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Computer Hardware Computer Software

Computer Hardware Computer Software

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Computer Hardware Computer Software

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  1. Computer HardwareComputer Software

  2. Computer Components CPU Input Devices Secondary Storage Buses Communications Devices Output Devices Primary Storage

  3. How Computers Represent Data • Bit • Binary Digit. On/off, 0/1, Magnetic/not • Byte • Group of Bits for One Character • EBCDIC- Extended Binary Coded Decimal Interchange Code (8 or 9 Bits Per Byte) • ASCII- American Standard Code for Information Exchange (7 or 8 Bits Per Byte) • Parity Bit • Extra Bit Added to Each Byte to Help Detect Errors

  4. C: 1100 0011 0 100 0011 1 A: 1100 0001 1 100 0001 0 T: 1110 0011 1 101 0100 1 Note how sum for each byte is an EVEN number Examples Of Bytes EBCDIC ASCII (assume even-parity system)

  5. CPU - Central Processing Unit • It is the Heart of the Computer. • A Collection Of Electronic Circuits. • Electronic Impulses Enter The CPU From An Input Device. • These Impulses Are Sent Under Program Control Through Circuits To Create A Series Of New Impulses. • A Set Of Impulses Leaves The CPU For The Output Device.

  6. Two CPU Sections • Arithmetic/Logic Unit (ALU) - Performs Arithmetic And Logical Operations On Data. • Arithmetic Operations: + - * / • Logical Operations: Comparing Data • Control Unit - Section Of The CPU That Directs The Flow Of Electronic Traffic Between: • Memory And The ALU • CPU and Input And Output Devices

  7. Memory • Primary (Internal) Storage Holds: • Programs And Data Passed To The Computer For Processing • Intermediate Processing Results • Output That Is Ready To Be Transmitted To Secondary Storage Or To An Output Device. Eg: RAM

  8. Memory Address • Once Programs, Data, Intermediate Results, And Output Are Stored In Memory, The CPU Must Be Able To Find Them Again. • Each Location In Memory Has An Address.

  9. Memory Size • Kilobyte (KB): 210 Bytes... 1024 Bytes • Megabyte (MB): 210 KB... “Million” Bytes • Gigabyte (GB): 210 MB... “Billion” Bytes • Terabyte (TB): 210 GB... “Trillion” Bytes

  10. Registers • A High Speed Staging Area Within The Computer That Temporarily Stores Data During Processing. • These Areas Called Registers. • Part Of The CPU

  11. Instruction Address Storage Accumulator Holds The Part Of The Instruction Indicating What The Computer IsTo Do Next. Contains The Memory LocationOf Data To Be Used. Prior To Processing, The RegisterThat Temporarily Stores Data That Have Been Retrieved From Memory. Stores The Result Of An ArithmeticOr Logical Operator. Four Types Of Registers

  12. Types Of Memory • RAM : Random Access Memory • Dynamic: Changes Thru Processing • Static: Remains Constant (Power On) • ROM : Read Only Memory (preprogrammed) • PROM: Program Can Be Changed Once • EPROM: Erasable Thru Ultraviolet Light • EEPROM: Electrically Erasable

  13. How Devices Are Linked I/O Devices CPU RAM ROM Add-In Boards BUS BUS allows CPU to communicate with RAM, ROM, and peripheral devices connected through either boards or ports. Ports I/O Devices

  14. Secondary Storage • Disk • Tape • Optical Storage

  15. Optical Storage • CD-ROM: 500-660 MEGABYTES • LAND: Flat parts of disk surface reflects light • PITS: small scratch on surface scatters light • WRITE ONCE / READ MANY (WORM): • CD-R: Compact Disk - Recordable • CD-RW: CD - Rewritable • DIGITAL VIDEO DISK (DVD): CD size, up to 10 gigabytes of data

  16. Input/Output Devices • Pointing Devices • Source Data Automation • Output Devices

  17. Pointing Devices • Keyboard • Mouse • Wired • Infra-red • Trackball • Touch Pad • Joystick • Touch Screen

  18. Source Data Automation • Captures Data In Computer Form At Time & Place Of Transaction • Barcode • Identifies Products in Stores, Warehouses, Shipments • Magnetic Ink Character Recognition (MICR) • Special Ink Identifies Bank, Account, Amount

  19. Source Data Automation • Pen-Based Input • Digitizes Signature • Digital Scanner • Translates Images & Characters Into Digital Form • Voice Input Devices • Converts Spoken Word Into Digital Form • Sensors • Devices That Collect Data From Environment for Computer Input (E.G., Thermometers, Pressure Gauges)

  20. Output Devices • Cathode Ray Tube (CRT) • Printer • Plotter • Voice Output Device

  21. Data Processing • Batch Processing • Transaction Data Stored Until Convenient to Process As a Group. Useful for Less Time-sensitive Actions. • On-line Processing • Transaction Data Entered Directly Into System, Constantly Updating Files. Requires Direct-access Devices.

  22. Categories Of Computers • Supercomputer • Mainframe • Midrange & Minicomputer • Server • Personal Computer (PC) • Workstation

  23. Supercomputer • Highly Sophisticated • Complex Computations • FASTEST CPUs • Large Simulations • State-of-the-art Components • Expensive

  24. Mainframe • Largest Enterprise Computer • 50 Megabytes to Over One Gigabyte RAM • Commercial, Scientific, Military Applications • Massive Data • Complicated Computations

  25. Midrange/Minicomputer • Middle-Range • 10 Megabytes To Over One Gigabyte RAM • Universities, Factories, Labs • Used As Front-End Processor For Mainframe

  26. Client / Server • Networked Computers • Client • User (PC, Workstation, Laptop) Requires Data, Application, Communications It Does Not Have • Server • Component (Computer) Having Desired Data, Application, Communications

  27. Requests Data, Service Client / Server Client Server User Interface Application Function Data Application Function Network Resources

  28. Microcomputer • Desktop or Portable • 64 Kilobytes to Over 128 Megabytes RAM • Personal or Business Computers • Affordable • Many Available Components • Can Be Networked

  29. Workstation • Desktop Computer • Powerful Graphics • Extensive Math Capabilities • Multi-tasking • Usually Configured To Special Function: e.g.; CAD, Engineering, Graphics

  30. Centralized / Distributed • Centralized • Processing By Central Computer Site • One Standard • Greater Control • Distributed • Processing By Several Computer Sites Linked By Networks • More Flexibility • Faster Response

  31. Sharing Computers • Network Computer • Simplified Desktop Computer Stores Minimum Data to Function (Uses Server) • Peer-to-Peer Computing • Networked Computers Share Data, Disk Space, Processing. Parallel Processing on a Smaller Scale

  32. Managing Hardware Assets • Understand Technology Requirements • Determine Total Cost Of Ownership • Hardware, Software, Installation, Training, Support, Maintenance, Infrastructure • Plan Capacity & Scalability • Identify Trends

  33. Computer Software

  34. Software • Detailed Instructions To Control Computer Operation • Program • Set Of Instructions To The Computer • Stored • Program Must Be In Primary Storage • System Software • Manages Computer Resources • Application Software • Specific Business Application

  35. Application Software • Operating System: • Scheduled Computer Events • Allocates Computer Resources Monitors Events • Language Translators: • Interpreters • Compilers • Utility Programs: • Routine Operations Manage Data System Software Hardware Software Programming Languages: Assembly Language; Fortran; Cobol; Pl / 1; QBasic; Pascal; C; C++; Fourth Generation Languages

  36. Language Translation • Source Code • High-level Language Instructions • Compiler • Translates High-level Code Into Machine Language • Object Code • Translated Instructions Ready For Computer

  37. Graphical User Interface (GUI) • Operating System Uses • Graphic Icons • Icons, Buttons, Bars, Boxes • Pointer • Mouse, Pen, Touch Screen • To Issue Commands • Make Selections

  38. 32-bit operating system, GUI, multitasking, networking Windows 98 & 95 Windows NT Me & 2000 32-bit operating system not limited to Intel chips. Multitasking, multiprocessing, networking Windows CE Paired-down for handheld computers, wireless communication devices 32-bit. Developed for IBM PS/2. Multitasking, networking OS/2 Microcomputer Operating Systems Operating System Features

  39. Microcomputer Operating Systems Operating System Features Unix For powerful microcomputers, workstations, minicomputers. Multitasking, multi-user processing, networking. Portable to various computer platforms Linux Free, reliable alternative to Unix, Windows. Runs on many Platforms. Open-source Mac OS For Macintosh computers. Multitasking. Powerful graphics, multimedia DOS For IBM (PC-DOS) and PC (MS-DOS). Program memory: 640K

  40. Generations Of Programming Languages • 1st. Since 1940s. Machine Language: Binary Code • 2nd. Since Early ’50s. Assembly Language: Mnemonics for Numeric Code • 3rd. Since Mid ‘50s. High-level Languages • 4th. Since Late ‘70s. Modern Application Packages

  41. High-Level Languages • FORTRAN (Formula Translator): Scientific, Engineering Applications • COBOL (Common Business Oriented Language): Predominant for Transaction Processing • BASIC (Beginners All-purpose Symbolic Instruction Code): General Purpose PC Language

  42. High-level Languages • PASCAL: Used to Teach Structured Programming Practices. Weak in File Handling, Input / Output • C and C++: Powerful PC Language for Developing Applications. Efficient Execution; Cross Platform. C++ Is Object Oriented

  43. Fourth Generation Languages (4GL) • Can Be Employed By End Users • Nonprocedural • Can Develop Applications Quickly • Natural Languages • Six Categories

  44. Fourth Generation Languages (4GL) • Query Languages: • Rapidly Retrieve Data • Interactive/ On-line • May Use NATURAL LANGUAGE • Support Special Requests for Data From Relational Databases

  45. Fourth Generation Languages (4GL) • Report Generators: • Create Customized Reports • Wide Range of Formats • Graphics Languages: • Can Manipulate Drawings, Graphs,Photos, Videos • Presentation Managers

  46. Fourth Generation Languages (4GL) • Application Generators • User Specifies Computer Needs • Generator Creates Logic and Code for Application • Greatly Reduces Development Time • Very High-level Programming Languages • Professional Programmer Productivity Tool • Uses Fewer Instructions • Reduces Development Time

  47. Fourth Generation Languages (4GL) • Software Package: Commercially Available Set of Programs. • Word Processing • Spreadsheets • Data Management • Presentation Management • Integrated Software Package Now Combine These To Simplify Learning And Use

  48. Software Tools • Word Processing • Spreadsheets • Data Management • Presentation Graphics • Integrated Software Suites • E-mail • Web Browsers • Groupware