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• Solid State controls movements of electrons within a microchip
• Optical uses precision lasers to access data
• Magnetic uses magnetic patterns to access data
Types of Storage Media
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Fixed Hard Disk
• Used to store operating system and working data
• Used for storing app software that needs fast retrieval
• Used by real-time systems and online systems
• Used in file servers for computer networks
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Portable Hard Disk Drives• Used as back-up to prevent data loss
• Used to transfer data, files and software between computers
Advantages Disadvantages
• Data access time/transfer rate is very fast
• Large memory capacities• Used as method of
transferring information between computers
• Easily damaged if user accidentally drops it or fails to shut it down correctly
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Floppy Disk Drives
• Used where small files need to be transferred or stored (i.e. word documents)
• Still used by older computer systems
Advantages Disadvantages
• Efficient use of space; using CDs would be more wasteful
• Cheap
• Very low memory capacity compared to CD/DVDs
• Few modern computers have floppy disk drives
• Data transfer is slow• Not very robust
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Magnetic Tapes
• Used in apps where batch processing is used (i.e. utility billing, bank checks)
• Used as back-up media since all data needs to be stored
Advantages Disadvantages
• Cheaper than equivalent-capacity hard disk
• Robust technology• Date transfer rate is fast
• Access time is slow• Another tape is required to
update info
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CD-ROM/DVD-ROM
• CD-ROMs are used to store music files, software, and computer games
• DVD-ROMs are used to store films
Advantages Disadvantages
• Hold far more data than floppy disks
• Cheaper than hard disk drive systems
• Data transfer rate/data access time are slower than hard disks
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CD-RW/DVD-RW
• CD-RWs/DVD-RWs are used to record radio/TV programs, but can be rewritten.
• Used in CCTV systems
Advantages Disadvantages
• Can be reused many times• Use diff. file formats each
time• Less wasteful because more
data can be added later
• Relatively expensive• Possible to accidentally
overwrite data
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Blu-Ray Disks
• Used in home video consoles
• Store and play back films (about 25 GB for 1)
• PCs can use it for data storage or backup
Advantages Disadvantages
• Very large storage capacity• Ideal for storing HD films• Fast data transfer rate• Data access speed is greater
than with other optical media
• Disks are relatively expensive
• Lack of encryption (at time of writing)
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Memory Sticks/Pen Drives• Used for backup or file transport
• Used as security devices
Advantages Disadvantages
• Compact and portable• Robust
• Impossible to protect data and files
• Easy to lose
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Flash Memory Cards
• Used to store digital camera photos/MP3 music
• Used as memory cards on mobile phones
• Used as backup in handheld computer devicesAdvantages Disadvantages
• Compact and portable• Robust• Use solid state memories
• Expensive per GB of memory when compared to hard drive disks
• Lower storage capacity than hard disks
• Finite number of times they can be read/written