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MY LAPTOP CONFIGURATION
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TYPES OF OPERATING SYSTEMS
1. 1. Multiprocessing operating systems allow for the use of more than one central processing unit (CPUs) within one computer system. The CPUs within the computer can be equal, or they can have specific purposes and functions. If processors are tightly coupled, they will usually share a single memory base, whereas if the CPUs are loosely coupled, they will have separate memory bases that are connected via a high speed connection.
2.A multiuser operating system allows a number of users to access the material on one particular server at the same time. This is beneficial for use in companies and businesses, as the server can be accessed by remote users – ideal for workers who travel or work from home. The multi-task operating system is another name for this concept, although multi-tasking operating systems can also be used to refer to batch processing systems for mainframe computers in large companies or organizations.
3. A multithreaded operating system allows the computer to undertake more than one unit of processing at one time. This is beneficial as problematic processes, or threads, will not prevent the success of straightforward threads. However, executing too many threads at one time can cause the treads to interfere with each other.
4. A real-time operating system must have a pre-known maximum time limit for each of the functions to be performed on the computer. A hard real-time operating system can completely guarantee the maximum amount of time that a process will take, whereas a soft real-time operating system may only be able to guarantee this time limit occasionally.
CLASSIFICATION BY GENERATION
The First Generation: 1946-1958 (The Vacuum Tube Years)
The first generation computers were huge, slow, expensive, and often undependable. In 1946
two Americans, Presper Eckert, and John Mauchly built the ENIAC electronic computer which used vacuum tubes instead of the mechanical switches of the Mark I. The ENIAC used thousands of vacuum tubes, which took up a lot of space and gave off a great deal of heat just like light bulbs do. The ENIAC led to other vacuum tube type computers like the EDVAC (Electronic Discrete Variable Automatic Computer) and the UNIVAC I (Universal Automatic Computer).
The vacuum tube was an extremely important step in the advancement of computers. Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs. It’s purpose was to act like an amplifier and a switch. Without any moving parts, vacuum tubes could take very weak signals and make the signal stronger (amplify it). Vacuum tubes could also stop and start the flow of electricity instantly (switch). These two properties made the ENIAC computer possible.
The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners. However even with these huge coolers, vacuum tubes still overheated regularly. It was time for something new.
The Second Generation: 1959-1964 (The Era of the Transistor)
The transistor computer did not last as long as the vacuum tube computer lasted, but it was no less important in the advancement of computer technology. In 1947 three scientists, John Bardeen, William Shockley, and Walter Brattain working at AT&T’s Bell Labs invented what would replace the vacuum tube forever.This invention was the transistor which functions like a vacuum tube in that it can be used to relay and switch electronic signals.
There were obvious differences between the transisitor and the vacuum tube. The transistor was faster, more reliable, smaller, and much cheaper to build than a vacuum tube. One transistor replaced the equivalent of 40 vacuum tubes. These transistors were made of solid material, some of which is silicon, an abundant element (second only to oxygen) found in beach sand and glass. Therefore they were very cheap to produce. Transistors were found to conduct electricity faster and better than vacuum tubes. They were also much smaller and gave off virtually no heat compared to vacuum tubes. Their use marked a new beginning for the computer. Without this invention, space travel in the 1960’s would not have been possible. However, a new invention would even further advance our ability to use computers.
The Third Generation: 1965-1970 (Integrated Circuits – Miniaturizing the Computer)
Transistors were a tremendous breakthrough in advancing the computer. However no one could predict that thousands even now millions of transistors (circuits) could be compacted in such a small space. The integrated circuit, or as it is sometimes referred to as semiconductor chip, packs a huge number of transistors onto a single wafer of silicon. Robert Noyce of Fairchild Corporation and Jack Kilby of Texas Instruments independently discovered the amazing attributes of integrated circuits. Placing such large numbers of transistors on a single chip vastly increased the power of a single computer and lowered its cost considerably.
Since the invention of integrated circuits, the number of transistors that can be placed on a single chip has doubled every two years, shrinking both the size and cost of computers even further and further enhancing its power. Most electronic devices today use some form of integrated circuits placed on printed circuit boards— thin pieces of bakelite or fiberglass that have electrical connections etched onto them — sometimes called a mother board.
These third generation computers could carry out instructions in billionths of a second. The size of these machines dropped to the size of small file cabinets. Yet, the single biggest advancement in the computer era was yet to be discovered.
The Fourth Generation 1971-Today (The Microprocessor)
This generation can be characterized by both the jump to monolithic integrated circuits(millions of transistors put onto one integrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer). By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers. Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers. However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor. Ted Hoff, employed by Intel (Robert Noyce’s new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer. The microprocessor was made to be used in calculators, not computers. It led, however, to the invention of personal computers, or microcomputers.
It wasn’t until the 1970’s that people began buying computers for personal use. One of the earliest personal computers was the Altair 8800 computer kit. In 1975 you could purchase this kit and put it together to make your own personal computer. In 1977 the Apple II was sold to the public and in 1981IBM entered the PC (personal computer) market.
Today we have all heard of Intel and its Pentium Processors and now we know how it all got started. The computers of the next generation will have millions upon millions of transistors on one chip and will perform over a billion calculations in a single second. There is no end in sight for the computer movement.
Fifth generation computers
Fifth generation computers are mainly future computers. Of course some modern computers also belong to this generation. The aim of these computers is to develop devices that respond to natural language input and are capable of learning and self-organization. In these computers massive numbers of CPUs are used for more efficient performance. Voice recognition is a special feature in these computers. By using superconductors and parallel processing computer geeks are trying to make artificial intelligence a reality. Quantum computing, molecular and nanotechnology will change the face of computers in the coming years.
CLASSIFICATION OF COMPUTERS BY DATA HANDLED
There are essentially two different types of computer processing. Each is made possible by a different kind of circuitry ,and each is suitable for different purposes.
- Analog Computers – The name analog comes from the word “analogous”, meaning similar. Analog computers are used for scientific, engineering, and process control purposes. Because they deal with quantities that are continuously variable., they give only approximate results. This types of computer provides an analog or simulation of the object or system it represents. It is especially useful for solving problems that involve relationships between variable quantities in systems that change with time. The analog compute may express changing relationships in output in the form of graphs. It is able to create such pictures because it responds to changes in electrical voltages that match changes invariable quantities.
- Digital Computers – Is a machine the specializes in counting. It operates by counting values that are discrete, or separate and distinct, unlike the continuous quantities that can be measured by the analog computer. Digital Computers are used for both business data processing and accuracy. The basic operation performed by a digital computer is addition. It can store the sums of addition problems as they accumulate, and can complete a single calculation in a fraction of a nanosecond. The digital computer is capable of storing data as long as needed, performing logical operations, editing input data, and printing out the results of its processing at hight speed.
- Hybrid Computers – Although both analog and digital computers are extremely used in widely accepted in various industries, manufacturers have to attempted to designed a computer that combines the best features of both types. This special-purpose machine called a hybrid, computer, combines the measuring capabilities of the analog computer and the logical and control capabilities of the digital computer. It offers an efficient and economical method of working out special types of problems in science and various areas of engineering. Some Hybrid machines contain special equipment to convert analog voltages into digital voltages,and vice-versa.
CLASSIFICATION OF COMPUTERS ACCORDING TO SIZE
SUPERCOMPUTER
Super computers are the fastest, largest and costliest computers available. The speed is in the 100 million instructions per second range. They tend to be used for specific applications in weather forecasting, aircraft design and nuclear research. Super computers are sometimes used for time sharing as well. Memory size is in hundreds of megabytes.
MAINFRAME COMPUTERS
Mainframes are the traditional medium and large scale computer systems used in most business organizations for information processing.
A mainframe typically has a advanced control system and is capable of linking up with dozens of input/output units and even minis for additional computer power. It can usually perform from 16 MIPS to onward. Memory size is from 2 MB to onward. Examples are IBM 4300 and 3300 series, Honeywell 700 series and NCR 800 series.
MINI COMPUTERS
Mini computers have been very popular in business. Minis are frequently used to add computer power with mainframes. Sometimes an organization decides to decentralize or distribute its computer power to various stations or locations within user’s departments. Mini computers are ideal for processing data in a decentralized mode since they are small. Moreover mini have also made it possible for many smaller organizations to afford a computer for the first time. The input/output devices are lesser as compared to mainframe. The speed is usually from 10 MIPS to onward. RAM is from 2 MB to onward.
WORKSTATIONS
• Workstations are powerful single-user computers.
• Workstations are used for tasks that require a great deal of number-crunching power, such as product design and computer animation.
• Workstations are often used as network and Internet servers.
MACRO COMPUTERS
The increasing use of micros in home, school, business and professional offices has been even more revolutionary. Although these computers have limited memory and speed, their cost makes them very attractive for applications that would otherwise not be feasible. Moreover micros are frequently used to provide additional computer power for companies that already have mainframes or minis. These are rare input/output devices with micro computers. It is mostly used as a single user. Its speed is usually counted in MHz rather than MIPS. The speed is generally from 8 MHz to onward. The RAM is from 640 KB to onward.
• Microcomputers are more commonly known as personal computers. The term “PC” is applied to IBM-PCs or compatible computers.
• Desktop computers are the most common type of PC.
• Notebook (laptop) computers are used by people who need the power of a desktop system, but also portability.
• Handheld PCs (such as PDAs) lack the power of a desktop or notebook PC, but offer features for users who need limited functions and small size.
Personal Computers(PC)
Desk Top
Lap Top
Palm Top
PDA
CLASSIFICATIONS OF COMPUTERS- INTRODUCTION
There is an almost bewildering variety of computers, and the number of models available is rapidly growing. To some extent this variety is redundant; many machines are similar in capacity. But to a greater extent the variety of computers is related to important differences in capacity and functions. The distinctions among the various categories of computers has been subject to controversy. Computers may be classified according to their purpose, according to the kind of processing they do or types of data they use, and also according to the size of the machine and the speed of its internal operations. Speed of operation is often the most important consideration in deciding which equipment to choose for a particular task. With today’s machines, It is generally true that the bigger the machine, the faster the operating speed.
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