You know that your PC has BIOS but, do you know what it is exactly?
We all know that PCs have a BIOS, that famous blue screen with yellow characters that allows you to modify some of the PC’s settings, but do you know what it is? In this post, we will explain what the BIOS is, what its definition is, what its characteristics are, and what its functions are in detail.
The BIOS is a “concept” that is frequently mentioned in the computer world, and while virtually everyone has a general idea of what it is and what it is used for, few know exactly what it is. So, in this section, we will explain everything so that you fully understand the notion.
What is BIOS?
BIOS stands for “Basic Input Output System”. Although at the dawn of the PC era it meant “Basic Input Operating System” and it is actually the first operating system that runs on the PC and its job is to start up the hardware before passing it on to the main operating system.
In the MS-DOS era many of the system routines were performed in combination with the system BIOS. This is no longer the case today, but it is the reason why there are certain problems when emulating MS-DOS today. Because of the fact that with the jump from BIOS to UEFI a good part of these functions were lost.
And where can you find the BIOS? Well, you will not find it anywhere in the storage unit, since it is located in a ROM (non-volatile) memory of the computer, often on a dedicated chip. This dedicated chip has the first memory addresses accessed by the processor, as it is a fundamental element in the boot of a PC because it is the bridge between the hardware and the system software. In essence, it is what communicates to the program how the hardware should function.
Although the purpose of all of them is the same, there are several BIOS manufacturers that can be found, the main ones being the following:
- Phoenix Technologies.
- American Megatrends (AMI).
- Insyde Software.
All contain the basic BIOS functions, but some manufacturers add additional functions for their motherboards and/or systems while limiting others. The two most commonly used are from American Megatrends and Phoenix Technologies.
What is the BIOS used for in a PC?
The BIOS manages very low-level PC tasks such as the boot sequence (which storage media the operating system is on and how to boot from it) and keyboard operation.
It also serves to identify and configure hardware components such as hard disks, external storage devices, the processor, or RAM memory, and it is from the BIOS that we can modify the operating parameters of the processor, for example, to disable cores, enable and disable Hyper-Threading / SMT, or modify its speed to Overclock or Underclock without having to go directly through the operando.
Main functions of the BIOS in a PC
We will be able to adjust a large number of hardware configuration options in a PC’s BIOS. As a general rule, you will only need to access the BIOS, modify the parameter, save the changes, and restart the PC for them to take effect, because, as stated previously, the BIOS affects the PC’s boot system and is the first thing hardware consults.
These are the main functions that you will be able to modify:
- Change the order of the boot sequence.
- Load factory-settings.
- Update the BIOS.
- Create / change / disable the access password.
- Change the date and time of the computer.
- Change the settings of the storage drives.
- Modify optical / disk drive settings.
- Examine the memory installed in the machine.
- Configure whether or not the numeric keypad is active at start-up.
- Enable or disable the motherboard manufacturer’s logo at boot time.
- Enable or disable POST (Power-On Self-Test).
- Enable or disable the internal processor cache.
- Change processor options and behavior.
- Modify RAM memory options and speed.
- Change voltages.
- Create RAID systems of storage devices.
- Enable or disable IEE1394.
- Enable or disable the on-board sound card.
- Enable or disable RS232/LPT ports.
- Enable or disable ACPI.
- Change the behavior of the PC power button.
- Modify boot options.
- Enable or disable multiple monitors at boot time.
- Change PWM fan behavior.
- Monitor PC temperatures.
All these functions can be done directly from the BIOS, without the need to access the operating system. This is extremely useful if we do not have an operating system installed on the PC and we need to perform one of the tasks listed above.
How to access the BIOS of the PC?
As a general rule, as soon as we push the power button on the PC, we can gain access by continuously pressing the DELETE key on the keyboard. However, on other systems, the BIOS key is either F2 (Insyde) or F1 (Microid). On certain PCs, we may also partially access specific BIOS features, such as selecting the storage device from which we want the system to boot by hitting F10.
To access the BIOS, you will therefore have to press a specific key, which will depend on the motherboard manufacturer. Mostly, it is the F2 key or the F1 key for Lenovo laptops.