Реферат: Digital computers

Digital computers can be divided into three main types, depending on their size and power: mainframes, minicomputers and microcomputers.

“Mainframes” are the largest and most powerful computers. The basic configuration of a mainframe consists of a central system which processes immense amounts of data very quickly. This central system provides data information and computing facilities for hundreds of terminals connected together in a network. Mainframes are used by large companies, factories and universities.

“Minicomputers” are smaller and less powerful than mainframes. They can handle multitasking, that is, they can perform more than one task at the same time. Minicomputers are mainly used as file servers for terminals. Typical applications include academic computing, software engineering and other sophisticated applications in which many users share resources.

“Microcomputers” are smaller than mainframes and minis, and carry out their processing on a single microchip. They are used as personal computers in the home or as workstations for group work. Examples of micros are the IBM PC or the Apple Macintosh. Broadly speaking, there two classes of personal computers: (a) desktop PCs, which are designed to be placed on your desk, and (b) portable PCs, which can be as tiny as a notebook. This is why they are also called “notebooks” and “laptops”. These are the smallest and least powerful computers, but the latest models can run as fast as similar desktop computers and can have similar configurations. They are ideal for business executives who travel a lot.