ie storage, multimedia and file organization
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Storage, Multimedia andFile Organization
CIS 105
List the benefits of secondary storage Identify and describe storage media that are
available for personal computers Differentiate among the principal types of secondary
storage Describe how data is stored on a disk Discuss the benefits of multimedia Explain how data is organized, accessed, and
processed
Storage and Multimedia: The Facts and More
Secondary Storage
Separate from the computer itself Software and data stored on a semipermanent
basis (Unlike memory, not lost when power is lost)
Benefits Space Reliability Convenience Economy
Memory vs. Storage (Volatile) (Non-volatile)
Temporarily holds instructions to be completed and data to be used with those instructions
Holds data, instructions, and information for future use.
Access time = nanoseconds
(billionths of a second)
Access time = milliseconds
(thousandths of a second)
Cost and Speed
Formatting
Formatting is the process of preparing a disk, hard disk, or CD for reading or writing.
Formatting organizes the disk into storage locations called tracks ( a band that forms a circle on the disk).
Formatting breaks the tracks into sectors which are small pie-shaped areas.
Data stored in sectors must be retrieved for use and placed in memory. The time required to access and retrieve data is called access time.
Tracks
Sectors
(Cluster: 2-8 sectors)
Care of Floppy Disks
Hard Disk Characteristics
Platter Low (vendor) and High Level (operating system
defines), Format Partitions Removable available IDE (Integrated Drive Electronics) SCSI (Small Computer System Interface) – daisy
chaining RAID (Redundant Array of Independent Disks) –
level 1 (mirroring) and Striping
RAID (Redundant Array of Independent Disks)
(RAID LEVEL 0)
Compact Disks
CD-ROM - drive can only read data from CDs CD-ROM stores up to 700 MB per disk Primary medium for software distribution
CD-R - drive can write to disk once Disk can be read by CD-ROM or CD-R
drive
CD-RW - drive can erase and record over data multiple times Some compatibility problems trying to read
CD-RW disks on CD-ROM drives
Digital Versatile Disk (DVD)
Short wavelength laser can read densely packed spots DVD drive can read CD-ROMs Capacity up to 17GB Allows for full-length movies Sound is better than on audio CDs
Several versions of writable and rewritable DVDs exist
CDs and DVDs
CD-ROM (compact disk) 700 MB Single track
DVD-ROM (digital video disk) 4.7-17 GB Denser; 2
layers
Disk Terms
Floppy disk/diskette Portable, inexpensive, 3.5”
Formatting Process of preparing disk by organizing into locations (tracks/sectors)
Track Narrow recording band; forms circle on disk surface
Sector Pie-shaped arcs making up track. 512 bytes;
Cluster 2-8 sectors; smallest unit of space to store data
Density # sides (2) x tracks (80) x sectors/track (18) x 512 (bytes/sector) = 1.44MB
FAT (File Allocation Table) Table of info used to locate files on a disk
Write protect notch Small opening in floppy disk with tab to slide to cover/expose notch; indicates whether info can be written to disk
High Capacity Portable Disks/Drives Superdisk, Zip, USB Flash
Storage Strategies
Enterprise Storage Systems (ESS) Focuses on availability,
protection, organization, and back up of storage in a company.
Goal: Consolidate storage so that
operations run as efficiently as possible.
Examples: RAID, tape libraries, Storage
Area Networks (SAN)
Data Warehouses Centralizes the computing
environment, in which large megaservers store data, information, and programs, and less powerful client devices connect to the megaservers to access these items
Storage vs Memory?
3 Types of RAID?
Storage Strategies?
Temporary vs future;
SpeedEnterprise Storage
SystemsData Warehouse
MirroredStriped
Combination
Multimedia
Presents information with text, illustrations, photos, narration, music, animation, and film clips
Not practical until the advent of the optical disk
Organizing and Accessing Data
Database File Record Field Character
Key Field
File Organization
Three major methods of organizing data files in secondary storage Sequential Direct Indexed
the benefits of secondary storage The types of storage media that are available
for personal computers the principal types of secondary storage how data is stored on a disk the benefits of multimedia how data is organized, accessed, and processed
If asked, can you explain…
Questions?
?
? ???
Terms to Know: Storage, Multimedia & File Management
Access time Backup Bad sectors Character Cluster CD-ROM Database Digital Versatile disk (DVD) FAT (File Allocation Table) Field Formatting Fragmented Key field
Preformatted RAID Record Secondary Storage Sectors Server
Striping Tracks USB Flash Drive Zip drive
Sources
Capron; Computers: Tools for An Information Age, 8th Ed. 2003
Pfaffenberger; Computers in Your Future 2003
Microsoft Clipart