What is the function of the BIOS?

first, what is the BIOS

The BIOS is the English "basic Input Output system" abbreviation, after literal translation after the Chinese name is "the basic input to export systems". Its full name should be Rom-bios, which means read-only memory basic input and output system.

　Second, the role of Biso

The main functions of the BIOS are as follows:

The first is the Self-Test and initialization program: After the computer is powered on, the system will have a process for checking internal devices, which is done by a program commonly called post (Power On Self test/), which is also a function of the BIOS program. The complete self-test includes the CPU, 640K basic memory, 1M above the extended memory, ROM, motherboard, CMOS memory, serial port, display card, soft and hard plate system and keyboard test. If a problem is found during the self-test, the system will give a message or whistle warning. If there is no problem, after the completion of the self-test BIOS will be in accordance with the system CMOS settings in the boot sequence search software, hard drive and CDROM, network server and other effective boot drive, read into the operating system boot record, and then the system control to the boot record, by the boot record to complete the system start You can safely use your baby. The second is hardware interrupt processing: When the computer is powered on, the BIOS will tell the CPU and other hardware device interrupt number, when you have entered the operation of the use of a hardware command, it will be based on the interrupt number of the corresponding hardware to complete the operation of the command, and finally according to its interrupt to jump the original state. Then there is the program service request: From the BIOS definition can know that it is always dealing with the computer's input, it through the most specific data port issued instructions, send or receive data from various external devices, so that software applications to the hardware operation.

　　Third, the relationship between the BIOS and CMOS

CMOS is the abbreviation of "complementary Metal oxide Semiconductor", the original meaning of which is complementary metal oxide semiconductor memory, which refers to a kind of raw material used in IC chip manufacture. But the exact meaning of CMOS here is a battery-powered, read-write RAM chip that is used by most computers today. And the meaning of the BIOS is explained in the previous. So what exactly does CMOS have to do with the BIOS? CMOS is a memory chip, of course, is the hardware, its role is to have data preservation function, but it can only play the role of storage, and can not be stored in which the data set, to the CMOS parameters in the settings must be set through a special program. Now most manufacturers will CMOS parameter setup program to do the BIOS chip, in the computer when the power on the special button to enter the Setup program can easily set up the system. In other words, the System Setup program in the BIOS is the means to complete the CMOS parameter setting, and the CMOS RAM is the place where the data is set up, and they all have a lot to do with the system parameter settings of the computer. For this reason, there are quot; CMOS settings "and" BIOS settings ", in fact, the accurate statement should be" through the BIOS setup program to set the CMOS parameters. " BIOS and CMOS are both related and different, "CMOS settings" and "BIOS settings" are only two ways to simplify the setup process, in this sense they refer to a matter.

The CMOS memory chip can be powered by the motherboard's battery, and the stored data will not be lost even if the system loses power. But what happens if you take off the battery? Good question! If the battery doesn't have electricity, or if there is a problem, or if you take it off, then the CMOS loses all of the data stored internally because of a power outage. But if there is such a situation is not a big problem, you can change the battery, or check the cause of bad contact, in short, to ensure that the CMOS power. Then boot into the BIOS program, select the main Menu "load BIOS DEFAULTS" or "Load SETUP DEFAULTS" after the return, and finally determine the input "Y" enter can. You may have heard other players have talked about if you forget the power-on password on the CMOS discharge, in fact, that is, including the password to throw away all the information, when the boot does not need to enter the password, and then to write data again.