Computer Generations

Most users think that computers are a modern invention, a few years ago. However, the reality is that since before World War II existed research and even devices that were dedicated to science. In this article we will study as generations have succeeded each computer. Starting from 1946 until today.

Computer Generations

The First Generation

J.P. Eckert and John Mauchly, from University of Pennsylvania, inaugurated the new computer on 14 February 1946. Called ENIAC, which was a thousand times faster than any previous machine, since was able to solve 5,000 additions and subtractions, 350 multiplications or 50 divisions per second. And was twice the size of the Mark I: 40 cabinets filled with 100,000 components, including about 17 thousand electronic valves. It weighed 27 tons and measured 5.50 x 24.40 m and consumed 150 KW.

Despite his countless fans, the ambient temperature reached 153 F°. He ran 300 multiplications per second, but as it was designed to solve a particular set of problems, reprogramming was very slow. Furthermore a need to replace 19,000 vacuum tubes every year made ENIAC very expensive to operate. In 1943, before the entry into operation of the ENIAC, England already had the Colossus, computer created by Alan Turing as a machine to decode German secret codes.

Computer Generations

In 1945, Von Neumann suggested that the binary system was adopted in all computers, and that the instructions and data were compiled and stored internally in the computer, using the correct sequence. These suggestions served as the philosophical basis for computer projects. From these ideas (currently computers “not Von Neumann” running fuzzy logic), and mathematics and algebra Boolean logic, introduced by Boole in the early nineteenth century, is that Mauchly and Eckert designed and built the EDVAC, (Electronic Discrete Variable Automatic Computer), completed in 1952, which was the first commercial electronic data processing machine in the world.

Both scientists had already tried this concept with the BINAC, (Binary Automatic Computer), 1949, which was more compact (1.40 x 1.60 x 0.30 m) enough to be carried aboard an airplane, but it never worked. The memories based on EDVAC used mercury delay lines, very expensive and slower than CRTs, but with greater storage capacity. Also in that same year Wilkes built EDSAC, (Electronic Delay Storage Automatic Calculator), which operates according to the technique of stored programs.

The first large-scale commercial computer was the american UNIVAC, (Universal Automatic Computer), in the year 1951, which it had to be programmed turning on or off about 6,000 switches, besides having to connect countless cables to a panel. The input and output of information was carried out by a metal tape 1/2 inch wide and 400 m long.

Computer Generations

In total, were sold 46 units of Model UNIVAC I, which were usually accompanied by a printing device called UNIPRINTER, which consumed 14,000 W. Another commercial computer was the IBM 701, 1952, which used plastic tape, sold faster than the UNIVAC metal tape, and the IBM 704, with the phenomenal ability of storing 8,192 words of 36 bits, both from IBM.

Also arise in England at that time MADAM (Manchester Automatic Digital Machine), SEC (Simple Electronic Computer), and APEC (All-Purpose Electronic Computer).

Between 1945 and 1951, the Whirlwind of MIT was the first computer that processed information in real time, with input from punched tapes and output through CRT (monitor video), or Flexowriter, a heavy-duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods, including direct attachment to a computer system and by use of paper tape.

Computer Generations

In 1947 Bardeen, Brattain and Schockley invent the transistor, and in 1953 Jay Forrester constructed a magnetic memory. Computers transistor emerge in the ’50s, weighing 150 kg, with lower power consumption to 1500w, and with a much greater capacity than its predecessors equipped with electronic valves.

The Second Generation

Examples of this period are the IBM 1401 and BURROUGHS B 200. In 1954 IBM sold the 650, a middle-sized model. The first fully transistorized computer was the TRADIC, of ​​Bell Laboratories. In the other hand, the IBM TX-0, from 1958, had a video monitor better quality, was fast and relatively small, also offers sound output device.

The PDP-1, (Programmable Data Processor), built by Olsen, was a sensation at the MIT: The students played Spacewar! and Mouse in the Maze, through a joystick and a stylus.

In 1957 the mathematician Von Neumann worked to build an advanced computer, which, as a joke, was named MANIAC, (Mathematical Analyser Numerator Integrator and Computer). In January 1959, Texas Instruments announces to the world a creation of Jack Kilby: the integrated circuit.

While a person midlevel would take about five minutes to multiply two ten-digit numbers, MARK I did in five seconds, the ENIAC in two milliseconds, a computer transistorized in about four billionths of a second, and, third generation machine, even less time.

Third Generation

The third generation born in the 1960s, with the introduction of integrated circuits. The Burroughs B-2500 was one of the first. While the ENIAC could store twenty ten-digit numbers, computers like this could store millions of numbers. Also emerge technologies and concepts such as virtual memory and multiprogramming complex operational systems. Examples of this period are the IBM 360 and BURROUGHS B-3500.

Computer Generations

In 1960 there were about 5,000 computers in the US. At that time the term software also arises. In 1964, the CSC, Computer Sciences Corporation, established in 1959 with a capital of $ 100, became the first software company with shares traded on the stock exchange.

The first commercial mini computers emerged in 1965, the PDP-5, released by the american DEC (Digital Equipment Corporation). Depending on your configuration and accessories, this computer could be purchased by the affordable price of US $ 18,000.00. The PDP-5 model was followed by the PDP-8, with a much more competitive price. Following the way, other companies released their models, reason why at the end of that decade there were already about 100,000 computers throughout the world.

Computer Generations

In the 70s, precisely in 1971, the company introduces to the market the popular microprocessor 4004, four bits, in 1972, released the 8008, in 1974 the 8080 and 1976, the 8085, to which followed a very popular line of integrated circuits that were able to make history in computing, since there arise the microcomputers.

Computer Generations

Fourth Generation (1981-1990)

For many people, the fourth generation emerges with VLSI chips, integrating a very large scale, that emerged in the course of using the technique of LSI (large scale integration) and VLSI (very large scale integration) circuits. In that period also it arose the distributed processing and the optic disc, which it allowed the expansion of the use of computers which happened to be used for word processing, calculations and others task.

Things begin to develop more quickly and frequently. In 1972, Nolan Bushnell founded the company Atari for the development and distribution of video games. Kildall release CP/M in 1974, the first microcomputer kit, the Altair 8800 in 1975.

Also in 1975, Paul Allen and Bill Gates created Microsoft and the first microcomputer software: MS-DOS, an adaptation for ALTAIR BASIC. In 1976 Kildall’s Digital Research Incorporation sets in the market to sell the CP/M operating system. In 1977 Jobs and Wozniak created the Apple microcomputer, Radio Shack the TRS-80 and Commodore the PET.

Computer Generations

In the late 70s, Software Arts release the first commercial program, VisiCalc. In 1979 Rubinstein began to market software written by Barnaby: the WordStar, and Paul Lutus produces the Apple Writer. The program of a NASA engineer, Waine Ratliff, dBase II, 1981. 1981 also IBM-PC and Lotus 1-2-3, Kapor, who reached the bestseller list in 1982.


The zx81 / ZX Spectrum was a tiny computer conceived by John Sinclair, a professor at the University of Cambridge in U.K. Initially the ZX Spectrum was designed for the use of students at the University of Cambridge. The Zilog Z80A CPU had an 8 bit processor at 3.25 MHz, a memory composed of a ROM and a RAM and a ULA.

It also offers an ROM with 8K of capacity to store programs or tables permanently. It was also necessary for the operation of the system and the translator for the BASIC programming language. RAM had a workspace available for the user of 1K, but was expandable to 16K.

Computer Generations

In the plastic box, it is also housed a communications subsystem for serial connection to peripheral, called SCL (Sinclair Computer Logic), a unit for input and output sound and an image encoder for TV. In the back of the plastic box, had a connector where you could connect a printer that used a tiny roll of special paper. The computer was supplied with a cable for connecting to the TV and another for connection to a recorder of “cassettes” (Philips standard). The AC power to DC was purchased separately. Programs and data were recorded and read in a magnetic tape.

The keyboard had no keys. ASCII characters were printed on a membrane. This technology and lack of ventilation in the power unit were the main cause of failures that sent the ZX81 to the trash can. However it was a very popular computer due to its low price.

Osborne 1

Manufactured by Osborne in USA around 1982. The CPU had a 64KB memory, ULA Zilog Z80A processor of 8-bit to 4 MHZ. The case, type attaché weighed about of 24 lb, housed two floppy drives 5 ´1/4 with 204 KB or 408 KB option capacity, a monitor 5″ (24 lines by 54 columns) in black and white and a toggle keyboard (which it was also the top of the computer) with two key blocks, one with alphanumeric characters and other ASCII numeric.

As external connectors offers one for an external monitor, RS-232C serial ports and parallel IEEE-488 or Centronics. The system was powered by a rechargeable battery with a range of 5 hours, but also it could be powered by a car battery or a wall adapter.

Computer Generations

The operating system was CP/M, developed by Digital Corporation. The software supplied included a Basic interpreter developed by Microsoft, a BASIC compiler developed by the Compyler Systems, a spreadsheet SuperCalc (derived from Visicalc) and a word processor called WordStar. It could be programmed in BASIC, FORTRAN, COBOL, PASCAL, PL 1 Algol, C, FORTH, ADA, ASSEMBLER and CROSS-ASSEMBLER.


Manufactured by IBM in USA around 1980, started with the PC-XT version, which was followed by a PC-AT. This equipment includes a 40KB ROM and 64KB RAM expandable to 640KB, a ULA and a processor Intel 8088 of 16 bit, with a clock frequency of 4.77 MHZ.

This device are built with three separate modules: CPU, monitor and keyboard. The monitor was black and white with 25 lines by 80 columns that may be replaced by a monitor with 16 colors. The CPU processor also housed a floppy drive 5 “1/4 with a capacity of 360KB and can accommodate another identical diskette drive or a hard drive with 10MB capacity, which was integrated into the PC-XT version part.

The keyboard includes 83 keys, 10 of which corresponded to pre-programmed, also available accented characters functions. This computer offers an connector for printer and an interface for async communications. The operating system was the PC/MS-DOS, which was an MS-DOS developed by Microsoft for IBM. The programming language used was the BASIC.

Computer Generations

It is important to mention at this point that only two years later, with the introduction of the PS / 2-50 and PS / 2-60 models, which were equipped with an Intel 80286 processor, IBM regained the market sector of the PCs, using the penetration effect in companies where he had installed mainframes, and devices at that time called “small computers”.

1982: Emerge 286

Using 30-pin memory and 16-bit ISA slots, was equipped with cache memory, to assist the processor in its functions. The included CGA monitors was, amber, green or gray, except in rare cases, where the screen was color.

1985: Emerge 386

These computers also include 30-pin memory, but because processing speed, it was possible to run more advanced graphics software such as was the case of Windows 3.1. Its predecessor could run only version 3.0 of this OS, due to the low quality of CGA monitors. Instead the 386 had VGA video cards that could reach up to 256 colors if the monitor would support that configuration.

1989: Emerge 486 DX

With the addition of the math coprocessor, the 32-bit PCI cards, several times faster than ISA cards, coupled with the emergence of the memory of 72-pin, much faster than the memory of 30-pin, a substantial improvement was achieved performance of these computers. The equipment already had capacity for SVGA video cards that could reach up to 16 million colors, however this would be used commercially later with the advent of Windows 95.

Computer Generations

Fifth Generation (Since 1991)

Applications increasingly demand greater processing power and data storage. Special systems, multimedia systems (combination of text, graphics, images and sounds), distributed databases and neutral networks are just some examples of those needs.

One of the main features of this generation is the simplification and miniaturization of computer, plus increased performance and storage capacity. All this with an increasingly affordable price.

The VLSI technology is being replaced by the ULSI (Ultra Large Scale Integration) .The processing concept is moving toward parallel processors, that is, the execution of many operations simultaneously by multiple processors. Reducing production costs and volume of the components allowed the application of these computers called embedded systems, which control aircraft, ships, cars and small-sized computers. Examples of this generation of computers are devices that include Pentium microprocessors, from Intel.

1993: Born the Pentium

From the appearance on the market of new technologies such as memory modules of 108-pins, AGP video cards, plus changes in the PCI protocol, which got much better performance, they paved the way for the emergence of processors Pentium, Intel, which was a significant jump in performance for all types of implementations.

The appearance of this processor was carried out with impressive economic movement, ending the competition, which until then produced equivalent processors, such as the 80386, the 80486. From the appearance of Pentium I in 1993 and their descendants as the Pentium II in the year 1997, the Pentium III in 1999 and the Pentium 4 in 2001, the panorama of the processors changed forever, fortunately for good.

Computer Generations


Currently, in the field of manufacturing high-performance microprocessors, survived only two major contenders: Intel and AMD. Between the two manufacturers cover almost the entire computing process needs, in areas such as home, office and industry, and have put on the market CPUs with speeds and performance impossible to imagine just a decade ago.

Among the most important products of these manufacturers, can mention the Intel Core processors in its variants i3, i5 and i7 two or four cores and clock speeds that far exceed the 3.4 Ghz.

Regarding AMD, the Fusion model is one of the most advanced designs, since combined in the same capsule, the CPU and the GPU (graphics processing unit). Another success of the firm is the Phenom II, which may get to ride inside up to 6 cores running at 3.6 Ghz.

Computer Generations

The Future: Here comes the quantum computer!

IBM announced the construction of the most advanced quantum computer in the world. The novelty represents a major step in relation to the current manufacturing process with silicon chips that according to experts, should achieve maximum physical limitation of processing between 10 and 20 years.

The quantum computer uses, to count ones and zeros, instead of traditional silicon microprocessor chips, a device based on physical properties of atoms, such as their sense of direction, instead of electrical charges, like current computers.

Another feature is that atoms can also overlap, allowing the equipment to process equations much faster.