Putting the boot in on your PC
Yet another techno-word for you, is ?boot?, which is a historical word for the operating system load process that takes your PC from a bunch of wires and silicon into an intelligent item of technology.
Today, we?re going to start looking at the boot process so that you will understand what your PC is doing during those two or three minutes from switch on when it is unuseable. Firstly, the name boot comes from the good old days of computing, when the boot media (which in our case, now is the Hard Disk Drive), was a separate item of hardware, which was removed from the computer once it was up and running.
This boot-media was so called because it was very heavy, and was about the size of a man?s football boot. In addition, it was connected to the computer and held in place with a strap, hence the other, similar term, ?bootstrap?. In those days, if a computer needed to be reloaded, the boot would have to be found and attached ? thus the system was re-booted.
So, what happens when you switch on? Well first, you need to be aware of a slightly complex couple of items of equipment, held on the motherboard. Meet BIOS and CMOS. CMOS stands for complementary metal-oxide semiconductor, and is a semiconductor chip held on your motherboard which holds certain critical system information. BIOS stands for Basic Input Output System and holds the basic instructions for booting and controlling the low-level hardware of your computer, and, it runs on the CMOS chip. They are completely separate from your PC processor, but they control the initial boot process.
First thing that happens, is that the BIOS initiates a POST (Power On Self Test), which will check that the items that are connected to the motherboard are all working (at this stage, working simply means that they are receiving an electrical current and are responding accordingly). If your PC completes its POST, you will often hear one or two beeps from the motherboard, indicating it has moved to the next stage of the boot process. If it fails POST, it is often the case that there will be a motherboard ?beep code? ? that is a succession of beeps, much the same as Morse Code ? make a note of them and refer to your owners manual or IT specialist, as these codes often mean something has failed or become disconnected, and you can often determine which from the beep code.
If your PC completes POST, it will move on to ascertaining the boot-sequence. The boot-sequence is a configurable option which allows you to determine which peripherals the PC is permitted to boot from, and which the BIOS should go to first, then second, and so on. The options available are the floppy-disk drive; the hard-drive; the CD-drive; the network card; It is quite common for these to have been set incorrectly, such that your computer might not boot, even though it can. These things are changed within the BIOS, and you can gain access to the BIOS at initial boot ? almost as soon as you turn on your computer ? by pressing down the ?F2? (or on some F12) key. Let me caution you not to play around with the BIOS unless you are sure what you are doing. Nevertheless, knowing of its existence will help you understand what is going on.
From within the BIOS, you can control many elements of your computers low-level hardware: You can enable and disable certain connections, set or reset the system clock, and of course, as we are dealing with here, alter the boot sequence. Once you have located the boot-sequence information within the BIOS, altering the boot sequence is usually a simple matter of following the instructions to move each of the bootable devices up or down the boot-sequence. Once done, you will have to save your changes to the CMOS chip and the PC will reboot again, this time, following your new sequence settings. Let me stress again that unless you really know what you?re doing you should stay out of the BIOS as you can cause a lot of problems by changing things.
Next time, we?ll look a little closer at the BIOS and then move onto the next parts of the boot process.
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