Types of Computers Esay

Overview A computer is an electronic device that receives (input) data, processes that data, stores data and produces results (output). Computer can be classified according to their data representation that is functionality, based on their purpose or based on their physical size. It’s the classifications that bring about types of computers.There are four types of computers that is, micro computer, minicomputer, mainframe computer and super computer. 1. 2 Justifications Understanding the types of computers will be helpful in determining whether it’s suitable for the intended purpose. For example if it’s a simple task for an individual or small organization then the microcomputer will be more suitable than a main frame computer which serve large organization. 1. 3 In brief In this essay we define what a computer is in detail in terms of the input, process and output.The features, purposes, functioning, subclasifications and costs of the four types of computers are also discussed. 3. 0 TYPES OF COMPUTERS 2. 1 Defining A Computer According to Saleemi (2009), â€Å"A computer may be defined as a machine which accepts data from an input device performs arithmetical and logical operations in accordance with a predefined program and finally transfers the processed data to an output device. The definition of computer can be viewed broadly in three major cases as illustrated below: Input Process Output Data and instructions Execution and storageInformation â€Å"(All computers can perform the functions of inputting, storing, processing, controlling, styling and outputting data and information (Ravichdndran, 2001 pg2). † It works upon the input data using the issued instructions, this means that the computer cannot do any useful job on its own; hence it’s a clever fool. The term GIGO is also oftenly used to explain this notion that is the computer can only work as per the instructions sets issued, hence if instructions sets conform to t he solving of the problem at hand then it will do it even faster and accurately.But if instructions set do not conform to the solving of the problem then the computer also solves it in the same manner of the instructions set. Hence Garbage in Garbage Out (GIGO). There are varieties of computers with a variety of their operational characteristics. The computer can be classified in many useful ways depending on the objective of whoever is doing the classification. 2. 2 Four types of computers compared The four major categories of computers based on their physical size are micro computers, mini computers, mainframe computers and super computers.These categories are based on the differences in size, speed, processing capabilities and price of computers. Due to rapidly changing technology, the categories cannot be defined precisely. For example the speed used to define a mainframe today may be used to define mini computers next year. Some characteristics may overlap categories still; the y frequently are used and should be understood. Mainframe computers They are most expensive of all computers and very big in size and offer the maximum computing power (Saleemi 2009).They are generally used in large networks of computers with the mainframe being the node point of the network. Smaller computer or terminals are then attached through satellites so that data could be centralized at one place will data processing could be performed via the satellites. A good example is the airline reservation system. The airlines have a mainframe computer at their head office where information of all the flights is stored. Small computers installed at the booking offices are attached to the central data bank so that up to date information of all flights is always available.According to Saleemi (2009) important characteristics include * These are big general purpose computers capable of handling all kinds of problems whether scientific or commercial. * They can accept and transfer data fr om input/output devices at the rate of millions of bytes per second. * They accept all types’ high level languages. * They can support large number of terminals. * Their processing speed is up to several billions of instructions per second. They have a large online secondary storage capability and can support a large number of and variety of peripheral device like magnetic tapes drives, hard disk drives, visual display UNITS, printers and telecommunication terminals. * They usually have high speed cache memory which enables them to process applications faster than mini or micro computer. Mini computers The mini computers are medium sized computers. They are physically bigger than the micro computers but smaller than the mainframe computers.Due to advanced circuit technology some mini computers are almost the size of micro computers. They support average internal and backing storage, that is their storage capacity both internal and external are comparatively higher than the mi cro computers but lower than the main frames (Saleemi 2009). These computers support several users at a time, that is several work stations or terminals are connected to one central minicomputer whose resources (e. g. C. P. U time, storage media, memory etc) are shared among the users connected.If central computers and terminals ate networked (WAN) then telecommunication links are used for a network within the same locality, on the other hand, the cables are used in connecting the terminals and the host computer. The later network configuration is known as local area network (LAN). At the workstation the information is output through the terminal screen or a printer. Sometimes the output can be at the central computer e. g. through a shared printer (usually line printer). Mini computers are used mainly in medium scale business functions. In business they are being used for invoicing stock control, payroll, sales analysis etc.Micro computers According to Saleemi (2009), â€Å"These are computers of advanced technology that become available in late 1970’s. They are the most common form of computers in most offices today as desktop, personal or stand alone systems†. Their design is based on large scale Integrated Circuitry (LSIC) that confines several physical components per small element thumb size I. C (integrated circuit), hence the size dramatically reduced. Their internal memory is smaller than the mini computers and main frame computers. They support limited backing storage media. They are cheaper than the mini and mainframe computers.Where the micro computers are used as terminals, that is connected to the central computer for enhanced processing beyond its capabilities then communication facilities are also to be provided. In small business the micro computers are used in several Min functions that require information to be produced e. g. purchasing, sales, marketing, production, accounting, in word processing for the production of business documents etc. Two popular series of micro computers are the personal computer (PC) and apple Macintosh. Micro computers nowadays come in varied sizes: Desktop computer – Largest and designed to fit entirely on or under a desk or table. * Laptop /notebook computers – second largest and designed such that can be placed on user’s laps. * Palm top computers – smaller and designed so that can be placed on users hand. * PDA (Personal Digital Assistant) – it’s also hand held and provides personal organizer functions such as calendar, appointments etc. Super computers Super computers are the largest, fastest, most expensive computers ever made. They are sometimes referred to as monster computers and have the processing speed of trillion of instructions per second.In many installations super computers are used for limited classes of computations. These computers are often used in numerical application like weather forecast, large matrix calculations such as those required for linear programming to solve problem in economic program or some military statistics. A small number of super computers are built each year for use in applications requiring complex, sophisticated mathematical calculations as in large government research agencies, military defense system, national weather forecast agencies, nuclear energy research, and petroleum exploration etc. 4. CONCLUSION 3. 1 Summary This essay has comprehensively discussed what a computer is in terms of input, process and output. The superiority of the super computers over all the other computers has also been captured. Subclasification of the micro computer thus desktop, laptop, palmtop and personal digital assistant has also been discussed. 3. 2 Insights The development of computers from mainframe to micro computers and super computers is evident from the essay. It’s also worth noting that the advancement of micro computers will continued to diminish the importance of the ma inframe / mini computers. . 3 Recommendations Given that computers facilitate more accurate and faster processing of data developers of computers should invest more in research and development. This will ensure that the computers available in the market for personal or SME use have not only enhanced capabilities but also affordable costs. REFERENCE LIST 1. Saleemi, N. A. (2009). Information Technology Simplified. Nairobi: Saleemi Publications. 2. Rauchandran, D. (2001). Introduction to Computers and Communication. New Delphi: Tata McGraw Hill.