Ah, that familiar whir and beep of a computer turning on. So much is happening in there that users only know what not to do: Never interrupt a computer when it’s turning on–don’t unplug it, don’t remove the battery and don’t turn it off immediately. But what is happening that is so fragile? Why is this system so susceptible to destruction if users make a simple mistake during this delicate period of booting up? Well, wonder no more; here’s a peek at what happens when you turn on that precious computer of yours.
When your system is first powered up, there is only one thing the machine is capable of doing. It is programmed to find the Basic Input Output System (BIOS) Read Only Memory (ROM). The computer does this to get started and BIOS takes care of all the rest. BIOS is programmed to seek all the necessary ports, slots, drivers and systems that run the entirety of the hard drive and motherboard. BIOS gives the computer all the necessary code to begin the complete start-up process. Then, the computer takes over again and begins to start itself up. An applicable analogy might be to a car being started up. The battery has stored energy and is meant to get the alternator going. Once the alternator is powered up, the engine starts off of its power. Once the engine is going, the battery is recharged so it is ready to begin the whole process the next time the key is turned.
The computer takes all of these instructions off of the BIOS chip and follows them in order. It inventories all of its equipment and runs self-diagnostic tests as it starts up to ensure it hasn’t suffered any damage. Everything is configured to run according to the specifications programmed into BIOS. Together, your computer and BIOS get the whole system up and running.