Stratatm IT FUNDAMENTALS

Transcription

1 Stratatm IT FUNDAMENTALS Lesson 2: Devices and Connections Lesson Objectives In this lesson, you will look at ports and connectors; examine keyboard and mouse properties; examine different types of monitors; and examine printers, scanners and other peripheral devices. On completion, you will be familiar with: The hexadecimal numbering system. The function of device drivers. Serial ports, parallel ports, video ports and audio ports. Various types of monitors. Various types of printers. The function and characteristics of input devices. The function and characteristics of peripheral devices. Exam Objectives 1.1 Identify basic IT vocabulary. 1.2 Demonstrate the proper use of the following devices: monitors, desktop, server, portables. 1.4 Explain the characteristics and functions of peripheral devices. 1.5 Explain the characteristics and functions of core input devices. 1.7 Demonstrate the ability to set up a basic PC workstation v1.00 CCI Learning Solutions Inc. 27

2 Lesson 2 Devices and Connections Objective 1.1 Connectivity Overview In Lesson 1, you learned about the motherboard and various internal components (processor, RAM, etc.) that make up a PC. As you already know, a standard desktop PC is not truly useful until you properly connect its peripherals. Peripherals are external components, such as keyboards, monitors, speakers, printers, etc., that allow us to interact with the PC. In this lesson, we will discuss the characteristics and functions of various peripherals, examine the connection types used by peripherals, and walk through the process of setting up a basic PC workstation. Drivers and the Operating System Communication between a PC and its devices is ultimately controlled by the operating system. For any device to communicate with the operating system (and in turn, with the user and other devices), a device driver is required. A device driver is a small program that enables a device to communicate with the operating system. Drivers are required for every device attached to a computer, both internal and external. When you install a new device that Windows recognizes, Windows will automatically install drivers for the device. Resource Assignments Windows also automatically handles resource assignments. Resource assignment is the allocation of specific communication channels and memory locations through which devices communicate with the processor. Resource assignments, memory addresses and other values used in computing are often represented in the hexadecimal numbering system. Hexadecimal The hexadecimal system is a Base-16 numbering system that uses the digits 0 through 9, and the letters A through F. The numbers 0 through 9 are the same in both decimal and hexadecimal; the alphabetic values are as follows: 10=A, 11=B, 12=C, 13=D, 14=E, 15-F. In a hexadecimal number, each column (read from right to left) represents a power of 16. The first column represents 16 0, the next column to the left represents 16 1, the next column to the left represents 16 2, and so on. The powers of 16 are shown in the following table: Power of 16 Equal to , , ,048,576 MMM More on Hexadecimal Numbers Hexadecimal numbers can represent very large decimal numbers with a relatively small number of hexadecimal digits. For example, 3E8 is equivalent to 1,000, and F4240 is equivalent to 1,000,000. Hexadecimal numbers are often written in a special notation to avoid confusing them with decimal numbers. The notation can be a prefix of 0x or a suffix of h or sometimes both. For example, the hexadecimal number 0x64 (or 64h or 0x64h) is hexadecimal 64, which is equal to 100 (6x16+4). Adapters Throughout this course you will see the term adapter used in reference to connecting devices. In many cases, an adapter is an expansion board (a circuit board added to the expansion bus to provide additional functionality) that includes a special socket called a port into which you can connect either a cable or a device. For example, a video adapter is a card that includes one or more video ports. You can plug a video cable from a monitor into one of the video ports and use the monitor to see what is taking place on the system v1.00 CCI Learning Solutions Inc.

3 Devices and Connections Lesson 2 An adapter can also be a device that includes one type of interface on one end, and a different type of interface on the other end, along with some conversion circuitry in the middle. In either case, an adapter s function is to allow devices to connect to each other. Windows Device Manager The Windows Device Manager is a utility you can use to see a listing of the devices installed on a system, view resource assignments, view device driver details, and view or change the current status (enabled or disabled) of each device. The Device Manager is shown in the following figure. Click an arrow to the left of a category to expand the list. Exercise 2-1 Viewing Devices in Device Manager In this exercise, you will use the Windows Device Manager to view the devices installed on your system. 1. Click Start, click Control Panel, click Hardware and Sound, then click Device Manager to open the Device Manger window. Notice that the window lists the devices connected to your computer and that the devices are arranged into categories, such as Display adapters, Keyboards, Monitors, etc. 2. Click the arrow icon to the left of Display adapters to expand the category. Notice that your video adapter is listed. 3. Right-click your adapter, then click Properties to open the Properties dialog box specific to your video card. 4. Click the Driver tab to view information on the video driver currently installed. 5. Click the Resources tab to view the resources allocated to the video card. Close the video card window. 6. In the menu at the top of the Device Manager window, click View, then click Devices by connection. Notice how you can examine and group devices by their different properties. 7. Click View, then click Devices by type to return the list to its original configuration. 8. Expand other categories in the window and examine other devices. 9. When you are finished, close the Device Manager, then close the Control Panel. In this exercise, you used Device Manager to view devices installed on your system v1.00 CCI Learning Solutions Inc. 29

4 Lesson 2 Objective Ports and Connectors Devices and Connections A peripheral port is a socket into which you can plug in cables from external devices, or as in the case of a USB flash drive, plug in the device itself. Usually, peripheral ports are located on the back panel of the computer, although some systems include USB ports on the front as well. Sometime ports are color-coded and often a port name or icon will display next to the port, but not always. Ports are either built into the motherboard, or into expansion cards which have been added to the expansion bus. Depending on the age of the computer system, the available ports will vary. The PC in the following figure was built in Notice that it includes PS/2 ports for the mouse and keyboard, a 25-pin parallel port, 2 9-pin serial ports, and a 15-pin game port as part of the sound card. This particular unit has two Ethernet cards, which is uncommon for a desktop PC. Notice also that it includes only two USB ports. Note: The ports in the figure will be described in detail later in this lesson. PS/2 Keyboard PS/2 Mouse USB Ports Serial Ports Parallel Port Video Port Ethernet Game Port Sound Card Ports Newer desktop systems come with four or six USB ports and many do not have PS/2 ports, or parallel and serial ports. The following figure shows a desktop PC that was built in Notice the absence of PS/2 ports, the increased number of USB ports, and the six sound ports indicating that the PC will support surround sound v1.00 CCI Learning Solutions Inc.

5 Devices and Connections Lesson 2 Line Out / Front Speakers / Headphones Line In (Stereo) Microphone In Rear Surround Speakers Mid Surround Speakers Center Speaker and Subwoofer Ethernet Port USB Ports Video Port Now that you have seen what some peripheral ports look like, we can look at them in more depth. Parallel Ports and Connectors Parallel communication moves several bits (typically 8 or 16 bits) at a time. In contrast, serial communication moves one bit of data at a time. Parallel communication requires a separate line for each data bit and additional control lines to manage the transfer of data. Parallel ports were commonly used to connect printers, removable disks, ZIP drives, tape backups, etc., to a computer. Parallel ports (if present) are built into the motherboard. In the past, they were included on IDE host adapter cards or available on an expansion card. Parallel ports adhere to the IEEE 1284 standard, which provides bi-directional parallel communication and defines a cable type that allows data transfers up to 32 feet on a parallel cable. Line Print Terminal (LPT) In the recent past, printers were connected to PCs through a parallel port named LPT1. LPT stands for Line Print Terminal. LPT ports are 8-bit parallel ports that transfer data at 12,000 Kbps. The parallel port has twentyfive sockets, arranged in two rows, as shown in the following figure. If color-coded, a parallel port is magenta. Devices connect to a parallel port using a parallel cable. These cables have a 25-pin connector (DB-25 connector) on the end that connects to the PC; the configuration of the other end depends on the device. Most printers designed to use a parallel port use a specialized port that takes a 36-pin connector called a Centronics connector. A parallel printer cable is shown in the following figure: v1.00 CCI Learning Solutions Inc. 31

6 Lesson 2 Devices and Connections DB-25 Connector Centronics Connector Most printers today connect directly to a PC through a USB port. Networked printers connect to the network using a network cable or a wireless connection. Small computer system interface (SCSI) The small computer system interface (SCSI) (pronounced skuzzy ) is a fast bus that can connect several devices (such as hard drives, printers, scanners, CD-ROM drives, tape drives, etc.) to a computer at the same time. Traditional SCSI uses a parallel interface and can provide data transfer rates of up to 320 MBps (megabytes per second). Other technologies such as serial-ata (SATA) have largely replaced SCSI in new systems, but SCSI is still in use in servers, workstations and high-end desktop systems. Parallel SCSI allows as many as 15 devices to be daisy-chained using one SCSI controller (30 with two controllers). A SCSI controller is an expansion board that gives SCSI capability to a computer. The last device in a SCSI daisy chain must have a SCSI terminator, which is a resistor circuit that closes the SCSI bus. SCSI can be used for internal and external devices. A SCSI port and the SCSI logo are shown in the following figures: The numerous parallel SCSI interfaces are described in the following table: Interface Bus Speed Connectors used SCSI-1 8-bit 5 MBps 50-pin IDC50 internal connector 50-pin Centronics C50 external SCSI-2 (Fast SCSI) SCSI-3 (Fast-Wide) 8-bit 10 MBps 50-pin IDC50 internal connector 50-pin Centronics C50 external 16-bit 20 MBps 2 x 50-pin or 1 x 68-pin Ultra Wide SCSI 16-bit 40 MBps 68-pin Centronics Ultra2 SCSI 8-bit 40 MBps 50-pin Ultra2 Wide 16-bit 80 MBps 68-pin; 80-pin SCA internal connector Single Connector Attachment (SCA) connectors combine power and data signals into one cable. Devices that use this interface are hot swappable Ultra3 16-bit 160 MBps 68-pin; 80-pin Ultra bit 320 MBps 68-pin; 80-pin Ultra bit 640 MBps 68-pin; 80-pin The newest type of SCSI is Serial Attached SCSI (SAS). SAS uses SCSI commands but transmits data serially at up 6.0 Gbps. (When SAS was first introduced, it performed at 3.0 Gbps. 6.0 Gbps devices became available in February 2009.) Each SAS port can support as many as 128 devices or expanders, and SAS is backwardcompatible with second-generation SATA drives. The SAS connector is much smaller than traditional parallel SCSI connectors, with variants that include 7, 19, 26, 32 or 36 pins v1.00 CCI Learning Solutions Inc.

7 Devices and Connections Lesson 2 Serial Ports and Connectors Although internally, computers communicate in parallel, serial communication is used for communication links and for mouse devices, keyboards, modems and scanners. Serial communication takes place one bit at a time over a single line. Data bits move through a serial communication channel as a stream known as a datastream or a bitstream. Although they are rarely seen today on modern systems, older PCs included two serial communication ports called COM1 and COM2. When color-coded, these ports are teal. COM1 was a 9-pin port and was used to support a serial mouse, although other devices could use this port as well. COM2 was usually a 25-pin port that was used to support a modem. Modern systems that still include a serial port include only a 9-pin port. Some systems include two 9-pin ports. The old COM ports had a maximum transmission speed of about 115 Kbps and have been replaced by universal serial bus (USB) ports on today's systems. USB devices use serial communication at rates of 12 Mbps for USB 1.0/1.1 or 480 Mbps for USB 2.0. Devices attach to COM ports using a serial cable with either a 9-pin or a 25-pin connector on the end of the cable. Connectors come in one of two genders, male or female. Male connectors have pins, and female connectors have sockets. The male connector is typically found on the PC; devices connecting to the port use a female connector. A serial port and connector are shown in the following figures. A serial port on a PC A serial connector PS/2 ports and connectors Older systems have PS/2-style ports for the mouse and keyboard. These accommodate six-pin mini DIN connectors. Both are shown in the following figure. As you can see, each connector is round, and includes six pins. The block in the middle of the connector is for keying that is, the connector will fit only one way, to prevent improper connection. When color coded, the port and connector for the mouse are green and the port and connector for the keyboard are purple. On some systems, mouse and keyboard icons also help identify the port and/or connector. The name PS/2 comes from IBM Personal System/2, a series of personal computers introduced to the public in These were the first systems to use this type of dedicated connection for mouse and keyboard. Before the PS/2 connector, keyboards were attached using a larger 5-pin DIN connector, and mouse devices were attached using a 9-pin serial port and connector. PS/2 keyboard and mouse ports and connectors are not interchangeable. You must insert the PS/2 connector attached to the mouse into the mouse port and not into the keyboard port. Because you can physically plug a connector into the wrong port (that is, you could inadvertently plug the keyboard connector into the mouse port), the ports and connectors are color-coded. Keyboard ports and connectors are purple, and mouse ports and connectors are green. Some laptops, however, have one PS/2 port, which will accept either a mouse or a keyboard. The connected device is detected when you start up the computer. PS/2 devices are not hot swappable. That is, you should not connect or disconnect them while the system is turned on. If you want to connect a PS/2 device, power down the system, insert the connector, then turn the system back on. The PC will detect the devices during startup. Most modern systems do not include PS/2 ports, offering six USB ports instead (usually four in the back and two in the front for easy access) since USB mouse devices and keyboards are readily available v1.00 CCI Learning Solutions Inc. 33

8 Lesson 2 Devices and Connections USB ports and connectors Universal Serial Bus (USB) interfaces have largely replaced serial and parallel ports because USB supports the same peripherals, such as mouse devices, keyboards, printers, telephone devices, modems and video devices. USB wireless cards are also in wide use. As you learned earlier, most modern desktop systems ship with four to six USB ports, and portables often offer two or four USB ports. There are three versions of USB: USB 1.1 Maximum transfer rate of 12 Mbps/1.5 Mbps for slow devices. Communication is half-duplex (that is, the device can upload or download, but cannot do both simultaneously). USB 2.0 USB 3.0 Maximum transfer rate of 480 Mbps. Communication is half-duplex. USB 2.0 is the current de facto standard. Maximum transfer rate of 4.8 Gbps. Communication is full-duplex and USB 3.0 includes power management which allows devices to move into idle, suspend and sleep modes. USB 2.0 is backward-compatible with USB 1.1 in that you can connect a USB 1.1 device to a USB 2.0 port, but the device will operate at USB 1.1 speeds and the speed of the entire bus will be slowed to USB 1.1 speeds as well. You can also plug a USB 2.0 device into a USB 1.1 port, but the device will be limited to the speed of the USB 1.1 bus. USB 3.0 is not yet in wide use, although a few companies have begun implementing the standard on their mass storage devices, video capture cards and expansion cards. For the time being, USB 3.0 is included only in high-end systems. Microsoft announced that Windows 7 plans to implement support for USB 3.0, probably through a service pack or other updates. USB 3.0 is backward-compatible with USB 2.0 in that you can plug a USB 3.0 device into a USB 2.0 port; however, only a USB 3.0 device can connect to a USB 3.0 port. USB offers many advantages over the older ports it has replaced. These include: Selfconfiguration Devices identify themselves to the bus controller, which in turn alerts the operating system that a new device is present. Windows loads the necessary drivers (if they are present on the system) and enables the USB device, assigning it a drive letter. The device is then immediately available for use. Support for multiple devices Power Ability to hot swap PCs include several USB ports, and if you have more devices than there are available ports, you can plug a USB hub into one of the USB ports and then plug your devices into the hub. Standalone USB hubs usually offer between four and seven ports and come in many varieties. USB hubs are also commonly built into devices such as keyboards, printers and monitors. Devices can receive power (up to 5 volts at 6 amps or a total of 30 watts) and recharge batteries through a USB port. For some devices, such as card readers or numeric keypads, this power supply is sufficient. Other peripheral devices, such as optical drives, need to be plugged into an electrical outlet. You can plug or unplug a USB device while the system is running. There is no need to power down, connect a device, then power back up. USB ports and connectors come in two basic shapes and sizes generally called Type A and Type B. Type A ports and connectors are used on the PC end of a USB-to-device connection. A Type A port and connector, and the USB icon are shown in the figure to the right v1.00 CCI Learning Solutions Inc.

9 Devices and Connections Lesson 2 If a device uses a removable cable rather than a permanently connected one (for example, a scanner or a digital camera), it uses the Type B connector on the device end. (These devices still use a Type A connector on the end of the cable that connects to the PC.) The following figure shows a USB cable that connects a flatbed scanner to a PC. Note the two different connectors. Other types of USB connectors are available for small devices. These mini-connectors are commonly found on digital cameras and sound recorders. The figure on the right shows a USB cable for a digital camera. Windows automatically recognizes many common USB devices, but sometimes you need to run an installation program. Printers and scanners, for example, come with installation CDs which copy device drivers into the Windows system folder. Usually, you are instructed to install these drivers before you connect your device to the PC. USB devices rely on a single host (the PC) to control access and data transfer, and the devices cannot communicate with the host unless the host specifically requests communication. The actual performance speed of USB devices on the network depends on the speed and efficiency of the processor on the host computer. Speeds of 480 Mbps are rarely attained. FireWire (IEEE 1394) ports and connectors FireWire is a serial bus that gained popularity for attaching video devices to computers, although it is also commonly used for external disk drives, and network connections. Apple Computers Corporation designed the original version, naming it FireWire. The standards group formerly known as the Institute of Electrical and Electronics Engineers (now known simply as IEEE) formalized the standard as IEEE Sony Corporation developed its own implementation of the technology and called it i.link. Texas Instruments calls their implementation of the technology Lynx. Like USB, FireWire offers the advantages of hot-swapping and self-configuration, high-speed data transfer, and support for multiple devices. FireWire also delivers power (up to 1.5 amps at 30 volts) to devices except over the 4-pin connector, which does not support power. Unlike USB, FireWire devices are organized into a peer-to-peer arrangement when they plug into the bus. Each device is an intelligent node and has a unique self-id. The devices communicate directly with each other and elect one node to manage the bus. As a result, because the devices do not depend on the host processor, FireWire often outperforms USB v1.00 CCI Learning Solutions Inc. 35

10 Lesson 2 Devices and Connections FireWire was designed for high performance, allows up to 63 devices to be daisy-chained, supports hot swapping, and guarantees bandwidth for multimedia. As the standard has developed, newer versions have been released, as shown in the following table. MMM Reviewing Standards and Speeds Standard Max speed Connector FireWire Mbps 4-pin (device end) 6-pin (PC end) FireWire Mbps 9-pin (both ends) FireWire S Gbps Same connector as FireWire 800 As with USB devices, FireWire devices can be plugged in and expected to work. You seldom need to load device drivers. Common FireWire devices include video cameras and printers. FireWire is sometimes used for direct system-to-system connections for high-speed data transfer. The FireWire icon is shown here: Video Ports and Connectors The video port, also called a graphics port, connects a monitor to the PC. However, before we discuss video ports and connectors, we should review the available options for video cards. Video cards There are three types of video cards you can use, depending on the bus in the motherboard. The video card converts computer data into the signals your monitor uses to produce the images that you see on screen. The available card types are: PCI (Peripheral Component Interconnect) the oldest type of video card. These cards use a single parallel connection and share the PCI bus with other devices on the bus. A 32-bit PCI card operating at 33 MHz transfers data at 133 MBps; a 64-bit card operating at 66 MHz supports 533 MBps. Most PCI video cards include memory installed directly on the card. AGP (Accelerated Graphics Port) this type of connection was designed for use with 3-D graphics applications. AGP cards use a dedicated point-to-point channel so the graphics controller can directly access main memory. The base speed for AGP is 266 MBps. The available speed multipliers are listed in the following table: AGP Speed 1x 2x 4x 8x Data Transfer Rate 266 MBps 533 MBps 1,066 MBps 2,133 MBps PCI Express doubles the transfer rate of the standard PCI interface by using a point-to-point serial connection, eliminating the need to share bandwidth on the bus. Speed multipliers are shown in the following table: PCIe Speed PCIe 1.0 PCIe 1.0 x2 PCIe 1.0 x4 PCIe 1.0 x8 PCIe 1.0 x16 PCIe 2.0 x8 PCIe 1.0 x32 PCIe 2.0 x16 PCIe 2.0 x32 Data Transfer Rate 250 MBps 500 MBps 1,000 MBps 2,000 MBps 4,000 MBps 8,000 MBps 16,000 MBps v1.00 CCI Learning Solutions Inc.

11 Devices and Connections Lesson 2 Graphics Processing Unit (GPU) Many high-end video cards, such as those in the NVidia GeForce series or the ATI Radeon series, include a graphics processing unit (GPU) in order to provide the power to render 3D graphics. A GPU is a specialized processor that has a highly parallel structure, enabling it to perform calculations on large matrices of numbers in parallel. GPUs have enormous floating point computational power. Floating point is a system for representing numbers that are either too large or too small to be represented as integers. This computational power makes a GPU much faster than a CPU at rendering graphics and 3D animation. A General Purpose Computing GPU is one that can be used for purposes other than graphics rendering. Using a parallel computing architecture known as Compute Unified Device Architecture (CUDA), programs can take advantage of a GPU's parallel structure and computational power, resulting in faster execution. General Purpose Computing GPUs are now competing with CPUs in such areas such as oil exploration computers and medical imaging equipment. Video ports/connectors When you examine the cable that comes out of a monitor, you will see that the cable ends in a male connector that plugs into a female port on the video card. There are different types of video ports, and the port and the connector on the cable must be compatible. The available types include: Video Graphics Adapter (VGA) and Super VGA (SVGA) Digital Video Interface (DVI) These ports convert computer digital signals into analog signals that an analog monitor, such as a CRT, can interpret. (Monitor types will be discussed later in this lesson.) These ports take a 15-pin serial connector. The connector includes screws that attach on each side of the port to keep the connection securely fastened. This type of port provides a digital connection; no conversion is made from digital to analog if you are using a digital monitor. However, DVI ports can also support analog signals for backward compatibility with analog monitors. A DVI connector, therefore, contains pins to pass digital signals and pins that provide the same analog signals found on a VGA connector. (VGA monitors can be connected to a DVI port using an adapter plug.) There are different types of DVI connections: DVI-D: these ports provide digital signals only. DVI-I: these ports provide digital and analog signals. The connector includes four more pins than the DVI-D connector, and these additional pins carry the analog signals. These are located above and below the grounding slot. DVI-A: these ports provide analog signals only. The various DVI connection ports are illustrated in the following figure: DVI-I (Single Link) DVI-I (Dual Link) DVI-D (Single Link) DVI-D (Dual Link) DVI-A v1.00 CCI Learning Solutions Inc. 37

12 Lesson 2 Devices and Connections DVI is the only widespread video standard that includes analog and digital transmissions in the same connector, and the technology maximizes the quality of flat-panel LCD monitors and digital projectors. Until recently, the DVI standard was the digital transfer method used for enhanced-definition television (EDTV), highdefinition television (HDTV), plasma displays, and other high-end video displays for television, movies and DVDs. HDMI is now replacing DVI as the technology of choice. High Definition Multimedia Interface (HDMI) these ports are used to transmit high-definition digital video and high-resolution digital audio data using the Transition Minimized Differential Signaling (TMDS) protocol. HDMI is fully backward compatible with DVI-D and DVI-I, meaning that a DVI port can run an HDMI monitor or vice versa. The connector types are different, however, and require a simple adapter. HDMI connectors are: Type A 19 pins: supports standard, enhanced and high-definition television at 10.2 Gbps. The outside dimensions of the connector are 13.9 mm x 4.45 mm. Type B 29 pins: can carry double the video bandwidth of Type A and is designed for use with very highresolution displays (for example, pixels). The outside dimensions of the connector are 21.2 mm 4.45 mm. Type C 19 pins, mini connector. The outside dimensions are mm x 2.42 mm. Type D 19 pins, micro connector. The outside dimensions are 6.4 mm x 2.8 mm. HDMI supports any TV or PC video format, including standard, enhanced and high-definition video, and up to eight channels of digital audio. It is commonly used for high-definition televisions (HDTVs) and home theater systems that have surround-sound audio. Every new HDTV has at least two HDMI inputs, and other devices such as digital video recorders (DVRs), DVD players, Blu-ray players, game consoles and personal computers include HDMI outputs to deliver audio and video. Separate Video (S-Video) Many graphics cards include an S-Video connector, which you can use to connect televisions and other video devices to a PC. S-Video is an analog video connection in which the signals for brightness (luminescence) and color (chrominance) are carried separately. This is in contrast to standard composite video, in which the signals for brightness and color are carried together, resulting in a degradation of image quality. An S-Video port is round and takes a 4-pin mini-din connector. These ports may look like PS/2 ports at first glance, but they take 4-pin connectors as opposed to the 5-pin connectors used by mouse devices and keyboards. Audio Ports and Connectors Before the introduction of sound cards, PCs could only beep or click through an onboard speaker. Sound cards have two basic functions: They play sound by converting digital data into analog sound waves. They capture (or record) audio by converting analog sound signals into digital ones. Many sound cards also allow you to connect a game device (such as a joystick) or a Musical Instrument Digital Interface (MIDI) instrument. A typical sound card includes 3.5mm audio ports called jacks for speakers, microphones, line input or line output devices, and game adapters. There are at least two audio jacks on a sound card, and very often there are more. The function of each jack is typically marked with an icon or text, and sometimes the jacks are colorcoded v1.00 CCI Learning Solutions Inc.

13 Devices and Connections Lesson 2 Several audio jacks are described in the following table: Name Icon Color Function Mic Pink Used to connect a microphone. Line In Light blue Used to connect input devices (a tape player, for example) with an ⅛" connector. Line Out Lime green Supports speakers or headphones. Rear Surround Black Used with surround-sound systems. Mid-Surround Gray Used with surround-sound systems. Center-Surround Tan Used with surround-sound systems. Network Ports and Connectors There is a variety of connection or cabling options to access information to or from a network. Newer connection types allow data to flow much more quickly, and more people are setting up or switching to faster connection methods. Some popular connection options include: Coaxial Fiber Optics Twisted Pair A copper wire surrounded with insulation with a grounded cover of braided wire to minimize electrical and radio frequency interference. This was the main type of cable used for cable television distribution and (now obsolete) computer networks. Bundled glass or plastic fibers (threads) are used to transmit data. This has a much larger bandwidth for transmitting data than metal cables and is less susceptible to interference. A type of cable containing 1, 2, 3 or 4 pairs of copper wires carrying analog or digital signals. Telephone and computer networks commonly use this form of connection. Networking will be discussed at length in Lesson 3, but it is important to know that for a computer to participate on a network, the computer must include a network interface card (NIC). The NIC includes a network port into which you plug a network cable. The other end of the cable is connected to a network port on a device that attaches physically to the network. A NIC is usually added to the expansion bus, but can also be connected via a PCMCIA, Express Card or USB port. PCMCIA and Express Card The Personal Computer Memory Card International Association (PCMCIA) developed both the PC Card and Express Card standards. Both standards allow peripheral devices to be connected to a computer, and are most often implemented on portable computers. Originally called the PCMCIA card, the PC Card is a small form factor card that allows peripheral devices to be attached to a laptop or other portable. PCMCIA devices are built onto the card, then the card is inserted into the PCMCIA slot on the portable. Typical PCMCIA devices include network cards, modems and hard disks. These devices are hot-swappable. The PC card slot has been superseded by the faster Express Card interface. Common Express Card devices include SATA external disk drives, solid-state drives, wireless network interface cards, TV tuner cards and soundcards. The Express Card standard supports both PCI Express and USB 2.0 connectivity through the host. In USB mode, the bandwidth is 480 Mbps; in PCI Express mode, the bandwidth is 2.5 Gbps. The cards themselves, which are hot-swappable, can be designed to use either mode v1.00 CCI Learning Solutions Inc. 39

14 Lesson 2 Devices and Connections Objective 1.7 Bluetooth and Wireless Connectors Wireless devices use a variety of technologies such as infrared or short-range radio waves to send and receive data over short distances. Bluetooth uses short-range radio signals. These devices do not use a cable, as traditional devices do, but they do use a connector that plugs into the appropriate port on your computer. These connectors could be an antenna or infrared reader. Bluetooth and wireless devices do not have specific ports designated as Bluetooth ports or wireless ports. Instead, these types of devices use standard ports, such as USB ports or Express Card or FireWire ports for connecting to a desktop or portable. Power Connectors The external connector for a desktop computer power supply has been standardized for many years, and the power cord from almost any desktop computer will work on any other. The socket end of the power cord connects to the three-prong connector on the back of the PC. The pronged end of the connector plugs into an electrical outlet. You can also use these cords on various types of music equipment such as guitar amplifiers, effects boxes, etc. The power connectors for laptops and other portables, however, are customized and specific to the portable. Typically these power connectors include a standard three-prong plug for connecting into an electrical outlet, a transformer in the cable to convert AC power from the outlet to the DC power required by the computer, and a specialized connector at the other end for connecting to the portable. Often these connectors are designed so that you cannot connect the wrong type of power cord to the computer, and the transformers are rated for specific voltages. You should always ensure that you use only the power cord that shipped with your portable. Substituting a power cord with the incorrect voltage, even if the connector fits, can damage the portable. Keep the following points in mind when connecting a computer to a power source: Use a surge suppressor or an Uninterruptible Power Supply (UPS) unit to protect the system from power surges, brownouts or general fluctuations in voltage (dirty power) that may occur due to the electrical requirements of other equipment connected to the same electrical circuit. A UPS is a dedicated device that sits between the wall outlet and the computer. It can help protect the computer in the case of a power surge or failure. Ensure there are not too many electrical devices connected to a single wall outlet or power bar. Similarly avoid connecting other electrical equipment such as laser printers, space heaters, vacuum cleaners and coffee makers that draw large quantities of power on the same electrical circuit (generally all the wall outlets in the same room of a house). When traveling to another country that uses a different voltage system, use a converter that adapts to the different electrical system and voltage. Always turn off the computer during stormy weather to protect it against any sudden power surges v1.00 CCI Learning Solutions Inc.

15 Devices and Connections Lesson 2 Objective Activity 2-1 What s My Line? In this activity, your instructor will present various connectors and you will identify the type of connector, state its purpose and point out an appropriate port on the PC to create a connection. 1. Instructor: Uncover a table that contains various connectors. Select one connector and hold it up and call on the first student who can identify the connector. After the connector is correctly identified, have the student point out a suitable port on the PC for completing the connection. 2. Class: As each connector is correctly identified, pass it around. Hold it in your hands, feel its weight and examine it closely. Have you used a connector like it before? 3. Time permitting, open a Web browser and try to find pricing information on the connectors. Are they readily available? Are several options available for each type of connector? In this activity, you examined, identified and researched connectors. Looking at Peripheral Devices External devices that you attach to your computer are called peripheral devices. Peripheral devices can be classified by their function as input or output devices. Input or output (I/O) devices enable communication between the user and the computer. There are three classifications of I/O devices you can use to: send information to the computer (for example, the keyboard, mouse, trackball or scanner). display or transmit information from the computer (examples include the monitor, printer and speakers). communicate between computers (for example, modems and networks). In simple terms, anything used to enter information into a computer is an input device. Anything that can display information from a computer is an output device. Standard input devices include a keyboard, mouse and microphone. Common output devices are a monitor, printer and speakers. The devices we will examine in this section are keyboards, mouse devices, gamepads, digital and Web cameras, microphones, speakers, and tuners. Monitors and printers will be covered in separate sections. Keyboards The keyboard is an input device that allows you to send information to the computer. It is the primary tool for inputting data. You can also use the keyboard to input commands for a task in an application program Escape Key Function Keys Numeric Keys Control Key Windows Key Alt Key Cursor Movement Keys The previous graphic shows a traditional keyboard. Some keyboards are ergonomically designed to reduce or prevent stress on the wrists (i.e., carpal tunnel syndrome) or eyestrain. Many newer keyboards also contain buttons to enhance the multimedia experience while using your computer v1.00 CCI Learning Solutions Inc. 41

16 Lesson 2 Devices and Connections Objective 1.7 Keyboards used to connect to a computer using a PS/2 port and connector. Most modern keyboards connect through a USB or wireless connection. Regardless of keyboard type, the same keys are available for document processing. Special keyboards can be purchased for game enthusiasts or for people with disabilities. The cursor movement and numeric keypad keys are located at the far right of the keyboard, and can be toggled on and off by pressing the key in the pad. When the toggle light is on, the pad becomes a calculator or numeric pad; when off, the pad becomes an arrow or cursor movement pad. The keyboard shown in the graphic includes separate cursor movement keys in addition to those on the numeric keypad. Some older keyboards do not include these keys. Keyboards on portables The keyboards on most portables do not include a numeric keypad and the user must use the row of number keys across the top of the keyboard to enter numeric data. However, users who need to enter numeric data quickly and accurately and prefer the layout of a numeric keypad can purchase a separate numeric keypad as an accessory. These attach to the computer usually through a USB connection. Customizing keyboard properties Keyboard properties that you can set include: Repeat delay This setting specifies how long Windows waits before repeating a character when you press a key. Repeat rate Cursor blink rate This setting specifies how quickly a character is repeated when you hold down a key. This setting specifies the rate at which the insertion point blinks on the screen. You can modify these properties in the Keyboard Properties dialog box, shown in the following figure v1.00 CCI Learning Solutions Inc.

17 Devices and Connections Lesson 2 You can also change the language or layout of the keyboard using tabs in the Region and Language dialog box shown in the following figure. You can use the settings in this dialog box to install a new language or change the regionalization of the keyboard. Exercise 2-2 Examining Keyboard Properties In this exercise you will examine various keyboard properties. 1. Click Start, click Control Panel, click in the Search Control Panel text box at the upper-right corner of the Control Panel window, and type keyboard. 2. When the Keyboard link appears, click it to open the Keyboard Properties dialog box. 3. Click the Speed tab if necessary. 4. Adjust the Repeat rate by dragging the slider, then test the rate by clicking in the Click here and hold down a key to test repeat rate box, and holding down a key. What do you think of the new rate? Is it too fast? Too slow? 5. Drag the slider until the rate is set where you like it. 6. Click the Hardware tab and view the current device status. 7. Click the Properties button to open the Device Keyboard Properties dialog box. 8. Click the Driver tab to view details on the driver. 9. Close both the Keyboard Properties dialog boxes, then click the Change keyboards or other input methods link in the Control Panel. 10. Click the Change keyboards button to open the Text Services and Input Languages dialog box. Notice that the default input language is indicated. 11. Click the Add button and scroll through the Add Input Language dialog box to get an idea of how many different languages you can add. 12. Click Cancel twice to return to the Region and Language dialog box v1.00 CCI Learning Solutions Inc. 43

18 Lesson 2 Devices and Connections 13. Click the Location tab to view your current location setting. Display the Current location drop-down list to view the available regions from which to select. 14. Click anywhere outside the drop-down list, then close the Region and Language dialog box. 15. Close any open dialog boxes, then close the Control Panel window. In this exercise, you examined keyboard settings. Objective Mouse Devices A mouse is an input device that enables you to point at graphical elements on the monitor and interact with the computer. As you move a mouse along a flat surface, the mouse pointer moves on the screen. A mouse usually has two buttons that are used to select and activate features on the screen. You can perform the following actions with a mouse: pointing positioning the mouse pointer over an object. clicking pressing and releasing the left mouse button to select an item on the screen. double-clicking pressing and releasing the left mouse button twice in rapid succession to launch programs or open files. dragging holding down the left mouse button while moving the mouse pointer to move or select multiple items on the screen. right-clicking pressing and releasing the right mouse button to open a shortcut menu. Some mouse devices include a scroll wheel between the buttons that you can use to scroll through the contents on the screen. Most also include an additional button on the side of the device where your thumb would rest. This can be set to perform specific tasks, such as starting a program or working as an alternative control key. The traditional mouse used a ball that rotated to initiate this movement as you moved the mouse device on the desk. Newer mouse models use an optical light or diode technology to move the pointer on the screen Trackballs The trackball is a pointing device that operates like a mouse; however, with a trackball, you rotate the exposed ball using your thumb, finger or palm to move the mouse pointer on the screen. Because the trackball remains stationary, it is very useful with notebook PCs or with desktop PCs that have minimal desk space. Trackballs contain two or three buttons that are analogous to the buttons on a mouse. Touchpad Mouse devices are available in the traditional style or as wireless devices. The traditional mouse connects to either a PS/2 or USB port on the computer. A wireless mouse has a separate connector that plugs into the USB port. A wireless mouse requires a battery, whereas a traditional mouse just needs to be plugged into a port. A touchpad device enables you to use your finger to move the mouse pointer around on the screen. This is common on a notebook, although these devices can be purchased separately for a desktop. A touchpad has two buttons that work in the same manner as the left and right buttons on a mouse. To move the mouse pointer around on the screen, place your finger anywhere on the touchpad, then glide your finger around the touchpad in the direction you want to move the mouse pointer. To select an item, position the mouse pointer over the item, then tap the touchpad once or click the left button below the touchpad v1.00 CCI Learning Solutions Inc.

19 Devices and Connections Lesson 2 To activate an item, position the mouse pointer over the item, then tap the touchpad twice in quick succession or double-click the left button below the touchpad. To drag an item, position the mouse pointer over the item, press, then glide your finger on the touchpad to the required location. To display a shortcut menu, position the mouse pointer over the item, then click the right button below the touchpad. One drawback of touchpads is that oil from your finger and dust can make the touchpad less sensitive to the touch over time, thereby diminishing its performance. You must keep touchpads clean and static-free to ensure optimum performance. Customizing mouse properties You can customize the mouse settings to suit your needs and work preferences. For example, if you are lefthanded, you can configure the right button as the primary button and the left as the secondary. That way, you can then use the right button to double-click, drag, select and use the left button for opening shortcut menus. You can also change the double-click speed, motion speed or mouse pointers. These options will vary based on the type of mouse or pointing device installed. You may also want to customize the mouse if you have a new pointing device or need to update the device driver for your existing one. To make these changes, you can: Click Start, Control Panel, Hardware and Sound, Mouse; or Right-click anywhere on the desktop and then click Personalize, Change Mouse Pointers. The Mouse Properties dialog box is shown in the following figure. If you are using a portable computer without a mouse, you may have an additional tab to customize the glide pad or touchpad included with the portable. You use the various tabs in the Mouse Properties dialog box to set different properties. Buttons Pointers Pointer Options Wheel Hardware Use this tab to specify whether the mouse is set for right-handed or left-handed use. You can also set double-click speed and activate clicklock. Use this tab to specify the appearance of the mouse pointer. Use this tab to specify how you want the pointer to act on screen. Use this tab to specify the number of lines the screen moves for each wheel notch. Use this tab to set your mouse driver properties v1.00 CCI Learning Solutions Inc. 45

20 Lesson 2 Devices and Connections Exercise 2-3 Modifying mouse properties In this exercise, you will modify mouse properties. 1. Click Start, click Control Panel, click Hardware and Sound, then click Mouse to open the Mouse Properties dialog box. 2. Click the Buttons tab if necessary, then, in the Button configuration section, select the Switch primary and secondary buttons check box. You can use this option to set a mouse for left-handed or right-handed use. 3. Try to deselect the check box by clicking. What happens? Notice that the buttons are switched even before you click the Apply button. 4. Right-click the check box to deselect it, then close the Mouse Properties dialog box. 5. Close the Control Panel. In this exercise, you demonstrated how to set a mouse for right-handed and left-handed use. Gamepads Sound cards often included dedicated ports for gaming devices, such as joysticks and gamepads. The old style game port is a 15-pin socket (color-coded yellow). Newer joysticks and gamepads, however, can connect to USB ports. Microsoft discontinued game port support with the release of Windows Vista. If you want to connect a dedicated game system, such as an Xbox, to a Windows computer, you must first install software that will allow the Xbox game controller to work with Windows. Digital Cameras Digital cameras allow you to take sharp, clear pictures without the use of film. The images in digital cameras are stored on memory cards, such as the type you examined in Lesson 1. Digital cameras use batteries, which may run down quickly due to the high power drain. You should always select a battery that is rated for your digital device. The quality of the picture is expressed in megapixels (millions of pixels). Low-resolution cameras take pictures wherein the resolution is less than one megapixel, whereas high-end cameras can take pictures whose resolution exceeds eight megapixels. The higher the resolution, the larger the file size. Most cameras include settings for taking lower-quality pictures in order to fit more pictures onto a memory card. The default setting on the camera usually provides the highest picture quality. As you learned in Lesson 1, you can transfer digital photos directly to your computer by inserting the memory card into a card reader. Using a card reader to transfer your pictures can help prolong battery life because you simply need to remove the card; you do not need to power up the camera v1.00 CCI Learning Solutions Inc.

21 Devices and Connections Lesson 2 You can also attach the camera to the PC using a USB or FireWire cable and transfer the pictures that way. Some cameras require special drivers for transferring pictures, but other cameras simply appear as additional storage devices on the computer when the connection is made. Transferring images in this manner is simple, but requires a connection cable and that you turn on the camera. Web Cameras Web cameras (or webcams) are specialized cameras that are designed to record live video and transmit it across a network or the Internet. A webcam must be connected to either a computer or a network. If connected to a computer, the connection is usually USB. If connected to a network, the connection is generally Ethernet or a wireless connection. The most popular use for webcams is for making video phone calls. Many webcams include built-in microphones and most include software for video , video capture, videoconferencing, and still-image capture. Many people use their webcams to make video calls using an instant messaging service such as Skype, Windows Live Messenger or Yahoo Messenger. The webcam, combined with these free services, enables people across the globe to communicate often at no charge. Speakers and Microphones Sound cards are designed to work with external speakers on a desktop system and special built-in speakers on a laptop. External speakers require a power source. Although some small USB-powered computer speakers are available, speakers that produce high-quality sound must be plugged in to an electrical outlet. Speakers are rated by three factors: Frequency The range of high and low sounds (measured in Hz) that the speakers can produce. Distortion Power Called total harmonic distortion (THD), which is the amount of distortion that occurs when the sound is amplified. The amount of amplification available (measured in watts). Speaker systems are available in a wide range of capability. With a basic set of computer speakers, you can adjust the volume and the balance between the right and left channels. Advanced systems, such as those which can provide surround sound, usually include separate sub-woofers, which produce low frequency sounds (e.g., low bass audio frequencies such as those in the Hz range). Speakers are connected to a computer through the Line-out 3.5mm audio jack on the sound card. Sound cards with separate jacks for rear, mid and center surround sound allow you to fine tune the sound produced by your system. Microphones Microphones are input devices that connect to the sound card and enable the computer to record sounds that are stored as WAV files. A microphone connects to the sound card through the Mic 3.5mm audio jack. Headphones Headphones are a pair of small speakers held close to the user's ears. These can connect to a computer through a dedicated headphone jack or a Line-In jack on the sound card. Some CD-ROM drives also include a headphone jack. Headsets Headsets usually consist of small speakers and a microphone configured into a wearable unit that positions the speakers close to the user's ears and the microphone close to the user's jaw. Headsets are often used in digital phone calls (such as those available through Skype) and video calls. Headsets can eliminate the echo and feedback that can be experienced when a microphone picks up output from the speakers and feeds that signal back into the speakers. Unlike headphones and microphones, which plug into audio jacks, headsets usually connect to a computer through a USB or wireless connection v1.00 CCI Learning Solutions Inc. 47

22 Lesson 2 Devices and Connections Objective 1.7 Tuners A TV tuner card is a computer component that allows television signals to be received by a computer, enabling you to watch television programs on a computer monitor. Most TV tuners can also capture video, enabling the computer to record television programs onto a hard disk and eliminating the need for a DVR. Tuner cards are available as PCIe, Express Card and USB devices. External TV tuner card attachments are also available for mobile phone handsets such as the iphone, enabling users to watch mobile TV. Monitors A monitor displays output on a screen. When you enter information at the keyboard, or open a program or access a file, the results of your actions are displayed on the monitor. Various types of display technology and connection interfaces offer a wide range of choice when selecting a monitor. Cathode Ray Tubes (CRT) A cathode ray tube (CRT) is the old-style analog monitor that has been taking up desk space for decades. A CRT uses the same technology as the old analog television set it uses a large vacuum tube as a display screen and the inside of the screen is coated with phosphor. An electron gun shoots electron beams at the screen, exciting the phosphor and causing it to glow, thereby creating hues and images. CRTs range in size from 5-inch to 21-inch sizes (38-53 cm) and larger, but the actual viewing screen is about 1 inch (2.5 cm) smaller than the rated size. Screens are measured diagonally from corner to corner, including the case. Compared to flat-panel displays, CRTs are heavier, take up a lot more space and consume considerably more power. However, they can show true color and graphic detail with a great deal of clarity. Resolution The resolution of a monitor refers to its degree of clarity and is measured by the number of pixels (or dots) the screen can accommodate. For example, a resolution of 800 x 600 displays 800 pixels horizontally on the screen and 600 pixels vertically. The more dots per inch, the clearer the picture. For example, 1024 x 768 resolution will be sharper than 800 x 600 resolution because the former uses more dots, creating a more detailed picture. Because the actual number of pixels is determined by the video card, monitors can accommodate a range of resolutions. Refresh Rate The refresh rate is the number of times per second the monitor redraws the picture on the screen. A CRT screen must be refreshed several times per second to maintain the image even when the image is unchanging. The refresh rate is measured in hertz (Hz). A refresh rate of 60 Hz means that the monitor redraws the picture on the screen 60 times per second. The faster the refresh rate, the less the screen flickers. Older monitors had a refresh rate of 60 Hz and the screens would flicker, causing eyestrain. The current standard refresh rate is 75 Hz for monitors that display resolutions of 640 x 480 and higher v1.00 CCI Learning Solutions Inc.

23 Objective 1.5 Devices and Connections Lesson 2 Liquid Crystal Display (LCD) While a CRT is usually several inches deep and weighs between 30 and 50 pounds (13-23 kilograms), an LCD is commonly 1-3 inches ( cm) thick and weighs less than 10 pounds (4.5 kilograms). An LCD monitor consists of five layers: a backlight, a sheet of polarized glass, a mask of colored pixels, a layer of liquid crystal solution and a second sheet of polarized glass. Electrical charges manipulate the crystals which open and close in response to the stimulus. As the crystals open or close, they allow various degrees of light to pass through specific colored pixels to illuminate the screen and create a picture. When shopping for an LCD monitor, you will want to take the following into consideration: contrast ratio relates to the difference between the brightest white values and the darkest black values. A higher contrast ratio shows truer color. The standard ratio for low-end models is around 350:1. Many experts recommend a contrast ratio of 500:1 or higher. brightness measured in nits or one candela per square meter. A value of nits is considered standard. response time measured in milliseconds (ms), the response time is how long it takes the pixels to turn from completely white to black and back again. The smaller the response time, the faster the monitor. If the response time is too slow, ghosts or trails can appear on the screen as fast-moving images are redrawn. A maximum response time of 17ms is good. LCD monitors come in standard sizes from 15 inches to 21 inches, and larger. The viewing screen is the same size as the rated display. That is, a 15-inch LCD will have a 15-inch viewing screen. LCDs use only one-third to one-half the electricity of their CRT counterparts. They are easier on the eyes, and take up 90% less space. They also emit less low-frequency radiation than CRTs. A drawback to LCD monitors is that the image on the screen becomes fuzzy as you increase your viewing angle to the screen. Most LCD monitors can be connected to either a VGA port or a DVI port. Many are shipped with both types of cables so you will be able to use the monitor with whichever type of video card you have installed. Touchscreen Monitors Touchscreen monitors are becoming more common and are found in a variety of devices, including Tablet PCs, Smartphones and automatic teller machines. These monitors take the place of mouse devices. The drivers for the monitor communicate with the operating system and the information is interpreted as equivalent to mouse clicks, pointing and other mouse-type actions. The three systems used today for touchscreen technology are: Resistive A normal glass panel is covered with a conductive and a resistive metallic layer. The conductive and resistive layers are held apart by spacers, and the entire system is covered by a scratchresistant layer. An electrical current runs between the resistive and conductive layers. When a user touches the screen, the two layers make contact in that exact spot. The coordinates of the point of contact are calculated and a driver translates the touch into a click or a drag, or some other action that the operating system can understand. The resistive system will register a touch using almost any object, as long as the two layers make contact v1.00 CCI Learning Solutions Inc. 49

24 Lesson 2 Capacitive Surface Acoustic Wave Devices and Connections In a capacitive system, a layer that stores electrical charge is placed on the monitor s glass panel. When a user touches the monitor, some of the charge is transferred to the user, and the charge on the capacitive layer decreases accordingly. The decrease is measured in circuits located at each corner of the monitor. Then using the relative differences in charge at each corner, the computer calculates exactly where the touch event took place. The coordinates are then relayed to the touchscreen driver software. Capacitive systems have a much clearer picture than resistive systems. The capacitive system must be touched by a conductive object, usually a finger, to register a touch. In an acoustic wave system, two transducers are placed along the X and Y axes of the monitor's glass plate. One transducer sends electrical signals across the glass and the other transducer receives the signals. Reflectors are also placed on the glass; they reflect the electrical signal sent from the sending transducer to the receiving transducer. The receiving transducer can tell if the wave has been disturbed by a touch and can locate it accordingly. Images are very clear on these touchscreens, making them suitable for displaying detailed graphics. The surface acoustic wave system will register a touch from almost any object. Objective 1.2 Adjusting Monitor Settings After you connect and power on a monitor, you may find that you need to adjust the display settings. For example, if an image is not visible, the brightness or contrast may be set too low. On the other hand, if an image is distorted, the brightness or contrast might be set too high. Sometimes an image is not centered or positioned properly on the screen, resulting in parts of the image disappearing off the top, sides or bottom. In such cases, you should adjust the positioning. The specific method for adjusting brightness, contrast and image position varies from monitor to monitor. Some monitors include a separate button for each setting; others display a menu of configuration settings that can be accessed by pressing a button on the monitor. In addition to adjusting the settings of the monitor itself, you can adjust various Windows display settings, such as text size and resolution in order to make viewing more comfortable. You can access these settings in the Display window of the Control Panel, shown in the following figure v1.00 CCI Learning Solutions Inc.

25 Devices and Connections Lesson 2 You can select the Smaller, Medium or Larger settings, or you can specify a custom setting by clicking the Set custom text size (DPI) link. Click the Adjust resolution link to access settings for your screen resolution, as shown in the following figure. Exercise 2-4 Adjusting the monitor (Desktop) In this exercise, you will examine the video ports on your system, connect your monitor and adjust the monitor settings. 1. Shut down Windows, turn off the monitor, then disconnect the monitor. 2. Examine your video cable. What type of cable is it? 3. Locate the video port(s) on your system. Are there more than one? What type of video port(s) does your system include? 4. Reconnect your monitor, making sure the connection is securely fastened. 5. Turn on the monitor, then restart your computer. 6. Experiment with the adjustment buttons on your monitor. Which settings can you access? How easy is it to adjust the brightness? The contrast? If there is a settings menu, is it easy or difficult to navigate? 7. Ensure the monitor is set to a comfortable configuration. 8. Log into Windows, click Start, click Control Panel, then click the Adjust screen resolution link. 9. Display the Resolution drop-down list, drag the slider to a lower setting than the current setting, then click the Apply button. Notice how the resolution settings affect the display on the screen. 10. Click the Revert button in the Display Settings dialog box, or allow your system to revert to the original settings on its own. 11. Close the Control Panel. In this exercise, you examined the video ports on your system, connected a monitor and adjusted monitor settings v1.00 CCI Learning Solutions Inc. 51

26 Lesson 2 Devices and Connections Objective 1.4 Case Scenario 2-1 A Day at the Help Desk Ken works at the Computer Support Help Desk at DreamPages, LLC. Today Hillary has just returned to work after undergoing eye surgery. She says she is having such a hard time reading the text on her screen that she cannot be productive proofreading new contracts. Ken visits her cubicle and does the following: He uses the buttons on the monitor to increase the contrast. He uses the Display window of the Control Panel to change the text size on her screen to the Larger setting. As a class, discuss what else Ken might do to make it easier for Hillary to do her job. Scanners Scanners convert pictures or text to digital data. A scanner can be a standalone device or part of a multifunction printer. The standalone types are usually flatbed scanners, whereas the scanners that are built into multi-function printers come in both flatbed and sheet-feed versions. With a flatbed scanner, you place a picture or document on a glass window for scanning and close the cover. In a sheet-feed scanner, pages are pulled one at a time into the machine, scanned inside the printer and then ejected into a paper tray after the scanning is complete. Most scanners support the TWAIN standard. Twain is a protocol and an application programming interface (API) that regulates communication between software applications and imaging devices such as scanners and digital cameras. Most scanners come with specific software that allows you to use all the features of the device. Such vendor software usually provides much more functionality than you could get using just the TWAIN interface. For example, most scanners include options that allow you to specify an image source, set the resolution for scanning and specify an output type. That is, you can specify whether you want to send the scanned output to a printer, or to an message or to a file saved in a storage location. Usually you can set options for scanning in color or black and white, and you can often scale, rotate and crop images before saving or printing them. Generally when you scan text, the saved output is an image file, and is therefore not editable in a word processing application. However, special optical character recognition (OCR) software can be installed (if the scanner supports it) and scanned text can be saved as an editable, searchable document. You should always review documents that have been scanned through OCR carefully to ensure that the characters have been accurately interpreted. Connecting a scanner used to be a slow and tedious process. Scanners used to be connected to parallel or SCSI ports and they were difficult to configure. Modern scanners can connect via USB or FireWire, and those in multifunction printers can be accessed wirelessly as well. Although modern scanners are mostly plug-andplay compatible, you will want to install the drivers that come with them so you can use all the scanner features. When you need to connect a scanner, always read the manufacturer documentation before making any connections. Often scanners ship with a quick start flyer and a software installation CD. In many cases, you will be directed to run the installation program on the CD before you connect the scanner to the system. Installing the manufacturer's drivers first ensures that Windows does not install and use a generic device driver for the scanner instead of using the feature-rich drivers supplied by the manufacturer. Once your scanner is attached, you should always scan a test page to be sure it is functioning properly v1.00 CCI Learning Solutions Inc.

27 Objective Devices and Connections Lesson 2 Printers A printer is an output device that prints text and graphics from the computer onto paper. Print quality, or print resolution, is usually measured in dots per inch (dpi). The more dots per inch a printer can generate, the better the print quality. Inkjet Printers Inkjet printers produce images by spraying ink through tiny nozzles in the print head onto the paper. Text and images are created by dots of ink, much as they are in a newspaper. Print resolution is measured in dots per inch (dpi), with most inkjets offering from 300 to 600 dpi. Various color hues are created using cyan (a specific shade of blue), yellow, magenta and black, and these four colors are often referred to as CYMK, with K representing black. Ink cartridges are the reservoirs that hold ink for inkjet printers. The number of cartridges you need to install varies among manufacturers and specific models, but most have a black cartridge plus a three-color cartridge with which includes compartments for yellow, cyan and magenta inks. Some inkjet printers use separate cartridges for each of the colors. Inkjets are well suited for low-volume printing environments, such as homes and small offices. They are inexpensive and easy to setup and install. In most inkjet printers, the print head is part of the ink cartridge, which allows you to get a new print head each time you replace a cartridge. The average life expectancy of an ink cartridge is determined by its size and by how many pages you print. Prices for ink cartridges vary by vendor, but most are around $20 USD for a black ink cartridge, and $35 USD for a color (tri-color) cartridge. In inkjets where separate cartridges for each color are used, the prices are a bit lower. For example, the separate color cartridges for a Canon inkjet are around $9 USD a piece, but you need to buy five -- a high-capacity black cartridge for black and white printing, then one black, one yellow, one cyan and one magenta cartridge for color printing. Most modern inkjets can connect directly to a computer via a USB connection. Some older models offered USB and parallel connections. In most cases, Windows will automatically detect the printer when you connect it and attempt to install a generic driver for it. In most situations, you need to install the manufacturer s drivers to use all the printer s features. Laser Printers Laser printers produce high-quality documents and are well suited to a high-volume printing environment. A laser printer produces images by using an electrophotographic process that involves attracting toner to a page with an electrostatic charge and fusing the toner onto the page using pressure and heat. Laser printers are much more complex machines than inkjet printers. They weigh considerably more, require regular (somewhat complex) maintenance, and are more expensive. The inside of a laser printer can get hot enough to cause serious burns, and care should be taken whenever you open one to clean the printer or clear a paper jam. Laser printers are also much faster than inkjets, and for high-volume offices they are often more economical due to the high number of pages you can print from a single toner cartridge as opposed to the number of pages you can print from an ink cartridge. High-end laser printers can have resolutions of 1,200 or 1,800 dpi. Single-color laser printers use black toner cartridges. Color laser printers operate in the same manner as single-color laser printers except the process is repeated four times and a different toner color is used for each pass: black, cyan, magenta and yellow. Laser toner can be expensive, approximately $100 USD per toner cartridge; however, a cartridge will probably produce between 1,000 and 1,500 pages. If you are considering purchasing a laser printer, check the specifications carefully to see how many pages on average you can get from a toner cartridge and consider the price of toner v1.00 CCI Learning Solutions Inc. 53

28 Lesson 2 Devices and Connections Most laser printers offer two or more connection interfaces. These include parallel, SCSI, USB, Serial, FireWire, and wired or wireless network connections. Printing in Windows At one time in the not-too-distant past, there was no standard to connect printers or to instruct various application programs on how to use a printer that was attached to a system. Windows offers a standard method of connecting to and accessing printers through the creation of a virtual, software-based printer built into the operating system. To print in Windows, you need a printer and a print device. In the Windows definition, a printer is the set of software components running on the computer that manage the printing process, whereas a print device is the actual physical machine that produces the printed output. That is, the printer is virtual and the print device is the laser or inkjet connected to the computer. Using this arrangement, software developers write their programs to print to the virtual printer, and Windows converts the applications' data into the correct format for your actual print device. Windows also manages the process of communicating with the print device. This model is advantageous because you need set up and configure your print device only once (instead of having to set it up for each application you want to use), you can install more than one print device, and printing works the same way whether you are printing to a device attached to your computer or to a print device attached to someone else's computer, or to a network print device. Connecting Printers With many modern printers, you have the option to connect the printer directly to a computer, or to set the printer up for use over a network. When connecting a printer, you should always read the manufacturer documentation before making any connections. Often printers ship with a quick start flyer and a software installation CD. In many cases, you will be directed to run the installation program on the CD before you connect the printer to the system. Installing the manufacturer's drivers first ensures that Windows does not install and use a generic device driver for the printer instead of using the feature-rich drivers supplied by the manufacturer. Once a printer is connected, you should always print a test page to be sure it is functioning properly. Direct connections and printer sharing A direct connection is made by attaching the printer directly to a PC. Direct connections use a parallel cable or, more commonly, a USB cable. If a computer is participating on a network, and that computer has a printer directly attached to it, the user may opt to share the printer with other users on the network by enabling printer sharing. This is different from making a printer a network printer. When a user has enabled print sharing, other computers connect to the printer through the user's computer. That is, the computer with the printer attached must be turned on and logged onto the network in order for anyone else to send a document to the printer. Sharing a printer in Windows 7 is a two-part process. First you must enable file and printer sharing, then you need to share your printer. To turn on file and printer sharing: Open the Control Panel and click the Choose homegroup and sharing options link. In the Other homegroup actions section, click the Change advanced sharing settings link to access the Advanced sharing settings screen. In the File and printer sharing section, select Turn on file and printer sharing, then click Save changes. Close the open Control Panel windows. To share the printer: Open the Control Panel and click the View devices and printers link. Right-click the printer you want to share, and then click Printer properties. Click the Sharing tab, click the Share this printer check box, as shown in the following figure, then click OK v1.00 CCI Learning Solutions Inc.

29 Devices and Connections Lesson 2 You can clear the Share this printer check box at any time to stop sharing the printer. When you elect to share a printer, you may choose to install additional printer drivers on your system. Doing so makes the drivers available to other users who want to connect to your printer. To view a video on sharing a printer in Windows, visit Network printers Printers can also be set up as network printers. A network printer is different from a shared printer. When you share a printer, other users connect to the shared printer through the computer to which the printer is directly attached. A network printer, on the other hand, is not directly attached to a computer. Rather, the printer is connected to the network. In order to be set up as a network printer, the print device itself must include an interface for connecting to a network. For example, many printers can be set up as wireless network printers. These connect to a network using wireless networking protocols. Other printers include a network port for wired connectivity. You can plug one end of a network cable into the network port on the printer, and plug the other end into an appropriate device on the network. Connecting a Wired network printer When you first set up a printer as a network printer, you must initially connect the printer directly to a PC via a USB cable so you can configure the printer for network use. The PC to which you connect the printer should have an active connection to the network. You begin by inserting the installation CD into the computer and starting the install program. For printers that include networking options, the installation CDs offer a menu of setup configurations. You would choose an option equivalent to set up the printer for network use for the first time. Follow the prompts in the installation program and do not connect any cables until instructed to do so v1.00 CCI Learning Solutions Inc. 55