This chapter describes different types of storage devices used in computers. It discusses magnetic storage devices like hard disks and floppy disks, which use magnetism to store data. Optical storage devices like CDs and DVDs are also covered, which use lasers to read and write data. Finally, solid-state storage options like flash memory, smart cards, and solid-state drives are introduced. The document provides details on how each storage type works and its common uses. It also discusses topics like formatting disks, finding data locations, and measuring/improving drive performance.

1. Chapter 5 Types of Storage Devices

2. Describing Storage Devices Storage devices hold data permanently, even when the computer is turned off . Two processes Writing data Reading data 6A-

3. Describing Storage Devices Storage terms The physical material that actually holds data is called a storage medium. A floppy disk is a storage medium. The hardware that writes data to or reads data from a storage medium is called a storage device . A floppy disk drive is a storage device. Types of Storage Devices : Magnetic devices use a magnet Optical devices use lasers Solid-state devices have physical switches 6A-

4. Magnetic Storage Devices The primary types of magnetic storage are: Hard disks. floppy disks(Diskettes). High-capacity floppy disks. magnetic tape. All magnetic drives work the same 6A- Floppy Disk Hard Disk Tape

5. Magnetic Storage Devices Data storage and retrieval A magnetic disk's medium contains iron particles, A disk drive uses read/write heads containing electromagnets to create magnetic charges on the medium. 6A-

6. Magnetic Storage Devices Data organization Disks must be formatted before use Determines how data will be stored: Format draws tracks on the disk Tracks is divided into sectors Purpose of formatting a magnetic disk: Before the computer can use a magnetic disk to store data, the disk’s surface must be magnetically formatted, so that the computer can go directly to a specific point on it without searching through data . 6A-

7. Tracks and Sectors 6A-

8. Magnetic Storage Devices Finding data on disk Each track and sector is labeled Listing of where files are stored File Allocation Table (FAT) – a log that records each File's location and each sector's status FAT32 NTFS The OS(Operating system) organizes sectors into groups, called clusters 6A-

9. Magnetic Storage Devices Diskettes Also known as floppy disks Spin at 300 RPM Takes .2 second to find data 3 ½ floppy disk holds 1.44 MB 6A-

10. Magnetic Storage Devices Hard disks Primary storage device in a computer 2 or more aluminum platters Each platter has 2 sides Spin between 5,400 to 15,000 RPM Data found in 9.5 ms or less Drive capacity greater than 40 GB 6A-

11. Illustrated Hard Disk 6A- Contain multiple disks called platters

12. Magnetic Storage Devices Removable high capacity disks Speed of hard disk Portability of floppy disk There are 2 types : High capacity floppy disk Stores up to 750 MB of data Hot swappable hard disks Provide GB of data Connect via USB 6A-

13. Magnetic Storage Devices 6A- Hot swappable hard disks Hot swappable hard disk : can be removed and replaced while the computer is still running.

14. Magnetic Storage Devices Tape drives Best used for Infrequently accessed data Back-up solutions Slow sequential access Capacity exceeds 200 GB 6A-

15. Optical Storage Devices List seven types of optical storage devices commonly used in PCs. Compact Disc Read-Only Memory (CD-ROM). CD-Recordable (CD-R). CD-ReWritable (CD-RW). Digital Video Disc Read-Only Memory (DVD-ROM). DVD-Recordable (DVD-R). DVD-ReWritable (DVD-RW). PhotoCD. 6A-

16. Optical Storage Devices CD-ROM Most software ships on a CD Read using a laser Written from the inside out Standard CD holds 650 MB 6A-

17. Recordable Optical Technologies CD Recordable (CD-R) Create a data or audio CD Data cannot be changed Can continue adding until full 6A-

18. Recordable Optical Technologies CD Rewritable (CD-RW) Create a reusable CD Can reuse about 100 times 6A-

19. Recordable Optical Technologies Photo CD Provides for photo storage Photos added to CD until full Original pictures cannot be changed 6A-

20. Optical Storage Devices DVD-ROM Digital Video Disk Use both sides of the disk Capacities can reach 18 GB DVD players can read CDs 6A-

21. Recordable Optical Technologies DVD Recordable (DVD-R) Allows home users to create DVDs Data cannot be changed DVD-RAM Allow reusing of DVD media 6A-

22. Solid State Devices Data is stored physically Store data on memory circuits. No magnets or laser Very fast The primary types of Solid State Devices are: Flash memory Smart cards Solid-state disks 6A-

23. Solid State Devices Flash memory Found in cameras and USB drives Combination of RAM and ROM Long term updateable storage 6A-

24. Solid State Devices Solid-state disks Large amount of SDRAM Extremely fast. Require battery backups Most have hard disks copying data 6A-

25. Solid State Devices Solid-state disks 6A-

26. Solid State Devices Smart cards Credit cards with a chip Chip stores data A smart card contain memory and microprocessor components. The card is made of plastic. Hotels use for electronic keys 6A-

27. Questions List four types of magnetic storage devices commonly used in PCs. List seven types of optical storage devices commonly used in PCs. Name three types of solid-state storage devices. What is the purpose of formatting a magnetic disk? What is the storage capacity of a standard floppy disk? 6A-

28. Measuring and Improving Drive Performance

29. Drive Performance Average access time Also known as seek time Time to find desired data Measured in milliseconds(ms) Hard drive between 6 and 12 ms CD between 80 and 800 ms 6B-

30. Drive Performance Data transfer rate the amount of data that one device can send to another in a given amount of time. Measured in Bps( mega bytes per second ) Hard drive ranges from 15 to 160 MBps Floppy disks transfer at 45 KBps 6B-

31. Data Transfer Rate 6B-

32. Optimizing Performance 1. Disk optimization Handled by operating system(OS) tool Routine disk maintenance Optimization should be run monthly 6B-

33. Optimizing Performance 2. Clean up unnecessary files Delete temp files Uninstall unused programs Delete obsolete data files Files should be cleaned weekly 6B-

34. Optimizing Performance 3. Scan a disk for errors Bad spots on the media Find and fix the error Move data to a good spot Mark the spot as bad Disks should be scanned monthly 6B-

35. Optimizing Performance 4. Defragment a disk Files fragment when resaved Fragmented files load slower Defragment puts the fragments together Disks should be defragged monthly 6B-

36. Defragment 6B-

37. Optimizing Performance 5.File compression Shrinks the size of a file Takes up less space on disk Reduce a disks performance Will increase disk capacity PKZip, WinZip and WinRAR 6B-

38. File Compression 6B- 763 KB on disk Compressed 157 KB

39. Chapter 6 End of Chapter