(Complementary Metal Oxide Semiconductor) Pronounced "c-moss." The most widely used integrated circuit design. It is found in almost every electronic product from handheld devices to mainframes. CMOS uses PMOS and NMOS transistors wired together in a balanced fashion that causes less power to be used than NMOS or PMOS transistors by themselves. The first transistors were bipolar, which are still used when higher power is required. CMOS and bipolar are also used in combination for many applications. See MOSFET, FET and bipolar transistor. See also CMOS memory.
The set of routines stored in read-only memory that enable a computer to start the operating system and to communicate with the various devices in the system, such as disk drives, keyboard, monitor, printer, and communications ports.
[b(asic) i(nput/)o(utput) s(ystem).]