BIOS explanation: What is the BIOS? What is the role of BIOS? CMOS and its relationship to the BIOS?

1. What is the BIOS ?

The BIOS is an abbreviation for the English basic input output system, and the Chinese name is the basic input and output systems after translation. Its full name should be Rom-bios, meaning read-only memory basic input/output system. In fact, it is a set of solidified into the computer board on a ROM chip program, it holds the most important basic input and output of the computer program, System setup information, power on the self-test program and the system startup bootstrap program. Some people think that since the BIOS is a program, it should belong to the software, it feels like a common word or Excel. But many people do not think so, because it and the general software there are some differences, and it is also closely related to hardware. Visually speaking, the BIOS should be a bridge between the software program and the hardware, which is responsible for the immediate requirements of the hardware. A motherboard performance is superior or not, to a large extent depends on the BIOS program management function is reasonable, advanced. The BIOS chip on the motherboard may be the only chip on the motherboard that is labeled with a label, typically a 32-pin, dual-inline integrated circuit with the BIOS lettering printed on it. More than 586 of the previous BIOS is a rewritable EPROM chip, the above label plays the role of protecting the BIOS content (ultraviolet irradiation will make the EPROM content lost), can not be arbitrarily torn off. 586 later ROM BIOS use EEPROM (electrically erasable read ROM), through the jumper switch and the system with the driver disk, EEPROM can be rewritten to facilitate the implementation of the BIOS upgrade. The common BIOS chip has award, AMI, Phoenix, Mr, etc., can see the manufacturer's mark on the chip.

2,the role of the main role of the BIOS has the following aspects:
The first is the self-test and initialization program: After the computer power is switched on, the system will have a process for inspecting the internal devices, which is a function of the BIOS program, which is usually called post (Power On Self test/) program. The complete self-test includes tests on CPUs, 640K of basic memory, expanded memory above 1M, ROM, motherboard, CMOS memory, serial and display cards, soft and hard plate systems and keyboards. 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 follow the system in the boot sequence in the CMOS setup to search for a valid boot drive such as soft, hard disk drive and CDROM, network server and so on, read into the operating system boot record, and then give the system control to the boot record, the boot record to complete the system startup, You'll be able to use your baby with confidence. The second is the hardware interrupt processing: When the computer boot, the BIOS will tell the CPU and other hardware device interrupt number, when you enter the use of a hardware command, it will be based on the interrupt number using the appropriate hardware to complete the command, and finally according to its break number jumps will be the original state. Then there is the program service request: From the definition of the BIOS can know that it always with the computer's input, it through the most specific data port issued instructions, send or receive data from various external devices, so as to achieve software application hardware operation.

    a lot of friends confused the BIOS and CMOS concept, here to talk to you about CMOS and its relationship to bios :
 
     CMOS is the abbreviation of Complementary metal oxide semiconductor, the original meaning of the translation is complementary metal oxide semiconductor memory, Refers to a large-scale application of integrated circuit chip manufacturing raw materials. But the exact meaning of CMOS here is a battery-powered, read-and-write RAM chip used in most computers today. And the meaning of the BIOS we have explained in the previous.
So, what does CMOS have to do with bios? CMOS is a memory chip, of course, belongs to 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 the data set, to the CMOS parameters in the setting of the special set of procedures. Now most manufacturers will be the CMOS parameter setup program to the BIOS chip, the computer when the power is turned on by special keys to enter the Setup program can be easily set up the system. That is, the system Setup program in the BIOS is

The CMOS memory chip can be powered by the motherboard's battery, and even if the system loses power, the stored data is not lost. But what happens if I get rid of the battery? Good question! If the battery is out of power, or if it comes into contact with a problem, or if you take him down, the CMOS loses all the data inside the store because of a power outage. But if this happens, it is not a big problem, you can change the battery, or check the cause of poor contact, in short, to ensure that the CMOS power. Then boot into the BIOS program, select the main menu string 7
Load BIOS defaults or load SETUP defaults enter, and finally confirm the input y return. You may have heard other players have talked about if you forget the power-on password to the CMOS discharge, in fact, including the password to discard all the information, the boot will not need to enter the password, and then to re-write data. String 3

4, upgrade the meaning of the BIOS

There are usually several reasons to upgrade the BIOS:

(1) Provide support for new hardware or technical specifications.

Computer hardware technology development too fast, the motherboard for some new hardware (such as K6-III Celeron II CPU) or new technology (such as DMA100, DMA66, more than 35GB hard disk, etc.) did not correctly identify or provide support, You will need to upgrade the BIOS to gain support for new hardware or technology.

(2) Resolve the bug in the old version of the BIOS. String 6

(3) solve the 2000 problem. Many motherboards produced before 1997 have 2000 problems, while some new motherboards have resolved the 2000 issue, but under the individual Y2K test software can not be passed, these issues can be resolved by upgrading the BIOS

5, what kind of bios can upgrade

Observe the BIOS chip on your motherboard (typically a 28-pin or 32-pin dual-inline integrated circuit with BIOS lettering), which is mostly award or AMI products. Remove the label from the BIOS chip and you will see the number of the BIOS chip. For some motherboards, manufacturers use a non-upgradeable BIOS for cost savings. Of course, you can also directly check the motherboard manual to see if there is a motherboard BIOS can be upgraded instructions. However, even if there is no explanation on the motherboard manual, do not lose heart, you can try it out for yourself. Because not all motherboards write this feature on the manual.

Here we need to understand the following concepts, in order to be able to more fully understand the BIOS-related knowledge, of course, can also be used to boast in front of friends, hehe. Word 3

(1) PROM: This is the abbreviation for the English programmable read-only memory, which is a memory chip that cannot be modified once the content is written, and the contents will not disappear after the main body is dropped. Prom and ROM differ in the factory, prom is a blank content of the chip, and Rom factory, where the content has been written. To write to the prom, you need a tool called the Prom programmer, which is also called a prom burner, and the process of writing content to the prom is called Burn-write.

(2) EPROM: This is an abbreviation of the English erasable programmable read-only memory, which is a special prom chip that can erase the contents of the ultraviolet rays. Once the content is erased, you can re-write the new content.

(3) EEPROM: This is an English erasable programmable read-only memory, which can be used in the use of electricity-related means to erase the content of the write. As with other prom, the content will not disappear if the host loses power.

6, sometimes the system fails, and can not be displayed, we need to interpret the PC Speaker "language" to analyze the cause of the failure.

Therefore, to understand the "language" of PC speakers is still very important, below please see our post Bell code meaning parsing string 6

1.CMOS Battery failed (CMOS battery fails).

Reason: The power of the CMOS battery is insufficient, please replace the new battery. String 7

2.CMOS Check sum error-defaults loaded (CMOS performs all checks when errors are found, so load the preset system setpoint).

Cause: This usually happens because the battery is low on electricity, so try changing the battery first. If the problem persists, then there may be a problem with the CMOS RAM, preferably sent back to the original processing. String 2

3.Display switch is set incorrectly (display switch configuration error).

Cause: The older motherboard has jumpers to set the display as monochrome or color, and this error indicates that the settings on the motherboard are inconsistent with the settings in the BIOS and can be re-set.

4.Press ESC to skip memory test (can be skipped by pressing the ESC key).

Cause: If you do not set a fast power-up self-test in the BIOS, then the boot will perform a memory test, if you do not want to wait, you can press the ESC key to skip or into the BIOS to open the quick Power on the auto test.

5.HARD disk Initializing "Please wait a moment ..." (The hard disk is initializing for a moment).

String 9

Cause: This problem is not visible at all on newer hard drives. But on older hard drives, it starts slower, so this problem occurs.

6.HARD Disk Install FAILURE (hard disk installation failed). String 8

Cause: The power cord of the hard drive, the data cable may not be connected, or the hard drive jumper is wrong (for example, two hard drives on a data cable are set to Master or Slave. )

7.Secondary slave hard Fail (detects slave disk failure).

Cause: 1 The CMOS settings are improper (for example, there is no slave disk but there is a slave in the CMOS) 2 hard drive power cord, the data cable may not be connected or the hard drive jumper is set improperly.

8.Hard disk (s) diagnosis fail (error occurred while performing hard drive diagnostics).

Cause: This usually represents a failure of the hard disk itself. You can try it on another computer first, if the problem is the same, it has to be repaired. String 8

9.Floppy disk (s) fail or floppy disk (s) fail (80) or floppy disk (s) fail (40) (floppy drive cannot be driven).

Cause: Is the floppy cable connection wrong or loose? is the power cord connected? If that's all right, then buy a new one.

10.Keyboard error or no Keyboard present (keyboard wrong or missed keyboard)

Cause: Is the keyboard cable plugged in? Is the cable damaged? String 7

11.Memory test fail (memory detection failed)

Cause: This is usually caused by a memory incompatibility or a failure. String 5

12.Override Enable-defaults Loaded (current CMOS setting does not boot system, load BIOS preset to boot system).

Reason: It may be that your settings in the BIOS are not suitable for your computer (like your memory can only run 100MHz but you let it run 133MHz), then enter the BIOS settings to readjust.

13.Press tab to show POST screens (press TAB to toggle on-screen display) string 4

Cause: Some OEMs will replace the BIOS preset display screen with their own design, which
Show that the user can press TAB to switch between the manufacturer's custom screen and the BIOS preset boot screen.

14.Resuming from Disk,press tab to show post screen (resume boot from hard drive, press TAB to open
Machine self-test screen). String 9

Cause: Some motherboard BIOS provides the Suspend to disk (suspend to disk) function, when the user is Suspend to disk's way to shut down, then the next time you turn on the display this prompt message.

In the event of a computer malfunction, the machine rings continuously. At this time, if you are a master, may be based on experience to determine the fault, if the experience can not be judged, or you know nothing about hardware equipment, then only to consult a professional. Because of a computer failure, after the boot only machine error ring, can not find the point of failure, had to surf the internet to check the meaning of the PC self-Test bell code, the final code to find the exact location of the fault and exclude it. Good things dare not to be concealed, special recommendation to you, I hope you can accurately determine the fault where, when a master.

This article describes the specific meaning of the post Bell code in the more common three BIOS (award BIOS, AMI BIOS, and Phoenix BIOS) computers (the BIOS model used by the computer can be seen from the BIOS chip or from the post information.  If you see the word ami as the AMI BIOS, see Award as the award BIOS). String 9

One, award BIOS self-Test bell meaning:

1 Short: The system starts normally. Congratulations, there's nothing wrong with your machine.
2 short: General error, please go to CMOS setup and reset the incorrect option.
1 long 1 short: Error in RAM or motherboard. To change a memory try, if still not, had to replace the motherboard.
1 long 2 short: Incorrect display or display card.
1 Long 3 short: Keyboard controller error. Check the motherboard.
1 Long 9 short: motherboard Flash RAM or EPROM error, bios corrupted. Try swapping flash RAM.
constant Ringing (long sound): The memory strip is not plugged in or damaged. Reseat the memory bar, if not, only replace one memory.
Keep ringing: power, monitor is not connected to the display card. Check all the plugs.
Repeat short ring: there is a problem with the power supply.
no sound no display: There is a problem with the power supply.  Second, the AMI BIOS self-test bell meaning:

1 Short: Memory refresh failed. Replace the memory bar.
2 Short: Memory ECC is more error-tested. In CMOS setup, the option to set the memory about ECC checksum to disabled can be resolved, but the most fundamental solution is to replace a memory.
3 Short: System basic Memory (1th 64kB) check failed. Change the memory.
4 Short: System clock error.
5 Short: Central processing unit (CPU) error.
6 Short: Keyboard controller error.
7 short: System Real mode error, cannot switch to protected mode.
8 Short: Memory error is displayed. Display memory problems, replace the video card to try.
9 Short: ROM BIOS check and error.
1 Long 3 short: Memory error. Memory corruption, replacement can be.
1 Long 8 short: Displays Test errors. The display data cable is not plugged in or the card is not plugged in.

BIOS explanation: What is the BIOS? What is the role of BIOS? CMOS and its relationship to the BIOS?