A Critical History of Computer Graphics and Animation

As mentioned in the previous section, activities at the Massachusetts Institute of Technology helped shape the early computer and computer graphics industries. Development at M.I.T. took place in several different laboratories, including the Lincoln Labs, Electronics System Laboratory, the Center for Advanced Visual Studies, the Architecture Machine Group and the Media Lab. As mentioned in Section 1, Jay Forrester of the Servomechanisms Lab was chosen by Gordon Brown to develop the Whirlwind computer in the mid-40s. The Whirlwind and Forrester were moved to the Digital Computer Lab and started focusing on using the computer for graphics displays, for air traffic control and gunfire control, and became part of the government's SAGE (Semi-Automatic Ground Environment) program.

Ivan Sutherland, acknowledged by many to be the "grandfather" of interactive computer graphics and graphical user interfaces, worked on his PhD in EE in the Lincoln Labs on their TX-2 computer. Sutherland learned to program in high school using a small relay computer called SIMON (see image to the right). This was the beginning of a distinguished career in computers, graphics, and integrated circuit design. He earned his B.S. in Electrical Engineering at Carnegie Institute of Technology (now Carnegie Mellon University) on a full scholarship. He received an M.S. from Cal Tech, and then enrolled at MIT to work on his Ph.D. His dissertation centered around an interactive computer drawing program that he called Sketchpad, which was published in 1963. His contributions moved graphics from a military laboratory tool to the world of engineering and design. Sutherland made a movie of the interactive use of Sketchpad, which became somewhat of a cult film. It is widely acknowledged that every major lab in the country had a copy of the film, and researchers and students still refer to it over and over, as it influenced their developmental work so significantly.

Sutherland Sketchpad demo excerpt

Sutherland's software, described in a 1963 paper, "Sketchpad: A Man-machine Graphical Communications System," used the lightpen to create engineering drawings directly on the CRT. Highly precise drawings could be created, manipulated, duplicated, and stored. The software provided a scale of 2000:1, offering large areas of drawing space. Sketchpad pioneered the concepts of graphical computing, including memory structures to store objects, rubber-banding of lines, the ability to zoom in and out on the display, and the ability to make perfect lines, corners, and joints. This was the first GUI (Graphical User Interface) long before the term was coined.

Toward a Machine with Interactive Skills
from Understanding Computers: Computer Images
Time-Life Books, 1986

The following text is from a citation for Dr. Sutherland when he won the Franklin Institute Certificate of Merit:

At a time when cathode ray tube monitors were themselves a novelty, Dr. Ivan Sutherland's 1963 software-hardware combination, Sketchpad, enabled users to draw points, line segments and circular arcs on a cathode ray tube with a light pen. In addition Sketchpad users could assign constraints to whatever they drew and specify relationships among the segments and arcs. The diameter of arcs could be specified, lines could be drawn horizontally or vertically, and figures could be built up from combinations of elements and shapes. Figures could be copied, moved, rotated, or resized and their constraints were preserved. Sketchpad also included the first window-drawing program and clipping algorithm which made possible the capability of zooming in on objects while preventing the display of parts of the object whose coordinates fall outside the window.

The development of the Graphical User Interface, which is ubiquitous today, has revolutionized the world of computing, bringing to large numbers of discretionary uses the power and utility of the desk top computer. Several of the ideas first demonstrated in Sketchpad are now part of the computing environments used by millions in scientific research, in business applications, and for recreation. These ideas include:

1. the concept of the internal hierarchic structure of a computer-represented picture and the definition of that picture in terms of sub-pictures;
2. the concept of a master picture and of picture instances which are transformed versions of the master;
3. the concept of the constraint as a method of specifying details of the geometry of the picture;
4. the ability to display and manipulate iconic representations of constraints;
5. the ability to copy as well as instance both pictures and constraints;
6. some elegant techniques for picture construction using a light pen;
7. the separation of the coordinate system in which a picture is defined from that on which it is displayed; and
8. recursive operations such as "move" and "delete" applied to hierarchically defined pictures.

The implications of some of these innovations (e.g., constraints) are still being explored by Computer Science researchers today.

More on Ivan Sutherland can be found in the sections related to the University of Utah and Evans & Sutherland Computer Company.

http://www.cc.gatech.edu/classes/cs6751_97_fall/projects/abowd_team/ivan/ivan.html

The Center for Advanced Visual Studies at MIT was founded in 1967 by Gyorgy Kepes with the intent to combine the efforts of the disciplines of art and science. Other fellows at CAVS extended this idea of artists working on projects with the assistance of engineers and scientists. According to the MIT CAVS website,

The CAVS was establishedProfessor Kepes, who emphasized the responsibilities of artists in building bridges between individuals and their environment, between individuals in groups, and between each of us and our inner lives.

The Media Laboratory was formed in 1980 by Nicholas Negroponte and Jerome Wiesner, growing out of the Architecture Machine Group, and building on the seminal work of faculty members such as Marvin Minsky in cognition, Seymour Papert in learning, Barry Vercoe in music, Muriel Cooper in graphic design, Andrew Lippman in video, and Stephen Benton in holography. The media Lab carries on advanced research into a broad range of information technologies including digital television, holographic imaging, computer music, computer vision, electronic publishing, artificial intelligence, human/machine interface design, and education-related technologies. Its charter is to invent and creatively exploit new media for human well-being and individual satisfaction without regard to present-day constraints. They employ supercomputers and extraordinary input/output devices to experiment today with notions that will be commonplace tomorrow. The not-so-hidden agenda is to drive technological inventions and break engineering deadlocks with new perspectives and demanding applications.

http://www.media.mit.edu/about/index.html

Click on the images below to view a larger version (if available).

SIMON  was a relay-based computer with six words of two bit memory.  Its 12 bits of memory permitted SIMON to add up to 15.  Sutherland's first big computer program was to make SIMON divide. To make division possible, he added a conditional stop to SIMON's instruction set.  This program was a great accomplishment, it was the longest program ever written for SIMON, a total of eight pages of paper tape. 

SIMON FAQ

Sutherland, Ivan, SKETCHPAD: A Man-Machine Graphical Communication System, PhD dissertation, MIT, 1963. Reproduced as Technical Report Number 574 University of Cambridge Computer Laboratory, UCAM-CL-TR-574, ISSN 1476-2986, http://www.cl.cam.ac.uk/

Sutherland, Ivan, SKETCHPAD: A Man-Machine Graphical Communication System, proceedings of the AFIPS Spring Joint Computer Conference, Detroit, Michigan, May 21-23, 1963, pp. 329-346. http://www.guidebookgallery.org/articles/

Another MIT engineer, Ken Olsen, was working at Lincoln Labs on the TX-2 project. In 1957 Olsen founded the Digital Equipment Corporation (DEC). He shepherded the transition of the TX-2 technology into a commercial environment, and in 1961 started construction of their DEC's first computer, the PDP-1. The PDP-1 was considered a milestone in the computer era, because it was the world's first commercial interactive computer. It was used by its purchasers to pioneer timesharing systems, making it possible to have access to much more (affordable) computing power than ever before.

In 1961 a young computer programmer from MIT, Steve Russell led a team that created the first computer game. It took the team about 200 man-hours to write the first version of Spacewar. They wrote Spacewar on a PDP-1 which was a donation to MIT from DEC, who hoped MIT's think tank would be able to do something remarkable with their product.

The PDP-1's operating system was the first to allow multiple users to share the computer simultaneously. This was perfect for playing Spacewar, which was a two-player game involving warring spaceships firing photon torpedoes. Each player could maneuver a spaceship and score by firing missiles at his opponent while avoiding the gravitational pull of the sun. Russell transferred to Stanford University, where he introduced computer game programming and Spacewar to an engineering student named Nolan Bushnell, who went on to write the first coin-operated computer arcade game and start Atari Computers .

Through the 1960s DEC produced a series of machines aimed at a price/performance point below IBM 's 18-bit word, core memory mainframe machines. In 1964 they introduced the PDP-8. It was a smaller 12-bit word machine that sold for about $16,000. The PDP-8 is generally regarded as the first minicomputer. It was important historically because their low cost and portability made it the first computer that could be purchased by the end users as an alternative to using a larger system in a data center. Many small computer graphics labs could now have a dedicated computer on which to experiment with new software and hardware.

Arguably the most important computer in the PDP series was the PDP-11 , which switched to a 16-bit word now that everyone in the computer industry was using ASCII. PDP-11 machines started in the market essentially as upscale PDP-8s, but as improvements to integrated circuits continued, they eventually were packaged in cases no larger than a modern PC . Their larger PDP-10 cousins, which used a 36-bit architecture, were aimed at data-processing centers instead, eventually being sold as the DECsystem 10 and 20.

While the PDP-11 systems supported several operating systems, including DEC's RSTS system, their most important role was to run Bell Labs' new UNIX operating system that was being made available to educational institutions.

The PDP-11 had a 64K address space. Most models had a paged architecture and memory protection features to allow timesharing , and could support split I&D architectures for an effective address size of 128K.

http://www.wikipedia.org/wiki/PDP-11

In 1976 DEC decided to move to an entirely new 32-bit platform, which they referred to as the super-mini. They released this as the VAX 11/780 in 1978 , and immediately took over the vast majority of the minicomputer market. Desperate attempts by competitors such as Data General (which had been formed in 1968 by a former DEC engineer who had worked on a 16-bit design that DEC had rejected) to win back market share failed, due not only to DEC's successes, but the emergence of the microcomputer and workstation into the lower-end of the minicomputer market. In 1983 , DEC cancelled their "Jupiter" project, which had been intended to build a successor to the PDP-10, and instead focused on promoting the VAX as their flagship model.

The VAX series had an instruction set that is rich even by today's standards. In addition to the paging and memory protection features of the PDP series, the VAX supported virtual memory.

http://williambader.com/museum/vax/vaxhistory.html

DEC was also an important contributor to the graphics display and terminal market. Their products were influenced by work  in the Electronic Systems Laboratory (ESL) at MIT. In 1968 they introduced the DEC 338 intelligent graphics terminal, which was a refresh display with point, vector and character drawing capability. Other devices in this class were the DEC 340, IBM 2250, and IMLAC PDS-1. In 1974 they marketed the VT-52, which incorporated the first addressable cursor in a graphics display terminal. One of their most functional terminals, the VT-100 was introduced in 1981, and is still in operation in hundreds of computer rooms around the world.

A common object in graphics labs was the disk cartridge, such as the DEC RL02. It had approximately 2.2 MB of storage (1.1 on each side) and a 60 ms seek time.

DEC PDP-1

Screenshot of Russel's Spacewar

DEC PDP-8f

DEC PDP-11/45

DEC 340 display

DEC VT52

DEC VT100

DEC RL02 Disk Cartridge

Beginning in 1959, General Motors and IBM embarked on a project to create a unified computer assisted design environment. Originally called "Digital Design", its name was changed to DAC, for Design Augmented by Computer. It was formally disclosed at the 1964 Fall Joint Computer Conference. Called DAC-1, the first system was built by IBM using specifications provided by a team of engineers from General Motors, including Fred Krull and Dr. Patrick Hanratty who later founded the CADD company MCS. The display system, sometimes considered as the first CAD system, introduced transformations on geometric objects for display, including rotation and and zoom, and a no-display (later called "clipping") function (see automobile image at the right). It used a light pencil, instead of the commonly used light gun or light pen. This device read coordinate voltages from a conductive transparent sheet that was positioned over the IBM Alpine display head.

The DAC-1 display console was connected to an IBM 7094 computer. It utilized a very creative group design collaboration system, which consisted of a photo "readout" system connected to a projection device. When collaboration on the design drawing was desired, the operator could select a view which would be displayed on an auxiliary CRT film recorder, and it would be scanned and quickly processed, and could then be projected  onto the screen. These components are all shown in the image of the system at the right. DAC-1 also could input drawings from other sources, such as traditional hand drawings, using a computer controlled film reader.

The technology developed in the DAC project at GM resulted in the development by IBM of (among other things - see Note 1 below) the workhorse IBM 2250 graphics display, which was the interface with the IBM 1130 and 360 mainframes, and which was one of the most commonly used graphics displays of the 60s and early 70s. The 2250 was a vector device with 1024x1024 addressable resolution, a 12x12 inch display screen, and a .0200 inch spot size. The model 1 had a storage buffer of 8,192 bytes and a cycle time of 4 ms per byte. It had 64 non-changable characters in a built in character generator for on-screen labeling. Like many display units to follow, the 2250 had a function keyboard, an alphanumeric keyboard and a light pen. Its basic cost was around $100K. More detailed information can be obtained from an article by Arthur Appel, et al from IBM in the IBM Systems Journal, Volume 7, Numbers 3/4, Page 176 (1968) (Click here for a pdf version of the paper.)

Toward a Machine with Interactive Skills
from Understanding Computers: Computer Images
Time-Life Books, 1986

The Joint Computer Conference was held twice a year in Fall and Spring, and was a conference of a federation of the major computer societies, the American Federation of Information Processing Societies (AFIPS). It was held until 1973 when it was replaced by the National Computer Conference.

Ref: The Origin of Computer Graphics within General Motors, Fred Krull, IEEE Annals of the History of Computing, Fall 1994 (Vol. 16, No. 3); Interactive Graphics for Computer-Aided Design, by M. David Prince, Addison Wesley, 1971. (PDF file)

IBM 2250

Other significant display devices and systems were also introduced around the same period. Many people believe that the Adage was the first stand alone computer-aided design workstation (see Note 2 below). The Adage display had the advantage of extremely high speed (for the time) display rates, allowing for the representation of moving objects and flicker free rotations. The Adage AGT-30, like the IBM 2250 became a mainstay in graphics labs around the world.

The ITEK Corporation involved personnel that got their start in the SAGE program at MIT (in particular, Thurber Moffett and Norm Taylor), and in fact was located near the Lincoln Labs facility. The ITEK project was to design optical lenses, and resulted in a system called The Electronic Drafting Machine (EDM). The EDM used a DEC PDP-1 computer from Digital Equipment Corp., a vector-refresh display and a large disk memory device used to refresh the graphic display. Input commands were done with a light pen. The EDM was developed in 1961 and was reported on in Time Magazine, March 2, 1962.

"Technology: ... to beat the language barrier between man and machine, ITEK has, in effect hitched the digital computer to the draftsman's stylus. With a photoelectric light pen, the operator can formulate engineering problem's graphically (instead of reducing them to equations) ....".

Itek marketed the EDM machine and it was later sold to Control Data Corporation. It was marketed as the CDC Digigraphics System and it was heavily used in the aerospace industry at such companies as Lockheed and Martin Marietta. One of the more pricey systems, the Digigraphics system was available for approximately $500K.

Other display devices included the storage tube display, such as the Computer Displays, Inc. ARDS and the Tektronix 4010 devices shown to the right. Tektronix invented the direct view storage tube (DVST) vector graphics approach in 1965, and dominated the market for the next 15 years. They actually used their 564 storage tube oscilloscope as a computer graphics display in timeshare systems. Their 601 and 611 models introduced in 1967 were the first in their product line designed specifically for CG display. (They sold for $1050 and $2500, respectively.) The CDI ARDS (Advanced Remote Display System) shown to the right actually used the Tektronix 611 6x8 storage tube, as did other systems like the Computek Display System. They were priced in the $12K range. Tektronix first commercial model was the 4002A, which was priced at about $9K.

One problem with refresh vector displays is that they must continuously redraw the image on the screen, fast enough that the image doesn't "flicker". Storage tube vector graphics terminals differ from refresh vector graphics terminals in that the display maintains a "history" of what is drawn on the screen and therefore doesn't need to be refreshed. Only when the image changes does it need to be redrawn.  For example, one storage tube approach uses two electron guns - one draws lines on the screen, the other bathes the entire display in electrons at a lower intensity. This second beam keeps any phosphor that has been activated continuously illuminated. However, it cannot erase anything except by clearing the entire screen. This last issue (no dynamic capability and the inability to update without erasure of the entire screen) coupled with the low light output made it not as popular for CG people as the refresh tube.

When large quantities of semi permanent information such as maps must be combined with dynamic or variable data, a system such as the rear projection CRT display can be used. For example, the Bunker Ramo display shown to the right can project color or black and white film images onto the screen of the CRT with a compensated, off-axis projector. The dynamic data is drawn using the electron gun of the CRT.

Other output devices include the charactron and the plotter. The charactron uses a stencil mask within the CRT to efficiently draw characters on the screen. It has also been used in several film recording devices, such as the Stromberg Carlson 4020 from General Dynamics. More discussion of the film recorder will take place in the sections on CGI production facilities. The first plotter developed was the CalComp 565, developed in 1958. The 565 was a high-speed drum-type XY plotter driven by step motors. Each step causes the pen to move horizontally (relative to the paper) a fixed increment (0.1 mm) in either a positive or negative direction at a rate of 250 steps per second. The drum provided the vertical movement. A solenoid permitted the pen to be lifted or lowered onto the paper. CalComp  was incorporated in 1958, and introduced the 565 shortly thereafter. In 1986, CalComp became a unit of Lockheed after the company purchased Sanders Associates.

The plasma panel was a technology developed at the University of Illinois in 1964, as part of the PLATO automated teaching system. The technology used arrays of cells filled with neon gas, sandwiched between glass. Capacitors at each cell provided the driving circuitry to address and activate each cell. The plasma panel was patented in 1971 and sold to Owens-Illinois, who developed displays for use with the PLATO system. Later, Japanese and US companies licensed the technology for computer graphics displays, but the technology failed to displace the CRT technology.
(See "A Colorful History of an Illinois Technology")

Adage

Digigraphics

Computer Displays, Inc ARDS

Tektronix 4002A Direct View Storage Tube display
(University of Amsterdam Computer Museum)

Tektronix 4010 display

Bunker Ramo rear projection CRT

Calcomp 565 drum plotter

Input devices were also a very important part of the systems that were evolving during this early part of CG history. As mentioned earlier, typical input was accomplished with an alphanumeric terminal, function buttons and/or dials, and the light pen (or light pencil, in the case of the DAC-1 system). Also, the DAC-1 system pioneered the use of photographic input (what would later give rise to scanning technology.) The joystick was adapted to provide numerical input.

Tom Diamond patented an approach to handwriting recognition in 1957 that utilized an innovative tablet that detected the regions of interaction, giving rise to the graphics tablet. Sylvania introduced a tablet that operated on analog voltage principles. One of the most innovative input approaches at the time was manifested by the Rand Tablet. It consisted of a matrix of crossed conductors. The circuitry of the tablet used switching techniques to apply pulses to the conductors in sequence, thus coding their individual locations. When a stylus was touched to the surface of the tablet,  it picked up pulses capacitively from the closest of the horizontal and vertical conductors which was converted into an (x,y) coordinate value. The tablet was marketed commercially as the Grafacon tablet, and was often bundled with early DEC computers. It was priced around $18K.

A variation on the graphics tablet approach to input was the sonic pen input tablet introduced in 1970. This technology used three microphones, positioned perpendicularly in the same configuration as the cartesian coordinate axes. A stylus generated a sound, for example with a spark generator, and the position was determined by the triangulation of the distances determined by the microphones. A three dimensional (x,y,z) coordinate resulted from the input. The image to the right shows a sonic pen device developed at Ohio State University, being used to control an image on the screen of a Vector General graphics display behind it. It was also used to "trace" three dimensional objects or paths.

Rand Tablet

Sonic Pen input device (Ohio State)

In 1963, Douglas Englebart was working at the Stanford Research Institute. He set up his own research lab, which he called the Augmentation Research Center. Throughout the 1960s and 1970s his lab developed an elaborate hypermedia groupware system called NLS (oNLine System). NLS facilitated the creation of digital libraries and storage and retrieval of electronic documents using hypertext. NLS used a new device to facilitate computer interaction — the mouse. The design of the mouse included two opposing rollers set in the bottom of a block of wood. As it was rolled over a surface, the distance and the speed of the rollers inside the block could be sensed and returned to the computer to which it was attached. It could therefore control how a tracking cursor on the display moved and was positioned. A selector button on top could be pressed, defining an event that the computer could use to identify the position of the tracking cursor at the time of the event.

On December 9, 1968, Douglas C. Engelbart and the group of 17 researchers working with him in the Augmentation Research Center at Stanford Research Institute presented a 90-minute live public demonstration of the online system, NLS, they had been working on since 1962. The public presentation was a session in the of the Fall Joint Computer Conference held at the Convention Center in San Francisco. This was the public debut of the computer mouse. But the mouse was only one of many innovations demonstrated that day, including hypertext, object addressing and dynamic file linking, as well as shared-screen collaboration  involving two persons at different sites communicating over a network with audio and video interface. This demonstration has become known as "the mother of all demos" at the 1968 Spring Joint Computer Conference. The entire 90 minute demo, in 35 sections (section 12 describes the mouse), is online at

http://sloan.stanford.edu/mousesite/1968Demo.html

Notes:

1. IBM developed three graphics related devices for DAC-1 — the 2250 display device, the 2280 film recorder, and the 2281 film scanner. The last two were discontinued because they were not received well in the industry.

2. In a 1998 paper in the IEEE Annals of the History of Computing, Don Bissell notes that the IDIIOM CAD workstation, running the IDADS CAD software, actually preceded the Adage workstation, being introduced earlier in 1967 than Adage. Therefore, according to Bissell, "...one must respect IDIIOM's claim to historical primacy" as the first stand-alone CAD platform.