System Configuration

1
System Configuration

• Definitions

2
Chapter Objectives

• After completing this chapter you will
• Understand the different ways to configure a
  microcomputer.
• Understand how to replace a battery.
• Understand and be able to identify system
  resources such as interrupts, DMA channels,
  memory addresses, and I/O addresses.
• Understand how different architectures and local
  bus adapters are configured.
• Understand the effects of plug and play, Windows
  9x, NT, 2000, and XP on configuring adapters.

3
Configuration Overview

• Setup program Used to configure a computer
  system.
• It indicates
• How much RAM is installed.
• The type and number of hard drives and floppy
  drives.
• Where the boot disk is located.
• Date and time, etc.
• Displays an error message if information in the
  setup program doesnt match the hardware or if a
  specific device fails to operate properly.

4
Setup Software

• Most computers require Setup software to access
  the Setup program that is often built into the
  BIOS chip and accessed by specific keystrokes.
• Sometimes BIOS requires updating and this can
  require replacing one or more chips on the
  motherboard or using an executable file.
• Computers may need a BIOS upgrade for supporting
  more floppy drives, higher capacity hard drives,
  virus protection, password protection, or to
  solve problems with the current BIOS.

5
Setup Software
Setup Keystrokes
Configuration Table 1
6
Flash BIOS

• Flash BIOS A type of memory that allows the
  BIOS to be changed without installing a new chip.
  The BIOS is updated via files that have been
  downloaded from the Internet.
• Viruses can infect the Flash BIOS. Keep the BIOS
  write-protected until you need to update it.

7
CMOS Memory

• CMOS (Complementary Metal Oxide Semiconductor)
  chip A special type of static memory on the
  motherboard that holds the setup configuration
  information. CMOS holds the computers current
  configuration information.
• Part of the BIOS software routine that runs after
  power on checks CMOS for information about which
  components are supposed to be installed. After
  the information is read from CMOS, these
  components are tested. This the POST that runs
  whenever the computer cold boots.
• A small battery on the motherboard keeps the CMOS
  memory from losing the setting information. If
  the battery dies, the information is lost and
  must be reentered.
• The wrong configuration information causes POST
  error codes or error messages that might indicate
  a hardware problem.
• The correct Setup information should be kept by a
  technician for each computer. The wrong
  information entered into the Setup program may
  cause the computer to operate improperly or fail
  to boot.

8
Advanced Configuration Information

• Many computers have an Advanced Setup with the
  following options
• Boot Sequence This option determines if the
  computer looks first to the floppy drive, the
  hard drive, CD, or DVD drive for the operating
  system.
• System BIOS Shadow or System BIOS Cacheable
  This setting puts a copy of the software
  contained in the BIOS into RAM.
• PNP/PCI Configuration Setup This option is used
  to configure the PCI slots, configure the
  computer for a PNP operating system, and allow
  the BIOS to control IRQ and DMA assignments.
• Power Saver This option turns the system off
  after a period of non-use.
• When installing a new system, use the default
  BIOS settings until all components are tested.
• Passwords that have been set and forgotten can be
  cleared by jumpering pins together to clear
  either the power-on password or all of the CMOS
  settings.

9
Batteries

• Computer batteries come in various shapes and
  sizes, the most common today being a lithium
  battery about the size of a nickel (see Fig. 1).
  They slide into a special holder making them easy
  to change.
• Older computers also used a cylindrical battery
  about 1.5 inches long that was soldered to the
  motherboard, but these batteries usually failed
  in a few years and were difficult to change.
• Other computers use a 3.6 volt cylinder of
  lithium batteries or alkaline 4.5 volt batteries.
• AA flashlight batteries were also used in a
  special holder and mounted inside the computer
  using velcro.
• Other manufacturers use their own version of a
  battery pack.

10
Batteries
Motherboard with Lithium Battery
Configuration Figure 1
11
Batteries
Computer Batteries
Configuration Figure 2
12
Laptop and Device Batteries

• Up until 1996, the most popular laptop battery
  was the NiCad (Nickel Cadmium) battery.
• NiMH (Nickel-Metal Hydride) batteries replaced
  the NiCad. These were lighter and stored 50 more
  power.
• Li-Ion (Lithium Ion) batteries are replacing the
  NiMH, which are very light and can hold a charge
  longer than any other type of battery, but are
  also expensive.
• Li-Ion Polymer batteries are similar to Li-Ion,
  but are packed in pouched cells, allowing for
  smaller batteries and more efficient use of
  space.
• Zinc-Air battery is environmentally friendly and
  hold a charge for extended amount of time.
• Fuel Cells an upcoming technology that can hold
  a charge for 5 to 10 hours when used with a
  laptop.

13
Replacing a Battery

• Computer batteries last 7 to 10 years, with
  Li-Ion batteries currently lasting the longest.
• Some users will change a battery with the power
  on to prevent the loss of configuration
  information.
• The only way to ensure the settings arent lost
  is that setup configurations must be printed or
  written down before replacing a battery.
• Always refer to the motherboard documentation for
  the proper battery specifications and follow all
  manufacturer instructions for the proper way to
  change the battery.

14
Plug and Play

• PnP (or Plug and Play) A specification that
  allows automatic configuration of an adapter.
• There are 3 conditions that must be met for plug
  and play to work. The following items must
  support plug and play
• The motherboard BIOS
• The adapter thats being installed
• The operating system
• Adapters that are PnP may still need a device
  driver loaded due to the operating system or an
  updated version of the driver being available.

15
Configuration Through Switches

• Some older computers do not have batteries or
  CMOS memory to store the configuration
  information, instead they are configured using
  special switches on the motherboard called DIP
  switches.
• DIP switches Used to set the computers
  configuration and located on the motherboard (or
  sometimes ISA adapters).
• There are two basic models of DIP switches slide
  and rocker.

16
Slide DIP Switch

• With a slide DIP switch, a sliding tab sticks up
  out of the switch bank for each switch that can
  be turned either on (closed or 1) or off (open or
  0).
• Switch bank A group of DIP switches located
  together on the motherboard.
• There are many different ways to label DIP
  switches and these are determined by the
  manufacturer of the particular switch or switch
  bank.

17
Slide DIP Switch
Slide Type DIP Switch
Configuration Figure 5
18
Rocker DIP Switch

• Rocker DIP switch Has a rocker switch in each
  switch position that presses down to either the
  On or Off position.
• CAUTION Never use a pencil to change a DIP
  switch. The pencil lead may break and damage the
  switch. A small screwdriver is recommended.

19
Rocker DIP Switch
Rocker Type DIP Switch
Configuration Figure 6
20
Other Configuration Parameters

• System Resources Parameters that are assigned
  to adapters and ports, known as Interrupt
  Requests (IRQs), I/O (Input/Output) addresses,
  DMA (Direct Memory Access) channels, and memory
  addresses.
• These parameters are assigned to devices like
• Individual adapters and ports such as disk
  controllers
• Serial, parallel, mouse, and keyboard ports
• These are not the same as system resources used
  when discussing Windows operating systems.

21
IRQ (Interrupt Request)

• IRQ (Interrupt ReQuest) A number assigned to
  expansion adapters for communication between the
  device or port and the microprocessor.
• Cascaded Interrupts The two interrupt
  controller chips use IRQ 2 and IRQ 9 to bridge or
  cascade to the other controller chip.
• Non-cascaded Interrupts When two interrupt
  controller chips are not bridged together. Each
  chip handles eight interrupts that connect
  directly with the microprocessor.
• Interrupts are set through the systems Setup
  program, an adapter or devices setup program,
  switches or jumpers, Device Manager (in Windows
  9x/2000/XP), or NT Diagnostics (NT Workstation).
• MSINFO (System Information) Shows interrupt
  conflicts in Windows 98 and Windows 2000.
• Ports that support multiple devices only require
  one interrupt per port.

22
IRQ (Interrupt Request)
Cascaded Interrupts
Configuration Figure 8
23
IRQ (Interrupt Request)
Common Interrupt Assignments
Configuration Table 5
24
IRQ (Interrupt Request)
IRQs in Device Manager
Configuration Figure 9
25
PCI Interrupts

• PCI devices use interrupts called INTA, INTB,
  INTC, INTD, etc. PCI devices share interrupts,
  but must still be mapped to one of the
  traditional IRQ addresses. However, using PCI
  interrupts extends the range of interrupts
  through the use of this sharing ability.
• IRQ Steering Allows multiple PCI adapters to be
  mapped to the same traditional interrupt.
• Some PCI cards do not share well, however it
  works reliably in most cases. If you suspect a
  resource conflict with a PCI card, move the card
  to another slot.

26
PCI Interrupts
IRQ Steering Window
Configuration Figure 10
27
I/O (Input/Output) Addresses

• I/O addresses (Input/Output addresses) Also
  known as port addresses allow the device and the
  microprocessor to exchange data.
• Most computers have 65,535 different I/O
  addresses.
• Each device must have a unique I/O address in
  order for the microprocessor to distinguish
  between the devices and communicate with them.

28
I/O (Input/Output) Addresses
Decimal, Binary, and Hexadecimal Numbers
Configuration Table 6
29
I/O (Input/Output) Addresses
Common I/O Addresses
Configuration Table 7
30
I/O (Input/Output) Addresses
System Informations I/O Addresses
Configuration Figure 11
31
DMA (Direct Memory Access) Channels

• DMA channel (Direct Memory Access) Allows
  adapters to bypass the microprocessor and
  communicate directly with the RAM chips.
• This technique speeds transfers by allowing
  transferring data directly to memory.
• A drawback is that sometime the processor must be
  put on hold for a DMA data transfer to complete.
• Each device or adapter must have a unique DMA
  channel assigned.
• A better and more efficient method than DMA is
  bus-mastering.

32
DMA (Direct Memory Access) Channels
Common DMA Channel Assignments
Configuration Table 5
33
Memory Addresses

• Memory Address A unique address assigned to the
  BIOS, ROM chips installed on adapters, and RAM
  chips installed in the system. The memory
  address is used by the microprocessor when it
  accesses information inside the chip. Conflicts
  can prevent an adapter or device from functioning
  properly.
• Memory addresses are shown in hexadecimal
  numbers. An example is the memory address range
  for all ROM chips is usually A00000h to FFFFFh.
• System resources for integrated ports and
  motherboard connectors are configured through the
  BIOS Setup program.

34
Memory Addresses
Common Memory Address Assignments
Configuration Table 9
35
Memory Addresses
System Informations Memory Addresses
Configuration Figure 12
36
Utilities

• Utility programs Computers will use their own
  utility programs to display the interrupt, DMA,
  and I/O address information.
• Refer to the computer documentation for
  information on how to access and use these
  programs.
• There are external utility programs such
  Symantecs System Works and others. Because of
  the many utility programs that come with
  operating systems and support for plug and play,
  these are not as necessary for technicians as in
  the past.

37
Configuration Overview

• ISA, EISA, PCI, and AGP adapters must be
  configured with the proper IRQ, I/O address,
  memory address, and DMA channel.
• Methods of configuration differ and normally
  depend on the system architecture.
• There are standards, but manufacturers have the
  final say, so refer to documentation for the
  correct configuration.

38
Configuration of ISA Adapters

• Configuration methods for ISA adapters varies and
  may be done manually through jumper and switches,
  and/or through software.
• Configuration is determined by the manufacturer
  of the adapter and the documentation should be
  consulted for the specific instructions.

39
Configuration of EISA Adapters

• EISA adapters are configured with software, very
  similar to MicroChannel adapters. The file
  extension .CFG is used for EISA configuration
  files.
• Sometimes manufacturers recommend that all ISA
  adapters are removed during the initial
  configuration of EISA adapters. Just remember not
  to remove the video adapter.

40
More About Plug and Play

• Fully supported by Windows 95, 98, 2000
  Professional, and XP.
• Windows NT only provides minimal support and may
  require extra steps for plug and play
  configuration.
• Older adapters must still be configured manually.
• If a plug and play adapter is required to boot
  the computer (such as a video adapter), it starts
  up in an active mode with a power-on default
  configuration that allows startup and must be
  customized for the system. Conflicts with other
  adapters can occur.
• Other adapters that dont activate during boot-up
  will stay inactive until the operating system
  activates them.
• Again, different vendors handle the process
  different ways consult the documentation and
  dont assume anything.

41
Configuration of PCI and AGP Adapters

• Easiest adapters to configure.
• Dont have interrupt conflicts because of the
  interrupt sharing of the PCI standard.
• Configured through the BIOS and system Setup
  software, as well as with software that comes
  with the adapter.
• In the Windows environment, the operating system
  detects the PCI adapter and add the configuration
  information to the registry.
• Registry A central database that holds hardware
  information and other information.

42
Configuration of Adapters Using Windows 9x, 2000
Professional, and XP

• Each version of Windows operating system, whether
  its 9X, NT Workstation, 2000, or XP have
  software utilities called wizards that assist
  with configuring adapters, both manually and
  through plug and play.
• Refer to the specific operating system
  documentation for the appropriate method of
  installing and configuring adapters.
• Always use the specific operating system device
  driver provided with the adapter when installing
  new hardware devices. If the driver is missing,
  check the adapter manufacturers website for the
  latest version of the device driver.

43
Configuration of PC Cards

• Socket Services Allow each PC Card type to
  co-exist in the same system. It also allows the
  detection of PC Card insertion and removal.
• Device Driver A small piece of software that
  allows an operating system to access a piece of
  hardware.
• Card Services The second software layer that
  allows PC Cards to operate.
• Hot Swapping Allows the PC Card to be inserted
  into the slot when the computer is powered on.

44
Configuration of PC Cards

• Generic enabler A driver that can operate with
  different PC Cards and allows assignment of
  interrupts and I/O addresses.
• Vendor-specific enablers A driver that operates
  with one specific PC Card and requires socket
  services and card services software.
• Point enabler Similar to vendor-specific
  enabler, but doesnt require socket services or
  card services software. This a good feature if
  memory management is a problem.

45
Configuration of PC Cards
PC Card Software Overview
Configuration Figure 13
46
Installing a USB Device

• In order to use USB devices you must
• Have an operating system that supports USB
  (Windows 95 OSR2, Windows 98, Windows 2000, or
  Windows XP.
• Have a USB port on the computer (adapters can be
  added with USB ports if the are not already
  integrated into the motherboard).
• Once connected, USB devices act like plug and
  play adapters and are configured in similar
  fashion. Have the devices driver disk handy and
  follow all onscreen directions.
• Many USB devices require the driver to be
  installed prior to connecting the device.
• USB allows up to 127 devices to be connected
  together using hubs. USB hubs have two types of
  ports upstream and downstream. The Upstream
  port is used to connect to the computer or
  another hub. The Downstream port is used to
  connect a USB device.

47
Installing a USB Device
USB Hub Connectivity
Configuration Figure 15
48
USB Troubleshooting

• To troubleshoot USB device problems, always check
  the obvious first cabling, connection, and
  power.
• Restart the computer and retest the USB device.
• Swap the USB device with a known working device.
• A list of other USB troubleshooting tips can be
  found on 3-41

49
Installing an IEEE 1394 (FireWire) Device

• IEEE 1394 devices can connect to a port built
  into the motherboard, an IEEE 1394 port on an
  adapter, another IEEE1394 device, or a hub.
• Always follow the manufacturers instructions
  when connecting a FireWire device.
• If one or more FireWire devices connect to a
  FireWire port, the devices use one IRQ and I/O
  address.
• Installation steps for a FireWire adapter can be
  found on 3-42

50
IEEE 1394 Troubleshooting

• Use the Device Manager to verify the IEEE 1394
  installation.
• If a question mark appears by the host
  controller, remove the driver and reinstall.
• If a yellow or red symbol appears by the host
  controller, the driver is corrupt or is using the
  wrong driver. A resource conflict could also be
  causing the problem.
• FireWire has two types of connectors a 4-pin
  and a 6-pin.

51
Infrared Devices

• Infrared Port a small dark window that uses
  infrared light to perform wireless communication.
  Infrared is used in intrusion detection,
  cordless microphones, and home entertainment
  control devices.
• Infrared communication requires an infrared
  transceiver that can be integrated into the
  motherboard or attached to the computers serial
  port.
• Infrared ports should be placed six inches apart,
  but not more that three feet away from each other.