Category: Education

Presentation Description

Form Factor, Block Diagram, Identification of various parts of motherboard etc.


Presentation Transcript

Introduction to PC Motherboards:

Introduction to PC Motherboards

Designing of Main Board:

Designing of Main Board The designing of main board can be classified on the basis of Single Board based approach Back Planes Approach

Single Board Based Systems:

Single Board Based Systems A system in which single motherboard contains all the primary system components in it, is known as single board based system.

PowerPoint Presentation:

Block- Diagram of Motherboard

Main Components of Motherboard:

Main Components of Motherboard CPU Socket & Memory Slots ISA, PCI & AGP Expansion Slots CMOS Battery Power Connectors Memory Slots Chipset Serial/ Parallel/ USB etc ports.

Industry Standard Architecture (ISA):

Industry Standard Architecture (ISA)

ISA Contd…:

ISA Contd… First open system bus architecture. IBM introduced this 8-bit bus architecture in 1981. It had transfer rate of 4 MB/sec. in 1984, with the release of the 286 data processor which used a 16-bit data path, the ISA bus was expanded to 16 bits, with data rate 8MB/Sec. A major disadvantage of this bus was that IRQs had be manually defined through jumpers .

Peripheral Component Interconnect (PCI Slots):

Peripheral Component Interconnect (PCI Slots)

PCI Contd..:

PCI Contd.. Introduced by Intel in 1992. Widely in use today. Requires an additional bridge chip to connect to the I/O of the CPU. Operates on 33MHz, & capable of transferring data at 132 MB/sec.

PCI Contd..:

PCI Contd.. Important feature of PCI is the model for the PNP (Plug-n-Play) specification, which means that PCI cards could be configured via software, rather than through jumpers as was the case with ISA cards.

Accelerated Graphics Port (AGP):

Accelerated Graphics Port (AGP)

AGP Contd..:

AGP Contd.. The AGP port is a dedicated graphics port based on PCI. It’s a dedicated point-to-point channel that enables the graphics controller to access main memory, bypassing the bottleneck of the PCI bus. It allows textures to be stored in main memory rather than video memory.

PowerPoint Presentation:

AGP Contd.. The AGP channel is 32 bits wide and Runs at 66 MHz, giving a bandwidth of 266 MB/sec. AGP also supports two optional faster modes, giving throughputs of 533 MB/sec and 1.07 GB/sec.

Random Access Memory (RAM):

Random Access Memory (RAM) Old 72-pin SIMM-type memory sockets 168-pin DIMM-type memory sockets



Single In-line Memory Module (SIMM):

Single In-line Memory Module (SIMM) A SIMM is a small circuit board designed to hold a set of RAM chips. Two types of SIMM's have been in general use. 30-pin SIMM's and 72-pin SIMM's. 30-bit SIMM's have 8-bit data buses; 72-pin SIMM's have 32-bit data buses.

Dual Inline Memory Module (DIMM) :

Dual Inline Memory Module (DIMM) DIMMs have separate electrical contacts on each side of the module. DIMMs have a 64-bit data path.

Enhanced Integrated Drive Electronics (EIDE slot):

Enhanced Integrated Drive Electronics (EIDE slot)

EIDE Contd..:

EIDE Contd.. Enhanced (sometimes "Expanded") IDE is a standard electronic interface between your computer and its mass storage drives. Makes it possible to address a hard disk larger than 528 Mbytes. EIDE also provides faster access to the hard drive, support for Direct Memory Access (DMA), and additional drives, including CD-ROM

Analog Audio Input Connectors :

Analog Audio Input Connectors

Analog Audio Input Connectors:

Analog Audio Input Connectors These are typically used for CD ROM drives. Since the CD ROM drive can deliver audio via the 40-pin IDE connection, the analog audio connectors are not generally needed. If you have a video capture card, you may need to use the analog audio input to get the sound into the computer.

front panel switches and LEDs :

front panel switches and LEDs

front panel switches and LEDs:

front panel switches and LEDs There are typically 4 connections (hard drive LED, power/message LED, power switch and reset switch). The LED connections are polarity sensitive (if connected in reverse, the LEDs will not work). The colored wire is generally positive and the white/black wire is negative.

I/O Ports:

I/O Ports

Mouse & Keyboard Connectors:

Mouse & Keyboard Connectors

AT motherboard Power Supply:

AT motherboard Power Supply

ATX Power:

ATX Power

ATX Power:

ATX Power


Chipset A chipset or chip set refers to a group of integrated circuits, or chips, that are designed to work together. The chipset is the heart of the computer and is the hub for all data transfer. It determines how fast components like the processor, memory, keyboard and various plug-ins can function in relation to each other




Northbridge The actual function of a chipset is to communicate between all components of the modern PC. The Northbridge usually contains the CPU interface and the memory controller, sometimes the graphics unit is also on the Northbridge.


Southbridge The southbridge mainly deals with Input Output devces. The Southbridge contains at least a PCI controller, floppy/ IDE/ hard disk controllers, serial and parallel ports, USB support and power management functions.




BIOS A BIOS (Basic Input/Output System) is an electronic set of instructions that a computer uses to successfully start operating. A main function of the BIOS is to give instructions for the power-on self test (POST). It gives the computer basic information about how to interact with some critical components, such as drives and memory

ZIF Socket:

ZIF Socket

ZIF Contd..:

ZIF Contd.. ZIF is an acronym for zero insertion force , a concept used in the design of IC sockets, invented to avoid problems caused by applying force upon insertion and extraction.

ZIF Contd..:

ZIF Contd..

ZIF Contd..:

ZIF Contd..

CPU Fan Connector:

CPU Fan Connector

CPU Fan Connector:

CPU Fan Connector

Backplanes Style System:

Backplanes Style System No major chips on-board. Only CPU, RAM, BIOS etc are on board. Other devices like video adapter, disk drive controllers, CD controllers, sound board etc are connected to adjacent slots.

Motherboard Form Factor:

Motherboard Form Factor It determines the specifications for motherboard’s general shape and size. It also specifies what type of case and power supply will be supported, the placement of mounting holes, and the physical layout and organization of the board.

Common Form Factors:

Common Form Factors XT (Extended Technology) AT (Advance Technology) Baby-AT ATX (Advance Technology Extended) Micro-ATX NPX NLX BTX ( B alanced T echnology E xtended )

XT (Extended Technology):

XT (Extended Technology)

XT (Extended Technology):

XT (Extended Technology) When IBM came out with its first PC, there were no standards and the motherboard tended to be a little on the larger size. Within a short time, they had developed their Extended Technologies computer (XT), reducing the size of the motherboard. The XT quickly became a standard for motherboards.

Advance Technology (AT):

Advance Technology (AT)

AT Contd..:

AT Contd.. Computers quickly became more and more powerful with more system memory installed on the board, faster CPUs, and features that required more circuitry and components. IBM had to increase the size of their boards to accept all these components and developed the AT motherboard. At 13.5" X 12", this form factor soon became another standard.

AT Cont..:

AT Cont.. Advancements were tower design and power switch on front panel. It comes with keyboard connector only. All other ports (com, LPT, USB etc.) need to be plugged in separately.

Baby AT:

Baby AT

Baby AT:

Baby AT As technology advanced, circuits and components became smaller and more integrated. Many companies decided to reduce the size of the motherboard. Because the AT had been standard for so many years they retained the placement of the expansion slots and the screw positioning on a 13" X 8.5 or 9" board

ATX (Advance Technology Extended) :

ATX (Advance Technology Extended) ATX was developed as an evolution of the Baby AT form factor and was defined to address four areas of improvement: enhanced ease of use, better support for current and future I/O, better support for current and future processor technology, and reduced total system cost.

ATX (Advance Technology Extended):

ATX (Advance Technology Extended) The ATX is basically a Baby AT rotated 90 degrees and providing a new mounting configuration for the power supply. The processor is relocated away from the expansion slots, allowing them to hold full length add-in cards.

ATX (Advance Technology Extended):

ATX (Advance Technology Extended) The longer side of the board is used to host more on-board I/O. The ATX power supply, rather than blowing air out of the chassis, as in most Baby AT platforms, provides air-flow through the chassis and across the processor. Another improvement is that it has a new type of power connector with 20 pins instead of the earlier 12.

ATX (Advance Technology Extended):

ATX (Advance Technology Extended) First motherboard to include IO ports and place all the connectors directly soldered onto the motherboard.

ATX (Advance Technology Extended):

ATX (Advance Technology Extended)

ATX (Advance Technology Extended):

ATX (Advance Technology Extended)

Micro-ATX :

Micro-ATX This form factor was developed as a natural evolution of the ATX form factor to address new market trends and PC technologies. Micro-ATX supports: Current processor technologies The transition to newer processor technologies AGP high performance graphics solutions Smaller motherboard size Smaller power supply form factor



LPX (Low Profile eXtension) :

LPX (Low Profile eXtension)


LPX LPX is an older form factor (8.67" x 9.25") that has been replaced by NLX. The LPX form factor is usually found in desktop model PCs. The LPX case is a slim-line, low-profile case with a riser card arrangement for expansion cards.

PowerPoint Presentation:

LPX This means that expansion boards are parallel to the motherboard. This allows for smaller cases, but limits the number of expansion slots, usually to two or three. LPX motherboards often have the video adapters integrated onto the motherboard, and they may have integrated sound as well.


LPX This can provide a high-quality product at low cost, but can make upgrading or repair difficult. It is not always possible to disable the built-in video adapter cards to allow for an upgrade. LPX motherboards also usually come with serial, parallel, and mouse connectors attached to them, like ATX.


LPX The LPX case and motherboard design are not designed for a home PC builder, as they can be cramped and difficult to work in, as well as being non-standard. They also offer poor expandability, poor upgradability, poor cooling, and difficulty of use for the home PC builder.





Riser Card:

Riser Card

NLX (New Low Profile Extended) :

NLX (New Low Profile Extended) NLX is a new form factor designed to improve upon today’s low profile form factors. NLX does the following: Supports current and future processor technologies Supports new Accelerated Graphics Port (A.G.P.) high performance graphics solutions Supports tall memory technology Provides more system level design and integration flexibility.

NLX Motherboard:

NLX Motherboard

NLX Riser:

NLX Riser


NLX Several major PC vendors world-wide worked jointly to define the NLX form factor and to incorporate flexibility to accommodate the best designs for current and future PCs. NLX is a public specification intended for widespread use in many types of systems.

Another NLX example:

Another NLX example



BTX (Balanced Technology Extended):

BTX ( Balanced Technology Extended ) BTX is a form factor for motherboards, originally slated to be the replacement for the aging ATX motherboard. It has been designed to alleviate some of the issues that arose from using newer technologies (which often demand more power and create more heat) on motherboards

BTX-Enhancements :

BTX-Enhancements Low-profile - With the push for ever-smaller systems, a redesigned backplane. Thermal design - The BTX layout establishes a straighter path of airflow with fewer obstacles, resulting in better overall cooling capabilities.


BTX-Enhancements Structural design - The BTX standard specifies different locations for hardware mounting points, thereby reducing latency between devices and also reduces the physical strain imposed on the motherboard by heat sinks, capacitors and other components dealing with electrical and thermal regulation. For example, the Northbridge and Southbridge chips are located near each other and to the hardware they control.



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