1. Copyright©2008 N.AlJaffan®KSU1 Storage Chapter 6 Objectives

2. Copyright©2008 N.AlJaffan®KSU2 Storage  Storage holds data, instructions and information for future use.  Storage medium, also called secondary storage,  Is the physical material on which a computer keeps data, instructions and information.  For Example: hard disks, floppy disks, Zip disks, CDs and DVDs, tape, Pc Cards, flash memory cards, USB flash devices and microfilm. Chapter 6

3. Copyright©2008 N.AlJaffan®KSU3 Storage Capacity is the number of bytes (characters) a storage medium can hold. Chapter 6 Storage TermApproximate number of bytesExact number of bytes Kilobyte (KB)1 thousand2 10 Or 1,024 megabyte (MB)1 million2 20 Gigabyte (GB)1 Billion2 30 Terabyte (TB)1 trillion2 40 Petabyte (PB)1 quadrillion2 50 Exabyte (EB)1 quintillion2 60 Zettabyte (ZB)1 sextillion2 70 Yottabyte (YB)1 septillion2 80

4. Copyright©2008 N.AlJaffan®KSU4 Storage Storage device is the computer hardware that records and/or retrieves items to and form storage media.  Writing is the process of transferring data, instructions, and information from memory to a storage medium.  Reading is the process of transferring these items from a storage medium into memory. Chapter 6

5. Copyright©2008 N.AlJaffan®KSU5 Storage  The speed of storage devices is defined by access time.  Access time measures the amount of time it takes a storage device to locate an item on a storage medium.  The access time of storage device is slow ( millisecond ), compared with the access time of memory ( nanosecond ). Chapter 6

6. Copyright©2008 N.AlJaffan®KSU6 Storage Magnetic Disks  Use magnetic particles to store items such as data, instructions and information on a disk’s surface.  Depending on how the magnetic particles are aligned, they represent either a 0 bit or a 1 bit.  Store data and instructions in tracks and sectors.  Track is an narrow recording band that forms a full circle on the surface of the disk. Chapter 6 Track Sector

7. Copyright©2008 N.AlJaffan®KSU7 Storage Magnetic Disks  The disk’s storage locations consist of pie- shaped sections, which break the tracks into small arcs called sectors.  A sector typically stores up to 512 bytes of data.  Three type of magnetic disks are Hard disks,Floppy disks and Zip disks.  Some of these disks are portable which means you can remove the medium from one computer and carry it to another computer; others are not. Chapter 6

8. Copyright©2008 N.AlJaffan®KSU8 Storage Hard Disks Is a storage device that contains one or more inflexible, circular platter that store data, instructions and information.  The System unit on most desktop and notebook computers contains at least one hard disk.  The entire device is enclosed in an airtight, sealed case to protect it from contamination.  A hard disk that is mounted inside the system unit sometimes is called a fixed disk because it is not portable. Chapter 6

9. Copyright©2008 N.AlJaffan®KSU9 Storage Hard Disks  Current personal computer hard disks have storage capacities from 80 to 500 GB and more.  Longitudinal recording, which aligned the magnetic particles horizontally around the surface of the disk.  Perpendicular recording, by contrast, hard disks align the magnetic particles vertically, or perpendicular to the disk’s surface, making much greater storage capacities possible. Chapter 6

10. Copyright©2008 N.AlJaffan®KSU10 Chapter 6

11. Copyright©2008 N.AlJaffan®KSU11 Characteristics of a Hard Disks Chapter 6

12. Copyright©2008 N.AlJaffan®KSU12 Storage Characteristics of a Hard Disks  The capacity of a hard disk is determined from the number of platters it contains, together with composition of the magnetic coating on the platters. Chapter 6

13. Copyright©2008 N.AlJaffan®KSU13 Storage Characteristics of a Hard Disks  Platter is made of aluminum, glass, or ceramic and is coated with an alloy material that allows items to be recorded magnetically on its surface.  On desktop computer, platters most often have size of approximately 3.5 inches in diameter. Chapter 6

14. Copyright©2008 N.AlJaffan®KSU14 Chapter 6 Hard disk has multiple platters stacked on top of one another Each platter has 2 read/write head, one each side. The location of the read/write heads often is referred to by its cylinder Cylinder is the vertical section of a track that passes through all platters A single movement of the read/write head arms accesses all the platters in a cylinder 2 platters each with 1000 tracks, then it will have 1000 cylinders each cylinder consisting of 4 tracks

15. Copyright©2008 N.AlJaffan®KSU15 Storage Characteristics of a Hard Disks  While the computer is running, the platters rotate at a high rate of speed.  The rate of spinning usually is 5.400 to 15,000 revolutions per minute (rpm).  The platters typically continue to spin until power is removed from the computer.  On many computers, the hard disk stops spinning after a specified time to save power. Chapter 6

16. Copyright©2008 N.AlJaffan®KSU16 Storage Characteristics of a Hard Disks  The spinning motion creates a cushion of air between the platter and its read/write head.  This cushion ensures that the read/write head floats above the platter instead of making direct contact with the platter surface.  The distance between the read/write head and the platter is about 2 millionths of on inch. Chapter 6

17. Copyright©2008 N.AlJaffan®KSU17 Storage Characteristics of a Hard Disks Dirt, hair, dust, smoke and other particles could cause the hard disk to have a head crash. A head crash occurs when a read/write head touches the surface of a platter, usually resulting in a loss of data or sometimes loss of the entire drive. Backup is a duplicate of a file, program, or disk that you can use in case the original is lost, damaged, or destroyed. Access time for today’s hard disks ranges from approximately 3 to 12 ms (milliseconds). Chapter 6

18. Copyright©2008 N.AlJaffan®KSU18 Storage Miniature Hard Disks  Many mobile device and consumer electronics include miniature hard disks.  These tiny hard disks are found in devices such as audio players, digital cameras, smart phones, and PDAs.  It has a greater storage capacities than flash memory.  Miniature hard disk have storage capacities that range from 2 GB to 120 GB. Chapter 6

19. Copyright©2008 N.AlJaffan®KSU19 Storage Portable Hard Disks Its either are external or removable and have storage capacities up to 500 GB or higher. The entire hard disk is enclosed in an airtight, sealed case.  External hard disk  External hard disk is a separate freestanding hard disk that connects with a cable to a USB port or FireWire port on the system unit.  Removable hard disk  Removable hard disk is a hard disk that you insert and removed from either a dock or a drive. Chapter 6

20. Copyright©2008 N.AlJaffan®KSU20 Storage Portable Hard Disks Portable hard disk offer the following advantages over internal hard disks( fixed disk):  Transport a large number of files. Several external hard disk models allow you to back up simply by pushing a button on the disk ).  Back up important files or an entire internal hard disk (Several external hard disk models allow you to back up simply by pushing a button on the disk ).  Easily store large audio and video files.  Secure your data.  Add storage space to computer without having to open the system unit.  Share a drive with multiple computer. Chapter 6

21. Copyright©2008 N.AlJaffan®KSU21 Storage Hard Disk Controllers Its consists of a special-purpose chip and electronic circuits that controls the interface between the hard disk and system bus. Its may be part of a hard disk or the motherboard or may be a separate adapter card inside the system unit. The types of available hard disk interface  External hard disk interface  USB and FireWire.  Internal hard disk interface  SATA, EIDE and SCSI. Chapter 6

22. Copyright©2008 N.AlJaffan®KSU22 Storage Hard Disk Controllers SATA ( Serial Advanced Technology Attachment )  The newest type of hard disk interface  Uses serial signals to transfer data.  Their cables are thinner, longer, more flexible and less susceptible to interference than cable used by HD that use parallel signals.  Support connections to CD and DVD drivers. Chapter 6

23. Copyright©2008 N.AlJaffan®KSU23 Storage Hard Disk Controllers EIDE ( Enhanced Integrated Drive Electronics )  Uses parallel signals to transfer data.  Support up to 4 HD at 137 GB per disk.  Provide connections for CD, DVD driver and Tape Driver. Chapter 6

24. Copyright©2008 N.AlJaffan®KSU24 Storage Hard Disk Controllers SCSI ( Small Computer System Interface )  Uses parallel signals to transfer data.  Support up to 8 or 15 peripheral device.  Provide connections for CD, DVD driver and Tape Driver, printers, scanners, network cards and much more. Chapter 6

25. Copyright©2008 N.AlJaffan®KSU25 Storage Online Storage Is a service on the web that provides hard disk storage to computer users usually for a minimal monthly fee. User subscribe to an online storage service g for a variety reasons:  To access files on the Internet hard disk from any computer or device that has Internet access.  To share these file with other people instead of e-mailing the files to them.  To store offsite backups of data. Chapter 6

26. Copyright©2008 N.AlJaffan®KSU26 Storage Floppy Disks, also called Diskette  Is a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic Mylar film with a magnetic coating enclosed in square shape plastic shell  A typical floppy disk is 3.5 inches wide and can store up to 1.44 MB.  You can read from/ write on a floppy disk any number of times. Chapter 6

27. Copyright©2008 N.AlJaffan®KSU27 Storage Floppy disk drive  Is device that read from/write on floppy disk.  User inserts diskette in and removes it from floppy device  In past PCs and notebook computers had a floppy drive installed inside the system unit.  Most computer today do not include a floppy disk driver as standard equipment. On these computer you can use external floppy disk drive. Chapter 6

28. Copyright©2008 N.AlJaffan®KSU28 Storage Zip Disks Is a type of portable magnetic media that can store from 100 MB to 750 MB of data. Zip Drive Is a high capacity disk drive developed by Iomega Corporation that reads from and writes on a Zip disk. Chapter 6

29. Copyright©2008 N.AlJaffan®KSU29 Storage Optical Discs Is a type of optical storage media that consists of a flat, round, portable, disc made of metal, plastic, lacquer. The Disc Size usually are 4.75 inches in diameter. Some Optical disc formats re read only, others are read/write. Every PC today includes some type of optical disc drive installed in a drive bay. Chapter 6

30. Copyright©2008 N.AlJaffan®KSU30 Storage Optical Discs Other convenient features on most of these drives include a volume control button and headphone port so you can use it to listen to audio without disturbing others nearby. With some discs, you can read and / or write on one side only. Other discs are double-sided. Double-sided disc often have no label; instead each side of he disc is identified with small writing around the center of the disc. Chapter 6

31. Copyright©2008 N.AlJaffan®KSU31 Storage Optical Discs Optical discs store items by using microscopic pits ( indentations) and lands (flat areas) that are in the middle layer of the disc. A high-powered laser light create the pits. A low-powered laser reads items from the disc by reflecting light through the bottom of the disc, which usually is either solid gold or silver in color. The reflected light is converted into a series of bits the computer can process Chapter 6

32. Copyright©2008 N.AlJaffan®KSU32 Storage Optical Discs Chapter 6

33. Copyright©2008 N.AlJaffan®KSU33 Storage Optical Discs Many different formats of optical discs exist today. DVDs having a much greater storage capacity than CDs. Chapter 6 Optical DiscReadWriteErase CD-RomYNN CD-RYYN CD-RWYYY DVD-ROMYNN DVD-R /DVD+RYYN DVD-RW / DVD+RW/ DVD+RAMYYY

34. Copyright©2008 N.AlJaffan®KSU34 Storage CD-ROMS Compact disc read-only memory, is a type of optical disc that users can read but not write ( record) or erase. Manufacture write the contents of standard CD-ROM. A standard CD-ROM is called a single-session disc because manufacturers write all items on the disc at one time. SW manufacturers often distribute programs using CD-ROMs. Chapter 6

35. Copyright©2008 N.AlJaffan®KSU35 Storage CD-ROMS CD-ROM hold from 650 MB to 1 GB of data. To read a CD-ROM, insert the disc in a CD-ROM driver or CD-ROM player. Because audio CDs and CD-ROMs use the same laser technology, you may be able to use a CD-Rom driver to listen to an audio CD while working on the computer. Chapter 6

36. Copyright©2008 N.AlJaffan®KSU36 Storage Picture CDs A Kodak Picture CD is a type of single-session disc that stores digital versions of a single roll of film using a jpg file format. Many stores have kiosks at which you can print pictures from a Picture CD or other media. Chapter 6

37. Copyright©2008 N.AlJaffan®KSU37 Storage CD-Rs and CD-RWs Many Personal computers today include either a CD-R or CD-RW driver as a standard feature. Un like CD-ROM drivers, users record or write their own data on a disc with a CD-R or CD-RW driver. The process of writing on an optical disc is called burning. Chapter 6

38. Copyright©2008 N.AlJaffan®KSU38 Storage CD-Rs and CS-RWs CD-R ( compact disc-recordable) is a multisession optical disc on which users can write but not erase, their own items or data. Multisession means you can write on part of the disc at one time and another part at a later time. Each part of a CD-R can be written on only one time, and the content cannot be erased. Chapter 6

39. Copyright©2008 N.AlJaffan®KSU39 Storage CD-Rs and CS-RWs CD-RW ( compact disc-rewriteable) is an erasable multisession optical disc on which users can write on multiple times. Multisession means you can write on part of the disc at one time and another part at a later time. To write on a CD-RW disc, you must have CD-RW software and CD-RW drive. Chapter 6

40. Copyright©2008 N.AlJaffan®KSU40 Storage CD-Rs and CS-RWs Using a CD-RW disc to back up large files from a hard disk or to create audio CDs. The process of copying audio and/or video data from a purchases disc and saving it on digital media is called ripping. Chapter 6

41. Copyright©2008 N.AlJaffan®KSU41 Storage DVD-ROMs Digital versatile disc-read-only memory or digital video disc-read-only memory Is an extremely high-capacity optical disc on which users can read but not write or erase. DVD-ROMs store movies, music, huge databases and complex software. To read a DVD-ROM, you must have a DVD-ROM drive or DVD player. Most DVD-ROM drives also can read audio CDs, CD-ROMs, CD-Rs and CD-RWs. Chapter 6

42. Copyright©2008 N.AlJaffan®KSU42 Storage DVD-ROMs DVD-ROM uses one of 3 storage techniques. 1.Involves making the disc denser by packing the pits closer together. 2.Involves using two layers of pits. For the technique to work, the lower layer of pits is semitransparent so the laser can read through it to the upper layer. This technique doubles the capacities of disc. 3.Some DVD-ROMs are double sided. Chapter 6

43. Copyright©2008 N.AlJaffan®KSU43 Storage DVD-ROMs DVD-ROM Storage Capacity Chapter 6 SidesLayersStorage Capacity 114.7 GB 128.5 GB 219.4 GB 2217 GB

44. Copyright©2008 N.AlJaffan®KSU44 Storage Two newer, quite expensive competing DVD formats are Blu-ray and HD-DVD.  Blu-ray disc currently has storage capacities of 27 GB, with expectations of exceeding 100 GB in the future.  HD-DVD disc ( high- density- DVD) has storage capacities up to 45 GB. Mini-DVD that has grown in popularity is the UMD, which works specifically with the PlayStation Portable handheld game console. The UMD ( Universal Media Disc), which has a diameter of about 2.4 inches, can store up to 1.8 GB of games, movies or music. Chapter 6

45. Copyright©2008 N.AlJaffan®KSU45 Storage Recordable and Rewritable DVDs DVD-R and DVD+R allow users to write on the disc once and read it many times. DVD-RW an DVD+RW, a user can erase and record more than 1,000 times. DVD+RAM allows users to erase and record more than 100,000 times. Many industry professionals expect that DVD eventually will replace all CD media. Chapter 6

46. Copyright©2008 N.AlJaffan®KSU46 Storage TAPE One of the first storage media used with mainframe computer was tape. Tap is a magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost. Tape no longer is used as a primary storage. A tape drive reads and write data and information on a tape. Chapter 6

47. Copyright©2008 N.AlJaffan®KSU47 Storage TAPE Older computers used reel-to-reel tape drives, today’s tape drives use tape cartridges. Tap cartridges is a small, rectangular, plastic housing for tape. Tape cartridges that contain quarter-inch-wide tape are slightly larger than audiocassette tapes. Business and home users sometimes back up PC hard disks to tape. Chapter 6

48. Copyright©2008 N.AlJaffan®KSU48 Storage TAPE Some PC have external tape units. Other have the tape drive built into the system unit. On larger computer, tape cartridges are mounted in a separate cabinet called a tape library. Tap storage requires sequential access, which refers to reading or writing data one after the other. You must forward or rewind the tape to a specific point to access a specific piece of data. Chapter 6

49. Copyright©2008 N.AlJaffan®KSU49 Storage TAPE Hard disks, CDs and DVDs all use direct access. Direct access mean that the device can locate a particular data item or file immediately. When writing or reading specific data, direct access is much faster than sequential access. Chapter 6

50. Copyright©2008 N.AlJaffan®KSU50 Storage PC Cards Is a thin, credit-card-sized device that fits into a PC Card slot. Different types and size of PC Cards add Storage, Additional memory, Fax/modem, networking, sound and other capabilities to a desktop or notebook computer. Commonly are used in notebook computers. The Advantage of a PC Card for storage is portability. Chapter 6

51. Copyright©2008 N.AlJaffan®KSU51 Storage PC Cards Three Kinds of PC cards are available: Chapter 6 CategoryThicknessUse Type I3.3 mmRAM, SRAM, flash memory Type II5.0 mmModem, LAN,SCSI, Sound, TV tuner, Hard disk or other storage Type III10.5 mmRotating storage such as a hard disk

52. Copyright©2008 N.AlJaffan®KSU52 Storage Miniature Mobile Storage Media Allow mobile uses easily to transport digital images, music, or documents to and from computers and other device. Many Computers or devices have built-in ports or slots to hold miniature mobile storage media. If your computer or printer dose not have a built-in slot, you can use card reader/writer usually connect to USB port, FireWire port or parallel port on the system unit. Three types of Miniature mobile storage media: Flash memory cards, USB flash drives, and smart cards. Chapter 6

53. Copyright©2008 N.AlJaffan®KSU53 Storage Flash memory Cards Chapter 6 Media NameStorage CapacityUse CompactFlash 64 MB to 8 GB Digital Cameras, PDAS, Smart phone, photo printers, audio players, notebook computers, Desktop computer Smart Media 32MB to 128 MB Digital Cameras, photo printers, audio players.

54. Copyright©2008 N.AlJaffan®KSU54 Storage Flash memory Cards Chapter 6 Media NameStorage CapacityUse Secure Digital 64 MB to 1 GB Digital Cameras, PDAS, Smart phone, photo printers, music players, Digital video camera xD Picture Card 64 MB to 1 GB Digital Cameras, photo printers.

55. Copyright©2008 N.AlJaffan®KSU55 Storage Flash memory Cards Chapter 6 Media NameStorage CapacityUse Memory Stick 256 MB to 4 GB Digital Cameras, PDAS, Smart phone, photo printers, handheld game consoles, notebook computer

56. Copyright©2008 N.AlJaffan®KSU56 Storage USB Flash Drives Sometimes called a pen drive, is a flash memory storage device that plugs in a USB port on a computer or mobile device. Become the mobile user’s primary storage device. Current USB flash drive have storage capacities up to 4 GB. Chapter 6

57. Copyright©2008 N.AlJaffan®KSU57 Storage Smart Cards Which is similar in size to a credit card or ATM card, stores data on a thin microprocessor embedded in the card. Smart cards contain a processor and have input, process, output, and storage capabilities. Uses of smart cards include storing medical records, vaccination data, and other health-care or identification information; tracking information such as customer purchases or employee attendance Chapter 6

58. Copyright©2008 N.AlJaffan®KSU58 Storage Microfilm and Microfiche Microfilm and microfiche store microscopic images of documents on roll or sheet film. Microfilm is a 100-to 215- foot roll of film. Microfiche is a small sheet of film, usually about 4X6 inches. A computer output microfilm recorder is the device that records the images on the film. You can read them only with microfilm or microfiche reader Chapter 6

59. Copyright©2008 N.AlJaffan®KSU59 Storage Microfilm and Microfiche Libraries use these media to store back issues of newspapers, magazines and genealogy record. Some large organization use microfilm and microfiche to archive inactive files. Some banks use them to store transactions and canceled checks. The advantages of using it : 1.They greatly reduce the amount of paper firms must handle. 2.They are inexpensive and have the longest life of any storage media. Chapter 6

60. Copyright©2008 N.AlJaffan®KSU60 Storage Microfilm and Microfiche Libraries use these media to store back issues of newspapers, magazines and genealogy record. Some large organization use microfilm and microfiche to archive inactive files. Some banks use them to store transactions and canceled checks. The advantages of using it : 1.They greatly reduce the amount of paper firms must handle. 2.They are inexpensive and have the longest life of any storage media. Chapter 6