A+ Guide to Managing
and Maintaining Your PC
Fifth Edition
Chapter 10
Supporting I/O Devices
You Will Learn…

How to use ports and expansion slots for addon devices

How to install peripheral I/O devices

About keyboards and how to troubleshoot
them

About different types of pointing devices

How monitors and video cards relate to the
system, and how to troubleshoot them
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
2
Basic Principles of Peripheral
Installations





Both hardware and software must be installed
(hardware is controlled by software)
Install all levels of software
Device driver must be written specifically for
the OS
More than one peripheral device might attempt
to use same resources
Update drivers, the firmware, or both
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
3
Installation Overview
1. Install the device (internal or external)
2. Install the device driver
3. Install the application software
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
4
Ports
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
5
Using Ports and Expansion
Slots for Add-on Device


Ports

Serial

Parallel

USB

IEEE 1394

SCSI
Expansion slots
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
6
Port Speeds
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
7
Using Serial Ports

Transmit data in single bits (serially)

Nine or 25 pins

Almost always male

Originally intended for input and output
devices

Configured as COM1, COM2, COM3, or
COM4
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
8
Using Serial Ports (continued)

Port assignments are made in CMOS setup

Conform to standard interface called RS-232c

Data Terminal Equipment (DTE) and Data
Communications Equipment (DCE)
designations
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
9
Port Comparison
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
10
Default Port Assignments
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
11
Serial Port Specifications
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
12
Null Modem Connection

Enables data transmission between two DTE
devices without the need for modems

Special cable (null modem cable) has several
wires cross-connected to simulate modem
connection
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
13
Pin Connections for a 25-Pin
Null Modem Cable
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
14
Wire Connections on a 25-Pin
Null Modem Cable
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
15
Infrared Transceivers

Use resources of a serial port for communication

Create a virtual infrared serial port and virtual
infrared port for infrared devices

UART (Universal Asynchronous ReceiverTransmitter ) logic on the motherboard controls
serial ports on the board

Line-of-sight issue
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
16
Universal Asynchronous
Receiver-Transmitter

UART is a piece of computer hardware that translates
between parallel bits of data and serial bits.

A UART is usually an integrated circuit used for
serial communications over a computer or peripheral
device serial port.

UARTs are now built into some microcontrollers.
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
17
Using Parallel Ports

Transmit data in parallel, eight bits at a time

Almost always female

Originally intended for printers

Can be configured as LPT1, LPT2, or LPT3

Port assignments are made in CMOS setup

Avoid using a cable longer than 15 feet to
ensure data integrity
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
18
Types of Parallel Ports


Standard parallel port (SPP)

Allows data to flow in only one direction

Slowest of the three types
Enhanced Parallel Port (EPP)


Bi-directional
Extended Capabilities Port (ECP)

Bi-directional

Uses the DMA channel
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
19
A Standard Parallel Port
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
20
Configuring Parallel Ports

Setup can have up to four different settings for parallel
ports
PORT NAME
Interrupt #
Starting I/O
Ending I/O
LPT1
IRQ 7
378
37f
LPT2
IRQ 5
278
27f
LPT 3
IRQ 5 / IRQ 7
278
27A
LPT 4
IRQ 5 / IRQ 7
1378
137A
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
21
Using USB Ports

Effortless installation of slow peripheral
devices

Much faster than regular serial ports; use
higher-quality cabling

Easier to manage; eliminate need to manually
resolve resource conflicts

Likely to replace serial and parallel ports
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
22
Using USB Ports (continued)

Allow for hot-swapping; are hot-pluggable

Most current motherboards have one to four
USB ports

Managed by a USB host controller

As many as 127 USB devices can be daisychained together using USB devices
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
23
USB Ports
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
24
USB Host Controller
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
25
Requirements for Preparing to
Install a USB Device

Motherboard or expansion card that provides a
USB port

OS that supports USB

USB device

USB device driver
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
26
Installing a USB Device

Some devices (eg, printers) require the device
to be plugged in before installation

Some devices (eg, scanners) require the driver
to be installed before the device is plugged in

Using Device Manager, verify that USB
controller is installed and working properly
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
27
Using IEEE 1394 Ports




Transmit data serially; faster than USB
Likely to replace SCSI for high-volume,
multimedia external devices
Provide either a 4-pin or 6-pin connector
Hot-pluggable


Can be daisy-chained together and managed by a
host controller using one set of system resources
Use isochronous data transfer
Isochronous 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.
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
28
IEEE 1394 Port Standards


IEEE 1394A

Supports data speeds up to 1.2 Gbps

Allows for cable lengths up to 15 feet
IEEE 1394B

Supports speeds up to 3.2 Gbps

Allows for cable length up to 328 feet
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
29
IEEE 1394 Cable Connections
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
30
Using IEEE 1394 Ports
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
31
Installing an Expansion Card in
an Expansion Slot
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
32
Using Specialized Devices and
Extra Ports
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
33
Using PCI Expansion Slots

PCI bus



PCI bus controller



Currently the standard I/O bus
Uses an interim interrupt between PCI card and
IRQ line to the CPU
Manages the PCI bus and expansion slots
Assigns IRQ and I/O addresses to PCI expansion
cards
Use Device Manager to see which IRQ has
been assigned to a PCI device
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
34
Using PCI Expansion Slots
(continued)
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
35
Using ISA Expansion Slots

Configuration is not automated

ISA bus does not manage system resources, as
do USB and PCI bus controllers

ISA device must request system resources at
startup
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
36
Solving Problems with Legacy
ISA Expansion Cards

Resource conflicts between two legacy devices


Use Windows Device Manager
Problems using legacy device drivers

Try to locate a 32-bit driver for the device
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
37
Solving Problems with Legacy
ISA Expansion Cards (continued)

Create empty copy of Autoexec.bat and Config.sys
on hard drive then
• boot up into MS-DOS mode
• run setup program from command prompt
• copy appropriate command lines into original versions
of Autoexec.bat and Config.sys
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
38
Solving Problems with Legacy
ISA Cards
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
39
Solving Problems with Legacy
ISA Cards (continued)
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
40
Keyboards

Traditional straight design or ergonomic
design

Two technologies for keys making contact


Foil contact

Metal contact
Installing keyboards
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
41
Keyboard Connectors

PS/2 connector (or mini-DIN)


Small, round, with six pins
DIN (Deutsche Industrie Norm) connector

Round with five pins

USB port

Wireless connection

Requires a driver
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
42
Keyboard Connectors (continued)
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
43
Pinouts for Keyboard
Connectors
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
44
Pinouts for Keyboard
Connectors
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+ Guide to Managing and Maintaining Your PC, Fifth Edition
45
A 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.
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
46
Troubleshooting Keyboards

A few keys don’t work

Keyboard does not work at all

Key continues to repeat after being released

Keys produce the wrong characters

Major spills on the keyboard
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
47
Pointing Devices
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
48
How a Wheel Mouse Works
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
49
How a Mouse Connects
to the Computer

Dedicated round mouse port (motherboard
mouse or PS/2-compatible mouse)

Mouse bus card (bus mouse)

Serial port (serial mouse)

USB port

Y-connection with the keyboard

Cordless technology
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
50
Pointing Devices

Touch screens

Other pointing devices

Trackballs

Touch pads
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
51
Troubleshooting a Mouse

Check mouse port connection

Check for dust or dirt; reboot PC

Try new mouse

Uninstall and reinstall mouse driver; reboot PC

Reboot PC and select logged option from
startup menu to create Bootlog.exe file

Continue to boot and check log for errors
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
52
Computer Video

Necessary components for video output

Monitors

Video cards
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
53
Monitors

Rated by screen size, resolution, refresh rate,
and interlace features

Most meet standards for Super VGA

Use CRT (cathode-ray tube) or LCD (liquid
crystal display) technology
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
54
How a CRT Monitor Works
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
55
Choosing the Right Monitor
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
56
Monitors

Monitors and ELF emissions

Flat panel monitors


Active-matrix

Dual-scan passive matrix
Installing dual monitors

Increases size of Windows desktop

You must choose to activate a second monitor
before it will be used by Windows
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
57
Flat Panel Monitors
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
58
Video Cards

Methods of data transfer

RGB video port

DVI port

Composite video

S-Video
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
59
Methods of Data Transfer
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
60
Transferring Data with an
S-Video Cable
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
61
Video Cards

Quality is rated according to how video
subsystem affects overall system performance,
video quality, power-saving features, and ease
of use and installation

Main features to look for

Bus used (VESA, PCI, or AGP)

Amount and type of video RAM it has or can
support
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
62
AGP Bus
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
63
Graphics Accelerators

Type of video card that has its own processor
to boost performance

Features reduce burden on motherboard CPU,
(eg, MPEG decoding, 3-D graphics, dual
porting, color space conversion, interpolated
scaling, EPA Green PC support, digital output
to flat panel display monitors, application
support for high-intensity graphics software)
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
64
Video Memory

Stored on video cards as memory chips

Amount of data received from CPU is
determined by


Screen resolution

Color depth

Alpha blending
Several types (VRAM, SGRAM, WRAM,
3-D RAM)
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
65
Troubleshooting Video
Problems

Power light (LED) does not go on; no picture

Power LED is on, no picture on power-up

Power is on, but monitor displays wrong
characters

Monitor flickers, has wavy lines, or both

No graphics display on screen or screen goes
blank when loading certain programs
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
66
Troubleshooting Video
Problems (continued)

Screen goes blank 30 seconds or one minute
after keyboard is left untouched

Poor color display

Picture out of focus or out of adjustment

Crackling sound
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
67
Video Monitors

Configuring or changing monitor settings and
drivers in Windows

Changing video driver configuration

Returning to standard VGA settings
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
68
Summary

Procedures and guidelines common to most
installations, including how to use serial,
parallel, USB, and IEEE 1394 ports as well as
expansion slots

Essential I/O devices for a PC

Keyboard

Mouse

Video
A+ Guide to Managing and Maintaining Your PC, Fifth Edition
69