Leon Cooper was watching Jeopardy! earlier this year when an answer caught his attention: "In the 1960s, this firm introduced the first word processor, the MT/ST, based on its Selectric typewriter."
Cooper, 86, knew the question better than anyone. It was "What is IBM?"
But it had been years since the Lexington man had reflected on the fact that he and several other IBM engineers invented electronic word processing, a technology now so common and pervasive that it's hard to imagine modern society without it.
Fifty years ago — June 29, 1964 — IBM launched the Magnetic Tape Selectric Typewriter, or MT/ST, which was developed and manufactured in Lexington.
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The machine's launch made headlines in the New York Times and The Wall Street Journal. Cooper has those clippings neatly preserved in a binder, along with his reports, patent documents and photos of prototypes.
IBM hired a young Jim Henson to make a short movie promoting the MT/ST. That quirky 1967 film, The Paperwork Explosion, provided an early glimpse at the creative genius of the man whose Sesame Street Muppets would later help teach generations of children to read, count and get along with others.
Cooper was a mechanical engineer for IBM in Poughkeepsie, N.Y., in 1957 when his boss asked him to solve a big problem.
"When somebody sees a typewriter these days, they wonder, 'How in the world did you correct anything?' Well, the answer was you really didn't," Cooper said. "But the real answer was that the novice didn't type. The only people who typed were professional typists."
A good professional could type 90 words per minute a few errors. But if she — and virtually all typists in those days were women — needed to make multiple copies, it required several sheets of paper sandwiched with carbon paper. That slowed the process, because any mistakes had to be corrected on each copy.
Some punched-paper tape typewriters had been made since the 1930s, but they were better suited for form letters than general office use. Errors were hard to correct, and paper punch tape wasn't reusable.
"Our mission was to capture the keystroke on a correctable medium that could produce multiple clean copies, because copying technology in those days was crude," Cooper said.
The medium his team chose was reusable magnetic tape with sprockets so it could be moved forward and backward. The first prototype used an input keyboard to record keystrokes on tape and store them in electrical relays. If the typist made a mistake, she simply backspaced and typed over it. The stored information could then be printed multiple times using a connected electric typewriter.
"We didn't know what all we could do until we got further along on the program," Cooper said. "That we could do insertions and deletions and move things around and combine two tapes, names and addresses on one and messages on another."
Early prototype machines used vacuum tubes until transistors became more reliable. Electronic memory was the major challenge, he said, because "storage was a big, clumsy thing in those days."
Cooper and his project were moved to Lexington in 1958, where he worked with electrical engineers J.T. Turner and Donald Sims, among others. The IBM Selectric typewriter, introduced in 1961 with a keyboard capable of both input and output, helped make the MT/ST system commercially feasible.
"We called it power typing," Cooper said. "We were not sophisticated enough to know what word processing was."
In fact, IBM marketers would coin the term "word processing" when they began selling the MT/ST in 1964. The first model was the size of a small file cabinet, could store only 24,000 characters and printed 180 words per minute.
The MT/ST was expensive: $7,010 to $9,535, depending on optional features. "But I was told they sold the first year's projection in a month," Cooper said.
The MT/ST sold well into the 1970s, when it was replaced with typewriters using cassette tapes and then floppy disks. IBM introduced the personal computer in 1981 and the typewriter, an office fixture since the 1880s, was soon history.
Cooper retired from IBM in 1982 and started QED Medical, which makes headlamps for surgeons and other specialty lighting. His son, Ira Cooper, now runs the Lexington-based company.
"I really want to emphasize that this was a group effort," Cooper said of IBM's MT/ST project, which introduced the world to word processing. "But I was the first guy there."