Computer system hardware

1. What is a personal computer?
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A computer is a machine that can handle and manipulate data
in accordance with the instructions, and is also able to generate
visible results on a screen or monitor. Different computer do
different kinds of work, a small computer that has been
designed to be used by one person, at home or in an office. It is
often simply called a PC.
A personal computer is a computer small and low cost, which is
intended for personal use (or for use by a small group of
individuals). The term "personal computer" is used to
describe desktop computers(desktops).

2. Working of personal computer
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The following three steps give the understanding of how the
personal computer works.
1) Powering on the computer
2) BIOS and the POST
3) Booting the operating system

3. 1.Powering on the computer
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When you first press the power button, the computer sends a
signal to the computer power supply, which converts the
alternating current (AC) to a direct current (DC). This supplies
the computer and its components with the proper amount of
voltage and electricity.
Once the computer and its components have received ample
power and the power supply reports no errors it sends a signal
(using transistors) to the motherboard and the computer
processor (CPU).

4. 2.BIOS and the POST
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When the computer first looks at the BIOS, it begins the power-
on self-test (POST) sequence to make sure the components in
the computer are present and functioning properly. If the
computer does not pass any of these tests, it will encounter an
irregular POST. An irregular POST is a beep code that is different
from the standard one or two beeps.
If the computer passes POST, it looks at the first 64-bytes of
memory located in the CMOS chip, which is kept alive by
the CMOS battery even when the computer is turned off. This
chip contains information such as the system time and date and
information about all the hardware installed in your computer.

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After loading the CMOS information, the POST will begin
inspecting and comparing the system settings with what is
installed in the computer. If no errors are found it will then load
the basic device drivers such as the hard drive, keyboard, mouse,
and a floppy drive etc.
Next, the POST will check the real-time clock (RTC) or system
timer and the computer system bus to make sure both of these
are properly working on the computer.
Finally, the POST will send signals to the computer floppy,
optical, and hard drive to test these drives. If all drives pass the
test, the POST is complete and instruct the computer to start
the process of loading the operating system.

6. 3.Booting the operating system
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After the computer has passed the POST, the computer will start
the boot process. This process is what loads the operating
system and all of it's associated files.
Microsoft Windows is .the most commonly used operating
system

7. List the major connectors and services of a
typical pc
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Serial Port: Used for external modems and older computer mouse.
Parallel Port: Used for scanners and printers, Also called printer
port.
PS/2 Port: Used for old computer keyboard and mouse, Also
called mouse port.
Universal Serial Bus (or USB) Port: It can connect all kinds of
external USB devices such as external hard disk, printer, scanner,
mouse, keyboard, etc.
VGA Port: Connects monitor to a computer's video card, It has 15
holes.
Power Connector: Three-pronged plug, Connects to the computer's
power cable that plugs into a power bar or wall socket.

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Modem Port: Connects a PC's modem to the telephone network.
Ethernet Port: Connects to a network and high speed Internet,
Connects the network cable to a computer.
Game Port: Connect a joystick to a PC, Now replaced by USB
Digital Video Interface, DVI port: Connects Flat panel LCD
monitor to the computer's high-end video graphic cards.

9. COMPUTER EXTERNAL CONNECTOR TYPES AND
PICTURES
(AC Power, Mic/Line Input, Speaker/Headphone Output,
USB, Ethernet, VGA, Serial RS-232, eSATA, Parallel DB25,
Displayport )

10. • A mic-level or microphone-level signal is the voltage level that
comes out of a microphone when someone speaks into it,
typically just a few ten-thousandths of a volt.

11. PS/2, USB, Serial, Parallel

12. Motherboard
• The spine of the computer is the motherboard, otherwise known
as the system board and Mainboard. This is the printed circuit
board (PCB). It is the most important component in the
computer because it connects all the other components
together. On the system board, you will find the central
processing unit (CPU), underlying circuitry, expansion slots,
video components, random access memory (RAM) slots, and a
variety of other chips.

13. Motherboard

14. • ASUS P5AD2-E Motherboard

15. • IDE, an acronym for
Integrated Drive Electronics, is
a standard type of connection
for storage devices in a
computer. Generally, IDE it
refers to the types of cables
and ports used to connect
some hard drives and optical
drives to each other and to
the motherboard

16. System Board Form Factors
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The shape and layout of a motherboard is called the form factor.
Motherboards come in a variety of sizes and formats but there
are three which are the most popular for desktop PCs: ATX,
micro ATX, and ITX.
System boards are classified by their form factor (design), such
as ATX, micro ATX, and ITX.

17. ATX vs Micro ATX vs Mini ITX
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Size: As you can see from the image above, ATX is the largest format of the
bunch, measuring 305×244 mm. Following after it is Micro ATX which is a
tad shorter at 244×244 mm, and the Mini ITX is the smallest one, measuring
at 170×170 mm.
RAM Capacity: One of the big differences is the number of RAM slots
incorporated in a motherboard’s design. While ATX and Micro ATX
motherboards can both support up to four RAM modules, the Mini ITX can
only support two.
PCI(peripheral component interface) Slots: TX motherboards have 7 PCIe
slots. The other two are a bit more limited, with Micro ATX motherboards
having up to 4 and Mini ITX motherboards having only 1 PCIe slot.
Micro ATX motherboards to be the cheapest because they are in much
higher demand. Furthermore, it is the quality of the components that
determines a motherboard’s price tag, so there could be Mini ITX boards out
there which are more expensive than even an ATX one.

18. FORM FACTORS- continued
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ATX: Stands for "Advanced Technology extended."
ATX is a motherboard specification that defines the board's
physical dimensions, connector placement, I/O ports, and
supported power supplies.
It was introduced by Intel in 1995 and was designed to replace
the previous "AT" standard for desktop PCs.
Standard ATX motherboards measure 305 x 244 mm.

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2. Micro ATX
One form factor that is designed to work in standard ATX
cases, as well as its own smaller cases, is known as micro
ATX (also referred to as μATX).
Micro ATX follows the ATX principle of component
placement for enhanced cooling over pre-ATX designs but
with a smaller footprint.
Micro ATX systems tend to be designed with power supplies
of lower wattage to help keep down power consumption and
heat production.
Micro ATX motherboards share their width, mounting hole
pattern, and rear interface pattern with ATX motherboards
but are shallower and square, measuring 244 x 244 mm.

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3. ITX
The ITX line of motherboard form factors was developed by
VIA as a low-power, small form factor (SFF) board for
specialty uses, such as home-theater systems, set-top boxes
and as embedded components.
The ITX family consists of the following form factors:
Mini-ITX—170 n 170 mm
The mini-ITX motherboard has four mounting holes
that line up with three or four of the holes in the ATX
and micro ATX form factors.
In mini-ITX boards, the rear interfaces are placed in the
same location as those on the ATX motherboards.
Nano-ITX—120 n 120 mm
Pico-ITX—100 n 72 mm
Mobile-ITX—60 n 60 mm

21. Components of motherboard(System Board Components)
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Many of the following components can be found on a typical motherboard:
Chipsets
Expansion slots and buses
Memory slots and external
CPUs and their sockets
Power connectors
Onboard disk drive connectors
Keyboard connectors
Integrated peripheral ports and headers
BIOS/firmware
CMOS battery
Jumpers and DIP switches
Front-panel connectors

22. Bus Architecture
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Parallel computer-system components work based on a bus.
A bus is a common collection of signal pathways over which related
devices communicate within the computer system.
Expansion buses of various architectures, such as PCI and AGP,
incorporate slots at certain points in the bus to allow insertion of external
devices.
Chipsets
A chipset is a collection of chips or circuits that perform interface and
peripheral functions for the processor.
This collection of chips is usually the circuitry that provides interfaces for
memory, expansion cards, and onboard peripherals and generally dictates
how a motherboard will communicate with the installed peripherals.
The functions of chipsets can be divided into two major functional groups,
called Northbridge and Southbridge.

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Northbridge
A chip forms an interface between the CPU, the main memory and other
components. On many types of motherboards, this is referred to as the
Northbridge. This chip also contains a large heat sink.
The Northbridge subset of a motherboard’s chipset is the set of circuitry or chips
that manages the high-speed peripheral communications.
The Northbridge is responsible primarily for communications with integrated video
using AGP and PCIe, for instance, and processor-to-memory communications.
The communications between the CPU and memory occur over what is known as
the front side bus (FSB), which is just a set of signal pathways connecting the CPU
and main memory
The backside bus (BSB), if present, is a set of signal pathways between the CPU
and Level 2 or 3 (external) cache memory.
The Northbridge is directly connected to the Southbridge
It controls the Southbridge and helps to manage the communications between the
Southbridge and the rest of the computer.

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Southbridge
A second chip controls the input and output (I/O) functions. It is
not connected directly to the CPU but to the Northbridge. This I/
O controller is referred to as the Southbridge. The Northbridge
and Southbridge combined are referred to as the chipset.
The Southbridge subset of the chipset is responsible for
providing support to the onboard slower peripherals (PS/2,
parallel ports, serial ports, Serial and Parallel ATA, and so on).
The Southbridge is also responsible for managing
communications with the slower expansion buses, such as PCI,
and legacy buses.

25. Bus Architecture

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Expansion Slots
ISA slots. These were the oldest expansion slots in the history of
motherboards. They were found in AT boards and are identified
by black color. Conventional display cards or sound cards were
installed in these slots. The full form of ISA is Industry Standard
Architecture and is a 16- bit bus.
PCI Slots. The full form of PCI is Peripheral Component Interconnect.
The PCI slot is one of the important motherboard components today
and is vastly used to install add-on cards on the motherboard. The
PCI supports 64-bit high-speed bus.
PCI express. Also known as PCIe, these are the latest and the fastest
component of the motherboard to support add-on cards. It supports
full duplex serial bus.
AGP slot. Accelerated graphics port(AGP) is specifically used to
install a latest graphics card. AGP runs on a 32-bit bus and both PCIe
and AGP can be used to install high-end gaming display cards.

27. Types of Memory

28. Explain the characteristics of memory
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A memory is just like a human brain. It is used to store data and
instructions. Computer memory is the storage space in the
computer, where data is to be processed and instructions
required for processing are stored. The memory is divided into
large number of small parts called cells.
Memory is primarily of three types −
Cache Memory
Primary Memory/Main Memory
Secondary Memory

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1.Cache Memory
Cache memory is a very high speed semiconductor memory which can
speed up the CPU. It acts as a buffer between the CPU and the main
memory. It is used to hold those parts of data and program which are most
frequently used by the CPU. The parts of data and programs are transferred
from the disk to cache memory by the operating system.
Advantages
Cache memory is faster than main memory.
It consumes less access time as compared to main memory.
It stores the program that can be executed within a short period of time.
It stores data for temporary use.
Disadvantages
Cache memory has limited capacity.
It is very expensive.

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2.Primary Memory (Main Memory)
Primary memory holds only those data and instructions on which the
computer is currently working. It has a limited capacity and data is lost
when power is switched off. It is generally made up of semiconductor
device. The data and instruction required to be processed resides in the
main memory. It is divided into two subcategories RAM and ROM.
Characteristics of Main Memory
These are semiconductor memories.
It is known as the main memory.
Usually volatile memory.
Data is lost in case power is switched off.
It is the working memory of the computer.
Faster than secondary memories.
A computer cannot run without the primary memory.

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3.Secondary Memory
This type of memory is also known as external memory or non-volatile. It is
slower than the main memory. These are used for storing data/information
permanently. CPU directly does not access these memories, instead they
are accessed via input-output routines. The contents of secondary
memories are first transferred to the main memory, and then the CPU can
access it. For example, disk, CD-ROM, DVD, etc.
Characteristics of Secondary Memory
These are magnetic and optical memories.
It is known as the backup memory.
It is a non-volatile memory.
Data is permanently stored even if power is switched off.
It is used for storage of data in a computer.
Computer may run without the secondary memory.
Slower than primary memories.

33. Identify the different types of DRAM packaging
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The following list gives you an idea of the vast array of memory types and
subtypes:
DRAM
Asynchronous DRAM
FPM DRAM
EDO DRAM
BEDO DRAM
Synchronous DRAM
SDR SDRAM
DDR SDRAM
DDR2 SDRAM
DDR3 SDRAM
DRDRAM
SRAM
ROM

34. DRAM (Dynamic Random Access Memory)
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Dynamic random-access memory (DRAM) is a type of random access
semiconductor memory.
Each DRAM memory cell is made up of a transistor and a capacitor
within an integrated circuit, and a data bit is stored in the capacitor.
The capacitor can either be charged or discharged; these two states are
taken to represent the two values of a bit, conventionally called 0 and 1.
The main advantages of DRAM are its simple design, speed and low
cost in comparison to alternative types of memory.
The main disadvantages of DRAM are volatility and high power
consumption relative to other options.
Currently, the most popular implementations of DRAM are based on
synchronous DRAM and include SDR SDRAM, DDR, DDR2, DDR3, and
DRDRAM.

35. Asynchronous DRAM
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Asynchronous DRAM is an older type of DRAM used in the first
personal computers. It is called "asynchronous" because
memory access is not synchronized with the computer system
clock.
Asynchronous memory works fine in lower-speed memory bus
systems but is not nearly as suitable for use in high-speed (>66
MHz) memory systems.
Common asynchronous DRAM technologies included Fast Page
Mode (FPM), Extended Data Out (EDO), and Burst EDO (BEDO).

36. Synchronous DRAM (SDRAM)
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"Synchronous" tells about the behavior of the DRAM type.
A newer type of DRAM, called "synchronous DRAM" or "SDRAM",
is synchronized to the system clock
This enables the memory controller to know the exact clock
cycle when the requested data will be ready, so the CPU no
longer has to wait between memory accesses.
This type of memory is much faster than asynchronous DRAM
and can be used to improve the performance of the system.
It is more suitable to the higher-speed memory systems of the
newest PCs.
Typical SDRAM transfers data at speeds up to 133 MHz.

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SDR SDRAM (Single Data Rate SDRAM):
This type of SDRAM is slower than the DDR variants, because
only one word of data is transmitted per clock cycle (single data
rate).
Single Data Rate means that SDR SDRAM can only read/write
one time in a clock cycle. SDRAM have to wait for the
completion of the previous command to be able to do another
read/write operation.
With today’s processors interfacing with memory using a
parallel data-bus width of 8 bytes (hence the term 64-bit
processor), a 100MHz clock signal produces 800MBps. Such
memory modules are referred to as PC100

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DDR SDRAM (Double Data Rate SDRAM)
The next generation of SDRAM is DDR, which achieves greater
bandwidth than the preceding single data rate SDRAM by
transferring data on the rising and falling edges of the clock
signal (double pumped).
Effectively, it doubles the transfer rate without increasing the
frequency of the clock.
The transfer rate of DDR SDRAM is the double of SDR SDRAM
without changing the internal clock.

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DDR2 SDRAM(Double Data Rate Two SDRAM):
Its primary benefit is the ability to operate the external data bus
twice as fast as DDR SDRAM.
This is achieved by improved bus signal. The prefetch buffer of
DDR2 is 4 bit(double of DDR SDRAM).
DDR2 memory is at the same internal clock speed
(133~200MHz) as DDR, but the transfer rate of DDR2 can reach
533~800 MT/s with the improved I/O bus signal.
DDR2 533 and DDR2 800 memory types are on the market.

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DDR3 SDRAM
DDR3 memory reduces 40% power consumption compared to
current DDR2 modules, allowing for lower operating currents
and voltages (1.5 V, compared to DDR2's 1.8 V or DDR's 2.5 V).
The transfer rate of DDR3 is 800~1600 MT/s. DDR3's prefetch
buffer width is 8 bit, whereas DDR2's is 4 bit, and DDR's is 2 bit.
DDR3 also adds two functions, such as ASR (Automatic Self-
Refresh) and SRT (Self-Refresh Temperature).
They can make the memory control the refresh rate according to
the temperature variation's Data Rate Three SDRAM):

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Direct Rambus DRAM (DRDRAM) or Rambus DRAM (RDRAM)
Rambus Dynamic Random Access Memory (RDRAM) is a memory
subsystem designed to transfer data at faster rates.
RDRAM is made up of a random access memory (RAM), a RAM
controller and a bus path that connect RAM to microprocessors and
other PC devices.
RDRAM was introduced in 1999 by Rambus.
RDRAM technology was considerably faster than older memory
models, like the Synchronous DRAM (SDRAM).
Typical SDRAM has a data transfer rate of up to 133 MHz, while the
RDRAM can transfer data at a speed of upto 800 MHz.
RDRAM is also known as Direct RDRAM or Rambus.

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Static Random Access Memory (SRAM)
Static Random Access Memory (Static RAM or SRAM) is a type of
RAM that holds data in a static form, that is, as long as the memory
has power.
Unlike dynamic RAM, it does not need to be refreshed.
There are two types of RAM: static random access memory (SRAM) (
cache memory)and dynamic random access memory (DRAM).
The main memory in a computer is dynamic RAM.
All DRAM chips on Rambus in-line memory modules (RIMMs), single
in-line memory module (SIMM’s) and dual in-line memory module
(DIMMs) need to refresh every few milliseconds.
DRAM continuously refreshes 100+ times per second.
Static random access memory (SRAM) is a lot faster and does not
require refreshing like dynamic RAM.

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ROM (Read Only Memory)
Once data has been written onto a ROM chip, it cannot be removed and
can only be read. Unlike main memory (RAM), ROM retains its contents
even when the computer is turned off.
ROM is referred to as being nonvolatile, whereas RAM is volatile.
ROM is normally used to store the computer’s BIOS because this
information normally does not change very often.
Through the years, different forms of ROM were developed that could be
altered
The first generation was the programmable ROM (PROM), which could be
written to for the first time in the field using a special programming device
but then no more.
Following the PROM came erasable PROM (EPROM), which was able to be
erased using ultraviolet light and subsequently reprogrammed using the
original programming device.
The next generation of ROM is electronically erasable PROM (EEPROM),
which does not require UV light to erase its contents but rather a slightly
higher than normal electrical pulse.

44. CPU and processor socket( CPU packaging)
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A CPU socket is a single connector between a microprocessor and
motherboard.
A CPU socket is a distinct mount used only for the CPU on the
motherboard to ensure correct circuit chip insertion.
It facilitates CPU access and prevents damage when a unit is
inserted or removed.
A CPU socket also has a lock to prevent CPU movement, and its
design helps secure heat sink placement above the CPU.
Most PCs and a variety of server systems have CPU sockets.
Some laptops and certain types of servers do not use a CPU socket
but have a totally different processor style.
Generally, CPU socket platforms are keyed for correct insertion.
A CPU socket is also known as a CPU slot.

45. CPU and processor socket( CPU packaging)
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Modern CPU sockets and processors are based on a pin grid array (PGA)
architecture.
PGA is a type of packaging used for integrated circuits (IC), such as a
microprocessor.
It is basically a square with pins that are organized below the packaging.
Pins are spaced approximately 0.1 inches (2.54 mm) apart to cover a
portion or entire underside of the package.
A CPU socket is shaped like a square or rectangle and made of durable
and heat-resistant plastic and metal contacts for pins or lands, in
addition to a metal latch or lever.
Hundreds of tiny holes cover the plastic casing's surface, and the
plastic color is usually light tan or burgundy, depending on the
manufacturer.

46. CPU and processor socket( CPU packaging)
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Chips with high numbers of pin-outs often use land grid array
(LGA) or zero insertion force (ZIF) sockets.
LGA sockets apply firm force with a surface plate, and ZIF
sockets apply compression force with a handle.
Each method ensures that upon insertion, the pins are not
damaged or broken.
A CPU socket is specifically designed for a particular CPU and
is usually not interchangeable with other types of processors.
In many cases, manufacturers classify sockets into groups.
A socket may be identified on its side by a three-five digit ID
number. The ID number ensures that the CPU uses the correct
CPU socket.

47. Identifying Purposes and Characteristics of
Processors
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The role of the CPU, or central processing unit, is to control and
direct all the activities of the computer using both external and
internal buses.
Intel and Advanced Micro Devices (AMD) are the two largest PC-
compatible CPU manufacturers.
You can easily identify which component inside the computer is
the CPU because it is a large square lying flat on the
motherboard with a very large heat sink and fan.

48. Explain the varities of modern CPU
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A modern CPU is usually small and square, with many short,
rounded, metallic connectors on its underside. Some older CPUs
have pins instead of metallic connectors.
The CPU attaches directly to a CPU "socket" (or sometimes a "slot")
on the motherboard. The CPU is inserted into the socket pin-side-
down, and a small lever helps to secure the processor.
After running even a short while, modern CPUs can get very hot. To
help dissipate this heat, it's almost always necessary to attach a heat
sink and a fan directly on top of the CPU.
Some devices have a single-core processor while others may have a
dual-core (or quad-core, etc.) processor.
As might already be apparent, having two processor units working
side by side means that the CPU can simultaneously manage twice
the instructions every second, drastically improving performance.

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Some CPUs can virtualize two cores for every one physical core
that's available, known as Hyper-Threading.
Virtualizing means that a CPU with only four cores can function
as if it has eight, with the additional virtual CPU cores referred to
as separate threads.
Physical cores, though, do perform better than virtual ones.
CPU permitting, some applications can use what's called
multithreading.
If a thread is understood as a single piece of a computer process,
then using multiple threads in a single CPU core means more
instructions can be understood and processed at once.
Some software can take advantage of this feature on more than
one CPU core, which means that even more instructions can be
processed simultaneously.

50. Socket types and the processors they support
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A CPU socket : the actual CPU is directly soldered onto the socket.
Since high speed CPUs generate a lot of heat, there are heat sinks
and mounting points for fans right next to the CPU socket.
Socket7. It is a 321 pin socket that supported older processors like
Intel Pentium 1/2/MMX, AMD k5/K6, and Cyrix M2.
Socket370. It is a 370 pin socket that supports Celeron processors
and Pentium-3 processors.
Socket 775. It is a 775-pin socket that supports Inter dual core, C2D,
P-4 and Xeon processors.
Socket 1156. Found on latest types of motherboards, it is an 1156-
pin socket that supports latest Intel i-3, i-5 and i-7 processors.
Socket 1366. The socket is of 1366 pins and supports latest i-7 900
processors.

51. BIOS and POST
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The BIOS includes instructions on how to load basic computer hardware.
It also includes a test referred to as a POST (Power-On Self-Test) that
helps verify the computer meets requirements to boot up properly.
If the computer does not pass the POST, you will receive a combination of
beeps indicating what is malfunctioning in the computer.
Bios is software that contains hundreds of programs that allow for
communication between the CPU and devices.
Bios is stored on ROM, which is a permanent chip on the motherboard.
Bios is software, ROM is hardware.
This BIOS is called firmware, since it is software that does not change.
It is stored on nonvolatile memory called a ROM chip (Read Only Memory).
The Newer Flash ROM enables users to change this ROM.

52. The four main functions of a PC BIOS
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POST - Test the computer hardware and make sure no errors exist
before loading the operating system. Additional information on
the POST is available on our POST and beep codes page.
BIOS drivers - Low-level drivers that give the computer basic
operational control over your computer's hardware.
BIOS or CMOS Setup - Configuration program that allows you to
configure hardware settings including system settings such as
computer passwords, time, and date.
Bootstrap loader -The last BIOS function called by POST is the
bootstrap loader . The bootstrap loader loads the operating
system either from the floppy or the hard drive. The bootstrap
loader generates an error if it cannot find the bootable disk.

53. POST
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The Power-On Self Test (POST) is a special program stored on the ROM
chip.
When power is turned on, POST (Power-On Self-Test) is the diagnostic
testing sequence that a computer's basic input/output system (or "
starting program") runs to determine if the computer keyboard, random
access memory, disk drives, and other hardware are working correctly.
If the necessary hardware is detected and found to be operating properly,
the computer begins to boot.
If the hardware is not detected or is found not to be operating properly, the
BIOS issues an error message which may be text on the display screen
and/or a series of coded beeps, depending on the nature of the problem.
The pattern of beeps may be a variable numbers of short beeps or a
mixture of long and short beeps, depending on what type of BIOS is
installed.
The patterns of beeps contain messages about the nature of the problem
detected.

54. CMOS
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When you make changes to your BIOS configuration, the
settings are not stored on the BIOS chip itself. Instead, they are
stored on a special memory chip, which is referred to as "the
CMOS." CMOS stands for "Complementary Metal-Oxide-
Semiconductor."
Like most RAM chips, the chip that stores your BIOS settings is
manufactured using the CMOS process. It holds a small amount
of data, usually 256 bytes.
The information on the CMOS chip includes what types of disk
drives are installed on your computer, the current date and time
of your system clock, and your computer's boot sequence.

55. CMOS battery
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Your BIOS memory is non-volatile: it retains its information even
when your computer has no power because your computer
needs to remember its BIOS settings even when it's turned off.
That's why the CMOS has its own dedicated power source,
which is the CMOS battery.
The CMOS battery is a Lithium-ion battery about the size of a
coin. It can hold a charge for up to ten years before needing to
be replaced.
If your CMOS battery dies, your BIOS settings will reset to their
defaults when your computer is turned off.

56. CMOS Setup Utilities
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1.
•
The data on the CMOS chip can be accessed and updated via the CMOS
setup program.
• Main manufacturers of BIOS – American Megatrends (AMI) – Award
software – Phoenix Technologies
• The CMOS setup can be accessed when the system boots, but there are
different ways of doing that
Accessing the CMOS
AMI and Award – Press DEL, Phoenix – Press Ctrl-Alt-Esc or F2
2. CMOS Setup
The floppy drive, hard drive, and the date/time settings can be changed
using the standard CMOS setup.
• Modern computers provide extra CMOS settings for memory
management, password and booting options, error handling, and power
management.

57. CMOS Setup Utilities
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•
•
•
•
•
The following CMOS setting options are available:
CPU soft menu – Enables you to set the voltage and multiplier
settings on the motherboard for the CPU.
Advanced BIOS feature – Used for selecting boot options.
Advanced chipset features – Deals with extremely low-level chipset
functions.
Integrated peripherals – Allows you to configure, enable, or disable
onboard ports.
Power management setup – Used to setup power management
settings for the system.
PnP/PCI configurations – Used for assigning IRQs to certain
resources.

58. •
•
•
•
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Other options include:
Load Fail-Safe Defaults: used when low-level problems occur
Load Optimized Defaults: sets the CMOS to the best possible
speed and stability of the system
Set Password
Save and Exit Setup
Exit Without Saving

59. Device Drivers
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•
•
•
A device driver is a file that contains the BIOS commands
necessary to communicate with the devices they support
Loaded in to the RAM when the system boots
All devices come with their own device drivers
Where are the Device Drivers?
Registry – Binary file that contains the configuration settings
and device driver information.
• Control Panel – Applets that enable the configuration of a broad
range of system devices.
• Device Manager – Used for changing or removing drivers for any
particular device.
• REGEDIT and REGEDIT32 – Enables you to access and update
the Registry directly.