The choice of an appropriate input device for a product is often based on both the type of device being used and the target market for that device. For instanc

The choice of an appropriate input device for a product is often based on both the type of device being used and the target market for that device. For instance, a device targeted to college students and one targeted to older individuals may use different input methods. Suppose that you are developing a device to be used primarily for Internet access that will be marketed to senior citizens. What type of hardware would you select as the primary input device? Why? What are the advantages and disadvantages of your selected input device? How could the disadvantages be minimized? What are other groups that have special technology needs? As future technology developers and innovators, do we have a responsibility to ensure technology is accessible to all groups? Incorporate Christian scripture and faith in your post and provide technical depth to all of your responses.

9781305656314_PPT_ch03_.pdf

9781305656314_PPT_ch04_.pdf

Chapter 3 Storage

© 2017 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Learning Objectives

• Name several general characteristics of storage systems. • Describe the three most common types of hard drives

and what they are used for today. • Discuss the various types of optical discs available today

and how they differ from each other. • Identify some flash memory storage devices and media

and explain how they are used today. • List at least three other types of storage systems. • Summarize the storage alternatives for a typical personal

computer.

Overview

• This chapter covers: – The characteristics common among all storage systems – The primary storage for most personal computers—the

hard drive – How optical discs work and the various types that are

available today – Flash memory storage systems – Network and cloud storage, smart cards, and the storage

systems used with large computer systems – Storage alternatives for a typical personal computer

Storage System Characteristics

• A storage system consists of a storage medium and a storage device – The storage medium is the hardware where data is stored

• DVD disc, flash memory card, etc. – The storage device is the hardware into which the storage

medium is inserted • DVD drive, flash memory card reader, etc. • Can be internal, external, or remote • Storage devices are typically identified by letter

– Some storage media is removable; some is not

Examples of Storage Device Identifiers

Volatility and Random vs. Sequential Access

• Volatility – Storage media are nonvolatile and, therefore, is used for

data to be saved for later use • Random vs. sequential access

– Random access (direct access) allows data to be retrieved from any location on the storage medium

• Virtually all storage devices use random access – Sequential access means that retrieval of data can occur

only in the order in which it was physically stored on the storage medium; for example, a magnetic tape drive

Files, Filenames, and Folders

• A file is anything stored on a storage medium, such as a program, document, digital image, or song

• A filename is a name given to a file by the user • A folder is a named place on a storage medium

into which files can be stored

Logical vs. Physical Representation and Types of Storage Technologies Used

• Logical file representation – Individuals view a document stored as one complete unit

in a particular folder on a particular drive • Physical file representation

– Computers access a particular document stored on a storage medium using its physical location or locations

• Types of storage technology – Magnetic (conventional hard drives) – Optical (optical discs) – Electrons (flash memory media)

Hard Drives

• A hard drive stores most programs and data for a personal computer – Can be internal or external – Available with built-in encryption that limits access to only

authorized users

Magnetic Hard Drives

• A magnetic hard drive or hard disk drive (HDD) contains particles on the metal disks inside the drive that are magnetized to represent the data’s 0s and 1s

Magnetic Hard Drives (cont’d)

• One or more metal hard disks are permanently sealed inside the drive along with an access mechanism and read/write heads

Hard Disk Organization

• Tracks are concentric paths on the disk where data is recorded

• Sectors are small pieces of a track • Clusters consist of one or more sectors

• Smallest addressable area of a disk • Cylinders are a collection of tracks located in the same

location on a set of hard disk surfaces

Examples of Tracks, Sectors, Clusters, and Cylinders

Magnetic Hard Drive Technologies

• Traditional: Longitudinal magnetic recording aligns magnetic particles on a hard disk horizontally, parallel to the hard disk’s surface

• Newer: Perpendicular magnetic recording (PMR) places bits upright and closer together to increase capacity and reliability

• Newest: Shingled magnetic recording (SMR) squeezes more data onto disks by overlapping the data tracks on them like the shingles on a roof

• Emerging: Heat-assisted magnetic recording (HAMR) uses lasers to temporarily heat the surface of the hard disks when storing data in order to store more data

How It Works

More Storage for Your Tablet • Tablets often have between

16 GB and 128 GB of storage • To extend storage, you can

transfer content to and from desktops or notebooks

• Easier to use a wireless hard drive and Wi-Fi – Download the

appropriate app The 2 TB Seagate Wireless Plus magnetic hard drive.

Inside the Industry

Data Recovery Experts • Recover data from damaged storage devices • Used when devices are physically damaged or just stop

working • It is important to back up data to prevent data loss

Data recovery. The data on this destroyed computer (left) was recovered by data recovery experts in a clean room (right).

Solid-State Drives (SSDs)

• A solid-state drive (SSD) uses flash memory technology to store data – Uses less power and has no

moving parts – Much faster than magnetic

hard drives, but more expensive

– The norm for netbooks, mobile devices, and other portable devices

Solid-State Hybrid Drives (SSHDs)

• A solid-state hybrid drive (SSHD) or hybrid drive uses a combination of magnetic disks and flash memory chips – The data that is most

directly associated with performance is stored in the flash memory

– Nearly as fast as solid-state drives (SSDs)

– Slightly more expensive than magnetic hard disk drives (HDDs)

Internal and External Hard Drives

• Internal hard drives are permanent storage devices located inside the system unit – Removed only if a problem develops

• External hard drives transport large amounts of data from one computer to another, for backup, and for additional storage – Full-sized external hard drives are often used for backup – Portable external hard drives: smaller and easier to

transport – Most connect with a USB connection, although some may

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Examples of External Hard Drives

Hard Drive Speed and Disk Caching

• Disk access time is the total time that it takes for a hard drive to read or write data • Consists of seek time, rotational delay, and data

movement time • SSDs don’t require seek time or rotational delays

• Disk cache consists of memory used in conjunction with a magnetic hard drive to improve system performance – Typically consists of RAM-based disk cache located inside

the hard drive case – Can speed up performance and save battery life

Hard Drive Partitioning

• Partitioning divides the physical capacity of a single drive logically into separate areas, called partitions – Each partition functions as an independent hard drive – Referred to as logical drives – Increases efficiency (smaller drives use smaller clusters)

• Partitions are used to create: – A recovery partition – A new logical drive

for data – A dual boot system

Hard Drive File Systems and Interface Standards

• File system determines the partition size, cluster size, maximum drive size, and maximum file size – FAT, FAT32, and NTFS

• Interface standards determine how a drive connects to the computer

• Common standards – Serial ATA (SATA): most common internal hard drive

interface standard – Serial attached SCSI (SAS) – Fibre Channel – Internet SCSI (iSCSI)

Quick Quiz (1)

1. Of the following three options, the storage media that would likely hold the most data is a(n) __________. a. HDD b. USB flash drive c. SSD

2. True or False: SSDs are subject to mechanical failures just like magnetic hard drives.

3. The circular rings on a magnetic disk on which data is stored are called __________.

Answers: 1) a; 2) False; 3) tracks Understanding Computers: Today and Tomorrow, 15th Edition 24

Optical Discs

• Optical discs are thin circular plastic discs – Are read from and written to using laser beams – Are commonly used for software delivery – Divided into sectors like magnetic discs but use a single

spiral track (groove) – Have a relatively large capacity and are durable – Used for backup purposes and for storing and transporting

music, photos, video, etc.

Representing Data on an Optical Disc

• Pits and lands are used to represent 1s and 0s • The transition between a pit and a land represents a 1;

no transition represents a 0 • Read-only optical disc

– Surface of disc is molded or stamped to represent data • Recordable or rewritable disc

– The reflectivity of the disc is changed using a laser beam to represent the data

– Different types of optical discs use different types of laser beams

How Recorded Optical Discs Work

Optical Drives

• Optical discs are read by optical drives – The optical drive must support the type

of optical disc being used – Almost always backward-compatible – Recording data onto a optical disc is

called burning; requires burning software – Optical drives can be internal or external

• External drives typically connect via USB port

• External drives can be used with netbooks and other devices without an optical drive

Optical Disc Shapes, Sizes, and Capacities

• Standard size is 120-mm (about 4.7 inches) – Mini discs are smaller (about 3 inches)

• Theoretically can be made into various shapes, but patent battle has resulted in custom shapes not being available

• Clear background is sometimes used to make a disc look custom shaped

Advantage of Optical Discs

• Major advantage: Large capacity – CD discs are normally single layer and hold 700 MB – DVD discs hold 4.7 GB (single-layer) or 8.5 GB (dual-layer) – BD discs hold 25 GB (single-layer) or 50 GB (dual-layer) – BDXL standard uses even more layers to boost capacity up

to 128 GB – Newest BD discs are Ultra HD Blu-ray discs that hold up to

100 GB and are designed to deliver Ultra HD (4K) movies – Discs can also be double-sided

• Read on one side at a time; must be turned over to access the second side

Summary of Optical Discs

Read-Only Optical Discs: CD-ROM, DVD-ROM, and BD-ROM Discs

• CD-ROM, DVD-ROM, and BD-ROM discs can be written to, but not erased and reused – Pits are permanent – CD-ROM and DVD-ROM discs come prerecorded with

software, music, movies, etc. – BD-ROM discs come prerecorded with movies

• Ultra HD Blu-ray discs can be used for 4K movies – Additional proprietary read-only discs

• Gaming systems like Wii, Xbox, PlayStation, etc.

Recordable Optical Discs: CD-R, DVD-R, DVD+R, and BD-R Discs

• CD-R, DVD-R, DVD+R, and BD-R discs can be written to, but cannot be erased and reused – Pits are created in the disc when the disc is recorded – Most discs have a recording layer containing organic light-

sensitive dye between disc’s plastic and reflective layers • BD-R discs use inorganic material instead

– DVD-R DL and DVD+R DL are dual-layer discs – BD-R DL discs are dual-layer discs; BD-R XL use 3 or 4 layers – Used for backing up files, sending large files to others, and

storing multimedia files

Rewritable Optical Discs: CD-RW, DVD- RW, DVD+RW, and BD-RE Discs

• CD-RW, DVD-RW, DVD+RW, and BD-RE discs can be written to, erased, and overwritten just like magnetic hard disks – Uses phase change technology

• Heating and cooling process is used to change the reflectivity of the disc

– The capacities are the same as their read-only and recordable counterparts

– Appropriate for transferring large files from one computer to another or otherwise temporarily storing data (disc can be reused)

Trend

Ultra HD (4K) • Is the next big step in high-definition

(HD) TVs and content • Four times the resolution of ordinary HD • Requires four times as much data as

regular HD video • Many Internet connections are not fast

enough to support the large amounts of data required for 4K quality

• Available for those individuals who have the speed and bandwidth to support it; also available on Ultra HD discs

An example of a 4K movie.

Quick Quiz (2)

1. The capacity of the standard DVD disc is _____. a. 50 GB b. 650 MB c. 4.7 GB

2. True or False: A DVD-RW disc can be written to and rewritten to.

3. The tiny depressions, dark areas, or otherwise altered spots on an optical disc that are used to represent data are called __________.

Answers: 1) c; 2) True; 3) pits

Understanding Computers: Today and Tomorrow, 15th Edition 36

Flash Memory Storage Systems

• Flash memory is a chip-based storage medium that represents data using electrons – Used in a variety of storage systems

• Embedded flash memory refers to flash memory chips embedded into products – Smartphones, tablets, smart watches, and even sunglasses

and wristwatches – Usually the primary storage for mobile devices such as

tablets and smartphones

Examples of Embedded Flash Memory

38© 2017 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

This tablet contains 64 GB of embedded flash memory.

An embedded flash memory chip.

Flash Memory Cards and Readers

• A flash memory card is a small card containing one or more flash memory chips, a controller chip, and metal contacts to connect the card to the device or reader being used – Available in a variety of formats; these formats are not

interchangeable – Secure Digital (SD) is one of the most widely used types of flash

memory media – Most common type of storage media for digital cameras,

smartphones, and other portable devices • Many devices today have a built-in flash memory card reader;

an external reader via USB port is also used • Adapters allow the use of smaller flash memory cards in a

larger slot of the same type (microSD to SD, etc.)

Examples of Flash Memory Cards, Readers, and Adapters

Flash Memory Cards

• General-purpose flash memory card – Appropriate for most

applications • Specialized flash memory cards

– Professional flash memory cards

– Gaming flash memory cards – Encrypted flash memory cards

• Project Vault is a computer on a flash memory card

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