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<h2> What is BIOS?</h2>
“BIOS” stands for “Basic Input Output System”. This is the first program that starts after turning on the CPU to work. In a way the PC’s BIOS program “come alive” and is introduced after the start of an operating system. The BIOS is the manufacturer of the motherboard in a read only memory chip (ROM) is provided, which is soldered onto the board. In case of power failure, the stored bits are not lost.
BIOS chip on the motherboard
The BIOS is an integrated mini-operating system that works automatically and can not be served. It provides a simple driver ready for the main PC components. The BIOS checks after switching the basic functions of the PC and loads the operating system. Most BIOS drivers are later replaced by the operating system by its own optimized drivers.
The BIOS takes an intermediate position between hardware and software.
“Normal” software such as operating system and applications, delivered on disks. It has a great selection, what software is installed and you can uninstall them too.
The BIOS software, however, is permanently installed in the hardware and can not be removed or replaced.
Because of this hybrid status, the BIOS has been given the name “firmware”.
What responsibilities does the BIOS?
The BIOS program starts after turning on the “POST” (Power On Self Test). Here, the basic functions of the PC to be checked (eg memory test). If errors occur, they are displayed on the screen. If the display output is not possible, errors are signaled by a different number of beeps.
the hardware is configured (Plug and Play) – Power-saving features (power management). Resources are distributed, such as interrupts.
On-board components (chipset, interfaces, …) are supplied with operating parameters (eg number of wait states), and initializes
basic protection against boot sector viruses
Date and time manage
Temperature monitoring of the processor and the board
Search on the disks for an operating system. The found operating system is loaded into memory and starts the operating system.
As for memory, the BIOS will now flash EEPROM (Flash Electrical Erasable Programmable Read Only Memory = “lightning-fast electrically erasable read only memory”) is used. These memory blocks can be erased and rewritten without special equipment, this allows the user to perform a so-called BIOS update itself.
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