Powering on the Computer

When you first press the power button, the computer sends a signal to the computer power supply, which converts the alternating current (AC) to a direct current (DC). This supplies the computer and its components with the proper amount of voltage and electricity.

Once the computer and its components have received ample power and the power supply reports no errors it sends a signal (using transistors) to the motherboard and the computer processor (CPU). While this is happening, the processor will clear any leftover data in the memory registers and give the CPU program counter a F000 hexadecimal number. This number is the location of the first instruction and tells the CPU that it's ready to process the instructions contained in the basic input/output system (BIOS).