How Computers Work

By John Bradley

Have you ever wondered how that desktop computer worked? Do you ever wonder how your digital pictures show up on your screen? Well, I’m going to tell you how this all happens in this lovely little article today.

The Computer

Although you may not realize it, computers have an enormous impact on our everyday lives. From supermarket checkouts and offices to cars and jumbo jet, computers are constantly being used to aid us in our daily endeavors.

Computers work by turning information into a stream of electrical pulses. The electrical pulses in the computer are like people working inside it. In computers programs (detailed sets of instructions) are being carried out and calculations are performed with unbelievable speed.

What’s a chip?

No, I’m not talking about potato chips; I’m talking about microchips. A microchip contains thousands or millions of electronic switches, all packed into an extremely small space. By using pulses of electricity, the switches can be turned on or off with lighting speed. Each switch represents one unit of information call a bit. A powerful chip can store and process millions of bits a second. A collection of bits can represent anything from words or music to complex 3d images.

Floppy and Zip™ disks

Zip disks are the newest form of portable media, but they have roots in floppies. They work in the same way as the spinning disk in the hard drive, although they can’t store as much information. They can also be used to transfer information from one computer to another.

CD’s, CD-R’s, and CD-RW’s

These are the newest forms of portable media. They are used in many ways. They replace tapes. They replace floppy disks, but they have one disadvantage. They cannot be written on. But with the recent invention of CD-R’s and CD-RW’s, this has been made possible to the consumer. CD-R’s can be made into music CD’s. There is one disadvantage to it. If you want to add more information to it, it cannot be done. But, with CD-RW’s, if you forgot to put something on it, then you can still add it. You may not be able to make a music CD, but it’s very good for data.

Signals on the move

We aren’t talking about radio signals, but electronic signals. Inside the computer, the different microchips are connected by printed circuits. Electronic signals flash along these circuits almost instantaneously, enabling the computer to process information very quickly.

The hard drive

The hard drive is used to store information, including programs and data files. When activated, a disk inside the hard drive spins at high speed. A special arm moves across it and magnetically reads information from the disk, records new information onto it, or erases unwanted files. A program is able to run only after it has been loaded from the hard drive into the RAM (Random-Access Memory).

Files on the move

A file is a self-contained batch of information. Files are like jigsaw puzzles. Files are assembled in the RAM, then sent to the hard drive for storage.

Random-Access Memory (RAM)

A Random-Access Memory is a microchip that works like a waiting room. It serves as a temporarily store for programs, data, and the results of calculations. Unlike information stored in a Read-Only Memory, the contents of a RAM chip can be changed as often as necessary. When a program is running, this may happen thousands of times a second. The information in the chip is usually lost, however, when the computer’s power supply is switched off.

Read-Only Memory (ROM)

A Read-Only Memory is a microchip that works like a library. It contains basic information needed for the computer to work. This information can be consulted, but it cannot be changed. It remains stored in the microchip even when the power is turned off.

Keeping in time

For the computer to work, it is essential that the different parts stay in sync with one another. A system of electronic clocks makes sure that signals travel from one component to another at exactly the right instant.

Central Processing Unit (CPU)

The central processing unit is the computer’s brain. It follows instructions stored in the RAM and ROM chips and also receives commands and data from input devices, such as a mouse or keyboard. The CPU also controls the signals that are sent to output devices such as a screen or printer.