Overview

You will see a big metal box with a fan on it. That's the power supply. It takes house current (110 volts, alternating) and steps it down to 5 and 12 volts direct current, to supply the computer's needs.

You will see the disk drives. You will also see some large printed circuit boards that plug into long sockets on an even bigger printed circuit board. The big one is on the bottom of a standard desktop case, and on one side of tower and mini-tower cases. It is called the motherboard. The boards that plug into it are called expansion cards.

The motherboard holds the most essential parts of a computer, the Central Processing Unit, called CPU, the RAM and ROM memory, and an assortment of other important parts. The expansion cards contain special circuits for "accessories" such as your monitor, disk drives, and options you might have such as a scanner or modem. On many modern computers, there are fewer expansion cards than in computers from the past, since more functions are now built directly into the motherboard.

Tell Your Friends About this Website

And, please link your web pages to mine.