Introduction
Computer is an electronic system designed to manipulate data. It comes from the word "to compute" which means "to calculate".
Like human computers differ in appearance, size and capacity. They perform different tasks according to the purpose of their creation. Controversy comes out when we talk about distinctions among the various categories of computers. Computers may be classified according to their purpose, performance, and capacity.
CLASSIFICATION BY PURPOSE
Digital computers may be classified for two purposes: general and special.
1. GENERAL-PURPOSE COMPUTERS
These machines have the capability of performing several applications. It has the ability to store different programs of instruction and can perform a variety of operations.
The personal computers are the best example of this type of computer. A teacher for example may compute grades in spreadsheet, make excuse letter for his coming school activity in word processing next, and running a slide show for his lesson later. All tasks can be done while listening to your favorite radio station. New programs can be prepared and old programs can be modify or delete.
In choosing this type of machine, one should consider the size of memory, speed of processor, and efficiency of the software and hardware used.
2. SPECIAL-PURPOSE COMPUTERS
These machines have the capability of performing one applications. It is designed to perform specific tasks. It is also called "dedicated computers" because of their limitations to perform other operations. Some examples are used in the following: satellite systems, traffic control, telecommunicators, highway tolls, and industrial tracking.
CLASSIFICATION BY PERFORMANCE
1. ANALOG COMPUTERS
Analog or analogous meaning similar are computers that measure physical quantities that are continuously variable. They give only an approximate result and can output the result in graphical form. Some examples include are:
a.) Antikythera mechanism = an ancient mechanical calculator, designed to calculate astronomical positions. b.) Astrolabe = an astronomical instrument used by astronomers, astrologers, and navigators. It is used to locate and predict the positions of the Sun, Moon, planets and stars. c.) Potentiometer = a variable tapped resistor that is used as a voltage divider.
d.) Oscilloscope = a type of electronic test equipment that allows signal voltages to be viewed.
e.) Richter scale = a device used to measure the strength of an earthquake.
f.) Speedometer = a device used to measure the speed of a land vehicle.
g.) Old gas pump = a machine used to put gasoline in a vehicles.
2. DIGITAL COMPUTERS
As the term implies, a digital computer is a machine that specializes in counting. It can perform 100% error-free arithmetic operations. This type of computer is widely used in both in business and scientific purposes. Digital computer capabilities as follows: (1) It can store the sum of addition problems; (2) It can subtract, multiply, divide and compare; (3) It can programmed to recognize and manipulate numeric symbols; (4) It is capable of storing data; (5) It can perform logical operations; (6) It can edit input data and print out the results.
3. HYBRID COMPUTERS
These are computers that combines the features of analog and digital computers. The measuring capabilities of the analog computers and the logical and control capabilities of digital computes can be both performed by this device. Some hybrid machines can convert analog voltages into digital voltages, and vice-versa. Some examples are as follows:
a.) Hybrid Electric Vehicle = a car the combines a gasoline engine with electric motors.
b.) Hybrid coupler = a type of directional coupler used in radio and telecommunications.
c.) Telephone hybrid = an electronic circuit used in telephones.
d.) Radio-frequency hybrids = are used to split radio signals, including television. The splitter divides the antenna signal to feed multiple receivers.
CLASSIFICATION ACCORDING TO CAPACITY
The term "capacity" refers to the amount of data that can be stored by a computer device. The early generation computer determines its capacity in terms of its physical size - the larger the device, the greater the amount of data that can be stored in memory. Nowadays, it is measured in terms of applications it can run, speed of internal operation, number and type of peripheral devices, amount and type of software available for use with the computer, and of course the amount of data that can be stored in memory.
Computer systems are classified as microcomputers, minicomputers, mainframe computers, large computers and supercomputers.
1.) MICROCOMPUTERS
It is the smallest type of computers basically designed for a single user. It is a computer with a microprocessor as its central processing unit. It has 4K to 64K storage locations and is capable of handling small business, sales analysis, billing, payroll, inventory, industrial automation, and data acquisition. Other uses are as follows:
a.) Controller for the so-called "intelligent" robot arms and hands capable of factory assembly operations;
b.) Handler of a variety of engineering, scientific, and other common business applications;
c.) Control in ways that greatly simplify product testing and manufacturing processes;
d.) Plants and laboratories;
e.) Business offices;
f.) Auto-dealer showrooms;
g.) Medical laboratories;
h.) Insurance agencies;
i.) Construction sites
Microcomputers is a complete computing system, less powerful in speed and computing power than a minicomputer. Many microcomputers are also personal computers. PC may be a desktop, laptop, or a table computer.
2. MINICOMPUTERS
It is also known as "small mainframe computers", a small stand-alone device which can be used to handle tasks that large computers can not perform economically. It provides faster operating speeds and larger storage capacities than microcomputer systems. It usually has 8K to 256K memory storage locations. Some uses are as follows:
a.) Handle a number of high speed input/output devices;
b.) Provide direct access to remote terminals;
c.) Used for laboratory process control applications;
d.) Used in a wide variety of commercial operations such as airline reservations, car rentals, banking transactions, and inventory control.
Minicomputers can performs many of the processes of a mainframe but more slowly and at a much lower cost. Some examples include: IBM Systems 3, AS-400, PDP-8, Honeywell 200 and 1200 computers.
3. MAINFRAME COMPUTERS (MEDIUM-SIZE COMPUTERS)
They are capable of storing large quantities of information and serving over one hundred terminals at a faster operating speed. This type of computer does all operations faster than minicomputers. They usually have memory sizes ranging from 32K to 512K. Some uses includes:
a.) Support a large number of high-speed input/output devices;
b.) Provide online access to large data files;
c.) Used for batch processing;
d.) Support both multiprogramming and virtual storage;
e.) Used in electrical circuit design and structural analysis;
f.) Support a management information system;
g.) Used on a time-sharing basis;
Mainframe computers are very flexible that they can be expanded to meet the needs of the users. Some examples include: IBM System 370, IBM-4331, Burroughs 3500 System and NCR Century 200 System.
4. LARGE COMPUTERS
Large computers have storage capacities from 512K to 8192K. They are ultimate in system sophistication, speed and flexibility. They contain full control systems with minimal user intervention. Their speed are measured in terms of nanoseconds, as compared to smaller computers are measured in terms of microseconds. Some uses are as follows:
a.) Maintain organization's corporate files and integrated data bases;
b.) Used by government agencies, large corporations, and computer service organizations;
c.) Used in complex simulation, business operations, product testing, and development of space technology;
d.) Connects vast numbers of terminals, including even smaller computers and minicomputers at remote locations.
Large computers can be expanded up to 8 or even 16 million characters. It ranges from single-processing configurations to nationwide computer-based networks.
5.) SUPERCOMPUTERS
The largest and fastest machines today. They are used when billions or even trillions of calculations are needed. Their speed is in the range of 100 million instructions per second. Some uses include:
a.) Used in product testing;
b.) Development of space technology;
c.) Nuclear weapon development;
d.) Accurate weather forecasting;
e.) Aircraft design;
f.) Host processors for local computer and time sharing networks;
Supercomputers are not flexible. They need smaller machines to handle minor programs.
CONCLUSION
"No matter what type of computers you are using as long as you used it for the betterment of everything that surrounds you, there is nothing to worry about."
Coming up next, "What computers can and can't do".
THANKS TO INTERNET
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http://discover-computer.blogspot.com
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16 years ago