MOTHERBOARDS

         TALKING ABOUT MOTHERBOARDS

Motherboard

The main circuit board of a microcomputer. The motherboard contains the connectors for attaching additional boards. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the motherboard's chip set

DESCRIPTION

·      Pathways for all communication

·      Various system Buses for data and signal transmission

·      Provide connectors for attaching external component

North bridge

Sometimes abbreviated as nb, the north bridge is an integrated circuit that is responsible for communications between the CPU interface, AGP, PCI, and the memory. The north-bridge gets its name for commonly being North of the PCI bus. the north-bridge is usually slightly larger than the south-bridge and is the closest to the CPU and memory.

When the CPU needs data from RAM, a request is sent to the north-bridge memory controller

South-bridge

An integrated circuit on the motherboard that is responsible for the hard drive controller, I/O controller and integrated hardware such as sound card, video card if present on the motherboard, USB, and Ethernet. The South-bridge gets its name for commonly being South of the PCI bus

Case fan

A fan located inside a computer case attached to the front or back of the computer that helps bring air into the case and also take hot air out of the case. Computer case fans are available in a wide variety of sizes, however, 80mm, 92mm, and 120mm (12cm) with a width of 25mm are the most commonly used case fans in a computer. Below is a graphic example of what a computer case fan may look like\
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S/PDIF

Short for Sony and Phillips Digital Interconnect Format, the S/PDIF or SPDIF interface is used to transmit digital audio, in a compressed form, between audio equipment and home theater systems. The S/PDIF interface can utilize a coaxial cable or a fiber optic cable to transmit the audio. Common equipment to use this interface are DVD Players and CD Players, connecting to a home theater system for Dolby Digital or DTS surround sound. High quality sound cards and laptops will also have this connector. In the first picture to the right, is an example of what the SPDIF connector may look like on your computer motherboard.

BIOS

Short for Basic Input/Output System, the BIOS, ROM BIOS, or System BIOS is a chip located on all motherboards that contain instructions and setup for how your system should boot and how it operates. In the picture to the right, is an example of what a BIOS chip may look like on your computer motherboard. In this example, this is a picture of an AMIBIOS, a type of BIOS manufacturered by the AMI another good example of a BIOS manufacturer is Phoenix
The BIOS includes instructions on how to load basic computer hardware and 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 within the computer.

In most PCs, the BIOS has 4 main functions as mentioned below.

1. POST - Test the computer hardware and make no errors exist before loading the operating system. Additional information on the POST can be found on our POST and Beep Codes page.
2. Bootstrap Loader - Locate the operating system. If a capable operating system is located, the BIOS will pass control to it.
3. BIOS drivers - Low level drivers that give the computer basic operational control over your computer's hardware.
4. BIOS or CMOS Setup - Configuration program that allows you to configure hardware settings including system settings such as computer passwords, time, and date.

MOTHERBOARD FORM FACTORS

Full AT

Commonly referred to as the AT, the Full AT is a motherboard form factor introduced by IBM and widely used in the 1980s. The Full AT is 12" wide x 13.8" deep and only fits into a full size AT tower case that support this form factor. Today, this form factor is rarely found or used and has been replaced by ATX and Baby AT. Below is an example of what an early IBM AT motherboard looked like.

Baby AT

A replacement for the Full AT motherboard and sometimes referred to as BAT; the Baby AT is a motherboard form factor introduced by IBM in 1985 and used with the 286, 386, 486, and Pentium computers up until the early 1990's. The Baby AT is 8.57" wide x 13.04" deep, which is almost the same as the original IBM XT motherboard with modifications in the screw hole position to fit into AT-style case. This board is now considered obsolete and has been replaced by ATX.

ATX

Sometimes referred to as the Full-ATX, the ATX motherboard is one of most commonly found and used motherboards even today. ATX is an Intel trademark and not an acronym that was first designed and released in 1995 by Intel and revised to version 2.01 in February 1997. The ATX motherboard is 12" wide x 9.6" deep and has the COM port, LPT port, PS/2, and USB mounted directly on the motherboard. Below is a picture and example of what this form factor of motherboard may look like.

Types (Family) of ATX Motherboards

BTX

Short for Balanced Technology Extended, BTX is a motherboard form factor first announced by Intel on September 17, 2003 as a replacement for ATX. The BTX includes features such as a low profile, more efficient layout to help with cooling, scalable board to allow for different system sizes, and support mechanisms to help support high-mass motherboard components. In September 2006, Intel announced that it was stopping all future development of BTX.

advantages and methods of identifying a computer with an BTX motherboard.

Designed to mitigate the poor cooling effect of ATX, developed in 2004
i. Better airflow as a result of better cooling
2. The processor socket is mounted at 45-degree angle to the front of the motherboard to improve cooling
3. A thermal module with a horizontal fan fits over the Processor for cooling
4. The port cluster is moved to the rear left Conner of the motherboard
5. BTX tower cases uses a right –opening as viewed from the front

NOTE: Although BTX designs are easier to cool than ATX designs, the development of coolers running processors has enabled system designers to continue to favor ATX. There are relatively few BTX-based motherboards and systems currently in the market.

BTX vs ATX DIAGRAM

NLX

Short for New Low Profile Extended, NLX is a motherboard form factor originally developed by Intel and first finalized March 1997. The NLX motherboard is 9" wide x 13.6" deep maximum to 8" x 10" deep minimum and included the below features.
A small formfactor board designed to integrate a Riser Card

RISER CARD: A circuit board that connects directly into the computer motherboard and provides the ability for additional expansion cards to be added to the computer. Riser boards were used with LPX motherboards and today are rarely used with the introduction of ATX motherboards that allow expansion cards to be connected directly to the computer.

LPX

Motherboard form factor originally developed by Western Digital when it was making motherboards that was used in the 1990s. The LPX motherboard is 9" wide x 13" deep, uses a riser card, and has different placement of the video, parallel, serial, and PS/2 ports on the back. Below is a picture example of what a LPX motherboard may have looked like. This is a picture of a Packard Bell LPX motherboard and as can be seen has one large brown slot that the riser card would connect into.

DTX

DTX is a form factor for motherboards, a variation of the ATX form factor. It was originally developed by AMD in January 2007 and was designed for smaller computers like home theater PCs (media center computers). The physical dimensions of a DTX motherboard is 8.0 inches by 9.6 inches and the board allowed for 2 expansion slots. A somewhat smaller version was also developed, called the Mini-DTX, having dimensions of 8.0 inches by 6.7 inches.

The DTX form factor provided a lower cost of manufacturing, due to the fewer layers of printed circuit board wiring required to make the board. It was intended to be an industry standard for small form factor computers, like the Shuttle "SFF" design. DTX motherboards are backward compatible with the ATX form factor, fitting in computer cases designed for ATX motherboards. It also works with a standard power supply, requiring the same 24-pin power connector that the ATX motherboard requires.