ЧАСТЬ V. УЧЕБНЫЕ МАТЕРИАЛЫ ДЛЯ ЧТЕНИЯ И ПЕРЕВОДА Text 20
1. Computer can perform many functions: they can do mathematicall and logical operations, mathematical operations including arithmetic and algebraic operations, such as addition, subtraction, multiplication and division, raising to a power, differentiating and integrating. Logical operations include comparing, selecting, sorting and matching.
2. Computers are divided into four main classes: microcomputers, minicomputers, mainframes and supercomputers.
3. A minicomputer is a computer manufactured on a single printed board which contains one or more chips. Most microcomputers are personal computers. At present personal computers have become so powerful that they are used as CAD/CAM systems.
4. A microprocessor is a very small device used in microcomputers, which deals with memories by reading and writing process. Microprocessors can obtain from memory and execute a limited set of instructions in order to perform addition or subtraction on a binary word, and to input or output binary data.
5. Memory is a device for storing digital information. Memory should be small in size and large in capacity. It should take little power and work at the same speed as computer logic. There are many types of memories. All microcomputers use Random Access Memory (RAM) and Read Only Memory (ROM).
6. RAM is called so because information can be put into or out of any single byte of memory. ROM is permanent memory forprogram storage.
7. People know many types of memory units, hard disks and floppy disks being widely used. Floppy disks (flexible plastic disks) are used in personal computers.