Types Of Computer Systems You should be familiar with the differences among computer systems if you want to show a potential employer that you have a fundamental knowledge of computer.Computers come in a variety of sizes and shapes and with a variety of processing capabilities.The earliest computers were quite large because of the crude technologies used;as technological improvements were made in computer can be smaller than a postage stamp. To provide a basis for comparing their capabilities,computers are generally grouped into four basic categories: (1)Supercomputers,which are the powerful giants of the computer world; (2)Mainframe computers, which are large, extremely powerful computers used by many large companies; (3)Minicomputers, which are the next most powerful; (4)Microcomputers, which are the least powerful-but which you most likely will be required to use in business. It's hard to assign a worthwhile definition to each type of computer because definitions can get bogged down in potentially confusing technical jargon. Nevertheless, the following definitions can suffice: (1) A supercomputer can handle gigantic amounts of scientific computation. It’s usually maintained in a special room or environment, and may be about 50,000 times faster than a microcomputer. As a user in business, you probably would not have contact with a supercomputer. However, you might if you worked in the areas of defense and weaponry, weather forecasting, scientific research, at one of several large universities, or for the National Aeronautics and Space Administration. (2) A mainframe computer is a large computer, usually housed in a controlled environment, that can support the processing requirements of hundreds and often thousands of users and computer professionals. If you go to work for an airline, a bank, a large insurance company, a large accounting company, a large university, or the Social Security Administration, you will likely have contact, through your individual workstation, with a mainframe computer. (3) A minicomputer, also known as a midsize or low-end mainframe computer, is similar to but less powerful than a mainframe computer. It can support 2 to about 50 users and computer professionals. Minicomputers and mainframe computers can work much faster than microcomputers and have many storage locations in main memory. Many small and medium-sized companies today use minicomputers, so if you go into the business world, chances are good that you will have contact with minicomputer.
(4) The microcomputer is the type of computer that you undoubtedly will be dealing with as a user. Many readers are probably already familiar with the microcomputer, also known as a personal computer (PC). They vary in size from small portables, and laptop computers that you can carry around like a briefcase, to powerful desktop workstations, such as those used by engineers and scientists. A microcomputer-generally used by only one person at a time-uses a microprocessor chip as its CPU. As small as one quarter of an inch square, a chip is made of silicon, a material made from sand. Silicon is referred to as a semiconductor because it sometimes conducts electricity and sometimes does not (semi means "partly"), depending on applied voltages and added chemical impurities ("dopants").
In general, a computer's type is determined by the following seven factors:
(1) The type of CPU. As noted, microcomputers use microprocessors. The larger computers tend to use CPUs made up of separate, high-speed, sophisticated components.
(2) The amount of main memory the CPU can use. A computer equipped with a large amount of main memory can support more sophisticated programs and can even hold several different programs in memory at same time.
(3) The capacity of storage devices. The larger computer systems tend to be equipped with higher capacity storage devices.
(4) The speed of output devices. The speed of microcomputer output devices tends to be rated in terms of the number of characters per second (cps) that can be printed-usually in tens and hundreds of cps. Larger computers’ output devices are faster and are usually read at speeds of hundreds or thousands of lines that can be printed per minute.
(5) The processing speed in millions of instructions per second (MIPS). The term instruction is used here to describe a basic task the software asks the computer to perform while also identifying the data to be affected. The processing speed of the smaller computers ranges from.7 to 40 MIPS. The speed of large computers can be 30 to 150 MIPS or more, and supercomputers can process more than 200 MIPS. In other words, a mainframe computer can process your data a great deal faster than a microcomputer can.
(6) The number of users that can access the computer at one time. Most small computers can support as many as two or three at a time. Large computers can support hundreds of users simultaneously.
(7) The cost of the computer system. Businesses systems can cost as little as $500(for a microcomputer) or as much as $10 million (for a mainframe)-and much more for a supercomputer.
It's difficult to say exactly what kind of computer you'll be using in the business environment. Some companies use a combination of computers. For instance, a company with branch offices around the country might use a mainframe computer to manage company wide customer data. To access information from the mainframe, the user might use a microcomputer that sits on his or her desktop. In addition to accessing information from the mainframe computer, the microcomputer can be used to perform specialized tasks such as generating invoices or drafting letters to customers. Although it is still relatively easy to find a company that doesn't use a supercomputer, a mainframe, or a minicomputer to process data, it is difficult to locate a company that doesn't use a microcomputer for some of its processing..
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