From the 1920s through to the early 1960s the New York area was home to two major animation studios: The Fleischer Studios (which later became Paramount Pictures' Famous Studios) and Terrytoons.
The Fleischer Studios produced the Betty Boop, Popeye, and Superman cartoons; while Terrytoons had Mighty Mouse, Heckle & Jeckle, and Tom Terrific.
These studios were no longer in existence when I started my career in animation in the mid-1970s. However, my first job at New York Institute of Technology landed me right in the middle of the most talented group of animators who had worked at Fleischer/Famous and Terrytoons. It was from these animators (Johnny Gentilella, Marty Taras, Dante Barbetta and Earl James) that I received my on-the-job training in the basics and mechanics of animation.
A few years earlier, Dr. Alexander Schure, the founder of (and who basically owned and ran) New York Institute of Technology, had started working towards developing a computer graphics program. With this as a goal, he had put into production "Tubby the Tuba" as full-length animated feature. The basic purpose was to have a team of computer engineers study the process of putting together an animated feature and see what technical problems needed to be surmounted by a computer.
In March of 1975, I wound up being hired as the studio's first full-time inbetweener. (I worked at the studio and developed into an assistant animator, leaving in May of 1976 to work on the animated feature "Raggedy Ann & Andy".)
The animation studio was on the NY Tech campus in Long Island. As Tubby was being produced by a crew of animators headed by Chuck Harriton and Johnny Gentilella, a separate crew on the far side of the campus (headed by a young Edwin Catmull) was busy experimenting with ways to draw and color pictures on a computer screen.
This is the same Edwin Catmull who is the current president of Walt Disney Animation Studios and Pixar Animation Studios.
There were times when Johnny Gentilella and some of the other animators would work with the computer crew. The animators' task was to draw and animate simple objects with the tools the computer crew was developing, and explain to them what difficulties they had using these tools.
The eventual direct result of all this experimentation was the development of both Disney's CAPS system and Pixar's CGI systems.
I have posted two sets of documents. The first is from a 1997 interview given by Edwin Catmull, where he gives some of his background history, explaining how he became involved with Dr. Schure and how he left to go work with George Lucas.
The second set of documents is Catmull's analysis of the problems facing computer-assisted animation. This analysis was finished circa 1977. It is very informative, giving a clear and concise step-by-step outline of all the phases of producing an animated cartoon.