Power Supply

Power Supply

Ports and Connectors

Expansion board

Mother Board

Expansion Slots CPU

Memory

Hard Disk

Open Bay

Open Bay

Open Bay

CD-ROM

Floppy Drive

04/20/23 s k satapathy


BAYSOpen areas inside the computer base, specifically designed to facilitate the installation of additional equipment


ELEMENTS OF A COMPUTER SYSTEM

Storage devices

Input devices

Output devicesComputer components


MOTHERBOARDM Board (System Board)

a Circuit Board Containing Electronic Components of System Unit

Motherboard: The main circuit board responsible for checking that all the other circuit boards are eating properly and wearing clean clothes.

A Megabyte of Computer Jokes04/20/23 s k satapathy



PORTS


MICROPROCESSORAND THE CPU

Microprocessor - contains the central processing unit (CPU)

Top View Bottom View


SUB : MOTHER BOARD OF COMPUTER

MOTHER BOARD OF PC :- Mother board is the most important component in any PC . It contains almost every important parts of the computer system.

Mother board normally contains the CPU or the brain of the Computer , memory (ROM, RAM etc) and supports the circuits to make the computer work. Mother board also contains many expansion slots which we can connect various circuit board. These circuit boards are used to connect different devices such as Monitor, printer, scanner, key board, mouse etc with the computer.

This main board is called mother board because all other circuit board , inside the computer are attached to this board ie it is mother of the all boards.


Mother Boards/System Boards:-A motherboard is a multi-layered printed circuit board.

Copper circuit paths called traces that resemble a complicated roadmap carry signals and voltages across the motherboard. Layered fabrication techniques are used so that some layers of a board can carry data for the BIOS, processor and memory buses while other layers carry voltage and ground returns without the paths short-circuiting at intersections.

The insulated layers are manufactured into one complete, complex sandwich; chips and sockets are soldered onto this motherboard. For example the Intel Pentium 4 motherboard has got 3 PCI slot, 1 AGP slot and 1 CNR slot (Comn /Net work riser ), Memory slots and other components are marked .04/20/23 s k satapathy


Types of Motherboards1. Non-integrated MotherboardsNonintegrated motherboards have each major assembly installed in the computer as expansion cards. The major assemblies we’re talking about here are items like the video circuitry, disk controllers, and accessories. Nonintegrated boards can be easily identified because each expansion slot is usually occupied by one of the components we just mentioned.

2. Integrated MotherboardsIntegrated motherboards are called that because most of the component that would be installed as expansion cards is integrated into the motherboard circuitry. Integrated system boards were designed for their simplicity. Of course, there’s a drawback to this simplicity. When one component breaks, you can’t just replace the component that broken; the whole motherboard must be replaced. Although they are cheaper to produce, they are more expensive to repair.


Different types of mother boards are available in the market as per form factors and features. These are mainly two types

1. XT (Extended Technology)

2. AT. (Advanced technology )

XT is used in original IBM pc’s of the generation of INTEL 8088 and 8086 processor etc.

AT system board are used from the services of INTEL 80286 CPU and up to Pentium series.

Some advanced type are as fallows :-

Baby AT, LPX, ATX, NLX, MINI ATX.04/20/23 s k satapathy

AT :- System boards are also classified by their form factor (design): AT, ATX, or NLX different motherboard form factors viz., the AT, baby AT, and ATX. The AT system boards are same as the motherboards found in the original IBM AT in which processor, memory, and expansion slots are all in line with each other. Because of advances in technology the same number of components that were on the original AT motherboard (now called as “full” AT board) were later compressed into a smaller area.

AT is used to the most commonly used design, but it has some fundamental problems. Because the processor and memory were in line with the expansion slots, only one or two full-length cards could be used. Also, the processor was far from the power supply’s cooling fan, was directly attached to it..


These motherboard form factors are usually found in what are known as “clone” computers (those not manufactured by Fortune 500 PC company). Some manufacturers (e.g. Compaq and IBM) design and manufacture their own motherboard designs, which really don’t conform to either standard. This style of motherboard is known as a proprietary design motherboard. Basically, the components are laid out differently than an AT or ATX, but it will work as a PC.



Motherboard ComponentsNow you know the basic types of motherboards and their form factors, we take a look at the components found on the motherboard and their locations relative to each other. many of the following components found on a typical motherboard.

1. Expansion slots2. Memory slots3. Processor slots or sockets4. Power connectors5. On-board disk drive connectors6. Keyboard connector7. Peripheral port connectors8. BIOS chip9. CMOS battery10. Jumpers and DIP switches04/20/23 s k satapathy

PROCESSOR (CPU):-The main component of the mother board is the processor Chip which controls the inner functions of the system. The Central processing Unit (CPU) functions as the CPU is usually inserted in the socket and is not soldered on to the mother board .

Eg :- CPU Chips are Intel 8086,8088, 80286, 80386,80486, Pentium, Pentium MMX, Pentium-II, Pentium-III, Pentium-4 etc

CO- PROCESSOR:-Co processor is a special purpose micro processor which is used to speed up main processor by taking over some of the main processors work.

Main common type of co-processor is a math co processor helps main processor in performing mathematical calculation


Expansion Slots:The most visible part of any motherboard is the expansion slots. These look like small plastic “slots”, usually anywhere from 3” to 11” long and approximately ½” wide. As their name suggests, they are used to install various devices in the computer to expand its capabilities. Some expansion devices that might be installed in these slots include video, network, sound, and disk interface cards.

three main types of expansion slots 1. ISA (Industry Standard Architecture )2 PCI (Peripheral Component Interconnect)3 AGP ( Accelerated Graphics Port )Each type differs in its appearance and function, here you will learn how

to identify the different expansion slots on the motherboard.04/20/23 s k satapathy

ISA Expansion slots:-If you have a computer made before 1997, chances are the

motherboard in your computer has a few Industry Standard Architecture (ISA) slots. They’re easily recognizable as they are usually brown and have two parts, a shorter part and a longer part. Computers made after 1997 generally include a few ISA slots for backward compatibility with old expansion cards

PCI Expansion Slots:-Most computers made today contain primarily Peripheral Component

Interconnect (PCI) slots. They are easily recognizable as they are short (around 3” long) and usually white, PCI slots can usually be found in any computer that has a Pentium-class processor or higher.AGP Expansion Slots:-

Accelerated Graphics Port (AGP) slots are becoming more popular. In the past, if you wanted to use high speed, accelerated 3D graphics video cards, you has to install the card into an existing PCI or ISA slots. AGP slots were designed to be a direct connection between the video circuitry and the PC’s memory. They are also easily recognizable because they are usually brown, located right next to the PCI slots on the motherboard and are shorter than the PCI slots.04/20/23 s k satapathy

MEMORY :- Memory or random access memory (RAM) slots are

the next most prolific slots on a motherboard, and they contain the actual memory chips. There are many and varied types of memory for PCs today.

Memory slots are easy to identify on a motherboard. They are usually white; around 3” long, and placed very close together

For the most part, PCs today use memory chips arranged on a small circuit board. These circuit boards are called Single Inline Memory Module (SIMMs) or Dual Inline Memory Module (DIMMs), depending on if there are chips on one side of the circuit board or on both the sides, respectively.04/20/23 s k satapathy

BIOSThe BIOS is another very important part of

your computer that makes its home on the motherboard. "BIOS" stands for Basic Input/Output System. The BIOS provides an interface between the raw PC hardware and the standard operating system, it is firm ware and usually stored in ROM.

It is pronounced “Bye-os”. The BIOS also contains program called power on self test or POST. This POST program checks the mother board and other devices connected to the computer during the system power -On .


It is common in computer design to include a BIOS ROM for major sub systems, such as video and drive control.. In general, a PC can be fitted with up to five or more BIOS ROMs viz.

System BIOS (Motherboard BIOS) Video BIOS Drive Controller BIOS Network adapter BIOS SCSI adapter BIOS (Small Computer system interface)


Chipsets:-All the diverse support functions inside PC were

integrated into a few VLSI components individually termed application specific integrated circuits or ASICs. These ASICs are collectively called chip set.

The chipset on the motherboard is the most important part of the board itself as it defines almost everything about the system. The chipset controls the system and its capabilities. It is the hub of all data transfer. It is a series of chips on the motherboard, easily identified as the largest chips on the board with the exception of the CPU. Chip sets are integrated, meaning they are soldered onto the board and are not upgradeable without buying a whole new motherboard.

For eg:- Intel Mother board chip set model 810, 845, 915,945, 960 and 965 etc


Here is a small list of some of the items that chipsets dictate:1. Memory controller2. Real-time clock3. Keyboard and mouse controller4. Secondary cache controller5. DMA controller6. PCI Bridge7. EIDE controller (Extended Integrated drive electronics)


INTERRUPT :-

Interrupt is one of the most common method for an external device to communicate with the processor (CPU) . The interrupting device generates an interrupt signal to the processor to stop processors normal function and provide service to the interrupting device.


Connector

Number of pins or sockets

Male or Female Common Applications

DB-9 9 pins Male Serial port

DB-9 9 sockets Female EGA/CGA vide port (Might also be a Token Ring adapter port)

DB-15 15 sockets Female If there are three rows of five, it’s probably a VGA/SVGA video adapter. If it’s one row of eight and one row of seven, it might be a network transceiver port or, more commonly, a joystick port.

DB-25 25 pins Male Serial port

DB-25 25 sockets Female Most often a parallel port. On Macintoshes, however, this type of connector is used for the external SCSI bus.04/20/23 s k satapathy

RJ-11 4 pins Male Telephone wall jack phone cord

RJ-12 4 pins Male Telephone hand set cord

RJ-45 8 pins Male 10-Base T Ethernet cable

Centronics36 36 pins Male Parallel cable

Centronics50 50 pins Male SCSI connector(Small Computer system Interface)

DIN-6 6 sockets Female PS/2 mouse port

DIN-8 8 sockets Female Macintosh printer connector

DIN-9 9 sockets Female Bus mouse port04/20/23 s k satapathy

Modems: These allow you to connect to other computers via

phone lines. These things are what bring the Internet to your screen, allowing you to even see this page. Modems are considered tough to install because they need their own COM port, but I've never had much trouble with it. Also, modems have two phone jacks on the back of them. One is for the line to the wall; the other is for you to plug your phone into.

Sound Cards:

These cards let your computer produce awesome sound. They are sometimes hard to install because of IRQ conflicts. In order to hear anything, you need speakers as well. Plug the speakers into the back of sound cards. The nicer the speakers, the better your sound card will sound.


Video Display Cards:-A Video card provides the interface between your

computer and your monitor and transmits the signals that appear as images on the display. The following list of standards can serve as an abbreviated history of PC video-display technology:

1. MDA (Monochrome Display Adapter2. HGC (Hercules Graphics Card)3. CGA (Color Graphic Adapter)4. EGA (Enhanced Graphic Adapter)5. VGA (Video Graphics Array)6. SVGA (Super VGA)7. XGA (Extended Graphics Array)


VGA and Super VGAA standard VGA card displays up to 256 colors

onscreen, from a palette of 262, 144 (256KB) colors; when used in the 640x480 graphics or 720x400 text mode, 16 colors at a time can be displayed. Because the VGA outputs an analog signal, you must have a monitor that accepts an analog input.

Super VGA provides capabilities that surpass those offered by the VGA adapter. SVGA refers not to an adapter that meets a particular specification, but to a group of adapters that have different capabilities. The SVGA cards look much like their VGA counterparts. They have the same connectors, but because the technical specifications from different SVGA vendors vary tremendously.04/20/23 s k satapathy

Network Interface CardsOn most computers, the network interface

adapter takes the form of a network interface card (NIC) that fits into a PCI slot on a desktop computer or a PC Card (PCMCIA) slot on a notebook computer. Although network cards are older systems might use the ISA or EISA slot standards, these don’t support high-speed network standards and are obsolete. Many recent systems incorporate the network interface adapter onto the motherboard, but this practice is more commonly found in workstations and portable computers and rarely in servers because most network administrators prefer to select their own NICs.


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Power Supply