Complete these descriptions with the correct unit of memory.
1. A is about one trillion bytes - about as much text as the
books and magazines in a huge library. 2. A is about one million
bytes - about as much text as a 300-page novel. 3. A is about one
billion bytes - about as much text as 1,000 books. 4. A is about one
thousand bytes - equivalent to one sheet of A4. 5. A can store a
single character, such as the letter h or number 7.
What do you call a unit which:
accepts information from outside a computer?
memorizes information to be operated on?
brings information out of the computer?
Make up the summary of the text in writing.
Lesson 2. Magnetic storage
Read and translate the text.
Magnetic storage devices store data by magnetizing particles on a disk or tape. There are basically three types of magnetic storage devices available to the computer user — 3.5"floppy drives and diskettes, hard drives and tapes.
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 7,200rpm 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 though as a rule they come preformatted from the manufacturer. 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 heads to the correct sector and reads the file in the RAM area.
The OS allows you to create one or more partitions on the hard drive, in effect dividing it into several logical parts. Partitions allow installing more than one OS on the computer. The user can also split the hard drive to store the OS and programs on one partition (this is the internal hard drive usually called C: drive) and data files on another so that when a problem occurs the OS may be reinstalled without affecting the data partition.
External hard drives are connected to the USB or FireWire port of the computer. They can be as small as a wallet but can have as much capacity as internal drives; they are usually used for backup or as secondary storage.
Hard drives are very sensitive to vibration and shocks, especially when they are operating.
A tape drive 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 are used for data collection, backup and archiving.
The average time required for the read/ write heads to move and find data is called seek time (or access time) and is measured in milliseconds. Seek time shouldn’t be confused with transfer rate — the average speed required to transmit data from the disk to the CPU, measured in megabytes per second.
Decide whether these sentences are true or false. Correct the false
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 small disk. 4. Seek time and transfer rate mean the same thing. 5. Disk drives are not shock resistant, especially in operating mode.
Read each paragraph carefully and say briefly what they are
Speak on advantages and disadvantages of magnetic storage devices.
Read the text and translate it into Russian. Write a short summary of it.
The function of the memory unit is to store programs and data. This function can be accomplished with a variety of equipment. It is useful to distinguish between two classes of memory devices which comprise the prime and secondary storage. Primary storage, or the main memory, is a fast memory capable of operating at electronic speeds, where programs and data are stored during their execution. The main memory contains a large number of semiconductor storage cells, each capable of storing one bit of information. These cells are rarely read or written аs individual cells. Instead, they are processed in groups of fixed size called words. The
main memory is organized so that the contents of one word, containing n bits, can be stored or retrieved in one basic operation.
To provide easy access to any word in the main memory, it is useful to associate a distinct name with each word location. These names are numbers that identify successive locations, which are hence called address. A given word is accessed by specifying its address and issuing a control command that starts the storage or retrieval process.
The number of bits in each word is often referred to as the word length of the given computer. Large computers usually have 32 or more bits in a word, while microcomputer and minicomputer word lengths range from 8 to 32 bits. Small machines may have only a few thousand words, large machines often have millions of words. Data is usually manipulated within a machine in units of words, multiples of words, or submultiples of words. A typical access to the main memory results in one word of data being read from the memory or written into it.
Can be stored or retrieved - зд. могут быть найдены; successive locations - последовательные ячейки. Data is usually manipulated - С данными обычно работают.
Lesson 3. Optical discs and drives
I. Before reading the text discuss these questions:
What do CD and DVD stand for?
What is the main advantage of using DVDs instead of CDs?
What is the Blue-ray format? Where does it get its name?
Read and translate the text.
Optical discs can store data at much higher densities than magnetic discs. They are therefore ideal multimedia applications where images, animation and sound occupy a lot of disc space. Optical discs are not affected by magnetic fields, so they are secure and stable, and can be transported through metal detectors without damaging the data. However, optical drives are slower than hard drives.
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 a DVD, tracks are very close together, thus allowing more tracks. The pits in which data is stored are also smaller, so there are more pits per track. As a result, a CD can hold 650-700 MB, whereas a basic DVD can hold 4.7 GB.
CDs come in three different formats:
•CD-ROMs are read-only units, meaning you cannot change the data stored on them.
•CD-R (recordable) discs are write-only devices that let you duplicate other CDs.
•CD-RW (rewritable) discs enable a user to write onto them many times, just like a hard disk.
A CD-ROM drive is a device that can read information from a CD- ROM. CD-ROM drives can be either internal, in which case they fit in a bay, or external, in which case they generally connect to the computer’s USB or ESATA. ESATA CD-ROM drive is easier to install, but it has several disadvantages. It’s somewhat more expensive than internal drives and ESATA can be rarely implemented in the motherboards. USB is easier to install and connect. It’s possible to move USB drive between different PCs.
There are a number of features that distinguish CD-ROM drives, the most important of which is probably their speed. CD-ROM drives are generally classified as single-speed or some multiple of single-speed.
Two more precise measurements are the drive’s access time and data transfer rate. The access time measures how long, on average, it takes the drive to access a particular piece of information. The data transfer rate measures how much data can be read and sent to the computer in a second.
DVDs also come in several formats:
•DVD-ROMs are used in DVD computer drives. They allow for data archiving as well as interactive content.
•DVD-R or DVD+R can only be recorded on once.
•DVD-RW or DVD+RW discs can be erased and reused many times.
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.
HD-DVD and Blue-ray discs are expected to replace current DVD. HD stands for high definition. A Blue-ray disc has a capacity of 25GB, 50 GB and 100 GB. Unlike DVDs, which use a red laser to read and write data, Blue-ray uses a blue-violet laser, hence its name.
USB - Universal Serial Bus - универсальная последовательная шина; ESATA - External Serial Advanced Technology Attachment - последовательный интерфейс подключения внешних устройств (в отличие от SATA - последовательного интерфейса обмена данными с
накопителями); CD-ROM - compact disc read-only memory - компактный оптический диск с данными.
Give the Russian equivalents.
Device, disadvantage, bay, to distinguish, precise, measurement, access time, data transfer rate, average, to implement, feature, speed, to classify, laser beam, via, burner, high definition.
Give the English equivalents.
Данные, скорость, классифицировать, устройство, скорость передачи данных, особенность, среднее число, отсек, время доступа, различать, недостаток, измерение, осуществить, точный.
Complete the following sentences.
1. A CD-ROM drive is that can read information from a CD-
ROM. 2. CD-ROM drives can be either , or . 3. CD-ROM
drives are generally classified as . 4. Two more precise
measurements are and . 5. measures how long it
takes the drive to access a particular piece of information. 6.
measures how much data can be read and sent to the computer in a second.
Sum up the contents of the text by answering the following questions:
What is a CD-ROM? 2. What is the difference between the internal CD-ROM and external CD-ROM drives? 3. What advantages of USB CD-ROM drive can you name? 4. ESATA drives have some disadvantages. What are they? 5. There are a number of features that distinguish CD-ROM drives, aren’t there? What are they? 6. What does the data transfer rate measure? 7. What is the basic function of disk drives?
UNIT 4. PERIPHERALS Lesson 1. Monitor
Before reading the text look at the words bellow. How many of them do you know? Look up the unknown words in the dictionary.
An enclosure, to classify, a device, liquid, permanent, capability, monochromic, background, foreground, to measure, to accept, an inch.
Read and translate the text.
A monitor or display (sometimes called a visual display unit) is a piece of electrical equipment which displays images generated by devices such as computers, without producing a permanent record. The computer sends a signal to the video adapter, telling it what character, image or graphic to display. The video adapter converts that signal to a set of instructions that tell the display device (monitor) how to draw the image on the screen. The monitor comprises the actual display device, circuitry, and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), while older monitors use a cathode ray tube (CRT).
There are many ways to classify monitors. The most basic is in terms of colour capabilities, which separates monitors into three classes:
monochrome: Monochrome monitors actually display two colours, one for the background and one for the foreground. The colours can be black and white, green and black, or amber and black.
grey-scale: A grey-scale monitor is a special type of monochrome monitor capable of displaying different shades of grey.
colour: Colour monitors can display anywhere from 16 to over 1 million different colons. Colour monitors are sometimes called RGB monitors because they accept three separate signals — red, green, and blue.
After this classification, the most important aspect of a monitor is its screen size. Like televisions, screen sizes are measured in diagonal inches, the distance from one corner to the opposite corner diagonally. A typical size for small VGA monitors is 14 inches. Monitors that are 16 or more inches diagonally are often called full-page monitors.
The resolution of a monitor indicates how densely packed the pixels are. In general, the more pixels (often expressed in dots per inch), the sharper the image. Another common way of classifying monitors is in terms of the type of signal they accept — analogue or digital.
What do the following abbreviations stand for?
a) TFT; b) LCD; c) CRT; d) RGB (monitor); e) VGA (monitor)
Work with the dictionary and find the meanings of the following words. Try to explain them in English.
Equipment; video adapter; device; pixel
What do you call
a set of tools or devices used for a particular purpose?
the smallest discrete component of an image or picture on a CRT screen (usually a coloured dot)?
a machine or tool used for a particular purpose?
a board that plugs into a personal computer to give it display capabilities?
a screen used to display certain kinds of information, for example in airports or television studios?
a mental picture of someone or something produced by the imagination or memory?
Arrange synonyms in pairs and give their Russian equivalents.
Display, character, convert, separate, measure, indicate;
Point, quantify, symbol, monitor, divide, alter.