1 fundamentals of computer system
- 1. Fundamentals of Computer System Bali Thorat
- 2. What is a Computer? • A computer is an electronic device that accepts data from the user, processes it, produces results, displays them to the users, and stores the results for future usage. • Data is a collection of unorganized facts & figures and does not provide any further information regarding patterns, context, etc. Hence data means "unstructured facts and figures". • Information is a structured data i.e. organized meaningful and processed data. To process the data and convert into information, a computer is used. Bali Thorat
- 3. Characteristics and Features of the computer Bali Thorat
- 4. Speed • A computer works with much higher speed and accuracy compared to humans while performing mathematical calculations. Computers can process millions (1,000,000) of instructions per second. The time taken by computers for their operations is microseconds and nanoseconds. Bali Thorat
- 5. Accuracy • Computers perform calculations with 100% accuracy. Errors may occur due to data inconsistency or inaccuracy. Bali Thorat
- 6. Diligence • A computer can perform millions of tasks or calculations with the same consistency and accuracy. It doesn’t feel any fatigue or lack of concentration. Its memory also makes it superior to that of human beings. Bali Thorat
- 7. Versatility • Versatility refers to the capability of a computer to perform different kinds of works with same accuracy and efficiency. Bali Thorat
- 8. Reliability • A computer is reliable as it gives consistent result for similar set of data i.e., if we give same set of input any number of times, we will get the same result. Bali Thorat
- 9. Automation • Computer performs all the tasks automatically i.e. it performs tasks without manual intervention. Bali Thorat
- 10. Memory • A computer has built-in memory called primary memory where it stores data. • Secondary storage are removable devices such as CDs, pen drives, etc., which are also used to store data. Bali Thorat
- 11. Components of Computer • Computer systems consist of three components as shown in below image: – Central Processing Unit, – Input devices and – Output devices. Bali Thorat
- 12. Block Diagram of Computer Bali Thorat
- 13. Organization of Computer • Computer organization consist of following parts • CPU – central processing unit • Memory • Input devices • Output devices Bali Thorat
- 14. Input Devices • A device that can be used to insert data into a computer system is called as input device. It allows people to supply information to computers. • An input device is any hardware device that sends data to the computer, without any input devices, a computer would only be a display device and not allow users to interact with it, much like a TV. • The most fundamental pieces of information are keystrokes on a keyboard and clicks with a mouse. These two input devices are essential for you to interact with your computer. Input devices represent one type of computer peripheral. • Examples of input devices include keyboards, mouse, scanners, digital cameras and joysticks. • Input devices provide data input to processor, which processes data and generates useful information that’s displayed to the user through output devices. This is stored in computer’s memory. Bali Thorat
- 15. CPU – central processing unit • It is alternatively referred to as the brain of the computer, processor, central processor, or microprocessor, the CPU was first developed at Intel with the help of Ted Hoff in the early 1970’s and is short for Central Processing Unit. The computer CPU is responsible for handling all instructions it receives from hardware and software running on the computer. • 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. Bali Thorat
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- 17. • CPU itself has following three components • ALU (Arithmetic Logic Unit) • Memory Unit • Control Unit Bali Thorat
- 18. Arithmetic Logic Unit (ALU) • All arithmetic calculations and logical operation are performed using the Arithmetic/Logical Unit or ALU • Data entered into computer is sent to RAM, from where it is then sent to ALU, where rest of data processing takes place. All types of processing, such as comparisons, decision-making and processing of non-numeric information takes place here and once again data is moved to RAM. Bali Thorat
- 19. Control Unit • As name indicates, this part of CPU extracts instructions, performs execution, maintains and directs operations of entire system. • Control unit help to perform operations of input unit, output unit, Memory unit and ALU in a sequence. • Functions of Control Unit – It controls all activities of computer – Supervises flow of data within CPU – Directs flow of data within CPU – Transfers data to Arithmetic and Logic Unit – Transfers results to memory – Fetches results from memory to output devices Bali Thorat
- 20. Memory • A memory is just like a human brain. It is used to store data and instruction. Computer memory is use to Stores information being processed by the CPU • Computer memory is any physical device capable of storing information temporarily or permanently. For example, Random Access Memory RAM is a type of volatile memory that is stores information on an integrated circuit, and that is used by the operating system, software, hardware, or the user. • This is unit in which data and instructions given to computer as well as results given by computer are stored. Unit of memory is "Byte". • 1 Byte = 8 Bits • Computer memory divide into two parts • 1.Volatile memory • Volatile memory is a temporary memory that loses its contents when the computer or hardware device loses power.eg. RAM • 2.Non-volatile memory • Non-volatile memory keeps its contents even if the power is lost. Example: ROM or EPROM is a good example of a non-volatile memory Bali Thorat
- 21. Output Devices • A device which is used to display result from a computer is called as output device. It Allows people to receive information from computers. • An output device is any peripheral that receives or displays output from a computer. The picture shows an inkjet printer, an output device that can make a hard copy of anything being displayed on a monitor. • Output device is electronic equipment connected to a computer and used to transfer data out of the computer in the form of text, images, sounds or print. • Examples of output devices include Printer, Monitor, etc. Bali Thorat
- 22. Input Devices • Touch Screen • OMR • OBR • OCR • Light Pen • Scanner Bali Thorat
- 23. Touch Screen • A touch screen is a computer display screen that is also an input device. The screens are sensitive to pressure; a user interacts with the computer by touching pictures or words on the screen. Bali Thorat
- 24. OMR • OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked. • It is specially used for checking the answer sheets of examinations having multiple choice questions. Bali Thorat
- 25. OBR • Bar Code Reader is a device used for reading bar coded data (data in the form of light and dark lines). Bar coded data is generally used in labelling goods, numbering the books, etc. It may be a handheld scanner or may be embedded in a stationary scanner. • Bar Code Reader scans a bar code image, converts it into an alphanumeric value, which is then fed to the computer that the bar code reader is connected to. Bali Thorat
- 26. OCR • OCR is an input device used to read a printed text. • OCR scans the text optically, character by character, converts them into a machine readable code, and stores the text on the system memory. Bali Thorat
- 27. Light Pen • Light pen is a pointing device similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube. • When the tip of a light pen is moved over the monitor screen and the pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU. Bali Thorat
- 28. Scanner • Scanner is an input device, which works more like a photocopy machine. It is used when some information is available on paper and it is to be transferred to the hard disk of the computer for further manipulation. • Scanner captures images from the source which are then converted into a digital form that can be stored on the disk. These images can be edited before they are printed. Bali Thorat
- 29. Digitizers • Digitizer is an input device which converts analog information into digital form. Digitizer can convert a signal from the television or camera into a series of numbers that could be stored in a computer. They can be used by the computer to create a picture of whatever the camera had been pointed at. • Digitizer is also known as Tablet or Graphics Tablet as it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for fine works of drawing and image manipulation applications. Bali Thorat
- 30. Output Devices • Plotters • LCD Projector • Plasma Display • Printers Bali Thorat
- 31. Plotter • A plotter is a computer hardware device much like a printer that is used for printing vector graphics. Instead of toner, plotters use a pen, pencil, marker, or another writing tool to draw multiple, continuous lines onto paper rather than a series of dots like a traditional printer. Bali Thorat
- 32. LCD Projector • An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of the slide projector or overhead projector. • They are commonly used in business meetings, presentations and seminars. • LCD projectors work by using three liquid crystal panels, a lamp, a prism, and filters to create the image on the screen. From there the LCD panels send the light through the dichroic prism which recombines the light and sends it out the main lens in the LCD projector to the surface against which it is projected. Bali Thorat
- 33. Plasma Display • A plasma display is a computer video display in which each pixel on the screen is illuminated by a tiny bit of plasma or charged gas, somewhat like a tiny neon light. Plasma displays are thinner than cathode ray tube ( CRT ) displays and brighter than liquid crystal displays ( LCD ). Bali Thorat
- 34. Printers • Printer is an output device, which is used to print information on paper. • There are two types of printers − • Impact Printers • Non-Impact Printers Bali Thorat
- 35. • Impact Printers – Impact printers print the characters by striking them on the ribbon, which is then pressed on the paper. • Characteristics of Impact Printers are the following − – Very low consumable costs – Very noisy – Useful for bulk printing due to low cost – There is physical contact with the paper to produce an image • These printers are of two types − • Character printers • Line printers Bali Thorat
- 36. • Character Printers – Character printers are the printers which print one character at a time. • These are further divided into two types: – Dot Matrix Printer(DMP) – Daisy Wheel • Line Printers – Line printers are the printers which print one line at a time. • These are of two types − – Drum Printer – Chain Printer Bali Thorat
- 37. • Non-impact Printers – Non-impact printers print the characters without using the ribbon. These printers print a complete page at a time, thus they are also called as Page Printers. • Characteristics of Non-impact Printers – Faster than impact printers – They are not noisy – High quality – Supports many fonts and different character size • These printers are of two types − • Laser Printers • Inkjet Printers Bali Thorat
- 38. Software • Software is a set of programs, which is designed to perform a well-defined function. A program is a sequence of instructions written to solve a particular problem. • There are two types of software − • System Software • Application Software Bali Thorat
- 39. System Software • The system software is a collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. System software is generally prepared by the computer manufacturers. These software products comprise of programs written in low-level languages, which interact with the hardware at a very basic level. System software serves as the interface between the hardware and the end users. • Some examples of system software are Operating System, Compilers, Interpreter, Assemblers, etc. Bali Thorat
- 40. Features of a system software • Close to the system • Fast in speed • Difficult to design • Difficult to understand • Less interactive • Smaller in size • Difficult to manipulate • Generally written in low-level language Bali Thorat
- 41. Application Software • Application software products are designed to satisfy a particular need of a particular environment. All software applications prepared in the computer lab can come under the category of Application software. • Application software may consist of a single program, such as Microsoft's notepad for writing and editing a simple text. It may also consist of a collection of programs, often called a software package, which work together to accomplish a task, such as a spreadsheet package. • Examples of Application software are the following − • Payroll Software, Student Record Software, Inventory Management Software, Income Tax Software, Railways Reservation Software, Microsoft Office Suite Software, Microsoft Word, Microsoft Excel, Microsoft PowerPoint Bali Thorat
- 42. Features of application software • Close to the user • Easy to design • More interactive • Slow in speed • Generally written in high-level language • Easy to understand • Easy to manipulate and use • Bigger in size and requires large storage space Bali Thorat