1A-*The Computer DefinedA Computer is an electronic machine which is fast, accurate and controllable.

A computer is a device that accepts data, then perform arithmetic or logical operations that manipulate or change the data, and finally produces new results from that data.

Information Technology

Hardware, software,telecommunications,database management andother information processingtechnologies used in computerbased information systems.

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1A-*Data and InformationData are facts. The raw material of information.

Information is data arranged in ordered and useful form.

1A-*Software and HardwareSoftware: Any program (set of instructions) that causes a computer to carry out a task or function.

Hardware: The physical elements of the computer system.

1A-*Number SystemsDecimal : Base 10, 0-9

Binary: Base 2, 0-1

Octal: Base 8, 0-7

Hexadecimal: Base 16, 0-9 & A-F

1A-*Bits and Bytes1 Byte = 8 Bits

1 KB(Kilobyte)= 1024 bytes

1 MB(megabyte)= 1024 KB1 GB(gigabyte)= 1024 MB1 TB(terabyte)= 1024 GB

1A-*Computers For Individual UseDesktop computersThe most common type of computerSits on the desk or floorPerforms a variety of tasksWorkstationsSpecialized computersOptimized for science or graphicsMore powerful than a desktop

1A-*Computers For Individual UseNotebook computersSmall portable computersWeighs between 3 and 8 poundsAbout 8 by 11 inchesTypically as powerful as a desktopCan include a docking station

1A-*Computers For Individual UseTablet computersNewest development in portable computersInput is through a penRun specialized versions of office products

1A-*Handheld computersVery small computersPersonal Digital Assistants (PDA)Note taking or contact managementData can synchronize with a desktopSmart phonesHybrid of cell phone and PDAWeb surfing, e-mail accessComputers For Individual Use

1A-*Computers For OrganizationsNetwork serversCentralized computerAll other computers connectProvides access to network resourcesMultiple servers are called server farmsOften simply a powerful desktop

1A-*Computers For OrganizationsMainframesUsed in large organizationsHandle thousands of usersUsers access through a terminal

1A-*Computers For OrganizationsMinicomputersCalled midrange computersPower between mainframe and desktopHandle hundreds of usersUsed in smaller organizationsUsers access through a terminal

1A-*Computers For OrganizationsSupercomputersThe most powerful computers madeHandle large and complex calculationsProcess trillions of operations per secondFound in research organizations

1A-*Computers In SocietyMore impact than any other inventionChanged work and leisure activitiesUsed by all demographic groupsComputers are important because:Provide information to usersInformation is critical to our societyManaging information is difficult

1A-*Computers In SocietyComputers at homeMany homes have multiple computersMost American homes have InternetComputers are used forBusinessEntertainmentCommunicationEducation

1A-*Computers In SocietyComputers in educationComputer literacy required at all levelsComputers in small businessMakes businesses more profitableAllows owners to manageComputers in industryComputers are used to design productsAssembly lines are automated

1A-*Computers In SocietyComputers in health careRevolutionized health careNew treatments possibleScheduling of patients has improvedDelivery of medicine is safer

1A-*Computers In SocietyComputers in governmentNecessary to track data for populationPolice officersTax calculation and collectionGovernments were the first computer users

1A-* Basic Structure of a Computer SystemInput Unit Output Unit Arithmetic Logic Unit (ALU) Control Unit Memory Unit

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Input UnitEnter data into the computer.

Output UnitExtract data from the computer.

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Arithmetic Logic Unit (ALU)Calculates data and compares data. Basic arithmetic operations (add, subtract, multiply, divide etc. )Logical operations (AND, OR).

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Control Unit (CU)Selects, interprets and carries outthe execution of program instructions in their propersequence

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Memory UnitHolds data, instructions and results of processing

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(Hz) is a measure of cycles per second. Megahertz (MHz) means millions of cycles per second Gigahertz (GHz) means Billions of cycle per second. Computer Clock Speed

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A processor can execute an instruction in a given number of clock cycles. As the systems clock speed increases, so does the number of instructions it can carry out each second.

1A-*Input Devices- Keyboard- Pointing Devices- Mouse, Trackball, Joystick - Scanners

Input and Output Devices

1A-*Output Devices- Display Screen CRT Cathode Ray Tube LCD Liquid crystal display

Input and Output Devices

1A-*Output Devices- Printers Dot-matrix printer Laser Printer Ink-jet Printer

- PlotterInput and Output Devices

1A-*Main MemoryRAM (Random Access Memory) - Volatile memory - Read-write memory Everything stored there is lost when the computers power is shut offComputer Memory

1A-*Read Only MemoryROM - Non-Volatile memory - Read only memory ROM holds the start up program thatbegins when the computer is turned onComputer Memory

1A-*Sequential Access Storage Devices Sequential Access Storage means the data is stored in particular order. So the computer must sequentially search for data. Today sequential access storage devices are most commonly used for backup purposes. Magnetic Tape Tape Cartridges Secondary Storage Media & Devices

1A-*Direct Access Storage Devices Direct access means the data is stored in a particular memory location with a specific address so that any data can be found quickly. Direct access storage devices are magnetic disk drives used for secondary storage. Floppy Disk Hard Disk Drive Optical DiskSecondary Storage Media & Devices

1A-* The term bus refers to the paths between the components of a Computer. Data Bus Address BusBUS

1A-* High-speed memory that resides between the CPU and RAM in a computer. Cache memory stores data and instructions that the CPU is likely to need next. The CPU can retrieve data or instructions more quickly from cache than it can from RAM or a disk.CACHE MEMORY

1A-* Every device that is external to the system unit must be attached by a cable to the bus. This point of attachment is called a port or connector. There are six common types of ports and they are keyboard port, video port (for the display), mouse port, parallel port, serial port and USB port.INPUT/OUTPUT PORTS

1A-* The resolution of a computer monitor is classified by the number of pixels on the screen, expressed as a matrix. DISPLAYS

A resolution of 640 X 480 means that there are 640 pixels horizontally across the screen and 480 pixels vertically down the screen. The higher the resolution, the sharper and crisper the characters or image formed800 x 600 pixels1024 x 768 pixels1280 x 1024 pixels

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VIDEO CARDSThe quality of the images that a monitor can display is defines as much by the Video card /video controller as by the monitor itself. The video controller is an intermediary device between the CPU and the monitor, It contains the video-dedicated memory and other circuitry necessary to send information to the monitor to display on the screen1A-*

MOTHERBOARD The main circuit board of the computer, which contains the processor, memory, expansion slots, bus, and video controller. Also called the system board or mainboard1A-*

****Teaching tipAt this point, refer the students to the productivity tip on page 13. This tip helps the student determine what type of PC is best for them. ***Insider information Specialized mountain bikes are designed on Sun workstations. *Discussion pointPage 19 of the text introduces the first Norton Notebook, the Merging of Media and Meaning. The author draws an analogy between electricity and computers in our lives. Discuss with your students how difficult live would be without either of these devices. Remember that computers exist in nearly all of our modern devices, including cars, phones, kitchen appliances and entertainment devices. *******************