© Mark Ollig
As World War II drew to a close, the United States embarked on Project Whirlwind.
At the time, “whirlwind” evoked images of fast, powerful, and unstoppable motion.
Whirlwind was a US Navy research project in 1944 to develop a universal flight trainer using an analog computer.
In 1947, after recognizing its potential for national defense, the Whirlwind project was redirected to the US Air Force, where its focus shifted to the construction of a high-speed digital computer.
Computing engineer Jay Forrester (1918 to 2016) led the development of the Whirlwind I digital computer at the Massachusetts Institute of Technology (MIT) servomechanisms laboratory in 1948.
The Whirlwind I computer became operational in 1951. It occupied over 2,000 square feet and could quickly process substantial amounts of data.
The computer’s visual output was viewed on a round cathode-ray tube (CRT), similar to those used on an oscilloscope.
The Whirlwind computer depended on 5,000 vacuum tubes acting as switches within its logic circuits for core functionality and performing calculations.
However, a single faulty tube could cause errors or system-wide disruption.
To maintain operational reliability, the Whirlwind team designed circuitry to identify potentially failing vacuum tubes and replace them before they caused disruptions.
The Whirlwind I quickly performed computations by automatically executing stored program instructions.
The computer was used for air defense tracking and processed radar data at a speed of 50,000 operations per second.
The Whirlwind I pioneered magnetic-core memory, a technology where small ferrite rings resembling miniature donuts used magnetic polarities to represent binary data (ones and zeros).
This significantly increased speed and reliability compared to earlier vacuum tube memory, such as Williams-Kilburn tubes.
This innovation, magnetic-core memory, became the dominant form of random-access memory (RAM) in computers from the mid-1950s to the mid-1970s.
The Whirlwind I computer consumed 100 kW of power and required a cooling system due to the heat generated by the vacuum tubes.
This digital computer introduced graphical output capabilities, allowing users to see computer-generated information in real time – a significant leap forward in human-machine interaction.
During the 1950s, the Whirlwind project became a significant part of the US military’s multi-billion-dollar Semi-Automatic Ground Environment (SAGE) air defense system project.
MIT’s groundbreaking research on the Whirlwind I computer, especially its rapid computational and graphical visual data display, drove the specifications for SAGE.
IBM was the primary contracted system builder for SAGE and worked directly with designs based on MIT’s work.
Other company contracts for this massive air defense project included AT&T, Burroughs, Western Electric, and the RAND Corp.
SAGE was a vast network of radar stations and command centers designed to counter potential bomber threats from the Soviet Union during the Cold War.
This complex system relied on large digital computers and associated networking equipment to coordinate data obtained from radar sites, producing a single unified image of the airspace over a wide area.
SAGE computing centers were installed across the US, including in Minnesota.
In 1954, a $5 million, four-story windowless SAGE concrete blockhouse was constructed in Hermantown, MN, next to the Duluth airport to strengthen the nation’s air defense against trans-polar Soviet air attacks.
The SAGE network provided essential data and coordination for the North American Aerospace Defense Command (NORAD).
The blockhouse building, called Duluth SAGE Direction Center DC-10, became operational in 1959, and it housed the latest radar and computer technology.
It played a vital role in air defense operations while safeguarding the airspace in the northern region of the US.
At its peak, there were 29 SAGE building centers; however, all had been decommissioned by 1983.
Afterward, the SAGE Direction Center DC-10 building was remodeled and given to the University of Minnesota Duluth in 1985.
The Whirlwind I computer led to the development of the experimental 1955 “Transistorized eXperimental” TX-0 computer, which evaluated the practicality of using transistor-based technology instead of vacuum tubes.
The TX-0 was followed by the TX-2, a research computer designed in 1956 by MIT physicist Wesley A. Clark (1927 to 2016) to explore advanced memory technologies and human-computer interaction.
The TX-2 transistorized computer used magnetic-core memory storage, a CRT display, and a light-pen stylus, offering users a new way to interact directly with a computer.
MIT student Ivan Sutherland, while working with the TX-2, unlocked the field of computer graphics with his software program, Sketchpad.
Sutherland’s 1963 Ph. D. thesis, “Sketchpad, A Man-Machine Graphical Communication System,” introduced the foundation of object-oriented programming.
This software allowed users to draw, manipulate, and interact with complex shapes, designs, and objects directly on the computer screen using a light pen.
The TX-2’s light pen detected light emitted from the CRT screen, allowing users to point at and directly manipulate displayed objects.
The elements were responsive, laying the groundwork for modern graphical interaction.
Using the light pen, users could directly draw their ideas onto the screen using Sketchpad’s interactive visual elements instead of relying on text-based interfaces.
On Feb. 1, 1972, Sutherland was granted US Patent No. 3,639,736 for his invention.
Ivan Edward Sutherland, born May 16, 1938, is known as the “father of computer graphics” through his creation of Sketchpad.
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| Ivan Edward Sutherland demonstrating the Sketchpad program, located on page 11 of his thesis, “Sketchpad, A Man-Machine Graphical Communication System.” He referenced himself as “Author” in the typed text. |
