BIOS

BIOS

BIOS(Basic Input/Output System) is a program pre-installed based on Windows based computers that the microprocessor uses to start up. The BIOS is an integral part of your computer, and your CPU communicates through it to check all the hardware connections such as the hard disk, video adapter, keyboard, mouse, and printer. If all attachments are in place, it loads the operating system into the RAM. When device details change, only the BIOS program needs to be changed. It frees the operating system from worrying about the exact details of hardware attached to the system. BIOS is located in the EPROM(Erasable Programmable Read Only Memory). When the computer is switched on, the microprocessor passes control to the BIOS which is always located there. To reprogram the BIOS, the EPROM chips have to be physically removed from the motherboard. They may be erased by prolonged exposure to ultraviolet light. Modern systems use rewritable flash memory (which can be electrically erased) to store BIOS, as hardware manufacturers frequently release BIOS updates. Rewriting the contents of ROM is also called flashing. BIOS is being replaced by the more complex Extensible Firmware Interface (EFI) in many new machines.