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  1. Presented By Prof.Y.A.Pathak Assistant Professor In Electronics DEPARTMENT OF PHYSICS DADA PATIL MAHAVIDYALAYA KARJAT DATE: 2603/2014
  2. What is a Computer?  Computer  Device capable of performing computations and making logical decisions  Computers process data under the control of sets of instructions called computer programs  Personal computers: economical enough for individual  Distributed computing: computing distributed over networks  Client/server computing: sharing of information across computer networks between file servers and clients (personal computers) Dale Roberts
  3. 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 electricity, generated a lot of heat, which was often the cause of malfunctions.  The UNIVAC and ENIAC computers are examples of first-generation computing devices.
  4. First generation computers
  5. 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.
  6. Second generation computers
  7. 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.
  8. Third generation computers
  9. 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.
  10. Fourth generation computers
  11. 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.
  12. Fifth generation computers
  13. Input Devices  Input Devices: devices that input information into the computer such as a keyboard, mouse, scanner, and digital camera.
  14. Output Devices  Output: devices that output information from the computer such as a printer and monitor.
  15. Central Processing Unit  CPU (Central Processing Unit) also called the Microprocessor or “The Brain” of the Computer.  Processor speed: The speed at which a microprocessor executes instructions. This is usually measured in megahertz (MHz).  Brands of Processors include:  Pentium  Celeron  MAC  AMD  Cyrix
  16. Central Processing Unit  Computer chip: also called the microprocessor may contain an entire processing unit.  Computer chips contain millions of transistors. They are small pieces of semi-conducting material (silicon).  An integrated circuit is embedded in the silicon. Computers are made of many chips on a circuit board.
  17. Data Storage Devices  The hard-drive is a mechanical storage device typically located internally.  Fast recording and recovery of data  Large storage capacity  Magnetic  Primary storage device for data and programs  Speed is measured in R.P.M.’s
  18. Data Storage Devices (cont’d)  CD-ROM (compact disk read only memory)  Approximately 600 to 700 megabyte of storage  An optical device read by a diode laser
  19. Data Storage Devices (cont’d)  Floppy diskette is magnetic storage device for small amounts of data (1.44MB).  FLASH drive is a compact and portable electronic storage device.  USB (plug and play) supported
  20. Computer Memory  Computer memory is binary (0 or 1) (on or off).  The byte is the standard unit of measurement.  A byte is composed of 8 bits (binary digits).  Typical units of measurement:  1 KB (kilobyte) = 1000 bytes  1 MB (megabyte) =1000 kilobytes or 1 million bytes  1 GB (gigabyte) =1000 megabytes or 1 billion bytes
  21. Computer Memory  RAM (random access memory) stores data that is processing. This type of memory is erased when the computer is turned off.  ROM (read only memory) contains special instructions for the computer to operate.  Cache memory increases the speed of the processor by recording and anticipating instructions.
  22. Resolution  Screen resolution is measured in pixel per inch (ppi), and printer resolution is measured in dots per inch (dpi).  Computer screen resolution is approximately 72 ppi. Width x Height (Pixels) Video Display 640 x 480 Low Resolution 800 x 600 Medium Resolution 1600 x 1200 High Resolution
  24. Software  Program  a sequence of instructions to accomplish a result  a computer processes information under the direction of a program  Data  information to be processed by a program  Example  Data: for each employee, the employee number, hours worked & hourly pay rate  Program: instructions on how to process the data to produce pay cheques, payroll register, etc.
  25. Central Processing Unit Main Memory Floppy Disk Hard Disk Monitor Keyboard A simplified view of a computer system
  26. Hardware Devices  Input Devices (Get information)  Keyboard  Mouse  Scanner  Output Devices (Give information)  Screen/monitor  Printer
  27. Hardware Devices  Processing Device (Arithmetic/logic/repetition)  Central Processing Unit (CPU)  286, 386, 486, Pentium, K5, K6  Has three basic parts  Arithmetic Logic Unit (ALU)  executes all the arithmetic and logic instructions  Control Unit  decodes instructions and determines which is next to be executed  Buses/Registers  Buses are paths for information entering/exiting the CPU  Registers are memory for processing information
  28. The Central Processing Unit  The CPU continuously follows the fetch- decode-execute cycle: fetch Retrieve an instruction from main memory decode Determine what the instruction is execute Carry out the instruction
  29. Hardware Devices  Storage  Two types  Primary and secondary  Primary Storage (main memory)  On board memory (located on the motherboard)  Very fast, but expensive  Two types  RAM – Random Access Memory  ROM – Read Only Memory
  30. Hardware Devices  RAM - Random Access Memory  Read/write capability  Contents lost when computer is turned off (volatile)  A program must be in RAM for it to execute  128 to 256MB for a typical desktop computer
  31. Hardware Devices  ROM - Read Only Memory  Read but not write capability  Permanent (non volatile)  Stores the preliminary instructions to be executed when the computer is turned on, for example  To check RAM  To check communications with peripheral devices  Bootstrap loader program
  32. Hardware Devices Address 9278 9279 9280 9281 9282 9283 9284 9285 9286 Large values are stored in consecutive memory locations 10011010 Each memory cell stores a set number of bits (usually 8 bits, or one byte) Content Main memory is divided into many memory locations (or cells) Each memory cell has a numeric address, which uniquely identifies it
  33. Hardware Devices  Secondary Storage (secondary memory)  External devices (not on the motherboard); either inside or outside the computer  Store programs and data permanently  Slower, but cheaper  RAM - nanoseconds, Drive - milliseconds  Different sizes/styles  Floppy Disk - 1.4MB (portable)  Zip Drive - 100-750MB (portable)  CD - 650MB (portable)  Jaz Drive – 1-2GB (portable) discontinued  Hard Disk Drive >=20GB (not portable)  Tape - 50GB (portable, very slow)  Flash drives (portable)
  34. Hardware Devices  Other devices  Port  For connecting peripheral devices  USB, Parallel and serial ports  Modem (internal or external)  For communicating over telephone lines
  35. Software  A computer program is a series of instructions  each instruction is expressed in a format consistent with a predefined set of rules  a computer processes data under the direction of the instructions in a program  there are instructions to input, process, store and output data  the user of a program (as distinct from its creator) has no need to be aware of the details of its construction  the user is only interested in the services that the program is able to provide
  36. Software  Programming Languages  1st generation  machine language  instructions coded using combinations of 0’s & 1’s  2nd generation  assembly languages (low-level symbolic languages)  instructions coded using letters & numbers  one assembly language instruction is translated into one machine language instruction
  37. Software  Programming Languages  3rd generation  high-level symbolic languages  one instruction generates multiple machine language instructions  4th generation programming languages  non-procedural languages  code “what” not “how”
  38. Software HIGH LEVEL ASSEMBLY MACHINE z = x + y MOV AL, X 0010 1001 0001 MOV AH, Y 0010 1100 0010 ADD AL, AH 0100 0001 0010 MOV Z, AL 0010 0010 1011
  39. Software categories  Operating System  controls all machine activities  provides the user interface to the computer  manages resources such as the CPU and memory  Windows XP, Unix, Linux, Mac OS  Application program  generic term for any other kind of software  word processors, games, . . .  Most operating systems and application programs have a graphical user interface (GUI)
  40. Software  Operating Systems  The most important software on a computer  always running to perform the following tasks  create and manage files  run programs  control information going to/from the peripherals  Eg: MS-DOS  create and manage files - several programs  run programs - COMMAND.COM  peripherals - IO.SYS, MSDOS.SYS
  41. Additional COMPUTER CONCEPTS
  42. An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), manipulate the data according to specified rules (process), produce information (output) from the processing, and store the results for future use.
  43. What does a computer do?  Input  Process  Output  Storage Processor Control Unit/Arithmetic Logic Unit Memory Storage Devices Input Device s Output Devices
  44. Input Devices Any hardware component that allows you to enter data, programs, commands, and user responses into a computer Input Device Examples  Keyboard  Mouse
  45. Output Devices  Output devices make the information resulting from processing available for use  Output Device Examples  Printers  Impact  Nonimpact  Photo  Display Devices  CRT  LCD
  46. Storage Devices  Removable  Floppy disk, or diskette  Compact Disc CD-R, CD-RW, CD- ROM  DVDs – DVD-ROM, DVD-R, DVD- RW, DVD-RAM  Zip disk  Flash disk/USB drive  Tape  Non-Removable  Hard disk
  47. System Unit  The motherboard, or system board, is the main circuit board of the system unit  The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer  The control unit interprets the instructions  The arithmetic/logic unit (ALU) performs the logical and arithmetic processes  Memory, also called random access memory, or RAM, consists of electronic components that store data, instructions, and information, as needed by the processor
  48. Types of Computers Supercomputers and Mainframes Microcomputers  Desktops  Laptops (Notebooks)  Handhelds