chpt9a supporting io devices

8/9/2019 Chpt9a Supporting IO Devices

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Chapter 9Chapter 9Supporting I/O Devices


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Slide 2Ver 1.0 5 May 2001

ObjectivesObjectives

How to use standard resources on a computer system when installing add-on devices

How to resolve resource conflicts

How to install a new device on a computer

About keyboards, pointing devices and video subsystems


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Peripheral Installation OverviewPeripheral Installation Overview

Installing a

Peripheral

Install the device(learn about the driver:

Is the driver for your OS?

Lastest driver available?

Install the Driver(Check the Device

Manager after Installation)

Install the

Application Software(that comes with the

device)

1

2

3


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Device DriversDevice Drivers (page 451(page 451--453)453)

2 Types of Drivers: 16-bits and 32-bitsCharacteristics 16-bits Driver 32-bit Driver

Operating Mode Real Mode Protected Mode

User of Memory Use conventional memory

May use upper memory

Stored in extended memory

How loaded Loaded by a command line inconfig.sys or autoexec.bat Automatically loaded by Win9x atstartup or when the device isused

How changed Edit the config.sys orautoexec.bat

From Device Manager, select thedevice and use Properties, Drivertab

How to identify

the type

In Device Manager, look for an

exclamation point beside thedevice name

Look for no exclamation point

beside the device name in DeviceManager. Typically 32 isincluded in the driver name.

When to use thistype

Use 16-bit driver underWindows only when 32-bitdriver is not available.

When operating in DOS

Use 32-bit driver, they arefaster


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Serial PortsSerial Ports

What is the SerialPort use for?Use to connect Serial devices eg mouse,

modem. It convert PCs Parallel signal toserial and vice versa.

What is the Port also known as?

RS-232 port (RS-232C - standard)

How many ports are normally found in aPC?

2

What types of connector is found onthe PC?

Male D-connectors. 9-pin and 25-pin.

How can you disable a serial port?In BIOS


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Null Modem Cable ConnectionNull Modem Cable Connection

What is purpose of aN

ull ModemCable?

To connect your PC to another nearbyPC. Useful for file transfers

Which ports are being used?

The serial port in eachP

C.

What need to be Setup before bothPCscan be connected?

1. Direct Cable Connection

Control panel

Add/Remove program

Windows Setup

Communication

2. Install MicrosoftNetBUEIprotocol

Network Neighborhood

Properties

Add Protocol

3. Enable File and Printer Sharing Network Neighborhood

Properties

File and Print Sharing


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Infrared TransmissionInfrared Transmission

How is infrared radiation use inPC?Commonly implemented in Keyboard,

Mouse and Printer.

How is it supported?

Computers and other devices (such as

printers) come with IrDA ports. Thisenables you to transfer data from onedevice to another without any cables.

Example?

If both your laptop computer andprinter have IrDA ports, you can simply

put your computer in front of theprinter and output a document, withoutneeding to connect the 2 with a cable.

Is the transmission it fast?IrDA ports support roughly the sametransmission rates as traditionalparallel ports.

What is the limitation?

The 2 devices must be within a few feetof each other and there must be a clearline of sight between them.


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Parallel Port

What isParallel

Port used for?Connecting external devices eg printer

that requires relatively high band width

What are the 3 types of Parallel port?

1. Standard Parallel Port

2. EnhancedParallel

Port (E

PP)

3. Extended Capabilities Port (ECP).

What is SPP?

Support 1 direction flow of data, fromPC to printer. Use for printer, plotters,

etc. Currently, use for older printers.Maximum cable length is 15m.

What is SPP standard also known as?

Centronics

What is EPP

?Supports bi-directional communicationbetween the PC and attached devices.About 10 times faster than the olderCentronics standard. The standard ismerged in IEEE 1284.

DB25-pin Connector

(PC end)

36-pin Centronics

Connector(printer end)


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Parallel PortParallel Port ECP/IEEE 1284ECP/IEEE 1284

What is ECP?Supports bi-directional communication

between PC and printers.

What is IEEE 1284?

Supports SPP, EPP and ECP. Provide highspeed bi-directional communication upto 50 100x the original parallel port.

What is required to supports IEEE1284?

IEEE 1824 cable, printer must supportECP/EPP.


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Universal Serial BusUniversal Serial Bus

What type of data transfer is it goodfor?

Goof for asynchronous data, ie dataare transferred in Packets

What is the advantages?

Support 127 equipments yet sharingonly 1 set of System Resources. Itsupport Hot-swappable.

What is the current version?

Version 1 supports up to 12Mbps. USBVersion 2 supports up to 480Mbps


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IEEE 1394 PortIEEE 1394 Port

What is 1394 commonly known as?Firewire. In fact it is a Serial SCSI.

What type of data transfer is it goodfor?Fast, contiguous data transfer. Goodfor real-time transmission eg TV, video

Example of 1 application for Firewire?Digital Video Recorder

What types of connectors does it use?1. 4-pins and 6-pins (2 pins used for

voltage and ground)

Does Firewire support hot-pluggable?Yes. Device can be plugged into andremove without rebooting

What other advantages it has?Use only 1 set of System Resources andsupport 67 devices

What is the current standard?

Supports up to 400Mbps and cable upto 4.5m. In future, supports up to3.2gbps and cable up to 100m

What should you do if the PC does nothave the IEEE 1384 connector?

By a IEEE 1394 host adapter


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Keyboard and MouseKeyboard and Mouse

What are the types of keyboard andmouse available?

Serial

PS/2

USB

Wireless

What is the difference between serialkeyboard and mouse connector?

Serial keyboard uses 5-pin DIN. Serialmouse uses 9-pin D-connector(commonly used) or 25-pin D-connector.

What is the difference betweenP

S/2keyboard and mouse connector?

Same type of connector.


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MonitorMonitor Sreen Size/Refresh RateSreen Size/Refresh Rate

What is Screen Size?The diagonal width of the monitor.Measured in inches. The most popularsizes for monitors are 14", 15", 17", 20"and 21".

What is Viewable size of monitor?

This is the actual size of the screenthat is viewable. It is less than theScreen Size. Eg. 17 monitor probablyhas a viewable screen of 15.8

What is Screen Refresh?

To maintain a stable image, the electronbeam must sweep the entire surface ofthe screen and then return to redrawit, many times per second.

What is Refresh Rate?The number of time it refresh fromLeft to Right and Top to Bottom isknown as Refresh Rate.

What is the problem with slow RefreshRate?

Screen Flicker. Most individuals notice flicker at

refresh rates below 60 Hz. Many individuals have a problem

with flicker at 60 Hz. Some individuals see flicker at

refresh rates above 60 but below

72 Hz. A small percentage of individuals

notice flicker at 72 Hz. Very few people notice flicker at

refresh rates above 72 Hz


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MonitorMonitor -- InterlacedInterlaced

What is Interlaced?Redisplaying every line of the screen,when in an interlaced mode the electronguns sweep alternate lines on each pass.So the first pass, odd-numbered linesare refreshed, and the next pass, even-numbered lines, and so on.

What use Interlaced?

Enable the monitor and VGA card tosupport higher Refresh Rate than theypossibly could. Less Flicker.

Allows the refresh rate to be "doubled"

because only half the screen is redrawnat a time.

What make up an Image?Pixel

What is Pixel?

Horizontal and Vertical combination of3 colored dots: Red, Green, Blue

What is Dot Pitch?

Distance between adjacent colored dotson the screen. The smaller it is thesharper the display, eg 0.24 is sharperthan 0.28

What is Resolution?

The number of pixels that can bedisplayed on the screen at one time isnormally. Measured in Dot per inch (dpi)


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MonitorMonitor Flat PanelFlat Panel

Characteristics Thinner

Consume less power

Dont emit radiation

Digital

Types Active matrix

TFT (thin flim transistor)

sharper image, more expansiveDual-scan passive matrix

Signals Can receive both Analog and Digital signal

Requires

Digital Signal

Converts back

to Digital

Digital Data

Converts to

Analog

(RAMDAC)

Analog signal


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Cathode Ray Tube (CRT)Cathode Ray Tube (CRT)

What can you find the CRT?Inside the Monitor

Should you attempt to repair aMonitor?

No. Leave it to Trained Technician.

Why you should not Earth yourselfwhen working inside the monitor?

The high static charges may dischargethrough you. You body has much lowerpotential (voltage) compared to themonitor.

Where can you find the highest tensionarea in the monitor?

Anode. As high as 25,000 volts. Chargescan remains for weeks.

How can you discharged the Anode?Put the Screw driver blade into thesuction cap to discharge it. Repeatafter 15 mins

Discharging


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Video CardsVideo Cards (page494(page494--500)500)Known as Video controller card, graphics card, graphics adapters, display card

Interface between monitor and the PCBuying a card?

Bus it used and the amount of Video ram it has (or supported)

Digital signals get converted to Analog signal used by monitor

PCI Connector

RAM-DAC

Digital data goes from

system bus to Video chip1

Video RAM

2 3Video chip writes digital

data to video memory

Video chip set

Data in Video RAM

is passed to RAMDAC

for conversion to

Analog signal

RAM DAC

passes

Analog data

to Monitor

4


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Video RAMVideo RAM

What is Video RAM?

Special-purpose memory used by videoadapters.

How is different from normal RAM?

1. Can be accessed by 2 differentdevices simultaneously. This allowthe RAMDAC to access the VRAMfor screen updates at the sametime that the video processorprovides new data.

2. VRAM yields better graphics

performance but is more expensivethan normal RAM.

What are the other types of RAMused?

EDO RAM Extended Data Out RAM

SGRAM Synchronous Graphics RAM

WRAM Windows RAM

MDRAM multi-bank RAM

How does it affect the PC?

The amount of VRAM is a determiningfactor in the resolution and color depthof the display. VRAM is also used tohold graphics-specific information suchas 3-D geometry data and texture

maps.


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Video RAM RequiredVideo RAM Required

VideoResolution

16 colors

(4-bit)

256 colors

(8-bit)

65,000color

(16-bit)

16.7 millioncolor

(24-bitTrue)

32-bit color

640 X 480 256K 512K 1MB 1MB 2MB

800 X 600 512K 512K 1MB 2MB 2MB

1,024 X 768 1MB 1MB 2MB 4MB 4MB

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