Information Technology Reference
In-Depth Information
10
Networks
"There are only two industries that refer to their customers as 'users'."
- Edward Tufte, statistician, discussing both the computer business and the illicit drug trade
At first, the entire emphasis of personal computing had of course been on the "personal"
aspect of the technology - to each his own independent machine: utter and complete inde-
pendence and freedom. This had been the philosophy which arose out of the hobbyist clubs
where the small machines first spread their roots. But business users had other needs, wants
and desires, not the least of which were the economies to be achieved with shared use of
key computer resources and communication between machines. Thus the rise of Local Area
Networks (LANS) which, in contrast to Wide Area Networks (WANs), offer higher data-
transfer rates, are usually confined to one office or set of offices, and do not require leased
telecommunication lines.
The world's first commercially available LAN was installed in September 1977 at the
New York offices of Chase Manhattan Bank. ARCnet (Attached Resource Computer Net-
work) was developed by Datapoint Corporation in San Antonio, Texas. Designed by a team
led by John Murphy, with operating system code written by Gordon Peterson, ARCnet was
defined as a group of nodes that communicate over a geographically-limited area usually
within one building or, at most, a campus of buildings. To this day, ARCnet represents the
simplest, most economical type of LAN. It uses what is called a token-ring architecture, sup-
ports data rates of 2.5 Mbps, and connects up to 255 computers. At the time, ARCnet's most
radical innovation was that it allowed various types of transmission media to be mixed on
the same network: twisted-pair wire (maxaximum extension 150 meters), coaxial cable (650
m.) and fiber optic cable (2.000 m.).
"I worked for Chase Manhattan Bank from 1976 until 1986," comments veteran com-
puter engineer Chris Piggot, "and was one of the first to use the ARC in a live commercial
environment. I remember Gordon Peterson, Jonathan Schmidt and others at Datapoint well.
ARC allowed Datapoint to 'punch far above its weight' when compared to the IBM, DEC
and Wang alternatives at the time. Not bad considering its eight bit architecture. The first
system we developed using ARC was a funds transfer system connected to the New York
Clearing House, processing thousands of transactions per day, worth tens of billions dollars.
At its peak, Chase had scores of individual networks installed, some with 20 or more linked
processors."
Previously there had been several successful non-commercial LANs set up in various
educational institutions and research labs. By 1970 the Lawrence Radiation Laboratory had
an in-house "Octopus" network up and running. Shortly thereafter, in 1974, Cambridge Ring
