Introduction to Computer
- 1. Introduction to Computers By Ms.A.Thamizhiniyal, M.C.A., M.Phil., Assistant Professor, Bon Secours College for Women, Thanjavur. 1
- 2. 2 What Is A Computer? A computer is an electronic device, operating under the control of instructions (software) stored in its own memory unit, that can accept data (input), manipulate data (process), and produce information (output) from the processing. Generally, the term is used to describe a collection of devices that function together as a system.
- 3. 3 Devices that comprise a computer system Printer (output) Monitor (output) Speaker (output) Scanner (input) Mouse (input) Keyboard (input) System unit (processor, memory…) Storage devices (CD-RW, Floppy, Hard disk, zip,…)
- 4. 4 What Does A Computer Do? Computers can perform four general operations, which comprise the information processing cycle. Input Process Output Storage
- 5. 5 What Do Computers Do? Input, Process, Output, & Store data Input Process Output Store Data
- 6. 6 Data and Information All computer processing requires data, which is a collection of raw facts, figures and symbols, such as numbers, words, images, video and sound, given to the computer during the input phase. Computers manipulate data to create information. Information is data that is organized, meaningful, and useful. During the output Phase, the information that has been created is put into some form, such as a printed report. The information can also be put in computer storage for future use.
- 7. 7 Why Is A Computer So Powerful? The ability to perform the information processing cycle with amazing speed. Reliability (low failure rate). Accuracy. Ability to store huge amounts of data and information. Ability to communicate with other computers.
- 8. 8 How Does a Computer Know what to do? It must be given a detailed list of instructions, called a compute program or software, that tells it exactly what to do. Before processing a specific job, the computer program corresponding to that job must be stored in memory. Once the program is stored in memory the compute can start the operation by executing the program instructions one after the other.
- 9. 9 What Are The Primary Components Of A Computer ? Input devices. Central Processing Unit (containing the control unit and the arithmetic/logic unit). Memory. Output devices. Storage devices.
- 10. 10 Uses of Computer PC at Home Common uses for the computer within the home Computer games Working from Home Banking from Home Connecting to the Web
- 11. 11 Uses of Computer Office Applications Stock Control Stock control is ideal for automation and in many companies it is now completely computerized. The stock control system keeps track of the number of items in stock and can automatically order replacement items when required. Accounts / Payroll In most large organizations the accounts are maintained by a computerized system. Due to the repetitive nature of accounts a computer system is ideally suited to this task and accuracy is guaranteed.
- 12. 12 Uses of Computer Automated Production Systems Many car factories are almost completely automated and the cars are assembled by computer-controlled robots. This automation is becoming increasingly common throughout industry. Design Systems Many products are designed using CAD (Computer Aided Design) programs to produce exact specifications and detailed drawings on the computer before producing models of new products.
- 13. 13 Uses of Computer Computers in Daily Life Accounts Games Educational On-line banking Smart ID cards Supermarkets Working from home (Tele-working) Internet
- 15. The Five Generations of Computers The Five Generations of Computers
- 16. First generation computers (1940-1956) The first computers used vacuum tubes for circuitry and magnetic drums for memory. They were often enormous and taking up entire room. First generation computers relied on machine language. . They were very expensive to operate and in addition to using a great deal of
- 18. Second generation computers (1956-1963) • Transistors replaced vacuum tubes and ushered in the second generation of computers. • Second-generation computers moved from cryptic binary machine language to symbolic. • 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.
- 20. Third generation computers (1964-1971) The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on siliconchips, called semiconductors. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system. Allowed the device to run many different applications at one time.
- 22. Fourth generation computers (1971-present) The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. The Intel 4004 chip, developed in 1971, located all the components of the computer. From the central processing unit and memory to input/output controls—on a single chip. . Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.
- 24. Fifth generation computers (present and beyond) Fifth generation computing devices, based on artificial intelligence. Are still in development, though there are some applications, such as voice recognition. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.
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- 28. 28 Types of Computers Types of Computers Microcomputer Minicomputer Mainframe Supercomputer
- 29. 29 Microcomputer Can be classified into: Desktop PCs sits on desks, rarely moved, large and bulky. Memory capacity, graphics capacity and software availability vary from one computer to another Used both for business and home applications
- 30. 30 Microcomputer Portable PCs Can be moved easily from place to place Weight may varies Small PCs are popular known as laptop Widely used by students, scientist, reporters, etc
- 31. 31 Microcomputer Model Desktop NotebookLaptop SubnotebookSubnotebook PalmtopPalmtop
- 32. 32 Microcomputer Advantages Small size Low cost Portability Low Computing Power Commonly used for personal applications Disadvantages Low processing speed
- 33. 33 Uses of Microcomputer Word Processing Home entertainment Home banking Printing Surfing the internet etc
- 34. 34 Minicomputer Medium sized computer Also called the minis e.g. IBM36, HP9000, etc Computing power lies between microcomputer and mainframe computer
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- 36. 36 MiniComputer Characteristics Bigger size than PCs Expensive than PCs Multi-User Difficult to use More computing power than PCs Used by medium sized business organizations, colleges, libraries and banks.
- 37. 37 Uses of Minicomputer Control of Automated Teller Machine (ATMs) Payroll Hospital patients registration Inventory Control for supermarket Insurance claims processing Small bank accounting and customer details tracking
- 38. 38 Minicomputer Advantage Cater to multiple users Lower costs than mainframes Disadvantage Large Bulky
- 39. 39 Mainframe Known as enterprise servers Occupies entire rooms or floors Used for centralized computing Serve distributed users and small servers in a computing network
- 40. 40 Main Frame Large, fast and expensive computer Cost millions of dollar e.g. IBM3091, ICL39, etc Characteristics: Bigger in size than minicomputers Very expensive Support a few hundred users simultaneously (Multi-Users) Difficult to use More computing power than minicomputers Have to be kept in a special air-conditioned room Used in big business organizations and government departments
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- 43. 43 Mainframe Advantage Supports many users and instructions Large memory Disadvantage Huge size Expensive
- 44. 44 Supercomputer Fastest and expensive Used by applications for molecular chemistry, nuclear research, weather reports, and advanced physics Consists of several computers that work in parallel as a single system
- 45. 45 Super Computer Advantage Speed Disadvantage Generate a large amount of heat during operation
- 46. 46 Computer System A computer system consists of three primary units: Input units – accept data Processor unit – processes data by performing comparisons and calculations Output units – present the results
- 48. 48 Input Devices Data are facts, numbers and characters that are entered into the computer via keyboard. Other types of input devices are mouse, joystick, light pens, scanners, camera, etc.
- 49. 49 Computer Input DevicesComputer Input Devices Keyboard Mouse/Trackball Joystick Light pen Pointing Stick Touchpad Touch screen Bar code reader Scanner Microphone Graphics Tablet Digital Cameras
- 50. 50 Processor Unit Two main parts: CPU – where the actual processing takes place; and Main memory – where data are stored. The contents of main memory can be transferred to auxiliary storage devices such as hard disks, floppy diskettes, zip disks, compact disks, or USB flash disk.
- 51. 51 The microprocessor, the brains of the computer. Referred to a CPU or processor Housed on a tiny silicon chip Chip contains millions of switches and pathways that help your computer make important decisions. Central Processing UnitCentral Processing Unit
- 52. 52 •CPU knows which switches to turn on and which to turn off because it receives its instructions from computer programs (software). •CPU has two primary sections: • Arithmetic/logic unit • Control unit
- 53. 53 Arithmetic/logic unit (ALU):Arithmetic/logic unit (ALU): - Performs arithmetic computations and logical operations; by combining these two operations the ALU can execute complex tasks. - Arithmetic operations include addition, subtractions, multiplication, and division. - Logical operations involve comparisons.
- 54. 54 Control UnitControl Unit: •Uses programming instructions, it controls the flow of information through the processor by controlling what happens inside the processor. •We communicate with the computer through programming languages. Examples: COBOL, C++, HTML, Java Script or VisualBasic.net
- 55. 55 MemoryMemory Found on the motherboard Short term Random Access Memory (RAM)Random Access Memory (RAM) Long term Read Only Memory (ROM)Read Only Memory (ROM)
- 56. 56 Random Access Memory (RAM)Random Access Memory (RAM) •Memory on the motherboard that is short term; where data, information, and program instructions are stored temporarily on a RAM chip or a set of RAM chips. •Known as the main memory. •This memory is considered volatile. •The computer can read from and write to RAM.
- 57. 57 •When the computer is turned off or if there is loss of power, what ever is stored in RAM disappears. •“Temporary Memory” – Short Term
- 58. 58 Read-Only Memory (ROM)Read-Only Memory (ROM) •Memory on the motherboard that is long term; where the specific instructions that are needed for the computer to operate are stored. •This memory is nonvolatile and your computer can only read from a ROM chip.
- 59. 59 •The instructions remain on the chip regardless if the power is turned on or off. •Most common is the BIOS ROM; where the computer uses instructions contained on this chip to boot or start the system when you turn on your computer. •“Permanent Memory” – Long Term
- 60. 60 Output Unit After the data has been processed, the results are output in the form of useful information. Output units such as monitors and printers make the result accessible for use by people.
- 61. 61 Computer Output DevicesComputer Output Devices MonitorMonitor: screen that display information such as text, numbers, and pictures- softcopy. PrinterPrinter: gives you information from the computer in printed form – hardcopy. SpeakersSpeakers: allow you to hear voice, music, and other sounds from your computer. ModemModem: allows you to use your computer to communicate with other computers.
- 62. 62 Input Devices Keyboard. Mouse.
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