Popularize the basics of BIOS and CMOS

BIOS is an abbreviation of English, it should be spelled out "Ba-ic Input Output System", literal translation of winxp failure

Chinese name is the basic input and output system. Its full name should be ROM-BIOS, meaning that the read-only memory basically loses winxp fault

into the output system. In fact, it is a set of programs that are solidified onto a ROM chip on the motherboard of the computer. It stores the motherboard maintenance training.

The most important basic input and output program, system setting information, power-on and power-on The self-test program and the system start the bootloader.

Some people think that since the BIOS is "program", it should belong to the software, it feels like Word or Excel.

But many people don't think so, because it has some differences with general software, and its connection with hardware is also close to the local

local. To put it bluntly, the BIOS should be a “bridge” that connects software programs and hardware devices, and is responsible for solving the immediate requirements of hardware

.

The superior performance of a motherboard depends largely on whether the management functions of the BIOS program are reasonable and advanced.

The BIOS chip on the motherboard may be the only tagged chip on the motherboard. Generally, it is a 32-pin dual in-line

integrated circuit with "BIOS" printed on it. ; typeface. The BIOS before 586 is mostly a rewritable EPROM chip. The above standard

is used to protect the contents of the BIOS (ultraviolet illumination will cause the EPROM content to be lost) and cannot be torn off. After 586, the ROM BIOS of

mostly uses EEPROM (Electrically Erasable Read-Only ROM), and the EEPROM can be rewritten by the jumper switch and the driver

of the system. Conveniently implement BIOS upgrades. Common BIOS chips include Award, AMI,

Phoenix, MR, etc., and the manufacturer's mark can be seen on the chip.

2. The specific role of the BIOS

What is the specific role of the BIOS in the entire computer system? Generally speaking, from the definition and content of the base

, it can be seen that the main role of the BIOS is as follows.

The first is the self-test and initialization procedures. After the computer is powered on, the system will have a process to check the internal devices

, which is done by a program commonly called POST (PowerOn Self Test). Also a

function of the BIOS program. The complete self-test includes tests for CPU, 640K basic memory, extended memory of 1M or more,

ROM, motherboard, CMOS memory, serial port, display card, soft disk subsystem and keyboard. During the self-test

If a problem is found, the system will give a prompt or a whistle warning. If there is no problem, after the self-test is completed, the BIOS will search for the valid boot

drive of the soft, hard drive and CDROM, network server, etc. according to the boot sequence in the system CMOS settings. The operating system boots the record, and then gives the system control to the boot record, which is started by the boot record completion system

, and then you can use the computer with confidence;

followed by hardware interrupt processing, When the computer is turned on, the BIOS will tell the CPU and other hardware devices the interrupt number. When the

operation enters a command to use a certain hardware, it will use the corresponding hardware to complete the command according to the interrupt number. ,

Finally jump back to the original state according to its interrupt number;

Then there is the program service request, from the definition of the BIOS, it can be known that it always interacts with the computer's input and output devices. >

Road, which passes the most specific data port