- What is BIOS
The BIOS is a set of computer programs that set up hardware and is stored on a ROM chip on the motherboard. We are usually most familiar with the term CMOS. CMOS is a readable and writable RAM chip on the computer motherboard, which is used to save the hardware configuration of the current system and the user’s settings for certain parameters. The CMOS chip is powered by a rechargeable battery on the motherboard, and parameters will not be lost even if the system is powered off. The CMOS chip only has the function of saving data, and the modification of various parameters in the CMOS must be realized through the setting program of the BIOS.
- The role of BIOS
In the whole computer system, BIOS has three main functions: ①Self-inspection and initialization: BIOS is the most basic program of the computer. After the computer is turned on, the BIOS program is loaded first, and then it will conduct a complete and thorough inspection and testing of the hardware devices of the computer. . If a problem is found, it will be dealt with in two cases: serious fault shutdown, no prompt or signal will be given; non-serious fault will be given a screen prompt or sound alarm signal, waiting for the user to deal with it.
If no problems are found, set the hardware to standby, then start the operating system, handing control of the computer to the user. After the self-test and initialization work, the computer will boot the operating system and run the operating system.
②Hardware interrupt processing and program service: For the hardware in the computer system, the BIOS is responsible for the lowest level management. When the computer system is working, the BIOS directly deals with the I/O (Input/Output, that is, input/output) devices of the computer, issues commands through specific data ports, transmits or receives data from various external devices, and realizes the operating system to hardware. direct operation.
③Setting the interrupt: When the machine is turned on, the BIOS will tell the CPU and the interrupt number of each hardware device. When the user issues an instruction to use a certain device, the CPU will use the corresponding hardware to complete the work according to the interrupt number, and then jump back to the original according to the interrupt number. work. When working, the operating system reasonably assigns addresses to each hardware according to the information provided by the BIOS
- Types of BIOS
At present, the more popular BIOS on the market mainly include Award, AMI and Phoenix, among which Phoenix’s BIOS is mostly used in notebook computers. Award BIOS is a BIOS product developed by Award Software. It is currently the mainstream BIOS product on the market. Award BIOS has relatively complete functions and good support for operating systems, so it has been recognized by the majority of users. AMI BIOS is the BIOS system software produced by AMI Company. This BIOS is mostly used in early 286 machines and is no longer a mainstream product in the market.
