1. computing ESSENTIALS CHAPTER Copyright 2003 The McGraw-Hill Companies, Inc.Copyright 2003 The McGraw-Hill Companies, Inc. 1 66 Secondary Storage computing ESSENTIALS

2. Copyright 2003 The McGraw-Hill Companies, Inc. 2 Competencies Different types of media Floppy disks Hard disks Performance enhancements Optical disks Specialized media computing ESSENTIALS

3. Copyright 2003 The McGraw-Hill Companies, Inc. 3 Secondary Storage Stores information Non-volatile, permanent storage Characteristics Media Capacity Access time computing ESSENTIALS

4. Copyright 2003 The McGraw-Hill Companies, Inc. 4 Types of Storage Media Types widely used today Floppy disks Hard disks Optical disks Magnetic tape computing ESSENTIALS

5. Copyright 2003 The McGraw-Hill Companies, Inc. 5 Floppy Disks Portable and removable Flat circular Mylar media Magnetic charge on metal oxide film coating Standard 2HD 1.44 MB Parts Tracks Sectors computing ESSENTIALS

6. Copyright 2003 The McGraw-Hill Companies, Inc. 6 High Capacity Floppy Disks Floppy disk cartridges Zip Disks 250 MB SuperDisks 120 MB HiFD disks 200 MB computing ESSENTIALS

7. Copyright 2003 The McGraw-Hill Companies, Inc. 7 Hard Disks Metallic disks Fast retrieval, greater capacity Read/write heads ride cushion of air.000001 thick Three types Internal hard disk Hard-disk cartridge Hard-disk pack computing ESSENTIALS

8. Copyright 2003 The McGraw-Hill Companies, Inc. 8 computing ESSENTIALS

9. Copyright 2003 The McGraw-Hill Companies, Inc. 9 Internal Hard Disk Inside system unit Non-removable or portable Great capacity Over 100 Gigabytes Fast access speed computing ESSENTIALS

10. Copyright 2003 The McGraw-Hill Companies, Inc. 10 Hard-disk Cartridges Portable, removable Complement internal hard drive JAZ from Iomega SPARQ from SyQuest PC Card Hard Disks Laptop computers computing ESSENTIALS

11. Copyright 2003 The McGraw-Hill Companies, Inc. 11 Hard-disk Packs Used in mainframes Removable Resemble stack of vinyl records Multiple read/write heads Massive storage capacity Fast access time computing ESSENTIALS

12. Copyright 2003 The McGraw-Hill Companies, Inc. 12 Performance Enhancements Improving performance of hard disks Disk caching Redundant Arrays of Inexpensive Disks (RAID) File compression and decompression computing ESSENTIALS

13. Copyright 2003 The McGraw-Hill Companies, Inc. 13 Very large capacity Up to 17 gigabytes Use reflected light projected by a laser Lands and Pits represent 1s and 0s Formats Compact Disk (CD) Digital Versatile Disk (DVD) DataPlay Optical Disks computing ESSENTIALS

14. Copyright 2003 The McGraw-Hill Companies, Inc. 14 Compact Disks Widely used format today Can store from 650 MB to 1 GB Rotational speed = data transfer time Types of CDs CD-ROM CD-R CD-RW computing ESSENTIALS

15. Copyright 2003 The McGraw-Hill Companies, Inc. 15 CD-ROM Compact Disc-Read Only Memory Cannot be written to or erased Similar to commercial music CDs Used often to distribute large databases or references computing ESSENTIALS

16. Copyright 2003 The McGraw-Hill Companies, Inc. 16 CD-R & CD-RW CD-Recordable Written to once Custom made music CDs CD-ReWritable Erasable CD Ideal for multimedia presentations computing ESSENTIALS

17. Copyright 2003 The McGraw-Hill Companies, Inc. 17 DVD Digital Versatile Disk Rapidly replacing CDs Higher capacity 17 times the capacity of a CD computing ESSENTIALS

18. Copyright 2003 The McGraw-Hill Companies, Inc. 18 DVD Types DVD types DVD-ROM Read only memory DVD-R Recordable DVD-RAM or DVD-RW Competing rewritable formats computing ESSENTIALS

19. Copyright 2003 The McGraw-Hill Companies, Inc. 19 DataPlay Optical write-once format Similar to CD-R Size of a quarter Used for special applications Storing digital photographs Storing music for portable players computing ESSENTIALS

20. Copyright 2003 The McGraw-Hill Companies, Inc. 20 Other Secondary Storage Types Complement other secondary storage devices Specialized device types Magnetic tape Internet hard drives Solid state storage computing ESSENTIALS

21. Copyright 2003 The McGraw-Hill Companies, Inc. 21 Magnetic Tape Sequential access Commonly used for backing-up data Very large capacity Types of magnetic tape Tape cartridges Magnetic tape reels computing ESSENTIALS

22. Copyright 2003 The McGraw-Hill Companies, Inc. 22 Magnetic Tape Types Tape cartridges Backup tape for microcomputer Capacities range from 120 MB to 5 GB Digital audio tape (DAT) Tape reels Minicomputer and mainframe 1/2 inch wide and 1/2 mile long Stores 1600 to 6400 cpi computing ESSENTIALS

23. Copyright 2003 The McGraw-Hill Companies, Inc. 23 Internet Hard Drive and Solid State Internet hard drive Free or low-cost storage on the Web Access information from any location Access time is greater Solid-state storage No moving parts Flash memory cards computing ESSENTIALS

24. Copyright 2003 The McGraw-Hill Companies, Inc. 24 A Look to the Future Blue laser light optical devices Aimed more accurately Can increase storage capacity to 27 GB per standard optical disk New players will likely play both computing ESSENTIALS

25. Copyright 2003 The McGraw-Hill Companies, Inc. 25 computing ESSENTIALS