1955: Computer pioneer Doug Ross demonstrates the Director tape for MIT’s Whirlwind machine. It's a new idea: a permanent set of instructions on how the computer should operate.

Six years in the making, MIT's Whirlwind computer was the first digital computer that could display real-time text and graphics on a video terminal, which was then just a large oscilloscope screen. Whirlwind used 4,500 vacuum tubes to process data.

The Whirlwind occupied 3,300 square feet and was the fastest digital computer of its time. It also pioneered a number of new technologies, including magnetic core memory for RAM.

Another one of its contributions was Director, a set of programming instructions on paper tape that is regarded as the predecessor of operating systems in computers. The Director was designed to issue commands to the four-year-old Whirlwind machine.

The idea was to eliminate the need for manual intervention (.pdf) in reading the tapes for different problems during a computing session.

The Director tape would communicate with the computer through a separate input reader. That means different tapes with various problems to be computed would be recognized and appropriately processed. A Director tape would make a complete run possible by pushing a single button.

Programmers John Frankovich and Frank Helwig wrote the first Director tape program. The software concept was to connect a Flexowriter – a mechanical, heavy-duty tape reader – to a newer, faster photoelectric tape reader.

This allowed the team to feed the spliced-together paper tapes directly to Whirlwind, without having a separate human operator.

Lead programmer Doug Ross finally demonstrated it in 1955.

The Director tape was also probably the first example of a Job Control Language–driven operating system. JCL is a scripting language used on mainframe operating systems to instruct them how to run a batch job or start a subsystem.

The Whirlwind is credited with leading to development of the SAGE, or Semi-Automatic Ground Environment, system used by the U.S. Air Force. It's also said to have influenced most of the computers of the 1960s.

Source: Wikipedia, MIT Computer Science and Artificial Intelligence Laboratory

Photo: Stephen Dodd, Jay Forrester, Robert Everett and Ramona Ferenz test Whirlwind in 1950.

Courtesy Mitre Corp.

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