Alazka

A motherboard is the central printed circuit board (PCB) in some complex electronic systems, such as modern personal computers. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple computers, the logic board.


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, memory and peripherals were housed on individual printed circuit boards which plugged into the backplane.

During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard (see below). 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 supported 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 retained only the graphics card as a separate component.

The early pioneers of motherboard manufacturing were Micronics, Mylex, AMI, DTK, Hauppauge, Orchid Technology, Elitegroup, DFI, and a number of Taiwan-based manufacturers.

Popular personal computers such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse-engineering and third-party replacement motherboards. Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer's original equipment.

The term mainboard is archaically applied to devices with a single board and no additional expansions or capability. In modern terms this would include embedded systems, and controlling boards in televisions, washing machines etc. A motherboard specifically refers to a printed circuit with the capability to add/extend its performance/capabilities with the addition of "daughterboards".
Peripheral card slots

A typical motherboard of 2009 will have a different number of connections depending on its standard. A standard ATX motherboard will typically have 1x PCI-E 16x connection for a graphics card, 2x PCI slots for various expansion cards and 1x PCI-E 1x which will eventually supersede PCI.

A standard Super ATX motherboard will have 1x PCI-E 16x connection for a graphics card. It will also have a varying number of PCI and PCI-E 1x slots. It can sometimes also have a PCI-E 4x slot. This varies between brands and models.

Some motherboards have 2x PCI-E 16x slots, to allow more than 2 monitors without special hardware or to allow use of a special graphics technology called SLI (for Nvidia) and Crossfire (for ATI). These allow 2 graphics cards to be linked together, to allow better performance in intensive graphical computing tasks, such as gaming and video-editing.

As of 2007[update], virtually all motherboards come with at least 4x USB ports on the rear, with at least 2 connections on the board internally for wiring additional front ports that are built into the computer's case. Ethernet is also included now. This is a standard networking cable for connecting the computer to a network or a modem. A sound chip is always included on the motherboard, to allow sound to be output without the need for any extra components. This allows computers to be far more multimedia-based than before. Cheaper machines now often have their graphics chip built into the motherboard rather than a separate card.