PC Hardware Cont.............

Software

The physical parts of as computer are called hardware. These are things you can see and touch, and yes, they are hard.

These same pieces of hardware are used whether you want to write a letter, balance your checkbook or play a game of computer solitaire, so how does this hardware know what to do, and when to do it? Actually, the hardware parts don't have a clue. They need instructions to tell them what to do, so some of that information we're storing and processing must be the instructions telling the computer what to do.

These instructions are called software, and they are organized into sets of instructions called programs. If you want to play a game on the computer, the computer must have a program with the instructions for that particular game. If you want to send e-mail, there must be an e-mail program.

One program called the operating system contains the instructions for actually running the computer. Certain things need to be done no matter what you are using the computer for. These are things like getting data on and off the disk, getting information to the monitor screen, and so forth. A program called Windows is the most common operating systems for PCs, and the one used in this office.It comes from a little company called Microsoft. Perhaps you have heard of it.

Anyway, the operating system takes care of the basic details of running the computer, and allows other programs to concentrate on their particular tasks. These other programs are called applications, because their job is to apply the computer to a specific task. When we say software, that can mean the applications, the operating system, or both.

There are other little chunks of software that attach to the operating system and tell it how to run particular hardware components or applications. These little chunks are called drivers, and anytime you add a piece of hardware to a system or upgrade to a new version of a device, you will need to have the right driver for that new piece of hardware.

Circuits

The word 'circuit' means a path something follows that goes back to where it started. In an electrical or electronic circuit, the thing following the path is of course electricity. Whatever work it does and whatever components it must go through on the way, the 'circuit' just means there is a complete path back to the starting point. The word 'circuitry' means the components, and the connections between them, that make up the path. It's as simple as that.

In a computer, this word 'circuit' shows up in a couple of places. Most of the components will be found soldered to a 'circuit board', also called a printed circuit board. This is a thin board of fiberglass, with the connections between components (called traces) printed right on the board in copper.

The components themselves are often something called an Integrated Circuit, abbreviated IC. To integrate means to combine things together, so an integrated circuit is one that combines many circuits into the same part. These are formed on a thin wafer or 'chip' of silicon, and you will sometimes hear an IC being called a 'chip'. This is also where we get the name 'Silicon Valley', for the area in Central California where many of them are made.

This chip of silicon is put into a case with metal legs, and tiny wires between the wafer and the legs connect those circuits with the outside world. There are now ICs containing millions of transistors and other components, all in a package that will fit in your palm with lots of room to spare.