PLATO was the first (circa 1960, on ILLIAC I) generalized computer assisted instruction system. It was widely used starting in the early 1970s, with more than 1000 terminals worldwide. PLATO was originally built by the University of Illinois and ran in four decades, offering elementary through university coursework to UIUC students, local schools, and more than a dozen universities.
The project was later taken over by Control Data Corporation (CDC), who built the machines it ran on at the University. CDC President William Norris planned to make PLATO a major force in the computing world, and was a keystone of his ideas about corporate social responsibility. Although the project was economically a failure and supplanted by other technologies by the time the last production PLATO system was turned off in 2006, PLATO nevertheless pioneered key concepts such as online forums and message boards, online testing, email, chat rooms, picture languages, instant messaging, remote screen sharing, and multi-player online games.
The acronym PLATO stands for Programmed Logic for Automated Teaching Operations.
In 1957 the Soviet Union launched Sputnik I, and the United States suddenly felt a collective sense of educational inferiority. The result was massive spending on science and engineering education; computer-based education along with it. In 1958 the US Air Force's Office of Scientific Research held a conference on the topic at the University of Pennsylvania, and a number of groups—notably IBM—presented studies on the topic.
Bitzer, regarded as the "father of PLATO", succeeded largely due to his rejection of "modern" educational thinking. Returning to a basic drill-based system, his team improved on existing systems by allowing students to bypass lessons they already understood. Their first system, PLATO I first ran on the locally-built ILLIAC I computer in 1960. It included a TV for display and a special keyboard to navigate the system's menus. In 1961 they introduced PLATO II, which ran two users at once.
Convinced of the value of the project, the PLATO system entered a major redesign between 1963 and 1969. The new PLATO III allowed "anyone" to design new lesson modules using their TUTOR programming language, conceived one night in the summer of 1967 by biology grad student Paul Tenczar. Built on a CDC 1604 which had been given to them for free by William Norris, PLATO III could run up to 20 lessons at once, and was used by a number of local facilities in Champaign-Urbana that could be attached to the system with their custom terminals.
In 1972 a new system named PLATO IV was ready for operation. The PLATO IV terminal was a major innovation. It included Bitzer's orange plasma display invention which incorporated both memory and bitmapped graphics into one display. This plasma display included fast vector line drawing capability and ran at 1260 baud, rendering 60 lines or 180 characters per second. The display was a 512x512 bitmap, with both character and vector plotting done by hardwired logic. Users could provide their own characters to support rudimentary raster graphics. Compressed air powered a piston-driven microfiche image selector that permitted colored images to be projected on the back of the screen under program control. The PLATO IV display also included a 16-by-16 grid infrared touch panel allowing students to answer questions by touching anywhere on the screen.
It was also possible to connect the terminal to peripheral devices. One such peripheral was the Gooch Synthetic Woodwind (named after inventor Sherwin Gooch), a synthesizer that offered 4 voice music synthesis to provide sound in PLATO courseware. This was later supplanted on the PLATO V terminal by the Gooch Cybernetic Synthesizer, which had 16 voices that could be programmed individually or combined to make more complex sounds. This allowed for what today is known as multimedia experiences. A PLATO-compatible music language was developed for these synthesizers, as well as a compiler for the language, two music text editors, a filing system for music binaries, programs to play the music binaries in real time, and many debugging and compositional aids. A number of interactive compositional programs have also been written.
Another peripheral was the Votrax speech synthesizer, and a "talk" instruction was added to the Tutor programming language to support it.
The goal of this system was to provide tools for music educators to use in the development of instructional materials, which might possibly include music dictation drills, automatically graded keyboard performances, envelope and timbre ear-training, interactive examples or labs in musical acoustics, and composition and theory exercises with immediate feedback.
With the advent of microprocessor technology, new PLATO terminals were developed to be less expensive and more flexible than the PLATO IV terminals. At the University of Illinois, these were called PLATO V terminals, even though there never was a PLATO V system (the system continued to be called PLATO IV). The Intel 8080 microprocessors in these terminals made them capable of executing programs locally, much like today's Java applets and ActiveX controls, and allowed small software modules to be downloaded into the terminal to augment to the PLATO courseware with rich animation and other sophisticated capabilities that were not available otherwise using a traditional terminal-based approach.
Early in 1972, researchers from Xerox PARC were given a tour of the PLATO system at the University of Illinois. At this time they were shown parts of the system such as the Show Display application generator for pictures on PLATO (later translated into a graphics-draw program on the Xerox Star workstation), and the Charset Editor for "painting" new characters (later translated into a "Doodle" program at PARC), and the Term Talk and Monitor Mode communications program. Many of the new technologies they saw were adopted and improved upon when these researchers returned to Palo Alto, California. They subsequently transferred improved versions of this technology to Apple Inc..
By 1975 the PLATO System served almost 150 locations from a donated CDC Cyber 73, including not only the users of the PLATO III system, but a number of grammar schools, high schools, colleges and universities, and military installations. PLATO IV offered text, graphics and animation as intrinsic components of courseware content, and included a shared-memory construct ("common" variables) that allowed TUTOR programs to send data between various users. This latter construct was used both for chat-type programs, as well as the first multi-user flight simulator.
With the introduction of PLATO IV, Bitzer declared general success, claiming that the goal of generalized computer instruction was now available to all. However the terminals were very expensive (about $12,000), so as a generalized system PLATO would likely need to be scaled down for cost reasons alone.
Norris provided CERL with machines on which to develop their system in the late 1960s. In 1971 he set up a new division within CDC to develop PLATO "courseware", and eventually many of CDC's own initial training and technical manuals ran on it. In 1974 PLATO was running on in-house machines at CDC headquarters in Minneapolis, and in 1976 they purchased the commercial rights in exchange for a new CDC Cyber machine.
CDC announced the acquisition soon after, claiming that by 1985 50% of the company's income would be related to PLATO services. Through the 1970s CDC tirelessly promoted PLATO, both as a commercial tool and one for re-training unemployed workers in new fields. Norris refused to give up on the system, and invested in several non-mainstream courses, including a crop-information system for farmers, and various courses for inner-city youth. CDC even went as far as to place PLATO terminals in some shareholder's houses, to demonstrate the concept of the system.
In the early 1980s CDC started heavily advertising the service, apparently due to increasing internal dissent over the now $600 million project, taking out print and even radio ads promoting it as a general tool. The Minneapolis Tribune was unconvinced by their ad copy and started an investigation of the claims. In the end they concluded that while it was not proven to be a better education system, everyone using it nevertheless enjoyed it at least. An official evaluation by an external testing agency ended with roughly the same conclusions, suggesting that everyone enjoyed using it, but it was essentially equal to an average human teacher in terms of student advancement.
Of course a computerized system equal to a human should have been a major achievement, the very concept that the early pioneers in CBT were aiming for. A computer could serve all the students in a school for the cost of maintaining it, and wouldn't go on strike. However CDC charged $50 an hour for access to their data center, in order to recoup some of their development costs, making it considerably more expensive than a human on a per-student basis. PLATO was therefore a failure in any real sense, although it did find some use in large companies and government agencies willing to invest in the technology.
An attempt to mass-market the PLATO system was introduced in 1980 as Micro-PLATO, which ran the basic TUTOR system on a CDC "Viking-721" terminal and various home computers. Versions were built for the Texas Instruments TI-99/4A, Atari 8-bit family, Zenith Z-100 and (later)Radio Shack TRS-80 & IBM PC. Micro-PLATO could be used stand-alone for normal courses, or could connect to a CDC data center for multiuser programs. To make the latter affordable, CDC introduced the Homelink service for $5 an hour.
Norris continued to praise PLATO, announcing that it would be only a few years before it represented a major source of income for CDC as late as 1984. In 1986 Norris stepped down as CEO, and the PLATO service was slowly killed off. He later claimed that Micro-PLATO was one of the reasons PLATO got off-track. They had started on the TI-99/4A, but then TI pulled the plug and they moved to other systems like the Atari, who soon did the same. He felt that it was a waste of time anyway, as the system's value was in its online nature, which Micro-PLATO lacked (at least to start).
Bitzer was more forthright about CDC's failure, blaming their corporate culture for the problems. He noted that development of the courseware was averaging $300,000 per delivery hour, many times what the CERL was paying for similar products. This meant that CDC had to charge high prices in order to recoup their costs, prices that made the system unattractive. The reason, he suggested, for these high prices was that CDC had set up a division that had to keep itself profitable via courseware development, forcing them to raise the prices in order to keep their headcount up during slow periods.
This was perhaps the most unusual PLATO installation anywhere. Madadeni had about 1,000 students, all of them black and 99.5% of Zulu ancestry. The college was one of 10 teacher preparation institutions in kwaZulu, most of them much smaller. In many ways Madadeni was very primitive. None of the classrooms had electricity and there was only one telephone for the whole college, which one had to crank for several minutes before an operator might come on the line. So an air-conditioned, carpeted room with 16 computer terminals was a stark contrast to the rest of the college. At times the only way a person could communicate with the outside world was through PLATO term-talk.
For many of the Madadeni students, most of whom came from very rural areas, the PLATO terminal was the first time they encountered any kind of electronic technology. (Many of the first year students had never seen a flush toilet before.) There initially was skepticism that these technologically-illiterate students could effectively use PLATO, but those concerns were not borne out. Within an hour or less most students were using the system proficiently, mostly to learn math and science skills, although a lesson that taught keyboarding skills was one of the most popular. A few students even used on-line resources to learn TUTOR, the PLATO programming language, and a few wrote lessons on the system in the Zulu language.
PLATO was also used fairly extensively in South Africa for industrial training. Eskom successfully used PLM (PLATO learning management) and simulations to train power plant operators, South African Airways (SAA) used PLATO simulations for cabin attendant training, and there were a number of other large companies as well that were exploring the use of PLATO.
The South African subsidiary of CDC invested heavily in the development of an entire secondary school curriculum (SASSC) on PLATO, but unfortunately as the curriculum was nearing the final stages of completion, CDC began to falter in South Africa—partly because of financial problems back home, partly because of growing opposition in the United States to doing business in South Africa, and partly due to the rapidly evolving microcomputer, a paradigm shift that CDC failed to recognize.
PLATO's plasma panels were well suited to gaming, although its I/O bandwidth (180 characters per second or 60 graphic lines per second) was relatively slow. By virtue of 1500 shared 60-bit variables per game (initially), it was possible to implement online games. Because it was an educational computer system, most of the user community was keenly interested in gaming.
Many popular inter-terminal games were developed on PLATO during the 1970s and 1980s, such as Empire (a multiplayer game based on Star Trek), Airfight (a precursor to Microsoft Flight Simulator), Panther (a vector graphics based tankwar game, earlier than, but similar in many respects to Atari's BattleZone), the original Freecell, and several games inspired by the role-playing game Dungeons & Dragons, including dnd and Rogue. Moria, Dry Gulch (a western-style variation), and Bugs-n-Drugs (a medical variation) — these all presaged MUDs and MOOs as well as popular first-person shooters like Doom and Quake and MMORPGs like Everquest and World of Warcraft. Avatar, PLATO's most popular game, is one of the world's first MUDs and has over 1 million hours of use.
These communication tools and games formed the basis for an online community of thousands of PLATO users, which lasted for well over twenty years.
In September 2006 the Federal Aviation Administration retired its PLATO system, the last system that ran the PLATO software system on a CDC Cyber mainframe, from active duty. Existing PLATO-like systems now include NovaNET and Cyber1.org.
By early 1976, the original PLATO IV system had 950 terminals giving access to more than 3500 contact hours of courseware, and additional systems were in operation at CDC and Florida State University.. Eventually, over 12,000 contact hours of courseware was developed, much of it developed by university faculty for higher education. PLATO courseware covers a full range of high-school and college courses, as well as topics such as reading skills, family planning, Lamaze training and home budgeting. In addition, authors at the University of Illinois School of Basic Medical Sciences (now, the College of Medicine at Urbana-Champaign) devised a large number of basic science lessons and a self-testing system for first year students. However the most popular "courseware" remained their multi-user games and computer role playing games such as dnd, although it appears CDC was uninterested in this market. As the value of a CDC-based solution disappeared in the 1980s, interested educators ported the engine first to the IBM PC, and later to web-based systems. Today, however, even the web-based versions seem to have disappeared.
A number of smaller testing-related companies also evolved from the PLATO system. One of the few survivors of that group is The Examiner Corporation. Dr. Stanley Trollip (formerly of the University of Illinois Aviation Research Lab) and Gary Brown (formerly of Control Data) developed the prototype of The Examiner System in 1984.
In the early 1970s, James Schuyler developed a system at Northwestern University called HYPERTUTOR as part of Northwestern's MULTI-TUTOR computer assisted instruction system. This ran on several CDC mainframes at various sites.
Between 1973 and 1980, a group under the direction of Thomas T. Chen at the Medical Computing Laboratory of the School of Basic Medical Sciences at the University of Illinois at Urbana Champaign ported PLATO's TUTOR programming language to the Modcomp IV minicomputer. Douglas W. Jones, A.B. Baskin, Tom Szolyga, Vincent Wu and Lou Bloomfield did most of the implementation. This was the first port of TUTOR to a minicomputer and was largely operational by 1976 In 1980, Chen founded Global Information Systems Technology of Champaign Illinois to market this as the Simpler system. GIST eventually merged with the Defense Training and Technologies division of Adayana Inc Vincent Wu went on to develop the Atari Plato cartridge
CDC eventually sold the "PLATO" trademark and some courseware marketing segment rights to the newly-formed The Roach Organization (TRO) in 1989. In 2000 TRO changed their name to PLATO Learning and continue to sell and service PLATO courseware running on PCs.
CDC continued development of the basic system under the name CYBIS (CYber-Based Instructional System) after selling the trademarks to Roach, in order to service their commercial and government customers. CDC later sold off their CYBIS business to University Online, which was a descendant of IMSATT. University Online was later renamed to VCampus.
The University of Illinois also continued development of PLATO, eventually setting up a commercial on-line service called NovaNET in partnership with University Communications, Inc. CERL was closed in 1994, with the maintenance of the PLATO code passing to UCI. UCI was later renamed NovaNET Learning, which was bought by National Computer Systems (NCS). Shortly after that, NCS was bought by Pearson, and after several name changes now operates as Pearson Digital Learning
The PLATO software used on Cyber1 is the final release (99A) of CYBIS, by permission of VCampus. The underlying operating system is NOS 2.8.7, the final release of the NOS operating system, by permission of Syntegra (now British Telecom [BT]), which had acquired the remainder of CDC's mainframe business. Cyber1 runs this software on the Desktop CYBER emulator. Desktop CYBER accurately emulates in software a range of CDC CYBER mainframe models and many peripherals.
Cyber1 offers free access to the system, which contains over 16,000 of the original lessons, in an attempt to preserve the original PLATO communities that grew up at CERL and on CDC systems in the 1980s.