On recent motherboards the BIOS may also patch the central processor microcode if the BIOS detects that the installed CPU is one for which have been published.
Most modern motherboard designs use a , stored in an chip soldered to or socketed on the motherboard, to an . Non-operating system boot programs are still supported on modern IBM PC-descended machines, but nowadays it is assumed that the boot program will be a complex operating system such as Microsoft Windows or Linux. When power is first supplied to the motherboard, the BIOS firmware tests and configures memory, circuitry, and peripherals. This (POST) may include testing some of the following things:
Motherboards contain some to initialize the system and load some startup software, usually an , from some external peripheral device. Microcomputers such as the Apple II and IBM PC used chips mounted in sockets on the motherboard. At power-up, the central processor would load its with the address of the boot ROM and start executing instructions from the ROM. These instructions initialized and tested the system hardware, displayed system information on the screen, performed RAM checks, and then loaded an initial program from an external or peripheral device. If none was available, then the computer would perform tasks from other memory stores or display an error message, depending on the model and design of the computer and the ROM version. For example, both the Apple II and the original IBM PC had Microsoft Cassette BASIC in ROM and would start that if no program could be loaded from disk.
High rates of motherboard failures in China and India appear to be due to "" that's burned to generate electricity. Air pollution corrodes the circuitry, according to researchers.
|A Labelled Diagram of a Motherboard.|