Motherboard and

1
CHAPTER 6

• Motherboard and
• ROM BIOS

2
Chapter Overview

• Computer Cases
• Motherboards
• ROM BIOS

3
The Computer Case

• Case holds all the primary electronics of the PC
  and all the drives.
• It offers access to the outside world via ports
  and connectors.
• The case helps contain electromagnetic
  interference (EMI).
• It protects surrounding devices such as TV.

4
The Computer Case Cont.

• When considering the case, there are four general
  rules to keep in mind
• Larger cases usually have more expansion
  capability and are easier to work with.
• Smaller cases usually have less expansion
  potential and support fewer internal devices.
• Cases with more features cost more.
• You should never run a computer with an open
  case.

5
Electromagnetic Interference (EMI).

• It is a newer form of radio frequency
  interference (RFI)
• EMI is the radio frequency that is emitted from
  an electronic device that is harmful to the
  surrounding equipment
• Running a computer without its cover is a sure
  way to generate EMI

6
Working with Cases
Desktop
Tower
7
The Motherboard

• It defines the computers limits of speed ,
  memory and expandability.
• Is the large circuit board found inside the
  computer case.

8
things that you should keep in mind before
changing any m/b !

• Should be generic to fit into your PC
• Be sure to verify that it is compatible to your
  case and power supply
• Be sure to verify that it is compatible to RAM
  and Expansion cards
• Replace rather than repair a damaged motherboard.
• Before replacing a motherboard, double-check all
  other components to verify that the motherboard
  is the problem.

9
Chip Sets ?

• The chip set helps the CPU manage and control the
  computer.
• The CPU must be compatible with the chip set.
• Specialized chips control cache memory and
  high-speed buses.
• Different chip sets have different on-board
  components.
• On-board components might have fewer features
  than do expansion card versions.

10
Basic chip set consist of

• Bus controller.
• Memory controller.
• Data and address buffer.
• Peripheral controller.

11
ROM BIOS Chips

• Read-only memory (ROM) chips store basic
  input/output system (BIOS) dataeven when the
  computer power is off.
• This is necessary so that the system can access
  the data it needs to start up.
• The BIOS ( basic input output system) is a
  software in the form of programs stored on ROM
  chip.
• The system BIOS is a ROM chip on the MB used by
  the computer during the startup (boot process) to
  check out the system and prepare to run the
  hardware.
• Old computers with ROM chip
• Flash Rom or flash BIOS can update by software.

12
Major Exam 2

• Next Sunday
• Room 246
• Chs 4,5 and 6

Quiz 3 next Saturday Chapter 6
13
Classes of BIOS chips include Core chips
these chips commonly used for the keyboard,
parallel and serial ports and speakers, each ROM
chip contains between 16 and 64 KB of
programming.Updateable chipsseveral devices on
a computer often contain their own flash BIOS or
Updatable ROMs including SCSI Controller and
video cards. Information stored on a special chip
Called complementary metal-oxide semiconductor
(CMOS) chips.CMOS chip can store about 64 KB.
14
Information Stored in the CMOS

• Floppy disk and hard disk drive types
• CPU type and speed
• Random access memory (RAM) size
• Date and time
• Serial and parallel port information
• Plug and Play information
• Power-saving settings

15
BIOS and CMOS

• What's the difference between BIOS and CMOS?
• Many people use the terms BIOS (basic
  input/output system) and CMOS (complementary
  metal oxide semiconductor) to refer to the same
  thing. Though they are related, they are distinct
  and separate components of a computer. The BIOS
  is the program that starts a computer up, and the
  CMOS is where the BIOS stores the date, time, and
  system configuration details it needs to start
  the computer.

16
Cont

• The BIOS is a small program that controls the
  computer from the time it powers on until the
  time the operating system takes over. The BIOS is
  firmware, which means it cannot store variable
  data.
• CMOS is a type of memory technology, but most
  people use the term to refer to the chip that
  stores variable data for startup. A computer's
  BIOS will initialize and control components like
  the floppy and hard drive controllers and the
  computer's hardware clock, but the specific
  parameters for startup and initializing
  components are stored in the CMOS.

17
Updating CMOS
18
Determining the BIOS Manufacturer

• Watch the monitor when the computer boots.
• Check the computer or motherboard manual.
• Remove the computer cover and look at the chip.
• Use a third-party utility program.
• Cause an error that will launch the setup
  program.

19
The Most Common Ways to Access BIOS Setup
Programs

• AMI Press Delete when the machine begins to
  boot.
• Phoenix Press CtrlAltEsc, Delete, or F2 when
  requested.
• Award Follow the procedure for AMI or Phoenix.

20
Main BIOS Screen
21
Setup Screen for Hard Disk Drive
22
Advanced Tab
23
Security Tab
24
Power Tab
25
Maintaining CMOS

• Losing CMOS information is a common problem, some
  of the more common reasons that CMOS data is lost
  include the following
• The on-board battery has run out.
• Cards have been removed or inserted in a way that
  releases electronics discharge (ESD). What is
  EMI?
• Improper handling of the motherboard has caused
  electrical short circuits.
• Something has been dropped on the M/B.
• The power supply is Faulty.
• There have been electrical surges.

26
Errors indicate lost or corrupt CMOS data

• CMOS configuration mismatch.
• No boot device available
• CMOS battery state low (The system is giving you
  a warning that the battery is getting low on
  power.
• Recommendation
• Double-check the battery connection to the
  motherboard. If the battery is removable, remove
  and reinsert it.
• Replace the CMOS battery, if this is possible
  with your motherboard.
• Troubleshoot the motherboard.
• Can not locate HD or FDD.

27
Cont.

• You should write down CMOS setup information or
  back it up.
• There are many third-party CMOS save and restore
  utility programs available. H/W
• Plug and Play devices include their own BIOS
  information.

HW 4 Mention three third-party programs used to
save and restore the CMOS last day to submit
the HW after 2 weeks
28
The CMOS Battery

• The CMOS chip requires a small trickle voltage
  from a battery to keep its memory a live.
• The voltages of CMOS batteries ranges from 3 to 6
  volts.
• Look for battery requirements on the motherboard
  or in the documentation.
• The 3 volt lithium watch battery is becoming very
  popular with M/B suppliers.
• Expect 27 years of battery life, depending on
  the type of battery.
• Watch for battery failure indicators.
• Replace the battery if a computer loses stored
  CMOS information more than once in a week.

29
All Other Chips

• Add-on boards may have ROM chips with their own
  BIOS data.
• Display adapters , NIC and sound cards have their
  own on board ROM chip
• Device drivers could be required to provide BIOS
  support for hardware.
• A device driver is a program that acts as an
  interface between the O.S and the control
  circuits that operate the device.
• Every time the computer is booted up the
  CONFIG.SYS file is read and the device drivers
  are loaded from the hard disk into RAM.

30
Power-On Self Test

• The power-on self test (POST) checks every
  primary device at startup.
• Beep codes indicate problems before and during
  the video test.
• Errors displayed on the screen typically indicate
  problems after the video test.
• Errors can be fatal or nonfatal.
• Fatal errors will halt the system without
  attempting to load the operating system. memory ,
  disk and display adapter).
• Non fatal error like missing floppy disk drive.
  Will still result in the system attempting to
  load the O.S.
• Please check the following link for more details
• http//www.computerhope.com/beep.htm

31
Chapter Summary

• You should select a computer case for ease of use
  and expandability.
• EMI can harm surrounding equipment.
• Motherboards use different chip sets with
  differing capabilities.
• ROM BIOS chips can be static or updateable.
• A CMOS program accesses BIOS information stored
  in CMOS chips.
• If you change hardware, you must update the CMOS
  to reflect changes.
• A CMOS battery ensures that CMOS information is
  saved.