The Main components of today’s computer hardware are a monitor or visual display unit (VDU), a keyboard, the computer itself (the hard disk), a mouse, a disc drive, a CD drive, speakers, a microphone and a printer.
The VDU and printer are output devices. Signals from the computer go to them so that you can see what the computer has done. Tape and disc drives can act as output devices too. Instead of looking at a document on the screen, or printing it on paper, you can record it as signals on tape or disk for use at a later date. Recording material in this way is call storing or saving.
The keyboard is an input device – it allows you to feed in programs and data. Tape and disk drives can also act as input devices. They allow you to feed in programs and information from a magnetic tape or disk. Such signals are stored as electronic patterns in the computers random access memory (RAM). This is a temporary electronic store. The computer also has a read-only memory (ROM). This is a permanent electronic store and contains information the computer needs in order to work. For example, part of the ROM may contain details of how to form images of numerals and letters for display on the screen. Computers store programs and data in binary codes consisting of groups called bytes or bits. Both the RAM and ROM are in their form of one or more integrated circuits (ICs). The IC organizing the working of the computer is called a microprocessor.
Most computers today use a micro processing chip that is called Pentium. The speed of a processor is measured in Megahertz (MHz). The higher the number the faster the processor. Pentiums range from 75 MHz to 200MHz, and by the year 2000 should reach 500MHz. faster processor man not only quick response rates, but also sharper pictures and sound.
Computer Memory capacity has also increased, and other storage device s such as CD-ROM have reached the mass market. CDs are relatively cheap to produce. And much research ahs gone into hits from of storage. The CD-E is about to be launched, the ‘E’ standing for erasable, and the biggest leap forward in CD technology will be the launch of the DVD-ROM. This is a digital versatile disc, which means that the storage capacity will be huge, about 25 times greater than today’s CDs and they will be able to perform an enormous range of functions. DVD-ROM discs need specialized machines, but one day CD films could replace the use of video tapes.
A further range of computer hardware came into being during the early 1990s. These were the portable and palm top computers. Now there are widely used in business. They have their own power source and compare to desktop machines in processing power. Most cost more than a PC, but they can be used anywhere and can even be plugged into a telephone socket for linkage with an office. With this invention and the improvement of telecommunications, more and more people are now working from home.
Software refers to a computers operating system and to the programs that make a computer do particular tasks. The range of software that can run on the home PC is immense, and includes word processing programs, educational packages and leisure activities ranging from interactive games to cookery demonstrations. Today the information superhighway, or ‘internet’, is being used to connect homes and offices across the globe. There are even Cyber cafés, where customers can enjoy a coffee while using the PCs to talk to friends or scan a page from the day’s New York Times.