Fernando Corbató, whose work on computer time-sharing in the 1960s helped pave the way for the personal computer, as well as the computer password, died on Friday at a nursing home in Newburyport, Mass. He was 93.
His wife, Emily Corbató, said the cause was complications of diabetes. At his death he was a professor emeritus at the Massachusetts Institute of Technology (MIT).
Corbató, who spent his entire career at M.I.T., oversaw a project in the early 1960s called the Compatible Time-Sharing System, or C.T.S.S., which allowed multiple users in different locations to access a single computer simultaneously through telephone lines.
At the time, computing was done in large batches, and users typically had to wait until the next day to get the results of a computation.
In a 1963 public television interview, Dr. Corbató described batch processing as "infuriating" for its inefficiency. The advent of time-sharing, however, reinforced the notion, still in its infancy, that computers could be used interactively. It was an idea that would animate the computing field for decades.
"Long before personal computers made it possible for each person to have a computer, time-sharing transformed the way people used computers," said Stephen Crocker, a computer scientist and internet pioneer who worked on time-sharing systems.
Dr. Corbató explained his time-sharing methods in the 1963 interview, with the reporter John Fitch, broadcast as part of the WGBH series "M.I.T. Science Reporter." In place of an actual bulky computer of the day, he used a modified electric typewriter mounted on a box of electronics.
Computers, he said on the program, were so expensive to use that any idle time was a huge waste. But with time-sharing, computer time was carefully metered and wasted time all but eliminated.
The computer could carry out only one operation at a time, by means of a so-called supervisor program. Yet it worked so quickly that it could skip from one job to another, with users never noticing any lag.
Each user "would be able to create and modify and execute programs interactively, as if he or she had sole control of the computer," the science writer M. Mitchell Waldrop wrote in "The Dream Machine," his 2001 book on the personal computing visionary J. C. R. Licklider.
View Full Article