What is the BIOS and what is its function in a Computer or PC?

The BIOS is the basic input-output system and is already built with a small piece of software housed in the motherboard of our PC. It is basically in charge of the management and configuration of the motherboard and its components.

The operation of the BIOS is very simple, it is executed every time the computer is restarted, the processor finds the instruction in the reset vector and executes the first line of code of the BIOS that is unconditional jump and forwards to a more Low on the BIOS.

The BIOS is activated every time we turn on the machine. When activated, it verifies the all installed drivers and functions necessary for the proper functioning of the PC, giving the order of ignition to each peripheral so that it starts the system of efficient way.

The BIOS checks to see if we have connected the keyboard, mouse and monitor in our computer, and detects any configuration errors or problems with any peripheral or hard disk of the computer. It is also responsible for searching the operating system and getting it up and running.

The Importance of PC BIOS

Millions of times we have heard of the importance of Bios in the operation of our computer, but a lot of users who are not accustomed to the computer lexicon really do not know what is the meaning and function of that element.

On the other hand, although many are not aware of its importance, it is important to maintain a proper maintenance of the BIOS, making the relevant updates so that it is appropriate to the changes that may occur in both the software and the Hardware from our PC.

Types of Bios

The traditional BIOS is housed in ROM, but there are also other types of BIOS that, to increase PC performance and boot, use part of the RAM. This type of BIOS is known as Shadow BIOS.

Other common BIOS types are the Flash BIOS, which is housed in non-volatile memory and the PnP BIOS, which has the ability to control Plug & Play devices, being one of the most used today.

Currently, there are two types of BIOS: EEPROM and EEPROM Flash ROM.


They are the oldest and can only be updated through a special device that is responsible for rewriting them, so they must be removed from the motherboard.


In contrast, EEPROM Flash ROMs have the advantage of being able to be updated through a computer application, so that most modern motherboards, since the arrival of the Pentium to the market, incorporate this type of BIOS.

BIOS Functions

The main functions of the BIOS are as follows:

  • The entire process of starting and loading software.
  • Checking and inventory of all PC hardware.
  • Initialization of certain hardware devices and operating system startup.
  • Support for certain hardware devices in the system.

How does it work?

The BIOS locates the components of the hardware of our computer, to communicate them with the software so that the system goes into operation.

When the BIOS highlights some inconvenience in the communication of both elements, when starting our PC we will notice that it will execute a series of different beeps that we are accustomed to listen to.

These beeps are the message that the BIOS sends us to report the existence of an error, both in hardware and software, and the inability to communicate both elements.

On the other hand, its software component, through a simple interface and the use of the keyboard, allows to configure the various hardware options that is to say of the components that are included in the interior of our computer.

Where is it stored?

This basic system is stored on a motherboard chip, and is responsible for controlling and transmitting information between the operating system and hardware components, in order to establish a correct communication between them.

Because its existence is of paramount importance for PC startup, this program should never be deleted, so it is on a ROM-type memory chip, i.e. a read-only memory.

Punctually it is stored in a non-volatile memory EEPROM, i.e. not only characterized by read only, but also is electrically programmable, a point that allows its updating.

RAM and ROM memory

In a computer it is indispensable the proper functioning of each of the parts that are distributed in the same, among which we have all safely heard that one of the conditions for the execution of an application is RAM.

But there is not only this one, but rather there is also the video memory as well as the cache and ROM, each and every one that are indispensable and necessary for the proper functioning as well as for the stability of the operating system.

RAM, which is responsible for us being able to use more than one application on the computer or operating system, regardless of whether we use Windows, Linux or Mac; So the RAM is considered as a temporary data storage module or any information that each of the applications help us manage.

Thus, the RAM is completely clean and released when the computer restarts or, in the worst case, when all types of power supply are disconnected, which is why it is essential to have an energy storage unit or UPS , So that we can save all information that we find working if this situation happens, which is why they are referred to as volatile memories.

Not so, the ROM that if it is permanent, so there are electrical power failures, because the content of these memories is always active regardless of the activity of the computer. The definition of ROM is Read Only Memory, or translated into Spanish Memory for reading only.

The specific function of a ROM is to always keep the computer’s functions active, but mainly in terms of the characteristics of the processor as well as other devices such as hard disks and graphics card. This is only possible through the BIOS that contains every computer, which is stored on the ROM chip on the computer’s motherboard.

Add Comment