Computer and Information Technology.

Lesson 4 : Monitor Program 

4.1. Learning Objectives 
On completion of this lesson you will be able to describe:
 Monitor program or BIOS  Different types of BIOS
 Function of BIOS
 How the BIOS works

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4.2. Monitor Program in Microcomputer 

Monitor program is the program that is used to control the basic functions of different devices. In microcomputers the monitor program is known as BIOS. BIOS is the acronym for ‘Basic Input / Output System' in the PC, a set of instructions, stored in read-only memory (ROM), that let your computer's hardware and operating system communicate with application programs and peripheral devices such as hard disks, printers and video adapters. These instructions are stored in non-volatile memory as a permanent part of your computer. They are always available at specific addresses in memory, so all programs can access them to perform their basic input and output functions. 

4.3. Different BIOS Manufacturers 

IBM computers contain a copyrighted BIOS that only their computers can use; however, other companies such as Phoenix, Award, and American Megatrends have developed BIOS for other manufacturer's computers that emulate or mimic the IBM instructions without using the same code. If you use a non-IBM computer, the BIOS company's copyright message and BIOS version number are displayed every time you turn on your computer. 

4.4. BIOS Extensions 

BIOS extensions In the PC are extensions to the main BIOS that enable the computer to work with add-on devices such as hard disk controllers and EGA or VGA adapters. The ROM chips containing these extensions do not have to be located on the motherboard; they can also be on expansion boards plugged into the expansion bus. Any BIOS extensions needed to run these expansion boards are loaded automatically when you boot your computer.