Getting Acquainted with Personal Computer. Hardware.

Learning to use a personal computer is really no more difficult than learning to drive a car or use a VCR. Contrary to popular opinion, it's difficult to damage a personal computer in normal usage; at the very worst, you might lose something you typed. The two most important things to remember are: (1) take your time and (2) do things carefully. If you follow these two simple guidelines, you'll have very few problems with your personal computer.

We discussed the five data processing steps: input, processing, output, storage, and results. We also learned that a computer system is made up of people, data, procedures, hardware, and software. The computer system utilizes the following four hardware components to perform data processing operations:

■ A system unit, a cabinet that houses the electronic and mechanical components that comprise what we call the computer. This is where the data is input and processed according to the program instructions.

■ Input/output devices or peripherals, such as the keyboard and printer. The keyboard is an input device people use to enter data into the computer for processing. The printer is an output device that gives people a way to see and use the results of the processing.

■ Storage devices, such as disk drives or tape drives to store data for later use. These devices often have removable disks and tapes that actually contain the stored data.

■ Routing and control components, which direct the instructions and/or data from one component to the next, making sure each does its task properly. Some of these components are electronic in nature, and may reside within the system unit; others take the form of cables and other connecting devices.

All computer systems are made up of these four components, whether a personal computer, minicomputer, mainframe, or supercomputer system. The personal computer's system unit usually houses the processing, storage, and routing and control components. In larger computers, each component may be housed in its own refrigerator-sized cabinet; often there are multiple processing and storage cabinets.

In many ways, a computer system is similar to a stereo system. Most component stereo systems have an amplifier (or a receiver). Like the computer's system unit, the amplifier is the central component of the system. The amplifier receives input from a tuner, cassette deck, compact disc player, or turntable. Likewise, the computer's processor receives input from the keyboard. The amplifier processes the input, amplifies it, and then sends it to output devices, such as speakers or headphones. Similarly, the computer's processor sends output to the monitor or printer.

We can also compare the media used with a stereo to computer media. Media refers to the physical material used to store data and instructions. It might be a record, a cassette tape, a floppy disk, or a CD. In both systems, we have some devices that can only play, or read, media. Compact disc players only play CDs but do not record them. But both stereos and computers have other forms of media that can be recorded, or written on, such as tapes and disks. Reading and writing to media are discussed again shortly.

Although there are these similarities between stereo systems and computer systems, there is one big difference. Stereos play music, period. They don't have programs that allow them to perform a variety of tasks, as computers do. They produce sound but they can't switch between doing the payroll, word processing, spreadsheet analysis, inventory control, and organizing the quarterly sales figures.

It's helpful to think of the personal computer as a stereo boom box. All the components — usually excepting the printer, which is similar to the speakers — are contained within the system unit.