Understanding Essential Computer Concepts

Computer Applications 1Understanding Essential Computer ConceptsDefinition of a computerA computer is an electronic machine that receives, processes, stores and delivers information. Computers are classified by:SizeSpeedCapabilities2Types of ComputersTypes of computers include (but are not limited to)Personal computersDesktopLaptop (notebooks)Tablet PCHand-heldPDAs (personal digital assistants)MP3 playersCell phonesMainframe computersSupercomputers

3Computer System ComponentsComputer systems include hardware and softwareArchitecture or configuration is the design and construction of a computerSpecifications are the technical details about each hardware componentData refers to information (words, numbers, graphics, etc.)Processing is modifying data

4Computer Systems Components (continued)Motherboard is where processing tasks occurMain electronic componentIs a circuit boardMicroprocessor (CPU) Transistors and electronic circuits on a silicon chipMounted on the motherboardResponsible for executing instructions to process information

5Microprocessor SpeedsMicroprocessor speeds depend on:Speed of the microprocessor (clock speed, word size and cache size)Whether single or dual coreClock speed is measured in megahertz (MHz), millions of cycles per second or gigahertz (GHz), billions of cycles per secondWord size refers to the amount of data that is processed at one timeSingle core processor has one processor on a single chipDual-core processor has two processors on a single chip and can process information twice as fast

6Computer System Components (continued)Cards are removable circuit boards to expand the capabilities of the motherboardInput is the data or instructions you put into the computerOutput is the results of the computer processingPeripheral devices such as mouse, keyboards printers and storage devices accomplish input, output and storage functionsCommands are input instructions

7Examining Input DevicesKeyboardCan be ergonomicMousePointing deviceRolling ball or opticalClicking commandsScroll wheelTouchpadPointing stickScannerMicrophones

8Examining Output DevicesThe Monitor displays the output from a computerFlat panel monitor uses LCD (liquid crystal display)CRT (cathode ray tube) monitor uses gun-like devices that direct beams of electrons toward the screen to activate dots of colorA graphics display divides the screen into a matrix of small dots called pixelsResolution is the number of pixels the monitor displays. Standard resolutions range from 640 x 480 to 1600 x 1200.Dot pitch (dp) measures the distance between pixels. (.28 or .26 dp is typical)9Output Devices (continued)To display graphics, a computer must have a graphics card, also called a video display adapter or video card.SpeakersLike input devices, output devices can be connected to a computer using cables or a wireless connection

10Output Devices - PrintersPrinters produce a paper copy often call hard copyLaser printers a temporary laser image is transferred onto paper with a powdery substance called tonerInkjet printers spray ink onto paperDot matrix printers transfer ink to the aper by striking a rubbon with pins.11Investigating Data ProcessingAll data and programs are stored as filesA file is a named collection of stored dataAn executable file contains the instructions that tell a computer how to perform a specific taskA data file is created by a user with software12Investigating Data ProcessingA computer cannot understand characters used in human languageLike a light bulb, a computer interprets every signal as either on or off . These numbers are referred to as binary digits or bitsA series of eight bits is called a byteA kilobyte (KB or simply K) is one thousand bytesA megabyte (MB) is one million bytes A gigabyte (GB) is one billion bytesA terabyte (TB) is one trillion bytes13Binary Representations of NumbersNumberBinary representation000000000100000001200000010300000011400000100500000101600000110700000111800001000:25311111101254111111102551111111114Investigating Data ProcessingPersonal computers commonly use the ASCII (pronounced ASK-ee) system which stands for the American Standard Code for Information InterchangeComputers translate ASCII into binary data so they can process the data

15Sample ASCII code representing letters and symbolsCharacterASCII CodeBinary Number(space)3200100000$3600100100A6501000001B6601000010A9701100001B9801100010?1291000000116310100011217110110012331110100116Understanding MemoryTypes of memory include the following:Random access memory (RAM) temporarily holds programs and data while the computer is on and allows the computer to access that information randomly.Consists of chips on cards that plug into the motherboard.When the computer is off RAM is emptyCache memory (RAM cache or CPU cache) Special high speed memory chip on the motherboard that stores frequently accessed and recently accessed data and commands

17Understanding MemoryVirtual memory space on the computers storage devices that simulate additional RAM. It is much slower than RAMRead only memory (ROM) is a chip on the motherboard that has been prerecorded with data that gives instructions (BIOS or basic input/output system) used to check the computer systems components to make sure they are working and to activate the essential software that controls the processing function when the computer is turned on or booted up.ROM never changes and it remains intact when the computer is turned off. It is called non-volatile or permanent memory18Understanding MemoryComplimentary metal oxide semiconductor (CMOS, pronounced SEE-moss) memory chip installed on the motherboard that is activated during the boot process and identifies where essential software is stored.A small rechargeable battery powers CMOS so its contents are saved when the computer is turned off. CMOS changes every time you add or remove hardware on your computer system but does not empty when the computer is shut offThe date and time are stored in CMOSOften referred to as semi permanent memory19Understanding Storage Media20The types of storage media are:Magnetic storage devicesHard disk magnetic oxide-covered metal platters sealed inside the computerTape used to make back-up copies of data stored on hard drivesOptical storage devices polycarbonate discs coated with a reflective metal on which data is recorded using laser technologyCD (Compact disc) can store 700 MB of dataDVD- can store between 4.7 and 15.9 GB of dataBlu-ray discs and HD-DVD can store between 15 and 50 GB of data

Understanding Storage Media21Flash MemoryFlash memory cards used in digital cameras, handheld computers and other devicesUSB flash storage device can store 32 MB 16 GB of data. Popular for use as a secondary or backup storage device for date stored on a hard disk drive