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(computer science)
A common pathway over which information is transmitted between the hardware devices (the central processing unit, memory, and each of the peripheral control units) in a microcomputer.


(mobo) The main printed circuit board in an electronic device, particularly a computer, which may contain sockets that accept additional boards ("daughter-boards").

In a personal computer, the motherboard contains the bus, the microprocessor, and integrated circuits used for controlling any built-in peripherals such as the keyboard, text and graphics display, serial ports and parallel ports, joystick, and mouse interfaces.


Also called the "system board," "main board" "base board" or "logic board," it is the primary printed circuit board in a computer or other electronic device. In a modern desktop computer, the motherboard contains the CPU and memory sockets as well as the chipset, which houses the control circuits for all the peripheral devices. It also has a PCI-Express slot for a high-end graphics card and PCI slots for additional peripherals. Laptop motherboards have no expansion slots for more peripherals.

Want to Sound Like a Cool Geek?
Every now and then, say "mobo" instead of motherboard. See CPU, chipset, PCI Express, PCI and controller.

PC Motherboard
This earlier Baby AT style motherboard required plug-in expansion cards for almost all the peripheral devices. The ISA slots are long gone, and the AGP slot was replaced with PCI-Express.

Expansion Cards
On earlier PCs, expansion cards were required for almost all peripheral devices except keyboard and mouse. Today, enthusiasts may plug in a faster graphics card, but most peripheral control circuits are already on the motherboard.

The Mother of All Motherboards
This is the front and back of the prototype of the first IBM PC motherboard in 1981. The chips are wired together on a "breadboard." (Images courtesy of IBM.)

The Mother of All Motherboards
This is the front and back of the prototype of the first IBM PC motherboard in 1981. The chips are wired together on a "breadboard." (Images courtesy of IBM.)
References in periodicals archive ?
HONG Mingxian, Chairman and Executive Director of Differ Group, said, "Listing on the Main Board of SEHK today marks another important milestone in our history as the Group shifts to a wider platform to seize greater opportunities ahead.
Regan said: "We are delighted to welcome Ralph back to the main board, having already benefited from Peter's wealth of experience in the past year.
However, since the decision by the JSE to shelve the project early April after it failed to gain traction among African companies, bringing in only two companies, Trustco and Wilderness Safaris of Botswana, Trustco has now opted for a secondary listing on the NSX and a primary listing on the more prestigious JSE main board.
PwC expects there will be 110 new listings in 2011 including 100 on the Main Board and 10 on the GEM Board, while the total capital raised around HK$300-350 billion ($38.
While they hope to decide on the short-list for England manager and make approaches to their candidates from March 2, several of the 14-man main board are unhappy at the "British only" view taken by the three man sub-committee leading the search for Sven Goran Eriksson's successor.
Mr Walker, 59, joined the group in 1977 and was managing director of Barratt Manchester from 1988 until his appointment to the main board in July 1996 as chairman of Barratt Homes Central Region.
The main board will comprise three executive directors, Fred Duncan, David Salkeld and Iain Imray and five non-executive directors, John Lind, Paul Monk, Harry Tocher, Tony Pearce and Martin Gilbert.
Lancashire-born Mr Wall joined Pilkington in 1956 as assistant solicitor in the legal department, becoming a divisional director 10 years later and a main board director of what was then Pilkington Brothers in 1970.
Haste will also become a main board director of Royal & Sun Alliance.
INSURANCE group, NFU Mutual, has made its general manager, Bob Newton, (left) a main board director.
Mario Party 4 contains multiple ``mini-games'' within the main board game itself.
Secure Trust Banking's main board will today appoint Birmingham-based directors for the first time as part of the company's expansion drive following its acquisition in November of corporate broker Old Mutual Securities (OMS).