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The University of AkronSummit CollegeBusiness Technology DepartmentComputer Information Systems2440: 145 Operating Systems

Introduction to ComputersInstructor: Enoch E. DamsonIntroduction to Computers2ComputerA machine that performs four basic operations known as the information processing cycle (input, processing, output, and storage)Input computer gathers data from usersProcess data is converted into information Storage data or information is stored for future useOutput data or information is retrieved from the computerIntroduction to Computers3Types of ComputersThe four basic types of computers are:SupercomputersMainframesMinicomputersMicrocomputersIntroduction to Computers4Types of ComputersSupercomputers fastest, most expensive, large and powerful computers for specialized tasks such as mathematical calculations, weather tracking, satellite monitoring, etc Mainframes large computers designed to handle huge processing jobs in large corporations and government agenciesMainframe computers multitask perform different types of tasks at the same timeMinicomputers handle the computer needs of smaller corporationsMicrocomputers designed to meet individual needsSome of the most common types of microcomputers are: desktops, laptop/notebook, personal digital assistants (PDAs)Introduction to Computers5Types of Microcomputers

Introduction to Computers6Computer Information System (IS)A collection of components that work together to process data into informationComponents include:HardwareSoftware Procedures DataPeopleNetwork6Introduction to Computers7Computer Information System

Introduction to Computers8HardwareThe physical components of the computer controlled by the softwareThe way these components are put together and arranged is called system hardware configurationTypes of hardware devices (peripherals) include:Input DevicesSystems UnitProcessor UnitInternal memoryStorage DevicesOutput DevicesIntroduction to Computers9Types of Hardware Devices

Introduction to Computers10Input DevicesUsed to enter data into the computer for processingExamples include:KeyboardMouseScannerDigital cameraVideo cameraIntroduction to Computers11KeyboardThe primary input device for computersUses the following types of keys to send data to the computerAlphanumeric keysControl keysFunction keysCursor control keysToggle and other keysMultimedia and Internet control keysIntroduction to Computers12Keyboard KeysAlphanumeric keys sends alphabets and numeric values to the computerNumeric keypad provides alternate method of quickly entering numbersControl keys the Ctrl, Alt, and Windows keys that are used in combination with other keys to provide shortcuts or increased keyboard functionalityFunction keys numbered F1 through F12 and generally associated with certain software-specific commandsIntroduction to Computers13Keyboard KeysCursor control keys arrow keys that allow users to move the insertion pointToggle and other keys the Insert, Num Lock, Caps Lock and other keys used for various purposes like navigation and editingMultimedia and Internet control keys available on most modern keyboards for functions such as muting or volume control, opening a Web browser, sending an email, etc

Introduction to Computers14Keyboard Keys

Introduction to Computers15System UnitHolds the processing hardware, electrical power supply, disk drives, circuit cards, ports for connecting other hardware and the motherboard (system board)Motherboard ties everything in the system unit togetherThe motherboard holds two very important parts of the computer: Processor (central processing unit (CPU) or microprocessor) Memory (RAM)Introduction to Computers16Motherboard

Introduction to Computers17The ProcessorThe brain of the computer that controls all the commands and tasks of the computerHas three basic main parts:Control Unit obtains instructions from the computers memory and interprets these instructions and executes themArithmetic-Logic Unit (ALU) performs all the arithmetic (math operations) and logical (comparisons) operations for the computerRegisters a small set of temporary storage cells used to store data and instructions needed frequentlyMeasured by the speed at which they are capable of processing data also known as clock speedProcessing speed is measured in megahertz (MHz) in millions and gigahertz (GHz) in billionsExamples include:Pentium, Celeron, Centrino (by Intel Corporation)Athlon, Sempron, Turion (by Advanced Micro Devices)Introduction to Computers18MemoryHolds:Data raw facts for processingInstructions rules for processing dataInformation processed dataTwo basic types of memory include:Random Access Memory (RAM) the volatile part of memory that stores information temporarilyRead-Only Memory (ROM) the nonvolatile part of memory on which instructions have been prerecorded to help start the computer and perform other tasksMemory is measured by its size in bytes, kilobytes (thousands), megabytes (millions), and gigabytes (billions)Bit (Binary Digit) the smallest unit of information in computers that is made up of 0s and 1sByte represents a single character and consists of 8 bitsASCII (American Standard Code for Information Interchange) one of the coding schemes used to represent characters in 8-bit bytesCan represent a maximum of 256 characters (incl. uppercase and lowercase letters, numbers, punctuation marks, and special symbols)Word a group of bytesSystem-dependentVary from 16 bits (2 bytes), 32 bits ( 4 bytes) or even 64 bits (8 bytes)Introduction to Computers19Storage DevicesUsed to store data and information permanentlyData is generally stored using one of the following forms:Magnetic storage uses sectors that divide tracks to store dataE.g. hard disks, tapes, floppy disks, zip disksOptical storage also uses tracks and sectors but data is saved using a laser beamE.g. Compact discs (CDs), digital video discs (DVDs)Flash memory uses solid-state technology which is completely electronic and has no moving mechanical partsE.g. Flash drives (memory sticks), cards used in digital cameras, MP3 players, etcStorage devices are measured in bytes, kilobytes, megabytes, gigabytesIntroduction to Computers20Examples of Storage Devices

Introduction to Computers21Output DevicesThe devices used to display and print data and informationE.g. monitor, printer, speakers, etcMonitors output soft copy and their resolution identifies the number pixels (picture elements) per square inch that appear on a screenMost monitors today can display at least 256 colorsThe two main categories of monitors are:Cathode ray tubes (CRT) can be curved or flat and relatively inexpensiveFlat-panel/LCD monitors use liquid crystal display (LCD) technology and are much slimmer and expensivePrinters output hard copy and their resolution is measured in dots per inch (dpi)The two main categories of printers are:Impact printers like dot matrix printers that use small keys to strike an ink ribbon against a paperNon-impact printers like ink-jet printers and laser printers that do not touch the paper when printingIntroduction to Computers22Examples of Output DevicesMonitors

Printers

Introduction to Computers23SoftwareSoftware (program) - a set of instructions that direct the computer to accomplish certain tasks The two major categories of software are:System software Application softwareIntroduction to Computers24System SoftwareProvides the instructions needed for the computer to runThe background software that manages the fundamental operations of a computer system including:Starting up (booting) the computerExecuting programsThere are 4 types of system software:Operating systems E.g. Windows, Mac OS, LinuxUtilities programs Norton AntivirusDevice drivers printer softwareProgramming languages Java, C++Introduction to Computers25Operating SystemControls basic input and output, allocates system resources, manages storage space, maintains security, and detects equipment failureExamples include: DOSWindowsUNIXMac OS, etcIntroduction to Computers26Application Software End-user software that performs useful tasks such as word processing, desktop publishing, etcKinds of application software include:Word processing software e.g. Microsoft WordSpreadsheet software e.g. Microsoft ExcelDatabase software e.g. Microsoft AccessPresentation software e.g. Microsoft PowerPointCommunication & Organization software e.g. Microsoft OutlookIntroduction to Computers27ProceduresRules or guidelines for people to follow when using software, hardware, and dataE.g. Software ManualsIntroduction to Computers28PeopleMaking people more productive is what computers are all aboutExamples include:AnalystsDesignersDevelopersUsers

Introduction to Computers29DataRaw facts entered into the computer system for processingProcessed to produce informationIntroduction to Computers30NetworksTwo or more computers connected in some way to share hardware, software programs, data and other resourcesNode each object (computer, printer, etc) connected to a network The two main types of networks are:Local area network (LAN) uses direct cables, radio, or other signals to link computers within a small geographic area like a building or group of buildingsWide area network (WAN) uses long-distance transmission media to link computers separated by a few miles or even thousands of milesIntroduction to Computers31Network ConfigurationsThe two main categories of network configurations are:Peer-to-peer (P2P) networks most commonly found in homes and small-businesses with each node capable of communicating with every other nodeClient/server networks - consist of a server (host computer) and clients (workstations)Introduction to Computers32Networks Topology (Topography)The different types of network architecture how computers and other devices are arranged and connectedThe most common topographic layouts include:Bus network no server but each node connects to a central high-speed line (bus)Ring network all nodes connect to a circular line around which data travels in only one directionStar network each node connects to a centrally located switch to communicate with other nodesThe most frequently used networking style for businessesHas a server to which all clients and other devices are connectedWireless network devices connect to other computers and network resources using radio signals, microwaves, satellite signals, and other wireless mediaIntroduction to Computers33Network Topologies

Introduction to Computers34Network CablesComputers can be connected to a network using devices like:Coaxial cables typically used by most cable TV systemsThe ends are usually made with RF (radio frequency) connectors Twister pair cables (shielded and unshielded) two conductors are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sourcesThe ends are usually made with RJ (registered jack) 45 to plug into computer network interfacesTwo main types include:Shielded Twisted Pair (STP) cables Unshielded Twisted pair (UTP) /Ethernet cables primarily used for telephones and commonly for computer networking Fiber-optic cables a glass or plastic fiber that carries light along its lengthUsed by most high-speed Internet cable connectionsWireless transfers information without using wiresIntroduction to Computers34Introduction to Computers35Coaxial Cable

Introduction to Computers35Introduction to Computers36Twisted Pair Cable

Introduction to Computers36

Shielded Twisted Pair (STP)Unshielded Twisted Pair (UTP)Introduction to Computers37Fiber-Optic Cable

Introduction to Computers37Introduction to Computers38PortsWhere all the peripheral devices connect to the computer to enable data exchangeBecause input and output devices can exchange data with the computer using different methods, they might require different portsIntroduction to Computers39Types of PortsSerial and parallel ports are two of the oldest types of ports found on a computerSerial ports can only send data one bit at a timeTransfer data 115 Kilobits per second (Kbps) at mostDevices that use serial ports include the mouse, modemParallel ports send data in groups of bits, at transfer rates of up to 500 KbpsPrinters often use parallel portsIntroduction to Computers40Faster Types of PortsUniversal serial bus (USB) ports able to interface with several different peripheral devicesUSB 2.0 can attain a rate of 480 Mbps or 480,000 KbpsFireWire ports - usually used to connect digital cameras or digital video recorders to a computerConnectivity ports used to connect to a local network or to the InternetExamples include:Modem ports resemble phone jacks and are used to connect the modem to a phone system and enable dial-up Internet accessEthernet port - a bit larger than the standard phone jack and used for network access and can also be used to connect a cable modem or router

Introduction to Computers41Types of Ports