1.2.1.6 BIOS

Question 1

What is the BIOS?

Answer 1

• A program supplied with a peripheral device that allows the OS to control and communicate with the device.
• The Basic Input Output System is the first program that runs when a computer system is switched on.
• The Program Counter register points to the location of the BIOS upon each start-up of the computer as the BIOS is responsible for running various key tests before the operating system is loaded into memory.
• The BIOS is critical to the computer system as it is only after these checks are completed that the operating system
  can be loaded into RAM from the hard disk.

Question 2

What tests does the BIOS run?

Answer 2

• POST (Power-on self test):
  Which ensures that all hardware (keyboards, disk drives) are correctly connected and functional
• Checking the CPU Clock, memory and processor is operational
• Testing for external memory devices connected to the computer

Question 3

What is the Bootstrap?

Answer 3

• The name given to the program that loads the operating system from the hard disk into main memory.