ia syllabus 2017 pdf

1. Overview of Computer Overview of Computer System: What is a Computer? oComputer is a device that transforms data into meaningful information. Data can be anything like marks obtained by you in various subjects. It can also be name, age, sex, weight, height, etc. of all the students in a class. Computer can also be defined in terms of functions it can perform. A computer can i) accept data, ii) store data, iii) process data as desired, and iv) retrieve the stored data as and when required and v) print the result in desired format. The major characteristics of a computer are high speed, accuracy, diligence, versatility and storage. Type your text Figure: Why we need computer? www.onlinejobstudy.com 1 | P a g e

2. Overview of Computer Figure: Use of Computer What does computer do? oComputer collect data and does processing on the data. After the processing data is concerted to processing. Information is meaningful output of processed data.    It is an electronic device used to: Store Retrieve and process data Computer  Data Unprocessed data, figures and stats  Process Conversion of raw data into useful information Figure: Basic task of Computer www.onlinejobstudy.com 2 | P a g e

3. Overview of Computer Data processing: Input (data) Processing Output (Information) Figure: Data processing How does computer work? oA Computer is a machine which solves problems for people written as programs. oA Program is a sequence of statements/steps stating how to perform a task. For each step an arithmetic and logical operation is done. For each operation a different set of control signals is needed – i.e. an instruction. An instruction can be machine language instructions oOr assembly language instructions or even high level language instructions. oA hardware is something that is tangible. For e.g. CPU, Memory, I/O devices, Bus etc. www.onlinejobstudy.com 3 | P a g e

4. Overview of Computer Main components of a computer system Figure: main components of computer system www.onlinejobstudy.com 4 | P a g e

5. Overview of Computer Hardware Components : Figure: hardware components Computer main components: oCentral Processing Unit (CPU) oMain Memory oInput / Output devices oBus www.onlinejobstudy.com 5 | P a g e

6. Overview of Computer Block diagram of computer is below: Here we will study about CPU and memory. In the second part we will learn about I/O system. oCPU: CPU is the part of the computer that performs the bulk of the data processing operations. Its main function is to execute programs stored in the main memory by fetching the instructions, examining them and executing them. The ALU and the CU of a computer system are jointly known as the central processing unit (CPU). You may call CPU as the brain of any computer system. www.onlinejobstudy.com 6 | P a g e

7. Overview of Computer Parts of CPU oControl Unit ( CU ) oArithmetic and Logical Unit (ALU) oRegisters oControl Unit:The process of input, output, processing and storage is performed under the supervision of a unit called 'Control Unit'. It decides when to start receiving data, when to stop it, where to store data, etc. It takes care of step -by-step processing of all operations inside the computer. oThe control unit fetches program instructions from main memory, decodes these instructions and sends control signals to other units of a computer system. The execution of a machine instruction consists of a sequence of steps by accessing the main memory as and when necessary to read data. ALU oThe major operations performed by the ALU are addition, subtraction, multiplication, division, logic and comparison. REGISTERS oThe registers store intermediate data used during the execution of the instructions. We know that memory locations are needed for storing pointers, counters, return addresses, temporary results, partial products etc. But having to refer to memory locations for oApplications is time consuming as memory access is very time consuming. It is more convenient and more efficient to store these intermediate values in registers inside the processor. When a large no. of registers are included in the CPU, it is efficient to connect them through a common bus system. Von Neumann architecture - characteristics oOne processor oUse of stored programs oSequential processing of instructions oSingle Instruction, Single Data stream (SISD) mode 7 | P a g e www.onlinejobstudy.com

8. Overview of Computer Fetch-decode-execute cycle oFetch Phase oDecode Phase oExecute Phase Measures of CPU performance oMIPS (Million instructions par second) oClock Speed(How fast does clock move of processor) oFLOPS (Floating point operations execution par second) Memory oPlace to store programs and data oStored as bits/bytes/words. oA bit is binary digit taking a value of either 0 or 1. oA byte is collection of 8 bits. oA word is collection of 16, 32 or 64 bits. www.onlinejobstudy.com 8 | P a g e

9. Overview of Computer Categories oPrimary Memory oSecondary Memory oInternal Memory Memory Seconday memory Main memory Cache memory Registes RAM ROM Internal External Figure: Memory Types Primary Memory: oImplemented in high speed devices located outside CPU oCostly and volatile oHolds program contents currently being executed & small amount of data Example: RAM Secondary Memory: oLow speed oNon-volatile oHolds program not currently being executed oHolds large data 9 | P a g e www.onlinejobstudy.com

10. Overview of Computer Examples: Disk, Tape Internal Memory: oImplemented in very high-speed devices located within CPU oHolds currently execution instructions and few data related items oVery expensive oExamples: Registers Bus oParallel wires that carry several bits at a time Carries instructions, data, addresses or commands unidirectional or bi-directional. It is a ribbon like set of parallel wires that can carry several bits at the same time. www.onlinejobstudy.com 10 | P a g e

11. Overview of Computer Major Categories o–Data bus o– Address bus o– Control bus www.onlinejobstudy.com 11 | P a g e