A motherboard is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard usually contains significant sub-systems, such as the central processor, the chipset's input/output and memory controllers, interface connectors, and other components integrated for general use.
In computing, an expansion card is a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer's motherboard to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard.
ATX is a motherboard and power supply configuration specification, patented by David Dent in 1995 at Intel, to improve on previous de facto standards like the AT design. It was the first major change in desktop computer enclosure, motherboard and power supply design in many years, improving standardization and interchangeability of parts. The specification defines the dimensions; the mounting points; the I/O panel; and the power and connector interfaces among a computer case, a motherboard, and a power supply.
Mini-ITX is a 170 mm × 170 mm motherboard form factor developed by VIA Technologies in 2001. Mini-ITX motherboards have been traditionally used in small-configured computer systems. Originally, Mini-ITX was a niche standard designed for fanless cooling with a low power consumption architecture, which made them useful for home theater PC systems, where fan noise can detract from the cinema experience.
NLX was a form factor proposed by Intel and developed jointly with IBM, DEC, and other vendors for low profile, low cost, mass-marketed retail PCs. Release 1.2 was finalized in March 1997 and release 1.8 was finalized in April 1999. NLX was similar in overall design to LPX, including a riser card and a low-profile slimline case. It was modernized and updated to allow support for the latest technologies while keeping costs down and fixing the main problems with LPX. It specified motherboards from 10 × 8 in (254 × 203 mm) to 13.6 × 9 in (345 × 229 mm) in size.
BTX is a form factor for motherboards, originally intended to be the replacement for the aging ATX motherboard form factor in late 2004 and early 2005.
A computer case, also known as a computer chassis, is the enclosure that contains most of the hardware of a personal computer. The components housed inside the case are referred as the internal hardware, while hardware outside the case are known as peripherals.
In personal computing, a tower unit, or simply a tower, is a form factor of desktop computer case whose height is much greater than its width, thus having the appearance of an upstanding tower block, as opposed to a traditional "pizza box" computer case whose width is greater than its height and appears lying flat.
LPX, originally developed by Western Digital, was a loosely defined motherboard format widely used in the 1990s.
A drive bay is a standard-sized area for adding hardware to a computer. Most drive bays are fixed to the inside of a case, but some can be removed.
WTX was a motherboard form factor specification introduced by Intel at the IDF in September 1998, for its use at high-end, multiprocessor, multiple-hard-disk servers and workstations. The specification had support from major OEMs and motherboard manufacturers and was updated (1.1) in February 1999. As of 2008, the specification has been discontinued and the URL www.wtx.org no longer hosts a website and has not been owned by Intel since at least 2004.
In computer design, microATX is a standard motherboard form factor introduced in December 1997. The maximum size of a microATX motherboard is 9.6 × 9.6 in (244 × 244 mm). However, there are examples of motherboards using microATX designation despite having a smaller size of 244 × 205 mm (9.6 × 8.1 in). The standard ATX size is 25% longer, at 12 × 9.6 in (305 × 244 mm).
Berg connector is a brand of electrical connector used in computer hardware. Berg connectors are manufactured by Berg Electronics Corporation of St. Louis, Missouri, now part of Amphenol.
Small form factor is a term used for desktop computers and for some of its components, chassis and motherboard, to indicate that they are designed in accordance with one of several standardized computer form factors intended to minimize the volume and footprint of a desktop computer compared to the standard ATX form factor.
A Molex connector is a two-piece pin-and-socket interconnection which became an early electronic standard. Developed by Molex Connector Company in the late 1950s, the design features cylindrical spring-metal pins that fit into cylindrical spring-metal sockets, both held in a rectangular matrix in a nylon shell.
A computer fan is any fan inside, or attached to, a computer case used for active cooling. Fans are used to draw cooler air into the case from the outside, expel warm air from inside and move air across a heat sink to cool a particular component. Both axial and sometimes centrifugal (blower/squirrel-cage) fans are used in computers. Computer fans commonly come in standard sizes, such as 92 mm, 120 mm, 140 mm, and even 200–220 mm. Computer fans are powered and controlled using 3-pin or 4-pin fan connectors.
A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use switched-mode power supplies. Some power supplies have a manual switch for selecting input voltage, while others automatically adapt to the main voltage.
In computing, the motherboard form factor is the specification of a motherboard – the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc. Specifically, in the IBM PC compatible industry, standard form factors ensure that parts are interchangeable across competing vendors and generations of technology, while in enterprise computing, form factors ensure that server modules fit into existing rackmount systems. Traditionally, the most significant specification is for that of the motherboard, which generally dictates the overall size of the case. Small form factors have been developed and implemented.
The IBM Personal Computer XT is the second computer in the IBM Personal Computer line, released on March 8, 1983. Except for the addition of a built-in hard drive and extra expansion slots, it is very similar to the original IBM PC model 5150 from 1981.
On June 26, 2007, Dell released the new Inspiron desktop series, under the Dell Inspiron branding, as a replacement to the Dell Dimension desktop computers.
