| |
Late 1970s - Present: Fourth Generation Computers |
 |
Following the invention of the first  integrated circuits always more and more components could be fitted onto one chip. LSI (Large Scale Integration) was followed by VLSI (Very Large Scale Integration) and ULSI (Ultra-Large Scale Integration), which increased the number of components squeezed onto one chip into the millions and helped diminish the size as well as the price of computers. The new chips took the idea of the integrated circuit one step further as they allowed to manufacture one microprocessor which could then be programmed to meet any number of demands.
Also, ensuing the introduction of the minicomputer in the mid 1970s by the early 1980s a market for personal computers (PC) was established. As computers had become easier to use and cheaper they were no longer mainly utilized in offices and manufacturing, but also by the average consumer. Therefore the number of personal computers in use more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs were being used.
Further developments included the creation of mobile computers (laptops and palmtops) and especially networking technology. While mainframes shared time with many terminals for many applications, networking allowed individual computers to form electronic co-operations. LANs (Local Area Network) permitted computers to share memory space, information, software and communicate with each other. Although already LANs could reach enormous proportions with the invention of the Internet an information and communication-network on a global basis was established for the first time.
|
|
 |
|
Fiber-optic cable networks
Fiber-optic cable networks may become the dominant method for high-speed Internet connections. Since the first fiber-optic cable was laid across the Atlantic in 1988, the demand for faster Internet connections is growing, fuelled by the growing network traffic, partly due to increasing implementation of corporate networks spanning the globe and to the use of graphics-heavy contents on the World Wide Web.
Fiber-optic cables have not much more in common with copper wires than the capacity to transmit information. As copper wires, they can be terrestrial and submarine connections, but they allow much higher transmission rates. Copper wires allow 32 telephone calls at the same time, but fiber-optic cable can carry 40,000 calls at the same time. A capacity, Alexander Graham Bell might have not envisioned when he transmitted the first words - "Mr. Watson, come here. I want you" - over a copper wire.
Copper wires will not come out of use in the foreseeable future because of technologies as DSL that speed up access drastically. But with the technology to transmit signals at more than one wavelength on fiber-optic cables, there bandwidth is increasing, too.
For technical information from the Encyclopaedia Britannica on telecommunication cables, click  here. For technical information from the Encyclopaedia Britannica focusing on fiber-optic cables, click here.
An entertaining report of the laying of the FLAG submarine cable, up to now the longest fiber-optic cable on earth, including detailed background information on the cable industry and its history, Neal Stephenson has written for Wired: Mother Earth Mother Board. Click here for reading.
Susan Dumett has written a short history of undersea cables for Pretext magazine, Evolution of a Wired World. Click here for reading.
A timeline history of submarine cables and a detailed list of seemingly all submarine cables of the world, operational, planned and out of service, can be found on the Web site of the International Cable Protection Committee.
For maps of fiber-optic cable networks see the website of Kessler Marketing Intelligence, Inc.
 http://www.britannica.com/bcom/eb/article/4/0...
http://www.britannica.com/bcom/eb/article/4/0...
http://www.wired.com/wired/archive/4.12/ffgla...
http://www.pretext.com/mar98/features/story3....
|
|
|
