There is a guy who wrote a demoscene demo for a C64 disk drive: the drive itself contains a 6502 and the cable could transmit B/W video data. Audio amazingly obtained from mechanics.
But I have never seen a demoscene demo from the electronics of a monitor display.
A late comment, but this sortakinda vaguely leans in the general direction you're describing: https://github.com/RedBalloonShenanigans/MonitorDarkly