Sir Sadiq s computer notes for class IX. Chapter no 1. Introduction to computer

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2 Q: Define the term computer. Ans: Computer is an electronic device that accepts data and instruction as input process the data according to the given instruction and produce information as output. Q: Define the terms Hardware and Software. Ans: Hardware: The physical or tangible components forming a computer are called hardware. It includes not only the computer but also the cables, connecters, power supply units and peripheral devices such as the keyboard, mouse, audio speaker, printer etc. Software: Software refers to the program that instructs the computer what to do and how to do. The term software refers to the non-physical elements of a computer system. Windows, Microsoft Office, Flash, Photoshop are the example of software. Q: Define language translator. Ans: A translator is required to execute any high-level language program. Each language has a different language translator, while the function of each translator is to convert high-level program into machine code. Or Language translators are the programs that are used to convert source program to object program. Q: What are (machine language) low-level language & high-level language? Ans: Low-Level Language (Machine Language): Every creation of this universe has its own language, likewise, computer has language that is called machine language, for instructing computer to perform specific task. It is the language of 0s and 1s. High-Level Language: High level languages are closer to human language than low-level language and include statement like GOTO and PRINT which are regular words. Q: Why the source code is needed to be translated into machine code? Computer program written in a high-level language which is converted into object code or machine code by a compiler is called source code. Source code is the only stage where a programmer can read or modify a 2

3 computer program. It is needed to be translated into machine code to execute it. Because computer only understand machine language. Q: What is assembly language? Ans: Assembly Language: Assembly language is the next level of programming language. Each computer has its own unique assembly language. In assembly language, the statements are written in symbolic codes. Assembly language is very close to machine language that is why it is called a low-level language. Q: What are assemblers? Ans: Assemblers: The assemblers are language translator for low-level symbolic language used in assembly language. Assemblers can translate Source Program into Object Program. An assembler translates one source instruction program into exact one machine code. Each low-level symbolic language has its own assembler. Q: Define interpreter. Ans: Interpreter: An interpreter normally means a computer program that executes, i.e. Programs, instructions written in a programming language. Most interpreting systems also perform some translation work, just like compilers. An interpreter may be a program that either executes the source code directly. Q: Define compiler. Ans: Compiler: Compiler is similar to assembler in a way that it translates the high-level language program into machine language. It is used to translate entire program at once. The original program is called Source program while translated program is called Object program. Each high-level language has its own compiler. Q: What are the types of computer? Or Define the types of computer according to data handle. Ans: Computer can be classified into three types. This classification is based on the hardware structure & the way through which physical quantities are represented in a computer. The three types are: 1. Analog computer 2. Digital computer 3. Hybrid Computer 3

4 Analog computer: The term analog is taken from the word analogous which means similar. Analog computers are commonly used for scientific and engineering problems, particularly in chemical industries, electric power plant & petroleum refineries. Digital Computer: Digital computers are computers that specialize in counting. Unlike the analog computer which receives data in a continuous form, the digital computer handles values that are in binary O or 1. All commonly used computers are digital. Hybrid computer: Hybrid computer is combination of analog and digital computer system. These are the machines that incorporate in a single computer both analog & digital features. A hybrid computer uses analog to digital conversion & digital to analog conversion, and may input or output either analog or digital data. These computers are used such as space vehicle simulations and training of astronauts. Q: What do you know about ABACUS? & where is used now a day? Ans: ABACUS: The Abacus, which was invented about 5000 years ago. The Abacus was developed and used in China. This is the simplest manual device which consist of a rectangular frame with vertical wires containing are number of beads for representing units, tens, hundreds, thousands and so on calculation were done by moving the beads along with the wires. Early merchants used the Abacus to keep trading transactions. But as the use of paper and pencil spread, the ABACUS lost its importance. It looks nearly 12 countries, however, for the next significant advance in computing devices to emerge. Q: What are the impacts of computer and the internet on society? Ans: society: Today computers are constantly becoming a part of everyday life and have significantly influenced our life style. Computers are used in everything from the home PC or Laptop to appliances such as microwaves oven, washing machines, entertainment devices, mobile phones and even in our cars. Not only have computers had a great impact on our family, life but also on education and the work place. Education: The use of computer for education purpose has been highly beneficial for the students and teachers. As well news, assignment, tests, lectures, notes etc can be on the internet for students to access both at school & from home. Children now learn online through websites and 4

5 videos and audio conferencing. Computers are also very beneficial for research purpose. Work Places Business: Computer technology has advanced greatly in the past couple of years and in May large business, computers have begun taking the place of human. It is more that they are helping us to do our work. Stores use computer to keep track of their files & many stores have also started using cash registers. All business keep records on computer & many of them depend entirely on their computer system. Today Social media web site are also introduced their business. Mostly work is done online through compute. Q: What are the advantages of 2 nd and 4 th generation? Ans: Second Generation: 1. Smaller in size as compared to first generation 2. Much reliable 3. Computations were performed in microseconds 4. Less hardware failures 5. Better portability 6. Commercially used Fourth Generation: 1. Smallest in size 2. Very reliable 3. Heat generated was negligible 4. No air conditioning was required in many cases 5. Minimal maintenance was required 6. Hardware failure was negligible 7. Very easy moveable 8. Totally general purpose 9. Very inexpensive 5

6 Q: Describe the types of computer according to capacity. Ans: Super Computer: These are the largest and fastest machine. Today where numerical computations are carried out at speeds of up to 50 million operations per second. Super computers are very sophisticated machines designed to perform complex calculations at fastest speed. Super computers are used to model very large dynamic systems, such as weather patterns, national or global weather forecasting, satellite tracking, cold-testing of atomic & nuclear weapon etc. Cray research & Intel are well-known producers of super computer. Mainframe Computer: A mainframe originally meant the cabinet containing the central processor unit of a very large computer. After minicomputer became available, the word mainframe came to refer the large computer itself. Large scale computer are very expensive machines and their main concern is to prove their cost effectiveness. These computers are valuable to the larger firms, which can provide concurrent & continuous applications, involving thousands of employs and hundreds of thousands of 6

7 customers accounts on a daily basis, for example, bank to keep track of millions of checks and deposits, airlines to schedule thousands of flights and make seat reservation & governments to keep track of their citizens etc. Minicomputer: Minicomputers are increasingly powerful & do almost anything that large computers do, only more slowly & at much lower cost than mainframes. These computers are smaller than mainframe & larger than microcomputers in size. A minicomputer is a multi-processor system having terminals attached to it and it is capable of supporting 4 to 200 users simultaneously. Micro-computer: Microcomputers are computers that are powered by micro-processors. Sometimes they are referred as single-chip processor or a system on a chip. Micro-computers or personal computers are the smallest computers, designed to be used by individuals for writing, illustrating, budgeting, playing games & communicating with other computers. 7

8 Q: Define different state between hardware & software. Hardware The physical components of computer & other attached input output devices are called hardware. All hardware components may be connected mechanically, electrically or electronically with each other. Hardware includes input devices, output devices, central processing unit, Backing storage, electronic circuit. Software Software is the set of instructions stored as program that makes the hardware run. They are designed by the manufacture or the programs to fulfill the requirement. Software are of two types: System software (DOS, Windows, Unix, Linux etc.) Application software (Microsoft Office, Photoshop, Flash, Inpage, Corel Draw etc) Q: What are the capabilities and limitation of computer? Ans: The Capabilities: The capabilities of computer are: Speed, repetitions, accuracy, logical operations, store and recall information, self-checking and self-operating. While its limitations are that it cannot generate information on its own, it cannot correct wrong instructions. It cannot come up with an original decision. Q: What is the difference between analog and digital computer? Analog Represent data continuously. Signal types-continuously varying electromagnetic wave. Transmission-means of transmission of analog signal without regret to their content. Applications-measurement of different physical quantities scientific applications. Digital Represent data discretely as 0s and 1s. Single types-sequence of voltage pulses over time. Transmission-concerned with content of signal. Application-business, science and home. 8

9 Q: Describe the classification according to capacity. Processing Power Size Applications Use User Super Computer Mainframe computer Extremely high Very high High Very large Scientific research development & Simulations of highly complex system Federal agencies research organization & Moderately Large Business, academic learning Centralized computing. Business university Medium Business, academic learning Centralized Computing Business university Minicomputer Microcomputer Moderate low to Small to handy Business, scientific, research & development academic learning General to specialize for variety of used & needs. Professional in business, Scientific & academic fields Q: Write a short story of the history and development of computers? Ans: History of computers: Today computers do much more than simply computer numbers. Name of early computing machine are ABACUS (3000 B.C), Napier s bones (1612 A.D), Slide Rule (1622 A.D), Pascaline (1642 A.D), Babbage s difference engine (1822 A.D), Babbage s Analytical engine (1832 A.D) and Hollerith s Tabulating Machine. These innovations were developed in a period termed as Dark age and Middle age of the computer. After Dark and Middle Ages, the computer technology and ideology improved and the period was termed as Modern age of computer. The computers in Modern age are categorized in five generations: 1 st generation (Vacuum Tube), 2 nd generation (Transistor), 3 rd generation (I.C), 4 th generation (microprocessor), 5 th generation (artificial intelligence). 9

10 Q: Describe the five generation with the help of generation table. Period Specialties First Generation Second Generation Third Generation Fourth Generation Fifth Generation Internal Computer Components Vacuum Tube Transistor s Integrated circuit IC large scale integration Very large scale Integratio n VLSI + microprocessor Microprocessor Size of the computer Very Huge Smaller the first generation, mini computer Much smaller than second generation, micro computer Very small Laptop Ting computer diary Speed of the computer Low speed compute r 10 times faster than first generation 100 times faster than second generation 10 times faster than third generatio n Much faster than fourth generatio n Storage devices Punch card and magnetic tapes Magnetic tapes Magnetic disk Disk storage, floppy disk Floppy disk, disk storage, CD-ROM Main memory Magnetic drum ROM, RAM PROM, DRAM EPROM, SPRAM EPROM, SIMM Programmin g language Quantity Used Machine language Hundred s Assembly language High level language Much easier high-level language Artificial language Thousands Ten Thousand Million Billion 10

11 Q: Define Napier s bones. Ans: Napier s Bone: In 1612, John Napier made the first printed use of the decimal point (after it had been invented in the Netherlands), and invented logarithms and several machines for multiplication. Best known of his machines was the bones or Napier s bones. This device consisted of a set of eleven bones or rods with numbers marked on them. Q: Define Babbage s difference engine. Ans: Babbage s difference engine: In 1812, Babbage noticed a natural harmony between machines and mathematics. Babbage s first attempt at solving this problem was in 1822 when he proposed a machine to perform differential equations, called difference engine. Powered by steam and large as a locomotive, the machine would have a stored program and could perform calculations and print the results automatically. Its goal was to output data as printed tables, a necessity for a number of financial, military, government, and engineering endeavors. Q: Define Babbage s Analytical engine. Ans: Babbage s analytical engine: Ten years later (after creation of difference engine) Babbage proposed a more general-purpose computer and called it an Analytical engine. The Analytical Engine would use steam for power, have storage capacity (memory of 1,000 numbers of up to 50 decimal digits long), and the ability to process instructions in any sequence. For input, the computer would use punched cards to enter the machine s instructions. 11

12 Q: Write Artificial Intelligence. Or fifth generation. Ans: Fifth Generation: Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth- generation computing is to develop devices that respond to natural language input and are capable of learning and selforganization. Q: What is Artificial Intelligence. Or fifth generation Artificial intelligence (AI) is an area of computer science that emphasizes the creation of intelligent machines that work and react like humans. Some of the activities computers with artificial intelligence are designed for include: Speech recognition Learning Planning Problem Solving Sir Sadiq s Computer Notes for Class IX. Composed by: Sir Sadiq, smsadiqnoori@gmail.com 12