iAcademy iAcademy Introduction to Computers Introduction to IT Lecture 5 Hard Disk Drive Flash Memory Could Storage . This lecture and its associated materials have been produced by Dr. Weerachai Anotaipaiboon of iAcademy for the purposes of lecturing on the above described subject and the material should be viewed in this context. Unless otherwise stated, all pictures used in the lectures are taken from Discovering Computers by Gary B. Shelly and Misty E. Vermaat. The work does not constitute professional advice and no warranties are made regarding the information presented. The Author and iAcademy do not accept any liability for the consequences of any action taken as a result of the work or any recommendations made or inferred. Permission to use any of these materials must be first granted
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iAcademy
iAcademy
Introduction to Computers
Introduction to ITLecture 5
Hard Disk DriveFlash MemoryCould Storage
.This lecture and its associated materials have been produced by Dr. Weerachai Anotaipaiboon of iAcademy for the purposes of lecturing on the above described subject and the material should be viewed in this context. Unless otherwise stated, all pictures used in the lectures are taken from Discovering Computers by Gary B. Shelly and Misty E. Vermaat. The work does not constitute professional advice and no warranties are made regarding the information presented. The Author and iAcademy do not accept any liability for the consequences of any action taken as a result of the work or any recommendations made or inferred. Permission to use any of these materials must be first granted by iAcademy.
Lecture 4 Review1. What Are the Four Types of Output?2. What Are the Characteristics of Various Display
Devices?3. What Factors Affect the Quality of an LCD
monitor or LCD screen?
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iAcademy
Lecture 4 Review4. What Are the Various Ways to Print?5. How Is a Nonimpact Printer Different from an
Impact Printer?6. What Are the Uses and Characteristics of
Speakers, Headphones, and Earbuds?7. What Output Options Are Available for
Physically Challenged Users?
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iAcademy
Objectives Overview1. Differentiate between storage devices and
storage media2. Describe the characteristics of an internal hard
disk including capacity, platters, read/write heads, cylinders, sectors and tracks, revolutions per minute, transfer rate, and access time
3. Discuss the purpose of network attached storage devices, external and removable hard disks, and hard disk controllers
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iAcademy
Objectives Overview4. Describe the various types of flash memory
storage: solid state drives, memory cards, USB flash drives, and ExpressCard modules
5. Describe cloud storage and explain its advantages
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iAcademy
Storage
Storage holds data, instructions, and information for future use
A storage medium or secondary storage is the physical material on which a computer keeps data, instructions, and information
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iAcademy
Storage
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iAcademy
Storage
• Capacity is the number of bytes a storage medium can hold
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iAcademy
Storage
• A storage device is the computer hardware that records and/or retrieves items to and from storage media
Reading is the process of transferring items from a storage medium into memory (source of input)
Writing is the process of transferring items from memory to a storage medium (creating output)
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iAcademy
Storage
• Access time measures:– The amount of time it takes
a storage device to locate an item on a storage medium
– The time required to deliver an item from memory to the processor (also called transfer rate)
• Memory access time – nanoseconds
• Storage access time - milliseconds
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iAcademy
Hard Disks
• A hard disk (or hard disk drive) contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information– Fixed disk– Portable
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iAcademy
Hard Disks
• Hard disks can store data using longitudinal recording or perpendicular recording
• Perpendicular recording can provide storage capacities about 10 times greater than longitudinal recording
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iAcademy
Hard Disks
• Characteristics of a hard disk include:
Capacity Platters Read/Write Heads
Cylinders Sectors and Tracks
Cluster or allocation unit
(group of sectors)
Revolutions per Minute (5400-
15000 rpm)
Transfer Rate (15 – 320
MBps)
Access Time (3 – 12 ms)
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iAcademy
Hard Disks
• Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk
• form factor– Term that refers to the size of platters in a hard disk.
• 3.5 inches• 2.5 inches
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iAcademy
Hard Disks
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iAcademy
Hard Disks
• https://www.youtube.com/watch?v=kdmLvl1n82U
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iAcademy
Hard Disks
• The hard disk arms move the read/write head, which reads items and writes items in the drive– Location often is referred
to by its cylinder
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iAcademy
Hard Disks
• A head crash occurs when a read/write head touches the surface of a platter
• Always keep a backup of your hard disk
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iAcademy
Hard Disks
• disk cache– Memory chips on a hard disk that store frequently
accessed items such as data, instructions, and information. Also called a buffer.
– Improve access time– Work similar to memory cache– 2 MB – 32 MB
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iAcademy
Hard Disks
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iAcademy
Hard Disks
• RAID (redundant array of independent disks) is a group of two or more integrated hard disks– Connect multiple smaller disks into a single unit
• A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage– Often use RAID
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iAcademy
Hard Disks
• https://www.youtube.com/watch?v=PP0iQs8qBNU
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iAcademy
Hard Disks
An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly
A removable hard disk is a hard disk that you insert and remove from a drive
Internal and external hard disks are available in miniature sizes (miniature hard disks) 1.8, 1, 0.85 inch
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iAcademy
Hard Disks
• A disk controller consists of a special-purpose chip and electronic circuits that control the transfer of data, instructions, and information from a disk to and from the system bus and other components of the computer– Part of hard disk– On motherboard– Separate adapter SATA EIDE
SCSI SAS
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iAcademy
Hard Disks
• SATA (Serial Advanced Technology Attachment)– Hard disk interface that uses serial signals to transfer data, instructions, and information and has
transfer rates of up to 300 MBps and higher.– Cables are thinner, longer, more flexible and less susceptible to interference than cable that uses
parallel signals.– eSATA: Acronym for external SATA; hard disk interface that is much faster than USB and FireWire.
• EIDE (Enhanced Integrated Drive Electronics)– Interface that uses parallel signals to transfer data, instructions, and information and can support
up to four hard disks at 137 GB per disk.– Data transfer rates up to 133 MBps
• SCSI (Small Computer System Interface)– Type of high-speed parallel interface used to attach peripheral devices to a computer.– Data transfer rates up to 640 MBps
• SAS (serial-attached SCSI)– Newer type of SCSI that uses serial signals to transfer data, instructions, and information.– Data transfer rates up to 750 MBps
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iAcademy
Flash Memory Storage
• Flash memory chips are a type of solid state media and contain no moving parts
• Solid state drive (SSDs) is a storage device that typically uses flash memory to store data, instructions, and information.– Form factors: 3.5, 2.5, 1.8 inches– Capacities: 16 – 256 GB and more– have several advantages over magnetic hard disks:
Faster access timeAbout 0.1 ms (80
times faster)
Faster transfer rates
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iAcademy
Flash Memory Storage
• https://www.youtube.com/watch?v=MchPfwtYIXc
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iAcademy
Flash Memory Storage
• A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader/writer
CompactFlash (CF)
Secure Digital (SD)
Secure Digital High Capacity
(SDHC)microSD
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iAcademy
Flash Memory Storage
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iAcademy
Flash Memory Storage
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Flash Memory Storage
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iAcademy
Flash Memory Storage
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iAcademy
Flash Memory Storage
• USB flash drives (sometimes called a thumb drive, handy drive) plug into a USB port on a computer or mobile device
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iAcademy
Flash Memory Storage
• An ExpressCard module is a removable device that fits in an ExpressCard slot
• Commonly used in notebook computers
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iAcademy
Cloud Storage
• Cloud storage is an Internet service that provides storage to computer users
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iAcademy
Cloud Storage
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iAcademy
Cloud Storage
• Users subscribe to cloud storage for a variety of reasons:
Access files from any computer
Store large files instantaneously
Allow others to access their files
View time-critical data and images immediately
Store offsite backups
Provide data center functions
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iAcademy
Cloud Storage
• https://www.youtube.com/watch?v=OFb0NaeRmdg
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iAcademy
Optical Discs
• An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser
• Typically store software, data, digital photos, movies, and music
• Read only vs. rewritable• 4.75 inches in diameter– Mini disc – 3 inches or less
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iAcademy
Optical Discs
• Optical disc store items by using microscopic pits and lands• High-powered laser light creates the pits• Low-powered laser light reads item from the disc.
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iAcademy
Optical Discs
• https://www.youtube.com/watch?v=YF0Si5JNH9E
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iAcademy
Optical Discs
• Optical discs commonly store items in a single track that spirals from the center of the disc to the edge
• Track is divided into evenly sized sectors
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Care of optical discs
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iAcademy
Optical Discs
• Speed of CD-ROM drive determines how fast it installs programs and access the disc.– Original CD-ROM drives were single-speed drives with transfer
rates of 150 KBps– Manufacturers measure all optical disc drives relative to this
original transfer rate of 150 KBps• For example, a 48x CD-ROM drive has a data transfer rate of 7,200
(48x150) KBps or 7.2 MBps
– CD-RW drives have 3 speeds: write/rewrite/read• For example, 52/32/52
– The process of writing on optical disc is called burning– The process of copying disc is called ripping
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iAcademy
Other Types of Storage
TapeMagnetic stripe cards and smart
cards
Microfilm and microfiche
Enterprise storage
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iAcademy
Other Types of Storage
• Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information
• A tape drive reads and writes data and information on a tape
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iAcademy
Other Types of Storage
• https://www.youtube.com/watch?v=QavarOBke0w
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iAcademy
Other Types of Storage
• A magnetic stripe card contains a magnetic stripe that stores information
• A smart card stores data on a thin microprocessor embedded in the card
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iAcademy
Other Types of Storage
• Microfilm and microfiche store microscopic images of documents on a roll or sheet film– Microfilm is a 100- to 215-foot roll of film– Microfiche is a small sheet of film, usually about 4x6
inches
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iAcademy
Other Types of Storage
• https://www.youtube.com/watch?v=hBKb2CHcKYU
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iAcademy
Other Types of Storage
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iAcademy
Other Types of Storage
• Enterprise storage stores huge volumes of data and information for large businesses– Uses special hardware for heavy use, maximum