In 1963 most computers ran jobs in batch mode only, using punched cards or magnetic tape reels submitted by professional programmers or engineering students. A considerable amount of work was required to make the the TX-2 operate in interactive mode with a large CRT screen. When Sutherland had finished with it, it had to be reconverted to run in batch mode again. This involved some major hardware reconstruction as well as software work.
The Sketchpad program was part and parcel of Sutherland's PhD thesis at MIT. It was reprinted in 1980 under the title: Sketchpad : a man-machine graphical communication system. It is now out of print but several university libraries have copies and it is also present on the rare book market. For a PhD thesis it is remarkably clear and readable.