External Media
From IT Jalakam - Unofficial IT syllabus for grade 10 students
USB Drives
A USB flash drive consists of a NAND-type flash memory data storage device integrated with a USB (Universal Serial Bus) interface. USB flash drives are typically removable and rewritable, much smaller than a floppy disk, and most USB flash drives weigh less than an ounce (30 g).Storage capacities typically range from 64 MB to 128 GB with steady improvements in size and price per capacity. Some allow 1 million write or erase cycles and have 10-year data retention, connected by USB 1.1 or USB 2.0.
A SanDisk 16 GB USB retractable flash drive.
Nothing actually moves in a flash drive: the term drive persists because computers read and write flash-drive data using the same system commands as for a mechanical disk drive, with the storage appearing to the computer operating system and user interface as just another drive
Application carriers
Flash drives are used to carry applications that run on the host computer without requiring installation. While any standalone application can in principle be used this way, many programs store data, configuration information, etc. on the hard drive and registry of the host computer
The U3 company works with drive makers (parent company SanDisk as well as others) to deliver custom versions of applications designed for Microsoft Windows from a special flash drive; U3-compatible devices are designed to autoload a menu when plugged into a computer running Windows. Applications must be modified for the U3 platform not to leave any data on the host machine. U3 also provides a software framework for ISVs interested in their platform.
Used in computer forensics and law enforcement, as boot device, readyboost for some operating syatems, music storage and marketing, for backups, in arcade games
Note:
1. Give examples of each. 2. Discuss advantages and disadvantages. 3. Show them some USB flash drives.
External hard disk drive
An external hard disk drive is a type of hard disk drive which is externally connected to a computer. Modern entries into the market consist of standard SATA, IDE, or SCSI hard drives in portable disk enclosures with SCSI, USB, IEEE 1394 Firewire, eSATA client interfaces to connect to the host computer.
Note: (to myself):
Take photo of external HDDs and post. Need to add more details
Memory card
A memory card or flash memory card is a solid-state electronic flash memory data storage device capable of storing digital contents. These are mainly used with digital cameras, handheld and Mobile computers, mobile phones, music players, video game consoles, and other electronics. They offer high re-record-ability, power-free storage, small form factor, and rugged environmental specifications. There are also non-solid-state memory cards that do not use flash memory, and there are different types of flash memory.
There are many different types of memory cards and jobs they are used for. Some common places include in digital cameras, game consoles, cell phones, and industrial applications.
Note:
Details of different types, card reader etc.
Optical media
The various writable and rewritable forms of CD and DVD are portable storage media supported by the vast majority of computers as of 2008. CD-R, DVD-R, and DVD+R can be written to only once., RW varieties up to about 1,000 erase/write cycles, while modern NAND-based flash drives often last for 500,000 or more erase/write cycles.[citation needed] DVD-RAM discs are the most suitable optical discs for data storage involving much rewriting.
Optical storage devices are among the cheapest methods of mass data storage after the hard drive. They are slower than their flash-based counterparts. Standard 12 cm optical discs are larger than flash drives and more subject to damage. Smaller optical media do exist, such as business card CD-Rs which have the same dimensions as a credit card, and the slightly less convenient but higher capacity 8 cm recordable CD/DVDs. The small discs are more expensive than the standard size, and do not work in all drives.
The HDD plus case option
A disk enclosure is essentially a specialized chassis designed to hold and power disk drives while providing a mechanism to allow them to communicate to one or more separate computers.
Advantages, disadvantages, protocols etc.
Source - Wikipedia
