BIOS

All motherboards should have a special chip containing software system known as the computer storage BIOS or BIOS. BIOS symbolize Basic Input Output System.

BIOS in most PCs has four leading functions :

POST (Power-On Self Test): The POST tests your computers processor, memory, chipset, video adapter, Hard disks, Floppies, keyboard and alternative vital parts.

Bootstrap Loader: A routine that finds the OS and masses it in RAM.

BIOS(Basic Input Output System): This refers to the gathering of drivers for the assorted hardware parts hooked up to the computers.

CMOS setup : This can be commonly a menu driven program that enables you to put together the motherboard and chipset settings, beside date and time, passwords, disk drives, and alternative basic system settings.

Some older PC’s cannot co-operate with all the trendy hardware as a result of their BIOS doesn’t support that hardware. The OS cannot decision a BIOS routine to use it; this drawback will be resolved by exchange your BIOS with a more recent one, that will support your new hardware, or by putting in a tool driver for the hardware.

Bootstrap loader

A routine that finds the OS and masses or boots it. If AN OS is found it's loaded and given management of your computers.

This program doesn’t have the total practicality of AN OS, however is tailored specifically in order that it's capable of loading enough alternative software system for the OS to begin. Often, multiple-stage boot loaders area unit used, within which many tiny programs summon one another, till the last of them masses the OS. The name bootstrap loader comes from the image of 1 propulsion oneself up by one’s bootstraps

Boot loaders could face peculiar constraints, particularly in size; as an example, on the IBM laptop and compatibles, the primary stage of boot loaders is often 512 bytes long and ends with the AA55h worth (which the BIOS appearance at to confirm that it's a correct boot loader).

Second-stage boot loader

The small program is most frequently not itself AN OS, however solely a second- stage boot loader, like NTLDR, Lilo or GRUB. it'll then be ready to load the OS correct, and eventually transfer execution thereto. The system can initialize itself, and will load device drivers and alternative programs that area unit required for the conventional operation of the OS.

Booting :

In computing, booting could be a bootstrapping method that starts operational systems once the user activates a automatic data processing system. A boot sequence is that the set of operations the pc performs once it's switched on that load AN OS.

In trendy laptop machines the approach a laptop boots is roughly:

A BIOS (basic I/O system), hold on in computer storage, contains the program that checks the disk drives for a MBR's (master boot record).

The program found at the MBR is that the boot loader that is restricted to the OS being booted.

The boot loader finds the OS and prepares the hardware (memory, disk, etc.) for beginning the OS.

The OS finishes initializing itself then starts elective services and device drivers before the machine begins to retort to traditional input. In the case of a network boot, wherever a machine could also be diskless, the sequence is basically a similar, however the BIOS is within the computer storage of a network card that fetches the boot loader program from the network.

The boot method is taken into account complete once the pc is prepared to act with the user or the OS is capable of running normal applications. Typical trendy PCs boot in a couple of minute (of that concerning fifteen seconds area unit taken by the preliminary boot loaders, and also the rest by the one loading the operational system), whereas massive servers could take many minutes besides and to begin all services - to confirm high availableness, they carry up some services before others.

Most embedded systems should boot virtually instantly — as an example, waiting a second for the tv to come back up isn't acceptable. thus they need their whole OS in computer storage or non-volatile storage, thus it will be dead directly.

Standard BIOS features :

Date and time

Floppy hard drive

VGA/EGA

HALT

Advanced BIOS features :

Virus Program - can scan your drive at startup and warn you of hassle. alter or disable as you would like.

Cache – permits the system to use the cache memory

Quick POST - permits BIOS to boot-up quicker by skipping some tests.

Boot Sequence - Controls the order within which bootable info is searched.

Swap Floppy Drives – Used if you have got 2 floppy drives and you would like to assign the A and B drives letters interchangably

Fast A20 Gate – is employed to extend speed of the pc.

Typematic Rate Settings :

This deals with the speed by that holding a keyboard character down produces continual characters on the screen.

Boot Numlock

CPU Serial variety -This identifies the hardware serial variety in Intel hardwares.

Video BIOS Shadow

Advanced Chipset Settings :

You should not have to be compelled to hassle with this section. However, some basic settings area unit provided for your info. You will alter or disable the following:

Chipset Special options

L2 Cache Size

DRAM Parity Checking

DRAM Parity/ECC Mode

DRAM Clock management

DRAM Frequency

AGP Mode

AGP Aperture

There will presumably be more choices on the market to you. it's best to go away these alone a minimum of for the initial boot-up, and perhaps best left alone for good

Power Management :

This is for classy tweaking, that we have a tendency to aren't doing currently. Your manual can best describe the various choices on the market, if you're interested. except for currently, and perhaps forever, leave at default (disable) as on the market.

Integrated Peripherals :

Enable the ports you propose to use, disable the ports you propose to not use:

IDE Ports

Serial & Parallel Ports

Motherboard Integrated Hardware

Expansion Card Hardware-If you're mistreatment one or a lot of enlargement cards and your motherboard additionally has identical choices, you would like to disable the motherboard choices to permit the employment of the enlargement cards.

PnP/PCI Configuration :

This section controls aspects of “Plug-n-Play” and therefore the PCI bus. Most choices ought to be left at default; however two merits your attention:

PnP OS put in

Reset Configuration knowledge

PC Health :

Also better-known by alternative names, this section monitors some terribly basic operational settings, like voltage levels, fan speed, internal processor temperature. In some versions you'll be able to set the temperature at that the pc would mechanically stop working.
SoftMenu / Frequency-Voltage management
This is to be used by those with “jumperless” motherboards. This section permits you to manage pc settings associated with minute voltage settings, hardware multiplier factor choice, and therefore the system bus speed.

Defaults :

In several BIOS versions, a couple of clicks can set all default settings mechanically while not your got to attend to individual settings. Some versions provide “Failsafe” defaults similarly as “Optimized” defaults. If a Default section is on the market in your BIOS version, be at liberty to use it.

Passwords :

Many BIOS versions have a parole section to permit for the employment of passwords. If you utilize it, be terribly bound to record your parole somewhere safe. do you have to loose it, the complete BIOS system can lock and you may solely be able to use your pc when the complete BIOS system is reset.

There square measure two passwords, that we are able to set

System Password: This feature helps user to line parole to shield unauthorized users from mistreatment the system.

CMOS setup Password: this permits the supervisor to solely set the system configuration for the users.

What is BIOS