CLASSIFICATIONS OF COMPUTER

CLASSIFICATION BY GENERATION:

First Generation 1951 � 1958

The computers made where already programmable and the Cryptic was use to program the machine. Cryptic is one program used and the program was called Machine language, for the instruction were written in a form of a series of code particularly of zeros and ones.

The CPU of the first generation computers was composed of vacuum tubes. The first computer to be massed produced was the UNIVAC I (1958), designed by Eckert and Mauchly after they built the ENIAC and EDVAC. This marked the beginning of the first generation. It lasted through 1958. The computers before the UNIVAC, are called the zeroth generation.

The first generation computers did not use terminals. The UNIVAC used magnetic tapes. IBM 650 became popular because it reads punched cards instead of tapes.

The first generation computers had no RAM, nor ROM. The main memory was composed of liquid memory, or the cheaper but very slow magnetic drum or core memory.

At first programmers had to write programs in machine language. Then the assembly language was developed. The three (3) major high level languages then were: FORTRAN, ALGOL, and APT.

Second Generation (1959 - 1963)

In 1947 the first transistor where invented, by the Bell Telephone Company (Bell laboratories). and everyone realized it would be better than the vacuum tubes. Transistors were electronic components that functioned the same as a vacuum tube. Computers built using transistors were much more dependable, easier to maintain and cheaper to operate. The first company to make transistors for computer was Philco.

Computer companies started to deliver transistorized computers in 1959, then it marked the beginning of the second generation. Computers during the second generation were built smaller and more reliable and less consumption in electricity than the first generation computers.

The vacuum tubes computer stopped selling and all second generation computers were then using core memory. FORTRAN, ALGOL, and APT from the first generation were significantly improved. The new programming language were: COBOL, GPSS, LISP, RPG, SNOBOL, and the DYNAMO.

Third Generation 1964 - 1967

The third generation began with a big bang, in 1964, when the first modern computer families were shipped. They were the CDC 6000, the IBM 360, the PDP-6, the PDP-8, and the PDP-10.

The CDC ran fastest. The IBM 360 was not only the most flexible, it was also the first to use the Integrated circuits ( IC�s ). The PDP-6 and the PDP-8 were the best use for time sharing.

During the third generation, IBM developed a new language which is the PL / I, for the use of IBM 360. At the same time, BASIC was being developed in Darthmounth College, and Stanford University, also came up with the most popular language

for statistics called the SPSS.

Fourth Generation 1968 - 1974

The years 1968 - 1974 marked what is called today as the Era of Boredom. It is because nothing big or dramatic occurred. Although there was some progress, it was gradual and predictable.

Microprocessors is designed and manufactured making it possible of putting several integrated circuits together in a wafer of silicon. Using microprocessors made computers smaller in size and much wider in application.

The only �big� thing that took place at that time was IBM (International Business Machine) announcing its new IBM 370, which makes the IBM 360 obsolete. But the IBM 360 still exist. DEC�s ( Digital Electronic Corporation) PDP-8 and PDP-11 were the most popular minicomputers, that the IBM no longer had the upper hand in the field of minicomputers.

Beginners All-Purpose Symbolic Instruction Code (BASIC) became the most popular language for minicomputers (except IBM, which emphasized RPG), High School and business schools used BASIC in their introductory computer course.

Programming language of the past generation were just developed and some were switching to more progressive languages meant rewriting the programs.

In 1971, Intel began shipping the first microprocessors ( complete CPU and Chip ) It was called the 4004, and had a word of only 4 bits. In 1972, Intel came up with an improved version, the 8008, whose word had 8 bits. In 1973 Intel began producing an even better version, called the 8080.

Fifth Generation 1975 - present

Artificial Intelligence ( A I )

This can also be classified as a type of software that can generate and simulate human thoughts and judgment. This is the area in which the development of new technology will be combines with that of the performance of the machine and humans together and can act as a humanlike thinking and decision making. However the term artificial can only be accepted as literal, for Computer can not level with the abilities of humans to apply intuition in decision making. Hence the computer can only be able to enhance and simulate human thought, imagination and judgment.

Era of Personal Computer 1975 - ?

In January 1975, the popular electronic magazine featured a �complete set of computer for only $395�. That computer was manufactured by a company called �MITS�, which called the computer the �Altair 8800�. This marked the beginning of the Personal computer.

And in 1977 computer called the PET announced by the computer company Commodore. Radio Shack announced its TRS-80. But then the most popular computer that time was the APPLE and IBM.

Apple Computer The apple computers is manufactured by the Apple Computer Inc., was founded by Steve Wozniak and Steve Jobs. It was Wozniac who invented the machine and Steve Jobs took charged of the production and marketing.

IBM Computers

IBM started as early as 1953, and makes maxicomputers, minicomputers, and the micro computers. IBM immediately took a big slice of the microcomputers market and become one of the top three companies selling microcomputers.

Today, people use the IBM PC/XT (extended) and the IBM PC/AT (advance technology) which runs about 13 times faster than the XT, and the PS/2 (personal system 2) computers.

The Innovation Of Computer Cloners - When IBM introduced the original IBM PC/XT, it made the unprecedented move of �opening� the machine. The usual practice in the computer industry was towards proprietary systems - others were not supposed to know the internal working of the computer. They need to get a license from the original manufacturer if they wanted to build a compatible machine or an attachment to the original machine.

But IBM made the internal working of the PC/XT public, so that many manufacturer were able to sell assorted peripherals and cards for the PC/XT. And soon enough, there were companies selling computers that were functionally equivalent to the original IBM PC/XT. This computers which can run programs written for IBM PC/XT without modifications, are so called compatibles.

When IBM introduced the PC/AT, the Cloners also came up with equivalent machine.

By offering machines that were either technologically superior or cheaper than the IBM computers, cloners have been able to win loyal customers. Now, IBM wants to revert back to its good old days by inching back towards proprietary system.

CLASSIFICATION BY PURPOSE:

General-Purpose ComputerComputer machines where capable of executing different programs dealing with a variety of problems. In industry, for example, a general purpose computer can handle payroll, accounts receivable, and account payable, and keep an inventory of production materials as well as stock on hand according to the needs of the

particular business activity.

Microcomputers are general-purpose machine that can be used for business applications, education, games, or other personal applications.

Special-Purpose Computers

Computers are designed to hand specific problems. An example is a computer designed to land an aircraft. Sophisticated as it is, this computer can not do anything else, not even a small payroll. Most special purpose computers have the capability of performing only one task and are referred to as �dedicated� because of their limitation to the performance of the specific task they were designed for.

Special-Purpose computer employed for military and scientific applications.

These machines are generally sophisticated and expensive. It is usually use for military and scientific gadgets. However, there are cheaper special-purpose computers available like the computer games, computerized telephone answering machine, and computerized fuel injection system for the car.

CLASSIFICATION BY PROCESSING (DATA HANDLED)

The Analog Computer

Analog computer is so called because it provides an analogy or simulation of an object or system it represents. It is especially useful for solving engineering problems that involve variable quantities that change with time. The analog computer may express those changing relationships in the form of graphs.

An example of an Analog computer is the electronic synthesizer used in today�s music. Analog computers are limited in accuracy, largely because the solution to a typical problem involves many sets of connected components. A major disadvantage of analog computer is that they cannot represent non-numeric data. So, analog computers are not able to meet all the needs of a business and industry.

The Digital Computer

Digital computer is a machine that specializes in counting. It counts values that are discrete (separate and distinct), unlike the continuous quantities measured by an analog computer. The digital computer can be made increasingly accurate by specifying additional decimal places to number.

The basic operation performed by a digital computer is addition. It stores the sum of addition problems as they accumulate, and completes a single calculation in a fraction of a nanosecond (one trillion of a second). By simple rearrangement of problems, digital computers can perform other arithmetic function including numeric comparison, even to recognize and manipulate non-numeric symbols. These are a few features important for business data processing.

Combined features of Digital and Analog

This is also known as the �Hybrid computers�, this are advantageous in some scientific application such as simulating a space mission. Analog technology is used to simulate the motion of a vehicle, while a digital device computes its trajectory.

CLASSIFICATION BY SIZE and SPEED:

Super Computers

The fastest machine is called Super Computers that are used when billions of trillions of calculations are needed. These machines are necessary in applications ranging from nuclear weapons development to accurate weather forecasting. Example of super computer machine is the CRAY-2, costing millions to develop. A supercomputer is no regular computer. It is a extraordinary performance computing machine designed to have tremendously fast processing speeds. Supercomputers have numerous applications, such as performing multifaceted scientific calculations, modeling reproductions, and rendering large quantities of 3D graphics. They may also be built to simply showcase the important edge of computing technology.

If you are hoping to have a supercomputer on your desk, you may be out of luck. Supercomputers are typically several times the size of a typical desktop computer and require far more power. A supercomputer may also consist of a series of computers, which may fill an entire room

Mainframe

Usually include several large places of machinery wired together. Can communicate data with other terminal / computers located at a distance at the same time. A mainframe is an ultra-high-performance computer made for high-volume, processor-intensive computing. They are typically used by large businesses and for scientific purposes. You probably won't find a mainframe in any household. In the hierarchy of computers, mainframes are right below supercomputers, the most powerful computers in the world. (Which is why they are aptly named "supercomputers.") Yet a mainframe can usually execute many programs simultaneously at a high speed, whereas supercomputers are designed for a single process. Currently, the largest manufacturers of mainframes are IBM and Unisys.

Mini-Computer

Medium size computer (about a size of a refrigerator). This is smaller than a Mainframe. Has found applications in medium scale business, which requires computer power at a low cost. Can hold one tenth ( 1/10 ) as much memory as a mainframe. A minicomputer, a term no longer used, is a computer of a size intermediate between a microcomputer and a mainframe. Typically, minicomputers have been stand-alone computers (computer systems with attached terminals and other devices) sold to small and mid-size businesses for general business applications. In modern years, the minicomputer has changed into the "mid-range server" and is part of a network.

Micro Computer

The smallest and the least expensive. Can hold one tenth(1/10) as much memory as a minicomputer. Have found their way into offices of small businesses as well

as in the homes. A microcomputer is a computer with a microprocessor as its system unit (SU). It includes a microprocessor, memory, and input/output (I/O) facilities. Computers are physically small compared to mainframes and minicomputers, though modern mainframes such as the IBM System machines use one or more microprocessors as their System Unit. Microcomputers equipped with a keyboard and screen for input and output in the generic sense are also personal computers.