【 Weak current College 】 difference between BIOS and CMOS

In the daily operation and maintenance of computers, often you can hear the BIOS settings and some of the CMOS settings, many people often confuse the BIOS and CMOS. This article elaborates on BIOS Setup and CMOS settings in the basic conceptual distinction and contact.

BIOS?

The so-called BIOS, is actually a computer's basic input output system (BasicInput-OutputSystem), its contents integrated in the motherboard of a ROM chip, mainly kept on computer system the most important basic input output system information program, set up, power-on self-test program and system startup bootstrapping procedures.

The function of the BIOS

BIOSROM chip can not only see on the motherboard and BIOS management features can largely determine whether the superior performance of the motherboard. BIOS management features include:

1.BIOS interrupt service program

BIOS interrupt service program is essentially microcomputer system software and hardware of a programmable interface between, mainly used in software and computer hardware to achieve convergence between. For example, DOS and Windows operating system on the floppy disk, hard drive, optical drive, keyboard, monitor, and other peripheral devices of management, is directly based on the BIOS system interrupt service routines, and operations personnel can access INT5, INT13, break points and direct call BIOS interrupt service program.

2.BIOS system setup

Computer parts configuration record is placed in a read/write CMOSRAM chip, mainly holds system, CPU performance, soft-hard disk drive, monitor, keyboard, etc. In BIOSROM chip equipped with "System Setup", it is used for setting CMOSRAM in parameters. This program when you press the power on a particular key to enter the setup status and provides a good interface for operations personnel. In fact, the process of setting parameters, CMOS are also known as "BIOS settings. Once CMOSRAM chip on the computer's configuration information is incorrect, the light will make the system overall operating performance, the soft hard drive parts does not recognize the serious is resulting in a system of hardware and software failures.

3.POST post

The power of computer press pass, the system first by POST (PowerOnSelfTest, post) program to check the internal devices. Usually the complete POST post will include CPU, memory, 1M 640K basic more extended memory, ROM, motherboard, CMOS memory, serial and parallel communication, display cards, the soft hard disk subsystem and the keyboard to test, once found in the post, the system will prompt you for information or whistle warning.

4.BIOS system start bootstrapping program

System to complete the POST after post in accordance with the first ROMBIOS CMOS settings saved in the system boot sequence search soft hard disk drive and CD-ROM, network, servers, and so effectively reads the operating system boot drive, boot records, and the system control to the boot record, and the boot record to complete the system of smooth start.

What is CMOS?

CMOS (purported means complementary metal oxide semiconductor storage the lodge, is a large-scale application in integrated circuit chip manufacturing of raw materials) is a computerized Board on both readable and writable RAM chip, mainly used to save the current system's hardware configuration and operations staff on the setting of certain parameters. CMOSRAM chip from the system through a back-up battery, it is in a shutdown state, or in the event of system power down, CMOS information will not be lost.

Because CMOSRAM chip itself is a piece of memory, only have to save the data of the function, so all the parameters in the CMOS setting through specialized programs. Early in the CMOS Setup program reside on a floppy disk (such as the IBM PC/AT models), use very inconvenient. Now most manufacturers will do CMOS Setup, BIOS chip in the boot time by pressing a specific key to access the CMOS Setup program and very easy to set up the system, so that the CMOS Setup and is usually called the BIOS settings.

BIOS settings and CMOS settings differences and relations

BIOS is a EPROM on the motherboard or EEPROM chips, which is equipped with a system of important information and setting system parameters of the Setup program (BIOSSetup program); CMOS is the motherboard of a readable and writable RAM chip, it contained on the system configuration of specific parameters, the content available through the Setup program for reading and writing. CMOSRAM chip on back-up battery power, even if the system power off after the information is not lost. BIOS and CMOS is both relevant and different: the BIOS system setup program is completed CMOS parameter settings; CMOSRAM is both a BIOS setting system parameters of storage places, and a BIOS setting system parameters. Therefore, the complete argument should be "through the BIOS Setup program is set to CMOS parameters". Since the BIOS and CMOS are beginning with system settings and dense, so in practice associated with the process resulted in the BIOS settings and CMOS settings, actually refers to is the same thing, but the BIOS and CMOS are two completely different concepts, not to get confused.

When you want to set the BIOS or CMOS?
BR > is well known for the BIOS or CMOS settings are determined by the operator based on microprocessor and artificial completed a very important system initialization. In the following cases, you must set the BIOS or CMOS:

1. new computer

Even with PnP functionality of the system can only identify the part of computer peripherals, and the soft hard disk parameters, current date, clock, and other basic information must be set by the operator, the new computer must be purchased through the CMOS parameter is set to tell the system your entire computer's basic configuration.

2. additional equipment

Since the system may not recognize the new device, you must pass the CMOS settings to tell it. In addition, once the new equipment with original equipment between IRQ, DMA conflicts, often require a BIOS setting to be excluded.

3.CMOS accidental data loss

In the system backup battery failure, virus has damaged the CMOS data program, unexpected clear CMOS parameter, for example, if often cause CMOS accidental data loss. You can only enter the BIOS Setup program again to complete the new CMOS parameter settings.

4. system tuning

For memory read and write latency, hard drive data transfer mode, the external Cache within/use, energy-saving protection, power management, power up the boot sequence and other parameters in the BIOS settings on the target system is not necessarily the best, and often requires repeated to experiment to find the best combination of system optimization.