First Generation

First Generation

The period of first generation was 1946-1959. The computers of first generation used vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes, like electric bulbs, produced a lot of heat and were prone to frequent fusing of the installations, therefore, were very expensive and could be afforded only by very large organisations. In this generation mainly batch processing operating system were used. Punched cards, paper tape, and magnetic tape were used as input and output devices. The computers in this generation used machine code as programming language.

The main features of first generation are:

• Vacuum tube technology
• Unreliable
• Supported machine language only
• Very costly
• Generated lot of heat
• Slow input and output devices
• Huge size
• Need of A.C.
• Non-portable
• Consumed lot of electricity

Some computers of this generation were:

• ENIAC
• EDVAC
• UNIVAC
• IBM-701
• IBM-650

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.

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 in 1946 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 of Electrical 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

1G (or 1-G) refers to the first generation of wireless telephone technology (mobile telecommunications). These are the analog telecommunications standards that were introduced in the 1980s and continued until being replaced by 2G digital telecommunications. The main difference between the two mobile telephone systems (1G and 2G), is that the radio signals used by 1G networks are analog, while 2G networks are digital.

Although both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system, the voice itself during a call is encoded to digital signals in 2G whereas 1G is only modulated to higher frequency, typically 150 MHz and up. The inherent advantages of digital technology over that of analog meant that 2G networks eventually replaced them almost everywhere.

One such standard is Nordic Mobile Telephone (NMT), used in Nordic countries, Switzerland, the Netherlands, Eastern Europe and Russia. Others include Advanced Mobile Phone System (AMPS) used in North America and Australia, TACS (Total Access Communications System) in the United Kingdom, C-450 in West Germany, Portugal andSouth Africa, Radiocom 2000 in France, TMA in Spain, and RTMI in Italy. In Japan there were multiple systems. Three standards, TZ-801, TZ-802, and TZ-803 were developed by NTT (Nippon Telegraph and Telephone Corporation), while a competing system operated by Daini Denden Planning, Inc. (DDI) used the Japan Total Access Communications System (JTACS) standard.