HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
PC Hardware Troubleshooting and Assembly Guide
1. 19-204-0307 Hardware Design Laboratory-
A: PC HARDWARE
CO-1: Familiarize, trouble shoot, maintenance and
Assembling a PC
More on Mother boards
Trouble shooting/maintenance/Assembling
3. What is (ROM)?
Read Only Memory
Memory chips that contain data, instructions, or
information that is recorded permanently.
Data can only be read, cannot be modified
Nonvolatile — Contents not lost when the computer is
turned off
Program stored on ROM are known as firmware not a
Software.
4. Read Only Memory (ROM)
ROM have different type:ROM, PROM
Programmable Read-Only Memory (only once)
EPROM
Erasable PROM by Ultraviolet
EEPROM
Electrically Erasable PROM
A type of PROM containing microcode that a
programmer can erase using electricity.
5. What is Flash Memory?
Variation of EEPROM
Also called flash ROM or flash RAM
Nonvolatile memory that can be erased electronically
and reprogrammed.
Stores data and programs on many handheld
computers and devices such as Camera and mobile
phone.
Flash memory cards
store flash memory on
removable devices
instead of chips
6. Basic Input Output Systems
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A special kind of Program is required to enable the CPU
to talk to other devices
These programs are collectively known as the basic
input/output service (BIOS)
When CPU wants to talk to KB controller, it goes to BIOS
ROM chip to access the proper program.
Similar to
codebook
7. BIOS
Basic Input Output Systems
Permanently stored on ROM chip called System ROM or
System BIOS
Contains small programs - each program is called a
service- that enable CPU to
Communicate with the devices (keyboard, hard drive,
monitor, …)
They are necessary to start the computer
load the operating system
and other files when you first turn on the computer
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9. ROM BIOS
There is One ROM chip on the system board that contains
BIOS.
Modern motherboards use Flash ROM (you can change the
contents through a very specific process called “flashing the
ROM”)
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10. System BIOS
Every system BIOS has two types of hardware to support.
First:
All hardware that never changes.
Ex: KB, PC speaker.
You cannot change keyboard controller chip.
Second:
All hardware that might change.
Ex: RAM (you could add RAM), hard drives (replacing/ adding).
The system ROM stores the BIOS for them, but it needs another
place to store information about the specific details of them
CMOS
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11. CMOS
A separate memory chip, called Complementary Metal-
Oxide Semiconductor (CMOS) chip stores the
information that describes specific device parameters.
CMOS does not store programs, only data that is read by
BIOS to be able to talk to the changeable hardware.
CMOS also acts as a clock to keep date and time
Years ago: CMOS was in separate chip.
Today: CMOS is built into Southbridge.
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12. CMOS
CMOS can store up to 64KB of data but usually only
uses about 128 bytes
CMOS chip is volatile (kept alive by battery). This
way the information contained in the CMOS are
always present even if the computer power is
turned off.
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13. CMOS
Stores only changeable data.
Customizable via SETUP program.
If data in CMOS about certain hardware is different
from its actual specs, PC can not access that
hardware.
If you change one of changeable devices,
parameters have to be changed in CMOS how to
change data on CMOS?
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14. CMOS SETUP Program
Special program that allows you to access and update
CMOS data
Stored on system ROM (BIOS)
Companies that write the BIOS and how to access
CMOS at boot:
Phoenix Technologies - Ctrl Alt Esc
Award Software - uses DEL key
American Megatrends (AMI) - DEL key
Other key combinations are: Ctrl Alt Ins, Ctrl A, Ctrl S,
Ctrl F1, or F10
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17. Device drivers-(Windows)
A device driver is a file that contains the BIOS commands
necessary to communicate with the devices they support
.
Operating system loads these drivers into RAM when
booting
They come with the device - in a CD- when you buy it.
The generic name for CD is installation disc
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18. POST
The power-on self test (POST) is a special program stored
on the ROM chip (BIOS)
Initiated when the computer is turned on or is reset
Checks out the system every time the computer boots
POST program sends out a standard command that says
to all the devices “check yourselves out”.
PCs convey POST information to user in two ways:
beep codes
or text message
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20. (Booting -Steps)
Once the power is turned on, the PC “pulls itself up by its
bootstraps”
First component to wake up is the CPU.
By reads a special wire called power good wire once the
power supply provides the certain voltage to the CPU
Built in memory address is sent on address bus.This
address represent the first line of POST program on the
system ROM
POST is run-If problem happen beep code or text message
displayed.
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21. Boot Process
After POST finishes, it passes control to last BIOS
function: the bootstrap loader. Its job is to find the
operating system.
The bootstrap loader loads the operating system from
the boot sector
Search for the hard drive
Boot order set in CMOS
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22. Boot Process
If the device is bootable (called system disk), its boot
sector will contain special programming designed to
tell the system where to locate the operating system.
If bootstrap loader locates a good boot sector, it passes
control to operating system and removes itself from
memory.
Otherwise it goes to next device specified in CMOS.
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