Computers are such an integral part of our everyday life now most people take them and what they have added to life totally for granted.

Even more so the generation who have grown from infancy within the global desktop and laptop revolution since the 1980s.

The first computers of this generation were developed for the atomic energy industry. Third Generation (1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which. Jul 12, 2018 A list of popular first generation computers ENIAC, UNIVAC,EDVAC, and EDSAC. A) Computer Characteristics & Capabilities – Size – Relatively big size.Size was equivalent to a room. First Generation: Used vacuum tubes. Vacuum tubes were heated so often, so they have to be cooled down by an AC. Vacuum tubes also Burnt so they had to be replaced. Computers were very large taking the size of a room. Machine language was used in these computers. Input was based on punch cards. Sep 29, 2011 First Generation Computers. The first generation of computers is said by some to have started in 1946 with ENIAC, the first 'computer' to use electronic valves (ie. Vacuum tubes). Others would say it started in May 1949 with the introduction of EDSAC, the first stored program computer. Whichever, the distinguishing feature of the first generation computers was the use of electronic valves. First Generation: Used vacuum tubes. Vacuum tubes were heated so often, so they have to be cooled down by an AC. Vacuum tubes also Burnt so they had to be replaced. Computers were very large taking the size of a room. Machine language was used in these computers. Input was based on punch cards.

The history of the computer goes back several decades however and there are five definable generations of computers.

Each generation is defined by a significant technological development that changes fundamentally how computers operate – leading to more compact, less expensive, but more powerful, efficient and robust machines.

1940 – 1956: First Generation – Vacuum Tubes

These early computers used vacuum tubes as circuitry and magnetic drums for memory. As a result they were enormous, literally taking up entire rooms and costing a fortune to run. These were inefficient materials which generated a lot of heat, sucked huge electricity and subsequently generated a lot of heat which caused ongoing breakdowns.

These first generation computers relied on ‘machine language’ (which is the most basic programming language that can be understood by computers). These computers were limited to solving one problem at a time. Input was based on punched cards and paper tape. Output came out on print-outs. The two notable machines of this era were the UNIVAC and ENIAC machines – the UNIVAC is the first every commercial computer which was purchased in 1951 by a business – the US Census Bureau.

1956 – 1963: Second Generation – Transistors

The replacement of vacuum tubes by transistors saw the advent of the second generation of computing. Although first invented in 1947, transistors weren’t used significantly in computers until the end of the 1950s. They were a big improvement over the vacuum tube, despite still subjecting computers to damaging levels of heat. However they were hugely superior to the vacuum tubes, making computers smaller, faster, cheaper and less heavy on electricity use. They still relied on punched card for input/printouts.

The language evolved from cryptic binary language to symbolic (‘assembly’) languages. This meant programmers could create instructions in words. About the same time high level programming languages were being developed (early versions of COBOL and FORTRAN). Transistor-driven machines were the first computers to store instructions into their memories – moving from magnetic drum to magnetic core ‘technology’. The early versions of these machines were developed for the atomic energy industry.

1964 – 1971: Third Generation – Integrated Circuits

By this phase, transistors were now being miniaturised and put on silicon chips (called semiconductors). This led to a massive increase in speed and efficiency of these machines. These were the first computers where users interacted using keyboards and monitors which interfaced with an operating system, a significant leap up from the punch cards and printouts. This enabled these machines to run several applications at once using a central program which functioned to monitor memory.

As a result of these advances which again made machines cheaper and smaller, a new mass market of users emerged during the ‘60s.

1972 – 2010: Fourth Generation – Microprocessors

This revolution can be summed in one word: Intel. The chip-maker developed the Intel 4004 chip in 1971, which positioned all computer components (CPU, memory, input/output controls) onto a single chip. What filled a room in the 1940s now fit in the palm of the hand. The Intel chip housed thousands of integrated circuits. The year 1981 saw the first ever computer (IBM) specifically designed for home use and 1984 saw the MacIntosh introduced by Apple. Microprocessors even moved beyond the realm of computers and into an increasing number of everyday products.

The increased power of these small computers meant they could be linked, creating networks. Which ultimately led to the development, birth and rapid evolution of the Internet. Other major advances during this period have been the Graphical user interface (GUI), the mouse and more recently the astounding advances in lap-top capability and hand-held devices.

2010- : Fifth Generation – Artificial Intelligence

Computer devices with artificial intelligence are still in development, but some of these technologies are beginning to emerge and be used such as voice recognition.

AI is a reality made possible by using parallel processing and superconductors. Leaning to the future, computers will be radically transformed again by quantum computation, molecular and nano technology.

The essence of fifth generation will be using these technologies to ultimately create machines which can process and respond to natural language, and have capability to learn and organise themselves.

• David Burns is Marketing and Communications Manager for Origin IT davidb@originit.co.nz www.originit.co.nz

Do you remember this computer?

It is the Bendix G-15 General Purpose Digital Computer, a First Generation computer introduced in 1956.

Another picture (66k). And another (105k). You can download larger versions of the following pictures on this page by clicking on them.

Why this interest in the Bendix G-15?

Against the odds, the Western Australian branch of The Australian Computer Museum Inc has rescued one from the scrap heap.That's it, over on the right.

It is in pretty good condition, considering its age, and we hope one day we can get it working again. We also have various programming, operating and technical manuals, and schematics. They have been scanned and you can download them here.

This web site started life in 1998 as a sort of begging letter, seeking more information about the maintenance procedures. We have since been told that there was no formal maintenance manual and that our documentation is complete so far as maintaining the machine is concerned. Still, if you can help with some of the other items we are missing or add anything at all to our store of knowledge about the Bendix G-15, please get in touch with me, David Green at .

First Generation Computers.

The first generation of computers is said by some to have started in 1946 with ENIAC, the first 'computer' to use electronic valves (ie. vacuum tubes). Others would say it started in May 1949 with the introduction of EDSAC, the first stored program computer. Whichever, the distinguishing feature of the first generation computers was the use of electronic valves.

Key Features Of First Generation Computers

My personal take on this is that ENIAC was the World's first electronic calculator and that the era of the first generation computers began in1946 because that was the year when people consciously set out to build stored program computers (many won't agree, and I don't intend to debate it). The first past the post, as it were, was the EDSAC in 1949. The period closed about 1958 with the introduction of transistors and the general adoption of ferrite core memories.

OECD figures indicate that by the end of 1958 about 2,500 first generation computers were installed world-wide. (Compare this with the number of PCs shipped world-wide in just the third quarter of 2006, quoted as 59.1 million units by research company Gartner).

Two key events took place in the summer of 1946 at the Moore School ofElectrical Engineering at the University of Pennsylvania. One was the completion of the ENIAC. The other was the delivery of a course of lectures on 'The Theory and Techniques of Electronic Digital Computers'. In particular,they described the need to store the instructions to manipulate data in the computer along with the data. The design features worked out by John von Neumann and his colleagues and described in these lectures laid the foundation for the development of the first generation of computers. That just left the technical problems!

One of the projects to commence in 1946 was the construction of the IAS computer at the Institute of Advanced Study at Princeton. The IAS computer used a random access electrostatic storage system and parallel binary arithmetic. It was very fast when compared with the delay line computers, with their sequential memories and serial arithmetic.

The Princeton group was liberal with information about their computer and before long many universities around the world were building their own, close copies. One of these was the SILLIAC at Sydney University in Australia.

I have written an emulator for SILLIAC. You can find it here, along with a link to a copy of the SILLIAC Programming Manual.

First Generation Technologies

In 1946 there was no 'best' way of storing instructions and data in a computer memory. There were four competing technologies for providing computer memory: electrostatic storage tubes, acoustic delay lines (mercury or nickel), magnetic drums (and disks?), and magnetic core storage.

A high-speed electrostatic store was the heart of several early computers, including the computer at the Institute for Advanced Studies in Princeton. Professor F. C. Williams and Dr. T. Kilburn, who invented this type of store, described it in Proc.I.E.E. 96, Pt.III, 40 (March, 1949). A simple account of the Williams tube is given here.

The great advantage of this type of 'memory' is that, by suitably controlling the deflector plates of the cathode ray tube, it is possible to redirect the beam almost instantaneously to any part of the screen: random access memory.

Acoustic delay lines are based on the principle that electricity travels at the speed of light while mechanical vibrations travel at about the speed of sound. So data can be stored as a string of mechanical pulses circulating in a loop, through a delay line with its output connected electrically back to its input. Of course, converting electric pulses to mechanical pulses and back again uses up energy, and travel through the delay line distorts the pulses, so the output has to be amplified and reshaped before it is fed back to the start of the tube.

The sequence of bits flowing through the delay line is just a continuouslyrepeating stream of pulses and spaces, so a separate source of regular clockpulses is needed to determine the boundaries between words in the stream and toregulate the use of the stream.

Delay lines have some obvious drawbacks. One is that the match between their length and the speed of the pulses is critical, yet both are dependent on temperature.This required precision engineering on the one hand and careful temperature controlon the other. Another is a programming consideration. The data is available onlyat the instant it leaves the delay line. If it is not used then, it is not availableagain until all the other pulses have made their way through the line. This made forvery entertaining programming!

A mercury delay line is a tube filled with mercury, with a piezo-electriccrystal at each end. Piezo-electric crystals, such as quartz, have the special property that they expand or contract when the electrical voltage across the crystal faces is changed. Conversley, they generate a change in electrical voltage when they are deformed. So when a series of electrical pulses representing binary data is applied to the transmitting crystal at one end of the mercury tube, it is transformed into corresponding mechanical pressure waves. The waves travel through the mercury until they hit the receiving crystal at the far end of the tube, where the crystal transforms the mechanical vibrations back into the original electrical pulses.

Mercury delay lines had been developed for data storage in radar applications.Although far from ideal, they were an available form of computer memory around which a computer could be designed. Computers using mercury delay lines included the ACE computer developed at the National Physical Laboratory, Teddington, andits successor, the English Electric DEUCE.

A good deal of information about DEUCE (manuals, operating instructions, program and subroutine codes and so on) is available on the Web and you can findlinks to it here.

Nickel delay lines take the form of a nickel wire. Pulses of current representing bits of data are passed through a coil surrounding one end of the wire. They set up pulses of mechanical stress due to the 'magnetostrictive' effect. A receiving coil at the other end of the wire is used to convert these pressure waves back into electrical pulses. The Elliott 400 series, including the 401, 402, 403 used nickel delay lines. Much later, in 1966, the Olivetti Programma 101 desk top calculator also used nickel delay lines.

The magnetic drum is a more familiar technology, comparable with modern magnetic discs. It consisted of a non-magnetic cylinder coated with a magnetic material, and an array of read/write heads to provide a set of parallel tracks of data round the circumference of the cylinder as it rotated. Drums had the same program optimisation problem as delay lines.

Windows server 2003 r2 product key generator. Two of the most (commercially) successful computers of the time, the IBM 650 and the Bendix G-15, used magnetic drums as their main memory.

The Massachusetts Institute of Technology Whirlwind 1 was another early computerand building started in 1947. However, the most important contribution made by the MIT group was the development of the magnetic core memory, which they later installed in Whirlwind. The MIT group made their core memory designs available to the computer industry and core memories rapidly superceded the other three memorytechnologies.

Where Does the Bendix G-15 Fit In?

Table 1 shows, in chronological order between 1950 and 1958, the initial operating date of computing systems in the USA. This is not to suggest that all of these computers were first generation computers, or that no first generation computers were made after 1958. It does give a rough guide to the number of first generation computers made.

Bendix introduced their G-15 in 1956. It was not the first Bendix computing machine. They introduced a model named the D-12, in 1954. However, the D-12 was a digital differential analyser and not a general purpose computer.

We don't know when the last Bendix G-15 was built, but about three hundred of the computers were ultimately installed in the USA. Three found their way to Australia. The one we have was purchased by the Department of Main Roads in Perth in 1962. It was used in the design of the Mitchell Freeway, the main road connecting the Northern suburbs to the city.

The G-15 was superceded by the second generation (transistorised) Bendix G-20.

Table 2 shows the computers installed or on order, in Australia, about December 1962. The three Bendix G-15s were in Perth (Department of Main Roads), Sydney (A.W.A. Service Bureau) and Melbourne (E.D.P Pty Ltd).

Features Of First Generation Computers

Overview of the G-15

The Bendix G-15 was a fairly sophisticated, medium size computer for its day. It used a magnetic drum for internal memory storage and had 180 tube packages and 300 germanium diode packages for logical circuitry. Cooling was by internal forced air.

Storage on the Magnetic Drum comprised 2160 words in twenty channels of 108 words each. Average access time was 4.5 milliseconds. In addition, there were 16 words of fast-access storage in four channels of 4 words each, with average access time of 0.54 milliseconds; and eight words in registers consisting of 1 one-word command register, 1 one-word arithmetic register, and 3 two-word arithmetic registers for double-precision operations.

A 108-word buffer channel on the magnetic drum allowed input-output to proceed simultaneously with computation.

Word size was 29 bits, allowing single-precision numbers of seven decimal digits plus sign during input-output and twenty nine binary digits internally, and double-precision numbers of fourteen decimal digits plus sign during input-output, fifty eight binary digits internally.

Each machine language instruction specified the address of the operand and the address of the next instruction. Double-length arithmetic registers permitted the programming of double-precision operations with the same ease as single-precision ones.

An interpreter called Intercom 1000 and a compiler called Algo provided simpler alternatives to machine language programming. Algo followed the principles set forth in the international algorithmic language, Algol, and permitted the programmer to state a problem in algebraic form. The Bendix Corporation claimed to be the first manufacturer to introduce a programming system patterned on Algol.

Fifth Generation Computer

The basic computation times, in milliseconds, were as follows (including the time required for the computer to read the command prior to its execution). The time range for multiplication and division represents the range between single decimal digit precision and maximum precision.

External Storage was provided on searchable paper tape (2,500 words per magazine) and, optionally, on one to four, magnetic tape units with 300,000 words per tape unit reel.

More detail about the Bendix G-15 General Purpose Digital Computer.

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Last update Thursday, 29 September 2011.