IX Computer Studies - Complete Notes + Practicals and Flow Charts

COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 1 COMPUTER The word computer is derived from an English word „COMPUTE‟ which means “To Calculate”. The basic objective to build-up a computer is the formation of an electronic machine which can solve human problem in very efficient way. It can be define as: “Computer is an electronic device that accepts data and instructions (in form of programs) as input, process the data according to the given instructions and produce information as output.” A computer is divided into two basic parts  Hardware Software HARDWARE: All the physical and tangible (touchable) parts of computer are called HARDWARE. It not only include input and output components like (monitor, keyboard etc.) but also includes processing components, wires, ports and other physical devices. SOFTWARE: All those parts of computer which can only be visualized are called SOFTWARE. Software is the general name given to all those instruction which make a computer usable. Software is the nonphysical element of a computer system. Examples MS Windows, Ms Office etc. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 2 CAPABILITIES OF A COMPUTER A computer can achieve many objectives better then a human, means it is too quick, accurate and reliable as compare to a human. Some of the important capabilities of a computer are shown below. Speed: it is the prime factor of a computer due to which it is used now days. Any task which a normal person can complete in days, weeks and months a computer can complete it in seconds or less without any error. Accuracy: computer generated results are too much accurate. If any calculation is made by human then chances of error was there but computer never make any mistake by the time user provide wrong information. Memory: In terms of memory computer is also superior over humans. It can store information quite safely and securely and can retrieve it upon user‟s request. Artificial Intelligence: This is the latest area in computer science. Its purpose is to develop a machine which can think and behave like humans or to produce such qualities in a computer. Self-Checking: A computer has a built-in setup of self-checking it means it check itself continuously or analyze progress by its own self. Self-operating: During the execution of any program computer never need human help anymore it means once the program start computer executes it automatically. Disadvantages/Limitations of a Computer Human Dependent: a computer can not do anything by its own self. It always needed some information from user then on the basis of it produces output. Efficiency: It can only execute correct instructions but have no tendency to correct wrong instructions. Decision Making: During the execution of a program if computer got stuck then it has no ability to resolve the problem by its own. HISTORY OF COMPUTER DEVELOPMENT Abacus Abacus was invented by Chinese about 5,000 years ago. Its basic purpose is to done basic counting. It is consider as the first basic manual calculating device. Abacus consists of a rectangular wooden frame holding horizontal wires with beads strung on them. These wires or rods represent the unit, ten, hundred, and other digit places. Shifting the beads from one side to another COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 3 does counting. The abacus has remained in use for many centuries, mainly by the merchants to record trading transactions. NAPIER‟S BONES In the year 1612, John Napier first invents the decimal based calculating device. Afterwards this device was famous as “Bones” or “Napier‟s bones”. ”. It consisted of eleven bones with numbers marked on them. By placing these rods parallel (side by side) to each other, products and quotients of large numbers could be easily found. Slide Rule In 1622, Oghtred created the slide rule. It was based on john Napier algorithm. It is a manual calculating device, consisting of two rulers marked with scales, one sliding inside the other. Using this slide rule one can quickly multiply and divide two large numbers. Pascaline (Pascal‟s Calculator) In 1640, Blaise Pascal (1623-1662) started developing a device for the calculation of numeric digits. It was famous as “Numerical wheel calculator”. It was introduced in 1642. Its structure is consist on a brass rectangular box called as Pascaline having 8 moveable dials. This device can only add and subtract but cannot multiply and divide numbers directly. Compliment technique was also first introduced from here in which in order to subtract two numbers we take its first compliment, then second and then add both. This method is still used in many numerical programmes. Leibniz‟s Calculator In 1964, a German mathematician and philosopher, Gottfried Wilhem (1946-1716) , made some positive changes in pascaline calculator. Now it is able to multiply two numbers. BABBAGE DIFFERENCE ENGINE In 1812, Charles Babbage, an English mathematician noticed that long mathematical calculations were a series of repeated actions. From this point the idea of automatic machine was developed. In 1823, Charles Babbage started developing a mechanical which could perform mathematical computations by calculating the difference between them. This machine (engine) was based on pre-defined formulae.Thus; it was called the “Babbage Difference Engine”. It was to be controlled by a stored program and was to print the results automatically. BABBAGE ANALYTICAL ENGINE After working on the Babbage Difference Engine for 10 years, Babbage became more interested in the idea of a general-purpose, programmable computer called the “Babbage Analytical Engine”. The basic steps are: COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 4 STORE: To save the numbers or results. CONTROL: TO supervise the working of all units and their coordination. OUTPUT: To display the results of calculations. These five units later on become the basic blocks of modern computer. Since Babbage‟s design driven the path for the development of modern digital computers, due to this reason he is called “The Father of Computers” Hollerith‟s tabulating machine In 1889, an American scientist, “Dr. Herman Hollerith” developed a machine by applying Jacquard‟s punching concept. He developed a punch card of 35 inches in order to record data. That was the first time when punch card invent which are too common now a days in many formats. Hollerith bring this punch card reader to business world, which causes the formation of IBM (international business machine) in 1924. TYPES OF COMPUTER Computers can be differentiate into different types on the basis of  By Purpose By processing structure By Capacity BY PURPOSE According to the purpose, computers are classified as, Special Purpose Computer General Purpose Computer GENERAL PURPOSE COMPUTER Those computers which can perform multiple tasks are called GENERAL PURPOSE COMPUTER. They are also termed as versatile computers because they can perform many tasks very efficiently. They are widely used for business applications like payroll, accounts, inventory control etc. SPECIAL PURPOSE COMPURTER Any computer design specially to solve a particular problem is known as SPECIAL PURPOSE COMPURTER. For example, an ATM machine can only perform some certain operations for which it is designed therefore it is known as Special Purpose Computer. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 5 BY PROCESSING STRUCTURE According to the type of processing structure, computers are classified as,  Analog computer Digital computer Hybrid computer ANALOG COMPUTERS The word analog is derive from a word analogous which means similar or continues. Since working of this computer is based on continuous signaling therefore they are called ANALOG COMPUTER. They are mostly used in measuring instruments. DIGITAL COMPUTER All those computer work on the basis of Digital signals or discrete signals are called DIGITAL COMPUTERS. Now a day all the modern computers are digital means they are operating in 0 and 1. These computers are mostly fast and accurate with respect to their working. HYBRID COMPUTER It is the combination of analog and digital computers. It means it has both functionalities of digital and analog computers. These computers are used to solve various types of problems of science and engineering. These computers are widely used in robotics. BY CAPACITY SUPER COMPUTER The fastest computer in the universe is SUPER COMPUTER. They are not only fastest but also highest capacity computer. Due to these reasons they are very expensive. They are mainly used for research purposes. Structure of super computer consists on 1000s of processors along with large memory capacity. Examples of super computers are Crayon, Option Red, and Blue Mountain. MAIN-FRAME COMPUTERS Mainframe computer means the cabinet containing the central processing unit. It consumes less power as compare to Supercomputers. But they are also one of the most expensive computers. Its structure is spread over a large scale due to which it requires special support staff to maintain this computer. This computer requires special physical environment. It is usually used in large business or government sector. It consist on 100 to 1000s of processors. The COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 6 difference between Supercomputers and Mainframes is that Supercomputers are usually dedicated towards a certain task while mainframes are not. MINI-COMPUTER Mini computers are built to perform complex computations while dealing efficiently with a high level of input and output from users connected via terminals. They frequently connect to other minicomputers on a network and distribute processing among all the attached machines. Minicomputers are used heavily in transaction-processing applications and as interfaces between mainframe computer systems Minicomputers are smaller than mainframes, both in size and other facilities such as speed, storage capacity and other services. They are versatile in a sense that they can be fitted wherever they are needed. They are mostly used in scientific places for research purposes. MICRO COMPUTER Micro Computer is a Desktop (notebook-size) computing device that uses a microprocessor as its CPU (Central Processing Unit). Microcomputers are also called Personal Computers (PC‟s), Home Computers, Small-Business Computers, and Micros. These computers were introduced in 1970s. A micro computer consists of a microprocessor unit as its CPU, a memory unit, and is equipped with input, output and storage devices. These computers are most widely used in home computing, business applications, education, media, etc. The micro computers commonly used in homes are termed as PC‟s. LAPTOP COMPUTER The smallest computers in size, which look like an office briefcase are known as Laptop Computers. The laptop computers are also termed as “Portable Computers”. Laptop computers are typically used in businesses by businessmen especially during traveling and when they are away from office. They are equipped with a keyboard, a mouse, trackball, or other pointing device; and a Video display Unit or Liquid Crystal Display (LCD) to display information. Laptop computers usually have similar hardware and software as PC‟s, but they are more compact and have flat, lightweight LCD‟s instead of video display monitors. Day by day its size and weight is reducing and it is getting more and more popular among the computer users. The new version of laptop is known as “Note Book” while the smallest laptop is known as “Palmtop”. PROGRAMMING LANGUAGE A computer language by means of which we can write a computer program to instruct computer to do some particular job is known as PROGRAMMING LANGUAGE. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 7 A program is a set of instruction that directs the computer. it is a set of rule which directs a computer towards a certain goal. There are too many types of computer language as follows MACHINE LANGUAGE (LOW LEVEL LANGUAGE) A computer language which can easily understandable by a computer system is known as machine language. It is in binary format means 0‟s and 1‟s. Machine language is consist on a series of 0‟s and 1‟s which is computer readable format. For a computer programmer it is very difficult to understand this format. ASSEMBLY LANGUAGE Assembly language is the modified form of a low level language using few instructions and symbols. Statements are written in symbolic codes (mnemonics). The main reason to write program in assembly language because it is very close to low level language so computer can easily understand it. All the hardware related computer programmes (soundcard driver, VGA card driver) are written in assembly language. E.g. MASM , TASM etc. HIGH LEVEL LANGUAGE Language which is closer to human language (user understandable) but difficult for a computer to understand. All the programs written in high level language first translate into machine language by using any language translator. In High-level languages, common English words are used as instructions to the computer. High-level language statements resemble English phrases combined with the mathematical terms needed to express the problem or task being programmed. EXAMPLE COBOL, PASCAL, BASIC, RPG, ADA, FORTRAN etc. VERY-HIGH-LEVEL LANGUAGES OR 4GL‟S These languages provide all the facilities of high-level languages along with enhanced facilities of file handling and report preparation. And application generation Thus, they are regarded as the evolution of 3rd generation high-level languages, and are called Very-High-Level Languages, 4GL‟s (4th Generation Languages). EXAMPLE SQL, FoxPro, ORACLE, PROLOG etc. NATURAL LANGUAGES OR A.I. LANGUAGES OR 5GL‟S Natural Languages are highly sophisticated programming languages, which can interact with humans and situations in natural way. The main goal of these languages is to simplify the human‟s task and to communicate with the computer easily. e.g. PROLOG , AJAX. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 8 LANGUAGE TRANSLATORS The software which translates codes of human understandable programming languages into computer‟s machine language is called Language Translators. TYPES OF LANGUAGE TRANSLATORS  Interpreter Compiler Assembler INTERPRETER A program that translates instructions of high-level language into machine language, one instruction at a time, is called an Interpreter. The interpreters are slow in speed as compared to compilers. It takes a single line of the source code, translates that line into object code and carries it out immediately. The process is repeated line by line until the whole program has been translated and run. If the program loops back to earlier statements, they will be translated afresh (once again) each time round. This means that both the source program and the interpreter must remain in the main memory together, which may limit the space available for data. Perhaps the biggest drawback of an interpreter is the time it takes to translate and run a program including all the repetition, which can be involved. COMPILER A program that translates the entire code of a high-level language into machine code is known as Compiler. The original program is called “Source Program” and its machine translation is known as “Object Program”. A compiler can translate only that program which has been written in the language for which the computer is meant e.g., FORTRAN compiler is only capable of translating source program, which have been written in FORTRAN. Each machine requires a separate compiler for each high level language. Compiler can diagnose the following kinds of errors in a source program during translation. Illegal characters. Illegal combination of characters. Improper sequence of instruction in a program. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 9 A source program containing an error diagnosed by compiler will not be compiled into an object program. The compiler will print (display) a suitable message. ASSEMBLER A program that translates instructions of Assembly Language (low-level symbolic language) into machine language is known as ASSEMBLERS. In Assembly language, there is exactly one code corresponding to a machine code, called “MNEMONIC”. The assembly program is known as “SOURCE PROGRAM” while its translation into machine code is termed as “OBJECT PROGRAM”. Thus, the assembler‟s task is relatively easier than that of interpreters or compilers. Since each computer has its distinct machine code, thus has its own mnemonics. As a result, each computer has its own assembler. Linking process is always required in the end to execute the object program. GENERATIONS OF COMPUTERS Generations of computer science is divided into many distinct generations which are as follows. TYPES OFGENERATIONS  First Generation (1940 – 1956) Second Generation (1956 – 1963) Third Generation (1965 – 1971) Fourth Generation (1971 – 1981) Fifth Generation (1981 – Onward) FIRST GENERATION (19401956) First generation computers were consist on thousands of Vacuum Tubes. Computers size was large because of the great number of tubes that was used in it. The vacuum tubes required great amount of energy and they generated a lot of heat. Most of the data were entered into the computer through punch cards. UNIVAC was the first computer of this generation developed in the U.S in 1951. Remaining are ENIAC, EDVAC, IBM-709 etc. Advantages: Vacuum tubes were used as electronic components. They were declaring as the first Electronic digital computers. This generation computers were the fastest calculating devices of that time. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 10 Disadvantages: Computers are too much heavy in size. They require air conditioning. First generation computers produced large amount of heat due to vacuum tubes. SECOND GENERATION (19561963) In the second-generation computers the “Transistor” technology was implemented. Transistors are electronic devices that are built in 1947, and used in different digital electronic components. Usually it consists of small layers of silicon or germanium. Transistor was faster, less expensive, smaller and emitted less heat than vacuum tubes. Examples of 2nd generation computers are IBM-1401, UNIVAC-III, NCR 300 etc. Advantages: Computers of 2nd generation are smaller in size as compare to first generation computers. They are much more reliable. They generate less heat and Computations were performed in microsecond‟s .Due to above reason they are widely used commercially. Disadvantages: Computers of this age required Air conditioning. They require heavy maintenance work. Commercial production was difficult and costly as compare to the third generation computers. THIRD GENERATION (19641971) Third generation is the Integrated Circuits (IC‟s) generation. Computers of this generation were smaller, more efficient and more reliable than previous generations. Unlike transistors and vacuum tubes, integrated circuits (IC‟s) were used. Programming becomes easy in this generation of computers. Computers prices also decrease and computer becomes a very popular counting machine. Examples of 3rd generation computers are INTEL 4004 etc Advantages They are smaller in size as compare to previous generations. Reliability increase as compared to previous generations. Heat generation was decreasing .Hardware failure was also reduces. Very easy to shift from one place to another. Their production start on a very vast scale.. Disadvantages Air conditioning is still a great problem in it. IC chips production is a costly process so computer in this generation was a bit costly. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 11 FOURTH GENERATION (1971 1981) Integrated circuits were also used in this generation of computers. Initially they were used on a very small scale termed as Small Scale Integration (SSI). After some time the technology became more sophisticated and known as Large-Scale Integration (LSI). In LSI each chip consists of thousand of small electronic components on a single small board. These boards are known as microprocessor. In 1971, a powerful microprocessor chip INTEL 8008 was introduced. It was the first microprocessor, which is used in PC. Examples of Computers of 4th generation are IBM-3033, IBM system 34 etc Advantages: In fourth generation size reduces a lot. Computer becomes Very reliable. Heat generation was reduced. Much faster computation was possible. Easily portability because of their small size. Commercial production of computer was easier and cheaper. Disadvantages: Technology of IC manufacturing becomes too complex. FIFTH GENERATION (1981PRESENT) In fifth generation two new technologies are used for the production of IC chips, these technologies are,  Very Large Scale Integration (VLSI) Ultra Large Scale Integration (ULSI) In fifth generation computers become much faster as well as smaller as compare to the previous generations. The goal of the fifth generation is to have the computer which can understand human language and also can recognize voices. Artificial Intelligence (AI) is the basic field of interest in fifth generation. In this generation computer size and weight reduces and it becomes more and more popular among the computer users like Laptop or potable computers The new versions of laptop were introduced named as “Note Book” while the smallest laptops are termed as “Palmtop”. Advantages: This is the best generation according to computer‟s size and speed. Long bit processors were built. Small size Laptop computers introduced. Artificial intelligence languages developed directing us toward robotic world. Disadvantage: The only disadvantage of this generation computers are they make humans too much busy. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 12 COMPUTER COMPONENTS Central Processing Unit CPU (Central Processing Unit) is the main component of a computer system, which acts like a HUB or central point for the machine. The most important component in a CPU is microprocessor. The central processing unit (CPU) is the most significant part of the computer system directing most of the activities taking place inside the computer. It is also known as the “BRIAN OF COMPUTER”. Its basic objectives are  Generate control signals. Control the flow of data and instruction signal. Perform arithmetic and logic operation. Control all the other peripheral components. A General Microprocessor The main components of a microprocessor are Arithmetic Logic Unit. Control Unit Instruction unit. Memory Unit. Arithmetic and Logic Unit: Arithmetic means mathematical operations (+,-,*, /) while logic define as comparison between two numbers (<, >). As it name shows this component perform all these task. The ALU perform all arithmetic and logical tasks on data received from the primary storage based on instruction from control unit. Registers are another feature of ALU. This is the fastest memory accessible area already built-in inside ALU. These registers temporary store data during arithmetic and logical operations. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 13 Register is a type of volatile memory (temporary). Data currently processed is stores in registers. There are fourteen basic registers shared by ALU and CU. Control Unit: The most important part of a computer system is known as CPU and the most important component in the CPU is Control Unit (CU). CU checks the input output flow of data and signals its main responsibilities are,  Catch and execute instructions properly. Select program from memory and execute it. Control flow of signals and carries out instruction properly. It controls the INPUT/OUTPUT devices. Control unit works like a traffic controller, it is place at the central position and it controls each and every type of activity in CPU. It also directs the flow of data and information. Instruction Unit: This component is responsible for the execution of instruction. Especially all type of arithmetic and logic instruction. Its responsibility is the execution of an instruction according to user‟s requirements. Memory Unit: Memory is define as A place where data stores and can be retrieve correctly upon request. This whole process took place at a single unit called Memory Unit. This component is divided into two main types, Internal Memory External Memory Internal Memory: (Built-in memory) It is the basic memory of a computer system, also known as Primary memory. It is relatively fast as compare to external memory. It is divided into two types Ram and Rom. Ram (random access memory) is volatile memory i.e. its content will lost when power is turned off. It requires the electricity to retain its information. It is the minimum requirement of a computer to operate. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 14 Rom (Read only memory) is permanent memory unlike RAM it never loss data when power is turned off. Rom contains the computer‟s essential programs that are necessary to startup the machine. Rom only allows reading data we can never write or alter data stored in ROM. External Memory: The secondary memory of a computer system is known as external memory. It is the additional memory which user added just for his convenience. This memory is cheap as compare to internal memory but its speed is slow as compare to internal memory. This memory includes HDD (Hard Disk Drive), USB (universal serial bus) and floppy disks. INPUT/OUTPUT DEVICES Input Devices: All those physical devices used to enter data in computer or to instruct it what to do are called INPUT DEVICES. The purpose of input devices is to pass information to memory unit of the CPU and convert the data into signals (binary patterns) so that it can be transformed into machine readable format. Output Devices: The output devices are used to display the result generated by the computer. The purpose of output devices is to convert data and information expressed in electronic pulses into text or graphical format so that user can understand it easily. BUSES The collection of wires which control the flow of data from one part to another is known as a Computer Bus. Its main types are:  Data bus Address bus Control bus Data Bus: It is the transportation path of data signals in a computer. The speed of data bus is determined by the number of wires present in it. In data bus each wire transmits a single bit at a time so higher the number of wires greater will be the speed. Address Bus: COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 15 Connection between the CPU and memory which transmit the address, from which the CPU will read or write. Address is the physical memory location where data exist. So a bus connecting the CPU with main memory and used to identify particular locations in main memory is called Address Bus. Control Bus: This bus is the directing bus for data and address buses or it controls them. It is the most important bus among all the buses because it controls the flow of all type of computer signals. It decides which path to be follow to transmit data and information. PORTS A computer PORT is a socket at the back of a computer used to plug-in various computer related devices. “Or “, The intermediate connector between CPU and other peripherals are known as PORTS. Internally ports used for connecting disk drives, controllers and other sub-component. Externally ports are used to connect all I/O devices like Monitor, Printer, Scanner, Keyboard etc. There are basically two types of ports in a computer system Serial Ports: A port which can transmit a single bit at a time is known as serial port. It is called serial because all the transmission follows a particular series of flow of bits. It is used when flow of bits in small amount. A serial port has normally 9 or 25 pins and in old versions of architecture it is known as Male Connector. Parallel Ports: A port in which number of signals transmits at a same time (parallel to each other) is known as Parallel Port. This port is used when data flow is in large amount and a lot of data flow is required simultaneously like Monitor port. Parallel port contain 8, 16, 32 channels each contain a single bit. A parallel port also called a female connector contains 25 holes. This type of ports is used to connect tape drives like CD-ROM. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 16 SERIAL Vs PARALLEL PORTS Mother Board The most important component of a computer system after microprocessor is the Mother Board. It is the main circuit board which controls the overall processes including input and output signaling. Many extra features like video cards, sound cards, and some tines Modems are directly connected with the board. TO ACHIVE SOMETHING WHICH YOU NEVER HAD, DO SOMETHING WHICH YOU NEVER DID! SERIAL PORT PARALLEL PORT 1. Its flow of data is in a series of bits. 2. It is relatively slow. 3. It is used for small data transfer. 4. Used for keyboard and mouse. Its flow of data is in bulky amount of bits. It is relatively fast. It is used for large data transfer. Used for monitors. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 17 Device A hardware component which can convert data into computer understandable format or user understandable format is known as a computer Device. In short any sub-component of a machine is known a device. Peripheral devices All those devices which are attached to computer externally are known as Peripheral devices. INPUT DEVICES All those devices which are used to translate user provided data into machine readable form are called Input Devices. E.g. keyboard, mouse, trackball etc. KEYBOARD The most common input device used all over the world is Keyboard. It is a text based input device because by using it we can only input text data. It is just like a type writer and its working is also like a typewriter. It is sometime pronounced as QWERTY keyboard. It is because of the reason that the starting first character of the alphabetic portion consist on these six letters. A keyboard is divided into many parts some of which are as follows:  Alphanumeric keypad Numeric keypad Function keys Screen navigation keys Modifier keys. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 18 Alphanumeric Keypad: This name is consisting of two different word “Alphabets” and “Numeric”. As its name shows it consist on alphabets from A-Z and numeric digits. It also contain some special characters like !, @, # , $, %, ^, &, *, (, ) , { , } ,: , ” , < , > , ? Etc. it also contain some very important keys like Enter, Spacebar. These keys are also known as execution keys. Numeric Keypad: The numeric keypad, at the right side of keyboard and also at the top of keyboard is responsible for all numeric operation on computer so called numeric keys. It also contain basic numeric operations like +, -, *, /. Function Keys: Keys from F1 to F12 at the top of keyboard called function keys because they perform some extra functions like open, save and to run a program directly from keyboard. These are called function keys because each key contain a special function. Screen Navigation or Cursor Movement Keys: All those keys use to change screen properties like cursor and display properties are called Screen Navigation or Cursor Movement Keys. It contain  Arrow keys Home and End keys Page Up and Page Down keys Arrow Keys: There are four arrow keys to change arrow position. These keys are right, left, up and down keys to move cursor from one place to another according to user. HOME and END: HOME key move cursor at the beginning of a line and END key at the last character of the line. PAGE-UP and PAGE-DOWN: Page-up key move the cursor from 8 to 12 lines up from its current position. Just opposite Page-Down key moves the cursor from 8 to 12 lines down from its current positions. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 19 Modifier Keys: Shift, Alt, Ctrl these keys are normally use in combination with other keys to enhance their working so normally called Modifier keys. Some other keys are,  Delete Key: Use to delete a character. Insert Key: Use to insert a character between two letters without deleting any one of them. Esc key: The function of this key varies from program to program. Print Screen: Print the current screen position either in soft or hard format. MOUSE The most common pointing input device is Mouse. It is called pointing device because it is used to point a place on display screen and to select one or more action. The concept of mouse was first given by APPLE COMPUTERS with its brand new PC APPLE MACINTOSH. But now it is a basic need of each and every GUI (Graphical user interface) based operating system. Structure: Its body is made up of hard plastic with a ball at its base, and has a cable from the front. This structure is very similar to the real mice therefore this device is known as Mouse. It also contains two buttons relatively called LEFT and RIGHT buttons. Normally we use left button for most of the task. In between both buttons a scroll wheel is placed which is used to scroll up and scroll down the page without disturbing the actual position of the mouse. TRACKBALL Trackball is another pointing device work on exactly on the principle of mouse. Its structure is just the opposite structure of a mouse. Its ball is at the top while buttons are at the base. In order to use trackball user use its fingers to rotate the ball Advantage of trackball over mouse is simply that it require less space to use as compare to a mouse and it can use any where on any surface. Majority of the Trackball users have to face wrist pain. This is due to the reason during using mouse our whole hand moves while in trackball only our wrist is working which is its only disadvantage. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 20 SCANNER Scanner is the third most common input device after keyboard and mouse. It can input only image base data and convert it into digital signals. Normally scanners are available in black and white” and “colored” modes. The most common type of scanner are  Hand-Held scanner Flatbed scanner Sheet-Fed scanner Hand-Held Scanner: These scanners can be used by means of human hands. They are normally common and relatively cheap but their output quality is not so good because they require steady hand movement. These scanners are easy to use by passing it over the surface of image in steady position. Flat-Bed Scanner: This is the most common type of scanner also known as horizontal scanners. It produces relatively good result as compare to handheld scanners. It is due to the reason that object is static at its place and machine scan it automatically so both are steady at there places so end result is good. Their working is just like Photostat machine. The difference is it copy image into computer. Sheet-Fed Scanner: It contain a long continues sheet and print it continuously. It is normally used to scan large images like portraits but this is the type of scanner which is normally not used for official purpose. It is different from the above two scanners because it scan both side of images simultaneously. So their speed is also greater then any other scanners. JOYSTICK Joystick is also a pointing device. It consists of a vertical handle like a gearshift lever mounted on a base with one or two buttons. These buttons are generally known as triggers. They are primarily used for playing games. Joysticks are popular for flight simulator and driving games. Today joystick is consider as the basic device in order to design computer animations because its working is much smooth as compare to mouse. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 21 LIGHT PEN It is a light-sensitive, or pen-like device, connected by a wire to the computer terminal. It contains a photo detector which allow user to interact with the computer with a special design monitor. It is approximately 3.5 inches in length and 0.5 inches in width. It also contains cord at one of its end through which it connect to the computer. The user brings the pen closer to a desired point on the display screen and presses the pen button, which identifies that screen location to the computer. MICROPHNONE Microphone or MIC is another widely used input device but it is categorized in the multimedia family. Microphone is only use to input sound signals. Sound signals are transformed into digital signals by microphone so that computer can understand it. Now days it is widely used for communication purposes over internet and video conferencing. DIGITAL CAMERA The only input device which can input both still and motional pictures is Digital Camera. The basic difference between normal and digital camera is we have to use a thin sheet of film in normal camera while there is no concept of film in digital camera. Data store in it electronically and then can be store in computer. The image quality of digital camera is quite better as compare to normal camera. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 22 Output Devices All those devices which are used to translate computer generated signals into user understandable form are called Output Devices. Output could be of two types Softcopy output. It is the temporary output taken on monitor screen. which can only be visualized. Hardcopy output. Hardcopy means the output is in a form that can be physically touched. It is the permanent output taken on a paper by means of printer. It can be both visualized and storable physically. MONITORS Monitor is the most common and most basic softcopy output device. The basic structure of a PC is not complete without this component. The size of monitor screen is starting from 14 inches to onwards. If monitor screen is horizontal then called LANDSCAPE monitor and in case of vertical it is known as PORTRAIT monitor. TYPES OF MONITORS BY STRUCTURE According to structure monitors are divide into two types  CRT monitors Flat-Panel display. OR LCD (Liquid crystal display) monitors. CRT Monitors: CRT (cathode ray tube) monitors contain a tube at its center by using which electrons are fired at phosphor dots on the screen. The dots are grouped into pixels, which glow when struck by electrons. In color CRTs; each pixel contains a red, green, and blue dot. So by different combination of these colors many other colors appear. These are still the most common type of monitors used today. Flat-Panel display: Most flat-panel monitors use liquid crystal display (LCD) technology or Electro-luminescent (EL). It is a new semiconductor technology in which monitor contains a special liquid at the top of the screen instead of CRT. Due to which its size reduces. This is the reason flat-panel monitors take up less desk COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 23 space and are less in weight. BY COLOUR: According to color the basic type of computer monitors are  Monochrome monitors Gray-scale monitors. Color monitors. Monochrome Monitors: Mono means one and chrome stands for color. These are called monochrome monitors because it can show data by using only one color (normally dirty white or bright white). It has black color on its background. This is the most basic type of monitors. Gray-Scale Monitors: As its name shows gray-scale is a special type of monitor which can show almost 16 different shades of gray color but it is not famous as compare to other two. Color Monitors: Today the mostly used type of computer monitors is Color monitors. It has the capability to show 16 to1 million different colors. These are also called RGB monitors because their working based on three basic colors Red, Green, Blue. All the other color can be produced by using different combinations of these colors. Properties of a Monitor Screen Resolution: Resolution means number of pixel on a screen. It tells about the sharpness of image of a monitor screen. As much as the pixels as good as the image. Bandwidth: Bandwidth means the no of signal a monitor can handle at a time. As much as the bandwidth as higher will be the refresh rata and as good will be the output. Refresh Rate: Refresh rate is the number of times each second that the electron guns scan the screen's pixels. Refresh rate is measured in Hertz (Hz), or cycles per second. If refresh rate of a monitor is 72 Hz or higher then it is consider as a good monitor. Dot Pitch: Dot pitch is the distance between the phosphor dots that make up a single pixel. In color monitors, three dots (red, green, and blue) make each pixel. Dots pitch no greater than .31 millimeters consider reliable. Convergence: The clarity and sharpness of each pixel known as Convergence. It means how greater the picture quality is. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 24 PRINTERS The most famous hardcopy output device is printer. It accepts data in the form of both text and graphics from the CPU and then produces its hardcopy on paper. In early days it was not consider as important device with a computer system but now it is an essential device. With respect to structure, size, and cost printers are divided into two basic types,  Impact printers Non-impact printers. IMPACT PRINTERS: Impact means effect; it means these printers work by producing striking effects. Its basic structure contains a hammer behind an ink ribbon and in front of ink ribbon we place our paper so whenever hammer strikes the ribbon, it produce its impact on the paper. During the whole process they produce a great noise. There basic types are Daisy-Wheel Dot-matrix Line printers Daisy wheel: As its name shows this type of printer contain a wheel over which all the alphabets and different symbols are written. A hammer sticks the wheel from back on a particular character and as a result it produces the impact of that particular character. Daisy wheel can only print data in text format. Dot-matrix: Dot matrix printers are the most common type of impact printer. A dot matrix printer's head contains a cluster of pins. The printer can push the pins out to form patterns in rapid sequence. The pins press an inked ribbon against the paper, creating an image on the paper. Some dot matrix printers print 500 cps (characters per second). These printers are still popular due to their low printing cost. Line printer: COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 25 Printers which can print a whole line on a single strike of hammer are called Line Printers. Their hammer size is relatively larger then the others printers. They are fast but printing quality is not too good. Drum and chain printers are the examples of line printers. Non-Impact printers: These printers are also known as hammerless printers. They print by means of laser and ink spread technology. Examples are  Ink jet printers Laser printers LCD & LED printers Thermal printers Inkjet Printers: These printers print by means of ink cartridge. Its head spray ink on sheet of paper. These printers can print very high quality image and text output. Ink jet printers are available for color and black-and-white printing. Due to their efficient working they are widely used for offices and home use. Laser printers: Laser printers are the most famous type of non-impact printers. They use heat and pressure to bond particles to paper. Laser printers are available for color and black-and-white printing. Laser printers provide resolutions from 300 – 1200 dpi (dots per inch) and higher. Black-and-white laser printers usually produce 4 – 16 ppm (pages per minute). Laser printers produce higher-quality print than ink jet printers, but are more expensive. LCD & LED Printers: LCD (liquid crystal display) and LED (light emitting diode) work on the same mechanism of laser but in these we use different diodes for printing instead of laser beam. Normally they are not use for commercial purposes. Most of the LED and LCD printers are used in research laboratories. Thermal Printers: COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 26 Thermal means heat energy. It means this printer print by means of heat. These type of printer contain their head at hot state. So on making contact with a surface they produce their impact on it. They are widely used on industrial level. Characteristics of a Printer Basic characteristics of a printer are  Quality of print Speed Graphics Fonts Color Quality of print: The quality of print is divided into two types, either “LETTER” or “DRAFT”. Daisy wheel, inkjet and laser printers produce letter quality (relatively good) while most of the printers produce draft quality. Speed: Speed is another very important issue in printing. Printers speed is measured in CPS (characters per second) and PPM (pages per minute). Daisy wheel is the slowest printer print with 30 cps. Still Laser printers are the fastest printers which can print about 4 to 20 or more pages per minute. Line printer can print 3,000 lines in a minute. Generally speed of the printer is directly proportional to its cost. Graphics: Now-a-days graphics printing is another very important issue. Printer like laser, inkjet done this task with high quality while other like dot matrix are not capable of such kind of printing. Fonts: Font means size, shape and design of a letter. New printers are capable of working with different fonts. Old printers like dot-matrix can deal with a limited number of fonts. Color: In modern printing, color printing is very important. In different documents like maps, presentations and banners these color are of great importance. Some printers can print in only two colors black and white. All the other advanced printers can print by using thousands of colors. Resolution: It is measured in DPI (dots per inch). It means how sharp and good is the printing. Printing resolution from 600dpi to onwards consider as a better one. PLOTTERS COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 27 Plotters are specialized output devices to produce high-quality graphics in a variety of colors. They are mostly used for print-outs that are too large to be printed by printers. Plotters use mechanical, ink jet, or thermal technology to create large-format images for architectural or engineering uses. Now-a-days there are two basic types of plotters,  Pen plotters Electrostatic plotters Pen Plotters: Pen plotters structure based on a pen to do all the task regarding printing either images or text. Pen plotters are further divided into two types, Drum plotters Flatbed plotters Drum Plotters: It consists on a pen which writes over a paper which is roll over a drum. This kind of plotters are using for the printing of those banners of a fixed width with large length. Flatbed Plotters: It is a plotter in which paper is fixed over a surface and pen is move over its surface. It is normally used in engineering purposes because of its high quality image. Electrostatic Plotters: They work like a photocopy machine. They are faster and more expensive. They work by using electric charges (electricity). They consume a large amount of electricity but image quality is not so great as compare to drum or flatbed plotters. DUAL PURPOSE DEVICES Dual means “ two way ” so All those devices which can input and output at a time are known as DUAL PURPOSE DEVICES. There are many Dual Purpose Devices some of them are as follows: DISK DRIVE: Disk drive is the peripheral device that reads or writes the data from the disks (Hard disk drive, floppy disk, etc). This device contains a motor to rotate the disk at the constant speed. It also contains one or more heads to read/write data from these disks. The surface of a disk is divided into many sub parts. These are tracks, cylinders and sectors. In order to write data on a disk head reaches any free track (where no data is present already) and COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 28 write data over it. During this process disk is rotating constantly. This rotation is called as REDIAL Motion. When user wants to access some data from the disk then this head start searching the place of data over the disk. The time required for this is known as “SEEK TIME”. CD-WRITER: After HDD and floppy disk drive the most common drive use today is CD –Writer. It works with two types of diskettes CD-R(CD Recordable), CD-RW(CD Readable and writeable). Its speed is measured in “X” where 1X = 150 Kilobytes/Second Now-a-days all types are floppy devices are replaced by these CD-R and CD-RW. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 29 MEMORY and STORAGE Memory is a place to store data safe and secure. In computer science the word MEMORY identifies as the data storage in the form of a CHIP. While word STORAGE is termed for DISK, TAPES, etc. In computer memory is divided into two types.  Primary memory Secondary memory PRIMARY MEMORY Primary memory/Main memory/Built-in memory is the basic memory of a computer system which is the minimum requirement to operate a computer. It is faster and expensive as compare to secondary memory. It is divided into two main types: RAM (Random access memory) ROM (Read only memory) RAM (RANDOM ACCESS MEMORY): It is type of computer memory that can be accessed randomly due to this reason it is known as random access memory. It is a temporary memory means it loss its data when power is turned off that‟s why it is also known as VOLATILE memory. It is much faster then other memory areas. All the processes perform in a computer first load in the Ram then they could be accessed by the CPU. Ram is also divided into two types: SRAM (Static Ram) DRAM (Dynamic Ram) SRAM (STATIC RAM): As its name shows it keep the data once load in the memory (static data). Due to this reason it does not need to be refreshed. It is faster then DRAM but more expensive. It also lost data when power is turn off. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 30 DRAM (DYNAMIC RAM): Dynamic means multi-dimensional. It refreshes its data continuously. This is the most common type of RAM which is used now a day. Its refresh rate is approximately thousand times per second. Which also make it slow. It is relatively cheaper then SRAM. ROM (READ ONLY MEMORY): This is the highly secured memory area. Where all the routine of micro-processor have been written. It is only readable memory area. End-user can only read it. It is a permanent memory (non-volatile). I.e. data will not loss even when power is turned off. It also contains special programs used to boot a computer system. These programs are called FIRMWARE. Its main types are,  PROM (Programmable read only memory) EPROM (Erasable Programmable read only memory) EEPROM (Electrically erasable Programmable read only memory) PROM (Programmable read only memory): A special type of ROM chip on which we store our data. In this type of ROM data once stored can never be erased or removed. This is the most common type of ROM. EPROM (Erasable Programmable read only memory): In this type of ROM data can be erased when it is subjected to ultraviolet lights. This type belongs to advance technologies family. Where data can be altered after storing it. EEPROM (Electrically erasable Programmable read only memory): It is the most advance type of Rom that can be erased by exposing it to electricity (electric charges). After erasing data can also written on it due to this these type of ROM is known as alterable ROM. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 31 SIMM (single in-line memory module) SIMM (single in-line memory module) is a memory module in which data can travel only in one direction at a time. It consists on many RAM chips connected with the mother board. Normally RAM used in SIMM is DRAM. Its data flow is slow because it can not perform both input and out put operations simultaneously. It performs one operation at a time either INPUT or OUTPUT. Due to this reason it is known as single inline memory module. DIMM (dual in-line memory module) DIMM (dual in-line memory module) is a special memory module which can perform both input output operations simultaneously. This memory module is consisting on several RAM. It is because of the reason that module is divided into two parts, upper part is responsible for the input while the lower part is of output. In DIMM, data flow rate is 64 bit per second. Today all the modern computers are standardized on DIMM. UNITS OF MEMORY 8 bits = 1 byte 1,024 bytes = 1 kilobyte (KB) 1,024 kilobytes – 1 megabyte (MB) 1,024 megabytes = 1 gigabyte (GB) 1,024 gigabytes = 1 terabyte (TB) SECONDARY MEMORY Secondary storage is known as Auxiliary storage/external memory that is used to store large quantity of data. It is nonvolatile type of memory means data will not lost when power is turned off. Secondary memory is relatively slow and cheap as compare to primary memory. It cannot be processed directly by the CPU. Secondary storage devices used magnetic tape, magnetic disks and some optical disks like CDs etc. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 32 Floppy Disk It is the most commonly used secondary storage device used in the 1990‟s. it is made up of polyester film coated with metal oxide compound. The rotation speed of the film is from 45 to 70 rpm (rotation per minute). It is available in two sizes 5.25 inches and another one is 3.5 inches. With respect to storage ability floppies are available in two types single sided and double sided. Those floppies which can store data on a single side called single sided floppy disk. While floppies which can store data on both sides are known as double sided floppies. Today two new terms HD (high density) and DD (double density) are also associated with the storage capability of a floppy disk. Hard disk Hard disk is the most commonly used secondary storage device used now a days. Today without hard disk concept of computer is not getting complete. As compare to floppy hard disk is less portable (transferable). But due to its large capacity it is used widely. It is made up of rigid aluminum or glass disk of about 3.5 inches in diameter. They are also coated with oxide or any ferromagnetic substance. A hard disk is consisting of many magnetic plates. On the surface of these plates there are circular spaced area called TRACKS. That track over which writing and reading process is going on is simply known as sectors. The reading and writing process is done by means of a head and the process is termed as “SEEK”. The rotation speed of hard disk is normally from 4500 to 7200 rpm (rotations per minute). While is seeking time is measured in milliseconds. CD-ROM CD-ROM (compact disk read only memory) formally known as CD. It can store data in both formats text and graphics and audio or visual based data. It is a non-volatile optical disk. Its storage capacity is from 650MB to 1GB. Today it is the most common device for distribution of bulky (large) amount of data. Its speed is measured in “X” where COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 33 1X = 150 kilo bytes/second. Structure of CD-ROM consist of a spiral originate from the center and ending at outermost edge of the disc. These circular paths are called PITS. The distance between two consecutive pits is from 1.5 to 1.7 microns. In the initial period of CD-ROM there were some heating and vibration problems but now they are completely resolved. Magnetic Tape All those devices in which data stored follow a single pattern or data store in a straight path are known as SERIAL STORAGE DEVICES. A magnetic tape is also a serial storage device. Serial storage devices are always slower then dynamic storage devices. In serial to access data at the last of the magnetic tape we have to cover the complete length in order to catch the desired position. The width of the tape is normally 1.27cm (0.5 inches) and the length is about 731.5meters. On the back there is a ring used to write data on the disk. The magnetic tape is divided into logical blocks. A file consists of a single block at least. There are two other gaps known as Interblock gap: it separates logical block and at very small distance to each other. Interrecord gap: they are relatively wider and separate different records. Magnetic tape is used today because they are still the cheapest technology. They can store large amount of data for long periods. All the telecom companies in Pakistan use magnetic tape to store there call records. The only disadvantage of magnetic tape is that it is a sequential or serial media which means that you have to start from the beginning of the tape to access a record in the middle. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 34 DIFFRENCE BETWEEN PRIMARY AND SECONDARY MEMORY PRIMARY MEMORY SECONDARY MEMORY 1 It is a faster memory area. It is relatively slow. 2 It consists on both volatile (RAM) and non-volatile memory areas. It consists on only non-volatile memory areas. 3 Usually primary memory is not portable. Secondary memory is mostly portable except HDD. 4 It is relatively costly. It is cheaper as compare to primary memory. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 35 DATA NUMERIC DATA CHARACTER DATA REAL DATA INTEGER DATA ALPHABETIC DATA ALPHANUMERIC DATA FIXED POINT DATA FLOATING POINT DATA GRAPHICAL DATA STRING DATA DATA The word „Data‟ is derived from a latin word „Datum‟ which means a singular object which is in use. So we can say that all the useful objects, facts, and raw material are data for us. According to standard definition of data, Collection of facts and figures is known as Data Types of data Data may be categorized as follows DATA N ``` Numeric Data String data The most basic type of Data that contains alphabets (A-Z or a-z), digits (0-9), and special typing characters (@, #, !, ~ etc) is known as String Data. It is like a house no. Example, Sheet # 12/44 Abc, Karachi -75080 Alphabetic Data The data consist on only alphabetical characters (A -Z) are known as Alphabetic Data. Example, Career, Pakistan, Computer etc. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 36 Alphanumeric data The data composed of alphabets (A – Z ) with numeric ( 0 – 9 ) digits is known as Alphanumeric Data. Examples, RS 10000, Honda-125 Numeric data The data represented in the form of numbers ( 0 – 9 ) only is known as NUMERIC DATA. Numeric data normally consist of a decimal point () and a sign (,) along with numeric digits. Integer Data Integer data is known as decimal less number. It is in the form of whole numbers. It cannot contain a decimal point, however it could be a positive or a negative number. Example, 125, 94, 3678, 15 etc. Real Data Real data consists of numbers both having decimal points and non-decimal points. It can also deal with the exponent based numbers. Examples, 3.142, 6.023  1023, 9.1 E –31 etc Fixed Point Data Fixed point data includes an integer part, decimal point, a fractional part and a sign of „+‟ or „-„. Examples, 3.3333, 1.25, -273.15, etc. Floating Point Data Floating point data is used to represent very big numbers (like scientific values) or very small numbers which cannot be expressed in normal way. Examples, Avogadro‟s No.: 6.023 X 1023 or represented as 6.023E23, Electron‟s mass: 9.1 X 10-31 represented as 9.1E-31, Planck‟s constant: 6.625 X 10-34 represented as 6.625E-34, etc. Graphical data Data which consist on an image or a collection of images are called Graphical data. This particular type of data is consisting on images and photographs. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 37 Information The meaningful result of of data is known as information. Or Computer data that has been organized and presented in a systematic fashion to clarify the hidden meaning is known as information. Processing Input (Data) Output (Information) NUMBER SYSTEM A collection of numbers used in different form of computing are called NUMBER SYSTEMS. The most common type of number systems are  Binary number system Decimal number system Octal number system Hexadecimal number system The binary system Binary number system consist on only two digits 0 and 1. it is the backbone of modern computer science and digital science in which every logic is true (1) or false (0). Radix or base of binary number system is 2. Example: (100101)2 (110101)2 (101111)2 etc The decimal system The decimal system is consist on 10 numbers or symbols. These 10 numbers are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9; using these numbers, we can express any quantity. The decimal system, also called the base-10 system because it has 10 digits. The decimal system is important because it is universally used to represent quantities outside a digital system. Its radix (base) is 10. Example: (490)10 (5368)10 (6898)10 etc The octal system The octal number system has a base of 8, meaning that it has eight possible digits: 0, 1,2,3,4,5,6,7. Its radix (base) is 8. Example: (45210)8 (4568)8 (10151)8 etc The hexadecimal system The hexadecimal system has base 16. Thus, it has 16 possible digit symbols. It uses the digits 0 through 9 and the letters A for 10, B for 11, C for 12, D for 13, E for 14 , and F as the 15 digit symbols. Its radix (base) is 16. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 38 Example (AB04)16 (DG105)16 (F1630)16 etc COMPLEMENT The invert (flipping) of the given binary number is termed as its complement.  1‟s complement 2‟s complement 1‟s Complement The 1‟s complement of a number is found by changing all the 1‟s by 0‟s and 0‟s by 1‟s. Example 0 1 0 0 1 0 0 1 (Binary Number) 1 0 1 1 0 1 1 0. (1‟s Complement) 2‟s Complement The 2‟s complement of a binary number is found by adding 1 to the LSB (Least Significant Bit) of the 1‟s complement. 2‟s complement = (1‟s complement) + 1 Example 0 1 0 0 1 1 0 1 (Binary Number) 1 0 1 1 0 0 1 0. (1‟s Complement) + 1 (Addition of 1 to the LSB) 1 0 1 1 0 0 1 1 ARITHMETIC OPERATIONS ON BINARY NUMBERS Arithmetic in binary is much like arithmetic in other numeral systems. Addition, subtraction, multiplication, and division can be performed on binary numerals. 1. Addition The simplest arithmetic operation in binary is addition. Adding two single-digit binary numbers is relatively simple. Since each bit has only two possible values, 0 or 1, therefore there are only four possible combinations of inputs. These four possibilities (rules) are as follows, COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 39 Rules of Binary Addition  0 + 0 = 0 0 + 1 = 1 1 + 0 = 1 1 + 1 = 10 (carry 1 to the next more significant bit) 0 0 1 1 + 0 + 1 + 0 + 1 0 1 1 10 EXAMPLE BINARY SYSTEM 00011101 DECIMAL EQUIVALENT 29 + 00000111 +7 00100100 36 2. Subtraction To perform a binary subtraction first we have to represent the number to be subtracted in its negative form. This is known as its two's complement. The two's complement of a binary number is obtained by: Replacing all the 1's with 0's and the 0's with 1's. This is known as its one's complement. Adding 1 to this number by the rules of binary addition. Now you have the two's complement. Since each bit has only two possible values, 0 or 1, therefore there are only four possible combinations of inputs. These four possibilities (rules) are as follows, Rules of Binary Subtraction 0 -0 = 0 0 -1 = 1, and borrow 1 from the next more significant bit 1 -0 = 1 1 -1 = 0 3. Multiplication Multiplication in binary is similar to its decimal counterpart. Two numbers A and B can be multiplied by partial products: for each digit in B, the product of that digit in A is calculated and written on a new line, shifted leftward so that its rightmost digit COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 40 lines up with the digit in B that was used. The sum of all these partial products gives the final result. Since there are only two digits in binary, there are only two possible outcomes of each partial multiplication: If the digit in B is 0, the partial product is also 0 If the digit in B is 1, the partial product is equal to A Rules of Binary Multiplication  0 x 0 = 0 0 x 1 = 0 1 x 0 = 0 1 x 1 = 1, and no carry or borrow bits For example, the binary numbers 1011 and 1010 are multiplied as follows: EXAMPLE: 1 0 1 1 (A) × 1 0 1 0 (B) ---------0 0 0 0 ← Corresponds to a zero in B 1 0 1 1 ← Corresponds to a one in B 0 0 0 0 + 1 0 1 1 ---------------= 1 1 0 1 1 1 0 4. Division Binary division is again similar to its decimal counterpart: __________ 1 0 1 | 1 1 0 1 1 Here, the divisor is 101, or 5 decimal, while the dividend is 11011, or 27 decimal. The procedure is the same as that of decimal long division; here, the divisor 101 goes into the first three digits 110 of the dividend one time, so a "1" is written on the top line. This result is multiplied by the divisor, and subtracted from the first three digits of the dividend; the next digit (a "1") is included to obtain a new three-digit sequence: COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 41 1 __________ 1 0 1 | 1 1 0 1 1 -1 0 1 -----0 1 1 The procedure is then repeated with the new sequence, continuing until the digits in the dividend have been exhausted: 1 0 1 __________ 1 0 1 | 1 1 0 1 1 -1 0 1 -----0 1 1 -0 0 0 -----1 1 1 -1 0 1 -----1 0 Codes used in computer The usual way of expressing a decimal number in terms of a binary number is known as pure binary coding. There are many specialized codes used in digital systems. Some codes are strictly numeric like BCD, and other are alphanumeric (means they are used to represent numbers, letters, symbols and instructions) like ASCII and EBCDIC. The BCD code One of the most widely used representations of numerical data is the Binary Coded Decimal (BCD). BCD is the earliest code used to represent decimal digits into computer. In this code each integer of a decimal number is represented by a 4-bit binary number. 4-bit BCD table DIGIT BCD CODE 0 0000 1 0001 2 0010 3 0011 4 0100 5 0101 6 0110 7 0111 8 1000 9 1001 COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 42 The ASCII code ASCII stands for American Standard Code for Information Interchange. It is universally accepted alphanumeric code used in most computers and other electronic equipment. ASCII is quite elegant in the way it represents characters, and it is very easy to write code to manipulate upper/lowercase and check for valid data ranges. ASCII is essentially a 7-bit code which allows the 8th most significant bit (MSB) to be used for error checking. This bit is known as Parity bit. The EBCDIC code EBCDIC (Extended Binary Coded Decimal Interchange Code) is a character encoding set used by IBM mainframes. Unlike virtually every computer system in the world which uses a variant of ASCII, IBM mainframes and midrange systems such as the AS/400 tend to use a wholly incompatible character set primarily designed for ease of use on punched cards. (For an excellent page on punched cards, see Doug Jones's Punched Card Codes). EBCDIC uses the full 8 bits available to it, so parity checking cannot be used on an 8 bit system. Also, EBCDIC has a wider range of control characters than ASCII. The character encoding is based on Binary Coded Decimal (BCD), so the contiguous characters in the alphanumeric range are formed up in blocks of up to 10 from 0000 binary to 1001 binary. Non alphanumeric characters are almost all outside the BCD range. There are four main blocks in the EBCDIC code page: 0000 0000 to 0011 1111 is reserved for control characters; 0100 0000 to 0111 1111 are for punctuation; 1000 0000 to 1011 1111 for lowercase characters and 1100 0000 to 1111 1111 for uppercase characters and numbers. There are several different dialects of EBCDIC, and these tend to differ in the punctuation coding. The following table uses some fairly common EBCDIC codings. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 43 In these chapter the symbol „ means bar ‟-‟ on any variable or constant BOOLEAN ALGEBRA ALGEBRA Combination of known and unknown quantities is known as Algebra. BOOLEAN ALGEBRA An English mathematician famous as George Boolean introduces a form of mathematical logic known as Boolean algebra. It refers to all those type of expression whose answers are discrete. i.e. Tomorrow will be our paper. It is a Boolean statements because its two answers are possible either YES or NO. In Boolean algebra if answer is yes then it is represented as 1 and if answer is no then represented as 0. 1 is also known as a true case and 0 is known as false case. IMPORTANT TERMS 1. BOOLEAN ALGEBRA Variables are those quantities whose values are not confirmed. In Boolean algebra all type of variables are termed as Boolean variable. A Boolean variable is a symbol used to represent a logical quantity. A Boolean variable have only two possible values 1 or 0. These symbols 0‟s and 1's may be given different names like For 1 ON , HIGH , TRUE , YES For 0 OFF , LOW , FALSE , NO In Boolean algebra all variables are represented by capital letters. 2. BOOLEAN CONSTANT Constants are those quantities whose values are fixed. In Boolean algebra all type of constants are termed as Boolean constants. A Boolean constant value is either 0 or 1. 3. COMPLIMENTS Compliment means to invert (reverse) of the given value. Usually a complemented value is indicated by a bar over the Boolean variable or a constant. 4. TRUTH TABLE The tabular format of the combination of variables and constant is known as Truth Table. It is a standard way to check the authentication of a Boolean statement. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 44 5. LOGICAL OPERATORS Representation of a logical operation is known as logical operator. The logical perorations combine two or more relational expressions and form a logical statement which results in either TRUE (1) or FALSE (0). They are also used for making decisions regarding the program flow. 6. BOOLEAN EXPRSSIONS In Boolean algebra an expression that results in a value of either TRUE or FALSE is termed as Boolean expression. A Boolean expression is consists of statements, which are represented by variables and connected by logical operators. STATEMENTS RESULT 2 = 4 /2 TRUE Today is Friday FALSE Sun revolve around earth FALSE Man is mortal TRUE STANDARD FORM OF BOOLEAN EXPRESSIONS SUM OF PRODUCT (SOP) WHEN TWO OR MORE PRODUCT TERMS ARE SUM BY BOOLEAN ADDITION THE RESULTING EXPRESSION IS SUM OF PRODUCT EXPRESSION A + A . B . C A . B + C . D PRODUCT OF SUM (POS) WHEN TWO OR MORE SUM TERMS ARE MULTIPLIED AND THEN ADDED THE RESULTING EXPRESSION IS KNOWN AS PRODUCT OF SUM. (A + B) ( B + C + D) = AB + AC + AD + BB + BC + BD 7. BOOLEAN FUNCTION In Boolean algebra a Boolean function is an expression that is formed with variables, binary operations OR, AND, unary operator NOT, parenthesis and an equal sign. A Boolean function is consisting of all the variable in the Boolean expression. Like, W = X + Y . Z Now its Boolean function will be, W = F(X, Y, Z) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 45 8. LOGICAL OPERATORS The important Boolean operators are 1. NOT OPERATOR (-) A Boolean operator that returns the reverse value i.e. Value is TRUE if its operand is FALSE, and value is FALSE if its operand is TRUE. It s represented by a bar over a variable or a constant value. 2. AND OPERATOR ( .) A Boolean operator that returns a value TRUE if both of its operands is TRUE, otherwise it returns FALSE. It is represented by a dot operator between both the operands. 3. OR OPERATOR ( + ) A Boolean operator that returns a value TRUE if either (or both) of its operands are TRUE. It is represented by a plus sign between both the operands. LAWS OF BOOLEAN ALGEBRA In order to solve a Boolean expression we have to follow certain rules. By using these rules we can simplify a Boolean expression.  COMMUTATIVE LAW  A + B = B + A A . B = B . A ASSOCIATE LAW  (A + B) + C = A + (B + C) (A . B) . C = A . (B . C) A B A . B 0 0 0 0 1 0 1 0 0 1 1 1 A B A+B 0 0 0 0 1 1 1 0 1 1 1 1 COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 46  DISTRIBUTIVE LAW  A . (B + C) = A . B + A . C DEMORGAN‟S LAW Demorgan a famous mathematician done a lot of work on set and number theory. On the basis of his working he present a law later on famous as DEMORGAN‟S LAW. According to Law, The inverse of the OR of two terms is equal to the AND of the inverse of individual terms and vice versa. _____ _ _ (A + B) = A. B ____ _ _ (A. B) = A + B BOOLEAN RULES (NOTE: symbol ( „ ) means bar ( -) or not of the variables and for proofs see class lectures 1. A + 0 = A 2. A + 1 = 1 3. A . 0 = 0 4. A . 1 = A 5. A + A = A 6. A . A = A 7. A + A‟ = 1 8. A . A‟ = 0 9. A‟‟ = A 10. A + A .B = A 11. A + A‟ . B = A + B 12. (A + B) . (A + C) = A + B . C CONSTRUCTION OF TRUTH TABLE Construct truth table for the following Boolean expressions. F = A + B F = (A+B+C) . (A+B‟+C) . (A+B‟+C‟) . (A‟+B+C‟) . (A‟+B‟+C) TRUTH TABLE F = A + B A B F 0 0 0 0 1 1 1 0 1 1 1 0 COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 47 F = (A+B+C) . (A+B‟+C) . (A+B‟+C‟) . (A‟+B+C‟) . (A‟+B‟+C) A B C A‟ B‟ C‟ A+B+C A+B‟+C A+B‟+C‟ A‟+B+C‟ A‟+B‟+C F 0 0 0 1 1 1 0 1 1 1 1 0 0 0 1 1 1 0 1 1 1 1 1 1 0 1 0 1 0 1 1 0 1 1 1 0 0 1 1 1 0 0 1 1 0 1 1 0 1 0 0 0 1 1 1 1 1 1 1 1 1 0 1 0 1 0 1 1 1 0 1 0 1 1 0 0 0 1 1 1 1 1 0 0 1 1 1 0 0 0 1 1 1 1 1 1 SIMPLIFICATION OF BOOLEAN EXPRESSIONS Here the symbol ( „ ) means ( -) in any expression. 1. XY + X‟Y = Y(X+X‟) X+X‟=1 = Y 2. (X+Y)(X+Y‟) = X + XY‟ + XY + YY‟ = X(1 + Y + Y‟) + YY‟ = > X( 1 + 1 ) 1+1=1 = X 3. (A + B)‟ . (A‟ + B‟)‟ = (A‟. B‟) (A” .B”) = A‟B‟AB A‟' = A = 0 A‟. A=0 4. Y. (WZ‟ + WZ) = YW (Z‟ + Z) = YW A‟+A=1 & A.1=A 5. ABC + A‟B‟C + A‟BC +ABC‟+A‟B‟C‟ COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 48 = A‟B‟C + A‟B‟C‟ + ABC + ABC‟ + A‟BC = A‟B‟(C + C‟) + AB(C + C‟) +A‟BC = A‟B‟ + AB + A‟BC A‟+A=1 & A.1=A = A‟B‟ + B[A + A‟C] = A‟B‟ + B[A(1 + C) + A‟C] = A‟B‟ + B[A + AC + A‟C] = A‟B‟ + B[A + C(A + A‟)] = A‟B‟ + B[A + C] = A‟B‟ + AB +BC 6. ((CD)‟ + A)‟ + A + CD + AB = (C‟ + D‟ + A)‟ + A + CD + AB DEMORGAN‟S LAW = ACD +A + CD + AB DEMORGAN‟S LAW = CD(A + 1) + A(1 + B) = CD + A A+1 = 1 = A + CD 7. BC + AC‟ + BCD + AB = BC(1 + D) + AC‟ + AB = BC + AC‟ + AB A+1=1 8. A(A + B) = AA + AB = A + AB A.A=A = A(1+B) = A A+1=1 9. A(A‟ + AB) = AA‟ + AAB = AB 10. BC + B‟C = C(B + B‟) = C 11. A(A + A‟B) = AA + AA‟B = A 12. AB‟C + A‟B‟C + A‟BC = AB‟C + A‟C(B‟ + B) = AB‟C + A‟C = C(AB‟ +A‟) = C (A‟ + B‟) = A‟C + B‟C 13. (A + B‟) ( A + C) = AA + AC + AB‟ + B‟C = A + AC + AB‟ + B‟C = A(1 + C) + AB‟ + B‟C = A + AB‟ + B‟C = A(1 + B‟) + B‟C COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 49 = A + B‟C 14. A‟B + A‟BC‟ + A‟BCD + A‟BC‟D‟E = A‟B + A‟BCD + A‟BC‟ + A‟BC‟D‟E = A‟B (1 + CD) + A‟BC‟(1 + D‟E) = A‟B + A‟BC‟ = A‟B(1 + C‟) = A‟B 15. AB + (AB)‟C + A = AB + (A‟ + B‟)C + A = A(1 + B) + A‟C + B‟C = A + A‟C + B‟C = (A + A‟) (A + C) + B‟C = A + C + B‟C = A + C (1 + B‟) = A + C 16. (A + A‟) . (AB + ABC‟) = AB + ABC‟ = AB(1 + C‟) = ABC COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 50 K-MAP (KARNAUGH MAP) In 1950‟s, Maurice Karnaugh a telecommunications engineer at Bell Labs, introduces a very useful tool to minimize Boolean expressions without having to use Boolean algebra rules, equations or truth tables. Karnaugh map (K-map) is a graphical representation of truth table. Where every input combination is represented by a cell (square). We simplify a Boolean expression by placing certain values correspondingly to each square then solving them by combination rules. The Karnaugh map is also known as a K-map. A k-map formation depends on the number of variables in a Boolean expression. Some are as follows, THE 2-VARIABLE KARNAUGH MAP k-map of 2 variable is consist of 4 cells (Boxes). Lat the variables are A and B. assign one variable in horizontal and one in vertical directions. THE 3 VARIABLE KARNAUGH MAP The 3-vaiable Karnaugh Map is consist of 8 cells (Boxes). We have to draw group among these 8 cells in order to solve any Boolean expression. K-MAP SIMPLIFICATION RULES  Construct the truth table of the given Boolean function. Represent the given function in K-map by placing value 1 for each product that return 1 as output in the truth table. Fill the remaining cells by entering 0 in them. Construct groups among adjacent cells. o Size of group should be in the range of 2n. means 2,4,8,16…. . o Construct group among only those cells in which value is 1. o Number of groups should be as minimum as possible. o The size of group should be as maximum as possible. Generate product term for every group. Construct simplified expression in sum of product form Small is the number of people who see with their eyes And think with their minds. (ALBERT EINSTEIN) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 51 COMPUTER SOFTWARE Software All those parts of a computer system which can only be visualized by a computer user are called computer software. It can also be define as all the intangible parts of a computer system are called Computer software. There are two basic types of computer software  System software Application software System software All those computer software which can run a computer machine or can perform administrative tasks are called system software. In broad manner they are also known as “Operating System” which can operate a computer system. For example: All type of operating system falls in the category of system software Windows 9X Linux Ubuntu Classification of System software Following are the major components of system software Operating system Language Translators Utility Programs Loaders Linkers Editors Operating system An operating system is particular software which is responsible for all the operations of a computer system. . It performs basic tasks such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. In short an operating system is responsible for all the input, output and processing tasks for a computer system COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 52 Language Translator A computer program which can convert human language into machine language is known as a language translator. Types of language translators  Interpreter Compiler Assembler Interpreter A program that translates instructions of high-level language into machine language, one instruction at a time, is called an Interpreter. The interpreters are slow in speed as compared to compilers. It takes a single line of the source code, translates that line into object code and carries it out immediately. The process is repeated line by line until the whole program has been translated and run. If the program loops back to earlier statements, they will be translated afresh (once again) each time round. This means that both the source program and the interpreter must remain in the main memory together, which may limit the space available for data. Perhaps the biggest drawback of an interpreter is the time it takes to translate and run a program including all the repetition, which can be involved. Compiler A program that translates the entire code of a high-level language into machine code is known as Compiler. The original program is called “Source Program” and its machine translation is known as “Object Program”. A compiler can translate only that program which has been written in the language for which the computer is meant e.g., FORTRAN compiler is only capable of translating source program, which have been written in FORTRAN. Each machine requires a separate compiler for each high level language. Compiler can diagnose the following kinds of errors in a source program during translation. Illegal characters. Illegal combination of characters. Improper sequence of instruction in a program. A source program containing an error diagnosed by compiler will not be compiled into an object program. The compiler will print (display) a suitable message. Assembler A program that translates instructions of Assembly Language (low-level symbolic language) into machine language is known as ASSEMBLERS. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 53 In Assembly language, there is exactly one code corresponding to a machine code, called “MNEMONIC”. The assembly program is known as “SOURCE PROGRAM” while its translation into machine code is termed as “OBJECT PROGRAM”. Thus, the assembler‟s task is relatively easier than that of interpreters or compilers. Since each computer has its distinct machine code, thus has its own mnemonics. As a result, each computer has its own assembler. Linking process is always required in the end to execute the object program. Utility programs All programs used to enhance the capabilities of existing programs (operating system), or to provide services not provided by other programs (operating system) are called utility programs. Examples are  Virus protection software (Norton Antivirus etc) Memory management software ( MemPro, RAM Booster etc) Animation software (MAYA, Dream weaver ) Data management software Its basic responsibility is to manage all the data in computer system. Data-Management software include database and file management programs that manage data for an Operating System. Data management means to keep a certain save file at its memory location and to keep track of each file in a computer. Loaders The loader loads a program from secondary memory to main or primary memory for execution and removes it from physical memory when its job has finished. Linkers The software component that links different instructions of the object program with peripheral resources, considering the hardware type and operating system of the computer is called Linker. Editors An area of a operating system where we can write data, can save it and then alter it is known as Editor. The instructions in a written program can be altered and updated using an editor. Any type of program can be written in an editor, while many programming languages have their separate editors. Like, In DOS the famous command “EDIT” open the dos editor while in windows we use NOTEPAD as a primary editor. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 54 Application software All those compute software which runs due to a system software are called Application software. They are also known as secondary software and can enhance different capabilities of a computer system. For example:  Word processing software Database management system Graphical animation Types of Application Software General purpose application software Special purpose application software General purpose application software General purpose application software‟s are designed to accomplish a common task required by most users. It is a kind of software which provide a same solution problem. Like MS-Office provides same functionality all over the world so its known as a general purpose application software. Some examples are given below Editing MS WORD Accounting MS EXCEL Data Base MS Access Internet Browsers Internet Explorer Some software‟s of this type (General Purpose Application Software) are available without any cost; they are called "Shareware”. The purpose behind them is either to advertise the product or to provide an overview of the complete software before its final release. Special purpose application software Application software which is design to resolve a particular problem of an organization is known as Special purpose Application Software. They are specially design to resolve a specific problem and are not available as common software in market. The price for this software depends upon the complexity of the problems being faced by the client, as well as upon mutual understanding of the client and the software designer/house. Warranty and maintenance of the software for a limited time is also offered. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 55 BEST OPERATING SYSTEMS IN COMPUTER HISTORY MS – DOS History MS-DOS was originally released in 1981. 86-DOS was designed to run on the Intel 8086 processor. Microsoft negotiated a license for 86-DOS from SCP in December 1980 for $25,000, then re-licensed 86-DOS to IBM. Microsoft then acquired all rights to 86-DOS for only $50,000 from SCP in July, 1981, shortly before the PC's release. INTRODUCTION DOS stands for Disk Operating System. DOS controls the computer's hardware and provides an environment for programs to run. Everything you can do with a GUI can be done at the DOS prompt. There are two types of commands in DOS, internal and external. Internal commands are part of the command processor, whereas external commands exist as executable files. The entire operating system is small enough to fit on a floppy disk. UNIX UNIX is an operating system which was first developed in the 1960s, and has been under constant development ever since. UNIX systems have a graphical user interface (GUI) similar to Microsoft Windows which provides an easy to use environment. MS WINDOWS The only operating which is declare as the operating system of the 21st century is none other then MS-WINDOWS. Since its arrival it becomes the first choice of each computer user. Till 2008 there are a number of windows version in the market specially XP, NT SERVER and VISTA. The interesting element about windows operating system is, its name is windows because for each option and instance this operating system contains a separate window therefore this operating system is known as windows. If you can't explain it simply, you don't understand it well enough ! ALBERT EINSTEIN COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 56 MS-DOS COMMANDS An operating system is of two type in terms of communication  CLI -Command Line Interface (like DOS) GUI-Graphical user Interface (like WINDOWS) Command Command is a way to communicate with your computer system. We can instruct our computer by typing a command at command prompt and tell it what to do. Like „C :\> CLS‟ means clear the current screen and this whole process completed by typing the whole command through keyboard. In DOS there are two basic types of commands Internal command External command Internal command All those command already built-in in „COMMAND.COM‟ file are called Internal commands. They remain in the main memory until the computer is in workin state. Some important internal commands are listed below External Commands The External Commands are stored in the disk as a separate file. They are loaded into the RAM only when the user needs them. Some important external commands are listed below BACKUP CHKDSK DISKCOPY FORMAT GRAPHICS LABEL RECOVER RESTORE SORT SYS XCOPY MODE INTERNAL COMMANDS 1. MD OR MKDIR Purpose Creates a new sub directory in the current directory or the specified one DEL CD CLS COPY DATE DEL DIR TYPE MD PATH PROMPT RD REN TIME COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 57 Syntax MD [drive :][path] MKDIR [drive :][PATH] 2. CD OR CHDIR Purpose Changes the current directory to the specified directory Syntax CD [drive:] [path] CD [..] 3. DIR Purpose Displays a list of files and sub-directories in a directory Syntax DIR [drive:] [path] [filename] [/p] [/w] DIR/P displays the contents of the directory one page at a time. DIR/W displays names of files and sub-directories of a directory using wide list style When DIR without any parameters is given, all the contents (files and sub-directories) of the current directory are displayed. 4. CLS Purpose Clears the screen Syntax CLS 5. COPY Purpose Copies one or more files from one location to another location It does not destroy the original file but only makes a duplicate of it. Syntax Copy source [destination] Source specifies the file(s) to be copied Destination specific the directory and/or filename for new copied files COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 58 6) DATE Purpose Displays or sets the system date Syntax DATE [mm-dd-yy] WHERE mm : month dd : date yy : year DATE without any parameters will display the current date and asks for a new one. Then pressing ENTER keeps the same date. 7) TIME Purpose Displays or sets the system time Syntax DATE [hh:mm:ss] WHERE hh : hour mm : minute ss : second TIME without any parameters will display the current time and asks for a new one. Then pressing ENTER key keeps the same time. 8) DEL OR ERASE Purpose Deletes one or more files Syntax DEL [drive:] [path] filename ERASE [drive:] [path] filename MULTIPLE files can be deleted by using wildcards. 9) EXIT Purpose Returns to the previous software (normally WINDOWS) Syntax EXIT 10) PATH Purpose Displays or sets a search path for executable files COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 59 Syntax PATH [drive:] [path] PATH ; PATH without parameters displays the current path. 11) RD OR RMDIR Purpose Removes a directory form the current directory or the specified one Syntax RD [drive:] [path] RMDIR [drive] [path] 12) VER Purpose Displays the DOS version Syntax VER 13) RENAME OR REN Purpose Renames a file/directory or multiple files/directories SYNTAX: REN [drive:] [path] name1 name2 RENAME [drive:] [path] name1 name2 14) VOL Purpose Displays the label and serial no. of a disk volume Syntax VOL [drive:] 15) BREAK Purpose Sets or clears CTRL or CTRL+BREAK setup Syntax COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 60 BREAK [ON | OFF] BREAK without a parameter displays current setting. EXTERNAL COMMANDS 1) BACKUP Purpose To save files in disk(s) as a backup 2) CHKDSK Purpose To check a disk for any error 3) DISKCOPY Purpose To copy the contents of one floppy disk to another Syntax DISKCOPY drive1:dreve2: 4) FORMAT Purpose To prepare a disk for Ms DOS Syntax FORMAT drive:[/V][/S][/Q] /V will also set the volume label after format /S copies System files to the formatted disk /Q perfoms a quick format (delete files only) 5) LABEL Purpose To give a name (label) to a disk Syntax LABEL [drive:] [label] COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 61 6) MODE Purpose To set screen, printer and other I/Q devices 7) RECIVER Purpose To recover files from deleted disk 8) RESTORE Purpose To restore the backup disk(S) 9) SORT Purpose To sort alphabetic data 10) SYS Purpose To make a system disk 11) XCOPY Purpose To copy a directory and sub-directories of a disk If I had eight hours to chop down a tree, I'd spend six hours sharpening my axe (ABRAHAM LINCOLN) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 62 INTRODUCTION TO WINDOWS OPERATING SYSTEM Operating System Computer software which can handle all the hardware attached to a computer and can also control all the software is known as Operating System. Operating systems are divided into basic two types.  Graphical user interface (GUI) Command line interface (CLI) Graphical user interface (GUI) A graphical user interface is one on which all the basic tasks are performed through graphical environment i.e. on pictures and images like windows. Command line interface (CLI) In a command line interface all the basic tasks are performed by typing commands on the console screen. The best example is MS-DOS. BASIC COMPONENTS OF WINDOWS OPERATING SYSTEM Desktop The Microsoft Windows desktop is divided into various parts. From the upper left to the lower left side of the screen, there are small pictures or images called icons. Each one is used to make the computer do something. a desktop is the metaphor used to portray file systems. Icons A computer icon is a small picture, which represents a file, folder, application or device on a computer system. It is the backbone of any GUI like windows because a user has to perform most of is task on these Icons. The icons on desktop can be renamed by right clicking on them and selecting rename, similarly they can be deleted by right clicking and selecting delete. Following is the major categories of icon, System Files Icons Application Files Icons Executable files Icons Folder Icons Drive Icons COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 63 My computer My Computer is the most important icon for a computer user. It is a standard icon for any version of Microsoft windows and is very useful; we can access the different drives (Hard Drive, Floppy Drive, Network Drives) inside My Computer. My Documents This folder containing the most important files and data of a computer user. It is a good habit to keep your data inside My Documents instead of your Desktop. Internet Explorer Internet is the greatest invention of 21st centuary.This icon is a shortcut to Microsoft's Internet Explorer program, Internet Explorer is used to view web pages on the internet The Internet Explorer icon launches the Internet Explorer browser. It is used for browsing purposes. Network Neighborhood Network Neighborhood is used to communicate with other computers if we are the part of a computer network. The Network Neighborhood Icon points to a folder that contains links to any other computers that are in the network. Recycle Bin When we delete a file, Windows will place the file into the recycle bin instead of deleting. This operation allows us to restore the file if we deleted any file by mistake. Folder A folder is a general icons inside which we can save other icons or files (data). Folder is one of the containers you will be using to store or locate your work. The My Computer, Network Neighborhood, and Recycle Bin programs are a kind of folder referred to as System Folder(s), they come standard with your computer. They have fancy (artistic) icons. The folders you create are in yellow color with a small tab and are considered "user created" folders. Short cut Icons with an arrow in the lower left corner (picture on left) are shortcut icons. If you double click on them they will open up the program that the icon displays on it. Task bar The taskbar is usually located on the bottom of the desktop. The Start button, active program buttons, and the system tray are located on the Taskbar COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 64 System tray System Tray is in the lower right hand corner of the Windows Desktop. The system tray contains a display of the current computer time, and the icons representing the programs activated when Windows first starts up. Quick Launch Bar A very useful area of the taskbar is the quick launch bar. This bar allows direct access to the programs, files or a folder with just one click. COMPUTER VIRUS A computer virus is a disastrous kind of software which is capable to destroy or washed up user‟s data and can steal its personal information for any unauthorized use. Viruses are divided into several categories like WORM, TROJEN HORSES, TIME BOMBS, FILE INFECTOR, MACRO VIRUSES and BOOT SECTOR VIRUS. Trojan horse: It destroy the middle data of a file and capable of to write any unusual routine their. Normally this virus enters in a users system by a game or any other interesting application especially from the internet. Time bombs: Time bomb as this name shows this virus waits for a certain event or data running moment, and as it reaches it explodes out with its full intensity. They are also known as logic bombs. File infector: This kind of viruses infect a certain kind of file only e.g. *.exe, *.sys, *.com, *.dll etc. their common source is a floppy or sometime internet as a floppy come into contact with a drive this virus transfers to the hard disk. Macro virus: Macros are small programmers that execute some commands normally present in Ms Office utilities. If a virus infects the computer by macros then simply termed as macro virus. Boot sector virus: Area from where operating system takes up called as boot virus. The most horrible kind of viruses which enters in the booting area and destroys all the booting files or create interruption during booting routine. Worms A worm is a program which spreads its destruction on a network of computers. The WORM is an acronym for write once Read Many. They exhibit the same characteristics as viruses, and go through the same phases. Bacteria Bacteria are that program that copies itself or another program repeatedly into memory or onto a disk until no more space is left. A bacteria usually does nothing special, except replicating itself or some other program, finally taking up all the processor capacity, memory space or disk space. Consequently, the user can no longer utilize them. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 65 ANTIVIRUS Software working against a virus called Anti virus. A anti virus never bring our lost data but it can only create resistance on the way of a virus or try to reduce or completely block its effect. Most common anti viruses are  Norton anti virus MacAfee anti virus AVG Kaspersky anti virus MacAfee anti virus IBM anti virus Dr.Solomon anti virus Microsoft Windows The term Windows collectively describes any or all of several generations of Microsoft (MS) operating system (OS) products. Microsoft Windows was the first operating system which make a blast in the history of OS. Microsoft launches first version of windows as Windows 3.1 which proved to be an ordinary version of it. In 1995 when Microsoft windows launched Windows 95 it proved to be a great hit for Microsoft then Windows 98 and Windows XP. Microsoft released Windows 2000 in February 2000. The consumer version following Windows 98 was Windows Me (Windows Millennium Edition). Released in September 2000, Windows Me attempted to implement a number of new technologies for Microsoft: most notably publicized was "Universal Plug and Play”. In October 2001, Microsoft released Windows XP, a version built on the Windows NT kernel that also retained the consumer-oriented usability of Windows 95 and its successors. Windows Vista is the first end-user version of Windows that Microsoft has released simultaneously in 32-bit and x64 editions. The latest version of windows is WINDOWS NT SERVER 2008. Microsoft released it on Feburary 2008. Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. (ALBERT EINSTEIN) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 66 FILL IN THE BLANKS Complete the following blanks with suitable answers 1. The processing unit responsible for mathematical computation is called _________. (Arithmetic logic unit) 2. A kilobyte is equal to __________ bytes. (1024) 3. The electronic technology used in second generation computer system was _______. (Transistors) 4. A __________ translates program language instructions one at a time. (Interpreter) 5. Output on the screen is called __________ whereas output by the printer on paper is called __________. (Softcopy, Hardcopy) 6. IBM stands for __________. (International business machine) 7. In BASIC, function key F4 is used for __________. (Save) 8. Machine language is a __________ level language. (Low) 9. GOTO statement is known as __________ statement. (Jump) 10. __________ is a set of well-defined instructions. (Program) 11. The diagrammatic representation of logic is called __________. (Flow Chart) 12. A computer output taken on paper is called the __________ copy. (Hard) 13. Monitors and printers are __________ devices.(Output) 14. Mathematical calculation is carried out by __________ of C.P.U.(A.L.U) 15. The use of _________ was a marked feature of the 1st generation of computers. (Vacuum tubes) 16. __________ command branches unconditionally to a specified line number. (Goto) 17. Vacuum tubes were used in the __________ generation of computers. (1st) 18. Charles Babbage invented __________. (Mathematical engine) 19. __________ statement in DOS is used to delete a file from the disk. (DEL) 20. The volatile part of internal memory is called __________. (RAM) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 67 21. __________ is the set of instructions that tells the computers what to do. (Program) 22. A kilobyte is equal to __________ bytes. (1024) 23. Each statement or command is preceded by a line number in the __________ mode. (Indirect) 24. The keyboard and the mouse are __________ devices. (Input) 25. A diagram to plan a program is called __________. (Flow Chart) 26. Data processing consists of three basic steps __________, __________ and ______. (Input, Process, Output) 27. __________ memory is that type of memory which does not lose the information stored when the power is turned off. (Secondary/Non-Volatile) 28. Every BASIC statement consists of a __________, keyword and the parameter. (Line number) 29. __________ statement is used to transmit numeric or string output data from the computer and displays it on the screen. (Print) 30. We use __________ to convert the digital data into analog data. (Modem) 31. The introduction of __________ brought the computer age into the third generation. (Integrated Circuits) 32. A software developed for general purpose is called__________ software. (General purpose) 33. A software developed for specific purpose is called__________ software. (Special purpose) 34. Data processing devices are __________, __________, and __________. (Keyboard, CPU, Monitor) 35. In first generation __________ size computers was used. (very large) 36. Integrated circuit based computers were introduced in __________ generation. (3rd) 37. A micro second is equivalent to 1/__________. (106) 38. PC stands for __________. (Personal computer) 39. The term VLSI is used for __________. (Very large scale integration) 40. CU is an alternative word for __________. (Control unit) 41. An __________ is necessary to operate the computer. (Operating System) 42. __________ computers have both analog and digital methods of processing information. (Hybrid) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 68 43. The introduction of __________ brought the computer age into fourth generation. (VLSI) 44. The physical units making up a computer system are known as computer __________. (Hardware) 45. Charless Babbage is called the father of __________. (Computer) 46. EDP stands for __________. (Electronic data processing) 47. A __________ data processing system consists of various input and output devices connected with an electronic computer. (Electronic) 48. A microprocessor chip consists of three basic parts __________, __________ and ______. (ALU, CU, Memory or Registers) 49. A blinking point on the CRT, whose position can be controlled by the operator of the computer, is known as __________. (Cursor) 50. The very small bulbs on the keyboard or CPU are called __________. (Light emitting diode, LED) 51. In BASIC function key F2 is used to __________. (Run) 52. ASCII stands for __________. (American standard code for information interchange) 53. A __________ is used to play games. (Joystick) 54. __________ and __________ are the latest input devices. (Light pen, Digital camera) 55. CRT stands for __________. (Cathode ray tube) 56. SVGA stands for __________. (Super video graphics Adapter) 57. __________ and __________ are impact printers. (Daisy wheel, Line printers) 58. __________ and __________ are non-impact printers. (Laser, Ink-jet) 59. A small spot of light displayed on the screen is called __________. (Pixel) 60. The devices through which we enter data into the computer are known as __________ devices. (Input) 61. A blinking cell on the display screen is known as __________. (Cursor) 62. __________ and __________ are the only figures used in binary number system. (0 and 1) 63. DOS is an acronym for __________. (Disk operating system) 64. __________ data represents only numbers. (Numeric) 65. There are three types of languages translators: __________, __________ and __________. COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 69 (Compiler, Interpreter, Assembler) 66. A keyboard has a number of keys, but usually it has __________ keys. (101) 67. Types of data are __________, __________ and __________. (Alphabetic, Numeric, Alphanumeric) 68. Types of numeric data are __________ and __________. (Real, Integer) 69. Types of numerical real data are __________ and __________. (Fixed point, Floating point) 70. Machine language programs are usually written in __________ number system. (Binary) 71. A program translated by the compiler is called __________. (Object program) 72. Destructive programs are classified as __________. (Viruses) 73. BASIC is an acronym for __________. (Beginners all purpose symbolic instruction code) 74. 75. In BASIC each statement must begin with a __________. (Line number) 76. __________ statement clears VDU. (CLS) 77. 78. Before a value is assigned to a numeric variable, its value is assumed to be __________. (ZERO) 79. 80. __________ and __________ statements may be used to define the beginning and the end of a loop. (For, Next) 81. 82. In _________ each statement must begin with a Line number. (Interpreter) 83. __________ command automatically generates line numbers. (Auto) 84. BASIC program is a collection of __________. (Statements) 117. A computer __________ is a set of instructions sequenced in a logical manner to achieve a definite task. (Software) 119. __________ is the person who designs and writes the computer program. (Software developer) 120. __________ level language is nearest to the human language. (High level language) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 70 121. Assembly language is __________ level language. (Low level language) 123. A __________ is a way of communicating with the computer. (Program) 124. Internal Command is a part of __________. (DOS) 125. CLS is an __________ command. (Internal) 126. FORMAT is an __________ command. (External) 128. The bi-stable state ON is known as the state of __________. (High voltage) 129. The bi-stable state OFF is known as the state of __________. (Low voltage) 131. The computer stores an extra bit, called __________ bit. (Parity/Extended) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 71 MATCH THE COLUMNS Match the correct answer from Column A to Column B Exercise 1 Column A Column B A set of instruction for computer Byte Volatile Memory Program Grouping of Bits RAM Charles Babbage Machine Language The language that computer can understand Analytical Engine Exercise 2 Column A Column B Parallelogram Used to connect page Diamond Process Box Connector Used to connect symbols Rectangle Used for decision Flow Lines I/O Box Exercise 3 Column A Column B Converts high level language into machine language Backing Storage The manipulation of data into a more useful form Vacuum Tube Permanent storage outside the computer DIR An electrical component which was used in the first generation of computers. Data Processing COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 72 An internal DOS command Compiler Exercise 4 Column A Column B Vacuum Tube First Generation Integrated Circuit Second Generation Artificial Intelligence Third Generation Transistors Fourth Generation Physical parts of computer Fifth Generation Large Scale Integrated Circuit Hardware Exercise 5 Column A Column B Result Flowchart Set of instructions Final output The process of understanding the problem Diamond shape Algorithm Program Manual Documentation of program Condition box Step wise solution Block diagram Problem analysis Exercise 6 Column A Column B High level language BASIC 222 Ok Arithmetic expression Integer value BASIC prompt A = 111 + 111 COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 73 MULTIPLE CHOICE QUESTIONS Choose any one of the following correct answers 1. __________ is a category of computer hardware. (Input, Output, Storage, Processing, all of the above) 2. __________ is an important component of microcomputer system. (Kilobyte, Microprocessor, Megabyte, Byte, None of the above) 3. __________ is not found in C.P.U. (ALU, Control Unit, RAM, Processing Register) 4. __________ is a type of impact printers. (Laser, Thermal, Dot-Matrix, Inkjet) 5. __________ program design technique shows program logic. (Flow chart, Logical Operation, Computer, None of the above) 6. __________ is used as counter in BASIC programs. (A = A+1, A<1, A or 1, None of the above) 7. __________ characteristic is applied to the third generation of computers. (Integrated Circuit, Transistor, Vacuum Tubes, All of the above) 8. The most important characteristic of ROM is __________. (It performs mathematical calculation, it is volatile, it is non – volatile, None of the above) 9. __________ statement is used to transfer the control of program conditionally. (GOTO, ON GOTO, END, All of the above) 10. Disk operating system is abbreviated as __________. (DOS, DS, OS, None of above) 11. __________ is an example of integer data. (HASAN, D-143, 143, all of the above) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 74 12. High level languages were designed in __________. (Laboratory, Third generation, Computers, New York) 13. __________ is a high level language. (BASIC, BESIK, BACIK, BESIC) 14. Binary number system has __________. (Ten digits (0,9), Three digits (-1,0,1), One digit (1), Two digits (0,1)) 15. LET statement is __________. (Optional statement, Assigning statement, Used for expression assignment, all of the above) 17. BASIC stands for __________. (Basic All-purpose Symbolic Instructon Code, Beginners Assembly Symbols Instruction Code, Basic All Standards In COBOL, Beginners All-purpose Symbolic Instruction Code) 19. ANSI stands for __________. (All New Small Integration, A National Small Institute, American National Standard Institute, None of the above) 20. Sign of exclamation is __________. ( ! , : , I , % ) 21. The example of random access storage media is __________. (Floppy disk drive, Hard disk drive, Tape unit, 51/4‟‟ floppy disk) 22. The type of memory whose contents can not be changed is __________. (ROM, RAM, Cache, EAPROM) 23. The command to see the contents of a disk is __________. (DIR, CD, MD, TYPE) 24. DISKCOPY command can format the destination disk __________. (Before copying, after copying, can not format, format while copying) 25. TYPE command is used to __________. (To see the contents of a file, Chage the type of a file, make a sub directory, Type a file in the computer) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 75 26. Each statement of BASIC must have a __________. (Function, Statement number, Program name, File name) 27. The command to create a sub-directory is __________. (DIR, CD, MD, APPEND) TRUE AND FALSE Write True or False for the following sentences 1. The central processing Unit (C.P.U) is the brain of computer system. T 2. Logical errors are caused by faulty program designs. T 3. Diamond-shaped symbol in program flow chart is used for decision points. T 4. Dot Matix printers are non-impact printers. F 5. Data stored in ROM can be changed. F 6. Impact printers work by hitting an inked ribbon against the paper, T 7. High level language is used to convert the source program into object program. F 8. Mark-1 is the first Digital Computer. F 9. ROM stores data or program permanently and RAM stores data or program temporarily. T 10. A set of bits considered as a unit, normally consisting of 8 bits is known as Byte. T 11. Abacus is an early Manual device for counting. T 12. Software comprehends computers programming languages; translates application programs and operating systems programs. T 13. Mark-I is the first digital computer. F 14. First microprocessor chip INTEL 4004 was developed in 1990. T 15. The heavy computers are called “Laptops‟. F 16. A digital computer can work at high speed. T 17. Registers are the part of ROM. F COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 76 18. RAM stands for Read Access Memory. F 19. Convention memory and extended memory almost work at the same speed. T 20. EPROM is a special type of RAM. F 21. The main memory of CPU is the place where the computer programs and data is stored permanently. F 22. RAM is a volatile memory for temporary storage of data or programs. T 23. Data processing is the manipulation of data into more useful form. T 24. EDP stands for Extended Data Processing Cycle. T 25. An input device receives data from computer. F 26. Mouse is an input device. T 27. It is possible to display several colors on a monochrome monitor. F 28. A printer does not provide a soft copy of output. T 29. Impact printers can produce carbon copies. T 31. Keyboard is a backing storage device. F 32. Magnetic tape is the fastest media for data storage. F 33. There are several tracks on a floppy disk, which are further divided into sectors. T 34. 2KB = 2024 bytes. F (IT IS EQUAL TO 2048 BYTES) 35. Impact printer work by hitting an inked ribbon against the paper. T “If A is success in life, then A equals x plus y plus z.x Is work, y is play, and z is keeping your mouth shut!” (Albert Einstein) CCAARREEEERR TTHHEE PPAATTHH OOFF SSOOUUNNDD SSUUCCEEEESSSS IINN EEDDUUCCAATTIIOONN COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 77 EXPERIMENT NO 1 PART A 10 CLS 20 FOR A = 1 TO 10 30 PRINT “ CAREER ” 40 NEXT A 50 END PART B 10 CLS 20 A = A + 1 30 PRINT “ CAREER ” 40 IF A = 10 THEN END ELSE GOTO 20 50 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 78 EXPERIMENT NO 2 10 CLS 20 PRINT TAB(30) “ NUMBER ” , ” SQUARE ” , ” CUBE ” 30 FOR A = 1 TO 10 40 S = A ^ 2 50 C = A ^ 3 60 PRINT TAB(30) A , S , C 70 NEXT A 70 END FOR A=1 TO 10 For A =1 to 10 Start End NEXT A S = A^2 PRINT A,S,C C = A^3 COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 79 EXPERIMENT NO 3 A) 10 CLS 20 INPUT “ ENTER TABLE NUMBER:” ; T 30 FOR N = 1 TO 10 40 A = T * N 50 PRINT T ; “ * ” ; N ; “ = ” ; A 60 NEXT N 70 END B) 10 CLS 20 INPUT “ ENTER 1ST NUMBER:”; N1 30 INPUT “ ENTER 2ND NUMBER:”; N2 40 INPUT “ ENTER 3RD NUMBER:”; N3 50 INPUT “ ENTER 4TH NUMBER:”; N4 60 T = N1 + N2 + N3 + N4 70 AVG = T /4 80 PRINT “ FIRST NUMBER:” N1 90 PRINT “ SECOND NUMBER:” N2 100 PRINT “ THIRD NUMBER:” N3 110 PRINT “ FOURTH NUMBER:” N4 120 PRINT “ SUM OF FOUR NUMBERS IS” ; T 130 PRINT “AVERAGE OF FOUR NUMBERS IS ”;AVG 140 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 80 EXPERIMENT NO 4 10 CLS 20 FOR A = 3 TO 28 STEP 5 40 PRINT A 50 NEXT A 70 FOR B = 28 TO 3 STEP -5 80 PRINT B 90 NEXT B 90 END EXPERIMENT NO 5 10 CLS 20 INPUT “ ENTER YOUR NAME: ”;N$ 30 INPUT “ ENTER YOUR FATHER NAME: ”;F$ 40 INPUT “ ENTER ROLL NUMBER:”;R 50 INPUT “ ENTER GROUP: ”; G$ 60 INPUT “ ENTER ENGLISH MARKS:”;E 70 INPUT “ ENTER SINDHI MARKS:”;S 80 INPUT “ ENTER PAKISTAN STUDIES MARKS:”; PS 90 INPUT “ ENTER CHEMISTRY MARKS:”; CH 100 INPUT “ ENTER COMPUTER MARKS:”; C 110 T = E + S + PS + CH + C 120 P = T /500 *100 130 PRINT “ NAME: ”; N$ 140 INPUT “ FATHER NAME: ”;F$ 150 INPUT “ ROLL NUMBER:”;R 160 INPUT “ GROUP: ”; G$ 170 INPUT “ ENGLISH MARKS:”;E 180 INPUT “ SINDHI MARKS:”;S 190 INPUT “ PAKISTAN STUDIES MARKS:”; PS 200 INPUT “ CHEMISTRY MARKS:”; CH 210 INPUT “ COMPUTER MARKS:”; C 220 PRINT “ TOTAL MARKS:”;T 230 PRINT “ PERCENTAGE: ”;P 240 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 81 EXPERIMENT NO 6 10 CLS 20 INPUT “ ENTER DOLLAR: ”; D 30 INPUT “ ENTER RUPEES ”; R 40 DR = R /55 50 RS = D * 55 60 PRINT “GIVEN DOLLAR ”; D 70 PRINT “ RUPEES = ”; RS 80 PRINT “ GIVEN RUPEES: ”;R 90 PRINT “ DOLLAR: ”;DR 100 END EXPERIMENT NO 7 10 REM PROGRAM TO CONVERT TEMPERATURE FAHRENHIET INTO CENTIGRADE AND CENTIGRADE INTO FAHRENHEIT . 20 CLS 30 INPUT “ENTER FAHRENHEIT TEMPERATURE”;F 40 INPUT “ENTER CENTIGRADE TEMPERATURE”;C 50 CT= 5/9 * (F-32) 60 FT= (9/5 *C) +32 70 PRINT “GIVEN FAHRENHEIT TEMPERATURE : ”;F 80 PRINT “CENTIGRADE : ”;CT 90 PRINT “GIVEN CENTIGRADE TEMPERATURE : ”;C 100 PRITN “FAHRENHEIT : ”;FT 110 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 82 EXPERIMENT NO 8 10 REM PROGRAM TO PREPARE REECORD OF 10 STUDENTSWITH GENDER. 20 CLS 30 DIM N$(10), S$(10) 40 FOR A=1 TO 10 50 PRINT “DATA NUMBER: ”;A 60 INPUT “ENTER NAME”;N$(A) 70 INPUT “ENTER GENDER”;S$(A) 80 IF S$(A)=“M” OR S$(A)=“M” THEN M=M+1 90 IF S$(A)=“F” OR S$(A)=“F” THEN F=F+1 100 NEXT A 110 CLS 120 PRINT “RECORD NUMBER”;“NAME”;“GENDER” 130 FOR A=1 TO 10 140 PRINT A;N$(A);S$(A) 150 NEXT A 160 PRINT “TOTAL NUMBER OF MALES : ”;M 170 PRINT “TOTAL NUMBER OF FEMALES : ”;F 180 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 83 EXPERIMENT NO 9 \10 REM PROGRAM TO GENERATE ELECTRICITY BILL. 20 CLS 30 INPUT “ENTER CONSUMER NAME”;N$ 40 INPUT “ENTER METER NO”;M$ 50 INPUT “ENTER PRESENT READING”;PR 60 INPUT “ENTER PREVIOUS READING”;PV 70 UC=PR-PV 80 AC=UC*0.25 90 PRINT “CONSUMER NAME : ”;N$ 100 PRINT “METER NO : ”;M$ 110 PRINT “PRESENT READING : ”;PR 120 PRITN “PREVIOUS READING : ”;PV 130 PRINT “UNIT CONSUMED : ”;UC 140 PRINT “AMOUNT CHARGED : ”;AC 150 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 84 EXPERIMENT NO 10 10 REM PROGRAM TO GENERATE BIO DATA. 20 CLS 30 INPUT “ENTER YOUR NAME”;N$ 40 INPUT “ENTER YOUR FATHER NAME”;F$ 50 INPUT “ENTER YOUR FATE OF BIRTH”;DS 60 INPUT “ENTER YOUR GENDER”;S$ 70 INPUT “ENTER YOUR NATIONALITY”;NT$ 80 INPUT “ENTER YOUR QUALIFICATION”;Q$ 90 INPUT “ENTER YOUR RELIGION”;R$ 100 PRINT “ *************** BIO – DATA **********************” 110 PRINT “NAME : ”;N$ 120 PRINT “FATHER NAME : ”;F$ 130 PRINT “DATE OF BIRTH : ”;D$ 140 PRITN “GENDER : ”;S$ 150 PRINT “NATIONALITY : ”;NT$ 160 PRINT “QUALIFICATION : ”;Q$ 170 PRINT “RELIGION : ”;R$ 180 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 85 EXPERIMENT NO 11 10 REM A PROGRAM TO GENERATE THE SUM OF 1ST TEN NATURAL NOS. 20 CLS 30 FOR N=1 TO 10 40 S=S+N 50 PRINT N 60 NEXT N 70 PRINT S 80 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 86 EXPERIMENT NO 12 10 REM SALARY SHEET. 20 CLS 30 INPUT “ENTER EMPLOYEES NAME”;N$ 40 INPUT “ENTER DESIGNATION”;D$ 50 INPUT “ENTER BASIC SALARY”;BS 60 INPUT “ENTER TOTAL ALLOWANCES”;TA 70 INPUT “ENTER TOTAL DEDUCTIONS”;TD 80 GS=BS+TA 90 NS=GS-TD 100 PRINT “*** SALARY SHEET ***” 110 PRINT “EMPLOYEE NAME ”;N$ 120 PRINT “DESIGNATION ”;D$ 130 PRITN “BASIC SALARY ”BS 140 PRINT “TOTAL ALLOWANCES ”;TA 150 PRINT “TOTAL DEDUCTIONS ”;TD 160 PRINT “GROSS SALARY ”;GS 170 PRINT “NET SALARY ”;NS 180 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 87 EXPERIMENT NO 13 10 REM PROGRAM TO FIND THE GREATEST NUMBERS AMONG THREE NUMBERS. 20 CLS 30 INPUT “ENTER FIRST NUMBER”;N1 40 INPUT “ENTER SECOND NUMBER”;N2 50 INPUT “ENTER THIRD NUMBER”;N3 60 CLS 70 PRINT “FIRST NUMBER”;N1 80 PRINT “SECOND NUMBER”;N2 90 PRINT “THIRD NUMBER”;N3 100 IF N1>N2 AND N1>N3 THEN PRINT “FIRST NO IS GREATER:”;N1 110 100 IF N2>N1 AND N2>N3 THEN PRINT “SECOND NO IS GREATER:”;N2 120 100 IF N3>N1 AND N3>N2 THEN PRINT “THIRD NO IS GREATER:”;N3 130 100 IF N1=N2 AND N1=N3 THEN PRINT “ALL NUMBERS ARE EQUAL” 140 END COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 88 Experiment No 1(a) Start End NEXT A PRINT “CAREER” FOR A=1 TO 10 Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 89 Experiment No 1(b) Start End A = A + 1 PRINT “CAREER” IF A=10 A A YES NO Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 90 Experiment No 2 FOR A=1 TO 10 For A =1 to 10 Start End NEXT A S = A^2 PRINT A,S,C C = A^3 Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 91 Experiment No 3(a) INPUT T Start End NEXT N FOR N = 1 TO 10 PRINT T;”*”;N;”=”;A A = T*N Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 92 Experiment No 3(b) Start PRINT N1 INPUT N1 INPUT N2 INPUT N3 INPUT N4 T = N1+N2+N3+N4 AVG = T/4 PRINT N2 PRINT N3 PRINT N4 B B End PRINT T PRINT AVG Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 93 Experiment No 4 Start End NEXT A PRINT A FOR A=3 TO 28 STEP 5 NEXT B PRINT B FOR B=28 TO 3 STEP -5 Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 94 Experiment No 5 PRINT N$ P = (T*100) /500 PRINT F$ PRINT R PRINT G$ B End PRINT E PRINT S Start INPUT N$ INPUT F$ INPUT R INPUT G$ INPUT E INPUT S INPUT PS INPUT CH INPUT C T=E+S+PS+CH+C B PRINT PS PRINT CH PRINT C PRINT T PRINT P COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 95 Experiment No 6 INPUT “ENTER DOLLAR”;D Start End DR=R/64 PRINT “GIVEN DOLLAR=”;D INPUT “ENTER RUPEES”;R RS=D*64 PRINT “RUPEES =”;RS PRINT “GIVEN RUPEES=”;R PRINT “DOLLAR=”;DR Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 96 Experiment No 7 Start End CT = 5/9 * ( F-32) INPUT “ENTER FAHRENHIET”;F INPUT “ENTER CENTIGRADE”;C FT = (9/5 *C) + 32 PRINT “GIVEN FAHRENHIET”;F PRINT “CENTIGRADE”;CT PRINT “GIVEN CENTIGRADE”;C PRINT “FAHRENHIET”;FT Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 97 Experiment No 8 Start DIM N$(10),S$(10) FOR A=1 TO 10 PRINT “DATA NUMBER”;A INPUT “ENTER NAME”;N$(A) INPUT “ENTER GENDER”;S$(A) PRINT “RECORD NO”;”NAME”;”GENDER” NEXT A M=M+1 IF S$(A)=“M” OR S$(A)=“m” F=F+1 IF S$(A)=“F” OR S$(A)=“f” YES NO NO YES FOR A=1 TO 10 A COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 98 End A PRINT A;N$(A);S$(A) NEXT A PRINT “TOTAL NO OF MALES”;M PRINT “TOTAL NO OF FEMALES”;F Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 99 Experiment No 9 PRINT C$ AC=UC*0.25 PRINT M$ PRINT PR PRINT PV B End PRINT UC PRINT AC Start INPUT C$ INPUT M$ INPUT PR INPUT PV UC=PR-PV B Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 100 Experiment No 10 B Start INPUT N$ INPUT F$ INPUT D$ INPUT S$ INPUT NT$ INPUT Q$ INPUT R$ PRINT N$ PRINT F$ B PRINT D$ PRINT S$ PRINT NT$ PRINT Q$ PRINT R$ End Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 101 Experiment No 11 Start End S=S+N PRINT N FOR N = 1 TO 10 NEXT N PRINT S Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 102 Experiment No 12 PRINT BS PRINT TA B End PRINT TD PRINT GS PRINT NS PRINT N$ NS=GS-TD PRINT D$ Start INPUT N$ INPUT D$ INPUT BS INPUT TA INPUT TD GS=BD+TA B Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED) COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 103 Experiment No 13 Start INPUT N1 INPUT N2 INPUT N3 PRINT N1 PRINT N2 PRINT N3 PRINT N2 PRINT N1 IF N1>N2 AND N1>N3 IF N2>N3 AND N2>N13 NO NO YES YES B COMPUTER STUDIES-IX CAREER W r i t t e n B y: SAIYED SHAHAB AHMED (MS – IBA, BS – UoK) 104 End B IF N3>N1 AND N2>N2 YES PRINT N3 IF N1=N2 AND N1=N3 YES PRINT “ALL NOS ARE EQUAL” NO NO Flow Chart Designed by Engr. Syed Ali Habib (BE (Electrical -NED)