<P> A desktop computer is a personal computer designed for regular use at a single location on or near a desk or table due to its size and power requirements . The most common configuration has a case that houses the power supply, motherboard (a printed circuit board with a microprocessor as the central processing unit (CPU), memory, bus, and other electronic components), disk storage (usually one or more hard disk drives, optical disc drives, and in early models a floppy disk drive); a keyboard and mouse for input; and a computer monitor, speakers, and, often, a printer for output . The case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk . </P> <P> Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small; the type of computers most commonly used were minicomputers, which were themselves desk - sized . Early computers took up the space of a whole room . Minicomputers generally fit into one or a few refrigerator - sized racks . </P>

Describe any 2 main components that are found on a typical desktop