Brilliant graphics, touchscreens, speech synthesizers, messaging apps, games, educational software, and more are not your child’s iPad. It’s the mid-1970s and you’re using a PLATO.
A far cry from its relatively primitive contemporaries of teleprinters and punch cards, PLATO was something else altogether. If you were lucky enough to be near the University of Illinois at Urbana-Champaign (UIUC) about half a century ago, you might have had the chance to create the future. Many of the computer innovations we take for granted began with this system. Even today, some of PLATO’s features have never been fully replicated. Today we take a look back at this influential tech testbed and see how you can experience it now.
From space race to space war
Don Bitzer said that in 1959 he was an electrical engineering graduate student at the UIUC, but his eyes were on something bigger than circuits. “I read a prediction that 50% of the students graduating from our high school would be functionally illiterate,” he later told his Wired interviewer. “We had a physicist, Chalmers Sherwin, who was not afraid to ask big questions. Can’t you use it?”
The system was to be, in Sherwin’s words, a “feedback book.”
The question came in time. Higher education faced a massive influx of students, and with the launch of Sputnik in 1957 and the apparent victory of the Soviet Union in the space race, science and technology quickly became a national priority. The “automatic education” devised attracted interest from both academia and the military. Sherwin contacted his engineering dean, William Everett, who asked Daniel Alpert, a physicist, director of the Control Systems Laboratory, to gather a group of engineers, educators, mathematicians, and psychologists. I encourage you to study the concept. However, the group faced serious hurdles as members who could teach did not understand the potential skills needed and vice versa.
Exhausted after weeks of decisive debate, Alpert was about to terminate the committee, but an impromptu discussion with Bitzer led to Bitzer’s “as part of an interface for computer-aided education.” Alpert gave him two weeks, and Bitzer got to work.
For the actual processing, Bitzer used an existing university computer, the ILLIAC I (then simply “ILLIAC”). It was the first computer entirely built and owned by an educational institution, a clone of his ORDVAC some time ago. Both he was manufactured in 1952 and had full software compatibility. His 2,718 tubes at IILIAC gave him more computing power than Bell Labs in 1956, with an addition time of 75 microseconds and an average multiplication time of 700 microseconds, 1024 40-bit memory words, and a 10,240-word magnetic drum unit. Bitzer designed the software in collaboration with his programmer Peter Braunfeld.
The front end was a consumer television connected to a self-maintaining memory tube display and small keyboard originally used in naval tactical defense systems. The slides were displayed on a screen from a projector under ILLIAC control and operated with control buttons. Through what Bitzer and Braunfeld called an “electronic board,” ILLIAC was able to overlay vector graphics and text onto slides at a rate of 45 characters per second. The system provided interactive feedback in an era when computer interaction was mostly piling up. This computer he in 1960 he named PLATO, later renamed “programmed logic for automatic teaching operations”. He could only teach one user at a time, but the prototype worked
The concept was soon expanded. In 1961 he came out with the PLATO II, with a full alphanumeric keyboard and special keys based on the PLATO I. These buttons include NEXT (next slide), BACKWARD (previous), RATE (to check if the answer is correct), DELETE, HELP (for supplementary material or to clarify the answer), and an interesting AHA button. was included. Choose “Answers to main sequence questions” and choose to answer immediately.
But the biggest innovation is time-sharing, allowing multiple students to use the system simultaneously for the first time. The user’s slice of her time required careful programming so that no keystrokes were lost in each session. Unfortunately, ILLIAC’s storage capacity stymied this progress, limiting system capacity to only two users at a time and limiting interactivity by limiting “secondary help sequences.”
