Doug Engelbart’s 1968 demo
In the shots over his shoulder you see him using the original mouse with his right hand, and a "chord keyboard" with his left. He calls it a "keyset". That's a set of buttons, basically function keys, except they can be "played" in combinations. The chord keyboard was also an I/O device on the Xerox Alto, but AFAIK wasn't used again.<p>I notice also, things didn't go as expected; he makes quite a few mistakes and very charmingly apologizes. But the fact that you can make mistakes and smoothly recover from them, was an important part of the demo.<p>For context, by 1968 the concept of interacting directly with a computer in what we today would call command-line mode had been around for several years. The DEC PDP-1 was released in 1959; the IBM 1620 in 1960; Multics had started in 1964; the IBM 360 series began deliveries in 1965; all allowed an operator who had the privilege of being in the "machine room" to enter commands and get responses at a typewriter. The PDP-1 was alone (I think?) in having a 2-dimensional vector-based screen, but it was used for graphics (including the original Space War), not for text.<p>Overwhelmingly, the paradigm for working with a computer was to prepare a "job" consisting of commands and blocks of data, all in punch cards, which was run as a "batch", producing output to print a/o disk or tape. If you made a mistake in setting up your job, you found out about it later, and could only "edit" by re-punching some cards, and re-running it.<p>So when Englebart showed smooth interaction with data, editing and changing data ad-hoc, and making mistakes and correcting them ad-hoc without drama, on a two-dimensional screen -- that alone was a revolution. Hyper-linked media, hierarchical lists, that was icing.