2. Analyze grammar in the underlined words and word combinations (in writing).

2. Make up 5 questions of different types to the text (in writing). Text 23

1. Read and translate the text in writing.

The beginning of electric telegraphy

The electric telegraph did not burst suddenly upon the scene but rather resulted from a scientific evolution that had been taking place since the 18th century in the field of electricity. One of the key developments was the invention of the voltaic cell in 1800 by Alessandro Volta of Italy. This made it possible to power electric devices in a more effective manner using relatively low voltages and high currents. Previous methods of producing electricity employed frictional generation of static electricity, which led to high voltages and low currents. Many devices incorporating high-voltage static electricity and various detectors such as pith balls and sparks were proposed for use in telegraphic systems. All were unsuccessful, however, because the severe losses in the transmission wires, particularly in bad weather, limited reliable operation to relatively short distances. Application of the battery to telegraphy was made possible by several further developments in the new science of electromagnetism.

In 1820 Hans Christian Orsted of Denmark discovered that a magnetic needle could be deflected by a wire carrying an electric current. In 1825 in Britain William Sturgeon discovered the multiturn electromagnet, and in 1831 Michael Faraday of Britain and Joseph Henry of the United States refined the science of electromagnetism sufficiently to make it possible to design practical electromagnetic devices. The first two practical electric telegraphs appeared at almost the same time. In 1837 the British inventors Sir William Fothergill Cooke and Sir Charles Wheatstone obtained a patent on a telegraph system that employed six wires and actuated five needle pointers attached to five galvanoscopes at the receiver. If currents were sent through the proper wires, the needles could be made to point to specific letters and numbers on their mounting plate. In 1832 Samuel F.B. Morse, a professor of painting and sculpture at the University of the City of New York (later New York University), became interested in the possibility of electric telegraphy and made sketches of ideas for such a system.

2. Analyze grammar in the underlined words and word combinations (in writing).

2. Make up 5 questions of different types to the text (in writing). Text 24

1. Read and translate the text in writing.

System Board

The system board is also called the motherboard. It con­sists of a flat board that usually contains the CPU and some memory chips. A chip consists of a tiny circuit board etched on a small square of sand like material called silicon. A chip is also called a silicon chip, semiconductor, or integrated circuit. Chips are mounted on carrier packages, which then plug into sockets on the system board. In addition, system boards usually contain expansion slots.

Microprocessor Chips

In a microcomputer, the CPU is contained on a single silicon chip called the micro­processor—"microscopic processor." Different microprocessors have different capabilities.

Some chips or "families" of chips have become famous as the basis for several important lines of microcomputers. However, they are known by distinctly undramatic names: Their names are just their product numbers.

Chip capacities are often expressed in word sizes. A word is the number of bits (such as 16, 32, or 64) that can be accessed at one time by the CPU. The more bits in a word, the more powerful - and the faster - the computer. A 32-bit-word com­puter can access 4 bytes at a time. A 64-bit-word computer can access 8 bytes at a time. Therefore, the 64-bit computer is faster.

Microcomputers process data and instructions in millionths of a second, or microseconds. Supercomputers, by contrast, operate at speeds measured in nanoseconds and even picoseconds - 1 thousand to 1 million times as fast as microcomputers.

As we mentioned, the growing power of microprocessor chips is what is chang­ing everything about microcomputers. Intel's Pentium Pro chip, for example, is twice as powerful as its predecessor. Intel's new microprocessor, code-named P55C, promises multimedia capabilities that far exceed the Pentium Pro. Motorola's Power PC chip used in Apple's Power PC Macintosh 710 is four times faster than its predecessor.