1 CSE 101 Lesson - 2 An Overview on Computer System

2 This Lesson Includes Following section The parts of the computer systemLooking Inside the machineSoftware bring the machine to lifeComputers Today

3 A computer is an electronic device which-  can respond to a specific set of instructions in a well-defined manner.  can execute a prerecorded list of instructions (a program).

4 UserData SoftwareHardware WhatHow WhoWhich A complete computer system includes four distinct parts

5 A computer hardware consists of electronic device; the part we can see and touch. The term "device" refers to any piece of hardware used by the computer, keyboard, monitor, modem, mouse, etc. A computer hardware consists of many different part. They are divided in two different groups.  Internal Hardware  External Hardware

6 Internal Hardware: An Internal Hardware means hardware that surrounded by the computer's casing. External Hardware: By external hardware we mean all the computer device that we can see from outside.

7 Software What is Software? Software is a set of electronic instructions that tells the computer how to do certain tasks. A set of instructions is often called a program. The two most common types of programs are : System software Application software. What is System Software? System Software refers to the operating system and all utility programs that manage computer resources at a low level. Systems software includes compilers, loaders, linkers, and debuggers. What is Application Software? Applications software comprises programs designed for an end user, such as word processors, database systems, and spreadsheet programs.

8 System Software – Operating System Operating Systems (OS) An Operating system is a program that controls the hardware directly.  They provide an interface between the user and the computer hardware.  They provide a way for applications software to communicate with the hardware. The OS is a program that conducts the communication between the various pieces of hardware like the video card, sound card, printer, the motherboard and the applications.  They manage the system resourses such as memory and also allocate CPU time to the task being run.  They manage system security.

9 System Software – Operating System Function of the Operating Systems User Interface Resource Management Task Management File Management SecuityUtilities User Interface The User interface is what you see when you turn on the computer. It Consists of the cursors, prompts, icons, menus, etc.

10 Operating System – User Interface Type of User Interface User Interfaces can be: 1 Command Driven 2 Menu Driven 3 Graphical (GUI – Graphical User Interface)

11 OS – User Interface – GUI GUI Component Main four components found in most graphical user interfaces. Graphical User Interface GUI Tools Application and the Interface MenusDialog Box

12 OS – User Interface – GUI Designing a user interface To make an interface as user friendly as possible it is necessary to take care when designing it and takes into account the following: User Interface Consistency Positioning of item on Screen Use of Color Use of sounds Availability of help

13 System Software – Operating System Operating system’s role in running software programs 1 Basic Services 2 Sharing Information 3 Multi-Tasking

14 Application Software Software System Software System Management Program System Support Program System Development Program Application Software General Application Program Specific Application Program

15 The Part of Computer system - Data Data consists of raw facts, which the computer can manipulate and process into information that is useful to people. Computerized data is digital, meaning that it has been reduced to digits, or numbers. The computer stores and reads all data as numbers. Although computers use data in digital form, they convert data into forms that people can understand, such as text, numerals, sounds, and images.

16 The Part of Computer system - USERS People are the computer's operators, or users. Some types of computers can operate without much intervention from people, but personal computers are designed specifically for use by people.

17 Looking inside the machine A computer hardware devices are categorized as follows: CPU Processor Memory / Storage Device Control Unit (I/O) Device Input Device Output Device

18 How Computer Process Data Where Processing Occurs: The Control Unit The Arithmetic Logic Unit Machine Cycles Processing takes place in the PC's central processing unit (CPU). The system's memory also plays a crucial role in processing data. Both the CPU and memory are attached to the system's motherboard, which connects all the computer's devices together, enabling them to communicate.

19 How Computer Process Data – The Control Unit The two main parts of a CPU are the control unit and the arithmetic logic unit (ALU) The control unit directs the flow of data through the CPU, and to and from other devices. The control unit stores the CPU's microcode, which contains the instructions for all the tasks the CPU can perform.

20 How Computer Process Data – The Arithmatic Logic Unit The actual manipulation of data takes place in the ALU. The ALU can perform arithmetic and logic operations. The ALU is connected to a set of registers—small memory areas in the CPU, which hold data and program instructions while they are being processed Arithmetic Operations Logical Operations + Add ,  equal to, not equal to  Subtract >, > greater than, not greater than x Multiply<, < less than, not less than  Divide ,  greater than or equal to, not greater than or equal to ^ Raise by a power ,  less than or equal to, not less than or equal to ALU Operations List

21 How Computer Process Data – Machine Cycle The CPU follows a set of steps-called a machine cycle-for each instruction it carries out. By using a technique called pipelining, many CPUs can process more than one instruction at a time. The machine cycle includes two smaller cycles:  During the instruction cycle, the CPU "fetches" a command or data from memory and "decodes" it for the processing.  During the execution cycle, the CPU carries out the instruction, and may store the instruction's result in memory.

22 Looking inside the machine – Memory (Count.)  The smallest usable unit of measure for memory is the byte  The amount of memory required to hold one character, like the letter A or the numeral 2.  Computers work with larger chunks of data, measured in multiple bytes, as shown below: 1 byte = 8 bits 1 kilobyte (K / Kb) = 2^10 bytes = 1,024 bytes 1 megabyte (M / MB) = 2^20 bytes = 1,048,576 bytes 1 gigabyte (G / GB) = 2^30 bytes = 1,073,741,824 bytes 1 terabyte (T / TB) = 2^40 bytes = 1,099,511,627,776 bytes 1 petabyte (P / PB) = 2^50 bytes = 1,125,899,906,842,624 bytes 1 1 exabyte (E / EB) = 2^60 bytes = 1,152,921,504,606,846,976 bytes

23 Computers Today SupercomputersMainframe ComputersMinicomputersWorkstations Microcomputers, or Personal Computers

24 Supercomputer A supercomputer is a computer that is considered, or was considered at the time of its introduction, to be at the frontline in terms of processing capacity, particularly speed of calculation. Supercomputers introduced in the 1960s were designed primarily by Seymour Cray at Control Data Corporation (CDC), and led the market into the 1970s until Cray left to form his own company, Cray Research. Today, supercomputers are typically one-of-a-kind custom designs produced by "traditional" companies such as IBM and HP, who had purchased many of the 1980s companies to gain their experience, although still specializes in building supercomputer The term supercomputer itself is rather fluid, and today's supercomputer tends to become tomorrow's normal computer.

25 Supercomputer – Common Uses Supercomputers are used for  Highly calculation-intensive tasks such as problems involving quantum mechanical physics,  Weather forecasting, climate research (including research into global warming),  Molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals),  Physical simulations (such as simulation of airplanes in wind tunnels,  Simulation of the detonation of nuclear weapons, and research into nuclear fusion),  Cryptanalysis, and the like.  Major universities, military agencies, scientific research laboratories are heavy users.

26 Supercomputer – Today Roadrunner is a supercomputer built by IBM at the Los Alamos National Laboratory in New Mexico, USA. Price - US$133-million = TK 919,99,99,977.00

27 Supercomputer – Today The systems ranked #1 since 1993 [ Fujitsu K computer ( Japan, June 2011 – present)K computerJapan NUDT Tianhe-1A ( China, November June 2011)Tianhe-1AChina Cray Jaguar ( United States, November November 2010)JaguarUnited States IBM Roadrunner ( United States, June 2008 – November 2009)RoadrunnerUnited States IBM Blue Gene/L ( United States, November 2004 – June 2008)Blue GeneUnited States NEC Earth Simulator ( Japan, June 2002 – November 2004)Earth SimulatorJapan IBM ASCI White ( United States, November 2000 – June 2002)ASCI WhiteUnited States Intel ASCI Red ( United States, June 1997 – November 2000)ASCI RedUnited States Hitachi CP-PACS ( Japan, November 1996 – June 1997)CP-PACSJapan Hitachi SR2201 ( Japan, June 1996 – November 1996)SR2201Japan Fujitsu Numerical Wind Tunnel ( Japan, November 1994 – June 1996)Numerical Wind TunnelJapan Intel Paragon XP/S140 ( United States, June 1994 – November 1994)Paragon XP/SUnited States Fujitsu Numerical Wind Tunnel ( Japan, November 1993 – June 1994)Numerical Wind TunnelJapan TMC CM-5 ( United States, June 1993 – November 1993)CM-5United States

28 Mainframe Computer Mainframes are computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics, ERP, and financial transaction processing. Mainframe computers can support hundreds or thousands of users, handling massive amounts of input, output, and storage. Mainframe computers are used in large organizations where many users need access to shared data and programs. Mainframes are also used as e- commerce servers, handling transactions over the Internet. Nearly all mainframes have the ability to run (or host) multiple operating systems and thereby operate not as a single computer but as a number of virtual machines. In this role, a single mainframe can replace dozens or even hundreds of smaller servers, reducing management and administrative costs while providing greatly improved scalability and reliability.

29 Mini Computer Minicomputers are smaller than mainframes but larger than microcomputers. Minicomputers usually have multiple terminals. Minicomputers may be used as network servers and Internet servers.

30 Workstations Workstations are powerful single-user computers. Workstations are used for tasks that require a great deal of number-crunching power, such as product design and computer animation. Workstations are often used as network and Internet servers.

31 Microcomputers Microcomputers are more commonly known as personal computers. The term "PC" is applied to IBM-PCs or compatible computers. Full-size desktop computers are the most common type of PC. Notebook (laptop) computers are used by people who need the power of a desktop system, but also portability. Handheld PCs (such as PDAs) lack the power of a desktop or notebook PC, but offer features for users who need limited functions and small size.

32 Microcomputers Today

33 Any Question ?

34 Thank You “Its not the end, its not even the beginning of the end. Its only the end of beginning.”