Unit 1- Reading(the computer)
ducanhtran11cdth02 > 10-13-2012, 01:22 AM
Reading 1: The computer
A computer is a machine with an intricate network of electronic circuits that operate switches or magnetize tiny metal cores. The switches, like the cores, are capable of being in one of two possible states, that is, on or off; magnetized or demagnetized. The machine is capable of storing and manipulating numbers, letters, and characters.The basic idea of a computer is that we can make the machine do what we want by inputting signals that turn certain switches on and turn others off, or that magnetize or do not magnetize the cores.
The basic job of computers is the processing of information. For this reason, computer can be defined as devices which accept information in the form of instructions called a program and characters called data, perform mathematical and/or logical operations on the information, and then supply results of these operations. The program, or part of it, which tells the computers what to do and the data, which provide the information needed to solve the problem, are kept inside the computer in a place called memory.
Computers are thought to have many remarkable powers. However, most computers, whether large or small have three basic capabilities. First, computers have circuits for performing arithmetic operations, such as: addition, subtraction, division, multiplication and exponentiation.
Second, computers have a means of communicating with the user. After all, if we couldn't feed information in and get results back, these machines wouldn't be of much use. However,. Certain computers (commonly minicomputers and microcomputers) are used to control directly things such as robots, aircraft navigation systems, medical instruments, etc.
Some of the most common methods of inputting information are to use punched cards, magnetic tape, disks, and terminals. The computer's input device (which might be a card reader, a tape drive or disk drive, depending on the medium used in inputting information) reads theinformation into the computer. For outputting infonnation, two common devices used are a printer which prints the new information on paper, or a CRT display screen which shows the results on a TV-like screen.
Third, computers have circuits which can make decisions. The kinds of decisions which computer circuits can make are not of the type: "Who would win a war between two countries?" or "Who is the richest person in the world?" Unfortunately, the computer can only decide three things, named: Is one number less than another? Are two numbers equal? and, Is one number greater than another?
A computer can solve a series of problems and make hundreds, even thousands, of logical decisions without becoming tired or bored. It can find the solution to a problem in a fraction of the time it takes a human being to do the job. A computer can replace people in dull, routine tasks, but it has no originality; it works according to the instructions given to it and cannot exercise any value judgements. There are times when a computer seems to operate like a mechanical "brain", but its achievements are limited by the minds of human beings. A computer cannot do anything unless a person tells it what to do and gives it the appropriate infonnation; but because electric pulses can move at the speed of light, a computer can carry out vast numbers of arithmeticlogical operations almost instantaneously. A person can do everything a computer can do, but in many cases that person would be dead long before the job was finished.
a. Main idea
Which statement best expresses the main idea of the text? Why did you eliminate the other choices?
1. Computers have changed the way in which many kinds of jobs are done.
2. Instructions and data must be given to the computer.
3. Computers are machines capable of processing and outputting data.
4. Without computers, many tasks would take much longer to do.
b. Understanding the passage
Decide whether the following statements are true or false (T/F) by referring to the information in the text. Then make the necessary changes so that the false statements become true.
1. A computer can store or handle any data even if it hasn't received information to do so.
2. All computers accept and process information in the form of instructions and characters.
3. The information necessary for solving problems is found in the memory of the computer.
4. Not all computers can perform arithmetic operations, make decisions, and communicate in some ways with the users.
5.Computers can still be useful machines even if they can't communicate with the users.
6.There are many different devices used for feeding information into a computer.
7.There aren't as many different types of devices used for giving results as there are for accepting information.
8.Computers can make any type of decisions they are asked to do.
9. Computers can work endlessly without having to stop to rest unless there is a breakdown.
c. Contextual reference
Find out what the words in bold typeface refer to.
1. that operate switches (l.1) electronic circuits..........
2. which accept information (l.7) ......................................
3. or part of it (l.9) ....................................
4. which tells the computer (l.9) ....................................
5. which prints the new information (l.23) ....................................
6. which show the results (l.24) ....................................
7. which can make decisions (l.25) ....................................
8. It can find the solution (l.30) ....................................
9. it has no originality (l.31) ....................................
10. tells it what to do (l.34) ....................................
d. Advanced
Translate the following passage into Vietnamese
Input-process-output
Processing systems accomplish a task: they take one or more inputs and carry out a process to produce one or more outputs. An input is something put into the system, a process is a series of actions or changes carried out by the system, while an output is something taken from the system.
e. Communication
Pair work. Practice the conversations.
Dialogue 1: Buying your first computer.
Mary: Hi Jim. How's it going?
Jim: Pretty good. I'm going to buy a new computer this afternoon.
Mary: What kind are you going to buy?
Jim: I think I'll buy a desktop, maybe a Gateway or Compaq.
Mary: Those are very popular in America, and the prices are really coming down.
Dialogue 2: Printer problems
Linda: I finished my report, but the printer is broken.
What can I do?
Mary: Save the file on a floppy and bring it to my house. We can use my printer.
Linda: That's a great idea.
Mary: Or, email it to me - that might be faster.
Linda: Hmm, that won't work. The report has graphs.
f. Consolidation
1) Write down whether the following statements are true or false.
1 Computers can think.
2 All systems are made up of groups of elements.
3 Computers can remember a set of instructions.
4 Computers make few mistakes.
5 A computer does not learn from past experiences.
6 Output is something put into the system.
7 A computer was first developed to perform numerical calculations.
8 Computers are human.
9 Our modern society is dependent on computers.
10 Computers hate people.
2) Use the correct form of the verbs in brackets.
1. Various terminals (connect) to this workstation.
2. Microcomputers (know) as 'PUs'.
3. Magazines (typeset) by computers.
4. When a particular program is run, the data (process) .................by the computer very
rapidly
5. Hard disks (use) for the permanent storage of information.
6. The drug-detecting test in the Tour de France (support)…… by computers.
7. All the activities of the computer system (coordinate) .................by the central processing unit.
8. In some modern systems information (hold) in optical disks.
Reading 2
It is common practice in computer science for the words "computer" and "processor" to be used interchangeably. More precisely, "computer" refers to the central processing unit (CPU) together with an internal memory. The internal memory or main storage, control and processing components make up the heart of the computer system. Manufacturers design the CPU to control and carry out basic instructions for their particular computer.
The CPU coordinates all the activities of the various components of the computer. It determines which operations should be carried out and in what order. The CPU can also retrieve information from memory and can store the results of manipulations back into the memory unit for later reference.
In digital computers the CPU can be divided into two functional units called the control unit (CU) and the arithmetic - logical unit (ALU).
These two units are made up of electronic circuits with millions of switches that can be in one of two states, either on or off.
The function of the control unit within the central processor is to transmit coordinating control signals and commands. The control unit is that portion of the computer that directs the sequence or step-by-step operations of the system, selects instructions and data from memory, interprets the program instructions, and controls the flow between main storage and the arithmetic - logical unit.
The arithmetic - logical unit, on the other hand, is that portion of the computer in which the actual arithmetic operations, namely, addition, subtraction, multiplication, division and exponentiation, called for in the ' instructions are performed. It also performs some kinds of logical operations such as comparing or selecting information. All the operations of the ALU are under the direction of the control unit.
Programs and the data on which the control unit and the ALU operate, must be in internal memory in order to be processed. Thus, if located on : secondary memory devices such as disks or tapes, programs and data and ftrst loaded into internal memory.
Main storage and the CPU are connected to a console, where manual control operations can be performed by an operator. The console is an important, but special purpose, piece of equipment. It is used mainly when the computer is being started up, or during maintenance and repair. Many mini and micro systems do not have a console.
A. Main idea : Which statement best expresses the main idea of the text? Why did you eliminate the other choices?
1. Main storage is not a part of the processor.
2. The CPU is made up of the control unit, the arithmetic - logical unit and internal memory.
3. The CPU is composed of the arithmetic - logical unit and control unit only.
B. Understanding the passage
Decide whether the following statements are true or false (T/F) by referring to the
information in the text.
1. The central processing unit is made up of three components.
2.The CPU is responsible for all the activities taking place within a computer.
3.The processor itself has three components.
4. The control unit directs the flow of information within the processor.
5.The arithmetic-logical unit of the processor is responsible for the interpretation of program instructions.
6.The arithmetic-logical unit is also responsible for choosing and comparing the appropriate information within a program.
7. The processor cannot operate on any information if that information is not in main storage.
8.Secondary memory and internal memory are located in the same place in the computer
system.
9. Only after the data has been processed by the CPU can results be transmitted to an output device.
10. Computers can solve problems more quickly if they operate on new information.