A motherboard is the central or primary printed circuit board (PCB) making up a complex electronic system, such as a modern computer . It is also known as a mainboard, baseboard, system board, planar board, or, on Apple computers, a logic board , and is sometimes abbreviated casually as mobo.
Most motherboards produced today are designed for so-called IBM-compatible computers, which held over 96% of the global personal computer market in 2005. Motherboards for IBM-compatible computers are specifically covered in the PC motherboard article.
AS A BACKPLANE:
A motherboard, like a backplane , provides the electrical connections by which the other components of the system communicate, but unlike a backplane also contains the central processing unit and other subsystems such as real time clock, and some peripheral interfaces.
A typical desktop computer is built with the microprocessor , main memory , and other essential components on the motherboard. Other components such as external storage , controllers for video display and sound , and peripheral devices are typically attached to the motherboard via edge connectors and cables, although in modern computers it is increasingly common to integrate these "peripherals" into the motherboard.
Components and functions :
Connect the CD ROM to the motherboard with the help of the connector
Mount the memory modules on the motherboard
Connect the hard disk
to the motherboard
through ATA 66
4) Mount the video and other cards needed
Mount the graphic card on to the motherboard
Mount the sound card on the motherboard
The 2004 K7VT4A Pro motherboard by ASRock . The chipset on this board consists of northbridge and southbridge chips.
The motherboard of a typical desktop consists of a large printed circuit board .
It holds electronic components and interconnects, as well as physical connectors (sockets, slots, and headers ) into which other computer components may be inserted or attached.
Most motherboards include, at a minimum:
sockets (or slots) in which one or more microprocessors ( CPUs ) are installed
slots into which the system's main memory is installed (typically in the form of DIMM modules containing DRAM chips)
a chipset which forms an interface between the CPU's front-side bus , main memory, and peripheral buses
non-volatile memory chips (usually Flash ROM in modern motherboards)
Integrated peripherals :
With the steadily declining costs and size of integrated circuits , it is now possible to include support for many peripherals on the motherboard. By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly-integrated motherboards are thus especially popular in small form factor and budget computers.
Temperature and reliability :
Motherboards are generally air cooled with heat sinks often mounted on larger chips, such as the northbridge, in modern motherboards. Passive cooling, or a single fan mounted on the power supply, was sufficient for many desktop computer CPUs until the late 1990s; since then, most have required CPU fans mounted on their heatsinks, due to rising clock speeds and power consumption.
HEAT SINK AND FAN:
It is used for lowering the temperature of processor by dissipating the heat.
Heat sink with fan are called ‘active heat sinks’ while those without fans are called ‘passive heat sinks’.
Are made of aluminium alloys.
Form factors :
Motherboards are produced in a variety of sizes and shapes (" form factors "), some of which are specific to individual computer manufacturers . However, the motherboards used in IBM-compatible commodity computers have been standardized to fit various case sizes. As of 2007 , most desktop computer motherboards use one of these standard form factors—even those found in Macintosh and Sun computers which have not traditionally been built from commodity components.
Laptop computers generally use highly integrated, miniaturized, and customized motherboards. This is one of the reasons that laptop computers are difficult to upgrade and expensive to repair. Often the failure of one laptop component requires the replacement of the entire motherboard, which is usually more expensive than a desktop motherboard due to the large number of integrated components.
Prior to the advent of the microprocessor , a computer was usually built in a card-cage case or mainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed-circuit boards soon became the standard practice;The central processing unit
During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard. In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards support a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3D gaming and computer graphics typically retain only the graphics card as a separate component.
The microprocessor is the heart of any normal computer, whether it is a desktop machine , a server or a laptop
A microprocessor -- also known as a CPU or central processing unit -- is a complete computation engine that is fabricated on a single chip
Intel 4004-1 st microprocessor,4 bit,
add and subtract.
Intel 8080, a complete 8-bit computer on one chip.
The socket for the microprocessor determines what kind of Central Processing Unit (CPU) the motherboard uses.
In early PC’s , processors had the same set of pins that would connect the CPU to the motherboard, called the Pin Grid Array (PGA). These pins fit into a socket layout called Socket 7.
Commonly used sockets are:
Socket 478 - for older Pentium and Celeron processors
Socket 754 - for AMD Sempron and some AMD Athlon processors
Socket 939 - for newer and faster AMD Athlon processors
Socket AM2 - for the newest AMD Athlon processors
Socket A - for older AMD Athlon processors
The newest Intel CPU does not have a PGA. It has an LGA, also known as Socket T.
It is an optional plug in component on the motherboard.
Increases execution speed of a processor.
Examples :Math coprocessor and Graphics coprocessor.
Basic input output system:
BIOS is a set of programs that resides in ROM that perform the most basic low level and intimate control and supervision operations for the computer.
What BIOS Contains?
It contains the program code required to control all the basic operating components of the computer system.
BIOS contains the software required to test hardware at boot up, load the operating system, and support the transfer of data between hardware components.
Basic input output system:
It is a firmware.It is the interface between hardware and software.
BIOS makes sure all the other chips, hard drives, ports and CPU function together.
Uses flash memory.
The system BIOS and the information required to configure it is stored on a Complementary Metal-Oxide Semiconductor (CMOS) chip.
CMOS is a battery-powered storage chip located on the system board.
The CMOS chip has rewritable memory since the configuration data can be changed or updated as the components or devices in the computer are changed.
Real time clock chip:
The RTC is essentially a quartz watch that runs all the time, whether or not the computer has power. The battery powers this clock.
RTC gets the correct time and date when system is booted.
The chipset is the "glue" that connects the microprocessor to the rest of the computer.
It consists of two basic parts -- the northbridge and the southbridge .
The chipset is an integrated part of the motherboard and must work optimally with the CPU.
Peripheral component Interconnect:
Expansion cards like sound cards, video cards, network cards and so on (except graphics card) can be connected to the computer's processor through these slots.
PCI cards use 47 pins to connect (49 pins for a mastering card, which can control the PCI bus without CPU intervention). The PCI bus is able to work with so few pins because of hardware multiplexing, which means that the device sends more than one signal over a single pin.
ACCELERATED GRAPHICS PORT:
AGP enables your computer to have a dedicated way to communicate with the graphics card, enhancing both the look and speed of your computer's graphics.
A Graphics card
Integrated Drive Electronics:
An IDE interface is a standard way for a storage device to connect to a computer. Like
Floppy Disk Drive
Hard Disk Drive
CD ROM Drive
The original name, AT Attachment (ATA)
Most Motherboards have 3-4 Memory slots.
Allow up to or beyond 1Gb of total system memory.
Most commonly allow 384 to 512 Mb of System RAM.
Newer Technology Incorporated in Motherboards
Redundant Array of Independent Disc (RAID) controllers allow the computer to recognize multiple drives as one drive.
PCI Express is a newer protocol that acts more like a network than a bus. It can eliminate the need for other ports, including the AGP port.
Rather than relying on plug-in cards, some motherboards have on-board sound, networking, video or other peripheral support.