Amii Stewart - Knock On Wood [1979], SCANIMATE special video effects.

Video entirely created with the once state of the art SCANIMATE analog computer (yes, analog!). This amazing piece of hardware created mind blowing special effects por TV production, it was so large that had to be housed in a dedicated entire room, and was so expensive that fewer than 10 where built and installed in the world. The original design turned out so flexible that the results where only limited to the "programmer's" skills.
As a result of being totally analog there wasn´t a software running inside. Instead the technician had to make lots of patches with coaxial cables between the connectors of the jungle of video modulators, deflection generators, etc, that combined produced the animation he has imagined in his mind. As a result of its analog nature (and once all the cables were connected in the right way) the complete animation (or video effect) was rendered in real time since there was no calculation involved. It could also support transparent layers (please don´t ask me how). Complex effects were rendered in multiple layers of video, each one recorded in a ultra high quality videotape recorder, independent layers that were finally recorded together to create the final master tape.
Obviously its high cost and the gradual introduction of the digital video computer (more powerful and versatile) led the SCANIMATE to obsolescence.
However, in spite of the time past, special effects like the one of this video still surprise us, if we take into account the time when it was designed and the few technical resources available it was far ahead of the current technology.
For more on SCANIMATE video computer: • Scanimate: The Origins...
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[@BPDMF2024]

That's Not Scanimate, That's the Howlaround Effect From Doctor who

[@EduardoSeijas]

You are right. Thank you very much for your correction. I am going to read about this technique from the good old days of analog television 👍