PIR AMIR HUSSAIN NOSHAHI Computer
- 1. Advantages of using computers There are severaladvantages and benefits of using computers.someof them are discussed below Speed Speed is the most important characteristic of a computer.the computer can performbillions of calculations in a fraction of a second . For exampleif a student is asked to calculate the following product The student will take few minutes to solveit, but a computer can solve millions of Such problems in less then second. Accurarcy Computer is almost 100% accurate and it never makes mistakes. Diligence Besides being fast, a computer can do things over and over agai. Itnever gets tired are bored. If wehave to write letter 100 times we will get tired. A cputer can write letter even a million times but never gets tried are bored Generation of computer 1 First Generation The periodof first generation:1946-1954. Vacuumtube based. Advantages Vacuumtubes were the only electronic component available during those days. Vacuumtube technology made possibleto make electronic digital computers. These computers could calculate data in millisecond
- 2. Disadvantages The computers were very large in size. They consumed a large amount of energy. They heated very soon due to thousands of vacuumtubes. They were not very reliable. Air conditioning was required. Constantmaintenance was required. Non-portable. Costly commercial production. Limited commercial use. Very slow speed. Limited programming capabilities. Used machine language only. Used magnetic drums which providevery less data storage. Used punch cards for input. Not versatile and very faulty 2 Second Generation The period of second generation: 1954-1963. Transistor based. Advantages Smaller in size as compared to the first generation computers. The 2nd generation Computers weremore reliable Used less energy and were not heated. Wider commercial use Better portability as compared to the firstgeneration computers.
- 3. Better speed and could calculate data in microseconds Used faster peripherals like tape drives, magnetic disks, printer etc. Used Assembly languageinstead of Machine language. Accuracy improved. Disadvantages Cooling systemwas required Constantmaintenance was required Commercial production was difficult Only used for specific purposes Costly and not versatile Puch cards were used for input 3 Third Generation The periodof thirdgeneration:1965-1971. IntegratedCircuit based. Advantages Smaller in size as compared to the first generation computers. The 2nd generation Computers weremore reliable Used less energy and were not heated. Wider commercial use Better portability as compared to the firstgeneration computers. Better speed and could calculate data in microseconds Used faster peripherals like tape drives, magnetic disks, printer etc. Used Assembly languageinstead of Machine language. Accuracy improved. Disadvantages Cooling systemwas required
- 4. Constantmaintenance was required Commercial production was difficult Only used for specific purposes Costly and not versatile Puch cards were used for input. 4 Fourth Generation The period of fourthgeneration:1975-present. VLSI microprocessor based. Advantages Smaller in size as compared to previous generations. More reliable. Used less energy Produced less heat as compared to the previous two generations of computers. Better speed and could calculate data in nanoseconds. Used fan for heat dischargeto prevent damage. Maintenance costwas low becausehardwarefailure is reare. Totally general purpose Could be used for high-level languages. Good storage Versatile to an extent Less expensive Better accuracy Commercial production increased. Used mouseand keyboard for input.
- 5. Disadvantages Air conditioning was required. Highly sophisticated technology required for the manufacturing of IC chips. 5 Fifth Generation The periodof fifthgeneration:1980-onwards. ULSI microprocessor based Advantages More powerfuland reliable than previous generations. Small in size Fastprocessing power with less power consumption Fan for heat discharging and thus to keep cold. No air conditioning required. Totally general purpose Commercial production Less need of repair. Cheapest among all generations All types of High level languages can be used in this type of computers Disadvantages The latest technology is required for manufacturing of Microprocessors Computer component
- 6. InputUnit This unit contains devices with the help of which we enter data into computer. This unit makes link between user and computer. The input devices translate the information into the form understandable by computer. CPU(CentralProcessingUnit) CPU is considered as the brain of the computer. CPU performs all types of data processing operations. It stores data, intermediate results and instructions(program). It controls the operation of all parts of computer. CPU itself has following three components ALU(Arithmetic Logic Unit) Memory Unit Control Unit OutputUnit Output unit consists of devices with the help of which we get the information from computer. This unit is a link between computer and users. Output devices translate the computer's output into the form understandable by users. How Do Computers Work? Computer Basics To accomplish a task using a computer, you need a combination of hardware, software, and input. Hardware consists of devices, like the computer itself, the monitor, keyboard, printer, mouseand speakers. Insideyour computer there are morebits of hardware, including the motherboard, whereyou would find the main processing chips that make up the central processing unit (CPU). Thehardwareprocesses thecommands it receives fromthe software, and performs tasks of calculations. Software
- 7. is the name given to the programs thatyou install on the computer to perform certain types of activities. There is operating systemsoftware, such as the Apple OS for a Macintosh, or Windows 95 or Windows 98 for a PC. There is also application software, like the games we play or the tools we useto compose letters or do math problems. input You providethe input. When you type a command or click on an icon, you are telling the computer what to do. That is called input Input, output and storage unit • Input devices • Identify input devices • List input devices • Functions of Input devices • Output devices • Identify Output devices • List Output devices • Functions of Output devices • Storage devices • Identify storage devices • List storage devices • Functions of storage devices