 75X about 650 MB 75 X 150 KB per second = • Commonly used to 11,250 KB per second or 12.25 MB per second distribute software and games Next Next p. 7. 20 p. 7.20

CD-R and CD-RW CD-R and CD-RW What is a CD-R (compact disc-recordable)? What is a CD-RW (compact disc-rewritable)? • Compact disc onto which you can record text, • Erasable disc you can write on graphics, and audio multiple times • Write on CD-R using CD burner (recorder) or CD- • Must have a CD-RW disc, R drive and special software CD-RW software, • CD-R drive can read and CD-RW drive and write both audio CDs and standard CD-ROMs • Cannot erase disc’s contents Next Next p. 7. 22 p. 7. 22

CD-R and CD-RW DVD-ROMs

How is an audio 1 What is a DVD-ROM (digital CD created? video disc-ROM)? Step 1: Artist composes song and 2a 2b creates CD 2b • High capacity compact disc Step 2a: Song stored on audio CD and purchased by user capable of storing from 4.7 OR GB to 17 GB Step 2b: Song compressed and stored on Internet • Must have DVD-ROM drive or Step 3a: User inserts audio CD into DVD player to read DVD- CD-ROM drive, plays song, and copies it to hard disk 5 ROM 3a 3b OR • Primarily used for movies Step 3b: User downloads song as audio file to hard disk • Next-generation software will Step 4: User copies file to CD-RW disc be delivered on DVD Step 5: User listens to Next song on personal Next computer or removes p. 7. 23 Fig. 7-29 4 p. 7.24 Fig. 7-30 CD and listens to song on portable CD player

7 DVD-ROMs Tapes How does a DVD-ROM store data? What is tape? • Two layers of pits are used, where lower layer is • Magnetically coated ribbon of plastic capable of semitransparent storing large amounts of data and information at a • Laser can read through it to upper layer low cost •DVD+RWis a rewritable DVD • Primarily used for backup

Next Next p. 7. 25 Fig. 7-31 p. 7. 26 Fig. 7-32

Enterprise Storage Tapes Systems What is sequential access versus direct access? What is an enterprise storage system?

• Strategy that focuses on availability, CD-ROM sequential access protection , RAID jukeboxes Reading and writing data direct access organization, consecutively You can locate a particular data and backup of Method used for tape item or file immediately storage in a Method used for floppy disks, company servers hard disks, and compact discs Also called

Next Next p. 7. 26 p. 7.27 Fig. 7-34 Network Storagestorage Internet backup

Miniature Mobile PC Cards Storage Media What are uses of PC Cards? What is miniature mobile storage media? • Handheld CompactFlash 40 MB Cartridge devices Digital cameras, notebook use to augment 2 to 256 MB internal Digital cameras, handheld computers, notebook storage computers, printers, cellular telephones 1 GB Memory Card Digital cameras, handheld computers, music players, video cameras

SmartMedia 2 to 128 MB Memory Card Next Next Digital cameras, handheld computers, photo printers, p. 7. 28 Fig. 7-36 p. 7. 28 Fig. 7-37 cellular telephones

8 Miniature Mobile Miniature Mobile Storage Media Storage Media How is miniature storage media used? What is a ? • Stores data on thin • Handheld devices, such as players and embedded in credit card wallets, read or display contents of miniature storage media such as memory cards smart card

Next Next p. 7. 29 Fig. 7-38 p. 7. 29 Fig. 7-39

Miniature Mobile Miniature Mobile Storage Media Storage Media What are the types of smart cards? What is electronic money? • Intelligent smart card Store data such as • Means of contains processor and photographs, music, books, paying for and video clips Bank issues has input, process, goods and unique digital cash numbers When you output, and storage services over purchase digital Store a prepaid dollar amount that represent an capabilities amount of money cash, the amount that is updated when the card is the Internet of money is • Memory card has only used • Also called withdrawn from your bank storage capabilities Store patient records, e-money or account vaccination data, and other healthcare information digital cash To use the card, swipe it through a

Next Store tracking information such Next as customer purchases or p. 7. 29 p. 7. 29 employee attendance

Microfilm and Microfilm and Microfiche Microfiche What are microfilm and microfiche? How do life expectancies of various media • Store microscopic images of compare? documents on a roll or a sheet of film • Images recorded using a computer output microfilm (COM) recorder

Microfilm Microfiche Uses a 100- to 215- Uses a small sheet foot roll of film of film, usually Next 4” x 6” Next p. 7. 30 Fig. 7-40 p. 7.30 Fig. 7-41

9 Summary Summary What are suggested storage devices for the What are suggested storage devices for the Home user? SOHO user? Home Home Mobile‰3.5-inch HD floppyLarge Business Home Mobile Large Business disk drive Small Office/Home Office ‰3.5-inch HD floppy disk drive ‰250 MB Zip® drive ‰60 GB hard disk ‰40 GB hard disk ‰Internet hard drive Small Office/Home Office ‰Internet hard drive Small Office/Home Office Power ‰CD-ROMPower drive ‰CD-ROM drive ‰CD-RW/DVD drive ‰CD-RW/DVD drive ‰20 GB Peerless drive

Next Next p. 7. 31 Fig. 7-42 p. 7. 31 Fig. 7-42

Summary Summary What are suggested storage devices for the What are suggested storage devices for the Mobile user? Large Business user? Mobile Large Business ‰3.5-inch HD floppy disk driveMobile Large Business Mobile Home ‰3.5-inch HD floppy disk Home Large Business drive ‰80 GB hard disk ‰CD-ROM drive ‰10 GB hard disk ‰CD-RW/DVD drive ‰1 GB PC Card hard disk ‰Microfilm or microfiche Small Office/Home Office Small Office/Home Office ‰Internet hardPower drive ‰Smart card reader Power ‰CD-RW/DVD drive ‰RAID ‰ ‰Enterprise storage system Next Next p. 7. 31 Fig. 7-42 p. 7. 31 Fig. 7-42

Summary Summary of Storage

What are suggested storage devices for the • Memory versus storage Power user? • Floppy disks ‰3.5-inch HD floppy diskMobile Large Business Home Power drive • High-capacity disks ‰DVD+RW drive • Hard disks • Compact discs ‰100 GB hard disk • CD-ROMs ‰CD-ROM drive Small Office/Home Office Power • CD-R and CD-RW ‰Internet hard drive ‰20 GB Peerless drive

Next Next p. 7. 31 Fig. 7-42 (Continued)

10 Summary of Storage

• DVD+RW and DVD-ROM • Tapes • Enterprise storage systems • PC Cards • Miniature mobile storage media • Microfilm and microfiche

Chapter 7 Complete

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