Donald Bitzer, Unsung Pioneer of Interactive Computing, Dies at 90

Donald Bitzer, an electrical engineer whose groundbreaking computer system PLATO, developed in the 1960s and ’70s at the University of Illinois, was a telegram from the digital future that combined instant messaging, email, chat rooms and gaming on flat-screen plasma displays, died on Dec. 10 at his home in Cary, N.C. He was 90.

His son, David, confirmed the death.

Unfashionably attired and prone to performing magic tricks during lectures, Dr. Bitzer was a charismatic and overlooked character in the history of computing — an industry whose stories about inventive Silicon Valley prodigies have sometimes overshadowed the contributions of the industrious university professors who came first.

“The level to which PLATO, its people and its history have been ignored is extraordinary given not only how seminal the innovations were and how early its online community flourished, but also how recently it all happened,” the tech entrepreneur Brian Dear wrote in “The Friendly Orange Glow: The Untold Story of the Rise of Cyberculture” (2018).

Dr. Bitzer, a professor of electrical and computer engineering at the University of Illinois, began developing PLATO in 1960 as a tool for educators to create interactive, individualized coursework. It swiftly evolved into “a culture, both physical and online,” Mr. Dear wrote, “with its own jargon, customs and idioms.”

PLATO, an acronym for Programmed Logic for Automatic Teaching Operations, initially ran on television-like screens connected to the university’s ILLIAC I computer, a five-ton machine powered by 2,800 vacuum tubes.

To increase interactivity, in 1964 Dr. Bitzer, along with a fellow professor, H. Gene Slottow, and a graduate student, Robert Willson, invented a plasma display illuminated by gas-infused pixels — the same technology that would later power flat-screen televisions.