Introduction to computer science
- 1. INTRODUCTION TOCOMPUTER SCIENCE CSC 1302 LECTURE 2 Department of Maths and Computer- Science Faculty of Natural and Applied Science BY UMAR DANJUMA MAIWADA
- 2. HARDWARE It is the physical component of the computer which we can see and touch. Hardware is made up of devices or units. These include: input devices Processing devices Output devices Storage devices 2
- 3. RELATIONSHIP BETWEEN HARDWARE AND SOFTWARE Both of them must work together to make a computer produce a useful output. Software cannot be utilized without supporting hardware. Software development is very expensive and is a continuing expense. A software acts as an interface between the user and the hardware. 3
- 4. SOFTWARE It is the collection of programs in the computer Which we can see at times but cannot touch A program is a sequence of instructions written to solve a particular problem. There are two types of software; System Software and Application Software. 4
- 5. SYSTEM SOFTWARE These are programs that control the operation of any computer. Example booting, loading, execution. System software include OS, language translators System software are generally prepared by computer manufactures. 5
- 6. APPLICATION SOFTWARE They are designed to perform specific task for us. All software applications prepared in the computer lab can come under the category of Application software. Types of application software include: Word processing e.g Ms word, word star, word perfect Spreadsheet e.g Ms excel, LOTUS Computer graphics e.g photopaint, corel draw, photoshop Database e.g Ms access, 6
- 7. UTILITY SOFTWARE Example Norton, McAfee 7
- 8. PERIPHERALS They are those external devices that must be attached to the system unit for them to work. Example: mouse Lightpen Printer Modem Ups Scanner Projector 8
- 9. CHARACTERISTICS OF A COMPUTER Speed: Computer carries out every assignment and processing very fast. It works faster than calculators, four figure table, etc. it’s internal speed is almost instantaneous. Storage: A computer would store information or data once you instruct it to do so. It stores them inside its storage devices. Accuracy: Every instruction is reliably carried out. Computers can perform operations and process data faster but with accurate results and no errors. Versatility: Computer is a versatile machine. They are used in various fields. Multitasking: Multitasking is also a computer characteristic. Computers can perform several tasks at a time. Communication: Computers have the ability to communicate, but of course there needs some sort of 9
- 10. CLASSIFICATION OF COMPUTERS Computers can be classified according to i) Mode of operation ii) Size and speed iii) Generation 10
- 11. MODE OF OPERATION Computers can be divided into Analog, Digital and Hybrid systems. 11
- 12. ANALOG COMPUTERS Data is recognized as a continuous measurement of a physical property like voltage, speed, pressure. Readings on a dial or graphs are obtained as the output. They do not directly interact with numbers They deal with variables measured along a continues scale an analog computer must be able to accept inputs which vary with respect to time and directly apply these inputs to various devices within the computer which performs the computing operations of additions, subtraction, multiplication, division, integration and function generation. 12
- 13. DIGITAL COMPUTERS These are high speed electronic devices. These devices are programmable. They operate on discrete data. They process data by way of mathematical calculations, comparison, sorting. It works basically by directly counting numbers that represent numerals. They represent information discretely and use a binary (two-step) system that represents each piece of information as a series of zeroes and ones. They are divided into two Specific purpose: which has been designed to perform one specific task. General purpose: which can store different programs and is also reprogrammable. 13
- 14. HYBRID COMPUTERS They combine the speed of analog computers and accuracy of digital computers. It is the one in which desirable characteristics of both the Analog and Digital computers are integrated. It has the speed of analog computer and the memory and accuracy of digital computer. An analog device is used to measures patient's blood pressure and temperature etc, which are then converted and displayed in the form of digits. Hybrid computers for example are used for scientific calculations, in defence and radar systems. 14
- 15. SIZE 15 Continuat ion Supercomputer Mainframe Computer Minicomputer Microcomputer
- 16. SUPERCOMPUTER It is the most powerful It is the most expensive They are designed to perform scientific application Its speed is very important This is known as parallel processing. The speed of each address in the location holds 64bits of information. The time required to execute a single operation may be as low as 4 nanoseconds. It can be accommodated in large air-conditioned rooms. Super computers have multiple processors which process multiple instructions at the same time. 16
- 17. Uses of Supercomputer 17 • Space exploration • Earthquake studies • Weather forecasting • Nuclear weapons testing
- 18. Mainframe computer Main frame computers are very large computers which process data at very high speeds of the order of several million instructions per second. They have the flexibility to operate automatically from 2 to 8 bytes in the same unit of time. Several microprocessors are used in place of the single microprocessor used in micro and mini. The result is that these systems can process data much faster. Government organizations uses Mainframes to run their business operations. Mainframes can also process and store large amount of data. Banks, educational institutions and insurance companies use mainframe computers to store data about their customers, students & insurance policy 18
- 19. MINICOMPUTER It is a small general purpose computers varying in size from a desktop model to a unit the size of a four drawer filing cabinet. They have higher memory capacity and more storage capacity with higher speeds. They are mainly used in applications like payrolls, financial accounting, Computer aided design. One of the most important uses of minis is in the distributed data processing networks. A minicomputer is a multiprocessing system capable of supporting from 4 to 200 users simultaneously. Minicomputers are used by small businesses and 19
- 20. MICROCOMPUTER They are widely used in day to day applications like office automation, and professional applications. They have Smallest memory and less power. It is the smallest general purpose computer system which can execute programs to perform a variety of instructions. It has all the functional elements found in a larger systems. Desktop computers, laptops, personal digital assistant (PDA), tablets and smartphones are all types of microcomputers. These computers are the cheapest among the other three types of computers. They are specially designed for general usage like entertainment, education and work purposes. 20
- 21. COMPUTER GENERATIONS The present day computer, however, has also undergone rapid change during the last fifty years. This period, during which the evolution of computer took place, can be divided into five distinct phases known as Generations of Computers. Each phase is distinguished from others on the basis of the type of switching circuits used. 21
- 22. FIRST GENERATION COMPUTERS 1940-1956 Vacuum Tubes First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time, and it could take days or weeks to set-up a new problem. They were huge, slow, expensive, and often unreliable. They gave off so much heat, even with huge coolers Vacuum tubes still overheated regularly 22
- 23. PUNCHED CARDS FOR DATA INPUT, PUNCHED CARDS AND PAPER TAPE FOR OUTPUT, MACHINE LANGUAGE FOR WRITING PROGRAMS, MAGNETIC TAPES AND DRUMS FOR EXTERNAL STORAGE. 23 Punch card Vacuum tube Paper tape
- 24. SECOND GENERATION 1956-1963 Transistors The transistors was faster, more reliable, smaller and much cheaper to build than the vacuum tube. They gave off no heat compared to vacuum tube. One transistor replaced the equivalent of 40 vacuum tubes. Second-generation computers still relied on punched cards for input and printouts for output. Second-generation computers moved from cryptic binary machine language to symbolic, or assembly languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a 24
- 25. SIZE OF THE COMPUTERS STARTED REDUCING, ASSEMBLY LANGUAGE STARTED BEING USED IN PLACE OF MACHINE LANGUAGE, CONCEPT OF STORED PROGRAM EMERGED, HIGH LEVEL LANGUAGES WERE INVENTED. Transistor 25
- 26. THIRD GENERATION 1964-1971 Integrated Circuits (ICs) They carry out instructions in billionths of a second. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. 26
- 27. PHENOMENAL INCREASE IN COMPUTATION SPEED, SUBSTANTIAL REDUCTION IN SIZE AND POWER CONSUMPTION OF THE MACHINES, USE OF MAGNETIC TAPES AND DRUMS FOR EXTERNAL STORAGE, DESIGN-OF OPERATING SYSTEMS AND NEW HIGHER LEVEL LANGUAGES, COMMERCIAL PRODUCTION OF COMPUTERS. 27 Integrated circuit Integrated circuit
- 28. FOURTH GENERATION 1971- Present Microprocessors Very large scale Ics which is millions of transistors put together onto one Ics chip. More calculation and faster speed could be reached by computers. They are used for personal use. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. 28
- 29. USE OF VERY LARGE SCALE INTEGRATION, INVENTION OF MICROCOMPUTERS, INTRODUCTION OF PERSONAL COMPUTERS, NETWORKING, FOURTH GENERATION LANGUAGES. Very large scale integrated circuit 29
- 30. FIFTH GENERATION Present and Beyond Artificial Intelligence They are still in development, though there are some applications, such as voice recognition, that are being used today. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization. Computers would be able to accept spoken words as input (voice recognition). Two such advances are parallel processing where many CPUs work as one and advance in superconductor technology which allows the flow of electricity with little or no resistance, greatly improving 30
- 31. QUESTIONS??? THANK YOU FOR YOUR ATTENTION 31
Editor's Notes
- #6: Scalability of handover framework to handle increased handovers without compromising latency performance Flexibility to support various 4G deployments
- #17: Mobility framework designed to cover: all possible deployment scenarios enable and optimize handover between IEEE 802.16m Bss handover from an IEEE 802.16e BS to an IEEE 802.16m BS (note: under a legacy ASN network) intra-BS zone switch between LZone and Mzone