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Computer graphics wasn't invented by one man, but Ivan Sutherland had a lot to do with it and his is the name you generally think of first in connection with its development.
Today we live in a world of where we take computer graphics for granted. It is inconceivable that we could go back to the days when the only interface was character-based - even if there are lots of Linux programmers who claim the command line is all you need and some IBM 360 fans who counter claim that in fact the punch card is all you need.
What you might find remarkable is that in those bygone days we even managed to find games, like Star Trek, that could be played on an entirely graphic-less computer – and they were judged exciting, addictive even. Now we have graphical interfaces to wordprocessors that are more exciting!
Many people have been involved in bringing us this graphics revolution but perhaps the one who deserves to be called the father of computer graphics is Ivan Sutherland. When asked,
"How could you possibly have done the first interactive graphics program, the first non-procedural programming language, the first object oriented software system, all in one year?" Ivan replied: "Well, I didn't know it was hard."
Ivan E Sutherland, born 1938, Hartings, Nebraska
Ivan Sutherland was born to middle class parents of Scottish and New Zealand decent. His father was a PhD in civil engineering and his mother was a teacher and this environment instilled an interest in learning into him and his brother Bert. Of the two Ivan was probably the more academically oriented but Bert was also deeply involved with computers and technology.
Sutherland's first experience with a computer was with SIMON, a relay-based mechanical computer that was lent to the Sutherland household in 1950 by its designer, Edmund Berkeley. His first big computer program was to make SIMON divide. To make division possible, he added a conditional stop to SIMON's instruction set. His brother Bert helped with the modifications to the hardware.
Ivan and Bert must certainly have been among the first high school students to learn to program and it seems to have had almost as much effect as it did on that other great teenage computer enthusiast, Bill Gates. The relay computer was programmed using punched tape and Ivan's division algorithm was the longest program ever written for SIMON - a paper tape about eight feet long.
Despite being good at many subjects Ivan had problems with the written word. Many years later he described his spelling as “original” and his writing as “illegible”. This caused him great embarrassment but he never refrained from expressing himself despite the risk.
After high school Ivan Sutherland went to Carnegie Institute of Technology (now Carnegie Mellon University) to study Electrical Engineering. From there he moved on to the University of California to do a Master’s in Electrical Engineering and then on to MIT to work on a PhD.
His supervisor was Claude Shannon, the inventor of information theory, one of the great intellectual achievements of the 20th century. The first problem was what to do work on there as there were so many exciting challenges. At the time the SAGE air defence project needed computers that were fast and had graphical inputs and output. The light pen was invented for the SAGE project but the output displays were crude adaptations of radar displays.
MIT had been paid to develop an all-transistor computer, the TX0, to replace and upgrade the Whirlwind valve based machine used in the early days of the SAGE project. In doing so MIT learned not only how to build computers but how useful they were.
Soon after they went on to build the TX2, which not only used transistors but also had an array of real time input and output devices. The TX2, completed in 1959, was a 38-bit word machine with a 68Kword main memory. It was slow by today’s standards but very fast for the time with a clock speed of around 0.16MHz. It had a light pen, 16 words of switches that could be tested, 4 digital control knobs, a microphone and speakers. Its graphical output was a 9 inch 1024 x 1024 pixel direct access device that lacked any hardware character generator. For software it had virtually nothing – no operating system just a macro assembler.
The TX-1 and TX-2 were the starting points for DEC’s PDP1 and PDP 6 machines – but that’s another story.
The atmosphere of academic freedom at MIT allowed some students to start to think of more exciting lines of research.
Graduate students began to play Spacewar on the TX-2. This was probably the first graphics-based game. Two space ships on opposite sides of a sun fired missiles at each other. The sun had gravity and there were lots of extra complications to be mastered before you could blow your enemy’s ship up.
Sutherland was impressed and he decided that the TX-2 should be a good machine with which to implement a realtime drawing program. (SpaceWar is also responsible for the creation of the Unix operating system. Ken Thompson salvaged a PDP-1 and started writing Unix just with the aim of playing SpaceWar!)
Sutherland's PhD thesis was entitled “Sketchpad: A Man-Machine Graphical Communication System”. As a graduate student the only time he could get the TX-2 to himself was between 3.00 and 5.00 a.m. and so this is yet again another tale of late night programming!
Sketchpad may look obvious and under-powered as a drawing program from today’s perspective but nothing like it had existed before. Sutherland introduced many of the graphical conventions we now take for granted.
It used a scale of 2000:1, making the virtual drawing space huge, and pioneered techniques such as “rubberbanding”, zooming and object-oriented drawing. A light pen provided co-ordinates for drawing commands entered using the keyboard. Previously drawn primitive objects could be recalled and rotated, scaled and moved. Finished drawings could be stored on magnetic tape and re-edited at a later date.
Sketchpad with Sutherland at the controls
The nature of the interaction between the TX2 and its user inspired many a computer scientist to take up computer graphics and to dream of the day when all computers would be capable of working in this way. Sutherland’s thesis was completed in 1963 and it included a short film of him sitting at the TX2 console drawing a bolt. Computer graphics and Computer Aided Design in particular had been invented in one step.
In 1963 Sutherland found himself drafted into the army and assigned to the National Security Agency – because he knew about computers. He realised that the government’s involvement in computers was huge. The NSA measured its computer power in “acres”. In 1964 he was transferred to the Advanced Research Projects Agency, ARPA, who were responsible for many of the computing projects, including the Internet. At the age of 26 First Lieutenant Ivan E. Sutherland was given control of $15 million dollars a year, an office, a secretary and told to “go sponsor computer research”.
Over the following two years he commissioned and managed a range of computer projects that included AI and timesharing. He also met Dave Evans, then at the University of California at Berkely working on timesharing. It turned out that Evan’s understanding of real time computing held the key to implementing practical computer graphics.