CHAPTER 8 - DIGITAL STORAGE
❖Storage❖
↷ Storage medium is the physical material on which a computer keeps data, information, programs, and applications
⛅ Cloud storage is another storage option, in which the actual online storage media used is transparent to the user
Types of storage:
❐ Capacity is the number of bytes a storage medium can hold
More information at: https://www.youtube.com/watch?v=HRmfXA4EUBs
❐ Items on a storage medium remain intact even when you turn off a computer or mobile device
🖪Hard disk🖪
Hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information
Video on how hard disk work: https://www.youtube.com/watch?v=wteUW2sL7bc&t=135s
❥ A head crash occurs when a read/write head touches the surface of a platter (Hard disk cannot read)
❥ An external hard disk is a separate freestanding storage device that connects with a cable to a USB port or other port on a computer or mobile device
❖Flash Memory Storage❖
Flash memory chips are a type of solid state media and contain no moving parts
Differences between SSD and HDD
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SSD
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HDD
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High price(1TB≈RM1000)
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Low price(1TB≈RM160-200)
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Smaller capacity (max1TB lp/4TB pc)
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Big capacity (max4TB lp/10TB pc)
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Short lifespan
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Long lifespan
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Low power consumption (2W)
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Higher power consumption (7W)
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High speed (200-550Mb/s)
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Lower speed (50-120Mb/s)
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- 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
- USB flash drives plug into a USB port on a computer or mobile device
⛅Cloud Storage⛅
Cloud storage is an Internet service that provides storage to computer or mobile device users
💿Optical Discs💿
Video available at: https://www.youtube.com/watch?v=SMQXD2p3syA
➺ Optical discs commonly store items in a single track that spirals from the center of the disc to the edge of the disc
➺ Track is divided into evenly sized sectors
❖Other Types of Storage❖
1) Magnetic Stripe Card
Contains a magnetic stripe that stores information
2) Smart Card
Stores data on an integrated circuit embedded in the card
3) Radio Frequency Identification (RFID)
- RFID tag consists of an antenna and a memory chip that contains the information to be transmitted via radio waves
- RFID reader reads the radio signal and transfers the information to a computer or computing device
- Types of RFID tags:
4) Microfilm and Microfiche
Store microscopic images of documents on a roll or sheet film
