Ah, SketchPad. You put http://catb.org/jargon/html/story-of-mel.html to shame.
The https://en.wikipedia.org/wiki/TX-2, the machine SketchPad ran on, had 460KB of 36-bit memory, and it. ran. at. 400kHz - yes - 400k instructions per second.
The CAD system that introduced the idea of the GUI, clipboard, OOP, and so many other things, ran only a little faster than the masked-ROM calculators you can buy for a couple dollars at the store down the road nowadays. It's kind of depressing.
If you liked the OP video, you must watch https://archive.org/details/AlanKeyD1987. It's only 46:29 long.
I really, REALLY want the SketchPad program. If I had a bunch of money tucked away I would easily dedicate a decade of my life to trying to track it down.
As an aside, I'm not quite sure how to refer to the amount of memory it has, particularly considering that the memory is 36-bit and not 8-bit. Wikipedia says it has 64KB; the video says (I quote) "460 K bytes".
References:
- I waxed philosophical about SketchPad a few months ago: https://news.ycombinator.com/item?id=13102757 (article: https://news.ycombinator.com/item?id=13097121)