1. 88 CHAPTER SECONDARY STORAGE

2. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-2 Competencies Distinguish between primary & secondary storage Discuss the different types of storage media Floppy disk, hard disk and optical disk Describe the traditional floppy disk and the high capacity floppy disks Describe various types of hard disk devices Internal HD, HD cartridge and HD packs.

3. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-3 Competencies cont. Describe ways to improve hard-disk operations Disk caching, data compression Describe the different types of optical disks Describe other kinds of secondary storage devices. Solid state storage, internet drives and magnetic tape

4. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-4 Storage Primary storage Volatile Temporary It loses all of its contents when power to the system unit is shut off. Secondary storage Nonvolatile Permanent Writing : is the process of saving information. Reading: is the process of accessing information.

5. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-5 Secondary storage characteristics Media ( actual physical material that holds the data and programs, Example: CD). Capacity( measured how much a particular storage medium can hold) Storage devices (are hardware that reads data and program from storage media) Access speed ( measures the amount of time required by storage device to retrieve data and program).

6. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-6 Secondary Storage Devices

7. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-7 Floppy Disks Diskettes Flexible disk and Floppies The plastic disk inside the diskette cover is flexible Portable storage media Floppy disk drives (FDD) Store data and programs by altering the electromagnetic charges on the Disk surface to represent ones and zeroes. Characters are represented by positive + and – charges using ASCII code. Traditional Floppy Disk

8. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-8 Traditional Floppy Diskette 3.5 inch, 1.44 MB

9. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-9 Types of Floppies High capacity Known as a floppy-disk cartridge Require special disk drives Three well known types Zip disks (Iomega) 100MB, 250MB, 750MB HiFD disks (Sony) 200MB, 720MB, read and store data on 1.44MB disk SuperDisks (Imation) 240MB, 120MB

10. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-10 Zip disks (Iomega) SuperDisks (Imation) HiFD disks (Sony)

11. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-11 Hard Disks Use thicker, metallic platters for storage Faster than a floppy diskette Large capacity Sensitive instruments

12. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-12 Materials that Cause a Head Crash A head crash occurs when a read/write head makes contact with the hard disks surface or with particles on its surface. Three types of HD Internal H.D H.D Cartridge. H.D Pack.

13. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-13 Internal Hard Disk Located inside system unit Known as a fixed disk Designated as the C drive Advantages over floppies Access speed Capacity

14. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-14 Hard-Disk Cartridges Removable hard disks Used to complement internal hard disk Capacities of 10 to 20 GB PC Card Hard Disks

15. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-15 Peerless Disk PC Card Hard Disks

16. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-16 Hard-Disk Packs Removable Massive storage capacity Common in mainframes Used in Banks and credit cards companies.

17. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-17 Hard-Disk Pack

18. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-18 Performance Enhancements Disk caching Redundant arrays of inexpensive disks (RAID) expanding external storage several hard disk drives are connected to one another. File compression and decompression

19. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-19 Optical Disks Compact Permanent storage Optical disk use reflected light. The 1s and 0s are represented by flat areas called lands and bumpy areas called pits. Two common types CD ( 650 MB to 1GB) DVD ( 4.7 GB to 17 GB)

20. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-20 Compact Disc Optical format From 650 MB to 1 GB capacity Rotation speeds vary It determines how fast data can be transferred from the CD 24X or 24- speed CD drive can transfer 3.6 MB per second. Types Read only: CD-ROM Write once: CD-R Rewriteable: CD-RW Picture CDs and Photo CDs

21. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-21 Digital Versatile Disc Digital Versatile Disk or Digital Video Disk (DVD) Similar to CDs, but can store more data Types Read only Write once Rewritable

22. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-22 DataPlay CD-R Optical disk Write once format Quarter size 500 MB capacity Holds 5 hours of CD-quality sound Use for storing and playing music files Data play format ( search for it)

23. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-23 Other Types of Secondary Storage Solid-state storage Internet hard drives Magnetic tape

24. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-24 Solid-State Storage Flash memory cards Widely used in notebook computers Used to record MP3 music files Key chain hard drives Key chain flash memory devices Connects to a USB port

25. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-25 Internet Hard Drives Special service sites on the WEB provide users With storage

26. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-26 Magnetic Tape External storage Provides sequential access Information stored in sequence Slower than disks which provide direct access Magnetic tape streamers or tape cartridges used by both mainframes and microcomputers

27. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-27 A Look to the Future Blu-Ray Technology New standard in storage Blu-Ray New disks use blue laser light instead of the red laser light used in traditional CD players Disks may ultimately hold Over 30GB on one-sided disks Over 50GB on two-sided disks

28. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-28 Key Terms 1.44 MB 31/2-inch disk (211) 2HD (211) access time (210) C drive (213) capacity (210) CD (compact disc) (216) CD burner (216) CD-R (CD-recordable) (216) CD-ROM (compact disc- read only memory) (216) CD-RW (compact disc rewritable) (217) DataPlay (220) density (211) direct access (221) disk caching (213) Diskette (210)

29. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-29 Key Terms disk (210) DVD (digital versatile disc or digital video disc) (217) DVD-RW or DVD+RW (DVD rewritable) (217) DVD-R or DVD+R (DVD recordable) (217) DVD-RAM (DVD- random-access memory) (217) DVD player (217) DVD-ROM (digital versatile disc-read only memory) (217) Erasable optical disk (217) file compression (215)

30. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-30 Key Terms file decompression (215) fixed disk (212) flash memory card (221) flexible disk (211) floppies (211) floppy disk (210) floppy disk drive (FDD) (210) Floppy-disk cartridge (211) hard disk (212) hard-disk cartridge (213) hard-disk pack (214) head crash (212) HiFD disk (212) high capacity floppy disk (211)

31. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-31 Key Terms i-drive (221) internal hard disk (212) Internet hard drive (221) jewel box (216) key chain hard drives (221) label (211) land (216) magnetic tape (222) magnetic tape reel (222) magnetic tape streamer (222) media (210) medium (210) multiread (217) multisession (217) nonvolatile storage (210) online storage (221)

32. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-32 Key Terms optical disk (216) optical disk drive (216) PC Card hard disk (214) Photo CD (217) Picture CD (217) pit (216) platters (212) primary storage (210) reading (210) redundant arrays of inexpensive disks (RAID) (215) removable hard disk (213) rotational speed (216) secondary storage (210) secondary storage device (210) sector (211)

33. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-33 Key Terms sequential access (221) shutter (211) single-session (217) solid-state storage (220) storage devices (210) SuperDisk (212) tape cartridge (222) track (211) volatile storage (210) write-protection notch (211) writing (210) Zip disk (211)

34. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-34 FAQs What is the difference between primary storage and secondary storage? What kinds of floppy disks are available? What is the C drive of a computer? When would I use a hard-disk cartridge? What is the difference between a CD and a DVD?

35. © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 8-35 Discussion Questions Discuss three ways to improve the performance of hard disks. Describe the different types of compact discs. Describe the different types of DVDs. What are the advantages and disadvantages of using an Internet hard drive? Describe solid state technology. Discuss the many uses for key chain flash memory devices.