BIOS: Basic Input Output System
BIOS stand for Basic Input Output System. It is built-in software. It is the first software run by the computer when you turned on your computer system. This software is usually stored in Read Only Memory (ROM) and located on the motherboard. In modern computer systems, the BIOS contents are stored in a flash memory. It is not possible for an operating system to continue without BIOS as it is the BIOS that loads the drivers of the hard disk and primary portions of the operating system like MBR, FAT, GPT etc, into the memory to enable the operating system to continue loading itself.
It is also known as System BIOS, ROM BIOS, PC BIOS etc.
BIOS was first appeared in the CP/M operating system in 1975. The term BIOS was invented by Gary Kildall.
Functions of BIOS
The main function of Basic Input Output System (BIOS) is to initialize and test all hardware components attach to the computer and load the part of operating system. BIOS also provide a medium which facilitates the application programs and operating system to interact with the keyboard, display and other I/O devices.
Following is a list of activities performed by BIOS:
- BIOS handles the power management and initialize registers.
- It checks and loads the device drivers and interrupts handlers to the RAM.
- It is used to display system settings.
- BIOS specifies the devices that are Bootable.
- BIOS initializes the Bootstrap sequence.