For a long time I’ve been wanting to make video glitch hardware but I didn’t know where to start. At a electric flee market I stumbled upon a bag of VGA breakout boards and thought that the VGA signal must be pretty convenient to hack into since all signals are split up on different pins.
Said and done. I screwed jumper wires to the VGA boards and attached the other ends to a breadboard and started messing around. I measured the R,G and B signals with a multimeter to see how much voltage they carried by sending reed, green and blue test screens through the VGA connector. I compared that to the specifications I found on-line and started messing around with resistors and also adding voltage by attaching sound which worked great. Next I tried messing with the vertical and horizontal sync. That worked for the H-sync but it was very sensitive and only a very small range of the potentiometer could be used.
I never built this into a box because I wanted to find more sophisticated or at least more controlled ways of creating glitches.