Significant Technology from Module 2 - ETHERNET.

Prior to the establishment of the Palo Alto Research Centre by Xerox in 1970, the idea of connecting computers together in order to share programs and files had hardly been explored. Generally speaking, computers still meant huge mainframes, isolated, expensive, very complex and requiring specialist operators for their day-to-day running. However, time-sharing had been used in the NLS system by Douglas Engelbart’s team in the late 1960s at the Augmentation Research Centre at Stanford Research Institute in California. This used a mainframe computer serving several workstations and was, in fact, very much ahead of its time, as evidenced by The Mother of All Demos. http://sloan.stanford.edu/mousesite/1968Demo.html

When SRI closed down ARC, many of Engelbart’s colleagues moved on to Xerox PARC and it was hardly surprising when aspects of its most notable achievements resurfaced there. In late 1972, another scientist working at PARC, Bob Metcalfe, developed the idea of a physical cable network. Its initial purpose was to connect the newly developed Xerox Alto, a personal workstation, with laser printers to make the best use of an expensive resource.

He chose to base the name on the word "ether" as a way of describing an essential feature of the system: the physical medium (i.e., a cable) carries bits to all stations, much the same way that the old "luminiferous ether" was once thought to propagate electromagnetic waves through space. Thus, Ethernet was born.
http://www.ots.utexas.edu/ethernet/ethername.html
Date/Time accessed: 09/26/2001 18:32:44

As you can see from the above illustration, Ethernet is a BUS network - that is, it has a single line of high speed cable (the Ether) connecting each node, like stops on a bus route. Nodes might be a minicomputer, several PCs or workstations, and several printers with Ethernet enabling the sharing of expensive resources. Networks are classified by their ‘topology’ or physical structure with others having a star-shaped layout or a ring-shaped network.

An integral part of the Ethernet system is the Network Software which uses protocols or rules to govern communications over the cable system. Software such as Novell Netware acts as a ‘traffic cop’ enforcing these rules and ensuring its smooth operation. The primary aim of such software is to avoid collisions of data, ensure a smooth flow of traffic, minimise blockages or delays, check for possible corruption of data and ensure that all the nodes are ‘speaking the same language’ so they can handle the data effectively.

Ethernet was an extremely important step in the development of the personal computer. Earlier, it was believed, by Steve Jobs amongst others, that a computer was a stand-alone machine offering all that its user needed to be productive, there was no necessity to link it to other computers.

The subsequent development of TCP/IP as an open-standard networking protocol was the point at which Ethernet’s influence in the world of the PC also spread to the Internet. When TCP/IP was swiftly incorporated into Ethernet, it went on to be the ‘de facto’ standard for Internet protocols despite competition from the opposing OSI standard. Ethernet created the local networks of computers which, when linked together, became the Internet, ‘the global network of networks’.

LINKS

Novell Web Site - Novell History.
URL: http://www.novell.com/news/press/pressroom/history.html
Date/Time accessed: 09/21/2001 17:59:14

Networks - Tying it all together ©:Andrew Grygus - Automation Access
URL: http://www.aaxnet.com/design/nets.html
Date/Time accessed: 09/21/2001 18:27:57

"The Legend of Bob Metcalfe" by Scott Kirsner for Wired Magazine 1998
URL: http://www.wired.com/wired/archive/6.11/metcalfe.html
Date/Time accessed: 09/27/2001 17:00:45

From: "Inventing the Enterprise" - Robert M. Metcalfe -
from the Dec. 15, 1999/Jan. 1 2000 Issue of CIO Magazine
http://www.cio.com/archive/010100/metcalfe.html
Date/Time accessed: 09/27/2001 17:10:45

From: "An Interview with Bob Metcalfe" for The Revolutionaries Series
Interview by Jill Wolfson, San Jose Mercury News; and Trevor Getsla, Willow Glen High School
http://www.thetech.org/revolutionaries/metcalfe/i_a.html
Date/Time accessed: 09/27/2001 17:33:45