16 supporting io devices
DESCRIPTION
Comptia A+ noteTRANSCRIPT
Supporting I/O Supporting I/O DevicesDevices
Basic Principles of Basic Principles of Peripheral Peripheral InstallationsInstallations Both hardware and software must be Both hardware and software must be
installed (hardware is controlled by installed (hardware is controlled by software) software)
Install all levels of softwareInstall all levels of software Device driver must be written specifically Device driver must be written specifically
for the OSfor the OS More than one peripheral device might More than one peripheral device might
attempt to use same resources attempt to use same resources Update drivers, the firmware, or bothUpdate drivers, the firmware, or both
Installation OverviewInstallation Overview
1.1. Install the device (internal or Install the device (internal or external)external)
2.2. Install the device driverInstall the device driver
3.3. Install the application softwareInstall the application software
PortsPorts
Using Ports and Using Ports and Expansion Slots for Add-Expansion Slots for Add-on Deviceon Device PortsPorts
– SerialSerial
– ParallelParallel
– USBUSB
– IEEE 1394IEEE 1394
– SCSISCSI
Expansion slotsExpansion slots
Port SpeedsPort Speeds
Using Serial PortsUsing Serial Ports
Transmit data in single bits (serially)Transmit data in single bits (serially)
Nine or 25 pinsNine or 25 pins
Almost always maleAlmost always male
Originally intended for input and Originally intended for input and output devicesoutput devices
Configured as COM1, COM2, COM3, Configured as COM1, COM2, COM3, or COM4or COM4
Using Serial Ports Using Serial Ports ((continuedcontinued))
Port assignments are made in CMOS Port assignments are made in CMOS setupsetup
Conform to standard interface called Conform to standard interface called RS-232cRS-232c
Data Terminal Equipment (DTE) and Data Terminal Equipment (DTE) and Data Communications Equipment Data Communications Equipment (DCE) designations(DCE) designations
Port ComparisonPort Comparison
Default Port Default Port AssignmentsAssignments
Serial Port Serial Port SpecificationsSpecifications
Null Modem Null Modem ConnectionConnection Enables data transmission Enables data transmission
between two DTE devices without between two DTE devices without the need for modemsthe need for modems
Special cable (null modem cable) Special cable (null modem cable) has several wires cross-connected has several wires cross-connected to simulate modem connectionto simulate modem connection
Pin Connections for a Pin Connections for a 25-Pin Null Modem 25-Pin Null Modem Cable Cable
Wire Connections on a Wire Connections on a 25-Pin Null Modem 25-Pin Null Modem Cable Cable
Infrared TransceiversInfrared Transceivers
Use resources of a serial port for Use resources of a serial port for communicationcommunication
Create a virtual infrared serial port and Create a virtual infrared serial port and virtual infrared port for infrared devicesvirtual infrared port for infrared devices
UART logic on the motherboard UART logic on the motherboard controls serial ports on the boardcontrols serial ports on the board
Line-of-sight issueLine-of-sight issue
Using Parallel PortsUsing Parallel Ports Transmit data in parallel, eight bits at a Transmit data in parallel, eight bits at a
timetime
Almost always femaleAlmost always female
Originally intended for printersOriginally intended for printers
Can be configured as LPT1, LPT2, or LPT3Can be configured as LPT1, LPT2, or LPT3
Port assignments are made in CMOS setupPort assignments are made in CMOS setup
Avoid using a cable longer than 15 feet to Avoid using a cable longer than 15 feet to ensure data integrityensure data integrity
Types of Parallel PortsTypes of Parallel Ports
Standard parallel port (SPP)Standard parallel port (SPP)– Allows data to flow in only one directionAllows data to flow in only one direction
– Slowest of the three typesSlowest of the three types
Enhanced Parallel Port (EPP)Enhanced Parallel Port (EPP)– Bi-directionalBi-directional
Extended Capabilities Port (ECP)Extended Capabilities Port (ECP)– Bi-directionalBi-directional
– Uses the DMA channelUses the DMA channel
A Standard Parallel A Standard Parallel PortPort
Configuring Parallel Configuring Parallel PortsPorts Setup can have up to four Setup can have up to four
different settings for parallel portsdifferent settings for parallel ports
Using USB PortsUsing USB Ports
Effortless installation of slow Effortless installation of slow peripheral devicesperipheral devices
Much faster than regular serial ports; Much faster than regular serial ports; use higher-quality cablinguse higher-quality cabling
Easier to manage; eliminate need to Easier to manage; eliminate need to manually resolve resource conflictsmanually resolve resource conflicts
Likely to replace serial and parallel Likely to replace serial and parallel portsports
Using USB Ports Using USB Ports ((continuedcontinued)) Allow for hot-swapping; are hot-Allow for hot-swapping; are hot-
pluggablepluggable
Most current motherboards have one Most current motherboards have one to four USB portsto four USB ports
Managed by a USB host controllerManaged by a USB host controller
As many as 127 USB devices can be As many as 127 USB devices can be daisy-chained together using USB daisy-chained together using USB devicesdevices
USB PortsUSB Ports
USB Host ControllerUSB Host Controller
Requirements for Requirements for Preparing to Install a Preparing to Install a USB DeviceUSB Device Motherboard or expansion card Motherboard or expansion card
that provides a USB portthat provides a USB port
OS that supports USBOS that supports USB
USB deviceUSB device
USB device driverUSB device driver
Installing a USB DeviceInstalling a USB Device
Some devices (eg, printers) require the Some devices (eg, printers) require the device to be plugged in before installationdevice to be plugged in before installation
Some devices (eg, scanners) require the Some devices (eg, scanners) require the driver to be installed before the device is driver to be installed before the device is plugged inplugged in
Using Device Manager, verify that USB Using Device Manager, verify that USB controller is installed and working properlycontroller is installed and working properly
Using IEEE 1394 PortsUsing IEEE 1394 Ports
Transmit data serially; faster than USBTransmit data serially; faster than USB Likely to replace SCSI for high-volume, Likely to replace SCSI for high-volume,
multimedia external devicesmultimedia external devices Provide either a 4-pin or 6-pin connectorProvide either a 4-pin or 6-pin connector Hot-pluggableHot-pluggable
– Can be daisy-chained together and managed Can be daisy-chained together and managed by a host controller using one set of system by a host controller using one set of system resourcesresources
Use isochronous data transferUse isochronous data transferIsochronous transfers involve large streams of data. This format is used to move continuous, real-time data streams such as voice or video. Data delivery rates are predetermined and correspond to the sampling rate o the device.
IEEE 1394 Port IEEE 1394 Port StandardsStandards IEEE 1394AIEEE 1394A
– Supports data speeds up to 1.2 GbpsSupports data speeds up to 1.2 Gbps
– Allows for cable lengths up to 15 feetAllows for cable lengths up to 15 feet
IEEE 1394BIEEE 1394B
– Supports speeds up to 3.2 GbpsSupports speeds up to 3.2 Gbps
– Allows for cable length up to 328 feet Allows for cable length up to 328 feet
IEEE 1394 Cable IEEE 1394 Cable ConnectionsConnections
Using IEEE 1394 PortsUsing IEEE 1394 Ports
KeyboardsKeyboards
Traditional straight design or ergonomic Traditional straight design or ergonomic designdesign
Two technologies for keys making Two technologies for keys making contactcontact
– Foil contactFoil contact
– Metal contactMetal contact
Installing keyboardsInstalling keyboards
Keyboard ConnectorsKeyboard Connectors
PS/2 connector (or mini-DIN)PS/2 connector (or mini-DIN)
– Small, round, with six pinsSmall, round, with six pins
DIN (Deutsche Industrie Norm) DIN (Deutsche Industrie Norm) connectorconnector
– Round with five pinsRound with five pins
USB portUSB port
Wireless connectionWireless connection
– Requires a driverRequires a driver
Keyboard Connectors Keyboard Connectors ((continuedcontinued) )
Pinouts for Keyboard Pinouts for Keyboard ConnectorsConnectors
Pinouts for Keyboard Pinouts for Keyboard ConnectorsConnectors
You'll notice a few things about the table. First, there are only four actual signals used in the standard keyboard interface; the extra pins on both types of connector are not used
(This mismatch means that the connectors were chosen either from existing designs to save development costs, or that room was left for future expansion that was never used. Both occur commonly in the PC industry.)
A Keyboard AdapterA Keyboard Adapter
Since the signals are the same for the two types of connector--they just use different pins. This means that simple mechanical adapters can be made to convert between the two. These adapters let a keyboard that terminates in a large connector work on a system that requires a small connector, and vice-versa.
Troubleshooting Troubleshooting KeyboardsKeyboards A few keys don’t workA few keys don’t work
Keyboard does not work at allKeyboard does not work at all
Key continues to repeat after being Key continues to repeat after being releasedreleased
Keys produce the wrong charactersKeys produce the wrong characters
Major spills on the keyboardMajor spills on the keyboard
Pointing DevicesPointing Devices
How a Wheel Mouse How a Wheel Mouse Works Works
How a Mouse ConnectsHow a Mouse Connectsto the Computerto the Computer Dedicated round mouse port Dedicated round mouse port
(motherboard mouse or PS/2-compatible (motherboard mouse or PS/2-compatible mouse)mouse)
Mouse bus card (bus mouse)Mouse bus card (bus mouse)
Serial port (serial mouse)Serial port (serial mouse)
USB portUSB port
Y-connection with the keyboardY-connection with the keyboard
Cordless technologyCordless technology
Pointing DevicesPointing Devices
Touch screensTouch screens
Other pointing devicesOther pointing devices
– TrackballsTrackballs
– Touch padsTouch pads
Troubleshooting a Troubleshooting a MouseMouse Check mouse port connectionCheck mouse port connection
Check for dust or dirt; reboot PCCheck for dust or dirt; reboot PC
Try new mouseTry new mouse
Uninstall and reinstall mouse driver; reboot Uninstall and reinstall mouse driver; reboot PCPC
Reboot PC and select logged option from Reboot PC and select logged option from startup menu to create Bootlog.exe filestartup menu to create Bootlog.exe file
– Continue to boot and check log for errorsContinue to boot and check log for errors
Other DevicesOther Devices
Scanners Web Cameras Biometric Devices Bar Code Readers Touch Screens