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CGS 1000. Introduction to Computers and Technology Fall 2006. Topics. Chapter 6 Class Activity EX 81 to 111 PPT 4 to PPT 65. Topics Covered. Chapter 5 Objectives Defined Input Discussed about Keyboard Mouse Voice Input Touch Screen Voice input Digital Cameras.
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CGS 1000 Introduction to Computers and Technology Fall 2006 Discovering Computers Fundamentals, Third Edition
Topics • Chapter 6 • Class Activity • EX 81 to 111 • PPT 4 to PPT 65 Discovering Computers Fundamentals, Third Edition
Topics Covered • Chapter 5 Objectives • Defined Input • Discussed about • Keyboard • Mouse • Voice Input • Touch Screen • Voice input • Digital Cameras Discovering Computers Fundamentals, Third Edition
Chapter 6 Objectives Describe the characteristics ofmagnetic disks Differentiate among various CD and DVD formats Identify the uses of tape Describe the characteristics of a hard disk Discuss PC Cards and the various typesof miniature mobile storage media Differentiate between floppy disks and Zip disks Identify uses of microfilm and microfiche Describe the characteristics of optical disks Discovering Computers Fundamentals, Third Edition
Storage • Holds data, instructions, and information for future use • Storage medium is physical material used for storage • Also called secondary storage • What isstorage? Discovering Computers Fundamentals, Third Edition
Kilobyte (KB) 1 thousand Megabyte (MB) 1 million Gigabyte (GB) 1 billion Terabyte (TB) 1 trillion Petabyte (PB) 1 quadrillion Exabyte (EB) 1 quintillion Zettabyte (ZB) 1 sextillion Yottabyte (YB) 1 septillion Storage • Number of bytes (characters) a storage medium can hold • What iscapacity? Discovering Computers Fundamentals, Third Edition
Functions as source of input Creates output Storage • What is astorage device? Hardware that records and retrieves items to and from storage media Reading Process of transferring items from storage media to memory Writing Process of transferring items from memory to storage media Discovering Computers Fundamentals, Third Edition
Storage • What isaccess time? • Time it takes storage device to locate item on storage medium • Time required to deliver item from memory to processor Discovering Computers Fundamentals, Third Edition
Trackis narrow recording bandthat forms fullcircle on disk Sectorstores up to512 bytesof data Magnetic Disks • What aretracks andsectors? Formatting prepares disk for use and marks bad sectors as unusable Discovering Computers Fundamentals, Third Edition
Magnetic Disks hard disk installedin system unit • What is ahard disk? • High-capacity storage • Consists of several inflexible, circular platters that store items electronically • Components enclosed in airtight, sealed case for protection Discovering Computers Fundamentals, Third Edition
Sample Hard Disk Characteristics Advertised capacity 120 GB Platters 3 Read/write heads 6 Cylinders 16,383 Bytes per second 512 Sectors per track 63 Sectors per drive 234,441,648 Revolutions per minute 7,200 Transfer rate 133 MB per second Access time 8.9 ms Magnetic Disks • What are characteristics of a hard disk? actualdiskcapacity Discovering Computers Fundamentals, Third Edition
Magnetic Disks • How does a hard disk work? Step 3.When software requests a disk access, read/write heads determine current or new location of data. Step 2.Small motor spins platters while computer is running. Step 4.Head actuator positions read/write head arms over correct location on platters to read or write data. Step 1.Circuit board controls movement of head actuator and a small motor. Discovering Computers Fundamentals, Third Edition
Magnetic Disks platter track sector • What is acylinder? • Vertical section of track through all platters • Single movement of read/write head arms accesses all plattersin cylinder read/writehead platter sides cylinder Discovering Computers Fundamentals, Third Edition
Magnetic Disks • Occurs when read/write head touches platter surface • Spinning creates cushion of air that floats read/write head above platter • Clearance between head and platter is approximately two-millionths of an inch • A smoke particle, dust particle, or human hair could render drive unusable • What is ahead crash? hair read/write head dust smoke clearance platter Discovering Computers Fundamentals, Third Edition
Magnetic Disks • What is aminiature hard disk? • Provide users with greater storage capacities than flash memory • Some have a form factor of less than 1 inch • Storage capacities range from 2 GB to 120 GB Discovering Computers Fundamentals, Third Edition
Magnetic Disks • What areexternal hard disksandremovable hard disks? • Used to back up or transfer files Removable hard disk—hard diskthat you insert and removefrom hard disk drive External hard disk—freestandinghard disk that connects to system unit Discovering Computers Fundamentals, Third Edition
SATA (Serial Advanced Technology Attachment) controller uses serial signals to transfer data, instructions, and information EIDE (EnhancedIntegratedDrive Electronics) controller supports four hard disks, provides connections for CD and DVD drives Chip and circuits that control transfer of items from disk SCSI(SmallComputerSystemInterface)controller supports up to fifteendevices including hard disks, CDand DVD drives, tape drives, printers,scanners, network cards Magnetic Disks • What is adisk controller? Discovering Computers Fundamentals, Third Edition
Magnetic Disks • What is online storage? • Files can be accessed from any computer with Web access • Service on Web that provides storage for minimal monthly fee • Large files can be downloaded instantaneously • Others can be authorized to access your data Discovering Computers Fundamentals, Third Edition
Magnetic Disks shutter • What is afloppy disk? • Portable, inexpensive storage medium (also called diskette) shell liner magneticcoating Thin, circular, flexible film enclosedin 3.5” wide plastic shell metal hub flexible thin film Discovering Computers Fundamentals, Third Edition
Magnetic Disks • What is afloppy disk drive? • Device that reads from and writes to floppy disk • One floppy drive, named drive A • Also called secondary storage Floppy disk drive built intoa desktop computer External floppy disk drive attaches to a computer with a cable Discovering Computers Fundamentals, Third Edition
Magnetic Disks • What is aZip disk? • Magnetic medium that stores 100 MB to 750 MB of data • Used to back up and to transfer files • Backup is duplicate of file, program, or disk in case original is lost • Zip disks require a Zip drive-high capacity drive that reads from and writes on a Zip disk c Discovering Computers Fundamentals, Third Edition
Questions? Discovering Computers Fundamentals, Third Edition