ESSENTIALS CHAPTER computing 6 Secondary Storage Copyright 2003

ESSENTIALS CHAPTER computing 6 Secondary Storage Copyright 2003 The Mc. Graw-Hill Companies, Inc. 1

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

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

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

computing ESSENTIALS Floppy Disks l l Portable and removable Flat circular Mylar media l Magnetic charge on metal oxide film coating Standard 2 HD 1. 44 MB Parts l Tracks l Sectors Copyright 2003 The Mc. Graw-Hill Companies, Inc. 5

computing ESSENTIALS High Capacity Floppy Disks l Floppy disk cartridges l Zip Disks l l Super. Disks l l 250 MB 120 MB Hi. FD disks l 200 MB Copyright 2003 The Mc. Graw-Hill Companies, Inc. 6

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

computing ESSENTIALS A Look to the Future l l 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 Copyright 2003 The Mc. Graw-Hill Companies, Inc. 24

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