https://www.youtube.com/watch?v=jDrqR9XssJI
I'm in the progress of researching and writing an article about the subject of this video (light pen driven pie menus on a PDP-7 with a 340 vector display, in an early CAD system called PIXIE developed at Cambridge University), which I'll submit to HN when it's ready some time soon I hope.
Neil E. Wiseman, Heinz U. Lemke, John O. Hiles, PIXIE: A New Approach to Graphical Man-Machine Communication, Proceedings of 1969 CAD Conference Southampton IEEE Conference Publication 51, pp. 463–471.
https://www.donhopkins.com/home/documents/PIXIE%20a%20new%20...
https://www.cl.cam.ac.uk/library/archives.html
Check out Munching Squares on the same kind of hardware currently running at the Living Computer Museum, with an AM radio so the computer can play its own music synchronized with the graphics:
https://www.youtube.com/watch?v=V4oRHv-Svwc
Here's the fucking manual!
http://bitsavers.trailing-edge.com/pdf/dec/graphics/7-13_340...
(Be sure to order all the luxury add-on options for your 340 Precision Incremental Vector Graphics CRT Display, including the 342 Symbol Generator for drawing text along with your vector graphics, the 370 High Speed Light Pen for pointing at said text and graphics, and definitely the Type 347 Subroutine Option -- a big fan cooled cabinet with a powerful hardware subroutine accelerator that is super useful! Otherwise you have to simulate subroutines in software, which sucks.)
This you would not notice in the cinema or on a CRT TV in a darkened room but is quite apparent in a YouTube video.
In latter years when the ident would be put onto videotape for playback the bouncing on the sprockets would still be there as a result of the telecine process.
This did not come to an immediate end with the introduction of proper tools from the likes of Quantel. Some broadcasters were quite small, regional and proud of their long-standing analog idents. The whole channel would have to be rebranded and, as part of that exercise, the proper hardware added to do modern idents.