Computers Basic information: Computing is commonly practised today and in nearly all spheres of life computerization Is on the increase. Computers, mostly PCs, can be found in millions of homes and every major firm makes use of microcomputers , minicomputers and even in some cases, mainframes. All these computers store , process and retrieve large amounts of data, but they differ in size, memory capacity and speed. Computers are used in data – processing departments in business, industry , modern medicine, space exploration and by public authorities – the police, schools , traffic control etc. There is a wide range of applications. 16785fcc98mnh5h For example word processing, stock control , spreadsheet and chemical analysis. An increasing number of people have begun to work from home, using a computer and a telephone modem. Today the software is more user friendly, the hardware more compact. More and more book- size PCs- so called notebooks (previously known as ‘laptops’) are being produced. Although computers are time saving, it takes a while to learn how to work with them: a special programming language is required (e.g. BASIC, PASCAL, or ASSEMBLER). All computers have a central processing unit ( CPU), which processes the data fed into it . A computer does not use digits like 1,2 or 3 for it calculations , but only the two ‘symbols’ or binary digits 0 and 1, the so called bits. The system is called the binary system: a binary number normally consists of eight bits, for example the number one is 0000 0001, number two 0000 000100 and number three 00000 0011 in the binary code. cn785f6198mnnh This combination of eight bits is called one byte. How a large computer works: - to enter /gain access to the system , a code password is required , which can be typed into the computer on the keyboard. - A command is keyed in and the data is entered into the computer from a keyboard , tape or floppy disc/disk (=input) - The microprocessor in the computer performs the logical analyses or the arithmetical calculations, - Data is stored in the computer’s memory system, - The result of the analyses and calculations (= output ) can be printed on paper by the printer, shown in the form of graphics on the monitor ( or VDU) and can be stored on tapes , disks etc. A computer simply follows instructions. No computer can produced useful results if the information/ data put into the computer or programme is inferior or incomplete. In other words, GIGO = Garbage In – Garbage Out. Hacking: A hacker who wants to invade sophisticated data networks illegally - calls up a programme, -breaks into a system by using other people’s passwords, -may even delete a system by means of this kind of electronic infiltration: a’ virus’ ( a destructive programme) that can wipe out a computer’s data files may be planted deliberately. As a result , various antiviral programmes have been invented to detect and delete the viruses. General dangers: - The linking of information from every source available may make it possible to from a complete and accurate picture of every citizen. People may thus become ‘transparent’. - Growing data banks constitute a threat to privacy. Total control over human beings is no longer inconceivable. - Misuse of data or data manipulation is possible: data protection may become more and more difficult , even impossible, to guarantee and supervise.
