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Storage Devices. By Artiom Nistrean, Jimmy Aky ü z . Not forgetting Daniel Brown. Introduction. With out a storage devices you can not save anything and all your hard work will be for NOTHING! There is a different storage device for different tasks. Such as: floppy disk USB sticks CDs
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Storage Devices By Artiom Nistrean, Jimmy Akyüz. Not forgetting Daniel Brown
Introduction • With out a storage devices you can not save anything and all your hard work will be for NOTHING! • There is a different storage device for different tasks. Such as: • floppy disk • USB sticks • CDs • DVDs • Hard Disk • Ram and ROM
Storage capacity Data can be stored either in the 'internal memory' or on a 'storage device'. The amount of data and instructions that can be stored is measured in 'bytes'. One byte contains 8 bits This is the smallest unit of data that can be stored. Each bit is represented as a binary number.
Advantages Very large storage capacity Sound picture quality is excellent making it used mainly for video and sound storage. Relatively cheap. DVD players can read CDs. Disadvantages DVDs do not work in CD drives There is no single standard of DVD. Easily damaged. Digital Versatile Disks • A DVD is similar to a CD • It is one of the most common uses of copying and backing up data. • You can store up to 4.7GB of data on one side. Usually there is only one side to a DVD
Compact Disks (CDs) There are 3 main types of CDs: • CD ROM (Read Only Memory) E.g. when you buy a CD you can only read what’s on it. • CD worm this type of CD can mean you can burn data or memory on to the disk only once but can read it many times. • Cd-rw you can save data as many times as you want. e.g. rewritable. Such as a floppy disk which is like a portable hard drive.` 4. A CD can store about 650mb. Disadvantages • Very fragile • Smaller memory capacity than a hard drive or DVD • Slower to access than a hard drive Advantages • Small, portable, and cheap. • Most computers can read CDs • Fast access to data stored on the disc
Read only Memory (ROM) • Rom is a special kind of memory. It stores the BIOS (basic input output system) • It allows you to check the amount of ram installed, the type of CPU and the type of hard disk, ect. • Can only be read by user. • Data is stored permanently which is called non volatile memory. • ROM chip is attached to motherboard
Random access memory (RAM) • RAM is volatile memory which means it is temporary. • Most computers are sold with 1-2GB of RAM. • RAM stores modules need to make application work. e.g. opening a program may take time. • RAM is needed to have multiple windows and applications open. • However if you open too many applications and windows the system will slow down and even crash, this is because you ram is full so it has to decide which memory is temporarily saved and what can be realized.
Hard Disk • The hard disk is the main storage device in you computer. • All of you data files are stored on there. • A typical Hard disk stores 120GB- 1 Terabyte • It is possible to have an external hard drive plugged into your computer through an USB port.
Flash memory (USB) Flash memory storage devices are typically small removable and rewritable. They consist of a small printed circuit board which is encased in plastic or metal casing for protection. They are inserted into a USB port in the computer
Zip disks Zip disks look similar to a floppy disk but are a little bit thicker. They can store around 100Mb of data - 70 times more than a floppy disk.
Magnetic tapes Large organisations who need to back up their systems use magnetic. Magnetic tape uses 'serial access' to find a piece of data. It works in much the same way as a video tape that you might have at home. To find a specific piece of data, you have to start at the beginning of the tape and continue fast forwarding until you get to the piece of data that you need.
Floppy disks Floppy disks are the oldest use of storage and are still used. A floppy disk can store up to 1.44 Mb of data which is equivalent to around 300 pages of A4 text. Floppy disks are a magnetic storage device.
Floppy disks Advantages Disadvantages Not very strong- easy to break Data can be erased if the disk comes into contact with a magnetic field Quite slow to access and retrieve data when compared to a hard disk Can transport viruses from one machine to another Small storage capacity New computers may not have floppy disk readers • Portable. • Cheap. • Useful for transferring small files. • Security tab to stop data being over written. • Can used many times
Question Quick quiz What does MB stand for? A. Megabytes B. Mean bear C. Mini-bytes D. Mega-burger?
Quick quiz How many bytes make up 2MB? A. 6 bites to finish the two Burger B. Errrrmmmm none? C. 2,000 D. 2,048
Quick quiz What does RAM stand for? A. Rock and Metal B. Relative Application Measurement C. Random Access Memory D. Read and Memorize
Quick quiz • What is a type of Volatile memory? A. RAM B. ROM C. Sodium Hydroxide D. Me no speek English
Quick quiz • What is the usual size of RAM installed into a computer? A. 1 terabyte B. 20cmx40cm? C. 0.00000002574591261 bites D. 1 Gigabyte
Conclusion Hope you have learned and expanded your knowledge about storage devices. Thanks for watching. Source of information: http://www.teach-ict.com/gcse/hardware/storage/miniweb/floppydisk.htm