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Exercise 1. Which device or format would be most suitable for storing these things?

1. The operating system and the programs on a home computer.

2. An electronic encyclopedia for children.

3. A movie in digital format.

4. The music tracks by your favourite artist.

5. All the files generated by a company in one day.

6. The photos taken with a digital camera.

Exercise 2. Remember the following words and word combinations.

magnetic devices магнітні пристрої

disk drive дисковод

data дані

floppy disk дискета

internal hard disk внутрішній жорсткий диск

surface поверхня

concentric circles концентричні кола

read/write heads зчитуюча і записуюча головка

external unit зовнішній пристрій

flash memory флеш-пам'ять

non-volatile той, що довго зберігається

Exercise 3. Read the text and translate it into Ukrainian.

Different Types of Storage

Magnetic Storage. Magnetic devices store data magnetically. A disk drive spins the disk at high speed and reads its data or writes new data onto it.

· A floppy disk drive uses 3.5 inch diskettes which can only hold 1.44 MB of data; it’s often called A: drive and is relatively slow. Floppy drives are becoming increasingly rare.

· The inside of a hard drive Most PCs have one internal hard drive, usually called C: drive. It is used to store the operating system, the programs and the user’s files in a convenient way. A hard drive can hold hundreds of gigabytes of data.

When you format a disk, or prepare it for use, its surface is divided into concentric circles called tracks. Each track is further divided into a number of sectors. The computer remembers where information is stored by noting the track and sector numbers in a directory.

The average time required for the read\ write heads to move and find data is called access time; it is measured in milliseconds. Don’t confuse access time’ with transfer rate, the rate of transmission of data from the disk to the CPU (e.g. 15 megabytes per second).

A portable hard drive is an external unit with the drive mechanism and the media all in one sealed case. You can use it to make a backup, a spare copy of your files, or to transport data between computers. External hard drives are connected to the USB or FireWire port of the computer. They can be small as a wallet but can have as much capacity as internal drives.

Magnetic tapes and drives: A tape drive and reads and writes data on tapes. It is sequential-access – i.e. to get to a particular point on the tape, it must go through all the preceding points. Tapes can hold hundreds of gigabytes of data and are used for data collection, backup and archiving.

Optical storage. Optical drives use a laser to read and write data, so they are not affected by magnetic fields; but they are slower than hard drives. Modern DVD recorders accept all CD and DVD formats.

Portable DVD players let you watch movies or TV, play games and listen to music, wherever you are. They usually run on batteries, have a widescreen (rectangular 16:9 format) LCD and support multi-format playback, allowing you access to many file formats including DVD video, JPEG pictures, MP3 music, etc. They have two built-in stereo speakers or headphones if you don’t want to disturb other people.

Optical discs and drives. Optical discs can data at much higher densities than magnetic disks. They are therefore ideal for multimedia applications were images, animation and sound occupy a lot of disc space. Furthermore, optical discs are not affected by magnetic fields, meaning that they are secure and stable, and can be transported through airport metal detectors without damaging the data. However, optical drives are slower than hard drives.

Look at the table and compare CD and DVD:

CD (compact disks) can store up to 650-700 MB of data DVDs (digital versatile discs) are similar in size to CDs (both are 1.2 mm thick), but they differ in structure and capacity. DVDs have more tracks and more pits (tiny holes) per track, and can store from 4.7 GB to 17 GB of data, movies, high-definition sound, etc., so they will probably replace CDs, DVD formats include:
CD-ROMs (read only memory) are ‘read-only’ units, so you cannot changed data stored on them (e.g. a dictionary or a game). DVD-ROM (read only memory)
CD-R (recordable) discs are write-once devices which let you duplicate CDs DVD-R or DVD+R (recordable only once)
CD-RW (rewritable) discs enable you to write onto them in multiple sessions, like a hard disk. DVD-RW DVD+RW(rewritable, so it can be erased and reused many times)

At first sight, a DVD is similar to a CD. Both discs are 120 mm in diameter and 1.2 mm thick. They also both use a laser beam to read data. However they are very different in internal structure and data capacity. In DVD, the tracks are very close together, thus allowing more tracks. The pits in which data is stored are also smaller, so there are more pits than track. As a result, a CD can hold 650-700MB, whereas a basic DVD can hold 4.7 GB. In addition, a DVD can be double-sided and dual layer, with a capacity of 17 GB.

CDs come in three different formats:

-CD-Roms (read-only memory) are read-only units, meaning you cannot change the stored on them (for example, a dictionary or a game).

-CD-R (recordable) discs are write-once devices which let you duplicate music CDs and other data CDs.

-CD-RW (rewritable) discs enable you to write onto them many times, just like a hard disk.

DVDs also come in several format:

-DVD-ROMs are used in DVD computer drives. They allow for data archiving as well as interactive content (for example, an encyclopedia or a movie).

-DVD-RW or DVD=RW discs can be erased and reused many times. They are used to back up data files and to record audio and video.

The DVD drive used in computers is also called a DVD burner because it records information by burning via a laser to a blank DVD disc. However, a DVD recorder typically refers to a standalone unit which resembles a video cassette recorder. New DVD recorders can play all CD and DVD formats. There are also portable DVD players – handled devices which let you watch movies or TV, play games and listen to music, wherever you are. They come with a built-in DVD drive and widescreen (rectangular 16:9 format) LCD display. They usually support multi-format playback – that is, they can play many file formats, including DVD-video, DivX, CD audio discs, MP3 music and JPEG images.

HD-DVD and Blu-ray discs

These two competing formats are expected to replace current DVD as the standard for watching movies at home. On one side are Toshiba, Microsoft and the DVD Forum, who support the High Definition-DVD (HD-DVD). Sony, Panasonic, Samsung, JVC and many movie studios are behind Blu-ray format.

A Blu-ray disc has a capacity of 25 GB (single layer), 50 GB (dual layer) and 100 GB (four layer). Unlike DVDs, which use a red laser to read and write data, Blu-ray uses a blue-violet laser, hence its name. Blu-ray dusk can record and play back high-definition television and digital audio, as well as computer data.

Magnetic storage. Magnetic storage devices store data by magnetizing particles on a disk or tape.

A floppy disk is so called because it consists of a flexible sheet of plastic, coated with iron oxide – a magnetizable material. A floppy disk drive spins at 360 revolutions per minute (rpm), so it’s relatively slow. However, a hard drive spins at over 7,200 rpm and stores data on a stack of metal rotating disks called platters. This means you can store much more data and retrieve information much faster.

New disks need to be formatted before you can use them, unless they come preformatted from the manufacturer. When the disk is formatted, the operating system (OS) organizes the disk surface into circular tracks and divides each track into sectors. The OS creates a directory which will record the specific location of files. When you save a file, the OS moves the read\write head of the drive towards empty sectors, records the data and writes an entry for the directory. Later on, when you open that file, the OS looks for its entry in the directory, moves the read\write head to the correct sector, and reads the file in the RAM area. However, formatting erases any existing files on a disk, so do not format disks on which data that you don’t want to lose is stored.

The OS allows you to create one or more partitions on your hard drive, in effect dividing it into several logical parts. Partitions let you install more than one operating system (e.g. Windows and Linux) on your computer. You may also decide to split your hand drive because you want to store the OS and programs on one partition and your data files on another; this allows you to reinstall the OS when a problem occurs, without affecting the data partition.

The average time required for the read\write heads to move and find data is called seek time (or access time) and it is measured in milliseconds (ms); most hard drives have a seek time of 7 to 14 ms. Don’t confuse this with transfer rate – the average speed required to transmit data from the disk to the CPU, measured in megabytes per second.

How to protect your hard drive

- don’t hit or move the computer while the hard drive is spinning. Hard drives are very sensitive to vibration and shocks, especially they are operating; when the read/write head touching the rotating disk, it can scratch and damage the disk surface. This is known as head crash.

- you shouldn’t turn your computer off and quickly. Wait at least ten seconds to ensure that the drive has stopped spinning.

- check your hard drive regularly for logical and physical errors. To check and repair a drive, you can use a disk diagnosis utility like Windows ScanDisk.

- to minimize the risk of data loss or corruption, you should install an up-to-date virus scanner. You should also back up your hard drive regularly.

Removable flash memory

Flash memory is solid-state, rewritable memory; it is non-volatile, so it retains data when the power is turned off. This explains its popularity in small devices.

Flash memory cards such as Compact Flash or Secure Digital are found in cameras, PDAs and music players.

Flash drives, also known as thumb or pen drives, are connected to a USB port of the computer. They let you save and transfer data easily.

Exercise 4. Read the text and decide whether these statements are true or false. Correct the false ones.

1. A hard drive spins at the same speed as a floppy disk drive.

2. If you format a hard drive that has files on it, the files will be deleted.

3. Hard drives cannot be partitioned to run separate operating systems on the disk.

4. Seek time and transfer rate mean the same thing.

5. Disk drives are not shock resistant, especially in operating mode.

Exercise 5.Match the words (1-5) with their definitions (a-e).

1. formatted a. a file system that defines the structure for keeping track on the files

2. directory b. the part of a drive that reads and records data on a disk

3. read/write head c. to make a copy of data or software in case the original disk is damaged

4. head crash d. initialized; when the tracks and sectors on magnetic disks are set

5. back up e. a serious disk malfunction; when the read/ write head touches the rotating disk

 

Exercise 6. Look at the text above and find.

1. The CD and DVD formats that can be rewritten many times.

2. The CD and DVD formats that can be written to by the user only once.

3. The CD and DVD formats that can be read by a computer but not written to.

4. The type of cards used in digital cameras.

5. A type of drive that plugs into a USB port and lets you share photos and music with friends.

6. The memory without moving parts; its erasable, non-volatile and used in small devices.

7. The expression that means to “initialize a disk and prepare it to receive data”.

 

Exercise 7. Read the text again and make notes about the features of CDs, DVDs and Blu-ray discs.

  Capacity and format Possible uses
CD    
DVD    
Blu-ray    

 

 

Exercise 8. Complete the sentences with the words from the box:

hard disk access time floppy disk drive portable hard drive tracks sectors backup transfer rate

1. The first rule of data storage is to make a ______ of all important files.

2. A ______ is slower the drive and can only hold 1.44 MB disks.

3. The _____ inside your PC is made of aluminum alloy covered with a magnetic coating. This makes the disk itself a rigid plate, hence its name.

4. The ___ are circles around the disk and the ____ are segments within each circle.

5. This hard drive is a 60 GB IBM model with a fast ____ of 8 ms.

6. The ______ is the rate of transmission of data from the disk to the CPU. This is usually described in megabytes per second.

7. Apple’s iPod music player can double as a ____ for transporting computer data.

Exercise 9. Complete this product description with words from the text above.

The Panasonic DVD-LS91 is a top-of-the-range (1) _____, which provides pure entertainment wherever you go.

It has a big 9 inch built-in (2) ______ LCD, so you can really enjoy movies. The built-in stereo-speakers allow you to listen along, or if you want to listen alone, just plug in a pair of (3) _____.

This portable machine provides (4) _____ -_____ _____, so you can play DVD Audio/Video, CD-R/RW, DVD-RAM, DivX and MP3 files. Its compact design features a built-in rechargeable 6 hour battery pack.

The DVD-LS91 allows 6 hours of playback, and provides a perfect way to entertain yourself and your kids during long trips.

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