Basic Input
Output System


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BIOS or Basic Input Output System

BIOS with out it your computer wouldn't do 1/1000th of the things it does today...

What is it Anyway? Why do I need it? Do I care?

Well if you want your computer to start you need it. With out the BIOS (Basic Input Output System) you would not be able to use your computer, no keyboard, no video, no mouse, you get the picture.

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Screen shot of Phoenix BIOS, VM Ware virtual machine.

Basic Input Output System. This is a small program that starts your computer when you power it up and sets the parameters for all the devices, memory ranges and processor specifications. For older computers and Main Frames it was called a Boot Strap program, it pulled the computer up by it's "boot straps" (weird eh?) So now when you talk to a computer 'Geek' they don't say start your computer or power your computer up, or turn on your computer they say 'Boot your computer'. Makes ya want to kick the darn thing.

When computers were in their infancy the Basic Input Output System program was on a tape or floppy disk, you had to have this tape in the tape drive or floppy disk in the floppy disk drive when you powered up the computer or all you would see on the video screen was a flashing -, the cursor. And no matter what you typed on the keyboard the - would not  change.

With the advent of the IC (Integrated Circuit) chip, and a special chip called CMOS (Complementary Metal Oxide Semiconductor ) the little program that was on the floppy disk could be stored inside the computer. Now when you powered up the computer you would get more action out of the flashing -, the prompt. But still this did not get you where you needed to go. You still have to load a program called an Operating System ( OS ). The Basic Input Output System tells the processor where to look for the code to start loading the OS, then you are ready to use the computer. Not to be nostalgic but back in the day of the 8086 and 286 computers took longer to load a much smaller Basic Input Output System and OS. It may not seem like it is fast but believe me that then you could literally drink a cup of coffee while the computer went through the startup procedure.

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The Basic Input Output System is a machine (or Binary) coded program. Machine code is the tightest code with the fewest frills and is very compact. To create the program requires special training and logical skills. This program is 'complied' to create the code which is in turn 'burned' into the CMOS Chip that is on your motherboard.

Newer motherboards use what is called a 'Flash' chip for the Basic Input Output System program. In essence the 'Flash' Chip is like the small USB drive you have in your pocket. It takes a special file and program to change the BIOS or update the one currently in the flash chip on your motherboard.

So what exactly is in the 'Basic Input Output System' program anyway?

The Basic Input Output System program contains parameters and data pertinent to the operation of your motherboard. The time and date, the hard drive or drives specifications, your cd or dvd rom drive specifications. And most importantly information and parameters about the processor installed on the motherboard. Also information about the memory, serial ports (USB), parallel ports, the keyboard type, and sometimes the mouse type (such as laptops that have different types of pointing devices). It will also list the interrupts and DMA (Direct Memory Access) settings. 

Why do you care about the Basic Input Output System?

Well you don't have to care, I mean if you don't change any hardware components or want to 'Overclock' your processor then all you would care about the BIOS is that it is up to date.

On the other hand if you add a hard drive, cd/dvd rom drive, memory, or an add-on card you would want to go in to the Basic Input Output System and insure that the motherboard sees the new item. (If you add a new component and the Basic Input Output System does not 'see' and read the parameters then when you power up the computer it will not initialize or start).

If you are having problems with one device you can look at and change the Interrupt. (An interrupt is a code that tells the processor that the device wants to function or that the processor has information to send to the device). If you don't use a parallel printer you can disable this port. If you want to use all the interrupts for the serial ports for something else you can disable them.

If you want to 'Overclock' your processor the Basic Input Output System is where you would make the changes. A word of caution here about 'Overclocking' you processor: YOU CAN DESTROY THE PROCESSOR! with the wrong settings.

So poking around in the BIOS can and will cause you problems, on the other hand knowing the parameters that are present in the Basic Input Output System can assist you when you are troubleshooting a problem or add a device to the computer.

How do you get into the Basic Input Output System setup?

Depends on the Basic Input Output System publisher. For ASUS motherboards it is the 'Del' key at start up. For IBM's it is the F1 key at startup. For HP and older Compaq systems it is the F10 key at startup. Dell laptops it was the 'Alt' plus the 'A' key at start up. Check your users manual that came with your motherboard or computer or check the manufactures web site for the key press to get to the BIOS setup.

Updating the Basic Input Output System.

Sometimes it is necessary to update the Basic Input Output System, this is called a 'Firmware' update. This is a special file that requires a special program to re-program the Basic Input Output System chip. The format for the file will more than likely be a 'bin' or binary type file. You would go to the motherboard or computer manufactures web site, enter the make and model of you motherboard or computer and search for "BIOS updates".

The web site should give you a list of current and past Basic Input Output System binary files and the program that you would use to re-program the Basic Input Output System chip.

Newer motherboards have what is called a 'Flash' chip in place of the older CMOS chips.

The older CMOS chips required two pieces of equipment to program it, a burner and an eraser. The EEPROM burner as it was called would program the chip, the EEPROM Eraser, as it was called used an Ultra Violet light to remove the previous program from the chip.

The 'Flash' chip takes advantage of the newer chip designs that retain the data programmed into it when power is removed. It takes a special program that allows the chip to be erased and re-programmed to update the Basic Input Output System program.

To use the program you need to have a DOS boot floppy drive or a DOS bootable USB device because the program has to operate in a mode that allows it access to the hardware, Windows does not allow this access.

Normally there will be a readme.txt or some information file that will assist you in re-programming the BIOS Flash chip. Follow the instructions or you may be sending the computer or motherboard back to the manufacture to have the Basic Input Output System changed.

So now you know what a BIOS is and why you don't kick yer computer when you 'Boot' it.

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