Completely Electronic Device

There are many different kinds of com­puters in the world today. Computers are operating at the bank, in your car, and at the grocery store. Many of these computers are special–purpose computers; that is, they serve specific functions. There are also gen­eral–purpose computers in the office, at home, and at school, versatile enough to handle all kinds of tasks. The existence of all these different types of computers raises an im­portant question: What is a computer? Sim­ply put, a computer is a device that proc­esses raw data into useful information. But from that perspective, a typewriter, a calcu­lator, or even an abacus could be called a computer. What distinguishes a computer from other information-processing devices are three basic characteristics:

• A computer is completely electronic. That is, all its functions are carried out with electrical signals.

• A computer can remember informa­tion and hold it for future use. Computers
do this on a temporary basis with memory circuits and permanently with storage de­vices such as magnetic disk and tape.

• A computer is programmable. Unlike other devices built to perform a single func­tion or limited range of functions a compu­ter can be instructed to do whatever task we tell it to do. This opens up a vast realm of possibilities for computers to solve prob­lems for us in everyday life: at home, at school, or at work.

The most common kind of general-pur­pose computer in use today is the personal computer or microcomputer. It gets the name microcomputer from the tiny electronic de­vice, called the microprocessor that does the actual processing. The use of personal computers has grown greatly during the last ten years. Only a few million personal com­puters were in use in 1980, so they were a relative novelty. Now there are almost a hundred million in this country alone.

Answer the questions:

  1. Where are computers operating nowadays?
  2. What is the definition of a computer?
  3. What are three basic characteristics of a computer?
  4. What is the most common kind of general-purpose computer?
  5. How many personal computers (approximately) are there in this country?

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