The Motherboard
Mothers and Daughters
Early in the history of the personal computer, the motherboard (also called the mainboard) was little more than a skeleton to which the CPU, chipset, BIOS, and other boards called daughter boards or risers, were attached. The daughter boards contained such peripherals as the drive controllers, input/output controllers, memory banks, and other devices.
Nowadays, virtually all motherboards (or mobo's, to those in the know) integrate these components onto the motherboards themselves. Devices that are included on modern motherboards, but which typically were separate components in earlier PC's, are commonly known as integrated peripherals.
Being able to identify the components on the motherboard is essential to any home computer builder. (It's also a great way to impress family and friends.)
The parts
Modern motherboards usually include the following on-board components:
The CPU socket (or slot).- The chipset (divided into two parts commonly called the Northbridge and the Southbridge).
- Memory (RAM) slots.
- Controllers and connections for for the hard drive, floppy drive, and other storage devices.
- The BIOS.
- Controllers and connectors for the serial ports, parallel ports, USB ports, and sometimes other interfaces such as SCSI or Firewire ports.
- In most cases, expansion slots that can accommodate aftermarket expansion cards.
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On-Board Cards
Some motherboards also include on-board audio, video, network, or modem "cards." These are usually built right onto the motherboard and are configured through the BIOS setup, but they're commonly called "cards" nonetheless.
Integrating peripheral components onto the motherboard helps keep the cost of a new computer down by reducing or eliminating the need for add-on cards. The quality of built-in components ranges from awful (on el-cheapo boards), to excellent (on high-end boards).
One downside to built-in cards is that they usually are neither repairable nor upgradeable (except, on occasion, for ROM updates). That's one reason why most motherboards that feature integrated audio, video, modem, or network interface cards also offer the option to disable the onboard devices and install add-on cards to take their place if the integrated cards should fail or become obsolete.
How, exactly, to disable an onboard device varies from mobo to mobo. On some boards, you have to enter BIOS setup and disable the device, usually in the "Integrated Peripherals" menu. Sometimes (especially on older boards) you have to move a jumper on the board itself. Finally, some newer motherboards will automatically sense when an add-on card has been installed and will disable the built-in device automatically.
If you are planning to install an operating system other than Windows on your homebuilt computer, bear in mind that most integrated cards are designed with Windows in mind. Sometimes these components will work under Linux or other operating systems, but sometimes not. Check the hardware newsgroups to make sure before you plunk down any money for the board.
- Components
- Motherboards
- The Motherboard (This Page)
- Expansion Interfaces
- Choosing a Motherboard
- Motherboards
