Geoscience Reference
In-Depth Information
FIGURE 19.2
Jacquard's weaving loom of 1805, found still in use in Assam, India. (Author.)
The system could eventually automatically guide defensive aircraft by transmitting instructions
directly to their autopilot systems. The original concept came from George E. Valley and Jay
Forrester at MIT's Lincoln Laboratories (Forrester went on to build simulation systems for urban
modelling). Principal contractors for SAGE were IBM, Burroughs, the Mitre Corporation (formed
for the project), Bell, Western Electric and the Systems Development Corporation, a RAND corpo-
ration spin-off (Jacobs, 1986). The network of radar sites extended offshore and included the Dew,
Pine Tree and Mid-Canada lines, as well as many control stations in the United States. In 1964,
the project was estimated to have cost between 8 and 12 billion dollars to design and deploy, and
the project pushed the limits of theory and capability in computing, networking and control (NRC,
1999). The IBM AN/FSQ-7 computer used for the project contained 55,000 vacuum tubes, occupied
about 2000 m
2
of floor space, weighed 275 tons and used up to 3 MW of power. Telecommunications
for the project were radio and telephone based, but many accounts attribute the early concept of the
Internet and packet switching to SAGE.
The computer workstation for SAGE, a combination computer display and radar scope, was
developed at the RAND corporation in Santa Monica, California (Figure 19.3). The workstation
involved several elements now considered essential components of GIS, input of data from distrib-
uted databases, real-time entry of positions using an on-screen stylus or
gun
, symbolic encoding
