Open architecture

The term "open architecture" is of recent vintage and pertains primarily to personal computers. An open architecture is one that allows insertion of additional logic cards to the interior of the computer chassis beyond those used with the most primitive configuration of the system. This is done by inserting the cards into slots in the computer's motherboard (q.v.), the main logic board that holds its central processing unit (CPU-q.v.) and memory chips. A computer vendor who adopts such a design knows full well that, since the electronic characteristics of the motherboard slots will be public knowledge, other vendors who wish to do so can design and market customized logic cards. The rationale is that the greater the variety of cards marketed, the greater will be sales of the host computer itself. The logic cards provide a host of services, such as one form of hard disk (q.v.), greater degrees of color graphics resolution, supplemental memory, sound, and enhanced floating-point processing power through use of coprocessor boards.