computer fundamentals i n.
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  2. Introduction to Computers • A Computer System is an electronic data processing device, which accept and store an input data, process the input, and output the processed data in the required format. • Any digital computer carries out five basic functions: • Takes data as input. • Stores the data/instructions in its memory and can use them when required. • Process the data and convert it into useful information. • Output the information. • Control all the above four steps

  3. Characteristic Features of a Computer • Speed • Storage • Accuracy • Versatility • Automation • Diligence • Networking capabilities

  4. Types of Computers • PC (personal Computer): Single user computer system. Moderately powerful microprocessor. • Workstation: Single user computer system. Similar to personal computer but have more powerful microprocessor. • Mini computer: Multi-user computer system. Capable of supporting hundreds of users simultaneously. • Mainframe computer: Multi-user computer system. Capable of supporting hundreds of users simultaneously. Software technology is different from minicomputer • Super computer: An extremely fast computer which can perform hundreds of millions of instructions per second.

  5. Functional Diagram of a Computer

  6. Components of a Computer The Computer consists of the following basic Components: • Input Devices • Output Devices • CPU (Central {Processing Unit): • Memory Unit • Control Unit • ALU (Arithmetic Logic Unit) • Computer Memory: • Primary Memory • Secondary storage devices

  7. Components of a Computer: Input Devices Devices that are used to enter information and instructions into a computer for storage or processing are called Input devices. The main Input devices of a computer are: • Keyboard • Mouse • Touchpad • Trackball • Touch screen • Light pen • Magnetic ink character recognition (MICR) • Bar code reader • Optical mark reader • Scanner • Microphone

  8. Components of a Computer: Output Devices Output unit consists of devices with the help of which we get the information from the computer. The main Output devices of a computer are: • Monitor • Printer • Plotter • Facsimile (FAX) • Speaker

  9. Components of a Computer: CPU CPU is considered as the brain of the computer. CPU perform all types of data processing operations. It stores data, intermediate results and instructions (program). It (CPU) takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given and the type of data provided. • CPU itself has the following three components. • Memory Unit :This unit can store instructions, data and intermediate results. • Control Unit: This unit controls the operations of all parts of computer. It does not carry out any actual data processing operations. • ALU (Arithmetic Logic Unit): It perform arithmetic operations like addition, subtraction,multiplication& division; and logic operations such as comparing, selecting, matching andmerging of data.

  10. Components of a Computer: Memory • Computer memory is the storage space in computer where data to be processed and instructions required for processing are stored. • Memory is measured in terms of Bytes. Kilobytes (KB), Megabytes (MB), Gigabytes (GB) and Terabytes (TB) are the other units of measure of storage. • Computer’s memory can be classified into two types: • Primary Memory (RAM and ROM) • Secondary storage devices(magnetic and optical)

  11. Components of a Computer: Memory Primary Memory: • The primary/main memory is used to store data and instructions currently required for processing. The software and programs are stored in the primary memory. Since primary storage is small, only a limited amount can be stored therein. Primary memory is of two types: • RAM or Random Access Memory: A RAM constitutes the internal memory of the CPU for storing data, program and program result. It is read/write memory. This memory is volatile hence the contents of RAM are accessible only as long as the computer is on. RAM is small, both in terms of its physical size and in the amount of data it can hold. • ROM or Read Only Memory: This type of memory is non-volatile and contents of this are not lost even when the computer is switched off. This memory is used to store frequently used programs in the system. ROM chip are not only used in the computer but also in other electronic items like washing machine.

  12. Components of a Computer: Memory Secondary Memory / Secondary Storage Devices: • These include devices that are peripheral and are connected and controlled by the computer to enable permanent storage of programs and data. Large files and databases are stored on secondary storage devices. • Secondary Storage Devices can be divided into: • Magnetic Storage Devices • Floppy Disk • Hard Drive • Optical Storage Devices • CD ROM • DV ROM